Massive cleanup of the ip_mroute code.

No functional changes, but:

  + the mrouting module now should behave the same as the compiled-in
    version (it did not before, some of the rsvp code was not loaded
    properly);
  + netinet/ip_mroute.c is now truly optional;
  + removed some redundant/unused code;
  + changed many instances of '0' to NULL and INADDR_ANY as appropriate;
  + removed several static variables to make the code more SMP-friendly;
  + fixed some minor bugs in the mrouting code (mostly, incorrect return
    values from functions).

This commit is also a prerequisite to the addition of support for PIM,
which i would like to put in before DP2 (it does not change any of
the existing APIs, anyways).

Note, in the process we found out that some device drivers fail to
properly handle changes in IFF_ALLMULTI, leading to interesting
behaviour when a multicast router is started. This bug is not
corrected by this commit, and will be fixed with a separate commit.

Detailed changes:
--------------------
netinet/ip_mroute.c     all the above.
conf/files              make ip_mroute.c optional
net/route.c             fix mrt_ioctl hook
netinet/ip_input.c      fix ip_mforward hook, move rsvp_input() here
                        together with other rsvp code, and a couple
                        of indentation fixes.
netinet/ip_output.c     fix ip_mforward and ip_mcast_src hooks
netinet/ip_var.h        rsvp function hooks
netinet/raw_ip.c        hooks for mrouting and rsvp functions, plus
                        interface cleanup.
netinet/ip_mroute.h     remove an unused and optional field from a struct

Most of the code is from Pavlin Radoslavov and the XORP project

Reviewed by: sam
MFC after: 1 week

sys/conf/files

@@ -1318,7 +1318,7 @@ netinet/ip_flow.c	optional inet
 netinet/ip_fw2.c	optional ipfirewall
 netinet/ip_icmp.c	optional inet
 netinet/ip_input.c	optional inet
-netinet/ip_mroute.c	optional inet
+netinet/ip_mroute.c	optional mrouting
 netinet/ip_output.c	optional inet
 netinet/raw_ip.c	optional inet
 netinet/tcp_debug.c	optional tcpdebug

sys/net/route.c

@@ -403,7 +403,7 @@ rtioctl(req, data)
 {
 #ifdef INET
 	/* Multicast goop, grrr... */
-	return mrt_ioctl(req, data);
+	return mrt_ioctl ? mrt_ioctl(req, data) : EOPNOTSUPP;
 #else /* INET */
 	return ENXIO;
 #endif /* INET */

sys/netinet/ip_input.c

@@ -600,7 +600,8 @@ ip_input(struct mbuf *m)
 			 * ip_mforward() returns a non-zero value, the packet
 			 * must be discarded, else it may be accepted below.
 			 */
-			if (ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) {
+			if (ip_mforward &&
+			    ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) {
 				ipstat.ips_cantforward++;
 				m_freem(m);
 				return;
@@ -2073,10 +2074,10 @@ ip_rsvp_init(struct socket *so)
 {
 	if (so->so_type != SOCK_RAW ||
 	    so->so_proto->pr_protocol != IPPROTO_RSVP)
-	  return EOPNOTSUPP;
+		return EOPNOTSUPP;
 
 	if (ip_rsvpd != NULL)
-	  return EADDRINUSE;
+		return EADDRINUSE;
 
 	ip_rsvpd = so;
 	/*
@@ -2105,3 +2106,29 @@ ip_rsvp_done(void)
 	}
 	return 0;
 }
+
+void
+rsvp_input(struct mbuf *m, int off)	/* XXX must fixup manually */
+{
+	if (rsvp_input_p) { /* call the real one if loaded */
+		rsvp_input_p(m, off);
+		return;
+	}
+
+	/* Can still get packets with rsvp_on = 0 if there is a local member
+	 * of the group to which the RSVP packet is addressed.  But in this
+	 * case we want to throw the packet away.
+	 */
+	
+	if (!rsvp_on) {
+		m_freem(m);
+		return;
+	}
+
+	if (ip_rsvpd != NULL) { 
+		rip_input(m, off);
+		return;
+	}
+	/* Drop the packet */
+	m_freem(m);
+}

sys/netinet/ip_mroute.h

@@ -215,9 +215,6 @@ struct rtdetq {
     struct mbuf 	*m;		/* A copy of the packet		    */
     struct ifnet	*ifp;		/* Interface pkt came in on	    */
     vifi_t		xmt_vif;	/* Saved copy of imo_multicast_vif  */
-#ifdef UPCALL_TIMING
-    struct timeval	t;		/* Timestamp */
-#endif /* UPCALL_TIMING */
     struct rtdetq	*next;		/* Next in list of packets          */
 };
 

sys/netinet/ip_output.c

@@ -325,7 +325,9 @@ ip_output(m0, opt, ro, flags, imo, inp)
 			ip->ip_ttl = imo->imo_multicast_ttl;
 			if (imo->imo_multicast_vif != -1)
 				ip->ip_src.s_addr =
-				    ip_mcast_src(imo->imo_multicast_vif);
+				    ip_mcast_src ?
+				    ip_mcast_src(imo->imo_multicast_vif) :
+				    INADDR_ANY;
 		} else
 			ip->ip_ttl = IP_DEFAULT_MULTICAST_TTL;
 		/*
@@ -385,14 +387,15 @@ ip_output(m0, opt, ro, flags, imo, inp)
 			 */
 			if (ip_mrouter && (flags & IP_FORWARDING) == 0) {
 				/*
-				 * Check if rsvp daemon is running. If not, don't
+				 * If rsvp daemon is not running, do not
 				 * set ip_moptions. This ensures that the packet
 				 * is multicast and not just sent down one link
 				 * as prescribed by rsvpd.
 				 */
 				if (!rsvp_on)
-				  imo = NULL;
-				if (ip_mforward(ip, ifp, m, imo) != 0) {
+					imo = NULL;
+				if (ip_mforward &&
+				    ip_mforward(ip, ifp, m, imo) != 0) {
 					m_freem(m);
 					goto done;
 				}

sys/netinet/ip_var.h

@@ -191,9 +191,10 @@ void	ipip_input(struct mbuf *, int);
 void	rsvp_input(struct mbuf *, int);
 int	ip_rsvp_init(struct socket *);
 int	ip_rsvp_done(void);
-int	ip_rsvp_vif_init(struct socket *, struct sockopt *);
-int	ip_rsvp_vif_done(struct socket *, struct sockopt *);
-void	ip_rsvp_force_done(struct socket *);
+extern int	(*ip_rsvp_vif)(struct socket *, struct sockopt *);
+extern void	(*ip_rsvp_force_done)(struct socket *);
+extern void	(*rsvp_input_p)(struct mbuf *m, int off);
+
 
 #ifdef IPDIVERT
 void	div_init(void);

sys/netinet/raw_ip.c

@@ -85,6 +85,28 @@ struct	inpcbinfo ripcbinfo;
 ip_fw_ctl_t *ip_fw_ctl_ptr;
 ip_dn_ctl_t *ip_dn_ctl_ptr;
 
+/*
+ * hooks for multicast routing. They all default to NULL,
+ * so leave them not initialized and rely on BSS being set to 0.
+ */
+
+/* The socket used to communicate with the multicast routing daemon.  */
+struct socket  *ip_mrouter;
+
+/* The various mrouter and rsvp functions */
+int (*ip_mrouter_set)(struct socket *, struct sockopt *);
+int (*ip_mrouter_get)(struct socket *, struct sockopt *);
+int (*ip_mrouter_done)(void);
+int (*ip_mforward)(struct ip *, struct ifnet *, struct mbuf *,
+                   struct ip_moptions *);
+int (*mrt_ioctl)(int, caddr_t);
+int (*legal_vif_num)(int);
+u_long (*ip_mcast_src)(int);
+
+void (*rsvp_input_p)(struct mbuf *m, int off);
+int (*ip_rsvp_vif)(struct socket *, struct sockopt *);
+void (*ip_rsvp_force_done)(struct socket *);
+
 /*
  * Nominal space allocated to a raw ip socket.
  */
@@ -351,7 +373,8 @@ rip_ctloutput(so, sopt)
 		case MRT_DEL_MFC:
 		case MRT_VERSION:
 		case MRT_ASSERT:
-			error = ip_mrouter_get(so, sopt);
+			error = ip_mrouter_get ? ip_mrouter_get(so, sopt) :
+				EOPNOTSUPP;
 			break;
 
 		default:
@@ -401,13 +424,10 @@ rip_ctloutput(so, sopt)
 			error = ip_rsvp_done();
 			break;
 
-			/* XXX - should be combined */
 		case IP_RSVP_VIF_ON:
-			error = ip_rsvp_vif_init(so, sopt);
-			break;
-			
 		case IP_RSVP_VIF_OFF:
-			error = ip_rsvp_vif_done(so, sopt);
+			error = ip_rsvp_vif ?
+				ip_rsvp_vif(so, sopt) : EINVAL;
 			break;
 
 		case MRT_INIT:
@@ -418,7 +438,8 @@ rip_ctloutput(so, sopt)
 		case MRT_DEL_MFC:
 		case MRT_VERSION:
 		case MRT_ASSERT:
-			error = ip_mrouter_set(so, sopt);
+			error = ip_mrouter_set ? ip_mrouter_set(so, sopt) :
+					EOPNOTSUPP;
 			break;
 
 		default:
@@ -546,9 +567,10 @@ rip_detach(struct socket *so)
 	inp = sotoinpcb(so);
 	if (inp == 0)
 		panic("rip_detach");
-	if (so == ip_mrouter)
+	if (so == ip_mrouter && ip_mrouter_done)
 		ip_mrouter_done();
-	ip_rsvp_force_done(so);
+	if (ip_rsvp_force_done)
+		ip_rsvp_force_done(so);
 	if (so == ip_rsvpd)
 		ip_rsvp_done();
 	in_pcbdetach(inp);