Signed-off-by: Marek Lindner mareklindner@neomailbox.ch --- v3: prevent inconsistencies when adding new neighbors v2: last_seen added & checkpatch cleaner

net/batman-adv/hard-interface.c | 3 + net/batman-adv/originator.c | 156 ++++++++++++++++++++++++++++++++++++++++ net/batman-adv/originator.h | 7 ++ net/batman-adv/types.h | 22 ++++++ 4 files changed, 188 insertions(+)

diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index f4a15d2..608ea4a 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -596,9 +596,12 @@ batadv_hardif_add_interface(struct net_device *net_dev) goto free_sysfs;

INIT_LIST_HEAD(&hard_iface->list); + INIT_HLIST_HEAD(&hard_iface->neigh_list); INIT_WORK(&hard_iface->cleanup_work, batadv_hardif_remove_interface_finish);

+ spin_lock_init(&hard_iface->neigh_list_lock); + hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT; if (batadv_is_wifi_netdev(net_dev)) hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS; diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 7b03fa9..4029bbe 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -202,6 +202,46 @@ void batadv_neigh_ifinfo_free_ref(struct batadv_neigh_ifinfo *neigh_ifinfo) }

/** + * batadv_hardif_neigh_free_rcu - free the hardif neigh_node + * @rcu: rcu pointer of the neigh_node + */ +static void batadv_hardif_neigh_free_rcu(struct rcu_head *rcu) +{ + struct batadv_hardif_neigh_node *hardif_neigh; + + hardif_neigh = container_of(rcu, struct batadv_hardif_neigh_node, rcu); + + spin_lock_bh(&hardif_neigh->if_incoming->neigh_list_lock); + hlist_del_init_rcu(&hardif_neigh->list); + spin_unlock_bh(&hardif_neigh->if_incoming->neigh_list_lock); + + batadv_hardif_free_ref_now(hardif_neigh->if_incoming); + kfree(hardif_neigh); +} + +/** + * batadv_hardif_neigh_free_now - decrement the hardif neighbors refcounter + * and possibly free it (without rcu callback) + * @hardif_neigh: hardif neigh neighbor to free + */ +void batadv_hardif_neigh_free_now(struct batadv_hardif_neigh_node *hardif_neigh) +{ + if (atomic_dec_and_test(&hardif_neigh->refcount)) + batadv_hardif_neigh_free_rcu(&hardif_neigh->rcu); +} + +/** + * batadv_hardif_neigh_free_ref - decrement the hardif neighbors refcounter + * and possibly free it + * @hardif_neigh: hardif neigh neighbor to free + */ +void batadv_hardif_neigh_free_ref(struct batadv_hardif_neigh_node *hardif_neigh) +{ + if (atomic_dec_and_test(&hardif_neigh->refcount)) + call_rcu(&hardif_neigh->rcu, batadv_hardif_neigh_free_rcu); +} + +/** * batadv_neigh_node_free_rcu - free the neigh_node * @rcu: rcu pointer of the neigh_node */ @@ -209,6 +249,7 @@ static void batadv_neigh_node_free_rcu(struct rcu_head *rcu) { struct hlist_node *node_tmp; struct batadv_neigh_node *neigh_node; + struct batadv_hardif_neigh_node *hardif_neigh; struct batadv_neigh_ifinfo *neigh_ifinfo; struct batadv_algo_ops *bao;

@@ -220,6 +261,14 @@ static void batadv_neigh_node_free_rcu(struct rcu_head *rcu) batadv_neigh_ifinfo_free_ref_now(neigh_ifinfo); }

+ hardif_neigh = batadv_hardif_neigh_get(neigh_node->if_incoming, + neigh_node->addr); + if (hardif_neigh) { + /* batadv_hardif_neigh_get() increases refcount too */ + batadv_hardif_neigh_free_now(hardif_neigh); + batadv_hardif_neigh_free_now(hardif_neigh); + } + if (bao->bat_neigh_free) bao->bat_neigh_free(neigh_node);

@@ -443,6 +492,102 @@ out: }

/** + * batadv_hardif_neigh_create - create a hardif neighbour node + * @hard_iface: the interface this neighbour is connected to + * @neigh_addr: the interface address of the neighbour to retrieve + * + * Returns the hardif neighbour node if found or created or NULL otherwise. + */ +static struct batadv_hardif_neigh_node * +batadv_hardif_neigh_create(struct batadv_hard_iface *hard_iface, + const u8 *neigh_addr) +{ + struct batadv_hardif_neigh_node *hardif_neigh = NULL; + + spin_lock_bh(&hard_iface->neigh_list_lock); + + /* check if neighbor hasn't been added in the meantime */ + hardif_neigh = batadv_hardif_neigh_get(hard_iface, neigh_addr); + if (hardif_neigh) + goto out; + + if (!atomic_inc_not_zero(&hard_iface->refcount)) + goto out; + + hardif_neigh = kzalloc(sizeof(*hardif_neigh), GFP_ATOMIC); + if (!hardif_neigh) { + batadv_hardif_free_ref(hard_iface); + goto out; + } + + INIT_HLIST_NODE(&hardif_neigh->list); + ether_addr_copy(hardif_neigh->addr, neigh_addr); + hardif_neigh->if_incoming = hard_iface; + hardif_neigh->last_seen = jiffies; + + atomic_set(&hardif_neigh->refcount, 1); + + hlist_add_head(&hardif_neigh->list, &hard_iface->neigh_list); + +out: + spin_unlock_bh(&hard_iface->neigh_list_lock); + return hardif_neigh; +} + +/** + * batadv_hardif_neigh_get_or_create - retrieve or create a hardif neighbour + * node + * @hard_iface: the interface this neighbour is connected to + * @neigh_addr: the interface address of the neighbour to retrieve + * + * Returns the hardif neighbour node if found or created or NULL otherwise. + */ +static struct batadv_hardif_neigh_node * +batadv_hardif_neigh_get_or_create(struct batadv_hard_iface *hard_iface, + const u8 *neigh_addr) +{ + struct batadv_hardif_neigh_node *hardif_neigh = NULL; + + /* first check without locking to avoid the overhead */ + hardif_neigh = batadv_hardif_neigh_get(hard_iface, neigh_addr); + if (hardif_neigh) + return hardif_neigh; + + return batadv_hardif_neigh_create(hard_iface, neigh_addr); +} + +/** + * batadv_hardif_neigh_get - retrieve a hardif neighbour from the list + * @hard_iface: the interface where this neighbour is connected to + * @neigh_addr: the address of the neighbour + * + * Looks for and possibly returns a neighbour belonging to this hard interface. + * Returns NULL if the neighbour is not found. + */ +struct batadv_hardif_neigh_node * +batadv_hardif_neigh_get(const struct batadv_hard_iface *hard_iface, + const u8 *neigh_addr) +{ + struct batadv_hardif_neigh_node *tmp_hardif_neigh, *hardif_neigh = NULL; + + rcu_read_lock(); + hlist_for_each_entry_rcu(tmp_hardif_neigh, + &hard_iface->neigh_list, list) { + if (!batadv_compare_eth(tmp_hardif_neigh->addr, neigh_addr)) + continue; + + if (!atomic_inc_not_zero(&tmp_hardif_neigh->refcount)) + continue; + + hardif_neigh = tmp_hardif_neigh; + break; + } + rcu_read_unlock(); + + return hardif_neigh; +} + +/** * batadv_neigh_node_new - create and init a new neigh_node object * @orig_node: originator object representing the neighbour * @hard_iface: the interface where the neighbour is connected to @@ -457,11 +602,17 @@ batadv_neigh_node_new(struct batadv_orig_node *orig_node, const u8 *neigh_addr) { struct batadv_neigh_node *neigh_node; + struct batadv_hardif_neigh_node *hardif_neigh = NULL;

neigh_node = batadv_neigh_node_get(orig_node, hard_iface, neigh_addr); if (neigh_node) goto out;

+ hardif_neigh = batadv_hardif_neigh_get_or_create(hard_iface, + neigh_addr); + if (!hardif_neigh) + goto out; + neigh_node = kzalloc(sizeof(*neigh_node), GFP_ATOMIC); if (!neigh_node) goto out; @@ -488,11 +639,16 @@ batadv_neigh_node_new(struct batadv_orig_node *orig_node, hlist_add_head_rcu(&neigh_node->list, &orig_node->neigh_list); spin_unlock_bh(&orig_node->neigh_list_lock);

+ /* increment unique neighbor refcount */ + atomic_inc(&hardif_neigh->refcount); + batadv_dbg(BATADV_DBG_BATMAN, orig_node->bat_priv, "Creating new neighbor %pM for orig_node %pM on interface %s\n", neigh_addr, orig_node->orig, hard_iface->net_dev->name);

out: + if (hardif_neigh) + batadv_hardif_neigh_free_ref(hardif_neigh); return neigh_node; }

diff --git a/net/batman-adv/originator.h b/net/batman-adv/originator.h index fde3438..458ce81 100644 --- a/net/batman-adv/originator.h +++ b/net/batman-adv/originator.h @@ -41,6 +41,13 @@ void batadv_orig_node_free_ref(struct batadv_orig_node *orig_node); void batadv_orig_node_free_ref_now(struct batadv_orig_node *orig_node); struct batadv_orig_node *batadv_orig_node_new(struct batadv_priv *bat_priv, const u8 *addr); +struct batadv_hardif_neigh_node * +batadv_hardif_neigh_get(const struct batadv_hard_iface *hard_iface, + const u8 *neigh_addr); +void +batadv_hardif_neigh_free_ref(struct batadv_hardif_neigh_node *hardif_neigh); +void +batadv_hardif_neigh_free_now(struct batadv_hardif_neigh_node *hardif_neigh); struct batadv_neigh_node * batadv_neigh_node_get(const struct batadv_orig_node *orig_node, const struct batadv_hard_iface *hard_iface, diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index d260efd..71c7d9f 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -100,6 +100,8 @@ struct batadv_hard_iface_bat_iv { * @bat_iv: BATMAN IV specific per hard interface data * @cleanup_work: work queue callback item for hard interface deinit * @debug_dir: dentry for nc subdir in batman-adv directory in debugfs + * @neigh_list: list of unique single hop neighbors via this interface + * @neigh_list_lock: lock protecting neigh_list */ struct batadv_hard_iface { struct list_head list; @@ -115,6 +117,9 @@ struct batadv_hard_iface { struct batadv_hard_iface_bat_iv bat_iv; struct work_struct cleanup_work; struct dentry *debug_dir; + struct hlist_head neigh_list; + /* neigh_list_lock protects: neigh_list */ + spinlock_t neigh_list_lock; };

/** @@ -341,6 +346,23 @@ struct batadv_gw_node { };

/** + * batadv_hardif_neigh_node - unique neighbor per hard interface + * @list: list node for batadv_hard_iface::neigh_list + * @addr: the MAC address of the neighboring interface + * @if_incoming: pointer to incoming hard interface + * @refcount: number of contexts the object is used + * @rcu: struct used for freeing in a RCU-safe manner + */ +struct batadv_hardif_neigh_node { + struct hlist_node list; + u8 addr[ETH_ALEN]; + struct batadv_hard_iface *if_incoming; + unsigned long last_seen; + atomic_t refcount; + struct rcu_head rcu; +}; + +/** * struct batadv_neigh_node - structure for single hops neighbors * @list: list node for batadv_orig_node::neigh_list * @orig_node: pointer to corresponding orig_node