svn commit: r340781 - head/sys/netinet/tcp_stacks

[Michael Tuexen]

Author: tuexen
Date: Thu Nov 22 20:02:39 2018
New Revision: 340781
URL: https://svnweb.freebsd.org/changeset/base/340781

Log:
  Ensure that the TCP RACK stack honours the setting of the
  net.inet.tcp.drop_synfin sysctl-variable.
  
  Reviewed by:		rrs@
  MFC after:		1 week
  Sponsored by:		Netflix, Inc.
  Differential Revision:	https://reviews.freebsd.org/D18033

Modified:
  head/sys/netinet/tcp_stacks/rack.c

Modified: head/sys/netinet/tcp_stacks/rack.c
==============================================================================
--- head/sys/netinet/tcp_stacks/rack.c	Thu Nov 22 20:00:56 2018	(r340780)
+++ head/sys/netinet/tcp_stacks/rack.c	Thu Nov 22 20:02:39 2018	(r340781)
@@ -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