The following commit has been merged in the master branch: commit e8829f007e982a9a8fb4023109233d5f344d4657 Author: Linus Lüssing linus.luessing@c0d3.blue Date: Thu Oct 30 05:40:46 2014 +0100

batman-adv: fix counter for multicast supporting nodes

A miscounting of nodes having multicast optimizations enabled can lead to multicast packet loss in the following scenario:

If the first OGM a node receives from another one has no multicast optimizations support (no multicast tvlv) then we are missing to increase the counter. This potentially leads to the wrong assumption that we could safely use multicast optimizations.

Fixings this by increasing the counter if the initial OGM has the multicast TVLV unset, too.

Introduced by 60432d756cf06e597ef9da511402dd059b112447 ("batman-adv: Announce new capability via multicast TVLV")

Reported-by: Tobias Hachmer tobias@hachmer.de Signed-off-by: Linus Lüssing linus.luessing@c0d3.blue Signed-off-by: Marek Lindner mareklindner@neomailbox.ch Signed-off-by: Antonio Quartulli antonio@meshcoding.com

diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index ab6bb2a..d3503fb 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -685,11 +685,13 @@ static void batadv_mcast_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv, if (orig_initialized) atomic_dec(&bat_priv->mcast.num_disabled); orig->capabilities |= BATADV_ORIG_CAPA_HAS_MCAST; - /* If mcast support is being switched off increase the disabled - * mcast node counter. + /* If mcast support is being switched off or if this is an initial + * OGM without mcast support then increase the disabled mcast + * node counter. */ } else if (!orig_mcast_enabled && - orig->capabilities & BATADV_ORIG_CAPA_HAS_MCAST) { + (orig->capabilities & BATADV_ORIG_CAPA_HAS_MCAST || + !orig_initialized)) { atomic_inc(&bat_priv->mcast.num_disabled); orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_MCAST; }