add an interface detach hook and use it with the vlan(4) driver. this

fixes a possible crash if the parent interface has been destroyed
(like vlan on trunk) before destroying the vlan interface.

ok brad@

4 files changed, 46 insertions, 7 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index 0d616d5f8cf..4cd166fb3c9 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if.c,v 1.142 2006/01/05 03:28:34 deraadt Exp $	*/
+/*	$OpenBSD: if.c,v 1.143 2006/02/09 00:05:55 reyk Exp $	*/
 /*	$NetBSD: if.c,v 1.35 1996/05/07 05:26:04 thorpej Exp $	*/
 
 /*
@@ -405,6 +405,11 @@ if_attachhead(struct ifnet *ifp)
 	if (ifp->if_linkstatehooks == NULL)
 		panic("if_attachhead: malloc");
 	TAILQ_INIT(ifp->if_linkstatehooks);
+	ifp->if_detachhooks = malloc(sizeof(*ifp->if_detachhooks),
+	    M_TEMP, M_NOWAIT);
+	if (ifp->if_detachhooks == NULL)
+		panic("if_attachhead: malloc");
+	TAILQ_INIT(ifp->if_detachhooks);
 	TAILQ_INSERT_HEAD(&ifnet, ifp, if_list);
 	if_attachsetup(ifp);
 }
@@ -431,6 +436,11 @@ if_attach(struct ifnet *ifp)
 	if (ifp->if_linkstatehooks == NULL)
 		panic("if_attach: malloc");
 	TAILQ_INIT(ifp->if_linkstatehooks);
+	ifp->if_detachhooks = malloc(sizeof(*ifp->if_detachhooks),
+	    M_TEMP, M_NOWAIT);
+	if (ifp->if_detachhooks == NULL)
+		panic("if_attach: malloc");
+	TAILQ_INIT(ifp->if_detachhooks);
 
 #if NCARP > 0
 	if (ifp->if_type != IFT_CARP)
@@ -500,6 +510,9 @@ if_detach(struct ifnet *ifp)
 	ifp->if_init = if_detached_init;
 	ifp->if_watchdog = if_detached_watchdog;
 
+	/* Call detach hooks, ie. to remove vlan interfaces */
+	dohooks(ifp->if_detachhooks, HOOK_REMOVE | HOOK_FREE);
+
 #if NTRUNK > 0
 	if (ifp->if_type == IFT_IEEE8023ADLAG)
 		trunk_port_ifdetach(ifp);
@@ -626,6 +639,7 @@ do { \
 
 	free(ifp->if_addrhooks, M_TEMP);
 	free(ifp->if_linkstatehooks, M_TEMP);
+	free(ifp->if_detachhooks, M_TEMP);
 
 	for (dp = domains; dp; dp = dp->dom_next) {
 		if (dp->dom_ifdetach && ifp->if_afdata[dp->dom_family])
diff --git a/sys/net/if.h b/sys/net/if.h
index 1db23f36d84..4bab20af4c1 100644
--- a/sys/net/if.h
+++ b/sys/net/if.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if.h,v 1.76 2005/06/14 04:00:39 henning Exp $	*/
+/*	$OpenBSD: if.h,v 1.77 2006/02/09 00:05:55 reyk Exp $	*/
 /*	$NetBSD: if.h,v 1.23 1996/05/07 02:40:27 thorpej Exp $	*/
 
 /*
@@ -177,6 +177,7 @@ struct ifnet {				/* and the entries */
 	TAILQ_HEAD(, ifg_list) if_groups; /* linked list of groups per if */
 	struct hook_desc_head *if_addrhooks; /* address change callbacks */
 	struct hook_desc_head *if_linkstatehooks; /* link change callbacks */
+	struct hook_desc_head *if_detachhooks; /* detach callbacks */
 	char	if_xname[IFNAMSIZ];	/* external name (name + unit) */
 	int	if_pcount;		/* number of promiscuous listeners */
 	caddr_t	if_bpf;			/* packet filter structure */
diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c
index 3f4ce7e8bd9..c47b3178c6c 100644
--- a/sys/net/if_vlan.c
+++ b/sys/net/if_vlan.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_vlan.c,v 1.62 2006/01/05 14:57:24 norby Exp $	*/
+/*	$OpenBSD: if_vlan.c,v 1.63 2006/02/09 00:05:55 reyk Exp $	*/
 
 /*
  * Copyright 1998 Massachusetts Institute of Technology
@@ -97,6 +97,7 @@ int	vlan_ether_delmulti(struct ifvlan *, struct ifreq *);
 void	vlan_ether_purgemulti(struct ifvlan *);
 int	vlan_clone_create(struct if_clone *, int);
 int	vlan_clone_destroy(struct ifnet *);
+void	vlan_ifdetach(void *);
 
 struct if_clone vlan_cloner =
     IF_CLONE_INITIALIZER("vlan", vlan_clone_create, vlan_clone_destroy);
@@ -159,6 +160,20 @@ vlan_clone_destroy(struct ifnet *ifp)
 }
 
 void
+vlan_ifdetach(void *ptr)
+{
+	struct ifvlan *ifv = (struct ifvlan *)ptr;
+	/*
+	 * Destroy the vlan interface because the parent has been
+	 * detached. Set the dh_cookie to NULL because we're running
+	 * inside of dohooks which is told to disestablish the hook
+	 * for us (otherwise we would kill the TAILQ element...).
+	 */
+	ifv->dh_cookie = NULL;
+	vlan_clone_destroy(&ifv->ifv_if);
+}
+
+void
 vlan_start(struct ifnet *ifp)
 {
 	struct ifvlan *ifv;
@@ -389,6 +404,11 @@ vlan_config(struct ifvlan *ifv, struct ifnet *p, u_int16_t tag)
 	/* Register callback for physical link state changes */
 	ifv->lh_cookie = hook_establish(p->if_linkstatehooks, 1,
 	    vlan_vlandev_state, ifv);
+
+	/* Register callback if parent wants to unregister */
+	ifv->dh_cookie = hook_establish(p->if_detachhooks, 1,
+	    vlan_ifdetach, ifv);
+
 	vlan_vlandev_state(ifv);
 	splx(s);
 
@@ -407,15 +427,18 @@ vlan_unconfig(struct ifnet *ifp)
 
 	ifv = ifp->if_softc;
 	p = ifv->ifv_p;
-	ifr = (struct ifreq *)&ifp->if_data;
-	ifr_p = (struct ifreq *)&ifv->ifv_p->if_data;
-
 	if (p == NULL)
 		return 0;
 
+	ifr = (struct ifreq *)&ifp->if_data;
+	ifr_p = (struct ifreq *)&ifv->ifv_p->if_data;
+
 	s = splnet();
 	LIST_REMOVE(ifv, ifv_list);
 	hook_disestablish(p->if_linkstatehooks, ifv->lh_cookie);
+	/* The cookie is NULL if disestablished externally */
+	if (ifv->dh_cookie != NULL)
+		hook_disestablish(p->if_detachhooks, ifv->dh_cookie);
 	splx(s);
 
 	/*
diff --git a/sys/net/if_vlan_var.h b/sys/net/if_vlan_var.h
index d29a9bd8c5c..3534f92d7e0 100644
--- a/sys/net/if_vlan_var.h
+++ b/sys/net/if_vlan_var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_vlan_var.h,v 1.17 2006/01/05 14:57:24 norby Exp $	*/
+/*	$OpenBSD: if_vlan_var.h,v 1.18 2006/02/09 00:05:55 reyk Exp $	*/
 
 /*
  * Copyright 1998 Massachusetts Institute of Technology
@@ -58,6 +58,7 @@ struct	ifvlan {
 	LIST_ENTRY(ifvlan) ifv_list;
 	int ifv_flags;
 	void *lh_cookie;
+	void *dh_cookie;
 };
 
 #define	ifv_if		ifv_ac.ac_if