bridge: mdb: Marking port-group as offloaded
There is a race-condition when updating the mdb offload flag without using
the mulicast_lock. This reverts commit 9e8430f8d60d98 ("bridge: mdb:
Passing the port-group pointer to br_mdb module").
This patch marks offloaded MDB entry as "offload" by changing the port-
group flags and marks it as MDB_PG_FLAGS_OFFLOAD.
When switchdev PORT_MDB succeeded and adds a multicast group, a completion
callback is been invoked "br_mdb_complete". The completion function
locks the multicast_lock and finds the right net_bridge_port_group and
marks it as offloaded.
Fixes: 9e8430f8d60d98 ("bridge: mdb: Passing the port-group pointer to br_mdb module")
Reported-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Elad Raz <eladr@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.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 b258120..7dbc80d 100644
--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c
@@ -256,9 +256,45 @@
+ nla_total_size(sizeof(struct br_mdb_entry));
}
-static void __br_mdb_notify(struct net_device *dev, struct br_mdb_entry *entry,
- int type, struct net_bridge_port_group *pg)
+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_htable *mdb;
+ 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);
+ mdb = mlock_dereference(br->mdb, br);
+ mp = br_mdb_ip_get(mdb, &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_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,
@@ -281,9 +317,14 @@
mdb.obj.orig_dev = port_dev;
if (port_dev && type == RTM_NEWMDB) {
- err = switchdev_port_obj_add(port_dev, &mdb.obj);
- if (!err && pg)
- pg->flags |= MDB_PG_FLAGS_OFFLOAD;
+ 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;
+ switchdev_port_obj_add(port_dev, &mdb.obj);
+ }
} else if (port_dev && type == RTM_DELMDB) {
switchdev_port_obj_del(port_dev, &mdb.obj);
}
@@ -304,21 +345,21 @@
rtnl_set_sk_err(net, RTNLGRP_MDB, err);
}
-void br_mdb_notify(struct net_device *dev, struct net_bridge_port_group *pg,
- int type)
+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));
- entry.ifindex = pg->port->dev->ifindex;
- entry.addr.proto = pg->addr.proto;
- entry.addr.u.ip4 = pg->addr.u.ip4;
+ entry.ifindex = port->dev->ifindex;
+ entry.addr.proto = group->proto;
+ entry.addr.u.ip4 = group->u.ip4;
#if IS_ENABLED(CONFIG_IPV6)
- entry.addr.u.ip6 = pg->addr.u.ip6;
+ entry.addr.u.ip6 = group->u.ip6;
#endif
- entry.vid = pg->addr.vid;
- __mdb_entry_fill_flags(&entry, pg->flags);
- __br_mdb_notify(dev, &entry, type, pg);
+ 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,
@@ -463,8 +504,7 @@
}
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_port_group **pg)
+ struct br_ip *group, unsigned char state)
{
struct net_bridge_mdb_entry *mp;
struct net_bridge_port_group *p;
@@ -495,7 +535,6 @@
if (unlikely(!p))
return -ENOMEM;
rcu_assign_pointer(*pp, p);
- *pg = p;
if (state == MDB_TEMPORARY)
mod_timer(&p->timer, now + br->multicast_membership_interval);
@@ -503,8 +542,7 @@
}
static int __br_mdb_add(struct net *net, struct net_bridge *br,
- struct br_mdb_entry *entry,
- struct net_bridge_port_group **pg)
+ struct br_mdb_entry *entry)
{
struct br_ip ip;
struct net_device *dev;
@@ -525,7 +563,7 @@
__mdb_entry_to_br_ip(entry, &ip);
spin_lock_bh(&br->multicast_lock);
- ret = br_mdb_add_group(br, p, &ip, entry->state, pg);
+ ret = br_mdb_add_group(br, p, &ip, entry->state);
spin_unlock_bh(&br->multicast_lock);
return ret;
}
@@ -533,7 +571,6 @@
static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh)
{
struct net *net = sock_net(skb->sk);
- struct net_bridge_port_group *pg;
struct net_bridge_vlan_group *vg;
struct net_device *dev, *pdev;
struct br_mdb_entry *entry;
@@ -563,15 +600,15 @@
if (br_vlan_enabled(br) && vg && entry->vid == 0) {
list_for_each_entry(v, &vg->vlan_list, vlist) {
entry->vid = v->vid;
- err = __br_mdb_add(net, br, entry, &pg);
+ err = __br_mdb_add(net, br, entry);
if (err)
break;
- __br_mdb_notify(dev, entry, RTM_NEWMDB, pg);
+ __br_mdb_notify(dev, p, entry, RTM_NEWMDB);
}
} else {
- err = __br_mdb_add(net, br, entry, &pg);
+ err = __br_mdb_add(net, br, entry);
if (!err)
- __br_mdb_notify(dev, entry, RTM_NEWMDB, pg);
+ __br_mdb_notify(dev, p, entry, RTM_NEWMDB);
}
return err;
@@ -659,12 +696,12 @@
entry->vid = v->vid;
err = __br_mdb_del(br, entry);
if (!err)
- __br_mdb_notify(dev, entry, RTM_DELMDB, NULL);
+ __br_mdb_notify(dev, p, entry, RTM_DELMDB);
}
} else {
err = __br_mdb_del(br, entry);
if (!err)
- __br_mdb_notify(dev, entry, RTM_DELMDB, NULL);
+ __br_mdb_notify(dev, p, entry, RTM_DELMDB);
}
return err;