| Message ID | 4A43356B.7060005@cn.fujitsu.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Wei Yongjun <yjwei@cn.fujitsu.com> Date: Thu, 25 Jun 2009 16:29:31 +0800 > RFC0793 defined that in FIN-WAIT-2 state if the ACK bit is off drop > the segment and return[Page 72]. But this check is missing in function > tcp_timewait_state_process(). This cause the segment with FIN flag but > no ACK has two diffent action: ... > This patch fixed the problem. > > Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> Patch applied, thank you. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 43bbba7..f8d67cc 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -128,7 +128,8 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb, goto kill_with_rst; /* Dup ACK? */ - if (!after(TCP_SKB_CB(skb)->end_seq, tcptw->tw_rcv_nxt) || + if (!th->ack || + !after(TCP_SKB_CB(skb)->end_seq, tcptw->tw_rcv_nxt) || TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq) { inet_twsk_put(tw); return TCP_TW_SUCCESS;
RFC0793 defined that in FIN-WAIT-2 state if the ACK bit is off drop the segment and return[Page 72]. But this check is missing in function tcp_timewait_state_process(). This cause the segment with FIN flag but no ACK has two diffent action: Case 1: Node A Node B <------------- FIN,ACK (enter FIN-WAIT-1) ACK -------------> (enter FIN-WAIT-2) FIN -------------> discard (move sk to tw list) Case 2: Node A Node B <------------- FIN,ACK (enter FIN-WAIT-1) ACK -------------> (enter FIN-WAIT-2) (move sk to tw list) FIN -------------> <------------- ACK This patch fixed the problem. Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> --- net/ipv4/tcp_minisocks.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)