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]>
Acked-by: David Ahern <[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 e4ddca6178ca..7b9762ab4df8 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -366,6 +366,11 @@ 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 a8af93972ee5..ecbf2e217f29 100644
--- a/net/ipv4/tcp_ao.c
+++ b/net/ipv4/tcp_ao.c
@@ -562,7 +562,8 @@ 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);
@@ -610,7 +611,8 @@ 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))
@@ -1403,7 +1405,7 @@ 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