If the skb is fragmented, the checksum must be computed on the
individual fragments, just using skb->data may fail on fragmented
data. Instead of doing linearizing the packet, use the new
batadv_crc32 to do that more efficiently- it should not hurt
replacing the old crc16 by the new crc32.
Reported-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

This is especially useful if there are no claims yet, but we still want
to know which gateways are using bridge loop avoidance in the network.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

If the gateway functionality is used, some broadcast packets (DHCP
requests) may be transmitted as unicast packets. As the bridge loop
avoidance code now only considers the payload Ethernet destination,
it may drop the DHCP request for clients which are claimed by other
backbone gateways, because it falsely infers from the broadcast address
that the right backbone gateway should havehandled the broadcast.

Fix this by checking and delegating the batman-adv packet type used
for transmission.
Reported-by: NGuido Iribarren <guidoiribarren@buenosaireslibre.org>
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>

Reported-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

Reported-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

Reported-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

batman-adv doesn't follow the style for multiline comments that David S. Miller
prefers. All comments should be reformatted to follow this consistent style to
make the code slightly more readable.
Signed-off-by: NSven Eckelmann <sven@narfation.org>

batman-adv can be compiled as part of the kernel instead of an module. In that
case the linker will see all non-static symbols of batman-adv and all other
non-static symbols of the kernel. This could lead to symbol collisions. A
prefix for the batman-adv symbols that defines their private namespace avoids
such a problem.
Reported-by: NDavid Miller <davem@davemloft.net>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

update copyright years in order to include 2012
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

The define CONFIG_BATMAN_ADV_BLA switches the bridge loop avoidance
on - skip it, and the bridge loop avoidance is not compiled in.

This is useful if binary size should be saved or the feature is
not needed.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

When multiple backbone gateways relay the same broadcast from the
backbone into the mesh, other nodes in the mesh may receive this
broadcast multiple times. To avoid this, the crc checksums of
received broadcasts are recorded and new broadcast packets with
the same content may be dropped if received by another gateway.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

As the backbone gateways are connected to the same backbone, they
should announce the same clients on the backbone non-exclusively.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

This second version of the bridge loop avoidance for batman-adv
avoids loops between the mesh and a backbone (usually a LAN).

By connecting multiple batman-adv mesh nodes to the same ethernet
segment a loop can be created when the soft-interface is bridged
into that ethernet segment. A simple visualization of the loop
involving the most common case - a LAN as ethernet segment:

node1  <-- LAN  -->  node2
  |                   |
wifi   <-- mesh -->  wifi

Packets from the LAN (e.g. ARP broadcasts) will circle forever from
node1 or node2 over the mesh back into the LAN.

With this patch, batman recognizes backbone gateways, nodes which are
part of the mesh and backbone/LAN at the same time. Each backbone
gateway "claims" clients from within the mesh to handle them
exclusively. By restricting that only responsible backbone gateways
may handle their claimed clients traffic, loops are effectively
avoided.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

batman-adv uses pointers which are marked as const and should not
violate that type qualifier by passing it to functions which force a
cast to the non-const version.
Signed-off-by: NSven Eckelmann <sven@narfation.org>

Signed-off-by: NSven Eckelmann <sven@narfation.org>

B.A.T.M.A.N. (better approach to mobile ad-hoc networking) is a routing
protocol for multi-hop ad-hoc mesh networks. The networks may be wired or
wireless. See http://www.open-mesh.org/ for more information and user space
tools.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

B.A.T.M.A.N. (better approach to mobile ad-hoc networking) is
a routing protocol for multi-hop ad-hoc mesh networks. The
networks may be wired or wireless. See
http://www.open-mesh.org/ for more information and user space
tools.

This is the first submission for inclusion in staging.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>