1. 29 2月, 2016 2 次提交
    • A
      batman-adv: ELP - compute the metric based on the estimated throughput · c833484e
      Antonio Quartulli 提交于
      In case of wireless interface retrieve the throughput by
      querying cfg80211. To perform this call a separate work
      must be scheduled because the function may sleep and this
      is not allowed within an RCU protected context (RCU in this
      case is used to iterate over all the neighbours).
      
      Use ethtool to retrieve information about an Ethernet link
      like HALF/FULL_DUPLEX and advertised bandwidth (e.g.
      100/10Mbps).
      
      The metric is updated each time a new ELP packet is sent,
      this way it is possible to timely react to a metric
      variation which can imply (for example) a neighbour
      disconnection.
      Signed-off-by: NAntonio Quartulli <antonio@open-mesh.com>
      Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
      c833484e
    • L
      batman-adv: ELP - adding basic infrastructure · d6f94d91
      Linus Luessing 提交于
      The B.A.T.M.A.N. protocol originally only used a single
      message type (called OGM) to determine the link qualities to
      the direct neighbors and spreading these link quality
      information through the whole mesh. This procedure is
      summarized on the BATMAN concept page and explained in
      details in the RFC draft published in 2008.
      
      This approach was chosen for its simplicity during the
      protocol design phase and the implementation. However, it
      also bears some drawbacks:
      
       *  Wireless interfaces usually come with some packet loss,
          therefore a higher broadcast rate is desirable to allow
          a fast reaction on flaky connections.
          Other interfaces of the same host might be connected to
          Ethernet LANs / VPNs / etc which rarely exhibit packet
          loss would benefit from a lower broadcast rate to reduce
          overhead.
       *  It generally is more desirable to detect local link
          quality changes at a faster rate than propagating all
          these changes through the entire mesh (the far end of
          the mesh does not need to care about local link quality
          changes that much). Other optimizations strategies, like
          reducing overhead, might be possible if OGMs weren't
          used for all tasks in the mesh at the same time.
      
      As a result detecting local link qualities shall be handled
      by an independent message type, ELP, whereas the OGM message
      type remains responsible for flooding the mesh with these
      link quality information and determining the overall path
      transmit qualities.
      
      Developed by Linus during a 6 months trainee study period in
      Ascom (Switzerland) AG.
      Signed-off-by: NLinus Luessing <linus.luessing@web.de>
      Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
      Signed-off-by: NAntonio Quartulli <antonio@open-mesh.com>
      d6f94d91
  2. 03 2月, 2016 1 次提交
  3. 08 1月, 2015 1 次提交
  4. 22 3月, 2014 1 次提交
  5. 16 1月, 2014 1 次提交
  6. 12 1月, 2014 1 次提交
  7. 14 3月, 2013 1 次提交
    • M
      batman-adv: network coding - add the initial infrastructure code · d353d8d4
      Martin Hundebøll 提交于
      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/CatwomanSigned-off-by: NMartin Hundebøll <martin@hundeboll.net>
      Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
      Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
      d353d8d4
  8. 21 11月, 2012 1 次提交
  9. 08 11月, 2012 2 次提交
  10. 11 4月, 2012 3 次提交
  11. 20 6月, 2011 1 次提交
    • A
      batman-adv: improved client announcement mechanism · a73105b8
      Antonio Quartulli 提交于
      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: NAntonio Quartulli <ordex@autistici.org>
      Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
      Signed-off-by: NSven Eckelmann <sven@narfation.org>
      a73105b8
  12. 17 12月, 2010 1 次提交
  13. 09 7月, 2010 1 次提交
  14. 04 3月, 2010 2 次提交
  15. 24 12月, 2009 1 次提交
  16. 12 12月, 2009 3 次提交