svn commit: r310213 - stable/11/sys/netinet

[Michael Tuexen]

Author: tuexen
Date: Sun Dec 18 12:27:35 2016
New Revision: 310213
URL: https://svnweb.freebsd.org/changeset/base/310213

Log:
  MFC r309397:
  
  Fix the handling of  TCP FIN-segments in the CLOSED state
  
  When a TCP segment with the FIN bit set was received in the CLOSED state,
  a TCP RST-ACK-segment is sent. When computing SEG.ACK for this, the
  FIN counts as one byte. This accounting was missing and is fixed by this
  patch.
  
  Sponsored by:	Netflix, Inc.

Modified:
  stable/11/sys/netinet/tcp_input.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/netinet/tcp_input.c
==============================================================================
--- stable/11/sys/netinet/tcp_input.c	Sun Dec 18 12:23:48 2016	(r310212)
+++ stable/11/sys/netinet/tcp_input.c	Sun Dec 18 12:27:35 2016	(r310213)
@@ -3316,6 +3316,8 @@ tcp_dropwithreset(struct mbuf *m, struct
 	} else {
 		if (th->th_flags & TH_SYN)
 			tlen++;
+		if (th->th_flags & TH_FIN)
+			tlen++;
 		tcp_respond(tp, mtod(m, void *), th, m, th->th_seq+tlen,
 		    (tcp_seq)0, TH_RST|TH_ACK);
 	}