svn commit: r341500 - stable/12/sys/netinet/tcp_stacks

[Michael Tuexen]

Author: tuexen
Date: Tue Dec  4 22:13:05 2018
New Revision: 341500
URL: https://svnweb.freebsd.org/changeset/base/341500

Log:
  MFC r340781:
  
  Ensure that the TCP RACK stack honours the setting of the
  net.inet.tcp.drop_synfin sysctl-variable.
  
  Reviewed by:		rrs@
  Sponsored by:		Netflix, Inc.
  Differential Revision:	https://reviews.freebsd.org/D18033

Modified:
  stable/12/sys/netinet/tcp_stacks/rack.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/netinet/tcp_stacks/rack.c
==============================================================================
--- stable/12/sys/netinet/tcp_stacks/rack.c	Tue Dec  4 22:11:41 2018	(r341499)
+++ stable/12/sys/netinet/tcp_stacks/rack.c	Tue Dec  4 22:13:05 2018	(r341500)
@@ -6528,6 +6528,10 @@ rack_hpts_do_segment(struct mbuf *m, struct tcphdr *th
 		TCP_LOG_EVENT(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
 		    tlen, &log, true);
 	}
+	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
+		way_out = 4;
+		goto done_with_input;
+	}
 	/*
 	 * Segment received on connection. Reset idle time and keep-alive
 	 * timer. XXX: This should be done after segment validation to