Staging: batman-adv: Add bonding functionality

This patch introduces bonding functionality to batman-advanced, targeted
for the 0.3 release. As we are able to route the payload traffic as we
want, we may use multiple interfaces on multihomed hosts to transfer data
to achieve higher bandwidth. This can be considered as "light Multi Path
Routing" for single hop connections.

To detect which interfaces of a peer node belong to the same host, a
new flag PRIMARIES_FIRST_HOP is introduced. This flag is set on the first hop
of OGMs of the primary (first) interface, which is broadcasted on all
interfaces. When receiving such an OGM, we can learn which interfaces
belong to the same host (by assigning them to the primary originator).

Bonding works by sending packets in a round-robin fashion to the available
interfaces of a neighbor host, if multiple interfaces are available. The
neighbor interfaces should be almost equally good to reach.

To avoid interferences (i.e. sending on the same channel), only neighbor
interfaces with different mac addresses and different outgoing interfaces
are considered as candidates.

Bonding is deactivated by default, and can be activated by

echo 1 > /sys/class/net/bat0/mesh/bonding

for each individual node.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
[sven.eckelmann@gmx.de: Rework on top of current version]
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/staging/batman-adv/types.h b/drivers/staging/batman-adv/types.h
index d0af489..84c3f43 100644
--- a/drivers/staging/batman-adv/types.h
+++ b/drivers/staging/batman-adv/types.h
@@ -52,6 +52,7 @@ struct batman_if {
 
 /**
   *	orig_node - structure for orig_list maintaining nodes of mesh
+  *	@primary_addr: hosts primary interface address
   *	@last_valid: when last packet from this node was received
   *	@bcast_seqno_reset: time when the broadcast seqno window was reset
   *	@batman_seqno_reset: time when the batman seqno window was reset
@@ -59,9 +60,13 @@ struct batman_if {
   *	@last_real_seqno: last and best known squence number
   *	@last_ttl: ttl of last received packet
   *	@last_bcast_seqno: last broadcast sequence number received by this host
+  *
+  *	@candidates: how many candidates are available
+  *	@selected: next bonding candidate
  */
 struct orig_node {
 	uint8_t orig[ETH_ALEN];
+	uint8_t primary_addr[ETH_ALEN];
 	struct neigh_node *router;
 	TYPE_OF_WORD *bcast_own;
 	uint8_t *bcast_own_sum;
@@ -78,6 +83,10 @@ struct orig_node {
 	TYPE_OF_WORD bcast_bits[NUM_WORDS];
 	uint32_t last_bcast_seqno;
 	struct list_head neigh_list;
+	struct {
+		uint8_t candidates;
+		struct neigh_node *selected;
+	} bond;
 };
 
 /**
@@ -92,6 +101,7 @@ struct neigh_node {
 	uint8_t tq_index;
 	uint8_t tq_avg;
 	uint8_t last_ttl;
+	struct neigh_node *next_bond_candidate;
 	unsigned long last_valid;
 	TYPE_OF_WORD real_bits[NUM_WORDS];
 	struct orig_node *orig_node;
@@ -101,6 +111,7 @@ struct neigh_node {
 struct bat_priv {
 	struct net_device_stats stats;
 	atomic_t aggregation_enabled;
+	atomic_t bonding_enabled;
 	atomic_t vis_mode;
 	atomic_t orig_interval;
 	char num_ifaces;