20 Nov, 2011

1 commit

  • Several functions in the translation table management code assume that the
    tt_global_entry and tt_local_entry structures have the same initial fields such
    as 'addr' and 'hash_entry'. To improve the code readability and to avoid
    mistakes in later changes, a common substructure that substitute the shared
    fields has been introduced (struct tt_common_entry).

    Thanks to this modification, it has also been possible to slightly reduce the
    code length by merging some functions like compare_ltt/gtt() and
    tt_local/global_hash_find()

    Signed-off-by: Antonio Quartulli
    Signed-off-by: Sven Eckelmann

    Antonio Quartulli
     

30 Oct, 2011

1 commit


25 Oct, 2011

1 commit

  • Function tt_response_fill_table() actually uses a tt_local_entry pointer to
    iterate either over the local or the global table entries (it depends on the
    what hash table is passed as argument). To iterate over such entries the
    hlist_for_each_entry_rcu() macro has to access their "hash_entry" field which
    MUST be at the same position in both the tt_global/local_entry structures.

    Reported-by: Simon Wunderlich
    Signed-off-by: Antonio Quartulli
    Signed-off-by: Marek Lindner

    Antonio Quartulli
     

22 Aug, 2011

2 commits


05 Jul, 2011

1 commit

  • 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
    Signed-off-by: Marek Lindner

    Antonio Quartulli
     

20 Jun, 2011

4 commits

  • The gateway election mechanism has been a little revised. Now the
    gw_election is trigered by an atomic_t flag (gw_reselect) which is set
    to 1 in case of election needed, avoding to set curr_gw to NULL.

    Signed-off-by: Antonio Quartulli
    Signed-off-by: Marek Lindner
    Signed-off-by: Sven Eckelmann

    Antonio Quartulli
     
  • The local and the global translation-tables are now lock free and rcu
    protected.

    Signed-off-by: Antonio Quartulli
    Acked-by: Simon Wunderlich
    Signed-off-by: Sven Eckelmann

    Antonio 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
    Signed-off-by: Sven Eckelmann

    Antonio 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
    Signed-off-by: Marek Lindner
    Signed-off-by: Sven Eckelmann

    Antonio Quartulli
     

30 May, 2011

1 commit


08 May, 2011

3 commits


02 May, 2011

1 commit


18 Apr, 2011

3 commits


05 Mar, 2011

17 commits


31 Jan, 2011

1 commit


16 Jan, 2011

1 commit

  • Linux 2.6.21 defines different macros for __attribute__ which are also
    used inside batman-adv. The next version of checkpatch.pl warns about
    the usage of __attribute__((packed))).

    Linux 2.6.33 defines an extra macro __always_unused which is used to
    assist source code analyzers and can be used to removed the last
    existing __attribute__ inside the source code.

    Signed-off-by: Sven Eckelmann

    Sven Eckelmann
     

17 Dec, 2010

1 commit

  • 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
    Signed-off-by: David S. Miller

    Sven Eckelmann