diff mbox

[2/2] bridge: Use IPv6 link-local address for multicast listener queries

Message ID 1297966672-3457-3-git-send-email-linus.luessing@web.de
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Linus Lüssing Feb. 17, 2011, 6:17 p.m. UTC
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>
---
 net/bridge/br_multicast.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

Comments

David Miller Feb. 22, 2011, 6:08 p.m. UTC | #1
From: Linus Lüssing <linus.luessing@web.de>
Date: Thu, 17 Feb 2011 19:17:52 +0100

> 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>

Applied.
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diff mbox

Patch

diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index f904a2e..2d88861 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -446,7 +446,8 @@  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);