Checkpoint the beginnings of the new kernel interface for

multicast group memberships.  This is not actually operative
at the moment (a lot of other code still needs to be changed), but
this seemed like a useful reference point to check in so that
others (i.e. Bill Fenner) have fair warning of where we are going.

3 files changed, 254 insertions, 3 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index 65ec137..e523df8 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)if.c	8.3 (Berkeley) 1/4/94
- * $Id: if.c,v 1.37 1996/12/11 20:38:14 wollman Exp $
+ * $Id: if.c,v 1.38 1996/12/13 21:28:37 wollman Exp $
  */
 
 #include <sys/param.h>
@@ -125,6 +125,7 @@ if_attach(ifp)
 	 * this unlikely case.
 	 */
 	TAILQ_INIT(&ifp->if_addrhead);
+	LIST_INIT(&ifp->if_multiaddrs);
 	microtime(&ifp->if_lastchange);
 	if (ifnet_addrs == 0 || if_index >= if_indexlim) {
 		unsigned n = (if_indexlim <<= 1) * sizeof(ifa);
@@ -758,5 +759,182 @@ ifconf(cmd, data)
 	return (error);
 }
 
+/*
+ * Just like if_promisc(), but for all-multicast-reception mode.
+ */
+int
+if_allmulti(ifp, onswitch)
+	struct ifnet *ifp;
+	int onswitch;
+{
+	int error = 0;
+	int s = splimp();
+
+	if (onswitch) {
+		if (ifp->if_amcount++ == 0) {
+			ifp->if_flags |= IFF_ALLMULTI;
+			error = ifp->if_ioctl(ifp, SIOCSIFFLAGS, 0);
+		}
+	} else {
+		if (ifp->if_amcount > 1) {
+			ifp->if_amcount--;
+		} else {
+			ifp->if_amcount = 0;
+			ifp->if_flags &= ~IFF_ALLMULTI;
+			error = ifp->if_ioctl(ifp, SIOCSIFFLAGS, 0);
+		}
+	}
+	splx(s);
+	return error;
+}
+
+/*
+ * Add a multicast listenership to the interface in question.
+ * The link layer provides a routine which converts 
+ */
+int
+if_addmulti(ifp, sa)
+	struct ifnet *ifp;	/* interface to manipulate */
+	struct sockaddr *sa;	/* address to add */
+{
+	struct sockaddr *llsa, *dupsa;
+	int error, s;
+	struct ifmultiaddr *ifma;
+
+	for (ifma = ifp->if_multiaddrs.lh_first; ifma; 
+	     ifma = ifma->ifma_link.le_next) {
+		if (equal(sa, ifma->ifma_addr))
+			break;
+	}
+
+	if (ifma) {
+		ifma->ifma_refcount++;
+		return 0;
+	}
+
+	/*
+	 * Give the link layer a chance to accept/reject it, and also
+	 * find out which AF_LINK address this maps to, if it isn't one
+	 * already.
+	 */
+	if (ifp->if_resolvemulti) {
+		error = ifp->if_resolvemulti(ifp, &llsa, sa);
+		if (error) return error;
+	} else {
+		llsa = 0;
+	}
+
+	MALLOC(ifma, struct ifmultiaddr *, sizeof *ifma, M_IFMADDR, M_WAITOK);
+	MALLOC(dupsa, struct sockaddr *, sa->sa_len, M_IFMADDR, M_WAITOK);
+	bcopy(sa, dupsa, sa->sa_len);
+
+	ifma->ifma_addr = dupsa;
+	ifma->ifma_lladdr = llsa;
+	ifma->ifma_ifp = ifp;
+	ifma->ifma_refcount = 1;
+	/*
+	 * Some network interfaces can scan the address list at
+	 * interrupt time; lock them out.
+	 */
+	s = splimp();
+	LIST_INSERT_HEAD(&ifp->if_multiaddrs, ifma, ifma_link);
+	splx(s);
+
+	if (llsa != 0) {
+		for (ifma = ifp->if_multiaddrs.lh_first; ifma;
+		     ifma = ifma->ifma_link.le_next) {
+			if (equal(ifma->ifma_addr, llsa))
+				break;
+		}
+		if (ifma) {
+			ifma->ifma_refcount++;
+		} else {
+			MALLOC(ifma, struct ifmultiaddr *, sizeof *ifma,
+			       M_IFMADDR, M_WAITOK);
+			ifma->ifma_addr = llsa;
+			ifma->ifma_ifp = ifp;
+			ifma->ifma_refcount = 1;
+		}
+		s = splimp();
+		LIST_INSERT_HEAD(&ifp->if_multiaddrs, ifma, ifma_link);
+		splx(s);
+	}
+	/*
+	 * We are certain we have added something, so call down to the
+	 * interface to let them know about it.
+	 */
+	s = splimp();
+	ifp->if_ioctl(ifp, SIOCADDMULTI, 0);
+	splx(s);
+
+	return 0;
+}
+
+/*
+ * Remove a reference to a multicast address on this interface.  Yell
+ * if the request does not match an existing membership.
+ */
+int
+if_delmulti(ifp, sa)
+	struct ifnet *ifp;
+	struct sockaddr *sa;
+{
+	struct ifmultiaddr *ifma;
+	int s;
+
+	for (ifma = ifp->if_multiaddrs.lh_first; ifma; 
+	     ifma = ifma->ifma_link.le_next)
+		if (equal(sa, ifma->ifma_addr))
+			break;
+	if (ifma == 0)
+		return ENOENT;
+
+	if (ifma->ifma_refcount > 1) {
+		ifma->ifma_refcount--;
+		return 0;
+	}
+
+	sa = ifma->ifma_lladdr;
+	s = splimp();
+	LIST_REMOVE(ifma, ifma_link);
+	splx(s);
+	free(ifma->ifma_addr, M_IFMADDR);
+	free(ifma, M_IFMADDR);
+	if (sa == 0)
+		return 0;
+
+	/*
+	 * Now look for the link-layer address which corresponds to
+	 * this network address.  It had been squirreled away in
+	 * ifma->ifma_lladdr for this purpose (so we don't have
+	 * to call ifp->if_resolvemulti() again), and we saved that
+	 * value in sa above.  If some nasty deleted the
+	 * link-layer address out from underneath us, we can deal because
+	 * the address we stored was is not the same as the one which was
+	 * in the record for the link-layer address.  (So we don't complain
+	 * in that case.)
+	 */
+	for (ifma = ifp->if_multiaddrs.lh_first; ifma; 
+	     ifma = ifma->ifma_link.le_next)
+		if (equal(sa, ifma->ifma_addr))
+			break;
+	if (ifma == 0)
+		return 0;
+
+	if (ifma->ifma_refcount > 1) {
+		ifma->ifma_refcount--;
+		return 0;
+	}
+
+	s = splimp();
+	LIST_REMOVE(ifma, ifma_link);
+	splx(s);
+	free(ifma->ifma_addr, M_IFMADDR);
+	free(sa, M_IFMADDR);
+	free(ifma, M_IFMADDR);
+
+	return 0;
+}
+
 SYSCTL_NODE(_net, PF_LINK, link, CTLFLAG_RW, 0, "Link layers");
 SYSCTL_NODE(_net_link, 0, generic, CTLFLAG_RW, 0, "Generic link-management");
diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index 3aefabe..38d4911 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)if_ethersubr.c	8.1 (Berkeley) 6/10/93
- * $Id: if_ethersubr.c,v 1.28 1996/12/10 07:29:48 davidg Exp $
+ * $Id: if_ethersubr.c,v 1.29 1996/12/13 21:28:38 wollman Exp $
  */
 
 #include <sys/param.h>
@@ -101,6 +101,8 @@ extern u_char	at_org_code[ 3 ];
 extern u_char	aarp_org_code[ 3 ];
 #endif NETATALK
 
+static	int ether_resolvemulti __P((struct ifnet *, struct sockaddr **, 
+				    struct sockaddr *));
 u_char	etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 #define senderr(e) { error = (e); goto bad;}
 
@@ -651,6 +653,7 @@ ether_ifattach(ifp)
 	ifp->if_addrlen = 6;
 	ifp->if_hdrlen = 14;
 	ifp->if_mtu = ETHERMTU;
+	ifp->if_resolvemulti = ether_resolvemulti;
 	if (ifp->if_baudrate == 0)
 	    ifp->if_baudrate = 10000000;
 	ifa = ifnet_addrs[ifp->if_index - 1];
@@ -946,3 +949,51 @@ ether_ioctl(struct ifnet *ifp, int command, caddr_t data)
 	}
 	return (error);
 }
+
+int
+ether_resolvemulti(ifp, llsa, sa)
+	struct ifnet *ifp;
+	struct sockaddr **llsa;
+	struct sockaddr *sa;
+{
+	struct sockaddr_dl *sdl;
+	struct sockaddr_in *sin;
+	u_char *e_addr;
+
+	switch(sa->sa_family) {
+	case AF_LINK:
+		sdl = (struct sockaddr_dl *)sa;
+		e_addr = LLADDR(sdl);
+		if ((e_addr[0] & 1) != 1)
+			return EADDRNOTAVAIL;
+		*llsa = 0;
+		return 0;
+
+#ifdef INET
+	case AF_INET:
+		sin = (struct sockaddr_in *)sa;
+		if (!IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
+			return EADDRNOTAVAIL;
+		MALLOC(sdl, struct sockaddr_dl *, sizeof *sdl, M_IFMADDR,
+		       M_WAITOK);
+		sdl->sdl_len = sizeof *sdl;
+		sdl->sdl_family = AF_LINK;
+		sdl->sdl_index = ifp->if_index;
+		sdl->sdl_type = IFT_ETHER;
+		sdl->sdl_nlen = 0;
+		sdl->sdl_alen = ETHER_ADDR_LEN;
+		sdl->sdl_slen = 0;
+		e_addr = LLADDR(sdl);
+		ETHER_MAP_IP_MULTICAST(&sin->sin_addr, e_addr);
+		*llsa = (struct sockaddr *)sdl;
+		return 0;
+#endif
+
+	default:
+		/* 
+		 * Well, the text isn't quite right, but it's the name
+		 * that counts...
+		 */
+		return EAFNOSUPPORT;
+	}
+}
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index 6f9f9e1..98842df 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	From: @(#)if.h	8.1 (Berkeley) 6/10/93
- *	$Id: if.h,v 1.41 1996/12/13 21:28:37 wollman Exp $
+ *	$Id: if_var.h,v 1.1 1997/01/03 19:50:26 wollman Exp $
  */
 
 #ifndef	_NET_IF_VAR_H_
@@ -77,6 +77,7 @@ struct	ether_header;
 
 TAILQ_HEAD(ifnethead, ifnet);	/* we use TAILQs so that the order of */
 TAILQ_HEAD(ifaddrhead, ifaddr);	/* instantiation is preserved in the list */
+LIST_HEAD(ifmultihead, ifmultiaddr);
 
 /*
  * Structure defining a queue for a network interface.
@@ -109,6 +110,8 @@ struct ifnet {
 	void	*if_linkmib;		/* link-type-specific MIB data */
 	size_t	if_linkmiblen;		/* length of above data */
 	struct	if_data if_data;
+	struct	ifmultihead if_multiaddrs; /* multicast addresses configured */
+	int	if_amcount;		/* number of all-multicast requests */
 /* procedure handles */
 	int	(*if_output)		/* output routine (enqueue) */
 		__P((struct ifnet *, struct mbuf *, struct sockaddr *,
@@ -131,6 +134,8 @@ struct ifnet {
 		__P((struct ifnet *, struct mbuf *));
 	void	(*if_init)		/* Init routine */
 		__P((void *));
+	int	(*if_resolvemulti)	/* validate/resolve multicast */
+		__P((struct ifnet *, struct sockaddr **, struct sockaddr *));
 	struct	ifqueue if_snd;		/* output queue */
 	struct	ifqueue *if_poll_slowq;	/* input queue for slow devices */
 };
@@ -252,6 +257,20 @@ struct ifaddr {
 };
 #define	IFA_ROUTE	RTF_UP		/* route installed */
 
+/*
+ * Multicast address structure.  This is analogous to the ifaddr
+ * structure except that it keeps track of multicast addresses.
+ * Also, the reference count here is a count of requests for this
+ * address, not a count of pointers to this structure.
+ */
+struct ifmultiaddr {
+	LIST_ENTRY(ifmultiaddr) ifma_link;
+	struct	sockaddr *ifma_addr;
+	struct	sockaddr *ifma_lladdr;
+	struct	ifnet *ifma_ifp;
+	u_int	ifma_refcount;
+};
+
 #ifdef KERNEL
 #define	IFAFREE(ifa) \
 	if ((ifa)->ifa_refcnt <= 0) \
@@ -271,7 +290,10 @@ int	ether_output __P((struct ifnet *,
 	   struct mbuf *, struct sockaddr *, struct rtentry *));
 int	ether_ioctl __P((struct ifnet *, int, caddr_t));
 
+int	if_addmulti __P((struct ifnet *, struct sockaddr *));
+int	if_allmulti __P((struct ifnet *, int));
 void	if_attach __P((struct ifnet *));
+int	if_delmulti __P((struct ifnet *, struct sockaddr *));
 void	if_down __P((struct ifnet *));
 void	if_up __P((struct ifnet *));
 #ifdef vax