1 files changed, 377 insertions, 97 deletions

diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index 068ee6518254..edf167e3b8f3 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -14,9 +14,16 @@
 #include <linux/spinlock.h>
 #include <linux/string.h>
 #include <net/mac80211.h>
+#include "wme.h"
 #include "ieee80211_i.h"
 #include "mesh.h"
 
+#ifdef CONFIG_MAC80211_VERBOSE_MPATH_DEBUG
+#define mpath_dbg(fmt, args...)	printk(KERN_DEBUG fmt, ##args)
+#else
+#define mpath_dbg(fmt, args...)	do { (void)(0); } while (0)
+#endif
+
 /* There will be initially 2^INIT_PATHS_SIZE_ORDER buckets */
 #define INIT_PATHS_SIZE_ORDER	2
 
@@ -42,8 +49,10 @@ static struct mesh_table __rcu *mpp_paths; /* Store paths for MPP&MAP */
 int mesh_paths_generation;
 
 /* This lock will have the grow table function as writer and add / delete nodes
- * as readers. When reading the table (i.e. doing lookups) we are well protected
- * by RCU
+ * as readers. RCU provides sufficient protection only when reading the table
+ * (i.e. doing lookups).  Adding or adding or removing nodes requires we take
+ * the read lock or we risk operating on an old table.  The write lock is only
+ * needed when modifying the number of buckets a table.
  */
 static DEFINE_RWLOCK(pathtbl_resize_lock);
 
@@ -103,6 +112,7 @@ static struct mesh_table *mesh_table_alloc(int size_order)
 			sizeof(newtbl->hash_rnd));
 	for (i = 0; i <= newtbl->hash_mask; i++)
 		spin_lock_init(&newtbl->hashwlock[i]);
+	spin_lock_init(&newtbl->gates_lock);
 
 	return newtbl;
 }
@@ -118,6 +128,7 @@ static void mesh_table_free(struct mesh_table *tbl, bool free_leafs)
 {
 	struct hlist_head *mesh_hash;
 	struct hlist_node *p, *q;
+	struct mpath_node *gate;
 	int i;
 
 	mesh_hash = tbl->hash_buckets;
@@ -129,6 +140,17 @@ static void mesh_table_free(struct mesh_table *tbl, bool free_leafs)
 		}
 		spin_unlock_bh(&tbl->hashwlock[i]);
 	}
+	if (free_leafs) {
+		spin_lock_bh(&tbl->gates_lock);
+		hlist_for_each_entry_safe(gate, p, q,
+					 tbl->known_gates, list) {
+			hlist_del(&gate->list);
+			kfree(gate);
+		}
+		kfree(tbl->known_gates);
+		spin_unlock_bh(&tbl->gates_lock);
+	}
+
 	__mesh_table_free(tbl);
 }
 
@@ -146,6 +168,7 @@ static int mesh_table_grow(struct mesh_table *oldtbl,
 	newtbl->free_node = oldtbl->free_node;
 	newtbl->mean_chain_len = oldtbl->mean_chain_len;
 	newtbl->copy_node = oldtbl->copy_node;
+	newtbl->known_gates = oldtbl->known_gates;
 	atomic_set(&newtbl->entries, atomic_read(&oldtbl->entries));
 
 	oldhash = oldtbl->hash_buckets;
@@ -198,6 +221,7 @@ void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta)
 	while ((skb = __skb_dequeue(&mpath->frame_queue)) != NULL) {
 		hdr = (struct ieee80211_hdr *) skb->data;
 		memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN);
+		memcpy(hdr->addr2, mpath->sdata->vif.addr, ETH_ALEN);
 		__skb_queue_tail(&tmpq, skb);
 	}
 
@@ -205,62 +229,129 @@ void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta)
 	spin_unlock_irqrestore(&mpath->frame_queue.lock, flags);
 }
 
+static void prepare_for_gate(struct sk_buff *skb, char *dst_addr,
+			     struct mesh_path *gate_mpath)
+{
+	struct ieee80211_hdr *hdr;
+	struct ieee80211s_hdr *mshdr;
+	int mesh_hdrlen, hdrlen;
+	char *next_hop;
+
+	hdr = (struct ieee80211_hdr *) skb->data;
+	hdrlen = ieee80211_hdrlen(hdr->frame_control);
+	mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
+
+	if (!(mshdr->flags & MESH_FLAGS_AE)) {
+		/* size of the fixed part of the mesh header */
+		mesh_hdrlen = 6;
+
+		/* make room for the two extended addresses */
+		skb_push(skb, 2 * ETH_ALEN);
+		memmove(skb->data, hdr, hdrlen + mesh_hdrlen);
+
+		hdr = (struct ieee80211_hdr *) skb->data;
+
+		/* we preserve the previous mesh header and only add
+		 * the new addreses */
+		mshdr = (struct ieee80211s_hdr *) (skb->data + hdrlen);
+		mshdr->flags = MESH_FLAGS_AE_A5_A6;
+		memcpy(mshdr->eaddr1, hdr->addr3, ETH_ALEN);
+		memcpy(mshdr->eaddr2, hdr->addr4, ETH_ALEN);
+	}
+
+	/* update next hop */
+	hdr = (struct ieee80211_hdr *) skb->data;
+	rcu_read_lock();
+	next_hop = rcu_dereference(gate_mpath->next_hop)->sta.addr;
+	memcpy(hdr->addr1, next_hop, ETH_ALEN);
+	rcu_read_unlock();
+	memcpy(hdr->addr2, gate_mpath->sdata->vif.addr, ETH_ALEN);
+	memcpy(hdr->addr3, dst_addr, ETH_ALEN);
+}
 
 /**
- * mesh_path_lookup - look up a path in the mesh path table
- * @dst: hardware address (ETH_ALEN length) of destination
- * @sdata: local subif
  *
- * Returns: pointer to the mesh path structure, or NULL if not found
+ * mesh_path_move_to_queue - Move or copy frames from one mpath queue to another
  *
- * Locking: must be called within a read rcu section.
+ * This function is used to transfer or copy frames from an unresolved mpath to
+ * a gate mpath.  The function also adds the Address Extension field and
+ * updates the next hop.
+ *
+ * If a frame already has an Address Extension field, only the next hop and
+ * destination addresses are updated.
+ *
+ * The gate mpath must be an active mpath with a valid mpath->next_hop.
+ *
+ * @mpath: An active mpath the frames will be sent to (i.e. the gate)
+ * @from_mpath: The failed mpath
+ * @copy: When true, copy all the frames to the new mpath queue.  When false,
+ * move them.
  */
-struct mesh_path *mesh_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
+static void mesh_path_move_to_queue(struct mesh_path *gate_mpath,
+				    struct mesh_path *from_mpath,
+				    bool copy)
 {
-	struct mesh_path *mpath;
-	struct hlist_node *n;
-	struct hlist_head *bucket;
-	struct mesh_table *tbl;
-	struct mpath_node *node;
+	struct sk_buff *skb, *cp_skb = NULL;
+	struct sk_buff_head gateq, failq;
+	unsigned long flags;
+	int num_skbs;
 
-	tbl = rcu_dereference(mesh_paths);
+	BUG_ON(gate_mpath == from_mpath);
+	BUG_ON(!gate_mpath->next_hop);
 
-	bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)];
-	hlist_for_each_entry_rcu(node, n, bucket, list) {
-		mpath = node->mpath;
-		if (mpath->sdata == sdata &&
-				memcmp(dst, mpath->dst, ETH_ALEN) == 0) {
-			if (MPATH_EXPIRED(mpath)) {
-				spin_lock_bh(&mpath->state_lock);
-				if (MPATH_EXPIRED(mpath))
-					mpath->flags &= ~MESH_PATH_ACTIVE;
-				spin_unlock_bh(&mpath->state_lock);
-			}
-			return mpath;
+	__skb_queue_head_init(&gateq);
+	__skb_queue_head_init(&failq);
+
+	spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
+	skb_queue_splice_init(&from_mpath->frame_queue, &failq);
+	spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
+
+	num_skbs = skb_queue_len(&failq);
+
+	while (num_skbs--) {
+		skb = __skb_dequeue(&failq);
+		if (copy) {
+			cp_skb = skb_copy(skb, GFP_ATOMIC);
+			if (cp_skb)
+				__skb_queue_tail(&failq, cp_skb);
 		}
+
+		prepare_for_gate(skb, gate_mpath->dst, gate_mpath);
+		__skb_queue_tail(&gateq, skb);
 	}
-	return NULL;
+
+	spin_lock_irqsave(&gate_mpath->frame_queue.lock, flags);
+	skb_queue_splice(&gateq, &gate_mpath->frame_queue);
+	mpath_dbg("Mpath queue for gate %pM has %d frames\n",
+			gate_mpath->dst,
+			skb_queue_len(&gate_mpath->frame_queue));
+	spin_unlock_irqrestore(&gate_mpath->frame_queue.lock, flags);
+
+	if (!copy)
+		return;
+
+	spin_lock_irqsave(&from_mpath->frame_queue.lock, flags);
+	skb_queue_splice(&failq, &from_mpath->frame_queue);
+	spin_unlock_irqrestore(&from_mpath->frame_queue.lock, flags);
 }
 
-struct mesh_path *mpp_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
+
+static struct mesh_path *path_lookup(struct mesh_table *tbl, u8 *dst,
+					  struct ieee80211_sub_if_data *sdata)
 {
 	struct mesh_path *mpath;
 	struct hlist_node *n;
 	struct hlist_head *bucket;
-	struct mesh_table *tbl;
 	struct mpath_node *node;
 
-	tbl = rcu_dereference(mpp_paths);
-
 	bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)];
 	hlist_for_each_entry_rcu(node, n, bucket, list) {
 		mpath = node->mpath;
 		if (mpath->sdata == sdata &&
-		    memcmp(dst, mpath->dst, ETH_ALEN) == 0) {
+				memcmp(dst, mpath->dst, ETH_ALEN) == 0) {
 			if (MPATH_EXPIRED(mpath)) {
 				spin_lock_bh(&mpath->state_lock);
-				if (MPATH_EXPIRED(mpath))
-					mpath->flags &= ~MESH_PATH_ACTIVE;
+				mpath->flags &= ~MESH_PATH_ACTIVE;
 				spin_unlock_bh(&mpath->state_lock);
 			}
 			return mpath;
@@ -269,6 +360,25 @@ struct mesh_path *mpp_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
 	return NULL;
 }
 
+/**
+ * mesh_path_lookup - look up a path in the mesh path table
+ * @dst: hardware address (ETH_ALEN length) of destination
+ * @sdata: local subif
+ *
+ * Returns: pointer to the mesh path structure, or NULL if not found
+ *
+ * Locking: must be called within a read rcu section.
+ */
+struct mesh_path *mesh_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
+{
+	return path_lookup(rcu_dereference(mesh_paths), dst, sdata);
+}
+
+struct mesh_path *mpp_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
+{
+	return path_lookup(rcu_dereference(mpp_paths), dst, sdata);
+}
+
 
 /**
  * mesh_path_lookup_by_idx - look up a path in the mesh path table by its index
@@ -293,8 +403,7 @@ struct mesh_path *mesh_path_lookup_by_idx(int idx, struct ieee80211_sub_if_data
 		if (j++ == idx) {
 			if (MPATH_EXPIRED(node->mpath)) {
 				spin_lock_bh(&node->mpath->state_lock);
-				if (MPATH_EXPIRED(node->mpath))
-					node->mpath->flags &= ~MESH_PATH_ACTIVE;
+				node->mpath->flags &= ~MESH_PATH_ACTIVE;
 				spin_unlock_bh(&node->mpath->state_lock);
 			}
 			return node->mpath;
@@ -304,6 +413,94 @@ struct mesh_path *mesh_path_lookup_by_idx(int idx, struct ieee80211_sub_if_data
 	return NULL;
 }
 
+static void mesh_gate_node_reclaim(struct rcu_head *rp)
+{
+	struct mpath_node *node = container_of(rp, struct mpath_node, rcu);
+	kfree(node);
+}
+
+/**
+ * mesh_path_add_gate - add the given mpath to a mesh gate to our path table
+ * @mpath: gate path to add to table
+ */
+int mesh_path_add_gate(struct mesh_path *mpath)
+{
+	struct mesh_table *tbl;
+	struct mpath_node *gate, *new_gate;
+	struct hlist_node *n;
+	int err;
+
+	rcu_read_lock();
+	tbl = rcu_dereference(mesh_paths);
+
+	hlist_for_each_entry_rcu(gate, n, tbl->known_gates, list)
+		if (gate->mpath == mpath) {
+			err = -EEXIST;
+			goto err_rcu;
+		}
+
+	new_gate = kzalloc(sizeof(struct mpath_node), GFP_ATOMIC);
+	if (!new_gate) {
+		err = -ENOMEM;
+		goto err_rcu;
+	}
+
+	mpath->is_gate = true;
+	mpath->sdata->u.mesh.num_gates++;
+	new_gate->mpath = mpath;
+	spin_lock_bh(&tbl->gates_lock);
+	hlist_add_head_rcu(&new_gate->list, tbl->known_gates);
+	spin_unlock_bh(&tbl->gates_lock);
+	rcu_read_unlock();
+	mpath_dbg("Mesh path (%s): Recorded new gate: %pM. %d known gates\n",
+		  mpath->sdata->name, mpath->dst,
+		  mpath->sdata->u.mesh.num_gates);
+	return 0;
+err_rcu:
+	rcu_read_unlock();
+	return err;
+}
+
+/**
+ * mesh_gate_del - remove a mesh gate from the list of known gates
+ * @tbl: table which holds our list of known gates
+ * @mpath: gate mpath
+ *
+ * Returns: 0 on success
+ *
+ * Locking: must be called inside rcu_read_lock() section
+ */
+static int mesh_gate_del(struct mesh_table *tbl, struct mesh_path *mpath)
+{
+	struct mpath_node *gate;
+	struct hlist_node *p, *q;
+
+	hlist_for_each_entry_safe(gate, p, q, tbl->known_gates, list)
+		if (gate->mpath == mpath) {
+			spin_lock_bh(&tbl->gates_lock);
+			hlist_del_rcu(&gate->list);
+			call_rcu(&gate->rcu, mesh_gate_node_reclaim);
+			spin_unlock_bh(&tbl->gates_lock);
+			mpath->sdata->u.mesh.num_gates--;
+			mpath->is_gate = false;
+			mpath_dbg("Mesh path (%s): Deleted gate: %pM. "
+				  "%d known gates\n", mpath->sdata->name,
+				  mpath->dst, mpath->sdata->u.mesh.num_gates);
+			break;
+		}
+
+	return 0;
+}
+
+/**
+ * mesh_gate_num - number of gates known to this interface
+ * @sdata: subif data
+ */
+int mesh_gate_num(struct ieee80211_sub_if_data *sdata)
+{
+	return sdata->u.mesh.num_gates;
+}
+
 /**
  * mesh_path_add - allocate and add a new path to the mesh path table
  * @addr: destination address of the path (ETH_ALEN length)
@@ -481,6 +678,7 @@ int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata)
 	new_mpath->flags = 0;
 	skb_queue_head_init(&new_mpath->frame_queue);
 	new_node->mpath = new_mpath;
+	init_timer(&new_mpath->timer);
 	new_mpath->exp_time = jiffies;
 	spin_lock_init(&new_mpath->state_lock);
 
@@ -539,28 +737,53 @@ void mesh_plink_broken(struct sta_info *sta)
 	struct hlist_node *p;
 	struct ieee80211_sub_if_data *sdata = sta->sdata;
 	int i;
+	__le16 reason = cpu_to_le16(WLAN_REASON_MESH_PATH_DEST_UNREACHABLE);
 
 	rcu_read_lock();
 	tbl = rcu_dereference(mesh_paths);
 	for_each_mesh_entry(tbl, p, node, i) {
 		mpath = node->mpath;
-		spin_lock_bh(&mpath->state_lock);
 		if (rcu_dereference(mpath->next_hop) == sta &&
 		    mpath->flags & MESH_PATH_ACTIVE &&
 		    !(mpath->flags & MESH_PATH_FIXED)) {
+			spin_lock_bh(&mpath->state_lock);
 			mpath->flags &= ~MESH_PATH_ACTIVE;
 			++mpath->sn;
 			spin_unlock_bh(&mpath->state_lock);
 			mesh_path_error_tx(sdata->u.mesh.mshcfg.element_ttl,
 					mpath->dst, cpu_to_le32(mpath->sn),
-					cpu_to_le16(PERR_RCODE_DEST_UNREACH),
-					bcast, sdata);
-		} else
-		spin_unlock_bh(&mpath->state_lock);
+					reason, bcast, sdata);
+		}
 	}
 	rcu_read_unlock();
 }
 
+static void mesh_path_node_reclaim(struct rcu_head *rp)
+{
+	struct mpath_node *node = container_of(rp, struct mpath_node, rcu);
+	struct ieee80211_sub_if_data *sdata = node->mpath->sdata;
+
+	del_timer_sync(&node->mpath->timer);
+	atomic_dec(&sdata->u.mesh.mpaths);
+	kfree(node->mpath);
+	kfree(node);
+}
+
+/* needs to be called with the corresponding hashwlock taken */
+static void __mesh_path_del(struct mesh_table *tbl, struct mpath_node *node)
+{
+	struct mesh_path *mpath;
+	mpath = node->mpath;
+	spin_lock(&mpath->state_lock);
+	mpath->flags |= MESH_PATH_RESOLVING;
+	if (mpath->is_gate)
+		mesh_gate_del(tbl, mpath);
+	hlist_del_rcu(&node->list);
+	call_rcu(&node->rcu, mesh_path_node_reclaim);
+	spin_unlock(&mpath->state_lock);
+	atomic_dec(&tbl->entries);
+}
+
 /**
  * mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches
  *
@@ -581,42 +804,59 @@ void mesh_path_flush_by_nexthop(struct sta_info *sta)
 	int i;
 
 	rcu_read_lock();
-	tbl = rcu_dereference(mesh_paths);
+	read_lock_bh(&pathtbl_resize_lock);
+	tbl = resize_dereference_mesh_paths();
 	for_each_mesh_entry(tbl, p, node, i) {
 		mpath = node->mpath;
-		if (rcu_dereference(mpath->next_hop) == sta)
-			mesh_path_del(mpath->dst, mpath->sdata);
+		if (rcu_dereference(mpath->next_hop) == sta) {
+			spin_lock_bh(&tbl->hashwlock[i]);
+			__mesh_path_del(tbl, node);
+			spin_unlock_bh(&tbl->hashwlock[i]);
+		}
 	}
+	read_unlock_bh(&pathtbl_resize_lock);
 	rcu_read_unlock();
 }
 
-void mesh_path_flush(struct ieee80211_sub_if_data *sdata)
+static void table_flush_by_iface(struct mesh_table *tbl,
+				 struct ieee80211_sub_if_data *sdata)
 {
-	struct mesh_table *tbl;
 	struct mesh_path *mpath;
 	struct mpath_node *node;
 	struct hlist_node *p;
 	int i;
 
-	rcu_read_lock();
-	tbl = rcu_dereference(mesh_paths);
+	WARN_ON(!rcu_read_lock_held());
 	for_each_mesh_entry(tbl, p, node, i) {
 		mpath = node->mpath;
-		if (mpath->sdata == sdata)
-			mesh_path_del(mpath->dst, mpath->sdata);
+		if (mpath->sdata != sdata)
+			continue;
+		spin_lock_bh(&tbl->hashwlock[i]);
+		__mesh_path_del(tbl, node);
+		spin_unlock_bh(&tbl->hashwlock[i]);
 	}
-	rcu_read_unlock();
 }
 
-static void mesh_path_node_reclaim(struct rcu_head *rp)
+/**
+ * mesh_path_flush_by_iface - Deletes all mesh paths associated with a given iface
+ *
+ * This function deletes both mesh paths as well as mesh portal paths.
+ *
+ * @sdata - interface data to match
+ *
+ */
+void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
 {
-	struct mpath_node *node = container_of(rp, struct mpath_node, rcu);
-	struct ieee80211_sub_if_data *sdata = node->mpath->sdata;
+	struct mesh_table *tbl;
 
-	del_timer_sync(&node->mpath->timer);
-	atomic_dec(&sdata->u.mesh.mpaths);
-	kfree(node->mpath);
-	kfree(node);
+	rcu_read_lock();
+	read_lock_bh(&pathtbl_resize_lock);
+	tbl = resize_dereference_mesh_paths();
+	table_flush_by_iface(tbl, sdata);
+	tbl = resize_dereference_mpp_paths();
+	table_flush_by_iface(tbl, sdata);
+	read_unlock_bh(&pathtbl_resize_lock);
+	rcu_read_unlock();
 }
 
 /**
@@ -647,12 +887,7 @@ int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata)
 		mpath = node->mpath;
 		if (mpath->sdata == sdata &&
 		    memcmp(addr, mpath->dst, ETH_ALEN) == 0) {
-			spin_lock(&mpath->state_lock);
-			mpath->flags |= MESH_PATH_RESOLVING;
-			hlist_del_rcu(&node->list);
-			call_rcu(&node->rcu, mesh_path_node_reclaim);
-			atomic_dec(&tbl->entries);
-			spin_unlock(&mpath->state_lock);
+			__mesh_path_del(tbl, node);
 			goto enddel;
 		}
 	}
@@ -681,38 +916,68 @@ void mesh_path_tx_pending(struct mesh_path *mpath)
 }
 
 /**
+ * mesh_path_send_to_gates - sends pending frames to all known mesh gates
+ *
+ * @mpath: mesh path whose queue will be emptied
+ *
+ * If there is only one gate, the frames are transferred from the failed mpath
+ * queue to that gate's queue.  If there are more than one gates, the frames
+ * are copied from each gate to the next.  After frames are copied, the
+ * mpath queues are emptied onto the transmission queue.
+ */
+int mesh_path_send_to_gates(struct mesh_path *mpath)
+{
+	struct ieee80211_sub_if_data *sdata = mpath->sdata;
+	struct hlist_node *n;
+	struct mesh_table *tbl;
+	struct mesh_path *from_mpath = mpath;
+	struct mpath_node *gate = NULL;
+	bool copy = false;
+	struct hlist_head *known_gates;
+
+	rcu_read_lock();
+	tbl = rcu_dereference(mesh_paths);
+	known_gates = tbl->known_gates;
+	rcu_read_unlock();
+
+	if (!known_gates)
+		return -EHOSTUNREACH;
+
+	hlist_for_each_entry_rcu(gate, n, known_gates, list) {
+		if (gate->mpath->sdata != sdata)
+			continue;
+
+		if (gate->mpath->flags & MESH_PATH_ACTIVE) {
+			mpath_dbg("Forwarding to %pM\n", gate->mpath->dst);
+			mesh_path_move_to_queue(gate->mpath, from_mpath, copy);
+			from_mpath = gate->mpath;
+			copy = true;
+		} else {
+			mpath_dbg("Not forwarding %p\n", gate->mpath);
+			mpath_dbg("flags %x\n", gate->mpath->flags);
+		}
+	}
+
+	hlist_for_each_entry_rcu(gate, n, known_gates, list)
+		if (gate->mpath->sdata == sdata) {
+			mpath_dbg("Sending to %pM\n", gate->mpath->dst);
+			mesh_path_tx_pending(gate->mpath);
+		}
+
+	return (from_mpath == mpath) ? -EHOSTUNREACH : 0;
+}
+
+/**
  * mesh_path_discard_frame - discard a frame whose path could not be resolved
  *
  * @skb: frame to discard
  * @sdata: network subif the frame was to be sent through
  *
- * If the frame was being forwarded from another MP, a PERR frame will be sent
- * to the precursor.  The precursor's address (i.e. the previous hop) was saved
- * in addr1 of the frame-to-be-forwarded, and would only be overwritten once
- * the destination is successfully resolved.
- *
  * Locking: the function must me called within a rcu_read_lock region
  */
 void mesh_path_discard_frame(struct sk_buff *skb,
 			     struct ieee80211_sub_if_data *sdata)
 {
-	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
-	struct mesh_path *mpath;
-	u32 sn = 0;
-
-	if (memcmp(hdr->addr4, sdata->vif.addr, ETH_ALEN) != 0) {
-		u8 *ra, *da;
-
-		da = hdr->addr3;
-		ra = hdr->addr1;
-		mpath = mesh_path_lookup(da, sdata);
-		if (mpath)
-			sn = ++mpath->sn;
-		mesh_path_error_tx(sdata->u.mesh.mshcfg.element_ttl, skb->data,
-				   cpu_to_le32(sn),
-				   cpu_to_le16(PERR_RCODE_NO_ROUTE), ra, sdata);
-	}
-
 	kfree_skb(skb);
 	sdata->u.mesh.mshstats.dropped_frames_no_route++;
 }
@@ -728,8 +993,7 @@ void mesh_path_flush_pending(struct mesh_path *mpath)
 {
 	struct sk_buff *skb;
 
-	while ((skb = skb_dequeue(&mpath->frame_queue)) &&
-			(mpath->flags & MESH_PATH_ACTIVE))
+	while ((skb = skb_dequeue(&mpath->frame_queue)) != NULL)
 		mesh_path_discard_frame(skb, mpath->sdata);
 }
 
@@ -790,6 +1054,7 @@ static int mesh_path_node_copy(struct hlist_node *p, struct mesh_table *newtbl)
 int mesh_pathtbl_init(void)
 {
 	struct mesh_table *tbl_path, *tbl_mpp;
+	int ret;
 
 	tbl_path = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
 	if (!tbl_path)
@@ -797,21 +1062,40 @@ int mesh_pathtbl_init(void)
 	tbl_path->free_node = &mesh_path_node_free;
 	tbl_path->copy_node = &mesh_path_node_copy;
 	tbl_path->mean_chain_len = MEAN_CHAIN_LEN;
+	tbl_path->known_gates = kzalloc(sizeof(struct hlist_head), GFP_ATOMIC);
+	if (!tbl_path->known_gates) {
+		ret = -ENOMEM;
+		goto free_path;
+	}
+	INIT_HLIST_HEAD(tbl_path->known_gates);
+
 
 	tbl_mpp = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
 	if (!tbl_mpp) {
-		mesh_table_free(tbl_path, true);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto free_path;
 	}
 	tbl_mpp->free_node = &mesh_path_node_free;
 	tbl_mpp->copy_node = &mesh_path_node_copy;
 	tbl_mpp->mean_chain_len = MEAN_CHAIN_LEN;
+	tbl_mpp->known_gates = kzalloc(sizeof(struct hlist_head), GFP_ATOMIC);
+	if (!tbl_mpp->known_gates) {
+		ret = -ENOMEM;
+		goto free_mpp;
+	}
+	INIT_HLIST_HEAD(tbl_mpp->known_gates);
 
 	/* Need no locking since this is during init */
 	RCU_INIT_POINTER(mesh_paths, tbl_path);
 	RCU_INIT_POINTER(mpp_paths, tbl_mpp);
 
 	return 0;
+
+free_mpp:
+	mesh_table_free(tbl_mpp, true);
+free_path:
+	mesh_table_free(tbl_path, true);
+	return ret;
 }
 
 void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
@@ -828,14 +1112,10 @@ void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
 		if (node->mpath->sdata != sdata)
 			continue;
 		mpath = node->mpath;
-		spin_lock_bh(&mpath->state_lock);
 		if ((!(mpath->flags & MESH_PATH_RESOLVING)) &&
 		    (!(mpath->flags & MESH_PATH_FIXED)) &&
-		     time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE)) {
-			spin_unlock_bh(&mpath->state_lock);
+		     time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE))
 			mesh_path_del(mpath->dst, mpath->sdata);
-		} else
-			spin_unlock_bh(&mpath->state_lock);
 	}
 	rcu_read_unlock();
 }
@@ -843,6 +1123,6 @@ void mesh_path_expire(struct ieee80211_sub_if_data *sdata)
 void mesh_pathtbl_unregister(void)
 {
 	/* no need for locking during exit path */
-	mesh_table_free(rcu_dereference_raw(mesh_paths), true);
-	mesh_table_free(rcu_dereference_raw(mpp_paths), true);
+	mesh_table_free(rcu_dereference_protected(mesh_paths, 1), true);
+	mesh_table_free(rcu_dereference_protected(mpp_paths, 1), true);
 }