bridge: Use IPv6 link-local address for multicast listener queries

Currently the bridge multicast snooping feature periodically issues
IPv6 general multicast listener queries to sense the absence of a
listener.

For this, it uses :: as its source address - however RFC 2710 requires:
"To be valid, the Query message MUST come from a link-local IPv6 Source
Address". Current Linux kernel versions seem to follow this requirement
and ignore our bogus MLD queries.

With this commit a link local address from the bridge interface is being
used to issue the MLD query, resulting in other Linux devices which are
multicast listeners in the network to respond with a MLD response (which
was not the case before).

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Linus Lüssing 2011-02-17 08:17:52 +00:00 committed by David S. Miller
parent 36cff5a10c
commit fe29ec41aa

View File

@ -445,7 +445,8 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
ip6h->payload_len = htons(8 + sizeof(*mldq));
ip6h->nexthdr = IPPROTO_HOPOPTS;
ip6h->hop_limit = 1;
ipv6_addr_set(&ip6h->saddr, 0, 0, 0, 0);
ipv6_dev_get_saddr(dev_net(br->dev), br->dev, &ip6h->daddr, 0,
&ip6h->saddr);
ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));
ipv6_eth_mc_map(&ip6h->daddr, eth->h_dest);