diff options
Diffstat (limited to 'net/mac80211/mesh_pathtbl.c')
-rw-r--r-- | net/mac80211/mesh_pathtbl.c | 848 |
1 files changed, 848 insertions, 0 deletions
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c new file mode 100644 index 00000000..0d2faacc --- /dev/null +++ b/net/mac80211/mesh_pathtbl.c @@ -0,0 +1,848 @@ +/* + * Copyright (c) 2008, 2009 open80211s Ltd. + * Author: Luis Carlos Cobo <luisca@cozybit.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/etherdevice.h> +#include <linux/list.h> +#include <linux/random.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/string.h> +#include <net/mac80211.h> +#include "ieee80211_i.h" +#include "mesh.h" + +/* There will be initially 2^INIT_PATHS_SIZE_ORDER buckets */ +#define INIT_PATHS_SIZE_ORDER 2 + +/* Keep the mean chain length below this constant */ +#define MEAN_CHAIN_LEN 2 + +#define MPATH_EXPIRED(mpath) ((mpath->flags & MESH_PATH_ACTIVE) && \ + time_after(jiffies, mpath->exp_time) && \ + !(mpath->flags & MESH_PATH_FIXED)) + +struct mpath_node { + struct hlist_node list; + struct rcu_head rcu; + /* This indirection allows two different tables to point to the same + * mesh_path structure, useful when resizing + */ + struct mesh_path *mpath; +}; + +static struct mesh_table __rcu *mesh_paths; +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 + */ +static DEFINE_RWLOCK(pathtbl_resize_lock); + + +static inline struct mesh_table *resize_dereference_mesh_paths(void) +{ + return rcu_dereference_protected(mesh_paths, + lockdep_is_held(&pathtbl_resize_lock)); +} + +static inline struct mesh_table *resize_dereference_mpp_paths(void) +{ + return rcu_dereference_protected(mpp_paths, + lockdep_is_held(&pathtbl_resize_lock)); +} + +/* + * CAREFUL -- "tbl" must not be an expression, + * in particular not an rcu_dereference(), since + * it's used twice. So it is illegal to do + * for_each_mesh_entry(rcu_dereference(...), ...) + */ +#define for_each_mesh_entry(tbl, p, node, i) \ + for (i = 0; i <= tbl->hash_mask; i++) \ + hlist_for_each_entry_rcu(node, p, &tbl->hash_buckets[i], list) + + +static struct mesh_table *mesh_table_alloc(int size_order) +{ + int i; + struct mesh_table *newtbl; + + newtbl = kmalloc(sizeof(struct mesh_table), GFP_ATOMIC); + if (!newtbl) + return NULL; + + newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) * + (1 << size_order), GFP_ATOMIC); + + if (!newtbl->hash_buckets) { + kfree(newtbl); + return NULL; + } + + newtbl->hashwlock = kmalloc(sizeof(spinlock_t) * + (1 << size_order), GFP_ATOMIC); + if (!newtbl->hashwlock) { + kfree(newtbl->hash_buckets); + kfree(newtbl); + return NULL; + } + + newtbl->size_order = size_order; + newtbl->hash_mask = (1 << size_order) - 1; + atomic_set(&newtbl->entries, 0); + get_random_bytes(&newtbl->hash_rnd, + sizeof(newtbl->hash_rnd)); + for (i = 0; i <= newtbl->hash_mask; i++) + spin_lock_init(&newtbl->hashwlock[i]); + + return newtbl; +} + +static void __mesh_table_free(struct mesh_table *tbl) +{ + kfree(tbl->hash_buckets); + kfree(tbl->hashwlock); + kfree(tbl); +} + +static void mesh_table_free(struct mesh_table *tbl, bool free_leafs) +{ + struct hlist_head *mesh_hash; + struct hlist_node *p, *q; + int i; + + mesh_hash = tbl->hash_buckets; + for (i = 0; i <= tbl->hash_mask; i++) { + spin_lock_bh(&tbl->hashwlock[i]); + hlist_for_each_safe(p, q, &mesh_hash[i]) { + tbl->free_node(p, free_leafs); + atomic_dec(&tbl->entries); + } + spin_unlock_bh(&tbl->hashwlock[i]); + } + __mesh_table_free(tbl); +} + +static int mesh_table_grow(struct mesh_table *oldtbl, + struct mesh_table *newtbl) +{ + struct hlist_head *oldhash; + struct hlist_node *p, *q; + int i; + + if (atomic_read(&oldtbl->entries) + < oldtbl->mean_chain_len * (oldtbl->hash_mask + 1)) + return -EAGAIN; + + newtbl->free_node = oldtbl->free_node; + newtbl->mean_chain_len = oldtbl->mean_chain_len; + newtbl->copy_node = oldtbl->copy_node; + atomic_set(&newtbl->entries, atomic_read(&oldtbl->entries)); + + oldhash = oldtbl->hash_buckets; + for (i = 0; i <= oldtbl->hash_mask; i++) + hlist_for_each(p, &oldhash[i]) + if (oldtbl->copy_node(p, newtbl) < 0) + goto errcopy; + + return 0; + +errcopy: + for (i = 0; i <= newtbl->hash_mask; i++) { + hlist_for_each_safe(p, q, &newtbl->hash_buckets[i]) + oldtbl->free_node(p, 0); + } + return -ENOMEM; +} + +static u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata, + struct mesh_table *tbl) +{ + /* Use last four bytes of hw addr and interface index as hash index */ + return jhash_2words(*(u32 *)(addr+2), sdata->dev->ifindex, tbl->hash_rnd) + & tbl->hash_mask; +} + + +/** + * + * mesh_path_assign_nexthop - update mesh path next hop + * + * @mpath: mesh path to update + * @sta: next hop to assign + * + * Locking: mpath->state_lock must be held when calling this function + */ +void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta) +{ + struct sk_buff *skb; + struct ieee80211_hdr *hdr; + struct sk_buff_head tmpq; + unsigned long flags; + + rcu_assign_pointer(mpath->next_hop, sta); + + __skb_queue_head_init(&tmpq); + + spin_lock_irqsave(&mpath->frame_queue.lock, flags); + + while ((skb = __skb_dequeue(&mpath->frame_queue)) != NULL) { + hdr = (struct ieee80211_hdr *) skb->data; + memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN); + __skb_queue_tail(&tmpq, skb); + } + + skb_queue_splice(&tmpq, &mpath->frame_queue); + spin_unlock_irqrestore(&mpath->frame_queue.lock, flags); +} + + +/** + * 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(mesh_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) { + 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) +{ + 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) { + 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; +} + + +/** + * mesh_path_lookup_by_idx - look up a path in the mesh path table by its index + * @idx: index + * @sdata: local subif, or NULL for all entries + * + * 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_by_idx(int idx, struct ieee80211_sub_if_data *sdata) +{ + struct mesh_table *tbl = rcu_dereference(mesh_paths); + struct mpath_node *node; + struct hlist_node *p; + int i; + int j = 0; + + for_each_mesh_entry(tbl, p, node, i) { + if (sdata && node->mpath->sdata != sdata) + continue; + 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; + spin_unlock_bh(&node->mpath->state_lock); + } + return node->mpath; + } + } + + return NULL; +} + +/** + * mesh_path_add - allocate and add a new path to the mesh path table + * @addr: destination address of the path (ETH_ALEN length) + * @sdata: local subif + * + * Returns: 0 on success + * + * State: the initial state of the new path is set to 0 + */ +int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata) +{ + struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; + struct ieee80211_local *local = sdata->local; + struct mesh_table *tbl; + struct mesh_path *mpath, *new_mpath; + struct mpath_node *node, *new_node; + struct hlist_head *bucket; + struct hlist_node *n; + int grow = 0; + int err = 0; + u32 hash_idx; + + if (memcmp(dst, sdata->vif.addr, ETH_ALEN) == 0) + /* never add ourselves as neighbours */ + return -ENOTSUPP; + + if (is_multicast_ether_addr(dst)) + return -ENOTSUPP; + + if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0) + return -ENOSPC; + + err = -ENOMEM; + new_mpath = kzalloc(sizeof(struct mesh_path), GFP_ATOMIC); + if (!new_mpath) + goto err_path_alloc; + + new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC); + if (!new_node) + goto err_node_alloc; + + read_lock_bh(&pathtbl_resize_lock); + memcpy(new_mpath->dst, dst, ETH_ALEN); + new_mpath->sdata = sdata; + new_mpath->flags = 0; + skb_queue_head_init(&new_mpath->frame_queue); + new_node->mpath = new_mpath; + new_mpath->timer.data = (unsigned long) new_mpath; + new_mpath->timer.function = mesh_path_timer; + new_mpath->exp_time = jiffies; + spin_lock_init(&new_mpath->state_lock); + init_timer(&new_mpath->timer); + + tbl = resize_dereference_mesh_paths(); + + hash_idx = mesh_table_hash(dst, sdata, tbl); + bucket = &tbl->hash_buckets[hash_idx]; + + spin_lock_bh(&tbl->hashwlock[hash_idx]); + + err = -EEXIST; + hlist_for_each_entry(node, n, bucket, list) { + mpath = node->mpath; + if (mpath->sdata == sdata && memcmp(dst, mpath->dst, ETH_ALEN) == 0) + goto err_exists; + } + + hlist_add_head_rcu(&new_node->list, bucket); + if (atomic_inc_return(&tbl->entries) >= + tbl->mean_chain_len * (tbl->hash_mask + 1)) + grow = 1; + + mesh_paths_generation++; + + spin_unlock_bh(&tbl->hashwlock[hash_idx]); + read_unlock_bh(&pathtbl_resize_lock); + if (grow) { + set_bit(MESH_WORK_GROW_MPATH_TABLE, &ifmsh->wrkq_flags); + ieee80211_queue_work(&local->hw, &sdata->work); + } + return 0; + +err_exists: + spin_unlock_bh(&tbl->hashwlock[hash_idx]); + read_unlock_bh(&pathtbl_resize_lock); + kfree(new_node); +err_node_alloc: + kfree(new_mpath); +err_path_alloc: + atomic_dec(&sdata->u.mesh.mpaths); + return err; +} + +static void mesh_table_free_rcu(struct rcu_head *rcu) +{ + struct mesh_table *tbl = container_of(rcu, struct mesh_table, rcu_head); + + mesh_table_free(tbl, false); +} + +void mesh_mpath_table_grow(void) +{ + struct mesh_table *oldtbl, *newtbl; + + write_lock_bh(&pathtbl_resize_lock); + oldtbl = resize_dereference_mesh_paths(); + newtbl = mesh_table_alloc(oldtbl->size_order + 1); + if (!newtbl) + goto out; + if (mesh_table_grow(oldtbl, newtbl) < 0) { + __mesh_table_free(newtbl); + goto out; + } + rcu_assign_pointer(mesh_paths, newtbl); + + call_rcu(&oldtbl->rcu_head, mesh_table_free_rcu); + + out: + write_unlock_bh(&pathtbl_resize_lock); +} + +void mesh_mpp_table_grow(void) +{ + struct mesh_table *oldtbl, *newtbl; + + write_lock_bh(&pathtbl_resize_lock); + oldtbl = resize_dereference_mpp_paths(); + newtbl = mesh_table_alloc(oldtbl->size_order + 1); + if (!newtbl) + goto out; + if (mesh_table_grow(oldtbl, newtbl) < 0) { + __mesh_table_free(newtbl); + goto out; + } + rcu_assign_pointer(mpp_paths, newtbl); + call_rcu(&oldtbl->rcu_head, mesh_table_free_rcu); + + out: + write_unlock_bh(&pathtbl_resize_lock); +} + +int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata) +{ + struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; + struct ieee80211_local *local = sdata->local; + struct mesh_table *tbl; + struct mesh_path *mpath, *new_mpath; + struct mpath_node *node, *new_node; + struct hlist_head *bucket; + struct hlist_node *n; + int grow = 0; + int err = 0; + u32 hash_idx; + + if (memcmp(dst, sdata->vif.addr, ETH_ALEN) == 0) + /* never add ourselves as neighbours */ + return -ENOTSUPP; + + if (is_multicast_ether_addr(dst)) + return -ENOTSUPP; + + err = -ENOMEM; + new_mpath = kzalloc(sizeof(struct mesh_path), GFP_ATOMIC); + if (!new_mpath) + goto err_path_alloc; + + new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC); + if (!new_node) + goto err_node_alloc; + + read_lock_bh(&pathtbl_resize_lock); + memcpy(new_mpath->dst, dst, ETH_ALEN); + memcpy(new_mpath->mpp, mpp, ETH_ALEN); + new_mpath->sdata = sdata; + new_mpath->flags = 0; + skb_queue_head_init(&new_mpath->frame_queue); + new_node->mpath = new_mpath; + new_mpath->exp_time = jiffies; + spin_lock_init(&new_mpath->state_lock); + + tbl = resize_dereference_mpp_paths(); + + hash_idx = mesh_table_hash(dst, sdata, tbl); + bucket = &tbl->hash_buckets[hash_idx]; + + spin_lock_bh(&tbl->hashwlock[hash_idx]); + + err = -EEXIST; + hlist_for_each_entry(node, n, bucket, list) { + mpath = node->mpath; + if (mpath->sdata == sdata && memcmp(dst, mpath->dst, ETH_ALEN) == 0) + goto err_exists; + } + + hlist_add_head_rcu(&new_node->list, bucket); + if (atomic_inc_return(&tbl->entries) >= + tbl->mean_chain_len * (tbl->hash_mask + 1)) + grow = 1; + + spin_unlock_bh(&tbl->hashwlock[hash_idx]); + read_unlock_bh(&pathtbl_resize_lock); + if (grow) { + set_bit(MESH_WORK_GROW_MPP_TABLE, &ifmsh->wrkq_flags); + ieee80211_queue_work(&local->hw, &sdata->work); + } + return 0; + +err_exists: + spin_unlock_bh(&tbl->hashwlock[hash_idx]); + read_unlock_bh(&pathtbl_resize_lock); + kfree(new_node); +err_node_alloc: + kfree(new_mpath); +err_path_alloc: + return err; +} + + +/** + * mesh_plink_broken - deactivates paths and sends perr when a link breaks + * + * @sta: broken peer link + * + * This function must be called from the rate control algorithm if enough + * delivery errors suggest that a peer link is no longer usable. + */ +void mesh_plink_broken(struct sta_info *sta) +{ + struct mesh_table *tbl; + static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; + struct mesh_path *mpath; + struct mpath_node *node; + struct hlist_node *p; + struct ieee80211_sub_if_data *sdata = sta->sdata; + int i; + + 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)) { + 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); + } + rcu_read_unlock(); +} + +/** + * mesh_path_flush_by_nexthop - Deletes mesh paths if their next hop matches + * + * @sta - mesh peer to match + * + * RCU notes: this function is called when a mesh plink transitions from + * PLINK_ESTAB to any other state, since PLINK_ESTAB state is the only one that + * allows path creation. This will happen before the sta can be freed (because + * sta_info_destroy() calls this) so any reader in a rcu read block will be + * protected against the plink disappearing. + */ +void mesh_path_flush_by_nexthop(struct sta_info *sta) +{ + 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); + 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); + } + rcu_read_unlock(); +} + +void mesh_path_flush(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); + for_each_mesh_entry(tbl, p, node, i) { + mpath = node->mpath; + if (mpath->sdata == sdata) + mesh_path_del(mpath->dst, mpath->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); +} + +/** + * mesh_path_del - delete a mesh path from the table + * + * @addr: dst address (ETH_ALEN length) + * @sdata: local subif + * + * Returns: 0 if successful + */ +int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata) +{ + struct mesh_table *tbl; + struct mesh_path *mpath; + struct mpath_node *node; + struct hlist_head *bucket; + struct hlist_node *n; + int hash_idx; + int err = 0; + + read_lock_bh(&pathtbl_resize_lock); + tbl = resize_dereference_mesh_paths(); + hash_idx = mesh_table_hash(addr, sdata, tbl); + bucket = &tbl->hash_buckets[hash_idx]; + + spin_lock_bh(&tbl->hashwlock[hash_idx]); + hlist_for_each_entry(node, n, bucket, list) { + mpath = node->mpath; + if (mpath->sdata == sdata && + memcmp(addr, mpath->dst, ETH_ALEN) == 0) { + spin_lock_bh(&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_bh(&mpath->state_lock); + goto enddel; + } + } + + err = -ENXIO; +enddel: + mesh_paths_generation++; + spin_unlock_bh(&tbl->hashwlock[hash_idx]); + read_unlock_bh(&pathtbl_resize_lock); + return err; +} + +/** + * mesh_path_tx_pending - sends pending frames in a mesh path queue + * + * @mpath: mesh path to activate + * + * Locking: the state_lock of the mpath structure must NOT be held when calling + * this function. + */ +void mesh_path_tx_pending(struct mesh_path *mpath) +{ + if (mpath->flags & MESH_PATH_ACTIVE) + ieee80211_add_pending_skbs(mpath->sdata->local, + &mpath->frame_queue); +} + +/** + * 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++; +} + +/** + * mesh_path_flush_pending - free the pending queue of a mesh path + * + * @mpath: mesh path whose queue has to be freed + * + * Locking: the function must me called within a rcu_read_lock region + */ +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)) + mesh_path_discard_frame(skb, mpath->sdata); +} + +/** + * mesh_path_fix_nexthop - force a specific next hop for a mesh path + * + * @mpath: the mesh path to modify + * @next_hop: the next hop to force + * + * Locking: this function must be called holding mpath->state_lock + */ +void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop) +{ + spin_lock_bh(&mpath->state_lock); + mesh_path_assign_nexthop(mpath, next_hop); + mpath->sn = 0xffff; + mpath->metric = 0; + mpath->hop_count = 0; + mpath->exp_time = 0; + mpath->flags |= MESH_PATH_FIXED; + mesh_path_activate(mpath); + spin_unlock_bh(&mpath->state_lock); + mesh_path_tx_pending(mpath); +} + +static void mesh_path_node_free(struct hlist_node *p, bool free_leafs) +{ + struct mesh_path *mpath; + struct mpath_node *node = hlist_entry(p, struct mpath_node, list); + mpath = node->mpath; + hlist_del_rcu(p); + if (free_leafs) { + del_timer_sync(&mpath->timer); + kfree(mpath); + } + kfree(node); +} + +static int mesh_path_node_copy(struct hlist_node *p, struct mesh_table *newtbl) +{ + struct mesh_path *mpath; + struct mpath_node *node, *new_node; + u32 hash_idx; + + new_node = kmalloc(sizeof(struct mpath_node), GFP_ATOMIC); + if (new_node == NULL) + return -ENOMEM; + + node = hlist_entry(p, struct mpath_node, list); + mpath = node->mpath; + new_node->mpath = mpath; + hash_idx = mesh_table_hash(mpath->dst, mpath->sdata, newtbl); + hlist_add_head(&new_node->list, + &newtbl->hash_buckets[hash_idx]); + return 0; +} + +int mesh_pathtbl_init(void) +{ + struct mesh_table *tbl_path, *tbl_mpp; + + tbl_path = mesh_table_alloc(INIT_PATHS_SIZE_ORDER); + if (!tbl_path) + return -ENOMEM; + 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_mpp = mesh_table_alloc(INIT_PATHS_SIZE_ORDER); + if (!tbl_mpp) { + mesh_table_free(tbl_path, true); + return -ENOMEM; + } + tbl_mpp->free_node = &mesh_path_node_free; + tbl_mpp->copy_node = &mesh_path_node_copy; + tbl_mpp->mean_chain_len = MEAN_CHAIN_LEN; + + /* Need no locking since this is during init */ + RCU_INIT_POINTER(mesh_paths, tbl_path); + RCU_INIT_POINTER(mpp_paths, tbl_mpp); + + return 0; +} + +void mesh_path_expire(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); + for_each_mesh_entry(tbl, p, node, i) { + 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); + 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); +} |