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| author | Michael Tuexen <tuexen@FreeBSD.org> | 2022-10-03 12:46:47 +0000 |
|---|---|---|
| committer | Michael Tuexen <tuexen@FreeBSD.org> | 2023-02-01 23:47:53 +0000 |
| commit | cd4974672ad3204ebb27efb623f3aabfcc2b82ef (patch) | |
| tree | bd06ec6dcfef7ecfb7f358126ff99155a8f1d253 | |
| parent | e52b662a3b5f509c3b4b6676b38beaa620b8c1a5 (diff) | |
| download | src-cd4974672ad3204ebb27efb623f3aabfcc2b82ef.tar.gz src-cd4974672ad3204ebb27efb623f3aabfcc2b82ef.zip | |
tcp: improve handling of SYN-ACK segments in TIMEWAIT state
Only consider segments with the SYN bit set and the ACK bit cleared
as "new connection attempts", which result in re-using a connection
being in TIMEWAIT state. This results in consistent handling of
SYN-ACK segments.
Reviewed by: rscheff@
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D36864
(cherry picked from commit 2515552e6216095c3fa61d93ee024bb8861e07c2)
| -rw-r--r-- | sys/netinet/tcp_timewait.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/sys/netinet/tcp_timewait.c b/sys/netinet/tcp_timewait.c index f15cf6dae762..86c5e62fc9b6 100644 --- a/sys/netinet/tcp_timewait.c +++ b/sys/netinet/tcp_timewait.c @@ -456,7 +456,8 @@ tcp_twcheck(struct inpcb *inp, struct tcpopt *to, struct tcphdr *th, * are above the previous ones. * Allow UDP port number changes in this case. */ - if ((thflags & TH_SYN) && SEQ_GT(th->th_seq, tw->rcv_nxt)) { + if (((thflags & (TH_SYN | TH_ACK)) == TH_SYN) && + SEQ_GT(th->th_seq, tw->rcv_nxt)) { tcp_twclose(tw, 0); TCPSTAT_INC(tcps_tw_recycles); return (1); |