From: Javier Cardona <javier@xxxxxxxxxxx>
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@xxxxxxxxxxx>
---
v2:
- fix uninitialized pointer
include/linux/ieee80211.h | 4 +
net/mac80211/ieee80211_i.h | 1 +
net/mac80211/mesh.c | 3 +-
net/mac80211/mesh.h | 11 ++
net/mac80211/mesh_hwmp.c | 41 +++++--
net/mac80211/mesh_pathtbl.c | 283 +++++++++++++++++++++++++++++++++++++++++++
6 files changed, 334 insertions(+), 9 deletions(-)
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 03cfbf3..37f95f2 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -633,6 +633,10 @@ struct ieee80211_rann_ie {
u32 rann_metric;
} __attribute__ ((packed));
+enum ieee80211_rann_flags {
+ RANN_FLAG_IS_GATE = 1 << 0,
+};
+
#define WLAN_SA_QUERY_TR_ID_LEN 2
struct ieee80211_mgmt {
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index ea74190..c204cee 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -514,6 +514,7 @@ struct ieee80211_if_mesh {
struct mesh_config mshcfg;
u32 mesh_seqnum;
bool accepting_plinks;
+ int num_gates;
const u8 *ie;
u8 ie_len;
enum {
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index ecdde6c..e120fef 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -545,7 +545,7 @@ void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
- /* use atomic bitops in case both timers fire at the same time */
+ /* use atomic bitops in case all timers fire at the same time */
if (del_timer_sync(&ifmsh->housekeeping_timer))
set_bit(TMR_RUNNING_HK, &ifmsh->timers_running);
@@ -752,6 +752,7 @@ void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
ifmsh->accepting_plinks = true;
ifmsh->preq_id = 0;
ifmsh->sn = 0;
+ ifmsh->num_gates = 0;
atomic_set(&ifmsh->mpaths, 0);
mesh_rmc_init(sdata);
ifmsh->last_preq = jiffies;
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index 3c7d0f8..9d9116e 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -81,6 +81,7 @@ enum mesh_deferred_task_flags {
* @discovery_retries: number of discovery retries
* @flags: mesh path flags, as specified on &enum mesh_path_flags
* @state_lock: mesh path state lock
+ * @is_gate: the destination station of this path is a mesh gate
*
*
* The combination of dst and sdata is unique in the mesh path table. Since the
@@ -104,6 +105,7 @@ struct mesh_path {
u8 discovery_retries;
enum mesh_path_flags flags;
spinlock_t state_lock;
+ bool is_gate;
};
/**
@@ -120,6 +122,9 @@ struct mesh_path {
* buckets
* @mean_chain_len: maximum average length for the hash buckets' list, if it is
* reached, the table will grow
+ * @known_gates: list of known mesh gates and their mpaths by the station. The
+ * gate's mpath may or may not be resolved and active.
+ *
* rcu_head: RCU head to free the table
*/
struct mesh_table {
@@ -133,6 +138,8 @@ struct mesh_table {
int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
int size_order;
int mean_chain_len;
+ struct hlist_head *known_gates;
+ spinlock_t gates_lock;
struct rcu_head rcu_head;
};
@@ -236,6 +243,10 @@ void mesh_path_flush(struct ieee80211_sub_if_data *sdata);
void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt, size_t len);
int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
+
+int mesh_path_add_gate(struct mesh_path *mpath);
+int mesh_path_send_to_gates(struct mesh_path *mpath);
+int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
/* Mesh plinks */
void mesh_neighbour_update(u8 *hw_addr, u32 rates,
struct ieee80211_sub_if_data *sdata,
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index abd0347..7b517c4 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
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index 55ccd62..3c2bcb2 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -66,6 +66,8 @@ static inline struct mesh_table *resize_dereference_mpp_paths(void)
lockdep_is_held(&pathtbl_resize_lock));
}
+static int mesh_gate_add(struct mesh_table *tbl, struct mesh_path *mpath);
+
/*
* CAREFUL -- "tbl" must not be an expression,
* in particular not an rcu_dereference(), since
@@ -109,6 +111,7 @@ 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;
}
@@ -124,6 +127,7 @@ 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;
@@ -135,6 +139,17 @@ 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);
}
@@ -152,6 +167,7 @@ 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;
@@ -211,6 +227,111 @@ 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->addr3, dst_addr, ETH_ALEN);
+}
+
+/**
+ *
+ * mesh_path_move_to_queue - Move or copy frames from one mpath queue to another
+ *
+ * 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.
+ */
+static void mesh_path_move_to_queue(struct mesh_path *gate_mpath,
+ struct mesh_path *from_mpath,
+ bool copy)
+{
+ struct sk_buff *skb, *cp_skb = NULL;
+ struct sk_buff_head gateq, failq;
+ unsigned long flags;
+ int num_skbs;
+
+ BUG_ON(gate_mpath == from_mpath);
+ BUG_ON(!gate_mpath->next_hop);
+
+ __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);
+
+ prepare_for_gate(skb, gate_mpath->dst, gate_mpath);
+ __skb_queue_tail(&gateq, skb);
+
+ if (copy && cp_skb)
+ __skb_queue_tail(&failq, cp_skb);
+ }
+
+ 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);
+}
+
/**
* mesh_path_lookup - look up a path in the mesh path table
@@ -310,6 +431,109 @@ 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_gate_add - mark mpath as path to a mesh gate and add to known_gates
+ * @mesh_tbl: table which contains known_gates list
+ * @mpath: mpath to known mesh gate
+ *
+ * Returns: 0 on success
+ *
+ */
+static int mesh_gate_add(struct mesh_table *tbl, struct mesh_path *mpath)
+{
+ struct mpath_node *gate, *new_gate;
+ struct hlist_node *n;
+ int err;
+
+ rcu_read_lock();
+ tbl = rcu_dereference(tbl);
+
+ 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;
+
+ tbl = rcu_dereference(tbl);
+
+ 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_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)
+{
+ return mesh_gate_add(mesh_paths, mpath);
+}
+
+/**
+ * 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)
@@ -655,6 +879,8 @@ int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata)
if (mpath->sdata == sdata &&
memcmp(addr, mpath->dst, ETH_ALEN) == 0) {
spin_lock_bh(&mpath->state_lock);
+ if (mpath->is_gate)
+ mesh_gate_del(tbl, mpath);
mpath->flags |= MESH_PATH_RESOLVING;
hlist_del_rcu(&node->list);
call_rcu(&node->rcu, mesh_path_node_reclaim);
@@ -688,6 +914,58 @@ 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
@@ -803,6 +1081,9 @@ 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);
+ INIT_HLIST_HEAD(tbl_path->known_gates);
+
tbl_mpp = mesh_table_alloc(INIT_PATHS_SIZE_ORDER);
if (!tbl_mpp) {
@@ -812,6 +1093,8 @@ int mesh_pathtbl_init(void)
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);
+ INIT_HLIST_HEAD(tbl_mpp->known_gates);
/* Need no locking since this is during init */
RCU_INIT_POINTER(mesh_paths, tbl_path);
--
1.7.4.1
--
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