Introduce in_ifdetach() a function to remove all the IPv4 addresses

of an interface, named after its IPv6 equivalent.

Make use of it instead of removing addresses by hand when detaching
or destroying an interface.  As a bonus, multicast records linked
to the just divorced^Wdetached interface are no longer leaked.

No objection from the gang, ok mikeb@

2 files changed, 16 insertions, 2 deletions

diff --git a/sys/netinet/in.c b/sys/netinet/in.c
index b5723f8f5c1..386ea9732be 100644
--- a/sys/netinet/in.c
+++ b/sys/netinet/in.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: in.c,v 1.85 2013/09/26 08:53:17 mpi Exp $	*/
+/*	$OpenBSD: in.c,v 1.86 2013/10/09 09:33:43 mpi Exp $	*/
 /*	$NetBSD: in.c,v 1.26 1996/02/13 23:41:39 christos Exp $	*/
 
 /*
@@ -1017,3 +1017,16 @@ in_delmulti(struct in_multi *inm)
 }
 
 #endif
+
+void
+in_ifdetach(struct ifnet *ifp)
+{
+	struct ifaddr *ifa, *next;
+
+	/* nuke any of IPv4 addresses we have */
+	TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrlist, ifa_list, next) {
+		if (ifa->ifa_addr->sa_family != AF_INET)
+			continue;
+		in_purgeaddr(ifa);
+	}
+}
diff --git a/sys/netinet/in.h b/sys/netinet/in.h
index 175129f9829..6df6ffab0d1 100644
--- a/sys/netinet/in.h
+++ b/sys/netinet/in.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: in.h,v 1.96 2013/03/28 15:05:32 bluhm Exp $	*/
+/*	$OpenBSD: in.h,v 1.97 2013/10/09 09:33:43 mpi Exp $	*/
 /*	$NetBSD: in.h,v 1.20 1996/02/13 23:41:47 christos Exp $	*/
 
 /*
@@ -840,6 +840,7 @@ int	   in_localaddr(struct in_addr, u_int);
 void	   in_socktrim(struct sockaddr_in *);
 char	  *inet_ntoa(struct in_addr);
 void	   in_proto_cksum_out(struct mbuf *, struct ifnet *);
+void	   in_ifdetach(struct ifnet *);
 
 #define	in_hosteq(s,t)	((s).s_addr == (t).s_addr)
 #define	in_nullhost(x)	((x).s_addr == INADDR_ANY)