Return a rtentry* in arplookup()

[Martin Pieuchot]

This brings arplookup() in sync with nd6_lookup() and is necessary for
upcoming "struct rtentry" reference count.

Ok?

Index: netinet/if_ether.c
===================================================================
RCS file: /cvs/src/sys/netinet/if_ether.c,v
retrieving revision 1.160
diff -u -p -r1.160 if_ether.c
--- netinet/if_ether.c  17 Aug 2015 09:58:10 -0000      1.160
+++ netinet/if_ether.c  17 Aug 2015 10:02:22 -0000
@@ -93,7 +93,7 @@ int   arpt_down = 20;         /* once declared do
 
 void arptfree(struct llinfo_arp *);
 void arptimer(void *);
-struct llinfo_arp *arplookup(u_int32_t, int, int, u_int);
+struct rtentry *arplookup(u_int32_t, int, int, u_int);
 void in_arpinput(struct mbuf *);
 
 LIST_HEAD(, llinfo_arp) llinfo_arp;
@@ -372,9 +372,9 @@ arpresolve(struct ifnet *ifp, struct rte
                            "local address\n", __func__, inet_ntop(AF_INET,
                                &satosin(dst)->sin_addr, addr, sizeof(addr)));
        } else {
-               if ((la = arplookup(satosin(dst)->sin_addr.s_addr, 1, 0,
+               if ((rt = arplookup(satosin(dst)->sin_addr.s_addr, 1, 0,
                    ifp->if_rdomain)) != NULL)
-                       rt = la->la_rt;
+                       la = ((struct llinfo_arp *)rt->rt_llinfo);
                else
                        log(LOG_DEBUG, "%s: %s: can't allocate llinfo\n",
                            __func__,
@@ -633,9 +633,10 @@ in_arpinput(struct mbuf *m)
                itaddr = myaddr;
                goto reply;
        }
-       la = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0,
+       rt = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0,
            rtable_l2(m->m_pkthdr.ph_rtableid));
-       if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) {
+       if (rt != NULL && (la = (struct llinfo_arp *)rt->rt_llinfo) &&
+           (sdl = SDL(rt->rt_gateway))) {
                if (sdl->sdl_alen) {
                    if (memcmp(ea->arp_sha, LLADDR(sdl), sdl->sdl_alen)) {
                        if (rt->rt_flags &
@@ -730,11 +731,10 @@ out:
                memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha));
                memcpy(ea->arp_sha, enaddr, sizeof(ea->arp_sha));
        } else {
-               la = arplookup(itaddr.s_addr, 0, SIN_PROXY,
+               rt = arplookup(itaddr.s_addr, 0, SIN_PROXY,
                    rtable_l2(m->m_pkthdr.ph_rtableid));
-               if (la == NULL)
+               if (rt == NULL)
                        goto out;
-               rt = la->la_rt;
                if (rt->rt_ifp->if_type == IFT_CARP && ifp->if_type != IFT_CARP)
                        goto out;
                memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha));
@@ -790,7 +790,7 @@ arptfree(struct llinfo_arp *la)
 /*
  * Lookup or enter a new address in arptab.
  */
-struct llinfo_arp *
+struct rtentry *
 arplookup(u_int32_t addr, int create, int proxy, u_int tableid)
 {
        struct rtentry *rt;
@@ -818,7 +818,7 @@ arplookup(u_int32_t addr, int create, in
                }
                return (0);
        }
-       return ((struct llinfo_arp *)rt->rt_llinfo);
+       return (rt);
 }
 
 /*
@@ -827,13 +827,15 @@ arplookup(u_int32_t addr, int create, in
 int
 arpproxy(struct in_addr in, u_int rdomain)
 {
+       struct rtentry *rt;
        struct llinfo_arp *la;
        struct ifnet *ifp;
        int found = 0;
 
-       la = arplookup(in.s_addr, 0, SIN_PROXY, rdomain);
-       if (la == NULL)
+       rt = arplookup(in.s_addr, 0, SIN_PROXY, rdomain);
+       if (rt == NULL)
                return (0);
+       la = ((struct llinfo_arp *)rt->rt_llinfo);
 
        TAILQ_FOREACH(ifp, &ifnet, if_list) {
                if (ifp->if_rdomain != rdomain)