batman-adv: add bat_neigh_cmp API function

This new API allows to compare the two neighbours based on
the metric avoiding the user to deal with any routing
algorithm specific detail

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

3 files changed, 25 insertions, 1 deletions

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 4aabd554ca75..b288d90855d1 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -1475,6 +1475,25 @@ next:
                 seq_puts(seq, "No batman nodes in range ...\n");
 }
 
+/**
+ * batadv_iv_ogm_neigh_cmp - compare the metrics of two neighbors
+ * @neigh1: the first neighbor object of the comparison
+ * @neigh2: the second neighbor object of the comparison
+ *
+ * Returns a value less, equal to or greater than 0 if the metric via neigh1 is
+ * lower, the same as or higher than the metric via neigh2
+ */
+static int batadv_iv_ogm_neigh_cmp(struct batadv_neigh_node *neigh1,
+                                   struct batadv_neigh_node *neigh2)
+{
+        uint8_t tq1, tq2;
+
+        tq1 = neigh1->bat_iv.tq_avg;
+        tq2 = neigh2->bat_iv.tq_avg;
+
+        return tq1 - tq2;
+}
+
 static struct batadv_algo_ops batadv_batman_iv __read_mostly = {
         .name = "BATMAN_IV",
         .bat_iface_enable = batadv_iv_ogm_iface_enable,
@@ -1483,6 +1502,7 @@ static struct batadv_algo_ops batadv_batman_iv __read_mostly = {
         .bat_primary_iface_set = batadv_iv_ogm_primary_iface_set,
         .bat_ogm_schedule = batadv_iv_ogm_schedule,
         .bat_ogm_emit = batadv_iv_ogm_emit,
+        .bat_neigh_cmp = batadv_iv_ogm_neigh_cmp,
         .bat_orig_print = batadv_iv_ogm_orig_print,
 };
 
diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index 3159a148c1ac..1f2f1ac67a4c 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -501,7 +501,8 @@ int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
             !bat_algo_ops->bat_iface_update_mac ||
             !bat_algo_ops->bat_primary_iface_set ||
             !bat_algo_ops->bat_ogm_schedule ||
-            !bat_algo_ops->bat_ogm_emit) {
+            !bat_algo_ops->bat_ogm_emit ||
+            !bat_algo_ops->bat_neigh_cmp) {
                 pr_info("Routing algo '%s' does not implement required ops\n",
                         bat_algo_ops->name);
                 ret = -EINVAL;
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 72fd617b2e73..7a00932a55bd 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -992,6 +992,7 @@ struct batadv_forw_packet {
  * @bat_primary_iface_set: called when primary interface is selected / changed
  * @bat_ogm_schedule: prepare a new outgoing OGM for the send queue
  * @bat_ogm_emit: send scheduled OGM
+ * @bat_neigh_cmp: compare the metrics of two neighbors
  * @bat_orig_print: print the originator table (optional)
  */
 struct batadv_algo_ops {
@@ -1003,6 +1004,8 @@ struct batadv_algo_ops {
         void (*bat_primary_iface_set)(struct batadv_hard_iface *hard_iface);
         void (*bat_ogm_schedule)(struct batadv_hard_iface *hard_iface);
         void (*bat_ogm_emit)(struct batadv_forw_packet *forw_packet);
+        int (*bat_neigh_cmp)(struct batadv_neigh_node *neigh1,
+                             struct batadv_neigh_node *neigh2);
         /* orig_node handling API */
         void (*bat_orig_print)(struct batadv_priv *priv, struct seq_file *seq);
 };