diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-02-01 21:03:08 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-02-06 03:11:59 -0500 |
| commit | 9d691539eea2d977e3eb86766c389a19a9c13146 (patch) | |
| tree | 21f14703c42c81bc67063ab7fd9fe0cdda86265b /net/ipv4 | |
| parent | 61d2bcae99f66a640b3dd9632180209143fb5512 (diff) | |
| download | blackbird-op-linux-9d691539eea2d977e3eb86766c389a19a9c13146.tar.gz blackbird-op-linux-9d691539eea2d977e3eb86766c389a19a9c13146.zip | |
tcp: do not enqueue skb with SYN flag
If we remove the SYN flag from the skbs that tcp_fastopen_add_skb()
places in socket receive queue, then we can remove the test that
tcp_recvmsg() has to perform in fast path.
All we have to do is to adjust SEQ in the slow path.
For the moment, we place an unlikely() and output a message
if we find an skb having SYN flag set.
Goal would be to get rid of the test completely.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp.c | 8 | ||||
| -rw-r--r-- | net/ipv4/tcp_fastopen.c | 3 |
2 files changed, 9 insertions, 2 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 19746b3fcbbe..c5075779e017 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1466,8 +1466,10 @@ static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off) while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) { offset = seq - TCP_SKB_CB(skb)->seq; - if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN) + if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { + pr_err_once("%s: found a SYN, please report !\n", __func__); offset--; + } if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) { *off = offset; return skb; @@ -1657,8 +1659,10 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, break; offset = *seq - TCP_SKB_CB(skb)->seq; - if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN) + if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) { + pr_err_once("%s: found a SYN, please report !\n", __func__); offset--; + } if (offset < skb->len) goto found_ok_skb; if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c index 467d3e985411..6a6e11e54bae 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -143,6 +143,9 @@ void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb) __skb_pull(skb, tcp_hdrlen(skb)); skb_set_owner_r(skb, sk); + TCP_SKB_CB(skb)->seq++; + TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_SYN; + tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq; __skb_queue_tail(&sk->sk_receive_queue, skb); tp->syn_data_acked = 1; |
