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Commit ee07c6e7 authored by Cong Wang's avatar Cong Wang Committed by David S. Miller
Browse files

bridge: export multicast database via netlink 



V5: fix two bugs pointed out by Thomas
    remove seq check for now, mark it as TODO

V4: remove some useless #include
    some coding style fix

V3: drop debugging printk's
    update selinux perm table as well

V2: drop patch 1/2, export ifindex directly
    Redesign netlink attributes
    Improve netlink seq check
    Handle IPv6 addr as well

This patch exports bridge multicast database via netlink
message type RTM_GETMDB. Similar to fdb, but currently bridge-specific.
We may need to support modify multicast database too (RTM_{ADD,DEL}MDB).

(Thanks to Thomas for patient reviews)

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: default avatarCong Wang <amwang@redhat.com>
Acked-by: default avatarThomas Graf <tgraf@suug.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5d248c49

include/uapi/linux/if_bridge.h

+55 −0
Original line number Diff line number Diff line
@@ -116,4 +116,59 @@ enum { 
	__IFLA_BRIDGE_MAX,

};

#define IFLA_BRIDGE_MAX (__IFLA_BRIDGE_MAX - 1)



/* Bridge multicast database attributes

 * [MDBA_MDB] = {

 *     [MDBA_MDB_ENTRY] = {

 *         [MDBA_MDB_ENTRY_INFO]

 *     }

 * }

 * [MDBA_ROUTER] = {

 *    [MDBA_ROUTER_PORT]

 * }

 */

enum {

	MDBA_UNSPEC,

	MDBA_MDB,

	MDBA_ROUTER,

	__MDBA_MAX,

};

#define MDBA_MAX (__MDBA_MAX - 1)



enum {

	MDBA_MDB_UNSPEC,

	MDBA_MDB_ENTRY,

	__MDBA_MDB_MAX,

};

#define MDBA_MDB_MAX (__MDBA_MDB_MAX - 1)



enum {

	MDBA_MDB_ENTRY_UNSPEC,

	MDBA_MDB_ENTRY_INFO,

	__MDBA_MDB_ENTRY_MAX,

};

#define MDBA_MDB_ENTRY_MAX (__MDBA_MDB_ENTRY_MAX - 1)



enum {

	MDBA_ROUTER_UNSPEC,

	MDBA_ROUTER_PORT,

	__MDBA_ROUTER_MAX,

};

#define MDBA_ROUTER_MAX (__MDBA_ROUTER_MAX - 1)



struct br_port_msg {

	__u32 ifindex;

};



struct br_mdb_entry {

	__u32 ifindex;

	struct {

		union {

			__be32	ip4;

			struct in6_addr ip6;

		} u;

		__be16		proto;

	} addr;

};



#endif /* _UAPI_LINUX_IF_BRIDGE_H */

include/uapi/linux/rtnetlink.h

+3 −0
Original line number Diff line number Diff line
@@ -125,6 +125,9 @@ enum { 
	RTM_GETNETCONF = 82,

#define RTM_GETNETCONF RTM_GETNETCONF



	RTM_GETMDB = 86,

#define RTM_GETMDB RTM_GETMDB



	__RTM_MAX,

#define RTM_MAX		(((__RTM_MAX + 3) & ~3) - 1)

};

net/bridge/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -12,6 +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

bridge-$(CONFIG_BRIDGE_IGMP_SNOOPING) += br_multicast.o br_mdb.o



obj-$(CONFIG_BRIDGE_NF_EBTABLES) += netfilter/

net/bridge/br_mdb.c

0 → 100644
+163 −0
Original line number Diff line number Diff line 
#include <linux/err.h>

#include <linux/igmp.h>

#include <linux/kernel.h>

#include <linux/netdevice.h>

#include <linux/rculist.h>

#include <linux/skbuff.h>

#include <net/ip.h>

#include <net/netlink.h>

#if IS_ENABLED(CONFIG_IPV6)

#include <net/ipv6.h>

#endif



#include "br_private.h"



static int br_rports_fill_info(struct sk_buff *skb, struct netlink_callback *cb,

			       struct net_device *dev)

{

	struct net_bridge *br = netdev_priv(dev);

	struct net_bridge_port *p;

	struct hlist_node *n;

	struct nlattr *nest;



	if (!br->multicast_router || hlist_empty(&br->router_list))

		return 0;



	nest = nla_nest_start(skb, MDBA_ROUTER);

	if (nest == NULL)

		return -EMSGSIZE;



	hlist_for_each_entry_rcu(p, n, &br->router_list, rlist) {

		if (p && nla_put_u32(skb, MDBA_ROUTER_PORT, p->dev->ifindex))

			goto fail;

	}



	nla_nest_end(skb, nest);

	return 0;

fail:

	nla_nest_cancel(skb, nest);

	return -EMSGSIZE;

}



static int br_mdb_fill_info(struct sk_buff *skb, struct netlink_callback *cb,

			    struct net_device *dev)

{

	struct net_bridge *br = netdev_priv(dev);

	struct net_bridge_mdb_htable *mdb;

	struct nlattr *nest, *nest2;

	int i, err = 0;

	int idx = 0, s_idx = cb->args[1];



	if (br->multicast_disabled)

		return 0;



	mdb = rcu_dereference(br->mdb);

	if (!mdb)

		return 0;



	nest = nla_nest_start(skb, MDBA_MDB);

	if (nest == NULL)

		return -EMSGSIZE;



	for (i = 0; i < mdb->max; i++) {

		struct hlist_node *h;

		struct net_bridge_mdb_entry *mp;

		struct net_bridge_port_group *p, **pp;

		struct net_bridge_port *port;



		hlist_for_each_entry_rcu(mp, h, &mdb->mhash[i], hlist[mdb->ver]) {

			if (idx < s_idx)

				goto skip;



			nest2 = nla_nest_start(skb, MDBA_MDB_ENTRY);

			if (nest2 == NULL) {

				err = -EMSGSIZE;

				goto out;

			}



			for (pp = &mp->ports;

			     (p = rcu_dereference(*pp)) != NULL;

			      pp = &p->next) {

				port = p->port;

				if (port) {

					struct br_mdb_entry e;

					e.ifindex = port->dev->ifindex;

					e.addr.u.ip4 = p->addr.u.ip4;

#if IS_ENABLED(CONFIG_IPV6)

					e.addr.u.ip6 = p->addr.u.ip6;

#endif

					e.addr.proto = p->addr.proto;

					if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(e), &e)) {

						nla_nest_cancel(skb, nest2);

						err = -EMSGSIZE;

						goto out;

					}

				}

			}

			nla_nest_end(skb, nest2);

		skip:

			idx++;

		}

	}



out:

	cb->args[1] = idx;

	nla_nest_end(skb, nest);

	return err;

}



static int br_mdb_dump(struct sk_buff *skb, struct netlink_callback *cb)

{

	struct net_device *dev;

	struct net *net = sock_net(skb->sk);

	struct nlmsghdr *nlh = NULL;

	int idx = 0, s_idx;



	s_idx = cb->args[0];



	rcu_read_lock();



	/* TODO: in case of rehashing, we need to check

	 * consistency for dumping.

	 */

	cb->seq = net->dev_base_seq;



	for_each_netdev_rcu(net, dev) {

		if (dev->priv_flags & IFF_EBRIDGE) {

			struct br_port_msg *bpm;



			if (idx < s_idx)

				goto skip;



			nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,

					cb->nlh->nlmsg_seq, RTM_GETMDB,

					sizeof(*bpm), NLM_F_MULTI);

			if (nlh == NULL)

				break;



			bpm = nlmsg_data(nlh);

			bpm->ifindex = dev->ifindex;

			if (br_mdb_fill_info(skb, cb, dev) < 0)

				goto out;

			if (br_rports_fill_info(skb, cb, dev) < 0)

				goto out;



			cb->args[1] = 0;

			nlmsg_end(skb, nlh);

		skip:

			idx++;

		}

	}



out:

	if (nlh)

		nlmsg_end(skb, nlh);

	rcu_read_unlock();

	cb->args[0] = idx;

	return skb->len;

}



void br_mdb_init(void)

{

	rtnl_register(PF_BRIDGE, RTM_GETMDB, NULL, br_mdb_dump, NULL);

}

net/bridge/br_multicast.c

+1 −0
Original line number Diff line number Diff line
@@ -1605,6 +1605,7 @@ void br_multicast_init(struct net_bridge *br) 
		    br_multicast_querier_expired, (unsigned long)br);

	setup_timer(&br->multicast_query_timer, br_multicast_query_expired,

		    (unsigned long)br);

	br_mdb_init();

}



void br_multicast_open(struct net_bridge *br)