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, 8 insertions, 16 deletions

diff --git a/sys/net/if_arcsubr.c b/sys/net/if_arcsubr.c
index 47d7b5c..b4aa519 100644
--- a/sys/net/if_arcsubr.c
+++ b/sys/net/if_arcsubr.c
@@ -107,8 +107,6 @@ arc_output(ifp, m, dst, rt0)
 	struct sockaddr *dst;
 	struct rtentry *rt0;
 {
-	struct rtentry		*rt;
-	struct arccom		*ac;
 	struct arc_header	*ah;
 	int			error;
 	u_int8_t		atype, adst;
@@ -119,11 +117,6 @@ arc_output(ifp, m, dst, rt0)
 		return(ENETDOWN); /* m, m1 aren't initialized yet */
 
 	error = 0;
-	ac = (struct arccom *)ifp;
-
-	error = rt_check(&rt, &rt0, dst);
-	if (error)
-		goto bad;
 
 	switch (dst->sa_family) {
 #ifdef INET
@@ -136,8 +129,11 @@ arc_output(ifp, m, dst, rt0)
 			adst = arcbroadcastaddr; /* ARCnet broadcast address */
 		else if (ifp->if_flags & IFF_NOARP)
 			adst = ntohl(SIN(dst)->sin_addr.s_addr) & 0xFF;
-		else if (!arpresolve(ifp, rt, m, dst, &adst))
-			return 0;	/* not resolved yet */
+		else {
+			error = arpresolve(ifp, rt0, m, dst, &adst);
+			if (error)
+				return (error == EWOULDBLOCK ? 0 : error);
+		}
 
 		atype = (ifp->if_flags & IFF_LINK0) ?
 			ARCTYPE_IP_OLD : ARCTYPE_IP;
@@ -172,13 +168,9 @@ arc_output(ifp, m, dst, rt0)
 #endif
 #ifdef INET6
 	case AF_INET6:
-#ifdef OLDIP6OUTPUT
-		if (!nd6_resolve(ifp, rt, m, dst, (u_char *)&adst))
-			return(0);	/* if not yet resolves */
-#else
-		if (!nd6_storelladdr(ifp, rt, m, dst, (u_char *)&adst))
-			return(0); /* it must be impossible, but... */
-#endif /* OLDIP6OUTPUT */
+		error = nd6_storelladdr(ifp, rt0, m, dst, (u_char *)&adst);
+		if (error)
+			return (error);
 		atype = ARCTYPE_INET6;
 		break;
 #endif