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  1. Jun 20, 2011
    • Antonio Quartulli's avatar
      batman-adv: improved client announcement mechanism · a73105b8
      Antonio Quartulli authored 
      

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: default avatarAntonio Quartulli <ordex@autistici.org>
Signed-off-by: default avatarMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
      a73105b8
    • Antonio Quartulli's avatar
      batman-adv: Unify the first 3 bytes in each packet · 3b27ffb0
      Antonio Quartulli authored 
      

The amount of duplicated code in the receive and routing code can be
reduced when all headers provide the packet type, version and ttl in the
same first bytes.

Signed-off-by: default avatarAntonio Quartulli <ordex@autistici.org>
Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
      3b27ffb0
    • Sven Eckelmann's avatar
      batman-adv: Reduce usage of char · b4e17054
      Sven Eckelmann authored 
      

char was used in different places to store information without really
using the characteristics of that data type or by ignoring the fact that
char has not a well defined signedness.

Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
      b4e17054
    • David Howells's avatar
      batman-adv: count_real_packets() in batman-adv assumes char is signed · b2c44a53
      David Howells authored 
      

count_real_packets() in batman-adv assumes char is signed, and returns -1
through it:

net/batman-adv/routing.c: In function 'receive_bat_packet':
net/batman-adv/routing.c:739: warning: comparison is always false due to limited range of data type

Use int instead.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
[sven@narfation.org: Rebase on top of current version]
Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
      b2c44a53
    • Sven Eckelmann's avatar
      batman-adv: Keep interface_tx as local function · db69ecfc
      Sven Eckelmann authored 
      

interface_tx is not used outside of soft-interface.c and thus doesn't
need to be declared inside soft-interface.h

Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
      db69ecfc
    • Sven Eckelmann's avatar
      batman-adv: Move compare_orig to originator.c · b8e2dd13
      Sven Eckelmann authored 
      

compare_orig is only used in context of orig_node which is managed
inside originator.c. It is not necessary to keep that function inside
the header originator.h.

Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
      b8e2dd13
  3. Jun 10, 2011
  5. May 30, 2011