batman-adv: Convert batman-adv.txt to reStructuredText

Converting the freeform text to parsable reStructuredText, allows the
integration in the sphinx based documentation system of the kernel. It will
therefore be accessible as hypertext under
https://www.kernel.org/doc/html/latest/

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

1 files changed, 220 insertions, 0 deletions

diff --git a/Documentation/networking/batman-adv.rst b/Documentation/networking/batman-adv.rst
new file mode 100644
index 000000000000..a342b2cc3dc6
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+==========
+batman-adv
+==========
+
+Batman advanced is a new approach to wireless networking which does no longer
+operate on the IP basis. Unlike the batman daemon, which exchanges information
+using UDP packets and sets routing tables, batman-advanced operates on ISO/OSI
+Layer 2 only and uses and routes (or better: bridges) Ethernet Frames. It
+emulates a virtual network switch of all nodes participating. Therefore all
+nodes appear to be link local, thus all higher operating protocols won't be
+affected by any changes within the network. You can run almost any protocol
+above batman advanced, prominent examples are: IPv4, IPv6, DHCP, IPX.
+
+Batman advanced was implemented as a Linux kernel driver to reduce the overhead
+to a minimum. It does not depend on any (other) network driver, and can be used
+on wifi as well as ethernet lan, vpn, etc ... (anything with ethernet-style
+layer 2).
+
+
+Configuration
+=============
+
+Load the batman-adv module into your kernel::
+
+  $ insmod batman-adv.ko
+
+The module is now waiting for activation. You must add some interfaces on which
+batman can operate. After loading the module batman advanced will scan your
+systems interfaces to search for compatible interfaces. Once found, it will
+create subfolders in the ``/sys`` directories of each supported interface,
+e.g.::
+
+  $ ls /sys/class/net/eth0/batman_adv/
+  elp_interval iface_status mesh_iface throughput_override
+
+If an interface does not have the ``batman_adv`` subfolder, it probably is not
+supported. Not supported interfaces are: loopback, non-ethernet and batman's
+own interfaces.
+
+Note: After the module was loaded it will continuously watch for new
+interfaces to verify the compatibility. There is no need to reload the module
+if you plug your USB wifi adapter into your machine after batman advanced was
+initially loaded.
+
+The batman-adv soft-interface can be created using the iproute2 tool ``ip``::
+
+  $ ip link add name bat0 type batadv
+
+To activate a given interface simply attach it to the ``bat0`` interface::
+
+  $ ip link set dev eth0 master bat0
+
+Repeat this step for all interfaces you wish to add. Now batman starts
+using/broadcasting on this/these interface(s).
+
+By reading the "iface_status" file you can check its status::
+
+  $ cat /sys/class/net/eth0/batman_adv/iface_status
+  active
+
+To deactivate an interface you have to detach it from the "bat0" interface::
+
+  $ ip link set dev eth0 nomaster
+
+
+All mesh wide settings can be found in batman's own interface folder::
+
+  $ ls /sys/class/net/bat0/mesh/
+  aggregated_ogms       fragmentation isolation_mark routing_algo
+  ap_isolation          gw_bandwidth  log_level      vlan0
+  bonding               gw_mode       multicast_mode
+  bridge_loop_avoidance gw_sel_class  network_coding
+  distributed_arp_table hop_penalty   orig_interval
+
+There is a special folder for debugging information::
+
+  $ ls /sys/kernel/debug/batman_adv/bat0/
+  bla_backbone_table log         neighbors         transtable_local
+  bla_claim_table    mcast_flags originators
+  dat_cache          nc          socket
+  gateways           nc_nodes    transtable_global
+
+Some of the files contain all sort of status information regarding the mesh
+network. For example, you can view the table of originators (mesh
+participants) with::
+
+  $ cat /sys/kernel/debug/batman_adv/bat0/originators
+
+Other files allow to change batman's behaviour to better fit your requirements.
+For instance, you can check the current originator interval (value in
+milliseconds which determines how often batman sends its broadcast packets)::
+
+  $ cat /sys/class/net/bat0/mesh/orig_interval
+  1000
+
+and also change its value::
+
+  $ echo 3000 > /sys/class/net/bat0/mesh/orig_interval
+
+In very mobile scenarios, you might want to adjust the originator interval to a
+lower value. This will make the mesh more responsive to topology changes, but
+will also increase the overhead.
+
+
+Usage
+=====
+
+To make use of your newly created mesh, batman advanced provides a new
+interface "bat0" which you should use from this point on. All interfaces added
+to batman advanced are not relevant any longer because batman handles them for
+you. Basically, one "hands over" the data by using the batman interface and
+batman will make sure it reaches its destination.
+
+The "bat0" interface can be used like any other regular interface. It needs an
+IP address which can be either statically configured or dynamically (by using
+DHCP or similar services)::
+
+  NodeA: ip link set up dev bat0
+  NodeA: ip addr add 192.168.0.1/24 dev bat0
+
+  NodeB: ip link set up dev bat0
+  NodeB: ip addr add 192.168.0.2/24 dev bat0
+  NodeB: ping 192.168.0.1
+
+Note: In order to avoid problems remove all IP addresses previously assigned to
+interfaces now used by batman advanced, e.g.::
+
+  $ ip addr flush dev eth0
+
+
+Logging/Debugging
+=================
+
+All error messages, warnings and information messages are sent to the kernel
+log. Depending on your operating system distribution this can be read in one of
+a number of ways. Try using the commands: ``dmesg``, ``logread``, or looking in
+the files ``/var/log/kern.log`` or ``/var/log/syslog``. All batman-adv messages
+are prefixed with "batman-adv:" So to see just these messages try::
+
+  $ dmesg | grep batman-adv
+
+When investigating problems with your mesh network, it is sometimes necessary to
+see more detail debug messages. This must be enabled when compiling the
+batman-adv module. When building batman-adv as part of kernel, use "make
+menuconfig" and enable the option ``B.A.T.M.A.N. debugging``
+(``CONFIG_BATMAN_ADV_DEBUG=y``).
+
+Those additional debug messages can be accessed using a special file in
+debugfs::
+
+  $ cat /sys/kernel/debug/batman_adv/bat0/log
+
+The additional debug output is by default disabled. It can be enabled during
+run time. Following log_levels are defined:
+
+.. flat-table::
+
+   * - 0
+     - All debug output disabled
+   * - 1
+     - Enable messages related to routing / flooding / broadcasting
+   * - 2
+     - Enable messages related to route added / changed / deleted
+   * - 4
+     - Enable messages related to translation table operations
+   * - 8
+     - Enable messages related to bridge loop avoidance
+   * - 16
+     - Enable messages related to DAT, ARP snooping and parsing
+   * - 32
+     - Enable messages related to network coding
+   * - 64
+     - Enable messages related to multicast
+   * - 128
+     - Enable messages related to throughput meter
+   * - 255
+     - Enable all messages
+
+The debug output can be changed at runtime using the file
+``/sys/class/net/bat0/mesh/log_level``. e.g.::
+
+  $ echo 6 > /sys/class/net/bat0/mesh/log_level
+
+will enable debug messages for when routes change.
+
+Counters for different types of packets entering and leaving the batman-adv
+module are available through ethtool::
+
+  $ ethtool --statistics bat0
+
+
+batctl
+======
+
+As batman advanced operates on layer 2, all hosts participating in the virtual
+switch are completely transparent for all protocols above layer 2. Therefore
+the common diagnosis tools do not work as expected. To overcome these problems,
+batctl was created. At the moment the batctl contains ping, traceroute, tcpdump
+and interfaces to the kernel module settings.
+
+For more information, please see the manpage (``man batctl``).
+
+batctl is available on https://www.open-mesh.org/
+
+
+Contact
+=======
+
+Please send us comments, experiences, questions, anything :)
+
+IRC:
+  #batman on irc.freenode.org
+Mailing-list:
+  b.a.t.m.a.n@open-mesh.org (optional subscription at
+  https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n)
+
+You can also contact the Authors:
+
+* Marek Lindner <mareklindner@neomailbox.ch>
+* Simon Wunderlich <sw@simonwunderlich.de>