mac80211: mesh gate implementation

In this implementation, a mesh gate is a root node with a certain bit
set in its RANN flags. The mpath to this root node is marked as a path
to a gate, and added to our list of known gates for this if_mesh. Once a
path discovery process fails, we forward the unresolved frames to a
known gate. Thanks to Luis Rodriguez for refactoring and bug fix help.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 33 insertions, 8 deletions

diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index abd03473cca4..7b517c46100d 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -696,6 +696,7 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
         u8 *orig_addr;
         u32 orig_sn, metric;
         u32 interval = cpu_to_le32(IEEE80211_MESH_RANN_INTERVAL);
+        bool root_is_gate;
 
         ttl = rann->rann_ttl;
         if (ttl <= 1) {
@@ -704,12 +705,19 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
         }
         ttl--;
         flags = rann->rann_flags;
+        root_is_gate = !!(flags & RANN_FLAG_IS_GATE);
         orig_addr = rann->rann_addr;
         orig_sn = rann->rann_seq;
         hopcount = rann->rann_hopcount;
         hopcount++;
         metric = rann->rann_metric;
-        mhwmp_dbg("received RANN from %pM\n", orig_addr);
+
+        /*  Ignore our own RANNs */
+        if (memcmp(orig_addr, sdata->vif.addr, ETH_ALEN) == 0)
+                return;
+
+        mhwmp_dbg("received RANN from %pM (is_gate=%d)", orig_addr,
+                        root_is_gate);
 
         rcu_read_lock();
         mpath = mesh_path_lookup(orig_addr, sdata);
@@ -721,9 +729,16 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
                         sdata->u.mesh.mshstats.dropped_frames_no_route++;
                         return;
                 }
-                mesh_queue_preq(mpath,
-                                PREQ_Q_F_START | PREQ_Q_F_REFRESH);
         }
+
+        if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) ||
+             time_after(jiffies, mpath->exp_time - 1*HZ)) &&
+             !(mpath->flags & MESH_PATH_FIXED)) {
+                mhwmp_dbg("%s time to refresh root mpath %pM", sdata->name,
+                                                               orig_addr);
+                mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH);
+        }
+
         if (mpath->sn < orig_sn) {
                 mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
                                        cpu_to_le32(orig_sn),
@@ -733,6 +748,9 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
                                        0, sdata);
                 mpath->sn = orig_sn;
         }
+        if (root_is_gate)
+                mesh_path_add_gate(mpath);
+
         rcu_read_unlock();
 }
 
@@ -994,25 +1012,32 @@ void mesh_path_timer(unsigned long data)
 {
         struct mesh_path *mpath = (void *) data;
         struct ieee80211_sub_if_data *sdata = mpath->sdata;
+        int ret;
 
         if (sdata->local->quiescing)
                 return;
 
         spin_lock_bh(&mpath->state_lock);
         if (mpath->flags & MESH_PATH_RESOLVED ||
-                        (!(mpath->flags & MESH_PATH_RESOLVING)))
+                        (!(mpath->flags & MESH_PATH_RESOLVING))) {
                 mpath->flags &= ~(MESH_PATH_RESOLVING | MESH_PATH_RESOLVED);
-        else if (mpath->discovery_retries < max_preq_retries(sdata)) {
+                spin_unlock_bh(&mpath->state_lock);
+        } else if (mpath->discovery_retries < max_preq_retries(sdata)) {
                 ++mpath->discovery_retries;
                 mpath->discovery_timeout *= 2;
+                spin_unlock_bh(&mpath->state_lock);
                 mesh_queue_preq(mpath, 0);
         } else {
                 mpath->flags = 0;
                 mpath->exp_time = jiffies;
-                mesh_path_flush_pending(mpath);
+                spin_unlock_bh(&mpath->state_lock);
+                if (!mpath->is_gate && mesh_gate_num(sdata) > 0) {
+                        ret = mesh_path_send_to_gates(mpath);
+                        if (ret)
+                                mhwmp_dbg("no gate was reachable");
+                } else
+                        mesh_path_flush_pending(mpath);
         }
-
-        spin_unlock_bh(&mpath->state_lock);
 }
 
 void