batman-adv: make the TT global purge routine VLAN specific

Instead of unconditionally removing all the TT entries
served by a given originator, make tt_global_orig_del()
remove only entries matching a given VLAN identifier
provided as argument.

If such argument is negative all the global entries
served by the originator are removed.

This change is used into the BLA code to purge entries
served by a newly discovered Backbone node, but limiting
the operation only to those connected to the VLAN where the
backbone has been discovered.

Cc: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

net/batman-adv/bridge_loop_avoidance.c

@@ -411,10 +411,10 @@ batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, uint8_t *orig,
 		return NULL;
 	}
 
-	/* this is a gateway now, remove any tt entries */
+	/* this is a gateway now, remove any TT entry on this VLAN */
 	orig_node = batadv_orig_hash_find(bat_priv, orig);
 	if (orig_node) {
-		batadv_tt_global_del_orig(bat_priv, orig_node,
+		batadv_tt_global_del_orig(bat_priv, orig_node, vid,
 					  "became a backbone gateway");
 		batadv_orig_node_free_ref(orig_node);
 	}

net/batman-adv/originator.c

@@ -230,7 +230,7 @@ static void batadv_orig_node_free_rcu(struct rcu_head *rcu)
 
 	batadv_frag_purge_orig(orig_node, NULL);
 
-	batadv_tt_global_del_orig(orig_node->bat_priv, orig_node,
+	batadv_tt_global_del_orig(orig_node->bat_priv, orig_node, -1,
 				  "originator timed out");
 
 	kfree(orig_node->tt_buff);

net/batman-adv/routing.c

@@ -47,7 +47,7 @@ static void _batadv_update_route(struct batadv_priv *bat_priv,
 	if ((curr_router) && (!neigh_node)) {
 		batadv_dbg(BATADV_DBG_ROUTES, bat_priv,
 			   "Deleting route towards: %pM\n", orig_node->orig);
-		batadv_tt_global_del_orig(bat_priv, orig_node,
+		batadv_tt_global_del_orig(bat_priv, orig_node, -1,
 					  "Deleted route towards originator");
 
 	/* route added */

net/batman-adv/translation-table.c

@@ -1581,8 +1581,18 @@ out:
 		batadv_tt_local_entry_free_ref(local_entry);
 }
 
+/**
+ * batadv_tt_global_del_orig - remove all the TT global entries belonging to the
+ *  given originator matching the provided vid
+ * @bat_priv: the bat priv with all the soft interface information
+ * @orig_node: the originator owning the entries to remove
+ * @match_vid: the VLAN identifier to match. If negative all the entries will be
+ *  removed
+ * @message: debug message to print as "reason"
+ */
 void batadv_tt_global_del_orig(struct batadv_priv *bat_priv,
 			       struct batadv_orig_node *orig_node,
+			       int32_t match_vid,
 			       const char *message)
 {
 	struct batadv_tt_global_entry *tt_global;
@@ -1604,6 +1614,10 @@ void batadv_tt_global_del_orig(struct batadv_priv *bat_priv,
 		spin_lock_bh(list_lock);
 		hlist_for_each_entry_safe(tt_common_entry, safe,
 					  head, hash_entry) {
+			/* remove only matching entries */
+			if (match_vid >= 0 && tt_common_entry->vid != match_vid)
+				continue;
+
 			tt_global = container_of(tt_common_entry,
 						 struct batadv_tt_global_entry,
 						 common);
@@ -2570,7 +2584,8 @@ static void batadv_tt_fill_gtable(struct batadv_priv *bat_priv,
 		goto out;
 
 	/* Purge the old table first.. */
-	batadv_tt_global_del_orig(bat_priv, orig_node, "Received full table");
+	batadv_tt_global_del_orig(bat_priv, orig_node, -1,
+				  "Received full table");
 
 	_batadv_tt_update_changes(bat_priv, orig_node, tt_change, num_entries,
 				  ttvn);

net/batman-adv/translation-table.h

@@ -30,7 +30,7 @@ int batadv_tt_local_seq_print_text(struct seq_file *seq, void *offset);
 int batadv_tt_global_seq_print_text(struct seq_file *seq, void *offset);
 void batadv_tt_global_del_orig(struct batadv_priv *bat_priv,
 			       struct batadv_orig_node *orig_node,
-			       const char *message);
+			       int32_t match_vid, const char *message);
 struct batadv_orig_node *batadv_transtable_search(struct batadv_priv *bat_priv,
 						  const uint8_t *src,
 						  const uint8_t *addr,