Repository : ssh://git@open-mesh.org/batctl
On branch : next
commit 3ce90d7311b697cb9402def914bf2bfd31a6ada6 Author: Linus Luessing linus.luessing@web.de Date: Sat Jan 16 16:40:09 2016 +0800
batctl: ELP - adding basic infrastructure
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: Linus Luessing linus.luessing@web.de Signed-off-by: Marek Lindner mareklindner@neomailbox.ch Signed-off-by: Antonio Quartulli antonio@open-mesh.com Signed-off-by: Marek Lindner mareklindner@neomailbox.ch
3ce90d7311b697cb9402def914bf2bfd31a6ada6 packet.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/packet.h b/packet.h index e7f9151..c698b64 100644 --- a/packet.h +++ b/packet.h @@ -26,6 +26,7 @@ * @BATADV_IV_OGM: originator messages for B.A.T.M.A.N. IV * @BATADV_BCAST: broadcast packets carrying broadcast payload * @BATADV_CODED: network coded packets + * @BATADV_ELP: echo location packets for B.A.T.M.A.N. V * * @BATADV_UNICAST: unicast packets carrying unicast payload traffic * @BATADV_UNICAST_FRAG: unicast packets carrying a fragment of the original @@ -40,6 +41,7 @@ enum batadv_packettype { BATADV_IV_OGM = 0x00, BATADV_BCAST = 0x01, BATADV_CODED = 0x02, + BATADV_ELP = 0x03, /* 0x40 - 0x7f: unicast */ #define BATADV_UNICAST_MIN 0x40 BATADV_UNICAST = 0x40, @@ -235,6 +237,24 @@ struct batadv_ogm_packet { #define BATADV_OGM_HLEN sizeof(struct batadv_ogm_packet)
/** + * struct batadv_elp_packet - elp (neighbor discovery) packet + * @packet_type: batman-adv packet type, part of the general header + * @version: batman-adv protocol version, part of the genereal header + * @orig: originator mac address + * @seqno: sequence number + * @elp_interval: currently used ELP sending interval in ms + */ +struct batadv_elp_packet { + u8 packet_type; + u8 version; + u8 orig[ETH_ALEN]; + __be32 seqno; + __be32 elp_interval; +}; + +#define BATADV_ELP_HLEN sizeof(struct batadv_elp_packet) + +/** * struct batadv_icmp_header - common members among all the ICMP packets * @packet_type: batman-adv packet type, part of the general header * @version: batman-adv protocol version, part of the genereal header