diff options
| -rw-r--r-- | net/bridge/br_fdb.c | 35 | ||||
| -rw-r--r-- | net/bridge/br_private.h | 4 |
2 files changed, 37 insertions, 2 deletions
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c index 7738e1b56452..c622de5eccd0 100644 --- a/net/bridge/br_fdb.c +++ b/net/bridge/br_fdb.c @@ -329,11 +329,18 @@ static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f, hlist_del_init_rcu(&f->fdb_node); rhashtable_remove_fast(&br->fdb_hash_tbl, &f->rhnode, br_fdb_rht_params); + if (test_and_clear_bit(BR_FDB_DYNAMIC_LEARNED, &f->flags)) + atomic_dec(&br->fdb_n_learned); fdb_notify(br, f, RTM_DELNEIGH, swdev_notify); call_rcu(&f->rcu, fdb_rcu_free); } -/* Delete a local entry if no other port had the same address. */ +/* Delete a local entry if no other port had the same address. + * + * This function should only be called on entries with BR_FDB_LOCAL set, + * so even with BR_FDB_ADDED_BY_USER cleared we never need to increase + * the accounting for dynamically learned entries again. + */ static void fdb_delete_local(struct net_bridge *br, const struct net_bridge_port *p, struct net_bridge_fdb_entry *f) @@ -388,9 +395,20 @@ static struct net_bridge_fdb_entry *fdb_create(struct net_bridge *br, __u16 vid, unsigned long flags) { + bool learned = !test_bit(BR_FDB_ADDED_BY_USER, &flags) && + !test_bit(BR_FDB_LOCAL, &flags); + u32 max_learned = READ_ONCE(br->fdb_max_learned); struct net_bridge_fdb_entry *fdb; int err; + if (likely(learned)) { + int n_learned = atomic_read(&br->fdb_n_learned); + + if (unlikely(max_learned && n_learned >= max_learned)) + return NULL; + __set_bit(BR_FDB_DYNAMIC_LEARNED, &flags); + } + fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC); if (!fdb) return NULL; @@ -407,6 +425,9 @@ static struct net_bridge_fdb_entry *fdb_create(struct net_bridge *br, return NULL; } + if (likely(learned)) + atomic_inc(&br->fdb_n_learned); + hlist_add_head_rcu(&fdb->fdb_node, &br->fdb_list); return fdb; @@ -912,8 +933,12 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source, clear_bit(BR_FDB_LOCKED, &fdb->flags); } - if (unlikely(test_bit(BR_FDB_ADDED_BY_USER, &flags))) + if (unlikely(test_bit(BR_FDB_ADDED_BY_USER, &flags))) { set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags); + if (test_and_clear_bit(BR_FDB_DYNAMIC_LEARNED, + &fdb->flags)) + atomic_dec(&br->fdb_n_learned); + } if (unlikely(fdb_modified)) { trace_br_fdb_update(br, source, addr, vid, flags); fdb_notify(br, fdb, RTM_NEWNEIGH, true); @@ -1091,6 +1116,8 @@ static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source, } set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags); + if (test_and_clear_bit(BR_FDB_DYNAMIC_LEARNED, &fdb->flags)) + atomic_dec(&br->fdb_n_learned); } if (fdb_to_nud(br, fdb) != state) { @@ -1465,6 +1492,10 @@ int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p, if (!p) set_bit(BR_FDB_LOCAL, &fdb->flags); + if ((swdev_notify || !p) && + test_and_clear_bit(BR_FDB_DYNAMIC_LEARNED, &fdb->flags)) + atomic_dec(&br->fdb_n_learned); + if (modified) fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify); } diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index cbbe35278459..27a7a06660f3 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -274,6 +274,7 @@ enum { BR_FDB_NOTIFY, BR_FDB_NOTIFY_INACTIVE, BR_FDB_LOCKED, + BR_FDB_DYNAMIC_LEARNED, }; struct net_bridge_fdb_key { @@ -555,6 +556,9 @@ struct net_bridge { struct kobject *ifobj; u32 auto_cnt; + atomic_t fdb_n_learned; + u32 fdb_max_learned; + #ifdef CONFIG_NET_SWITCHDEV /* Counter used to make sure that hardware domains get unique * identifiers in case a bridge spans multiple switchdev instances. |