svn commit: r358621 - head/sys/netinet

[Michael Tuexen]

Author: tuexen
Date: Wed Mar  4 16:41:25 2020
New Revision: 358621
URL: https://svnweb.freebsd.org/changeset/base/358621

Log:
  When using automatically generated flow labels and using TCP SYN
  cookies, use the same flow label for the segments sent during the
  handshake and after the handshake.
  This fixes a bug by making sure that sc_flowlabel is always stored in
  network byte order.
  
  Reviewed by:		bz@
  MFC after:		3 days
  Sponsored by:		Netflix, Inc.
  Differential Revision:	https://reviews.freebsd.org/D23957

Modified:
  head/sys/netinet/tcp_syncache.c

Modified: head/sys/netinet/tcp_syncache.c
==============================================================================
--- head/sys/netinet/tcp_syncache.c	Wed Mar  4 16:20:59 2020	(r358620)
+++ head/sys/netinet/tcp_syncache.c	Wed Mar  4 16:41:25 2020	(r358621)
@@ -2224,7 +2224,8 @@ syncookie_lookup(struct in_conninfo *inc, struct synca
 #ifdef INET6
 	case INC_ISIPV6:
 		if (sotoinpcb(lso)->inp_flags & IN6P_AUTOFLOWLABEL)
-			sc->sc_flowlabel = sc->sc_iss & IPV6_FLOWLABEL_MASK;
+			sc->sc_flowlabel =
+			    htonl(sc->sc_iss) & IPV6_FLOWLABEL_MASK;
 		break;
 #endif
 	}