Commit 5ee68e5b authored by Javier Cardona's avatar Javier Cardona Committed by John W. Linville

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: default avatarJavier Cardona <javier@cozybit.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 00e3f25c
......@@ -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 {
......
......@@ -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 {
......
......@@ -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;
......
......@@ -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,
......
......@@ -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;
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
......
......@@ -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;
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);
......@@ -687,6 +913,58 @@ void mesh_path_tx_pending(struct mesh_path *mpath)
&mpath->frame_queue);
}
/**
* 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
*
......@@ -804,6 +1082,9 @@ 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) {
......@@ -813,6 +1094,9 @@ 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;
/* XXX: not needed */
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);
......
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