Add multicast routing to GENERIC.

It is now possible to enable multicast routing in the kernel with
the sysctl option net.inet.ip.mforwarding=1

Based on intial work by msf@

help claudio@
ok claudio@ deraadt@

4 files changed, 15 insertions, 10 deletions

diff --git a/sys/conf/GENERIC b/sys/conf/GENERIC
index 6b124fdeb63..0578234fdc4 100644
--- a/sys/conf/GENERIC
+++ b/sys/conf/GENERIC
@@ -1,4 +1,4 @@
-#	$OpenBSD: GENERIC,v 1.119 2005/06/08 04:52:45 henning Exp $
+#	$OpenBSD: GENERIC,v 1.120 2005/10/05 17:32:22 norby Exp $
 #
 #	Machine-independent option; used by all architectures for their
 #	GENERIC kernel
@@ -68,7 +68,7 @@ option		IPSEC		# IPsec
 #option		NETATALK	# AppleTalk
 option		PPP_BSDCOMP	# PPP BSD compression
 option		PPP_DEFLATE
-#option		MROUTING	# Multicast router
+option		MROUTING	# Multicast router
 #option		PIM		# Protocol Independent Multicast
 
 pseudo-device	pf		# packet filter
diff --git a/sys/netinet/in.h b/sys/netinet/in.h
index 4ed07fe2eed..a24968ca1e4 100644
--- a/sys/netinet/in.h
+++ b/sys/netinet/in.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: in.h,v 1.67 2005/06/06 04:49:10 henning Exp $	*/
+/*	$OpenBSD: in.h,v 1.68 2005/10/05 17:32:22 norby Exp $	*/
 /*	$NetBSD: in.h,v 1.20 1996/02/13 23:41:47 christos Exp $	*/
 
 /*
@@ -476,7 +476,8 @@ struct ip_mreq {
 #define	IPCTL_MTUDISCTIMEOUT	28	/* allow path MTU discovery */
 #define	IPCTL_IPSEC_IPCOMP_ALGORITHM	29
 #define	IPCTL_IFQUEUE		30
-#define	IPCTL_MAXID		31
+#define	IPCTL_MFORWARDING	31
+#define	IPCTL_MAXID		32
 
 #define	IPCTL_NAMES { \
 	{ 0, 0 }, \
@@ -510,6 +511,7 @@ struct ip_mreq {
 	{ "mtudisctimeout", CTLTYPE_INT }, \
 	{ "ipsec-comp-alg", CTLTYPE_STRING }, \
 	{ "ifq", CTLTYPE_NODE }, \
+	{ "mforwarding", CTLTYPE_INT }, \
 }
 #define	IPCTL_VARS { \
 	NULL, \
@@ -543,6 +545,7 @@ struct ip_mreq {
 	NULL, \
 	NULL, \
 	NULL, \
+	&ipmforwarding, \
 }
 
 /* INET6 stuff */
diff --git a/sys/netinet/ip_input.c b/sys/netinet/ip_input.c
index 898272a0d9e..4058f537758 100644
--- a/sys/netinet/ip_input.c
+++ b/sys/netinet/ip_input.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip_input.c,v 1.133 2005/09/19 01:48:05 deraadt Exp $	*/
+/*	$OpenBSD: ip_input.c,v 1.134 2005/10/05 17:32:22 norby Exp $	*/
 /*	$NetBSD: ip_input.c,v 1.30 1996/03/16 23:53:58 christos Exp $	*/
 
 /*
@@ -86,6 +86,7 @@ char ipsec_def_comp[20];
 
 /* values controllable via sysctl */
 int	ipforwarding = 0;
+int	ipmforwarding = 0;
 int	ipsendredirects = 1;
 int	ip_dosourceroute = 0;
 int	ip_defttl = IPDEFTTL;
@@ -410,8 +411,7 @@ ipv4_input(m)
 			}
 			ip = mtod(m, struct ip *);
 		}
-
-		if (ip_mrouter) {
+		if (ipmforwarding && ip_mrouter) {
 			/*
 			 * If we are acting as a multicast router, all
 			 * incoming multicast packets are passed to the
diff --git a/sys/netinet/ip_output.c b/sys/netinet/ip_output.c
index f1eb4f209b2..dae7a979b9e 100644
--- a/sys/netinet/ip_output.c
+++ b/sys/netinet/ip_output.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip_output.c,v 1.172 2005/06/10 15:53:07 markus Exp $	*/
+/*	$OpenBSD: ip_output.c,v 1.173 2005/10/05 17:32:22 norby Exp $	*/
 /*	$NetBSD: ip_output.c,v 1.28 1996/02/13 23:43:07 christos Exp $	*/
 
 /*
@@ -78,6 +78,7 @@ extern int ipsec_esp_trans_default_level;
 extern int ipsec_esp_network_default_level;
 extern int ipsec_ipcomp_default_level;
 extern int ipforwarding;
+extern int ipmforwarding;
 #endif /* IPSEC */
 
 static struct mbuf *ip_insertoptions(struct mbuf *, struct mbuf *, int *);
@@ -501,7 +502,8 @@ ip_output(struct mbuf *m0, ...)
 			 */
 			extern struct socket *ip_mrouter;
 
-			if (ip_mrouter && (flags & IP_FORWARDING) == 0) {
+			if (ipmforwarding && ip_mrouter &&
+			    (flags & IP_FORWARDING) == 0) {
 				if (ip_mforward(m, ifp) != 0) {
 					m_freem(m);
 					goto done;
@@ -1509,7 +1511,7 @@ ip_ctloutput(op, so, level, optname, mp)
 						 error = ENOBUFS;
 						 break;
 					 }
-						 
+
 				}
 				m->m_len = len;
 				*mtod(m, u_int16_t *) = ipr->ref_type;