batman-adv: network coding - detect coding nodes and remove these after timeout

To use network coding efficiently, a relay must know when neighbor nodes
are likely to have enough information to be able to decode a network
coded packet. This is detected by using OGMs from batman-adv to discover
when one neighbor is in range of another neighbor. The relay check the
TLL to detect when an OGM is forwarded from one neighbor by another
neighbor, and thereby knows that the two neighbors are in range and thus
overhear packets sent by each other.

This information is saved in the orig_node struct to be used when
searching for coding opportunities. Two lists are added to the
orig_node struct: One for neighbors that can hear the orig_node
(outgoing nc_nodes) and one for neighbors that the orig_node can hear
(incoming nc_nodes).

Information about nc_nodes is kept for 10 seconds and is available
through debugfs in batman_adv/nc_nodes to use when debugging network
coding.

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

1 files changed, 47 insertions, 0 deletions

diff --git a/net/batman-adv/network-coding.h b/net/batman-adv/network-coding.h
index 7483cba4b5d4..4c56cd98d9de 100644
--- a/net/batman-adv/network-coding.h
+++ b/net/batman-adv/network-coding.h
@@ -24,7 +24,19 @@
 
 int batadv_nc_init(struct batadv_priv *bat_priv);
 void batadv_nc_free(struct batadv_priv *bat_priv);
+void batadv_nc_update_nc_node(struct batadv_priv *bat_priv,
+                              struct batadv_orig_node *orig_node,
+                              struct batadv_orig_node *orig_neigh_node,
+                              struct batadv_ogm_packet *ogm_packet,
+                              int is_single_hop_neigh);
+void batadv_nc_purge_orig(struct batadv_priv *bat_priv,
+                          struct batadv_orig_node *orig_node,
+                          bool (*to_purge)(struct batadv_priv *,
+                                           struct batadv_nc_node *));
 void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv);
+void batadv_nc_init_orig(struct batadv_orig_node *orig_node);
+int batadv_nc_nodes_seq_print_text(struct seq_file *seq, void *offset);
+int batadv_nc_init_debugfs(struct batadv_priv *bat_priv);
 
 #else /* ifdef CONFIG_BATMAN_ADV_NC */
 
@@ -38,11 +50,46 @@ static inline void batadv_nc_free(struct batadv_priv *bat_priv)
         return;
 }
 
+static inline void
+batadv_nc_update_nc_node(struct batadv_priv *bat_priv,
+                         struct batadv_orig_node *orig_node,
+                         struct batadv_orig_node *orig_neigh_node,
+                         struct batadv_ogm_packet *ogm_packet,
+                         int is_single_hop_neigh)
+{
+        return;
+}
+
+static inline void
+batadv_nc_purge_orig(struct batadv_priv *bat_priv,
+                     struct batadv_orig_node *orig_node,
+                     bool (*to_purge)(struct batadv_priv *,
+                                      struct batadv_nc_node *))
+{
+        return;
+}
+
 static inline void batadv_nc_init_bat_priv(struct batadv_priv *bat_priv)
 {
         return;
 }
 
+static inline void batadv_nc_init_orig(struct batadv_orig_node *orig_node)
+{
+        return;
+}
+
+static inline int batadv_nc_nodes_seq_print_text(struct seq_file *seq,
+                                                 void *offset)
+{
+        return 0;
+}
+
+static inline int batadv_nc_init_debugfs(struct batadv_priv *bat_priv)
+{
+        return 0;
+}
+
 #endif /* ifdef CONFIG_BATMAN_ADV_NC */
 
 #endif /* _NET_BATMAN_ADV_NETWORK_CODING_H_ */