Commit Graph

29 Commits

Author SHA1 Message Date
Antonio Quartulli d4ff40f683 batman-adv: pass a 16bit long flag argument to tt_global_add()
it may be the case that we want to store some local TT client flags in a global
entry, therefore the tt_global_add needs to get a proper argument for this

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2013-05-29 02:44:55 +02:00
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
Antonio Quartulli 7c1fd91da5 batman-adv: substitute tt_poss_change with a per-tt_entry flag
tt_poss_change is a node-wide flag which tells whether the node is in a roaming
state (a client recently moved to/away from it) in order to let it apply special
re-routing rules. However this flag does not give a clear idea of the current
state because it is not possible to understand *which client* is actually
involved in the roaming. For this reason a better approach has been chosen:
instead of using a node-wide variable, the roaming state is now given by a
per-tt_entry ROAM flag which, in case of packet coming through the node, tells
the node whether the real destination is in roaming state or not.

With this flag change, batadv_check_unicast_ttvn() has also been rearranged in
order to better fit the new re-routing logic and to be much more readable.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-11-14 21:00:35 +01:00
Antonio Quartulli 7f91d06c90 batman-adv: pass the WIFI flag from the local to global entry
in case of client roaming a new global entry is added while a corresponding
local one is still present. In this case the node can safely pass the WIFI flag
from the local to the global entry.

This change is required to let the AP-isolation correctly working in case of
roaming: if a generic WIFI client C roams from node A to B, A adds a global
entry for C without adding any WIFI flag. The latter will be set only later,
once A has received C's advertisement from B. In this time period the
AP-Isolation (if enabled) would not correctly work since C is not marked as
WIFI, so allowing it to communicate with other WIFI clients.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-10-29 09:42:49 +01:00
Antonio Quartulli 30cfd02b60 batman-adv: detect not yet announced clients
With the current TT mechanism a new client joining the network is not
immediately able to communicate with other hosts because its MAC address has not
been announced yet. This situation holds until the first OGM containing its
joining event will be spread over the mesh network.

This behaviour can be acceptable in networks where the originator interval is a
small value (e.g. 1sec) but if that value is set to an higher time (e.g. 5secs)
the client could suffer from several malfunctions like DHCP client timeouts,
etc.

This patch adds an early detection mechanism that makes nodes in the network
able to recognise "not yet announced clients" by means of the broadcast packets
they emitted on connection (e.g. ARP or DHCP request). The added client will
then be confirmed upon receiving the OGM claiming it or purged if such OGM
is not received within a fixed amount of time.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-08-23 14:20:22 +02:00
Sven Eckelmann 56303d34a3 batman-adv: Prefix types structs with batadv_
Reported-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2012-07-01 22:47:21 +02:00
Sven Eckelmann 9641269011 batman-adv: Prefix packet structs with batadv_
Reported-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2012-07-01 22:47:21 +02:00
Antonio Quartulli d4f4469255 batman-adv: beautify tt_global_add() argument list
Instead of adding a new bool argument each time it is needed, it is better (and
simpler) to pass an 8bit flag argument which contains all the needed flags

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2012-06-28 08:44:52 +02:00
Sven Eckelmann 9cfc7bd608 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>
2012-06-20 22:15:33 +02:00
Sven Eckelmann 08c36d3e8a batman-adv: Prefix translation-table 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>
2012-06-20 22:15:29 +02:00
Marek Lindner be9aa4c1e0 batman-adv: turn tt commit code into routing protocol agnostic API
Prior to this patch the translation table code made assumptions about how
the routing protocol works and where its buffers are stored (to directly
modify them).
Each protocol now calls the tt code with the relevant pointers, thereby
abstracting the code.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2012-06-18 18:01:05 +02:00
Antonio Quartulli 3275e7cc84 batman-adv: improve unicast packet (re)routing
In case of a client X roaming from a generic node A to another node B, it is
possible that a third node C gets A's OGM but not B's. At this point in time, if
C wants to send data to X it will send a unicast packet destined to A. The
packet header will contain A's last ttvn (C got A's OGM and so it knows it).

The packet will travel towards A without being intercepted because the ttvn
contained in its header is the newest for A.

Once A will receive the packet, A's state will not report to be in a "roaming
phase" (because, after a roaming, once A sends out its OGM, all the changes are
committed and the node is considered not to be in the roaming state anymore)
and it will match the ttvn carried by the packet. Therefore there is no reason
for A to try to alter the packet's route, thus dropping the packet because the
destination client is not there anymore.

However, C is well aware that it's routing information towards the client X is
outdated as it received an OGM from A saying that the client roamed away.
Thanks to this detail, this patch introduces a small change in behaviour: as
long as C is in the state of not knowing the new location of client X it will
forward the traffic to its last known location using ttvn-1 of the destination.
By using an older ttvn node A will be forced to re-route the packet.
Intermediate nodes are also allowed to update the packet's destination as long
as they have the information about the client's new location.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-05-13 19:06:38 +02:00
Antonio Quartulli 35c133a000 batman-adv: add contributor name
translation_table.{c,h} have been heavily modified by another contributor and
for legal purposes it is better to include his name into the contributor list

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-05-11 13:56:08 +02:00
Sven Eckelmann de7aae6570 batman-adv: Remove declaration of only locally used functions
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:28:58 +02:00
Sven Eckelmann 567db7b0b7 batman-adv: Update copyright years
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2012-02-17 02:50:21 +08:00
Marek Lindner a943cac144 batman-adv: merge update_transtable() into tt related code
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2011-08-22 15:16:22 +02:00
Antonio Quartulli 3d393e4732 batman-adv: implement AP-isolation on the sender side
If a node has to send a packet issued by a WIFI client to another WIFI client,
the packet is dropped.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2011-08-22 15:16:21 +02:00
Antonio Quartulli 59b699cdee batman-adv: implement AP-isolation on the receiver side
When a node receives a unicast packet it checks if the source and the
destination client can communicate or not due to the AP isolation

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2011-08-22 15:16:20 +02:00
Antonio Quartulli bc2790808a batman-adv: detect clients connected through a 802.11 device
Clients connected through a 802.11 device are now marked with the
TT_CLIENT_WIFI flag. This flag is also advertised with the tt
announcement.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2011-08-22 15:16:20 +02:00
Antonio Quartulli 015758d002 batman-adv: correct several typ0s in the comments
Several typos have been corrected and some sentences have been rephrased

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2011-08-22 15:16:19 +02:00
Antonio Quartulli 058d0e2698 batman-adv: keep local table consistency for further TT_RESPONSE
To keep transtable consistency among all the nodes, an originator must
not send not yet announced clients within a full table TT_RESPONSE.
Instead, deleted client have to be kept in the table in order to be sent
within an immediate TT_RESPONSE. In this way all the nodes in the
network will always provide the same response for the same request.

All the modification are committed at the next ttvn increment event.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2011-07-07 18:49:26 +02:00
Antonio Quartulli 5fbc1598c2 batman-adv: unify flags for tt_change/tt_local_entry/tt_global_entry
The tt_local_entry structure now has a 'flags' field. This helps to
unify the flags format to all the client related structures (tt_global_entry
and tt_change). The 'never_purge' field is now encoded in the 'flags' one.
To optimise the usage of this field, its length has been increased to 16bit
in order to use the eight leading bits (from 0 to 7) to store flags that
have to be sent on the wire, while the eight ending ones are used for local
computation only.

Moreover 'enum tt_change_flags' is now called 'enum tt_client_flags' and the
defined values apply to the tt_local_entry, tt_global_entry and the tt_change
'flags' field.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2011-07-05 14:28:54 +02:00
Antonio Quartulli cc47f66e6b batman-adv: improved roaming mechanism
With the current client announcement implementation, in case of roaming,
an update is triggered on the new AP serving the client. At that point
the new information is spread around by means of the OGM broadcasting
mechanism. Until this operations is not executed, no node is able to
correctly route traffic towards the client. This obviously causes packet
drops and introduces a delay in the time needed by the client to recover
its connections.

A new packet type called ROAMING_ADVERTISEMENT is added to account this
issue.

This message is sent in case of roaming from the new AP serving the
client to the old one and will contain the client MAC address. In this
way an out-of-OGM update is immediately committed, so that the old node
can update its global translation table. Traffic reaching this node will
then be redirected to the correct destination utilising the fresher
information. Thus reducing the packet drops and the connection recovery
delay.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-06-20 11:37:27 +02:00
Antonio Quartulli a73105b8d4 batman-adv: improved client announcement mechanism
The client announcement mechanism informs every mesh node in the network
of any connected non-mesh client, in order to find the path towards that
client from any given point in the mesh.

The old implementation was based on the simple idea of appending a data
buffer to each OGM containing all the client MAC addresses the node is
serving. All other nodes can populate their global translation tables
(table which links client MAC addresses to node addresses) using this
MAC address buffer and linking it to the node's address contained in the
OGM. A node that wants to contact a client has to lookup the node the
client is connected to and its address in the global translation table.

It is easy to understand that this implementation suffers from several
issues:
 - big overhead (each and every OGM contains the entire list of
   connected clients)
 - high latencies for client route updates due to long OGM trip time and
   OGM losses

The new implementation addresses these issues by appending client
changes (new client joined or a client left) to the OGM instead of
filling it with all the client addresses each time. In this way nodes
can modify their global tables by means of "updates", thus reducing the
overhead within the OGMs.

To keep the entire network in sync each node maintains a translation
table version number (ttvn) and a translation table checksum. These
values are spread with the OGM to allow all the network participants to
determine whether or not they need to update their translation table
information.

When a translation table lookup is performed in order to send a packet
to a client attached to another node, the destination's ttvn is added to
the payload packet. Forwarding nodes can compare the packet's ttvn with
their destination's ttvn (this node could have a fresher information
than the source) and re-route the packet if necessary. This greatly
reduces the packet loss of clients roaming from one AP to the next.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-06-20 11:37:24 +02:00
Sven Eckelmann 747e4221a0 batman-adv: Add const type qualifier for pointers
batman-adv uses pointers which are marked as const and should not
violate that type qualifier by passing it to functions which force a
cast to the non-const version.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-05-30 07:39:31 +02:00
Antonio Quartulli 2dafb49d84 batman-adv: rename everything from *hna* into *tt* (translation table)
To be coherent, all the functions/variables/constants have been renamed
to the TranslationTable style

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-05-08 16:10:42 +02:00
Linus Lüssing ee1e884194 batman-adv: Remove duplicate types.h inclusions
types.h is included by main.h, which is included at the beginning of any
other c-file anyway. Therefore this commit removes those duplicate
inclussions.

Signed-off-by: Linus Lüssing <linus.luessing@ascom.ch>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-02-11 23:30:29 +01:00
Sven Eckelmann 64afe35398 batman-adv: Update copyright years
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-01-31 14:57:12 +01:00
Sven Eckelmann c6c8fea297 net: Add batman-adv meshing protocol
B.A.T.M.A.N. (better approach to mobile ad-hoc networking) is a routing
protocol for multi-hop ad-hoc mesh networks. The networks may be wired or
wireless. See http://www.open-mesh.org/ for more information and user space
tools.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-16 13:44:24 -08:00