From 45ebcce56823d14d196dbdecd26783b3d5f464a6 Mon Sep 17 00:00:00 2001 From: Elad Raz Date: Thu, 21 Apr 2016 12:52:45 +0200 Subject: 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 Signed-off-by: Elad Raz Signed-off-by: Jiri Pirko Reviewed-by: Ido Schimmel Acked-by: Nikolay Aleksandrov Signed-off-by: David S. Miller 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 @@ 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; diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index a4c15df..191ea66 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -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)) diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 1b5d145..d9da857 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -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); -- cgit v0.10.2