batman-adv: add WiFi penalty

If the same interface is used for sending and receiving, there might be
throughput degradation on half-duplex interfaces such as WiFi. Add a
penalty if the same interface is used to reflect this problem in the
metric. At the same time, change the hop penalty from 30 to 15 so there
will be no change for single wifi mesh network. the effective hop
penalty will stay at 30 due to the new wifi penalty for these networks.

Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 1f9fe4270454957f2bad5581ae64629e38d73720..789aaa9f2e3a4c800d3b8a26adb78134417c1b24 100644 (file)
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -1088,6 +1088,7 @@ static int batadv_iv_ogm_calc_tq(struct batadv_orig_node *orig_node,
        unsigned int neigh_rq_inv_cube, neigh_rq_max_cube;
        int tq_asym_penalty, inv_asym_penalty, if_num, ret = 0;
        unsigned int combined_tq;
+       int tq_iface_penalty;
 
        /* find corresponding one hop neighbor */
        rcu_read_lock();
@@ -1169,15 +1170,31 @@ static int batadv_iv_ogm_calc_tq(struct batadv_orig_node *orig_node,
        inv_asym_penalty /= neigh_rq_max_cube;
        tq_asym_penalty = BATADV_TQ_MAX_VALUE - inv_asym_penalty;
 
-       combined_tq = batadv_ogm_packet->tq * tq_own * tq_asym_penalty;
-       combined_tq /= BATADV_TQ_MAX_VALUE * BATADV_TQ_MAX_VALUE;
+       /* penalize if the OGM is forwarded on the same interface. WiFi
+        * interfaces and other half duplex devices suffer from throughput
+        * drops as they can't send and receive at the same time.
+        */
+       tq_iface_penalty = BATADV_TQ_MAX_VALUE;
+       if (if_outgoing && (if_incoming == if_outgoing) &&
+           batadv_is_wifi_netdev(if_outgoing->net_dev))
+               tq_iface_penalty = batadv_hop_penalty(BATADV_TQ_MAX_VALUE,
+                                                     bat_priv);
+
+       combined_tq = batadv_ogm_packet->tq *
+                     tq_own *
+                     tq_asym_penalty *
+                     tq_iface_penalty;
+       combined_tq /= BATADV_TQ_MAX_VALUE *
+                      BATADV_TQ_MAX_VALUE *
+                      BATADV_TQ_MAX_VALUE;
        batadv_ogm_packet->tq = combined_tq;
 
        batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
-                  "bidirectional: orig = %-15pM neigh = %-15pM => own_bcast = %2i, real recv = %2i, local tq: %3i, asym_penalty: %3i, total tq: %3i\n",
+                  "bidirectional: orig = %-15pM neigh = %-15pM => own_bcast = %2i, real recv = %2i, local tq: %3i, asym_penalty: %3i, iface_penalty: %3i, total tq: %3i, if_incoming = %s, if_outgoing = %s\n",
                   orig_node->orig, orig_neigh_node->orig, total_count,
-                  neigh_rq_count, tq_own,
-                  tq_asym_penalty, batadv_ogm_packet->tq);
+                  neigh_rq_count, tq_own, tq_asym_penalty, tq_iface_penalty,
+                  batadv_ogm_packet->tq, if_incoming->net_dev->name,
+                  if_outgoing ? if_outgoing->net_dev->name : "DEFAULT");
 
        /* if link has the minimum required transmission quality
         * consider it bidirectional

diff --git a/net/batman-adv/hard-interface.h b/net/batman-adv/hard-interface.h
index 8d4304b74b5d0f9a7797b7d92c261d083bc0f48d..ccd42c2b95bad4d596c1310ed0d393f7006a61a7 100644 (file)
--- a/net/batman-adv/hard-interface.h
+++ b/net/batman-adv/hard-interface.h
@@ -40,6 +40,7 @@ enum batadv_hard_if_cleanup {
 extern struct notifier_block batadv_hard_if_notifier;
 
 bool batadv_is_wifi_netdev(struct net_device *net_device);
+bool batadv_is_wifi_iface(int ifindex);
 struct batadv_hard_iface*
 batadv_hardif_get_by_netdev(const struct net_device *net_dev);
 int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,

diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index c50f64337f55af4af152f51c6021c584e06862fa..2dc22702dd11bd0b89673cd04f89f06a89ff0937 100644 (file)
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -697,7 +697,7 @@ static int batadv_softif_init_late(struct net_device *dev)
        atomic_set(&bat_priv->gw.bandwidth_down, 100);
        atomic_set(&bat_priv->gw.bandwidth_up, 20);
        atomic_set(&bat_priv->orig_interval, 1000);
-       atomic_set(&bat_priv->hop_penalty, 30);
+       atomic_set(&bat_priv->hop_penalty, 15);
 #ifdef CONFIG_BATMAN_ADV_DEBUG
        atomic_set(&bat_priv->log_level, 0);
 #endif