ipv6: Do not leave router anycast address for /127 prefixes.

Original commit 2bda8a0... "Disable router anycast address for /127 prefixes" says: | No need for matching code in addrconf_leave_anycast() as it | will silently ignore any attempt to leave an unknown anycast | address. After analysis, because 1) we may add two or more prefixes on the same interface, or 2)user may have manually joined that anycast, we may hit chances to have anycast address which as if we had generated one by /127 prefix and we should not leave from subnet- router anycast address unconditionally. CC: Bjørn Mork <[email protected]> CC: Brian Haley <[email protected]> Signed-off-by: YOSHIFUJI Hideaki <[email protected]> Signed-off-by: David S. Miller <[email protected]>
realfirst · Jul 25, 2011 · 32019e6 · 32019e6
1 parent 5ec9e63
commit 32019e6
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
@@ -1481,6 +1481,8 @@ static void addrconf_join_anycast(struct inet6_ifaddr *ifp)
 static void addrconf_leave_anycast(struct inet6_ifaddr *ifp)
 {
 	struct in6_addr addr;
+	if (ifp->prefix_len == 127) /* RFC 6164 */
+		return;
 	ipv6_addr_prefix(&addr, &ifp->addr, ifp->prefix_len);
 	if (ipv6_addr_any(&addr))
 		return;