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)

9 files changed, 118 insertions, 111 deletions

diff --git a/sys/net/if_arcsubr.c b/sys/net/if_arcsubr.c
index 47d7b5c021a2..b4aa519988dc 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
diff --git a/sys/net/if_atmsubr.c b/sys/net/if_atmsubr.c
index f404984dc82d..e7df9c324c41 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 */
 
diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index ae599476b319..47ba291ef281 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -132,9 +132,8 @@ ether_output(struct ifnet *ifp, struct mbuf *m,
 	struct sockaddr *dst, struct rtentry *rt0)
 {
 	short type;
-	int error = 0, hdrcmplt = 0;
+	int error, hdrcmplt = 0;
 	u_char esrc[ETHER_ADDR_LEN], edst[ETHER_ADDR_LEN];
-	struct rtentry *rt;
 	struct ether_header *eh;
 	int loop_copy = 0;
 	int hlen;	/* link layer header length */
@@ -150,16 +149,13 @@ ether_output(struct ifnet *ifp, struct mbuf *m,
 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
 		senderr(ENETDOWN);
 
-	error = rt_check(&rt, &rt0, dst);
-	if (error)
-		goto bad;
-
 	hlen = ETHER_HDR_LEN;
 	switch (dst->sa_family) {
 #ifdef INET
 	case AF_INET:
-		if (!arpresolve(ifp, rt, m, dst, edst))
-			return (0);	/* if not yet resolved */
+		error = arpresolve(ifp, rt0, m, dst, edst);
+		if (error)
+			return (error == EWOULDBLOCK ? 0 : error);
 		type = htons(ETHERTYPE_IP);
 		break;
 	case AF_ARP:
@@ -192,10 +188,9 @@ ether_output(struct ifnet *ifp, struct mbuf *m,
 #endif
 #ifdef INET6
 	case AF_INET6:
-		if (!nd6_storelladdr(ifp, rt, m, dst, (u_char *)edst)) {
-			/* Something bad happened */
-			return(0);
-		}
+		error = nd6_storelladdr(ifp, rt0, m, dst, (u_char *)edst);
+		if (error)
+			return error;
 		type = htons(ETHERTYPE_IPV6);
 		break;
 #endif
@@ -216,15 +211,12 @@ ether_output(struct ifnet *ifp, struct mbuf *m,
 	  {
 	    struct at_ifaddr *aa;
 
-	    if ((aa = at_ifawithnet((struct sockaddr_at *)dst)) == NULL) {
-		    goto bad;
-	    }
-	    if (!aarpresolve(IFP2AC(ifp), m, (struct sockaddr_at *)dst, edst))
+	    if ((aa = at_ifawithnet((struct sockaddr_at *)dst)) == NULL)
+		    senderr(EHOSTUNREACH); /* XXX */
+	    if (!aarpresolve(ifp, m, (struct sockaddr_at *)dst, edst))
 		    return (0);
 	    /*
 	     * In the phase 2 case, need to prepend an mbuf for the llc header.
-	     * Since we must preserve the value of m, which is passed to us by
-	     * value, we m_copy() the first mbuf, and use it for our llc header.
 	     */
 	    if ( aa->aa_flags & AFA_PHASE2 ) {
 		struct llc llc;
diff --git a/sys/net/if_fddisubr.c b/sys/net/if_fddisubr.c
index d9330ee51cad..47bf0c312fee 100644
--- a/sys/net/if_fddisubr.c
+++ b/sys/net/if_fddisubr.c
@@ -117,7 +117,6 @@ fddi_output(ifp, m, dst, rt0)
 	u_int16_t type;
 	int loop_copy = 0, error = 0, hdrcmplt = 0;
  	u_char esrc[FDDI_ADDR_LEN], edst[FDDI_ADDR_LEN];
-	struct rtentry *rt;
 	struct fddi_header *fh;
 
 #ifdef MAC
@@ -132,15 +131,12 @@ fddi_output(ifp, m, dst, rt0)
 		senderr(ENETDOWN);
 	getmicrotime(&ifp->if_lastchange);
 
-	error = rt_check(&rt, &rt0, dst);
-	if (error)
-		goto bad;
-
 	switch (dst->sa_family) {
 #ifdef INET
 	case AF_INET: {
-		if (!arpresolve(ifp, rt, m, dst, edst))
-			return (0);	/* if not yet resolved */
+		error = arpresolve(ifp, rt0, m, dst, edst);
+		if (error)
+			return (error == EWOULDBLOCK ? 0 : error);
 		type = htons(ETHERTYPE_IP);
 		break;
 	}
@@ -174,10 +170,9 @@ fddi_output(ifp, m, dst, rt0)
 #endif /* INET */
 #ifdef INET6
 	case AF_INET6:
-		if (!nd6_storelladdr(ifp, rt, m, dst, (u_char *)edst)) {
-			/* Something bad happened */
-			return (0);
-		}
+		error = nd6_storelladdr(ifp, rt0, m, dst, (u_char *)edst);
+		if (error)
+			return (error); /* Something bad happened */
 		type = htons(ETHERTYPE_IPV6);
 		break;
 #endif /* INET6 */
@@ -191,7 +186,7 @@ fddi_output(ifp, m, dst, rt0)
 #ifdef NETATALK
 	case AF_APPLETALK: {
 	    struct at_ifaddr *aa;
-            if (!aarpresolve(IFP2AC(ifp), m, (struct sockaddr_at *)dst, edst))
+            if (!aarpresolve(ifp, m, (struct sockaddr_at *)dst, edst))
                 return (0);
 	    /*
 	     * ifaddr is the first thing in at_ifaddr
diff --git a/sys/net/if_iso88025subr.c b/sys/net/if_iso88025subr.c
index 72b246f84f86..a34f92903af0 100644
--- a/sys/net/if_iso88025subr.c
+++ b/sys/net/if_iso88025subr.c
@@ -259,11 +259,12 @@ iso88025_output(ifp, m, dst, rt0)
 		senderr(ENETDOWN);
 	getmicrotime(&ifp->if_lastchange);
 
+	/* Calculate routing info length based on arp table entry */
+	/* XXX any better way to do this ? */
 	error = rt_check(&rt, &rt0, dst);
 	if (error)
 		goto bad;
 
-	/* Calculate routing info length based on arp table entry */
 	if (rt && (sdl = (struct sockaddr_dl *)rt->rt_gateway))
 		if (SDL_ISO88025(sdl)->trld_rcf != 0)
 			rif_len = TR_RCF_RIFLEN(SDL_ISO88025(sdl)->trld_rcf);
@@ -286,8 +287,9 @@ iso88025_output(ifp, m, dst, rt0)
 	switch (dst->sa_family) {
 #ifdef INET
 	case AF_INET:
-		if (!arpresolve(ifp, rt, m, dst, edst))
-			return (0);	/* if not yet resolved */
+		error = arpresolve(ifp, rt0, m, dst, edst);
+		if (error)
+			return (error == EWOULDBLOCK ? 0 : error);
 		snap_type = ETHERTYPE_IP;
 		break;
 	case AF_ARP:
@@ -320,10 +322,9 @@ iso88025_output(ifp, m, dst, rt0)
 #endif	/* INET */
 #ifdef INET6
 	case AF_INET6:
-		if (!nd6_storelladdr(ifp, rt, m, dst, (u_char *)edst)) {
-			/* Something bad happened */
-			return(0);
-		}
+		error = nd6_storelladdr(ifp, rt0, m, dst, (u_char *)edst);
+		if (error)
+			return (error);
 		snap_type = ETHERTYPE_IPV6;
 		break;
 #endif	/* INET6 */
diff --git a/sys/netatalk/aarp.c b/sys/netatalk/aarp.c
index 97ff87f5e301..c8e511db2fab 100644
--- a/sys/netatalk/aarp.c
+++ b/sys/netatalk/aarp.c
@@ -29,7 +29,7 @@
 #include <netatalk/at_extern.h>
 
 static void aarptfree(struct aarptab *aat);
-static void at_aarpinput(struct arpcom *ac, struct mbuf *m);
+static void at_aarpinput(struct ifnet *ifp, struct mbuf *m);
 
 #define AARPTAB_BSIZ	9
 #define AARPTAB_NB	19
@@ -130,7 +130,7 @@ at_ifawithnet(struct sockaddr_at  *sat)
 }
 
 static void
-aarpwhohas(struct arpcom *ac, struct sockaddr_at *sat)
+aarpwhohas(struct ifnet *ifp, struct sockaddr_at *sat)
 {
     struct mbuf		*m;
     struct ether_header	*eh;
@@ -144,7 +144,7 @@ aarpwhohas(struct arpcom *ac, struct sockaddr_at *sat)
 	return;
     }
 #ifdef MAC
-    mac_create_mbuf_linklayer(&ac->ac_if, m);
+    mac_create_mbuf_linklayer(ifp, m);
 #endif
     m->m_len = sizeof(*ea);
     m->m_pkthdr.len = sizeof(*ea);
@@ -158,7 +158,7 @@ aarpwhohas(struct arpcom *ac, struct sockaddr_at *sat)
     ea->aarp_hln = sizeof(ea->aarp_sha);
     ea->aarp_pln = sizeof(ea->aarp_spu);
     ea->aarp_op = htons(AARPOP_REQUEST);
-    bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->aarp_sha,
+    bcopy(IFP2AC(ifp)->ac_enaddr, (caddr_t)ea->aarp_sha,
 	    sizeof(ea->aarp_sha));
 
     /*
@@ -195,7 +195,7 @@ aarpwhohas(struct arpcom *ac, struct sockaddr_at *sat)
 	ea->aarp_spnode = AA_SAT(aa)->sat_addr.s_node;
 	ea->aarp_tpnode = sat->sat_addr.s_node;
     } else {
-	bcopy(ac->ac_if.if_broadcastaddr, (caddr_t)eh->ether_dhost,
+	bcopy(ifp->if_broadcastaddr, (caddr_t)eh->ether_dhost,
 		sizeof(eh->ether_dhost));
 	eh->ether_type = htons(ETHERTYPE_AARP);
 
@@ -211,13 +211,12 @@ aarpwhohas(struct arpcom *ac, struct sockaddr_at *sat)
 
     sa.sa_len = sizeof(struct sockaddr);
     sa.sa_family = AF_UNSPEC;
-    (*ac->ac_if.if_output)(&ac->ac_if,
-	m, &sa, NULL); 	/* XXX NULL should be routing information */
+    ifp->if_output(ifp, m, &sa, NULL /* route */);
 }
 
 int
-aarpresolve(ac, m, destsat, desten)
-    struct arpcom	*ac;
+aarpresolve(ifp, m, destsat, desten)
+    struct ifnet	*ifp;
     struct mbuf		*m;
     struct sockaddr_at	*destsat;
     u_char		*desten;
@@ -234,8 +233,8 @@ aarpresolve(ac, m, destsat, desten)
 	if (aa->aa_flags & AFA_PHASE2) {
 	    bcopy(atmulticastaddr, (caddr_t)desten, sizeof(atmulticastaddr));
 	} else {
-	    bcopy(ac->ac_if.if_broadcastaddr, (caddr_t)desten,
-		    sizeof(ac->ac_if.if_addrlen));
+	    bcopy(ifp->if_broadcastaddr, (caddr_t)desten,
+		    sizeof(ifp->if_addrlen));
 	}
 	return (1);
     }
@@ -244,13 +243,10 @@ aarpresolve(ac, m, destsat, desten)
     AARPTAB_LOOK(aat, destsat->sat_addr);
     if (aat == NULL) {			/* No entry */
 	aat = aarptnew(&destsat->sat_addr);
-	if (aat == NULL) {
+	if (aat == NULL) { /* we should fail more gracefully! */
 	    panic("aarpresolve: no free entry");
 	}
-	aat->aat_hold = m;
-	AARPTAB_UNLOCK();
-	aarpwhohas(ac, destsat);
-	return (0);
+	goto done;
     }
     /* found an entry */
     aat->aat_timer = 0;
@@ -264,9 +260,10 @@ aarpresolve(ac, m, destsat, desten)
     if (aat->aat_hold) {
 	m_freem(aat->aat_hold);
     }
+done:
     aat->aat_hold = m;
     AARPTAB_UNLOCK();
-    aarpwhohas(ac, destsat);
+    aarpwhohas(ifp, destsat);
     return (0);
 }
 
@@ -275,10 +272,10 @@ aarpintr(m)
     struct mbuf		*m;
 {
     struct arphdr	*ar;
-    struct arpcom	*ac;
+    struct ifnet	*ifp;
 
-    ac = (struct arpcom *)m->m_pkthdr.rcvif;
-    if (ac->ac_if.if_flags & IFF_NOARP)
+    ifp = m->m_pkthdr.rcvif;
+    if (ifp->if_flags & IFF_NOARP)
 	goto out;
 
     if (m->m_len < sizeof(struct arphdr)) {
@@ -297,7 +294,7 @@ aarpintr(m)
     
     switch(ntohs(ar->ar_pro)) {
     case ETHERTYPE_AT :
-	at_aarpinput(ac, m);
+	at_aarpinput(ifp, m);
 	return;
 
     default:
@@ -309,7 +306,7 @@ out:
 }
 
 static void
-at_aarpinput(struct arpcom *ac, struct mbuf *m)
+at_aarpinput(struct ifnet *ifp, struct mbuf *m)
 {
     struct ether_aarp	*ea;
     struct at_ifaddr	*aa;
@@ -327,8 +324,8 @@ at_aarpinput(struct arpcom *ac, struct mbuf *m)
     ea = mtod(m, struct ether_aarp *);
 
     /* Check to see if from my hardware address */
-    if (!bcmp((caddr_t)ea->aarp_sha, (caddr_t)ac->ac_enaddr,
-	    sizeof(ac->ac_enaddr))) {
+    if (!bcmp((caddr_t)ea->aarp_sha, IFP2AC(ifp)->ac_enaddr,
+	    sizeof(IFP2AC(ifp)->ac_enaddr))) {
 	m_freem(m);
 	return;
     }
@@ -351,7 +348,7 @@ at_aarpinput(struct arpcom *ac, struct mbuf *m)
 	 * Since we don't know the net, we just look for the first
 	 * phase 1 address on the interface.
 	 */
-	for (aa = (struct at_ifaddr *)TAILQ_FIRST(&ac->ac_if.if_addrhead); aa;
+	for (aa = (struct at_ifaddr *)TAILQ_FIRST(&ifp->if_addrhead); aa;
 		aa = (struct at_ifaddr *)aa->aa_ifa.ifa_link.tqe_next) {
 	    if (AA_SAT(aa)->sat_family == AF_APPLETALK &&
 		    (aa->aa_flags & AFA_PHASE2) == 0) {
@@ -380,7 +377,7 @@ at_aarpinput(struct arpcom *ac, struct mbuf *m)
 	     * probed for the same address we'd like to use. Change the
 	     * address we're probing for.
 	     */
-	    untimeout(aarpprobe, ac, aa->aa_ch);
+	    untimeout(aarpprobe, ifp, aa->aa_ch);
 	    wakeup(aa);
 	    m_freem(m);
 	    return;
@@ -424,7 +421,7 @@ at_aarpinput(struct arpcom *ac, struct mbuf *m)
 	    sat.sat_len = sizeof(struct sockaddr_at);
 	    sat.sat_family = AF_APPLETALK;
 	    sat.sat_addr = spa;
-	    (*ac->ac_if.if_output)(&ac->ac_if, mhold,
+	    (*ifp->if_output)(ifp, mhold,
 		    (struct sockaddr *)&sat, NULL); /* XXX */
 	} else
 	    AARPTAB_UNLOCK();
@@ -451,7 +448,7 @@ at_aarpinput(struct arpcom *ac, struct mbuf *m)
 
     bcopy((caddr_t)ea->aarp_sha, (caddr_t)ea->aarp_tha,
 	    sizeof(ea->aarp_sha));
-    bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->aarp_sha,
+    bcopy(IFP2AC(ifp)->ac_enaddr, (caddr_t)ea->aarp_sha,
 	    sizeof(ea->aarp_sha));
 
     /* XXX */
@@ -484,7 +481,7 @@ at_aarpinput(struct arpcom *ac, struct mbuf *m)
 
     sa.sa_len = sizeof(struct sockaddr);
     sa.sa_family = AF_UNSPEC;
-    (*ac->ac_if.if_output)(&ac->ac_if, m, &sa, NULL); /* XXX */
+    (*ifp->if_output)(ifp, m, &sa, NULL); /* XXX */
     return;
 }
 
@@ -540,7 +537,7 @@ out:
 void
 aarpprobe(void *arg)
 {
-    struct arpcom	*ac = arg;
+    struct ifnet	*ifp = arg;
     struct mbuf		*m;
     struct ether_header	*eh;
     struct ether_aarp	*ea;
@@ -555,7 +552,7 @@ aarpprobe(void *arg)
      * interface with the same address as we're looking for. If the
      * net is phase 2, generate an 802.2 and SNAP header.
      */
-    for (aa = (struct at_ifaddr *)TAILQ_FIRST(&ac->ac_if.if_addrhead); aa;
+    for (aa = (struct at_ifaddr *)TAILQ_FIRST(&ifp->if_addrhead); aa;
 	    aa = (struct at_ifaddr *)aa->aa_ifa.ifa_link.tqe_next) {
 	if (AA_SAT(aa)->sat_family == AF_APPLETALK &&
 		(aa->aa_flags & AFA_PROBING)) {
@@ -572,14 +569,14 @@ aarpprobe(void *arg)
 	wakeup(aa);
 	return;
     } else {
-	aa->aa_ch = timeout(aarpprobe, (caddr_t)ac, hz / 5);
+	aa->aa_ch = timeout(aarpprobe, (caddr_t)ifp, hz / 5);
     }
 
     if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) {
 	return;
     }
 #ifdef MAC
-    mac_create_mbuf_linklayer(&ac->ac_if, m);
+    mac_create_mbuf_linklayer(ifp, m);
 #endif
     m->m_len = sizeof(*ea);
     m->m_pkthdr.len = sizeof(*ea);
@@ -593,7 +590,7 @@ aarpprobe(void *arg)
     ea->aarp_hln = sizeof(ea->aarp_sha);
     ea->aarp_pln = sizeof(ea->aarp_spu);
     ea->aarp_op = htons(AARPOP_PROBE);
-    bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->aarp_sha,
+    bcopy(IFP2AC(ifp)->ac_enaddr, (caddr_t)ea->aarp_sha,
 	    sizeof(ea->aarp_sha));
 
     eh = (struct ether_header *)sa.sa_data;
@@ -618,7 +615,7 @@ aarpprobe(void *arg)
 		sizeof(ea->aarp_tpnet));
 	ea->aarp_spnode = ea->aarp_tpnode = AA_SAT(aa)->sat_addr.s_node;
     } else {
-	bcopy(ac->ac_if.if_broadcastaddr, (caddr_t)eh->ether_dhost,
+	bcopy(ifp->if_broadcastaddr, (caddr_t)eh->ether_dhost,
 		sizeof(eh->ether_dhost));
 	eh->ether_type = htons(ETHERTYPE_AARP);
 	ea->aarp_spa = ea->aarp_tpa = AA_SAT(aa)->sat_addr.s_node;
@@ -632,7 +629,7 @@ aarpprobe(void *arg)
 
     sa.sa_len = sizeof(struct sockaddr);
     sa.sa_family = AF_UNSPEC;
-    (*ac->ac_if.if_output)(&ac->ac_if, m, &sa, NULL); /* XXX */
+    (*ifp->if_output)(ifp, m, &sa, NULL); /* XXX */
     aa->aa_probcnt--;
 }
 
diff --git a/sys/netatalk/at_extern.h b/sys/netatalk/at_extern.h
index 8afdad144b61..bbb1bc9227a8 100644
--- a/sys/netatalk/at_extern.h
+++ b/sys/netatalk/at_extern.h
@@ -6,7 +6,7 @@ struct sockaddr_at;
 
 #ifdef _NET_IF_ARP_H_
 extern timeout_t	aarpprobe;
-extern int	aarpresolve	(struct arpcom *,
+extern int	aarpresolve	(struct ifnet *,
 					struct mbuf *,
 					struct sockaddr_at *,
 					u_char *);
diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c
index 4c91522c8900..1bdc1fb9eb9f 100644
--- a/sys/netinet/if_ether.c
+++ b/sys/netinet/if_ether.c
@@ -341,21 +341,42 @@ arprequest(ifp, sip, tip, enaddr)
  * that desten has been filled in and the packet should be sent
  * normally; a 0 return indicates that the packet has been
  * taken over here, either now or for later transmission.
+ *
+ * NEW COMMENT
+ * Resolve an IP address into an ethernet address.
+ * On input:
+ *    ifp is the interface we use
+ *    dst is the next hop,
+ *    rt0 is the route to the final destination (possibly useless)
+ *    m is the mbuf
+ *    desten is where we want the address.
+ *
+ * On success, desten is filled in and the function returns 0;
+ * If the packet must be held pending resolution, we return EWOULDBLOCK
+ * On other errors, we return the corresponding error code.
  */
 int
-arpresolve(struct ifnet *ifp, struct rtentry *rt, struct mbuf *m,
+arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
 	struct sockaddr *dst, u_char *desten)
 {
 	struct llinfo_arp *la = 0;
 	struct sockaddr_dl *sdl;
+	int error;
+	struct rtentry *rt;
+
+	error = rt_check(&rt, &rt0, dst);
+	if (error) {
+		m_freem(m);
+		return error;
+	}
 
 	if (m->m_flags & M_BCAST) {	/* broadcast */
 		(void)memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen);
-		return (1);
+		return (0);
 	}
 	if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {/* multicast */
 		ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
-		return(1);
+		return (0);
 	}
 	if (rt)
 		la = (struct llinfo_arp *)rt->rt_llinfo;
@@ -369,7 +390,7 @@ arpresolve(struct ifnet *ifp, struct rtentry *rt, struct mbuf *m,
 			inet_ntoa(SIN(dst)->sin_addr), la ? "la" : "",
 				rt ? "rt" : "");
 		m_freem(m);
-		return (0);
+		return (EINVAL); /* XXX */
 	}
 	sdl = SDL(rt->rt_gateway);
 	/*
@@ -393,7 +414,7 @@ arpresolve(struct ifnet *ifp, struct rtentry *rt, struct mbuf *m,
 		} 
 
 		bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
-		return 1;
+		return (0);
 	}
 	/*
 	 * If ARP is disabled or static on this interface, stop.
@@ -403,7 +424,7 @@ arpresolve(struct ifnet *ifp, struct rtentry *rt, struct mbuf *m,
 	 */
 	if (ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) {
 		m_freem(m);
-		return (0);
+		return (EINVAL);
 	}
 	/*
 	 * There is an arptab entry, but no ethernet address
@@ -433,7 +454,7 @@ arpresolve(struct ifnet *ifp, struct rtentry *rt, struct mbuf *m,
 		}
 		RT_UNLOCK(rt);
 	}
-	return (0);
+	return (EWOULDBLOCK);
 }
 
 /*
diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index d90750587ee3..4523f53f5636 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);