Commit eb1d1641 authored Feb 27, 2010 by Herbert Xu Committed by David S. Miller Feb 28, 2010

bridge: Add core IGMP snooping support



This patch adds the core functionality of IGMP snooping support
without actually hooking it up.  So this patch should be a no-op
as far as the bridge's external behaviour is concerned.

All the new code and data is controlled by the Kconfig option
BRIDGE_IGMP_SNOOPING.  A run-time toggle is also available.

The multicast switching is done using an hash table that is
lockless on the read-side through RCU.  On the write-side the
new multicast_lock is used for all operations.  The hash table
supports dynamic growth/rehashing.

The hash table will be rehashed if any chain length exceeds a
preset limit.  If rehashing does not reduce the maximum chain
length then snooping will be disabled.

These features may be added in future (in no particular order):

* IGMPv3 source support
* Non-querier router detection
* IPv6

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 025d89c2

net/bridge/Kconfig

+12 −0

Original line number	Diff line number	Diff line
		@@ -31,3 +31,15 @@ config BRIDGE
		will be called bridge.

		If unsure, say N.

		config BRIDGE_IGMP_SNOOPING
		bool "IGMP snooping"
		default y
		---help---
		If you say Y here, then the Ethernet bridge will be able selectively
		forward multicast traffic based on IGMP traffic received from each
		port.

		Say N to exclude this support and reduce the binary size.

		If unsure, say Y.

net/bridge/Makefile

+2 −0

Original line number	Diff line number	Diff line
		@@ -12,4 +12,6 @@ bridge-$(CONFIG_SYSFS) += br_sysfs_if.o br_sysfs_br.o

		bridge-$(CONFIG_BRIDGE_NETFILTER) += br_netfilter.o

		bridge-$(CONFIG_BRIDGE_IGMP_SNOOPING) += br_multicast.o

		obj-$(CONFIG_BRIDGE_NF_EBTABLES) += netfilter/