This commit does two things:

1. rt_check() cleanup:
    rt_check() is only necessary for some address families to gain access
    to the corresponding arp entry, so call it only in/near the *resolve()
    routines where it is actually used -- at the moment this is
    arpresolve(), nd6_storelladdr() (the call is embedded here),
    and atmresolve() (the call is just before atmresolve to reduce
    the number of changes).
    This change will make it a lot easier to decouple the arp table
    from the routing table.

    There is an extra call to rt_check() in if_iso88025subr.c to
    determine the routing info length. I have left it alone for
    the time being.

    The interface of arpresolve() and nd6_storelladdr() now changes slightly:
     + the 'rtentry' parameter (really a hint from the upper level layer)
       is now passed unchanged from *_output(), so it becomes the route
       to the final destination and not to the gateway.
     + the routines will return 0 if resolution is possible, non-zero
       otherwise.
     + arpresolve() returns EWOULDBLOCK in case the mbuf is being held
       waiting for an arp reply -- in this case the error code is masked
       in the caller so the upper layer protocol will not see a failure.

2. arpcom untangling
    Where possible, use 'struct ifnet' instead of 'struct arpcom' variables,
    and use the IFP2AC macro to access arpcom fields.
    This mostly affects the netatalk code.

=== Detailed changes: ===
net/if_arcsubr.c
   rt_check() cleanup, remove a useless variable

net/if_atmsubr.c
   rt_check() cleanup

net/if_ethersubr.c
   rt_check() cleanup, arpcom untangling

net/if_fddisubr.c
   rt_check() cleanup, arpcom untangling

net/if_iso88025subr.c
   rt_check() cleanup

netatalk/aarp.c
   arpcom untangling, remove a block of duplicated code

netatalk/at_extern.h
   arpcom untangling

netinet/if_ether.c
   rt_check() cleanup (change arpresolve)

netinet6/nd6.c
   rt_check() cleanup (change nd6_storelladdr)

1 files changed, 13 insertions, 6 deletions

diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index d907505..4523f53 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -2032,15 +2032,16 @@ nd6_need_cache(ifp)
 }
 
 int
-nd6_storelladdr(ifp, rt, m, dst, desten)
+nd6_storelladdr(ifp, rt0, m, dst, desten)
 	struct ifnet *ifp;
-	struct rtentry *rt;
+	struct rtentry *rt0;
 	struct mbuf *m;
 	struct sockaddr *dst;
 	u_char *desten;
 {
 	int i;
 	struct sockaddr_dl *sdl;
+	struct rtentry *rt;
 
 	if (m->m_flags & M_MCAST) {
 		switch (ifp->if_type) {
@@ -2073,26 +2074,32 @@ nd6_storelladdr(ifp, rt, m, dst, desten)
 		}
 	}
 
+	i = rt_check(&rt, &rt0, dst);
+	if (i) {
+		m_freem(m);
+		return i;
+	}
+
 	if (rt == NULL) {
 		/* this could happen, if we could not allocate memory */
 		m_freem(m);
-		return (0);
+		return (ENOMEM);
 	}
 	if (rt->rt_gateway->sa_family != AF_LINK) {
 		printf("nd6_storelladdr: something odd happens\n");
 		m_freem(m);
-		return (0);
+		return (EINVAL);
 	}
 	sdl = SDL(rt->rt_gateway);
 	if (sdl->sdl_alen == 0) {
 		/* this should be impossible, but we bark here for debugging */
 		printf("nd6_storelladdr: sdl_alen == 0\n");
 		m_freem(m);
-		return (0);
+		return (EINVAL);
 	}
 
 	bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
-	return (1);
+	return (0);
 }
 
 static int nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS);