From: Antonio Quartulli ordex@autistici.org

To keep transtable consistency among all the nodes, an originator must not send not yet announced clients within a full table TT_RESPONSE. Instead, deleted client have to be kept in the table in order to be sent within an immediate TT_RESPONSE. In this way all the nodes in the network will always provide the same response for the same request.

All the modification are committed at the next ttvn increment event.

Signed-off-by: Antonio Quartulli ordex@autistici.org Signed-off-by: Marek Lindner lindner_marek@yahoo.de --- net/batman-adv/packet.h | 4 +- net/batman-adv/send.c | 4 +- net/batman-adv/translation-table.c | 146 +++++++++++++++++++++++++++++------- net/batman-adv/translation-table.h | 1 + 4 files changed, 125 insertions(+), 30 deletions(-)

diff --git a/net/batman-adv/packet.h b/net/batman-adv/packet.h index 590e4a6..b76b4be 100644 --- a/net/batman-adv/packet.h +++ b/net/batman-adv/packet.h @@ -84,7 +84,9 @@ enum tt_query_flags { enum tt_client_flags { TT_CLIENT_DEL = 1 << 0, TT_CLIENT_ROAM = 1 << 1, - TT_CLIENT_NOPURGE = 1 << 8 + TT_CLIENT_NOPURGE = 1 << 8, + TT_CLIENT_NEW = 1 << 9, + TT_CLIENT_PENDING = 1 << 10 };

struct batman_packet { diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index 4b8e11b..58d1447 100644 --- a/net/batman-adv/send.c +++ b/net/batman-adv/send.c @@ -309,10 +309,8 @@ void schedule_own_packet(struct hard_iface *hard_iface) if (hard_iface == primary_if) { /* if at least one change happened */ if (atomic_read(&bat_priv->tt_local_changes) > 0) { + tt_commit_changes(bat_priv); prepare_packet_buffer(bat_priv, hard_iface); - /* Increment the TTVN only once per OGM interval */ - atomic_inc(&bat_priv->ttvn); - bat_priv->tt_poss_change = false; }

/* if the changes have been sent enough times */ diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index 06d361d..7cc67c0 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -215,11 +215,14 @@ void tt_local_add(struct net_device *soft_iface, const uint8_t *addr)

tt_local_event(bat_priv, addr, tt_local_entry->flags);

+ /* The local entry has to be marked as NEW to avoid to send it in + * a full table response going out before the next ttvn increment + * (consistency check) */ + tt_local_entry->flags |= TT_CLIENT_NEW; + hash_add(bat_priv->tt_local_hash, compare_ltt, choose_orig, tt_local_entry, &tt_local_entry->hash_entry);

- atomic_inc(&bat_priv->num_local_tt); - /* remove address from global hash if present */ tt_global_entry = tt_global_hash_find(bat_priv, addr);

@@ -358,19 +361,17 @@ out: return ret; }

-static void tt_local_del(struct bat_priv *bat_priv, - struct tt_local_entry *tt_local_entry, - const char *message) +static void tt_local_set_pending(struct bat_priv *bat_priv, + struct tt_local_entry *tt_local_entry, + uint16_t flags) { - bat_dbg(DBG_TT, bat_priv, "Deleting local tt entry (%pM): %s\n", - tt_local_entry->addr, message); + tt_local_event(bat_priv, tt_local_entry->addr, + tt_local_entry->flags | flags);

- atomic_dec(&bat_priv->num_local_tt); - - hash_remove(bat_priv->tt_local_hash, compare_ltt, choose_orig, - tt_local_entry->addr); - - tt_local_entry_free_ref(tt_local_entry); + /* The local client has to be merked as "pending to be removed" but has + * to be kept in the table in order to send it in an full tables + * response issued before the net ttvn increment (consistency check) */ + tt_local_entry->flags |= TT_CLIENT_PENDING; }

void tt_local_remove(struct bat_priv *bat_priv, const uint8_t *addr, @@ -379,14 +380,14 @@ void tt_local_remove(struct bat_priv *bat_priv, const uint8_t *addr, struct tt_local_entry *tt_local_entry = NULL;

tt_local_entry = tt_local_hash_find(bat_priv, addr); - if (!tt_local_entry) goto out;

- tt_local_event(bat_priv, tt_local_entry->addr, - tt_local_entry->flags | TT_CLIENT_DEL | - (roaming ? TT_CLIENT_ROAM : NO_FLAGS)); - tt_local_del(bat_priv, tt_local_entry, message); + tt_local_set_pending(bat_priv, tt_local_entry, TT_CLIENT_DEL | + (roaming ? TT_CLIENT_ROAM : NO_FLAGS)); + + bat_dbg(DBG_TT, bat_priv, "Local tt entry (%pM) pending to be removed: " + "%s\n", tt_local_entry->addr, message); out: if (tt_local_entry) tt_local_entry_free_ref(tt_local_entry); @@ -411,18 +412,19 @@ static void tt_local_purge(struct bat_priv *bat_priv) if (tt_local_entry->flags & TT_CLIENT_NOPURGE) continue;

+ /* entry already marked for deletion */ + if (tt_local_entry->flags & TT_CLIENT_PENDING) + continue; + if (!is_out_of_time(tt_local_entry->last_seen, TT_LOCAL_TIMEOUT * 1000)) continue;

- tt_local_event(bat_priv, tt_local_entry->addr, - tt_local_entry->flags | TT_CLIENT_DEL); - atomic_dec(&bat_priv->num_local_tt); - bat_dbg(DBG_TT, bat_priv, "Deleting local " - "tt entry (%pM): timed out\n", + tt_local_set_pending(bat_priv, tt_local_entry, + TT_CLIENT_DEL); + bat_dbg(DBG_TT, bat_priv, "Local tt entry (%pM) " + "pending to be removed: timed out\n", tt_local_entry->addr); - hlist_del_rcu(node); - tt_local_entry_free_ref(tt_local_entry); } spin_unlock_bh(list_lock); } @@ -846,6 +848,10 @@ uint16_t tt_local_crc(struct bat_priv *bat_priv) rcu_read_lock(); hlist_for_each_entry_rcu(tt_local_entry, node, head, hash_entry) { + /* not yet committed clients have not to be taken into + * account while computing the CRC */ + if (tt_local_entry->flags & TT_CLIENT_NEW) + continue; total_one = 0; for (j = 0; j < ETH_ALEN; j++) total_one = crc16_byte(total_one, @@ -935,6 +941,16 @@ unlock: return tt_req_node; }

+/* data_ptr is useless here, but has to be kept to respect the prototype */ +static int tt_local_valid_entry(const void *entry_ptr, const void *data_ptr) +{ + const struct tt_local_entry *tt_local_entry = entry_ptr; + + if (tt_local_entry->flags & TT_CLIENT_NEW) + return 0; + return 1; +} + static int tt_global_valid_entry(const void *entry_ptr, const void *data_ptr) { const struct tt_global_entry *tt_global_entry = entry_ptr; @@ -1275,7 +1291,8 @@ static bool send_my_tt_response(struct bat_priv *bat_priv,

skb = tt_response_fill_table(tt_len, ttvn, bat_priv->tt_local_hash, - primary_if, NULL, NULL); + primary_if, tt_local_valid_entry, + NULL); if (!skb) goto out;

@@ -1400,6 +1417,10 @@ bool is_my_client(struct bat_priv *bat_priv, const uint8_t *addr) tt_local_entry = tt_local_hash_find(bat_priv, addr); if (!tt_local_entry) goto out; + /* Check if the client has been logically deleted (but is kept for + * consistency purpose) */ + if (tt_local_entry->flags & TT_CLIENT_PENDING) + goto out; ret = true; out: if (tt_local_entry) @@ -1620,3 +1641,76 @@ void tt_free(struct bat_priv *bat_priv)

kfree(bat_priv->tt_buff); } + +/* This function will reset the specified flags from all the entries in + * the given hash table and will increment num_local_tt for each involved + * entry */ +static void tt_local_reset_flags(struct bat_priv *bat_priv, uint16_t flags) +{ + int i; + struct hashtable_t *hash = bat_priv->tt_local_hash; + struct hlist_head *head; + struct hlist_node *node; + struct tt_local_entry *tt_local_entry; + + if (!hash) + return; + + for (i = 0; i < hash->size; i++) { + head = &hash->table[i]; + + rcu_read_lock(); + hlist_for_each_entry_rcu(tt_local_entry, node, + head, hash_entry) { + tt_local_entry->flags &= ~flags; + atomic_inc(&bat_priv->num_local_tt); + } + rcu_read_unlock(); + } + +} + +/* Purge out all the tt local entries marked with TT_CLIENT_PENDING */ +static void tt_local_purge_pending_clients(struct bat_priv *bat_priv) +{ + struct hashtable_t *hash = bat_priv->tt_local_hash; + struct tt_local_entry *tt_local_entry; + struct hlist_node *node, *node_tmp; + struct hlist_head *head; + spinlock_t *list_lock; /* protects write access to the hash lists */ + int i; + + if (!hash) + return; + + for (i = 0; i < hash->size; i++) { + head = &hash->table[i]; + list_lock = &hash->list_locks[i]; + + spin_lock_bh(list_lock); + hlist_for_each_entry_safe(tt_local_entry, node, node_tmp, + head, hash_entry) { + if (!(tt_local_entry->flags & TT_CLIENT_PENDING)) + continue; + + bat_dbg(DBG_TT, bat_priv, "Deleting local tt entry " + "(%pM): pending\n", tt_local_entry->addr); + + atomic_dec(&bat_priv->num_local_tt); + hlist_del_rcu(node); + tt_local_entry_free_ref(tt_local_entry); + } + spin_unlock_bh(list_lock); + } + +} + +void tt_commit_changes(struct bat_priv *bat_priv) +{ + tt_local_reset_flags(bat_priv, TT_CLIENT_NEW); + tt_local_purge_pending_clients(bat_priv); + + /* Increment the TTVN only once per OGM interval */ + atomic_inc(&bat_priv->ttvn); + bat_priv->tt_poss_change = false; +} diff --git a/net/batman-adv/translation-table.h b/net/batman-adv/translation-table.h index 460e583..d4122cb 100644 --- a/net/batman-adv/translation-table.h +++ b/net/batman-adv/translation-table.h @@ -61,5 +61,6 @@ void handle_tt_response(struct bat_priv *bat_priv, struct tt_query_packet *tt_response); void send_roam_adv(struct bat_priv *bat_priv, uint8_t *client, struct orig_node *orig_node); +void tt_commit_changes(struct bat_priv *bat_priv);

#endif /* _NET_BATMAN_ADV_TRANSLATION_TABLE_H_ */

From: Antonio Quartulli ordex@autistici.org

In case of tt_crc mismatching for a certain orig_node after applying the changes, the node must request the full table immediately.

Signed-off-by: Antonio Quartulli ordex@autistici.org Signed-off-by: Marek Lindner lindner_marek@yahoo.de --- net/batman-adv/routing.c | 12 ++++++++++++ 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index 2cb98be..0f32c81 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -91,6 +91,18 @@ static void update_transtable(struct bat_priv *bat_priv, * to recompute it to spot any possible inconsistency * in the global table */ orig_node->tt_crc = tt_global_crc(bat_priv, orig_node); + + /* The ttvn alone is not enough to guarantee consistency + * because a single value could repesent different states + * (due to the wrap around). Thus a node has to check whether + * the resulting table (after applying the changes) is still + * consistent or not. E.g. a node could disconnect while its + * ttvn is X and reconnect on ttvn = X + TTVN_MAX: in this case + * checking the CRC value is mandatory to detect the + * inconsistency */ + if (orig_node->tt_crc != tt_crc) + goto request_table; + /* Roaming phase is over: tables are in sync again. I can * unset the flag */ orig_node->tt_poss_change = false;