[src/trunk]: src/sys/netinet6 inet6: discard any received NA with a LL addres...

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

details:   https://anonhg.NetBSD.org/src/rev/882137a99705
branches:  trunk
changeset: 837643:882137a99705
user:      roy <roy%NetBSD.org@localhost>
date:      Thu Dec 13 10:27:51 2018 +0000

description:
inet6: discard any received NA with a LL address we own

This matches ARP behaviour.

diffstat:

 sys/netinet6/nd6_nbr.c |  30 ++++++++++++++++++++----------
 1 files changed, 20 insertions(+), 10 deletions(-)

diffs (60 lines):

diff -r f091792f2ed6 -r 882137a99705 sys/netinet6/nd6_nbr.c
--- a/sys/netinet6/nd6_nbr.c    Thu Dec 13 10:20:51 2018 +0000
+++ b/sys/netinet6/nd6_nbr.c    Thu Dec 13 10:27:51 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nd6_nbr.c,v 1.162 2018/12/07 14:47:24 roy Exp $        */
+/*     $NetBSD: nd6_nbr.c,v 1.163 2018/12/13 10:27:51 roy Exp $        */
 /*     $KAME: nd6_nbr.c,v 1.61 2001/02/10 16:06:14 jinmei Exp $        */
 
 /*
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nd6_nbr.c,v 1.162 2018/12/07 14:47:24 roy Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nd6_nbr.c,v 1.163 2018/12/13 10:27:51 roy Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -653,9 +653,26 @@
                goto freeit;
        }
 
-       if (ndopts.nd_opts_tgt_lladdr) {
+       if (ndopts.nd_opts_tgt_lladdr != NULL) {
+               struct ifnet *ifp_ll;
+               struct psref psref_ll;
+
                lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
                lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
+
+               if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
+                       nd6log(LOG_INFO, "lladdrlen mismatch for %s "
+                           "(if %d, NA packet %d)\n", IN6_PRINT(ip6buf, &taddr6),
+                           ifp->if_addrlen, lladdrlen - 2);
+                       goto bad;
+               }
+
+               ifp_ll = if_get_bylla(lladdr, ifp->if_addrlen, &psref_ll);
+               if (ifp_ll != NULL) {
+                       /* it's from me, ignore it. */
+                       if_put(ifp_ll, &psref_ll);
+                       goto freeit;
+               }
        }
 
        ifa = (struct ifaddr *)in6ifa_ifpwithaddr_psref(ifp, &taddr6, &psref_ia);
@@ -691,13 +708,6 @@
                goto bad;
        }
 
-       if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
-               nd6log(LOG_INFO, "lladdrlen mismatch for %s "
-                   "(if %d, NA packet %d)\n", IN6_PRINT(ip6buf, &taddr6),
-                   ifp->if_addrlen, lladdrlen - 2);
-               goto bad;
-       }
-
        /*
         * If no neighbor cache entry is found, NA SHOULD silently be
         * discarded.