Using BATMAN_OGM_LEN leaves one with the impression that this is
the full packet size which is not the case. Therefore the variable
is renamed.
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.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>

In packet.h the numeric constant 6 is used instead of the more portable ETH_ALEN
define. This patch substitute any hardcoded value with such define.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Acked-by: NSven Eckelmann <sven@narfation.org>

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

All batman-adv packets have a common 3 byte header. It can be used to share
some code between different code paths, but it was never explicit stated that
this header has to be always the same for all packets. Therefore, new code
changes always have the problem that they may accidently introduce regressions
by moving some elements around.

A new structure is introduced that contains the common header and makes it
easier visible that these 3 bytes have to be the same for all on-wire packets.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

The follow-up routing code changes are going to introduce additional
routing packet types which make this distinction necessary.
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Clients connected through a 802.11 device are now marked with the
TT_CLIENT_WIFI flag. This flag is also advertised with the tt
announcement.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

To keep transtable consistency among all the nodes, an originator must
not send not yet announced clients within a full table TT_RESPONSE.
Instead, deleted client have to be kept in the table in order to be sent
within an immediate TT_RESPONSE. In this way all the nodes in the
network will always provide the same response for the same request.

All the modification are committed at the next ttvn increment event.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

The tt_local_entry structure now has a 'flags' field. This helps to
unify the flags format to all the client related structures (tt_global_entry
and tt_change). The 'never_purge' field is now encoded in the 'flags' one.
To optimise the usage of this field, its length has been increased to 16bit
in order to use the eight leading bits (from 0 to 7) to store flags that
have to be sent on the wire, while the eight ending ones are used for local
computation only.

Moreover 'enum tt_change_flags' is now called 'enum tt_client_flags' and the
defined values apply to the tt_local_entry, tt_global_entry and the tt_change
'flags' field.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

With the current client announcement implementation, in case of roaming,
an update is triggered on the new AP serving the client. At that point
the new information is spread around by means of the OGM broadcasting
mechanism. Until this operations is not executed, no node is able to
correctly route traffic towards the client. This obviously causes packet
drops and introduces a delay in the time needed by the client to recover
its connections.

A new packet type called ROAMING_ADVERTISEMENT is added to account this
issue.

This message is sent in case of roaming from the new AP serving the
client to the old one and will contain the client MAC address. In this
way an out-of-OGM update is immediately committed, so that the old node
can update its global translation table. Traffic reaching this node will
then be redirected to the correct destination utilising the fresher
information. Thus reducing the packet drops and the connection recovery
delay.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

The client announcement mechanism informs every mesh node in the network
of any connected non-mesh client, in order to find the path towards that
client from any given point in the mesh.

The old implementation was based on the simple idea of appending a data
buffer to each OGM containing all the client MAC addresses the node is
serving. All other nodes can populate their global translation tables
(table which links client MAC addresses to node addresses) using this
MAC address buffer and linking it to the node's address contained in the
OGM. A node that wants to contact a client has to lookup the node the
client is connected to and its address in the global translation table.

It is easy to understand that this implementation suffers from several
issues:
 - big overhead (each and every OGM contains the entire list of
   connected clients)
 - high latencies for client route updates due to long OGM trip time and
   OGM losses

The new implementation addresses these issues by appending client
changes (new client joined or a client left) to the OGM instead of
filling it with all the client addresses each time. In this way nodes
can modify their global tables by means of "updates", thus reducing the
overhead within the OGMs.

To keep the entire network in sync each node maintains a translation
table version number (ttvn) and a translation table checksum. These
values are spread with the OGM to allow all the network participants to
determine whether or not they need to update their translation table
information.

When a translation table lookup is performed in order to send a packet
to a client attached to another node, the destination's ttvn is added to
the payload packet. Forwarding nodes can compare the packet's ttvn with
their destination's ttvn (this node could have a fresher information
than the source) and re-route the packet if necessary. This greatly
reduces the packet loss of clients roaming from one AP to the next.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

The amount of duplicated code in the receive and routing code can be
reduced when all headers provide the packet type, version and ttl in the
same first bytes.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

CodingStyle "Chapter 12: Macros, Enums and RTL" recommends to use enums
for several related constants. Internal states can be used without
defining the actual value, but all values which are visible to the
outside must be defined as before. Normal values are assigned as usual
and flags are defined by shifts of a bit.
Signed-off-by: NSven Eckelmann <sven@narfation.org>

It is slightly irritating that comments after a long line span over
multiple lines without any code. It is easier to put them before the
actual code and reduce the number of lines which the eye has to read.
Signed-off-by: NSven Eckelmann <sven@narfation.org>

To be coherent, all the functions/variables/constants have been renamed
to the TranslationTable style
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

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

The routing algorithm must be able to decide if a fragment can be merged with
the missing part and still be passed to a forwarding interface. The fragments
can only differ by one byte in case that the original payload had an uneven
length. In that situation the sender has to inform all possible receivers that
the tail is one byte longer using the flag UNI_FRAG_LARGETAIL.

The combination of UNI_FRAG_LARGETAIL and UNI_FRAG_HEAD flag makes it possible
to calculate the correct length for even and uneven sized payloads.

The original formula missed to add the unicast header at all and forgot to
remove the fragment header of the second fragment. This made the results highly
unreliable and only useful for machines with large differences between the
configured MTUs.
Reported-by: NRussell Senior <russell@personaltelco.net>
Reported-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

Linux 2.6.21 defines different macros for __attribute__ which are also
used inside batman-adv. The next version of checkpatch.pl warns about
the usage of __attribute__((packed))).

Linux 2.6.33 defines an extra macro __always_unused which is used to
assist source code analyzers and can be used to removed the last
existing __attribute__ inside the source code.
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>

Via the /sys filesystem you can change the gateway mode of a node using
gw_mode. Adjustments to it can be done using gw_bandwidth for server
mode and gw_sel_class for client mode.
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
[sven.eckelmann@gmx.de: Rework on top of current version]
Signed-off-by: NSven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

checkpatch now detects the start of a comment and warns about usage of
multiple spaces at the beginning of a line. We have to replace the '   '
in multiple lines comments by ' * ' to fix it.

Checkpatch also wants a comment after a definition of a spinlock_t which
describes what it protects. It is currently not possible to add it
before the actual struct which includes the spinlock.
Signed-off-by: NSven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch implements a simple layer2 fragmentation to allow traffic
exchange over network interfaces with a MTU smaller than 1500 bytes. The
fragmentation splits the big packets into two parts and marks the frames
accordingly. The receiving end buffers the packets to reassemble the
orignal packet before passing it to the higher layers. This feature
makes it necessary to modify the batman-adv encapsulation for unicast
packets by adding a sequence number, flags and the originator address.
This modifcation is part of a seperate packet type for fragemented
packets to keep the original overhead as low as possible. This patch
enables the feature by default to ensure the data traffic can travel
through the network. But it also prints a warning to notify the user
about the performance implications.

Note: Fragmentation should be avoided at all costs since it has a
dramatic impact on the performance, especially when it comes wifi
networks. Instead of a single packet, 2 packets have to be sent! Not
only valuable airtime is wasted but also packetloss decreases the
throughput. A link with 50% packetloss and fragmentation enabled is
pretty much unusable.
Signed-off-by: NAndreas Langer <an.langer@gmx.de>
[sven.eckelmann@gmx.de: Rework on top of current version]
Signed-off-by: NSven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

We include different header files indirectly to the same source file.
This creates weird compiler errors from time to time. Include guards
should prefend that functions/variables/... gets redefined by itself.
Signed-off-by: NSven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The standard layer 3 ping utility can use the record route (RR) option
of IP to collect route data for sent ping messages (ping -R). This
patch introduces comparable functionality for batman-adv ICMP messages.

The patch adds a second batman ICMP packet format (icmp_packet_rr) such
that up to 17 MAC addresses can be recorded (sufficient for up to 8
hops per direction). When no RR is wanted, the old icmp_packet without
the RR overhead can be sent.
Signed-off-by: NDaniel Seither <post@tiwoc.de>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
[sven.eckelmann@gmx.de: Rework on top of current version]
Signed-off-by: NSven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch introduces bonding functionality to batman-advanced, targeted
for the 0.3 release. As we are able to route the payload traffic as we
want, we may use multiple interfaces on multihomed hosts to transfer data
to achieve higher bandwidth. This can be considered as "light Multi Path
Routing" for single hop connections.

To detect which interfaces of a peer node belong to the same host, a
new flag PRIMARIES_FIRST_HOP is introduced. This flag is set on the first hop
of OGMs of the primary (first) interface, which is broadcasted on all
interfaces. When receiving such an OGM, we can learn which interfaces
belong to the same host (by assigning them to the primary originator).

Bonding works by sending packets in a round-robin fashion to the available
interfaces of a neighbor host, if multiple interfaces are available. The
neighbor interfaces should be almost equally good to reach.

To avoid interferences (i.e. sending on the same channel), only neighbor
interfaces with different mac addresses and different outgoing interfaces
are considered as candidates.

Bonding is deactivated by default, and can be activated by

echo 1 > /sys/class/net/bat0/mesh/bonding

for each individual node.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
[sven.eckelmann@gmx.de: Rework on top of current version]
Signed-off-by: NSven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch changes the sequence number range from 8 or 16 bit to 32 bit.
This should avoid problems with the sequence number sliding window algorithm
which we had seen in the past for broadcast floods or malicious packet
injections. We can not assure 100% security with this patch, but it is quite
an improvement over the old 16 bit sequence numbers:

 * expected window size can be increased (4096 -> 65536)
 * 64k packets in the right order would now be needed to cause a loop,
   which seems practically impossible.

Furthermore, a TTL field has been added to the broadcast packet type, just to
make sure.

These changes required to increase the compatibility level once again.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
[sven.eckelmann@gmx.de: Change atomic64_* back to atomic_*, Rework on
top of current version]
Signed-off-by: NSven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

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>

we have written "neighbors", "neighbours" and bad spelled versions of this
word, this patch should make it consistent.
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>