Revert MFC of 310847 and 310864

Requested by glebius who had questions about the original
head commit that I didn't see.

1 files changed, 16 insertions, 110 deletions

diff --git a/sys/netinet/ip_carp.c b/sys/netinet/ip_carp.c
index 0a5fed7..7855af2 100644
--- a/sys/netinet/ip_carp.c
+++ b/sys/netinet/ip_carp.c
@@ -581,96 +581,27 @@ carp6_input(struct mbuf **mp, int *offp, int proto)
 }
 #endif /* INET6 */
 
-/*
- * This routine should not be necessary at all, but some switches
- * (VMWare ESX vswitches) can echo our own packets back at us,
- * and we must ignore them or they will cause us to drop out of
- * MASTER mode.
- *
- * We cannot catch all cases of network loops.  Instead, what we
- * do here is catch any packet that arrives with a carp header
- * with a VHID of 0, that comes from an address that is our own.
- * These packets are by definition "from us" (even if they are from
- * a misconfigured host that is pretending to be us).
- *
- * The VHID test is outside this mini-function.
- */
-static int
-carp_source_is_self(struct mbuf *m, struct ifaddr *ifa, sa_family_t af)
-{
-#ifdef INET
-	struct ip *ip4;
-	struct in_addr in4;
-#endif
-#ifdef INET6
-	struct ip6_hdr *ip6;
-	struct in6_addr in6;
-#endif
-
-	switch (af) {
-#ifdef INET
-	case AF_INET:
-		ip4 = mtod(m, struct ip *);
-		in4 = ifatoia(ifa)->ia_addr.sin_addr;
-		return (in4.s_addr == ip4->ip_src.s_addr);
-#endif
-#ifdef INET6
-	case AF_INET6:
-		ip6 = mtod(m, struct ip6_hdr *);
-		in6 = ifatoia6(ifa)->ia_addr.sin6_addr;
-		return (memcmp(&in6, &ip6->ip6_src, sizeof(in6)) == 0);
-#endif
-	default:
-		break;
-	}
-	return (0);
-}
-
 static void
 carp_input_c(struct mbuf *m, struct carp_header *ch, sa_family_t af)
 {
 	struct ifnet *ifp = m->m_pkthdr.rcvif;
-	struct ifaddr *ifa, *match;
+	struct ifaddr *ifa;
 	struct carp_softc *sc;
 	uint64_t tmp_counter;
 	struct timeval sc_tv, ch_tv;
-	int error;
 
-	/*
-	 * Verify that the VHID is valid on the receiving interface.
-	 *
-	 * There should be just one match.  If there are none
-	 * the VHID is not valid and we drop the packet.  If
-	 * there are multiple VHID matches, take just the first
-	 * one, for compatibility with previous code.  While we're
-	 * scanning, check for obvious loops in the network topology
-	 * (these should never happen, and as noted above, we may
-	 * miss real loops; this is just a double-check).
-	 */
+	/* verify that the VHID is valid on the receiving interface */
 	IF_ADDR_RLOCK(ifp);
-	error = 0;
-	match = NULL;
-	IFNET_FOREACH_IFA(ifp, ifa) {
-		if (match == NULL && ifa->ifa_carp != NULL &&
-		    ifa->ifa_addr->sa_family == af &&
-		    ifa->ifa_carp->sc_vhid == ch->carp_vhid)
-			match = ifa;
-		if (ch->carp_vhid == 0 && carp_source_is_self(m, ifa, af))
-			error = ELOOP;
-	}
-	ifa = error ? NULL : match;
-	if (ifa != NULL)
-		ifa_ref(ifa);
+	IFNET_FOREACH_IFA(ifp, ifa)
+		if (ifa->ifa_addr->sa_family == af &&
+		    ifa->ifa_carp->sc_vhid == ch->carp_vhid) {
+			ifa_ref(ifa);
+			break;
+		}
 	IF_ADDR_RUNLOCK(ifp);
 
 	if (ifa == NULL) {
-		if (error == ELOOP) {
-			CARP_DEBUG("dropping looped packet on interface %s\n",
-			    ifp->if_xname);
-			CARPSTATS_INC(carps_badif);	/* ??? */
-		} else {
-			CARPSTATS_INC(carps_badvhid);
-		}
+		CARPSTATS_INC(carps_badvhid);
 		m_freem(m);
 		return;
 	}
@@ -856,41 +787,12 @@ carp_send_ad_error(struct carp_softc *sc, int error)
 	}
 }
 
-/*
- * Pick the best ifaddr on the given ifp for sending CARP
- * advertisements.
- *
- * "Best" here is defined by ifa_preferred().  This function is much
- * much like ifaof_ifpforaddr() except that we just use ifa_preferred().
- *
- * (This could be simplified to return the actual address, except that
- * it has a different format in AF_INET and AF_INET6.)
- */
-static struct ifaddr *
-carp_best_ifa(int af, struct ifnet *ifp)
-{
-	struct ifaddr *ifa, *best;
-
-	if (af >= AF_MAX)
-		return (NULL);
-	best = NULL;
-	IF_ADDR_RLOCK(ifp);
-	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
-		if (ifa->ifa_addr->sa_family == af &&
-		    (best == NULL || ifa_preferred(best, ifa)))
-			best = ifa;
-	}
-	IF_ADDR_RUNLOCK(ifp);
-	if (best != NULL)
-		ifa_ref(best);
-	return (best);
-}
-
 static void
 carp_send_ad_locked(struct carp_softc *sc)
 {
 	struct carp_header ch;
 	struct timeval tv;
+	struct sockaddr sa;
 	struct ifaddr *ifa;
 	struct carp_header *ch_ptr;
 	struct mbuf *m;
@@ -939,7 +841,9 @@ carp_send_ad_locked(struct carp_softc *sc)
 		ip->ip_sum = 0;
 		ip_fillid(ip);
 
-		ifa = carp_best_ifa(AF_INET, sc->sc_carpdev);
+		bzero(&sa, sizeof(sa));
+		sa.sa_family = AF_INET;
+		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
 		if (ifa != NULL) {
 			ip->ip_src.s_addr =
 			    ifatoia(ifa)->ia_addr.sin_addr.s_addr;
@@ -983,9 +887,11 @@ carp_send_ad_locked(struct carp_softc *sc)
 		ip6->ip6_vfc |= IPV6_VERSION;
 		ip6->ip6_hlim = CARP_DFLTTL;
 		ip6->ip6_nxt = IPPROTO_CARP;
+		bzero(&sa, sizeof(sa));
 
 		/* set the source address */
-		ifa = carp_best_ifa(AF_INET6, sc->sc_carpdev);
+		sa.sa_family = AF_INET6;
+		ifa = ifaof_ifpforaddr(&sa, sc->sc_carpdev);
 		if (ifa != NULL) {
 			bcopy(IFA_IN6(ifa), &ip6->ip6_src,
 			    sizeof(struct in6_addr));