Commit 45ebcce5 authored by Elad Raz's avatar Elad Raz Committed by David S. Miller
Browse files

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 9e8430f8 ("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: 9e8430f8 ("bridge: mdb: Passing the port-group pointer to br_mdb module")
Reported-by: default avatarNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: default avatarElad Raz <eladr@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Reviewed-by: default avatarIdo Schimmel <idosch@mellanox.com>
Acked-by: default avatarNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6dd684c0

net/bridge/br_mdb.c

+64 −27
Original line number Diff line number Diff line
@@ -256,9 +256,45 @@ static inline size_t rtnl_mdb_nlmsg_size(void) 
		+ 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 @@ static void __br_mdb_notify(struct net_device *dev, struct br_mdb_entry *entry, 


	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 @@ errout: 
	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_parse(struct sk_buff *skb, struct nlmsghdr *nlh, 
}



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 @@ static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port, 
	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_group(struct net_bridge *br, struct net_bridge_port *port, 
}



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 @@ static int __br_mdb_add(struct net *net, struct net_bridge *br, 
	__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 net *net, struct net_bridge *br, 
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 @@ static int br_mdb_add(struct sk_buff *skb, struct nlmsghdr *nlh) 
	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 @@ static int br_mdb_del(struct sk_buff *skb, struct nlmsghdr *nlh) 
			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;

net/bridge/br_multicast.c

+5 −3
Original line number Diff line number Diff line
@@ -283,7 +283,8 @@ static void br_multicast_del_pg(struct net_bridge *br, 
		rcu_assign_pointer(*pp, p->next);

		hlist_del_init(&p->mglist);

		del_timer(&p->timer);

		br_mdb_notify(br->dev, p, RTM_DELMDB);

		br_mdb_notify(br->dev, p->port, &pg->addr, RTM_DELMDB,

			      p->flags);

		call_rcu_bh(&p->rcu, br_multicast_free_pg);



		if (!mp->ports && !mp->mglist &&
@@ -705,7 +706,7 @@ static int br_multicast_add_group(struct net_bridge *br, 
	if (unlikely(!p))

		goto err;

	rcu_assign_pointer(*pp, p);

	br_mdb_notify(br->dev, p, RTM_NEWMDB);

	br_mdb_notify(br->dev, port, group, RTM_NEWMDB, 0);



found:

	mod_timer(&p->timer, now + br->multicast_membership_interval);
@@ -1461,7 +1462,8 @@ br_multicast_leave_group(struct net_bridge *br, 
			hlist_del_init(&p->mglist);

			del_timer(&p->timer);

			call_rcu_bh(&p->rcu, br_multicast_free_pg);

			br_mdb_notify(br->dev, p, RTM_DELMDB);

			br_mdb_notify(br->dev, port, group, RTM_DELMDB,

				      p->flags);



			if (!mp->ports && !mp->mglist &&

			    netif_running(br->dev))

net/bridge/br_private.h

+2 −2
Original line number Diff line number Diff line
@@ -560,8 +560,8 @@ br_multicast_new_port_group(struct net_bridge_port *port, struct br_ip *group, 
			    unsigned char flags);

void br_mdb_init(void);

void br_mdb_uninit(void);

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);

void br_rtr_notify(struct net_device *dev, struct net_bridge_port *port,

		   int type);

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