Kerneldoc required single line documentation in the past (before 2009).
Therefore, the 80 columns limit per line check of checkpatch was disabled
for kerneldoc. But kerneldoc is not excluded anymore from it and checkpatch
now enabled the check again.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>

(s|u)(8|16|32|64) are the preferred types in the kernel. The use of the
standard C99 types u?int(8|16|32|64)_t are objected by some people and even
checkpatch now warns about using them.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>

Bitwise OR/AND assignments in C aren't guaranteed to be atomic. One
OGM handler might undo the set/clear of a specific bit from another
handler run in between.

Fix this by using the atomic set_bit()/clear_bit()/test_bit() functions.

Fixes: 3f4841ff ("batman-adv: tvlv - add network coding container")
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>

The header files could not be build indepdent from each other. This is
happened because headers didn't include the files for things they've used.
This was problematic because the success of a build depended on the
knowledge about the right order of local includes.

Also source files were not including everything they've used explicitly.
Instead they required that transitive includes are always stable. This is
problematic because some transitive includes are not obvious, depend on
config settings and may not be stable in the future.

The order for include blocks are:

 * primary headers (main.h and the *.h file of a *.c file)
 * global linux headers
 * required local headers
 * extra forward declarations for pointers in function/struct declarations

The only exceptions are linux/bitops.h and linux/if_ether.h in packet.h.
This header file is shared with userspace applications like batctl and must
therefore build together with userspace applications. The header
linux/bitops.h is not part of the uapi headers and linux/if_ether.h
conflicts with the musl implementation of netinet/if_ether.h. The
maintainers rejected the use of __KERNEL__ preprocessor checks and thus
these two headers are only in main.h. All files using packet.h first have
to include main.h to work correctly.
Reported-by: NMarkus Pargmann <mpa@pengutronix.de>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>

An unoptimized version of the Jenkins one-at-a-time hash function is used
and partially copied all over the code wherever an hashtable is used.
Instead the optimized version shared between the whole kernel should be
used to reduce code duplication and use better optimized code.

Only the DAT code must use the old implementation because it is used as
distributed hash function which has to be common for all nodes.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>

Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>

The current default settings for optional features in batman-adv seems to
be based around the idea that the user only compiles what he requires. They
will automatically enabled when they are compiled in. For example the
network coding part of batman-adv is by default disabled in the out-of-tree
module but will be enabled when the code is compiled during the module
build.

But distributions like Debian just enable all features of the batman-adv
kernel module and hope that more experimental features or features with
possible negative effects have to be enabled using some runtime
configuration interface.

The network_coding feature can help in specific setups but also has
drawbacks and is not disabled by default in the out-of-tree module.
Disabling by default in the runtime config seems to be also quite sane.

The bridge_loop_avoidance is the only feature which is disabled by default
but may be necessary even in simple setups. Packet loops may even be
created during the initial node setup when this is not enabled. This is
different than STP on bridges because mesh is usually used on Adhoc WiFi.
Having two nodes (by accident) in the same LAN segment and in the same mesh
network is rather common in this situation.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Acked-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>

Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>

Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>

batadv_has_set_lock_class() is called with the wrong hash table as first
argument (probably due to a copy-paste error), which leads to false
positives when running with lockdep.

Introduced-by: 612d2b4f
("batman-adv: network coding - save overheard and tx packets for decoding")
Signed-off-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>

There are several instances where a pskb_copy or __pskb_copy is
immediately followed by an skb_clone.

Add a couple of new functions to allow the copy skb to be allocated
from the fclone cache and thus speed up subsequent skb_clone calls.

Cc: Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Marek Lindner <mareklindner@neomailbox.ch>
Cc: Simon Wunderlich <sw@simonwunderlich.de>
Cc: Antonio Quartulli <antonio@meshcoding.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Arvid Brodin <arvid.brodin@alten.se>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Cc: Lauro Ramos Venancio <lauro.venancio@openbossa.org>
Cc: Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Allan Stephens <allan.stephens@windriver.com>
Cc: Andrew Hendry <andrew.hendry@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Reviewed-by: NChristoph Paasch <christoph.paasch@uclouvain.be>
Signed-off-by: NOctavian Purdila <octavian.purdila@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reported by checkpatch with the following message:
"WARNING: Missing a blank line after declarations"
Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>

On some architectures ether_addr_copy() is slightly faster
than memcpy() therefore use the former when possible.
Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>

net/batman-adv/network-coding.c:1535:1-7: Replace memcpy with struct assignment

Generated by: coccinelle/misc/memcpy-assign.cocci
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>

Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>

For the network wide multi interface optimization there are different
routers for each outgoing interface (outgoing from the OGM perspective,
incoming for payload traffic). To reflect this, change the router and
associated data to a list of routers.

While at it, rename batadv_orig_node_get_router() to
batadv_orig_router_get() to follow the new naming scheme.
Signed-off-by: NSimon Wunderlich <simon@open-mesh.com>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>

For the network wide multi interface optimization it is required to save
metrics per outgoing interface in one neighbor. Therefore a new type is
introduced to keep interface-specific information. This also requires
some changes in access and list management.

The compare and equiv_or_better API calls are changed to take the
outgoing interface into consideration.
Signed-off-by: NSimon Wunderlich <simon@open-mesh.com>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>

As suggested by checkpatch, remove all the references to the
FSF address since the kernel already has one reference in
its documentation.

In this way it is easier to update it in case of future
changes.
Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>

The size of the batadv_header of 3 is problematic on some architectures
which automatically pad all structures to a 32 bit boundary. To not lose
performance by packing this struct, better embed it into the various
host structures.
Reported-by: NRussell King <linux@arm.linux.org.uk>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>

some of the fields in struct batadv_neigh_node are strictly
related to the B.A.T.M.A.N. IV algorithm. In order to
make the struct usable by any routing algorithm it has to be
split and made more generic
Signed-off-by: NAntonio Quartulli <antonio@open-mesh.com>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Create network coding container to announce network coding
capabilities (if enabled).
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>

batman-adv saves its table of packet handlers as a global state, so handlers
must be set up only once (and setting them up a second time will fail).

The recently-added network coding support tries to set up its handler each time
a new softif is registered, which obviously fails when more that one softif is
used (and in consequence, the softif creation fails).

Fix this by splitting up batadv_nc_init into batadv_nc_init (which is called
only once) and batadv_nc_mesh_init (which is called for each softif); in
addition batadv_nc_free is renamed to batadv_nc_mesh_free to keep naming
consistent.
Signed-off-by: NMatthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NAntonio Quartulli <antonio@meshcoding.com>

The call to batadv_nc_skb_forward() fits better in
batadv_send_skb_to_orig(), as this is where the actual next hop is
looked up.

To let the caller of batadv_send_skb_to_orig() know wether the skb is
transmitted, buffered or failed, the return value is changed from
boolean to int.
Signed-off-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

Instead of casting the result of skb_mac_header() to
"struct ethhdr *" every time, the eth_hdr inline function
can be use to beautify the code and improve its readability.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Reported-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Acked-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

As reported by checkpatch, seq_puts has to be preferred with
respect to seq_printf when the format is a constant string
(no va_args)
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Add a htonl() in network_coding.c when reading the sequence number
from received ogm_packet, to avoid wrong byte ordering when comparing
with a host value. This bug was introduced in
3ed7ada3f0bbcd058567bc0a8f9729a73eba7db6 ("batman-adv: network coding -
detect coding nodes and remove these after timeout").

Change the type of coded_packet->coded_len from uint16 to __be16 to
avoid wrong assumptions about endianness in later uses. Introduced in
c3289f3650d34b60296000a629c99f2488f7c3dd ("batman-adv: network coding -
code and transmit packets if possible").
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

When receiving a network coded packet, the decoding buffer is searched
for a packet to use for decoding. The source, destination, and crc32 from
the coded packet is used to identify the wanted packet. The decoded
packet is passed to the usual unicast receiver function, as had it never
been network coded.
Signed-off-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

To be able to decode a network coded packet, a node must already know
one of the two coded packets. This is done by buffering skbs before
transmission and buffering packets sniffed with promiscuous mode from
other hosts.

Packets are kept in a buffer similar to the one with forward-skbs: A
hash table, where each entry, which corresponds to a src-dst pair, has a
linked list packets.
Signed-off-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

Before adding forward-skbs to the coding buffer, the buffer is searched
for a potential coding opportunity. If one is found, the two packets are
network coded and transmitted right away. If not, the forward-skb is
added to the buffer.

Network coded packets are transmitted with information about the two
receivers and the two coded packets. The first receiver is given by the
MAC header, while the second is given in the payload/bat-header. The
second receiver uses promiscuous mode to receive the packet and check
the second destination.
Signed-off-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

Two be able to network code two packets, one packet must be buffered
until the next is available. This is done in a "coding buffer", which is
essentially a hash table with lists of packets. Each entry in the hash
table corresponds to a specific src-dst pair, which has a linked list of
packets that are buffered.

This patch adds skbs to the buffer just before forwarding them. The
buffer is traversed every 10 ms, where timed skbs are removed from the
buffer and transmitted. To allow experiments with the network coding
scheme, the timeout is tunable through a file in debugfs.
Signed-off-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

To use network coding efficiently, a relay must know when neighbor nodes
are likely to have enough information to be able to decode a network
coded packet. This is detected by using OGMs from batman-adv to discover
when one neighbor is in range of another neighbor. The relay check the
TLL to detect when an OGM is forwarded from one neighbor by another
neighbor, and thereby knows that the two neighbors are in range and thus
overhear packets sent by each other.

This information is saved in the orig_node struct to be used when
searching for coding opportunities. Two lists are added to the
orig_node struct: One for neighbors that can hear the orig_node
(outgoing nc_nodes) and one for neighbors that the orig_node can hear
(incoming nc_nodes).

Information about nc_nodes is kept for 10 seconds and is available
through debugfs in batman_adv/nc_nodes to use when debugging network
coding.
Signed-off-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

Network coding exploits the 802.11 shared medium to allow multiple
packets to be sent in a single transmission. In brief, a relay can XOR
two packets, and send the coded packet to two destinations. The
receivers can decode one of the original packets by XOR'ing the coded
packet with the other original packet. This will lead to increased
throughput in topologies where two packets cross one relay.

In a simple topology with three nodes, it takes four transmissions
without network coding to get one packet from Node A to Node B and one
from Node B to Node A:

 1.  Node A  ---- p1 --->  Node R                Node B
 2.  Node A                Node R  <--- p2 ----  Node B
 3.  Node A  <--- p2 ----  Node R                Node B
 4.  Node A                Node R  ---- p1 --->  Node B

With network coding, the relay only needs one transmission, which saves
us one slot of valuable airtime:

 1.  Node A  ---- p1 --->  Node R                Node B
 2.  Node A                Node R  <--- p2 ----  Node B
 3.  Node A  <- p1 x p2 -  Node R  - p1 x p2 ->  Node B

The same principle holds for a topology including five nodes. Here the
packets from Node A and Node B are overheard by Node C and Node D,
respectively. This allows Node R to send a network coded packet to save
one transmission:

   Node A                  Node B

    |     \              /    |
    |      p1          p2     |
    |       \          /      |
    p1       > Node R <       p2
    |                         |
    |         /      \        |
    |    p1 x p2    p1 x p2   |
    v       /          \      v
           /            \
   Node C <              > Node D

More information is available on the open-mesh.org wiki[1].

This patch adds the initial code to support network coding in
batman-adv. It sets up a worker thread to do house keeping and adds a
sysfs file to enable/disable network coding. The feature is disabled by
default, as it requires a wifi-driver with working promiscuous mode, and
also because it adds a small delay at each hop.

[1] http://www.open-mesh.org/projects/batman-adv/wiki/CatwomanSigned-off-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>