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bridge: add support of adding and deleting mdb entries
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This patch implents adding/deleting mdb entries via netlink.
Currently all entries are temp, we probably need a flag to distinguish
permanent entries too.

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>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Cong Wang authored and David S. Miller committed Dec 12, 2012
1 parent 37a393b commit cfd5675
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Showing 4 changed files with 297 additions and 29 deletions.
8 changes: 8 additions & 0 deletions include/uapi/linux/if_bridge.h
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Original file line number Diff line number Diff line change
Expand Up @@ -157,6 +157,7 @@ enum {
#define MDBA_ROUTER_MAX (__MDBA_ROUTER_MAX - 1)

struct br_port_msg {
__u8 family;
__u32 ifindex;
};

Expand All @@ -171,4 +172,11 @@ struct br_mdb_entry {
} addr;
};

enum {
MDBA_SET_ENTRY_UNSPEC,
MDBA_SET_ENTRY,
__MDBA_SET_ENTRY_MAX,
};
#define MDBA_SET_ENTRY_MAX (__MDBA_SET_ENTRY_MAX - 1)

#endif /* _UAPI_LINUX_IF_BRIDGE_H */
240 changes: 240 additions & 0 deletions net/bridge/br_mdb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@
#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>
#if IS_ENABLED(CONFIG_IPV6)
Expand Down Expand Up @@ -235,7 +236,246 @@ void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
__br_mdb_notify(dev, &entry, type);
}

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_is_transient_multicast(&entry->addr.u.ip6))
return false;
#endif
} else
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;

if (!capable(CAP_NET_ADMIN))
return -EPERM;

err = nlmsg_parse(nlh, sizeof(*bpm), tb, MDBA_SET_ENTRY, 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)
{
struct net_bridge_mdb_entry *mp;
struct net_bridge_port_group *p;
struct net_bridge_port_group __rcu **pp;
struct net_bridge_mdb_htable *mdb;
int err;

mdb = mlock_dereference(br->mdb, br);
mp = br_mdb_ip_get(mdb, group);
if (!mp) {
mp = br_multicast_new_group(br, port, group);
err = PTR_ERR(mp);
if (IS_ERR(mp))
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);
if (unlikely(!p))
return -ENOMEM;
rcu_assign_pointer(*pp, p);

br_mdb_notify(br->dev, port, group, RTM_NEWMDB);
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->multicast_disabled)
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;

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

spin_lock_bh(&br->multicast_lock);
ret = br_mdb_add_group(br, p, &ip);
spin_unlock_bh(&br->multicast_lock);
return ret;
}

static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
struct net *net = sock_net(skb->sk);
struct br_mdb_entry *entry;
struct net_device *dev;
struct net_bridge *br;
int err;

err = br_mdb_parse(skb, nlh, &dev, &entry);
if (err < 0)
return err;

br = netdev_priv(dev);

err = __br_mdb_add(net, br, entry);
if (!err)
__br_mdb_notify(dev, entry, RTM_NEWMDB);
return err;
}

static int __br_mdb_del(struct net_bridge *br, struct br_mdb_entry *entry)
{
struct net_bridge_mdb_htable *mdb;
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->multicast_disabled)
return -EINVAL;

if (timer_pending(&br->multicast_querier_timer))
return -EBUSY;

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

spin_lock_bh(&br->multicast_lock);
mdb = mlock_dereference(br->mdb, br);

mp = br_mdb_ip_get(mdb, &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;

rcu_assign_pointer(*pp, p->next);
hlist_del_init(&p->mglist);
del_timer(&p->timer);
call_rcu_bh(&p->rcu, br_multicast_free_pg);
err = 0;

if (!mp->ports && !mp->mglist &&
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, void *arg)
{
struct net_device *dev;
struct br_mdb_entry *entry;
struct net_bridge *br;
int err;

err = br_mdb_parse(skb, nlh, &dev, &entry);
if (err < 0)
return err;

br = netdev_priv(dev);

err = __br_mdb_del(br, entry);
if (!err)
__br_mdb_notify(dev, entry, RTM_DELMDB);
return err;
}

void br_mdb_init(void)
{
rtnl_register(PF_BRIDGE, RTM_GETMDB, NULL, br_mdb_dump, NULL);
rtnl_register(PF_BRIDGE, RTM_NEWMDB, br_mdb_add, NULL, NULL);
rtnl_register(PF_BRIDGE, RTM_DELMDB, br_mdb_del, NULL, NULL);
}
55 changes: 26 additions & 29 deletions net/bridge/br_multicast.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -27,27 +27,14 @@
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
#include <net/mld.h>
#include <net/addrconf.h>
#include <net/ip6_checksum.h>
#endif

#include "br_private.h"

#define mlock_dereference(X, br) \
rcu_dereference_protected(X, lockdep_is_held(&br->multicast_lock))

static void br_multicast_start_querier(struct net_bridge *br);
unsigned int br_mdb_rehash_seq;

#if IS_ENABLED(CONFIG_IPV6)
static inline int ipv6_is_transient_multicast(const struct in6_addr *addr)
{
if (ipv6_addr_is_multicast(addr) && IPV6_ADDR_MC_FLAG_TRANSIENT(addr))
return 1;
return 0;
}
#endif

static inline int br_ip_equal(const struct br_ip *a, const struct br_ip *b)
{
if (a->proto != b->proto)
Expand Down Expand Up @@ -104,8 +91,8 @@ static struct net_bridge_mdb_entry *__br_mdb_ip_get(
return NULL;
}

static struct net_bridge_mdb_entry *br_mdb_ip_get(
struct net_bridge_mdb_htable *mdb, struct br_ip *dst)
struct net_bridge_mdb_entry *br_mdb_ip_get(struct net_bridge_mdb_htable *mdb,
struct br_ip *dst)
{
if (!mdb)
return NULL;
Expand Down Expand Up @@ -208,7 +195,7 @@ static int br_mdb_copy(struct net_bridge_mdb_htable *new,
return maxlen > elasticity ? -EINVAL : 0;
}

static void br_multicast_free_pg(struct rcu_head *head)
void br_multicast_free_pg(struct rcu_head *head)
{
struct net_bridge_port_group *p =
container_of(head, struct net_bridge_port_group, rcu);
Expand Down Expand Up @@ -584,9 +571,8 @@ static struct net_bridge_mdb_entry *br_multicast_get_group(
return mp;
}

static struct net_bridge_mdb_entry *br_multicast_new_group(
struct net_bridge *br, struct net_bridge_port *port,
struct br_ip *group)
struct net_bridge_mdb_entry *br_multicast_new_group(struct net_bridge *br,
struct net_bridge_port *port, struct br_ip *group)
{
struct net_bridge_mdb_htable *mdb;
struct net_bridge_mdb_entry *mp;
Expand Down Expand Up @@ -633,6 +619,26 @@ static struct net_bridge_mdb_entry *br_multicast_new_group(
return mp;
}

struct net_bridge_port_group *br_multicast_new_port_group(
struct net_bridge_port *port,
struct br_ip *group,
struct net_bridge_port_group *next)
{
struct net_bridge_port_group *p;

p = kzalloc(sizeof(*p), GFP_ATOMIC);
if (unlikely(!p))
return NULL;

p->addr = *group;
p->port = port;
p->next = next;
hlist_add_head(&p->mglist, &port->mglist);
setup_timer(&p->timer, br_multicast_port_group_expired,
(unsigned long)p);
return p;
}

static int br_multicast_add_group(struct net_bridge *br,
struct net_bridge_port *port,
struct br_ip *group)
Expand Down Expand Up @@ -668,18 +674,9 @@ static int br_multicast_add_group(struct net_bridge *br,
break;
}

p = kzalloc(sizeof(*p), GFP_ATOMIC);
err = -ENOMEM;
p = br_multicast_new_port_group(port, group, *pp);
if (unlikely(!p))
goto err;

p->addr = *group;
p->port = port;
p->next = *pp;
hlist_add_head(&p->mglist, &port->mglist);
setup_timer(&p->timer, br_multicast_port_group_expired,
(unsigned long)p);

rcu_assign_pointer(*pp, p);
br_mdb_notify(br->dev, port, group, RTM_NEWMDB);

Expand Down
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