| /* |
| * 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" |
| |
| #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 |
| |
| /* 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)); |
| } |
| |
| 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 |
| * 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]); |
| spin_lock_init(&newtbl->gates_lock); |
| |
| 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; |
| struct mpath_node *gate; |
| 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]); |
| } |
| 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); |
| } |
| |
| 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; |
| newtbl->known_gates = oldtbl->known_gates; |
| 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); |
| } |
| |
| 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 |
| * @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; |
| } |
| |
| 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) |
| * @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; |
| __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)) { |
| 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(); |
| } |
| |
| /** |
| * 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; |
| |
| if (node->mpath->timer.function) |
| 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); |
| 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); |
| 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_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; |
| __le16 reason = cpu_to_le16(WLAN_REASON_MESH_PATH_NOFORWARD); |
| |
| 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), reason, 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)) != NULL) |
| 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) { |
| if (mpath->timer.function) |
| 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_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) { |
| 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; |
| /* 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); |
| 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); |
| } |