#include <linux/spinlock.h>
#include <linux/string.h>
#include <net/mac80211.h>
+#include "wme.h"
#include "ieee80211_i.h"
#include "mesh.h"
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);
}
-/**
- * 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)
+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(mesh_paths);
-
bucket = &tbl->hash_buckets[mesh_table_hash(dst, sdata, tbl)];
hlist_for_each_entry_rcu(node, n, bucket, list) {
mpath = node->mpath;
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;
return NULL;
}
-struct mesh_path *mpp_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
+/**
+ * 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)
{
- 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);
+ return path_lookup(rcu_dereference(mesh_paths), dst, sdata);
+}
- 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;
- }
- }
- return NULL;
+struct mesh_path *mpp_path_lookup(u8 *dst, struct ieee80211_sub_if_data *sdata)
+{
+ return path_lookup(rcu_dereference(mpp_paths), dst, sdata);
}
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;
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),
reason, bcast, sdata);
- } else
- spin_unlock_bh(&mpath->state_lock);
+ }
}
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
*
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();
}
/**
mpath = node->mpath;
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);
- atomic_dec(&tbl->entries);
- spin_unlock_bh(&mpath->state_lock);
+ __mesh_path_del(tbl, node);
goto enddel;
}
}
da = hdr->addr3;
ra = hdr->addr1;
+ rcu_read_lock();
mpath = mesh_path_lookup(da, sdata);
- if (mpath)
+ if (mpath) {
+ spin_lock_bh(&mpath->state_lock);
sn = ++mpath->sn;
+ spin_unlock_bh(&mpath->state_lock);
+ }
+ rcu_read_unlock();
mesh_path_error_tx(sdata->u.mesh.mshcfg.element_ttl, skb->data,
cpu_to_le32(sn), reason, ra, sdata);
}
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)
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(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)
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();
}
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);
}
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