[PATCH AUTOSEL for 4.4 14/35] mac80211: fix the update of path metric for RANN frame

[Sasha Levin]

From: Chun-Yeow Yeoh <yeohchuny...@gmail.com>

[ Upstream commit fbbdad5edf0bb59786a51b94a9d006bc8c2da9a2 ]

The previous path metric update from RANN frame has not considered
the own link metric toward the transmitting mesh STA. Fix this.

Reported-by: Michael65535
Signed-off-by: Chun-Yeow Yeoh <yeohchuny...@gmail.com>
Signed-off-by: Johannes Berg <johannes.b...@intel.com>
Signed-off-by: Sasha Levin <alexander.le...@microsoft.com>
---
 net/mac80211/mesh_hwmp.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index c6be0b4f4058..e68a409fc351 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -776,7 +776,7 @@ static void hwmp_rann_frame_process(struct 
ieee80211_sub_if_data *sdata,
        struct mesh_path *mpath;
        u8 ttl, flags, hopcount;
        const u8 *orig_addr;
-       u32 orig_sn, metric, metric_txsta, interval;
+       u32 orig_sn, new_metric, orig_metric, last_hop_metric, interval;
        bool root_is_gate;
 
        ttl = rann->rann_ttl;
@@ -787,7 +787,7 @@ static void hwmp_rann_frame_process(struct 
ieee80211_sub_if_data *sdata,
        interval = le32_to_cpu(rann->rann_interval);
        hopcount = rann->rann_hopcount;
        hopcount++;
-       metric = le32_to_cpu(rann->rann_metric);
+       orig_metric = le32_to_cpu(rann->rann_metric);
 
        /*  Ignore our own RANNs */
        if (ether_addr_equal(orig_addr, sdata->vif.addr))
@@ -804,7 +804,10 @@ static void hwmp_rann_frame_process(struct 
ieee80211_sub_if_data *sdata,
                return;
        }
 
-       metric_txsta = airtime_link_metric_get(local, sta);
+       last_hop_metric = airtime_link_metric_get(local, sta);
+       new_metric = orig_metric + last_hop_metric;
+       if (new_metric < orig_metric)
+               new_metric = MAX_METRIC;
 
        mpath = mesh_path_lookup(sdata, orig_addr);
        if (!mpath) {
@@ -817,7 +820,7 @@ static void hwmp_rann_frame_process(struct 
ieee80211_sub_if_data *sdata,
        }
 
        if (!(SN_LT(mpath->sn, orig_sn)) &&
-           !(mpath->sn == orig_sn && metric < mpath->rann_metric)) {
+           !(mpath->sn == orig_sn && new_metric < mpath->rann_metric)) {
                rcu_read_unlock();
                return;
        }
@@ -835,7 +838,7 @@ static void hwmp_rann_frame_process(struct 
ieee80211_sub_if_data *sdata,
        }
 
        mpath->sn = orig_sn;
-       mpath->rann_metric = metric + metric_txsta;
+       mpath->rann_metric = new_metric;
        mpath->is_root = true;
        /* Recording RANNs sender address to send individually
         * addressed PREQs destined for root mesh STA */
@@ -855,7 +858,7 @@ static void hwmp_rann_frame_process(struct 
ieee80211_sub_if_data *sdata,
                mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
                                       orig_sn, 0, NULL, 0, broadcast_addr,
                                       hopcount, ttl, interval,
-                                      metric + metric_txsta, 0, sdata);
+                                      new_metric, 0, sdata);
        }
 
        rcu_read_unlock();
-- 
2.11.0