[IPV6]: Unify ip6_onlink() and ipip6_onlink().

Both are identical, let's create ipv6_chk_prefix() and use it
in both places.

include/net/addrconf.h

@@ -71,6 +71,10 @@ extern int			ipv6_chk_addr(struct net *net,
 extern int			ipv6_chk_home_addr(struct net *net,
 						   struct in6_addr *addr);
 #endif
+
+extern int			ipv6_chk_prefix(struct in6_addr *addr,
+						struct net_device *dev);
+
 extern struct inet6_ifaddr      *ipv6_get_ifaddr(struct net *net,
 						 struct in6_addr *addr,
 						 struct net_device *dev,

net/ipv6/addrconf.c

@@ -1249,6 +1249,31 @@ int ipv6_chk_same_addr(struct net *net, const struct in6_addr *addr,
 	return ifp != NULL;
 }
 
+int ipv6_chk_prefix(struct in6_addr *addr, struct net_device *dev)
+{
+	struct inet6_dev *idev;
+	struct inet6_ifaddr *ifa;
+	int	onlink;
+
+	onlink = 0;
+	rcu_read_lock();
+	idev = __in6_dev_get(dev);
+	if (idev) {
+		read_lock_bh(&idev->lock);
+		for (ifa = idev->addr_list; ifa; ifa = ifa->if_next) {
+			onlink = ipv6_prefix_equal(addr, &ifa->addr,
+						   ifa->prefix_len);
+			if (onlink)
+				break;
+		}
+		read_unlock_bh(&idev->lock);
+	}
+	rcu_read_unlock();
+	return onlink;
+}
+
+EXPORT_SYMBOL(ipv6_chk_prefix);
+
 struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, struct in6_addr *addr,
 				     struct net_device *dev, int strict)
 {

net/ipv6/anycast.c

@@ -48,29 +48,6 @@ static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr);
 /* Big ac list lock for all the sockets */
 static DEFINE_RWLOCK(ipv6_sk_ac_lock);
 
-static int
-ip6_onlink(struct in6_addr *addr, struct net_device *dev)
-{
-	struct inet6_dev	*idev;
-	struct inet6_ifaddr	*ifa;
-	int	onlink;
-
-	onlink = 0;
-	rcu_read_lock();
-	idev = __in6_dev_get(dev);
-	if (idev) {
-		read_lock_bh(&idev->lock);
-		for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) {
-			onlink = ipv6_prefix_equal(addr, &ifa->addr,
-						   ifa->prefix_len);
-			if (onlink)
-				break;
-		}
-		read_unlock_bh(&idev->lock);
-	}
-	rcu_read_unlock();
-	return onlink;
-}
 
 /*
  *	socket join an anycast group
@@ -142,7 +119,7 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr)
 	 * This obviates the need for propagating anycast routes while
 	 * still allowing some non-router anycast participation.
 	 */
-	if (!ip6_onlink(addr, dev)) {
+	if (!ipv6_chk_prefix(addr, dev)) {
 		if (ishost)
 			err = -EADDRNOTAVAIL;
 		if (err)

net/ipv6/sit.c

@@ -344,31 +344,6 @@ ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
 	return 0;
 }
 
-/* copied directly from anycast.c */
-static int
-ipip6_onlink(struct in6_addr *addr, struct net_device *dev)
-{
-	struct inet6_dev	*idev;
-	struct inet6_ifaddr	*ifa;
-	int	onlink;
-
-	onlink = 0;
-	rcu_read_lock();
-	idev = __in6_dev_get(dev);
-	if (idev) {
-		read_lock_bh(&idev->lock);
-		for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) {
-			onlink = ipv6_prefix_equal(addr, &ifa->addr,
-						   ifa->prefix_len);
-			if (onlink)
-				break;
-		}
-		read_unlock_bh(&idev->lock);
-	}
-	rcu_read_unlock();
-	return onlink;
-}
-
 static int
 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t)
 {
@@ -386,7 +361,7 @@ isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t)
 		struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
 		if (ipv6_addr_is_isatap(addr6) &&
 		    (addr6->s6_addr32[3] == iph->saddr) &&
-		    ipip6_onlink(addr6, t->dev))
+		    ipv6_chk_prefix(addr6, t->dev))
 			skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
 		else
 			ok = 0;