nl80211/mac80211: mesh: add hop count to mpath info

Expose hop count to destination information in mpath info
Signed-off-by: Julan Hsu <julanhsu@google.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -1429,6 +1429,7 @@ enum monitor_flags {
  * @MPATH_INFO_DISCOVERY_TIMEOUT: @discovery_timeout filled
  * @MPATH_INFO_DISCOVERY_RETRIES: @discovery_retries filled
  * @MPATH_INFO_FLAGS: @flags filled
+ * @MPATH_INFO_HOP_COUNT: @hop_count filled
  */
 enum mpath_info_flags {
 	MPATH_INFO_FRAME_QLEN		= BIT(0),
@@ -1438,6 +1439,7 @@ enum mpath_info_flags {
 	MPATH_INFO_DISCOVERY_TIMEOUT	= BIT(4),
 	MPATH_INFO_DISCOVERY_RETRIES	= BIT(5),
 	MPATH_INFO_FLAGS		= BIT(6),
+	MPATH_INFO_HOP_COUNT		= BIT(7)
 };
 
 /**
@@ -1457,6 +1459,7 @@ enum mpath_info_flags {
  *	This number should increase every time the list of mesh paths
  *	changes, i.e. when a station is added or removed, so that
  *	userspace can tell whether it got a consistent snapshot.
+ * @hop_count: hops to destination
  */
 struct mpath_info {
 	u32 filled;
@@ -1467,6 +1470,7 @@ struct mpath_info {
 	u32 discovery_timeout;
 	u8 discovery_retries;
 	u8 flags;
+	u8 hop_count;
 
 	int generation;
 };

include/uapi/linux/nl80211.h

@@ -3287,6 +3287,7 @@ enum nl80211_mpath_flags {
  * 	&enum nl80211_mpath_flags;
  * @NL80211_MPATH_INFO_DISCOVERY_TIMEOUT: total path discovery timeout, in msec
  * @NL80211_MPATH_INFO_DISCOVERY_RETRIES: mesh path discovery retries
+ * @NL80211_MPATH_INFO_HOP_COUNT: hop count to destination
  * @NL80211_MPATH_INFO_MAX: highest mesh path information attribute number
  *	currently defind
  * @__NL80211_MPATH_INFO_AFTER_LAST: internal use
@@ -3300,6 +3301,7 @@ enum nl80211_mpath_info {
 	NL80211_MPATH_INFO_FLAGS,
 	NL80211_MPATH_INFO_DISCOVERY_TIMEOUT,
 	NL80211_MPATH_INFO_DISCOVERY_RETRIES,
+	NL80211_MPATH_INFO_HOP_COUNT,
 
 	/* keep last */
 	__NL80211_MPATH_INFO_AFTER_LAST,

net/mac80211/cfg.c

@@ -1745,7 +1745,8 @@ static void mpath_set_pinfo(struct mesh_path *mpath, u8 *next_hop,
 			MPATH_INFO_EXPTIME |
 			MPATH_INFO_DISCOVERY_TIMEOUT |
 			MPATH_INFO_DISCOVERY_RETRIES |
-			MPATH_INFO_FLAGS;
+			MPATH_INFO_FLAGS |
+			MPATH_INFO_HOP_COUNT;
 
 	pinfo->frame_qlen = mpath->frame_queue.qlen;
 	pinfo->sn = mpath->sn;
@@ -1765,6 +1766,7 @@ static void mpath_set_pinfo(struct mesh_path *mpath, u8 *next_hop,
 		pinfo->flags |= NL80211_MPATH_FLAG_FIXED;
 	if (mpath->flags & MESH_PATH_RESOLVED)
 		pinfo->flags |= NL80211_MPATH_FLAG_RESOLVED;
+	pinfo->hop_count = mpath->hop_count;
 }
 
 static int ieee80211_get_mpath(struct wiphy *wiphy, struct net_device *dev,

net/mac80211/mesh_hwmp.c

@@ -386,6 +386,7 @@ static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
 	unsigned long orig_lifetime, exp_time;
 	u32 last_hop_metric, new_metric;
 	bool process = true;
+	u8 hopcount;
 
 	rcu_read_lock();
 	sta = sta_info_get(sdata, mgmt->sa);
@@ -404,6 +405,7 @@ static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
 		orig_sn = PREQ_IE_ORIG_SN(hwmp_ie);
 		orig_lifetime = PREQ_IE_LIFETIME(hwmp_ie);
 		orig_metric = PREQ_IE_METRIC(hwmp_ie);
+		hopcount = PREQ_IE_HOPCOUNT(hwmp_ie) + 1;
 		break;
 	case MPATH_PREP:
 		/* Originator here refers to the MP that was the target in the
@@ -415,6 +417,7 @@ static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
 		orig_sn = PREP_IE_TARGET_SN(hwmp_ie);
 		orig_lifetime = PREP_IE_LIFETIME(hwmp_ie);
 		orig_metric = PREP_IE_METRIC(hwmp_ie);
+		hopcount = PREP_IE_HOPCOUNT(hwmp_ie) + 1;
 		break;
 	default:
 		rcu_read_unlock();
@@ -482,6 +485,7 @@ static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
 			mpath->sn = orig_sn;
 			mpath->exp_time = time_after(mpath->exp_time, exp_time)
 					  ?  mpath->exp_time : exp_time;
+			mpath->hop_count = hopcount;
 			mesh_path_activate(mpath);
 			spin_unlock_bh(&mpath->state_lock);
 			ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);
@@ -523,6 +527,7 @@ static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
 			mpath->metric = last_hop_metric;
 			mpath->exp_time = time_after(mpath->exp_time, exp_time)
 					  ?  mpath->exp_time : exp_time;
+			mpath->hop_count = 1;
 			mesh_path_activate(mpath);
 			spin_unlock_bh(&mpath->state_lock);
 			ewma_mesh_fail_avg_init(&sta->mesh->fail_avg);

net/wireless/nl80211.c

@@ -5827,7 +5827,10 @@ static int nl80211_send_mpath(struct sk_buff *msg, u32 portid, u32 seq,
 			 pinfo->discovery_timeout)) ||
 	    ((pinfo->filled & MPATH_INFO_DISCOVERY_RETRIES) &&
 	     nla_put_u8(msg, NL80211_MPATH_INFO_DISCOVERY_RETRIES,
-			pinfo->discovery_retries)))
+			pinfo->discovery_retries)) ||
+	    ((pinfo->filled & MPATH_INFO_HOP_COUNT) &&
+	     nla_put_u8(msg, NL80211_MPATH_INFO_HOP_COUNT,
+			pinfo->hop_count)))
 		goto nla_put_failure;
 
 	nla_nest_end(msg, pinfoattr);