batman-adv: Remove the repeated declaration

Function 'batadv_bla_claim_dump' is declared twice, so remove the
repeated declaration.

Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Drop publication years from copyright info

The batman-adv source code was using the year of publication (to net-next)
as "last" year for the copyright statement. The whole source code mentioned
in the MAINTAINERS "BATMAN ADVANCED" section was handled as a single entity
regarding the publishing year.

This avoided having outdated (in sense of year information - not copyright
holder) publishing information inside several files. But since the simple
"update copyright year" commit (without other changes) in the file was not
well received in the upstream kernel, the option to not have a copyright
year (for initial and last publication) in the files are chosen instead.
More detailed information about the years can still be retrieved from the
SCM system.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Drop deprecated debugfs support

The debugfs support in batman-adv was marked as deprecated by the commit
00caf6a2b318 ("batman-adv: Mark debugfs functionality as deprecated") and
scheduled for removal in 2021.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: mcast: fix duplicate mcast packets in BLA backbone from mesh

Scenario:
* Multicast frame send from mesh to a BLA backbone (multiple nodes
with their bat0 bridged together, with BLA enabled)

Issue:
* BLA backbone nodes receive the frame multiple times on bat0,
once from mesh->bat0 and once from each backbone_gw from LAN

For unicast, a node will send only to the best backbone gateway
according to the TQ. However for multicast we currently cannot determine
if multiple destination nodes share the same backbone if they don't share
the same backbone with us. So we need to keep sending the unicasts to
all backbone gateways and let the backbone gateways decide which one
will forward the frame. We can use the CLAIM mechanism to make this
decision.

One catch: The batman-adv gateway feature for DHCP packets potentially
sends multicast packets in the same batman-adv unicast header as the
multicast optimizations code. And we are not allowed to drop those even
if we did not claim the source address of the sender, as for such
packets there is only this one multicast-in-unicast packet.

How can we distinguish the two cases?

The gateway feature uses a batman-adv unicast 4 address header. While
the multicast-to-unicasts feature uses a simple, 3 address batman-adv
unicast header. So let's use this to distinguish.

Fixes: fe2da6ff27c7 ("batman-adv: check incoming packet type for bla")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Update copyright years for 2020

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Use includes instead of fwdecls

While it can be slightly beneficial for the build performance to use
forward declarations instead of includes, the handling of them together
with changes in the included headers makes it unnecessary complicated and
fragile. Just replace them with actual includes since some parts (hwmon,
..) of the kernel even request avoidance of forward declarations and net/
is mostly not using them in *.c file.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Drop license boilerplate

All files got a SPDX-License-Identifier with commit 7db7d9f369a4
("batman-adv: Add SPDX license identifier above copyright header"). All the
required information about the license conditions can be found in
LICENSES/.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Update copyright years for 2019

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Update copyright years for 2018

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Use parentheses in function kernel-doc

The documentation describing kernel-doc comments for functions ("How to
format kernel-doc comments") uses parentheses at the end of the function
name. Using this format allows to use a consistent style when adding
documentation to a function and when referencing this function in a
different kernel-doc section.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Add SPDX license identifier above copyright header

The "Linux kernel licensing rules" require that each file has a SPDX
license identifier as first line (and sometimes as second line).

The FSFE REUSE practices [1] would also require the same tags but have no
restrictions on the placement in the source file. Using the "Linux kernel
licensing rules" is therefore also fulfilling the FSFE REUSE practices
requirements at the same time.

[1] https://reuse.software/practices/

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: prevent multiple ARP replies sent by gateways if dat enabled

If dat is enabled it must be made sure that only the backbone gw which has
claimed the remote destination for the ARP request answers the ARP request
directly if the MAC address is known due to the local dat table. This
prevents multiple ARP replies in a common backbone if more than one
gateway already knows the remote mac searched for in the ARP request.

Signed-off-by: Andreas Pape <apape@phoenixcontact.com>
Acked-by: Simon Wunderlich <sw@simonwunderlich.de>
[sven@narfation.org: fix conflicts with current version]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: update copyright years for 2017

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: don't add loop detect macs to TT

The bridge loop avoidance (BLA) feature of batman-adv sends packets to
probe for Mesh/LAN packet loops. Those packets are not sent by real
clients and should therefore not be added to the translation table (TT).

Signed-off-by: Simon Wunderlich <simon.wunderlich@open-mesh.com>

batman-adv: add backbone table netlink support

Dump the list of bridge loop avoidance backbones via the netlink socket.

Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

batman-adv: add B.A.T.M.A.N. Dump BLA claims via netlink

Dump the list of bridge loop avoidance claims via the netlink socket.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
[sven.eckelmann@open-mesh.com: add policy for attributes, fix includes, fix
soft_iface reference leak]
Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>
[sw@simonwunderlich.de: fix kerneldoc, fix error reporting]
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

batman-adv: Use bool as return type for boolean functions

It is easier to understand that the returned value of a specific function
doesn't have to be 0 when the functions was successful when the actual
return type is bool. This is especially true when all surrounding functions
with return type int use negative values to return the error code.

Reported-by: Nicholas Krause <xerofoify@gmail.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

batman-adv: update copyright years for 2016

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

batman-adv: purge bridge loop avoidance when its disabled

When bridge loop avoidance is disabled through sysfs, the internal
datastructures are not disabled, but only BLA operations are disabled.
To be sure that they are removed, purge the data immediately. That is
especially useful if a firmwares network state is changed, and the BLA
wait periods should restart on the new network.

Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

batman-adv: Remove batadv_ types forward declarations

main.h is included in every file and is the only way to access types.h.
This makes forward declarations for all types defined in types.h
unnecessary.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

batman-adv: Replace C99 int types with kernel type

(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: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

batman-adv: Add required includes to all files

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: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

batman-adv: update copyright years for 2015

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

batman-adv: update copyright years for 2014

Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

batman-adv: remove FSF address from GPL disclaimer

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

batman-adv: make the backbone gw check VLAN specific

The backbone gw check has to be VLAN specific so that code
using it can specify VID where the check has to be done.

In the TT code, the check has been moved into the
tt_global_add() function so that it can be performed on a
per-entry basis instead of ignoring all the TT data received
from another backbone node. Only TT global entries belonging
to the VLAN where the backbone node is connected to are
skipped.
All the other spots where the TT code was checking whether a
node is a backbone have been removed.

Moreover, batadv_bla_is_backbone_gw_orig() now returns bool
since it used to return only 1 or 0.

Cc: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

batman-adv: change VID semantic in the BLA code

In order to make batman-adv fully vlan aware later, the
semantic used for variables storing the VLAN ID values has
to be changed in order to be adapted to the new one which
will be used batman-adv wide.

In particular, the VID has to be an "_unsigned_ short int"
and its 4 MSB will be used as a flag bitfield, while the
remaining 12 bits are used to store the real VID value

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>

batman-adv: update copyright years

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

batman-adv: Fix broadcast duplist for fragmentation

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: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: Add the backbone gateway list to debugfs

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

batman-adv: move function arguments on one line

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

batman-adv: check incoming packet type for bla

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: Guido Iribarren <guidoiribarren@buenosaireslibre.org>
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>

batman-adv: Prefix types structs with batadv_

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

batman-adv: Prefix packet structs with batadv_

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

batman-adv: Prefix bridge_loop_avoidance defines with BATADV_

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

batman-adv: Reformat multiline comments to consistent style

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: Sven Eckelmann <sven@narfation.org>

batman-adv: Prefix bridge_loop_avoidance non-static functions with batadv_

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: David Miller <davem@davemloft.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>

batman-adv: update copyright years

update copyright years in order to include 2012

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

batman-adv: add bridge loop avoidance compile option

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

batman-adv: add broadcast duplicate check

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

batman-adv: don't let backbone gateways exchange tt entries

As the backbone gateways are connected to the same backbone, they
should announce the same clients on the backbone non-exclusively.

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

batman-adv: export claim tables through debugfs

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

batman-adv: add basic bridge loop avoidance code

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