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

Sasha Levin
2018-01-24T04:29:14Z

From: Chun-Yeow Yeoh <yeohchunyeow@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 <yeohchunyeow@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@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