On 27/04/16(Wed) 18:13, Martin Pieuchot wrote:
> gif(4) is the only p2p interface for which the kernel does some kind of
> link-layer address resolution when it comes to IPv6 & ND.
>
> I don't believe this is necessary because we do not install any cloning
> route on p2p interfaces. However the rt_checkgate() call *is* necessary
> because your default IPv6 route, or any gateway route, might go through
> your tunnel.
>
> So the diff below removes gif(4) interfaces from the list of interfaces
> that need a link-layer cache and move the check *after* calling
> rt_checkgate(). This way all the p2p-specific code in nd6_output()
> can go away.
>
> I'd like to hear from people using such setup to know if this break
> anything.
Here's a non broken diff, thanks to naddy@ for finding that.
Index: netinet6/nd6.c
===================================================================
RCS file: /cvs/src/sys/netinet6/nd6.c,v
retrieving revision 1.178
diff -u -p -r1.178 nd6.c
--- netinet6/nd6.c 27 Apr 2016 14:47:27 -0000 1.178
+++ netinet6/nd6.c 7 May 2016 11:49:28 -0000
@@ -1512,9 +1512,6 @@ nd6_output(struct ifnet *ifp, struct mbu
if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
goto sendpkt;
- if (nd6_need_cache(ifp) == 0)
- goto sendpkt;
-
/*
* next hop determination.
*/
@@ -1524,21 +1521,11 @@ nd6_output(struct ifnet *ifp, struct mbu
m_freem(m);
return (error);
}
-
- /*
- * We skip link-layer address resolution and NUD
- * if the gateway is not a neighbor from ND point
- * of view, regardless of the value of nd_ifinfo.flags.
- * The second condition is a bit tricky; we skip
- * if the gateway is our own address, which is
- * sometimes used to install a route to a p2p link.
- */
- if ((ifp->if_flags & IFF_POINTOPOINT) &&
- ((nd6_is_addr_neighbor(satosin6(rt_key(rt)), ifp) == 0) ||
- in6ifa_ifpwithaddr(ifp, &satosin6(rt_key(rt))->sin6_addr)))
- goto sendpkt;
}
+ if (nd6_need_cache(ifp) == 0)
+ goto sendpkt;
+
/*
* Address resolution or Neighbor Unreachability Detection
* for the next hop.
@@ -1565,8 +1552,7 @@ nd6_output(struct ifnet *ifp, struct mbu
}
}
if (ln == NULL || rt == NULL) {
- if ((ifp->if_flags & IFF_POINTOPOINT) == 0 &&
- !(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
+ if ((ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD) == 0) {
char addr[INET6_ADDRSTRLEN];
log(LOG_DEBUG, "%s: can't allocate llinfo for %s "
@@ -1591,13 +1577,6 @@ nd6_output(struct ifnet *ifp, struct mbu
TAILQ_REMOVE(&nd6_list, ln, ln_list);
TAILQ_INSERT_HEAD(&nd6_list, ln, ln_list);
- /* We don't have to do link-layer address resolution on a p2p link. */
- if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
- ln->ln_state < ND6_LLINFO_REACHABLE) {
- ln->ln_state = ND6_LLINFO_STALE;
- nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
- }
-
/*
* The first time we send a packet to a neighbor whose entry is
* STALE, we have to change the state to DELAY and a sets a timer to
@@ -1658,11 +1637,8 @@ nd6_need_cache(struct ifnet *ifp)
*/
switch (ifp->if_type) {
case IFT_ETHER:
- case IFT_IEEE1394:
- case IFT_PROPVIRTUAL:
case IFT_IEEE80211:
case IFT_CARP:
- case IFT_GIF: /* XXX need more cases? */
return (1);
default:
return (0);
