linux/net/bridge/br_mdb.c
Nikolay Aleksandrov 3247b27204 net: bridge: mcast: add delete due to fast-leave mdb flag
In user-space there's no way to distinguish why an mdb entry was deleted
and that is a problem for daemons which would like to keep the mdb in
sync with remote ends (e.g. mlag) but would also like to converge faster.
In almost all cases we'd like to age-out the remote entry for performance
and convergence reasons except when fast-leave is enabled. In that case we
want explicit immediate remote delete, thus add mdb flag which is set only
when the entry is being deleted due to fast-leave.

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-31 19:13:40 -04:00

789 lines
18 KiB
C

// SPDX-License-Identifier: GPL-2.0
#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 <linux/if_ether.h>
#include <net/ip.h>
#include <net/netlink.h>
#include <net/switchdev.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
#include <net/addrconf.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 nlattr *nest, *port_nest;
if (!br->multicast_router || hlist_empty(&br->router_list))
return 0;
nest = nla_nest_start_noflag(skb, MDBA_ROUTER);
if (nest == NULL)
return -EMSGSIZE;
hlist_for_each_entry_rcu(p, &br->router_list, rlist) {
if (!p)
continue;
port_nest = nla_nest_start_noflag(skb, MDBA_ROUTER_PORT);
if (!port_nest)
goto fail;
if (nla_put_nohdr(skb, sizeof(u32), &p->dev->ifindex) ||
nla_put_u32(skb, MDBA_ROUTER_PATTR_TIMER,
br_timer_value(&p->multicast_router_timer)) ||
nla_put_u8(skb, MDBA_ROUTER_PATTR_TYPE,
p->multicast_router)) {
nla_nest_cancel(skb, port_nest);
goto fail;
}
nla_nest_end(skb, port_nest);
}
nla_nest_end(skb, nest);
return 0;
fail:
nla_nest_cancel(skb, nest);
return -EMSGSIZE;
}
static void __mdb_entry_fill_flags(struct br_mdb_entry *e, unsigned char flags)
{
e->state = flags & MDB_PG_FLAGS_PERMANENT;
e->flags = 0;
if (flags & MDB_PG_FLAGS_OFFLOAD)
e->flags |= MDB_FLAGS_OFFLOAD;
if (flags & MDB_PG_FLAGS_FAST_LEAVE)
e->flags |= MDB_FLAGS_FAST_LEAVE;
}
static void __mdb_entry_to_br_ip(struct br_mdb_entry *entry, struct br_ip *ip)
{
memset(ip, 0, sizeof(struct br_ip));
ip->vid = entry->vid;
ip->proto = entry->addr.proto;
if (ip->proto == htons(ETH_P_IP))
ip->u.ip4 = entry->addr.u.ip4;
#if IS_ENABLED(CONFIG_IPV6)
else
ip->u.ip6 = entry->addr.u.ip6;
#endif
}
static int br_mdb_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
struct net_device *dev)
{
int idx = 0, s_idx = cb->args[1], err = 0;
struct net_bridge *br = netdev_priv(dev);
struct net_bridge_mdb_entry *mp;
struct nlattr *nest, *nest2;
if (!br_opt_get(br, BROPT_MULTICAST_ENABLED))
return 0;
nest = nla_nest_start_noflag(skb, MDBA_MDB);
if (nest == NULL)
return -EMSGSIZE;
hlist_for_each_entry_rcu(mp, &br->mdb_list, mdb_node) {
struct net_bridge_port_group *p;
struct net_bridge_port_group __rcu **pp;
struct net_bridge_port *port;
if (idx < s_idx)
goto skip;
nest2 = nla_nest_start_noflag(skb, MDBA_MDB_ENTRY);
if (!nest2) {
err = -EMSGSIZE;
break;
}
for (pp = &mp->ports; (p = rcu_dereference(*pp)) != NULL;
pp = &p->next) {
struct nlattr *nest_ent;
struct br_mdb_entry e;
port = p->port;
if (!port)
continue;
memset(&e, 0, sizeof(e));
e.ifindex = port->dev->ifindex;
e.vid = p->addr.vid;
__mdb_entry_fill_flags(&e, p->flags);
if (p->addr.proto == htons(ETH_P_IP))
e.addr.u.ip4 = p->addr.u.ip4;
#if IS_ENABLED(CONFIG_IPV6)
if (p->addr.proto == htons(ETH_P_IPV6))
e.addr.u.ip6 = p->addr.u.ip6;
#endif
e.addr.proto = p->addr.proto;
nest_ent = nla_nest_start_noflag(skb,
MDBA_MDB_ENTRY_INFO);
if (!nest_ent) {
nla_nest_cancel(skb, nest2);
err = -EMSGSIZE;
goto out;
}
if (nla_put_nohdr(skb, sizeof(e), &e) ||
nla_put_u32(skb,
MDBA_MDB_EATTR_TIMER,
br_timer_value(&p->timer))) {
nla_nest_cancel(skb, nest_ent);
nla_nest_cancel(skb, nest2);
err = -EMSGSIZE;
goto out;
}
nla_nest_end(skb, nest_ent);
}
nla_nest_end(skb, nest2);
skip:
idx++;
}
out:
cb->args[1] = idx;
nla_nest_end(skb, nest);
return err;
}
static int br_mdb_valid_dump_req(const struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct br_port_msg *bpm;
if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*bpm))) {
NL_SET_ERR_MSG_MOD(extack, "Invalid header for mdb dump request");
return -EINVAL;
}
bpm = nlmsg_data(nlh);
if (bpm->ifindex) {
NL_SET_ERR_MSG_MOD(extack, "Filtering by device index is not supported for mdb dump request");
return -EINVAL;
}
if (nlmsg_attrlen(nlh, sizeof(*bpm))) {
NL_SET_ERR_MSG(extack, "Invalid data after header in mdb dump request");
return -EINVAL;
}
return 0;
}
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;
if (cb->strict_check) {
int err = br_mdb_valid_dump_req(cb->nlh, cb->extack);
if (err < 0)
return err;
}
s_idx = cb->args[0];
rcu_read_lock();
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);
memset(bpm, 0, sizeof(*bpm));
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;
}
static int nlmsg_populate_mdb_fill(struct sk_buff *skb,
struct net_device *dev,
struct br_mdb_entry *entry, u32 pid,
u32 seq, int type, unsigned int flags)
{
struct nlmsghdr *nlh;
struct br_port_msg *bpm;
struct nlattr *nest, *nest2;
nlh = nlmsg_put(skb, pid, seq, type, sizeof(*bpm), 0);
if (!nlh)
return -EMSGSIZE;
bpm = nlmsg_data(nlh);
memset(bpm, 0, sizeof(*bpm));
bpm->family = AF_BRIDGE;
bpm->ifindex = dev->ifindex;
nest = nla_nest_start_noflag(skb, MDBA_MDB);
if (nest == NULL)
goto cancel;
nest2 = nla_nest_start_noflag(skb, MDBA_MDB_ENTRY);
if (nest2 == NULL)
goto end;
if (nla_put(skb, MDBA_MDB_ENTRY_INFO, sizeof(*entry), entry))
goto end;
nla_nest_end(skb, nest2);
nla_nest_end(skb, nest);
nlmsg_end(skb, nlh);
return 0;
end:
nla_nest_end(skb, nest);
cancel:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static inline size_t rtnl_mdb_nlmsg_size(void)
{
return NLMSG_ALIGN(sizeof(struct br_port_msg))
+ nla_total_size(sizeof(struct br_mdb_entry));
}
struct br_mdb_complete_info {
struct net_bridge_port *port;
struct br_ip ip;
};
static void br_mdb_complete(struct net_device *dev, int err, void *priv)
{
struct br_mdb_complete_info *data = priv;
struct net_bridge_port_group __rcu **pp;
struct net_bridge_port_group *p;
struct net_bridge_mdb_entry *mp;
struct net_bridge_port *port = data->port;
struct net_bridge *br = port->br;
if (err)
goto err;
spin_lock_bh(&br->multicast_lock);
mp = br_mdb_ip_get(br, &data->ip);
if (!mp)
goto out;
for (pp = &mp->ports; (p = mlock_dereference(*pp, br)) != NULL;
pp = &p->next) {
if (p->port != port)
continue;
p->flags |= MDB_PG_FLAGS_OFFLOAD;
}
out:
spin_unlock_bh(&br->multicast_lock);
err:
kfree(priv);
}
static void br_mdb_switchdev_host_port(struct net_device *dev,
struct net_device *lower_dev,
struct br_mdb_entry *entry, int type)
{
struct switchdev_obj_port_mdb mdb = {
.obj = {
.id = SWITCHDEV_OBJ_ID_HOST_MDB,
.flags = SWITCHDEV_F_DEFER,
},
.vid = entry->vid,
};
if (entry->addr.proto == htons(ETH_P_IP))
ip_eth_mc_map(entry->addr.u.ip4, mdb.addr);
#if IS_ENABLED(CONFIG_IPV6)
else
ipv6_eth_mc_map(&entry->addr.u.ip6, mdb.addr);
#endif
mdb.obj.orig_dev = dev;
switch (type) {
case RTM_NEWMDB:
switchdev_port_obj_add(lower_dev, &mdb.obj, NULL);
break;
case RTM_DELMDB:
switchdev_port_obj_del(lower_dev, &mdb.obj);
break;
}
}
static void br_mdb_switchdev_host(struct net_device *dev,
struct br_mdb_entry *entry, int type)
{
struct net_device *lower_dev;
struct list_head *iter;
netdev_for_each_lower_dev(dev, lower_dev, iter)
br_mdb_switchdev_host_port(dev, lower_dev, entry, type);
}
static void __br_mdb_notify(struct net_device *dev, struct net_bridge_port *p,
struct br_mdb_entry *entry, int type)
{
struct br_mdb_complete_info *complete_info;
struct switchdev_obj_port_mdb mdb = {
.obj = {
.id = SWITCHDEV_OBJ_ID_PORT_MDB,
.flags = SWITCHDEV_F_DEFER,
},
.vid = entry->vid,
};
struct net_device *port_dev;
struct net *net = dev_net(dev);
struct sk_buff *skb;
int err = -ENOBUFS;
port_dev = __dev_get_by_index(net, entry->ifindex);
if (entry->addr.proto == htons(ETH_P_IP))
ip_eth_mc_map(entry->addr.u.ip4, mdb.addr);
#if IS_ENABLED(CONFIG_IPV6)
else
ipv6_eth_mc_map(&entry->addr.u.ip6, mdb.addr);
#endif
mdb.obj.orig_dev = port_dev;
if (p && port_dev && type == RTM_NEWMDB) {
complete_info = kmalloc(sizeof(*complete_info), GFP_ATOMIC);
if (complete_info) {
complete_info->port = p;
__mdb_entry_to_br_ip(entry, &complete_info->ip);
mdb.obj.complete_priv = complete_info;
mdb.obj.complete = br_mdb_complete;
if (switchdev_port_obj_add(port_dev, &mdb.obj, NULL))
kfree(complete_info);
}
} else if (p && port_dev && type == RTM_DELMDB) {
switchdev_port_obj_del(port_dev, &mdb.obj);
}
if (!p)
br_mdb_switchdev_host(dev, entry, type);
skb = nlmsg_new(rtnl_mdb_nlmsg_size(), GFP_ATOMIC);
if (!skb)
goto errout;
err = nlmsg_populate_mdb_fill(skb, dev, entry, 0, 0, type, NTF_SELF);
if (err < 0) {
kfree_skb(skb);
goto errout;
}
rtnl_notify(skb, net, 0, RTNLGRP_MDB, NULL, GFP_ATOMIC);
return;
errout:
rtnl_set_sk_err(net, RTNLGRP_MDB, err);
}
void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
struct br_ip *group, int type, u8 flags)
{
struct br_mdb_entry entry;
memset(&entry, 0, sizeof(entry));
if (port)
entry.ifindex = port->dev->ifindex;
else
entry.ifindex = dev->ifindex;
entry.addr.proto = group->proto;
entry.addr.u.ip4 = group->u.ip4;
#if IS_ENABLED(CONFIG_IPV6)
entry.addr.u.ip6 = group->u.ip6;
#endif
entry.vid = group->vid;
__mdb_entry_fill_flags(&entry, flags);
__br_mdb_notify(dev, port, &entry, type);
}
static int nlmsg_populate_rtr_fill(struct sk_buff *skb,
struct net_device *dev,
int ifindex, u32 pid,
u32 seq, int type, unsigned int flags)
{
struct br_port_msg *bpm;
struct nlmsghdr *nlh;
struct nlattr *nest;
nlh = nlmsg_put(skb, pid, seq, type, sizeof(*bpm), NLM_F_MULTI);
if (!nlh)
return -EMSGSIZE;
bpm = nlmsg_data(nlh);
memset(bpm, 0, sizeof(*bpm));
bpm->family = AF_BRIDGE;
bpm->ifindex = dev->ifindex;
nest = nla_nest_start_noflag(skb, MDBA_ROUTER);
if (!nest)
goto cancel;
if (nla_put_u32(skb, MDBA_ROUTER_PORT, ifindex))
goto end;
nla_nest_end(skb, nest);
nlmsg_end(skb, nlh);
return 0;
end:
nla_nest_end(skb, nest);
cancel:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static inline size_t rtnl_rtr_nlmsg_size(void)
{
return NLMSG_ALIGN(sizeof(struct br_port_msg))
+ nla_total_size(sizeof(__u32));
}
void br_rtr_notify(struct net_device *dev, struct net_bridge_port *port,
int type)
{
struct net *net = dev_net(dev);
struct sk_buff *skb;
int err = -ENOBUFS;
int ifindex;
ifindex = port ? port->dev->ifindex : 0;
skb = nlmsg_new(rtnl_rtr_nlmsg_size(), GFP_ATOMIC);
if (!skb)
goto errout;
err = nlmsg_populate_rtr_fill(skb, dev, ifindex, 0, 0, type, NTF_SELF);
if (err < 0) {
kfree_skb(skb);
goto errout;
}
rtnl_notify(skb, net, 0, RTNLGRP_MDB, NULL, GFP_ATOMIC);
return;
errout:
rtnl_set_sk_err(net, RTNLGRP_MDB, err);
}
static bool is_valid_mdb_entry(struct br_mdb_entry *entry)
{
if (entry->ifindex == 0)
return false;
if (entry->addr.proto == htons(ETH_P_IP)) {
if (!ipv4_is_multicast(entry->addr.u.ip4))
return false;
if (ipv4_is_local_multicast(entry->addr.u.ip4))
return false;
#if IS_ENABLED(CONFIG_IPV6)
} else if (entry->addr.proto == htons(ETH_P_IPV6)) {
if (ipv6_addr_is_ll_all_nodes(&entry->addr.u.ip6))
return false;
#endif
} else
return false;
if (entry->state != MDB_PERMANENT && entry->state != MDB_TEMPORARY)
return false;
if (entry->vid >= VLAN_VID_MASK)
return false;
return true;
}
static int br_mdb_parse(struct sk_buff *skb, struct nlmsghdr *nlh,
struct net_device **pdev, struct br_mdb_entry **pentry)
{
struct net *net = sock_net(skb->sk);
struct br_mdb_entry *entry;
struct br_port_msg *bpm;
struct nlattr *tb[MDBA_SET_ENTRY_MAX+1];
struct net_device *dev;
int err;
err = nlmsg_parse_deprecated(nlh, sizeof(*bpm), tb,
MDBA_SET_ENTRY_MAX, NULL, NULL);
if (err < 0)
return err;
bpm = nlmsg_data(nlh);
if (bpm->ifindex == 0) {
pr_info("PF_BRIDGE: br_mdb_parse() with invalid ifindex\n");
return -EINVAL;
}
dev = __dev_get_by_index(net, bpm->ifindex);
if (dev == NULL) {
pr_info("PF_BRIDGE: br_mdb_parse() with unknown ifindex\n");
return -ENODEV;
}
if (!(dev->priv_flags & IFF_EBRIDGE)) {
pr_info("PF_BRIDGE: br_mdb_parse() with non-bridge\n");
return -EOPNOTSUPP;
}
*pdev = dev;
if (!tb[MDBA_SET_ENTRY] ||
nla_len(tb[MDBA_SET_ENTRY]) != sizeof(struct br_mdb_entry)) {
pr_info("PF_BRIDGE: br_mdb_parse() with invalid attr\n");
return -EINVAL;
}
entry = nla_data(tb[MDBA_SET_ENTRY]);
if (!is_valid_mdb_entry(entry)) {
pr_info("PF_BRIDGE: br_mdb_parse() with invalid entry\n");
return -EINVAL;
}
*pentry = entry;
return 0;
}
static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
struct br_ip *group, unsigned char state)
{
struct net_bridge_mdb_entry *mp;
struct net_bridge_port_group *p;
struct net_bridge_port_group __rcu **pp;
unsigned long now = jiffies;
int err;
mp = br_mdb_ip_get(br, group);
if (!mp) {
mp = br_multicast_new_group(br, group);
err = PTR_ERR_OR_ZERO(mp);
if (err)
return err;
}
for (pp = &mp->ports;
(p = mlock_dereference(*pp, br)) != NULL;
pp = &p->next) {
if (p->port == port)
return -EEXIST;
if ((unsigned long)p->port < (unsigned long)port)
break;
}
p = br_multicast_new_port_group(port, group, *pp, state, NULL);
if (unlikely(!p))
return -ENOMEM;
rcu_assign_pointer(*pp, p);
if (state == MDB_TEMPORARY)
mod_timer(&p->timer, now + br->multicast_membership_interval);
return 0;
}
static int __br_mdb_add(struct net *net, struct net_bridge *br,
struct br_mdb_entry *entry)
{
struct br_ip ip;
struct net_device *dev;
struct net_bridge_port *p;
int ret;
if (!netif_running(br->dev) || !br_opt_get(br, BROPT_MULTICAST_ENABLED))
return -EINVAL;
dev = __dev_get_by_index(net, entry->ifindex);
if (!dev)
return -ENODEV;
p = br_port_get_rtnl(dev);
if (!p || p->br != br || p->state == BR_STATE_DISABLED)
return -EINVAL;
__mdb_entry_to_br_ip(entry, &ip);
spin_lock_bh(&br->multicast_lock);
ret = br_mdb_add_group(br, p, &ip, entry->state);
spin_unlock_bh(&br->multicast_lock);
return ret;
}
static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct net_bridge_vlan_group *vg;
struct net_device *dev, *pdev;
struct br_mdb_entry *entry;
struct net_bridge_port *p;
struct net_bridge_vlan *v;
struct net_bridge *br;
int err;
err = br_mdb_parse(skb, nlh, &dev, &entry);
if (err < 0)
return err;
br = netdev_priv(dev);
/* If vlan filtering is enabled and VLAN is not specified
* install mdb entry on all vlans configured on the port.
*/
pdev = __dev_get_by_index(net, entry->ifindex);
if (!pdev)
return -ENODEV;
p = br_port_get_rtnl(pdev);
if (!p || p->br != br || p->state == BR_STATE_DISABLED)
return -EINVAL;
vg = nbp_vlan_group(p);
if (br_vlan_enabled(br->dev) && vg && entry->vid == 0) {
list_for_each_entry(v, &vg->vlan_list, vlist) {
entry->vid = v->vid;
err = __br_mdb_add(net, br, entry);
if (err)
break;
__br_mdb_notify(dev, p, entry, RTM_NEWMDB);
}
} else {
err = __br_mdb_add(net, br, entry);
if (!err)
__br_mdb_notify(dev, p, entry, RTM_NEWMDB);
}
return err;
}
static int __br_mdb_del(struct net_bridge *br, struct br_mdb_entry *entry)
{
struct net_bridge_mdb_entry *mp;
struct net_bridge_port_group *p;
struct net_bridge_port_group __rcu **pp;
struct br_ip ip;
int err = -EINVAL;
if (!netif_running(br->dev) || !br_opt_get(br, BROPT_MULTICAST_ENABLED))
return -EINVAL;
__mdb_entry_to_br_ip(entry, &ip);
spin_lock_bh(&br->multicast_lock);
mp = br_mdb_ip_get(br, &ip);
if (!mp)
goto unlock;
for (pp = &mp->ports;
(p = mlock_dereference(*pp, br)) != NULL;
pp = &p->next) {
if (!p->port || p->port->dev->ifindex != entry->ifindex)
continue;
if (p->port->state == BR_STATE_DISABLED)
goto unlock;
__mdb_entry_fill_flags(entry, p->flags);
rcu_assign_pointer(*pp, p->next);
hlist_del_init(&p->mglist);
del_timer(&p->timer);
kfree_rcu(p, rcu);
err = 0;
if (!mp->ports && !mp->host_joined &&
netif_running(br->dev))
mod_timer(&mp->timer, jiffies);
break;
}
unlock:
spin_unlock_bh(&br->multicast_lock);
return err;
}
static int br_mdb_del(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(skb->sk);
struct net_bridge_vlan_group *vg;
struct net_device *dev, *pdev;
struct br_mdb_entry *entry;
struct net_bridge_port *p;
struct net_bridge_vlan *v;
struct net_bridge *br;
int err;
err = br_mdb_parse(skb, nlh, &dev, &entry);
if (err < 0)
return err;
br = netdev_priv(dev);
/* If vlan filtering is enabled and VLAN is not specified
* delete mdb entry on all vlans configured on the port.
*/
pdev = __dev_get_by_index(net, entry->ifindex);
if (!pdev)
return -ENODEV;
p = br_port_get_rtnl(pdev);
if (!p || p->br != br || p->state == BR_STATE_DISABLED)
return -EINVAL;
vg = nbp_vlan_group(p);
if (br_vlan_enabled(br->dev) && vg && entry->vid == 0) {
list_for_each_entry(v, &vg->vlan_list, vlist) {
entry->vid = v->vid;
err = __br_mdb_del(br, entry);
if (!err)
__br_mdb_notify(dev, p, entry, RTM_DELMDB);
}
} else {
err = __br_mdb_del(br, entry);
if (!err)
__br_mdb_notify(dev, p, entry, RTM_DELMDB);
}
return err;
}
void br_mdb_init(void)
{
rtnl_register_module(THIS_MODULE, PF_BRIDGE, RTM_GETMDB, NULL, br_mdb_dump, 0);
rtnl_register_module(THIS_MODULE, PF_BRIDGE, RTM_NEWMDB, br_mdb_add, NULL, 0);
rtnl_register_module(THIS_MODULE, PF_BRIDGE, RTM_DELMDB, br_mdb_del, NULL, 0);
}
void br_mdb_uninit(void)
{
rtnl_unregister(PF_BRIDGE, RTM_GETMDB);
rtnl_unregister(PF_BRIDGE, RTM_NEWMDB);
rtnl_unregister(PF_BRIDGE, RTM_DELMDB);
}