[PATCH] mac80211: fix the update of path metric for RANN frame

[PATCH] mac80211: fix the update of path metric for RANN frame

[Chun-Yeow Yeoh]

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>
---
 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 c1d1b86..35ad398 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -797,7 +797,7 @@ 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;
@@ -808,7 +808,7 @@ 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))
@@ -825,7 +825,10 @@ 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) {
@@ -838,7 +841,7 @@ 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;
 	}
@@ -856,7 +859,7 @@ 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 */
@@ -876,7 +879,7 @@ 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();
-- 
2.3.0

Re: [PATCH] mac80211: fix the update of path metric for RANN frame

[Thomas Pedersen]

Thanks Chun-Yeow, this is a good change.

On Tue, Nov 14, 2017 at 7:20 AM, Chun-Yeow Yeoh <yeohchunyeow@gmail.com> wrote:
> 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>
> ---
>  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 c1d1b86..35ad398 100644
> --- a/net/mac80211/mesh_hwmp.c
> +++ b/net/mac80211/mesh_hwmp.c
> @@ -797,7 +797,7 @@ 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;
> @@ -808,7 +808,7 @@ 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))
> @@ -825,7 +825,10 @@ 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) {
> @@ -838,7 +841,7 @@ 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;
>         }
> @@ -856,7 +859,7 @@ 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 */
> @@ -876,7 +879,7 @@ 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();
> --
> 2.3.0
>



-- 
thomas