Add rib_lookup_info() to provide API for retrieving individual route

  entries data in unified format.

There are control plane functions that require information other than
  just next-hop data (e.g. individual rtentry fields like flags or
  prefix/mask). Given that the goal is to avoid rte reference/refcounting,
  re-use rt_addrinfo structure to store most rte fields. If caller wants
  to retrieve key/mask or gateway (which are sockaddrs and are allocated
  separately), it needs to provide sufficient-sized sockaddrs structures
  w/ ther pointers saved in passed rt_addrinfo.

Convert:
  * lltable new records checks (in_lltable_rtcheck(),
    nd6_is_new_addr_neighbor().
  * rtsock pre-add/change route check.
  * IPv6 NS ND-proxy check (RADIX_MPATH code was eliminated because
     1) we don't support RTF_ANNOUNCE ND-proxy for networks and there should
       not be multiple host routes for such hosts 2) if we have multiple
       routes we should inspect them (which is not done). 3) the entire idea
       of abusing KRT as storage for ND proxy seems odd. Userland programs
       should be used for that purpose).

1 files changed, 29 insertions, 19 deletions

diff --git a/sys/netinet/in.c b/sys/netinet/in.c
index c30c1f3fdf88..80b14483654a 100644
--- a/sys/netinet/in.c
+++ b/sys/netinet/in.c
@@ -1106,34 +1106,48 @@ in_lltable_free_entry(struct lltable *llt, struct llentry *lle)
 static int
 in_lltable_rtcheck(struct ifnet *ifp, u_int flags, const struct sockaddr *l3addr)
 {
-	struct rtentry *rt;
+	struct rt_addrinfo info;
+	struct sockaddr_in rt_key, rt_mask;
+	struct sockaddr rt_gateway;
+	int rt_flags;
 
 	KASSERT(l3addr->sa_family == AF_INET,
 	    ("sin_family %d", l3addr->sa_family));
 
-	/* XXX rtalloc1_fib should take a const param */
-	rt = rtalloc1_fib(__DECONST(struct sockaddr *, l3addr), 0, 0,
-	    ifp->if_fib);
+	bzero(&rt_key, sizeof(rt_key));
+	rt_key.sin_len = sizeof(rt_key);
+	bzero(&rt_mask, sizeof(rt_mask));
+	rt_mask.sin_len = sizeof(rt_mask);
+	bzero(&rt_gateway, sizeof(rt_gateway));
+	rt_gateway.sa_len = sizeof(rt_gateway);
 
-	if (rt == NULL)
+	bzero(&info, sizeof(info));
+	info.rti_info[RTAX_DST] = (struct sockaddr *)&rt_key;
+	info.rti_info[RTAX_NETMASK] = (struct sockaddr *)&rt_mask;
+	info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway;
+
+	if (rib_lookup_info(ifp->if_fib, l3addr, NHR_REF, 0, &info) != 0)
 		return (EINVAL);
 
+	rt_flags = info.rti_flags;
+
 	/*
 	 * If the gateway for an existing host route matches the target L3
 	 * address, which is a special route inserted by some implementation
 	 * such as MANET, and the interface is of the correct type, then
 	 * allow for ARP to proceed.
 	 */
-	if (rt->rt_flags & RTF_GATEWAY) {
-		if (!(rt->rt_flags & RTF_HOST) || !rt->rt_ifp ||
-		    rt->rt_ifp->if_type != IFT_ETHER ||
-		    (rt->rt_ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) != 0 ||
-		    memcmp(rt->rt_gateway->sa_data, l3addr->sa_data,
+	if (rt_flags & RTF_GATEWAY) {
+		if (!(rt_flags & RTF_HOST) || !info.rti_ifp ||
+		    info.rti_ifp->if_type != IFT_ETHER ||
+		    (info.rti_ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) != 0 ||
+		    memcmp(rt_gateway.sa_data, l3addr->sa_data,
 		    sizeof(in_addr_t)) != 0) {
-			RTFREE_LOCKED(rt);
+			rib_free_info(&info);
 			return (EINVAL);
 		}
 	}
+	rib_free_info(&info);
 
 	/*
 	 * Make sure that at least the destination address is covered
@@ -1142,21 +1156,19 @@ in_lltable_rtcheck(struct ifnet *ifp, u_int flags, const struct sockaddr *l3addr
 	 * on one interface and the corresponding outgoing packet leaves
 	 * another interface.
 	 */
-	if (!(rt->rt_flags & RTF_HOST) && rt->rt_ifp != ifp) {
+	if (!(rt_flags & RTF_HOST) && info.rti_ifp != ifp) {
 		const char *sa, *mask, *addr, *lim;
 		int len;
 
-		mask = (const char *)rt_mask(rt);
+		mask = (const char *)&rt_mask;
 		/*
 		 * Just being extra cautious to avoid some custom
 		 * code getting into trouble.
 		 */
-		if (mask == NULL) {
-			RTFREE_LOCKED(rt);
+		if ((info.rti_addrs & RTA_NETMASK) == 0)
 			return (EINVAL);
-		}
 
-		sa = (const char *)rt_key(rt);
+		sa = (const char *)&rt_key;
 		addr = (const char *)l3addr;
 		len = ((const struct sockaddr_in *)l3addr)->sin_len;
 		lim = addr + len;
@@ -1167,13 +1179,11 @@ in_lltable_rtcheck(struct ifnet *ifp, u_int flags, const struct sockaddr *l3addr
 				log(LOG_INFO, "IPv4 address: \"%s\" is not on the network\n",
 				    inet_ntoa(((const struct sockaddr_in *)l3addr)->sin_addr));
 #endif
-				RTFREE_LOCKED(rt);
 				return (EINVAL);
 			}
 		}
 	}
 
-	RTFREE_LOCKED(rt);
 	return (0);
 }