Commit Graph

144 Commits

Author SHA1 Message Date
Simon Wunderlich 1b371d1307 batman-adv: use consistent kerneldoc style
Reported-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2014-01-16 00:16:00 +01:00
Simon Wunderlich e19f9759ed 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>
2014-01-12 14:41:19 +01:00
Simon Wunderlich cb1c92ec37 batman-adv: add debugfs support to view multiif tables
Show tables for the multi interface operation. Originator tables
are added per hard interface.

This patch also changes the API by adding the interface to the
bat_orig_print() parameters.

Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2014-01-12 14:41:16 +01:00
Simon Wunderlich 5bc7c1eb44 batman-adv: add debugfs structure for information per interface
To show information per interface, add a debugfs hardif structure
similar to the system in sysfs. Hard interface folders will be created
in "$debugfs/batman-adv/". Files are not yet added.

Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2014-01-12 14:41:15 +01:00
Simon Wunderlich f3b3d90189 batman-adv: add bonding again
With the new interface alternating, the first hop may send packets
in a round robin fashion to it's neighbors because it has multiple
valid routes built by the multi interface optimization. This patch
enables the feature if bonding is selected. Note that unlike the
bonding implemented before, this version is much simpler and may
even enable multi path routing to a certain degree.

Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2014-01-12 14:41:15 +01:00
Simon Wunderlich ef0a937f7a batman-adv: consider outgoing interface in OGM sending
The current OGM sending an aggregation functionality decides on
which interfaces a packet should be sent when it parses the forward
packet struct. However, with the network wide multi interface
optimization the outgoing interface is decided by the OGM processing
function.

This is reflected by moving the decision in the OGM processing function
and add the outgoing interface in the forwarding packet struct. This
practically implies that an OGM may be added multiple times (once per
outgoing interface), and this also affects aggregation which needs to
consider the outgoing interface as well.

Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2014-01-12 14:41:14 +01:00
Simon Wunderlich 7351a4822d batman-adv: split out router from orig_node
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: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2014-01-12 14:41:11 +01:00
Simon Wunderlich 89652331c0 batman-adv: split tq information in neigh_node struct
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: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2014-01-12 14:41:10 +01:00
Simon Wunderlich f6c8b71173 batman-adv: remove bonding and interface alternating
Remove bonding and interface alternating code - it will be replaced
by a new, network-wide multi interface optimization which enables
both bonding and interface alternating in a better way.

Keep the sysfs and find router function though, this will be needed
later.

Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2014-01-12 14:41:10 +01:00
Antonio Quartulli c42edfe382 batman-adv: add isolation_mark sysfs attribute
This attribute can be used to set and read the value and the
mask of the skb mark which will be used to classify the
source non-mesh client as ISOLATED. In this way a client can
be advertised as such and the mark can potentially be
restored at the receiving node before delivering the skb.

This can be helpful for creating network wide netfilter
policies.

This sysfs file expects a string of the shape "$mark/$mask".
Where $mark has to be a 32-bit number in any base, while
$mask must be a 32bit mask expressed in hex base. Only bits
in $mark covered by the bitmask are really stored.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
2014-01-08 20:49:42 +01:00
Antonio Quartulli 6c413b1c22 batman-adv: send every DHCP packet as bat-unicast
In different situations it is possible that the DHCP server
or client uses broadcast Ethernet frames to send messages
to each other. The GW component in batman-adv takes care of
using bat-unicast packets to bring broadcast DHCP
Discover/Requests to the "best" server.

On the way back the DHCP server usually sends unicasts,
but upon client request it may decide to use broadcasts as
well.

This patch improves the GW component so that it now snoops
and sends as unicast all the DHCP packets, no matter if they
were generated by a DHCP server or client.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
2014-01-08 20:49:42 +01:00
Antonio Quartulli ebf38fb7ab 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>
2014-01-08 20:49:39 +01:00
Simon Wunderlich da6b8c20a5 batman-adv: generalize batman-adv icmp packet handling
Instead of handling icmp packets only up to length of icmp_packet_rr,
the code should handle any icmp length size. Therefore the length
truncating is moved to when the packet is actually sent to userspace
(this does not support lengths longer than icmp_packet_rr yet). Longer
packets are forwarded without truncating.

This patch also cleans up some parts where the icmp header struct could
be used instead of other icmp_packet(_rr) structs to make the code more
readable.

Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-10-23 17:03:47 +02:00
Antonio Quartulli 0eb01568f0 batman-adv: include the sync-flags when compute the global/local table CRC
Flags covered by TT_SYNC_MASK are kept in sync among the
nodes in the network and therefore they have to be
considered while computing the global/local table CRC.

In this way a generic originator is able to understand if
its table contains the correct flags or not.

Bits from 4 to 7 in the TT flags fields are now reserved for
"synchronized" flags only.

This allows future developers to add more flags of this type
without breaking compatibility.

It's important to note that not all the remote TT flags are
synchronised. This comes from the fact that some flags are
used to inject an information once only.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
2013-10-23 17:03:46 +02:00
Antonio Quartulli 3c4f7ab60c batman-adv: improve the TT component to support runtime flag changes
Some flags (i.e. the WIFI flag) may change after that the
related client has already been announced. However it is
useful to informa the rest of the network about this change.

Add a runtime-flag-switch detection mechanism and
re-announce the related TT entry to advertise the new flag
value.

This mechanism can be easily exploited by future flags that
may need the same treatment.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
2013-10-23 17:03:45 +02:00
Marek Lindner a19d3d85e1 batman-adv: limit local translation table max size
The local translation table size is limited by what can be
transferred from one node to another via a full table request.

The number of entries fitting into a full table request depend
on whether the fragmentation is enabled or not. Therefore this
patch introduces a max table size check and refuses to add
more local clients when that size is reached. Moreover, if the
max full table packet size changes (MTU change or fragmentation
is disabled) the local table is downsized instantaneously.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Antonio Quartulli <ordex@autistici.org>
2013-10-23 17:03:43 +02:00
Antonio Quartulli d0015fdd3d batman-adv: provide orig_node routing API
Some operations executed on an orig_node depends on the
current routing algorithm being used. To easily make this
mechanism routing algorithm agnostic add a orig_node
specific API that each algorithm can populate with its own
routines.

Such routines are then invoked by the code when needed,
without knowing which routing algorithm is currently in use

With this patch 3 API functions are added:
- orig_free (to free routing depending internal structs)
- orig_add_if (to change the inner state of an orig_node
  when a new hard interface is added)
- orig_del_if (to change the inner state of an orig_node
  when an hard interface is removed)

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-10-23 17:03:21 +02:00
Antonio Quartulli c43c981e50 batman-adv: add bat_neigh_is_equiv_or_better API function
Each routing protocol has its own metric semantic and
therefore is the protocol itself the only component able to
compare two metrics to check their "similarity".

This new API allows each routing protocol to implement its
own logic and make the external code protocol agnostic.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-10-23 15:33:11 +02:00
Antonio Quartulli a3285a8f20 batman-adv: add bat_neigh_cmp API function
This new API allows to compare the two neighbours based on
the metric avoiding the user to deal with any routing
algorithm specific detail

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-10-23 15:33:10 +02:00
Antonio Quartulli 737a2a2297 batman-adv: add bat_orig_print API function
Each routing protocol has its own metric and private
variables, therefore it is useful to introduce a new API
for originator information printing.

This API needs to be implemented by each protocol in order
to provide its specific originator table output.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-10-23 15:33:10 +02:00
Antonio Quartulli bbad0a5e36 batman-adv: make struct batadv_orig_node algorithm agnostic
some of the struct batadv_orig_node members are B.A.T.M.A.N. IV
specific and therefore they are moved in a algorithm specific
substruct in order to make batadv_orig_node routing algorithm
agnostic

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-10-23 15:33:09 +02:00
Antonio Quartulli 0538f75991 batman-adv: make struct batadv_neigh_node algorithm agnostic
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: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-10-23 15:33:08 +02:00
Antonio Quartulli 7ea7b4a142 batman-adv: make the TT CRC logic VLAN specific
This change allows nodes to handle the TT table on a
per-VLAN basis. This is needed because nodes may have to
store only some of the global entries advertised by another
node.

In this scenario such nodes would re-create only a partial
global table and would not be able to compute a correct CRC
anymore.

This patch splits the logic and introduces one CRC per VLAN.
In this way a node fetching only some entries belonging to
some VLANs is still able to compute the needed CRCs and
still check the table correctness.

With this patch the shape of the TVLV-TT is changed too
because now a node needs to advertise all the CRCs of all
the VLANs that it is wired to.

The debug output of the local Translation Table now shows
the CRC along with each entry since there is not a common
value for the entire table anymore.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-10-19 23:25:12 +02:00
Antonio Quartulli a70a9aa990 batman-adv: lock around TT operations to avoid sending inconsistent data
A TT response may be prepared and sent while the local or
global translation table is getting updated.

The worst case is when one of the tables is accessed after
its content has been recently updated but the metadata
(TTVN/CRC) has not yet. In this case the reader will get a
table content which does not match the TTVN/CRC.
This will lead to an inconsistent state and so to a TT
recovery.

To avoid entering this situation, put a lock around those TT
operations recomputing the metadata and around the TT
Response creation (the latter is the only reader that
accesses the metadata together with the table).

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-10-19 17:31:56 +02:00
Antonio Quartulli b8cbd81d09 batman-adv: make the AP isolation attribute VLAN specific
AP isolation has to be enabled on one VLAN interface only.
This patch moves the AP isolation attribute to the per-vlan
interface attribute set, enabling it to have a different
value depending on the selected vlan.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-10-19 17:28:47 +02:00
Antonio Quartulli 5d2c05b213 batman-adv: add per VLAN interface attribute framework
Since batman-adv is now fully VLAN-aware, a proper framework
able to handle per-vlan-interface attributes is needed.

Those attributes will affect the associated VLAN interface
only, rather than the real soft_iface (which would result
in every vlan interface having the same attribute
configuration).

To make the code simpler and easier to extend, attributes
associated to the standalone soft_iface are now treated
like belonging to yet another vlan having a special vid.
This vid is different from the others because it is made up
by all zeros and the VLAN_HAS_TAG bit is not set.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-10-19 17:28:08 +02:00
Antonio Quartulli be1db4f661 batman-adv: make the Distributed ARP Table vlan aware
The same IP subnet can be used on different VLANs, therefore
DAT has to differentiate whether the IP to resolve belongs
to one or the other virtual LAN.
To accomplish this task DAT has to deal with the VLAN tag
and store it together with each ARP entry.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-10-19 17:28:07 +02:00
Antonio Quartulli c018ad3de6 batman-adv: add the VLAN ID attribute to the TT entry
To make the translation table code VLAN-aware, each entry
must carry the VLAN ID which it belongs to. This patch adds
such attribute to the related TT structures.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-10-19 15:11:21 +02:00
Marek Lindner 411d6ed93a batman-adv: consider network coding overhead when calculating required mtu
The module prints a warning when the MTU on the hard interface is too
small to transfer payload traffic without fragmentation. The required
MTU is calculated based on the encapsulation header size. If network
coding is compild into the module its header size is taken into
account as well.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-10-12 17:17:09 +02:00
Martin Hundebøll ee75ed8887 batman-adv: Fragment and send skbs larger than mtu
Non-broadcast packets larger than MTU are fragmented and sent with
an encapsulating header. Up to 16 fragments are supported, which are
sent in reverse order on the wire to allow minimal memory copying when
creating fragments.

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-10-12 11:58:35 +02:00
Martin Hundebøll 610bfc6bc9 batman-adv: Receive fragmented packets and merge
Fragments arriving at their destination are buffered for later merge.
Merged packets are passed to the main receive function as had they never
been fragmented.

Fragments are forwarded without merging if the MTU of the outgoing
interface is smaller than the size of the merged packet.

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-10-12 11:58:34 +02:00
Martin Hundebøll f097e25dbe batman-adv: Remove old fragmentation code
Remove the existing fragmentation code before adding the new version
and delete unicast.{h,c}.

batadv_unicast_send_skb() is moved to send.c and renamed to
batadv_send_skb_unicast().

fragmentation entry in sysfs (bat_priv->fragmentation) is kept for use in
the new fragmentation code.

BATADV_UNICAST_FRAG packet type is renamed to BATADV_FRAG for use in the
new fragmentation code.

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-10-12 11:58:33 +02:00
Simon Wunderlich 9f4980e68b batman-adv: remove vis functionality
This is replaced by a userspace program, we don't need this
functionality to bloat the kernel.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-10-09 21:22:32 +02:00
Antonio Quartulli ced72933a5 batman-adv: use CRC32C instead of CRC16 in TT code
CRC32C has to be preferred to CRC16 because of its possible
HW native support and because of the reduced collision
probability. With this change the Translation Table
component now uses CRC32C to compute the local and global
table checksum.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-10-09 21:22:31 +02:00
Marek Lindner e1bf0c1409 batman-adv: tvlv - convert tt data sent within OGMs
The translation table meta data (version number, crc checksum, etc)
as well as the translation table diff propgated within OGMs now uses
the newly introduced tvlv infrastructure.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-10-09 21:22:29 +02:00
Marek Lindner 3f4841ffb3 batman-adv: tvlv - add network coding container
Create network coding container to announce network coding
capabilities (if enabled).

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-10-09 21:22:28 +02:00
Marek Lindner 17cf0ea455 batman-adv: tvlv - add distributed arp table container
Create DAT container to announce DAT capabilities (if enabled).

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-10-09 21:22:27 +02:00
Marek Lindner 414254e342 batman-adv: tvlv - gateway download/upload bandwidth container
Prior to this patch batman-adv read the advertised uplink bandwidth
from userspace and compressed this information into a single byte
called "gateway class".
Now the download & upload bandwidth information is sent as-is. No
userspace change is necessary since the sysfs API always allowed
to specify a bandwidth.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Spyros Gasteratos <morfeas3000@gmail.com>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-10-09 21:22:27 +02:00
Marek Lindner ef26157747 batman-adv: tvlv - basic infrastructure
The goal is to provide the infrastructure for sending, receiving and
parsing information 'containers' while preserving backward
compatibility. TVLV (based on the commonly known Type Length Value
technique) was chosen as the format for those containers. Even if a
node does not know the tvlv type of a certain container it can simply
skip the current container and proceed with the next. Past experience
has shown features evolve over time, so a 'version' field was added
right from the start to allow differentiating between feature
variants - hence the name: T(ype) V(ersion) L(ength) V(alue).

This patch introduces the basic TVLV infrastructure:
 * register / unregister tvlv containers to be sent with each OGM
   (on primary interfaces only)
 * register / unregister callback handlers to be called upon
   finding the corresponding tvlv type in a tvlv buffer
 * unicast tvlv send / receive API calls

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Spyros Gasteratos <morfeas3000@gmail.com>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-10-09 21:22:26 +02:00
Antonio Quartulli eb2deb6b39 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>
2013-05-29 02:44:55 +02:00
Matthias Schiffer caf65bfcc5 batman-adv: send each broadcast only once on non-wireless interfaces
While it makes sense to send each broadcast thrice on 802.11 (WLAN) interfaces
as broadcasts are often unreliable on these, there is no reason to do so on
other interface types.

The increased the overhead can be harmful on low-bandwidth links like VPN
connections over slow internet lines, therefore it is better to reduce the
number of broadcast packets sent on non-wireless links to one.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-05-29 02:44:53 +02:00
Martin Hundebøll 2df5278b02 batman-adv: network coding - receive coded packets and decode them
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: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-03-13 22:53:51 +01:00
Martin Hundebøll 612d2b4fe0 batman-adv: network coding - save overheard and tx packets for decoding
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: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-03-13 22:53:50 +01:00
Martin Hundebøll 3c12de9a5c batman-adv: network coding - code and transmit packets if possible
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: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-03-13 22:53:50 +01:00
Martin Hundebøll 953324776d batman-adv: network coding - buffer unicast packets before forward
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: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-03-13 22:53:49 +01:00
Martin Hundebøll d56b1705e2 batman-adv: network coding - detect coding nodes and remove these after timeout
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: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-03-13 22:53:49 +01:00
Martin Hundebøll d353d8d4d9 batman-adv: network coding - add the initial infrastructure code
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/Catwoman

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-03-13 22:53:48 +01:00
Antonio Quartulli 0b87393146 batman-adv: update copyright years
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-01-19 21:18:12 +08:00
Simon Wunderlich 5bc44dc845 batman-adv: postpone sysfs removal when unregistering
When processing the unregister notify for a hard interface, removing
the sysfs files may lead to a circular deadlock (rtnl mutex <->
s_active).

To overcome this problem, postpone the sysfs removal in a worker.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
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>
2013-01-19 21:18:12 +08:00
Marek Lindner 88a32c9a8a batman-adv: kernel doc for types.h
Thanks to Sven Eckelmann and Simon Wunderlich for their support.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2013-01-19 21:18:11 +08:00