batman-adv: add tt_initialised flag to the orig_node struct

(ttvn == 0) is currently used as initial condition. However this is not a good
idea because ttvn gets the vale zero each time after reaching the maximum value
(wrap around). For this reason a new flag is added in order to define whether a
node has an initialised table or not. Moreover, after invoking
tt_global_del_orig(), tt_initialised has to be set to false

Reported-by: Alexey Fisher <bug-track@fisher-privat.net>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Tested-by: Alexey Fisher <bug-track@fisher-privat.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

1 files changed, 8 insertions, 3 deletions

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index ab8dea8b0b2e..c632475df375 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -733,6 +733,7 @@ void tt_global_del_orig(struct bat_priv *bat_priv,
                 spin_unlock_bh(list_lock);
         }
         atomic_set(&orig_node->tt_size, 0);
+        orig_node->tt_initialised = false;
 }
 
 static void tt_global_roam_purge(struct bat_priv *bat_priv)
@@ -1450,6 +1451,7 @@ static void _tt_update_changes(struct bat_priv *bat_priv,
                                  */
                                 return;
         }
+        orig_node->tt_initialised = true;
 }
 
 static void tt_fill_gtable(struct bat_priv *bat_priv,
@@ -1854,8 +1856,10 @@ void tt_update_orig(struct bat_priv *bat_priv, struct orig_node *orig_node,
         uint8_t orig_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
         bool full_table = true;
 
-        /* the ttvn increased by one -> we can apply the attached changes */
-        if (ttvn - orig_ttvn == 1) {
+        /* orig table not initialised AND first diff is in the OGM OR the ttvn
+         * increased by one -> we can apply the attached changes */
+        if ((!orig_node->tt_initialised && ttvn == 1) ||
+            ttvn - orig_ttvn == 1) {
                 /* the OGM could not contain the changes due to their size or
                  * because they have already been sent TT_OGM_APPEND_MAX times.
                  * In this case send a tt request */
@@ -1889,7 +1893,8 @@ void tt_update_orig(struct bat_priv *bat_priv, struct orig_node *orig_node,
         } else {
                 /* if we missed more than one change or our tables are not
                  * in sync anymore -> request fresh tt data */
-                if (ttvn != orig_ttvn || orig_node->tt_crc != tt_crc) {
+                if (!orig_node->tt_initialised || ttvn != orig_ttvn ||
+                    orig_node->tt_crc != tt_crc) {
 request_table:
                         bat_dbg(DBG_TT, bat_priv, "TT inconsistency for %pM. "
                                 "Need to retrieve the correct information "