2022-09-01 12:34:14

by David Howells

[permalink] [raw]
Subject: [PATCH net v3 0/6] rxrpc: Miscellaneous fixes


Here are some fixes for AF_RXRPC:

(1) Fix the handling of ICMP/ICMP6 packets. This is a problem due to
rxrpc being switched to acting as a UDP tunnel, thereby allowing it to
steal the packets before they go through the UDP Rx queue. UDP
tunnels can't get ICMP/ICMP6 packets, however. This patch adds an
additional encap hook so that they can.

(2) Fix the encryption routines in rxkad to handle packets that have more
than three parts correctly. The problem is that ->nr_frags doesn't
count the initial fragment, so the sglist ends up too short.

(3) Fix a problem with destruction of the local endpoint potentially
getting repeated.

(4) Fix the calculation of the time at which to resend.
jiffies_to_usecs() gives microseconds, not nanoseconds.

(5) Fix AFS to work out when callback promises and locks expire based on
the time an op was issued rather than the time the first reply packet
arrives. We don't know how long the server took between calculating
the expiry interval and transmitting the reply.

(6) Given (5), rxrpc_get_reply_time() is no longer used, so remove it.

The patches are tagged here:

git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git
rxrpc-fixes-20220901

and can also be found on the following branch:

https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=rxrpc-fixes

Changes
=======
ver #3)
- Fixed an uninitialised variable.

ver #2)
- Added some missing cpp-conditionals for rxrpc IPV6 support.
- Replaced the callback promise time calculation patch with one that used
the time of op issue rather than time of first reply packet as a base.
- Added an additional patch to remove the rxrpc function to retrieve the
time of first reply.

Link: http://lists.infradead.org/pipermail/linux-afs/2022-August/005547.html # v1
Link: http://lists.infradead.org/pipermail/linux-afs/2022-August/005552.html # v2

David
---
David Howells (6):
rxrpc: Fix ICMP/ICMP6 error handling
rxrpc: Fix an insufficiently large sglist in rxkad_verify_packet_2()
rxrpc: Fix local destruction being repeated
rxrpc: Fix calc of resend age
afs: Use the operation issue time instead of the reply time for callbacks
rxrpc: Remove rxrpc_get_reply_time() which is no longer used


Documentation/networking/rxrpc.rst | 11 --
fs/afs/flock.c | 2 +-
fs/afs/fsclient.c | 2 +-
fs/afs/internal.h | 3 +-
fs/afs/rxrpc.c | 7 +-
fs/afs/yfsclient.c | 3 +-
include/linux/udp.h | 1 +
include/net/af_rxrpc.h | 2 -
include/net/udp_tunnel.h | 4 +
net/ipv4/udp.c | 2 +
net/ipv4/udp_tunnel_core.c | 1 +
net/ipv6/udp.c | 5 +-
net/rxrpc/ar-internal.h | 1 +
net/rxrpc/call_event.c | 2 +-
net/rxrpc/local_object.c | 4 +
net/rxrpc/peer_event.c | 293 +++++++++++++++++++++++++----
net/rxrpc/recvmsg.c | 43 -----
net/rxrpc/rxkad.c | 2 +-
18 files changed, 280 insertions(+), 108 deletions(-)



2022-09-01 12:34:39

by David Howells

[permalink] [raw]
Subject: [PATCH net v3 2/6] rxrpc: Fix an insufficiently large sglist in rxkad_verify_packet_2()

rxkad_verify_packet_2() has a small stack-allocated sglist of 4 elements,
but if that isn't sufficient for the number of fragments in the socket
buffer, we try to allocate an sglist large enough to hold all the
fragments.

However, for large packets with a lot of fragments, this isn't sufficient
and we need at least one additional fragment.

The problem manifests as skb_to_sgvec() returning -EMSGSIZE and this then
getting returned by userspace. Most of the time, this isn't a problem as
rxrpc sets a limit of 5692, big enough for 4 jumbo subpackets to be glued
together; occasionally, however, the server will ignore the reported limit
and give a packet that's a lot bigger - say 19852 bytes with ->nr_frags
being 7. skb_to_sgvec() then tries to return a "zeroth" fragment that
seems to occur before the fragments counted by ->nr_frags and we hit the
end of the sglist too early.

Note that __skb_to_sgvec() also has an skb_walk_frags() loop that is
recursive up to 24 deep. I'm not sure if I need to take account of that
too - or if there's an easy way of counting those frags too.

Fix this by counting an extra frag and allocating a larger sglist based on
that.

Fixes: d0d5c0cd1e71 ("rxrpc: Use skb_unshare() rather than skb_cow_data()")
Reported-by: Marc Dionne <[email protected]>
Signed-off-by: David Howells <[email protected]>
cc: [email protected]
---

net/rxrpc/rxkad.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index 258917a714c8..78fa0524156f 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -540,7 +540,7 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
* directly into the target buffer.
*/
sg = _sg;
- nsg = skb_shinfo(skb)->nr_frags;
+ nsg = skb_shinfo(skb)->nr_frags + 1;
if (nsg <= 4) {
nsg = 4;
} else {


2022-09-01 12:34:41

by David Howells

[permalink] [raw]
Subject: [PATCH net v3 4/6] rxrpc: Fix calc of resend age

Fix the calculation of the resend age to add a microsecond value as
microseconds, not nanoseconds.

Signed-off-by: David Howells <[email protected]>
---

net/rxrpc/call_event.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index f8ecad2b730e..2a93e7b5fbd0 100644
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -166,7 +166,7 @@ static void rxrpc_resend(struct rxrpc_call *call, unsigned long now_j)
_enter("{%d,%d}", call->tx_hard_ack, call->tx_top);

now = ktime_get_real();
- max_age = ktime_sub(now, jiffies_to_usecs(call->peer->rto_j));
+ max_age = ktime_sub_us(now, jiffies_to_usecs(call->peer->rto_j));

spin_lock_bh(&call->lock);



2022-09-01 12:37:16

by David Howells

[permalink] [raw]
Subject: [PATCH net v3 6/6] rxrpc: Remove rxrpc_get_reply_time() which is no longer used

Remove rxrpc_get_reply_time() as that is no longer used now that the call
issue time is used instead of the reply time.

Signed-off-by: David Howells <[email protected]>
---

Documentation/networking/rxrpc.rst | 11 ---------
include/net/af_rxrpc.h | 2 --
net/rxrpc/recvmsg.c | 43 ------------------------------------
3 files changed, 56 deletions(-)

diff --git a/Documentation/networking/rxrpc.rst b/Documentation/networking/rxrpc.rst
index 39c2249c7aa7..39494a6ea739 100644
--- a/Documentation/networking/rxrpc.rst
+++ b/Documentation/networking/rxrpc.rst
@@ -1055,17 +1055,6 @@ The kernel interface functions are as follows:
first function to change. Note that this must be called in TASK_RUNNING
state.

- (#) Get reply timestamp::
-
- bool rxrpc_kernel_get_reply_time(struct socket *sock,
- struct rxrpc_call *call,
- ktime_t *_ts)
-
- This allows the timestamp on the first DATA packet of the reply of a
- client call to be queried, provided that it is still in the Rx ring. If
- successful, the timestamp will be stored into ``*_ts`` and true will be
- returned; false will be returned otherwise.
-
(#) Get remote client epoch::

u32 rxrpc_kernel_get_epoch(struct socket *sock,
diff --git a/include/net/af_rxrpc.h b/include/net/af_rxrpc.h
index cee5f83c0f11..b69ca695935c 100644
--- a/include/net/af_rxrpc.h
+++ b/include/net/af_rxrpc.h
@@ -66,8 +66,6 @@ int rxrpc_kernel_charge_accept(struct socket *, rxrpc_notify_rx_t,
void rxrpc_kernel_set_tx_length(struct socket *, struct rxrpc_call *, s64);
bool rxrpc_kernel_check_life(const struct socket *, const struct rxrpc_call *);
u32 rxrpc_kernel_get_epoch(struct socket *, struct rxrpc_call *);
-bool rxrpc_kernel_get_reply_time(struct socket *, struct rxrpc_call *,
- ktime_t *);
bool rxrpc_kernel_call_is_complete(struct rxrpc_call *);
void rxrpc_kernel_set_max_life(struct socket *, struct rxrpc_call *,
unsigned long);
diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
index 250f23bc1c07..7e39c262fd79 100644
--- a/net/rxrpc/recvmsg.c
+++ b/net/rxrpc/recvmsg.c
@@ -771,46 +771,3 @@ int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call,
goto out;
}
EXPORT_SYMBOL(rxrpc_kernel_recv_data);
-
-/**
- * rxrpc_kernel_get_reply_time - Get timestamp on first reply packet
- * @sock: The socket that the call exists on
- * @call: The call to query
- * @_ts: Where to put the timestamp
- *
- * Retrieve the timestamp from the first DATA packet of the reply if it is
- * in the ring. Returns true if successful, false if not.
- */
-bool rxrpc_kernel_get_reply_time(struct socket *sock, struct rxrpc_call *call,
- ktime_t *_ts)
-{
- struct sk_buff *skb;
- rxrpc_seq_t hard_ack, top, seq;
- bool success = false;
-
- mutex_lock(&call->user_mutex);
-
- if (READ_ONCE(call->state) != RXRPC_CALL_CLIENT_RECV_REPLY)
- goto out;
-
- hard_ack = call->rx_hard_ack;
- if (hard_ack != 0)
- goto out;
-
- seq = hard_ack + 1;
- top = smp_load_acquire(&call->rx_top);
- if (after(seq, top))
- goto out;
-
- skb = call->rxtx_buffer[seq & RXRPC_RXTX_BUFF_MASK];
- if (!skb)
- goto out;
-
- *_ts = skb_get_ktime(skb);
- success = true;
-
-out:
- mutex_unlock(&call->user_mutex);
- return success;
-}
-EXPORT_SYMBOL(rxrpc_kernel_get_reply_time);


2022-09-01 12:52:09

by David Howells

[permalink] [raw]
Subject: [PATCH net v3 5/6] afs: Use the operation issue time instead of the reply time for callbacks

rxrpc and kafs between them try to use the receive timestamp on the first
data packet (ie. the one with sequence number 1) as a base from which to
calculate the time at which callback promise and lock expiration occurs.

However, we don't know how long it took for the server to send us the reply
from it having completed the basic part of the operation - it might then,
for instance, have to send a bunch of a callback breaks, depending on the
particular operation.

Fix this by using the time at which the operation is issued on the client
as a base instead. That should never be longer than the server's idea of
the expiry time.

Fixes: 781070551c26 ("afs: Fix calculation of callback expiry time")
Fixes: 2070a3e44962 ("rxrpc: Allow the reply time to be obtained on a client call")
Suggested-by: Jeffrey E Altman <[email protected]>
Signed-off-by: David Howells <[email protected]>
---

fs/afs/flock.c | 2 +-
fs/afs/fsclient.c | 2 +-
fs/afs/internal.h | 3 +--
fs/afs/rxrpc.c | 7 +------
fs/afs/yfsclient.c | 3 +--
5 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/fs/afs/flock.c b/fs/afs/flock.c
index c4210a3964d8..bbcc5afd1576 100644
--- a/fs/afs/flock.c
+++ b/fs/afs/flock.c
@@ -76,7 +76,7 @@ void afs_lock_op_done(struct afs_call *call)
if (call->error == 0) {
spin_lock(&vnode->lock);
trace_afs_flock_ev(vnode, NULL, afs_flock_timestamp, 0);
- vnode->locked_at = call->reply_time;
+ vnode->locked_at = call->issue_time;
afs_schedule_lock_extension(vnode);
spin_unlock(&vnode->lock);
}
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 4943413d9c5f..7d37f63ef0f0 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -131,7 +131,7 @@ static void xdr_decode_AFSFetchStatus(const __be32 **_bp,

static time64_t xdr_decode_expiry(struct afs_call *call, u32 expiry)
{
- return ktime_divns(call->reply_time, NSEC_PER_SEC) + expiry;
+ return ktime_divns(call->issue_time, NSEC_PER_SEC) + expiry;
}

static void xdr_decode_AFSCallBack(const __be32 **_bp,
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 64ad55494349..723d162078a3 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -137,7 +137,6 @@ struct afs_call {
bool need_attention; /* T if RxRPC poked us */
bool async; /* T if asynchronous */
bool upgrade; /* T to request service upgrade */
- bool have_reply_time; /* T if have got reply_time */
bool intr; /* T if interruptible */
bool unmarshalling_error; /* T if an unmarshalling error occurred */
u16 service_id; /* Actual service ID (after upgrade) */
@@ -151,7 +150,7 @@ struct afs_call {
} __attribute__((packed));
__be64 tmp64;
};
- ktime_t reply_time; /* Time of first reply packet */
+ ktime_t issue_time; /* Time of issue of operation */
};

struct afs_call_type {
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index d5c4785c862d..eccc3cd0cb70 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -351,6 +351,7 @@ void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
if (call->max_lifespan)
rxrpc_kernel_set_max_life(call->net->socket, rxcall,
call->max_lifespan);
+ call->issue_time = ktime_get_real();

/* send the request */
iov[0].iov_base = call->request;
@@ -501,12 +502,6 @@ static void afs_deliver_to_call(struct afs_call *call)
return;
}

- if (!call->have_reply_time &&
- rxrpc_kernel_get_reply_time(call->net->socket,
- call->rxcall,
- &call->reply_time))
- call->have_reply_time = true;
-
ret = call->type->deliver(call);
state = READ_ONCE(call->state);
if (ret == 0 && call->unmarshalling_error)
diff --git a/fs/afs/yfsclient.c b/fs/afs/yfsclient.c
index fdc7d675b4b0..11571cca86c1 100644
--- a/fs/afs/yfsclient.c
+++ b/fs/afs/yfsclient.c
@@ -232,8 +232,7 @@ static void xdr_decode_YFSCallBack(const __be32 **_bp,
struct afs_callback *cb = &scb->callback;
ktime_t cb_expiry;

- cb_expiry = call->reply_time;
- cb_expiry = ktime_add(cb_expiry, xdr_to_u64(x->expiration_time) * 100);
+ cb_expiry = ktime_add(call->issue_time, xdr_to_u64(x->expiration_time) * 100);
cb->expires_at = ktime_divns(cb_expiry, NSEC_PER_SEC);
scb->have_cb = true;
*_bp += xdr_size(x);


2022-09-01 13:15:49

by David Howells

[permalink] [raw]
Subject: [PATCH net v3 1/6] rxrpc: Fix ICMP/ICMP6 error handling

Because rxrpc pretends to be a tunnel on top of a UDP/UDP6 socket, allowing
it to siphon off UDP packets early in the handling of received UDP packets
thereby avoiding the packet going through the UDP receive queue, it doesn't
get ICMP packets through the UDP ->sk_error_report() callback. In fact, it
doesn't appear that there's any usable option for getting hold of ICMP
packets.

Fix this by adding a new UDP encap hook to distribute error messages for
UDP tunnels. If the hook is set, then the tunnel driver will be able to
see ICMP packets. The hook provides the offset into the packet of the UDP
header of the original packet that caused the notification.

An alternative would be to call the ->error_handler() hook - but that
requires that the skbuff be cloned (as ip_icmp_error() or ipv6_cmp_error()
do, though isn't really necessary or desirable in rxrpc's case is we want
to parse them there and then, not queue them).

Changes
=======
ver #3)
- Fixed an uninitialised variable.

ver #2)
- Fixed some missing CONFIG_AF_RXRPC_IPV6 conditionals.

Fixes: 5271953cad31 ("rxrpc: Use the UDP encap_rcv hook")
Signed-off-by: David Howells <[email protected]>
---

include/linux/udp.h | 1
include/net/udp_tunnel.h | 4 +
net/ipv4/udp.c | 2
net/ipv4/udp_tunnel_core.c | 1
net/ipv6/udp.c | 5 +
net/rxrpc/ar-internal.h | 1
net/rxrpc/local_object.c | 1
net/rxrpc/peer_event.c | 293 ++++++++++++++++++++++++++++++++++++++------
8 files changed, 270 insertions(+), 38 deletions(-)

diff --git a/include/linux/udp.h b/include/linux/udp.h
index 254a2654400f..e96da4157d04 100644
--- a/include/linux/udp.h
+++ b/include/linux/udp.h
@@ -70,6 +70,7 @@ struct udp_sock {
* For encapsulation sockets.
*/
int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
+ void (*encap_err_rcv)(struct sock *sk, struct sk_buff *skb, unsigned int udp_offset);
int (*encap_err_lookup)(struct sock *sk, struct sk_buff *skb);
void (*encap_destroy)(struct sock *sk);

diff --git a/include/net/udp_tunnel.h b/include/net/udp_tunnel.h
index afc7ce713657..72394f441dad 100644
--- a/include/net/udp_tunnel.h
+++ b/include/net/udp_tunnel.h
@@ -67,6 +67,9 @@ static inline int udp_sock_create(struct net *net,
typedef int (*udp_tunnel_encap_rcv_t)(struct sock *sk, struct sk_buff *skb);
typedef int (*udp_tunnel_encap_err_lookup_t)(struct sock *sk,
struct sk_buff *skb);
+typedef void (*udp_tunnel_encap_err_rcv_t)(struct sock *sk,
+ struct sk_buff *skb,
+ unsigned int udp_offset);
typedef void (*udp_tunnel_encap_destroy_t)(struct sock *sk);
typedef struct sk_buff *(*udp_tunnel_gro_receive_t)(struct sock *sk,
struct list_head *head,
@@ -80,6 +83,7 @@ struct udp_tunnel_sock_cfg {
__u8 encap_type;
udp_tunnel_encap_rcv_t encap_rcv;
udp_tunnel_encap_err_lookup_t encap_err_lookup;
+ udp_tunnel_encap_err_rcv_t encap_err_rcv;
udp_tunnel_encap_destroy_t encap_destroy;
udp_tunnel_gro_receive_t gro_receive;
udp_tunnel_gro_complete_t gro_complete;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 34eda973bbf1..cd72158e953a 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -783,6 +783,8 @@ int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
*/
if (tunnel) {
/* ...not for tunnels though: we don't have a sending socket */
+ if (udp_sk(sk)->encap_err_rcv)
+ udp_sk(sk)->encap_err_rcv(sk, skb, iph->ihl << 2);
goto out;
}
if (!inet->recverr) {
diff --git a/net/ipv4/udp_tunnel_core.c b/net/ipv4/udp_tunnel_core.c
index 8efaf8c3fe2a..8242c8947340 100644
--- a/net/ipv4/udp_tunnel_core.c
+++ b/net/ipv4/udp_tunnel_core.c
@@ -72,6 +72,7 @@ void setup_udp_tunnel_sock(struct net *net, struct socket *sock,

udp_sk(sk)->encap_type = cfg->encap_type;
udp_sk(sk)->encap_rcv = cfg->encap_rcv;
+ udp_sk(sk)->encap_err_rcv = cfg->encap_err_rcv;
udp_sk(sk)->encap_err_lookup = cfg->encap_err_lookup;
udp_sk(sk)->encap_destroy = cfg->encap_destroy;
udp_sk(sk)->gro_receive = cfg->gro_receive;
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 16c176e7c69a..3366d6a77ff2 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -616,8 +616,11 @@ int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
}

/* Tunnels don't have an application socket: don't pass errors back */
- if (tunnel)
+ if (tunnel) {
+ if (udp_sk(sk)->encap_err_rcv)
+ udp_sk(sk)->encap_err_rcv(sk, skb, offset);
goto out;
+ }

if (!np->recverr) {
if (!harderr || sk->sk_state != TCP_ESTABLISHED)
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 571436064cd6..62c70709d798 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -982,6 +982,7 @@ void rxrpc_send_keepalive(struct rxrpc_peer *);
/*
* peer_event.c
*/
+void rxrpc_encap_err_rcv(struct sock *sk, struct sk_buff *skb, unsigned int udp_offset);
void rxrpc_error_report(struct sock *);
void rxrpc_peer_keepalive_worker(struct work_struct *);

diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c
index 96ecb7356c0f..79bb02eb67b2 100644
--- a/net/rxrpc/local_object.c
+++ b/net/rxrpc/local_object.c
@@ -137,6 +137,7 @@ static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net)

tuncfg.encap_type = UDP_ENCAP_RXRPC;
tuncfg.encap_rcv = rxrpc_input_packet;
+ tuncfg.encap_err_rcv = rxrpc_encap_err_rcv;
tuncfg.sk_user_data = local;
setup_udp_tunnel_sock(net, local->socket, &tuncfg);

diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c
index be032850ae8c..32561e9567fe 100644
--- a/net/rxrpc/peer_event.c
+++ b/net/rxrpc/peer_event.c
@@ -16,22 +16,105 @@
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include <net/ip.h>
+#include <net/icmp.h>
#include "ar-internal.h"

+static void rxrpc_adjust_mtu(struct rxrpc_peer *, unsigned int);
static void rxrpc_store_error(struct rxrpc_peer *, struct sock_exterr_skb *);
static void rxrpc_distribute_error(struct rxrpc_peer *, int,
enum rxrpc_call_completion);

/*
- * Find the peer associated with an ICMP packet.
+ * Find the peer associated with an ICMPv4 packet.
*/
static struct rxrpc_peer *rxrpc_lookup_peer_icmp_rcu(struct rxrpc_local *local,
- const struct sk_buff *skb,
+ struct sk_buff *skb,
+ unsigned int udp_offset,
+ unsigned int *info,
struct sockaddr_rxrpc *srx)
{
- struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
+ struct iphdr *ip, *ip0 = ip_hdr(skb);
+ struct icmphdr *icmp = icmp_hdr(skb);
+ struct udphdr *udp = (struct udphdr *)(skb->data + udp_offset);

- _enter("");
+ _enter("%u,%u,%u", ip0->protocol, icmp->type, icmp->code);
+
+ switch (icmp->type) {
+ case ICMP_DEST_UNREACH:
+ *info = ntohs(icmp->un.frag.mtu);
+ fallthrough;
+ case ICMP_TIME_EXCEEDED:
+ case ICMP_PARAMETERPROB:
+ ip = (struct iphdr *)((void *)icmp + 8);
+ break;
+ default:
+ return NULL;
+ }
+
+ memset(srx, 0, sizeof(*srx));
+ srx->transport_type = local->srx.transport_type;
+ srx->transport_len = local->srx.transport_len;
+ srx->transport.family = local->srx.transport.family;
+
+ /* Can we see an ICMP4 packet on an ICMP6 listening socket? and vice
+ * versa?
+ */
+ switch (srx->transport.family) {
+ case AF_INET:
+ srx->transport_len = sizeof(srx->transport.sin);
+ srx->transport.family = AF_INET;
+ srx->transport.sin.sin_port = udp->dest;
+ memcpy(&srx->transport.sin.sin_addr, &ip->daddr,
+ sizeof(struct in_addr));
+ break;
+
+#ifdef CONFIG_AF_RXRPC_IPV6
+ case AF_INET6:
+ srx->transport_len = sizeof(srx->transport.sin);
+ srx->transport.family = AF_INET;
+ srx->transport.sin.sin_port = udp->dest;
+ memcpy(&srx->transport.sin.sin_addr, &ip->daddr,
+ sizeof(struct in_addr));
+ break;
+#endif
+
+ default:
+ WARN_ON_ONCE(1);
+ return NULL;
+ }
+
+ _net("ICMP {%pISp}", &srx->transport);
+ return rxrpc_lookup_peer_rcu(local, srx);
+}
+
+#ifdef CONFIG_AF_RXRPC_IPV6
+/*
+ * Find the peer associated with an ICMPv6 packet.
+ */
+static struct rxrpc_peer *rxrpc_lookup_peer_icmp6_rcu(struct rxrpc_local *local,
+ struct sk_buff *skb,
+ unsigned int udp_offset,
+ unsigned int *info,
+ struct sockaddr_rxrpc *srx)
+{
+ struct icmp6hdr *icmp = icmp6_hdr(skb);
+ struct ipv6hdr *ip, *ip0 = ipv6_hdr(skb);
+ struct udphdr *udp = (struct udphdr *)(skb->data + udp_offset);
+
+ _enter("%u,%u,%u", ip0->nexthdr, icmp->icmp6_type, icmp->icmp6_code);
+
+ switch (icmp->icmp6_type) {
+ case ICMPV6_DEST_UNREACH:
+ *info = ntohl(icmp->icmp6_mtu);
+ fallthrough;
+ case ICMPV6_PKT_TOOBIG:
+ case ICMPV6_TIME_EXCEED:
+ case ICMPV6_PARAMPROB:
+ ip = (struct ipv6hdr *)((void *)icmp + 8);
+ break;
+ default:
+ return NULL;
+ }

memset(srx, 0, sizeof(*srx));
srx->transport_type = local->srx.transport_type;
@@ -41,6 +124,165 @@ static struct rxrpc_peer *rxrpc_lookup_peer_icmp_rcu(struct rxrpc_local *local,
/* Can we see an ICMP4 packet on an ICMP6 listening socket? and vice
* versa?
*/
+ switch (srx->transport.family) {
+ case AF_INET:
+ _net("Rx ICMP6 on v4 sock");
+ srx->transport_len = sizeof(srx->transport.sin);
+ srx->transport.family = AF_INET;
+ srx->transport.sin.sin_port = udp->dest;
+ memcpy(&srx->transport.sin.sin_addr,
+ &ip->daddr.s6_addr32[3], sizeof(struct in_addr));
+ break;
+ case AF_INET6:
+ _net("Rx ICMP6");
+ srx->transport.sin.sin_port = udp->dest;
+ memcpy(&srx->transport.sin6.sin6_addr, &ip->daddr,
+ sizeof(struct in6_addr));
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return NULL;
+ }
+
+ _net("ICMP {%pISp}", &srx->transport);
+ return rxrpc_lookup_peer_rcu(local, srx);
+}
+#endif /* CONFIG_AF_RXRPC_IPV6 */
+
+/*
+ * Handle an error received on the local endpoint as a tunnel.
+ */
+void rxrpc_encap_err_rcv(struct sock *sk, struct sk_buff *skb,
+ unsigned int udp_offset)
+{
+ struct sock_extended_err ee;
+ struct sockaddr_rxrpc srx;
+ struct rxrpc_local *local;
+ struct rxrpc_peer *peer;
+ unsigned int info = 0;
+ int err;
+ u8 version = ip_hdr(skb)->version;
+ u8 type = icmp_hdr(skb)->type;
+ u8 code = icmp_hdr(skb)->code;
+
+ rcu_read_lock();
+ local = rcu_dereference_sk_user_data(sk);
+ if (unlikely(!local)) {
+ rcu_read_unlock();
+ return;
+ }
+
+ rxrpc_new_skb(skb, rxrpc_skb_received);
+
+ switch (ip_hdr(skb)->version) {
+ case IPVERSION:
+ peer = rxrpc_lookup_peer_icmp_rcu(local, skb, udp_offset,
+ &info, &srx);
+ break;
+#ifdef CONFIG_AF_RXRPC_IPV6
+ case 6:
+ peer = rxrpc_lookup_peer_icmp6_rcu(local, skb, udp_offset,
+ &info, &srx);
+ break;
+#endif
+ default:
+ rcu_read_unlock();
+ return;
+ }
+
+ if (peer && !rxrpc_get_peer_maybe(peer))
+ peer = NULL;
+ if (!peer) {
+ rcu_read_unlock();
+ return;
+ }
+
+ memset(&ee, 0, sizeof(ee));
+
+ switch (version) {
+ case IPVERSION:
+ switch (type) {
+ case ICMP_DEST_UNREACH:
+ switch (code) {
+ case ICMP_FRAG_NEEDED:
+ rxrpc_adjust_mtu(peer, info);
+ rcu_read_unlock();
+ rxrpc_put_peer(peer);
+ return;
+ default:
+ break;
+ }
+
+ err = EHOSTUNREACH;
+ if (code <= NR_ICMP_UNREACH) {
+ /* Might want to do something different with
+ * non-fatal errors
+ */
+ //harderr = icmp_err_convert[code].fatal;
+ err = icmp_err_convert[code].errno;
+ }
+ break;
+
+ case ICMP_TIME_EXCEEDED:
+ err = EHOSTUNREACH;
+ break;
+ default:
+ err = EPROTO;
+ break;
+ }
+
+ ee.ee_origin = SO_EE_ORIGIN_ICMP;
+ ee.ee_type = type;
+ ee.ee_code = code;
+ ee.ee_errno = err;
+ break;
+
+#ifdef CONFIG_AF_RXRPC_IPV6
+ case 6:
+ switch (type) {
+ case ICMPV6_PKT_TOOBIG:
+ rxrpc_adjust_mtu(peer, info);
+ rcu_read_unlock();
+ rxrpc_put_peer(peer);
+ return;
+ }
+
+ icmpv6_err_convert(type, code, &err);
+
+ if (err == EACCES)
+ err = EHOSTUNREACH;
+
+ ee.ee_origin = SO_EE_ORIGIN_ICMP6;
+ ee.ee_type = type;
+ ee.ee_code = code;
+ ee.ee_errno = err;
+ break;
+#endif
+ }
+
+ trace_rxrpc_rx_icmp(peer, &ee, &srx);
+
+ rxrpc_distribute_error(peer, err, RXRPC_CALL_NETWORK_ERROR);
+ rcu_read_unlock();
+ rxrpc_put_peer(peer);
+}
+
+/*
+ * Find the peer associated with a local error.
+ */
+static struct rxrpc_peer *rxrpc_lookup_peer_local_rcu(struct rxrpc_local *local,
+ const struct sk_buff *skb,
+ struct sockaddr_rxrpc *srx)
+{
+ struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
+
+ _enter("");
+
+ memset(srx, 0, sizeof(*srx));
+ srx->transport_type = local->srx.transport_type;
+ srx->transport_len = local->srx.transport_len;
+ srx->transport.family = local->srx.transport.family;
+
switch (srx->transport.family) {
case AF_INET:
srx->transport_len = sizeof(srx->transport.sin);
@@ -104,10 +346,8 @@ static struct rxrpc_peer *rxrpc_lookup_peer_icmp_rcu(struct rxrpc_local *local,
/*
* Handle an MTU/fragmentation problem.
*/
-static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, struct sock_exterr_skb *serr)
+static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, unsigned int mtu)
{
- u32 mtu = serr->ee.ee_info;
-
_net("Rx ICMP Fragmentation Needed (%d)", mtu);

/* wind down the local interface MTU */
@@ -148,7 +388,7 @@ void rxrpc_error_report(struct sock *sk)
struct sock_exterr_skb *serr;
struct sockaddr_rxrpc srx;
struct rxrpc_local *local;
- struct rxrpc_peer *peer;
+ struct rxrpc_peer *peer = NULL;
struct sk_buff *skb;

rcu_read_lock();
@@ -172,41 +412,20 @@ void rxrpc_error_report(struct sock *sk)
}
rxrpc_new_skb(skb, rxrpc_skb_received);
serr = SKB_EXT_ERR(skb);
- if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
- _leave("UDP empty message");
- rcu_read_unlock();
- rxrpc_free_skb(skb, rxrpc_skb_freed);
- return;
- }

- peer = rxrpc_lookup_peer_icmp_rcu(local, skb, &srx);
- if (peer && !rxrpc_get_peer_maybe(peer))
- peer = NULL;
- if (!peer) {
- rcu_read_unlock();
- rxrpc_free_skb(skb, rxrpc_skb_freed);
- _leave(" [no peer]");
- return;
- }
-
- trace_rxrpc_rx_icmp(peer, &serr->ee, &srx);
-
- if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP &&
- serr->ee.ee_type == ICMP_DEST_UNREACH &&
- serr->ee.ee_code == ICMP_FRAG_NEEDED)) {
- rxrpc_adjust_mtu(peer, serr);
- rcu_read_unlock();
- rxrpc_free_skb(skb, rxrpc_skb_freed);
- rxrpc_put_peer(peer);
- _leave(" [MTU update]");
- return;
+ if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL) {
+ peer = rxrpc_lookup_peer_local_rcu(local, skb, &srx);
+ if (peer && !rxrpc_get_peer_maybe(peer))
+ peer = NULL;
+ if (peer) {
+ trace_rxrpc_rx_icmp(peer, &serr->ee, &srx);
+ rxrpc_store_error(peer, serr);
+ }
}

- rxrpc_store_error(peer, serr);
rcu_read_unlock();
rxrpc_free_skb(skb, rxrpc_skb_freed);
rxrpc_put_peer(peer);
-
_leave("");
}



2022-09-02 13:39:11

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH net v3 0/6] rxrpc: Miscellaneous fixes

Hello:

This series was applied to netdev/net.git (master)
by David Howells <[email protected]>:

On Thu, 01 Sep 2022 13:26:26 +0100 you wrote:
> Here are some fixes for AF_RXRPC:
>
> (1) Fix the handling of ICMP/ICMP6 packets. This is a problem due to
> rxrpc being switched to acting as a UDP tunnel, thereby allowing it to
> steal the packets before they go through the UDP Rx queue. UDP
> tunnels can't get ICMP/ICMP6 packets, however. This patch adds an
> additional encap hook so that they can.
>
> [...]

Here is the summary with links:
- [net,v3,1/6] rxrpc: Fix ICMP/ICMP6 error handling
https://git.kernel.org/netdev/net/c/ac56a0b48da8
- [net,v3,2/6] rxrpc: Fix an insufficiently large sglist in rxkad_verify_packet_2()
https://git.kernel.org/netdev/net/c/0d40f728e283
- [net,v3,3/6] rxrpc: Fix local destruction being repeated
https://git.kernel.org/netdev/net/c/d3d863036d68
- [net,v3,4/6] rxrpc: Fix calc of resend age
https://git.kernel.org/netdev/net/c/214a9dc7d852
- [net,v3,5/6] afs: Use the operation issue time instead of the reply time for callbacks
https://git.kernel.org/netdev/net/c/7903192c4b4a
- [net,v3,6/6] rxrpc: Remove rxrpc_get_reply_time() which is no longer used
https://git.kernel.org/netdev/net/c/21457f4a91cb

You are awesome, thank you!
--
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