batman-adv: keep local table consistency for further TT_RESPONSE
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>
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_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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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_ */