[IPV6] Unify common functions to compare ipv6 prefixes.

Signed-off-by: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>

include/net/ipv6.h

@@ -305,6 +305,32 @@ static inline int ipv6_addr_equal(const struct in6_addr *a1,
 		a1->s6_addr32[3] == a2->s6_addr32[3]);
 }
 
+static inline int __ipv6_prefix_equal(const u32 *a1, const u32 *a2,
+				      unsigned int prefixlen)
+{
+	unsigned pdw, pbi;
+
+	/* check complete u32 in prefix */
+	pdw = prefixlen >> 5;
+	if (pdw && memcmp(a1, a2, pdw << 2))
+		return 0;
+
+	/* check incomplete u32 in prefix */
+	pbi = prefixlen & 0x1f;
+	if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
+		return 0;
+
+	return 1;
+}
+
+static inline int ipv6_prefix_equal(const struct in6_addr *a1,
+				    const struct in6_addr *a2,
+				    unsigned int prefixlen)
+{
+	return __ipv6_prefix_equal(a1->s6_addr32, a2->s6_addr32,
+				   prefixlen);
+}
+
 static inline int ipv6_addr_any(const struct in6_addr *a)
 {
 	return ((a->s6_addr32[0] | a->s6_addr32[1] | 

net/ipv6/anycast.c

@@ -48,32 +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);
 
-/* XXX ip6_addr_match() and ip6_onlink() really belong in net/core.c */
-
-static int
-ip6_addr_match(struct in6_addr *addr1, struct in6_addr *addr2, int prefix)
-{
-	__u32	mask;
-	int	i;
-
-	if (prefix > 128 || prefix < 0)
-		return 0;
-	if (prefix == 0)
-		return 1;
-	for (i=0; i<4; ++i) {
-		if (prefix >= 32)
-			mask = ~0;
-		else
-			mask = htonl(~0 << (32 - prefix));
-		if ((addr1->s6_addr32[i] ^ addr2->s6_addr32[i]) & mask)
-			return 0;
-		prefix -= 32;
-		if (prefix <= 0)
-			break;
-	}
-	return 1;
-}
-
 static int
 ip6_onlink(struct in6_addr *addr, struct net_device *dev)
 {
@@ -87,8 +61,8 @@ ip6_onlink(struct in6_addr *addr, struct net_device *dev)
 	if (idev) {
 		read_lock_bh(&idev->lock);
 		for (ifa=idev->addr_list; ifa; ifa=ifa->if_next) {
-			onlink = ip6_addr_match(addr, &ifa->addr,
-					ifa->prefix_len);
+			onlink = ipv6_prefix_equal(addr, &ifa->addr,
+						   ifa->prefix_len);
 			if (onlink)
 				break;
 		}

net/ipv6/ip6_fib.c

@@ -116,36 +116,6 @@ static __inline__ u32 fib6_new_sernum(void)
  *	64bit processors)
  */
 
-/*
- *	compare "prefix length" bits of an address
- */
-
-static __inline__ int addr_match(void *token1, void *token2, int prefixlen)
-{
-	__u32 *a1 = token1;
-	__u32 *a2 = token2;
-	int pdw;
-	int pbi;
-
-	pdw = prefixlen >> 5;	  /* num of whole __u32 in prefix */
-	pbi = prefixlen &  0x1f;  /* num of bits in incomplete u32 in prefix */
-
-	if (pdw)
-		if (memcmp(a1, a2, pdw << 2))
-			return 0;
-
-	if (pbi) {
-		__u32 mask;
-
-		mask = htonl((0xffffffff) << (32 - pbi));
-
-		if ((a1[pdw] ^ a2[pdw]) & mask)
-			return 0;
-	}
-
-	return 1;
-}
-
 /*
  *	test bit
  */
@@ -261,7 +231,7 @@ static struct fib6_node * fib6_add_1(struct fib6_node *root, void *addr,
 		 *	Prefix match
 		 */
 		if (plen < fn->fn_bit ||
-		    !addr_match(&key->addr, addr, fn->fn_bit))
+		    !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
 			goto insert_above;
 		
 		/*
@@ -667,7 +637,7 @@ static struct fib6_node * fib6_lookup_1(struct fib6_node *root,
 			key = (struct rt6key *) ((u8 *) fn->leaf +
 						 args->offset);
 
-			if (addr_match(&key->addr, args->addr, key->plen))
+			if (ipv6_prefix_equal(&key->addr, args->addr, key->plen))
 				return fn;
 		}
 
@@ -718,7 +688,7 @@ static struct fib6_node * fib6_locate_1(struct fib6_node *root,
 		 *	Prefix match
 		 */
 		if (plen < fn->fn_bit ||
-		    !addr_match(&key->addr, addr, fn->fn_bit))
+		    !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
 			return NULL;
 
 		if (plen == fn->fn_bit)