Module Name: src
Committed By: martin
Date: Mon Dec 7 20:01:02 UTC 2020
Modified Files:
src/sys/netinet [netbsd-8]: ip_mroute.c
Log Message:
Pull up following revision(s) (requested by kardel in ticket #1632):
sys/netinet/ip_mroute.c: revision 1.164 (patch)
PR kern/55779:
restore non-desctructive guarantee of ip_mforward() mbuf
argument. This avoids generation invalid UDP checksums
on multicast packets in ip_output().
XXX the root cause of the misguided fix in 2008 should be
XXX investigated
To generate a diff of this commit:
cvs rdiff -u -r1.146.6.4 -r1.146.6.5 src/sys/netinet/ip_mroute.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/netinet/ip_mroute.c
diff -u src/sys/netinet/ip_mroute.c:1.146.6.4 src/sys/netinet/ip_mroute.c:1.146.6.5
--- src/sys/netinet/ip_mroute.c:1.146.6.4 Fri Jul 13 14:26:47 2018
+++ src/sys/netinet/ip_mroute.c Mon Dec 7 20:01:01 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: ip_mroute.c,v 1.146.6.4 2018/07/13 14:26:47 martin Exp $ */
+/* $NetBSD: ip_mroute.c,v 1.146.6.5 2020/12/07 20:01:01 martin Exp $ */
/*
* Copyright (c) 1992, 1993
@@ -93,7 +93,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ip_mroute.c,v 1.146.6.4 2018/07/13 14:26:47 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ip_mroute.c,v 1.146.6.5 2020/12/07 20:01:01 martin Exp $");
#ifdef _KERNEL_OPT
#include "opt_inet.h"
@@ -239,6 +239,8 @@ static int tbf_dq_sel(struct vif *, stru
static void tbf_send_packet(struct vif *, struct mbuf *);
static void tbf_update_tokens(struct vif *);
static int priority(struct vif *, struct ip *);
+static int ip_mforward_real(struct mbuf *, struct ifnet *);
+
/*
* Bandwidth monitoring
@@ -1309,6 +1311,34 @@ ip_mforward(struct mbuf *m, struct ifnet
ip_mforward(struct mbuf *m, struct ifnet *ifp)
#endif /* RSVP_ISI */
{
+ int rc;
+ /*
+ * save csum_flags to uphold the
+ * "unscathed" guarantee.
+ * ip_output() relies on that and
+ * without it we send out
+ * multicast packets with an invalid
+ * checksum
+ *
+ * see PR kern/55779
+ */
+ int csum_flags = m->m_pkthdr.csum_flags;
+
+ /*
+ * Temporarily clear any in-bound checksum flags for this packet.
+ */
+ m->m_pkthdr.csum_flags = 0;
+
+ rc = ip_mforward_real(m, ifp);
+
+ m->m_pkthdr.csum_flags = csum_flags;
+
+ return rc;
+}
+
+static int
+ip_mforward_real(struct mbuf *m, struct ifnet *ifp)
+{
struct ip *ip = mtod(m, struct ip *);
struct mfc *rt;
static int srctun = 0;
@@ -1340,11 +1370,6 @@ ip_mforward(struct mbuf *m, struct ifnet
return (1);
}
- /*
- * Clear any in-bound checksum flags for this packet.
- */
- m->m_pkthdr.csum_flags = 0;
-
#ifdef RSVP_ISI
if (imo && ((vifi = imo->imo_multicast_vif) < numvifs)) {
if (ip->ip_ttl < MAXTTL)
