[IPV6]: Define constants for link-local multicast addresses.

- Define link-local all-node / all-router multicast addresses.
- Remove ipv6_addr_all_nodes() and ipv6_addr_all_routers().
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

include/linux/in6.h

@@ -48,6 +48,14 @@ extern const struct in6_addr in6addr_any;
 #define IN6ADDR_ANY_INIT { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } } }
 extern const struct in6_addr in6addr_loopback;
 #define IN6ADDR_LOOPBACK_INIT { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1 } } }
+#ifdef __KERNEL__
+extern const struct in6_addr in6addr_linklocal_allnodes;
+#define IN6ADDR_LINKLOCAL_ALLNODES_INIT	\
+		{ { { 0xff,2,0,0,0,0,0,0,0,0,0,0,0,0,0,1 } } }
+extern const struct in6_addr in6addr_linklocal_allrouters;
+#define IN6ADDR_LINKLOCAL_ALLROUTERS_INIT \
+		{ { { 0xff,2,0,0,0,0,0,0,0,0,0,0,0,0,0,2 } } }
+#endif
 
 struct sockaddr_in6 {
 	unsigned short int	sin6_family;    /* AF_INET6 */

include/net/addrconf.h

@@ -205,17 +205,6 @@ static inline void addrconf_addr_solict_mult(const struct in6_addr *addr,
 		      htonl(0xFF000000) | addr->s6_addr32[3]);
 }
 
-
-static inline void ipv6_addr_all_nodes(struct in6_addr *addr)
-{
-	ipv6_addr_set(addr, htonl(0xFF020000), 0, 0, htonl(0x1));
-}
-
-static inline void ipv6_addr_all_routers(struct in6_addr *addr)
-{
-	ipv6_addr_set(addr, htonl(0xFF020000), 0, 0, htonl(0x2));
-}
-
 static inline int ipv6_addr_is_multicast(const struct in6_addr *addr)
 {
 	return (addr->s6_addr32[0] & htonl(0xFF000000)) == htonl(0xFF000000);

net/ipv6/addrconf.c

@@ -222,6 +222,8 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
 const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
 const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
+const struct in6_addr in6addr_linklocal_allnodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
+const struct in6_addr in6addr_linklocal_allrouters = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
 
 /* Check if a valid qdisc is available */
 static inline int addrconf_qdisc_ok(struct net_device *dev)
@@ -321,7 +323,6 @@ EXPORT_SYMBOL(in6_dev_finish_destroy);
 static struct inet6_dev * ipv6_add_dev(struct net_device *dev)
 {
 	struct inet6_dev *ndev;
-	struct in6_addr maddr;
 
 	ASSERT_RTNL();
 
@@ -406,8 +407,7 @@ static struct inet6_dev * ipv6_add_dev(struct net_device *dev)
 	rcu_assign_pointer(dev->ip6_ptr, ndev);
 
 	/* Join all-node multicast group */
-	ipv6_addr_all_nodes(&maddr);
-	ipv6_dev_mc_inc(dev, &maddr);
+	ipv6_dev_mc_inc(dev, &in6addr_linklocal_allnodes);
 
 	return ndev;
 }
@@ -433,18 +433,15 @@ static void dev_forward_change(struct inet6_dev *idev)
 {
 	struct net_device *dev;
 	struct inet6_ifaddr *ifa;
-	struct in6_addr addr;
 
 	if (!idev)
 		return;
 	dev = idev->dev;
 	if (dev && (dev->flags & IFF_MULTICAST)) {
-		ipv6_addr_all_routers(&addr);
-
 		if (idev->cnf.forwarding)
-			ipv6_dev_mc_inc(dev, &addr);
+			ipv6_dev_mc_inc(dev, &in6addr_linklocal_allrouters);
 		else
-			ipv6_dev_mc_dec(dev, &addr);
+			ipv6_dev_mc_dec(dev, &in6addr_linklocal_allrouters);
 	}
 	for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) {
 		if (ifa->flags&IFA_F_TENTATIVE)
@@ -2654,8 +2651,6 @@ static void addrconf_rs_timer(unsigned long data)
 
 	spin_lock(&ifp->lock);
 	if (ifp->probes++ < ifp->idev->cnf.rtr_solicits) {
-		struct in6_addr all_routers;
-
 		/* The wait after the last probe can be shorter */
 		addrconf_mod_timer(ifp, AC_RS,
 				   (ifp->probes == ifp->idev->cnf.rtr_solicits) ?
@@ -2663,9 +2658,7 @@ static void addrconf_rs_timer(unsigned long data)
 				   ifp->idev->cnf.rtr_solicit_interval);
 		spin_unlock(&ifp->lock);
 
-		ipv6_addr_all_routers(&all_routers);
-
-		ndisc_send_rs(ifp->idev->dev, &ifp->addr, &all_routers);
+		ndisc_send_rs(ifp->idev->dev, &ifp->addr, &in6addr_linklocal_allrouters);
 	} else {
 		spin_unlock(&ifp->lock);
 		/*
@@ -2806,16 +2799,12 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp)
 	    ifp->idev->cnf.rtr_solicits > 0 &&
 	    (dev->flags&IFF_LOOPBACK) == 0 &&
 	    (ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL)) {
-		struct in6_addr all_routers;
-
-		ipv6_addr_all_routers(&all_routers);
-
 		/*
 		 *	If a host as already performed a random delay
 		 *	[...] as part of DAD [...] there is no need
 		 *	to delay again before sending the first RS
 		 */
-		ndisc_send_rs(ifp->idev->dev, &ifp->addr, &all_routers);
+		ndisc_send_rs(ifp->idev->dev, &ifp->addr, &in6addr_linklocal_allrouters);
 
 		spin_lock_bh(&ifp->lock);
 		ifp->probes = 1;

net/ipv6/mcast.c

@@ -1766,10 +1766,9 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
 	struct inet6_dev *idev;
 	struct sk_buff *skb;
 	struct icmp6hdr *hdr;
-	struct in6_addr *snd_addr;
+	const struct in6_addr *snd_addr;
 	struct in6_addr *addrp;
 	struct in6_addr addr_buf;
-	struct in6_addr all_routers;
 	int err, len, payload_len, full_len;
 	u8 ra[8] = { IPPROTO_ICMPV6, 0,
 		     IPV6_TLV_ROUTERALERT, 2, 0, 0,
@@ -1780,11 +1779,10 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
 	IP6_INC_STATS(__in6_dev_get(dev),
 		      IPSTATS_MIB_OUTREQUESTS);
 	rcu_read_unlock();
-	snd_addr = addr;
-	if (type == ICMPV6_MGM_REDUCTION) {
-		snd_addr = &all_routers;
-		ipv6_addr_all_routers(&all_routers);
-	}
+	if (type == ICMPV6_MGM_REDUCTION)
+		snd_addr = &in6addr_linklocal_allrouters;
+	else
+		snd_addr = addr;
 
 	len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
 	payload_len = len + sizeof(ra);
@@ -2309,24 +2307,19 @@ void ipv6_mc_init_dev(struct inet6_dev *idev)
 void ipv6_mc_destroy_dev(struct inet6_dev *idev)
 {
 	struct ifmcaddr6 *i;
-	struct in6_addr maddr;
 
 	/* Deactivate timers */
 	ipv6_mc_down(idev);
 
 	/* Delete all-nodes address. */
-	ipv6_addr_all_nodes(&maddr);
-
 	/* We cannot call ipv6_dev_mc_dec() directly, our caller in
 	 * addrconf.c has NULL'd out dev->ip6_ptr so in6_dev_get() will
 	 * fail.
 	 */
-	__ipv6_dev_mc_dec(idev, &maddr);
+	__ipv6_dev_mc_dec(idev, &in6addr_linklocal_allnodes);
 
-	if (idev->cnf.forwarding) {
-		ipv6_addr_all_routers(&maddr);
-		__ipv6_dev_mc_dec(idev, &maddr);
-	}
+	if (idev->cnf.forwarding)
+		__ipv6_dev_mc_dec(idev, &in6addr_linklocal_allrouters);
 
 	write_lock_bh(&idev->lock);
 	while ((i = idev->mc_list) != NULL) {

net/ipv6/ndisc.c

@@ -818,10 +818,7 @@ static void ndisc_recv_ns(struct sk_buff *skb)
 		is_router = !!idev->cnf.forwarding;
 
 	if (dad) {
-		struct in6_addr maddr;
-
-		ipv6_addr_all_nodes(&maddr);
-		ndisc_send_na(dev, NULL, &maddr, &msg->target,
+		ndisc_send_na(dev, NULL, &in6addr_linklocal_allnodes, &msg->target,
 			      is_router, 0, (ifp != NULL), 1);
 		goto out;
 	}