Rework of multicast deletion code.

The previous code could wrongly delete multicast groups
on the parent interface. Now we forward only remembered
delete requests to the carpdev.
OK mcbride, mickey. "Get it in" deraadt.

1 files changed, 14 insertions, 15 deletions

diff --git a/sys/netinet/ip_carp.c b/sys/netinet/ip_carp.c
index ab48b90e0bd..a61b0204924 100644
--- a/sys/netinet/ip_carp.c
+++ b/sys/netinet/ip_carp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip_carp.c,v 1.109 2005/08/31 04:49:21 mcbride Exp $	*/
+/*	$OpenBSD: ip_carp.c,v 1.110 2005/09/29 19:39:41 mpf Exp $	*/
 
 /*
  * Copyright (c) 2002 Michael Shalayeff. All rights reserved.
@@ -789,7 +789,7 @@ carpdetach(struct carp_softc *sc)
 	splx(s);
 }
 
-/* Detach an interface from the carp.  */
+/* Detach an interface from the carp. */
 void
 carp_ifdetach(struct ifnet *ifp)
 {
@@ -2091,6 +2091,16 @@ carp_ether_delmulti(struct carp_softc *sc, struct ifreq *ifr)
 	if ((error = ether_multiaddr(&ifr->ifr_addr, addrlo, addrhi)) != 0)
 		return (error);
 	ETHER_LOOKUP_MULTI(addrlo, addrhi, &sc->sc_ac, enm);
+	if (enm == NULL)
+		return (EINVAL);
+
+	LIST_FOREACH(mc, &sc->carp_mc_listhead, mc_entries)
+		if (mc->mc_enm == enm)
+			break;
+
+	/* We won't delete entries we didn't add */
+	if (mc == NULL)
+		return (EINVAL);
 
 	error = ether_delmulti(ifr, (struct arpcom *)&sc->sc_ac);
 	if (error != ENETRESET)
@@ -2100,19 +2110,8 @@ carp_ether_delmulti(struct carp_softc *sc, struct ifreq *ifr)
 	error = (*ifp->if_ioctl)(ifp, SIOCDELMULTI, (caddr_t)ifr);
 	if (error == 0) {
 		/* And forget about this address. */
-		for (mc = LIST_FIRST(&sc->carp_mc_listhead); mc != NULL;
-		    mc = LIST_NEXT(mc, mc_entries)) {
-			if (mc->mc_enm == enm) {
-				LIST_REMOVE(mc, mc_entries);
-				FREE(mc, M_DEVBUF);
-				break;
-			}
-		}
-		/*
-		 * XXX We don't actually want KASSERT(mc != NULL) here
-		 * because we mess with the multicast addresses elsewhere.
-		 * Clean up after release.
-		 */
+		LIST_REMOVE(mc, mc_entries);
+		FREE(mc, M_DEVBUF);
 	} else
 		(void)ether_addmulti(ifr, (struct arpcom *)&sc->sc_ac);
 	return (error);