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, 18 insertions, 0 deletions

diff --git a/net/batman-adv/debugfs.c b/net/batman-adv/debugfs.c
index 6ae86516db4d..f186a55b23c3 100644
--- a/net/batman-adv/debugfs.c
+++ b/net/batman-adv/debugfs.c
@@ -32,6 +32,7 @@
 #include "icmp_socket.h"
 #include "bridge_loop_avoidance.h"
 #include "distributed-arp-table.h"
+#include "network-coding.h"
 
 static struct dentry *batadv_debugfs;
 
@@ -310,6 +311,14 @@ struct batadv_debuginfo {
         const struct file_operations fops;
 };
 
+#ifdef CONFIG_BATMAN_ADV_NC
+static int batadv_nc_nodes_open(struct inode *inode, struct file *file)
+{
+        struct net_device *net_dev = (struct net_device *)inode->i_private;
+        return single_open(file, batadv_nc_nodes_seq_print_text, net_dev);
+}
+#endif
+
 #define BATADV_DEBUGINFO(_name, _mode, _open)           \
 struct batadv_debuginfo batadv_debuginfo_##_name = {    \
         .attr = { .name = __stringify(_name),           \
@@ -348,6 +357,9 @@ static BATADV_DEBUGINFO(dat_cache, S_IRUGO, batadv_dat_cache_open);
 static BATADV_DEBUGINFO(transtable_local, S_IRUGO,
                         batadv_transtable_local_open);
 static BATADV_DEBUGINFO(vis_data, S_IRUGO, batadv_vis_data_open);
+#ifdef CONFIG_BATMAN_ADV_NC
+static BATADV_DEBUGINFO(nc_nodes, S_IRUGO, batadv_nc_nodes_open);
+#endif
 
 static struct batadv_debuginfo *batadv_mesh_debuginfos[] = {
         &batadv_debuginfo_originators,
@@ -362,6 +374,9 @@ static struct batadv_debuginfo *batadv_mesh_debuginfos[] = {
 #endif
         &batadv_debuginfo_transtable_local,
         &batadv_debuginfo_vis_data,
+#ifdef CONFIG_BATMAN_ADV_NC
+        &batadv_debuginfo_nc_nodes,
+#endif
         NULL,
 };
 
@@ -431,6 +446,9 @@ int batadv_debugfs_add_meshif(struct net_device *dev)
                 }
         }
 
+        if (batadv_nc_init_debugfs(bat_priv) < 0)
+                goto rem_attr;
+
         return 0;
 rem_attr:
         debugfs_remove_recursive(bat_priv->debug_dir);