From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Lindner Subject: [PATCH 4/4] batman-adv: request the full table if tt_crc doesn't match Date: Fri, 8 Jul 2011 00:35:46 +0200 Message-ID: <1310078146-29537-1-git-send-email-lindner_marek@yahoo.de> References: <1310078023-28958-1-git-send-email-lindner_marek@yahoo.de> Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, b.a.t.m.a.n-ZwoEplunGu2X36UT3dwllkB+6BGkLq7r@public.gmane.org, Marek Lindner To: davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org Return-path: In-Reply-To: <1310078023-28958-1-git-send-email-lindner_marek-LWAfsSFWpa4@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: b.a.t.m.a.n-bounces-ZwoEplunGu2X36UT3dwllkB+6BGkLq7r@public.gmane.org Errors-To: b.a.t.m.a.n-bounces-ZwoEplunGu2X36UT3dwllkB+6BGkLq7r@public.gmane.org List-Id: netdev.vger.kernel.org From: Antonio Quartulli 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 Signed-off-by: Marek Lindner --- 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; -- 1.7.5.3