When detaching an interface set the if_start, if_ioctl and if_watchdog

functions to 'nops'.

Some protocols might want to output some packets while detaching and
that could be a bad idea when the interface has gone away.
Do we need to change more functions?

1 files changed, 40 insertions, 1 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index c017a551ec8..d04d080a270 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if.c,v 1.41 2001/01/30 04:22:24 kjell Exp $	*/
+/*	$OpenBSD: if.c,v 1.42 2001/02/13 19:49:32 art Exp $	*/
 /*	$NetBSD: if.c,v 1.35 1996/05/07 05:26:04 thorpej Exp $	*/
 
 /*
@@ -124,6 +124,10 @@ int	if_mark_unignore __P((struct radix_node *, void *));
 
 int	ifqmaxlen = IFQ_MAXLEN;
 
+void	if_detached_start __P((struct ifnet *));
+int	if_detached_ioctl __P((struct ifnet *, u_long, caddr_t));
+void	if_detached_watchdog __P((struct ifnet *));
+
 #ifdef INET6
 /*
  * XXX: declare here to avoid to include many inet6 related files..
@@ -330,6 +334,11 @@ if_detach(ifp)
 	int i, s = splimp();
 	struct radix_node_head *rnh;
 
+	ifp->if_flags &= ~IFF_OACTIVE;
+	ifp->if_start = if_detached_start;
+	ifp->if_ioctl = if_detached_ioctl;
+	ifp->if_watchdog = if_detached_watchdog;
+
 #if NBRIDGE > 0
 	/* Remove the interface from any bridge it is part of.  */
 	if (ifp->if_bridge)
@@ -971,3 +980,33 @@ ifconf(cmd, data)
 	ifc->ifc_len -= space;
 	return (error);
 }
+
+/*
+ * Dummy functions replaced in ifnet during detach (if protocols decide to
+ * fiddle with the if during detach.
+ */
+void
+if_detached_start(struct ifnet *ifp)
+{
+	struct mbuf *m;
+
+	while (1) {
+		IF_DEQUEUE(&ifp->if_snd, m);
+
+		if (m == NULL)
+			return;
+		m_freem(m);
+	}
+}
+
+int
+if_detached_ioctl(struct ifnet *ifp, u_long a, caddr_t b)
+{
+	return ENODEV;
+}
+
+void
+if_detached_watchdog(struct ifnet *ifp)
+{
+	/* nothing */
+}
\ No newline at end of file