mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-21 11:44:01 +08:00
e45eba2467
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>
221 lines
7.5 KiB
ReStructuredText
221 lines
7.5 KiB
ReStructuredText
==========
|
|
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>
|