Improve the address and linkstate hooks and add an additional detach

hook to track any changes of the parent multicast interface.

1 files changed, 62 insertions, 33 deletions

diff --git a/sys/net/if_vxlan.c b/sys/net/if_vxlan.c
index 343ec9fedaf..de555f10572 100644
--- a/sys/net/if_vxlan.c
+++ b/sys/net/if_vxlan.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_vxlan.c,v 1.8 2013/10/19 14:46:31 mpi Exp $	*/
+/*	$OpenBSD: if_vxlan.c,v 1.9 2013/10/19 18:22:37 reyk Exp $	*/
 
 /*
  * Copyright (c) 2013 Reyk Floeter <reyk@openbsd.org>
@@ -64,13 +64,14 @@ void	 vxlanstart(struct ifnet *);
 int	 vxlan_clone_create(struct if_clone *, int);
 int	 vxlan_clone_destroy(struct ifnet *);
 void	 vxlan_multicast_cleanup(struct ifnet *);
-int	 vxlan_join_multicast(struct ifnet *, struct sockaddr_in *,
+int	 vxlan_multicast_join(struct ifnet *, struct sockaddr_in *,
 	    struct sockaddr_in *);
 int	 vxlan_media_change(struct ifnet *);
 void	 vxlan_media_status(struct ifnet *, struct ifmediareq *);
 int	 vxlan_config(struct ifnet *, struct sockaddr *, struct sockaddr *);
 int	 vxlan_output(struct ifnet *, struct mbuf *);
 void	 vxlan_addr_change(void *);
+void	 vxlan_if_change(void *);
 void	 vxlan_link_change(void *);
 
 struct if_clone	vxlan_cloner =
@@ -180,13 +181,21 @@ vxlan_multicast_cleanup(struct ifnet *ifp)
 	struct ip_moptions	*imo = &sc->sc_imo;
 	struct ifnet		*mifp = imo->imo_multicast_ifp;
 
-	if (mifp != NULL && sc->sc_ahcookie != NULL) {
-		hook_disestablish(mifp->if_addrhooks, sc->sc_ahcookie);
-		sc->sc_ahcookie = NULL;
-	}
-	if (mifp != NULL && sc->sc_lhcookie != NULL) {
-		hook_disestablish(mifp->if_linkstatehooks, sc->sc_lhcookie);
-		sc->sc_lhcookie = NULL;
+	if (mifp != NULL) {
+		if (sc->sc_ahcookie != NULL) {
+			hook_disestablish(mifp->if_addrhooks, sc->sc_ahcookie);
+			sc->sc_ahcookie = NULL;
+		}
+		if (sc->sc_lhcookie != NULL) {
+			hook_disestablish(mifp->if_linkstatehooks,
+			    sc->sc_lhcookie);
+			sc->sc_lhcookie = NULL;
+		}
+		if (sc->sc_dhcookie != NULL) {
+			hook_disestablish(mifp->if_detachhooks,
+			    sc->sc_dhcookie);
+			sc->sc_dhcookie = NULL;
+		}
 	}
 
 	if (imo->imo_num_memberships > 0) {
@@ -196,12 +205,13 @@ vxlan_multicast_cleanup(struct ifnet *ifp)
 }
 
 int
-vxlan_join_multicast(struct ifnet *ifp, struct sockaddr_in *src,
+vxlan_multicast_join(struct ifnet *ifp, struct sockaddr_in *src,
     struct sockaddr_in *dst)
 {
 	struct vxlan_softc	*sc = ifp->if_softc;
 	struct ip_moptions	*imo = &sc->sc_imo;
 	struct ifaddr		*ifa;
+	struct ifnet		*mifp;
 
 	if (!IN_MULTICAST(dst->sin_addr.s_addr))
 		return (0);
@@ -210,22 +220,35 @@ vxlan_join_multicast(struct ifnet *ifp, struct sockaddr_in *src,
 	    IN_MULTICAST(src->sin_addr.s_addr))
 		return (EINVAL);
 	if ((ifa = ifa_ifwithaddr(sintosa(src),
-	    sc->sc_rtableid)) == NULL || ifa->ifa_ifp == NULL ||
-	    (ifa->ifa_ifp->if_flags & IFF_MULTICAST) == 0)
+	    sc->sc_rtableid)) == NULL || (mifp = ifa->ifa_ifp) == NULL ||
+	    (mifp->if_flags & IFF_MULTICAST) == 0)
 		return (EADDRNOTAVAIL);
 
  	if ((imo->imo_membership[0] =
-	    in_addmulti(&dst->sin_addr, ifa->ifa_ifp)) == NULL)
+	    in_addmulti(&dst->sin_addr, mifp)) == NULL)
 		return (ENOBUFS);
 
 	imo->imo_num_memberships++;
-	imo->imo_multicast_ifp = ifa->ifa_ifp;
+	imo->imo_multicast_ifp = mifp;
 	if (sc->sc_ttl > 0)
 		imo->imo_multicast_ttl = sc->sc_ttl;
 	else
 		imo->imo_multicast_ttl = IP_DEFAULT_MULTICAST_TTL;
 	imo->imo_multicast_loop = 0;
 
+	/*
+	 * Use interface hooks to track any changes on the interface
+	 * that is used to send out the tunnel traffic as multicast.
+	 */
+	if ((sc->sc_ahcookie = hook_establish(mifp->if_addrhooks,
+	    0, vxlan_addr_change, sc)) == NULL ||
+	    (sc->sc_lhcookie = hook_establish(mifp->if_linkstatehooks,
+	    0, vxlan_link_change, sc)) == NULL ||
+	    (sc->sc_dhcookie = hook_establish(mifp->if_detachhooks,
+	    0, vxlan_if_change, sc)) == NULL)
+		panic("%s: cannot allocate interface hook",
+		    mifp->if_xname);
+
 	return (0);
 }
 
@@ -257,12 +280,10 @@ int
 vxlan_config(struct ifnet *ifp, struct sockaddr *src, struct sockaddr *dst)
 {
 	struct vxlan_softc	*sc = (struct vxlan_softc *)ifp->if_softc;
-	struct ip_moptions	*imo = &sc->sc_imo;
 #ifdef INET
 	struct sockaddr_in	*src4, *dst4;
 #endif
 	int			 reset = 0, error;
-	struct ifnet		*mifp = imo->imo_multicast_ifp;
 
 	if (src != NULL && dst != NULL) {
 		/* XXX inet6 is not supported */
@@ -287,22 +308,8 @@ vxlan_config(struct ifnet *ifp, struct sockaddr *src, struct sockaddr *dst)
 
 #ifdef INET
 	if (IN_MULTICAST(dst4->sin_addr.s_addr)) {
-		if ((error = vxlan_join_multicast(ifp, src4, dst4)) != 0)
+		if ((error = vxlan_multicast_join(ifp, src4, dst4)) != 0)
 			return (error);
-
-		mifp = imo->imo_multicast_ifp;
-
-		/* Insert addr and link state hooks at head */
-		if ((sc->sc_ahcookie =
-		    hook_establish(mifp->if_addrhooks,
-		    0, vxlan_addr_change, sc)) == NULL)
-			panic("%s: cannot allocate %s address hook",
-			    __func__, mifp->if_xname);
-		if ((sc->sc_lhcookie =
-		    hook_establish(mifp->if_linkstatehooks,
-		    0, vxlan_link_change, sc)) == NULL)
-			panic("%s: cannot allocate %s linkstate hook",
-			    __func__, mifp->if_xname);
 	}
 	if (dst4->sin_port)
 		sc->sc_dstport = dst4->sin_port;
@@ -642,14 +649,36 @@ vxlan_addr_change(void *arg)
 {
 	struct vxlan_softc	*sc = arg;
 	struct ifnet		*ifp = &sc->sc_ac.ac_if;
-	int			 s;
+	int			 s, error;
 
 	/*
 	 * Reset the configuration after resume or any possible address
 	 * configuration changes.
 	 */
 	s = splnet();
-	if (vxlan_config(ifp, NULL, NULL) != 0) {
+	if ((error = vxlan_config(ifp, NULL, NULL))) {
+		/*
+		 * The source address of the tunnel can temporarily disappear,
+		 * after a link state change when running the DHCP client,
+		 * so keep it configured.
+		 */
+	}
+	splx(s);
+}
+
+void
+vxlan_if_change(void *arg)
+{
+	struct vxlan_softc	*sc = arg;
+	struct ifnet		*ifp = &sc->sc_ac.ac_if;
+	int			 s, error;
+
+	/*
+	 * Reset the configuration after the parent interface disappeared.
+	 */
+	s = splnet();
+	if ((error = vxlan_config(ifp, NULL, NULL)) != 0) {
+		/* The configured tunnel addresses are invalid, remove them */
 		bzero(&sc->sc_src, sizeof(sc->sc_src));
 		bzero(&sc->sc_dst, sizeof(sc->sc_dst));
 	}