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_minisocks.c | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) (limited to 'net/ipv4/tcp_minisocks.c') diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 8245247a6ce..019c8c16e5c 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -571,10 +571,8 @@ struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb, does sequence test, SYN is truncated, and thus we consider it a bare ACK. - If icsk->icsk_accept_queue.rskq_defer_accept, we silently drop this - bare ACK. Otherwise, we create an established connection. Both - ends (listening sockets) accept the new incoming connection and try - to talk to each other. 8-) + Both ends (listening sockets) accept the new incoming + connection and try to talk to each other. 8-) Note: This case is both harmless, and rare. Possibility is about the same as us discovering intelligent life on another plant tomorrow. @@ -642,13 +640,6 @@ struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb, if (!(flg & TCP_FLAG_ACK)) return NULL; - /* If TCP_DEFER_ACCEPT is set, drop bare ACK. */ - if (inet_csk(sk)->icsk_accept_queue.rskq_defer_accept && - TCP_SKB_CB(skb)->end_seq == tcp_rsk(req)->rcv_isn + 1) { - inet_rsk(req)->acked = 1; - return NULL; - } - /* OK, ACK is valid, create big socket and * feed this segment to it. It will repeat all * the tests. THIS SEGMENT MUST MOVE SOCKET TO @@ -687,7 +678,24 @@ struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb, inet_csk_reqsk_queue_unlink(sk, req, prev); inet_csk_reqsk_queue_removed(sk, req); - inet_csk_reqsk_queue_add(sk, req, child); + if (inet_csk(sk)->icsk_accept_queue.rskq_defer_accept && + TCP_SKB_CB(skb)->end_seq == tcp_rsk(req)->rcv_isn + 1) { + + /* the accept queue handling is done is est recv slow + * path so lets make sure to start there + */ + tcp_sk(child)->pred_flags = 0; + sock_hold(sk); + sock_hold(child); + tcp_sk(child)->defer_tcp_accept.listen_sk = sk; + tcp_sk(child)->defer_tcp_accept.request = req; + + inet_csk_reset_keepalive_timer(child, + inet_csk(sk)->icsk_accept_queue.rskq_defer_accept * HZ); + } else { + inet_csk_reqsk_queue_add(sk, req, child); + } + return child; listen_overflow: -- cgit v1.2.3