diff options
Diffstat (limited to 'net/batman-adv/originator.c')
-rw-r--r-- | net/batman-adv/originator.c | 542 |
1 files changed, 497 insertions, 45 deletions
diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 8ab14340d10..6df12a2e360 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2009-2013 B.A.T.M.A.N. contributors: +/* Copyright (C) 2009-2014 B.A.T.M.A.N. contributors: * * Marek Lindner, Simon Wunderlich * @@ -12,9 +12,7 @@ * General Public License for more details. * * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA - * 02110-1301, USA + * along with this program; if not, see <http://www.gnu.org/licenses/>. */ #include "main.h" @@ -41,7 +39,7 @@ int batadv_compare_orig(const struct hlist_node *node, const void *data2) const void *data1 = container_of(node, struct batadv_orig_node, hash_entry); - return (memcmp(data1, data2, ETH_ALEN) == 0 ? 1 : 0); + return batadv_compare_eth(data1, data2); } /** @@ -150,20 +148,114 @@ err: return -ENOMEM; } +/** + * batadv_neigh_ifinfo_free_rcu - free the neigh_ifinfo object + * @rcu: rcu pointer of the neigh_ifinfo object + */ +static void batadv_neigh_ifinfo_free_rcu(struct rcu_head *rcu) +{ + struct batadv_neigh_ifinfo *neigh_ifinfo; + + neigh_ifinfo = container_of(rcu, struct batadv_neigh_ifinfo, rcu); + + if (neigh_ifinfo->if_outgoing != BATADV_IF_DEFAULT) + batadv_hardif_free_ref_now(neigh_ifinfo->if_outgoing); + + kfree(neigh_ifinfo); +} + +/** + * batadv_neigh_ifinfo_free_now - decrement the refcounter and possibly free + * the neigh_ifinfo (without rcu callback) + * @neigh_ifinfo: the neigh_ifinfo object to release + */ +static void +batadv_neigh_ifinfo_free_ref_now(struct batadv_neigh_ifinfo *neigh_ifinfo) +{ + if (atomic_dec_and_test(&neigh_ifinfo->refcount)) + batadv_neigh_ifinfo_free_rcu(&neigh_ifinfo->rcu); +} + +/** + * batadv_neigh_ifinfo_free_ref - decrement the refcounter and possibly free + * the neigh_ifinfo + * @neigh_ifinfo: the neigh_ifinfo object to release + */ +void batadv_neigh_ifinfo_free_ref(struct batadv_neigh_ifinfo *neigh_ifinfo) +{ + if (atomic_dec_and_test(&neigh_ifinfo->refcount)) + call_rcu(&neigh_ifinfo->rcu, batadv_neigh_ifinfo_free_rcu); +} + +/** + * batadv_neigh_node_free_rcu - free the neigh_node + * @rcu: rcu pointer of the neigh_node + */ +static void batadv_neigh_node_free_rcu(struct rcu_head *rcu) +{ + struct hlist_node *node_tmp; + struct batadv_neigh_node *neigh_node; + struct batadv_neigh_ifinfo *neigh_ifinfo; + + neigh_node = container_of(rcu, struct batadv_neigh_node, rcu); + + hlist_for_each_entry_safe(neigh_ifinfo, node_tmp, + &neigh_node->ifinfo_list, list) { + batadv_neigh_ifinfo_free_ref_now(neigh_ifinfo); + } + batadv_hardif_free_ref_now(neigh_node->if_incoming); + + kfree(neigh_node); +} + +/** + * batadv_neigh_node_free_ref_now - decrement the neighbors refcounter + * and possibly free it (without rcu callback) + * @neigh_node: neigh neighbor to free + */ +static void +batadv_neigh_node_free_ref_now(struct batadv_neigh_node *neigh_node) +{ + if (atomic_dec_and_test(&neigh_node->refcount)) + batadv_neigh_node_free_rcu(&neigh_node->rcu); +} + +/** + * batadv_neigh_node_free_ref - decrement the neighbors refcounter + * and possibly free it + * @neigh_node: neigh neighbor to free + */ void batadv_neigh_node_free_ref(struct batadv_neigh_node *neigh_node) { if (atomic_dec_and_test(&neigh_node->refcount)) - kfree_rcu(neigh_node, rcu); + call_rcu(&neigh_node->rcu, batadv_neigh_node_free_rcu); } -/* increases the refcounter of a found router */ +/** + * batadv_orig_node_get_router - router to the originator depending on iface + * @orig_node: the orig node for the router + * @if_outgoing: the interface where the payload packet has been received or + * the OGM should be sent to + * + * Returns the neighbor which should be router for this orig_node/iface. + * + * The object is returned with refcounter increased by 1. + */ struct batadv_neigh_node * -batadv_orig_node_get_router(struct batadv_orig_node *orig_node) +batadv_orig_router_get(struct batadv_orig_node *orig_node, + const struct batadv_hard_iface *if_outgoing) { - struct batadv_neigh_node *router; + struct batadv_orig_ifinfo *orig_ifinfo; + struct batadv_neigh_node *router = NULL; rcu_read_lock(); - router = rcu_dereference(orig_node->router); + hlist_for_each_entry_rcu(orig_ifinfo, &orig_node->ifinfo_list, list) { + if (orig_ifinfo->if_outgoing != if_outgoing) + continue; + + router = rcu_dereference(orig_ifinfo->router); + break; + } if (router && !atomic_inc_not_zero(&router->refcount)) router = NULL; @@ -173,6 +265,164 @@ batadv_orig_node_get_router(struct batadv_orig_node *orig_node) } /** + * batadv_orig_ifinfo_get - find the ifinfo from an orig_node + * @orig_node: the orig node to be queried + * @if_outgoing: the interface for which the ifinfo should be acquired + * + * Returns the requested orig_ifinfo or NULL if not found. + * + * The object is returned with refcounter increased by 1. + */ +struct batadv_orig_ifinfo * +batadv_orig_ifinfo_get(struct batadv_orig_node *orig_node, + struct batadv_hard_iface *if_outgoing) +{ + struct batadv_orig_ifinfo *tmp, *orig_ifinfo = NULL; + + rcu_read_lock(); + hlist_for_each_entry_rcu(tmp, &orig_node->ifinfo_list, + list) { + if (tmp->if_outgoing != if_outgoing) + continue; + + if (!atomic_inc_not_zero(&tmp->refcount)) + continue; + + orig_ifinfo = tmp; + break; + } + rcu_read_unlock(); + + return orig_ifinfo; +} + +/** + * batadv_orig_ifinfo_new - search and possibly create an orig_ifinfo object + * @orig_node: the orig node to be queried + * @if_outgoing: the interface for which the ifinfo should be acquired + * + * Returns NULL in case of failure or the orig_ifinfo object for the if_outgoing + * interface otherwise. The object is created and added to the list + * if it does not exist. + * + * The object is returned with refcounter increased by 1. + */ +struct batadv_orig_ifinfo * +batadv_orig_ifinfo_new(struct batadv_orig_node *orig_node, + struct batadv_hard_iface *if_outgoing) +{ + struct batadv_orig_ifinfo *orig_ifinfo = NULL; + unsigned long reset_time; + + spin_lock_bh(&orig_node->neigh_list_lock); + + orig_ifinfo = batadv_orig_ifinfo_get(orig_node, if_outgoing); + if (orig_ifinfo) + goto out; + + orig_ifinfo = kzalloc(sizeof(*orig_ifinfo), GFP_ATOMIC); + if (!orig_ifinfo) + goto out; + + if (if_outgoing != BATADV_IF_DEFAULT && + !atomic_inc_not_zero(&if_outgoing->refcount)) { + kfree(orig_ifinfo); + orig_ifinfo = NULL; + goto out; + } + + reset_time = jiffies - 1; + reset_time -= msecs_to_jiffies(BATADV_RESET_PROTECTION_MS); + orig_ifinfo->batman_seqno_reset = reset_time; + orig_ifinfo->if_outgoing = if_outgoing; + INIT_HLIST_NODE(&orig_ifinfo->list); + atomic_set(&orig_ifinfo->refcount, 2); + hlist_add_head_rcu(&orig_ifinfo->list, + &orig_node->ifinfo_list); +out: + spin_unlock_bh(&orig_node->neigh_list_lock); + return orig_ifinfo; +} + +/** + * batadv_neigh_ifinfo_get - find the ifinfo from an neigh_node + * @neigh_node: the neigh node to be queried + * @if_outgoing: the interface for which the ifinfo should be acquired + * + * The object is returned with refcounter increased by 1. + * + * Returns the requested neigh_ifinfo or NULL if not found + */ +struct batadv_neigh_ifinfo * +batadv_neigh_ifinfo_get(struct batadv_neigh_node *neigh, + struct batadv_hard_iface *if_outgoing) +{ + struct batadv_neigh_ifinfo *neigh_ifinfo = NULL, + *tmp_neigh_ifinfo; + + rcu_read_lock(); + hlist_for_each_entry_rcu(tmp_neigh_ifinfo, &neigh->ifinfo_list, + list) { + if (tmp_neigh_ifinfo->if_outgoing != if_outgoing) + continue; + + if (!atomic_inc_not_zero(&tmp_neigh_ifinfo->refcount)) + continue; + + neigh_ifinfo = tmp_neigh_ifinfo; + break; + } + rcu_read_unlock(); + + return neigh_ifinfo; +} + +/** + * batadv_neigh_ifinfo_new - search and possibly create an neigh_ifinfo object + * @neigh_node: the neigh node to be queried + * @if_outgoing: the interface for which the ifinfo should be acquired + * + * Returns NULL in case of failure or the neigh_ifinfo object for the + * if_outgoing interface otherwise. The object is created and added to the list + * if it does not exist. + * + * The object is returned with refcounter increased by 1. + */ +struct batadv_neigh_ifinfo * +batadv_neigh_ifinfo_new(struct batadv_neigh_node *neigh, + struct batadv_hard_iface *if_outgoing) +{ + struct batadv_neigh_ifinfo *neigh_ifinfo; + + spin_lock_bh(&neigh->ifinfo_lock); + + neigh_ifinfo = batadv_neigh_ifinfo_get(neigh, if_outgoing); + if (neigh_ifinfo) + goto out; + + neigh_ifinfo = kzalloc(sizeof(*neigh_ifinfo), GFP_ATOMIC); + if (!neigh_ifinfo) + goto out; + + if (if_outgoing && !atomic_inc_not_zero(&if_outgoing->refcount)) { + kfree(neigh_ifinfo); + neigh_ifinfo = NULL; + goto out; + } + + INIT_HLIST_NODE(&neigh_ifinfo->list); + atomic_set(&neigh_ifinfo->refcount, 2); + neigh_ifinfo->if_outgoing = if_outgoing; + + hlist_add_head_rcu(&neigh_ifinfo->list, &neigh->ifinfo_list); + +out: + spin_unlock_bh(&neigh->ifinfo_lock); + + return neigh_ifinfo; +} + +/** * batadv_neigh_node_new - create and init a new neigh_node object * @hard_iface: the interface where the neighbour is connected to * @neigh_addr: the mac address of the neighbour interface @@ -193,13 +443,13 @@ batadv_neigh_node_new(struct batadv_hard_iface *hard_iface, goto out; INIT_HLIST_NODE(&neigh_node->list); + INIT_HLIST_HEAD(&neigh_node->ifinfo_list); + spin_lock_init(&neigh_node->ifinfo_lock); memcpy(neigh_node->addr, neigh_addr, ETH_ALEN); neigh_node->if_incoming = hard_iface; neigh_node->orig_node = orig_node; - INIT_LIST_HEAD(&neigh_node->bonding_list); - /* extra reference for return */ atomic_set(&neigh_node->refcount, 2); @@ -207,30 +457,68 @@ out: return neigh_node; } +/** + * batadv_orig_ifinfo_free_rcu - free the orig_ifinfo object + * @rcu: rcu pointer of the orig_ifinfo object + */ +static void batadv_orig_ifinfo_free_rcu(struct rcu_head *rcu) +{ + struct batadv_orig_ifinfo *orig_ifinfo; + + orig_ifinfo = container_of(rcu, struct batadv_orig_ifinfo, rcu); + + if (orig_ifinfo->if_outgoing != BATADV_IF_DEFAULT) + batadv_hardif_free_ref_now(orig_ifinfo->if_outgoing); + + kfree(orig_ifinfo); +} + +/** + * batadv_orig_ifinfo_free_ref - decrement the refcounter and possibly free + * the orig_ifinfo (without rcu callback) + * @orig_ifinfo: the orig_ifinfo object to release + */ +static void +batadv_orig_ifinfo_free_ref_now(struct batadv_orig_ifinfo *orig_ifinfo) +{ + if (atomic_dec_and_test(&orig_ifinfo->refcount)) + batadv_orig_ifinfo_free_rcu(&orig_ifinfo->rcu); +} + +/** + * batadv_orig_ifinfo_free_ref - decrement the refcounter and possibly free + * the orig_ifinfo + * @orig_ifinfo: the orig_ifinfo object to release + */ +void batadv_orig_ifinfo_free_ref(struct batadv_orig_ifinfo *orig_ifinfo) +{ + if (atomic_dec_and_test(&orig_ifinfo->refcount)) + call_rcu(&orig_ifinfo->rcu, batadv_orig_ifinfo_free_rcu); +} + static void batadv_orig_node_free_rcu(struct rcu_head *rcu) { struct hlist_node *node_tmp; - struct batadv_neigh_node *neigh_node, *tmp_neigh_node; + struct batadv_neigh_node *neigh_node; struct batadv_orig_node *orig_node; + struct batadv_orig_ifinfo *orig_ifinfo; orig_node = container_of(rcu, struct batadv_orig_node, rcu); spin_lock_bh(&orig_node->neigh_list_lock); - /* for all bonding members ... */ - list_for_each_entry_safe(neigh_node, tmp_neigh_node, - &orig_node->bond_list, bonding_list) { - list_del_rcu(&neigh_node->bonding_list); - batadv_neigh_node_free_ref(neigh_node); - } - /* for all neighbors towards this originator ... */ hlist_for_each_entry_safe(neigh_node, node_tmp, &orig_node->neigh_list, list) { hlist_del_rcu(&neigh_node->list); - batadv_neigh_node_free_ref(neigh_node); + batadv_neigh_node_free_ref_now(neigh_node); } + hlist_for_each_entry_safe(orig_ifinfo, node_tmp, + &orig_node->ifinfo_list, list) { + hlist_del_rcu(&orig_ifinfo->list); + batadv_orig_ifinfo_free_ref_now(orig_ifinfo); + } spin_unlock_bh(&orig_node->neigh_list_lock); /* Free nc_nodes */ @@ -327,8 +615,8 @@ struct batadv_orig_node *batadv_orig_node_new(struct batadv_priv *bat_priv, return NULL; INIT_HLIST_HEAD(&orig_node->neigh_list); - INIT_LIST_HEAD(&orig_node->bond_list); INIT_LIST_HEAD(&orig_node->vlan_list); + INIT_HLIST_HEAD(&orig_node->ifinfo_list); spin_lock_init(&orig_node->bcast_seqno_lock); spin_lock_init(&orig_node->neigh_list_lock); spin_lock_init(&orig_node->tt_buff_lock); @@ -344,15 +632,11 @@ struct batadv_orig_node *batadv_orig_node_new(struct batadv_priv *bat_priv, orig_node->bat_priv = bat_priv; memcpy(orig_node->orig, addr, ETH_ALEN); batadv_dat_init_orig_node_addr(orig_node); - orig_node->router = NULL; atomic_set(&orig_node->last_ttvn, 0); orig_node->tt_buff = NULL; orig_node->tt_buff_len = 0; reset_time = jiffies - 1 - msecs_to_jiffies(BATADV_RESET_PROTECTION_MS); orig_node->bcast_seqno_reset = reset_time; - orig_node->batman_seqno_reset = reset_time; - - atomic_set(&orig_node->bond_candidates, 0); /* create a vlan object for the "untagged" LAN */ vlan = batadv_orig_node_vlan_new(orig_node, BATADV_NO_FLAGS); @@ -376,20 +660,76 @@ free_orig_node: return NULL; } +/** + * batadv_purge_orig_ifinfo - purge obsolete ifinfo entries from originator + * @bat_priv: the bat priv with all the soft interface information + * @orig_node: orig node which is to be checked + * + * Returns true if any ifinfo entry was purged, false otherwise. + */ +static bool +batadv_purge_orig_ifinfo(struct batadv_priv *bat_priv, + struct batadv_orig_node *orig_node) +{ + struct batadv_orig_ifinfo *orig_ifinfo; + struct batadv_hard_iface *if_outgoing; + struct hlist_node *node_tmp; + bool ifinfo_purged = false; + + spin_lock_bh(&orig_node->neigh_list_lock); + + /* for all ifinfo objects for this originator */ + hlist_for_each_entry_safe(orig_ifinfo, node_tmp, + &orig_node->ifinfo_list, list) { + if_outgoing = orig_ifinfo->if_outgoing; + + /* always keep the default interface */ + if (if_outgoing == BATADV_IF_DEFAULT) + continue; + + /* don't purge if the interface is not (going) down */ + if ((if_outgoing->if_status != BATADV_IF_INACTIVE) && + (if_outgoing->if_status != BATADV_IF_NOT_IN_USE) && + (if_outgoing->if_status != BATADV_IF_TO_BE_REMOVED)) + continue; + + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "router/ifinfo purge: originator %pM, iface: %s\n", + orig_node->orig, if_outgoing->net_dev->name); + + ifinfo_purged = true; + + hlist_del_rcu(&orig_ifinfo->list); + batadv_orig_ifinfo_free_ref(orig_ifinfo); + if (orig_node->last_bonding_candidate == orig_ifinfo) { + orig_node->last_bonding_candidate = NULL; + batadv_orig_ifinfo_free_ref(orig_ifinfo); + } + } + + spin_unlock_bh(&orig_node->neigh_list_lock); + + return ifinfo_purged; +} + + +/** + * batadv_purge_orig_neighbors - purges neighbors from originator + * @bat_priv: the bat priv with all the soft interface information + * @orig_node: orig node which is to be checked + * + * Returns true if any neighbor was purged, false otherwise + */ static bool batadv_purge_orig_neighbors(struct batadv_priv *bat_priv, - struct batadv_orig_node *orig_node, - struct batadv_neigh_node **best_neigh) + struct batadv_orig_node *orig_node) { - struct batadv_algo_ops *bao = bat_priv->bat_algo_ops; struct hlist_node *node_tmp; struct batadv_neigh_node *neigh_node; bool neigh_purged = false; unsigned long last_seen; struct batadv_hard_iface *if_incoming; - *best_neigh = NULL; - spin_lock_bh(&orig_node->neigh_list_lock); /* for all neighbors towards this originator ... */ @@ -418,15 +758,7 @@ batadv_purge_orig_neighbors(struct batadv_priv *bat_priv, neigh_purged = true; hlist_del_rcu(&neigh_node->list); - batadv_bonding_candidate_del(orig_node, neigh_node); batadv_neigh_node_free_ref(neigh_node); - } else { - /* store the best_neighbour if this is the first - * iteration or if a better neighbor has been found - */ - if (!*best_neigh || - bao->bat_neigh_cmp(neigh_node, *best_neigh) > 0) - *best_neigh = neigh_node; } } @@ -434,10 +766,57 @@ batadv_purge_orig_neighbors(struct batadv_priv *bat_priv, return neigh_purged; } +/** + * batadv_find_best_neighbor - finds the best neighbor after purging + * @bat_priv: the bat priv with all the soft interface information + * @orig_node: orig node which is to be checked + * @if_outgoing: the interface for which the metric should be compared + * + * Returns the current best neighbor, with refcount increased. + */ +static struct batadv_neigh_node * +batadv_find_best_neighbor(struct batadv_priv *bat_priv, + struct batadv_orig_node *orig_node, + struct batadv_hard_iface *if_outgoing) +{ + struct batadv_neigh_node *best = NULL, *neigh; + struct batadv_algo_ops *bao = bat_priv->bat_algo_ops; + + rcu_read_lock(); + hlist_for_each_entry_rcu(neigh, &orig_node->neigh_list, list) { + if (best && (bao->bat_neigh_cmp(neigh, if_outgoing, + best, if_outgoing) <= 0)) + continue; + + if (!atomic_inc_not_zero(&neigh->refcount)) + continue; + + if (best) + batadv_neigh_node_free_ref(best); + + best = neigh; + } + rcu_read_unlock(); + + return best; +} + +/** + * batadv_purge_orig_node - purges obsolete information from an orig_node + * @bat_priv: the bat priv with all the soft interface information + * @orig_node: orig node which is to be checked + * + * This function checks if the orig_node or substructures of it have become + * obsolete, and purges this information if that's the case. + * + * Returns true if the orig_node is to be removed, false otherwise. + */ static bool batadv_purge_orig_node(struct batadv_priv *bat_priv, struct batadv_orig_node *orig_node) { struct batadv_neigh_node *best_neigh_node; + struct batadv_hard_iface *hard_iface; + bool changed; if (batadv_has_timed_out(orig_node->last_seen, 2 * BATADV_PURGE_TIMEOUT)) { @@ -446,12 +825,39 @@ static bool batadv_purge_orig_node(struct batadv_priv *bat_priv, orig_node->orig, jiffies_to_msecs(orig_node->last_seen)); return true; - } else { - if (batadv_purge_orig_neighbors(bat_priv, orig_node, - &best_neigh_node)) - batadv_update_route(bat_priv, orig_node, - best_neigh_node); } + changed = batadv_purge_orig_ifinfo(bat_priv, orig_node); + changed = changed || batadv_purge_orig_neighbors(bat_priv, orig_node); + + if (!changed) + return false; + + /* first for NULL ... */ + best_neigh_node = batadv_find_best_neighbor(bat_priv, orig_node, + BATADV_IF_DEFAULT); + batadv_update_route(bat_priv, orig_node, BATADV_IF_DEFAULT, + best_neigh_node); + if (best_neigh_node) + batadv_neigh_node_free_ref(best_neigh_node); + + /* ... then for all other interfaces. */ + rcu_read_lock(); + list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { + if (hard_iface->if_status != BATADV_IF_ACTIVE) + continue; + + if (hard_iface->soft_iface != bat_priv->soft_iface) + continue; + + best_neigh_node = batadv_find_best_neighbor(bat_priv, + orig_node, + hard_iface); + batadv_update_route(bat_priv, orig_node, hard_iface, + best_neigh_node); + if (best_neigh_node) + batadv_neigh_node_free_ref(best_neigh_node); + } + rcu_read_unlock(); return false; } @@ -534,8 +940,54 @@ int batadv_orig_seq_print_text(struct seq_file *seq, void *offset) return 0; } - bat_priv->bat_algo_ops->bat_orig_print(bat_priv, seq); + bat_priv->bat_algo_ops->bat_orig_print(bat_priv, seq, + BATADV_IF_DEFAULT); + + return 0; +} + +/** + * batadv_orig_hardif_seq_print_text - writes originator infos for a specific + * outgoing interface + * @seq: debugfs table seq_file struct + * @offset: not used + * + * Returns 0 + */ +int batadv_orig_hardif_seq_print_text(struct seq_file *seq, void *offset) +{ + struct net_device *net_dev = (struct net_device *)seq->private; + struct batadv_hard_iface *hard_iface; + struct batadv_priv *bat_priv; + + hard_iface = batadv_hardif_get_by_netdev(net_dev); + + if (!hard_iface || !hard_iface->soft_iface) { + seq_puts(seq, "Interface not known to B.A.T.M.A.N.\n"); + goto out; + } + + bat_priv = netdev_priv(hard_iface->soft_iface); + if (!bat_priv->bat_algo_ops->bat_orig_print) { + seq_puts(seq, + "No printing function for this routing protocol\n"); + goto out; + } + + if (hard_iface->if_status != BATADV_IF_ACTIVE) { + seq_puts(seq, "Interface not active\n"); + goto out; + } + seq_printf(seq, "[B.A.T.M.A.N. adv %s, IF/MAC: %s/%pM (%s %s)]\n", + BATADV_SOURCE_VERSION, hard_iface->net_dev->name, + hard_iface->net_dev->dev_addr, + hard_iface->soft_iface->name, bat_priv->bat_algo_ops->name); + + bat_priv->bat_algo_ops->bat_orig_print(bat_priv, seq, hard_iface); + +out: + batadv_hardif_free_ref(hard_iface); return 0; } |