On 06/03/14(Thu) 09:34, Martin Pieuchot wrote:
> On 19/02/14(Wed) 12:53, Martin Pieuchot wrote:
> > Generally, when a NA is received we check if the receiving interface
> > has the target address advertised and if it's the case we warn about
> > duplicate addresses and bail.
> >
> > But in the case of a carp interface in BACKUP state it's different. In
> > this case we have a hack that sets the ifa to NULL and continue. This
> > hack relies on the fact that no cache entry will be found later on
> > (because it was removed when the state switch to BACKUP) or that there
> > is no lladdr change in the NA (like it is right now) to work properly.
> >
> > So instead of expecting such things, simply ignore NAs with matching
> > address on carp BACKUP nodes since they are more likely to come from
> > the carp MASTER.
> >
> > Less is more, ok?
>
> Anybody?
And now a correct version without a "typo" (|| should be &&) spotted by
sthen@. Here's a freshly retested the diff:
Index: netinet6/nd6_nbr.c
===================================================================
RCS file: /home/ncvs/src/sys/netinet6/nd6_nbr.c,v
retrieving revision 1.75
diff -u -p -r1.75 nd6_nbr.c
--- netinet6/nd6_nbr.c 24 Jan 2014 12:20:22 -0000 1.75
+++ netinet6/nd6_nbr.c 6 Mar 2014 10:08:17 -0000
@@ -570,9 +570,6 @@ nd6_na_input(struct mbuf *m, int off, in
struct rtentry *rt;
struct sockaddr_dl *sdl;
union nd_opts ndopts;
-#if NCARP > 0
- struct sockaddr_dl *proxydl = NULL;
-#endif
char addr[INET6_ADDRSTRLEN], addr0[INET6_ADDRSTRLEN];
if (ip6->ip6_hlim != 255) {
@@ -632,11 +629,6 @@ nd6_na_input(struct mbuf *m, int off, in
}
ifa = &in6ifa_ifpwithaddr(ifp, &taddr6)->ia_ifa;
-#if NCARP > 0
- if (ifp->if_type == IFT_CARP && ifa &&
- !carp_iamatch6(ifp, lladdr, &proxydl))
- ifa = NULL;
-#endif
/*
* Target address matches one of my interface address.
@@ -652,8 +644,18 @@ nd6_na_input(struct mbuf *m, int off, in
goto freeit;
}
- /* Just for safety, maybe unnecessary. */
if (ifa) {
+#if NCARP > 0
+ struct sockaddr_dl *proxydl = NULL;
+
+ /*
+ * Ignore NAs silently for carp addresses if we're not
+ * the CARP master.
+ */
+ if (ifp->if_type == IFT_CARP &&
+ !carp_iamatch6(ifp, lladdr, &proxydl))
+ goto freeit;
+#endif
log(LOG_ERR,
"nd6_na_input: duplicate IP6 address %s\n",
inet_ntop(AF_INET6, &taddr6, addr, sizeof(addr)));
