diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-04-21 22:13:01 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-25 15:48:10 -0400 |
| commit | 0aea76d35c9651d55bbaf746e7914e5f9ae5a25d (patch) | |
| tree | d0416ab07371c5bb704fd324e117183022b743b8 /net/ipv4/tcp_input.c | |
| parent | 1bc7fe64b60b40d50e42ba4bb870bbfb95d64e21 (diff) | |
| download | linux-0aea76d35c9651d55bbaf746e7914e5f9ae5a25d.tar.bz2 | |
tcp: SYN packets are now simply consumed
We now have proper per-listener but also per network namespace counters
for SYN packets that might be dropped.
We replace the kfree_skb() by consume_skb() to be drop monitor [1]
friendly, and remove an obsolete comment.
FastOpen SYN packets can carry payload in them just fine.
[1] perf record -a -g -e skb:kfree_skb sleep 1; perf report
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 19 |
1 files changed, 1 insertions, 18 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index dcad8f9f96eb..967520dbe0bf 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5815,24 +5815,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) if (icsk->icsk_af_ops->conn_request(sk, skb) < 0) return 1; - /* Now we have several options: In theory there is - * nothing else in the frame. KA9Q has an option to - * send data with the syn, BSD accepts data with the - * syn up to the [to be] advertised window and - * Solaris 2.1 gives you a protocol error. For now - * we just ignore it, that fits the spec precisely - * and avoids incompatibilities. It would be nice in - * future to drop through and process the data. - * - * Now that TTCP is starting to be used we ought to - * queue this data. - * But, this leaves one open to an easy denial of - * service attack, and SYN cookies can't defend - * against this problem. So, we drop the data - * in the interest of security over speed unless - * it's still in use. - */ - kfree_skb(skb); + consume_skb(skb); return 0; } goto discard; |