Hi,
This is version 8.1 of TCP-AO support. I base it on net-next as
there's commit 5e5265522a9a ("tcp: annotate data-races around
tcp_rsk(req)->txhash") which makes a minor conflict.
The good news is that all pre-required patches have merged to
Torvald's/master. Thanks to Herbert, crypto clone-tfm just works on
master for all TCP-AO supported algorithms.
So, this is the first version of the patch set that has only net-related
changes (well, selftests as well, but they'll be upstreamed separately).
In this version, I've finally spent time and written Documentation/ page
on TCP-AO. It has Frequently Asked Questions (FAQ) on RFC 5925 - I found
it very useful to answer those before writing the actual code.
It provides answers to common questions that arise on a quick read of
the RFC as well as how they were answered. There's also a comparison
to the TCP-MD5 option, an evaluation of per-socket vs in-kernel-DB
approaches and a description of uAPI provided.
I hope it will be as useful for reviewing the code as it was for writing.
The most important changes in this version are:
- CONFIG_TCP_AO implies CONFIG_IPV6 != m. I don't feel like that
combination would be useful to anyone and it'd be painful to fix.
- uAPI change in TCP_AO_REPAIR (introduced in version 7): I removed
{snd,rcv}_sne_seq counters. They were just copies of snd_nxt/snd_una.
No reason for polluting uAPI as well as needlessly copying them.
- TCP_AO_MAX_HASH_SIZE is removed and all temporary buffers are
kmalloc()'d. That also saves a couple of bytes for hmac(sha1) and
cmac(aes128) traffic keys as they now are allocated with
exact hash algo's digest_size.
There's an independent patch set for TCP-MD5 to verify segments on twsk:
https://lore.kernel.org/all/[email protected]/T/#u
That may be used to verify TCP-AO segments on twsk as well.
There seem to be more people that connected me off-list asking me about
the status of patches and when I expect them to merge. Cc'ing more
interested parties here (ping me directly if you don't want to be in
copy). It would be helpful if you provide your reviews and tested-by's.
As far as I'm aware, version 7 was ported to RHEL, so now there are
probably more downstream kernels with TCP-AO support.
Also available as a git branch for pulling:
https://github.com/0x7f454c46/linux/tree/tcp-ao-v8.1
And another branch with selftests, that will be sent later separately:
https://github.com/0x7f454c46/linux/tree/tcp-ao-v8-with-selftests
Thanks for your time and reviews,
Dmitry
--- Changelog ---
Changes from v8:
- Rebased/retested on linux-net-next
Version 8: https://lore.kernel.org/all/[email protected]/T/#u
Changes from v7:
- Fixed copy'n'paste typo in unsigned-md5.c selftest output
- Fix build error in tcp_v6_send_reset() (kernel test robot <[email protected]>)
- Make CONFIG_TCP_AO imply IPV6 != m
- Cleanup EXPORT_SYMBOL*() as they aren't needed with IPV6 != m
- Used scratch area instead of on-stack buffer for scatter-gather list
in tcp_v{4,6}_ao_calc_key(). Fixes CONFIG_VMAP_STACK=y + CONFIG_DEBUG_SG=y
- Allocated digest_size'd buffers for traffic keys in tcp_ao_key instead
of maximum-sized buffers of TCP_AO_MAX_HASH_SIZE. That will save
little space per key and also potentially allow algorithms with
digest size > TCP_AO_MAX_HASH_SIZE.
- Removed TCP_AO_MAX_HASH_SIZE and used kmalloc(GFP_ATOMIC) instead of
on-stack hash buffer.
- Don't treat fd=0 as invalid in selftests
- Make TCP-AO selftests work with CONFIG_CRYPTO_FIPS=y
- Don't tcp_ao_compute_sne() for snd_sne on twsk: it's redundant as
no data can be sent on twsk
- Get rid of {snd,rcv}_sne_seq: use snd_nxt/snd_una or rcv_nxt instead
- {rcv,snd}_sne and tcp_ao_compute_sne() now are introduced in
"net/tcp: Add TCP-AO SNE support" patch
- trivial copy_to_sockptr() fixup for tcp_ao_get_repair() - it could
try copying bigger struct than the kernel one (embarrassing!)
- Added Documentation/networking/tcp_ao.rst that describes:
uAPI, has FAQ on RFC 5925 and has implementation details of Linux TCP-AO
Version 7: https://lore.kernel.org/all/[email protected]/T/#u
Changes from v6:
- Some more trivial build warnings fixups (kernel test robot <[email protected]>)
- Added TCP_AO_REPAIR setsockopt(), getsockopt()
- Allowed TCP_AO_* setsockopts if (tp->repair) is on
- Added selftests for TCP_AO_REPAIR, that also check incorrect
ISNs/SNEs, which result in a broken TCP-AO connection - that verifies
that both Initial Sequence Numbers and Sequence Number Extension are
part of MAC generation
- Using TCP_AO_REPAIR added a selftest for SEQ numbers rollover,
checking that SNE was incremented, connection is alive post-rolloever
and no TCP segments with a wrong signature arrived
- Wrote a selftest for RST segments: both active reset (goes through
transmit_skb()) and passive reset (goes through tcp_v{4,6}_send_reset()).
- Refactored and made readable tcp_v{4,6}_send_reset(), also adding
support for TCP_LISTEN/TCP_NEW_SYN_RECV
- Dropped per-CPU ahash requests allocations in favor of Herbert's
clone-tfm crypto API
- Added Donald Cassidy to Cc as he's interested in getting it into RHEL.
Version 6: https://lore.kernel.org/all/[email protected]/T/#u
iperf[3] benchmarks for version 6:
v6.4-rc1 TCP-AO-v6
TCP 43.9 Gbits/sec 43.5 Gbits/sec
TCP-MD5 2.20 Gbits/sec 2.25 Gbits/sec
TCP-AO(hmac(sha1)) 2.53 Gbits/sec
TCP-AO(hmac(sha512)) 1.67 Gbits/sec
TCP-AO(hmac(sha384)) 1.77 Gbits/sec
TCP-AO(hmac(sha224)) 1.29 Gbits/sec
TCP-AO(hmac(sha3-512)) 481 Mbits/sec
TCP-AO(hmac(md5)) 2.07 Gbits/sec
TCP-AO(hmac(rmd160)) 1.01 Gbits/sec
TCP-AO(cmac(aes128)) 2.11 Gbits/sec
Changes from v5:
- removed check for TCP_AO_KEYF_IFINDEX in delete command:
VRF might have been destroyed, there still needs to be a way to delete
keys that were bound to that l3intf (should tcp_v{4,6}_parse_md5_keys()
avoid the same check as well?)
- corrected copy'n'paste typo in tcp_ao_info_cmd() (assign ao_info->rnext_key)
- simplified a bit tcp_ao_copy_mkts_to_user(); added more UAPI checks
for getsockopt(TCP_AO_GET_KEYS)
- More UAPI selftests in setsockopt-closed: 29 => 120
- ported TCP-AO patches on Herbert's clone-tfm changes
- adjusted iperf patch for TCP-AO UAPI changes from version 5
- added measures for TCP-AO with tcp_sigpool & clone_tfm backends
Version 5: https://lore.kernel.org/all/[email protected]/T/#u
Changes from v4:
- Renamed tcp_ao_matched_key() => tcp_ao_established_key()
- Missed `static` in function definitions
(kernel test robot <[email protected]>)
- Fixed CONFIG_IPV6=m build
- Unexported tcp_md5_*_sigpool() functions
- Cleaned up tcp_ao.h: undeclared tcp_ao_cache_traffic_keys(),
tcp_v4_ao_calc_key_skb(); removed tcp_v4_inbound_ao_hash()
- Marked "net/tcp: Prepare tcp_md5sig_pool for TCP-AO" as a [draft] patch
- getsockopt() now returns TCP-AO per-key counters
- Another getsockopt() now returns per-ao_info stats: counters
and accept_icmps flag state
- Wired up getsockopt() returning counters to selftests
- Fixed a porting mistake: TCP-AO hash in some cases was written in TCP
header without accounting for MAC length of the key, rewritting skb
shared info
- Fail adding a key with L3 ifindex when !TCP_AO_KEYF_IFINDEX, instead
of ignoring tcpa_ifindex (stricter UAPI check)
- Added more test-cases to setsockopt-closed.c selftest
- tcp_ao_hash_skb_data() was a copy'n'paste of tcp_md5_hash_skb_data()
share it now under tcp_sigpool_hash_skb_data()
- tcp_ao_mkt_overlap_v{4,6}() deleted as they just re-invented
tcp_ao_do_lookup(). That fixes an issue with multiple IPv4-mapped-IPv6
keys for different peers on a listening socket.
- getsockopt() now is tested to return correct VRF number for a key
- TCP-AO and TCP-MD5 interraction in non/default VRFs: added +19 selftests
made them SKIP when CONFIG_VRF=n
- unsigned-md5 selftests now checks both scenarios:
(1) adding TCP-AO key _after_ TCP-MD5 key
(2) adding TCP-MD5 key _after_ TCP-AO key
- Added a ratelimited warning if TCP-AO key.ifindex doesn't match
sk->sk_bound_dev_if - that will warn a user for potential VRF issues
- tcp_v{4,6}_parse_md5_keys() now allows adding TCP-MD5 key with
ifindex=0 and TCP_MD5SIG_FLAG_IFINDEX together with TCP-AO key from
another VRF
- Add TCP_AO_CMDF_AO_REQUIRED, which makes a socket TCP-AO only,
rejecting TCP-MD5 keys or any unsigned TCP segments
- Remove `tcpa_' prefix for UAPI structure members
- UAPI cleanup: I've separated & renamed per-socket settings
(such as ao_info flags + current/rnext set) from per-key changes:
TCP_AO => TCP_AO_ADD_KEY
TCP_AO_DEL => TCP_AO_DEL_KEY
TCP_AO_GET => TCP_AO_GET_KEYS
TCP_AO_MOD => TCP_AO_INFO, the structure is now valid for both
getsockopt() and setsockopt().
- tcp_ao_current_rnext() was split up in order to fail earlier when
sndid/rcvid specified can't be set, before anything was changed in ao_info
- fetch current_key before dumping TCP-AO keys in getsockopt(TCP_AO_GET_KEYS):
it may race with changing current_key by RX, which in result might
produce a dump with no current_key for userspace.
- instead of TCP_AO_CMDF_* flags, used bitfileds: the flags weren't
shared between all TCP_AO_{ADD,GET,DEL}_KEY{,S}, so bitfields are more
descriptive here
- use READ_ONCE()/WRITE_ONCE() for current_key and rnext_key more
consistently; document in comment the rules for accessing them
- selftests: check all setsockopts()/getsockopts() support extending
option structs
Version 4: https://lore.kernel.org/all/[email protected]/T/#u
Changes from v3:
- TCP_MD5 dynamic static key enable/disable patches merged separately [4]
- crypto_pool patches were nacked [5], so instead this patch set extends
TCP-MD5-sigpool to be used for TCP-AO as well as for TCP-MD5
- Added missing `static' for tcp_v6_ao_calc_key()
(kernel test robot <[email protected]>)
- Removed CONFIG_TCP_AO default=y and added "If unsure, say N."
- Don't leak ao_info and don't create an unsigned TCP socket if there was
a TCP-AO key during handshake, but it was removed from listening socket
while the connection was being established
- Migrate to use static_key_fast_inc_not_disabled() and check return
code of static_branch_inc()
- Change some return codes to EAFNOSUPPORT for error-pathes where
family is neither AF_INET nor AF_INET6
- setsockopt()s on a closed/listen socket might have created stray ao_info,
remove it if connect() is called with a correct TCP-MD5 key, the same
for the reverse situation: remove md5sig_info straight away from the
socket if it's going to be TCP-AO connection
- IPv4-mapped-IPv6 addresses + selftest in fcnal-test.sh (by Salam)
- fix using uninitialized sisn/disn from stack - it would only make
non-SYN packets fail verification on a listen socket, which are not
expected anyway (kernel test robot <[email protected]>)
- implicit padding in UAPI TCP-AO structures converted to explicit
(spotted-by David Laight)
- Some selftests missed zero-initializers for uapi structs on stack
- Removed tcp_ao_do_lookup_rcvid() and tcp_ao_do_lookup_sndid() in
favor of unified tcp_ao_matched_key()
- Disallowed setting current/rnext keys on listen sockets - that wasn't
supported and didn't affect anything, cleanup for the UAPI
- VRFs support for TCP-AO
Version 3: https://lore.kernel.org/all/[email protected]/T/#u
Changes from v2:
- Added more missing `static' declarations for local functions
(kernel test robot <[email protected]>)
- Building now with CONFIG_TCP_AO=n and CONFIG_TCP_MD5SIG=n
(kernel test robot <[email protected]>)
- Now setsockopt(TCP_AO) is allowed when it's TCP_LISTEN or TCP_CLOSE
state OR the key added is not the first key on a socket (by Salam)
- CONFIG_TCP_AO does not depend on CONFIG_TCP_MD5SIG anymore
- Don't leak tcp_md5_needed static branch counter when TCP-MD5 key
is modified/changed
- TCP-AO lookups are dynamically enabled/disabled with static key when
there is ao_info in the system (and when it is destroyed)
- Wired SYN cookies up to TCP-AO (by Salam)
- Fix verification for possible re-transmitted SYN packets (by Salam)
- use sockopt_lock_sock() instead of lock_sock()
(from v6.1 rebase, commit d51bbff2aba7)
- use sockptr_t in getsockopt(TCP_AO_GET)
(from v6.1 rebase, commit 34704ef024ae)
- Fixed reallocating crypto_pool's scratch area by IPI while
crypto_pool_get() was get by another CPU
- selftests on older kernels (or with CONFIG_TCP_AO=n) should exit with
SKIP, not FAIL (Shuah Khan <[email protected]>)
- selftests that check interaction between TCP-AO and TCP-MD5 now
SKIP when CONFIG_TCP_MD5SIG=n
- Measured the performance of different hashing algorithms for TCP-AO
and compare with TCP-MD5 performance. This is done with hacky patches
to iperf (see [3]). At this moment I've done it in qemu/KVM with CPU
affinities set on Intel(R) Core(TM) i7-7600U CPU @ 2.80GHz.
No performance degradation was noticed before/after patches, but given
the measures were done in a VM, without measuring it on a physical dut
it only gives a hint of relative speed for different hash algorithms
with TCP-AO. Here are results, averaging on 30 measures each:
TCP: 3.51Gbits/sec
TCP-MD5: 1.12Gbits/sec
TCP-AO(HMAC(SHA1)): 1.53Gbits/sec
TCP-AO(CMAC(AES128)): 621Mbits/sec
TCP-AO(HMAC(SHA512)): 1.21Gbits/sec
TCP-AO(HMAC(SHA384)): 1.20Gbits/sec
TCP-AO(HMAC(SHA224)): 961Mbits/sec
TCP-AO(HMAC(SHA3-512)): 157Mbits/sec
TCP-AO(HMAC(RMD160)): 659Mbits/sec
TCP-AO(HMAC(MD5): 1.12Gbits/sec
(the last one is just for fun, but may make sense as it provides
the same security as TCP-MD5, but allows multiple keys and a mechanism
to change them from RFC5925)
Version 2: https://lore.kernel.org/all/[email protected]/T/#u
Changes from v1:
- Building now with CONFIG_IPV6=n (kernel test robot <[email protected]>)
- Added missing static declarations for local functions
(kernel test robot <[email protected]>)
- Addressed static analyzer and review comments by Dan Carpenter
(thanks, they were very useful!)
- Fix elif without defined() for !CONFIG_TCP_AO
- Recursively build selftests/net/tcp_ao (Shuah Khan), patches in:
https://lore.kernel.org/all/[email protected]/T/#u
- Don't leak crypto_pool reference when TCP-MD5 key is modified/changed
- Add TCP-AO support for nettest.c and fcnal-test.sh
(will be used for VRF testing in later versions)
Comparison between Leonard proposal and this (overview):
https://lore.kernel.org/all/[email protected]/T/#u
Version 1: https://lore.kernel.org/all/[email protected]/T/#u
This patchset implements the TCP-AO option as described in RFC5925. There
is a request from industry to move away from TCP-MD5SIG and it seems the time
is right to have a TCP-AO upstreamed. This TCP option is meant to replace
the TCP MD5 option and address its shortcomings. Specifically, it provides
more secure hashing, key rotation and support for long-lived connections
(see the summary of TCP-AO advantages over TCP-MD5 in (1.3) of RFC5925).
The patch series starts with six patches that are not specific to TCP-AO
but implement a general crypto facility that we thought is useful
to eliminate code duplication between TCP-MD5SIG and TCP-AO as well as other
crypto users. These six patches are being submitted separately in
a different patchset [1]. Including them here will show better the gain
in code sharing. Next are 18 patches that implement the actual TCP-AO option,
followed by patches implementing selftests.
The patch set was written as a collaboration of three authors (in alphabetical
order): Dmitry Safonov, Francesco Ruggeri and Salam Noureddine. Additional
credits should be given to Prasad Koya, who was involved in early prototyping
a few years back. There is also a separate submission done by Leonard Crestez
whom we thank for his efforts getting an implementation of RFC5925 submitted
for review upstream [2]. This is an independent implementation that makes
different design decisions.
For example, we chose a similar design to the TCP-MD5SIG implementation and
used setsockopts to program per-socket keys, avoiding the extra complexity
of managing a centralized key database in the kernel. A centralized database
in the kernel has dubious benefits since it doesn’t eliminate per-socket
setsockopts needed to specify which sockets need TCP-AO and what are the
currently preferred keys. It also complicates traffic key caching and
preventing deletion of in-use keys.
In this implementation, a centralized database of keys can be thought of
as living in user space and user applications would have to program those
keys on matching sockets. On the server side, the user application programs
keys (MKTS in TCP-AO nomenclature) on the listening socket for all peers that
are expected to connect. Prefix matching on the peer address is supported.
When a peer issues a successful connect, all the MKTs matching the IP address
of the peer are copied to the newly created socket. On the active side,
when a connect() is issued all MKTs that do not match the peer are deleted
from the socket since they will never match the peer. This implementation
uses three setsockopt()s for adding, deleting and modifying keys on a socket.
All three setsockopt()s have extensive sanity checks that prevent
inconsistencies in the keys on a given socket. A getsockopt() is provided
to get key information from any given socket.
Few things to note about this implementation:
- Traffic keys are cached for established connections avoiding the cost of
such calculation for each packet received or sent.
- Great care has been taken to avoid deleting in-use MKTs
as required by the RFC.
- Any crypto algorithm supported by the Linux kernel can be used
to calculate packet hashes.
- Fastopen works with TCP-AO but hasn’t been tested extensively.
- Tested for interop with other major networking vendors (on linux-4.19),
including testing for key rotation and long lived connections.
[1]: https://lore.kernel.org/all/[email protected]/
[2]: https://lore.kernel.org/all/[email protected]/
[3]: https://github.com/0x7f454c46/iperf/tree/tcp-md5-ao
[4]: https://lore.kernel.org/all/166995421700.16716.17446147162780881407.git-patchwork-notify@kernel.org/T/#u
[5]: https://lore.kernel.org/all/[email protected]/T/#u
[6]: https://lore.kernel.org/all/[email protected]/T/#u
Cc: Andy Lutomirski <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Bob Gilligan <[email protected]>
Cc: Dan Carpenter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: David Laight <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: Donald Cassidy <[email protected]>
Cc: Eric Biggers <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Cc: Francesco Ruggeri <[email protected]>
Cc: Gaillardetz, Dominik <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Hideaki YOSHIFUJI <[email protected]>
Cc: Ivan Delalande <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Leonard Crestez <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: Salam Noureddine <[email protected]>
Cc: Tetreault, Francois <[email protected]>
Cc: [email protected]
Cc: [email protected]
Dmitry Safonov (23):
net/tcp: Prepare tcp_md5sig_pool for TCP-AO
net/tcp: Add TCP-AO config and structures
net/tcp: Introduce TCP_AO setsockopt()s
net/tcp: Prevent TCP-MD5 with TCP-AO being set
net/tcp: Calculate TCP-AO traffic keys
net/tcp: Add TCP-AO sign to outgoing packets
net/tcp: Add tcp_parse_auth_options()
net/tcp: Add AO sign to RST packets
net/tcp: Add TCP-AO sign to twsk
net/tcp: Wire TCP-AO to request sockets
net/tcp: Sign SYN-ACK segments with TCP-AO
net/tcp: Verify inbound TCP-AO signed segments
net/tcp: Add TCP-AO segments counters
net/tcp: Add TCP-AO SNE support
net/tcp: Add tcp_hash_fail() ratelimited logs
net/tcp: Ignore specific ICMPs for TCP-AO connections
net/tcp: Add option for TCP-AO to (not) hash header
net/tcp: Add TCP-AO getsockopt()s
net/tcp: Allow asynchronous delete for TCP-AO keys (MKTs)
net/tcp: Add static_key for TCP-AO
net/tcp: Wire up l3index to TCP-AO
net/tcp: Add TCP_AO_REPAIR
Documentation/tcp: Add TCP-AO documentation
Documentation/networking/index.rst | 1 +
Documentation/networking/tcp_ao.rst | 422 +++++
include/linux/sockptr.h | 23 +
include/linux/tcp.h | 30 +-
include/net/dropreason-core.h | 30 +
include/net/tcp.h | 224 ++-
include/net/tcp_ao.h | 349 ++++
include/uapi/linux/snmp.h | 5 +
include/uapi/linux/tcp.h | 105 ++
net/ipv4/Kconfig | 17 +
net/ipv4/Makefile | 2 +
net/ipv4/proc.c | 5 +
net/ipv4/syncookies.c | 4 +
net/ipv4/tcp.c | 236 +--
net/ipv4/tcp_ao.c | 2367 +++++++++++++++++++++++++++
net/ipv4/tcp_input.c | 97 +-
net/ipv4/tcp_ipv4.c | 333 +++-
net/ipv4/tcp_minisocks.c | 50 +-
net/ipv4/tcp_output.c | 232 ++-
net/ipv4/tcp_sigpool.c | 357 ++++
net/ipv6/Makefile | 1 +
net/ipv6/syncookies.c | 5 +
net/ipv6/tcp_ao.c | 167 ++
net/ipv6/tcp_ipv6.c | 334 +++-
24 files changed, 5026 insertions(+), 370 deletions(-)
create mode 100644 Documentation/networking/tcp_ao.rst
create mode 100644 include/net/tcp_ao.h
create mode 100644 net/ipv4/tcp_ao.c
create mode 100644 net/ipv4/tcp_sigpool.c
create mode 100644 net/ipv6/tcp_ao.c
base-commit: 2da6a8041699691df4269e756253fa04a1d6a5fd
--
2.41.0
Add 3 setsockopt()s:
1. TCP_AO_ADD_KEY to add a new Master Key Tuple (MKT) on a socket
2. TCP_AO_DEL_KEY to delete present MKT from a socket
3. TCP_AO_INFO to change flags, Current_key/RNext_key on a TCP-AO sk
Userspace has to introduce keys on every socket it wants to use TCP-AO
option on, similarly to TCP_MD5SIG/TCP_MD5SIG_EXT.
RFC5925 prohibits definition of MKTs that would match the same peer,
so do sanity checks on the data provided by userspace. Be as
conservative as possible, including refusal of defining MKT on
an established connection with no AO, removing the key in-use and etc.
(1) and (2) are to be used by userspace key manager to add/remove keys.
(3) main purpose is to set RNext_key, which (as prescribed by RFC5925)
is the KeyID that will be requested in TCP-AO header from the peer to
sign their segments with.
At this moment the life of ao_info ends in tcp_v4_destroy_sock().
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/linux/sockptr.h | 23 ++
include/net/tcp.h | 6 +
include/net/tcp_ao.h | 18 +-
include/uapi/linux/tcp.h | 46 +++
net/ipv4/Makefile | 1 +
net/ipv4/tcp.c | 17 +
net/ipv4/tcp_ao.c | 816 +++++++++++++++++++++++++++++++++++++++
net/ipv4/tcp_ipv4.c | 10 +-
net/ipv6/Makefile | 1 +
net/ipv6/tcp_ao.c | 19 +
net/ipv6/tcp_ipv6.c | 39 +-
11 files changed, 978 insertions(+), 18 deletions(-)
create mode 100644 net/ipv4/tcp_ao.c
create mode 100644 net/ipv6/tcp_ao.c
diff --git a/include/linux/sockptr.h b/include/linux/sockptr.h
index bae5e2369b4f..307961b41541 100644
--- a/include/linux/sockptr.h
+++ b/include/linux/sockptr.h
@@ -55,6 +55,29 @@ static inline int copy_from_sockptr(void *dst, sockptr_t src, size_t size)
return copy_from_sockptr_offset(dst, src, 0, size);
}
+static inline int copy_struct_from_sockptr(void *dst, size_t ksize,
+ sockptr_t src, size_t usize)
+{
+ size_t size = min(ksize, usize);
+ size_t rest = max(ksize, usize) - size;
+
+ if (!sockptr_is_kernel(src))
+ return copy_struct_from_user(dst, ksize, src.user, size);
+
+ if (usize < ksize) {
+ memset(dst + size, 0, rest);
+ } else if (usize > ksize) {
+ char *p = src.kernel;
+
+ while (rest--) {
+ if (*p++)
+ return -E2BIG;
+ }
+ }
+ memcpy(dst, src.kernel, size);
+ return 0;
+}
+
static inline int copy_to_sockptr_offset(sockptr_t dst, size_t offset,
const void *src, size_t size)
{
diff --git a/include/net/tcp.h b/include/net/tcp.h
index d1230ee888fd..98b970c078d1 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2122,6 +2122,12 @@ struct tcp_sock_af_ops {
sockptr_t optval,
int optlen);
#endif
+#ifdef CONFIG_TCP_AO
+ int (*ao_parse)(struct sock *sk,
+ int optname,
+ sockptr_t optval,
+ int optlen);
+#endif
};
struct tcp_request_sock_ops {
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 3870cc29af10..1739116c6902 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -82,10 +82,26 @@ struct tcp_ao_info {
*/
struct tcp_ao_key *current_key;
struct tcp_ao_key *rnext_key;
- u32 flags;
+ u32 ao_required :1,
+ __unused :31;
__be32 lisn;
__be32 risn;
struct rcu_head rcu;
};
+#ifdef CONFIG_TCP_AO
+int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family,
+ sockptr_t optval, int optlen);
+void tcp_ao_destroy_sock(struct sock *sk);
+/* ipv4 specific functions */
+int tcp_v4_parse_ao(struct sock *sk, int optname, sockptr_t optval, int optlen);
+/* ipv6 specific functions */
+int tcp_v6_parse_ao(struct sock *sk, int cmd,
+ sockptr_t optval, int optlen);
+#else
+static inline void tcp_ao_destroy_sock(struct sock *sk)
+{
+}
+#endif
+
#endif /* _TCP_AO_H */
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 5655bfe28b8d..250e0ce2cc38 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -129,6 +129,9 @@ enum {
#define TCP_TX_DELAY 37 /* delay outgoing packets by XX usec */
+#define TCP_AO_ADD_KEY 38 /* Add/Set MKT */
+#define TCP_AO_DEL_KEY 39 /* Delete MKT */
+#define TCP_AO_INFO 40 /* Modify TCP-AO per-socket options */
#define TCP_REPAIR_ON 1
#define TCP_REPAIR_OFF 0
@@ -350,6 +353,49 @@ struct tcp_diag_md5sig {
#define TCP_AO_MAXKEYLEN 80
+#define TCP_AO_KEYF_IFINDEX (1 << 0) /* L3 ifindex for VRF */
+
+struct tcp_ao_add { /* setsockopt(TCP_AO_ADD_KEY) */
+ struct __kernel_sockaddr_storage addr; /* peer's address for the key */
+ char alg_name[64]; /* crypto hash algorithm to use */
+ __s32 ifindex; /* L3 dev index for VRF */
+ __u32 set_current :1, /* set key as Current_key at once */
+ set_rnext :1, /* request it from peer with RNext_key */
+ reserved :30; /* must be 0 */
+ __u16 reserved2; /* padding, must be 0 */
+ __u8 prefix; /* peer's address prefix */
+ __u8 sndid; /* SendID for outgoing segments */
+ __u8 rcvid; /* RecvID to match for incoming seg */
+ __u8 maclen; /* length of authentication code (hash) */
+ __u8 keyflags; /* see TCP_AO_KEYF_ */
+ __u8 keylen; /* length of ::key */
+ __u8 key[TCP_AO_MAXKEYLEN];
+} __attribute__((aligned(8)));
+
+struct tcp_ao_del { /* setsockopt(TCP_AO_DEL_KEY) */
+ struct __kernel_sockaddr_storage addr; /* peer's address for the key */
+ __s32 ifindex; /* L3 dev index for VRF */
+ __u32 set_current :1, /* corresponding ::current_key */
+ set_rnext :1, /* corresponding ::rnext */
+ reserved :30; /* must be 0 */
+ __u16 reserved2; /* padding, must be 0 */
+ __u8 prefix; /* peer's address prefix */
+ __u8 sndid; /* SendID for outgoing segments */
+ __u8 rcvid; /* RecvID to match for incoming seg */
+ __u8 current_key; /* KeyID to set as Current_key */
+ __u8 rnext; /* KeyID to set as Rnext_key */
+ __u8 keyflags; /* see TCP_AO_KEYF_ */
+} __attribute__((aligned(8)));
+
+struct tcp_ao_info_opt { /* setsockopt(TCP_AO_INFO) */
+ __u32 set_current :1, /* corresponding ::current_key */
+ set_rnext :1, /* corresponding ::rnext */
+ ao_required :1, /* don't accept non-AO connects */
+ reserved :29; /* must be 0 */
+ __u8 current_key; /* KeyID to set as Current_key */
+ __u8 rnext; /* KeyID to set as Rnext_key */
+} __attribute__((aligned(8)));
+
/* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */
#define TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT 0x1
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index cd760793cfcb..e144a02a6a61 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -69,6 +69,7 @@ obj-$(CONFIG_NETLABEL) += cipso_ipv4.o
obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \
xfrm4_output.o xfrm4_protocol.o
+obj-$(CONFIG_TCP_AO) += tcp_ao.o
ifeq ($(CONFIG_BPF_JIT),y)
obj-$(CONFIG_BPF_SYSCALL) += bpf_tcp_ca.o
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index ca2c74c282ad..d0b0565fa11e 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3608,6 +3608,23 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname,
__tcp_sock_set_quickack(sk, val);
break;
+#ifdef CONFIG_TCP_AO
+ case TCP_AO_ADD_KEY:
+ case TCP_AO_DEL_KEY:
+ case TCP_AO_INFO: {
+ /* If this is the first TCP-AO setsockopt() on the socket,
+ * sk_state has to be LISTEN or CLOSE
+ */
+ if (((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) ||
+ rcu_dereference_protected(tcp_sk(sk)->ao_info,
+ lockdep_sock_is_held(sk)))
+ err = tp->af_specific->ao_parse(sk, optname, optval,
+ optlen);
+ else
+ err = -EISCONN;
+ break;
+ }
+#endif
#ifdef CONFIG_TCP_MD5SIG
case TCP_MD5SIG:
case TCP_MD5SIG_EXT:
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
new file mode 100644
index 000000000000..2b2696e24dcc
--- /dev/null
+++ b/net/ipv4/tcp_ao.c
@@ -0,0 +1,816 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * INET An implementation of the TCP Authentication Option (TCP-AO).
+ * See RFC5925.
+ *
+ * Authors: Dmitry Safonov <[email protected]>
+ * Francesco Ruggeri <[email protected]>
+ * Salam Noureddine <[email protected]>
+ */
+#define pr_fmt(fmt) "TCP: " fmt
+
+#include <crypto/hash.h>
+#include <linux/inetdevice.h>
+#include <linux/tcp.h>
+
+#include <net/tcp.h>
+#include <net/ipv6.h>
+
+/* Optimized version of tcp_ao_do_lookup(): only for sockets for which
+ * it's known that the keys in ao_info are matching peer's
+ * family/address/port/VRF/etc.
+ */
+static struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao,
+ int sndid, int rcvid)
+{
+ struct tcp_ao_key *key;
+
+ hlist_for_each_entry_rcu(key, &ao->head, node) {
+ if ((sndid >= 0 && key->sndid != sndid) ||
+ (rcvid >= 0 && key->rcvid != rcvid))
+ continue;
+ return key;
+ }
+
+ return NULL;
+}
+
+static inline int ipv4_prefix_cmp(const struct in_addr *addr1,
+ const struct in_addr *addr2,
+ unsigned int prefixlen)
+{
+ __be32 mask = inet_make_mask(prefixlen);
+
+ if ((addr1->s_addr & mask) == (addr2->s_addr & mask))
+ return 0;
+ return ((addr1->s_addr & mask) > (addr2->s_addr & mask)) ? 1 : -1;
+}
+
+static int __tcp_ao_key_cmp(const struct tcp_ao_key *key,
+ const union tcp_ao_addr *addr, u8 prefixlen,
+ int family, int sndid, int rcvid, u16 port)
+{
+ if (sndid >= 0 && key->sndid != sndid)
+ return (key->sndid > sndid) ? 1 : -1;
+ if (rcvid >= 0 && key->rcvid != rcvid)
+ return (key->rcvid > rcvid) ? 1 : -1;
+ if (port != 0 && key->port != 0 && port != key->port)
+ return (key->port > port) ? 1 : -1;
+
+ if (family == AF_UNSPEC)
+ return 0;
+ if (key->family != family)
+ return (key->family > family) ? 1 : -1;
+
+ if (family == AF_INET) {
+ if (key->addr.a4.s_addr == INADDR_ANY)
+ return 0;
+ if (addr->a4.s_addr == INADDR_ANY)
+ return 0;
+ return ipv4_prefix_cmp(&key->addr.a4, &addr->a4, prefixlen);
+#if IS_ENABLED(CONFIG_IPV6)
+ } else {
+ if (ipv6_addr_any(&key->addr.a6) || ipv6_addr_any(&addr->a6))
+ return 0;
+ if (ipv6_prefix_equal(&key->addr.a6, &addr->a6, prefixlen))
+ return 0;
+ return memcmp(&key->addr.a6, &addr->a6, prefixlen);
+#endif
+ }
+ return -1;
+}
+
+static int tcp_ao_key_cmp(const struct tcp_ao_key *key,
+ const union tcp_ao_addr *addr, u8 prefixlen,
+ int family, int sndid, int rcvid, u16 port)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+ if (family == AF_INET6 && ipv6_addr_v4mapped(&addr->a6)) {
+ __be32 addr4 = addr->a6.s6_addr32[3];
+
+ return __tcp_ao_key_cmp(key, (union tcp_ao_addr *)&addr4,
+ prefixlen, AF_INET, sndid, rcvid, port);
+ }
+#endif
+ return __tcp_ao_key_cmp(key, addr, prefixlen, family, sndid, rcvid, port);
+}
+
+static struct tcp_ao_key *__tcp_ao_do_lookup(const struct sock *sk,
+ const union tcp_ao_addr *addr, int family, u8 prefix,
+ int sndid, int rcvid, u16 port)
+{
+ struct tcp_ao_key *key;
+ struct tcp_ao_info *ao;
+
+ ao = rcu_dereference_check(tcp_sk(sk)->ao_info,
+ lockdep_sock_is_held(sk));
+ if (!ao)
+ return NULL;
+
+ hlist_for_each_entry_rcu(key, &ao->head, node) {
+ u8 prefixlen = min(prefix, key->prefixlen);
+
+ if (!tcp_ao_key_cmp(key, addr, prefixlen,
+ family, sndid, rcvid, port))
+ return key;
+ }
+ return NULL;
+}
+
+struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
+ const union tcp_ao_addr *addr,
+ int family, int sndid, int rcvid, u16 port)
+{
+ return __tcp_ao_do_lookup(sk, addr, family, U8_MAX,
+ sndid, rcvid, port);
+}
+
+static struct tcp_ao_info *tcp_ao_alloc_info(gfp_t flags)
+{
+ struct tcp_ao_info *ao;
+
+ ao = kzalloc(sizeof(*ao), flags);
+ if (!ao)
+ return NULL;
+ INIT_HLIST_HEAD(&ao->head);
+
+ return ao;
+}
+
+static void tcp_ao_link_mkt(struct tcp_ao_info *ao, struct tcp_ao_key *mkt)
+{
+ hlist_add_head_rcu(&mkt->node, &ao->head);
+}
+
+static void tcp_ao_key_free_rcu(struct rcu_head *head)
+{
+ struct tcp_ao_key *key = container_of(head, struct tcp_ao_key, rcu);
+
+ tcp_sigpool_release(key->tcp_sigpool_id);
+ kfree(key);
+}
+
+void tcp_ao_destroy_sock(struct sock *sk)
+{
+ struct tcp_ao_info *ao;
+ struct tcp_ao_key *key;
+ struct hlist_node *n;
+
+ ao = rcu_dereference_protected(tcp_sk(sk)->ao_info, 1);
+ tcp_sk(sk)->ao_info = NULL;
+
+ if (!ao)
+ return;
+
+ hlist_for_each_entry_safe(key, n, &ao->head, node) {
+ hlist_del_rcu(&key->node);
+ atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
+ call_rcu(&key->rcu, tcp_ao_key_free_rcu);
+ }
+
+ kfree_rcu(ao, rcu);
+}
+
+static bool tcp_ao_can_set_current_rnext(struct sock *sk)
+{
+ /* There aren't current/rnext keys on TCP_LISTEN sockets */
+ if (sk->sk_state == TCP_LISTEN)
+ return false;
+ return true;
+}
+
+static int tcp_ao_verify_port(struct sock *sk, u16 port)
+{
+ struct inet_sock *inet = inet_sk(sk);
+
+ if (port != 0) /* FIXME */
+ return -EINVAL;
+
+ /* Check that MKT port is consistent with socket */
+ if (port != 0 && inet->inet_dport != 0 && port != inet->inet_dport)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int tcp_ao_verify_ipv4(struct sock *sk, struct tcp_ao_add *cmd,
+ union tcp_ao_addr **addr, u16 *port)
+{
+ struct sockaddr_in *sin = (struct sockaddr_in *)&cmd->addr;
+ struct inet_sock *inet = inet_sk(sk);
+
+ if (sin->sin_family != AF_INET)
+ return -EINVAL;
+
+ if (tcp_ao_verify_port(sk, ntohs(sin->sin_port)))
+ return -EINVAL;
+
+ /* Check prefix and trailing 0's in addr */
+ if (cmd->prefix != 0) {
+ __be32 mask;
+
+ if (sin->sin_addr.s_addr == INADDR_ANY)
+ return -EINVAL;
+ if (cmd->prefix > 32)
+ return -EINVAL;
+
+ mask = inet_make_mask(cmd->prefix);
+ if (sin->sin_addr.s_addr & ~mask)
+ return -EINVAL;
+
+ /* Check that MKT address is consistent with socket */
+ if (inet->inet_daddr != INADDR_ANY &&
+ (inet->inet_daddr & mask) != sin->sin_addr.s_addr)
+ return -EINVAL;
+ } else {
+ if (sin->sin_addr.s_addr != INADDR_ANY)
+ return -EINVAL;
+ }
+
+ *addr = (union tcp_ao_addr *)&sin->sin_addr;
+ *port = ntohs(sin->sin_port);
+ return 0;
+}
+
+static int tcp_ao_parse_crypto(struct tcp_ao_add *cmd, struct tcp_ao_key *key)
+{
+ unsigned int syn_tcp_option_space;
+ bool is_kdf_aes_128_cmac = false;
+ struct crypto_ahash *tfm;
+ struct tcp_sigpool hp;
+ void *tmp_key = NULL;
+ int err;
+
+ /* RFC5926, 3.1.1.2. KDF_AES_128_CMAC */
+ if (!strcmp("cmac(aes128)", cmd->alg_name)) {
+ strscpy(cmd->alg_name, "cmac(aes)", sizeof(cmd->alg_name));
+ is_kdf_aes_128_cmac = (cmd->keylen != 16);
+ tmp_key = kmalloc(cmd->keylen, GFP_KERNEL);
+ if (!tmp_key)
+ return -ENOMEM;
+ }
+
+ key->maclen = cmd->maclen ?: 12; /* 12 is the default in RFC5925 */
+
+ /* Check: maclen + tcp-ao header <= (MAX_TCP_OPTION_SPACE - mss
+ * - tstamp - wscale - sackperm),
+ * see tcp_syn_options(), tcp_synack_options(), commit 33ad798c924b.
+ *
+ * In order to allow D-SACK with TCP-AO, the header size should be:
+ * (MAX_TCP_OPTION_SPACE - TCPOLEN_TSTAMP_ALIGNED
+ * - TCPOLEN_SACK_BASE_ALIGNED
+ * - 2 * TCPOLEN_SACK_PERBLOCK) = 8 (maclen = 4),
+ * see tcp_established_options().
+ *
+ * RFC5925, 2.2:
+ * Typical MACs are 96-128 bits (12-16 bytes), but any length
+ * that fits in the header of the segment being authenticated
+ * is allowed.
+ *
+ * RFC5925, 7.6:
+ * TCP-AO continues to consume 16 bytes in non-SYN segments,
+ * leaving a total of 24 bytes for other options, of which
+ * the timestamp consumes 10. This leaves 14 bytes, of which 10
+ * are used for a single SACK block. When two SACK blocks are used,
+ * such as to handle D-SACK, a smaller TCP-AO MAC would be required
+ * to make room for the additional SACK block (i.e., to leave 18
+ * bytes for the D-SACK variant of the SACK option) [RFC2883].
+ * Note that D-SACK is not supportable in TCP MD5 in the presence
+ * of timestamps, because TCP MD5’s MAC length is fixed and too
+ * large to leave sufficient option space.
+ */
+ syn_tcp_option_space = MAX_TCP_OPTION_SPACE;
+ syn_tcp_option_space -= TCPOLEN_TSTAMP_ALIGNED;
+ syn_tcp_option_space -= TCPOLEN_WSCALE_ALIGNED;
+ syn_tcp_option_space -= TCPOLEN_SACKPERM_ALIGNED;
+ if (tcp_ao_len(key) > syn_tcp_option_space) {
+ err = -EMSGSIZE;
+ goto err_kfree;
+ }
+
+ key->keylen = cmd->keylen;
+ memcpy(key->key, cmd->key, cmd->keylen);
+
+ err = tcp_sigpool_start(key->tcp_sigpool_id, &hp);
+ if (err)
+ goto err_kfree;
+
+ tfm = crypto_ahash_reqtfm(hp.req);
+ if (is_kdf_aes_128_cmac) {
+ void *scratch = hp.scratch;
+ struct scatterlist sg;
+
+ memcpy(tmp_key, cmd->key, cmd->keylen);
+ sg_init_one(&sg, tmp_key, cmd->keylen);
+
+ /* Using zero-key of 16 bytes as described in RFC5926 */
+ memset(scratch, 0, 16);
+ err = crypto_ahash_setkey(tfm, scratch, 16);
+ if (err)
+ goto err_pool_end;
+
+ err = crypto_ahash_init(hp.req);
+ if (err)
+ goto err_pool_end;
+
+ ahash_request_set_crypt(hp.req, &sg, key->key, cmd->keylen);
+ err = crypto_ahash_update(hp.req);
+ if (err)
+ goto err_pool_end;
+
+ err |= crypto_ahash_final(hp.req);
+ if (err)
+ goto err_pool_end;
+ key->keylen = 16;
+ }
+
+ err = crypto_ahash_setkey(tfm, key->key, key->keylen);
+ if (err)
+ goto err_pool_end;
+
+ tcp_sigpool_end(&hp);
+
+ if (tcp_ao_maclen(key) > key->digest_size)
+ return -EINVAL;
+
+ return 0;
+
+err_pool_end:
+ tcp_sigpool_end(&hp);
+err_kfree:
+ kfree(tmp_key);
+ return err;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static int tcp_ao_verify_ipv6(struct sock *sk, struct tcp_ao_add *cmd,
+ union tcp_ao_addr **paddr, u16 *port,
+ unsigned short int *family)
+{
+ struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd->addr;
+ struct in6_addr *addr = &sin6->sin6_addr;
+ u8 prefix = cmd->prefix;
+
+ if (sin6->sin6_family != AF_INET6)
+ return -EINVAL;
+
+ if (tcp_ao_verify_port(sk, ntohs(sin6->sin6_port)))
+ return -EINVAL;
+
+ /* Check prefix and trailing 0's in addr */
+ if (cmd->prefix != 0 && ipv6_addr_v4mapped(addr)) {
+ __be32 addr4 = addr->s6_addr32[3];
+ __be32 mask;
+
+ if (prefix > 32 || addr4 == INADDR_ANY)
+ return -EINVAL;
+
+ mask = inet_make_mask(prefix);
+ if (addr4 & ~mask)
+ return -EINVAL;
+
+ /* Check that MKT address is consistent with socket */
+ if (!ipv6_addr_any(&sk->sk_v6_daddr)) {
+ __be32 daddr4 = sk->sk_v6_daddr.s6_addr32[3];
+
+ if (!ipv6_addr_v4mapped(&sk->sk_v6_daddr))
+ return -EINVAL;
+ if ((daddr4 & mask) != addr4)
+ return -EINVAL;
+ }
+
+ *paddr = (union tcp_ao_addr *)&addr->s6_addr32[3];
+ *family = AF_INET;
+ *port = ntohs(sin6->sin6_port);
+ return 0;
+ } else if (cmd->prefix != 0) {
+ struct in6_addr pfx;
+
+ if (ipv6_addr_any(addr) || prefix > 128)
+ return -EINVAL;
+
+ ipv6_addr_prefix(&pfx, addr, prefix);
+ if (ipv6_addr_cmp(&pfx, addr))
+ return -EINVAL;
+
+ /* Check that MKT address is consistent with socket */
+ if (!ipv6_addr_any(&sk->sk_v6_daddr) &&
+ !ipv6_prefix_equal(&sk->sk_v6_daddr, addr, prefix))
+
+ return -EINVAL;
+ } else {
+ if (!ipv6_addr_any(addr))
+ return -EINVAL;
+ }
+
+ *paddr = (union tcp_ao_addr *)addr;
+ *port = ntohs(sin6->sin6_port);
+ return 0;
+}
+#else
+static inline int tcp_ao_verify_ipv6(struct sock *sk, struct tcp_ao_add *cmd,
+ union tcp_ao_addr **paddr, u16 *port,
+ unsigned short int *family)
+{
+ return -EOPNOTSUPP;
+}
+#endif
+
+static struct tcp_ao_info *setsockopt_ao_info(struct sock *sk)
+{
+ if (sk_fullsock(sk)) {
+ return rcu_dereference_protected(tcp_sk(sk)->ao_info,
+ lockdep_sock_is_held(sk));
+ }
+ return ERR_PTR(-ESOCKTNOSUPPORT);
+}
+
+#define TCP_AO_KEYF_ALL (0)
+
+static struct tcp_ao_key *tcp_ao_key_alloc(struct sock *sk,
+ struct tcp_ao_add *cmd)
+{
+ const char *algo = cmd->alg_name;
+ unsigned int digest_size;
+ struct crypto_ahash *tfm;
+ struct tcp_ao_key *key;
+ struct tcp_sigpool hp;
+ int err, pool_id;
+ size_t size;
+
+ /* Force null-termination of alg_name */
+ cmd->alg_name[ARRAY_SIZE(cmd->alg_name) - 1] = '\0';
+
+ /* RFC5926, 3.1.1.2. KDF_AES_128_CMAC */
+ if (!strcmp("cmac(aes128)", algo))
+ algo = "cmac(aes)";
+
+ /* Full TCP header (th->doff << 2) should fit into scratch area,
+ * see tcp_ao_hash_header().
+ */
+ pool_id = tcp_sigpool_alloc_ahash(algo, 60);
+ if (pool_id < 0)
+ return ERR_PTR(pool_id);
+
+ err = tcp_sigpool_start(pool_id, &hp);
+ if (err)
+ goto err_free_pool;
+
+ tfm = crypto_ahash_reqtfm(hp.req);
+ if (crypto_ahash_alignmask(tfm) > TCP_AO_KEY_ALIGN) {
+ err = -EOPNOTSUPP;
+ goto err_pool_end;
+ }
+ digest_size = crypto_ahash_digestsize(tfm);
+ tcp_sigpool_end(&hp);
+
+ size = sizeof(struct tcp_ao_key) + (digest_size << 1);
+ key = sock_kmalloc(sk, size, GFP_KERNEL);
+ if (!key) {
+ err = -ENOMEM;
+ goto err_free_pool;
+ }
+
+ key->tcp_sigpool_id = pool_id;
+ key->digest_size = digest_size;
+ return key;
+
+err_pool_end:
+ tcp_sigpool_end(&hp);
+err_free_pool:
+ tcp_sigpool_release(pool_id);
+ return ERR_PTR(err);
+}
+
+static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
+ sockptr_t optval, int optlen)
+{
+ struct tcp_ao_info *ao_info;
+ union tcp_ao_addr *addr;
+ struct tcp_ao_key *key;
+ struct tcp_ao_add cmd;
+ int ret;
+ bool first = false;
+ u16 port;
+
+ if (optlen < sizeof(cmd))
+ return -EINVAL;
+
+ ret = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
+ if (ret)
+ return ret;
+
+ if (cmd.keylen > TCP_AO_MAXKEYLEN)
+ return -EINVAL;
+
+ if (cmd.reserved != 0 || cmd.reserved2 != 0)
+ return -EINVAL;
+
+ if (family == AF_INET)
+ ret = tcp_ao_verify_ipv4(sk, &cmd, &addr, &port);
+ else
+ ret = tcp_ao_verify_ipv6(sk, &cmd, &addr, &port, &family);
+ if (ret)
+ return ret;
+
+ if (cmd.keyflags & ~TCP_AO_KEYF_ALL)
+ return -EINVAL;
+
+ if (cmd.set_current || cmd.set_rnext) {
+ if (!tcp_ao_can_set_current_rnext(sk))
+ return -EINVAL;
+ }
+
+ ao_info = setsockopt_ao_info(sk);
+ if (IS_ERR(ao_info))
+ return PTR_ERR(ao_info);
+
+ if (!ao_info) {
+ ao_info = tcp_ao_alloc_info(GFP_KERNEL);
+ if (!ao_info)
+ return -ENOMEM;
+ first = true;
+ } else {
+ /* Check that neither RecvID nor SendID match any
+ * existing key for the peer, RFC5925 3.1:
+ * > The IDs of MKTs MUST NOT overlap where their
+ * > TCP connection identifiers overlap.
+ */
+ if (__tcp_ao_do_lookup(sk, addr, family,
+ cmd.prefix, -1, cmd.rcvid, port))
+ return -EEXIST;
+ if (__tcp_ao_do_lookup(sk, addr, family,
+ cmd.prefix, cmd.sndid, -1, port))
+ return -EEXIST;
+ }
+
+ key = tcp_ao_key_alloc(sk, &cmd);
+ if (IS_ERR(key)) {
+ ret = PTR_ERR(key);
+ goto err_free_ao;
+ }
+
+ INIT_HLIST_NODE(&key->node);
+ memcpy(&key->addr, addr, (family == AF_INET) ? sizeof(struct in_addr) :
+ sizeof(struct in6_addr));
+ key->port = port;
+ key->prefixlen = cmd.prefix;
+ key->family = family;
+ key->keyflags = cmd.keyflags;
+ key->sndid = cmd.sndid;
+ key->rcvid = cmd.rcvid;
+
+ ret = tcp_ao_parse_crypto(&cmd, key);
+ if (ret < 0)
+ goto err_free_sock;
+
+ tcp_ao_link_mkt(ao_info, key);
+ if (first) {
+ sk_gso_disable(sk);
+ rcu_assign_pointer(tcp_sk(sk)->ao_info, ao_info);
+ }
+
+ if (cmd.set_current)
+ WRITE_ONCE(ao_info->current_key, key);
+ if (cmd.set_rnext)
+ WRITE_ONCE(ao_info->rnext_key, key);
+ return 0;
+
+err_free_sock:
+ atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
+ tcp_sigpool_release(key->tcp_sigpool_id);
+ kfree(key);
+err_free_ao:
+ if (first)
+ kfree(ao_info);
+ return ret;
+}
+
+static int tcp_ao_delete_key(struct sock *sk, struct tcp_ao_info *ao_info,
+ struct tcp_ao_key *key,
+ struct tcp_ao_key *new_current,
+ struct tcp_ao_key *new_rnext)
+{
+ int err;
+
+ hlist_del_rcu(&key->node);
+
+ /* At this moment another CPU could have looked this key up
+ * while it was unlinked from the list. Wait for RCU grace period,
+ * after which the key is off-list and can't be looked up again;
+ * the rx path [just before RCU came] might have used it and set it
+ * as current_key (very unlikely).
+ */
+ synchronize_rcu();
+ if (new_current)
+ WRITE_ONCE(ao_info->current_key, new_current);
+ if (new_rnext)
+ WRITE_ONCE(ao_info->rnext_key, new_rnext);
+
+ if (unlikely(READ_ONCE(ao_info->current_key) == key ||
+ READ_ONCE(ao_info->rnext_key) == key)) {
+ err = -EBUSY;
+ goto add_key;
+ }
+
+ atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
+ call_rcu(&key->rcu, tcp_ao_key_free_rcu);
+
+ return 0;
+add_key:
+ hlist_add_head_rcu(&key->node, &ao_info->head);
+ return err;
+}
+
+static int tcp_ao_del_cmd(struct sock *sk, unsigned short int family,
+ sockptr_t optval, int optlen)
+{
+ struct tcp_ao_key *key, *new_current = NULL, *new_rnext = NULL;
+ struct tcp_ao_info *ao_info;
+ union tcp_ao_addr *addr;
+ struct tcp_ao_del cmd;
+ int err;
+ __u8 prefix;
+ __be16 port;
+ int addr_len;
+
+ if (optlen < sizeof(cmd))
+ return -EINVAL;
+
+ err = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
+ if (err)
+ return err;
+
+ if (cmd.reserved != 0 || cmd.reserved2 != 0)
+ return -EINVAL;
+
+ if (cmd.set_current || cmd.set_rnext) {
+ if (!tcp_ao_can_set_current_rnext(sk))
+ return -EINVAL;
+ }
+
+ ao_info = setsockopt_ao_info(sk);
+ if (IS_ERR(ao_info))
+ return PTR_ERR(ao_info);
+ if (!ao_info)
+ return -ENOENT;
+
+ /* For sockets in TCP_CLOSED it's possible set keys that aren't
+ * matching the future peer (address/port/VRF/etc),
+ * tcp_ao_connect_init() will choose a correct matching MKT
+ * if there's any.
+ */
+ if (cmd.set_current) {
+ new_current = tcp_ao_established_key(ao_info, cmd.current_key, -1);
+ if (!new_current)
+ return -ENOENT;
+ }
+ if (cmd.set_rnext) {
+ new_rnext = tcp_ao_established_key(ao_info, -1, cmd.rnext);
+ if (!new_rnext)
+ return -ENOENT;
+ }
+
+ if (family == AF_INET) {
+ struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.addr;
+
+ addr = (union tcp_ao_addr *)&sin->sin_addr;
+ addr_len = sizeof(struct in_addr);
+ port = ntohs(sin->sin_port);
+ } else {
+ struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.addr;
+ struct in6_addr *addr6 = &sin6->sin6_addr;
+
+ if (ipv6_addr_v4mapped(addr6)) {
+ addr = (union tcp_ao_addr *)&addr6->s6_addr32[3];
+ addr_len = sizeof(struct in_addr);
+ family = AF_INET;
+ } else {
+ addr = (union tcp_ao_addr *)addr6;
+ addr_len = sizeof(struct in6_addr);
+ }
+ port = ntohs(sin6->sin6_port);
+ }
+ prefix = cmd.prefix;
+
+ /* We could choose random present key here for current/rnext
+ * but that's less predictable. Let's be strict and don't
+ * allow removing a key that's in use. RFC5925 doesn't
+ * specify how-to coordinate key removal, but says:
+ * "It is presumed that an MKT affecting a particular
+ * connection cannot be destroyed during an active connection"
+ */
+ hlist_for_each_entry_rcu(key, &ao_info->head, node) {
+ if (cmd.sndid != key->sndid ||
+ cmd.rcvid != key->rcvid)
+ continue;
+
+ if (family != key->family ||
+ prefix != key->prefixlen ||
+ port != key->port ||
+ memcmp(addr, &key->addr, addr_len))
+ continue;
+
+ if (key == new_current || key == new_rnext)
+ continue;
+
+ return tcp_ao_delete_key(sk, ao_info, key,
+ new_current, new_rnext);
+ }
+ return -ENOENT;
+}
+
+static int tcp_ao_info_cmd(struct sock *sk, unsigned short int family,
+ sockptr_t optval, int optlen)
+{
+ struct tcp_ao_info *ao_info;
+ struct tcp_ao_key *new_current = NULL, *new_rnext = NULL;
+ struct tcp_ao_info_opt cmd;
+ bool first = false;
+ int err;
+
+ if (optlen < sizeof(cmd))
+ return -EINVAL;
+
+ err = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
+ if (err)
+ return err;
+
+ if (cmd.set_current || cmd.set_rnext) {
+ if (!tcp_ao_can_set_current_rnext(sk))
+ return -EINVAL;
+ }
+
+ if (cmd.reserved != 0)
+ return -EINVAL;
+
+ ao_info = setsockopt_ao_info(sk);
+ if (IS_ERR(ao_info))
+ return PTR_ERR(ao_info);
+ if (!ao_info) {
+ ao_info = tcp_ao_alloc_info(GFP_KERNEL);
+ if (!ao_info)
+ return -ENOMEM;
+ first = true;
+ }
+
+ /* For sockets in TCP_CLOSED it's possible set keys that aren't
+ * matching the future peer (address/port/VRF/etc),
+ * tcp_ao_connect_init() will choose a correct matching MKT
+ * if there's any.
+ */
+ if (cmd.set_current) {
+ new_current = tcp_ao_established_key(ao_info, cmd.current_key, -1);
+ if (!new_current) {
+ err = -ENOENT;
+ goto out;
+ }
+ }
+ if (cmd.set_rnext) {
+ new_rnext = tcp_ao_established_key(ao_info, -1, cmd.rnext);
+ if (!new_rnext) {
+ err = -ENOENT;
+ goto out;
+ }
+ }
+
+ ao_info->ao_required = cmd.ao_required;
+ if (new_current)
+ WRITE_ONCE(ao_info->current_key, new_current);
+ if (new_rnext)
+ WRITE_ONCE(ao_info->rnext_key, new_rnext);
+ if (first) {
+ sk_gso_disable(sk);
+ rcu_assign_pointer(tcp_sk(sk)->ao_info, ao_info);
+ }
+ return 0;
+out:
+ if (first)
+ kfree(ao_info);
+ return err;
+}
+
+int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family,
+ sockptr_t optval, int optlen)
+{
+ if (WARN_ON_ONCE(family != AF_INET && family != AF_INET6))
+ return -EAFNOSUPPORT;
+
+ switch (cmd) {
+ case TCP_AO_ADD_KEY:
+ return tcp_ao_add_cmd(sk, family, optval, optlen);
+ case TCP_AO_DEL_KEY:
+ return tcp_ao_del_cmd(sk, family, optval, optlen);
+ case TCP_AO_INFO:
+ return tcp_ao_info_cmd(sk, family, optval, optlen);
+ default:
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+}
+
+int tcp_v4_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen)
+{
+ return tcp_parse_ao(sk, cmd, AF_INET, optval, optlen);
+}
+
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index b3b8a11daa71..8804eb801caf 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2269,11 +2269,16 @@ const struct inet_connection_sock_af_ops ipv4_specific = {
};
EXPORT_SYMBOL(ipv4_specific);
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
+#ifdef CONFIG_TCP_MD5SIG
.md5_lookup = tcp_v4_md5_lookup,
.calc_md5_hash = tcp_v4_md5_hash_skb,
.md5_parse = tcp_v4_parse_md5_keys,
+#endif
+#ifdef CONFIG_TCP_AO
+ .ao_parse = tcp_v4_parse_ao,
+#endif
};
#endif
@@ -2288,7 +2293,7 @@ static int tcp_v4_init_sock(struct sock *sk)
icsk->icsk_af_ops = &ipv4_specific;
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
tcp_sk(sk)->af_specific = &tcp_sock_ipv4_specific;
#endif
@@ -2339,6 +2344,7 @@ void tcp_v4_destroy_sock(struct sock *sk)
rcu_assign_pointer(tp->md5sig_info, NULL);
}
#endif
+ tcp_ao_destroy_sock(sk);
/* Clean up a referenced TCP bind bucket. */
if (inet_csk(sk)->icsk_bind_hash)
diff --git a/net/ipv6/Makefile b/net/ipv6/Makefile
index 3036a45e8a1e..d283c59df4c1 100644
--- a/net/ipv6/Makefile
+++ b/net/ipv6/Makefile
@@ -52,4 +52,5 @@ obj-$(subst m,y,$(CONFIG_IPV6)) += inet6_hashtables.o
ifneq ($(CONFIG_IPV6),)
obj-$(CONFIG_NET_UDP_TUNNEL) += ip6_udp_tunnel.o
obj-y += mcast_snoop.o
+obj-$(CONFIG_TCP_AO) += tcp_ao.o
endif
diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c
new file mode 100644
index 000000000000..049ddbabe049
--- /dev/null
+++ b/net/ipv6/tcp_ao.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * INET An implementation of the TCP Authentication Option (TCP-AO).
+ * See RFC5925.
+ *
+ * Authors: Dmitry Safonov <[email protected]>
+ * Francesco Ruggeri <[email protected]>
+ * Salam Noureddine <[email protected]>
+ */
+#include <linux/tcp.h>
+
+#include <net/tcp.h>
+#include <net/ipv6.h>
+
+int tcp_v6_parse_ao(struct sock *sk, int cmd,
+ sockptr_t optval, int optlen)
+{
+ return tcp_parse_ao(sk, cmd, AF_INET6, optval, optlen);
+}
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index afa8db712dfb..96ec9c03d9eb 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -76,16 +76,9 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
static const struct inet_connection_sock_af_ops ipv6_mapped;
const struct inet_connection_sock_af_ops ipv6_specific;
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
-#else
-static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
- const struct in6_addr *addr,
- int l3index)
-{
- return NULL;
-}
#endif
/* Helper returning the inet6 address from a given tcp socket.
@@ -239,7 +232,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
if (sk_is_mptcp(sk))
mptcpv6_handle_mapped(sk, true);
sk->sk_backlog_rcv = tcp_v4_do_rcv;
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
tp->af_specific = &tcp_sock_ipv6_mapped_specific;
#endif
@@ -252,7 +245,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
if (sk_is_mptcp(sk))
mptcpv6_handle_mapped(sk, false);
sk->sk_backlog_rcv = tcp_v6_do_rcv;
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
tp->af_specific = &tcp_sock_ipv6_specific;
#endif
goto failure;
@@ -768,7 +761,13 @@ static int tcp_v6_md5_hash_skb(char *md5_hash,
memset(md5_hash, 0, 16);
return 1;
}
-
+#else /* CONFIG_TCP_MD5SIG */
+static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
+ const struct in6_addr *addr,
+ int l3index)
+{
+ return NULL;
+}
#endif
static void tcp_v6_init_req(struct request_sock *req,
@@ -1228,7 +1227,7 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
if (sk_is_mptcp(newsk))
mptcpv6_handle_mapped(newsk, true);
newsk->sk_backlog_rcv = tcp_v4_do_rcv;
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
#endif
@@ -1892,11 +1891,16 @@ const struct inet_connection_sock_af_ops ipv6_specific = {
.mtu_reduced = tcp_v6_mtu_reduced,
};
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
+#ifdef CONFIG_TCP_MD5SIG
.md5_lookup = tcp_v6_md5_lookup,
.calc_md5_hash = tcp_v6_md5_hash_skb,
.md5_parse = tcp_v6_parse_md5_keys,
+#endif
+#ifdef CONFIG_TCP_AO
+ .ao_parse = tcp_v6_parse_ao,
+#endif
};
#endif
@@ -1918,11 +1922,16 @@ static const struct inet_connection_sock_af_ops ipv6_mapped = {
.mtu_reduced = tcp_v4_mtu_reduced,
};
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
+#ifdef CONFIG_TCP_MD5SIG
.md5_lookup = tcp_v4_md5_lookup,
.calc_md5_hash = tcp_v4_md5_hash_skb,
.md5_parse = tcp_v6_parse_md5_keys,
+#endif
+#ifdef CONFIG_TCP_AO
+ .ao_parse = tcp_v6_parse_ao,
+#endif
};
#endif
@@ -1937,7 +1946,7 @@ static int tcp_v6_init_sock(struct sock *sk)
icsk->icsk_af_ops = &ipv6_specific;
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
#endif
--
2.41.0
Similarly to RST segments, wire SYN-ACKs to TCP-AO.
tcp_rsk_used_ao() is handy here to check if the request socket used AO
and needs a signature on the outgoing segments.
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/tcp.h | 4 ++++
include/net/tcp_ao.h | 6 ++++++
net/ipv4/tcp_ao.c | 22 ++++++++++++++++++++
net/ipv4/tcp_ipv4.c | 1 +
net/ipv4/tcp_output.c | 48 +++++++++++++++++++++++++++++++++++++------
net/ipv6/tcp_ao.c | 22 ++++++++++++++++++++
net/ipv6/tcp_ipv6.c | 1 +
7 files changed, 98 insertions(+), 6 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index b8be3aefb9c4..ad300e5b6eb8 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2177,6 +2177,10 @@ struct tcp_request_sock_ops {
int sndid, int rcvid);
int (*ao_calc_key)(struct tcp_ao_key *mkt, u8 *key,
struct request_sock *sk);
+ int (*ao_synack_hash)(char *ao_hash, struct tcp_ao_key *mkt,
+ struct request_sock *req,
+ const struct sk_buff *skb,
+ int hash_offset, u32 sne);
#endif
#ifdef CONFIG_SYN_COOKIES
__u32 (*cookie_init_seq)(const struct sk_buff *skb,
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index b63c4f2c36ea..4979c993973f 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -144,6 +144,9 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
int tcp_v4_parse_ao(struct sock *sk, int optname, sockptr_t optval, int optlen);
struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int sndid, int rcvid);
+int tcp_v4_ao_synack_hash(char *ao_hash, struct tcp_ao_key *mkt,
+ struct request_sock *req, const struct sk_buff *skb,
+ int hash_offset, u32 sne);
int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk,
__be32 sisn, __be32 disn, bool send);
@@ -178,6 +181,9 @@ int tcp_v6_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
const u8 *tkey, int hash_offset, u32 sne);
int tcp_v6_parse_ao(struct sock *sk, int cmd,
sockptr_t optval, int optlen);
+int tcp_v6_ao_synack_hash(char *ao_hash, struct tcp_ao_key *ao_key,
+ struct request_sock *req, const struct sk_buff *skb,
+ int hash_offset, u32 sne);
void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb);
void tcp_ao_connect_init(struct sock *sk);
void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index be9349239139..0233cf363de9 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -546,6 +546,28 @@ int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
tkey, hash_offset, sne);
}
+int tcp_v4_ao_synack_hash(char *ao_hash, struct tcp_ao_key *ao_key,
+ struct request_sock *req, const struct sk_buff *skb,
+ int hash_offset, u32 sne)
+{
+ void *hash_buf = NULL;
+ int err;
+
+ hash_buf = kmalloc(tcp_ao_digest_size(ao_key), GFP_ATOMIC);
+ if (!hash_buf)
+ return -ENOMEM;
+
+ err = tcp_v4_ao_calc_key_rsk(ao_key, hash_buf, req);
+ if (err)
+ goto out;
+
+ err = tcp_ao_hash_skb(AF_INET, ao_hash, ao_key, req_to_sk(req), skb,
+ hash_buf, hash_offset, sne);
+out:
+ kfree(hash_buf);
+ return err;
+}
+
struct tcp_ao_key *tcp_v4_ao_lookup_rsk(const struct sock *sk,
struct request_sock *req,
int sndid, int rcvid)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 12b952d0dcf4..884d9f854276 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1678,6 +1678,7 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
#ifdef CONFIG_TCP_AO
.ao_lookup = tcp_v4_ao_lookup_rsk,
.ao_calc_key = tcp_v4_ao_calc_key_rsk,
+ .ao_synack_hash = tcp_v4_ao_synack_hash,
#endif
#ifdef CONFIG_SYN_COOKIES
.cookie_init_seq = cookie_v4_init_sequence,
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 27f7aaad5490..ed1164f287b7 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3722,6 +3722,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
struct inet_request_sock *ireq = inet_rsk(req);
const struct tcp_sock *tp = tcp_sk(sk);
struct tcp_md5sig_key *md5 = NULL;
+ struct tcp_ao_key *ao_key = NULL;
struct tcp_out_options opts;
struct sk_buff *skb;
int tcp_header_size;
@@ -3772,16 +3773,43 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
tcp_rsk(req)->snt_synack = tcp_skb_timestamp_us(skb);
}
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
rcu_read_lock();
- md5 = tcp_rsk(req)->af_specific->req_md5_lookup(sk, req_to_sk(req));
#endif
+ if (tcp_rsk_used_ao(req)) {
+#ifdef CONFIG_TCP_AO
+ u8 maclen = tcp_rsk(req)->maclen;
+ u8 keyid = tcp_rsk(req)->ao_keyid;
+
+ ao_key = tcp_sk(sk)->af_specific->ao_lookup(sk, req_to_sk(req),
+ keyid, -1);
+ /* If there is no matching key - avoid sending anything,
+ * especially usigned segments. It could try harder and lookup
+ * for another peer-matching key, but the peer has requested
+ * ao_keyid (RFC5925 RNextKeyID), so let's keep it simple here.
+ */
+ if (unlikely(!ao_key || tcp_ao_maclen(ao_key) != maclen)) {
+ rcu_read_unlock();
+ skb_dst_drop(skb);
+ kfree_skb(skb);
+ net_warn_ratelimited("TCP-AO: the keyid %u with maclen %u|%u from SYN packet is not present - not sending SYNACK\n",
+ keyid, maclen,
+ ao_key ? tcp_ao_maclen(ao_key) : 0);
+ return NULL;
+ }
+#endif
+ } else {
+#ifdef CONFIG_TCP_MD5SIG
+ md5 = tcp_rsk(req)->af_specific->req_md5_lookup(sk,
+ req_to_sk(req));
+#endif
+ }
skb_set_hash(skb, READ_ONCE(tcp_rsk(req)->txhash), PKT_HASH_TYPE_L4);
/* bpf program will be interested in the tcp_flags */
TCP_SKB_CB(skb)->tcp_flags = TCPHDR_SYN | TCPHDR_ACK;
tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts, md5,
- NULL, foc, synack_type,
- syn_skb) + sizeof(*th);
+ ao_key, foc, synack_type, syn_skb)
+ + sizeof(*th);
skb_push(skb, tcp_header_size);
skb_reset_transport_header(skb);
@@ -3801,7 +3829,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
/* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
th->window = htons(min(req->rsk_rcv_wnd, 65535U));
- tcp_options_write(th, NULL, NULL, &opts, NULL);
+ tcp_options_write(th, NULL, tcp_rsk(req), &opts, ao_key);
th->doff = (tcp_header_size >> 2);
TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);
@@ -3809,7 +3837,15 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
/* Okay, we have all we need - do the md5 hash if needed */
if (md5)
tcp_rsk(req)->af_specific->calc_md5_hash(opts.hash_location,
- md5, req_to_sk(req), skb);
+ md5, req_to_sk(req), skb);
+#endif
+#ifdef CONFIG_TCP_AO
+ if (ao_key)
+ tcp_rsk(req)->af_specific->ao_synack_hash(opts.hash_location,
+ ao_key, req, skb,
+ opts.hash_location - (u8 *)th, 0);
+#endif
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
rcu_read_unlock();
#endif
diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c
index 65fa52f8c2e3..ec320781bc5c 100644
--- a/net/ipv6/tcp_ao.c
+++ b/net/ipv6/tcp_ao.c
@@ -133,3 +133,25 @@ int tcp_v6_parse_ao(struct sock *sk, int cmd,
{
return tcp_parse_ao(sk, cmd, AF_INET6, optval, optlen);
}
+
+int tcp_v6_ao_synack_hash(char *ao_hash, struct tcp_ao_key *ao_key,
+ struct request_sock *req, const struct sk_buff *skb,
+ int hash_offset, u32 sne)
+{
+ void *hash_buf = NULL;
+ int err;
+
+ hash_buf = kmalloc(tcp_ao_digest_size(ao_key), GFP_ATOMIC);
+ if (!hash_buf)
+ return -ENOMEM;
+
+ err = tcp_v6_ao_calc_key_rsk(ao_key, hash_buf, req);
+ if (err)
+ goto out;
+
+ err = tcp_ao_hash_skb(AF_INET6, ao_hash, ao_key, req_to_sk(req), skb,
+ hash_buf, hash_offset, sne);
+out:
+ kfree(hash_buf);
+ return err;
+}
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 6905484077db..000e4e5309d3 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -845,6 +845,7 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
#ifdef CONFIG_TCP_AO
.ao_lookup = tcp_v6_ao_lookup_rsk,
.ao_calc_key = tcp_v6_ao_calc_key_rsk,
+ .ao_synack_hash = tcp_v6_ao_synack_hash,
#endif
#ifdef CONFIG_SYN_COOKIES
.cookie_init_seq = cookie_v6_init_sequence,
--
2.41.0
Using precalculated traffic keys, sign TCP segments as prescribed by
RFC5925. Per RFC, TCP header options are included in sign calculation:
"The TCP header, by default including options, and where the TCP
checksum and TCP-AO MAC fields are set to zero, all in network-
byte order." (5.1.3)
tcp_ao_hash_header() has exclude_options parameter to optionally exclude
TCP header from hash calculation, as described in RFC5925 (9.1), this is
needed for interaction with middleboxes that may change "some TCP
options". This is wired up to AO key flags and setsockopt() later.
Similarly to TCP-MD5 hash TCP segment fragments.
From this moment a user can start sending TCP-AO signed segments with
one of crypto ahash algorithms from supported by Linux kernel. It can
have a user-specified MAC length, to either save TCP option header space
or provide higher protection using a longer signature.
The inbound segments are not yet verified, TCP-AO option is ignored and
they are accepted.
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/tcp.h | 7 ++
include/net/tcp_ao.h | 13 ++++
net/ipv4/tcp_ao.c | 165 ++++++++++++++++++++++++++++++++++++++++++
net/ipv4/tcp_ipv4.c | 1 +
net/ipv4/tcp_output.c | 122 ++++++++++++++++++++++++++++---
net/ipv6/tcp_ao.c | 28 +++++++
net/ipv6/tcp_ipv6.c | 2 +
7 files changed, 328 insertions(+), 10 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 6a2e15a94214..d4344cc39893 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -186,6 +186,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo);
#define TCPOPT_SACK 5 /* SACK Block */
#define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */
#define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */
+#define TCPOPT_AO 29 /* Authentication Option (RFC5925) */
#define TCPOPT_MPTCP 30 /* Multipath TCP (RFC6824) */
#define TCPOPT_FASTOPEN 34 /* Fast open (RFC7413) */
#define TCPOPT_EXP 254 /* Experimental */
@@ -2147,6 +2148,12 @@ struct tcp_sock_af_ops {
struct tcp_ao_key *(*ao_lookup)(const struct sock *sk,
struct sock *addr_sk,
int sndid, int rcvid);
+ int (*calc_ao_hash)(char *location,
+ struct tcp_ao_key *ao,
+ const struct sock *sk,
+ const struct sk_buff *skb,
+ const u8 *tkey,
+ int hash_offset, u32 sne);
int (*ao_calc_key_sk)(struct tcp_ao_key *mkt,
u8 *key,
const struct sock *sk,
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 1aac82c1d22d..8d61f2690d52 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -111,6 +111,10 @@ struct tcp6_ao_context {
};
struct tcp_sigpool;
+int tcp_ao_hash_skb(unsigned short int family,
+ char *ao_hash, struct tcp_ao_key *key,
+ const struct sock *sk, const struct sk_buff *skb,
+ const u8 *tkey, int hash_offset, u32 sne);
int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family,
sockptr_t optval, int optlen);
int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
@@ -126,13 +130,22 @@ struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk,
__be32 sisn, __be32 disn, bool send);
+int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
+ const struct sock *sk, const struct sk_buff *skb,
+ const u8 *tkey, int hash_offset, u32 sne);
/* ipv6 specific functions */
+int tcp_v6_ao_hash_pseudoheader(struct tcp_sigpool *hp,
+ const struct in6_addr *daddr,
+ const struct in6_addr *saddr, int nbytes);
int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk, __be32 sisn,
__be32 disn, bool send);
struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
struct sock *addr_sk,
int sndid, int rcvid);
+int tcp_v6_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
+ const struct sock *sk, const struct sk_buff *skb,
+ const u8 *tkey, int hash_offset, u32 sne);
int tcp_v6_parse_ao(struct sock *sk, int cmd,
sockptr_t optval, int optlen);
void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb);
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index a5c70cbaa954..3ff7b1efacfa 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -264,6 +264,171 @@ static int tcp_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
return -EOPNOTSUPP;
}
+static int tcp_v4_ao_hash_pseudoheader(struct tcp_sigpool *hp,
+ __be32 daddr, __be32 saddr,
+ int nbytes)
+{
+ struct tcp4_pseudohdr *bp;
+ struct scatterlist sg;
+
+ bp = hp->scratch;
+ bp->saddr = saddr;
+ bp->daddr = daddr;
+ bp->pad = 0;
+ bp->protocol = IPPROTO_TCP;
+ bp->len = cpu_to_be16(nbytes);
+
+ sg_init_one(&sg, bp, sizeof(*bp));
+ ahash_request_set_crypt(hp->req, &sg, NULL, sizeof(*bp));
+ return crypto_ahash_update(hp->req);
+}
+
+static int tcp_ao_hash_pseudoheader(unsigned short int family,
+ const struct sock *sk,
+ const struct sk_buff *skb,
+ struct tcp_sigpool *hp, int nbytes)
+{
+ const struct tcphdr *th = tcp_hdr(skb);
+
+ /* TODO: Can we rely on checksum being zero to mean outbound pkt? */
+ if (!th->check) {
+ if (family == AF_INET)
+ return tcp_v4_ao_hash_pseudoheader(hp, sk->sk_daddr,
+ sk->sk_rcv_saddr, skb->len);
+#if IS_ENABLED(CONFIG_IPV6)
+ else if (family == AF_INET6)
+ return tcp_v6_ao_hash_pseudoheader(hp, &sk->sk_v6_daddr,
+ &sk->sk_v6_rcv_saddr, skb->len);
+#endif
+ else
+ return -EAFNOSUPPORT;
+ }
+
+ if (family == AF_INET) {
+ const struct iphdr *iph = ip_hdr(skb);
+
+ return tcp_v4_ao_hash_pseudoheader(hp, iph->daddr,
+ iph->saddr, skb->len);
+#if IS_ENABLED(CONFIG_IPV6)
+ } else if (family == AF_INET6) {
+ const struct ipv6hdr *iph = ipv6_hdr(skb);
+
+ return tcp_v6_ao_hash_pseudoheader(hp, &iph->daddr,
+ &iph->saddr, skb->len);
+#endif
+ }
+ return -EAFNOSUPPORT;
+}
+
+/* tcp_ao_hash_sne(struct tcp_sigpool *hp)
+ * @hp - used for hashing
+ * @sne - sne value
+ */
+static int tcp_ao_hash_sne(struct tcp_sigpool *hp, u32 sne)
+{
+ struct scatterlist sg;
+ __be32 *bp;
+
+ bp = (__be32 *)hp->scratch;
+ *bp = htonl(sne);
+
+ sg_init_one(&sg, bp, sizeof(*bp));
+ ahash_request_set_crypt(hp->req, &sg, NULL, sizeof(*bp));
+ return crypto_ahash_update(hp->req);
+}
+
+static int tcp_ao_hash_header(struct tcp_sigpool *hp,
+ const struct tcphdr *th,
+ bool exclude_options, u8 *hash,
+ int hash_offset, int hash_len)
+{
+ struct scatterlist sg;
+ u8 *hdr = hp->scratch;
+ int err, len = th->doff << 2;
+
+ /* We are not allowed to change tcphdr, make a local copy */
+ if (exclude_options) {
+ len = sizeof(*th) + sizeof(struct tcp_ao_hdr) + hash_len;
+ memcpy(hdr, th, sizeof(*th));
+ memcpy(hdr + sizeof(*th),
+ (u8 *)th + hash_offset - sizeof(struct tcp_ao_hdr),
+ sizeof(struct tcp_ao_hdr));
+ memset(hdr + sizeof(*th) + sizeof(struct tcp_ao_hdr),
+ 0, hash_len);
+ ((struct tcphdr *)hdr)->check = 0;
+ } else {
+ len = th->doff << 2;
+ memcpy(hdr, th, len);
+ /* zero out tcp-ao hash */
+ ((struct tcphdr *)hdr)->check = 0;
+ memset(hdr + hash_offset, 0, hash_len);
+ }
+
+ sg_init_one(&sg, hdr, len);
+ ahash_request_set_crypt(hp->req, &sg, NULL, len);
+ err = crypto_ahash_update(hp->req);
+ WARN_ON_ONCE(err != 0);
+ return err;
+}
+
+int tcp_ao_hash_skb(unsigned short int family,
+ char *ao_hash, struct tcp_ao_key *key,
+ const struct sock *sk, const struct sk_buff *skb,
+ const u8 *tkey, int hash_offset, u32 sne)
+{
+ const struct tcphdr *th = tcp_hdr(skb);
+ int tkey_len = tcp_ao_digest_size(key);
+ struct tcp_sigpool hp;
+ void *hash_buf = NULL;
+
+ hash_buf = kmalloc(tkey_len, GFP_ATOMIC);
+ if (!hash_buf)
+ goto clear_hash_noput;
+
+ if (tcp_sigpool_start(key->tcp_sigpool_id, &hp))
+ goto clear_hash_noput;
+
+ if (crypto_ahash_setkey(crypto_ahash_reqtfm(hp.req), tkey, tkey_len))
+ goto clear_hash;
+
+ /* For now use sha1 by default. Depends on alg in tcp_ao_key */
+ if (crypto_ahash_init(hp.req))
+ goto clear_hash;
+
+ if (tcp_ao_hash_sne(&hp, sne))
+ goto clear_hash;
+ if (tcp_ao_hash_pseudoheader(family, sk, skb, &hp, skb->len))
+ goto clear_hash;
+ if (tcp_ao_hash_header(&hp, th, false,
+ ao_hash, hash_offset, tcp_ao_maclen(key)))
+ goto clear_hash;
+ if (tcp_sigpool_hash_skb_data(&hp, skb, th->doff << 2))
+ goto clear_hash;
+ ahash_request_set_crypt(hp.req, NULL, hash_buf, 0);
+ if (crypto_ahash_final(hp.req))
+ goto clear_hash;
+
+ memcpy(ao_hash, hash_buf, tcp_ao_maclen(key));
+ tcp_sigpool_end(&hp);
+ kfree(hash_buf);
+ return 0;
+
+clear_hash:
+ tcp_sigpool_end(&hp);
+clear_hash_noput:
+ memset(ao_hash, 0, tcp_ao_maclen(key));
+ kfree(hash_buf);
+ return 1;
+}
+
+int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
+ const struct sock *sk, const struct sk_buff *skb,
+ const u8 *tkey, int hash_offset, u32 sne)
+{
+ return tcp_ao_hash_skb(AF_INET, ao_hash, key, sk, skb,
+ tkey, hash_offset, sne);
+}
+
struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int sndid, int rcvid)
{
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 447e0c6f132f..8222f14e4c32 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2285,6 +2285,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
#endif
#ifdef CONFIG_TCP_AO
.ao_lookup = tcp_v4_ao_lookup,
+ .calc_ao_hash = tcp_v4_ao_hash_skb,
.ao_parse = tcp_v4_parse_ao,
.ao_calc_key_sk = tcp_v4_ao_calc_key_sk,
#endif
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 937516aac99a..813d865095ac 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -415,6 +415,7 @@ static inline bool tcp_urg_mode(const struct tcp_sock *tp)
#define OPTION_FAST_OPEN_COOKIE BIT(8)
#define OPTION_SMC BIT(9)
#define OPTION_MPTCP BIT(10)
+#define OPTION_AO BIT(11)
static void smc_options_write(__be32 *ptr, u16 *options)
{
@@ -607,7 +608,8 @@ static void bpf_skops_write_hdr_opt(struct sock *sk, struct sk_buff *skb,
* (but it may well be that other scenarios fail similarly).
*/
static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
- struct tcp_out_options *opts)
+ struct tcp_out_options *opts,
+ struct tcp_ao_key *ao_key)
{
__be32 *ptr = (__be32 *)(th + 1);
u16 options = opts->options; /* mungable copy */
@@ -619,7 +621,33 @@ static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
opts->hash_location = (__u8 *)ptr;
ptr += 4;
}
+#ifdef CONFIG_TCP_AO
+ if (unlikely(OPTION_AO & options) && tp) {
+ struct tcp_ao_key *rnext_key;
+ struct tcp_ao_info *ao_info;
+ u8 maclen;
+ if (WARN_ON_ONCE(!ao_key))
+ goto out_ao;
+ ao_info = rcu_dereference_check(tp->ao_info,
+ lockdep_sock_is_held(&tp->inet_conn.icsk_inet.sk));
+ rnext_key = READ_ONCE(ao_info->rnext_key);
+ if (WARN_ON_ONCE(!rnext_key))
+ goto out_ao;
+ maclen = tcp_ao_maclen(ao_key);
+ *ptr++ = htonl((TCPOPT_AO << 24) |
+ (tcp_ao_len(ao_key) << 16) |
+ (ao_key->sndid << 8) |
+ (rnext_key->rcvid));
+ opts->hash_location = (__u8 *)ptr;
+ ptr += maclen / sizeof(*ptr);
+ if (unlikely(maclen % sizeof(*ptr))) {
+ memset(ptr, TCPOPT_NOP, sizeof(*ptr));
+ ptr++;
+ }
+ }
+out_ao:
+#endif
if (unlikely(opts->mss)) {
*ptr++ = htonl((TCPOPT_MSS << 24) |
(TCPOLEN_MSS << 16) |
@@ -760,7 +788,8 @@ static void mptcp_set_option_cond(const struct request_sock *req,
*/
static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
struct tcp_out_options *opts,
- struct tcp_md5sig_key **md5)
+ struct tcp_md5sig_key **md5,
+ struct tcp_ao_key *ao_key)
{
struct tcp_sock *tp = tcp_sk(sk);
unsigned int remaining = MAX_TCP_OPTION_SPACE;
@@ -777,6 +806,12 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
}
}
#endif
+#ifdef CONFIG_TCP_AO
+ if (ao_key) {
+ opts->options |= OPTION_AO;
+ remaining -= tcp_ao_len(ao_key);
+ }
+#endif
/* We always get an MSS option. The option bytes which will be seen in
* normal data packets should timestamps be used, must be in the MSS
@@ -844,6 +879,7 @@ static unsigned int tcp_synack_options(const struct sock *sk,
unsigned int mss, struct sk_buff *skb,
struct tcp_out_options *opts,
const struct tcp_md5sig_key *md5,
+ const struct tcp_ao_key *ao,
struct tcp_fastopen_cookie *foc,
enum tcp_synack_type synack_type,
struct sk_buff *syn_skb)
@@ -865,6 +901,14 @@ static unsigned int tcp_synack_options(const struct sock *sk,
ireq->tstamp_ok &= !ireq->sack_ok;
}
#endif
+#ifdef CONFIG_TCP_AO
+ if (ao) {
+ opts->options |= OPTION_AO;
+ remaining -= tcp_ao_len(ao);
+ ireq->tstamp_ok &= !ireq->sack_ok;
+ }
+#endif
+ WARN_ON_ONCE(md5 && ao);
/* We always send an MSS option. */
opts->mss = mss;
@@ -914,7 +958,8 @@ static unsigned int tcp_synack_options(const struct sock *sk,
*/
static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb,
struct tcp_out_options *opts,
- struct tcp_md5sig_key **md5)
+ struct tcp_md5sig_key **md5,
+ struct tcp_ao_key *ao_key)
{
struct tcp_sock *tp = tcp_sk(sk);
unsigned int size = 0;
@@ -933,6 +978,12 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb
}
}
#endif
+#ifdef CONFIG_TCP_AO
+ if (ao_key) {
+ opts->options |= OPTION_AO;
+ size += tcp_ao_len(ao_key);
+ }
+#endif
if (likely(tp->rx_opt.tstamp_ok)) {
opts->options |= OPTION_TS;
@@ -1244,6 +1295,10 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
unsigned int tcp_options_size, tcp_header_size;
struct sk_buff *oskb = NULL;
struct tcp_md5sig_key *md5;
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_info *ao;
+#endif
+ struct tcp_ao_key *ao_key = NULL;
struct tcphdr *th;
u64 prior_wstamp;
int err;
@@ -1275,11 +1330,17 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
tcb = TCP_SKB_CB(skb);
memset(&opts, 0, sizeof(opts));
+#ifdef CONFIG_TCP_AO
+ ao = rcu_dereference_protected(tcp_sk(sk)->ao_info,
+ lockdep_sock_is_held(sk));
+ if (ao)
+ ao_key = READ_ONCE(ao->current_key);
+#endif
if (unlikely(tcb->tcp_flags & TCPHDR_SYN)) {
- tcp_options_size = tcp_syn_options(sk, skb, &opts, &md5);
+ tcp_options_size = tcp_syn_options(sk, skb, &opts, &md5, ao_key);
} else {
tcp_options_size = tcp_established_options(sk, skb, &opts,
- &md5);
+ &md5, ao_key);
/* Force a PSH flag on all (GSO) packets to expedite GRO flush
* at receiver : This slightly improve GRO performance.
* Note that we do not force the PSH flag for non GSO packets,
@@ -1353,7 +1414,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
th->window = htons(min(tp->rcv_wnd, 65535U));
}
- tcp_options_write(th, tp, &opts);
+ tcp_options_write(th, tp, &opts, ao_key);
#ifdef CONFIG_TCP_MD5SIG
/* Calculate the MD5 hash, as we have all we need now */
@@ -1363,6 +1424,34 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
md5, sk, skb);
}
#endif
+#ifdef CONFIG_TCP_AO
+ if (ao) {
+ u8 *traffic_key;
+ void *tkey_buf = NULL;
+ u32 disn;
+
+ sk_gso_disable(sk);
+ if (unlikely(tcb->tcp_flags & TCPHDR_SYN)) {
+ if (tcb->tcp_flags & TCPHDR_ACK)
+ disn = ao->risn;
+ else
+ disn = 0;
+
+ tkey_buf = kmalloc(tcp_ao_digest_size(ao_key), GFP_ATOMIC);
+ if (!tkey_buf)
+ return -ENOMEM;
+ traffic_key = tkey_buf;
+ tp->af_specific->ao_calc_key_sk(ao_key, traffic_key,
+ sk, ao->lisn, disn, true);
+ } else {
+ traffic_key = snd_other_key(ao_key);
+ }
+ tp->af_specific->calc_ao_hash(opts.hash_location, ao_key, sk, skb,
+ traffic_key,
+ opts.hash_location - (u8 *)th, 0);
+ kfree(tkey_buf);
+ }
+#endif
/* BPF prog is the last one writing header option */
bpf_skops_write_hdr_opt(sk, skb, NULL, NULL, 0, &opts);
@@ -1814,6 +1903,10 @@ unsigned int tcp_current_mss(struct sock *sk)
unsigned int header_len;
struct tcp_out_options opts;
struct tcp_md5sig_key *md5;
+ struct tcp_ao_key *ao_key = NULL;
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_info *ao_info;
+#endif
mss_now = tp->mss_cache;
@@ -1822,8 +1915,17 @@ unsigned int tcp_current_mss(struct sock *sk)
if (mtu != inet_csk(sk)->icsk_pmtu_cookie)
mss_now = tcp_sync_mss(sk, mtu);
}
-
- header_len = tcp_established_options(sk, NULL, &opts, &md5) +
+#ifdef CONFIG_TCP_AO
+ ao_info = rcu_dereference_check(tp->ao_info, lockdep_sock_is_held(sk));
+ if (ao_info)
+ /* TODO: verify if we can access current_key or we need to pass
+ * it from every caller of tcp_current_mss instead. The reason
+ * is that the current_key pointer can change asynchronously
+ * from the rx path.
+ */
+ ao_key = READ_ONCE(ao_info->current_key);
+#endif
+ header_len = tcp_established_options(sk, NULL, &opts, &md5, ao_key) +
sizeof(struct tcphdr);
/* The mss_cache is sized based on tp->tcp_header_len, which assumes
* some common options. If this is an odd packet (because we have SACK
@@ -3664,7 +3766,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
/* bpf program will be interested in the tcp_flags */
TCP_SKB_CB(skb)->tcp_flags = TCPHDR_SYN | TCPHDR_ACK;
tcp_header_size = tcp_synack_options(sk, req, mss, skb, &opts, md5,
- foc, synack_type,
+ NULL, foc, synack_type,
syn_skb) + sizeof(*th);
skb_push(skb, tcp_header_size);
@@ -3685,7 +3787,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
/* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
th->window = htons(min(req->rsk_rcv_wnd, 65535U));
- tcp_options_write(th, NULL, &opts);
+ tcp_options_write(th, NULL, &opts, NULL);
th->doff = (tcp_header_size >> 2);
TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);
diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c
index 0b490738c366..54c3714a05b4 100644
--- a/net/ipv6/tcp_ao.c
+++ b/net/ipv6/tcp_ao.c
@@ -7,6 +7,7 @@
* Francesco Ruggeri <[email protected]>
* Salam Noureddine <[email protected]>
*/
+#include <crypto/hash.h>
#include <linux/tcp.h>
#include <net/tcp.h>
@@ -79,6 +80,33 @@ struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
return tcp_v6_ao_do_lookup(sk, addr, sndid, rcvid);
}
+int tcp_v6_ao_hash_pseudoheader(struct tcp_sigpool *hp,
+ const struct in6_addr *daddr,
+ const struct in6_addr *saddr, int nbytes)
+{
+ struct tcp6_pseudohdr *bp;
+ struct scatterlist sg;
+
+ bp = hp->scratch;
+ /* 1. TCP pseudo-header (RFC2460) */
+ bp->saddr = *saddr;
+ bp->daddr = *daddr;
+ bp->len = cpu_to_be32(nbytes);
+ bp->protocol = cpu_to_be32(IPPROTO_TCP);
+
+ sg_init_one(&sg, bp, sizeof(*bp));
+ ahash_request_set_crypt(hp->req, &sg, NULL, sizeof(*bp));
+ return crypto_ahash_update(hp->req);
+}
+
+int tcp_v6_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
+ const struct sock *sk, const struct sk_buff *skb,
+ const u8 *tkey, int hash_offset, u32 sne)
+{
+ return tcp_ao_hash_skb(AF_INET6, ao_hash, key, sk, skb, tkey,
+ hash_offset, sne);
+}
+
int tcp_v6_parse_ao(struct sock *sk, int cmd,
sockptr_t optval, int optlen)
{
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 1e67aaf42460..1dd7c8f3aff4 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1916,6 +1916,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
#endif
#ifdef CONFIG_TCP_AO
.ao_lookup = tcp_v6_ao_lookup,
+ .calc_ao_hash = tcp_v6_ao_hash_skb,
.ao_parse = tcp_v6_parse_ao,
.ao_calc_key_sk = tcp_v6_ao_calc_key_sk,
#endif
@@ -1949,6 +1950,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
#endif
#ifdef CONFIG_TCP_AO
.ao_lookup = tcp_v6_ao_lookup,
+ .calc_ao_hash = tcp_v4_ao_hash_skb,
.ao_parse = tcp_v6_parse_ao,
#endif
};
--
2.41.0
Add traffic key calculation the way it's described in RFC5926.
Wire it up to tcp_finish_connect() and cache the new keys straight away
on already established TCP connections.
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/tcp.h | 5 ++
include/net/tcp_ao.h | 43 +++++++++-
net/ipv4/tcp_ao.c | 191 ++++++++++++++++++++++++++++++++++++++++++
net/ipv4/tcp_input.c | 1 +
net/ipv4/tcp_ipv4.c | 1 +
net/ipv4/tcp_output.c | 1 +
net/ipv6/tcp_ao.c | 50 +++++++++++
net/ipv6/tcp_ipv6.c | 1 +
8 files changed, 292 insertions(+), 1 deletion(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 7e414873ef07..6a2e15a94214 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2147,6 +2147,11 @@ struct tcp_sock_af_ops {
struct tcp_ao_key *(*ao_lookup)(const struct sock *sk,
struct sock *addr_sk,
int sndid, int rcvid);
+ int (*ao_calc_key_sk)(struct tcp_ao_key *mkt,
+ u8 *key,
+ const struct sock *sk,
+ __be32 sisn, __be32 disn,
+ bool send);
#endif
};
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 1c24b586c876..1aac82c1d22d 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -90,8 +90,31 @@ struct tcp_ao_info {
};
#ifdef CONFIG_TCP_AO
+/* TCP-AO structures and functions */
+
+struct tcp4_ao_context {
+ __be32 saddr;
+ __be32 daddr;
+ __be16 sport;
+ __be16 dport;
+ __be32 sisn;
+ __be32 disn;
+};
+
+struct tcp6_ao_context {
+ struct in6_addr saddr;
+ struct in6_addr daddr;
+ __be16 sport;
+ __be16 dport;
+ __be32 sisn;
+ __be32 disn;
+};
+struct tcp_sigpool;
+
int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family,
sockptr_t optval, int optlen);
+int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
+ unsigned int len, struct tcp_sigpool *hp);
void tcp_ao_destroy_sock(struct sock *sk);
struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
const union tcp_ao_addr *addr,
@@ -100,13 +123,23 @@ struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
int tcp_v4_parse_ao(struct sock *sk, int optname, sockptr_t optval, int optlen);
struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int sndid, int rcvid);
+int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+ const struct sock *sk,
+ __be32 sisn, __be32 disn, bool send);
/* ipv6 specific functions */
+int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+ const struct sock *sk, __be32 sisn,
+ __be32 disn, bool send);
struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
struct sock *addr_sk,
int sndid, int rcvid);
int tcp_v6_parse_ao(struct sock *sk, int cmd,
sockptr_t optval, int optlen);
-#else
+void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb);
+void tcp_ao_connect_init(struct sock *sk);
+
+#else /* CONFIG_TCP_AO */
+
static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
const union tcp_ao_addr *addr,
int family, int sndid, int rcvid, u16 port)
@@ -117,6 +150,14 @@ static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
static inline void tcp_ao_destroy_sock(struct sock *sk)
{
}
+
+static inline void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb)
+{
+}
+
+static inline void tcp_ao_connect_init(struct sock *sk)
+{
+}
#endif
#endif /* _TCP_AO_H */
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index c2be72beab70..a5c70cbaa954 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -16,6 +16,34 @@
#include <net/tcp.h>
#include <net/ipv6.h>
+int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
+ unsigned int len, struct tcp_sigpool *hp)
+{
+ struct scatterlist sg;
+ int ret;
+
+ if (crypto_ahash_setkey(crypto_ahash_reqtfm(hp->req),
+ mkt->key, mkt->keylen))
+ goto clear_hash;
+
+ ret = crypto_ahash_init(hp->req);
+ if (ret)
+ goto clear_hash;
+
+ sg_init_one(&sg, ctx, len);
+ ahash_request_set_crypt(hp->req, &sg, key, len);
+ crypto_ahash_update(hp->req);
+
+ ret = crypto_ahash_final(hp->req);
+ if (ret)
+ goto clear_hash;
+
+ return 0;
+clear_hash:
+ memset(key, 0, tcp_ao_digest_size(mkt));
+ return 1;
+}
+
/* Optimized version of tcp_ao_do_lookup(): only for sockets for which
* it's known that the keys in ao_info are matching peer's
* family/address/port/VRF/etc.
@@ -171,6 +199,71 @@ void tcp_ao_destroy_sock(struct sock *sk)
kfree_rcu(ao, rcu);
}
+/* 4 tuple and ISNs are expected in NBO */
+static int tcp_v4_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
+ __be32 saddr, __be32 daddr,
+ __be16 sport, __be16 dport,
+ __be32 sisn, __be32 disn)
+{
+ /* See RFC5926 3.1.1 */
+ struct kdf_input_block {
+ u8 counter;
+ u8 label[6];
+ struct tcp4_ao_context ctx;
+ __be16 outlen;
+ } __packed *tmp;
+ struct tcp_sigpool hp;
+ int err;
+
+ err = tcp_sigpool_start(mkt->tcp_sigpool_id, &hp);
+ if (err)
+ return err;
+
+ tmp = hp.scratch;
+ tmp->counter = 1;
+ memcpy(tmp->label, "TCP-AO", 6);
+ tmp->ctx.saddr = saddr;
+ tmp->ctx.daddr = daddr;
+ tmp->ctx.sport = sport;
+ tmp->ctx.dport = dport;
+ tmp->ctx.sisn = sisn;
+ tmp->ctx.disn = disn;
+ tmp->outlen = htons(tcp_ao_digest_size(mkt) * 8); /* in bits */
+
+ err = tcp_ao_calc_traffic_key(mkt, key, tmp, sizeof(*tmp), &hp);
+ tcp_sigpool_end(&hp);
+
+ return err;
+}
+
+int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+ const struct sock *sk,
+ __be32 sisn, __be32 disn, bool send)
+{
+ if (send)
+ return tcp_v4_ao_calc_key(mkt, key, sk->sk_rcv_saddr,
+ sk->sk_daddr, htons(sk->sk_num),
+ sk->sk_dport, sisn, disn);
+ else
+ return tcp_v4_ao_calc_key(mkt, key, sk->sk_daddr,
+ sk->sk_rcv_saddr, sk->sk_dport,
+ htons(sk->sk_num), disn, sisn);
+}
+
+static int tcp_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+ const struct sock *sk,
+ __be32 sisn, __be32 disn, bool send)
+{
+ if (mkt->family == AF_INET)
+ return tcp_v4_ao_calc_key_sk(mkt, key, sk, sisn, disn, send);
+#if IS_ENABLED(CONFIG_IPV6)
+ else if (mkt->family == AF_INET6)
+ return tcp_v6_ao_calc_key_sk(mkt, key, sk, sisn, disn, send);
+#endif
+ else
+ return -EOPNOTSUPP;
+}
+
struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int sndid, int rcvid)
{
@@ -179,6 +272,98 @@ struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
return tcp_ao_do_lookup(sk, addr, AF_INET, sndid, rcvid, 0);
}
+static int tcp_ao_cache_traffic_keys(const struct sock *sk,
+ struct tcp_ao_info *ao,
+ struct tcp_ao_key *ao_key)
+{
+ u8 *traffic_key = snd_other_key(ao_key);
+ int ret;
+
+ ret = tcp_ao_calc_key_sk(ao_key, traffic_key, sk,
+ ao->lisn, ao->risn, true);
+ if (ret)
+ return ret;
+
+ traffic_key = rcv_other_key(ao_key);
+ ret = tcp_ao_calc_key_sk(ao_key, traffic_key, sk,
+ ao->lisn, ao->risn, false);
+ return ret;
+}
+
+void tcp_ao_connect_init(struct sock *sk)
+{
+ struct tcp_ao_info *ao_info;
+ struct tcp_ao_key *key;
+ struct tcp_sock *tp = tcp_sk(sk);
+ union tcp_ao_addr *addr;
+ int family;
+
+ ao_info = rcu_dereference_protected(tp->ao_info,
+ lockdep_sock_is_held(sk));
+ if (!ao_info)
+ return;
+
+ /* Remove all keys that don't match the peer */
+ family = sk->sk_family;
+ if (family == AF_INET)
+ addr = (union tcp_ao_addr *)&sk->sk_daddr;
+#if IS_ENABLED(CONFIG_IPV6)
+ else if (family == AF_INET6)
+ addr = (union tcp_ao_addr *)&sk->sk_v6_daddr;
+#endif
+ else
+ return;
+
+ hlist_for_each_entry_rcu(key, &ao_info->head, node) {
+ if (tcp_ao_key_cmp(key, addr, key->prefixlen, family,
+ -1, -1, sk->sk_dport) == 0)
+ continue;
+
+ if (key == ao_info->current_key)
+ ao_info->current_key = NULL;
+ if (key == ao_info->rnext_key)
+ ao_info->rnext_key = NULL;
+ hlist_del_rcu(&key->node);
+ tcp_sigpool_release(key->tcp_sigpool_id);
+ atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
+ kfree_rcu(key, rcu);
+ }
+
+ key = tp->af_specific->ao_lookup(sk, sk, -1, -1);
+ if (key) {
+ /* if current_key or rnext_key were not provided,
+ * use the first key matching the peer
+ */
+ if (!ao_info->current_key)
+ ao_info->current_key = key;
+ if (!ao_info->rnext_key)
+ ao_info->rnext_key = key;
+ tp->tcp_header_len += tcp_ao_len(key);
+
+ ao_info->lisn = htonl(tp->write_seq);
+ } else {
+ /* TODO: probably, it should fail to connect() here */
+ rcu_assign_pointer(tp->ao_info, NULL);
+ kfree(ao_info);
+ }
+}
+
+void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb)
+{
+ struct tcp_ao_info *ao;
+ struct tcp_ao_key *key;
+
+ ao = rcu_dereference_protected(tcp_sk(sk)->ao_info,
+ lockdep_sock_is_held(sk));
+ if (!ao)
+ return;
+
+ ao->risn = tcp_hdr(skb)->seq;
+
+ hlist_for_each_entry_rcu(key, &ao->head, node)
+ tcp_ao_cache_traffic_keys(sk, ao, key);
+}
+
static bool tcp_ao_can_set_current_rnext(struct sock *sk)
{
/* There aren't current/rnext keys on TCP_LISTEN sockets */
@@ -576,6 +761,12 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
if (ret < 0)
goto err_free_sock;
+ /* Change this condition if we allow adding keys in states
+ * like close_wait, syn_sent or fin_wait...
+ */
+ if (sk->sk_state == TCP_ESTABLISHED)
+ tcp_ao_cache_traffic_keys(sk, ao_info, key);
+
tcp_ao_link_mkt(ao_info, key);
if (first) {
sk_gso_disable(sk);
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 670c3dab24f2..7780ceef3415 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6082,6 +6082,7 @@ void tcp_finish_connect(struct sock *sk, struct sk_buff *skb)
struct tcp_sock *tp = tcp_sk(sk);
struct inet_connection_sock *icsk = inet_csk(sk);
+ tcp_ao_finish_connect(sk, skb);
tcp_set_state(sk, TCP_ESTABLISHED);
icsk->icsk_ack.lrcvtime = tcp_jiffies32;
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 65e9bcac45f9..447e0c6f132f 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2286,6 +2286,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
#ifdef CONFIG_TCP_AO
.ao_lookup = tcp_v4_ao_lookup,
.ao_parse = tcp_v4_parse_ao,
+ .ao_calc_key_sk = tcp_v4_ao_calc_key_sk,
#endif
};
#endif
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index e98083abd7fb..937516aac99a 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3745,6 +3745,7 @@ static void tcp_connect_init(struct sock *sk)
if (tp->af_specific->md5_lookup(sk, sk))
tp->tcp_header_len += TCPOLEN_MD5SIG_ALIGNED;
#endif
+ tcp_ao_connect_init(sk);
/* If user gave his TCP_MAXSEG, record it to clamp */
if (tp->rx_opt.user_mss)
diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c
index a56ab0a9cf55..0b490738c366 100644
--- a/net/ipv6/tcp_ao.c
+++ b/net/ipv6/tcp_ao.c
@@ -12,6 +12,56 @@
#include <net/tcp.h>
#include <net/ipv6.h>
+static int tcp_v6_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
+ const struct in6_addr *saddr,
+ const struct in6_addr *daddr,
+ __be16 sport, __be16 dport,
+ __be32 sisn, __be32 disn)
+{
+ struct kdf_input_block {
+ u8 counter;
+ u8 label[6];
+ struct tcp6_ao_context ctx;
+ __be16 outlen;
+ } __packed *tmp;
+ struct tcp_sigpool hp;
+ int err;
+
+ err = tcp_sigpool_start(mkt->tcp_sigpool_id, &hp);
+ if (err)
+ return err;
+
+ tmp = hp.scratch;
+ tmp->counter = 1;
+ memcpy(tmp->label, "TCP-AO", 6);
+ tmp->ctx.saddr = *saddr;
+ tmp->ctx.daddr = *daddr;
+ tmp->ctx.sport = sport;
+ tmp->ctx.dport = dport;
+ tmp->ctx.sisn = sisn;
+ tmp->ctx.disn = disn;
+ tmp->outlen = htons(tcp_ao_digest_size(mkt) * 8); /* in bits */
+
+ err = tcp_ao_calc_traffic_key(mkt, key, tmp, sizeof(*tmp), &hp);
+ tcp_sigpool_end(&hp);
+
+ return err;
+}
+
+int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
+ const struct sock *sk, __be32 sisn,
+ __be32 disn, bool send)
+{
+ if (send)
+ return tcp_v6_ao_calc_key(mkt, key, &sk->sk_v6_rcv_saddr,
+ &sk->sk_v6_daddr, htons(sk->sk_num),
+ sk->sk_dport, sisn, disn);
+ else
+ return tcp_v6_ao_calc_key(mkt, key, &sk->sk_v6_daddr,
+ &sk->sk_v6_rcv_saddr, sk->sk_dport,
+ htons(sk->sk_num), disn, sisn);
+}
+
struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk,
const struct in6_addr *addr,
int sndid, int rcvid)
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 5c7c9dbfdb73..1e67aaf42460 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1917,6 +1917,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
#ifdef CONFIG_TCP_AO
.ao_lookup = tcp_v6_ao_lookup,
.ao_parse = tcp_v6_parse_ao,
+ .ao_calc_key_sk = tcp_v6_ao_calc_key_sk,
#endif
};
#endif
--
2.41.0
Introduce segment counters that are useful for troubleshooting/debugging
as well as for writing tests.
Now there are global snmp counters as well as per-socket and per-key.
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/dropreason-core.h | 15 +++++++++++----
include/net/tcp.h | 15 +++++++++++----
include/net/tcp_ao.h | 10 ++++++++++
include/uapi/linux/snmp.h | 4 ++++
include/uapi/linux/tcp.h | 8 +++++++-
net/ipv4/proc.c | 4 ++++
net/ipv4/tcp_ao.c | 30 +++++++++++++++++++++++++++---
net/ipv4/tcp_ipv4.c | 2 +-
net/ipv6/tcp_ipv6.c | 4 ++--
9 files changed, 77 insertions(+), 15 deletions(-)
diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
index 1de089ab73fd..f93ab108df4e 100644
--- a/include/net/dropreason-core.h
+++ b/include/net/dropreason-core.h
@@ -166,17 +166,24 @@ enum skb_drop_reason {
*/
SKB_DROP_REASON_TCP_MD5FAILURE,
/**
- * @SKB_DROP_REASON_TCP_AONOTFOUND: no TCP-AO hash and one was expected
+ * @SKB_DROP_REASON_TCP_AONOTFOUND: no TCP-AO hash and one was expected,
+ * corresponding to LINUX_MIB_TCPAOREQUIRED
*/
SKB_DROP_REASON_TCP_AONOTFOUND,
/**
* @SKB_DROP_REASON_TCP_AOUNEXPECTED: TCP-AO hash is present and it
- * was not expected.
+ * was not expected, corresponding to LINUX_MIB_TCPAOKEYNOTFOUND
*/
SKB_DROP_REASON_TCP_AOUNEXPECTED,
- /** @SKB_DROP_REASON_TCP_AOKEYNOTFOUND: TCP-AO key is unknown */
+ /**
+ * @SKB_DROP_REASON_TCP_AOKEYNOTFOUND: TCP-AO key is unknown,
+ * corresponding to LINUX_MIB_TCPAOKEYNOTFOUND
+ */
SKB_DROP_REASON_TCP_AOKEYNOTFOUND,
- /** @SKB_DROP_REASON_TCP_AOFAILURE: TCP-AO hash is wrong */
+ /**
+ * @SKB_DROP_REASON_TCP_AOFAILURE: TCP-AO hash is wrong,
+ * corresponding to LINUX_MIB_TCPAOBAD
+ */
SKB_DROP_REASON_TCP_AOFAILURE,
/**
* @SKB_DROP_REASON_SOCKET_BACKLOG: failed to add skb to socket backlog (
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 6289ee642931..a58f95237ea3 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2605,7 +2605,7 @@ static inline int tcp_parse_auth_options(const struct tcphdr *th,
}
static inline bool tcp_ao_required(struct sock *sk, const void *saddr,
- int family)
+ int family, bool stat_inc)
{
#ifdef CONFIG_TCP_AO
struct tcp_ao_info *ao_info;
@@ -2617,8 +2617,13 @@ static inline bool tcp_ao_required(struct sock *sk, const void *saddr,
return false;
ao_key = tcp_ao_do_lookup(sk, saddr, family, -1, -1, 0);
- if (ao_info->ao_required || ao_key)
+ if (ao_info->ao_required || ao_key) {
+ if (stat_inc) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOREQUIRED);
+ atomic64_inc(&ao_info->counters.ao_required);
+ }
return true;
+ }
#endif
return false;
}
@@ -2640,8 +2645,10 @@ tcp_inbound_hash(struct sock *sk, const struct request_sock *req,
return SKB_DROP_REASON_TCP_AUTH_HDR;
if (req) {
- if (tcp_rsk_used_ao(req) != !!aoh)
+ if (tcp_rsk_used_ao(req) != !!aoh) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
return SKB_DROP_REASON_TCP_AOFAILURE;
+ }
}
/* sdif set, means packet ingressed via a device
@@ -2656,7 +2663,7 @@ tcp_inbound_hash(struct sock *sk, const struct request_sock *req,
* the last key is impossible to remove, so there's
* always at least one current_key.
*/
- if (tcp_ao_required(sk, saddr, family))
+ if (tcp_ao_required(sk, saddr, family, true))
return SKB_DROP_REASON_TCP_AONOTFOUND;
if (unlikely(tcp_md5_do_lookup(sk, l3index, saddr, family))) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 1b7ca7bf93a3..0a02098bddeb 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -19,6 +19,13 @@ struct tcp_ao_hdr {
u8 rnext_keyid;
};
+struct tcp_ao_counters {
+ atomic64_t pkt_good;
+ atomic64_t pkt_bad;
+ atomic64_t key_not_found;
+ atomic64_t ao_required;
+};
+
struct tcp_ao_key {
struct hlist_node node;
union tcp_ao_addr addr;
@@ -34,6 +41,8 @@ struct tcp_ao_key {
u8 rcvid;
u8 maclen;
struct rcu_head rcu;
+ atomic64_t pkt_good;
+ atomic64_t pkt_bad;
u8 traffic_keys[];
};
@@ -82,6 +91,7 @@ struct tcp_ao_info {
*/
struct tcp_ao_key *current_key;
struct tcp_ao_key *rnext_key;
+ struct tcp_ao_counters counters;
u32 ao_required :1,
__unused :31;
__be32 lisn;
diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
index 26f33a4c253d..06ddf4cd295c 100644
--- a/include/uapi/linux/snmp.h
+++ b/include/uapi/linux/snmp.h
@@ -296,6 +296,10 @@ enum
LINUX_MIB_TCPMIGRATEREQSUCCESS, /* TCPMigrateReqSuccess */
LINUX_MIB_TCPMIGRATEREQFAILURE, /* TCPMigrateReqFailure */
LINUX_MIB_TCPPLBREHASH, /* TCPPLBRehash */
+ LINUX_MIB_TCPAOREQUIRED, /* TCPAORequired */
+ LINUX_MIB_TCPAOBAD, /* TCPAOBad */
+ LINUX_MIB_TCPAOKEYNOTFOUND, /* TCPAOKeyNotFound */
+ LINUX_MIB_TCPAOGOOD, /* TCPAOGood */
__LINUX_MIB_MAX
};
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 250e0ce2cc38..3fe0612ec59a 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -391,9 +391,15 @@ struct tcp_ao_info_opt { /* setsockopt(TCP_AO_INFO) */
__u32 set_current :1, /* corresponding ::current_key */
set_rnext :1, /* corresponding ::rnext */
ao_required :1, /* don't accept non-AO connects */
- reserved :29; /* must be 0 */
+ set_counters :1, /* set/clear ::pkt_* counters */
+ reserved :28; /* must be 0 */
+ __u16 reserved2; /* padding, must be 0 */
__u8 current_key; /* KeyID to set as Current_key */
__u8 rnext; /* KeyID to set as Rnext_key */
+ __u64 pkt_good; /* verified segments */
+ __u64 pkt_bad; /* failed verification */
+ __u64 pkt_key_not_found; /* could not find a key to verify */
+ __u64 pkt_ao_required; /* segments missing TCP-AO sign */
} __attribute__((aligned(8)));
/* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index eaf1d3113b62..3f643cd29cfe 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -298,6 +298,10 @@ static const struct snmp_mib snmp4_net_list[] = {
SNMP_MIB_ITEM("TCPMigrateReqSuccess", LINUX_MIB_TCPMIGRATEREQSUCCESS),
SNMP_MIB_ITEM("TCPMigrateReqFailure", LINUX_MIB_TCPMIGRATEREQFAILURE),
SNMP_MIB_ITEM("TCPPLBRehash", LINUX_MIB_TCPPLBREHASH),
+ SNMP_MIB_ITEM("TCPAORequired", LINUX_MIB_TCPAOREQUIRED),
+ SNMP_MIB_ITEM("TCPAOBad", LINUX_MIB_TCPAOBAD),
+ SNMP_MIB_ITEM("TCPAOKeyNotFound", LINUX_MIB_TCPAOKEYNOTFOUND),
+ SNMP_MIB_ITEM("TCPAOGood", LINUX_MIB_TCPAOGOOD),
SNMP_MIB_SENTINEL
};
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 073be1680818..5ab66928a952 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -184,6 +184,8 @@ static struct tcp_ao_key *tcp_ao_copy_key(struct sock *sk,
*new_key = *key;
INIT_HLIST_NODE(&new_key->node);
tcp_sigpool_get(new_key->tcp_sigpool_id);
+ atomic64_set(&new_key->pkt_good, 0);
+ atomic64_set(&new_key->pkt_bad, 0);
return new_key;
}
@@ -745,8 +747,12 @@ tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb,
const struct tcphdr *th = tcp_hdr(skb);
void *hash_buf = NULL;
- if (maclen != tcp_ao_maclen(key))
+ if (maclen != tcp_ao_maclen(key)) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
+ atomic64_inc(&info->counters.pkt_bad);
+ atomic64_inc(&key->pkt_bad);
return SKB_DROP_REASON_TCP_AOFAILURE;
+ }
hash_buf = kmalloc(tcp_ao_digest_size(key), GFP_ATOMIC);
if (!hash_buf)
@@ -756,9 +762,15 @@ tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb,
tcp_ao_hash_skb(family, hash_buf, key, sk, skb, traffic_key,
(phash - (u8 *)th), sne);
if (memcmp(phash, hash_buf, maclen)) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
+ atomic64_inc(&info->counters.pkt_bad);
+ atomic64_inc(&key->pkt_bad);
kfree(hash_buf);
return SKB_DROP_REASON_TCP_AOFAILURE;
}
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOGOOD);
+ atomic64_inc(&info->counters.pkt_good);
+ atomic64_inc(&key->pkt_good);
kfree(hash_buf);
return SKB_NOT_DROPPED_YET;
}
@@ -778,8 +790,10 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
u32 sne = 0;
info = rcu_dereference(tcp_sk(sk)->ao_info);
- if (!info)
+ if (!info) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND);
return SKB_DROP_REASON_TCP_AOUNEXPECTED;
+ }
if (unlikely(th->syn)) {
sisn = th->seq;
@@ -875,6 +889,8 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
return ret;
key_not_found:
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND);
+ atomic64_inc(&info->counters.key_not_found);
return SKB_DROP_REASON_TCP_AOKEYNOTFOUND;
}
@@ -1460,6 +1476,8 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
key->keyflags = cmd.keyflags;
key->sndid = cmd.sndid;
key->rcvid = cmd.rcvid;
+ atomic64_set(&key->pkt_good, 0);
+ atomic64_set(&key->pkt_bad, 0);
ret = tcp_ao_parse_crypto(&cmd, key);
if (ret < 0)
@@ -1673,7 +1691,7 @@ static int tcp_ao_info_cmd(struct sock *sk, unsigned short int family,
return -EINVAL;
}
- if (cmd.reserved != 0)
+ if (cmd.reserved != 0 || cmd.reserved2 != 0)
return -EINVAL;
ao_info = setsockopt_ao_info(sk);
@@ -1708,6 +1726,12 @@ static int tcp_ao_info_cmd(struct sock *sk, unsigned short int family,
goto out;
}
}
+ if (cmd.set_counters) {
+ atomic64_set(&ao_info->counters.pkt_good, cmd.pkt_good);
+ atomic64_set(&ao_info->counters.pkt_bad, cmd.pkt_bad);
+ atomic64_set(&ao_info->counters.key_not_found, cmd.pkt_key_not_found);
+ atomic64_set(&ao_info->counters.ao_required, cmd.pkt_ao_required);
+ }
ao_info->ao_required = cmd.ao_required;
if (new_current)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index f09c0389ae11..d8d2499b5e26 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1528,7 +1528,7 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
/* Don't allow keys for peers that have a matching TCP-AO key.
* See the comment in tcp_ao_add_cmd()
*/
- if (tcp_ao_required(sk, addr, AF_INET))
+ if (tcp_ao_required(sk, addr, AF_INET, false))
return -EKEYREJECTED;
return tcp_md5_do_add(sk, addr, AF_INET, prefixlen, l3index, flags,
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 40266a3a99a6..c825d7c80f5b 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -660,7 +660,7 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
/* Don't allow keys for peers that have a matching TCP-AO key.
* See the comment in tcp_ao_add_cmd()
*/
- if (tcp_ao_required(sk, addr, AF_INET))
+ if (tcp_ao_required(sk, addr, AF_INET, false))
return -EKEYREJECTED;
return tcp_md5_do_add(sk, addr,
AF_INET, prefixlen, l3index, flags,
@@ -672,7 +672,7 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
/* Don't allow keys for peers that have a matching TCP-AO key.
* See the comment in tcp_ao_add_cmd()
*/
- if (tcp_ao_required(sk, addr, AF_INET6))
+ if (tcp_ao_required(sk, addr, AF_INET6, false))
return -EKEYREJECTED;
return tcp_md5_do_add(sk, addr, AF_INET6, prefixlen, l3index, flags,
--
2.41.0
Add a helper for logging connection-detailed messages for failed TCP
hash verification (both MD5 and AO).
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/tcp.h | 14 ++++++++++++--
include/net/tcp_ao.h | 29 +++++++++++++++++++++++++++++
net/ipv4/tcp.c | 23 +++++++++++++----------
net/ipv4/tcp_ao.c | 7 +++++++
4 files changed, 61 insertions(+), 12 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index a58f95237ea3..50636ee7ee2f 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2641,12 +2641,18 @@ tcp_inbound_hash(struct sock *sk, const struct request_sock *req,
int l3index;
/* Invalid option or two times meet any of auth options */
- if (tcp_parse_auth_options(th, &md5_location, &aoh))
+ if (tcp_parse_auth_options(th, &md5_location, &aoh)) {
+ tcp_hash_fail("TCP segment has incorrect auth options set",
+ family, skb, "");
return SKB_DROP_REASON_TCP_AUTH_HDR;
+ }
if (req) {
if (tcp_rsk_used_ao(req) != !!aoh) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
+ tcp_hash_fail("TCP connection can't start/end using TCP-AO",
+ family, skb, "%s",
+ !aoh ? "missing AO" : "AO signed");
return SKB_DROP_REASON_TCP_AOFAILURE;
}
}
@@ -2663,10 +2669,14 @@ tcp_inbound_hash(struct sock *sk, const struct request_sock *req,
* the last key is impossible to remove, so there's
* always at least one current_key.
*/
- if (tcp_ao_required(sk, saddr, family, true))
+ if (tcp_ao_required(sk, saddr, family, true)) {
+ tcp_hash_fail("AO hash is required, but not found",
+ family, skb, "L3 index %d", l3index);
return SKB_DROP_REASON_TCP_AONOTFOUND;
+ }
if (unlikely(tcp_md5_do_lookup(sk, l3index, saddr, family))) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
+ tcp_hash_fail("MD5 Hash not found", family, skb, "");
return SKB_DROP_REASON_TCP_MD5NOTFOUND;
}
return SKB_NOT_DROPPED_YET;
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index fc5674763730..801dca405df7 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -119,6 +119,35 @@ struct tcp_ao_info {
struct rcu_head rcu;
};
+#define tcp_hash_fail(msg, family, skb, fmt, ...) \
+do { \
+ const struct tcphdr *th = tcp_hdr(skb); \
+ char hdr_flags[5] = {}; \
+ char *f = hdr_flags; \
+ \
+ if (th->fin) \
+ *f++ = 'F'; \
+ if (th->syn) \
+ *f++ = 'S'; \
+ if (th->rst) \
+ *f++ = 'R'; \
+ if (th->ack) \
+ *f++ = 'A'; \
+ if (f != hdr_flags) \
+ *f = ' '; \
+ if (family == AF_INET) { \
+ net_info_ratelimited("%s for (%pI4, %d)->(%pI4, %d) %s" fmt "\n", \
+ msg, &ip_hdr(skb)->saddr, ntohs(th->source), \
+ &ip_hdr(skb)->daddr, ntohs(th->dest), \
+ hdr_flags, ##__VA_ARGS__); \
+ } else { \
+ net_info_ratelimited("%s for [%pI6c]:%u->[%pI6c]:%u %s" fmt "\n", \
+ msg, &ipv6_hdr(skb)->saddr, ntohs(th->source), \
+ &ipv6_hdr(skb)->daddr, ntohs(th->dest), \
+ hdr_flags, ##__VA_ARGS__); \
+ } \
+} while (0)
+
#ifdef CONFIG_TCP_AO
/* TCP-AO structures and functions */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index d7e18c528c7b..37d3eac0561b 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -4380,7 +4380,6 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
* o MD5 hash and we're not expecting one.
* o MD5 hash and its wrong.
*/
- const struct tcphdr *th = tcp_hdr(skb);
const struct tcp_sock *tp = tcp_sk(sk);
struct tcp_md5sig_key *key;
int genhash;
@@ -4390,6 +4389,7 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
if (!key && hash_location) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
+ tcp_hash_fail("Unexpected MD5 Hash found", family, skb, "");
return SKB_DROP_REASON_TCP_MD5UNEXPECTED;
}
@@ -4405,16 +4405,19 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
if (genhash || memcmp(hash_location, newhash, 16) != 0) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
if (family == AF_INET) {
- net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s L3 index %d\n",
- saddr, ntohs(th->source),
- daddr, ntohs(th->dest),
- genhash ? " tcp_v4_calc_md5_hash failed"
- : "", l3index);
+ tcp_hash_fail("MD5 Hash failed", AF_INET, skb, "%s L3 index %d",
+ genhash ? "tcp_v4_calc_md5_hash failed"
+ : "", l3index);
} else {
- net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u L3 index %d\n",
- genhash ? "failed" : "mismatch",
- saddr, ntohs(th->source),
- daddr, ntohs(th->dest), l3index);
+ if (genhash) {
+ tcp_hash_fail("MD5 Hash failed",
+ AF_INET6, skb, "L3 index %d",
+ l3index);
+ } else {
+ tcp_hash_fail("MD5 Hash mismatch",
+ AF_INET6, skb, "L3 index %d",
+ l3index);
+ }
}
return SKB_DROP_REASON_TCP_MD5FAILURE;
}
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 5ebbfadfbfd0..9ee7fc9f6a76 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -772,6 +772,8 @@ tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb,
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
atomic64_inc(&info->counters.pkt_bad);
atomic64_inc(&key->pkt_bad);
+ tcp_hash_fail("AO hash wrong length", family, skb,
+ "%u != %d", maclen, tcp_ao_maclen(key));
return SKB_DROP_REASON_TCP_AOFAILURE;
}
@@ -786,6 +788,7 @@ tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb,
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
atomic64_inc(&info->counters.pkt_bad);
atomic64_inc(&key->pkt_bad);
+ tcp_hash_fail("AO hash mismatch", family, skb, "");
kfree(hash_buf);
return SKB_DROP_REASON_TCP_AOFAILURE;
}
@@ -813,6 +816,8 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
info = rcu_dereference(tcp_sk(sk)->ao_info);
if (!info) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND);
+ tcp_hash_fail("AO key not found", family, skb,
+ "keyid: %u", aoh->keyid);
return SKB_DROP_REASON_TCP_AOUNEXPECTED;
}
@@ -915,6 +920,8 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
key_not_found:
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND);
atomic64_inc(&info->counters.key_not_found);
+ tcp_hash_fail("Requested by the peer AO key id not found",
+ family, skb, "");
return SKB_DROP_REASON_TCP_AOKEYNOTFOUND;
}
--
2.41.0
Similarly how TCP_MD5SIG_FLAG_IFINDEX works for TCP-MD5,
TCP_AO_KEYF_IFINDEX is an AO-key flag that binds that MKT to a specified
by L3 ifinndex. Similarly, without this flag the key will work in
the default VRF l3index = 0 for connections.
To prevent AO-keys from overlapping, it's restricted to add key B for a
socket that has key A, which have the same sndid/rcvid and one of
the following is true:
- !(A.keyflags & TCP_AO_KEYF_IFINDEX) or !(B.keyflags & TCP_AO_KEYF_IFINDEX)
so that any key is non-bound to a VRF
- A.l3index == B.l3index
both want to work for the same VRF
Additionally, it's restricted to match TCP-MD5 keys for the same peer
the following way:
|--------------|--------------------|----------------|---------------|
| | MD5 key without | MD5 key | MD5 key |
| | l3index | l3index=0 | l3index=N |
|--------------|--------------------|----------------|---------------|
| TCP-AO key | | | |
| without | reject | reject | reject |
| l3index | | | |
|--------------|--------------------|----------------|---------------|
| TCP-AO key | | | |
| l3index=0 | reject | reject | allow |
|--------------|--------------------|----------------|---------------|
| TCP-AO key | | | |
| l3index=N | reject | allow | reject |
|--------------|--------------------|----------------|---------------|
This is done with the help of tcp_md5_do_lookup_any_l3index() to reject
adding AO key without TCP_AO_KEYF_IFINDEX if there's TCP-MD5 in any VRF.
This is important for case where sysctl_tcp_l3mdev_accept = 1
Similarly, for TCP-AO lookups tcp_ao_do_lookup() may be used with
l3index < 0, so that __tcp_ao_key_cmp() will match TCP-AO key in any VRF.
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/tcp.h | 11 +--
include/net/tcp_ao.h | 17 +++--
net/ipv4/syncookies.c | 6 +-
net/ipv4/tcp_ao.c | 164 +++++++++++++++++++++++++++++++-----------
net/ipv4/tcp_ipv4.c | 13 ++--
net/ipv6/syncookies.c | 5 +-
net/ipv6/tcp_ao.c | 20 +++---
net/ipv6/tcp_ipv6.c | 15 ++--
8 files changed, 171 insertions(+), 80 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 4df3ee6e2722..4aa124ddde3a 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2605,7 +2605,7 @@ static inline int tcp_parse_auth_options(const struct tcphdr *th,
}
static inline bool tcp_ao_required(struct sock *sk, const void *saddr,
- int family, bool stat_inc)
+ int family, int l3index, bool stat_inc)
{
#ifdef CONFIG_TCP_AO
struct tcp_ao_info *ao_info;
@@ -2619,7 +2619,7 @@ static inline bool tcp_ao_required(struct sock *sk, const void *saddr,
if (!ao_info)
return false;
- ao_key = tcp_ao_do_lookup(sk, saddr, family, -1, -1, 0);
+ ao_key = tcp_ao_do_lookup(sk, l3index, saddr, family, -1, -1, 0);
if (ao_info->ao_required || ao_key) {
if (stat_inc) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOREQUIRED);
@@ -2672,21 +2672,22 @@ tcp_inbound_hash(struct sock *sk, const struct request_sock *req,
* the last key is impossible to remove, so there's
* always at least one current_key.
*/
- if (tcp_ao_required(sk, saddr, family, true)) {
+ if (tcp_ao_required(sk, saddr, family, l3index, true)) {
tcp_hash_fail("AO hash is required, but not found",
family, skb, "L3 index %d", l3index);
return SKB_DROP_REASON_TCP_AONOTFOUND;
}
if (unlikely(tcp_md5_do_lookup(sk, l3index, saddr, family))) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
- tcp_hash_fail("MD5 Hash not found", family, skb, "");
+ tcp_hash_fail("MD5 Hash not found",
+ family, skb, "L3 index %d", l3index);
return SKB_DROP_REASON_TCP_MD5NOTFOUND;
}
return SKB_NOT_DROPPED_YET;
}
if (aoh)
- return tcp_inbound_ao_hash(sk, skb, family, req, aoh);
+ return tcp_inbound_ao_hash(sk, skb, family, req, l3index, aoh);
return tcp_inbound_md5_hash(sk, skb, saddr, daddr, family,
l3index, md5_location);
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index e6d849d7179e..b56b49a98266 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -33,6 +33,7 @@ struct tcp_ao_key {
u8 key[TCP_AO_MAXKEYLEN] __tcp_ao_key_align;
unsigned int tcp_sigpool_id;
unsigned int digest_size;
+ int l3index;
u16 port;
u8 prefixlen;
u8 family;
@@ -197,10 +198,10 @@ int tcp_ao_get_mkts(struct sock *sk, sockptr_t optval, sockptr_t optlen);
int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockptr_t optlen);
enum skb_drop_reason tcp_inbound_ao_hash(struct sock *sk,
const struct sk_buff *skb, unsigned short int family,
- const struct request_sock *req,
+ const struct request_sock *req, int l3index,
const struct tcp_ao_hdr *aoh);
u32 tcp_ao_compute_sne(u32 next_sne, u32 next_seq, u32 seq);
-struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
+struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, int l3index,
const union tcp_ao_addr *addr,
int family, int sndid, int rcvid, u16 port);
int tcp_ao_hash_hdr(unsigned short family, char *ao_hash,
@@ -243,9 +244,6 @@ int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
__be32 disn, bool send);
int tcp_v6_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
struct request_sock *req);
-struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk,
- const struct in6_addr *addr,
- int sndid, int rcvid);
struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
struct sock *addr_sk,
int sndid, int rcvid);
@@ -264,12 +262,12 @@ void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb);
void tcp_ao_connect_init(struct sock *sk);
void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
struct tcp_request_sock *treq,
- unsigned short int family);
+ unsigned short int family, int l3index);
#else /* CONFIG_TCP_AO */
static inline void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
struct tcp_request_sock *treq,
- unsigned short int family)
+ unsigned short int family, int l3index)
{
}
@@ -280,13 +278,14 @@ static inline bool tcp_ao_ignore_icmp(struct sock *sk, int type, int code)
static inline enum skb_drop_reason tcp_inbound_ao_hash(struct sock *sk,
const struct sk_buff *skb, unsigned short int family,
- const struct request_sock *req, const struct tcp_ao_hdr *aoh)
+ const struct request_sock *req, int l3index,
+ const struct tcp_ao_hdr *aoh)
{
return SKB_NOT_DROPPED_YET;
}
static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
- const union tcp_ao_addr *addr,
+ int l3index, const union tcp_ao_addr *addr,
int family, int sndid, int rcvid, u16 port)
{
return NULL;
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index 23fca22bc992..213accdc3600 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -337,6 +337,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
struct rtable *rt;
__u8 rcv_wscale;
struct flowi4 fl4;
+ int l3index;
u32 tsoff = 0;
if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_syncookies) ||
@@ -394,13 +395,14 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
treq->snt_synack = 0;
treq->tfo_listener = false;
- tcp_ao_syncookie(sk, skb, treq, AF_INET);
-
if (IS_ENABLED(CONFIG_SMC))
ireq->smc_ok = 0;
ireq->ir_iif = inet_request_bound_dev_if(sk, skb);
+ l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
+ tcp_ao_syncookie(sk, skb, treq, AF_INET, l3index);
+
/* We throwed the options of the initial SYN away, so we hope
* the ACK carries the same options again (see RFC1122 4.2.3.8)
*/
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 54b35ee1edf1..3490b590bff0 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -137,7 +137,7 @@ static inline int ipv4_prefix_cmp(const struct in_addr *addr1,
return ((addr1->s_addr & mask) > (addr2->s_addr & mask)) ? 1 : -1;
}
-static int __tcp_ao_key_cmp(const struct tcp_ao_key *key,
+static int __tcp_ao_key_cmp(const struct tcp_ao_key *key, int l3index,
const union tcp_ao_addr *addr, u8 prefixlen,
int family, int sndid, int rcvid, u16 port)
{
@@ -147,6 +147,10 @@ static int __tcp_ao_key_cmp(const struct tcp_ao_key *key,
return (key->rcvid > rcvid) ? 1 : -1;
if (port != 0 && key->port != 0 && port != key->port)
return (key->port > port) ? 1 : -1;
+ if (l3index >= 0 && (key->keyflags & TCP_AO_KEYF_IFINDEX)) {
+ if (key->l3index != l3index)
+ return (key->l3index > l3index) ? 1 : -1;
+ }
if (family == AF_UNSPEC)
return 0;
@@ -171,7 +175,7 @@ static int __tcp_ao_key_cmp(const struct tcp_ao_key *key,
return -1;
}
-static int tcp_ao_key_cmp(const struct tcp_ao_key *key,
+static int tcp_ao_key_cmp(const struct tcp_ao_key *key, int l3index,
const union tcp_ao_addr *addr, u8 prefixlen,
int family, int sndid, int rcvid, u16 port)
{
@@ -179,14 +183,16 @@ static int tcp_ao_key_cmp(const struct tcp_ao_key *key,
if (family == AF_INET6 && ipv6_addr_v4mapped(&addr->a6)) {
__be32 addr4 = addr->a6.s6_addr32[3];
- return __tcp_ao_key_cmp(key, (union tcp_ao_addr *)&addr4,
+ return __tcp_ao_key_cmp(key, l3index,
+ (union tcp_ao_addr *)&addr4,
prefixlen, AF_INET, sndid, rcvid, port);
}
#endif
- return __tcp_ao_key_cmp(key, addr, prefixlen, family, sndid, rcvid, port);
+ return __tcp_ao_key_cmp(key, l3index, addr,
+ prefixlen, family, sndid, rcvid, port);
}
-static struct tcp_ao_key *__tcp_ao_do_lookup(const struct sock *sk,
+static struct tcp_ao_key *__tcp_ao_do_lookup(const struct sock *sk, int l3index,
const union tcp_ao_addr *addr, int family, u8 prefix,
int sndid, int rcvid, u16 port)
{
@@ -204,18 +210,18 @@ static struct tcp_ao_key *__tcp_ao_do_lookup(const struct sock *sk,
hlist_for_each_entry_rcu(key, &ao->head, node) {
u8 prefixlen = min(prefix, key->prefixlen);
- if (!tcp_ao_key_cmp(key, addr, prefixlen,
+ if (!tcp_ao_key_cmp(key, l3index, addr, prefixlen,
family, sndid, rcvid, port))
return key;
}
return NULL;
}
-struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
+struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, int l3index,
const union tcp_ao_addr *addr,
int family, int sndid, int rcvid, u16 port)
{
- return __tcp_ao_do_lookup(sk, addr, family, U8_MAX,
+ return __tcp_ao_do_lookup(sk, l3index, addr, family, U8_MAX,
sndid, rcvid, port);
}
@@ -682,18 +688,21 @@ struct tcp_ao_key *tcp_v4_ao_lookup_rsk(const struct sock *sk,
struct request_sock *req,
int sndid, int rcvid)
{
- union tcp_ao_addr *addr =
- (union tcp_ao_addr *)&inet_rsk(req)->ir_rmt_addr;
+ struct inet_request_sock *ireq = inet_rsk(req);
+ union tcp_ao_addr *addr = (union tcp_ao_addr *)&ireq->ir_rmt_addr;
+ int l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
- return tcp_ao_do_lookup(sk, addr, AF_INET, sndid, rcvid, 0);
+ return tcp_ao_do_lookup(sk, l3index, addr, AF_INET, sndid, rcvid, 0);
}
struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int sndid, int rcvid)
{
union tcp_ao_addr *addr = (union tcp_ao_addr *)&addr_sk->sk_daddr;
+ int l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
+ addr_sk->sk_bound_dev_if);
- return tcp_ao_do_lookup(sk, addr, AF_INET, sndid, rcvid, 0);
+ return tcp_ao_do_lookup(sk, l3index, addr, AF_INET, sndid, rcvid, 0);
}
int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
@@ -785,24 +794,26 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
static struct tcp_ao_key *tcp_ao_inbound_lookup(unsigned short int family,
const struct sock *sk, const struct sk_buff *skb,
- int sndid, int rcvid)
+ int sndid, int rcvid, int l3index)
{
if (family == AF_INET) {
const struct iphdr *iph = ip_hdr(skb);
- return tcp_ao_do_lookup(sk, (union tcp_ao_addr *)&iph->saddr,
- AF_INET, sndid, rcvid, 0);
+ return tcp_ao_do_lookup(sk, l3index,
+ (union tcp_ao_addr *)&iph->saddr,
+ AF_INET, sndid, rcvid, 0);
} else {
const struct ipv6hdr *iph = ipv6_hdr(skb);
- return tcp_ao_do_lookup(sk, (union tcp_ao_addr *)&iph->saddr,
- AF_INET6, sndid, rcvid, 0);
+ return tcp_ao_do_lookup(sk, l3index,
+ (union tcp_ao_addr *)&iph->saddr,
+ AF_INET6, sndid, rcvid, 0);
}
}
void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
struct tcp_request_sock *treq,
- unsigned short int family)
+ unsigned short int family, int l3index)
{
const struct tcphdr *th = tcp_hdr(skb);
const struct tcp_ao_hdr *aoh;
@@ -817,7 +828,7 @@ void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
if (!aoh)
return;
- key = tcp_ao_inbound_lookup(family, sk, skb, -1, aoh->keyid);
+ key = tcp_ao_inbound_lookup(family, sk, skb, -1, aoh->keyid, l3index);
if (!key)
/* Key not found, continue without TCP-AO */
return;
@@ -831,7 +842,7 @@ static enum skb_drop_reason
tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb,
unsigned short int family, struct tcp_ao_info *info,
const struct tcp_ao_hdr *aoh, struct tcp_ao_key *key,
- u8 *traffic_key, u8 *phash, u32 sne)
+ u8 *traffic_key, u8 *phash, u32 sne, int l3index)
{
u8 maclen = aoh->length - sizeof(struct tcp_ao_hdr);
const struct tcphdr *th = tcp_hdr(skb);
@@ -842,7 +853,8 @@ tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb,
atomic64_inc(&info->counters.pkt_bad);
atomic64_inc(&key->pkt_bad);
tcp_hash_fail("AO hash wrong length", family, skb,
- "%u != %d", maclen, tcp_ao_maclen(key));
+ "%u != %d L3index: %d", maclen,
+ tcp_ao_maclen(key), l3index);
return SKB_DROP_REASON_TCP_AOFAILURE;
}
@@ -857,7 +869,8 @@ tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb,
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD);
atomic64_inc(&info->counters.pkt_bad);
atomic64_inc(&key->pkt_bad);
- tcp_hash_fail("AO hash mismatch", family, skb, "");
+ tcp_hash_fail("AO hash mismatch", family, skb,
+ "L3index: %d", l3index);
kfree(hash_buf);
return SKB_DROP_REASON_TCP_AOFAILURE;
}
@@ -871,7 +884,7 @@ tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb,
enum skb_drop_reason
tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
unsigned short int family, const struct request_sock *req,
- const struct tcp_ao_hdr *aoh)
+ int l3index, const struct tcp_ao_hdr *aoh)
{
const struct tcphdr *th = tcp_hdr(skb);
u8 *phash = (u8 *)(aoh + 1); /* hash goes just after the header */
@@ -886,7 +899,7 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
if (!info) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND);
tcp_hash_fail("AO key not found", family, skb,
- "keyid: %u", aoh->keyid);
+ "keyid: %u L3index: %d", aoh->keyid, l3index);
return SKB_DROP_REASON_TCP_AOUNEXPECTED;
}
@@ -921,7 +934,7 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
/* Established socket, traffic key are cached */
traffic_key = rcv_other_key(key);
err = tcp_ao_verify_hash(sk, skb, family, info, aoh, key,
- traffic_key, phash, sne);
+ traffic_key, phash, sne, l3index);
if (err)
return err;
current_key = READ_ONCE(info->current_key);
@@ -942,7 +955,7 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
* - request sockets would race on those key pointers
* - tcp_ao_del_cmd() allows async key removal
*/
- key = tcp_ao_inbound_lookup(family, sk, skb, -1, aoh->keyid);
+ key = tcp_ao_inbound_lookup(family, sk, skb, -1, aoh->keyid, l3index);
if (!key)
goto key_not_found;
@@ -982,7 +995,7 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
return SKB_DROP_REASON_NOT_SPECIFIED;
tcp_ao_calc_key_skb(key, traffic_key, skb, sisn, disn, family);
ret = tcp_ao_verify_hash(sk, skb, family, info, aoh, key,
- traffic_key, phash, sne);
+ traffic_key, phash, sne, l3index);
kfree(traffic_key);
return ret;
@@ -990,7 +1003,7 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOKEYNOTFOUND);
atomic64_inc(&info->counters.key_not_found);
tcp_hash_fail("Requested by the peer AO key id not found",
- family, skb, "");
+ family, skb, "L3index: %d", l3index);
return SKB_DROP_REASON_TCP_AOKEYNOTFOUND;
}
@@ -1018,7 +1031,7 @@ void tcp_ao_connect_init(struct sock *sk)
struct tcp_ao_key *key;
struct tcp_sock *tp = tcp_sk(sk);
union tcp_ao_addr *addr;
- int family;
+ int family, l3index;
ao_info = rcu_dereference_protected(tp->ao_info,
lockdep_sock_is_held(sk));
@@ -1035,9 +1048,11 @@ void tcp_ao_connect_init(struct sock *sk)
#endif
else
return;
+ l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
+ sk->sk_bound_dev_if);
hlist_for_each_entry_rcu(key, &ao_info->head, node) {
- if (tcp_ao_key_cmp(key, addr, key->prefixlen, family,
+ if (tcp_ao_key_cmp(key, l3index, addr, key->prefixlen, family,
-1, -1, sk->sk_dport) == 0)
continue;
@@ -1097,7 +1112,7 @@ int tcp_ao_copy_all_matching(const struct sock *sk, struct sock *newsk,
struct hlist_node *key_head;
union tcp_ao_addr *addr;
bool match = false;
- int ret = -ENOMEM;
+ int l3index, ret = -ENOMEM;
ao = rcu_dereference(tcp_sk(sk)->ao_info);
if (!ao)
@@ -1125,9 +1140,11 @@ int tcp_ao_copy_all_matching(const struct sock *sk, struct sock *newsk,
ret = -EAFNOSUPPORT;
goto free_ao;
}
+ l3index = l3mdev_master_ifindex_by_index(sock_net(newsk),
+ newsk->sk_bound_dev_if);
hlist_for_each_entry_rcu(key, &ao->head, node) {
- if (tcp_ao_key_cmp(key, addr, key->prefixlen, family,
+ if (tcp_ao_key_cmp(key, l3index, addr, key->prefixlen, family,
-1, -1, 0))
continue;
@@ -1446,7 +1463,8 @@ static struct tcp_ao_info *setsockopt_ao_info(struct sock *sk)
return ERR_PTR(-ESOCKTNOSUPPORT);
}
-#define TCP_AO_KEYF_ALL (TCP_AO_KEYF_EXCLUDE_OPT)
+#define TCP_AO_KEYF_ALL (TCP_AO_KEYF_IFINDEX | TCP_AO_KEYF_EXCLUDE_OPT)
+#define TCP_AO_GET_KEYF_VALID (TCP_AO_KEYF_IFINDEX)
static struct tcp_ao_key *tcp_ao_key_alloc(struct sock *sk,
struct tcp_ao_add *cmd)
@@ -1510,7 +1528,7 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
union tcp_ao_addr *addr;
struct tcp_ao_key *key;
struct tcp_ao_add cmd;
- int ret;
+ int ret, l3index = 0;
bool first = false;
u16 port;
@@ -1542,9 +1560,46 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
return -EINVAL;
}
+ if (cmd.ifindex && !(cmd.keyflags & TCP_AO_KEYF_IFINDEX))
+ return -EINVAL;
+
+ /* For cmd.tcp_ifindex = 0 the key will apply to the default VRF */
+ if (cmd.keyflags & TCP_AO_KEYF_IFINDEX && cmd.ifindex) {
+ int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
+ struct net_device *dev;
+
+ rcu_read_lock();
+ dev = dev_get_by_index_rcu(sock_net(sk), cmd.ifindex);
+ if (dev && netif_is_l3_master(dev))
+ l3index = dev->ifindex;
+ rcu_read_unlock();
+
+ if (!dev || !l3index)
+ return -EINVAL;
+
+ /* It's still possible to bind after adding keys or even
+ * re-bind to a different dev (with CAP_NET_RAW).
+ * So, no reason to return error here, rather try to be
+ * nice and warn the user.
+ */
+ if (bound_dev_if && bound_dev_if != cmd.ifindex)
+ net_warn_ratelimited("AO key ifindex %d != sk bound ifindex %d\n",
+ cmd.ifindex, bound_dev_if);
+ }
+
/* Don't allow keys for peers that have a matching TCP-MD5 key */
- if (tcp_md5_do_lookup_any_l3index(sk, addr, family))
- return -EKEYREJECTED;
+ if (cmd.keyflags & TCP_AO_KEYF_IFINDEX) {
+ /* Non-_exact version of tcp_md5_do_lookup() will
+ * as well match keys that aren't bound to a specific VRF
+ * (that will make them match AO key with
+ * sysctl_tcp_l3dev_accept = 1
+ */
+ if (tcp_md5_do_lookup(sk, l3index, addr, family))
+ return -EKEYREJECTED;
+ } else {
+ if (tcp_md5_do_lookup_any_l3index(sk, addr, family))
+ return -EKEYREJECTED;
+ }
ao_info = setsockopt_ao_info(sk);
if (IS_ERR(ao_info))
@@ -1561,10 +1616,10 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
* > The IDs of MKTs MUST NOT overlap where their
* > TCP connection identifiers overlap.
*/
- if (__tcp_ao_do_lookup(sk, addr, family,
+ if (__tcp_ao_do_lookup(sk, l3index, addr, family,
cmd.prefix, -1, cmd.rcvid, port))
return -EEXIST;
- if (__tcp_ao_do_lookup(sk, addr, family,
+ if (__tcp_ao_do_lookup(sk, l3index, addr, family,
cmd.prefix, cmd.sndid, -1, port))
return -EEXIST;
}
@@ -1584,6 +1639,7 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
key->keyflags = cmd.keyflags;
key->sndid = cmd.sndid;
key->rcvid = cmd.rcvid;
+ key->l3index = l3index;
atomic64_set(&key->pkt_good, 0);
atomic64_set(&key->pkt_bad, 0);
@@ -1672,17 +1728,17 @@ static int tcp_ao_delete_key(struct sock *sk, struct tcp_ao_info *ao_info,
return err;
}
+#define TCP_AO_DEL_KEYF_ALL (TCP_AO_KEYF_IFINDEX)
static int tcp_ao_del_cmd(struct sock *sk, unsigned short int family,
sockptr_t optval, int optlen)
{
struct tcp_ao_key *key, *new_current = NULL, *new_rnext = NULL;
+ int err, addr_len, l3index = 0;
struct tcp_ao_info *ao_info;
union tcp_ao_addr *addr;
struct tcp_ao_del cmd;
- int err;
__u8 prefix;
__be16 port;
- int addr_len;
if (optlen < sizeof(cmd))
return -EINVAL;
@@ -1699,6 +1755,17 @@ static int tcp_ao_del_cmd(struct sock *sk, unsigned short int family,
return -EINVAL;
}
+ if (cmd.keyflags & ~TCP_AO_DEL_KEYF_ALL)
+ return -EINVAL;
+
+ /* No sanity check for TCP_AO_KEYF_IFINDEX as if a VRF
+ * was destroyed, there still should be a way to delete keys,
+ * that were bound to that l3intf. So, fail late at lookup stage
+ * if there is no key for that ifindex.
+ */
+ if (cmd.ifindex && !(cmd.keyflags & TCP_AO_KEYF_IFINDEX))
+ return -EINVAL;
+
ao_info = setsockopt_ao_info(sk);
if (IS_ERR(ao_info))
return PTR_ERR(ao_info);
@@ -1763,6 +1830,13 @@ static int tcp_ao_del_cmd(struct sock *sk, unsigned short int family,
memcmp(addr, &key->addr, addr_len))
continue;
+ if ((cmd.keyflags & TCP_AO_KEYF_IFINDEX) !=
+ (key->keyflags & TCP_AO_KEYF_IFINDEX))
+ continue;
+
+ if (key->l3index != l3index)
+ continue;
+
if (key == new_current || key == new_rnext)
continue;
@@ -1948,10 +2022,10 @@ static int tcp_ao_copy_mkts_to_user(struct tcp_ao_info *ao_info,
struct tcp_ao_key *key, *current_key;
bool do_address_matching = true;
union tcp_ao_addr *addr = NULL;
+ int err, l3index, user_len;
unsigned int max_keys; /* maximum number of keys to copy to user */
size_t out_offset = 0;
size_t bytes_to_write; /* number of bytes to write to user level */
- int err, user_len;
u32 matched_keys; /* keys from ao_info matched so far */
int optlen_out;
u16 port = 0;
@@ -1970,11 +2044,16 @@ static int tcp_ao_copy_mkts_to_user(struct tcp_ao_info *ao_info,
if (opt_in.pkt_good || opt_in.pkt_bad)
return -EINVAL;
+ if (opt_in.keyflags & ~TCP_AO_GET_KEYF_VALID)
+ return -EINVAL;
+ if (opt_in.ifindex && !(opt_in.keyflags & TCP_AO_KEYF_IFINDEX))
+ return -EINVAL;
if (opt_in.reserved != 0)
return -EINVAL;
max_keys = opt_in.nkeys;
+ l3index = (opt_in.keyflags & TCP_AO_KEYF_IFINDEX) ? opt_in.ifindex : -1;
if (opt_in.get_all || opt_in.is_current || opt_in.is_rnext) {
if (opt_in.get_all && (opt_in.is_current || opt_in.is_rnext))
@@ -2076,7 +2155,7 @@ static int tcp_ao_copy_mkts_to_user(struct tcp_ao_info *ao_info,
continue;
}
- if (tcp_ao_key_cmp(key, addr, opt_in.prefix,
+ if (tcp_ao_key_cmp(key, l3index, addr, opt_in.prefix,
opt_in.addr.ss_family,
opt_in.sndid, opt_in.rcvid, port) != 0)
continue;
@@ -2109,6 +2188,7 @@ static int tcp_ao_copy_mkts_to_user(struct tcp_ao_info *ao_info,
opt_out.nkeys = 0;
opt_out.maclen = key->maclen;
opt_out.keylen = key->keylen;
+ opt_out.ifindex = key->l3index;
opt_out.pkt_good = atomic64_read(&key->pkt_good);
opt_out.pkt_bad = atomic64_read(&key->pkt_bad);
memcpy(&opt_out.key, key->key, key->keylen);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 054897a13575..c14075254bfa 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1076,6 +1076,7 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
struct tcp_ao_key *ao_key = NULL;
const union tcp_md5_addr *addr;
u8 keyid = 0;
+ int l3index;
u8 *traffic_key = NULL;
#ifdef CONFIG_TCP_AO
const struct tcp_ao_hdr *aoh;
@@ -1087,6 +1088,7 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
u32 seq = (sk->sk_state == TCP_LISTEN) ? tcp_rsk(req)->snt_isn + 1 :
tcp_sk(sk)->snd_nxt;
addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
+ l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0;
if (tcp_rsk_used_ao(req)) {
#ifdef CONFIG_TCP_AO
@@ -1097,11 +1099,11 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
if (!aoh)
return;
- ao_key = tcp_ao_do_lookup(sk, addr, AF_INET,
+ ao_key = tcp_ao_do_lookup(sk, l3index, addr, AF_INET,
aoh->rnext_keyid, -1, 0);
if (unlikely(!ao_key)) {
/* Send ACK with any matching MKT for the peer */
- ao_key = tcp_ao_do_lookup(sk, addr,
+ ao_key = tcp_ao_do_lookup(sk, l3index, addr,
AF_INET, -1, -1, 0);
/* Matching key disappeared (user removed the key?)
* let the handshake timeout.
@@ -1123,9 +1125,6 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
tcp_v4_ao_calc_key_rsk(ao_key, traffic_key, req);
#endif
} else {
- int l3index;
-
- l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0;
md5_key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
}
/* RFC 7323 2.3
@@ -1485,6 +1484,7 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
const union tcp_md5_addr *addr;
u8 prefixlen = 32;
int l3index = 0;
+ bool l3flag;
u8 flags;
if (optlen < sizeof(cmd))
@@ -1497,6 +1497,7 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
return -EINVAL;
flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
+ l3flag = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
if (optname == TCP_MD5SIG_EXT &&
cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
@@ -1534,7 +1535,7 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
/* Don't allow keys for peers that have a matching TCP-AO key.
* See the comment in tcp_ao_add_cmd()
*/
- if (tcp_ao_required(sk, addr, AF_INET, false))
+ if (tcp_ao_required(sk, addr, AF_INET, l3flag ? l3index : -1, false))
return -EKEYREJECTED;
return tcp_md5_do_add(sk, addr, AF_INET, prefixlen, l3index, flags,
diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index ad7a8caa7b2a..500f6ed3b8cf 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -140,6 +140,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
struct dst_entry *dst;
__u8 rcv_wscale;
u32 tsoff = 0;
+ int l3index;
if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_syncookies) ||
!th->ack || th->rst)
@@ -214,7 +215,9 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
treq->snt_isn = cookie;
treq->ts_off = 0;
treq->txhash = net_tx_rndhash();
- tcp_ao_syncookie(sk, skb, treq, AF_INET6);
+
+ l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
+ tcp_ao_syncookie(sk, skb, treq, AF_INET6, l3index);
if (IS_ENABLED(CONFIG_SMC))
ireq->smc_ok = 0;
diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c
index 984a75f96e20..ef163e8928d2 100644
--- a/net/ipv6/tcp_ao.c
+++ b/net/ipv6/tcp_ao.c
@@ -87,30 +87,28 @@ int tcp_v6_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
htonl(tcp_rsk(req)->rcv_isn));
}
-struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk,
- const struct in6_addr *addr,
- int sndid, int rcvid)
-{
- return tcp_ao_do_lookup(sk, (union tcp_ao_addr *)addr, AF_INET6,
- sndid, rcvid, 0);
-}
-
struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
struct sock *addr_sk,
int sndid, int rcvid)
{
struct in6_addr *addr = &addr_sk->sk_v6_daddr;
+ int l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
+ addr_sk->sk_bound_dev_if);
- return tcp_v6_ao_do_lookup(sk, addr, sndid, rcvid);
+ return tcp_ao_do_lookup(sk, l3index, (union tcp_ao_addr *)addr,
+ AF_INET6, sndid, rcvid, 0);
}
struct tcp_ao_key *tcp_v6_ao_lookup_rsk(const struct sock *sk,
struct request_sock *req,
int sndid, int rcvid)
{
- struct in6_addr *addr = &inet_rsk(req)->ir_v6_rmt_addr;
+ struct inet_request_sock *ireq = inet_rsk(req);
+ struct in6_addr *addr = &ireq->ir_v6_rmt_addr;
+ int l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
- return tcp_v6_ao_do_lookup(sk, addr, sndid, rcvid);
+ return tcp_ao_do_lookup(sk, l3index, (union tcp_ao_addr *)addr,
+ AF_INET6, sndid, rcvid, 0);
}
int tcp_v6_ao_hash_pseudoheader(struct tcp_sigpool *hp,
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 9a427c0d48ab..dee42cba6c25 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -606,6 +606,7 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
union tcp_ao_addr *addr;
int l3index = 0;
u8 prefixlen;
+ bool l3flag;
u8 flags;
if (optlen < sizeof(cmd))
@@ -618,6 +619,7 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
return -EINVAL;
flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
+ l3flag = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
if (optname == TCP_MD5SIG_EXT &&
cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
@@ -664,7 +666,8 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
/* Don't allow keys for peers that have a matching TCP-AO key.
* See the comment in tcp_ao_add_cmd()
*/
- if (tcp_ao_required(sk, addr, AF_INET, false))
+ if (tcp_ao_required(sk, addr, AF_INET,
+ l3flag ? l3index : -1, false))
return -EKEYREJECTED;
return tcp_md5_do_add(sk, addr,
AF_INET, prefixlen, l3index, flags,
@@ -676,7 +679,7 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
/* Don't allow keys for peers that have a matching TCP-AO key.
* See the comment in tcp_ao_add_cmd()
*/
- if (tcp_ao_required(sk, addr, AF_INET6, false))
+ if (tcp_ao_required(sk, addr, AF_INET6, l3flag ? l3index : -1, false))
return -EKEYREJECTED;
return tcp_md5_do_add(sk, addr, AF_INET6, prefixlen, l3index, flags,
@@ -1223,10 +1226,14 @@ static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
return;
if (!aoh)
return;
- ao_key = tcp_v6_ao_do_lookup(sk, addr, aoh->rnext_keyid, -1);
+ ao_key = tcp_ao_do_lookup(sk, l3index,
+ (union tcp_ao_addr *)addr, AF_INET6,
+ aoh->rnext_keyid, -1, 0);
if (unlikely(!ao_key)) {
/* Send ACK with any matching MKT for the peer */
- ao_key = tcp_v6_ao_do_lookup(sk, addr, -1, -1);
+ ao_key = tcp_ao_do_lookup(sk, l3index,
+ (union tcp_ao_addr *)addr,
+ AF_INET6, -1, -1, 0);
/* Matching key disappeared (user removed the key?)
* let the handshake timeout.
*/
--
2.41.0
Now when the new request socket is created from the listening socket,
it's recorded what MKT was used by the peer. tcp_rsk_used_ao() is
a new helper for checking if TCP-AO option was used to create the
request socket.
tcp_ao_copy_all_matching() will copy all keys that match the peer on the
request socket, as well as preparing them for the usage (creating
traffic keys).
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/linux/tcp.h | 18 ++++
include/net/tcp.h | 7 ++
include/net/tcp_ao.h | 22 ++++
net/ipv4/syncookies.c | 2 +
net/ipv4/tcp_ao.c | 219 ++++++++++++++++++++++++++++++++++++++-
net/ipv4/tcp_input.c | 15 +++
net/ipv4/tcp_ipv4.c | 65 ++++++++++--
net/ipv4/tcp_minisocks.c | 10 ++
net/ipv4/tcp_output.c | 42 +++++---
net/ipv6/syncookies.c | 2 +
net/ipv6/tcp_ao.c | 21 ++++
net/ipv6/tcp_ipv6.c | 74 +++++++++++--
12 files changed, 466 insertions(+), 31 deletions(-)
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index bbc7db92f37c..f276e7222760 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -165,6 +165,11 @@ struct tcp_request_sock {
* after data-in-SYN.
*/
u8 syn_tos;
+#ifdef CONFIG_TCP_AO
+ u8 ao_keyid;
+ u8 ao_rcv_next;
+ u8 maclen;
+#endif
};
static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
@@ -172,6 +177,19 @@ static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
return (struct tcp_request_sock *)req;
}
+static inline bool tcp_rsk_used_ao(const struct request_sock *req)
+{
+ /* The real length of MAC is saved in the request socket,
+ * signing anything with zero-length makes no sense, so here is
+ * a little hack..
+ */
+#ifndef CONFIG_TCP_AO
+ return false;
+#else
+ return tcp_rsk(req)->maclen != 0;
+#endif
+}
+
#define TCP_RMEM_TO_WIN_SCALE 8
struct tcp_sock {
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 17991a6848ff..b8be3aefb9c4 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2171,6 +2171,13 @@ struct tcp_request_sock_ops {
const struct sock *sk,
const struct sk_buff *skb);
#endif
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_key *(*ao_lookup)(const struct sock *sk,
+ struct request_sock *req,
+ int sndid, int rcvid);
+ int (*ao_calc_key)(struct tcp_ao_key *mkt, u8 *key,
+ struct request_sock *sk);
+#endif
#ifdef CONFIG_SYN_COOKIES
__u32 (*cookie_init_seq)(const struct sk_buff *skb,
__u16 *mss);
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 7f6849f16d7a..b63c4f2c36ea 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -120,6 +120,9 @@ int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family,
sockptr_t optval, int optlen);
struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao,
int sndid, int rcvid);
+int tcp_ao_copy_all_matching(const struct sock *sk, struct sock *newsk,
+ struct request_sock *req, struct sk_buff *skb,
+ int family);
int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
unsigned int len, struct tcp_sigpool *hp);
void tcp_ao_destroy_sock(struct sock *sk, bool twsk);
@@ -144,6 +147,11 @@ struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int tcp_v4_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk,
__be32 sisn, __be32 disn, bool send);
+int tcp_v4_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
+ struct request_sock *req);
+struct tcp_ao_key *tcp_v4_ao_lookup_rsk(const struct sock *sk,
+ struct request_sock *req,
+ int sndid, int rcvid);
int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
const struct sock *sk, const struct sk_buff *skb,
const u8 *tkey, int hash_offset, u32 sne);
@@ -154,9 +162,17 @@ int tcp_v6_ao_hash_pseudoheader(struct tcp_sigpool *hp,
int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk, __be32 sisn,
__be32 disn, bool send);
+int tcp_v6_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
+ struct request_sock *req);
+struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk,
+ const struct in6_addr *addr,
+ int sndid, int rcvid);
struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
struct sock *addr_sk,
int sndid, int rcvid);
+struct tcp_ao_key *tcp_v6_ao_lookup_rsk(const struct sock *sk,
+ struct request_sock *req,
+ int sndid, int rcvid);
int tcp_v6_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
const struct sock *sk, const struct sk_buff *skb,
const u8 *tkey, int hash_offset, u32 sne);
@@ -169,6 +185,12 @@ void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
unsigned short int family);
#else /* CONFIG_TCP_AO */
+static inline void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
+ struct tcp_request_sock *treq,
+ unsigned short int family)
+{
+}
+
static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
const union tcp_ao_addr *addr,
int family, int sndid, int rcvid, u16 port)
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index dc478a0574cb..23fca22bc992 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -394,6 +394,8 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
treq->snt_synack = 0;
treq->tfo_listener = false;
+ tcp_ao_syncookie(sk, skb, treq, AF_INET);
+
if (IS_ENABLED(CONFIG_SMC))
ireq->smc_ok = 0;
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index dc1423239160..be9349239139 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -171,6 +171,23 @@ static void tcp_ao_link_mkt(struct tcp_ao_info *ao, struct tcp_ao_key *mkt)
hlist_add_head_rcu(&mkt->node, &ao->head);
}
+static struct tcp_ao_key *tcp_ao_copy_key(struct sock *sk,
+ struct tcp_ao_key *key)
+{
+ struct tcp_ao_key *new_key;
+
+ new_key = sock_kmalloc(sk, tcp_ao_sizeof_key(key),
+ GFP_ATOMIC);
+ if (!new_key)
+ return NULL;
+
+ *new_key = *key;
+ INIT_HLIST_NODE(&new_key->node);
+ tcp_sigpool_get(new_key->tcp_sigpool_id);
+
+ return new_key;
+}
+
static void tcp_ao_key_free_rcu(struct rcu_head *head)
{
struct tcp_ao_key *key = container_of(head, struct tcp_ao_key, rcu);
@@ -292,6 +309,18 @@ static int tcp_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
return -EOPNOTSUPP;
}
+int tcp_v4_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
+ struct request_sock *req)
+{
+ struct inet_request_sock *ireq = inet_rsk(req);
+
+ return tcp_v4_ao_calc_key(mkt, key,
+ ireq->ir_loc_addr, ireq->ir_rmt_addr,
+ htons(ireq->ir_num), ireq->ir_rmt_port,
+ htonl(tcp_rsk(req)->snt_isn),
+ htonl(tcp_rsk(req)->rcv_isn));
+}
+
static int tcp_v4_ao_hash_pseudoheader(struct tcp_sigpool *hp,
__be32 daddr, __be32 saddr,
int nbytes)
@@ -517,6 +546,16 @@ int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
tkey, hash_offset, sne);
}
+struct tcp_ao_key *tcp_v4_ao_lookup_rsk(const struct sock *sk,
+ struct request_sock *req,
+ int sndid, int rcvid)
+{
+ union tcp_ao_addr *addr =
+ (union tcp_ao_addr *)&inet_rsk(req)->ir_rmt_addr;
+
+ return tcp_ao_do_lookup(sk, addr, AF_INET, sndid, rcvid, 0);
+}
+
struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
int sndid, int rcvid)
{
@@ -545,7 +584,46 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
return -ENOTCONN;
if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV)) {
- return -1;
+ union tcp_ao_addr *addr;
+ unsigned int family;
+ __be32 disn, sisn;
+
+ if (sk->sk_state == TCP_NEW_SYN_RECV) {
+ struct request_sock *req = inet_reqsk(sk);
+
+ sisn = htonl(tcp_rsk(req)->rcv_isn);
+ disn = htonl(tcp_rsk(req)->snt_isn);
+ *sne = 0;
+ } else {
+ sisn = th->seq;
+ disn = 0;
+ }
+ if (IS_ENABLED(CONFIG_IPV6) && sk->sk_family == AF_INET6)
+ addr = (union tcp_md5_addr *)&ipv6_hdr(skb)->saddr;
+ else
+ addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
+ family = sk->sk_family;
+#if IS_ENABLED(CONFIG_IPV6)
+ if (family == AF_INET6 && ipv6_addr_v4mapped(&sk->sk_v6_daddr))
+ family = AF_INET;
+#endif
+
+ sk = sk_const_to_full_sk(sk);
+ ao_info = rcu_dereference(tcp_sk(sk)->ao_info);
+ if (!ao_info)
+ return -ENOENT;
+ *key = tcp_ao_do_lookup(sk, l3index, addr, family,
+ -1, aoh->rnext_keyid, ntohs(th->source));
+ if (!*key)
+ return -ENOENT;
+ *traffic_key = kmalloc(tcp_ao_digest_size(*key), GFP_ATOMIC);
+ if (!*traffic_key)
+ return -ENOMEM;
+ *allocated_traffic_key = true;
+ if (tcp_ao_calc_key_skb(*key, *traffic_key, skb,
+ sisn, disn, family))
+ return -1;
+ *keyid = (*key)->rcvid;
} else {
struct tcp_ao_key *rnext_key;
@@ -567,6 +645,50 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
return 0;
}
+static struct tcp_ao_key *tcp_ao_inbound_lookup(unsigned short int family,
+ const struct sock *sk, const struct sk_buff *skb,
+ int sndid, int rcvid)
+{
+ if (family == AF_INET) {
+ const struct iphdr *iph = ip_hdr(skb);
+
+ return tcp_ao_do_lookup(sk, (union tcp_ao_addr *)&iph->saddr,
+ AF_INET, sndid, rcvid, 0);
+ } else {
+ const struct ipv6hdr *iph = ipv6_hdr(skb);
+
+ return tcp_ao_do_lookup(sk, (union tcp_ao_addr *)&iph->saddr,
+ AF_INET6, sndid, rcvid, 0);
+ }
+}
+
+void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
+ struct tcp_request_sock *treq,
+ unsigned short int family)
+{
+ const struct tcphdr *th = tcp_hdr(skb);
+ const struct tcp_ao_hdr *aoh;
+ struct tcp_ao_key *key;
+
+ treq->maclen = 0;
+
+ /* Shouldn't fail as this has been called on this packet
+ * in tcp_inbound_hash()
+ */
+ tcp_parse_auth_options(th, NULL, &aoh);
+ if (!aoh)
+ return;
+
+ key = tcp_ao_inbound_lookup(family, sk, skb, -1, aoh->keyid);
+ if (!key)
+ /* Key not found, continue without TCP-AO */
+ return;
+
+ treq->ao_rcv_next = aoh->keyid;
+ treq->ao_keyid = aoh->rnext_keyid;
+ treq->maclen = tcp_ao_maclen(key);
+}
+
static int tcp_ao_cache_traffic_keys(const struct sock *sk,
struct tcp_ao_info *ao,
struct tcp_ao_key *ao_key)
@@ -659,6 +781,101 @@ void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb)
tcp_ao_cache_traffic_keys(sk, ao, key);
}
+int tcp_ao_copy_all_matching(const struct sock *sk, struct sock *newsk,
+ struct request_sock *req, struct sk_buff *skb,
+ int family)
+{
+ struct tcp_ao_key *key, *new_key, *first_key;
+ struct tcp_ao_info *new_ao, *ao;
+ struct hlist_node *key_head;
+ union tcp_ao_addr *addr;
+ bool match = false;
+ int ret = -ENOMEM;
+
+ ao = rcu_dereference(tcp_sk(sk)->ao_info);
+ if (!ao)
+ return 0;
+
+ /* New socket without TCP-AO on it */
+ if (!tcp_rsk_used_ao(req))
+ return 0;
+
+ new_ao = tcp_ao_alloc_info(GFP_ATOMIC);
+ if (!new_ao)
+ return -ENOMEM;
+ new_ao->lisn = htonl(tcp_rsk(req)->snt_isn);
+ new_ao->risn = htonl(tcp_rsk(req)->rcv_isn);
+ new_ao->ao_required = ao->ao_required;
+
+ if (family == AF_INET) {
+ addr = (union tcp_ao_addr *)&newsk->sk_daddr;
+#if IS_ENABLED(CONFIG_IPV6)
+ } else if (family == AF_INET6) {
+ addr = (union tcp_ao_addr *)&newsk->sk_v6_daddr;
+#endif
+ } else {
+ ret = -EAFNOSUPPORT;
+ goto free_ao;
+ }
+
+ hlist_for_each_entry_rcu(key, &ao->head, node) {
+ if (tcp_ao_key_cmp(key, addr, key->prefixlen, family,
+ -1, -1, 0))
+ continue;
+
+ new_key = tcp_ao_copy_key(newsk, key);
+ if (!new_key)
+ goto free_and_exit;
+
+ tcp_ao_cache_traffic_keys(newsk, new_ao, new_key);
+ tcp_ao_link_mkt(new_ao, new_key);
+ match = true;
+ }
+
+ if (!match) {
+ /* RFC5925 (7.4.1) specifies that the TCP-AO status
+ * of a connection is determined on the initial SYN.
+ * At this point the connection was TCP-AO enabled, so
+ * it can't switch to being unsigned if peer's key
+ * disappears on the listening socket.
+ */
+ ret = -EKEYREJECTED;
+ goto free_and_exit;
+ }
+
+ key_head = rcu_dereference(hlist_first_rcu(&new_ao->head));
+ first_key = hlist_entry_safe(key_head, struct tcp_ao_key, node);
+
+ key = tcp_ao_established_key(new_ao, tcp_rsk(req)->ao_keyid, -1);
+ if (key)
+ new_ao->current_key = key;
+ else
+ new_ao->current_key = first_key;
+
+ /* set rnext_key */
+ key = tcp_ao_established_key(new_ao, -1, tcp_rsk(req)->ao_rcv_next);
+ if (key)
+ new_ao->rnext_key = key;
+ else
+ new_ao->rnext_key = first_key;
+
+ sk_gso_disable(newsk);
+ rcu_assign_pointer(tcp_sk(newsk)->ao_info, new_ao);
+
+ return 0;
+
+free_and_exit:
+ hlist_for_each_entry_safe(key, key_head, &new_ao->head, node) {
+ hlist_del(&key->node);
+ tcp_sigpool_release(key->tcp_sigpool_id);
+ atomic_sub(tcp_ao_sizeof_key(key), &newsk->sk_omem_alloc);
+ kfree(key);
+ }
+free_ao:
+ kfree(new_ao);
+ return ret;
+}
+
static bool tcp_ao_can_set_current_rnext(struct sock *sk)
{
/* There aren't current/rnext keys on TCP_LISTEN sockets */
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index d9241385468a..2a7ed329f7cb 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6973,6 +6973,10 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
struct flowi fl;
u8 syncookies;
+#ifdef CONFIG_TCP_AO
+ const struct tcp_ao_hdr *aoh;
+#endif
+
syncookies = READ_ONCE(net->ipv4.sysctl_tcp_syncookies);
/* TW buckets are converted to open requests without
@@ -7058,6 +7062,17 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops,
inet_rsk(req)->ecn_ok = 0;
}
+#ifdef CONFIG_TCP_AO
+ if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
+ goto drop_and_release; /* Invalid TCP options */
+ if (aoh) {
+ tcp_rsk(req)->maclen = aoh->length - sizeof(struct tcp_ao_hdr);
+ tcp_rsk(req)->ao_rcv_next = aoh->keyid;
+ tcp_rsk(req)->ao_keyid = aoh->rnext_keyid;
+ } else {
+ tcp_rsk(req)->maclen = 0;
+ }
+#endif
tcp_rsk(req)->snt_isn = isn;
tcp_rsk(req)->txhash = net_tx_rndhash();
tcp_rsk(req)->syn_tos = TCP_SKB_CB(skb)->ip_dsfield;
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 3e5aa89ec3ae..12b952d0dcf4 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1066,33 +1066,78 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
struct request_sock *req)
{
+ struct tcp_md5sig_key *md5_key = NULL;
+ struct tcp_ao_key *ao_key = NULL;
const union tcp_md5_addr *addr;
- int l3index;
+ u8 keyid = 0;
+ u8 *traffic_key = NULL;
+#ifdef CONFIG_TCP_AO
+ const struct tcp_ao_hdr *aoh;
+#endif
/* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
* sk->sk_state == TCP_SYN_RECV -> for Fast Open.
*/
u32 seq = (sk->sk_state == TCP_LISTEN) ? tcp_rsk(req)->snt_isn + 1 :
tcp_sk(sk)->snd_nxt;
+ addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
+ if (tcp_rsk_used_ao(req)) {
+#ifdef CONFIG_TCP_AO
+ /* Invalid TCP option size or twice included auth */
+ if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
+ return;
+
+ if (!aoh)
+ return;
+
+ ao_key = tcp_ao_do_lookup(sk, addr, AF_INET,
+ aoh->rnext_keyid, -1, 0);
+ if (unlikely(!ao_key)) {
+ /* Send ACK with any matching MKT for the peer */
+ ao_key = tcp_ao_do_lookup(sk, addr,
+ AF_INET, -1, -1, 0);
+ /* Matching key disappeared (user removed the key?)
+ * let the handshake timeout.
+ */
+ if (!ao_key) {
+ net_info_ratelimited("TCP-AO key for (%pI4, %d)->(%pI4, %d) suddenly disappeared, won't ACK new connection\n",
+ addr,
+ ntohs(tcp_hdr(skb)->source),
+ &ip_hdr(skb)->daddr,
+ ntohs(tcp_hdr(skb)->dest));
+ return;
+ }
+ }
+ traffic_key = kmalloc(tcp_ao_digest_size(ao_key), GFP_ATOMIC);
+ if (!traffic_key)
+ return;
+
+ keyid = aoh->keyid;
+ tcp_v4_ao_calc_key_rsk(ao_key, traffic_key, req);
+#endif
+ } else {
+ int l3index;
+
+ l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0;
+ md5_key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
+ }
/* RFC 7323 2.3
* The window field (SEG.WND) of every outgoing segment, with the
* exception of <SYN> segments, MUST be right-shifted by
* Rcv.Wind.Shift bits:
*/
- addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
- l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0;
tcp_v4_send_ack(sk, skb, seq,
tcp_rsk(req)->rcv_nxt,
req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
READ_ONCE(req->ts_recent),
0,
- tcp_md5_do_lookup(sk, l3index, addr, AF_INET),
- NULL, NULL, 0, 0,
+ md5_key, ao_key, traffic_key, keyid, 0,
inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0,
ip_hdr(skb)->tos,
READ_ONCE(tcp_rsk(req)->txhash));
+ kfree(traffic_key);
}
/*
@@ -1630,6 +1675,10 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
.req_md5_lookup = tcp_v4_md5_lookup,
.calc_md5_hash = tcp_v4_md5_hash_skb,
#endif
+#ifdef CONFIG_TCP_AO
+ .ao_lookup = tcp_v4_ao_lookup_rsk,
+ .ao_calc_key = tcp_v4_ao_calc_key_rsk,
+#endif
#ifdef CONFIG_SYN_COOKIES
.cookie_init_seq = cookie_v4_init_sequence,
#endif
@@ -1731,12 +1780,16 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
/* Copy over the MD5 key from the original socket */
addr = (union tcp_md5_addr *)&newinet->inet_daddr;
key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
- if (key) {
+ if (key && !tcp_rsk_used_ao(req)) {
if (tcp_md5_key_copy(newsk, addr, AF_INET, 32, l3index, key))
goto put_and_exit;
sk_gso_disable(newsk);
}
#endif
+#ifdef CONFIG_TCP_AO
+ if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET))
+ goto put_and_exit; /* OOM, release back memory */
+#endif
if (__inet_inherit_port(sk, newsk) < 0)
goto put_and_exit;
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 3033f3187079..11b76fa601a7 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -506,6 +506,9 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
const struct tcp_sock *oldtp;
struct tcp_sock *newtp;
u32 seq;
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_key *ao_key;
+#endif
if (!newsk)
return NULL;
@@ -584,6 +587,13 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
if (treq->af_specific->req_md5_lookup(sk, req_to_sk(req)))
newtp->tcp_header_len += TCPOLEN_MD5SIG_ALIGNED;
#endif
+#ifdef CONFIG_TCP_AO
+ newtp->ao_info = NULL;
+ ao_key = treq->af_specific->ao_lookup(sk, req,
+ tcp_rsk(req)->ao_keyid, -1);
+ if (ao_key)
+ newtp->tcp_header_len += tcp_ao_len(ao_key);
+ #endif
if (skb->len >= TCP_MSS_DEFAULT + newtp->tcp_header_len)
newicsk->icsk_ack.last_seg_size = skb->len - newtp->tcp_header_len;
newtp->rx_opt.mss_clamp = req->mss;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 0d74bb4460a6..27f7aaad5490 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -608,6 +608,7 @@ static void bpf_skops_write_hdr_opt(struct sock *sk, struct sk_buff *skb,
* (but it may well be that other scenarios fail similarly).
*/
static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
+ const struct tcp_request_sock *tcprsk,
struct tcp_out_options *opts,
struct tcp_ao_key *ao_key)
{
@@ -622,23 +623,36 @@ static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
ptr += 4;
}
#ifdef CONFIG_TCP_AO
- if (unlikely(OPTION_AO & options) && tp) {
- struct tcp_ao_key *rnext_key;
- struct tcp_ao_info *ao_info;
+ if (unlikely(OPTION_AO & options)) {
u8 maclen;
if (WARN_ON_ONCE(!ao_key))
goto out_ao;
- ao_info = rcu_dereference_check(tp->ao_info,
- lockdep_sock_is_held(&tp->inet_conn.icsk_inet.sk));
- rnext_key = READ_ONCE(ao_info->rnext_key);
- if (WARN_ON_ONCE(!rnext_key))
- goto out_ao;
maclen = tcp_ao_maclen(ao_key);
- *ptr++ = htonl((TCPOPT_AO << 24) |
- (tcp_ao_len(ao_key) << 16) |
- (ao_key->sndid << 8) |
- (rnext_key->rcvid));
+
+ if (tp) {
+ struct tcp_ao_key *rnext_key;
+ struct tcp_ao_info *ao_info;
+
+ ao_info = rcu_dereference_check(tp->ao_info,
+ lockdep_sock_is_held(&tp->inet_conn.icsk_inet.sk));
+ rnext_key = READ_ONCE(ao_info->rnext_key);
+ if (WARN_ON_ONCE(!rnext_key))
+ goto out_ao;
+ *ptr++ = htonl((TCPOPT_AO << 24) |
+ (tcp_ao_len(ao_key) << 16) |
+ (ao_key->sndid << 8) |
+ (rnext_key->rcvid));
+ } else if (tcprsk) {
+ u8 aolen = maclen + sizeof(struct tcp_ao_hdr);
+
+ *ptr++ = htonl((TCPOPT_AO << 24) | (aolen << 16) |
+ (tcprsk->ao_keyid << 8) |
+ (tcprsk->ao_rcv_next));
+ } else {
+ WARN_ON_ONCE(1);
+ goto out_ao;
+ }
opts->hash_location = (__u8 *)ptr;
ptr += maclen / sizeof(*ptr);
if (unlikely(maclen % sizeof(*ptr))) {
@@ -1414,7 +1428,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
th->window = htons(min(tp->rcv_wnd, 65535U));
}
- tcp_options_write(th, tp, &opts, ao_key);
+ tcp_options_write(th, tp, NULL, &opts, ao_key);
#ifdef CONFIG_TCP_MD5SIG
/* Calculate the MD5 hash, as we have all we need now */
@@ -3787,7 +3801,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
/* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
th->window = htons(min(req->rsk_rcv_wnd, 65535U));
- tcp_options_write(th, NULL, &opts, NULL);
+ tcp_options_write(th, NULL, NULL, &opts, NULL);
th->doff = (tcp_header_size >> 2);
TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);
diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 5014aa663452..ad7a8caa7b2a 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -214,6 +214,8 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
treq->snt_isn = cookie;
treq->ts_off = 0;
treq->txhash = net_tx_rndhash();
+ tcp_ao_syncookie(sk, skb, treq, AF_INET6);
+
if (IS_ENABLED(CONFIG_SMC))
ireq->smc_ok = 0;
diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c
index 54c3714a05b4..65fa52f8c2e3 100644
--- a/net/ipv6/tcp_ao.c
+++ b/net/ipv6/tcp_ao.c
@@ -63,6 +63,18 @@ int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
htons(sk->sk_num), disn, sisn);
}
+int tcp_v6_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
+ struct request_sock *req)
+{
+ struct inet_request_sock *ireq = inet_rsk(req);
+
+ return tcp_v6_ao_calc_key(mkt, key,
+ &ireq->ir_v6_loc_addr, &ireq->ir_v6_rmt_addr,
+ htons(ireq->ir_num), ireq->ir_rmt_port,
+ htonl(tcp_rsk(req)->snt_isn),
+ htonl(tcp_rsk(req)->rcv_isn));
+}
+
struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk,
const struct in6_addr *addr,
int sndid, int rcvid)
@@ -80,6 +92,15 @@ struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
return tcp_v6_ao_do_lookup(sk, addr, sndid, rcvid);
}
+struct tcp_ao_key *tcp_v6_ao_lookup_rsk(const struct sock *sk,
+ struct request_sock *req,
+ int sndid, int rcvid)
+{
+ struct in6_addr *addr = &inet_rsk(req)->ir_v6_rmt_addr;
+
+ return tcp_v6_ao_do_lookup(sk, addr, sndid, rcvid);
+}
+
int tcp_v6_ao_hash_pseudoheader(struct tcp_sigpool *hp,
const struct in6_addr *daddr,
const struct in6_addr *saddr, int nbytes)
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 30db3fcab1ff..6905484077db 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -842,6 +842,10 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
.req_md5_lookup = tcp_v6_md5_lookup,
.calc_md5_hash = tcp_v6_md5_hash_skb,
#endif
+#ifdef CONFIG_TCP_AO
+ .ao_lookup = tcp_v6_ao_lookup_rsk,
+ .ao_calc_key = tcp_v6_ao_calc_key_rsk,
+#endif
#ifdef CONFIG_SYN_COOKIES
.cookie_init_seq = cookie_v6_init_sequence,
#endif
@@ -1194,9 +1198,51 @@ static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
struct request_sock *req)
{
+ struct tcp_md5sig_key *md5_key = NULL;
+ struct tcp_ao_key *ao_key = NULL;
+ const struct in6_addr *addr;
+ u8 *traffic_key = NULL;
+ u8 keyid = 0;
int l3index;
l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
+ addr = &ipv6_hdr(skb)->saddr;
+
+ if (tcp_rsk_used_ao(req)) {
+#ifdef CONFIG_TCP_AO
+ const struct tcp_ao_hdr *aoh;
+
+ /* Invalid TCP option size or twice included auth */
+ if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
+ return;
+ if (!aoh)
+ return;
+ ao_key = tcp_v6_ao_do_lookup(sk, addr, aoh->rnext_keyid, -1);
+ if (unlikely(!ao_key)) {
+ /* Send ACK with any matching MKT for the peer */
+ ao_key = tcp_v6_ao_do_lookup(sk, addr, -1, -1);
+ /* Matching key disappeared (user removed the key?)
+ * let the handshake timeout.
+ */
+ if (!ao_key) {
+ net_info_ratelimited("TCP-AO key for (%pI6, %d)->(%pI6, %d) suddenly disappeared, won't ACK new connection\n",
+ addr,
+ ntohs(tcp_hdr(skb)->source),
+ &ipv6_hdr(skb)->daddr,
+ ntohs(tcp_hdr(skb)->dest));
+ return;
+ }
+ }
+ traffic_key = kmalloc(tcp_ao_digest_size(ao_key), GFP_ATOMIC);
+ if (!traffic_key)
+ return;
+
+ keyid = aoh->keyid;
+ tcp_v6_ao_calc_key_rsk(ao_key, traffic_key, req);
+#endif
+ } else {
+ md5_key = tcp_v6_md5_do_lookup(sk, addr, l3index);
+ }
/* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
* sk->sk_state == TCP_SYN_RECV -> for Fast Open.
@@ -1212,9 +1258,10 @@ static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
READ_ONCE(req->ts_recent), sk->sk_bound_dev_if,
- tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index),
+ md5_key,
ipv6_get_dsfield(ipv6_hdr(skb)), 0, sk->sk_priority,
READ_ONCE(tcp_rsk(req)->txhash), NULL, NULL, 0, 0);
+ kfree(traffic_key);
}
@@ -1444,19 +1491,26 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
#ifdef CONFIG_TCP_MD5SIG
l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
- /* Copy over the MD5 key from the original socket */
- key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
- if (key) {
- const union tcp_md5_addr *addr;
+ if (!tcp_rsk_used_ao(req)) {
+ /* Copy over the MD5 key from the original socket */
+ key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
+ if (key) {
+ const union tcp_md5_addr *addr;
- addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr;
- if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) {
- inet_csk_prepare_forced_close(newsk);
- tcp_done(newsk);
- goto out;
+ addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr;
+ if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) {
+ inet_csk_prepare_forced_close(newsk);
+ tcp_done(newsk);
+ goto out;
+ }
}
}
#endif
+#ifdef CONFIG_TCP_AO
+ /* Copy over tcp_ao_info if any */
+ if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET6))
+ goto out; /* OOM */
+#endif
if (__inet_inherit_port(sk, newsk) < 0) {
inet_csk_prepare_forced_close(newsk);
--
2.41.0
Provide setsockopt() key flag that makes TCP-AO exclude hashing TCP
header for peers that match the key. This is needed for interraction
with middleboxes that may change TCP options, see RFC5925 (9.2).
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/uapi/linux/tcp.h | 5 +++++
net/ipv4/tcp_ao.c | 8 +++++---
2 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index ca7ed18ce67b..3275ade3293a 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -354,6 +354,11 @@ struct tcp_diag_md5sig {
#define TCP_AO_MAXKEYLEN 80
#define TCP_AO_KEYF_IFINDEX (1 << 0) /* L3 ifindex for VRF */
+#define TCP_AO_KEYF_EXCLUDE_OPT (1 << 1) /* "Indicates whether TCP
+ * options other than TCP-AO
+ * are included in the MAC
+ * calculation"
+ */
struct tcp_ao_add { /* setsockopt(TCP_AO_ADD_KEY) */
struct __kernel_sockaddr_storage addr; /* peer's address for the key */
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 4bde58ede63a..4fabd3ec5c71 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -567,7 +567,8 @@ int tcp_ao_hash_hdr(unsigned short int family, char *ao_hash,
WARN_ON_ONCE(1);
goto clear_hash;
}
- if (tcp_ao_hash_header(&hp, th, false,
+ if (tcp_ao_hash_header(&hp, th,
+ !!(key->keyflags & TCP_AO_KEYF_EXCLUDE_OPT),
ao_hash, hash_offset, tcp_ao_maclen(key)))
goto clear_hash;
ahash_request_set_crypt(hp.req, NULL, hash_buf, 0);
@@ -615,7 +616,8 @@ int tcp_ao_hash_skb(unsigned short int family,
goto clear_hash;
if (tcp_ao_hash_pseudoheader(family, sk, skb, &hp, skb->len))
goto clear_hash;
- if (tcp_ao_hash_header(&hp, th, false,
+ if (tcp_ao_hash_header(&hp, th,
+ !!(key->keyflags & TCP_AO_KEYF_EXCLUDE_OPT),
ao_hash, hash_offset, tcp_ao_maclen(key)))
goto clear_hash;
if (tcp_sigpool_hash_skb_data(&hp, skb, th->doff << 2))
@@ -1430,7 +1432,7 @@ static struct tcp_ao_info *setsockopt_ao_info(struct sock *sk)
return ERR_PTR(-ESOCKTNOSUPPORT);
}
-#define TCP_AO_KEYF_ALL (0)
+#define TCP_AO_KEYF_ALL (TCP_AO_KEYF_EXCLUDE_OPT)
static struct tcp_ao_key *tcp_ao_key_alloc(struct sock *sk,
struct tcp_ao_add *cmd)
--
2.41.0
TCP-AO, similarly to TCP-MD5, needs to allocate tfms on a slow-path,
which is setsockopt() and use crypto ahash requests on fast paths,
which are RX/TX softirqs. Also, it needs a temporary/scratch buffer
for preparing the hash.
Rework tcp_md5sig_pool in order to support other hashing algorithms
than MD5. It will make it possible to share pre-allocated crypto_ahash
descriptors and scratch area between all TCP hash users.
Internally tcp_sigpool calls crypto_clone_ahash() API over pre-allocated
crypto ahash tfm. Kudos to Herbert, who provided this new crypto API.
I was a little concerned over GFP_ATOMIC allocations of ahash and
crypto_request in RX/TX (see tcp_sigpool_start()), so I benchmarked both
"backends" with different algorithms, using patched version of iperf3[2].
On my laptop with i7-7600U @ 2.80GHz:
clone-tfm per-CPU-requests
TCP-MD5 2.25 Gbits/sec 2.30 Gbits/sec
TCP-AO(hmac(sha1)) 2.53 Gbits/sec 2.54 Gbits/sec
TCP-AO(hmac(sha512)) 1.67 Gbits/sec 1.64 Gbits/sec
TCP-AO(hmac(sha384)) 1.77 Gbits/sec 1.80 Gbits/sec
TCP-AO(hmac(sha224)) 1.29 Gbits/sec 1.30 Gbits/sec
TCP-AO(hmac(sha3-512)) 481 Mbits/sec 480 Mbits/sec
TCP-AO(hmac(md5)) 2.07 Gbits/sec 2.12 Gbits/sec
TCP-AO(hmac(rmd160)) 1.01 Gbits/sec 995 Mbits/sec
TCP-AO(cmac(aes128)) [not supporetd yet] 2.11 Gbits/sec
So, it seems that my concerns don't have strong grounds and per-CPU
crypto_request allocation can be dropped/removed from tcp_sigpool once
ciphers get crypto_clone_ahash() support.
[1]: https://lore.kernel.org/all/[email protected]/T/#u
[2]: https://github.com/0x7f454c46/iperf/tree/tcp-md5-ao
Signed-off-by: Dmitry Safonov <[email protected]>
Reviewed-by: Steen Hegelund <[email protected]>
---
include/net/tcp.h | 46 +++--
net/ipv4/Kconfig | 4 +
net/ipv4/Makefile | 1 +
net/ipv4/tcp.c | 135 +++------------
net/ipv4/tcp_ipv4.c | 97 ++++++-----
net/ipv4/tcp_minisocks.c | 21 ++-
net/ipv4/tcp_sigpool.c | 357 +++++++++++++++++++++++++++++++++++++++
net/ipv6/tcp_ipv6.c | 58 +++----
8 files changed, 510 insertions(+), 209 deletions(-)
create mode 100644 net/ipv4/tcp_sigpool.c
diff --git a/include/net/tcp.h b/include/net/tcp.h
index d17cb8ab4c48..95651f9c9242 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1692,12 +1692,35 @@ union tcp_md5sum_block {
#endif
};
-/* - pool: digest algorithm, hash description and scratch buffer */
-struct tcp_md5sig_pool {
- struct ahash_request *md5_req;
- void *scratch;
+/*
+ * struct tcp_sigpool - per-CPU pool of ahash_requests
+ * @scratch: per-CPU temporary area, that can be used between
+ * tcp_sigpool_start() and tcp_sigpool_end() to perform
+ * crypto request
+ * @req: pre-allocated ahash request
+ */
+struct tcp_sigpool {
+ void *scratch;
+ struct ahash_request *req;
};
+int tcp_sigpool_alloc_ahash(const char *alg, size_t scratch_size);
+void tcp_sigpool_get(unsigned int id);
+void tcp_sigpool_release(unsigned int id);
+int tcp_sigpool_hash_skb_data(struct tcp_sigpool *hp,
+ const struct sk_buff *skb,
+ unsigned int header_len);
+/**
+ * tcp_sigpool_start - disable bh and start using tcp_sigpool_ahash
+ * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash()
+ * @c: returned tcp_sigpool for usage (uninitialized on failure)
+ */
+int tcp_sigpool_start(unsigned int id, struct tcp_sigpool *c);
+/**
+ * tcp_sigpool_end - enable bh and stop using tcp_sigpool
+ */
+void tcp_sigpool_end(struct tcp_sigpool *c);
+size_t tcp_sigpool_algo(unsigned int id, char *buf, size_t buf_len);
/* - functions */
int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
const struct sock *sk, const struct sk_buff *skb);
@@ -1753,17 +1776,12 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
#define tcp_twsk_md5_key(twsk) NULL
#endif
-bool tcp_alloc_md5sig_pool(void);
+int tcp_md5_alloc_sigpool(void);
+void tcp_md5_release_sigpool(void);
+void tcp_md5_add_sigpool(void);
+extern int tcp_md5_sigpool_id;
-struct tcp_md5sig_pool *tcp_get_md5sig_pool(void);
-static inline void tcp_put_md5sig_pool(void)
-{
- local_bh_enable();
-}
-
-int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, const struct sk_buff *,
- unsigned int header_len);
-int tcp_md5_hash_key(struct tcp_md5sig_pool *hp,
+int tcp_md5_hash_key(struct tcp_sigpool *hp,
const struct tcp_md5sig_key *key);
/* From tcp_fastopen.c */
diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 2dfb12230f08..89e2ab023272 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -741,10 +741,14 @@ config DEFAULT_TCP_CONG
default "bbr" if DEFAULT_BBR
default "cubic"
+config TCP_SIGPOOL
+ tristate
+
config TCP_MD5SIG
bool "TCP: MD5 Signature Option support (RFC2385)"
select CRYPTO
select CRYPTO_MD5
+ select TCP_SIGPOOL
help
RFC2385 specifies a method of giving MD5 protection to TCP sessions.
Its main (only?) use is to protect BGP sessions between core routers
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index b18ba8ef93ad..cd760793cfcb 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -62,6 +62,7 @@ obj-$(CONFIG_TCP_CONG_SCALABLE) += tcp_scalable.o
obj-$(CONFIG_TCP_CONG_LP) += tcp_lp.o
obj-$(CONFIG_TCP_CONG_YEAH) += tcp_yeah.o
obj-$(CONFIG_TCP_CONG_ILLINOIS) += tcp_illinois.o
+obj-$(CONFIG_TCP_SIGPOOL) += tcp_sigpool.o
obj-$(CONFIG_NET_SOCK_MSG) += tcp_bpf.o
obj-$(CONFIG_BPF_SYSCALL) += udp_bpf.o
obj-$(CONFIG_NETLABEL) += cipso_ipv4.o
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index aca5620cf3ba..ca2c74c282ad 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -4310,141 +4310,44 @@ int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
EXPORT_SYMBOL(tcp_getsockopt);
#ifdef CONFIG_TCP_MD5SIG
-static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
-static DEFINE_MUTEX(tcp_md5sig_mutex);
-static bool tcp_md5sig_pool_populated = false;
+int tcp_md5_sigpool_id = -1;
+EXPORT_SYMBOL_GPL(tcp_md5_sigpool_id);
-static void __tcp_alloc_md5sig_pool(void)
+int tcp_md5_alloc_sigpool(void)
{
- struct crypto_ahash *hash;
- int cpu;
+ size_t scratch_size;
+ int ret;
- hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
- if (IS_ERR(hash))
- return;
-
- for_each_possible_cpu(cpu) {
- void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch;
- struct ahash_request *req;
-
- if (!scratch) {
- scratch = kmalloc_node(sizeof(union tcp_md5sum_block) +
- sizeof(struct tcphdr),
- GFP_KERNEL,
- cpu_to_node(cpu));
- if (!scratch)
- return;
- per_cpu(tcp_md5sig_pool, cpu).scratch = scratch;
- }
- if (per_cpu(tcp_md5sig_pool, cpu).md5_req)
- continue;
-
- req = ahash_request_alloc(hash, GFP_KERNEL);
- if (!req)
- return;
-
- ahash_request_set_callback(req, 0, NULL, NULL);
-
- per_cpu(tcp_md5sig_pool, cpu).md5_req = req;
+ scratch_size = sizeof(union tcp_md5sum_block) + sizeof(struct tcphdr);
+ ret = tcp_sigpool_alloc_ahash("md5", scratch_size);
+ if (ret >= 0) {
+ tcp_md5_sigpool_id = ret;
+ return 0;
}
- /* before setting tcp_md5sig_pool_populated, we must commit all writes
- * to memory. See smp_rmb() in tcp_get_md5sig_pool()
- */
- smp_wmb();
- /* Paired with READ_ONCE() from tcp_alloc_md5sig_pool()
- * and tcp_get_md5sig_pool().
- */
- WRITE_ONCE(tcp_md5sig_pool_populated, true);
+ return ret;
}
-bool tcp_alloc_md5sig_pool(void)
+void tcp_md5_release_sigpool(void)
{
- /* Paired with WRITE_ONCE() from __tcp_alloc_md5sig_pool() */
- if (unlikely(!READ_ONCE(tcp_md5sig_pool_populated))) {
- mutex_lock(&tcp_md5sig_mutex);
-
- if (!tcp_md5sig_pool_populated)
- __tcp_alloc_md5sig_pool();
-
- mutex_unlock(&tcp_md5sig_mutex);
- }
- /* Paired with WRITE_ONCE() from __tcp_alloc_md5sig_pool() */
- return READ_ONCE(tcp_md5sig_pool_populated);
+ tcp_sigpool_release(tcp_md5_sigpool_id);
}
-EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
-
-/**
- * tcp_get_md5sig_pool - get md5sig_pool for this user
- *
- * We use percpu structure, so if we succeed, we exit with preemption
- * and BH disabled, to make sure another thread or softirq handling
- * wont try to get same context.
- */
-struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
+void tcp_md5_add_sigpool(void)
{
- local_bh_disable();
-
- /* Paired with WRITE_ONCE() from __tcp_alloc_md5sig_pool() */
- if (READ_ONCE(tcp_md5sig_pool_populated)) {
- /* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */
- smp_rmb();
- return this_cpu_ptr(&tcp_md5sig_pool);
- }
- local_bh_enable();
- return NULL;
+ tcp_sigpool_get(tcp_md5_sigpool_id);
}
-EXPORT_SYMBOL(tcp_get_md5sig_pool);
-int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
- const struct sk_buff *skb, unsigned int header_len)
-{
- struct scatterlist sg;
- const struct tcphdr *tp = tcp_hdr(skb);
- struct ahash_request *req = hp->md5_req;
- unsigned int i;
- const unsigned int head_data_len = skb_headlen(skb) > header_len ?
- skb_headlen(skb) - header_len : 0;
- const struct skb_shared_info *shi = skb_shinfo(skb);
- struct sk_buff *frag_iter;
-
- sg_init_table(&sg, 1);
-
- sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
- ahash_request_set_crypt(req, &sg, NULL, head_data_len);
- if (crypto_ahash_update(req))
- return 1;
-
- for (i = 0; i < shi->nr_frags; ++i) {
- const skb_frag_t *f = &shi->frags[i];
- unsigned int offset = skb_frag_off(f);
- struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT);
-
- sg_set_page(&sg, page, skb_frag_size(f),
- offset_in_page(offset));
- ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
- if (crypto_ahash_update(req))
- return 1;
- }
-
- skb_walk_frags(skb, frag_iter)
- if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
- return 1;
-
- return 0;
-}
-EXPORT_SYMBOL(tcp_md5_hash_skb_data);
-
-int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
+int tcp_md5_hash_key(struct tcp_sigpool *hp,
+ const struct tcp_md5sig_key *key)
{
u8 keylen = READ_ONCE(key->keylen); /* paired with WRITE_ONCE() in tcp_md5_do_add */
struct scatterlist sg;
sg_init_one(&sg, key->key, keylen);
- ahash_request_set_crypt(hp->md5_req, &sg, NULL, keylen);
+ ahash_request_set_crypt(hp->req, &sg, NULL, keylen);
/* We use data_race() because tcp_md5_do_add() might change key->key under us */
- return data_race(crypto_ahash_update(hp->md5_req));
+ return data_race(crypto_ahash_update(hp->req));
}
EXPORT_SYMBOL(tcp_md5_hash_key);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 09cffbc82d32..b3b8a11daa71 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1220,10 +1220,6 @@ static int __tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
key = sock_kmalloc(sk, sizeof(*key), gfp | __GFP_ZERO);
if (!key)
return -ENOMEM;
- if (!tcp_alloc_md5sig_pool()) {
- sock_kfree_s(sk, key, sizeof(*key));
- return -ENOMEM;
- }
memcpy(key->key, newkey, newkeylen);
key->keylen = newkeylen;
@@ -1245,15 +1241,21 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
struct tcp_sock *tp = tcp_sk(sk);
if (!rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk))) {
- if (tcp_md5sig_info_add(sk, GFP_KERNEL))
+ if (tcp_md5_alloc_sigpool())
return -ENOMEM;
+ if (tcp_md5sig_info_add(sk, GFP_KERNEL)) {
+ tcp_md5_release_sigpool();
+ return -ENOMEM;
+ }
+
if (!static_branch_inc(&tcp_md5_needed.key)) {
struct tcp_md5sig_info *md5sig;
md5sig = rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk));
rcu_assign_pointer(tp->md5sig_info, NULL);
kfree_rcu(md5sig, rcu);
+ tcp_md5_release_sigpool();
return -EUSERS;
}
}
@@ -1270,8 +1272,12 @@ int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr,
struct tcp_sock *tp = tcp_sk(sk);
if (!rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk))) {
- if (tcp_md5sig_info_add(sk, sk_gfp_mask(sk, GFP_ATOMIC)))
+ tcp_md5_add_sigpool();
+
+ if (tcp_md5sig_info_add(sk, sk_gfp_mask(sk, GFP_ATOMIC))) {
+ tcp_md5_release_sigpool();
return -ENOMEM;
+ }
if (!static_key_fast_inc_not_disabled(&tcp_md5_needed.key.key)) {
struct tcp_md5sig_info *md5sig;
@@ -1280,6 +1286,7 @@ int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr,
net_warn_ratelimited("Too many TCP-MD5 keys in the system\n");
rcu_assign_pointer(tp->md5sig_info, NULL);
kfree_rcu(md5sig, rcu);
+ tcp_md5_release_sigpool();
return -EUSERS;
}
}
@@ -1379,7 +1386,7 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
cmd.tcpm_key, cmd.tcpm_keylen);
}
-static int tcp_v4_md5_hash_headers(struct tcp_md5sig_pool *hp,
+static int tcp_v4_md5_hash_headers(struct tcp_sigpool *hp,
__be32 daddr, __be32 saddr,
const struct tcphdr *th, int nbytes)
{
@@ -1399,38 +1406,35 @@ static int tcp_v4_md5_hash_headers(struct tcp_md5sig_pool *hp,
_th->check = 0;
sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
- ahash_request_set_crypt(hp->md5_req, &sg, NULL,
+ ahash_request_set_crypt(hp->req, &sg, NULL,
sizeof(*bp) + sizeof(*th));
- return crypto_ahash_update(hp->md5_req);
+ return crypto_ahash_update(hp->req);
}
static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
__be32 daddr, __be32 saddr, const struct tcphdr *th)
{
- struct tcp_md5sig_pool *hp;
- struct ahash_request *req;
+ struct tcp_sigpool hp;
- hp = tcp_get_md5sig_pool();
- if (!hp)
- goto clear_hash_noput;
- req = hp->md5_req;
+ if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp))
+ goto clear_hash_nostart;
- if (crypto_ahash_init(req))
+ if (crypto_ahash_init(hp.req))
goto clear_hash;
- if (tcp_v4_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
+ if (tcp_v4_md5_hash_headers(&hp, daddr, saddr, th, th->doff << 2))
goto clear_hash;
- if (tcp_md5_hash_key(hp, key))
+ if (tcp_md5_hash_key(&hp, key))
goto clear_hash;
- ahash_request_set_crypt(req, NULL, md5_hash, 0);
- if (crypto_ahash_final(req))
+ ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
+ if (crypto_ahash_final(hp.req))
goto clear_hash;
- tcp_put_md5sig_pool();
+ tcp_sigpool_end(&hp);
return 0;
clear_hash:
- tcp_put_md5sig_pool();
-clear_hash_noput:
+ tcp_sigpool_end(&hp);
+clear_hash_nostart:
memset(md5_hash, 0, 16);
return 1;
}
@@ -1439,8 +1443,7 @@ int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
const struct sock *sk,
const struct sk_buff *skb)
{
- struct tcp_md5sig_pool *hp;
- struct ahash_request *req;
+ struct tcp_sigpool hp;
const struct tcphdr *th = tcp_hdr(skb);
__be32 saddr, daddr;
@@ -1453,30 +1456,28 @@ int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
daddr = iph->daddr;
}
- hp = tcp_get_md5sig_pool();
- if (!hp)
- goto clear_hash_noput;
- req = hp->md5_req;
+ if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp))
+ goto clear_hash_nostart;
- if (crypto_ahash_init(req))
+ if (crypto_ahash_init(hp.req))
goto clear_hash;
- if (tcp_v4_md5_hash_headers(hp, daddr, saddr, th, skb->len))
+ if (tcp_v4_md5_hash_headers(&hp, daddr, saddr, th, skb->len))
goto clear_hash;
- if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
+ if (tcp_sigpool_hash_skb_data(&hp, skb, th->doff << 2))
goto clear_hash;
- if (tcp_md5_hash_key(hp, key))
+ if (tcp_md5_hash_key(&hp, key))
goto clear_hash;
- ahash_request_set_crypt(req, NULL, md5_hash, 0);
- if (crypto_ahash_final(req))
+ ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
+ if (crypto_ahash_final(hp.req))
goto clear_hash;
- tcp_put_md5sig_pool();
+ tcp_sigpool_end(&hp);
return 0;
clear_hash:
- tcp_put_md5sig_pool();
-clear_hash_noput:
+ tcp_sigpool_end(&hp);
+clear_hash_nostart:
memset(md5_hash, 0, 16);
return 1;
}
@@ -2294,6 +2295,18 @@ static int tcp_v4_init_sock(struct sock *sk)
return 0;
}
+#ifdef CONFIG_TCP_MD5SIG
+static void tcp_md5sig_info_free_rcu(struct rcu_head *head)
+{
+ struct tcp_md5sig_info *md5sig;
+
+ md5sig = container_of(head, struct tcp_md5sig_info, rcu);
+ kfree(md5sig);
+ static_branch_slow_dec_deferred(&tcp_md5_needed);
+ tcp_md5_release_sigpool();
+}
+#endif
+
void tcp_v4_destroy_sock(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
@@ -2318,10 +2331,12 @@ void tcp_v4_destroy_sock(struct sock *sk)
#ifdef CONFIG_TCP_MD5SIG
/* Clean up the MD5 key list, if any */
if (tp->md5sig_info) {
+ struct tcp_md5sig_info *md5sig;
+
+ md5sig = rcu_dereference_protected(tp->md5sig_info, 1);
tcp_clear_md5_list(sk);
- kfree_rcu(rcu_dereference_protected(tp->md5sig_info, 1), rcu);
- tp->md5sig_info = NULL;
- static_branch_slow_dec_deferred(&tcp_md5_needed);
+ call_rcu(&md5sig->rcu, tcp_md5sig_info_free_rcu);
+ rcu_assign_pointer(tp->md5sig_info, NULL);
}
#endif
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index c8f2aa003387..5616b6a34bee 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -261,10 +261,9 @@ static void tcp_time_wait_init(struct sock *sk, struct tcp_timewait_sock *tcptw)
tcptw->tw_md5_key = kmemdup(key, sizeof(*key), GFP_ATOMIC);
if (!tcptw->tw_md5_key)
return;
- if (!tcp_alloc_md5sig_pool())
- goto out_free;
if (!static_key_fast_inc_not_disabled(&tcp_md5_needed.key.key))
goto out_free;
+ tcp_md5_add_sigpool();
}
return;
out_free:
@@ -349,16 +348,26 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
}
EXPORT_SYMBOL(tcp_time_wait);
+#ifdef CONFIG_TCP_MD5SIG
+static void tcp_md5_twsk_free_rcu(struct rcu_head *head)
+{
+ struct tcp_md5sig_key *key;
+
+ key = container_of(head, struct tcp_md5sig_key, rcu);
+ kfree(key);
+ static_branch_slow_dec_deferred(&tcp_md5_needed);
+ tcp_md5_release_sigpool();
+}
+#endif
+
void tcp_twsk_destructor(struct sock *sk)
{
#ifdef CONFIG_TCP_MD5SIG
if (static_branch_unlikely(&tcp_md5_needed.key)) {
struct tcp_timewait_sock *twsk = tcp_twsk(sk);
- if (twsk->tw_md5_key) {
- kfree_rcu(twsk->tw_md5_key, rcu);
- static_branch_slow_dec_deferred(&tcp_md5_needed);
- }
+ if (twsk->tw_md5_key)
+ call_rcu(&twsk->tw_md5_key->rcu, tcp_md5_twsk_free_rcu);
}
#endif
}
diff --git a/net/ipv4/tcp_sigpool.c b/net/ipv4/tcp_sigpool.c
new file mode 100644
index 000000000000..93940761c4ec
--- /dev/null
+++ b/net/ipv4/tcp_sigpool.c
@@ -0,0 +1,357 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <crypto/hash.h>
+#include <linux/cpu.h>
+#include <linux/kref.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/percpu.h>
+#include <linux/workqueue.h>
+#include <net/tcp.h>
+
+static size_t __scratch_size;
+static DEFINE_PER_CPU(void __rcu *, sigpool_scratch);
+
+struct sigpool_entry {
+ struct crypto_ahash *hash;
+ const char *alg;
+ struct kref kref;
+ uint16_t needs_key:1,
+ reserved:15;
+};
+
+#define CPOOL_SIZE (PAGE_SIZE / sizeof(struct sigpool_entry))
+static struct sigpool_entry cpool[CPOOL_SIZE];
+static unsigned int cpool_populated;
+static DEFINE_MUTEX(cpool_mutex);
+
+/* Slow-path */
+struct scratches_to_free {
+ struct rcu_head rcu;
+ unsigned int cnt;
+ void *scratches[];
+};
+
+static void free_old_scratches(struct rcu_head *head)
+{
+ struct scratches_to_free *stf;
+
+ stf = container_of(head, struct scratches_to_free, rcu);
+ while (stf->cnt--)
+ kfree(stf->scratches[stf->cnt]);
+ kfree(stf);
+}
+
+/**
+ * sigpool_reserve_scratch - re-allocates scratch buffer, slow-path
+ * @size: request size for the scratch/temp buffer
+ */
+static int sigpool_reserve_scratch(size_t size)
+{
+ struct scratches_to_free *stf;
+ size_t stf_sz = struct_size(stf, scratches, num_possible_cpus());
+ int cpu, err = 0;
+
+ lockdep_assert_held(&cpool_mutex);
+ if (__scratch_size >= size)
+ return 0;
+
+ stf = kmalloc(stf_sz, GFP_KERNEL);
+ if (!stf)
+ return -ENOMEM;
+ stf->cnt = 0;
+
+ size = max(size, __scratch_size);
+ cpus_read_lock();
+ for_each_possible_cpu(cpu) {
+ void *scratch, *old_scratch;
+
+ scratch = kmalloc_node(size, GFP_KERNEL, cpu_to_node(cpu));
+ if (!scratch) {
+ err = -ENOMEM;
+ break;
+ }
+
+ old_scratch = rcu_replace_pointer(per_cpu(sigpool_scratch, cpu), scratch, lockdep_is_held(&cpool_mutex));
+ if (!cpu_online(cpu) || !old_scratch) {
+ kfree(old_scratch);
+ continue;
+ }
+ stf->scratches[stf->cnt++] = old_scratch;
+ }
+ cpus_read_unlock();
+ if (!err)
+ __scratch_size = size;
+
+ call_rcu(&stf->rcu, free_old_scratches);
+ return err;
+}
+
+static void sigpool_scratch_free(void)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ kfree(rcu_replace_pointer(per_cpu(sigpool_scratch, cpu),
+ NULL, lockdep_is_held(&cpool_mutex)));
+ __scratch_size = 0;
+}
+
+static int __cpool_try_clone(struct crypto_ahash *hash)
+{
+ struct crypto_ahash *tmp;
+
+ tmp = crypto_clone_ahash(hash);
+ if (IS_ERR(tmp))
+ return PTR_ERR(tmp);
+
+ crypto_free_ahash(tmp);
+ return 0;
+}
+
+static int __cpool_alloc_ahash(struct sigpool_entry *e, const char *alg)
+{
+ struct crypto_ahash *cpu0_hash;
+ int ret;
+
+ e->alg = kstrdup(alg, GFP_KERNEL);
+ if (!e->alg)
+ return -ENOMEM;
+
+ cpu0_hash = crypto_alloc_ahash(alg, 0, CRYPTO_ALG_ASYNC);
+ if (IS_ERR(cpu0_hash)) {
+ ret = PTR_ERR(cpu0_hash);
+ goto out_free_alg;
+ }
+
+ e->needs_key = crypto_ahash_get_flags(cpu0_hash) & CRYPTO_TFM_NEED_KEY;
+
+ ret = __cpool_try_clone(cpu0_hash);
+ if (ret)
+ goto out_free_cpu0_hash;
+ e->hash = cpu0_hash;
+ kref_init(&e->kref);
+ return 0;
+
+out_free_cpu0_hash:
+ crypto_free_ahash(cpu0_hash);
+out_free_alg:
+ kfree(e->alg);
+ e->alg = NULL;
+ return ret;
+}
+
+/**
+ * tcp_sigpool_alloc_ahash - allocates pool for ahash requests
+ * @alg: name of async hash algorithm
+ * @scratch_size: reserve a tcp_sigpool::scratch buffer of this size
+ */
+int tcp_sigpool_alloc_ahash(const char *alg, size_t scratch_size)
+{
+ int i, ret;
+
+ /* slow-path */
+ mutex_lock(&cpool_mutex);
+ ret = sigpool_reserve_scratch(scratch_size);
+ if (ret)
+ goto out;
+ for (i = 0; i < cpool_populated; i++) {
+ if (!cpool[i].alg)
+ continue;
+ if (strcmp(cpool[i].alg, alg))
+ continue;
+
+ if (kref_read(&cpool[i].kref) > 0)
+ kref_get(&cpool[i].kref);
+ else
+ kref_init(&cpool[i].kref);
+ ret = i;
+ goto out;
+ }
+
+ for (i = 0; i < cpool_populated; i++) {
+ if (!cpool[i].alg)
+ break;
+ }
+ if (i >= CPOOL_SIZE) {
+ ret = -ENOSPC;
+ goto out;
+ }
+
+ ret = __cpool_alloc_ahash(&cpool[i], alg);
+ if (!ret) {
+ ret = i;
+ if (i == cpool_populated)
+ cpool_populated++;
+ }
+out:
+ mutex_unlock(&cpool_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tcp_sigpool_alloc_ahash);
+
+static void __cpool_free_entry(struct sigpool_entry *e)
+{
+ crypto_free_ahash(e->hash);
+ kfree(e->alg);
+ memset(e, 0, sizeof(*e));
+}
+
+static void cpool_cleanup_work_cb(struct work_struct *work)
+{
+ unsigned int i;
+ bool free_scratch = true;
+
+ mutex_lock(&cpool_mutex);
+ for (i = 0; i < cpool_populated; i++) {
+ if (kref_read(&cpool[i].kref) > 0) {
+ free_scratch = false;
+ continue;
+ }
+ if (!cpool[i].alg)
+ continue;
+ __cpool_free_entry(&cpool[i]);
+ }
+ if (free_scratch)
+ sigpool_scratch_free();
+ mutex_unlock(&cpool_mutex);
+}
+
+static DECLARE_WORK(cpool_cleanup_work, cpool_cleanup_work_cb);
+static void cpool_schedule_cleanup(struct kref *kref)
+{
+ schedule_work(&cpool_cleanup_work);
+}
+
+/**
+ * tcp_sigpool_release - decreases number of users for a pool. If it was
+ * the last user of the pool, releases any memory that was consumed.
+ * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash()
+ */
+void tcp_sigpool_release(unsigned int id)
+{
+ if (WARN_ON_ONCE(id > cpool_populated || !cpool[id].alg))
+ return;
+
+ /* slow-path */
+ kref_put(&cpool[id].kref, cpool_schedule_cleanup);
+}
+EXPORT_SYMBOL_GPL(tcp_sigpool_release);
+
+/**
+ * tcp_sigpool_get - increases number of users (refcounter) for a pool
+ * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash()
+ */
+void tcp_sigpool_get(unsigned int id)
+{
+ if (WARN_ON_ONCE(id > cpool_populated || !cpool[id].alg))
+ return;
+ kref_get(&cpool[id].kref);
+}
+EXPORT_SYMBOL_GPL(tcp_sigpool_get);
+
+int tcp_sigpool_start(unsigned int id, struct tcp_sigpool *c)
+{
+ struct crypto_ahash *hash;
+
+ rcu_read_lock_bh();
+ if (WARN_ON_ONCE(id > cpool_populated || !cpool[id].alg)) {
+ rcu_read_unlock_bh();
+ return -EINVAL;
+ }
+
+ hash = crypto_clone_ahash(cpool[id].hash);
+ if (IS_ERR(hash)) {
+ rcu_read_unlock_bh();
+ return PTR_ERR(hash);
+ }
+
+ c->req = ahash_request_alloc(hash, GFP_ATOMIC);
+ if (!c->req) {
+ crypto_free_ahash(hash);
+ rcu_read_unlock_bh();
+ return -ENOMEM;
+ }
+ ahash_request_set_callback(c->req, 0, NULL, NULL);
+
+ /* Pairs with tcp_sigpool_reserve_scratch(), scratch area is
+ * valid (allocated) until tcp_sigpool_end().
+ */
+ c->scratch = rcu_dereference_bh(*this_cpu_ptr(&sigpool_scratch));
+ return 0;
+}
+EXPORT_SYMBOL_GPL(tcp_sigpool_start);
+
+void tcp_sigpool_end(struct tcp_sigpool *c)
+{
+ struct crypto_ahash *hash = crypto_ahash_reqtfm(c->req);
+
+ rcu_read_unlock_bh();
+ ahash_request_free(c->req);
+ crypto_free_ahash(hash);
+}
+EXPORT_SYMBOL_GPL(tcp_sigpool_end);
+
+/**
+ * tcp_sigpool_algo - return algorithm of tcp_sigpool
+ * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash()
+ * @buf: buffer to return name of algorithm
+ * @buf_len: size of @buf
+ */
+size_t tcp_sigpool_algo(unsigned int id, char *buf, size_t buf_len)
+{
+ if (WARN_ON_ONCE(id > cpool_populated || !cpool[id].alg))
+ return -EINVAL;
+
+ return strscpy(buf, cpool[id].alg, buf_len);
+}
+EXPORT_SYMBOL_GPL(tcp_sigpool_algo);
+
+/**
+ * tcp_sigpool_hash_skb_data - hash data in skb with initialized tcp_sigpool
+ * @hp: tcp_sigpool pointer
+ * @skb: buffer to add sign for
+ * @header_len: TCP header length for this segment
+ */
+int tcp_sigpool_hash_skb_data(struct tcp_sigpool *hp,
+ const struct sk_buff *skb,
+ unsigned int header_len)
+{
+ struct scatterlist sg;
+ const struct tcphdr *tp = tcp_hdr(skb);
+ struct ahash_request *req = hp->req;
+ unsigned int i;
+ const unsigned int head_data_len = skb_headlen(skb) > header_len ?
+ skb_headlen(skb) - header_len : 0;
+ const struct skb_shared_info *shi = skb_shinfo(skb);
+ struct sk_buff *frag_iter;
+
+ sg_init_table(&sg, 1);
+
+ sg_set_buf(&sg, ((u8 *)tp) + header_len, head_data_len);
+ ahash_request_set_crypt(req, &sg, NULL, head_data_len);
+ if (crypto_ahash_update(req))
+ return 1;
+
+ for (i = 0; i < shi->nr_frags; ++i) {
+ const skb_frag_t *f = &shi->frags[i];
+ unsigned int offset = skb_frag_off(f);
+ struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT);
+
+ sg_set_page(&sg, page, skb_frag_size(f),
+ offset_in_page(offset));
+ ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
+ if (crypto_ahash_update(req))
+ return 1;
+ }
+
+ skb_walk_frags(skb, frag_iter)
+ if (tcp_sigpool_hash_skb_data(hp, frag_iter, 0))
+ return 1;
+
+ return 0;
+}
+EXPORT_SYMBOL(tcp_sigpool_hash_skb_data);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Per-CPU pool of crypto requests");
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 4714eb695913..afa8db712dfb 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -670,7 +670,7 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
cmd.tcpm_key, cmd.tcpm_keylen);
}
-static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
+static int tcp_v6_md5_hash_headers(struct tcp_sigpool *hp,
const struct in6_addr *daddr,
const struct in6_addr *saddr,
const struct tcphdr *th, int nbytes)
@@ -691,39 +691,36 @@ static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
_th->check = 0;
sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
- ahash_request_set_crypt(hp->md5_req, &sg, NULL,
+ ahash_request_set_crypt(hp->req, &sg, NULL,
sizeof(*bp) + sizeof(*th));
- return crypto_ahash_update(hp->md5_req);
+ return crypto_ahash_update(hp->req);
}
static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
const struct in6_addr *daddr, struct in6_addr *saddr,
const struct tcphdr *th)
{
- struct tcp_md5sig_pool *hp;
- struct ahash_request *req;
+ struct tcp_sigpool hp;
- hp = tcp_get_md5sig_pool();
- if (!hp)
- goto clear_hash_noput;
- req = hp->md5_req;
+ if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp))
+ goto clear_hash_nostart;
- if (crypto_ahash_init(req))
+ if (crypto_ahash_init(hp.req))
goto clear_hash;
- if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
+ if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, th->doff << 2))
goto clear_hash;
- if (tcp_md5_hash_key(hp, key))
+ if (tcp_md5_hash_key(&hp, key))
goto clear_hash;
- ahash_request_set_crypt(req, NULL, md5_hash, 0);
- if (crypto_ahash_final(req))
+ ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
+ if (crypto_ahash_final(hp.req))
goto clear_hash;
- tcp_put_md5sig_pool();
+ tcp_sigpool_end(&hp);
return 0;
clear_hash:
- tcp_put_md5sig_pool();
-clear_hash_noput:
+ tcp_sigpool_end(&hp);
+clear_hash_nostart:
memset(md5_hash, 0, 16);
return 1;
}
@@ -734,8 +731,7 @@ static int tcp_v6_md5_hash_skb(char *md5_hash,
const struct sk_buff *skb)
{
const struct in6_addr *saddr, *daddr;
- struct tcp_md5sig_pool *hp;
- struct ahash_request *req;
+ struct tcp_sigpool hp;
const struct tcphdr *th = tcp_hdr(skb);
if (sk) { /* valid for establish/request sockets */
@@ -747,30 +743,28 @@ static int tcp_v6_md5_hash_skb(char *md5_hash,
daddr = &ip6h->daddr;
}
- hp = tcp_get_md5sig_pool();
- if (!hp)
- goto clear_hash_noput;
- req = hp->md5_req;
+ if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp))
+ goto clear_hash_nostart;
- if (crypto_ahash_init(req))
+ if (crypto_ahash_init(hp.req))
goto clear_hash;
- if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
+ if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, skb->len))
goto clear_hash;
- if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
+ if (tcp_sigpool_hash_skb_data(&hp, skb, th->doff << 2))
goto clear_hash;
- if (tcp_md5_hash_key(hp, key))
+ if (tcp_md5_hash_key(&hp, key))
goto clear_hash;
- ahash_request_set_crypt(req, NULL, md5_hash, 0);
- if (crypto_ahash_final(req))
+ ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
+ if (crypto_ahash_final(hp.req))
goto clear_hash;
- tcp_put_md5sig_pool();
+ tcp_sigpool_end(&hp);
return 0;
clear_hash:
- tcp_put_md5sig_pool();
-clear_hash_noput:
+ tcp_sigpool_end(&hp);
+clear_hash_nostart:
memset(md5_hash, 0, 16);
return 1;
}
--
2.41.0
Introduce getsockopt(TCP_AO_GET_KEYS) that lets a user get TCP-AO keys
and their properties from a socket. The user can provide a filter
to match the specific key to be dumped or ::get_all = 1 may be
used to dump all keys in one syscall.
Add another getsockopt(TCP_AO_INFO) for providing per-socket/per-ao_info
stats: packet counters, Current_key/RNext_key and flags like
::ao_required and ::accept_icmps.
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/tcp_ao.h | 12 ++
include/uapi/linux/tcp.h | 63 +++++++--
net/ipv4/tcp.c | 13 ++
net/ipv4/tcp_ao.c | 295 +++++++++++++++++++++++++++++++++++++++
4 files changed, 369 insertions(+), 14 deletions(-)
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index cb16af2a9f39..9209343878e1 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -191,6 +191,8 @@ int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
void tcp_ao_destroy_sock(struct sock *sk, bool twsk);
void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp);
bool tcp_ao_ignore_icmp(struct sock *sk, int type, int code);
+int tcp_ao_get_mkts(struct sock *sk, sockptr_t optval, sockptr_t optlen);
+int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockptr_t optlen);
enum skb_drop_reason tcp_inbound_ao_hash(struct sock *sk,
const struct sk_buff *skb, unsigned short int family,
const struct request_sock *req,
@@ -304,6 +306,16 @@ static inline void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw,
static inline void tcp_ao_connect_init(struct sock *sk)
{
}
+
+static inline int tcp_ao_get_mkts(struct sock *sk, sockptr_t optval, sockptr_t optlen)
+{
+ return -ENOPROTOOPT;
+}
+
+static inline int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockptr_t optlen)
+{
+ return -ENOPROTOOPT;
+}
#endif
#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 3275ade3293a..1109093bbb24 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -131,7 +131,8 @@ enum {
#define TCP_AO_ADD_KEY 38 /* Add/Set MKT */
#define TCP_AO_DEL_KEY 39 /* Delete MKT */
-#define TCP_AO_INFO 40 /* Modify TCP-AO per-socket options */
+#define TCP_AO_INFO 40 /* Set/list TCP-AO per-socket options */
+#define TCP_AO_GET_KEYS 41 /* List MKT(s) */
#define TCP_REPAIR_ON 1
#define TCP_REPAIR_OFF 0
@@ -392,21 +393,55 @@ struct tcp_ao_del { /* setsockopt(TCP_AO_DEL_KEY) */
__u8 keyflags; /* see TCP_AO_KEYF_ */
} __attribute__((aligned(8)));
-struct tcp_ao_info_opt { /* setsockopt(TCP_AO_INFO) */
- __u32 set_current :1, /* corresponding ::current_key */
- set_rnext :1, /* corresponding ::rnext */
- ao_required :1, /* don't accept non-AO connects */
- set_counters :1, /* set/clear ::pkt_* counters */
- accept_icmps :1, /* accept incoming ICMPs */
+struct tcp_ao_info_opt { /* setsockopt(TCP_AO_INFO), getsockopt(TCP_AO_INFO) */
+ /* Here 'in' is for setsockopt(), 'out' is for getsockopt() */
+ __u32 set_current :1, /* in/out: corresponding ::current_key */
+ set_rnext :1, /* in/out: corresponding ::rnext */
+ ao_required :1, /* in/out: don't accept non-AO connects */
+ set_counters :1, /* in: set/clear ::pkt_* counters */
+ accept_icmps :1, /* in/out: accept incoming ICMPs */
reserved :27; /* must be 0 */
__u16 reserved2; /* padding, must be 0 */
- __u8 current_key; /* KeyID to set as Current_key */
- __u8 rnext; /* KeyID to set as Rnext_key */
- __u64 pkt_good; /* verified segments */
- __u64 pkt_bad; /* failed verification */
- __u64 pkt_key_not_found; /* could not find a key to verify */
- __u64 pkt_ao_required; /* segments missing TCP-AO sign */
- __u64 pkt_dropped_icmp; /* ICMPs that were ignored */
+ __u8 current_key; /* in/out: KeyID of Current_key */
+ __u8 rnext; /* in/out: keyid of RNext_key */
+ __u64 pkt_good; /* in/out: verified segments */
+ __u64 pkt_bad; /* in/out: failed verification */
+ __u64 pkt_key_not_found; /* in/out: could not find a key to verify */
+ __u64 pkt_ao_required; /* in/out: segments missing TCP-AO sign */
+ __u64 pkt_dropped_icmp; /* in/out: ICMPs that were ignored */
+} __attribute__((aligned(8)));
+
+struct tcp_ao_getsockopt { /* getsockopt(TCP_AO_GET_KEYS) */
+ struct __kernel_sockaddr_storage addr; /* in/out: dump keys for peer
+ * with this address/prefix
+ */
+ char alg_name[64]; /* out: crypto hash algorithm */
+ __u8 key[TCP_AO_MAXKEYLEN];
+ __u32 nkeys; /* in: size of the userspace buffer
+ * @optval, measured in @optlen - the
+ * sizeof(struct tcp_ao_getsockopt)
+ * out: number of keys that matched
+ */
+ __u16 is_current :1, /* in: match and dump Current_key,
+ * out: the dumped key is Current_key
+ */
+
+ is_rnext :1, /* in: match and dump RNext_key,
+ * out: the dumped key is RNext_key
+ */
+ get_all :1, /* in: dump all keys */
+ reserved :13; /* padding, must be 0 */
+ __u8 sndid; /* in/out: dump keys with SendID */
+ __u8 rcvid; /* in/out: dump keys with RecvID */
+ __u8 prefix; /* in/out: dump keys with address/prefix */
+ __u8 maclen; /* out: key's length of authentication
+ * code (hash)
+ */
+ __u8 keyflags; /* in/out: see TCP_AO_KEYF_ */
+ __u8 keylen; /* out: length of ::key */
+ __s32 ifindex; /* in/out: L3 dev index for VRF */
+ __u64 pkt_good; /* out: verified segments */
+ __u64 pkt_bad; /* out: segments that failed verification */
} __attribute__((aligned(8)));
/* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 37d3eac0561b..82506300da6c 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -4289,6 +4289,19 @@ int do_tcp_getsockopt(struct sock *sk, int level,
return err;
}
#endif
+ case TCP_AO_GET_KEYS:
+ case TCP_AO_INFO: {
+ int err;
+
+ sockopt_lock_sock(sk);
+ if (optname == TCP_AO_GET_KEYS)
+ err = tcp_ao_get_mkts(sk, optval, optlen);
+ else
+ err = tcp_ao_get_sock_info(sk, optval, optlen);
+ sockopt_release_sock(sk);
+
+ return err;
+ }
default:
return -ENOPROTOOPT;
}
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 4fabd3ec5c71..faa6c5c0db28 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -1869,3 +1869,298 @@ int tcp_v4_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen)
return tcp_parse_ao(sk, cmd, AF_INET, optval, optlen);
}
+/* tcp_ao_copy_mkts_to_user(ao_info, optval, optlen)
+ *
+ * @ao_info: struct tcp_ao_info on the socket that
+ * socket getsockopt(TCP_AO_GET_KEYS) is executed on
+ * @optval: pointer to array of tcp_ao_getsockopt structures in user space.
+ * Must be != NULL.
+ * @optlen: pointer to size of tcp_ao_getsockopt structure.
+ * Must be != NULL.
+ *
+ * Return value: 0 on success, a negative error number otherwise.
+ *
+ * optval points to an array of tcp_ao_getsockopt structures in user space.
+ * optval[0] is used as both input and output to getsockopt. It determines
+ * which keys are returned by the kernel.
+ * optval[0].nkeys is the size of the array in user space. On return it contains
+ * the number of keys matching the search criteria.
+ * If tcp_ao_getsockopt::get_all is set, then all keys in the socket are
+ * returned, otherwise only keys matching <addr, prefix, sndid, rcvid>
+ * in optval[0] are returned.
+ * optlen is also used as both input and output. The user provides the size
+ * of struct tcp_ao_getsockopt in user space, and the kernel returns the size
+ * of the structure in kernel space.
+ * The size of struct tcp_ao_getsockopt may differ between user and kernel.
+ * There are three cases to consider:
+ * * If usize == ksize, then keys are copied verbatim.
+ * * If usize < ksize, then the userspace has passed an old struct to a
+ * newer kernel. The rest of the trailing bytes in optval[0]
+ * (ksize - usize) are interpreted as 0 by the kernel.
+ * * If usize > ksize, then the userspace has passed a new struct to an
+ * older kernel. The trailing bytes unknown to the kernel (usize - ksize)
+ * are checked to ensure they are zeroed, otherwise -E2BIG is returned.
+ * On return the kernel fills in min(usize, ksize) in each entry of the array.
+ * The layout of the fields in the user and kernel structures is expected to
+ * be the same (including in the 32bit vs 64bit case).
+ */
+static int tcp_ao_copy_mkts_to_user(struct tcp_ao_info *ao_info,
+ sockptr_t optval, sockptr_t optlen)
+{
+ struct tcp_ao_getsockopt opt_in, opt_out;
+ struct tcp_ao_key *key, *current_key;
+ bool do_address_matching = true;
+ union tcp_ao_addr *addr = NULL;
+ unsigned int max_keys; /* maximum number of keys to copy to user */
+ size_t out_offset = 0;
+ size_t bytes_to_write; /* number of bytes to write to user level */
+ int err, user_len;
+ u32 matched_keys; /* keys from ao_info matched so far */
+ int optlen_out;
+ u16 port = 0;
+
+ if (copy_from_sockptr(&user_len, optlen, sizeof(int)))
+ return -EFAULT;
+
+ if (user_len <= 0)
+ return -EINVAL;
+
+ memset(&opt_in, 0, sizeof(struct tcp_ao_getsockopt));
+ err = copy_struct_from_sockptr(&opt_in, sizeof(opt_in),
+ optval, user_len);
+ if (err < 0)
+ return err;
+
+ if (opt_in.pkt_good || opt_in.pkt_bad)
+ return -EINVAL;
+
+ if (opt_in.reserved != 0)
+ return -EINVAL;
+
+ max_keys = opt_in.nkeys;
+
+ if (opt_in.get_all || opt_in.is_current || opt_in.is_rnext) {
+ if (opt_in.get_all && (opt_in.is_current || opt_in.is_rnext))
+ return -EINVAL;
+ do_address_matching = false;
+ }
+
+ switch (opt_in.addr.ss_family) {
+ case AF_INET: {
+ struct sockaddr_in *sin;
+ __be32 mask;
+
+ sin = (struct sockaddr_in *)&opt_in.addr;
+ port = sin->sin_port;
+ addr = (union tcp_ao_addr *)&sin->sin_addr;
+
+ if (opt_in.prefix > 32)
+ return -EINVAL;
+
+ if (sin->sin_addr.s_addr == INADDR_ANY &&
+ opt_in.prefix != 0)
+ return -EINVAL;
+
+ mask = inet_make_mask(opt_in.prefix);
+ if (sin->sin_addr.s_addr & ~mask)
+ return -EINVAL;
+
+ break;
+ }
+ case AF_INET6: {
+ struct sockaddr_in6 *sin6;
+ struct in6_addr *addr6;
+
+ sin6 = (struct sockaddr_in6 *)&opt_in.addr;
+ addr = (union tcp_ao_addr *)&sin6->sin6_addr;
+ addr6 = &sin6->sin6_addr;
+ port = sin6->sin6_port;
+
+ /* We don't have to change family and @addr here if
+ * ipv6_addr_v4mapped() like in key adding:
+ * tcp_ao_key_cmp() does it. Do the sanity checks though.
+ */
+ if (opt_in.prefix != 0) {
+ if (ipv6_addr_v4mapped(addr6)) {
+ __be32 mask, addr4 = addr6->s6_addr32[3];
+
+ if (opt_in.prefix > 32 ||
+ addr4 == INADDR_ANY)
+ return -EINVAL;
+ mask = inet_make_mask(opt_in.prefix);
+ if (addr4 & ~mask)
+ return -EINVAL;
+ } else {
+ struct in6_addr pfx;
+
+ if (ipv6_addr_any(addr6) ||
+ opt_in.prefix > 128)
+ return -EINVAL;
+
+ ipv6_addr_prefix(&pfx, addr6, opt_in.prefix);
+ if (ipv6_addr_cmp(&pfx, addr6))
+ return -EINVAL;
+ }
+ } else if (!ipv6_addr_any(addr6)) {
+ return -EINVAL;
+ }
+ break;
+ }
+ case 0:
+ if (!do_address_matching)
+ break;
+ fallthrough;
+ default:
+ return -EAFNOSUPPORT;
+ }
+
+ if (!do_address_matching) {
+ /* We could just ignore those, but let's do stricter checks */
+ if (addr || port)
+ return -EINVAL;
+ if (opt_in.prefix || opt_in.sndid || opt_in.rcvid)
+ return -EINVAL;
+ }
+
+ bytes_to_write = min_t(int, user_len, sizeof(struct tcp_ao_getsockopt));
+ matched_keys = 0;
+ /* May change in RX, while we're dumping, pre-fetch it */
+ current_key = READ_ONCE(ao_info->current_key);
+
+ hlist_for_each_entry_rcu(key, &ao_info->head, node) {
+ if (opt_in.get_all)
+ goto match;
+
+ if (opt_in.is_current || opt_in.is_rnext) {
+ if (opt_in.is_current && key == current_key)
+ goto match;
+ if (opt_in.is_rnext && key == ao_info->rnext_key)
+ goto match;
+ continue;
+ }
+
+ if (tcp_ao_key_cmp(key, addr, opt_in.prefix,
+ opt_in.addr.ss_family,
+ opt_in.sndid, opt_in.rcvid, port) != 0)
+ continue;
+match:
+ matched_keys++;
+ if (matched_keys > max_keys)
+ continue;
+
+ memset(&opt_out, 0, sizeof(struct tcp_ao_getsockopt));
+
+ if (key->family == AF_INET) {
+ struct sockaddr_in *sin_out = (struct sockaddr_in *)&opt_out.addr;
+
+ sin_out->sin_family = key->family;
+ sin_out->sin_port = ntohs(key->port);
+ memcpy(&sin_out->sin_addr, &key->addr, sizeof(struct in_addr));
+ } else {
+ struct sockaddr_in6 *sin6_out = (struct sockaddr_in6 *)&opt_out.addr;
+
+ sin6_out->sin6_family = key->family;
+ sin6_out->sin6_port = ntohs(key->port);
+ memcpy(&sin6_out->sin6_addr, &key->addr, sizeof(struct in6_addr));
+ }
+ opt_out.sndid = key->sndid;
+ opt_out.rcvid = key->rcvid;
+ opt_out.prefix = key->prefixlen;
+ opt_out.keyflags = key->keyflags;
+ opt_out.is_current = (key == current_key);
+ opt_out.is_rnext = (key == ao_info->rnext_key);
+ opt_out.nkeys = 0;
+ opt_out.maclen = key->maclen;
+ opt_out.keylen = key->keylen;
+ opt_out.pkt_good = atomic64_read(&key->pkt_good);
+ opt_out.pkt_bad = atomic64_read(&key->pkt_bad);
+ memcpy(&opt_out.key, key->key, key->keylen);
+ tcp_sigpool_algo(key->tcp_sigpool_id, opt_out.alg_name, 64);
+
+ /* Copy key to user */
+ if (copy_to_sockptr_offset(optval, out_offset,
+ &opt_out, bytes_to_write))
+ return -EFAULT;
+ out_offset += user_len;
+ }
+
+ optlen_out = (int)sizeof(struct tcp_ao_getsockopt);
+ if (copy_to_sockptr(optlen, &optlen_out, sizeof(int)))
+ return -EFAULT;
+
+ out_offset = offsetof(struct tcp_ao_getsockopt, nkeys);
+ if (copy_to_sockptr_offset(optval, out_offset,
+ &matched_keys, sizeof(u32)))
+ return -EFAULT;
+
+ return 0;
+}
+
+int tcp_ao_get_mkts(struct sock *sk, sockptr_t optval, sockptr_t optlen)
+{
+ struct tcp_ao_info *ao_info;
+
+ ao_info = setsockopt_ao_info(sk);
+ if (IS_ERR(ao_info))
+ return PTR_ERR(ao_info);
+ if (!ao_info)
+ return -ENOENT;
+
+ return tcp_ao_copy_mkts_to_user(ao_info, optval, optlen);
+}
+
+int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockptr_t optlen)
+{
+ struct tcp_ao_info_opt out, in = {};
+ struct tcp_ao_key *current_key;
+ struct tcp_ao_info *ao;
+ int err, len;
+
+ if (copy_from_sockptr(&len, optlen, sizeof(int)))
+ return -EFAULT;
+
+ if (len <= 0)
+ return -EINVAL;
+
+ /* Copying this "in" only to check ::reserved, ::reserved2,
+ * that may be needed to extend (struct tcp_ao_info_opt) and
+ * what getsockopt() provides in future.
+ */
+ err = copy_struct_from_sockptr(&in, sizeof(in), optval, len);
+ if (err)
+ return err;
+
+ if (in.reserved != 0 || in.reserved2 != 0)
+ return -EINVAL;
+
+ ao = setsockopt_ao_info(sk);
+ if (IS_ERR(ao))
+ return PTR_ERR(ao);
+ if (!ao)
+ return -ENOENT;
+
+ memset(&out, 0, sizeof(out));
+ out.ao_required = ao->ao_required;
+ out.accept_icmps = ao->accept_icmps;
+ out.pkt_good = atomic64_read(&ao->counters.pkt_good);
+ out.pkt_bad = atomic64_read(&ao->counters.pkt_bad);
+ out.pkt_key_not_found = atomic64_read(&ao->counters.key_not_found);
+ out.pkt_ao_required = atomic64_read(&ao->counters.ao_required);
+ out.pkt_dropped_icmp = atomic64_read(&ao->counters.dropped_icmp);
+
+ current_key = READ_ONCE(ao->current_key);
+ if (current_key) {
+ out.set_current = 1;
+ out.current_key = current_key->sndid;
+ }
+ if (ao->rnext_key) {
+ out.set_rnext = 1;
+ out.rnext = ao->rnext_key->rcvid;
+ }
+
+ if (copy_to_sockptr(optval, &out, min_t(int, len, sizeof(out))))
+ return -EFAULT;
+
+ return 0;
+}
+
--
2.41.0
Similarly to IPsec, RFC5925 prescribes:
">> A TCP-AO implementation MUST default to ignore incoming ICMPv4
messages of Type 3 (destination unreachable), Codes 2-4 (protocol
unreachable, port unreachable, and fragmentation needed -- ’hard
errors’), and ICMPv6 Type 1 (destination unreachable), Code 1
(administratively prohibited) and Code 4 (port unreachable) intended
for connections in synchronized states (ESTABLISHED, FIN-WAIT-1, FIN-
WAIT-2, CLOSE-WAIT, CLOSING, LAST-ACK, TIME-WAIT) that match MKTs."
A selftest (later in patch series) verifies that this attack is not
possible in this TCP-AO implementation.
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/tcp_ao.h | 10 ++++++-
include/uapi/linux/snmp.h | 1 +
include/uapi/linux/tcp.h | 4 ++-
net/ipv4/proc.c | 1 +
net/ipv4/tcp_ao.c | 61 +++++++++++++++++++++++++++++++++++++++
net/ipv4/tcp_ipv4.c | 5 ++++
net/ipv6/tcp_ipv6.c | 4 +++
7 files changed, 84 insertions(+), 2 deletions(-)
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 801dca405df7..cb16af2a9f39 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -24,6 +24,7 @@ struct tcp_ao_counters {
atomic64_t pkt_bad;
atomic64_t key_not_found;
atomic64_t ao_required;
+ atomic64_t dropped_icmp;
};
struct tcp_ao_key {
@@ -93,7 +94,8 @@ struct tcp_ao_info {
struct tcp_ao_key *rnext_key;
struct tcp_ao_counters counters;
u32 ao_required :1,
- __unused :31;
+ accept_icmps :1,
+ __unused :30;
__be32 lisn;
__be32 risn;
/* Sequence Number Extension (SNE) are upper 4 bytes for SEQ,
@@ -188,6 +190,7 @@ int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
unsigned int len, struct tcp_sigpool *hp);
void tcp_ao_destroy_sock(struct sock *sk, bool twsk);
void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp);
+bool tcp_ao_ignore_icmp(struct sock *sk, int type, int code);
enum skb_drop_reason tcp_inbound_ao_hash(struct sock *sk,
const struct sk_buff *skb, unsigned short int family,
const struct request_sock *req,
@@ -266,6 +269,11 @@ static inline void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
{
}
+static inline bool tcp_ao_ignore_icmp(struct sock *sk, int type, int code)
+{
+ return false;
+}
+
static inline enum skb_drop_reason tcp_inbound_ao_hash(struct sock *sk,
const struct sk_buff *skb, unsigned short int family,
const struct request_sock *req, const struct tcp_ao_hdr *aoh)
diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
index 06ddf4cd295c..47a6b47da66f 100644
--- a/include/uapi/linux/snmp.h
+++ b/include/uapi/linux/snmp.h
@@ -300,6 +300,7 @@ enum
LINUX_MIB_TCPAOBAD, /* TCPAOBad */
LINUX_MIB_TCPAOKEYNOTFOUND, /* TCPAOKeyNotFound */
LINUX_MIB_TCPAOGOOD, /* TCPAOGood */
+ LINUX_MIB_TCPAODROPPEDICMPS, /* TCPAODroppedIcmps */
__LINUX_MIB_MAX
};
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 3fe0612ec59a..ca7ed18ce67b 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -392,7 +392,8 @@ struct tcp_ao_info_opt { /* setsockopt(TCP_AO_INFO) */
set_rnext :1, /* corresponding ::rnext */
ao_required :1, /* don't accept non-AO connects */
set_counters :1, /* set/clear ::pkt_* counters */
- reserved :28; /* must be 0 */
+ accept_icmps :1, /* accept incoming ICMPs */
+ reserved :27; /* must be 0 */
__u16 reserved2; /* padding, must be 0 */
__u8 current_key; /* KeyID to set as Current_key */
__u8 rnext; /* KeyID to set as Rnext_key */
@@ -400,6 +401,7 @@ struct tcp_ao_info_opt { /* setsockopt(TCP_AO_INFO) */
__u64 pkt_bad; /* failed verification */
__u64 pkt_key_not_found; /* could not find a key to verify */
__u64 pkt_ao_required; /* segments missing TCP-AO sign */
+ __u64 pkt_dropped_icmp; /* ICMPs that were ignored */
} __attribute__((aligned(8)));
/* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 3f643cd29cfe..5d3c9c96773e 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -302,6 +302,7 @@ static const struct snmp_mib snmp4_net_list[] = {
SNMP_MIB_ITEM("TCPAOBad", LINUX_MIB_TCPAOBAD),
SNMP_MIB_ITEM("TCPAOKeyNotFound", LINUX_MIB_TCPAOKEYNOTFOUND),
SNMP_MIB_ITEM("TCPAOGood", LINUX_MIB_TCPAOGOOD),
+ SNMP_MIB_ITEM("TCPAODroppedIcmps", LINUX_MIB_TCPAODROPPEDICMPS),
SNMP_MIB_SENTINEL
};
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 9ee7fc9f6a76..4bde58ede63a 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -15,6 +15,7 @@
#include <net/tcp.h>
#include <net/ipv6.h>
+#include <net/icmp.h>
int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
unsigned int len, struct tcp_sigpool *hp)
@@ -44,6 +45,63 @@ int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
return 1;
}
+bool tcp_ao_ignore_icmp(struct sock *sk, int type, int code)
+{
+ struct tcp_ao_info *ao;
+ bool ignore_icmp = false;
+
+ /* RFC5925, 7.8:
+ * >> A TCP-AO implementation MUST default to ignore incoming ICMPv4
+ * messages of Type 3 (destination unreachable), Codes 2-4 (protocol
+ * unreachable, port unreachable, and fragmentation needed -- ’hard
+ * errors’), and ICMPv6 Type 1 (destination unreachable), Code 1
+ * (administratively prohibited) and Code 4 (port unreachable) intended
+ * for connections in synchronized states (ESTABLISHED, FIN-WAIT-1, FIN-
+ * WAIT-2, CLOSE-WAIT, CLOSING, LAST-ACK, TIME-WAIT) that match MKTs.
+ */
+ if (sk->sk_family == AF_INET) {
+ if (type != ICMP_DEST_UNREACH)
+ return false;
+ if (code < ICMP_PROT_UNREACH || code > ICMP_FRAG_NEEDED)
+ return false;
+ } else if (sk->sk_family == AF_INET6) {
+ if (type != ICMPV6_DEST_UNREACH)
+ return false;
+ if (code != ICMPV6_ADM_PROHIBITED && code != ICMPV6_PORT_UNREACH)
+ return false;
+ } else {
+ WARN_ON_ONCE(1);
+ return false;
+ }
+
+ rcu_read_lock();
+ switch (sk->sk_state) {
+ case TCP_TIME_WAIT:
+ ao = rcu_dereference(tcp_twsk(sk)->ao_info);
+ break;
+ case TCP_SYN_SENT:
+ case TCP_SYN_RECV:
+ case TCP_LISTEN:
+ case TCP_NEW_SYN_RECV:
+ /* RFC5925 specifies to ignore ICMPs *only* on connections
+ * in synchronized states.
+ */
+ rcu_read_unlock();
+ return false;
+ default:
+ ao = rcu_dereference(tcp_sk(sk)->ao_info);
+ }
+
+ if (ao && !ao->accept_icmps) {
+ ignore_icmp = true;
+ __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAODROPPEDICMPS);
+ atomic64_inc(&ao->counters.dropped_icmp);
+ }
+ rcu_read_unlock();
+
+ return ignore_icmp;
+}
+
/* Optimized version of tcp_ao_do_lookup(): only for sockets for which
* it's known that the keys in ao_info are matching peer's
* family/address/port/VRF/etc.
@@ -1044,6 +1102,7 @@ int tcp_ao_copy_all_matching(const struct sock *sk, struct sock *newsk,
new_ao->lisn = htonl(tcp_rsk(req)->snt_isn);
new_ao->risn = htonl(tcp_rsk(req)->rcv_isn);
new_ao->ao_required = ao->ao_required;
+ new_ao->accept_icmps = ao->accept_icmps;
if (family == AF_INET) {
addr = (union tcp_ao_addr *)&newsk->sk_daddr;
@@ -1764,9 +1823,11 @@ static int tcp_ao_info_cmd(struct sock *sk, unsigned short int family,
atomic64_set(&ao_info->counters.pkt_bad, cmd.pkt_bad);
atomic64_set(&ao_info->counters.key_not_found, cmd.pkt_key_not_found);
atomic64_set(&ao_info->counters.ao_required, cmd.pkt_ao_required);
+ atomic64_set(&ao_info->counters.dropped_icmp, cmd.pkt_dropped_icmp);
}
ao_info->ao_required = cmd.ao_required;
+ ao_info->accept_icmps = cmd.accept_icmps;
if (new_current)
WRITE_ONCE(ao_info->current_key, new_current);
if (new_rnext)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 37497dec5eb9..054897a13575 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -494,6 +494,8 @@ int tcp_v4_err(struct sk_buff *skb, u32 info)
return -ENOENT;
}
if (sk->sk_state == TCP_TIME_WAIT) {
+ /* To increase the counter of ignored icmps for TCP-AO */
+ tcp_ao_ignore_icmp(sk, type, code);
inet_twsk_put(inet_twsk(sk));
return 0;
}
@@ -508,6 +510,9 @@ int tcp_v4_err(struct sk_buff *skb, u32 info)
}
bh_lock_sock(sk);
+ if (tcp_ao_ignore_icmp(sk, type, code))
+ goto out;
+
/* If too many ICMPs get dropped on busy
* servers this needs to be solved differently.
* We do take care of PMTU discovery (RFC1191) special case :
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 873ce0d72f34..9a427c0d48ab 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -395,6 +395,8 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
}
if (sk->sk_state == TCP_TIME_WAIT) {
+ /* To increase the counter of ignored icmps for TCP-AO */
+ tcp_ao_ignore_icmp(sk, type, code);
inet_twsk_put(inet_twsk(sk));
return 0;
}
@@ -406,6 +408,8 @@ static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
}
bh_lock_sock(sk);
+ if (tcp_ao_ignore_icmp(sk, type, code))
+ goto out;
if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
__NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
--
2.41.0
It has Frequently Asked Questions (FAQ) on RFC 5925 - I found it very
useful answering those before writing the actual code. It provides answers
to common questions that arise on a quick read of the RFC, as well as how
they were answered. There's also comparison to TCP-MD5 option,
evaluation of per-socket vs in-kernel-DB approaches and description of
uAPI provided.
Hopefully, it will be as useful for reviewing the code as it was for writing.
Signed-off-by: Dmitry Safonov <[email protected]>
---
Documentation/networking/index.rst | 1 +
Documentation/networking/tcp_ao.rst | 422 ++++++++++++++++++++++++++++
2 files changed, 423 insertions(+)
create mode 100644 Documentation/networking/tcp_ao.rst
diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
index 5b75c3f7a137..69c1e53ef88b 100644
--- a/Documentation/networking/index.rst
+++ b/Documentation/networking/index.rst
@@ -107,6 +107,7 @@ Contents:
sysfs-tagging
tc-actions-env-rules
tc-queue-filters
+ tcp_ao
tcp-thin
team
timestamping
diff --git a/Documentation/networking/tcp_ao.rst b/Documentation/networking/tcp_ao.rst
new file mode 100644
index 000000000000..819b4b630cbb
--- /dev/null
+++ b/Documentation/networking/tcp_ao.rst
@@ -0,0 +1,422 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+========================================================
+TCP Authentication Option Linux implementation (RFC5925)
+========================================================
+
+TCP Authentication Option (TCP-AO) provides a TCP extension aimed at verifying
+segments between trusted peers. It adds a new TCP header option with
+a Message Authentication Code (MAC). MACs are produced from the content
+of a TCP segment using a hashing function with a password known to both peers.
+The intent of TCP-AO is to deprecate TCP-MD5 providing better security,
+key rotation and support for variety of hashing algorithms.
+
+1. Introduction
+===============
+
+.. list-table:: Short and Limited Comparison of TCP-AO and TCP-MD5
+
+ * -
+ - TCP-MD5
+ - TCP-AO
+ * - Supported hashing algorithms
+ - MD5 (cryptographically weak).
+ - Must support HMAC-SHA1 (chosen-prefix attacks) and CMAC-AES-128
+ (only side-channel attacks). May support any hashing algorithm.
+ * - Length of MACs (bytes)
+ - 16
+ - Typically 12-16. Possible other variants that fit TCP header.
+ * - Number of keys per TCP connection
+ - 1
+ - Many
+ * - Possibility to change an active key
+ - Non-practical (both peers have to change them during MSL)
+ - Supported by protocol
+ * - Protection against ICMP 'hard errors'
+ - No
+ - Yes: ignoring them by default on established connections
+ * - Protection against traffic-crossing attack
+ - No
+ - Yes: pseudo-header includes TCP ports.
+ * - Protection against replayed TCP segments
+ - No
+ - Sequence Number Extension (SNE) and Initial Sequence Numbers (ISN)
+ * - Supports Connectionless Resets
+ - Yes
+ - No. ISNs+SNEs are needed to correctly sign RST.
+ * - Standards
+ - RFC 2385
+ - RFC 5925, RFC 5926
+
+1.1 Frequently Asked Questions (FAQ) with references to RFC 5925
+----------------------------------------------------------------
+
+Q: Can either SendID or RecvID be non-unique for the same 4-tuple
+(srcaddr, srcport, dstaddr, dstport)?
+
+A: No [3.1]::
+
+ >> The IDs of MKTs MUST NOT overlap where their TCP connection
+ identifiers overlap.
+
+Q: Can Master Key Tuple (MKT) for an active connection be removed?
+
+A: No, unless it's copied to Transport Control Block (TCB) [3.1]::
+
+ It is presumed that an MKT affecting a particular connection cannot
+ be destroyed during an active connection -- or, equivalently, that
+ its parameters are copied to an area local to the connection (i.e.,
+ instantiated) and so changes would affect only new connections.
+
+Q: If an old MKT needs to be deleted, how should it be done in order
+to not remove it for an active connection? (As it can be still in use
+at any moment later)
+
+A: Not specified by RFC 5925, seems to be a problem for key management
+to ensure that no one uses such MKT before trying to remove it.
+
+Q: Can an old MKT exist forever and be used by another peer?
+
+A: It can, it's a key management task to decide when to remove an old key [6.1]::
+
+ Deciding when to start using a key is a performance issue. Deciding
+ when to remove an MKT is a security issue. Invalid MKTs are expected
+ to be removed. TCP-AO provides no mechanism to coordinate their removal,
+ as we consider this a key management operation.
+
+also [6.1]::
+
+ The only way to avoid reuse of previously used MKTs is to remove the MKT
+ when it is no longer considered permitted.
+
+Linux TCP-AO will try its best to prevent you from removing a key that's
+being used, considering it a key management failure. But sine keeping
+an outdated key may become a security issue and as a peer may
+unintentionally prevent the removal of an old key by always setting
+it as RNextKeyID - a forced key removal mechanism is provided, where
+userspace has to supply KeyID to use instead of the one that's being removed
+and the kernel will atomically delete the old key, even if the peer is
+still requesting it. There are no guarantees for force-delete as the peer
+may yet not have the new key - the TCP connection may just break.
+Alternatively, one may choose to shut down the socket.
+
+Q: What happens when a packet is received on a new connection with no known
+MKT's RecvID?
+
+A: RFC 5925 specifies that by default it is accepted with a warning logged, but
+the behaviour can be configured by the user [7.5.1.a]::
+
+ If the segment is a SYN, then this is the first segment of a new
+ connection. Find the matching MKT for this segment, using the segment's
+ socket pair and its TCP-AO KeyID, matched against the MKT's TCP connection
+ identifier and the MKT's RecvID.
+
+ i. If there is no matching MKT, remove TCP-AO from the segment.
+ Proceed with further TCP handling of the segment.
+ NOTE: this presumes that connections that do not match any MKT
+ should be silently accepted, as noted in Section 7.3.
+
+[7.3]::
+
+ >> A TCP-AO implementation MUST allow for configuration of the behavior
+ of segments with TCP-AO but that do not match an MKT. The initial default
+ of this configuration SHOULD be to silently accept such connections.
+ If this is not the desired case, an MKT can be included to match such
+ connections, or the connection can indicate that TCP-AO is required.
+ Alternately, the configuration can be changed to discard segments with
+ the AO option not matching an MKT.
+
+[10.2.b]::
+
+ Connections not matching any MKT do not require TCP-AO. Further, incoming
+ segments with TCP-AO are not discarded solely because they include
+ the option, provided they do not match any MKT.
+
+Note that Linux TCP-AO implementation differs in this aspect. Currently, TCP-AO
+segments with unknown key signatures are discarded with warnings logged.
+
+Q: Does the RFC imply centralized kernel key management in any way?
+(i.e. that a key on all connections MUST be rotated at the same time?)
+
+A: Not specified. MKTs can be managed in userspace, the only relevant part to
+key changes is [7.3]::
+
+ >> All TCP segments MUST be checked against the set of MKTs for matching
+ TCP connection identifiers.
+
+Q: What happens when RNextKeyID requested by a peer is unknown? Should
+the connection be reset?
+
+A: It should not, no action needs to be performed [7.5.2.e]::
+
+ ii. If they differ, determine whether the RNextKeyID MKT is ready.
+
+ 1. If the MKT corresponding to the segment’s socket pair and RNextKeyID
+ is not available, no action is required (RNextKeyID of a received
+ segment needs to match the MKT’s SendID).
+
+Q: How current_key is set and when does it change? It is a user-triggered
+change, or is it by a request from the remote peer? Is it set by the user
+explicitly, or by a matching rule?
+
+A: current_key is set by RNextKeyID [6.1]::
+
+ Rnext_key is changed only by manual user intervention or MKT management
+ protocol operation. It is not manipulated by TCP-AO. Current_key is updated
+ by TCP-AO when processing received TCP segments as discussed in the segment
+ processing description in Section 7.5. Note that the algorithm allows
+ the current_key to change to a new MKT, then change back to a previously
+ used MKT (known as "backing up"). This can occur during an MKT change when
+ segments are received out of order, and is considered a feature of TCP-AO,
+ because reordering does not result in drops.
+
+[7.5.2.e.ii]::
+
+ 2. If the matching MKT corresponding to the segment’s socket pair and
+ RNextKeyID is available:
+
+ a. Set current_key to the RNextKeyID MKT.
+
+Q: If both peers have multiple MKTs matching the connection's socket pair
+(with different KeyIDs), how should the sender/receiver pick KeyID to use?
+
+A: Some mechanism should pick the "desired" MKT [3.3]::
+
+ Multiple MKTs may match a single outgoing segment, e.g., when MKTs
+ are being changed. Those MKTs cannot have conflicting IDs (as noted
+ elsewhere), and some mechanism must determine which MKT to use for each
+ given outgoing segment.
+
+ >> An outgoing TCP segment MUST match at most one desired MKT, indicated
+ by the segment’s socket pair. The segment MAY match multiple MKTs, provided
+ that exactly one MKT is indicated as desired. Other information in
+ the segment MAY be used to determine the desired MKT when multiple MKTs
+ match; such information MUST NOT include values in any TCP option fields.
+
+Q: Can TCP-MD5 connection migrate to TCP-AO (and vice-versa):
+
+A: No [1]::
+
+ TCP MD5-protected connections cannot be migrated to TCP-AO because TCP MD5
+ does not support any changes to a connection’s security algorithm
+ once established.
+
+Q: If all MKTs are removed on a connection, can it become a non-TCP-AO signed
+connection?
+
+A: [7.5.2] doesn't have the same choice as SYN packet handling in [7.5.1.i]
+that would allow accepting segments without a sign (which would be insecure).
+While switching to non-TCP-AO connection is not prohibited directly, it seems
+what the RFC means. Also, there's a requirement for TCP-AO connections to
+always have one current_key [3.3]::
+
+ TCP-AO requires that every protected TCP segment match exactly one MKT.
+
+[3.3]::
+
+ >> An incoming TCP segment including TCP-AO MUST match exactly one MKT,
+ indicated solely by the segment’s socket pair and its TCP-AO KeyID.
+
+[4.4]::
+
+ One or more MKTs. These are the MKTs that match this connection’s
+ socket pair.
+
+Q: Can a non-TCP-AO connection become a TCP-AO-enabled one?
+
+A: No: for already established non-TCP-AO connection it would be impossible
+to switch using TCP-AO as the traffic key generation requires the initial
+sequence numbers. Paraphrasing, starting using TCP-AO would require
+re-establishing the TCP connection.
+
+2. In-kernel MKTs database vs database in userspace
+===================================================
+
+Linux TCP-AO support is implemented using ``setsockopt()s``, in a similar way
+to TCP-MD5. It means that a userspace application that wants to use TCP-AO
+should perform ``setsockopt()`` on a TCP socket when it wants to add,
+remove or rotate MKTs. This approach moves the key management responsibility
+to userspace as well as decisions on corner cases, i.e. what to do if
+the peer doesn't respect RNextKeyID; moving more code to userspace, especially
+responsible for the policy decisions. Besides, it's flexible and scales well
+(with less locking needed than in the case of an in-kernel database). One also
+should keep in mind that mainly intended users are BGP processes, not any
+random applications, which means that compared to IPsec tunnels,
+no transparency is really needed and modern BGP daemons already have
+``setsockopt()s`` for TCP-MD5 support.
+
+.. list-table:: Considered pros and cons of the approaches
+
+ * -
+ - ``setsockopt()``
+ - in-kernel DB
+ * - Extendability
+ - ``setsockopt()`` commands should be extendable syscalls
+ - netlink messages are simple and extendable
+ * - Required userspace changes
+ - BGP or any application that wants TCP-AO needs to perform
+ ``setsockopt()s`` and do key management
+ - could be transparent as tunnels, providing something like
+ ``ip tcpao [add|delete|show|rotate] key``
+ * - MKTs removal or adding
+ - harder for userspace
+ - harder for kernel
+ * - Dump-ability
+ - ``getsockopt()``
+ - Netlink .dump() callback
+ * - Limits on kernel resources/memory
+ - equal
+ - equal
+ * - Scalability
+ - contention on ``TCP_LISTEN`` sockets
+ - contention on the whole database
+ * - Monitoring & warnings
+ - ``TCP_DIAG``
+ - Same Netlink socket
+ * - Matching of MKTs
+ - Half-problem: only listen sockets
+ - Hard
+
+3. uAPI
+=======
+
+Linux provides a set of ``setsockopt()s`` and ``getsockopt()s`` that let
+userspace manage TCP-AO on a per-socket basis. In order to add/delete MKTs
+``TCP_AO_ADD_KEY`` and ``TCP_AO_DEL_KEY`` TCP socket options must be used
+It is not allowed to add a key on an established non-TCP-AO connection
+as well as to remove the last key from TCP-AO connection.
+
+``setsockopt(TCP_AO_DEL_KEY)`` command may specify ``tcp_ao_del::current_key``
++ ``tcp_ao_del::set_current`` and/or ``tcp_ao_del::rnext``
++ ``tcp_ao_del::set_rnext`` which makes such delete "forced": it
+provides userspace a way to delete a key that's being used and atomically set
+another one instead. This is not intended for normal use and should be used
+only when the peer ignores RNextKeyID and keeps requesting/using an old key.
+It provides a way to force-delete a key that's not trusted but may break
+the TCP-AO connection.
+
+The usual/normal key-rotation can be performed with ``setsockopt(TCP_AO_INFO)``.
+It also provides a uAPI to change per-socket TCP-AO settings, such as
+ignoring ICMPs, as well as clear per-socket TCP-AO packet counters.
+The corresponding ``getsockopt(TCP_AO_INFO)`` can be used to get those
+per-socket TCP-AO settings.
+
+Another useful command is ``getsockopt(TCP_AO_GET_KEYS)``. One can use it
+to list all MKTs on a TCP socket or use a filter to get keys for a specific
+peer and/or sndid/rcvid, VRF L3 interface or get current_key/rnext_key.
+
+To repair TCP-AO connections ``setsockopt(TCP_AO_REPAIR)`` is available,
+provided that the user previously has checkpointed/dumped the socket with
+``getsockopt(TCP_AO_REPAIR)``.
+
+A tip here for scaled TCP_LISTEN sockets, that may have some thousands TCP-AO
+keys, is: use filters in ``getsockopt(TCP_AO_GET_KEYS)`` and asynchronous
+delete with ``setsockopt(TCP_AO_DEL_KEY)``.
+
+Linux TCP-AO also provides a bunch of segment counters that can be helpful
+with troubleshooting/debugging issues. Every MKT has good/bad counters
+that reflect how many packets passed/failed verification.
+Each TCP-AO socket has the following counters:
+- for good segments (properly signed)
+- for bad segments (failed TCP-AO verification)
+- for segments with unknown keys
+- for segments where an AO signature was expected, but wasn't found
+- for the number of ignored ICMPs
+
+TCP-AO per-socket counters are also duplicated with per-netns counters,
+exposed with SNMP. Those are ``TCPAOGood``, ``TCPAOBad``, ``TCPAOKeyNotFound``,
+``TCPAORequired`` and ``TCPAODroppedIcmps``.
+
+4. ``setsockopt()`` vs ``accept()`` race
+========================================
+
+In contrast with TCP-MD5 established connection which has just one key,
+TCP-AO connections may have many keys, which means that accepted connections
+on a listen socket may have any amount of keys as well. As copying all those
+keys on a first properly signed SYN would make the request socket bigger, that
+would be undesirable. Currently, the implementation doesn't copy keys
+to request sockets, but rather look them up on the "parent" listener socket.
+
+The result is that when userspace removes TCP-AO keys, that may break
+not-yet-established connections on request sockets as well as not removing
+keys from sockets that were already established, but not yet ``accept()``'ed,
+hanging in the accept queue.
+
+The reverse is valid as well: if userspace adds a new key for a peer on
+a listener socket, the established sockets in accept queue won't
+have the new keys.
+
+At this moment, the resolution for the two races:
+``setsockopt(TCP_AO_ADD_KEY)`` vs ``accept()``
+and ``setsockopt(TCP_AO_DEL_KEY)`` vs ``accept()`` is delegated to userspace.
+This means that it's expected that userspace would check the MKTs on the socket
+that was returned by ``accept()`` to verify that any key rotation that
+happened on listen socket is reflected on the newly established connection.
+
+This is a similar "do-nothing" approach to TCP-MD5 from the kernel side and
+may be changed later by introducing new flags to ``tcp_ao_add``
+and ``tcp_ao_del``.
+
+Note that this race is rare for it needs TCP-AO key rotation to happen
+during the 3-way handshake for the new TCP connection.
+
+5. Interaction with TCP-MD5
+===========================
+
+A TCP connection can not migrate between TCP-AO and TCP-MD5 options. The
+established sockets that have either AO or MD5 keys are restricted for
+adding keys of the other option.
+
+For listening sockets the picture is different: BGP server may want to receive
+both TCP-AO and (deprecated) TCP-MD5 clients. As a result, both types of keys
+may be added to TCP_CLOSED or TCP_LISTEN sockets. It's not allowed to add
+different types of keys for the same peer.
+
+6. SNE Linux implementation
+===========================
+
+RFC 5925 [6.2] describes the algorithm of how to extend TCP sequence numbers
+with SNE. In short: TCP has to track the previous sequence numbers and set
+sne_flag when the current SEQ number rolls over. The flag is cleared when
+both current and previous SEQ numbers cross 0x7fff, which is 32Kb.
+
+In times when sne_flag is set, the algorithm compares SEQ for each packet with
+0x7fff and if it's higher than 32Kb, it assumes that the packet should be
+verified with SNE before the increment. As a result, there's
+this [0; 32Kb] window, when packets with (SNE - 1) can be accepted.
+
+Linux implementation simplifies this a bit: as the network stack already tracks
+the first SEQ byte that ACK is wanted for (snd_una) and the next SEQ byte that
+is wanted (rcv_nxt) - that's enough information for a rough estimation
+on where in the 4GB SEQ number space both sender and receiver are.
+When they roll over to zero, the corresponding SNE gets incremented.
+
+tcp_ao_compute_sne() is called for each TCP-AO segment. It compares SEQ numbers
+from the segment with snd_una or rcv_nxt and fits the result into a 2GB window around them,
+detecting SEQ numbers rolling over. That simplifies the code a lot and only
+requires SNE numbers to be stored on every TCP-AO socket.
+
+The 2GB window at first glance seems much more permissive compared to
+RFC 5926. But that is only used to pick the correct SNE before/after
+a rollover. It allows more TCP segment replays, but yet all regular
+TCP checks in tcp_sequence() are applied on the verified segment.
+So, it trades a bit more permissive acceptance of replayed/retransmitted
+segments for the simplicity of the algorithm and what seems better behaviour
+for large TCP windows.
+
+7. Links
+========
+
+RFC 5925 The TCP Authentication Option
+ https://www.rfc-editor.org/rfc/pdfrfc/rfc5925.txt.pdf
+
+RFC 5926 Cryptographic Algorithms for the TCP Authentication Option (TCP-AO)
+ https://www.rfc-editor.org/rfc/pdfrfc/rfc5926.txt.pdf
+
+Draft "SHA-2 Algorithm for the TCP Authentication Option (TCP-AO)"
+ https://datatracker.ietf.org/doc/html/draft-nayak-tcp-sha2-03
+
+RFC 2385 Protection of BGP Sessions via the TCP MD5 Signature Option
+ https://www.rfc-editor.org/rfc/pdfrfc/rfc2385.txt.pdf
+
+:Author: Dmitry Safonov <[email protected]>
--
2.41.0
Add support for sockets in time-wait state.
ao_info as well as all keys are inherited on transition to time-wait
socket. The lifetime of ao_info is now protected by ref counter, so
that tcp_ao_destroy_sock() will destruct it only when the last user is
gone.
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/linux/tcp.h | 3 ++
include/net/tcp_ao.h | 11 ++++++--
net/ipv4/tcp_ao.c | 46 +++++++++++++++++++++++++-----
net/ipv4/tcp_ipv4.c | 61 ++++++++++++++++++++++++++++++++++++----
net/ipv4/tcp_minisocks.c | 4 ++-
net/ipv4/tcp_output.c | 2 +-
net/ipv6/tcp_ipv6.c | 41 ++++++++++++++++++++++++---
7 files changed, 147 insertions(+), 21 deletions(-)
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 9eb15e798c32..bbc7db92f37c 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -502,6 +502,9 @@ struct tcp_timewait_sock {
#ifdef CONFIG_TCP_MD5SIG
struct tcp_md5sig_key *tw_md5_key;
#endif
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_info *ao_info;
+#endif
};
static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk)
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 6e8567b5bbf8..7f6849f16d7a 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -86,6 +86,7 @@ struct tcp_ao_info {
__unused :31;
__be32 lisn;
__be32 risn;
+ atomic_t refcnt; /* Protects twsk destruction */
struct rcu_head rcu;
};
@@ -121,7 +122,8 @@ struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao,
int sndid, int rcvid);
int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
unsigned int len, struct tcp_sigpool *hp);
-void tcp_ao_destroy_sock(struct sock *sk);
+void tcp_ao_destroy_sock(struct sock *sk, bool twsk);
+void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp);
struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
const union tcp_ao_addr *addr,
int family, int sndid, int rcvid, u16 port);
@@ -174,7 +176,7 @@ static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
return NULL;
}
-static inline void tcp_ao_destroy_sock(struct sock *sk)
+static inline void tcp_ao_destroy_sock(struct sock *sk, bool twsk)
{
}
@@ -182,6 +184,11 @@ static inline void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb)
{
}
+static inline void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw,
+ struct tcp_sock *tp)
+{
+}
+
static inline void tcp_ao_connect_init(struct sock *sk)
{
}
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index b8b2e9caa096..dc1423239160 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -161,6 +161,7 @@ static struct tcp_ao_info *tcp_ao_alloc_info(gfp_t flags)
if (!ao)
return NULL;
INIT_HLIST_HEAD(&ao->head);
+ atomic_set(&ao->refcnt, 1);
return ao;
}
@@ -178,27 +179,54 @@ static void tcp_ao_key_free_rcu(struct rcu_head *head)
kfree(key);
}
-void tcp_ao_destroy_sock(struct sock *sk)
+void tcp_ao_destroy_sock(struct sock *sk, bool twsk)
{
struct tcp_ao_info *ao;
struct tcp_ao_key *key;
struct hlist_node *n;
- ao = rcu_dereference_protected(tcp_sk(sk)->ao_info, 1);
- tcp_sk(sk)->ao_info = NULL;
+ if (twsk) {
+ ao = rcu_dereference_protected(tcp_twsk(sk)->ao_info, 1);
+ tcp_twsk(sk)->ao_info = NULL;
+ } else {
+ ao = rcu_dereference_protected(tcp_sk(sk)->ao_info, 1);
+ tcp_sk(sk)->ao_info = NULL;
+ }
- if (!ao)
+ if (!ao || !atomic_dec_and_test(&ao->refcnt))
return;
hlist_for_each_entry_safe(key, n, &ao->head, node) {
hlist_del_rcu(&key->node);
- atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
+ if (!twsk)
+ atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
call_rcu(&key->rcu, tcp_ao_key_free_rcu);
}
kfree_rcu(ao, rcu);
}
+void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp)
+{
+ struct tcp_ao_info *ao_info = rcu_dereference_protected(tp->ao_info, 1);
+
+ if (ao_info) {
+ struct tcp_ao_key *key;
+ struct hlist_node *n;
+ int omem = 0;
+
+ hlist_for_each_entry_safe(key, n, &ao_info->head, node) {
+ omem += tcp_ao_sizeof_key(key);
+ }
+
+ atomic_inc(&ao_info->refcnt);
+ atomic_sub(omem, &(((struct sock *)tp)->sk_omem_alloc));
+ rcu_assign_pointer(tcptw->ao_info, ao_info);
+ } else {
+ tcptw->ao_info = NULL;
+ }
+}
+
/* 4 tuple and ISNs are expected in NBO */
static int tcp_v4_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
__be32 saddr, __be32 daddr,
@@ -522,8 +550,9 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
struct tcp_ao_key *rnext_key;
if (sk->sk_state == TCP_TIME_WAIT)
- return -1;
- ao_info = rcu_dereference(tcp_sk(sk)->ao_info);
+ ao_info = rcu_dereference(tcp_twsk(sk)->ao_info);
+ else
+ ao_info = rcu_dereference(tcp_sk(sk)->ao_info);
if (!ao_info)
return -ENOENT;
@@ -880,6 +909,9 @@ static struct tcp_ao_info *setsockopt_ao_info(struct sock *sk)
if (sk_fullsock(sk)) {
return rcu_dereference_protected(tcp_sk(sk)->ao_info,
lockdep_sock_is_held(sk));
+ } else if (sk->sk_state == TCP_TIME_WAIT) {
+ return rcu_dereference_protected(tcp_twsk(sk)->ao_info,
+ lockdep_sock_is_held(sk));
}
return ERR_PTR(-ESOCKTNOSUPPORT);
}
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index ee14a2405801..3e5aa89ec3ae 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -912,16 +912,16 @@ static void tcp_v4_send_ack(const struct sock *sk,
struct sk_buff *skb, u32 seq, u32 ack,
u32 win, u32 tsval, u32 tsecr, int oif,
struct tcp_md5sig_key *key,
+ struct tcp_ao_key *ao_key,
+ u8 *traffic_key,
+ u8 rcv_next,
+ u32 ao_sne,
int reply_flags, u8 tos, u32 txhash)
{
const struct tcphdr *th = tcp_hdr(skb);
struct {
struct tcphdr th;
- __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2)
-#ifdef CONFIG_TCP_MD5SIG
- + (TCPOLEN_MD5SIG_ALIGNED >> 2)
-#endif
- ];
+ __be32 opt[(MAX_TCP_OPTION_SPACE >> 2)];
} rep;
struct net *net = sock_net(sk);
struct ip_reply_arg arg;
@@ -966,6 +966,24 @@ static void tcp_v4_send_ack(const struct sock *sk,
key, ip_hdr(skb)->saddr,
ip_hdr(skb)->daddr, &rep.th);
}
+#endif
+#ifdef CONFIG_TCP_AO
+ if (ao_key) {
+ int offset = (tsecr) ? 3 : 0;
+
+ rep.opt[offset++] = htonl((TCPOPT_AO << 24) |
+ (tcp_ao_len(ao_key) << 16) |
+ (ao_key->sndid << 8) | rcv_next);
+ arg.iov[0].iov_len += round_up(tcp_ao_len(ao_key), 4);
+ rep.th.doff = arg.iov[0].iov_len / 4;
+
+ tcp_ao_hash_hdr(AF_INET, (char *)&rep.opt[offset],
+ ao_key, traffic_key,
+ (union tcp_ao_addr *)&ip_hdr(skb)->saddr,
+ (union tcp_ao_addr *)&ip_hdr(skb)->daddr,
+ &rep.th, ao_sne);
+ }
+ WARN_ON_ONCE(key && ao_key);
#endif
arg.flags = reply_flags;
arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
@@ -999,6 +1017,32 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
{
struct inet_timewait_sock *tw = inet_twsk(sk);
struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
+ struct tcp_ao_key *ao_key = NULL;
+ u8 *traffic_key = NULL;
+ u8 rcv_next = 0;
+ u32 ao_sne = 0;
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_info *ao_info;
+
+ /* FIXME: the segment to-be-acked is not verified yet */
+ ao_info = rcu_dereference(tcptw->ao_info);
+ if (ao_info) {
+ const struct tcp_ao_hdr *aoh;
+
+ if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
+ goto out; /* something is wrong with the sign */
+
+ if (aoh)
+ ao_key = tcp_ao_established_key(ao_info, aoh->rnext_keyid, -1);
+ }
+ if (ao_key) {
+ struct tcp_ao_key *rnext_key;
+
+ traffic_key = snd_other_key(ao_key);
+ rnext_key = READ_ONCE(ao_info->rnext_key);
+ rcv_next = rnext_key->rcvid;
+ }
+#endif
tcp_v4_send_ack(sk, skb,
tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
@@ -1007,11 +1051,15 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
tcptw->tw_ts_recent,
tw->tw_bound_dev_if,
tcp_twsk_md5_key(tcptw),
+ ao_key, traffic_key, rcv_next, ao_sne,
tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0,
tw->tw_tos,
tw->tw_txhash
);
+#ifdef CONFIG_TCP_AO
+out:
+#endif
inet_twsk_put(tw);
}
@@ -1041,6 +1089,7 @@ static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
READ_ONCE(req->ts_recent),
0,
tcp_md5_do_lookup(sk, l3index, addr, AF_INET),
+ NULL, NULL, 0, 0,
inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0,
ip_hdr(skb)->tos,
READ_ONCE(tcp_rsk(req)->txhash));
@@ -2402,7 +2451,7 @@ void tcp_v4_destroy_sock(struct sock *sk)
rcu_assign_pointer(tp->md5sig_info, NULL);
}
#endif
- tcp_ao_destroy_sock(sk);
+ tcp_ao_destroy_sock(sk, false);
/* Clean up a referenced TCP bind bucket. */
if (inet_csk(sk)->icsk_bind_hash)
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 5616b6a34bee..3033f3187079 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -279,7 +279,7 @@ static void tcp_time_wait_init(struct sock *sk, struct tcp_timewait_sock *tcptw)
void tcp_time_wait(struct sock *sk, int state, int timeo)
{
const struct inet_connection_sock *icsk = inet_csk(sk);
- const struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_sock *tp = tcp_sk(sk);
struct net *net = sock_net(sk);
struct inet_timewait_sock *tw;
@@ -316,6 +316,7 @@ void tcp_time_wait(struct sock *sk, int state, int timeo)
#endif
tcp_time_wait_init(sk, tcptw);
+ tcp_ao_time_wait(tcptw, tp);
/* Get the TIME_WAIT timeout firing. */
if (timeo < rto)
@@ -370,6 +371,7 @@ void tcp_twsk_destructor(struct sock *sk)
call_rcu(&twsk->tw_md5_key->rcu, tcp_md5_twsk_free_rcu);
}
#endif
+ tcp_ao_destroy_sock(sk, true);
}
EXPORT_SYMBOL_GPL(tcp_twsk_destructor);
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 813d865095ac..0d74bb4460a6 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -4059,7 +4059,7 @@ int tcp_connect(struct sock *sk)
* then free up ao_info if allocated.
*/
if (needs_md5) {
- tcp_ao_destroy_sock(sk);
+ tcp_ao_destroy_sock(sk, false);
} else if (needs_ao) {
tcp_clear_md5_list(sk);
kfree(rcu_replace_pointer(tp->md5sig_info, NULL,
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index bc4ef00621b4..30db3fcab1ff 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1137,24 +1137,57 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
struct tcp_md5sig_key *key, u8 tclass,
- __be32 label, u32 priority, u32 txhash)
+ __be32 label, u32 priority, u32 txhash,
+ struct tcp_ao_key *ao_key, char *tkey,
+ u8 rcv_next, u32 ao_sne)
{
tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
- tclass, label, priority, txhash, NULL, NULL, 0, 0);
+ tclass, label, priority, txhash,
+ ao_key, tkey, rcv_next, ao_sne);
}
static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
{
struct inet_timewait_sock *tw = inet_twsk(sk);
struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
+ struct tcp_ao_key *ao_key = NULL;
+ u8 *traffic_key = NULL;
+ u8 rcv_next = 0;
+ u32 ao_sne = 0;
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_info *ao_info;
+
+ /* FIXME: the segment to-be-acked is not verified yet */
+ ao_info = rcu_dereference(tcptw->ao_info);
+ if (ao_info) {
+ const struct tcp_ao_hdr *aoh;
+
+ /* Invalid TCP option size or twice included auth */
+ if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
+ goto out;
+ if (aoh)
+ ao_key = tcp_ao_established_key(ao_info, aoh->rnext_keyid, -1);
+ }
+ if (ao_key) {
+ struct tcp_ao_key *rnext_key;
+
+ traffic_key = snd_other_key(ao_key);
+ /* rcv_next switches to our rcv_next */
+ rnext_key = READ_ONCE(ao_info->rnext_key);
+ rcv_next = rnext_key->rcvid;
+ }
+#endif
tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
tcp_time_stamp_raw() + tcptw->tw_ts_offset,
tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority,
- tw->tw_txhash);
+ tw->tw_txhash, ao_key, traffic_key, rcv_next, ao_sne);
+#ifdef CONFIG_TCP_AO
+out:
+#endif
inet_twsk_put(tw);
}
@@ -1181,7 +1214,7 @@ static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
READ_ONCE(req->ts_recent), sk->sk_bound_dev_if,
tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index),
ipv6_get_dsfield(ipv6_hdr(skb)), 0, sk->sk_priority,
- READ_ONCE(tcp_rsk(req)->txhash));
+ READ_ONCE(tcp_rsk(req)->txhash), NULL, NULL, 0, 0);
}
--
2.41.0
Introduce a helper that:
(1) shares the common code with TCP-MD5 header options parsing
(2) looks for hash signature only once for both TCP-MD5 and TCP-AO
(3) fails with -EEXIST if any TCP sign option is present twice, see
RFC5925 (2.2):
">> A single TCP segment MUST NOT have more than one TCP-AO in its
options sequence. When multiple TCP-AOs appear, TCP MUST discard
the segment."
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/dropreason-core.h | 6 ++++++
include/net/tcp.h | 24 ++++++++++++++++++++-
include/net/tcp_ao.h | 17 ++++++++++++++-
net/ipv4/tcp.c | 3 ++-
net/ipv4/tcp_input.c | 39 ++++++++++++++++++++++++++---------
net/ipv4/tcp_ipv4.c | 15 +++++++++-----
net/ipv6/tcp_ipv6.c | 11 ++++++----
7 files changed, 93 insertions(+), 22 deletions(-)
diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
index f291a3b0f9e5..05255bffa2c8 100644
--- a/include/net/dropreason-core.h
+++ b/include/net/dropreason-core.h
@@ -20,6 +20,7 @@
FN(IP_NOPROTO) \
FN(SOCKET_RCVBUFF) \
FN(PROTO_MEM) \
+ FN(TCP_AUTH_HDR) \
FN(TCP_MD5NOTFOUND) \
FN(TCP_MD5UNEXPECTED) \
FN(TCP_MD5FAILURE) \
@@ -140,6 +141,11 @@ enum skb_drop_reason {
* drop out of udp_memory_allocated.
*/
SKB_DROP_REASON_PROTO_MEM,
+ /**
+ * @SKB_DROP_REASON_TCP_AUTH_HDR: TCP-MD5 or TCP-AO hashes are met
+ * twice or set incorrectly.
+ */
+ SKB_DROP_REASON_TCP_AUTH_HDR,
/**
* @SKB_DROP_REASON_TCP_MD5NOTFOUND: no MD5 hash and one expected,
* corresponding to LINUX_MIB_TCPMD5NOTFOUND
diff --git a/include/net/tcp.h b/include/net/tcp.h
index d4344cc39893..17991a6848ff 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -428,7 +428,6 @@ int tcp_mmap(struct file *file, struct socket *sock,
void tcp_parse_options(const struct net *net, const struct sk_buff *skb,
struct tcp_options_received *opt_rx,
int estab, struct tcp_fastopen_cookie *foc);
-const u8 *tcp_parse_md5sig_option(const struct tcphdr *th);
/*
* BPF SKB-less helpers
@@ -2571,6 +2570,29 @@ static inline u64 tcp_transmit_time(const struct sock *sk)
return 0;
}
+static inline int tcp_parse_auth_options(const struct tcphdr *th,
+ const u8 **md5_hash, const struct tcp_ao_hdr **aoh)
+{
+ const u8 *md5_tmp, *ao_tmp;
+ int ret;
+
+ ret = tcp_do_parse_auth_options(th, &md5_tmp, &ao_tmp);
+ if (ret)
+ return ret;
+
+ if (md5_hash)
+ *md5_hash = md5_tmp;
+
+ if (aoh) {
+ if (!ao_tmp)
+ *aoh = NULL;
+ else
+ *aoh = (struct tcp_ao_hdr *)(ao_tmp - 2);
+ }
+
+ return 0;
+}
+
static inline bool tcp_ao_required(struct sock *sk, const void *saddr,
int family)
{
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 8d61f2690d52..e97dfdc11451 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -150,7 +150,9 @@ int tcp_v6_parse_ao(struct sock *sk, int cmd,
sockptr_t optval, int optlen);
void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb);
void tcp_ao_connect_init(struct sock *sk);
-
+void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
+ struct tcp_request_sock *treq,
+ unsigned short int family);
#else /* CONFIG_TCP_AO */
static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
@@ -173,4 +175,17 @@ static inline void tcp_ao_connect_init(struct sock *sk)
}
#endif
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
+int tcp_do_parse_auth_options(const struct tcphdr *th,
+ const u8 **md5_hash, const u8 **ao_hash);
+#else
+static int tcp_do_parse_auth_options(const struct tcphdr *th,
+ const u8 **md5_hash, const u8 **ao_hash)
+{
+ *md5_hash = NULL;
+ *ao_hash = NULL;
+ return 0;
+}
+#endif
+
#endif /* _TCP_AO_H */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index d0b0565fa11e..c90b3c6df620 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -4395,7 +4395,8 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
l3index = sdif ? dif : 0;
hash_expected = tcp_md5_do_lookup(sk, l3index, saddr, family);
- hash_location = tcp_parse_md5sig_option(th);
+ if (tcp_parse_auth_options(th, &hash_location, NULL))
+ return SKB_DROP_REASON_TCP_AUTH_HDR;
/* We've parsed the options - do we have a hash? */
if (!hash_expected && !hash_location)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 7780ceef3415..d9241385468a 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4212,39 +4212,58 @@ static bool tcp_fast_parse_options(const struct net *net,
return true;
}
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
/*
- * Parse MD5 Signature option
+ * Parse Signature options
*/
-const u8 *tcp_parse_md5sig_option(const struct tcphdr *th)
+int tcp_do_parse_auth_options(const struct tcphdr *th,
+ const u8 **md5_hash, const u8 **ao_hash)
{
int length = (th->doff << 2) - sizeof(*th);
const u8 *ptr = (const u8 *)(th + 1);
+ unsigned int minlen = TCPOLEN_MD5SIG;
+
+ if (IS_ENABLED(CONFIG_TCP_AO))
+ minlen = sizeof(struct tcp_ao_hdr) + 1;
+
+ *md5_hash = NULL;
+ *ao_hash = NULL;
/* If not enough data remaining, we can short cut */
- while (length >= TCPOLEN_MD5SIG) {
+ while (length >= minlen) {
int opcode = *ptr++;
int opsize;
switch (opcode) {
case TCPOPT_EOL:
- return NULL;
+ return 0;
case TCPOPT_NOP:
length--;
continue;
default:
opsize = *ptr++;
if (opsize < 2 || opsize > length)
- return NULL;
- if (opcode == TCPOPT_MD5SIG)
- return opsize == TCPOLEN_MD5SIG ? ptr : NULL;
+ return -EINVAL;
+ if (opcode == TCPOPT_MD5SIG) {
+ if (opsize != TCPOLEN_MD5SIG)
+ return -EINVAL;
+ if (unlikely(*md5_hash || *ao_hash))
+ return -EEXIST;
+ *md5_hash = ptr;
+ } else if (opcode == TCPOPT_AO) {
+ if (opsize <= sizeof(struct tcp_ao_hdr))
+ return -EINVAL;
+ if (unlikely(*md5_hash || *ao_hash))
+ return -EEXIST;
+ *ao_hash = ptr;
+ }
}
ptr += opsize - 2;
length -= opsize;
}
- return NULL;
+ return 0;
}
-EXPORT_SYMBOL(tcp_parse_md5sig_option);
+EXPORT_SYMBOL(tcp_do_parse_auth_options);
#endif
/* Sorry, PAWS as specified is broken wrt. pure-ACKs -DaveM
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 8222f14e4c32..0e9c6cfd4ab2 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -670,7 +670,9 @@ EXPORT_SYMBOL(tcp_v4_send_check);
* Exception: precedence violation. We do not implement it in any case.
*/
-#ifdef CONFIG_TCP_MD5SIG
+#ifdef CONFIG_TCP_AO
+#define OPTION_BYTES MAX_TCP_OPTION_SPACE
+#elif defined(CONFIG_TCP_MD5SIG)
#define OPTION_BYTES TCPOLEN_MD5SIG_ALIGNED
#else
#define OPTION_BYTES sizeof(__be32)
@@ -686,7 +688,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
struct ip_reply_arg arg;
#ifdef CONFIG_TCP_MD5SIG
struct tcp_md5sig_key *key = NULL;
- const __u8 *hash_location = NULL;
+ const __u8 *md5_hash_location = NULL;
unsigned char newhash[16];
int genhash;
struct sock *sk1 = NULL;
@@ -727,8 +729,11 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
#ifdef CONFIG_TCP_MD5SIG
+ /* Invalid TCP option size or twice included auth */
+ if (tcp_parse_auth_options(tcp_hdr(skb), &md5_hash_location, NULL))
+ return;
+
rcu_read_lock();
- hash_location = tcp_parse_md5sig_option(th);
if (sk && sk_fullsock(sk)) {
const union tcp_md5_addr *addr;
int l3index;
@@ -739,7 +744,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0;
addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr;
key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
- } else if (hash_location) {
+ } else if (md5_hash_location) {
const union tcp_md5_addr *addr;
int sdif = tcp_v4_sdif(skb);
int dif = inet_iif(skb);
@@ -771,7 +776,7 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb);
- if (genhash || memcmp(hash_location, newhash, 16) != 0)
+ if (genhash || memcmp(md5_hash_location, newhash, 16) != 0)
goto out;
}
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 1dd7c8f3aff4..4c645160362e 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -989,7 +989,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
u32 seq = 0, ack_seq = 0;
struct tcp_md5sig_key *key = NULL;
#ifdef CONFIG_TCP_MD5SIG
- const __u8 *hash_location = NULL;
+ const __u8 *md5_hash_location = NULL;
unsigned char newhash[16];
int genhash;
struct sock *sk1 = NULL;
@@ -1011,8 +1011,11 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
#ifdef CONFIG_TCP_MD5SIG
+ /* Invalid TCP option size or twice included auth */
+ if (tcp_parse_auth_options(th, &md5_hash_location, NULL))
+ return;
+
rcu_read_lock();
- hash_location = tcp_parse_md5sig_option(th);
if (sk && sk_fullsock(sk)) {
int l3index;
@@ -1021,7 +1024,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
*/
l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index);
- } else if (hash_location) {
+ } else if (md5_hash_location) {
int dif = tcp_v6_iif_l3_slave(skb);
int sdif = tcp_v6_sdif(skb);
int l3index;
@@ -1050,7 +1053,7 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
goto out;
genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
- if (genhash || memcmp(hash_location, newhash, 16) != 0)
+ if (genhash || memcmp(md5_hash_location, newhash, 16) != 0)
goto out;
}
#endif
--
2.41.0
Add TCP_AO_REPAIR setsockopt(), getsockopt(). They let a user to repair
TCP-AO ISNs/SNEs. Also let the user hack around when (tp->repair) is on
and add ao_info on a socket in any supported state.
As SNEs now can be read/written at any moment, use
WRITE_ONCE()/READ_ONCE() to set/read them.
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/tcp_ao.h | 14 ++++++
include/uapi/linux/tcp.h | 8 ++++
net/ipv4/tcp.c | 24 ++++++++---
net/ipv4/tcp_ao.c | 92 ++++++++++++++++++++++++++++++++++++++--
4 files changed, 127 insertions(+), 11 deletions(-)
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index b56b49a98266..0027f4b4683d 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -196,6 +196,8 @@ void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp);
bool tcp_ao_ignore_icmp(struct sock *sk, int type, int code);
int tcp_ao_get_mkts(struct sock *sk, sockptr_t optval, sockptr_t optlen);
int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockptr_t optlen);
+int tcp_ao_get_repair(struct sock *sk, sockptr_t optval, sockptr_t optlen);
+int tcp_ao_set_repair(struct sock *sk, sockptr_t optval, unsigned int optlen);
enum skb_drop_reason tcp_inbound_ao_hash(struct sock *sk,
const struct sk_buff *skb, unsigned short int family,
const struct request_sock *req, int l3index,
@@ -317,6 +319,18 @@ static inline int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockpt
{
return -ENOPROTOOPT;
}
+
+static inline int tcp_ao_get_repair(struct sock *sk,
+ sockptr_t optval, sockptr_t optlen)
+{
+ return -ENOPROTOOPT;
+}
+
+static inline int tcp_ao_set_repair(struct sock *sk,
+ sockptr_t optval, unsigned int optlen)
+{
+ return -ENOPROTOOPT;
+}
#endif
#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 979ff960fddb..624198fa170d 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -133,6 +133,7 @@ enum {
#define TCP_AO_DEL_KEY 39 /* Delete MKT */
#define TCP_AO_INFO 40 /* Set/list TCP-AO per-socket options */
#define TCP_AO_GET_KEYS 41 /* List MKT(s) */
+#define TCP_AO_REPAIR 42 /* Get/Set SNEs and ISNs */
#define TCP_REPAIR_ON 1
#define TCP_REPAIR_OFF 0
@@ -445,6 +446,13 @@ struct tcp_ao_getsockopt { /* getsockopt(TCP_AO_GET_KEYS) */
__u64 pkt_bad; /* out: segments that failed verification */
} __attribute__((aligned(8)));
+struct tcp_ao_repair { /* {s,g}etsockopt(TCP_AO_REPAIR) */
+ __be32 snt_isn;
+ __be32 rcv_isn;
+ __u32 snd_sne;
+ __u32 rcv_sne;
+} __attribute__((aligned(8)));
+
/* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */
#define TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT 0x1
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 82506300da6c..95c9d3c9134e 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3608,20 +3608,28 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname,
__tcp_sock_set_quickack(sk, val);
break;
+ case TCP_AO_REPAIR:
+ err = tcp_ao_set_repair(sk, optval, optlen);
+ break;
#ifdef CONFIG_TCP_AO
case TCP_AO_ADD_KEY:
case TCP_AO_DEL_KEY:
case TCP_AO_INFO: {
/* If this is the first TCP-AO setsockopt() on the socket,
- * sk_state has to be LISTEN or CLOSE
+ * sk_state has to be LISTEN or CLOSE. Allow TCP_REPAIR
+ * in any state.
*/
- if (((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) ||
- rcu_dereference_protected(tcp_sk(sk)->ao_info,
+ if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
+ goto ao_parse;
+ if (rcu_dereference_protected(tcp_sk(sk)->ao_info,
lockdep_sock_is_held(sk)))
- err = tp->af_specific->ao_parse(sk, optname, optval,
- optlen);
- else
- err = -EISCONN;
+ goto ao_parse;
+ if (tp->repair)
+ goto ao_parse;
+ err = -EISCONN;
+ break;
+ao_parse:
+ err = tp->af_specific->ao_parse(sk, optname, optval, optlen);
break;
}
#endif
@@ -4289,6 +4297,8 @@ int do_tcp_getsockopt(struct sock *sk, int level,
return err;
}
#endif
+ case TCP_AO_REPAIR:
+ return tcp_ao_get_repair(sk, optval, optlen);
case TCP_AO_GET_KEYS:
case TCP_AO_INFO: {
int err;
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 3490b590bff0..70ff7822f57a 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -1463,6 +1463,16 @@ static struct tcp_ao_info *setsockopt_ao_info(struct sock *sk)
return ERR_PTR(-ESOCKTNOSUPPORT);
}
+static struct tcp_ao_info *getsockopt_ao_info(struct sock *sk)
+{
+ if (sk_fullsock(sk))
+ return rcu_dereference(tcp_sk(sk)->ao_info);
+ else if (sk->sk_state == TCP_TIME_WAIT)
+ return rcu_dereference(tcp_twsk(sk)->ao_info);
+
+ return ERR_PTR(-ESOCKTNOSUPPORT);
+}
+
#define TCP_AO_KEYF_ALL (TCP_AO_KEYF_IFINDEX | TCP_AO_KEYF_EXCLUDE_OPT)
#define TCP_AO_GET_KEYF_VALID (TCP_AO_KEYF_IFINDEX)
@@ -1647,11 +1657,13 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
if (ret < 0)
goto err_free_sock;
- /* Change this condition if we allow adding keys in states
- * like close_wait, syn_sent or fin_wait...
- */
- if (sk->sk_state == TCP_ESTABLISHED)
+ if (!((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))) {
tcp_ao_cache_traffic_keys(sk, ao_info, key);
+ if (first) {
+ ao_info->current_key = key;
+ ao_info->rnext_key = key;
+ }
+ }
tcp_ao_link_mkt(ao_info, key);
if (first) {
@@ -1899,6 +1911,8 @@ static int tcp_ao_info_cmd(struct sock *sk, unsigned short int family,
if (IS_ERR(ao_info))
return PTR_ERR(ao_info);
if (!ao_info) {
+ if (!((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)))
+ return -EINVAL;
ao_info = tcp_ao_alloc_info(GFP_KERNEL);
if (!ao_info)
return -ENOMEM;
@@ -2281,3 +2295,73 @@ int tcp_ao_get_sock_info(struct sock *sk, sockptr_t optval, sockptr_t optlen)
return 0;
}
+int tcp_ao_set_repair(struct sock *sk, sockptr_t optval, unsigned int optlen)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_ao_repair cmd;
+ struct tcp_ao_key *key;
+ struct tcp_ao_info *ao;
+ int err;
+
+ if (optlen < sizeof(cmd))
+ return -EINVAL;
+
+ err = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
+ if (err)
+ return err;
+
+ if (!tp->repair)
+ return -EPERM;
+
+ ao = setsockopt_ao_info(sk);
+ if (IS_ERR(ao))
+ return PTR_ERR(ao);
+ if (!ao)
+ return -ENOENT;
+
+ WRITE_ONCE(ao->lisn, cmd.snt_isn);
+ WRITE_ONCE(ao->risn, cmd.rcv_isn);
+ WRITE_ONCE(ao->snd_sne, cmd.snd_sne);
+ WRITE_ONCE(ao->rcv_sne, cmd.rcv_sne);
+
+ hlist_for_each_entry_rcu(key, &ao->head, node)
+ tcp_ao_cache_traffic_keys(sk, ao, key);
+
+ return 0;
+}
+
+int tcp_ao_get_repair(struct sock *sk, sockptr_t optval, sockptr_t optlen)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct tcp_ao_repair opt;
+ struct tcp_ao_info *ao;
+ int len;
+
+ if (copy_from_sockptr(&len, optlen, sizeof(int)))
+ return -EFAULT;
+
+ if (len <= 0)
+ return -EINVAL;
+
+ if (!tp->repair)
+ return -EPERM;
+
+ rcu_read_lock();
+ ao = getsockopt_ao_info(sk);
+ if (IS_ERR(ao))
+ return PTR_ERR(ao);
+ if (!ao) {
+ rcu_read_unlock();
+ return -ENOENT;
+ }
+
+ opt.snt_isn = ao->lisn;
+ opt.rcv_isn = ao->risn;
+ opt.snd_sne = READ_ONCE(ao->snd_sne);
+ opt.rcv_sne = READ_ONCE(ao->rcv_sne);
+ rcu_read_unlock();
+
+ if (copy_to_sockptr(optval, &opt, min_t(int, len, sizeof(opt))))
+ return -EFAULT;
+ return 0;
+}
--
2.41.0
Similarly to TCP-MD5, add a static key to TCP-AO that is patched out
when there are no keys on a machine and dynamically enabled with the
first setsockopt(TCP_AO) adds a key on any socket. The static key is as
well dynamically disabled later when the socket is destructed.
The lifetime of enabled static key here is the same as ao_info: it is
enabled on allocation, passed over from full socket to twsk and
destructed when ao_info is scheduled for destruction.
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/tcp.h | 3 +++
include/net/tcp_ao.h | 2 ++
net/ipv4/tcp_ao.c | 22 +++++++++++++++++++++
net/ipv4/tcp_input.c | 46 +++++++++++++++++++++++++++++---------------
4 files changed, 57 insertions(+), 16 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 50636ee7ee2f..4df3ee6e2722 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2611,6 +2611,9 @@ static inline bool tcp_ao_required(struct sock *sk, const void *saddr,
struct tcp_ao_info *ao_info;
struct tcp_ao_key *ao_key;
+ if (!static_branch_unlikely(&tcp_ao_needed.key))
+ return false;
+
ao_info = rcu_dereference_check(tcp_sk(sk)->ao_info,
lockdep_sock_is_held(sk));
if (!ao_info)
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 9209343878e1..e6d849d7179e 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -152,6 +152,8 @@ do { \
#ifdef CONFIG_TCP_AO
/* TCP-AO structures and functions */
+#include <linux/jump_label.h>
+extern struct static_key_false_deferred tcp_ao_needed;
struct tcp4_ao_context {
__be32 saddr;
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 567aa9400f7d..54b35ee1edf1 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -17,6 +17,8 @@
#include <net/ipv6.h>
#include <net/icmp.h>
+DEFINE_STATIC_KEY_DEFERRED_FALSE(tcp_ao_needed, HZ);
+
int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
unsigned int len, struct tcp_sigpool *hp)
{
@@ -50,6 +52,9 @@ bool tcp_ao_ignore_icmp(struct sock *sk, int type, int code)
struct tcp_ao_info *ao;
bool ignore_icmp = false;
+ if (!static_branch_unlikely(&tcp_ao_needed.key))
+ return false;
+
/* RFC5925, 7.8:
* >> A TCP-AO implementation MUST default to ignore incoming ICMPv4
* messages of Type 3 (destination unreachable), Codes 2-4 (protocol
@@ -188,6 +193,9 @@ static struct tcp_ao_key *__tcp_ao_do_lookup(const struct sock *sk,
struct tcp_ao_key *key;
struct tcp_ao_info *ao;
+ if (!static_branch_unlikely(&tcp_ao_needed.key))
+ return NULL;
+
ao = rcu_dereference_check(tcp_sk(sk)->ao_info,
lockdep_sock_is_held(sk));
if (!ao)
@@ -281,6 +289,7 @@ void tcp_ao_destroy_sock(struct sock *sk, bool twsk)
}
kfree_rcu(ao, rcu);
+ static_branch_slow_dec_deferred(&tcp_ao_needed);
}
void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp)
@@ -1142,6 +1151,11 @@ int tcp_ao_copy_all_matching(const struct sock *sk, struct sock *newsk,
goto free_and_exit;
}
+ if (!static_key_fast_inc_not_disabled(&tcp_ao_needed.key.key)) {
+ ret = -EUSERS;
+ goto free_and_exit;
+ }
+
key_head = rcu_dereference(hlist_first_rcu(&new_ao->head));
first_key = hlist_entry_safe(key_head, struct tcp_ao_key, node);
@@ -1585,6 +1599,10 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
tcp_ao_link_mkt(ao_info, key);
if (first) {
+ if (!static_branch_inc(&tcp_ao_needed.key)) {
+ ret = -EUSERS;
+ goto err_free_sock;
+ }
sk_gso_disable(sk);
rcu_assign_pointer(tcp_sk(sk)->ao_info, ao_info);
}
@@ -1850,6 +1868,10 @@ static int tcp_ao_info_cmd(struct sock *sk, unsigned short int family,
if (new_rnext)
WRITE_ONCE(ao_info->rnext_key, new_rnext);
if (first) {
+ if (!static_branch_inc(&tcp_ao_needed.key)) {
+ err = -EUSERS;
+ goto out;
+ }
sk_gso_disable(sk);
rcu_assign_pointer(tcp_sk(sk)->ao_info, ao_info);
}
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 4b37e82ab612..777f5f5f721d 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3528,41 +3528,55 @@ static inline bool tcp_may_update_window(const struct tcp_sock *tp,
(ack_seq == tp->snd_wl1 && nwin > tp->snd_wnd);
}
-/* If we update tp->snd_una, also update tp->bytes_acked */
-static void tcp_snd_una_update(struct tcp_sock *tp, u32 ack)
+static void tcp_snd_sne_update(struct tcp_sock *tp, u32 ack)
{
- u32 delta = ack - tp->snd_una;
#ifdef CONFIG_TCP_AO
struct tcp_ao_info *ao;
-#endif
- sock_owned_by_me((struct sock *)tp);
- tp->bytes_acked += delta;
-#ifdef CONFIG_TCP_AO
+ if (!static_branch_unlikely(&tcp_ao_needed.key))
+ return;
+
ao = rcu_dereference_protected(tp->ao_info,
lockdep_sock_is_held((struct sock *)tp));
if (ao && ack < tp->snd_una)
ao->snd_sne++;
#endif
+}
+
+/* If we update tp->snd_una, also update tp->bytes_acked */
+static void tcp_snd_una_update(struct tcp_sock *tp, u32 ack)
+{
+ u32 delta = ack - tp->snd_una;
+
+ sock_owned_by_me((struct sock *)tp);
+ tp->bytes_acked += delta;
+ tcp_snd_sne_update(tp, ack);
tp->snd_una = ack;
}
+static void tcp_rcv_sne_update(struct tcp_sock *tp, u32 seq)
+{
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_info *ao;
+
+ if (!static_branch_unlikely(&tcp_ao_needed.key))
+ return;
+
+ ao = rcu_dereference_protected(tp->ao_info,
+ lockdep_sock_is_held((struct sock *)tp));
+ if (ao && seq < tp->rcv_nxt)
+ ao->rcv_sne++;
+#endif
+}
+
/* If we update tp->rcv_nxt, also update tp->bytes_received */
static void tcp_rcv_nxt_update(struct tcp_sock *tp, u32 seq)
{
u32 delta = seq - tp->rcv_nxt;
-#ifdef CONFIG_TCP_AO
- struct tcp_ao_info *ao;
-#endif
sock_owned_by_me((struct sock *)tp);
tp->bytes_received += delta;
-#ifdef CONFIG_TCP_AO
- ao = rcu_dereference_protected(tp->ao_info,
- lockdep_sock_is_held((struct sock *)tp));
- if (ao && seq < tp->rcv_nxt)
- ao->rcv_sne++;
-#endif
+ tcp_rcv_sne_update(tp, seq);
WRITE_ONCE(tp->rcv_nxt, seq);
}
--
2.41.0
Wire up sending resets to TCP-AO hashing.
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/tcp_ao.h | 12 +++++
net/ipv4/tcp_ao.c | 105 ++++++++++++++++++++++++++++++++++++++++++-
net/ipv4/tcp_ipv4.c | 69 ++++++++++++++++++++++------
net/ipv6/tcp_ipv6.c | 66 +++++++++++++++++++++------
4 files changed, 224 insertions(+), 28 deletions(-)
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index e97dfdc11451..6e8567b5bbf8 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -117,12 +117,24 @@ int tcp_ao_hash_skb(unsigned short int family,
const u8 *tkey, int hash_offset, u32 sne);
int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family,
sockptr_t optval, int optlen);
+struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao,
+ int sndid, int rcvid);
int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
unsigned int len, struct tcp_sigpool *hp);
void tcp_ao_destroy_sock(struct sock *sk);
struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
const union tcp_ao_addr *addr,
int family, int sndid, int rcvid, u16 port);
+int tcp_ao_hash_hdr(unsigned short family, char *ao_hash,
+ struct tcp_ao_key *key, const u8 *tkey,
+ const union tcp_ao_addr *daddr,
+ const union tcp_ao_addr *saddr,
+ const struct tcphdr *th, u32 sne);
+int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
+ const struct tcp_ao_hdr *aoh, int l3index, u32 seq,
+ struct tcp_ao_key **key, char **traffic_key,
+ bool *allocated_traffic_key, u8 *keyid, u32 *sne);
+
/* ipv4 specific functions */
int tcp_v4_parse_ao(struct sock *sk, int optname, sockptr_t optval, int optlen);
struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 3ff7b1efacfa..b8b2e9caa096 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -48,8 +48,8 @@ int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
* it's known that the keys in ao_info are matching peer's
* family/address/port/VRF/etc.
*/
-static struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao,
- int sndid, int rcvid)
+struct tcp_ao_key *tcp_ao_established_key(struct tcp_ao_info *ao,
+ int sndid, int rcvid)
{
struct tcp_ao_key *key;
@@ -371,6 +371,66 @@ static int tcp_ao_hash_header(struct tcp_sigpool *hp,
return err;
}
+int tcp_ao_hash_hdr(unsigned short int family, char *ao_hash,
+ struct tcp_ao_key *key, const u8 *tkey,
+ const union tcp_ao_addr *daddr,
+ const union tcp_ao_addr *saddr,
+ const struct tcphdr *th, u32 sne)
+{
+ int tkey_len = tcp_ao_digest_size(key);
+ int hash_offset = ao_hash - (char *)th;
+ struct tcp_sigpool hp;
+ void *hash_buf = NULL;
+
+ hash_buf = kmalloc(tkey_len, GFP_ATOMIC);
+ if (!hash_buf)
+ goto clear_hash_noput;
+
+ if (tcp_sigpool_start(key->tcp_sigpool_id, &hp))
+ goto clear_hash_noput;
+
+ if (crypto_ahash_setkey(crypto_ahash_reqtfm(hp.req), tkey, tkey_len))
+ goto clear_hash;
+
+ if (crypto_ahash_init(hp.req))
+ goto clear_hash;
+
+ if (tcp_ao_hash_sne(&hp, sne))
+ goto clear_hash;
+ if (family == AF_INET) {
+ if (tcp_v4_ao_hash_pseudoheader(&hp, daddr->a4.s_addr,
+ saddr->a4.s_addr, th->doff * 4))
+ goto clear_hash;
+#if IS_ENABLED(CONFIG_IPV6)
+ } else if (family == AF_INET6) {
+ if (tcp_v6_ao_hash_pseudoheader(&hp, &daddr->a6,
+ &saddr->a6, th->doff * 4))
+ goto clear_hash;
+#endif
+ } else {
+ WARN_ON_ONCE(1);
+ goto clear_hash;
+ }
+ if (tcp_ao_hash_header(&hp, th, false,
+ ao_hash, hash_offset, tcp_ao_maclen(key)))
+ goto clear_hash;
+ ahash_request_set_crypt(hp.req, NULL, hash_buf, 0);
+ if (crypto_ahash_final(hp.req))
+ goto clear_hash;
+
+ memcpy(ao_hash, hash_buf, tcp_ao_maclen(key));
+ tcp_sigpool_end(&hp);
+ kfree(hash_buf);
+ return 0;
+
+clear_hash:
+ tcp_sigpool_end(&hp);
+clear_hash_noput:
+ memset(ao_hash, 0, tcp_ao_maclen(key));
+ kfree(hash_buf);
+ return 1;
+}
+
int tcp_ao_hash_skb(unsigned short int family,
char *ao_hash, struct tcp_ao_key *key,
const struct sock *sk, const struct sk_buff *skb,
@@ -437,6 +497,47 @@ struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
return tcp_ao_do_lookup(sk, addr, AF_INET, sndid, rcvid, 0);
}
+int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
+ const struct tcp_ao_hdr *aoh, int l3index, u32 seq,
+ struct tcp_ao_key **key, char **traffic_key,
+ bool *allocated_traffic_key, u8 *keyid, u32 *sne)
+{
+ const struct tcphdr *th = tcp_hdr(skb);
+ struct tcp_ao_info *ao_info;
+
+ *allocated_traffic_key = false;
+ /* If there's no socket - than initial sisn/disn are unknown.
+ * Drop the segment. RFC5925 (7.7) advises to require graceful
+ * restart [RFC4724]. Alternatively, the RFC5925 advises to
+ * save/restore traffic keys before/after reboot.
+ * Linux TCP-AO support provides TCP_AO_ADD_KEY and TCP_AO_REPAIR
+ * options to restore a socket post-reboot.
+ */
+ if (!sk)
+ return -ENOTCONN;
+
+ if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV)) {
+ return -1;
+ } else {
+ struct tcp_ao_key *rnext_key;
+
+ if (sk->sk_state == TCP_TIME_WAIT)
+ return -1;
+ ao_info = rcu_dereference(tcp_sk(sk)->ao_info);
+ if (!ao_info)
+ return -ENOENT;
+
+ *key = tcp_ao_established_key(ao_info, aoh->rnext_keyid, -1);
+ if (!*key)
+ return -ENOENT;
+ *traffic_key = snd_other_key(*key);
+ rnext_key = READ_ONCE(ao_info->rnext_key);
+ *keyid = rnext_key->rcvid;
+ *sne = 0;
+ }
+ return 0;
+}
+
static int tcp_ao_cache_traffic_keys(const struct sock *sk,
struct tcp_ao_info *ao,
struct tcp_ao_key *ao_key)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 0e9c6cfd4ab2..ee14a2405801 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -657,6 +657,52 @@ void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb)
}
EXPORT_SYMBOL(tcp_v4_send_check);
+#define REPLY_OPTIONS_LEN (MAX_TCP_OPTION_SPACE / sizeof(__be32))
+
+static bool tcp_v4_ao_sign_reset(const struct sock *sk, struct sk_buff *skb,
+ const struct tcp_ao_hdr *aoh,
+ struct ip_reply_arg *arg, struct tcphdr *reply,
+ __be32 reply_options[REPLY_OPTIONS_LEN])
+{
+#ifdef CONFIG_TCP_AO
+ int sdif = tcp_v4_sdif(skb);
+ int dif = inet_iif(skb);
+ int l3index = sdif ? dif : 0;
+ bool allocated_traffic_key;
+ struct tcp_ao_key *key;
+ char *traffic_key;
+ bool drop = true;
+ u32 ao_sne = 0;
+ u8 keyid;
+
+ rcu_read_lock();
+ if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, reply->seq,
+ &key, &traffic_key, &allocated_traffic_key,
+ &keyid, &ao_sne))
+ goto out;
+
+ reply_options[0] = htonl((TCPOPT_AO << 24) | (tcp_ao_len(key) << 16) |
+ (aoh->rnext_keyid << 8) | keyid);
+ arg->iov[0].iov_len += round_up(tcp_ao_len(key), 4);
+ reply->doff = arg->iov[0].iov_len / 4;
+
+ if (tcp_ao_hash_hdr(AF_INET, (char *)&reply_options[1],
+ key, traffic_key,
+ (union tcp_ao_addr *)&ip_hdr(skb)->saddr,
+ (union tcp_ao_addr *)&ip_hdr(skb)->daddr,
+ reply, ao_sne))
+ goto out;
+ drop = false;
+out:
+ rcu_read_unlock();
+ if (allocated_traffic_key)
+ kfree(traffic_key);
+ return drop;
+#else
+ return true;
+#endif
+}
+
/*
* This routine will send an RST to the other tcp.
*
@@ -670,28 +716,21 @@ EXPORT_SYMBOL(tcp_v4_send_check);
* Exception: precedence violation. We do not implement it in any case.
*/
-#ifdef CONFIG_TCP_AO
-#define OPTION_BYTES MAX_TCP_OPTION_SPACE
-#elif defined(CONFIG_TCP_MD5SIG)
-#define OPTION_BYTES TCPOLEN_MD5SIG_ALIGNED
-#else
-#define OPTION_BYTES sizeof(__be32)
-#endif
-
static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
{
const struct tcphdr *th = tcp_hdr(skb);
struct {
struct tcphdr th;
- __be32 opt[OPTION_BYTES / sizeof(__be32)];
+ __be32 opt[REPLY_OPTIONS_LEN];
} rep;
+ const __u8 *md5_hash_location = NULL;
+ const struct tcp_ao_hdr *aoh;
struct ip_reply_arg arg;
#ifdef CONFIG_TCP_MD5SIG
struct tcp_md5sig_key *key = NULL;
- const __u8 *md5_hash_location = NULL;
unsigned char newhash[16];
- int genhash;
struct sock *sk1 = NULL;
+ int genhash;
#endif
u64 transmit_time = 0;
struct sock *ctl_sk;
@@ -728,11 +767,15 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
arg.iov[0].iov_len = sizeof(rep.th);
net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
-#ifdef CONFIG_TCP_MD5SIG
+
/* Invalid TCP option size or twice included auth */
- if (tcp_parse_auth_options(tcp_hdr(skb), &md5_hash_location, NULL))
+ if (tcp_parse_auth_options(tcp_hdr(skb), &md5_hash_location, &aoh))
return;
+ if (aoh && tcp_v4_ao_sign_reset(sk, skb, aoh, &arg, &rep.th, rep.opt))
+ return;
+
+#ifdef CONFIG_TCP_MD5SIG
rcu_read_lock();
if (sk && sk_fullsock(sk)) {
const union tcp_md5_addr *addr;
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 4c645160362e..bc4ef00621b4 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -854,7 +854,9 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
u32 ack, u32 win, u32 tsval, u32 tsecr,
int oif, struct tcp_md5sig_key *key, int rst,
- u8 tclass, __be32 label, u32 priority, u32 txhash)
+ u8 tclass, __be32 label, u32 priority, u32 txhash,
+ struct tcp_ao_key *ao_key, char *tkey,
+ u8 rcv_next, u32 ao_sne)
{
const struct tcphdr *th = tcp_hdr(skb);
struct tcphdr *t1;
@@ -873,6 +875,13 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32
if (key)
tot_len += TCPOLEN_MD5SIG_ALIGNED;
#endif
+#ifdef CONFIG_TCP_AO
+ if (ao_key)
+ tot_len += tcp_ao_len(ao_key);
+#endif
+#if defined(CONFIG_TCP_MD5SIG) && defined(CONFIG_TCP_AO)
+ WARN_ON_ONCE(key && ao_key);
+#endif
#ifdef CONFIG_MPTCP
if (rst && !key) {
@@ -924,6 +933,17 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32
&ipv6_hdr(skb)->daddr, t1);
}
#endif
+#ifdef CONFIG_TCP_AO
+ if (ao_key) {
+ *topt++ = htonl((TCPOPT_AO << 24) | (tcp_ao_len(ao_key) << 16) |
+ (ao_key->sndid << 8) | (rcv_next));
+
+ tcp_ao_hash_hdr(AF_INET6, (char *)topt, ao_key, tkey,
+ (union tcp_ao_addr *)&ipv6_hdr(skb)->saddr,
+ (union tcp_ao_addr *)&ipv6_hdr(skb)->daddr,
+ t1, ao_sne);
+ }
+#endif
memset(&fl6, 0, sizeof(fl6));
fl6.daddr = ipv6_hdr(skb)->saddr;
@@ -988,17 +1008,23 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
struct ipv6hdr *ipv6h = ipv6_hdr(skb);
u32 seq = 0, ack_seq = 0;
struct tcp_md5sig_key *key = NULL;
-#ifdef CONFIG_TCP_MD5SIG
+ __be32 label = 0;
+ u32 priority = 0;
+ struct net *net;
+ struct tcp_ao_key *ao_key = NULL;
+ u8 rcv_next = 0;
+ u32 ao_sne = 0;
+ u32 txhash = 0;
+ int oif = 0;
const __u8 *md5_hash_location = NULL;
+ const struct tcp_ao_hdr *aoh;
+ char *traffic_key = NULL;
+ bool allocated_traffic_key = false;
+#ifdef CONFIG_TCP_MD5SIG
unsigned char newhash[16];
int genhash;
struct sock *sk1 = NULL;
#endif
- __be32 label = 0;
- u32 priority = 0;
- struct net *net;
- u32 txhash = 0;
- int oif = 0;
if (th->rst)
return;
@@ -1010,12 +1036,11 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
return;
net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
-#ifdef CONFIG_TCP_MD5SIG
/* Invalid TCP option size or twice included auth */
- if (tcp_parse_auth_options(th, &md5_hash_location, NULL))
+ if (tcp_parse_auth_options(th, &md5_hash_location, &aoh))
return;
-
rcu_read_lock();
+#ifdef CONFIG_TCP_MD5SIG
if (sk && sk_fullsock(sk)) {
int l3index;
@@ -1064,6 +1089,18 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
(th->doff << 2);
+#ifdef CONFIG_TCP_AO
+ if (aoh) {
+ int l3index;
+
+ l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
+ if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, seq, &ao_key,
+ &traffic_key, &allocated_traffic_key,
+ &rcv_next, &ao_sne))
+ goto out;
+ }
+#endif
+
if (sk) {
oif = sk->sk_bound_dev_if;
if (sk_fullsock(sk)) {
@@ -1086,10 +1123,13 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
}
tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1,
- ipv6_get_dsfield(ipv6h), label, priority, txhash);
+ ipv6_get_dsfield(ipv6h), label, priority, txhash,
+ ao_key, traffic_key, rcv_next, ao_sne);
-#ifdef CONFIG_TCP_MD5SIG
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
out:
+ if (allocated_traffic_key)
+ kfree(traffic_key);
rcu_read_unlock();
#endif
}
@@ -1100,7 +1140,7 @@ static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
__be32 label, u32 priority, u32 txhash)
{
tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
- tclass, label, priority, txhash);
+ tclass, label, priority, txhash, NULL, NULL, 0, 0);
}
static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
--
2.41.0
Introduce new kernel config option and common structures as well as
helpers to be used by TCP-AO code.
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/linux/tcp.h | 9 +++-
include/net/tcp.h | 8 +---
include/net/tcp_ao.h | 91 ++++++++++++++++++++++++++++++++++++++++
include/uapi/linux/tcp.h | 2 +
net/ipv4/Kconfig | 13 ++++++
5 files changed, 115 insertions(+), 8 deletions(-)
create mode 100644 include/net/tcp_ao.h
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index d16abdb3541a..9eb15e798c32 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -437,13 +437,18 @@ struct tcp_sock {
bool syn_smc; /* SYN includes SMC */
#endif
-#ifdef CONFIG_TCP_MD5SIG
-/* TCP AF-Specific parts; only used by MD5 Signature support so far */
+#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
+/* TCP AF-Specific parts; only used by TCP-AO/MD5 Signature support so far */
const struct tcp_sock_af_ops *af_specific;
+#ifdef CONFIG_TCP_MD5SIG
/* TCP MD5 Signature Option information */
struct tcp_md5sig_info __rcu *md5sig_info;
#endif
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_info __rcu *ao_info;
+#endif
+#endif
/* TCP fastopen related information */
struct tcp_fastopen_request *fastopen_req;
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 95651f9c9242..d1230ee888fd 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -37,6 +37,7 @@
#include <net/snmp.h>
#include <net/ip.h>
#include <net/tcp_states.h>
+#include <net/tcp_ao.h>
#include <net/inet_ecn.h>
#include <net/dst.h>
#include <net/mptcp.h>
@@ -1643,12 +1644,7 @@ static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp)
tp->retransmit_skb_hint = NULL;
}
-union tcp_md5_addr {
- struct in_addr a4;
-#if IS_ENABLED(CONFIG_IPV6)
- struct in6_addr a6;
-#endif
-};
+#define tcp_md5_addr tcp_ao_addr
/* - key database */
struct tcp_md5sig_key {
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
new file mode 100644
index 000000000000..3870cc29af10
--- /dev/null
+++ b/include/net/tcp_ao.h
@@ -0,0 +1,91 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _TCP_AO_H
+#define _TCP_AO_H
+
+#define TCP_AO_KEY_ALIGN 1
+#define __tcp_ao_key_align __aligned(TCP_AO_KEY_ALIGN)
+
+union tcp_ao_addr {
+ struct in_addr a4;
+#if IS_ENABLED(CONFIG_IPV6)
+ struct in6_addr a6;
+#endif
+};
+
+struct tcp_ao_hdr {
+ u8 kind;
+ u8 length;
+ u8 keyid;
+ u8 rnext_keyid;
+};
+
+struct tcp_ao_key {
+ struct hlist_node node;
+ union tcp_ao_addr addr;
+ u8 key[TCP_AO_MAXKEYLEN] __tcp_ao_key_align;
+ unsigned int tcp_sigpool_id;
+ unsigned int digest_size;
+ u16 port;
+ u8 prefixlen;
+ u8 family;
+ u8 keylen;
+ u8 keyflags;
+ u8 sndid;
+ u8 rcvid;
+ u8 maclen;
+ struct rcu_head rcu;
+ u8 traffic_keys[];
+};
+
+static inline u8 *rcv_other_key(struct tcp_ao_key *key)
+{
+ return key->traffic_keys;
+}
+
+static inline u8 *snd_other_key(struct tcp_ao_key *key)
+{
+ return key->traffic_keys + key->digest_size;
+}
+
+static inline int tcp_ao_maclen(const struct tcp_ao_key *key)
+{
+ return key->maclen;
+}
+
+static inline int tcp_ao_len(const struct tcp_ao_key *key)
+{
+ return tcp_ao_maclen(key) + sizeof(struct tcp_ao_hdr);
+}
+
+static inline unsigned int tcp_ao_digest_size(struct tcp_ao_key *key)
+{
+ return key->digest_size;
+}
+
+static inline int tcp_ao_sizeof_key(const struct tcp_ao_key *key)
+{
+ return sizeof(struct tcp_ao_key) + (key->digest_size << 1);
+}
+
+struct tcp_ao_info {
+ /* List of tcp_ao_key's */
+ struct hlist_head head;
+ /* current_key and rnext_key aren't maintained on listen sockets.
+ * Their purpose is to cache keys on established connections,
+ * saving needless lookups. Never dereference any of them from
+ * listen sockets.
+ * ::current_key may change in RX to the key that was requested by
+ * the peer, please use READ_ONCE()/WRITE_ONCE() in order to avoid
+ * load/store tearing.
+ * Do the same for ::rnext_key, if you don't hold socket lock
+ * (it's changed only by userspace request in setsockopt()).
+ */
+ struct tcp_ao_key *current_key;
+ struct tcp_ao_key *rnext_key;
+ u32 flags;
+ __be32 lisn;
+ __be32 risn;
+ struct rcu_head rcu;
+};
+
+#endif /* _TCP_AO_H */
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 879eeb0a084b..5655bfe28b8d 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -348,6 +348,8 @@ struct tcp_diag_md5sig {
__u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN];
};
+#define TCP_AO_MAXKEYLEN 80
+
/* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */
#define TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT 0x1
diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 89e2ab023272..8e94ed7c56a0 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -744,6 +744,19 @@ config DEFAULT_TCP_CONG
config TCP_SIGPOOL
tristate
+config TCP_AO
+ bool "TCP: Authentication Option (RFC5925)"
+ select CRYPTO
+ select TCP_SIGPOOL
+ depends on 64BIT && IPV6 != m # seq-number extension needs WRITE_ONCE(u64)
+ help
+ TCP-AO specifies the use of stronger Message Authentication Codes (MACs),
+ protects against replays for long-lived TCP connections, and
+ provides more details on the association of security with TCP
+ connections than TCP MD5 (See RFC5925)
+
+ If unsure, say N.
+
config TCP_MD5SIG
bool "TCP: MD5 Signature Option support (RFC2385)"
select CRYPTO
--
2.41.0
Be as conservative as possible: if there is TCP-MD5 key for a given peer
regardless of L3 interface - don't allow setting TCP-AO key for the same
peer. According to RFC5925, TCP-AO is supposed to replace TCP-MD5 and
there can't be any switch between both on any connected tuple.
Later it can be relaxed, if there's a use, but in the beginning restrict
any intersection.
Note: it's still should be possible to set both TCP-MD5 and TCP-AO keys
on a listening socket for *different* peers.
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/tcp.h | 43 +++++++++++++++++++++++++++++++++++++--
include/net/tcp_ao.h | 15 ++++++++++++++
net/ipv4/tcp_ao.c | 40 ++++++++++++++++++++++++++++++++++++
net/ipv4/tcp_ipv4.c | 14 ++++++++++---
net/ipv4/tcp_output.c | 47 +++++++++++++++++++++++++++++++++++++++++++
net/ipv6/tcp_ao.c | 17 ++++++++++++++++
net/ipv6/tcp_ipv6.c | 26 ++++++++++++++++++++----
7 files changed, 193 insertions(+), 9 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 98b970c078d1..7e414873ef07 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1729,6 +1729,7 @@ int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr,
int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr,
int family, u8 prefixlen, int l3index, u8 flags);
+void tcp_clear_md5_list(struct sock *sk);
struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk,
const struct sock *addr_sk);
@@ -1737,14 +1738,23 @@ struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk,
extern struct static_key_false_deferred tcp_md5_needed;
struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index,
const union tcp_md5_addr *addr,
- int family);
+ int family, bool any_l3index);
static inline struct tcp_md5sig_key *
tcp_md5_do_lookup(const struct sock *sk, int l3index,
const union tcp_md5_addr *addr, int family)
{
if (!static_branch_unlikely(&tcp_md5_needed.key))
return NULL;
- return __tcp_md5_do_lookup(sk, l3index, addr, family);
+ return __tcp_md5_do_lookup(sk, l3index, addr, family, false);
+}
+
+static inline struct tcp_md5sig_key *
+tcp_md5_do_lookup_any_l3index(const struct sock *sk,
+ const union tcp_md5_addr *addr, int family)
+{
+ if (!static_branch_unlikely(&tcp_md5_needed.key))
+ return NULL;
+ return __tcp_md5_do_lookup(sk, 0, addr, family, true);
}
enum skb_drop_reason
@@ -1762,6 +1772,13 @@ tcp_md5_do_lookup(const struct sock *sk, int l3index,
return NULL;
}
+static inline struct tcp_md5sig_key *
+tcp_md5_do_lookup_any_l3index(const struct sock *sk,
+ const union tcp_md5_addr *addr, int family)
+{
+ return NULL;
+}
+
static inline enum skb_drop_reason
tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
const void *saddr, const void *daddr,
@@ -2127,6 +2144,9 @@ struct tcp_sock_af_ops {
int optname,
sockptr_t optval,
int optlen);
+ struct tcp_ao_key *(*ao_lookup)(const struct sock *sk,
+ struct sock *addr_sk,
+ int sndid, int rcvid);
#endif
};
@@ -2539,4 +2559,23 @@ static inline u64 tcp_transmit_time(const struct sock *sk)
return 0;
}
+static inline bool tcp_ao_required(struct sock *sk, const void *saddr,
+ int family)
+{
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_info *ao_info;
+ struct tcp_ao_key *ao_key;
+
+ ao_info = rcu_dereference_check(tcp_sk(sk)->ao_info,
+ lockdep_sock_is_held(sk));
+ if (!ao_info)
+ return false;
+
+ ao_key = tcp_ao_do_lookup(sk, saddr, family, -1, -1, 0);
+ if (ao_info->ao_required || ao_key)
+ return true;
+#endif
+ return false;
+}
+
#endif /* _TCP_H */
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 1739116c6902..1c24b586c876 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -93,12 +93,27 @@ struct tcp_ao_info {
int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family,
sockptr_t optval, int optlen);
void tcp_ao_destroy_sock(struct sock *sk);
+struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
+ const union tcp_ao_addr *addr,
+ int family, int sndid, int rcvid, u16 port);
/* ipv4 specific functions */
int tcp_v4_parse_ao(struct sock *sk, int optname, sockptr_t optval, int optlen);
+struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
+ int sndid, int rcvid);
/* ipv6 specific functions */
+struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
+ struct sock *addr_sk,
+ int sndid, int rcvid);
int tcp_v6_parse_ao(struct sock *sk, int cmd,
sockptr_t optval, int optlen);
#else
+static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
+ const union tcp_ao_addr *addr,
+ int family, int sndid, int rcvid, u16 port)
+{
+ return NULL;
+}
+
static inline void tcp_ao_destroy_sock(struct sock *sk)
{
}
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 2b2696e24dcc..c2be72beab70 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -171,6 +171,14 @@ void tcp_ao_destroy_sock(struct sock *sk)
kfree_rcu(ao, rcu);
}
+struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk,
+ int sndid, int rcvid)
+{
+ union tcp_ao_addr *addr = (union tcp_ao_addr *)&addr_sk->sk_daddr;
+
+ return tcp_ao_do_lookup(sk, addr, AF_INET, sndid, rcvid, 0);
+}
+
static bool tcp_ao_can_set_current_rnext(struct sock *sk)
{
/* There aren't current/rnext keys on TCP_LISTEN sockets */
@@ -521,6 +529,10 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
return -EINVAL;
}
+ /* Don't allow keys for peers that have a matching TCP-MD5 key */
+ if (tcp_md5_do_lookup_any_l3index(sk, addr, family))
+ return -EKEYREJECTED;
+
ao_info = setsockopt_ao_info(sk);
if (IS_ERR(ao_info))
return PTR_ERR(ao_info);
@@ -720,6 +732,31 @@ static int tcp_ao_del_cmd(struct sock *sk, unsigned short int family,
return -ENOENT;
}
+/* cmd.ao_required makes a socket TCP-AO only.
+ * Don't allow any md5 keys for any l3intf on the socket together with it.
+ * Restricting it early in setsockopt() removes a check for
+ * ao_info->ao_required on inbound tcp segment fast-path.
+ */
+static inline int tcp_ao_required_verify(struct sock *sk)
+{
+#ifdef CONFIG_TCP_MD5SIG
+ const struct tcp_md5sig_info *md5sig;
+
+ if (!static_branch_unlikely(&tcp_md5_needed.key))
+ return 0;
+
+ md5sig = rcu_dereference_check(tcp_sk(sk)->md5sig_info,
+ lockdep_sock_is_held(sk));
+ if (!md5sig)
+ return 0;
+
+ if (rcu_dereference_check(hlist_first_rcu(&md5sig->head),
+ lockdep_sock_is_held(sk)))
+ return 1;
+#endif
+ return 0;
+}
+
static int tcp_ao_info_cmd(struct sock *sk, unsigned short int family,
sockptr_t optval, int optlen)
{
@@ -754,6 +791,9 @@ static int tcp_ao_info_cmd(struct sock *sk, unsigned short int family,
first = true;
}
+ if (cmd.ao_required && tcp_ao_required_verify(sk))
+ return -EKEYREJECTED;
+
/* For sockets in TCP_CLOSED it's possible set keys that aren't
* matching the future peer (address/port/VRF/etc),
* tcp_ao_connect_init() will choose a correct matching MKT
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 8804eb801caf..65e9bcac45f9 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1081,7 +1081,7 @@ static bool better_md5_match(struct tcp_md5sig_key *old, struct tcp_md5sig_key *
/* Find the Key structure for an address. */
struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index,
const union tcp_md5_addr *addr,
- int family)
+ int family, bool any_l3index)
{
const struct tcp_sock *tp = tcp_sk(sk);
struct tcp_md5sig_key *key;
@@ -1100,7 +1100,8 @@ struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index,
lockdep_sock_is_held(sk)) {
if (key->family != family)
continue;
- if (key->flags & TCP_MD5SIG_FLAG_IFINDEX && key->l3index != l3index)
+ if (!any_l3index && key->flags & TCP_MD5SIG_FLAG_IFINDEX &&
+ key->l3index != l3index)
continue;
if (family == AF_INET) {
mask = inet_make_mask(key->prefixlen);
@@ -1312,7 +1313,7 @@ int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family,
}
EXPORT_SYMBOL(tcp_md5_do_del);
-static void tcp_clear_md5_list(struct sock *sk)
+void tcp_clear_md5_list(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
struct tcp_md5sig_key *key;
@@ -1382,6 +1383,12 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
return -EINVAL;
+ /* Don't allow keys for peers that have a matching TCP-AO key.
+ * See the comment in tcp_ao_add_cmd()
+ */
+ if (tcp_ao_required(sk, addr, AF_INET))
+ return -EKEYREJECTED;
+
return tcp_md5_do_add(sk, addr, AF_INET, prefixlen, l3index, flags,
cmd.tcpm_key, cmd.tcpm_keylen);
}
@@ -2277,6 +2284,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
.md5_parse = tcp_v4_parse_md5_keys,
#endif
#ifdef CONFIG_TCP_AO
+ .ao_lookup = tcp_v4_ao_lookup,
.ao_parse = tcp_v4_parse_ao,
#endif
};
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 51d8638d4b4c..e98083abd7fb 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3928,6 +3928,53 @@ int tcp_connect(struct sock *sk)
tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_CONNECT_CB, 0, NULL);
+#if defined(CONFIG_TCP_MD5SIG) && defined(CONFIG_TCP_AO)
+ /* Has to be checked late, after setting daddr/saddr/ops.
+ * Return error if the peer has both a md5 and a tcp-ao key
+ * configured as this is ambiguous.
+ */
+ if (unlikely(rcu_dereference_protected(tp->md5sig_info,
+ lockdep_sock_is_held(sk)))) {
+ bool needs_md5 = !!tp->af_specific->md5_lookup(sk, sk);
+ bool needs_ao = !!tp->af_specific->ao_lookup(sk, sk, -1, -1);
+ struct tcp_ao_info *ao_info;
+
+ ao_info = rcu_dereference_check(tp->ao_info,
+ lockdep_sock_is_held(sk));
+ if (ao_info) {
+ /* This is an extra check: tcp_ao_required() in
+ * tcp_v{4,6}_parse_md5_keys() should prevent adding
+ * md5 keys on ao_required socket.
+ */
+ needs_ao |= ao_info->ao_required;
+ WARN_ON_ONCE(ao_info->ao_required && needs_md5);
+ }
+ if (needs_md5 && needs_ao)
+ return -EKEYREJECTED;
+
+ /* If we have a matching md5 key and no matching tcp-ao key
+ * then free up ao_info if allocated.
+ */
+ if (needs_md5) {
+ tcp_ao_destroy_sock(sk);
+ } else if (needs_ao) {
+ tcp_clear_md5_list(sk);
+ kfree(rcu_replace_pointer(tp->md5sig_info, NULL,
+ lockdep_sock_is_held(sk)));
+ }
+ }
+#endif
+#ifdef CONFIG_TCP_AO
+ if (unlikely(rcu_dereference_protected(tp->ao_info,
+ lockdep_sock_is_held(sk)))) {
+ /* Don't allow connecting if ao is configured but no
+ * matching key is found.
+ */
+ if (!tp->af_specific->ao_lookup(sk, sk, -1, -1))
+ return -EKEYREJECTED;
+ }
+#endif
+
if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk))
return -EHOSTUNREACH; /* Routing failure or similar. */
diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c
index 049ddbabe049..a56ab0a9cf55 100644
--- a/net/ipv6/tcp_ao.c
+++ b/net/ipv6/tcp_ao.c
@@ -12,6 +12,23 @@
#include <net/tcp.h>
#include <net/ipv6.h>
+struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk,
+ const struct in6_addr *addr,
+ int sndid, int rcvid)
+{
+ return tcp_ao_do_lookup(sk, (union tcp_ao_addr *)addr, AF_INET6,
+ sndid, rcvid, 0);
+}
+
+struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk,
+ struct sock *addr_sk,
+ int sndid, int rcvid)
+{
+ struct in6_addr *addr = &addr_sk->sk_v6_daddr;
+
+ return tcp_v6_ao_do_lookup(sk, addr, sndid, rcvid);
+}
+
int tcp_v6_parse_ao(struct sock *sk, int cmd,
sockptr_t optval, int optlen)
{
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 96ec9c03d9eb..5c7c9dbfdb73 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -599,6 +599,7 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
{
struct tcp_md5sig cmd;
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
+ union tcp_ao_addr *addr;
int l3index = 0;
u8 prefixlen;
u8 flags;
@@ -653,13 +654,28 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
return -EINVAL;
- if (ipv6_addr_v4mapped(&sin6->sin6_addr))
- return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
+ if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
+ addr = (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3];
+
+ /* Don't allow keys for peers that have a matching TCP-AO key.
+ * See the comment in tcp_ao_add_cmd()
+ */
+ if (tcp_ao_required(sk, addr, AF_INET))
+ return -EKEYREJECTED;
+ return tcp_md5_do_add(sk, addr,
AF_INET, prefixlen, l3index, flags,
cmd.tcpm_key, cmd.tcpm_keylen);
+ }
- return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
- AF_INET6, prefixlen, l3index, flags,
+ addr = (union tcp_md5_addr *)&sin6->sin6_addr;
+
+ /* Don't allow keys for peers that have a matching TCP-AO key.
+ * See the comment in tcp_ao_add_cmd()
+ */
+ if (tcp_ao_required(sk, addr, AF_INET6))
+ return -EKEYREJECTED;
+
+ return tcp_md5_do_add(sk, addr, AF_INET6, prefixlen, l3index, flags,
cmd.tcpm_key, cmd.tcpm_keylen);
}
@@ -1899,6 +1915,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
.md5_parse = tcp_v6_parse_md5_keys,
#endif
#ifdef CONFIG_TCP_AO
+ .ao_lookup = tcp_v6_ao_lookup,
.ao_parse = tcp_v6_parse_ao,
#endif
};
@@ -1930,6 +1947,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
.md5_parse = tcp_v6_parse_md5_keys,
#endif
#ifdef CONFIG_TCP_AO
+ .ao_lookup = tcp_v6_ao_lookup,
.ao_parse = tcp_v6_parse_ao,
#endif
};
--
2.41.0
Delete becomes very, very fast - almost free, but after setsockopt()
syscall returns, the key is still alive until next RCU grace period.
Which is fine for listen sockets as userspace needs to be aware of
setsockopt(TCP_AO) and accept() race and resolve it with verification
by getsockopt() after TCP connection was accepted.
The benchmark results (on non-loaded box, worse with more RCU work pending):
> ok 33 Worst case delete 16384 keys: min=5ms max=10ms mean=6.93904ms stddev=0.263421
> ok 34 Add a new key 16384 keys: min=1ms max=4ms mean=2.17751ms stddev=0.147564
> ok 35 Remove random-search 16384 keys: min=5ms max=10ms mean=6.50243ms stddev=0.254999
> ok 36 Remove async 16384 keys: min=0ms max=0ms mean=0.0296107ms stddev=0.0172078
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/uapi/linux/tcp.h | 3 ++-
net/ipv4/tcp_ao.c | 21 ++++++++++++++++++---
2 files changed, 20 insertions(+), 4 deletions(-)
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index 1109093bbb24..979ff960fddb 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -383,7 +383,8 @@ struct tcp_ao_del { /* setsockopt(TCP_AO_DEL_KEY) */
__s32 ifindex; /* L3 dev index for VRF */
__u32 set_current :1, /* corresponding ::current_key */
set_rnext :1, /* corresponding ::rnext */
- reserved :30; /* must be 0 */
+ del_async :1, /* only valid for listen sockets */
+ reserved :29; /* must be 0 */
__u16 reserved2; /* padding, must be 0 */
__u8 prefix; /* peer's address prefix */
__u8 sndid; /* SendID for outgoing segments */
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index faa6c5c0db28..567aa9400f7d 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -1606,7 +1606,7 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
}
static int tcp_ao_delete_key(struct sock *sk, struct tcp_ao_info *ao_info,
- struct tcp_ao_key *key,
+ bool del_async, struct tcp_ao_key *key,
struct tcp_ao_key *new_current,
struct tcp_ao_key *new_rnext)
{
@@ -1614,11 +1614,24 @@ static int tcp_ao_delete_key(struct sock *sk, struct tcp_ao_info *ao_info,
hlist_del_rcu(&key->node);
+ /* Support for async delete on listening sockets: as they don't
+ * need current_key/rnext_key maintaining, we don't need to check
+ * them and we can just free all resources in RCU fashion.
+ */
+ if (del_async) {
+ atomic_sub(tcp_ao_sizeof_key(key), &sk->sk_omem_alloc);
+ call_rcu(&key->rcu, tcp_ao_key_free_rcu);
+ return 0;
+ }
+
/* At this moment another CPU could have looked this key up
* while it was unlinked from the list. Wait for RCU grace period,
* after which the key is off-list and can't be looked up again;
* the rx path [just before RCU came] might have used it and set it
* as current_key (very unlikely).
+ * Free the key with next RCU grace period (in case it was
+ * current_key before tcp_ao_current_rnext() might have
+ * changed it in forced-delete).
*/
synchronize_rcu();
if (new_current)
@@ -1689,6 +1702,8 @@ static int tcp_ao_del_cmd(struct sock *sk, unsigned short int family,
if (!new_rnext)
return -ENOENT;
}
+ if (cmd.del_async && sk->sk_state != TCP_LISTEN)
+ return -EINVAL;
if (family == AF_INET) {
struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.addr;
@@ -1733,8 +1748,8 @@ static int tcp_ao_del_cmd(struct sock *sk, unsigned short int family,
if (key == new_current || key == new_rnext)
continue;
- return tcp_ao_delete_key(sk, ao_info, key,
- new_current, new_rnext);
+ return tcp_ao_delete_key(sk, ao_info, cmd.del_async, key,
+ new_current, new_rnext);
}
return -ENOENT;
}
--
2.41.0
Now there is a common function to verify signature on TCP segments:
tcp_inbound_hash(). It has checks for all possible cross-interactions
with MD5 signs as well as with unsigned segments.
The rules from RFC5925 are:
(1) Any TCP segment can have at max only one signature.
(2) TCP connections can't switch between using TCP-MD5 and TCP-AO.
(3) TCP-AO connections can't stop using AO, as well as unsigned
connections can't suddenly start using AO.
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/dropreason-core.h | 17 ++++
include/net/tcp.h | 53 ++++++++++-
include/net/tcp_ao.h | 17 ++++
net/ipv4/tcp.c | 39 ++------
net/ipv4/tcp_ao.c | 167 ++++++++++++++++++++++++++++++++++
net/ipv4/tcp_ipv4.c | 10 +-
net/ipv6/tcp_ao.c | 12 +++
net/ipv6/tcp_ipv6.c | 11 ++-
8 files changed, 283 insertions(+), 43 deletions(-)
diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
index 05255bffa2c8..1de089ab73fd 100644
--- a/include/net/dropreason-core.h
+++ b/include/net/dropreason-core.h
@@ -24,6 +24,10 @@
FN(TCP_MD5NOTFOUND) \
FN(TCP_MD5UNEXPECTED) \
FN(TCP_MD5FAILURE) \
+ FN(TCP_AONOTFOUND) \
+ FN(TCP_AOUNEXPECTED) \
+ FN(TCP_AOKEYNOTFOUND) \
+ FN(TCP_AOFAILURE) \
FN(SOCKET_BACKLOG) \
FN(TCP_FLAGS) \
FN(TCP_ZEROWINDOW) \
@@ -161,6 +165,19 @@ enum skb_drop_reason {
* to LINUX_MIB_TCPMD5FAILURE
*/
SKB_DROP_REASON_TCP_MD5FAILURE,
+ /**
+ * @SKB_DROP_REASON_TCP_AONOTFOUND: no TCP-AO hash and one was expected
+ */
+ SKB_DROP_REASON_TCP_AONOTFOUND,
+ /**
+ * @SKB_DROP_REASON_TCP_AOUNEXPECTED: TCP-AO hash is present and it
+ * was not expected.
+ */
+ SKB_DROP_REASON_TCP_AOUNEXPECTED,
+ /** @SKB_DROP_REASON_TCP_AOKEYNOTFOUND: TCP-AO key is unknown */
+ SKB_DROP_REASON_TCP_AOKEYNOTFOUND,
+ /** @SKB_DROP_REASON_TCP_AOFAILURE: TCP-AO hash is wrong */
+ SKB_DROP_REASON_TCP_AOFAILURE,
/**
* @SKB_DROP_REASON_SOCKET_BACKLOG: failed to add skb to socket backlog (
* see LINUX_MIB_TCPBACKLOGDROP)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index ad300e5b6eb8..6289ee642931 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1760,7 +1760,7 @@ tcp_md5_do_lookup_any_l3index(const struct sock *sk,
enum skb_drop_reason
tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
const void *saddr, const void *daddr,
- int family, int dif, int sdif);
+ int family, int l3index, const __u8 *hash_location);
#define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key)
@@ -1782,7 +1782,7 @@ tcp_md5_do_lookup_any_l3index(const struct sock *sk,
static inline enum skb_drop_reason
tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
const void *saddr, const void *daddr,
- int family, int dif, int sdif)
+ int family, int l3index, const __u8 *hash_location)
{
return SKB_NOT_DROPPED_YET;
}
@@ -2623,4 +2623,53 @@ static inline bool tcp_ao_required(struct sock *sk, const void *saddr,
return false;
}
+/* Called with rcu_read_lock() */
+static inline enum skb_drop_reason
+tcp_inbound_hash(struct sock *sk, const struct request_sock *req,
+ const struct sk_buff *skb,
+ const void *saddr, const void *daddr,
+ int family, int dif, int sdif)
+{
+ const struct tcphdr *th = tcp_hdr(skb);
+ const struct tcp_ao_hdr *aoh;
+ const __u8 *md5_location;
+ int l3index;
+
+ /* Invalid option or two times meet any of auth options */
+ if (tcp_parse_auth_options(th, &md5_location, &aoh))
+ return SKB_DROP_REASON_TCP_AUTH_HDR;
+
+ if (req) {
+ if (tcp_rsk_used_ao(req) != !!aoh)
+ return SKB_DROP_REASON_TCP_AOFAILURE;
+ }
+
+ /* sdif set, means packet ingressed via a device
+ * in an L3 domain and dif is set to the l3mdev
+ */
+ l3index = sdif ? dif : 0;
+
+ /* Fast path: unsigned segments */
+ if (likely(!md5_location && !aoh)) {
+ /* Drop if there's TCP-MD5 or TCP-AO key with any rcvid/sndid
+ * for the remote peer. On TCP-AO established connection
+ * the last key is impossible to remove, so there's
+ * always at least one current_key.
+ */
+ if (tcp_ao_required(sk, saddr, family))
+ return SKB_DROP_REASON_TCP_AONOTFOUND;
+ if (unlikely(tcp_md5_do_lookup(sk, l3index, saddr, family))) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
+ return SKB_DROP_REASON_TCP_MD5NOTFOUND;
+ }
+ return SKB_NOT_DROPPED_YET;
+ }
+
+ if (aoh)
+ return tcp_inbound_ao_hash(sk, skb, family, req, aoh);
+
+ return tcp_inbound_md5_hash(sk, skb, saddr, daddr, family,
+ l3index, md5_location);
+}
+
#endif /* _TCP_H */
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 4979c993973f..1b7ca7bf93a3 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -112,6 +112,9 @@ struct tcp6_ao_context {
};
struct tcp_sigpool;
+#define TCP_AO_ESTABLISHED (TCPF_ESTABLISHED|TCPF_FIN_WAIT1|TCPF_FIN_WAIT2|\
+ TCPF_CLOSE|TCPF_CLOSE_WAIT|TCPF_LAST_ACK|TCPF_CLOSING)
+
int tcp_ao_hash_skb(unsigned short int family,
char *ao_hash, struct tcp_ao_key *key,
const struct sock *sk, const struct sk_buff *skb,
@@ -127,6 +130,10 @@ int tcp_ao_calc_traffic_key(struct tcp_ao_key *mkt, u8 *key, void *ctx,
unsigned int len, struct tcp_sigpool *hp);
void tcp_ao_destroy_sock(struct sock *sk, bool twsk);
void tcp_ao_time_wait(struct tcp_timewait_sock *tcptw, struct tcp_sock *tp);
+enum skb_drop_reason tcp_inbound_ao_hash(struct sock *sk,
+ const struct sk_buff *skb, unsigned short int family,
+ const struct request_sock *req,
+ const struct tcp_ao_hdr *aoh);
struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
const union tcp_ao_addr *addr,
int family, int sndid, int rcvid, u16 port);
@@ -162,6 +169,9 @@ int tcp_v4_ao_hash_skb(char *ao_hash, struct tcp_ao_key *key,
int tcp_v6_ao_hash_pseudoheader(struct tcp_sigpool *hp,
const struct in6_addr *daddr,
const struct in6_addr *saddr, int nbytes);
+int tcp_v6_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
+ const struct sk_buff *skb, __be32 sisn,
+ __be32 disn);
int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk, __be32 sisn,
__be32 disn, bool send);
@@ -197,6 +207,13 @@ static inline void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
{
}
+static inline enum skb_drop_reason tcp_inbound_ao_hash(struct sock *sk,
+ const struct sk_buff *skb, unsigned short int family,
+ const struct request_sock *req, const struct tcp_ao_hdr *aoh)
+{
+ return SKB_NOT_DROPPED_YET;
+}
+
static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
const union tcp_ao_addr *addr,
int family, int sndid, int rcvid, u16 port)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index c90b3c6df620..d7e18c528c7b 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -4372,42 +4372,23 @@ EXPORT_SYMBOL(tcp_md5_hash_key);
enum skb_drop_reason
tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
const void *saddr, const void *daddr,
- int family, int dif, int sdif)
+ int family, int l3index, const __u8 *hash_location)
{
- /*
- * This gets called for each TCP segment that arrives
- * so we want to be efficient.
+ /* This gets called for each TCP segment that has TCP-MD5 option.
* We have 3 drop cases:
* o No MD5 hash and one expected.
* o MD5 hash and we're not expecting one.
* o MD5 hash and its wrong.
*/
- const __u8 *hash_location = NULL;
- struct tcp_md5sig_key *hash_expected;
const struct tcphdr *th = tcp_hdr(skb);
const struct tcp_sock *tp = tcp_sk(sk);
- int genhash, l3index;
+ struct tcp_md5sig_key *key;
+ int genhash;
u8 newhash[16];
- /* sdif set, means packet ingressed via a device
- * in an L3 domain and dif is set to the l3mdev
- */
- l3index = sdif ? dif : 0;
+ key = tcp_md5_do_lookup(sk, l3index, saddr, family);
- hash_expected = tcp_md5_do_lookup(sk, l3index, saddr, family);
- if (tcp_parse_auth_options(th, &hash_location, NULL))
- return SKB_DROP_REASON_TCP_AUTH_HDR;
-
- /* We've parsed the options - do we have a hash? */
- if (!hash_expected && !hash_location)
- return SKB_NOT_DROPPED_YET;
-
- if (hash_expected && !hash_location) {
- NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
- return SKB_DROP_REASON_TCP_MD5NOTFOUND;
- }
-
- if (!hash_expected && hash_location) {
+ if (!key && hash_location) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
return SKB_DROP_REASON_TCP_MD5UNEXPECTED;
}
@@ -4417,14 +4398,10 @@ tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb,
* IPv4-mapped case.
*/
if (family == AF_INET)
- genhash = tcp_v4_md5_hash_skb(newhash,
- hash_expected,
- NULL, skb);
+ genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb);
else
- genhash = tp->af_specific->calc_md5_hash(newhash,
- hash_expected,
+ genhash = tp->af_specific->calc_md5_hash(newhash, key,
NULL, skb);
-
if (genhash || memcmp(hash_location, newhash, 16) != 0) {
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE);
if (family == AF_INET) {
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 0233cf363de9..073be1680818 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -321,6 +321,30 @@ int tcp_v4_ao_calc_key_rsk(struct tcp_ao_key *mkt, u8 *key,
htonl(tcp_rsk(req)->rcv_isn));
}
+static int tcp_v4_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
+ const struct sk_buff *skb,
+ __be32 sisn, __be32 disn)
+{
+ const struct iphdr *iph = ip_hdr(skb);
+ const struct tcphdr *th = tcp_hdr(skb);
+
+ return tcp_v4_ao_calc_key(mkt, key, iph->saddr, iph->daddr,
+ th->source, th->dest, sisn, disn);
+}
+
+static int tcp_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
+ const struct sk_buff *skb, __be32 sisn,
+ __be32 disn, int family)
+{
+ if (family == AF_INET)
+ return tcp_v4_ao_calc_key_skb(mkt, key, skb, sisn, disn);
+#if IS_ENABLED(CONFIG_IPV6)
+ else if (family == AF_INET6)
+ return tcp_v6_ao_calc_key_skb(mkt, key, skb, sisn, disn);
+#endif
+ return -EAFNOSUPPORT;
+}
+
static int tcp_v4_ao_hash_pseudoheader(struct tcp_sigpool *hp,
__be32 daddr, __be32 saddr,
int nbytes)
@@ -711,6 +735,149 @@ void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,
treq->maclen = tcp_ao_maclen(key);
}
+static enum skb_drop_reason
+tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb,
+ unsigned short int family, struct tcp_ao_info *info,
+ const struct tcp_ao_hdr *aoh, struct tcp_ao_key *key,
+ u8 *traffic_key, u8 *phash, u32 sne)
+{
+ u8 maclen = aoh->length - sizeof(struct tcp_ao_hdr);
+ const struct tcphdr *th = tcp_hdr(skb);
+ void *hash_buf = NULL;
+
+ if (maclen != tcp_ao_maclen(key))
+ return SKB_DROP_REASON_TCP_AOFAILURE;
+
+ hash_buf = kmalloc(tcp_ao_digest_size(key), GFP_ATOMIC);
+ if (!hash_buf)
+ return SKB_DROP_REASON_NOT_SPECIFIED;
+
+ /* XXX: make it per-AF callback? */
+ tcp_ao_hash_skb(family, hash_buf, key, sk, skb, traffic_key,
+ (phash - (u8 *)th), sne);
+ if (memcmp(phash, hash_buf, maclen)) {
+ kfree(hash_buf);
+ return SKB_DROP_REASON_TCP_AOFAILURE;
+ }
+ kfree(hash_buf);
+ return SKB_NOT_DROPPED_YET;
+}
+
+enum skb_drop_reason
+tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
+ unsigned short int family, const struct request_sock *req,
+ const struct tcp_ao_hdr *aoh)
+{
+ const struct tcphdr *th = tcp_hdr(skb);
+ u8 *phash = (u8 *)(aoh + 1); /* hash goes just after the header */
+ struct tcp_ao_info *info;
+ enum skb_drop_reason ret;
+ struct tcp_ao_key *key;
+ __be32 sisn, disn;
+ u8 *traffic_key;
+ u32 sne = 0;
+
+ info = rcu_dereference(tcp_sk(sk)->ao_info);
+ if (!info)
+ return SKB_DROP_REASON_TCP_AOUNEXPECTED;
+
+ if (unlikely(th->syn)) {
+ sisn = th->seq;
+ disn = 0;
+ }
+
+ /* Fast-path */
+ /* TODO: fix fastopen and simultaneous open (TCPF_SYN_RECV) */
+ if (likely((1 << sk->sk_state) & (TCP_AO_ESTABLISHED | TCPF_SYN_RECV))) {
+ enum skb_drop_reason err;
+ struct tcp_ao_key *current_key;
+
+ /* Check if this socket's rnext_key matches the keyid in the
+ * packet. If not we lookup the key based on the keyid
+ * matching the rcvid in the mkt.
+ */
+ key = READ_ONCE(info->rnext_key);
+ if (key->rcvid != aoh->keyid) {
+ key = tcp_ao_established_key(info, -1, aoh->keyid);
+ if (!key)
+ goto key_not_found;
+ }
+
+ /* Delayed retransmitted SYN */
+ if (unlikely(th->syn && !th->ack))
+ goto verify_hash;
+
+ sne = 0;
+ /* Established socket, traffic key are cached */
+ traffic_key = rcv_other_key(key);
+ err = tcp_ao_verify_hash(sk, skb, family, info, aoh, key,
+ traffic_key, phash, sne);
+ if (err)
+ return err;
+ current_key = READ_ONCE(info->current_key);
+ /* Key rotation: the peer asks us to use new key (RNext) */
+ if (unlikely(aoh->rnext_keyid != current_key->sndid)) {
+ /* If the key is not found we do nothing. */
+ key = tcp_ao_established_key(info, aoh->rnext_keyid, -1);
+ if (key)
+ /* pairs with tcp_ao_del_cmd */
+ WRITE_ONCE(info->current_key, key);
+ }
+ return SKB_NOT_DROPPED_YET;
+ }
+
+ /* Lookup key based on peer address and keyid.
+ * current_key and rnext_key must not be used on tcp listen
+ * sockets as otherwise:
+ * - request sockets would race on those key pointers
+ * - tcp_ao_del_cmd() allows async key removal
+ */
+ key = tcp_ao_inbound_lookup(family, sk, skb, -1, aoh->keyid);
+ if (!key)
+ goto key_not_found;
+
+ if (th->syn && !th->ack)
+ goto verify_hash;
+
+ if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV)) {
+ /* Make the initial syn the likely case here */
+ if (unlikely(req)) {
+ sne = 0;
+ sisn = htonl(tcp_rsk(req)->rcv_isn);
+ disn = htonl(tcp_rsk(req)->snt_isn);
+ } else if (unlikely(th->ack && !th->syn)) {
+ /* Possible syncookie packet */
+ sisn = htonl(ntohl(th->seq) - 1);
+ disn = htonl(ntohl(th->ack_seq) - 1);
+ sne = 0;
+ } else if (unlikely(!th->syn)) {
+ /* no way to figure out initial sisn/disn - drop */
+ return SKB_DROP_REASON_TCP_FLAGS;
+ }
+ } else if (sk->sk_state == TCP_SYN_SENT) {
+ disn = info->lisn;
+ if (th->syn || th->rst)
+ sisn = th->seq;
+ else
+ sisn = info->risn;
+ } else {
+ WARN_ONCE(1, "TCP-AO: Unexpected sk_state %d", sk->sk_state);
+ return SKB_DROP_REASON_TCP_AOFAILURE;
+ }
+verify_hash:
+ traffic_key = kmalloc(tcp_ao_digest_size(key), GFP_ATOMIC);
+ if (!traffic_key)
+ return SKB_DROP_REASON_NOT_SPECIFIED;
+ tcp_ao_calc_key_skb(key, traffic_key, skb, sisn, disn, family);
+ ret = tcp_ao_verify_hash(sk, skb, family, info, aoh, key,
+ traffic_key, phash, sne);
+ kfree(traffic_key);
+ return ret;
+
+key_not_found:
+ return SKB_DROP_REASON_TCP_AOKEYNOTFOUND;
+}
+
static int tcp_ao_cache_traffic_keys(const struct sock *sk,
struct tcp_ao_info *ao,
struct tcp_ao_key *ao_key)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 884d9f854276..f09c0389ae11 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2200,9 +2200,9 @@ int tcp_v4_rcv(struct sk_buff *skb)
if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
drop_reason = SKB_DROP_REASON_XFRM_POLICY;
else
- drop_reason = tcp_inbound_md5_hash(sk, skb,
- &iph->saddr, &iph->daddr,
- AF_INET, dif, sdif);
+ drop_reason = tcp_inbound_hash(sk, req, skb,
+ &iph->saddr, &iph->daddr,
+ AF_INET, dif, sdif);
if (unlikely(drop_reason)) {
sk_drops_add(sk, skb);
reqsk_put(req);
@@ -2279,8 +2279,8 @@ int tcp_v4_rcv(struct sk_buff *skb)
goto discard_and_relse;
}
- drop_reason = tcp_inbound_md5_hash(sk, skb, &iph->saddr,
- &iph->daddr, AF_INET, dif, sdif);
+ drop_reason = tcp_inbound_hash(sk, NULL, skb, &iph->saddr, &iph->daddr,
+ AF_INET, dif, sdif);
if (drop_reason)
goto discard_and_relse;
diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c
index ec320781bc5c..984a75f96e20 100644
--- a/net/ipv6/tcp_ao.c
+++ b/net/ipv6/tcp_ao.c
@@ -49,6 +49,18 @@ static int tcp_v6_ao_calc_key(struct tcp_ao_key *mkt, u8 *key,
return err;
}
+int tcp_v6_ao_calc_key_skb(struct tcp_ao_key *mkt, u8 *key,
+ const struct sk_buff *skb,
+ __be32 sisn, __be32 disn)
+{
+ const struct ipv6hdr *iph = ipv6_hdr(skb);
+ const struct tcphdr *th = tcp_hdr(skb);
+
+ return tcp_v6_ao_calc_key(mkt, key, &iph->saddr,
+ &iph->daddr, th->source,
+ th->dest, sisn, disn);
+}
+
int tcp_v6_ao_calc_key_sk(struct tcp_ao_key *mkt, u8 *key,
const struct sock *sk, __be32 sisn,
__be32 disn, bool send)
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 000e4e5309d3..40266a3a99a6 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1779,9 +1779,9 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
struct sock *nsk;
sk = req->rsk_listener;
- drop_reason = tcp_inbound_md5_hash(sk, skb,
- &hdr->saddr, &hdr->daddr,
- AF_INET6, dif, sdif);
+ drop_reason = tcp_inbound_hash(sk, req, skb,
+ &hdr->saddr, &hdr->daddr,
+ AF_INET6, dif, sdif);
if (drop_reason) {
sk_drops_add(sk, skb);
reqsk_put(req);
@@ -1854,8 +1854,8 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
goto discard_and_relse;
}
- drop_reason = tcp_inbound_md5_hash(sk, skb, &hdr->saddr, &hdr->daddr,
- AF_INET6, dif, sdif);
+ drop_reason = tcp_inbound_hash(sk, NULL, skb, &hdr->saddr, &hdr->daddr,
+ AF_INET6, dif, sdif);
if (drop_reason)
goto discard_and_relse;
@@ -2083,6 +2083,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
.ao_lookup = tcp_v6_ao_lookup,
.calc_ao_hash = tcp_v4_ao_hash_skb,
.ao_parse = tcp_v6_parse_ao,
+ .ao_calc_key_sk = tcp_v4_ao_calc_key_sk,
#endif
};
#endif
--
2.41.0
Add Sequence Number Extension (SNE) for TCP-AO.
This is needed to protect long-living TCP-AO connections from replaying
attacks after sequence number roll-over, see RFC5925 (6.2).
Co-developed-by: Francesco Ruggeri <[email protected]>
Signed-off-by: Francesco Ruggeri <[email protected]>
Co-developed-by: Salam Noureddine <[email protected]>
Signed-off-by: Salam Noureddine <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
---
include/net/tcp_ao.h | 20 ++++++++++++++++++++
net/ipv4/tcp_ao.c | 40 +++++++++++++++++++++++++++++++++-------
net/ipv4/tcp_input.c | 28 ++++++++++++++++++++++++++++
net/ipv4/tcp_ipv4.c | 1 +
net/ipv4/tcp_minisocks.c | 15 ++++++++++++++-
net/ipv4/tcp_output.c | 6 +++++-
net/ipv6/tcp_ipv6.c | 1 +
7 files changed, 102 insertions(+), 9 deletions(-)
diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 0a02098bddeb..fc5674763730 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -96,6 +96,25 @@ struct tcp_ao_info {
__unused :31;
__be32 lisn;
__be32 risn;
+ /* Sequence Number Extension (SNE) are upper 4 bytes for SEQ,
+ * that protect TCP-AO connection from replayed old TCP segments.
+ * See RFC5925 (6.2).
+ * In order to get correct SNE, there's a helper tcp_ao_compute_sne().
+ * It needs SEQ basis to understand whereabouts are lower SEQ numbers.
+ * According to that basis vector, it can provide incremented SNE
+ * when SEQ rolls over or provide decremented SNE when there's
+ * a retransmitted segment from before-rolling over.
+ * - for request sockets such basis is rcv_isn/snt_isn, which seems
+ * good enough as it's unexpected to receive 4 Gbytes on reqsk.
+ * - for full sockets the basis is rcv_nxt/snd_una. snd_una is
+ * taken instead of snd_nxt as currently it's easier to track
+ * in tcp_snd_una_update(), rather than updating SNE in all
+ * WRITE_ONCE(tp->snd_nxt, ...)
+ * - for time-wait sockets the basis is tw_rcv_nxt/tw_snd_nxt.
+ * tw_snd_nxt is not expected to change, while tw_rcv_nxt may.
+ */
+ u32 snd_sne;
+ u32 rcv_sne;
atomic_t refcnt; /* Protects twsk destruction */
struct rcu_head rcu;
};
@@ -144,6 +163,7 @@ enum skb_drop_reason tcp_inbound_ao_hash(struct sock *sk,
const struct sk_buff *skb, unsigned short int family,
const struct request_sock *req,
const struct tcp_ao_hdr *aoh);
+u32 tcp_ao_compute_sne(u32 next_sne, u32 next_seq, u32 seq);
struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
const union tcp_ao_addr *addr,
int family, int sndid, int rcvid, u16 port);
diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
index 5ab66928a952..5ebbfadfbfd0 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -403,6 +403,21 @@ static int tcp_ao_hash_pseudoheader(unsigned short int family,
return -EAFNOSUPPORT;
}
+u32 tcp_ao_compute_sne(u32 next_sne, u32 next_seq, u32 seq)
+{
+ u32 sne = next_sne;
+
+ if (before(seq, next_seq)) {
+ if (seq > next_seq)
+ sne--;
+ } else {
+ if (seq < next_seq)
+ sne++;
+ }
+
+ return sne;
+}
+
/* tcp_ao_hash_sne(struct tcp_sigpool *hp)
* @hp - used for hashing
* @sne - sne value
@@ -641,7 +656,8 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
sisn = htonl(tcp_rsk(req)->rcv_isn);
disn = htonl(tcp_rsk(req)->snt_isn);
- *sne = 0;
+ *sne = tcp_ao_compute_sne(0, tcp_rsk(req)->snt_isn,
+ ntohl(seq));
} else {
sisn = th->seq;
disn = 0;
@@ -674,11 +690,15 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
*keyid = (*key)->rcvid;
} else {
struct tcp_ao_key *rnext_key;
+ u32 snd_basis;
- if (sk->sk_state == TCP_TIME_WAIT)
+ if (sk->sk_state == TCP_TIME_WAIT) {
ao_info = rcu_dereference(tcp_twsk(sk)->ao_info);
- else
+ snd_basis = tcp_twsk(sk)->tw_snd_nxt;
+ } else {
ao_info = rcu_dereference(tcp_sk(sk)->ao_info);
+ snd_basis = tcp_sk(sk)->snd_una;
+ }
if (!ao_info)
return -ENOENT;
@@ -688,7 +708,8 @@ int tcp_ao_prepare_reset(const struct sock *sk, struct sk_buff *skb,
*traffic_key = snd_other_key(*key);
rnext_key = READ_ONCE(ao_info->rnext_key);
*keyid = rnext_key->rcvid;
- *sne = 0;
+ *sne = tcp_ao_compute_sne(READ_ONCE(ao_info->snd_sne),
+ snd_basis, ntohl(seq));
}
return 0;
}
@@ -821,7 +842,8 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
if (unlikely(th->syn && !th->ack))
goto verify_hash;
- sne = 0;
+ sne = tcp_ao_compute_sne(info->rcv_sne, tcp_sk(sk)->rcv_nxt,
+ ntohl(th->seq));
/* Established socket, traffic key are cached */
traffic_key = rcv_other_key(key);
err = tcp_ao_verify_hash(sk, skb, family, info, aoh, key,
@@ -856,14 +878,16 @@ tcp_inbound_ao_hash(struct sock *sk, const struct sk_buff *skb,
if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV)) {
/* Make the initial syn the likely case here */
if (unlikely(req)) {
- sne = 0;
+ sne = tcp_ao_compute_sne(0, tcp_rsk(req)->rcv_isn,
+ ntohl(th->seq));
sisn = htonl(tcp_rsk(req)->rcv_isn);
disn = htonl(tcp_rsk(req)->snt_isn);
} else if (unlikely(th->ack && !th->syn)) {
/* Possible syncookie packet */
sisn = htonl(ntohl(th->seq) - 1);
disn = htonl(ntohl(th->ack_seq) - 1);
- sne = 0;
+ sne = tcp_ao_compute_sne(0, ntohl(sisn),
+ ntohl(th->seq));
} else if (unlikely(!th->syn)) {
/* no way to figure out initial sisn/disn - drop */
return SKB_DROP_REASON_TCP_FLAGS;
@@ -963,6 +987,7 @@ void tcp_ao_connect_init(struct sock *sk)
tp->tcp_header_len += tcp_ao_len(key);
ao_info->lisn = htonl(tp->write_seq);
+ ao_info->snd_sne = 0;
} else {
/* TODO: probably, it should fail to connect() here */
rcu_assign_pointer(tp->ao_info, NULL);
@@ -981,6 +1006,7 @@ void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb)
return;
ao->risn = tcp_hdr(skb)->seq;
+ ao->rcv_sne = 0;
hlist_for_each_entry_rcu(key, &ao->head, node)
tcp_ao_cache_traffic_keys(sk, ao, key);
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 2a7ed329f7cb..4b37e82ab612 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3532,9 +3532,18 @@ static inline bool tcp_may_update_window(const struct tcp_sock *tp,
static void tcp_snd_una_update(struct tcp_sock *tp, u32 ack)
{
u32 delta = ack - tp->snd_una;
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_info *ao;
+#endif
sock_owned_by_me((struct sock *)tp);
tp->bytes_acked += delta;
+#ifdef CONFIG_TCP_AO
+ ao = rcu_dereference_protected(tp->ao_info,
+ lockdep_sock_is_held((struct sock *)tp));
+ if (ao && ack < tp->snd_una)
+ ao->snd_sne++;
+#endif
tp->snd_una = ack;
}
@@ -3542,9 +3551,18 @@ static void tcp_snd_una_update(struct tcp_sock *tp, u32 ack)
static void tcp_rcv_nxt_update(struct tcp_sock *tp, u32 seq)
{
u32 delta = seq - tp->rcv_nxt;
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_info *ao;
+#endif
sock_owned_by_me((struct sock *)tp);
tp->bytes_received += delta;
+#ifdef CONFIG_TCP_AO
+ ao = rcu_dereference_protected(tp->ao_info,
+ lockdep_sock_is_held((struct sock *)tp));
+ if (ao && seq < tp->rcv_nxt)
+ ao->rcv_sne++;
+#endif
WRITE_ONCE(tp->rcv_nxt, seq);
}
@@ -6387,6 +6405,16 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
* simultaneous connect with crossed SYNs.
* Particularly, it can be connect to self.
*/
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_info *ao;
+
+ ao = rcu_dereference_protected(tp->ao_info,
+ lockdep_sock_is_held(sk));
+ if (ao) {
+ ao->risn = th->seq;
+ ao->rcv_sne = 0;
+ }
+#endif
tcp_set_state(sk, TCP_SYN_RECV);
if (tp->rx_opt.saw_tstamp) {
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index d8d2499b5e26..37497dec5eb9 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1039,6 +1039,7 @@ static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
struct tcp_ao_key *rnext_key;
traffic_key = snd_other_key(ao_key);
+ ao_sne = READ_ONCE(ao_info->snd_sne);
rnext_key = READ_ONCE(ao_info->rnext_key);
rcv_next = rnext_key->rcvid;
}
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 11b76fa601a7..3b367365dc7d 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -51,6 +51,18 @@ tcp_timewait_check_oow_rate_limit(struct inet_timewait_sock *tw,
return TCP_TW_SUCCESS;
}
+static void twsk_rcv_nxt_update(struct tcp_timewait_sock *tcptw, u32 seq)
+{
+#ifdef CONFIG_TCP_AO
+ struct tcp_ao_info *ao;
+
+ ao = rcu_dereference(tcptw->ao_info);
+ if (unlikely(ao && seq < tcptw->tw_rcv_nxt))
+ WRITE_ONCE(ao->rcv_sne, ao->rcv_sne + 1);
+#endif
+ tcptw->tw_rcv_nxt = seq;
+}
+
/*
* * Main purpose of TIME-WAIT state is to close connection gracefully,
* when one of ends sits in LAST-ACK or CLOSING retransmitting FIN
@@ -136,7 +148,8 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
/* FIN arrived, enter true time-wait state. */
tw->tw_substate = TCP_TIME_WAIT;
- tcptw->tw_rcv_nxt = TCP_SKB_CB(skb)->end_seq;
+ twsk_rcv_nxt_update(tcptw, TCP_SKB_CB(skb)->end_seq);
+
if (tmp_opt.saw_tstamp) {
tcptw->tw_ts_recent_stamp = ktime_get_seconds();
tcptw->tw_ts_recent = tmp_opt.rcv_tsval;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index ed1164f287b7..d87a3823fec5 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1443,6 +1443,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
u8 *traffic_key;
void *tkey_buf = NULL;
u32 disn;
+ u32 sne;
sk_gso_disable(sk);
if (unlikely(tcb->tcp_flags & TCPHDR_SYN)) {
@@ -1460,9 +1461,12 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
} else {
traffic_key = snd_other_key(ao_key);
}
+ sne = tcp_ao_compute_sne(READ_ONCE(ao->snd_sne),
+ READ_ONCE(tp->snd_una),
+ ntohl(th->seq));
tp->af_specific->calc_ao_hash(opts.hash_location, ao_key, sk, skb,
traffic_key,
- opts.hash_location - (u8 *)th, 0);
+ opts.hash_location - (u8 *)th, sne);
kfree(tkey_buf);
}
#endif
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index c825d7c80f5b..873ce0d72f34 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1180,6 +1180,7 @@ static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
/* rcv_next switches to our rcv_next */
rnext_key = READ_ONCE(ao_info->rnext_key);
rcv_next = rnext_key->rcvid;
+ ao_sne = READ_ONCE(ao_info->snd_sne);
}
#endif
--
2.41.0
On 7/21/23 10:18 AM, Dmitry Safonov wrote:
> Hi,
>
> This is version 8.1 of TCP-AO support. I base it on net-next as
> there's commit 5e5265522a9a ("tcp: annotate data-races around
> tcp_rsk(req)->txhash") which makes a minor conflict.
>
> The good news is that all pre-required patches have merged to
> Torvald's/master. Thanks to Herbert, crypto clone-tfm just works on
> master for all TCP-AO supported algorithms.
> So, this is the first version of the patch set that has only net-related
> changes (well, selftests as well, but they'll be upstreamed separately).
>
> In this version, I've finally spent time and written Documentation/ page
> on TCP-AO. It has Frequently Asked Questions (FAQ) on RFC 5925 - I found
> it very useful to answer those before writing the actual code.
> It provides answers to common questions that arise on a quick read of
> the RFC as well as how they were answered. There's also a comparison
> to the TCP-MD5 option, an evaluation of per-socket vs in-kernel-DB
> approaches and a description of uAPI provided.
> I hope it will be as useful for reviewing the code as it was for writing.
>
> The most important changes in this version are:
> - CONFIG_TCP_AO implies CONFIG_IPV6 != m. I don't feel like that
> combination would be useful to anyone and it'd be painful to fix.
> - uAPI change in TCP_AO_REPAIR (introduced in version 7): I removed
> {snd,rcv}_sne_seq counters. They were just copies of snd_nxt/snd_una.
> No reason for polluting uAPI as well as needlessly copying them.
> - TCP_AO_MAX_HASH_SIZE is removed and all temporary buffers are
> kmalloc()'d. That also saves a couple of bytes for hmac(sha1) and
> cmac(aes128) traffic keys as they now are allocated with
> exact hash algo's digest_size.
>
> There's an independent patch set for TCP-MD5 to verify segments on twsk:
> https://lore.kernel.org/all/[email protected]/T/#u
> That may be used to verify TCP-AO segments on twsk as well.
>
> There seem to be more people that connected me off-list asking me about
> the status of patches and when I expect them to merge. Cc'ing more
> interested parties here (ping me directly if you don't want to be in
> copy). It would be helpful if you provide your reviews and tested-by's.
> As far as I'm aware, version 7 was ported to RHEL, so now there are
> probably more downstream kernels with TCP-AO support.
>
> Also available as a git branch for pulling:
> https://github.com/0x7f454c46/linux/tree/tcp-ao-v8.1
> And another branch with selftests, that will be sent later separately:
> https://github.com/0x7f454c46/linux/tree/tcp-ao-v8-with-selftests
>
> Thanks for your time and reviews,
> Dmitry
>
> --- Changelog ---
>
> Changes from v8:
> - Rebased/retested on linux-net-next
>
> Version 8: https://lore.kernel.org/all/[email protected]/T/#u
>
> Changes from v7:
> - Fixed copy'n'paste typo in unsigned-md5.c selftest output
> - Fix build error in tcp_v6_send_reset() (kernel test robot <[email protected]>)
> - Make CONFIG_TCP_AO imply IPV6 != m
> - Cleanup EXPORT_SYMBOL*() as they aren't needed with IPV6 != m
> - Used scratch area instead of on-stack buffer for scatter-gather list
> in tcp_v{4,6}_ao_calc_key(). Fixes CONFIG_VMAP_STACK=y + CONFIG_DEBUG_SG=y
> - Allocated digest_size'd buffers for traffic keys in tcp_ao_key instead
> of maximum-sized buffers of TCP_AO_MAX_HASH_SIZE. That will save
> little space per key and also potentially allow algorithms with
> digest size > TCP_AO_MAX_HASH_SIZE.
> - Removed TCP_AO_MAX_HASH_SIZE and used kmalloc(GFP_ATOMIC) instead of
> on-stack hash buffer.
> - Don't treat fd=0 as invalid in selftests
> - Make TCP-AO selftests work with CONFIG_CRYPTO_FIPS=y
> - Don't tcp_ao_compute_sne() for snd_sne on twsk: it's redundant as
> no data can be sent on twsk
> - Get rid of {snd,rcv}_sne_seq: use snd_nxt/snd_una or rcv_nxt instead
> - {rcv,snd}_sne and tcp_ao_compute_sne() now are introduced in
> "net/tcp: Add TCP-AO SNE support" patch
> - trivial copy_to_sockptr() fixup for tcp_ao_get_repair() - it could
> try copying bigger struct than the kernel one (embarrassing!)
> - Added Documentation/networking/tcp_ao.rst that describes:
> uAPI, has FAQ on RFC 5925 and has implementation details of Linux TCP-AO
>
> Version 7: https://lore.kernel.org/all/[email protected]/T/#u
>
> Changes from v6:
> - Some more trivial build warnings fixups (kernel test robot <[email protected]>)
> - Added TCP_AO_REPAIR setsockopt(), getsockopt()
> - Allowed TCP_AO_* setsockopts if (tp->repair) is on
> - Added selftests for TCP_AO_REPAIR, that also check incorrect
> ISNs/SNEs, which result in a broken TCP-AO connection - that verifies
> that both Initial Sequence Numbers and Sequence Number Extension are
> part of MAC generation
> - Using TCP_AO_REPAIR added a selftest for SEQ numbers rollover,
> checking that SNE was incremented, connection is alive post-rolloever
> and no TCP segments with a wrong signature arrived
> - Wrote a selftest for RST segments: both active reset (goes through
> transmit_skb()) and passive reset (goes through tcp_v{4,6}_send_reset()).
> - Refactored and made readable tcp_v{4,6}_send_reset(), also adding
> support for TCP_LISTEN/TCP_NEW_SYN_RECV
> - Dropped per-CPU ahash requests allocations in favor of Herbert's
> clone-tfm crypto API
> - Added Donald Cassidy to Cc as he's interested in getting it into RHEL.
>
> Version 6: https://lore.kernel.org/all/[email protected]/T/#u
>
> iperf[3] benchmarks for version 6:
> v6.4-rc1 TCP-AO-v6
> TCP 43.9 Gbits/sec 43.5 Gbits/sec
> TCP-MD5 2.20 Gbits/sec 2.25 Gbits/sec
> TCP-AO(hmac(sha1)) 2.53 Gbits/sec
> TCP-AO(hmac(sha512)) 1.67 Gbits/sec
> TCP-AO(hmac(sha384)) 1.77 Gbits/sec
> TCP-AO(hmac(sha224)) 1.29 Gbits/sec
> TCP-AO(hmac(sha3-512)) 481 Mbits/sec
> TCP-AO(hmac(md5)) 2.07 Gbits/sec
> TCP-AO(hmac(rmd160)) 1.01 Gbits/sec
> TCP-AO(cmac(aes128)) 2.11 Gbits/sec
>
> Changes from v5:
> - removed check for TCP_AO_KEYF_IFINDEX in delete command:
> VRF might have been destroyed, there still needs to be a way to delete
> keys that were bound to that l3intf (should tcp_v{4,6}_parse_md5_keys()
> avoid the same check as well?)
> - corrected copy'n'paste typo in tcp_ao_info_cmd() (assign ao_info->rnext_key)
> - simplified a bit tcp_ao_copy_mkts_to_user(); added more UAPI checks
> for getsockopt(TCP_AO_GET_KEYS)
> - More UAPI selftests in setsockopt-closed: 29 => 120
> - ported TCP-AO patches on Herbert's clone-tfm changes
> - adjusted iperf patch for TCP-AO UAPI changes from version 5
> - added measures for TCP-AO with tcp_sigpool & clone_tfm backends
>
> Version 5: https://lore.kernel.org/all/[email protected]/T/#u
>
> Changes from v4:
> - Renamed tcp_ao_matched_key() => tcp_ao_established_key()
> - Missed `static` in function definitions
> (kernel test robot <[email protected]>)
> - Fixed CONFIG_IPV6=m build
> - Unexported tcp_md5_*_sigpool() functions
> - Cleaned up tcp_ao.h: undeclared tcp_ao_cache_traffic_keys(),
> tcp_v4_ao_calc_key_skb(); removed tcp_v4_inbound_ao_hash()
> - Marked "net/tcp: Prepare tcp_md5sig_pool for TCP-AO" as a [draft] patch
> - getsockopt() now returns TCP-AO per-key counters
> - Another getsockopt() now returns per-ao_info stats: counters
> and accept_icmps flag state
> - Wired up getsockopt() returning counters to selftests
> - Fixed a porting mistake: TCP-AO hash in some cases was written in TCP
> header without accounting for MAC length of the key, rewritting skb
> shared info
> - Fail adding a key with L3 ifindex when !TCP_AO_KEYF_IFINDEX, instead
> of ignoring tcpa_ifindex (stricter UAPI check)
> - Added more test-cases to setsockopt-closed.c selftest
> - tcp_ao_hash_skb_data() was a copy'n'paste of tcp_md5_hash_skb_data()
> share it now under tcp_sigpool_hash_skb_data()
> - tcp_ao_mkt_overlap_v{4,6}() deleted as they just re-invented
> tcp_ao_do_lookup(). That fixes an issue with multiple IPv4-mapped-IPv6
> keys for different peers on a listening socket.
> - getsockopt() now is tested to return correct VRF number for a key
> - TCP-AO and TCP-MD5 interraction in non/default VRFs: added +19 selftests
> made them SKIP when CONFIG_VRF=n
> - unsigned-md5 selftests now checks both scenarios:
> (1) adding TCP-AO key _after_ TCP-MD5 key
> (2) adding TCP-MD5 key _after_ TCP-AO key
> - Added a ratelimited warning if TCP-AO key.ifindex doesn't match
> sk->sk_bound_dev_if - that will warn a user for potential VRF issues
> - tcp_v{4,6}_parse_md5_keys() now allows adding TCP-MD5 key with
> ifindex=0 and TCP_MD5SIG_FLAG_IFINDEX together with TCP-AO key from
> another VRF
> - Add TCP_AO_CMDF_AO_REQUIRED, which makes a socket TCP-AO only,
> rejecting TCP-MD5 keys or any unsigned TCP segments
> - Remove `tcpa_' prefix for UAPI structure members
> - UAPI cleanup: I've separated & renamed per-socket settings
> (such as ao_info flags + current/rnext set) from per-key changes:
> TCP_AO => TCP_AO_ADD_KEY
> TCP_AO_DEL => TCP_AO_DEL_KEY
> TCP_AO_GET => TCP_AO_GET_KEYS
> TCP_AO_MOD => TCP_AO_INFO, the structure is now valid for both
> getsockopt() and setsockopt().
> - tcp_ao_current_rnext() was split up in order to fail earlier when
> sndid/rcvid specified can't be set, before anything was changed in ao_info
> - fetch current_key before dumping TCP-AO keys in getsockopt(TCP_AO_GET_KEYS):
> it may race with changing current_key by RX, which in result might
> produce a dump with no current_key for userspace.
> - instead of TCP_AO_CMDF_* flags, used bitfileds: the flags weren't
> shared between all TCP_AO_{ADD,GET,DEL}_KEY{,S}, so bitfields are more
> descriptive here
> - use READ_ONCE()/WRITE_ONCE() for current_key and rnext_key more
> consistently; document in comment the rules for accessing them
> - selftests: check all setsockopts()/getsockopts() support extending
> option structs
>
> Version 4: https://lore.kernel.org/all/[email protected]/T/#u
>
> Changes from v3:
> - TCP_MD5 dynamic static key enable/disable patches merged separately [4]
> - crypto_pool patches were nacked [5], so instead this patch set extends
> TCP-MD5-sigpool to be used for TCP-AO as well as for TCP-MD5
> - Added missing `static' for tcp_v6_ao_calc_key()
> (kernel test robot <[email protected]>)
> - Removed CONFIG_TCP_AO default=y and added "If unsure, say N."
> - Don't leak ao_info and don't create an unsigned TCP socket if there was
> a TCP-AO key during handshake, but it was removed from listening socket
> while the connection was being established
> - Migrate to use static_key_fast_inc_not_disabled() and check return
> code of static_branch_inc()
> - Change some return codes to EAFNOSUPPORT for error-pathes where
> family is neither AF_INET nor AF_INET6
> - setsockopt()s on a closed/listen socket might have created stray ao_info,
> remove it if connect() is called with a correct TCP-MD5 key, the same
> for the reverse situation: remove md5sig_info straight away from the
> socket if it's going to be TCP-AO connection
> - IPv4-mapped-IPv6 addresses + selftest in fcnal-test.sh (by Salam)
> - fix using uninitialized sisn/disn from stack - it would only make
> non-SYN packets fail verification on a listen socket, which are not
> expected anyway (kernel test robot <[email protected]>)
> - implicit padding in UAPI TCP-AO structures converted to explicit
> (spotted-by David Laight)
> - Some selftests missed zero-initializers for uapi structs on stack
> - Removed tcp_ao_do_lookup_rcvid() and tcp_ao_do_lookup_sndid() in
> favor of unified tcp_ao_matched_key()
> - Disallowed setting current/rnext keys on listen sockets - that wasn't
> supported and didn't affect anything, cleanup for the UAPI
> - VRFs support for TCP-AO
>
> Version 3: https://lore.kernel.org/all/[email protected]/T/#u
>
> Changes from v2:
> - Added more missing `static' declarations for local functions
> (kernel test robot <[email protected]>)
> - Building now with CONFIG_TCP_AO=n and CONFIG_TCP_MD5SIG=n
> (kernel test robot <[email protected]>)
> - Now setsockopt(TCP_AO) is allowed when it's TCP_LISTEN or TCP_CLOSE
> state OR the key added is not the first key on a socket (by Salam)
> - CONFIG_TCP_AO does not depend on CONFIG_TCP_MD5SIG anymore
> - Don't leak tcp_md5_needed static branch counter when TCP-MD5 key
> is modified/changed
> - TCP-AO lookups are dynamically enabled/disabled with static key when
> there is ao_info in the system (and when it is destroyed)
> - Wired SYN cookies up to TCP-AO (by Salam)
> - Fix verification for possible re-transmitted SYN packets (by Salam)
> - use sockopt_lock_sock() instead of lock_sock()
> (from v6.1 rebase, commit d51bbff2aba7)
> - use sockptr_t in getsockopt(TCP_AO_GET)
> (from v6.1 rebase, commit 34704ef024ae)
> - Fixed reallocating crypto_pool's scratch area by IPI while
> crypto_pool_get() was get by another CPU
> - selftests on older kernels (or with CONFIG_TCP_AO=n) should exit with
> SKIP, not FAIL (Shuah Khan <[email protected]>)
> - selftests that check interaction between TCP-AO and TCP-MD5 now
> SKIP when CONFIG_TCP_MD5SIG=n
> - Measured the performance of different hashing algorithms for TCP-AO
> and compare with TCP-MD5 performance. This is done with hacky patches
> to iperf (see [3]). At this moment I've done it in qemu/KVM with CPU
> affinities set on Intel(R) Core(TM) i7-7600U CPU @ 2.80GHz.
> No performance degradation was noticed before/after patches, but given
> the measures were done in a VM, without measuring it on a physical dut
> it only gives a hint of relative speed for different hash algorithms
> with TCP-AO. Here are results, averaging on 30 measures each:
> TCP: 3.51Gbits/sec
> TCP-MD5: 1.12Gbits/sec
> TCP-AO(HMAC(SHA1)): 1.53Gbits/sec
> TCP-AO(CMAC(AES128)): 621Mbits/sec
> TCP-AO(HMAC(SHA512)): 1.21Gbits/sec
> TCP-AO(HMAC(SHA384)): 1.20Gbits/sec
> TCP-AO(HMAC(SHA224)): 961Mbits/sec
> TCP-AO(HMAC(SHA3-512)): 157Mbits/sec
> TCP-AO(HMAC(RMD160)): 659Mbits/sec
> TCP-AO(HMAC(MD5): 1.12Gbits/sec
> (the last one is just for fun, but may make sense as it provides
> the same security as TCP-MD5, but allows multiple keys and a mechanism
> to change them from RFC5925)
>
> Version 2: https://lore.kernel.org/all/[email protected]/T/#u
>
> Changes from v1:
> - Building now with CONFIG_IPV6=n (kernel test robot <[email protected]>)
> - Added missing static declarations for local functions
> (kernel test robot <[email protected]>)
> - Addressed static analyzer and review comments by Dan Carpenter
> (thanks, they were very useful!)
> - Fix elif without defined() for !CONFIG_TCP_AO
> - Recursively build selftests/net/tcp_ao (Shuah Khan), patches in:
> https://lore.kernel.org/all/[email protected]/T/#u
> - Don't leak crypto_pool reference when TCP-MD5 key is modified/changed
> - Add TCP-AO support for nettest.c and fcnal-test.sh
> (will be used for VRF testing in later versions)
>
> Comparison between Leonard proposal and this (overview):
> https://lore.kernel.org/all/[email protected]/T/#u
>
> Version 1: https://lore.kernel.org/all/[email protected]/T/#u
>
> This patchset implements the TCP-AO option as described in RFC5925. There
> is a request from industry to move away from TCP-MD5SIG and it seems the time
> is right to have a TCP-AO upstreamed. This TCP option is meant to replace
> the TCP MD5 option and address its shortcomings. Specifically, it provides
> more secure hashing, key rotation and support for long-lived connections
> (see the summary of TCP-AO advantages over TCP-MD5 in (1.3) of RFC5925).
> The patch series starts with six patches that are not specific to TCP-AO
> but implement a general crypto facility that we thought is useful
> to eliminate code duplication between TCP-MD5SIG and TCP-AO as well as other
> crypto users. These six patches are being submitted separately in
> a different patchset [1]. Including them here will show better the gain
> in code sharing. Next are 18 patches that implement the actual TCP-AO option,
> followed by patches implementing selftests.
>
> The patch set was written as a collaboration of three authors (in alphabetical
> order): Dmitry Safonov, Francesco Ruggeri and Salam Noureddine. Additional
> credits should be given to Prasad Koya, who was involved in early prototyping
> a few years back. There is also a separate submission done by Leonard Crestez
> whom we thank for his efforts getting an implementation of RFC5925 submitted
> for review upstream [2]. This is an independent implementation that makes
> different design decisions.
>
> For example, we chose a similar design to the TCP-MD5SIG implementation and
> used setsockopts to program per-socket keys, avoiding the extra complexity
> of managing a centralized key database in the kernel. A centralized database
> in the kernel has dubious benefits since it doesn’t eliminate per-socket
> setsockopts needed to specify which sockets need TCP-AO and what are the
> currently preferred keys. It also complicates traffic key caching and
> preventing deletion of in-use keys.
>
> In this implementation, a centralized database of keys can be thought of
> as living in user space and user applications would have to program those
> keys on matching sockets. On the server side, the user application programs
> keys (MKTS in TCP-AO nomenclature) on the listening socket for all peers that
> are expected to connect. Prefix matching on the peer address is supported.
> When a peer issues a successful connect, all the MKTs matching the IP address
> of the peer are copied to the newly created socket. On the active side,
> when a connect() is issued all MKTs that do not match the peer are deleted
> from the socket since they will never match the peer. This implementation
> uses three setsockopt()s for adding, deleting and modifying keys on a socket.
> All three setsockopt()s have extensive sanity checks that prevent
> inconsistencies in the keys on a given socket. A getsockopt() is provided
> to get key information from any given socket.
>
> Few things to note about this implementation:
> - Traffic keys are cached for established connections avoiding the cost of
> such calculation for each packet received or sent.
> - Great care has been taken to avoid deleting in-use MKTs
> as required by the RFC.
> - Any crypto algorithm supported by the Linux kernel can be used
> to calculate packet hashes.
> - Fastopen works with TCP-AO but hasn’t been tested extensively.
> - Tested for interop with other major networking vendors (on linux-4.19),
> including testing for key rotation and long lived connections.
>
> [1]: https://lore.kernel.org/all/[email protected]/
> [2]: https://lore.kernel.org/all/[email protected]/
> [3]: https://github.com/0x7f454c46/iperf/tree/tcp-md5-ao
> [4]: https://lore.kernel.org/all/166995421700.16716.17446147162780881407.git-patchwork-notify@kernel.org/T/#u
> [5]: https://lore.kernel.org/all/[email protected]/T/#u
> [6]: https://lore.kernel.org/all/[email protected]/T/#u
>
For the set:
Acked-by: David Ahern <[email protected]>
On Fri, Jul 21, 2023 at 8:12 PM David Ahern <[email protected]> wrote:
>
> On 7/21/23 10:18 AM, Dmitry Safonov wrote:
> > Hi,
> >
> > This is version 8.1 of TCP-AO support. I base it on net-next as
> > there's commit 5e5265522a9a ("tcp: annotate data-races around
> > tcp_rsk(req)->txhash") which makes a minor conflict.
> >
> > The good news is that all pre-required patches have merged to
> > Torvald's/master. Thanks to Herbert, crypto clone-tfm just works on
> > master for all TCP-AO supported algorithms.
> > So, this is the first version of the patch set that has only net-related
> > changes (well, selftests as well, but they'll be upstreamed separately).
> >
> > In this version, I've finally spent time and written Documentation/ page
> > on TCP-AO. It has Frequently Asked Questions (FAQ) on RFC 5925 - I found
> > it very useful to answer those before writing the actual code.
> > It provides answers to common questions that arise on a quick read of
> > the RFC as well as how they were answered. There's also a comparison
> > to the TCP-MD5 option, an evaluation of per-socket vs in-kernel-DB
> > approaches and a description of uAPI provided.
> > I hope it will be as useful for reviewing the code as it was for writing.
> >
> > The most important changes in this version are:
> > - CONFIG_TCP_AO implies CONFIG_IPV6 != m. I don't feel like that
> > combination would be useful to anyone and it'd be painful to fix.
> > - uAPI change in TCP_AO_REPAIR (introduced in version 7): I removed
> > {snd,rcv}_sne_seq counters. They were just copies of snd_nxt/snd_una.
> > No reason for polluting uAPI as well as needlessly copying them.
> > - TCP_AO_MAX_HASH_SIZE is removed and all temporary buffers are
> > kmalloc()'d. That also saves a couple of bytes for hmac(sha1) and
> > cmac(aes128) traffic keys as they now are allocated with
> > exact hash algo's digest_size.
> >
> > There's an independent patch set for TCP-MD5 to verify segments on twsk:
> > https://lore.kernel.org/all/[email protected]/T/#u
> > That may be used to verify TCP-AO segments on twsk as well.
> >
> > There seem to be more people that connected me off-list asking me about
> > the status of patches and when I expect them to merge. Cc'ing more
> > interested parties here (ping me directly if you don't want to be in
> > copy). It would be helpful if you provide your reviews and tested-by's.
> > As far as I'm aware, version 7 was ported to RHEL, so now there are
> > probably more downstream kernels with TCP-AO support.
> >
> > Also available as a git branch for pulling:
> > https://github.com/0x7f454c46/linux/tree/tcp-ao-v8.1
> > And another branch with selftests, that will be sent later separately:
> > https://github.com/0x7f454c46/linux/tree/tcp-ao-v8-with-selftests
> >
> > Thanks for your time and reviews,
> > Dmitry
> >
> > --- Changelog ---
> >
> > Changes from v8:
> > - Rebased/retested on linux-net-next
> >
> > Version 8: https://lore.kernel.org/all/[email protected]/T/#u
> >
> > Changes from v7:
> > - Fixed copy'n'paste typo in unsigned-md5.c selftest output
> > - Fix build error in tcp_v6_send_reset() (kernel test robot <[email protected]>)
> > - Make CONFIG_TCP_AO imply IPV6 != m
> > - Cleanup EXPORT_SYMBOL*() as they aren't needed with IPV6 != m
> > - Used scratch area instead of on-stack buffer for scatter-gather list
> > in tcp_v{4,6}_ao_calc_key(). Fixes CONFIG_VMAP_STACK=y + CONFIG_DEBUG_SG=y
> > - Allocated digest_size'd buffers for traffic keys in tcp_ao_key instead
> > of maximum-sized buffers of TCP_AO_MAX_HASH_SIZE. That will save
> > little space per key and also potentially allow algorithms with
> > digest size > TCP_AO_MAX_HASH_SIZE.
> > - Removed TCP_AO_MAX_HASH_SIZE and used kmalloc(GFP_ATOMIC) instead of
> > on-stack hash buffer.
> > - Don't treat fd=0 as invalid in selftests
> > - Make TCP-AO selftests work with CONFIG_CRYPTO_FIPS=y
> > - Don't tcp_ao_compute_sne() for snd_sne on twsk: it's redundant as
> > no data can be sent on twsk
> > - Get rid of {snd,rcv}_sne_seq: use snd_nxt/snd_una or rcv_nxt instead
> > - {rcv,snd}_sne and tcp_ao_compute_sne() now are introduced in
> > "net/tcp: Add TCP-AO SNE support" patch
> > - trivial copy_to_sockptr() fixup for tcp_ao_get_repair() - it could
> > try copying bigger struct than the kernel one (embarrassing!)
> > - Added Documentation/networking/tcp_ao.rst that describes:
> > uAPI, has FAQ on RFC 5925 and has implementation details of Linux TCP-AO
> >
> > Version 7: https://lore.kernel.org/all/[email protected]/T/#u
> >
> > Changes from v6:
> > - Some more trivial build warnings fixups (kernel test robot <[email protected]>)
> > - Added TCP_AO_REPAIR setsockopt(), getsockopt()
> > - Allowed TCP_AO_* setsockopts if (tp->repair) is on
> > - Added selftests for TCP_AO_REPAIR, that also check incorrect
> > ISNs/SNEs, which result in a broken TCP-AO connection - that verifies
> > that both Initial Sequence Numbers and Sequence Number Extension are
> > part of MAC generation
> > - Using TCP_AO_REPAIR added a selftest for SEQ numbers rollover,
> > checking that SNE was incremented, connection is alive post-rolloever
> > and no TCP segments with a wrong signature arrived
> > - Wrote a selftest for RST segments: both active reset (goes through
> > transmit_skb()) and passive reset (goes through tcp_v{4,6}_send_reset()).
> > - Refactored and made readable tcp_v{4,6}_send_reset(), also adding
> > support for TCP_LISTEN/TCP_NEW_SYN_RECV
> > - Dropped per-CPU ahash requests allocations in favor of Herbert's
> > clone-tfm crypto API
> > - Added Donald Cassidy to Cc as he's interested in getting it into RHEL.
> >
> > Version 6: https://lore.kernel.org/all/[email protected]/T/#u
> >
> > iperf[3] benchmarks for version 6:
> > v6.4-rc1 TCP-AO-v6
> > TCP 43.9 Gbits/sec 43.5 Gbits/sec
> > TCP-MD5 2.20 Gbits/sec 2.25 Gbits/sec
> > TCP-AO(hmac(sha1)) 2.53 Gbits/sec
> > TCP-AO(hmac(sha512)) 1.67 Gbits/sec
> > TCP-AO(hmac(sha384)) 1.77 Gbits/sec
> > TCP-AO(hmac(sha224)) 1.29 Gbits/sec
> > TCP-AO(hmac(sha3-512)) 481 Mbits/sec
> > TCP-AO(hmac(md5)) 2.07 Gbits/sec
> > TCP-AO(hmac(rmd160)) 1.01 Gbits/sec
> > TCP-AO(cmac(aes128)) 2.11 Gbits/sec
> >
> > Changes from v5:
> > - removed check for TCP_AO_KEYF_IFINDEX in delete command:
> > VRF might have been destroyed, there still needs to be a way to delete
> > keys that were bound to that l3intf (should tcp_v{4,6}_parse_md5_keys()
> > avoid the same check as well?)
> > - corrected copy'n'paste typo in tcp_ao_info_cmd() (assign ao_info->rnext_key)
> > - simplified a bit tcp_ao_copy_mkts_to_user(); added more UAPI checks
> > for getsockopt(TCP_AO_GET_KEYS)
> > - More UAPI selftests in setsockopt-closed: 29 => 120
> > - ported TCP-AO patches on Herbert's clone-tfm changes
> > - adjusted iperf patch for TCP-AO UAPI changes from version 5
> > - added measures for TCP-AO with tcp_sigpool & clone_tfm backends
> >
> > Version 5: https://lore.kernel.org/all/[email protected]/T/#u
> >
> > Changes from v4:
> > - Renamed tcp_ao_matched_key() => tcp_ao_established_key()
> > - Missed `static` in function definitions
> > (kernel test robot <[email protected]>)
> > - Fixed CONFIG_IPV6=m build
> > - Unexported tcp_md5_*_sigpool() functions
> > - Cleaned up tcp_ao.h: undeclared tcp_ao_cache_traffic_keys(),
> > tcp_v4_ao_calc_key_skb(); removed tcp_v4_inbound_ao_hash()
> > - Marked "net/tcp: Prepare tcp_md5sig_pool for TCP-AO" as a [draft] patch
> > - getsockopt() now returns TCP-AO per-key counters
> > - Another getsockopt() now returns per-ao_info stats: counters
> > and accept_icmps flag state
> > - Wired up getsockopt() returning counters to selftests
> > - Fixed a porting mistake: TCP-AO hash in some cases was written in TCP
> > header without accounting for MAC length of the key, rewritting skb
> > shared info
> > - Fail adding a key with L3 ifindex when !TCP_AO_KEYF_IFINDEX, instead
> > of ignoring tcpa_ifindex (stricter UAPI check)
> > - Added more test-cases to setsockopt-closed.c selftest
> > - tcp_ao_hash_skb_data() was a copy'n'paste of tcp_md5_hash_skb_data()
> > share it now under tcp_sigpool_hash_skb_data()
> > - tcp_ao_mkt_overlap_v{4,6}() deleted as they just re-invented
> > tcp_ao_do_lookup(). That fixes an issue with multiple IPv4-mapped-IPv6
> > keys for different peers on a listening socket.
> > - getsockopt() now is tested to return correct VRF number for a key
> > - TCP-AO and TCP-MD5 interraction in non/default VRFs: added +19 selftests
> > made them SKIP when CONFIG_VRF=n
> > - unsigned-md5 selftests now checks both scenarios:
> > (1) adding TCP-AO key _after_ TCP-MD5 key
> > (2) adding TCP-MD5 key _after_ TCP-AO key
> > - Added a ratelimited warning if TCP-AO key.ifindex doesn't match
> > sk->sk_bound_dev_if - that will warn a user for potential VRF issues
> > - tcp_v{4,6}_parse_md5_keys() now allows adding TCP-MD5 key with
> > ifindex=0 and TCP_MD5SIG_FLAG_IFINDEX together with TCP-AO key from
> > another VRF
> > - Add TCP_AO_CMDF_AO_REQUIRED, which makes a socket TCP-AO only,
> > rejecting TCP-MD5 keys or any unsigned TCP segments
> > - Remove `tcpa_' prefix for UAPI structure members
> > - UAPI cleanup: I've separated & renamed per-socket settings
> > (such as ao_info flags + current/rnext set) from per-key changes:
> > TCP_AO => TCP_AO_ADD_KEY
> > TCP_AO_DEL => TCP_AO_DEL_KEY
> > TCP_AO_GET => TCP_AO_GET_KEYS
> > TCP_AO_MOD => TCP_AO_INFO, the structure is now valid for both
> > getsockopt() and setsockopt().
> > - tcp_ao_current_rnext() was split up in order to fail earlier when
> > sndid/rcvid specified can't be set, before anything was changed in ao_info
> > - fetch current_key before dumping TCP-AO keys in getsockopt(TCP_AO_GET_KEYS):
> > it may race with changing current_key by RX, which in result might
> > produce a dump with no current_key for userspace.
> > - instead of TCP_AO_CMDF_* flags, used bitfileds: the flags weren't
> > shared between all TCP_AO_{ADD,GET,DEL}_KEY{,S}, so bitfields are more
> > descriptive here
> > - use READ_ONCE()/WRITE_ONCE() for current_key and rnext_key more
> > consistently; document in comment the rules for accessing them
> > - selftests: check all setsockopts()/getsockopts() support extending
> > option structs
> >
> > Version 4: https://lore.kernel.org/all/[email protected]/T/#u
> >
> > Changes from v3:
> > - TCP_MD5 dynamic static key enable/disable patches merged separately [4]
> > - crypto_pool patches were nacked [5], so instead this patch set extends
> > TCP-MD5-sigpool to be used for TCP-AO as well as for TCP-MD5
> > - Added missing `static' for tcp_v6_ao_calc_key()
> > (kernel test robot <[email protected]>)
> > - Removed CONFIG_TCP_AO default=y and added "If unsure, say N."
> > - Don't leak ao_info and don't create an unsigned TCP socket if there was
> > a TCP-AO key during handshake, but it was removed from listening socket
> > while the connection was being established
> > - Migrate to use static_key_fast_inc_not_disabled() and check return
> > code of static_branch_inc()
> > - Change some return codes to EAFNOSUPPORT for error-pathes where
> > family is neither AF_INET nor AF_INET6
> > - setsockopt()s on a closed/listen socket might have created stray ao_info,
> > remove it if connect() is called with a correct TCP-MD5 key, the same
> > for the reverse situation: remove md5sig_info straight away from the
> > socket if it's going to be TCP-AO connection
> > - IPv4-mapped-IPv6 addresses + selftest in fcnal-test.sh (by Salam)
> > - fix using uninitialized sisn/disn from stack - it would only make
> > non-SYN packets fail verification on a listen socket, which are not
> > expected anyway (kernel test robot <[email protected]>)
> > - implicit padding in UAPI TCP-AO structures converted to explicit
> > (spotted-by David Laight)
> > - Some selftests missed zero-initializers for uapi structs on stack
> > - Removed tcp_ao_do_lookup_rcvid() and tcp_ao_do_lookup_sndid() in
> > favor of unified tcp_ao_matched_key()
> > - Disallowed setting current/rnext keys on listen sockets - that wasn't
> > supported and didn't affect anything, cleanup for the UAPI
> > - VRFs support for TCP-AO
> >
> > Version 3: https://lore.kernel.org/all/[email protected]/T/#u
> >
> > Changes from v2:
> > - Added more missing `static' declarations for local functions
> > (kernel test robot <[email protected]>)
> > - Building now with CONFIG_TCP_AO=n and CONFIG_TCP_MD5SIG=n
> > (kernel test robot <[email protected]>)
> > - Now setsockopt(TCP_AO) is allowed when it's TCP_LISTEN or TCP_CLOSE
> > state OR the key added is not the first key on a socket (by Salam)
> > - CONFIG_TCP_AO does not depend on CONFIG_TCP_MD5SIG anymore
> > - Don't leak tcp_md5_needed static branch counter when TCP-MD5 key
> > is modified/changed
> > - TCP-AO lookups are dynamically enabled/disabled with static key when
> > there is ao_info in the system (and when it is destroyed)
> > - Wired SYN cookies up to TCP-AO (by Salam)
> > - Fix verification for possible re-transmitted SYN packets (by Salam)
> > - use sockopt_lock_sock() instead of lock_sock()
> > (from v6.1 rebase, commit d51bbff2aba7)
> > - use sockptr_t in getsockopt(TCP_AO_GET)
> > (from v6.1 rebase, commit 34704ef024ae)
> > - Fixed reallocating crypto_pool's scratch area by IPI while
> > crypto_pool_get() was get by another CPU
> > - selftests on older kernels (or with CONFIG_TCP_AO=n) should exit with
> > SKIP, not FAIL (Shuah Khan <[email protected]>)
> > - selftests that check interaction between TCP-AO and TCP-MD5 now
> > SKIP when CONFIG_TCP_MD5SIG=n
> > - Measured the performance of different hashing algorithms for TCP-AO
> > and compare with TCP-MD5 performance. This is done with hacky patches
> > to iperf (see [3]). At this moment I've done it in qemu/KVM with CPU
> > affinities set on Intel(R) Core(TM) i7-7600U CPU @ 2.80GHz.
> > No performance degradation was noticed before/after patches, but given
> > the measures were done in a VM, without measuring it on a physical dut
> > it only gives a hint of relative speed for different hash algorithms
> > with TCP-AO. Here are results, averaging on 30 measures each:
> > TCP: 3.51Gbits/sec
> > TCP-MD5: 1.12Gbits/sec
> > TCP-AO(HMAC(SHA1)): 1.53Gbits/sec
> > TCP-AO(CMAC(AES128)): 621Mbits/sec
> > TCP-AO(HMAC(SHA512)): 1.21Gbits/sec
> > TCP-AO(HMAC(SHA384)): 1.20Gbits/sec
> > TCP-AO(HMAC(SHA224)): 961Mbits/sec
> > TCP-AO(HMAC(SHA3-512)): 157Mbits/sec
> > TCP-AO(HMAC(RMD160)): 659Mbits/sec
> > TCP-AO(HMAC(MD5): 1.12Gbits/sec
> > (the last one is just for fun, but may make sense as it provides
> > the same security as TCP-MD5, but allows multiple keys and a mechanism
> > to change them from RFC5925)
> >
> > Version 2: https://lore.kernel.org/all/[email protected]/T/#u
> >
> > Changes from v1:
> > - Building now with CONFIG_IPV6=n (kernel test robot <[email protected]>)
> > - Added missing static declarations for local functions
> > (kernel test robot <[email protected]>)
> > - Addressed static analyzer and review comments by Dan Carpenter
> > (thanks, they were very useful!)
> > - Fix elif without defined() for !CONFIG_TCP_AO
> > - Recursively build selftests/net/tcp_ao (Shuah Khan), patches in:
> > https://lore.kernel.org/all/[email protected]/T/#u
> > - Don't leak crypto_pool reference when TCP-MD5 key is modified/changed
> > - Add TCP-AO support for nettest.c and fcnal-test.sh
> > (will be used for VRF testing in later versions)
> >
> > Comparison between Leonard proposal and this (overview):
> > https://lore.kernel.org/all/[email protected]/T/#u
> >
> > Version 1: https://lore.kernel.org/all/[email protected]/T/#u
> >
> > This patchset implements the TCP-AO option as described in RFC5925. There
> > is a request from industry to move away from TCP-MD5SIG and it seems the time
> > is right to have a TCP-AO upstreamed. This TCP option is meant to replace
> > the TCP MD5 option and address its shortcomings. Specifically, it provides
> > more secure hashing, key rotation and support for long-lived connections
> > (see the summary of TCP-AO advantages over TCP-MD5 in (1.3) of RFC5925).
> > The patch series starts with six patches that are not specific to TCP-AO
> > but implement a general crypto facility that we thought is useful
> > to eliminate code duplication between TCP-MD5SIG and TCP-AO as well as other
> > crypto users. These six patches are being submitted separately in
> > a different patchset [1]. Including them here will show better the gain
> > in code sharing. Next are 18 patches that implement the actual TCP-AO option,
> > followed by patches implementing selftests.
> >
> > The patch set was written as a collaboration of three authors (in alphabetical
> > order): Dmitry Safonov, Francesco Ruggeri and Salam Noureddine. Additional
> > credits should be given to Prasad Koya, who was involved in early prototyping
> > a few years back. There is also a separate submission done by Leonard Crestez
> > whom we thank for his efforts getting an implementation of RFC5925 submitted
> > for review upstream [2]. This is an independent implementation that makes
> > different design decisions.
> >
> > For example, we chose a similar design to the TCP-MD5SIG implementation and
> > used setsockopts to program per-socket keys, avoiding the extra complexity
> > of managing a centralized key database in the kernel. A centralized database
> > in the kernel has dubious benefits since it doesn’t eliminate per-socket
> > setsockopts needed to specify which sockets need TCP-AO and what are the
> > currently preferred keys. It also complicates traffic key caching and
> > preventing deletion of in-use keys.
> >
> > In this implementation, a centralized database of keys can be thought of
> > as living in user space and user applications would have to program those
> > keys on matching sockets. On the server side, the user application programs
> > keys (MKTS in TCP-AO nomenclature) on the listening socket for all peers that
> > are expected to connect. Prefix matching on the peer address is supported.
> > When a peer issues a successful connect, all the MKTs matching the IP address
> > of the peer are copied to the newly created socket. On the active side,
> > when a connect() is issued all MKTs that do not match the peer are deleted
> > from the socket since they will never match the peer. This implementation
> > uses three setsockopt()s for adding, deleting and modifying keys on a socket.
> > All three setsockopt()s have extensive sanity checks that prevent
> > inconsistencies in the keys on a given socket. A getsockopt() is provided
> > to get key information from any given socket.
> >
> > Few things to note about this implementation:
> > - Traffic keys are cached for established connections avoiding the cost of
> > such calculation for each packet received or sent.
> > - Great care has been taken to avoid deleting in-use MKTs
> > as required by the RFC.
> > - Any crypto algorithm supported by the Linux kernel can be used
> > to calculate packet hashes.
> > - Fastopen works with TCP-AO but hasn’t been tested extensively.
> > - Tested for interop with other major networking vendors (on linux-4.19),
> > including testing for key rotation and long lived connections.
> >
> > [1]: https://lore.kernel.org/all/[email protected]/
> > [2]: https://lore.kernel.org/all/[email protected]/
> > [3]: https://github.com/0x7f454c46/iperf/tree/tcp-md5-ao
> > [4]: https://lore.kernel.org/all/166995421700.16716.17446147162780881407.git-patchwork-notify@kernel.org/T/#u
> > [5]: https://lore.kernel.org/all/[email protected]/T/#u
> > [6]: https://lore.kernel.org/all/[email protected]/T/#u
> >
>
> For the set:
> Acked-by: David Ahern <[email protected]>
I will have to review this series, of course, if bots are happy.
On 7/21/23 19:18, Eric Dumazet wrote:
> On Fri, Jul 21, 2023 at 8:12 PM David Ahern <[email protected]> wrote:
>>
>> On 7/21/23 10:18 AM, Dmitry Safonov wrote:
>>> Hi,
>>>
[..]
>>
>> For the set:
>> Acked-by: David Ahern <[email protected]>
>
> I will have to review this series, of course, if bots are happy.
Thanks David, Eric!
I appreciate both Acks and potential reviews.
Thanks,
Dmitry
On Fri, Jul 21, 2023 at 05:18:52PM +0100, Dmitry Safonov wrote:
Hi Dmitry,
some minor nits from my side.
...
> +/**
> + * tcp_sigpool_start - disable bh and start using tcp_sigpool_ahash
> + * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash()
> + * @c: returned tcp_sigpool for usage (uninitialized on failure)
> + */
> +int tcp_sigpool_start(unsigned int id, struct tcp_sigpool *c);
> +/**
> + * tcp_sigpool_end - enable bh and stop using tcp_sigpool
nit: as this is a kernel doc, please document @c here.
> + */
> +void tcp_sigpool_end(struct tcp_sigpool *c);
> +size_t tcp_sigpool_algo(unsigned int id, char *buf, size_t buf_len);
> /* - functions */
> int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
> const struct sock *sk, const struct sk_buff *skb);
...
> @@ -1439,8 +1443,7 @@ int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
> const struct sock *sk,
> const struct sk_buff *skb)
> {
> - struct tcp_md5sig_pool *hp;
> - struct ahash_request *req;
> + struct tcp_sigpool hp;
> const struct tcphdr *th = tcp_hdr(skb);
> __be32 saddr, daddr;
nit: please consider using reverse xmas tree - longest line to shortest -
for these local variable declarations.
const struct tcphdr *th = tcp_hdr(skb);
struct tcp_sigpool hp;
__be32 saddr, daddr;
Likewise, elsewhere, when it can be done without excess churn.
...
Hi Simon,
On 7/24/23 14:11, Simon Horman wrote:
> On Fri, Jul 21, 2023 at 05:18:52PM +0100, Dmitry Safonov wrote:
>
> Hi Dmitry,
>
> some minor nits from my side.
>
> ...
>
>> +/**
>> + * tcp_sigpool_start - disable bh and start using tcp_sigpool_ahash
>> + * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash()
>> + * @c: returned tcp_sigpool for usage (uninitialized on failure)
>> + */
>> +int tcp_sigpool_start(unsigned int id, struct tcp_sigpool *c);
>> +/**
>> + * tcp_sigpool_end - enable bh and stop using tcp_sigpool
>
> nit: as this is a kernel doc, please document @c here.
Thanks, yeah, I also noticed that on netdev/kdoc and there are some
other nits on the patchwork that Intel's build bot didn't report to my
surprise. Will address them in v9.
>> + */
>> +void tcp_sigpool_end(struct tcp_sigpool *c);
>> +size_t tcp_sigpool_algo(unsigned int id, char *buf, size_t buf_len);
>> /* - functions */
>> int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
>> const struct sock *sk, const struct sk_buff *skb);
>
> ...
>
>> @@ -1439,8 +1443,7 @@ int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
>> const struct sock *sk,
>> const struct sk_buff *skb)
>> {
>> - struct tcp_md5sig_pool *hp;
>> - struct ahash_request *req;
>> + struct tcp_sigpool hp;
>> const struct tcphdr *th = tcp_hdr(skb);
>> __be32 saddr, daddr;
>
> nit: please consider using reverse xmas tree - longest line to shortest -
> for these local variable declarations.
>
> const struct tcphdr *th = tcp_hdr(skb);
> struct tcp_sigpool hp;
> __be32 saddr, daddr;
>
> Likewise, elsewhere, when it can be done without excess churn.
Yeah, fail enough, I usually keep it Xmas-like, but sometimes they slip
in unnoticed. I'll take a look over the patches.
Thanks,
Dmitry
On Fri, Jul 21, 2023 at 05:18:54PM +0100, Dmitry Safonov wrote:
...
Hi Dimitry,
> diff --git a/include/linux/sockptr.h b/include/linux/sockptr.h
> index bae5e2369b4f..307961b41541 100644
> --- a/include/linux/sockptr.h
> +++ b/include/linux/sockptr.h
> @@ -55,6 +55,29 @@ static inline int copy_from_sockptr(void *dst, sockptr_t src, size_t size)
> return copy_from_sockptr_offset(dst, src, 0, size);
> }
>
> +static inline int copy_struct_from_sockptr(void *dst, size_t ksize,
> + sockptr_t src, size_t usize)
The indentation of the two lines above is not correct,
they should be aligned to the inside of the opening '('
on the preceding line.
In order to stop things being too far to the left,
which is perhaps the intent of the current indention scheme,
the return type of the function can be moved to it's own line.
static inline int
copy_struct_from_sockptr(void *dst, size_t ksize, sockptr_t src, size_t usize)
...
> diff --git a/include/net/tcp.h b/include/net/tcp.h
...
> +static inline int ipv4_prefix_cmp(const struct in_addr *addr1,
> + const struct in_addr *addr2,
> + unsigned int prefixlen)
> +{
> + __be32 mask = inet_make_mask(prefixlen);
> +
> + if ((addr1->s_addr & mask) == (addr2->s_addr & mask))
> + return 0;
> + return ((addr1->s_addr & mask) > (addr2->s_addr & mask)) ? 1 : -1;
> +}
Above, '>' is operating on two big endian values.
But typically such maths operates on host byte order values.
Flagged by Sparse.
...
> +static struct tcp_ao_key *__tcp_ao_do_lookup(const struct sock *sk,
> + const union tcp_ao_addr *addr, int family, u8 prefix,
> + int sndid, int rcvid, u16 port)
Same comment about indentation as above.
static struct tcp_ao_key *
__tcp_ao_do_lookup(const struct sock *sk, const union tcp_ao_addr *addr,
int family, u8 prefix, int sndid, int rcvid, u16 port)
...
> +struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
> + const union tcp_ao_addr *addr,
> + int family, int sndid, int rcvid, u16 port)
Should tcp_ao_do_lookup be static?
It seems to only be used in this file.
...
> +static int tcp_ao_verify_port(struct sock *sk, u16 port)
> +{
> + struct inet_sock *inet = inet_sk(sk);
> +
> + if (port != 0) /* FIXME */
I guess this should be fixed :)
> + return -EINVAL;
> +
> + /* Check that MKT port is consistent with socket */
> + if (port != 0 && inet->inet_dport != 0 && port != inet->inet_dport)
port is host byte order, but inet->inet_dport is big endian.
This does not seem correct.
> + return -EINVAL;
> +
> + return 0;
> +}
...
> +static int tcp_ao_parse_crypto(struct tcp_ao_add *cmd, struct tcp_ao_key *key)
> +{
> + unsigned int syn_tcp_option_space;
> + bool is_kdf_aes_128_cmac = false;
> + struct crypto_ahash *tfm;
> + struct tcp_sigpool hp;
> + void *tmp_key = NULL;
> + int err;
> +
> + /* RFC5926, 3.1.1.2. KDF_AES_128_CMAC */
> + if (!strcmp("cmac(aes128)", cmd->alg_name)) {
> + strscpy(cmd->alg_name, "cmac(aes)", sizeof(cmd->alg_name));
> + is_kdf_aes_128_cmac = (cmd->keylen != 16);
> + tmp_key = kmalloc(cmd->keylen, GFP_KERNEL);
> + if (!tmp_key)
> + return -ENOMEM;
> + }
> +
> + key->maclen = cmd->maclen ?: 12; /* 12 is the default in RFC5925 */
> +
> + /* Check: maclen + tcp-ao header <= (MAX_TCP_OPTION_SPACE - mss
> + * - tstamp - wscale - sackperm),
> + * see tcp_syn_options(), tcp_synack_options(), commit 33ad798c924b.
> + *
> + * In order to allow D-SACK with TCP-AO, the header size should be:
> + * (MAX_TCP_OPTION_SPACE - TCPOLEN_TSTAMP_ALIGNED
> + * - TCPOLEN_SACK_BASE_ALIGNED
> + * - 2 * TCPOLEN_SACK_PERBLOCK) = 8 (maclen = 4),
> + * see tcp_established_options().
> + *
> + * RFC5925, 2.2:
> + * Typical MACs are 96-128 bits (12-16 bytes), but any length
> + * that fits in the header of the segment being authenticated
> + * is allowed.
> + *
> + * RFC5925, 7.6:
> + * TCP-AO continues to consume 16 bytes in non-SYN segments,
> + * leaving a total of 24 bytes for other options, of which
> + * the timestamp consumes 10. This leaves 14 bytes, of which 10
> + * are used for a single SACK block. When two SACK blocks are used,
> + * such as to handle D-SACK, a smaller TCP-AO MAC would be required
> + * to make room for the additional SACK block (i.e., to leave 18
> + * bytes for the D-SACK variant of the SACK option) [RFC2883].
> + * Note that D-SACK is not supportable in TCP MD5 in the presence
> + * of timestamps, because TCP MD5’s MAC length is fixed and too
> + * large to leave sufficient option space.
> + */
> + syn_tcp_option_space = MAX_TCP_OPTION_SPACE;
> + syn_tcp_option_space -= TCPOLEN_TSTAMP_ALIGNED;
> + syn_tcp_option_space -= TCPOLEN_WSCALE_ALIGNED;
> + syn_tcp_option_space -= TCPOLEN_SACKPERM_ALIGNED;
> + if (tcp_ao_len(key) > syn_tcp_option_space) {
> + err = -EMSGSIZE;
> + goto err_kfree;
> + }
> +
> + key->keylen = cmd->keylen;
> + memcpy(key->key, cmd->key, cmd->keylen);
> +
> + err = tcp_sigpool_start(key->tcp_sigpool_id, &hp);
> + if (err)
> + goto err_kfree;
> +
> + tfm = crypto_ahash_reqtfm(hp.req);
> + if (is_kdf_aes_128_cmac) {
> + void *scratch = hp.scratch;
> + struct scatterlist sg;
> +
> + memcpy(tmp_key, cmd->key, cmd->keylen);
> + sg_init_one(&sg, tmp_key, cmd->keylen);
> +
> + /* Using zero-key of 16 bytes as described in RFC5926 */
> + memset(scratch, 0, 16);
> + err = crypto_ahash_setkey(tfm, scratch, 16);
> + if (err)
> + goto err_pool_end;
> +
> + err = crypto_ahash_init(hp.req);
> + if (err)
> + goto err_pool_end;
> +
> + ahash_request_set_crypt(hp.req, &sg, key->key, cmd->keylen);
> + err = crypto_ahash_update(hp.req);
> + if (err)
> + goto err_pool_end;
> +
> + err |= crypto_ahash_final(hp.req);
> + if (err)
> + goto err_pool_end;
> + key->keylen = 16;
> + }
> +
> + err = crypto_ahash_setkey(tfm, key->key, key->keylen);
> + if (err)
> + goto err_pool_end;
> +
> + tcp_sigpool_end(&hp);
> +
> + if (tcp_ao_maclen(key) > key->digest_size)
> + return -EINVAL;
tmp_key appears to be leaked here.
> +
> + return 0;
And here.
This is flagged by Smatch.
> +
> +err_pool_end:
> + tcp_sigpool_end(&hp);
> +err_kfree:
> + kfree(tmp_key);
> + return err;
> +}
...
> +static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
> + sockptr_t optval, int optlen)
> +{
> + struct tcp_ao_info *ao_info;
> + union tcp_ao_addr *addr;
> + struct tcp_ao_key *key;
> + struct tcp_ao_add cmd;
> + int ret;
> + bool first = false;
> + u16 port;
Please use reverse xmas tree - longest line to shortest - for
local variable declarations in new Networking code.
...
> +static int tcp_ao_del_cmd(struct sock *sk, unsigned short int family,
> + sockptr_t optval, int optlen)
> +{
> + struct tcp_ao_key *key, *new_current = NULL, *new_rnext = NULL;
> + struct tcp_ao_info *ao_info;
> + union tcp_ao_addr *addr;
> + struct tcp_ao_del cmd;
> + int err;
> + __u8 prefix;
> + __be16 port;
> + int addr_len;
> +
> + if (optlen < sizeof(cmd))
> + return -EINVAL;
> +
> + err = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
> + if (err)
> + return err;
> +
> + if (cmd.reserved != 0 || cmd.reserved2 != 0)
> + return -EINVAL;
> +
> + if (cmd.set_current || cmd.set_rnext) {
> + if (!tcp_ao_can_set_current_rnext(sk))
> + return -EINVAL;
> + }
> +
> + ao_info = setsockopt_ao_info(sk);
> + if (IS_ERR(ao_info))
> + return PTR_ERR(ao_info);
> + if (!ao_info)
> + return -ENOENT;
> +
> + /* For sockets in TCP_CLOSED it's possible set keys that aren't
> + * matching the future peer (address/port/VRF/etc),
> + * tcp_ao_connect_init() will choose a correct matching MKT
> + * if there's any.
> + */
> + if (cmd.set_current) {
> + new_current = tcp_ao_established_key(ao_info, cmd.current_key, -1);
> + if (!new_current)
> + return -ENOENT;
> + }
> + if (cmd.set_rnext) {
> + new_rnext = tcp_ao_established_key(ao_info, -1, cmd.rnext);
> + if (!new_rnext)
> + return -ENOENT;
> + }
> +
> + if (family == AF_INET) {
> + struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.addr;
> +
> + addr = (union tcp_ao_addr *)&sin->sin_addr;
> + addr_len = sizeof(struct in_addr);
> + port = ntohs(sin->sin_port);
port is big endian, but here it is assigned a host-byte order value.
It looks like port should be u16 rather than __bbe16.
As flagged by Smatch.
> + } else {
> + struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.addr;
> + struct in6_addr *addr6 = &sin6->sin6_addr;
> +
> + if (ipv6_addr_v4mapped(addr6)) {
> + addr = (union tcp_ao_addr *)&addr6->s6_addr32[3];
> + addr_len = sizeof(struct in_addr);
> + family = AF_INET;
> + } else {
> + addr = (union tcp_ao_addr *)addr6;
> + addr_len = sizeof(struct in6_addr);
> + }
> + port = ntohs(sin6->sin6_port);
Ditto.
> + }
> + prefix = cmd.prefix;
> +
> + /* We could choose random present key here for current/rnext
> + * but that's less predictable. Let's be strict and don't
> + * allow removing a key that's in use. RFC5925 doesn't
> + * specify how-to coordinate key removal, but says:
> + * "It is presumed that an MKT affecting a particular
> + * connection cannot be destroyed during an active connection"
> + */
> + hlist_for_each_entry_rcu(key, &ao_info->head, node) {
> + if (cmd.sndid != key->sndid ||
> + cmd.rcvid != key->rcvid)
> + continue;
> +
> + if (family != key->family ||
> + prefix != key->prefixlen ||
o
> + port != key->port ||
There is a similar problem here too.
port is host byte order but key->port is big endian.
> + memcmp(addr, &key->addr, addr_len))
> + continue;
> +
> + if (key == new_current || key == new_rnext)
> + continue;
> +
> + return tcp_ao_delete_key(sk, ao_info, key,
> + new_current, new_rnext);
> + }
> + return -ENOENT;
> +}
...
On Mon, Jul 24, 2023 at 05:06:30PM +0100, Dmitry Safonov wrote:
> Hi Simon,
>
> On 7/24/23 14:11, Simon Horman wrote:
> > On Fri, Jul 21, 2023 at 05:18:52PM +0100, Dmitry Safonov wrote:
> >
> > Hi Dmitry,
> >
> > some minor nits from my side.
> >
> > ...
> >
> >> +/**
> >> + * tcp_sigpool_start - disable bh and start using tcp_sigpool_ahash
> >> + * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash()
> >> + * @c: returned tcp_sigpool for usage (uninitialized on failure)
> >> + */
> >> +int tcp_sigpool_start(unsigned int id, struct tcp_sigpool *c);
> >> +/**
> >> + * tcp_sigpool_end - enable bh and stop using tcp_sigpool
> >
> > nit: as this is a kernel doc, please document @c here.
>
> Thanks, yeah, I also noticed that on netdev/kdoc and there are some
> other nits on the patchwork that Intel's build bot didn't report to my
> surprise. Will address them in v9.
Always room for improvement :)
> >> + */
> >> +void tcp_sigpool_end(struct tcp_sigpool *c);
> >> +size_t tcp_sigpool_algo(unsigned int id, char *buf, size_t buf_len);
> >> /* - functions */
> >> int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
> >> const struct sock *sk, const struct sk_buff *skb);
> >
> > ...
> >
> >> @@ -1439,8 +1443,7 @@ int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key,
> >> const struct sock *sk,
> >> const struct sk_buff *skb)
> >> {
> >> - struct tcp_md5sig_pool *hp;
> >> - struct ahash_request *req;
> >> + struct tcp_sigpool hp;
> >> const struct tcphdr *th = tcp_hdr(skb);
> >> __be32 saddr, daddr;
> >
> > nit: please consider using reverse xmas tree - longest line to shortest -
> > for these local variable declarations.
> >
> > const struct tcphdr *th = tcp_hdr(skb);
> > struct tcp_sigpool hp;
> > __be32 saddr, daddr;
> >
> > Likewise, elsewhere, when it can be done without excess churn.
>
> Yeah, fail enough, I usually keep it Xmas-like, but sometimes they slip
> in unnoticed. I'll take a look over the patches.
Thanks. I also flagged this in my review of 3/23,
as I hadn't noticed your response here.
On Fri, Jul 21, 2023 at 05:18:57PM +0100, Dmitry Safonov wrote:
...
Hi Dmitry,
> diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
...
> @@ -619,7 +621,33 @@ static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
> opts->hash_location = (__u8 *)ptr;
> ptr += 4;
> }
> +#ifdef CONFIG_TCP_AO
> + if (unlikely(OPTION_AO & options) && tp) {
Smatch warns that here we check if tp is NULL,
but later on in the same function (existing) code
uses tp unconditionally.
That code looks like this:
if (unlikely(opts->num_sack_blocks)) {
struct tcp_sack_block *sp = tp->rx_opt.dsack ?
tp->duplicate_sack : tp->selective_acks;
I would recommend running Smatch.
It points out a lot of interesting things.
> + struct tcp_ao_key *rnext_key;
> + struct tcp_ao_info *ao_info;
> + u8 maclen;
>
> + if (WARN_ON_ONCE(!ao_key))
> + goto out_ao;
> + ao_info = rcu_dereference_check(tp->ao_info,
> + lockdep_sock_is_held(&tp->inet_conn.icsk_inet.sk));
Checkpatch complains about indentation here.
Rather than point out each case in the series,
could I ask you to run ./scripts/checkpatch.pl --strict over the patchset?
...
> @@ -1363,6 +1424,34 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
> md5, sk, skb);
> }
> #endif
> +#ifdef CONFIG_TCP_AO
> + if (ao) {
> + u8 *traffic_key;
> + void *tkey_buf = NULL;
> + u32 disn;
> +
> + sk_gso_disable(sk);
> + if (unlikely(tcb->tcp_flags & TCPHDR_SYN)) {
> + if (tcb->tcp_flags & TCPHDR_ACK)
> + disn = ao->risn;
Sparse complains that there is an endian missmatch between disn and ao->risn ?
Rather than point out every problem flagged by Sparse,
could I ask you to run it over the series?
...
Hi Simon,
On 7/25/23 18:02, Simon Horman wrote:
> On Fri, Jul 21, 2023 at 05:18:57PM +0100, Dmitry Safonov wrote:
>
> ...
>
> Hi Dmitry,
>
>> diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
>
> ...
>
>> @@ -619,7 +621,33 @@ static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
>> opts->hash_location = (__u8 *)ptr;
>> ptr += 4;
>> }
>> +#ifdef CONFIG_TCP_AO
>> + if (unlikely(OPTION_AO & options) && tp) {
>
> Smatch warns that here we check if tp is NULL,
> but later on in the same function (existing) code
> uses tp unconditionally.
>
> That code looks like this:
>
> if (unlikely(opts->num_sack_blocks)) {
> struct tcp_sack_block *sp = tp->rx_opt.dsack ?
> tp->duplicate_sack : tp->selective_acks;
>
> I would recommend running Smatch.
> It points out a lot of interesting things.
>
>
>> + struct tcp_ao_key *rnext_key;
>> + struct tcp_ao_info *ao_info;
>> + u8 maclen;
>>
>> + if (WARN_ON_ONCE(!ao_key))
>> + goto out_ao;
>> + ao_info = rcu_dereference_check(tp->ao_info,
>> + lockdep_sock_is_held(&tp->inet_conn.icsk_inet.sk));
>
> Checkpatch complains about indentation here.
>
> Rather than point out each case in the series,
> could I ask you to run ./scripts/checkpatch.pl --strict over the patchset?
Yeah, but then it won't fit 80 columns here. As both aren't hard
requirements I tend to comply with 80 columns more than to indentation.
In this particular case I'll check if it could be a helper function.
If it won't make sense to separate it as a helper, I'll just move it to
the same line than, breaking 80 columns limit.
>> @@ -1363,6 +1424,34 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
>> md5, sk, skb);
>> }
>> #endif
>> +#ifdef CONFIG_TCP_AO
>> + if (ao) {
>> + u8 *traffic_key;
>> + void *tkey_buf = NULL;
>> + u32 disn;
>> +
>> + sk_gso_disable(sk);
>> + if (unlikely(tcb->tcp_flags & TCPHDR_SYN)) {
>> + if (tcb->tcp_flags & TCPHDR_ACK)
>> + disn = ao->risn;
>
> Sparse complains that there is an endian missmatch between disn and ao->risn ?
>
> Rather than point out every problem flagged by Sparse,
> could I ask you to run it over the series?
Yeah, I noticed it on netdev patchwork, running it over the patches now.
Thanks,
Dmitry
Hi Simon,
On 7/24/23 20:31, Simon Horman wrote:
> On Fri, Jul 21, 2023 at 05:18:54PM +0100, Dmitry Safonov wrote:
>
> ...
>
> Hi Dimitry,
>
>> diff --git a/include/linux/sockptr.h b/include/linux/sockptr.h
>> index bae5e2369b4f..307961b41541 100644
>> --- a/include/linux/sockptr.h
>> +++ b/include/linux/sockptr.h
>> @@ -55,6 +55,29 @@ static inline int copy_from_sockptr(void *dst, sockptr_t src, size_t size)
>> return copy_from_sockptr_offset(dst, src, 0, size);
>> }
>>
>> +static inline int copy_struct_from_sockptr(void *dst, size_t ksize,
>> + sockptr_t src, size_t usize)
>
> The indentation of the two lines above is not correct,
> they should be aligned to the inside of the opening '('
> on the preceding line.
>
> In order to stop things being too far to the left,
> which is perhaps the intent of the current indention scheme,
> the return type of the function can be moved to it's own line.
>
> static inline int
> copy_struct_from_sockptr(void *dst, size_t ksize, sockptr_t src, size_t usize)
Well, that would be a bit more GNU coding-style alike. Which I don't
mind, I can do that. Albeit it's a bit contrary to an example from
kernel's coding-style, where it seems preferred to keep it on the same
line with function name and rather not to indent argument list, see
(6.1), second example with action().
Yet, I don't feel particularly strong on either of options, so I can
just do as you suggest.
>
> ...
>
>> diff --git a/include/net/tcp.h b/include/net/tcp.h
>
> ...
>
>> +static inline int ipv4_prefix_cmp(const struct in_addr *addr1,
>> + const struct in_addr *addr2,
>> + unsigned int prefixlen)
>> +{
>> + __be32 mask = inet_make_mask(prefixlen);
>> +
>> + if ((addr1->s_addr & mask) == (addr2->s_addr & mask))
>> + return 0;
>> + return ((addr1->s_addr & mask) > (addr2->s_addr & mask)) ? 1 : -1;
>> +}
>
> Above, '>' is operating on two big endian values.
> But typically such maths operates on host byte order values.
>
> Flagged by Sparse.
Yeah, the function just has to provide any way to compare keys.
So, it's not very important, but just to silence Sparse I can convert
them to host's byte order before the comparison.
>
> ...
>
>> +static struct tcp_ao_key *__tcp_ao_do_lookup(const struct sock *sk,
>> + const union tcp_ao_addr *addr, int family, u8 prefix,
>> + int sndid, int rcvid, u16 port)
>
> Same comment about indentation as above.
>
> static struct tcp_ao_key *
> __tcp_ao_do_lookup(const struct sock *sk, const union tcp_ao_addr *addr,
> int family, u8 prefix, int sndid, int rcvid, u16 port)
>
> ...
>
>> +struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
>> + const union tcp_ao_addr *addr,
>> + int family, int sndid, int rcvid, u16 port)
>
> Should tcp_ao_do_lookup be static?
> It seems to only be used in this file.
Yeah, indeed. I think, I noticed previously, but probably managed to
forget. Will fix.
>
> ...
>
>> +static int tcp_ao_verify_port(struct sock *sk, u16 port)
>> +{
>> + struct inet_sock *inet = inet_sk(sk);
>> +
>> + if (port != 0) /* FIXME */
>
> I guess this should be fixed :)
Fair enough. I think, what I'll do is to remove from these initial
patches TCP-port from uAPI: we've expected that it will be useful to
implement port-matching, but so far none from customers requested it.
So, it was left as reserved member in uAPI, not meant to be used just yet.
Separately, as I've made UAPI structures for setsockopt() extendable,
see copy_struct_from_sockptr() and the extendable syscall ideas
(unfortunately, not in Documentation/):
https://lpc.events/event/7/contributions/657/attachments/639/1159/extensible_syscalls.pdf
https://lwn.net/Articles/830666/
So, as those structs can be extended in future, it won't be any hard to
add port-matching on the top of the patch set. RFC5925 is permissive on
how IP address and TCP-port matching may be performed:
: TCP connection identifier. A TCP socket pair, i.e., a local IP
: address, a remote IP address, a TCP local port, and a TCP remote port.
: Values can be partially specified using ranges (e.g., 2-30), masks
: (e.g., 0xF0), wildcards (e.g., "*"), or any other suitable indication.
I can see some utility of TCP-AO key port-range matching and it seems
most useful/flexible, so I'll add that. Unsure if that will go in
version 9 or rather later (even post-merge).
I probably have to add something on that mater to
Documentation/networking/tcp_ao.rst as well.
>> + return -EINVAL;
>> +
>> + /* Check that MKT port is consistent with socket */
>> + if (port != 0 && inet->inet_dport != 0 && port != inet->inet_dport)
>
> port is host byte order, but inet->inet_dport is big endian.
> This does not seem correct.
Thanks.
>
>> + return -EINVAL;
>> +
>> + return 0;
>> +}
>
> ...
>
>> +static int tcp_ao_parse_crypto(struct tcp_ao_add *cmd, struct tcp_ao_key *key)
>> +{
>> + unsigned int syn_tcp_option_space;
>> + bool is_kdf_aes_128_cmac = false;
>> + struct crypto_ahash *tfm;
>> + struct tcp_sigpool hp;
>> + void *tmp_key = NULL;
>> + int err;
>> +
>> + /* RFC5926, 3.1.1.2. KDF_AES_128_CMAC */
>> + if (!strcmp("cmac(aes128)", cmd->alg_name)) {
>> + strscpy(cmd->alg_name, "cmac(aes)", sizeof(cmd->alg_name));
>> + is_kdf_aes_128_cmac = (cmd->keylen != 16);
>> + tmp_key = kmalloc(cmd->keylen, GFP_KERNEL);
>> + if (!tmp_key)
>> + return -ENOMEM;
>> + }
>> +
>> + key->maclen = cmd->maclen ?: 12; /* 12 is the default in RFC5925 */
>> +
>> + /* Check: maclen + tcp-ao header <= (MAX_TCP_OPTION_SPACE - mss
>> + * - tstamp - wscale - sackperm),
>> + * see tcp_syn_options(), tcp_synack_options(), commit 33ad798c924b.
>> + *
>> + * In order to allow D-SACK with TCP-AO, the header size should be:
>> + * (MAX_TCP_OPTION_SPACE - TCPOLEN_TSTAMP_ALIGNED
>> + * - TCPOLEN_SACK_BASE_ALIGNED
>> + * - 2 * TCPOLEN_SACK_PERBLOCK) = 8 (maclen = 4),
>> + * see tcp_established_options().
>> + *
>> + * RFC5925, 2.2:
>> + * Typical MACs are 96-128 bits (12-16 bytes), but any length
>> + * that fits in the header of the segment being authenticated
>> + * is allowed.
>> + *
>> + * RFC5925, 7.6:
>> + * TCP-AO continues to consume 16 bytes in non-SYN segments,
>> + * leaving a total of 24 bytes for other options, of which
>> + * the timestamp consumes 10. This leaves 14 bytes, of which 10
>> + * are used for a single SACK block. When two SACK blocks are used,
>> + * such as to handle D-SACK, a smaller TCP-AO MAC would be required
>> + * to make room for the additional SACK block (i.e., to leave 18
>> + * bytes for the D-SACK variant of the SACK option) [RFC2883].
>> + * Note that D-SACK is not supportable in TCP MD5 in the presence
>> + * of timestamps, because TCP MD5’s MAC length is fixed and too
>> + * large to leave sufficient option space.
>> + */
>> + syn_tcp_option_space = MAX_TCP_OPTION_SPACE;
>> + syn_tcp_option_space -= TCPOLEN_TSTAMP_ALIGNED;
>> + syn_tcp_option_space -= TCPOLEN_WSCALE_ALIGNED;
>> + syn_tcp_option_space -= TCPOLEN_SACKPERM_ALIGNED;
>> + if (tcp_ao_len(key) > syn_tcp_option_space) {
>> + err = -EMSGSIZE;
>> + goto err_kfree;
>> + }
>> +
>> + key->keylen = cmd->keylen;
>> + memcpy(key->key, cmd->key, cmd->keylen);
>> +
>> + err = tcp_sigpool_start(key->tcp_sigpool_id, &hp);
>> + if (err)
>> + goto err_kfree;
>> +
>> + tfm = crypto_ahash_reqtfm(hp.req);
>> + if (is_kdf_aes_128_cmac) {
>> + void *scratch = hp.scratch;
>> + struct scatterlist sg;
>> +
>> + memcpy(tmp_key, cmd->key, cmd->keylen);
>> + sg_init_one(&sg, tmp_key, cmd->keylen);
>> +
>> + /* Using zero-key of 16 bytes as described in RFC5926 */
>> + memset(scratch, 0, 16);
>> + err = crypto_ahash_setkey(tfm, scratch, 16);
>> + if (err)
>> + goto err_pool_end;
>> +
>> + err = crypto_ahash_init(hp.req);
>> + if (err)
>> + goto err_pool_end;
>> +
>> + ahash_request_set_crypt(hp.req, &sg, key->key, cmd->keylen);
>> + err = crypto_ahash_update(hp.req);
>> + if (err)
>> + goto err_pool_end;
>> +
>> + err |= crypto_ahash_final(hp.req);
>> + if (err)
>> + goto err_pool_end;
>> + key->keylen = 16;
>> + }
>> +
>> + err = crypto_ahash_setkey(tfm, key->key, key->keylen);
>> + if (err)
>> + goto err_pool_end;
>> +
>> + tcp_sigpool_end(&hp);
>> +
>> + if (tcp_ao_maclen(key) > key->digest_size)
>> + return -EINVAL;
>
> tmp_key appears to be leaked here.
>
>> +
>> + return 0;
>
> And here.
>
> This is flagged by Smatch.
Ouch. Yeah, the change from v7 that got rid of TCP_AO_MAX_HASH_SIZE and
allocated traffic keys with kmalloc(), managed to add a leak as well.
Thanks, will fix.
>
>> +
>> +err_pool_end:
>> + tcp_sigpool_end(&hp);
>> +err_kfree:
>> + kfree(tmp_key);
>> + return err;
>> +}
>
> ...
>
>> +static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family,
>> + sockptr_t optval, int optlen)
>> +{
>> + struct tcp_ao_info *ao_info;
>> + union tcp_ao_addr *addr;
>> + struct tcp_ao_key *key;
>> + struct tcp_ao_add cmd;
>> + int ret;
>> + bool first = false;
>> + u16 port;
>
> Please use reverse xmas tree - longest line to shortest - for
> local variable declarations in new Networking code.
Will do.
>
>> +static int tcp_ao_del_cmd(struct sock *sk, unsigned short int family,
>> + sockptr_t optval, int optlen)
>> +{
>> + struct tcp_ao_key *key, *new_current = NULL, *new_rnext = NULL;
>> + struct tcp_ao_info *ao_info;
>> + union tcp_ao_addr *addr;
>> + struct tcp_ao_del cmd;
>> + int err;
>> + __u8 prefix;
>> + __be16 port;
>> + int addr_len;
>> +
>> + if (optlen < sizeof(cmd))
>> + return -EINVAL;
>> +
>> + err = copy_struct_from_sockptr(&cmd, sizeof(cmd), optval, optlen);
>> + if (err)
>> + return err;
>> +
>> + if (cmd.reserved != 0 || cmd.reserved2 != 0)
>> + return -EINVAL;
>> +
>> + if (cmd.set_current || cmd.set_rnext) {
>> + if (!tcp_ao_can_set_current_rnext(sk))
>> + return -EINVAL;
>> + }
>> +
>> + ao_info = setsockopt_ao_info(sk);
>> + if (IS_ERR(ao_info))
>> + return PTR_ERR(ao_info);
>> + if (!ao_info)
>> + return -ENOENT;
>> +
>> + /* For sockets in TCP_CLOSED it's possible set keys that aren't
>> + * matching the future peer (address/port/VRF/etc),
>> + * tcp_ao_connect_init() will choose a correct matching MKT
>> + * if there's any.
>> + */
>> + if (cmd.set_current) {
>> + new_current = tcp_ao_established_key(ao_info, cmd.current_key, -1);
>> + if (!new_current)
>> + return -ENOENT;
>> + }
>> + if (cmd.set_rnext) {
>> + new_rnext = tcp_ao_established_key(ao_info, -1, cmd.rnext);
>> + if (!new_rnext)
>> + return -ENOENT;
>> + }
>> +
>> + if (family == AF_INET) {
>> + struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.addr;
>> +
>> + addr = (union tcp_ao_addr *)&sin->sin_addr;
>> + addr_len = sizeof(struct in_addr);
>> + port = ntohs(sin->sin_port);
>
> port is big endian, but here it is assigned a host-byte order value.
> It looks like port should be u16 rather than __bbe16.
>
> As flagged by Smatch.
>
>> + } else {
>> + struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.addr;
>> + struct in6_addr *addr6 = &sin6->sin6_addr;
>> +
>> + if (ipv6_addr_v4mapped(addr6)) {
>> + addr = (union tcp_ao_addr *)&addr6->s6_addr32[3];
>> + addr_len = sizeof(struct in_addr);
>> + family = AF_INET;
>> + } else {
>> + addr = (union tcp_ao_addr *)addr6;
>> + addr_len = sizeof(struct in6_addr);
>> + }
>> + port = ntohs(sin6->sin6_port);
>
> Ditto.
>
>> + }
>> + prefix = cmd.prefix;
>> +
>> + /* We could choose random present key here for current/rnext
>> + * but that's less predictable. Let's be strict and don't
>> + * allow removing a key that's in use. RFC5925 doesn't
>> + * specify how-to coordinate key removal, but says:
>> + * "It is presumed that an MKT affecting a particular
>> + * connection cannot be destroyed during an active connection"
>> + */
>> + hlist_for_each_entry_rcu(key, &ao_info->head, node) {
>> + if (cmd.sndid != key->sndid ||
>> + cmd.rcvid != key->rcvid)
>> + continue;
>> +
>> + if (family != key->family ||
>> + prefix != key->prefixlen ||
> o
>> + port != key->port ||
>
> There is a similar problem here too.
> port is host byte order but key->port is big endian.
>
>> + memcmp(addr, &key->addr, addr_len))
>> + continue;
>> +
>> + if (key == new_current || key == new_rnext)
>> + continue;
>> +
>> + return tcp_ao_delete_key(sk, ao_info, key,
>> + new_current, new_rnext);
>> + }
>> + return -ENOENT;
>> +}
>
> ...
Thanks,
Dmitry
On Tue, Jul 25, 2023 at 08:10:21PM +0100, Dmitry Safonov wrote:
...
> >
> >> + struct tcp_ao_key *rnext_key;
> >> + struct tcp_ao_info *ao_info;
> >> + u8 maclen;
> >>
> >> + if (WARN_ON_ONCE(!ao_key))
> >> + goto out_ao;
> >> + ao_info = rcu_dereference_check(tp->ao_info,
> >> + lockdep_sock_is_held(&tp->inet_conn.icsk_inet.sk));
> >
> > Checkpatch complains about indentation here.
> >
> > Rather than point out each case in the series,
> > could I ask you to run ./scripts/checkpatch.pl --strict over the patchset?
>
> Yeah, but then it won't fit 80 columns here. As both aren't hard
> requirements I tend to comply with 80 columns more than to indentation.
> In this particular case I'll check if it could be a helper function.
> If it won't make sense to separate it as a helper, I'll just move it to
> the same line than, breaking 80 columns limit.
Thanks, I missed the 80 column thing here.
I'd actually think that what you have is better than an extra long line.
But it's your call.
...
Hi Dimitry,
On Tue, Jul 25, 2023 at 09:16:37PM +0100, Dmitry Safonov wrote:
> Hi Simon,
>
> On 7/24/23 20:31, Simon Horman wrote:
> > On Fri, Jul 21, 2023 at 05:18:54PM +0100, Dmitry Safonov wrote:
> >
> > ...
> >
> > Hi Dimitry,
> >
> >> diff --git a/include/linux/sockptr.h b/include/linux/sockptr.h
> >> index bae5e2369b4f..307961b41541 100644
> >> --- a/include/linux/sockptr.h
> >> +++ b/include/linux/sockptr.h
> >> @@ -55,6 +55,29 @@ static inline int copy_from_sockptr(void *dst, sockptr_t src, size_t size)
> >> return copy_from_sockptr_offset(dst, src, 0, size);
> >> }
> >>
> >> +static inline int copy_struct_from_sockptr(void *dst, size_t ksize,
> >> + sockptr_t src, size_t usize)
> >
> > The indentation of the two lines above is not correct,
> > they should be aligned to the inside of the opening '('
> > on the preceding line.
> >
> > In order to stop things being too far to the left,
> > which is perhaps the intent of the current indention scheme,
> > the return type of the function can be moved to it's own line.
> >
> > static inline int
> > copy_struct_from_sockptr(void *dst, size_t ksize, sockptr_t src, size_t usize)
>
> Well, that would be a bit more GNU coding-style alike. Which I don't
> mind, I can do that. Albeit it's a bit contrary to an example from
> kernel's coding-style, where it seems preferred to keep it on the same
> line with function name and rather not to indent argument list, see
> (6.1), second example with action().
>
> Yet, I don't feel particularly strong on either of options, so I can
> just do as you suggest.
For some reason I thought the style I suggested is acceptable,
at least in (some) Networking code.
In any case, I also don't feel strongly about this.
> > ...
> >
> >> diff --git a/include/net/tcp.h b/include/net/tcp.h
> >
> > ...
> >
> >> +static inline int ipv4_prefix_cmp(const struct in_addr *addr1,
> >> + const struct in_addr *addr2,
> >> + unsigned int prefixlen)
> >> +{
> >> + __be32 mask = inet_make_mask(prefixlen);
> >> +
> >> + if ((addr1->s_addr & mask) == (addr2->s_addr & mask))
> >> + return 0;
> >> + return ((addr1->s_addr & mask) > (addr2->s_addr & mask)) ? 1 : -1;
> >> +}
> >
> > Above, '>' is operating on two big endian values.
> > But typically such maths operates on host byte order values.
> >
> > Flagged by Sparse.
>
> Yeah, the function just has to provide any way to compare keys.
> So, it's not very important, but just to silence Sparse I can convert
> them to host's byte order before the comparison.
If you just care about equality, then perhaps you can use an equality
operator and avoid converting the endieness.
But, unless I am mistaken, '<' will give the wrong answer a little-endian host.
And this feels, well ..., wrong.
> > ...
> >
> >> +static struct tcp_ao_key *__tcp_ao_do_lookup(const struct sock *sk,
> >> + const union tcp_ao_addr *addr, int family, u8 prefix,
> >> + int sndid, int rcvid, u16 port)
> >
> > Same comment about indentation as above.
> >
> > static struct tcp_ao_key *
> > __tcp_ao_do_lookup(const struct sock *sk, const union tcp_ao_addr *addr,
> > int family, u8 prefix, int sndid, int rcvid, u16 port)
> >
> > ...
> >
> >> +struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk,
> >> + const union tcp_ao_addr *addr,
> >> + int family, int sndid, int rcvid, u16 port)
> >
> > Should tcp_ao_do_lookup be static?
> > It seems to only be used in this file.
>
> Yeah, indeed. I think, I noticed previously, but probably managed to
> forget. Will fix.
>
> >
> > ...
> >
> >> +static int tcp_ao_verify_port(struct sock *sk, u16 port)
> >> +{
> >> + struct inet_sock *inet = inet_sk(sk);
> >> +
> >> + if (port != 0) /* FIXME */
> >
> > I guess this should be fixed :)
>
> Fair enough. I think, what I'll do is to remove from these initial
> patches TCP-port from uAPI: we've expected that it will be useful to
> implement port-matching, but so far none from customers requested it.
> So, it was left as reserved member in uAPI, not meant to be used just yet.
Sounds good to me.
Thanks.
> Separately, as I've made UAPI structures for setsockopt() extendable,
> see copy_struct_from_sockptr() and the extendable syscall ideas
> (unfortunately, not in Documentation/):
> https://lpc.events/event/7/contributions/657/attachments/639/1159/extensible_syscalls.pdf
> https://lwn.net/Articles/830666/
>
> So, as those structs can be extended in future, it won't be any hard to
> add port-matching on the top of the patch set. RFC5925 is permissive on
> how IP address and TCP-port matching may be performed:
>
> : TCP connection identifier. A TCP socket pair, i.e., a local IP
> : address, a remote IP address, a TCP local port, and a TCP remote port.
> : Values can be partially specified using ranges (e.g., 2-30), masks
> : (e.g., 0xF0), wildcards (e.g., "*"), or any other suitable indication.
>
> I can see some utility of TCP-AO key port-range matching and it seems
> most useful/flexible, so I'll add that. Unsure if that will go in
> version 9 or rather later (even post-merge).
>
> I probably have to add something on that mater to
> Documentation/networking/tcp_ao.rst as well.
>
> >> + return -EINVAL;
> >> +
> >> + /* Check that MKT port is consistent with socket */
> >> + if (port != 0 && inet->inet_dport != 0 && port != inet->inet_dport)
> >
> > port is host byte order, but inet->inet_dport is big endian.
> > This does not seem correct.
>
> Thanks.
...