mac80211: implement RANN processing and forwarding

Process the RANN (Root Annoucement) Frame and try to find the HWMP
root station by sending a PREQ.

Signed-off-by: Rui Paulo <rpaulo@gmail.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Reviewed-by: Andrey Yurovsky <andrey@cozybit.com>
Tested-by: Brian Cavagnolo <brian@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 71 insertions, 8 deletions

diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index db1a33098a88..7b9dd87cf9f2 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -28,6 +28,8 @@
 /* Reply and forward */
 #define MP_F_RF 0x2
 
+static void mesh_queue_preq(struct mesh_path *, u8);
+
 static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
 {
         if (ae)
@@ -81,7 +83,8 @@ static inline u32 u32_field_get(u8 *preq_elem, int offset, bool ae)
 enum mpath_frame_type {
         MPATH_PREQ = 0,
         MPATH_PREP,
-        MPATH_PERR
+        MPATH_PERR,
+        MPATH_RANN
 };
 
 static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
@@ -109,7 +112,8 @@ static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
 
         memcpy(mgmt->da, da, ETH_ALEN);
         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
-        /* BSSID is left zeroed, wildcard value */
+        /* BSSID == SA */
+        memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
         mgmt->u.action.category = MESH_PATH_SEL_CATEGORY;
         mgmt->u.action.u.mesh_action.action_code = MESH_PATH_SEL_ACTION;
 
@@ -126,6 +130,12 @@ static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
                 pos = skb_put(skb, 2 + ie_len);
                 *pos++ = WLAN_EID_PREP;
                 break;
+        case MPATH_RANN:
+                mhwmp_dbg("sending RANN from %pM\n", orig_addr);
+                ie_len = sizeof(struct ieee80211_rann_ie);
+                pos = skb_put(skb, 2 + ie_len);
+                *pos++ = WLAN_EID_RANN;
+                break;
         default:
                 kfree_skb(skb);
                 return -ENOTSUPP;
@@ -143,8 +153,10 @@ static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
         pos += ETH_ALEN;
         memcpy(pos, &orig_dsn, 4);
         pos += 4;
-        memcpy(pos, &lifetime, 4);
-        pos += 4;
+        if (action != MPATH_RANN) {
+                memcpy(pos, &lifetime, 4);
+                pos += 4;
+        }
         memcpy(pos, &metric, 4);
         pos += 4;
         if (action == MPATH_PREQ) {
@@ -152,9 +164,11 @@ static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags,
                 *pos++ = 1;
                 *pos++ = dst_flags;
         }
-        memcpy(pos, dst, ETH_ALEN);
-        pos += ETH_ALEN;
-        memcpy(pos, &dst_dsn, 4);
+        if (action != MPATH_RANN) {
+                memcpy(pos, dst, ETH_ALEN);
+                pos += ETH_ALEN;
+                memcpy(pos, &dst_dsn, 4);
+        }
 
         ieee80211_tx_skb(sdata, skb, 1);
         return 0;
@@ -610,6 +624,54 @@ static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
         rcu_read_unlock();
 }
 
+static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata,
+                                struct ieee80211_mgmt *mgmt,
+                                struct ieee80211_rann_ie *rann)
+{
+        struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+        struct mesh_path *mpath;
+        u8 *ta;
+        u8 ttl, flags, hopcount;
+        u8 *orig_addr;
+        u32 orig_dsn, metric;
+
+        ta = mgmt->sa;
+        ttl = rann->rann_ttl;
+        if (ttl <= 1) {
+                ifmsh->mshstats.dropped_frames_ttl++;
+                return;
+        }
+        ttl--;
+        flags = rann->rann_flags;
+        orig_addr = rann->rann_addr;
+        orig_dsn = rann->rann_seq;
+        hopcount = rann->rann_hopcount;
+        metric = rann->rann_metric;
+        mhwmp_dbg("received RANN from %pM\n", orig_addr);
+
+        rcu_read_lock();
+        mpath = mesh_path_lookup(orig_addr, sdata);
+        if (!mpath) {
+                mesh_path_add(orig_addr, sdata);
+                mpath = mesh_path_lookup(orig_addr, sdata);
+                if (!mpath) {
+                        rcu_read_unlock();
+                        sdata->u.mesh.mshstats.dropped_frames_no_route++;
+                        return;
+                }
+                mesh_queue_preq(mpath,
+                                PREQ_Q_F_START | PREQ_Q_F_REFRESH);
+        }
+        if (mpath->dsn < orig_dsn) {
+                mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr,
+                                       cpu_to_le32(orig_dsn),
+                                       0, NULL, 0, sdata->dev->broadcast,
+                                       hopcount, ttl, 0, cpu_to_le32(metric),
+                                       0, sdata);
+                mpath->dsn = orig_dsn;
+        }
+        rcu_read_unlock();
+}
 
 
 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
@@ -654,7 +716,8 @@ void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
                         return;
                 hwmp_perr_frame_process(sdata, mgmt, elems.perr);
         }
-
+        if (elems.rann)
+                hwmp_rann_frame_process(sdata, mgmt, elems.rann);
 }
 
 /**