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authorEric Dumazet <edumazet@google.com>2012-05-04 05:14:02 +0000
committerBen Hutchings <ben@decadent.org.uk>2014-12-14 16:24:00 +0000
commit69cff65c8e35c2dc8763249e758ff55538809d27 (patch)
treec7c34a5a0c80c1008bde52bd89ba22d49075eafa /net
parent3d7b5eb99e9ee3317966426e86816d327c910eed (diff)
tcp: be more strict before accepting ECN negociation
commit bd14b1b2e29bd6812597f896dde06eaf7c6d2f24 upstream. It appears some networks play bad games with the two bits reserved for ECN. This can trigger false congestion notifications and very slow transferts. Since RFC 3168 (6.1.1) forbids SYN packets to carry CT bits, we can disable TCP ECN negociation if it happens we receive mangled CT bits in the SYN packet. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Perry Lorier <perryl@google.com> Cc: Matt Mathis <mattmathis@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Wilmer van der Gaast <wilmer@google.com> Cc: Ankur Jain <jankur@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Dave Täht <dave.taht@bufferbloat.net> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Florian Westphal <fw@strlen.de>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/tcp_ipv4.c2
-rw-r--r--net/ipv6/tcp_ipv6.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 92d71388bc23..26eb8e2a54e2 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1352,7 +1352,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
goto drop_and_free;
if (!want_cookie || tmp_opt.tstamp_ok)
- TCP_ECN_create_request(req, tcp_hdr(skb));
+ TCP_ECN_create_request(req, skb);
if (want_cookie) {
isn = cookie_v4_init_sequence(sk, skb, &req->mss);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index c69358cda2a4..057a9d21e6f8 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1254,7 +1254,7 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
ipv6_addr_copy(&treq->rmt_addr, &ipv6_hdr(skb)->saddr);
ipv6_addr_copy(&treq->loc_addr, &ipv6_hdr(skb)->daddr);
if (!want_cookie || tmp_opt.tstamp_ok)
- TCP_ECN_create_request(req, tcp_hdr(skb));
+ TCP_ECN_create_request(req, skb);
treq->iif = sk->sk_bound_dev_if;