[4/4] batman-adv: request the full table if tt_crc doesn't match
Commit Message
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(-)
@@ -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;