This patch is intended to solve the follwing issues in RANN propagation:
[1] The interval in propagated RANN should be based on the interval of received RANN.
[2] The aggregated path metric for propagated RANN is as received plus own link metric
towards the transmitting mesh STA (not root mesh STA).
[3] The comparison of path metric for RANN with same sequence number should be done
before deciding whether to propagate or not.
Signed-off-by: Chun-Yeow Yeoh <[email protected]>
---
v2:
revert back to plain conditionals (Javier and Thomas)
v3:
SN comparison in modulo 2^32 (Javier and Marek)
net/mac80211/mesh.h | 2 ++
net/mac80211/mesh_hwmp.c | 24 ++++++++++++++++++------
2 files changed, 20 insertions(+), 6 deletions(-)
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index 8d53b71..adf1be3 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -86,6 +86,7 @@ enum mesh_deferred_task_flags {
* mpath itself. No need to take this lock when adding or removing
* 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
* @is_root: the destination station of this path is a root node
* @is_gate: the destination station of this path is a mesh gate
*
@@ -112,6 +113,7 @@ struct mesh_path {
enum mesh_path_flags flags;
spinlock_t state_lock;
u8 rann_snd_addr[ETH_ALEN];
+ u32 rann_metric;
bool is_root;
bool is_gate;
};
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index f80a9e3..a80da37 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -86,8 +86,8 @@ static inline u32 u16_field_get(u8 *preq_elem, int offset, bool ae)
#define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0)
#define MSEC_TO_TU(x) (x*1000/1024)
-#define SN_GT(x, y) ((long) (y) - (long) (x) < 0)
-#define SN_LT(x, y) ((long) (x) - (long) (y) < 0)
+#define SN_GT(x, y) ((s32)(y - x) < 0)
+#define SN_LT(x, y) ((s32)(x - y) < 0)
#define net_traversal_jiffies(s) \
msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime)
@@ -732,11 +732,12 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
struct ieee80211_rann_ie *rann)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+ struct ieee80211_local *local = sdata->local;
+ struct sta_info *sta;
struct mesh_path *mpath;
u8 ttl, flags, hopcount;
u8 *orig_addr;
- u32 orig_sn, metric;
- u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval;
+ u32 orig_sn, metric, metric_txsta, interval;
bool root_is_gate;
ttl = rann->rann_ttl;
@@ -749,6 +750,7 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
orig_addr = rann->rann_addr;
orig_sn = le32_to_cpu(rann->rann_seq);
+ interval = le32_to_cpu(rann->rann_interval);
hopcount = rann->rann_hopcount;
hopcount++;
metric = le32_to_cpu(rann->rann_metric);
@@ -761,6 +763,14 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
orig_addr, mgmt->sa, root_is_gate);
rcu_read_lock();
+ sta = sta_info_get(sdata, mgmt->sa);
+ if (!sta) {
+ rcu_read_unlock();
+ return;
+ }
+
+ metric_txsta = airtime_link_metric_get(local, sta);
+
mpath = mesh_path_lookup(orig_addr, sdata);
if (!mpath) {
mesh_path_add(orig_addr, sdata);
@@ -780,14 +790,16 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
}
- if (mpath->sn < orig_sn && ifmsh->mshcfg.dot11MeshForwarding) {
+ if ((SN_LT(mpath->sn, orig_sn) || (mpath->sn == orig_sn &&
+ metric < mpath->rann_metric)) && ifmsh->mshcfg.dot11MeshForwarding) {
mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
cpu_to_le32(orig_sn),
0, NULL, 0, broadcast_addr,
hopcount, ttl, cpu_to_le32(interval),
- cpu_to_le32(metric + mpath->metric),
+ cpu_to_le32(metric + metric_txsta),
0, sdata);
mpath->sn = orig_sn;
+ mpath->rann_metric = metric + metric_txsta;
}
/* Using individually addressed PREQ for root node */
--
1.7.0.4