net: bridge: remove ipv6 zero address check in mcast queries

Nikolay Aleksandrov · davem330 · commit 0fe5119e267f · 2018-10-28T19:18:09.000-07:00
Recently a check was added which prevents marking of routers with zero source address, but for IPv6 that cannot happen as the relevant RFCs actually forbid such packets: RFC 2710 (MLDv1): "To be valid, the Query message MUST come from a link-local IPv6 Source Address, be at least 24 octets long, and have a correct MLD checksum." Same goes for RFC 3810. And also it can be seen as a requirement in ipv6_mc_check_mld_query() which is used by the bridge to validate the message before processing it. Thus any queries with :: source address won't be processed anyway. So just remove the check for zero IPv6 source address from the query processing function. Fixes: 5a2de63 ("bridge: do not add port to router list when receives query with source 0.0.0.0") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
@@ -1428,8 +1428,7 @@ static void br_multicast_query_received(struct net_bridge *br,
 	 * is 0.0.0.0 should not be added to router port list.
 	 */
 	if ((saddr->proto == htons(ETH_P_IP) && saddr->u.ip4) ||
-	    (saddr->proto == htons(ETH_P_IPV6) &&
-	     !ipv6_addr_any(&saddr->u.ip6)))
+	    saddr->proto == htons(ETH_P_IPV6))
 		br_multicast_mark_router(br, port);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -1428,8 +1428,7 @@ static void br_multicast_query_received(struct net_bridge *br,`
`1428`	`1428`	`* is 0.0.0.0 should not be added to router port list.`
`1429`	`1429`	`*/`
`1430`	`1430`	`if ((saddr->proto == htons(ETH_P_IP) && saddr->u.ip4) \|\|`
`1431`		`- (saddr->proto == htons(ETH_P_IPV6) &&`
`1432`		`- !ipv6_addr_any(&saddr->u.ip6)))`
	`1431`	`+ saddr->proto == htons(ETH_P_IPV6))`
`1433`	`1432`	`br_multicast_mark_router(br, port);`
`1434`	`1433`	`}`
`1435`	`1434`