[src/trunk]: src/sys/net reset the csum_flags in bridge_brodcast() also for b...

[jdolecek <jdolecek%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/06c55ee12b91
branches:  trunk
changeset: 1008501:06c55ee12b91
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Tue Mar 24 13:30:54 2020 +0000

description:
reset the csum_flags in bridge_brodcast() also for bmcast path

for destination interfaces with real hardware offloading this fixes
multicast packet corruption; for xvif(4) this fix stops treating them
as having no csum

may fix PR kern/42386

diffstat:

 sys/net/if_bridge.c |  10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)

diffs (31 lines):

diff -r 74ee2a034858 -r 06c55ee12b91 sys/net/if_bridge.c
--- a/sys/net/if_bridge.c       Tue Mar 24 13:07:46 2020 +0000
+++ b/sys/net/if_bridge.c       Tue Mar 24 13:30:54 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_bridge.c,v 1.168 2020/02/24 00:47:38 rin Exp $      */
+/*     $NetBSD: if_bridge.c,v 1.169 2020/03/24 13:30:54 jdolecek Exp $ */
 
 /*
  * Copyright 2001 Wasabi Systems, Inc.
@@ -80,7 +80,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_bridge.c,v 1.168 2020/02/24 00:47:38 rin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_bridge.c,v 1.169 2020/03/24 13:30:54 jdolecek Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_bridge_ipf.h"
@@ -2101,6 +2101,12 @@
                                if_statinc(&sc->sc_if, if_oerrors);
                                goto next;
                        }
+                       /*
+                        * Before enqueueing this packet to the destination
+                        * interface, clear any in-bound checksum flags to
+                        * prevent them from being misused as out-bound flags.
+                        */
+                       mc->m_pkthdr.csum_flags = 0;
 
                        m_set_rcvif(mc, dst_if);
                        mc->m_flags &= ~M_PROMISC;