[src/trunk]: src/sys/netinet6 use carp mac address when replying to neighbor ...

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

details:   https://anonhg.NetBSD.org/src/rev/33b0fc247f8f
branches:  trunk
changeset: 374059:33b0fc247f8f
user:      kardel <kardel%NetBSD.org@localhost>
date:      Wed Mar 29 13:01:44 2023 +0000

description:
use carp mac address when replying to neighbor solicitations referring
to carp interface addresses.
unconfuses commercial routers

diffstat:

 sys/netinet6/nd6_nbr.c |  25 ++++++++++++++++++-------
 1 files changed, 18 insertions(+), 7 deletions(-)

diffs (84 lines):

diff -r 7fdec4c96f9f -r 33b0fc247f8f sys/netinet6/nd6_nbr.c
--- a/sys/netinet6/nd6_nbr.c    Wed Mar 29 10:29:09 2023 +0000
+++ b/sys/netinet6/nd6_nbr.c    Wed Mar 29 13:01:44 2023 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nd6_nbr.c,v 1.182 2021/08/02 12:56:25 andvar Exp $     */
+/*     $NetBSD: nd6_nbr.c,v 1.183 2023/03/29 13:01:44 kardel 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 1.182 2021/08/02 12:56:25 andvar Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nd6_nbr.c,v 1.183 2023/03/29 13:01:44 kardel Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -100,7 +100,7 @@ static int dad_maxtry = 15; /* max # of 
 void
 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
 {
-       struct ifnet *ifp;
+       struct ifnet *ifp, *ifpc;
        struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
        struct nd_neighbor_solicit *nd_ns;
        struct in6_addr saddr6 = ip6->ip6_src;
@@ -116,10 +116,11 @@ nd6_ns_input(struct mbuf *m, int off, in
        union nd_opts ndopts;
        const struct sockaddr_dl *proxydl = NULL;
        struct psref psref;
+       struct psref psref_c;
        struct psref psref_ia;
        char ip6buf[INET6_ADDRSTRLEN], ip6buf2[INET6_ADDRSTRLEN];
 
-       ifp = m_get_rcvif_psref(m, &psref);
+       ifp = ifpc = m_get_rcvif_psref(m, &psref);
        if (ifp == NULL)
                goto freeit;
 
@@ -224,8 +225,15 @@ nd6_ns_input(struct mbuf *m, int off, in
        if (ifp->if_carp && ifp->if_type != IFT_CARP) {
                int s = pserialize_read_enter();
                ifa = carp_iamatch6(ifp->if_carp, &taddr6);
-               if (ifa != NULL)
+               if (ifa != NULL) {    
                        ifa_acquire(ifa, &psref_ia);
+                       if (ifa->ifa_ifp && ifa->ifa_ifp != ifp) {
+                               ifpc = ifa->ifa_ifp;
+                               if_acquire(ifpc, &psref_c);
+                       }
+               }
+               
+               
                pserialize_read_exit(s);
        } else
                ifa = NULL;
@@ -350,14 +358,14 @@ nd6_ns_input(struct mbuf *m, int off, in
                in6_all = in6addr_linklocal_allnodes;
                if (in6_setscope(&in6_all, ifp, NULL) != 0)
                        goto bad;
-               nd6_na_output(ifp, &in6_all, &taddr6,
+               nd6_na_output(ifpc, &in6_all, &taddr6,
                    ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
                    (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0),
                    tlladdr, (const struct sockaddr *)proxydl);
                goto freeit;
        }
 
-       nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_NEIGHBOR_SOLICIT, 0);
+       nd6_cache_lladdr(ifpc, &saddr6, lladdr, lladdrlen, ND_NEIGHBOR_SOLICIT, 0);
 
        nd6_na_output(ifp, &saddr6, &taddr6,
            ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
@@ -366,6 +374,9 @@ nd6_ns_input(struct mbuf *m, int off, in
  freeit:
        ifa_release(ifa, &psref_ia);
        m_put_rcvif_psref(ifp, &psref);
+       if (ifp != ifpc)
+               if_put(ifpc, &psref_c);
+
        m_freem(m);
        return;