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, 10 insertions, 8 deletions

diff --git a/sys/net/if_atmsubr.c b/sys/net/if_atmsubr.c
index f404984..e7df9c3 100644
--- a/sys/net/if_atmsubr.c
+++ b/sys/net/if_atmsubr.c
@@ -126,7 +126,6 @@ atm_output(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst,
 	int error = 0, sz;
 	struct atm_pseudohdr atmdst, *ad;
 	struct mbuf *m = m0;
-	struct rtentry *rt;
 	struct atmllc *atmllc;
 	struct atmllc *llc_hdr = NULL;
 	u_int32_t atm_flags;
@@ -141,13 +140,6 @@ atm_output(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst,
 		senderr(ENETDOWN);
 
 	/*
-	 * check route
-	 */
-	error = rt_check(&rt, &rt0, dst);
-	if (error)
-		goto bad;
-
-	/*
 	 * check for non-native ATM traffic   (dst != NULL)
 	 */
 	if (dst) {
@@ -156,6 +148,15 @@ atm_output(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst,
 #if defined(INET) || defined(INET6)
 		case AF_INET:
 		case AF_INET6:
+		{
+			struct rtentry *rt;
+			/*  
+			 * check route
+			 */
+			error = rt_check(&rt, &rt0, dst);
+			if (error)
+				goto bad;
+
 			if (dst->sa_family == AF_INET6)
 			        etype = ETHERTYPE_IPV6;
 			else
@@ -167,6 +168,7 @@ atm_output(struct ifnet *ifp, struct mbuf *m0, struct sockaddr *dst,
 				/* XXX: put ATMARP stuff here */
 				/* XXX: watch who frees m on failure */
 			}
+		}
 			break;
 #endif /* INET || INET6 */