From: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Hemminger <shemminger@vyatta.com>,
netdev@vger.kernel.org,
Hayato Kakuta <kakuta.hayato@oss.ntt.co.jp>
Subject: IGMP snooping: set mrouters_only flag for IPv4 traffic properly
Date: Mon, 13 Jun 2011 12:02:43 +0900 [thread overview]
Message-ID: <1307934163.3550.2.camel@nausicaa> (raw)
In-Reply-To: <1307933995.2704.11.camel@nausicaa>
Upon reception of a IGMP/IGMPv2 membership report the kernel sets the
mrouters_only flag in a skb that may be a clone of the original skb, which
means that sometimes the bridge loses track of membership report packets (cb
buffers are tied to a specifici skb and not shared) and it ends up forwading
join requests to the bridge interface.
This can cause unexpected membership timeouts and intermitent/permanent loss of connectivity as described in RFC 4541 [2.1.1. IGMP Forwarding Rules]:
A snooping switch should forward IGMP Membership Reports only to
those ports where multicast routers are attached.
[...]
Sending membership reports to other hosts can result, for IGMPv1
and IGMPv2, in unintentionally preventing a host from joining a
specific multicast group.
Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Tested-by: Hayato Kakuta <kakuta.hayato@oss.ntt.co.jp>
---
diff -urNp linux-3.0-rc2-orig/net/bridge/br_multicast.c linux-3.0-rc2/net/bridge/br_multicast.c
--- linux-3.0-rc2-orig/net/bridge/br_multicast.c 2011-06-09 13:34:04.164261031 +0900
+++ linux-3.0-rc2/net/bridge/br_multicast.c 2011-06-09 20:04:23.473930447 +0900
@@ -1424,7 +1424,7 @@ static int br_multicast_ipv4_rcv(struct
switch (ih->type) {
case IGMP_HOST_MEMBERSHIP_REPORT:
case IGMPV2_HOST_MEMBERSHIP_REPORT:
- BR_INPUT_SKB_CB(skb2)->mrouters_only = 1;
+ BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
err = br_ip4_multicast_add_group(br, port, ih->group);
break;
case IGMPV3_HOST_MEMBERSHIP_REPORT:
next prev parent reply other threads:[~2011-06-13 3:02 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-13 2:59 [PATCH 0/2] IGMP snooping: set mrouters_only flag properly Fernando Luis Vazquez Cao
2011-06-13 3:02 ` Fernando Luis Vazquez Cao [this message]
2011-06-14 17:22 ` IGMP snooping: set mrouters_only flag for IPv4 traffic properly Stephen Hemminger
2011-06-15 5:09 ` Fernando Luis Vázquez Cao
2011-06-13 3:21 ` [PATCH 2/2] IGMP snooping: set mrouters_only flag for IPv6 " Fernando Luis Vazquez Cao
2011-06-14 1:01 ` [PATCH 0/2] IGMP snooping: set mrouters_only flag properly Fernando Luis Vázquez Cao
2011-06-14 1:04 ` [PATCH 1/2] IGMP snooping: set mrouters_only flag for IPv4 traffic properly Fernando Luis Vázquez Cao
2011-06-17 3:14 ` David Miller
2011-06-17 4:39 ` Fernando Luis Vazquez Cao
2011-06-14 1:06 ` [PATCH 2/2] IGMP snooping: set mrouters_only flag for IPv6 " Fernando Luis Vázquez Cao
2011-06-17 3:14 ` David Miller
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