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Commit eb1d1641 authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller
Browse files

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: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid 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/

net/bridge/br_multicast.c

0 → 100644
+1135 −0

File added.

Preview size limit exceeded, changes collapsed.

net/bridge/br_private.h

+139 −0
Original line number Diff line number Diff line
@@ -57,6 +57,41 @@ struct net_bridge_fdb_entry 
	unsigned char			is_static;

};



struct net_bridge_port_group {

	struct net_bridge_port		*port;

	struct net_bridge_port_group	*next;

	struct hlist_node		mglist;

	struct rcu_head			rcu;

	struct timer_list		timer;

	struct timer_list		query_timer;

	__be32				addr;

	u32				queries_sent;

};



struct net_bridge_mdb_entry

{

	struct hlist_node		hlist[2];

	struct hlist_node		mglist;

	struct net_bridge		*br;

	struct net_bridge_port_group	*ports;

	struct rcu_head			rcu;

	struct timer_list		timer;

	struct timer_list		query_timer;

	__be32				addr;

	u32				queries_sent;

};



struct net_bridge_mdb_htable

{

	struct hlist_head		*mhash;

	struct rcu_head			rcu;

	struct net_bridge_mdb_htable	*old;

	u32				size;

	u32				max;

	u32				secret;

	u32				ver;

};



struct net_bridge_port

{

	struct net_bridge		*br;
@@ -84,6 +119,15 @@ struct net_bridge_port 


	unsigned long 			flags;

#define BR_HAIRPIN_MODE		0x00000001



#ifdef CONFIG_BRIDGE_IGMP_SNOOPING

	u32				multicast_startup_queries_sent;

	unsigned char			multicast_router;

	struct timer_list		multicast_router_timer;

	struct timer_list		multicast_query_timer;

	struct hlist_head		mglist;

	struct hlist_node		rlist;

#endif

};



struct net_bridge
@@ -124,6 +168,35 @@ struct net_bridge 
	unsigned char			topology_change;

	unsigned char			topology_change_detected;



#ifdef CONFIG_BRIDGE_IGMP_SNOOPING

	unsigned char			multicast_router;



	u8				multicast_disabled:1;



	u32				hash_elasticity;

	u32				hash_max;



	u32				multicast_last_member_count;

	u32				multicast_startup_queries_sent;

	u32				multicast_startup_query_count;



	unsigned long			multicast_last_member_interval;

	unsigned long			multicast_membership_interval;

	unsigned long			multicast_querier_interval;

	unsigned long			multicast_query_interval;

	unsigned long			multicast_query_response_interval;

	unsigned long			multicast_startup_query_interval;



	spinlock_t			multicast_lock;

	struct net_bridge_mdb_htable	*mdb;

	struct hlist_head		router_list;

	struct hlist_head		mglist;



	struct timer_list		multicast_router_timer;

	struct timer_list		multicast_querier_timer;

	struct timer_list		multicast_query_timer;

#endif



	struct timer_list		hello_timer;

	struct timer_list		tcn_timer;

	struct timer_list		topology_change_timer;
@@ -133,6 +206,8 @@ struct net_bridge 


struct br_input_skb_cb {

	struct net_device *brdev;

	int igmp;

	int mrouters_only;

};



#define BR_INPUT_SKB_CB(__skb)	((struct br_input_skb_cb *)(__skb)->cb)
@@ -204,6 +279,70 @@ extern struct sk_buff *br_handle_frame(struct net_bridge_port *p, 
extern int br_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);

extern int br_ioctl_deviceless_stub(struct net *net, unsigned int cmd, void __user *arg);



/* br_multicast.c */

#ifdef CONFIG_BRIDGE_IGMP_SNOOPING

extern int br_multicast_rcv(struct net_bridge *br,

			    struct net_bridge_port *port,

			    struct sk_buff *skb);

extern struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,

					       struct sk_buff *skb);

extern void br_multicast_add_port(struct net_bridge_port *port);

extern void br_multicast_del_port(struct net_bridge_port *port);

extern void br_multicast_enable_port(struct net_bridge_port *port);

extern void br_multicast_disable_port(struct net_bridge_port *port);

extern void br_multicast_init(struct net_bridge *br);

extern void br_multicast_open(struct net_bridge *br);

extern void br_multicast_stop(struct net_bridge *br);

#else

static inline int br_multicast_rcv(struct net_bridge *br,

				   struct net_bridge_port *port,

				   struct sk_buff *skb)

{

	return 0;

}



static inline struct net_bridge_mdb_entry *br_mdb_get(struct net_bridge *br,

						      struct sk_buff *skb)

{

	return NULL;

}



static inline void br_multicast_add_port(struct net_bridge_port *port)

{

}



static inline void br_multicast_del_port(struct net_bridge_port *port)

{

}



static inline void br_multicast_enable_port(struct net_bridge_port *port)

{

}



static inline void br_multicast_disable_port(struct net_bridge_port *port)

{

}



static inline void br_multicast_init(struct net_bridge *br)

{

}



static inline void br_multicast_open(struct net_bridge *br)

{

}



static inline void br_multicast_stop(struct net_bridge *br)

{

}

#endif



static inline bool br_multicast_is_router(struct net_bridge *br)

{

	return br->multicast_router == 2 ||

	       (br->multicast_router == 1 &&

		timer_pending(&br->multicast_router_timer));

}



/* br_netfilter.c */

#ifdef CONFIG_BRIDGE_NETFILTER

extern int br_netfilter_init(void);