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path: root/net/batman-adv/translation-table.h
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2012-11-14batman-adv: substitute tt_poss_change with a per-tt_entry flagAntonio Quartulli
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>
2012-10-29batman-adv: pass the WIFI flag from the local to global entryAntonio Quartulli
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>
2012-08-23batman-adv: detect not yet announced clientsAntonio Quartulli
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>
2012-07-01batman-adv: Prefix types structs with batadv_Sven Eckelmann
Reported-by: Martin Hundebøll <martin@hundeboll.net> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2012-07-01batman-adv: Prefix packet structs with batadv_Sven Eckelmann
Reported-by: Martin Hundebøll <martin@hundeboll.net> Signed-off-by: Sven Eckelmann <sven@narfation.org>
2012-06-28batman-adv: beautify tt_global_add() argument listAntonio Quartulli
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>
2012-06-20batman-adv: Reformat multiline comments to consistent styleSven Eckelmann
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>
2012-06-20batman-adv: Prefix translation-table non-static functions with batadv_Sven Eckelmann
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>
2012-06-18batman-adv: turn tt commit code into routing protocol agnostic APIMarek Lindner
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>
2012-05-13batman-adv: improve unicast packet (re)routingAntonio Quartulli
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>
2012-05-11batman-adv: add contributor nameAntonio Quartulli
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>
2012-04-11batman-adv: Remove declaration of only locally used functionsSven Eckelmann
Signed-off-by: Sven Eckelmann <sven@narfation.org> Acked-by: Antonio Quartulli <ordex@autistici.org> Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-02-17batman-adv: Update copyright yearsSven Eckelmann
Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2011-08-22batman-adv: merge update_transtable() into tt related codeMarek Lindner
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
2011-08-22batman-adv: implement AP-isolation on the sender sideAntonio Quartulli
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>
2011-08-22batman-adv: implement AP-isolation on the receiver sideAntonio Quartulli
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>
2011-08-22batman-adv: detect clients connected through a 802.11 deviceAntonio Quartulli
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>
2011-08-22batman-adv: correct several typ0s in the commentsAntonio Quartulli
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>
2011-07-07batman-adv: keep local table consistency for further TT_RESPONSEAntonio Quartulli
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>
2011-07-05batman-adv: unify flags for tt_change/tt_local_entry/tt_global_entryAntonio Quartulli
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>
2011-06-20batman-adv: improved roaming mechanismAntonio Quartulli
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>
2011-06-20batman-adv: improved client announcement mechanismAntonio Quartulli
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>
2011-05-30batman-adv: Add const type qualifier for pointersSven Eckelmann
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>
2011-05-08batman-adv: rename everything from *hna* into *tt* (translation table)Antonio Quartulli
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>
2011-02-11batman-adv: Remove duplicate types.h inclusionsLinus Lüssing
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>
2011-01-31batman-adv: Update copyright yearsSven Eckelmann
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2010-12-16net: Add batman-adv meshing protocolSven Eckelmann
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>