From ec3c0982a2dd1e671bad8e9d26c28dcba0039d87 Mon Sep 17 00:00:00 2001 From: Patrick McManus Date: Fri, 21 Mar 2008 16:33:01 -0700 Subject: [TCP]: TCP_DEFER_ACCEPT updates - process as established Change TCP_DEFER_ACCEPT implementation so that it transitions a connection to ESTABLISHED after handshake is complete instead of leaving it in SYN-RECV until some data arrvies. Place connection in accept queue when first data packet arrives from slow path. Benefits: - established connection is now reset if it never makes it to the accept queue - diagnostic state of established matches with the packet traces showing completed handshake - TCP_DEFER_ACCEPT timeouts are expressed in seconds and can now be enforced with reasonable accuracy instead of rounding up to next exponential back-off of syn-ack retry. Signed-off-by: Patrick McManus Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) (limited to 'net/ipv4/tcp_input.c') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 9cf446427cc..6e46b4c0f28 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4451,6 +4451,49 @@ static void tcp_urg(struct sock *sk, struct sk_buff *skb, struct tcphdr *th) } } +static int tcp_defer_accept_check(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + + if (tp->defer_tcp_accept.request) { + int queued_data = tp->rcv_nxt - tp->copied_seq; + int hasfin = !skb_queue_empty(&sk->sk_receive_queue) ? + tcp_hdr((struct sk_buff *) + sk->sk_receive_queue.prev)->fin : 0; + + if (queued_data && hasfin) + queued_data--; + + if (queued_data && + tp->defer_tcp_accept.listen_sk->sk_state == TCP_LISTEN) { + if (sock_flag(sk, SOCK_KEEPOPEN)) { + inet_csk_reset_keepalive_timer(sk, + keepalive_time_when(tp)); + } else { + inet_csk_delete_keepalive_timer(sk); + } + + inet_csk_reqsk_queue_add( + tp->defer_tcp_accept.listen_sk, + tp->defer_tcp_accept.request, + sk); + + tp->defer_tcp_accept.listen_sk->sk_data_ready( + tp->defer_tcp_accept.listen_sk, 0); + + sock_put(tp->defer_tcp_accept.listen_sk); + sock_put(sk); + tp->defer_tcp_accept.listen_sk = NULL; + tp->defer_tcp_accept.request = NULL; + } else if (hasfin || + tp->defer_tcp_accept.listen_sk->sk_state != TCP_LISTEN) { + tcp_reset(sk); + return -1; + } + } + return 0; +} + static int tcp_copy_to_iovec(struct sock *sk, struct sk_buff *skb, int hlen) { struct tcp_sock *tp = tcp_sk(sk); @@ -4811,6 +4854,9 @@ step5: tcp_data_snd_check(sk); tcp_ack_snd_check(sk); + + if (tcp_defer_accept_check(sk)) + return -1; return 0; csum_error: -- cgit v1.2.3