bridge: add support of adding and deleting mdb entries
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>
diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
index a8cfbf5..6f0a2ee 100644
--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c
@@ -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)
@@ -235,7 +236,246 @@
__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);
}