{nl,cfg,mac}80211: implement dot11MeshHWMPconfirmationInterval

As defined in section 13.10.9.3 Case D (802.11-2012), this
control variable is used to limit the mesh STA to send only
one PREQ to a root mesh STA within this interval of time
(in TUs). The default value for this variable is set to
2000 TUs. However, for current implementation, the maximum
configurable of dot11MeshHWMPconfirmationInterval is
restricted by dot11MeshHWMPactivePathTimeout.

Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow@gmail.com>
[line-break commit log]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

4 files changed, 14 insertions, 1 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 5bd316c0a63d..6e25ac4873c7 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1596,6 +1596,9 @@ static int ieee80211_update_mesh_config(struct wiphy *wiphy,
 	if (_chg_mesh_attr(NL80211_MESHCONF_HWMP_ROOT_INTERVAL, mask))
 		conf->dot11MeshHWMProotInterval =
 			nconf->dot11MeshHWMProotInterval;
+	if (_chg_mesh_attr(NL80211_MESHCONF_HWMP_CONFIRMATION_INTERVAL, mask))
+		conf->dot11MeshHWMPconfirmationInterval =
+			nconf->dot11MeshHWMPconfirmationInterval;
 	return 0;
 }
 
diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c
index a8cea70902e4..512c894893d6 100644
--- a/net/mac80211/debugfs_netdev.c
+++ b/net/mac80211/debugfs_netdev.c
@@ -514,6 +514,8 @@ IEEE80211_IF_FILE(dot11MeshHWMPactivePathToRootTimeout,
 		  u.mesh.mshcfg.dot11MeshHWMPactivePathToRootTimeout, DEC);
 IEEE80211_IF_FILE(dot11MeshHWMProotInterval,
 		  u.mesh.mshcfg.dot11MeshHWMProotInterval, DEC);
+IEEE80211_IF_FILE(dot11MeshHWMPconfirmationInterval,
+		  u.mesh.mshcfg.dot11MeshHWMPconfirmationInterval, DEC);
 #endif
 
 #define DEBUGFS_ADD_MODE(name, mode) \
@@ -617,6 +619,7 @@ static void add_mesh_config(struct ieee80211_sub_if_data *sdata)
 	MESHPARAMS_ADD(ht_opmode);
 	MESHPARAMS_ADD(dot11MeshHWMPactivePathToRootTimeout);
 	MESHPARAMS_ADD(dot11MeshHWMProotInterval);
+	MESHPARAMS_ADD(dot11MeshHWMPconfirmationInterval);
 #undef MESHPARAMS_ADD
 }
 #endif
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index c7400a23b64b..faaa39bcfd10 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -104,6 +104,7 @@ enum mesh_deferred_task_flags {
  * an mpath to a hash bucket on a path table.
  * @rann_snd_addr: the RANN sender address
  * @rann_metric: the aggregated path metric towards the root node
+ * @last_preq_to_root: Timestamp of last PREQ sent to root
  * @is_root: the destination station of this path is a root node
  * @is_gate: the destination station of this path is a mesh gate
  *
@@ -131,6 +132,7 @@ struct mesh_path {
 	spinlock_t state_lock;
 	u8 rann_snd_addr[ETH_ALEN];
 	u32 rann_metric;
+	unsigned long last_preq_to_root;
 	bool is_root;
 	bool is_gate;
 };
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index 35e3acbe2262..bea52479e3aa 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -98,6 +98,8 @@ static inline u32 u16_field_get(u8 *preq_elem, int offset, bool ae)
 #define max_preq_retries(s) (s->u.mesh.mshcfg.dot11MeshHWMPmaxPREQretries)
 #define disc_timeout_jiff(s) \
 	msecs_to_jiffies(sdata->u.mesh.mshcfg.min_discovery_timeout)
+#define root_path_confirmation_jiffies(s) \
+	msecs_to_jiffies(sdata->u.mesh.mshcfg.dot11MeshHWMPconfirmationInterval)
 
 enum mpath_frame_type {
 	MPATH_PREQ = 0,
@@ -811,11 +813,14 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
 	}
 
 	if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
-	     time_after(jiffies, mpath->exp_time - 1*HZ)) &&
+	     (time_after(jiffies, mpath->last_preq_to_root +
+				  root_path_confirmation_jiffies(sdata)) ||
+	     time_before(jiffies, mpath->last_preq_to_root))) &&
 	     !(mpath->flags & MESH_PATH_FIXED)) {
 		mhwmp_dbg("%s time to refresh root mpath %pM", sdata->name,
 							       orig_addr);
 		mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
+		mpath->last_preq_to_root = jiffies;
 	}
 
 	if ((SN_LT(mpath->sn, orig_sn) || (mpath->sn == orig_sn &&