batman-adv: Modified forwarding behaviour for multicast packets

With this patch a multicast packet is not always simply flooded anymore,
the behaviour for the following cases is changed to reduce
unnecessary overhead:

If all nodes within the horizon of a certain node have signalized
multicast listener announcement capability then an IPv6 multicast packet
with a destination of IPv6 link-local scope (excluding ff02::1) coming
from the upstream of this node...

* ...is dropped if there is no according multicast listener in the
  translation table,
* ...is forwarded via unicast if there is a single node with interested
  multicast listeners
* ...and otherwise still gets flooded.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-net-mesh b/Documentation/ABI/testing/sysfs-class-net-mesh
index 4793d3dff6af..c46406296631 100644
--- a/Documentation/ABI/testing/sysfs-class-net-mesh
+++ b/Documentation/ABI/testing/sysfs-class-net-mesh
@@ -76,6 +76,15 @@ Description:
                 is used to classify clients as "isolated" by the
                 Extended Isolation feature.
 
+What:           /sys/class/net/<mesh_iface>/mesh/multicast_mode
+Date:           Feb 2014
+Contact:        Linus Lüssing <linus.luessing@web.de>
+Description:
+                Indicates whether multicast optimizations are enabled
+                or disabled. If set to zero then all nodes in the
+                mesh are going to use classic flooding for any
+                multicast packet with no optimizations.
+
 What:           /sys/class/net/<mesh_iface>/mesh/network_coding
 Date:           Nov 2012
 Contact:        Martin Hundeboll <martin@hundeboll.net>