diff options
Diffstat (limited to 'net/mac80211/mesh_pathtbl.c')
| -rw-r--r-- | net/mac80211/mesh_pathtbl.c | 1072 |
1 files changed, 1072 insertions, 0 deletions
diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c new file mode 100644 index 0000000000..3e52aaa57b --- /dev/null +++ b/net/mac80211/mesh_pathtbl.c @@ -0,0 +1,1072 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2008, 2009 open80211s Ltd. + * Author: Luis Carlos Cobo <luisca@cozybit.com> + */ + +#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 "wme.h" +#include "ieee80211_i.h" +#include "mesh.h" +#include <linux/rhashtable.h> + +static void mesh_path_free_rcu(struct mesh_table *tbl, struct mesh_path *mpath); + +static u32 mesh_table_hash(const void *addr, u32 len, u32 seed) +{ + /* Use last four bytes of hw addr as hash index */ + return jhash_1word(__get_unaligned_cpu32((u8 *)addr + 2), seed); +} + +static const struct rhashtable_params mesh_rht_params = { + .nelem_hint = 2, + .automatic_shrinking = true, + .key_len = ETH_ALEN, + .key_offset = offsetof(struct mesh_path, dst), + .head_offset = offsetof(struct mesh_path, rhash), + .hashfn = mesh_table_hash, +}; + +static const struct rhashtable_params fast_tx_rht_params = { + .nelem_hint = 10, + .automatic_shrinking = true, + .key_len = ETH_ALEN, + .key_offset = offsetof(struct ieee80211_mesh_fast_tx, addr_key), + .head_offset = offsetof(struct ieee80211_mesh_fast_tx, rhash), + .hashfn = mesh_table_hash, +}; + +static void __mesh_fast_tx_entry_free(void *ptr, void *tblptr) +{ + struct ieee80211_mesh_fast_tx *entry = ptr; + + kfree_rcu(entry, fast_tx.rcu_head); +} + +static void mesh_fast_tx_deinit(struct ieee80211_sub_if_data *sdata) +{ + struct mesh_tx_cache *cache; + + cache = &sdata->u.mesh.tx_cache; + rhashtable_free_and_destroy(&cache->rht, + __mesh_fast_tx_entry_free, NULL); +} + +static void mesh_fast_tx_init(struct ieee80211_sub_if_data *sdata) +{ + struct mesh_tx_cache *cache; + + cache = &sdata->u.mesh.tx_cache; + rhashtable_init(&cache->rht, &fast_tx_rht_params); + INIT_HLIST_HEAD(&cache->walk_head); + spin_lock_init(&cache->walk_lock); +} + +static inline bool mpath_expired(struct mesh_path *mpath) +{ + return (mpath->flags & MESH_PATH_ACTIVE) && + time_after(jiffies, mpath->exp_time) && + !(mpath->flags & MESH_PATH_FIXED); +} + +static void mesh_path_rht_free(void *ptr, void *tblptr) +{ + struct mesh_path *mpath = ptr; + struct mesh_table *tbl = tblptr; + + mesh_path_free_rcu(tbl, mpath); +} + +static void mesh_table_init(struct mesh_table *tbl) +{ + INIT_HLIST_HEAD(&tbl->known_gates); + INIT_HLIST_HEAD(&tbl->walk_head); + atomic_set(&tbl->entries, 0); + spin_lock_init(&tbl->gates_lock); + spin_lock_init(&tbl->walk_lock); + + /* rhashtable_init() may fail only in case of wrong + * mesh_rht_params + */ + WARN_ON(rhashtable_init(&tbl->rhead, &mesh_rht_params)); +} + +static void mesh_table_free(struct mesh_table *tbl) +{ + rhashtable_free_and_destroy(&tbl->rhead, + mesh_path_rht_free, tbl); +} + +/** + * 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; + unsigned long flags; + + rcu_assign_pointer(mpath->next_hop, sta); + + spin_lock_irqsave(&mpath->frame_queue.lock, flags); + skb_queue_walk(&mpath->frame_queue, skb) { + hdr = (struct ieee80211_hdr *) skb->data; + memcpy(hdr->addr1, sta->sta.addr, ETH_ALEN); + memcpy(hdr->addr2, mpath->sdata->vif.addr, ETH_ALEN); + ieee80211_mps_set_frame_flags(sta->sdata, sta, hdr); + } + + 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 addresses */ + 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->addr2, gate_mpath->sdata->vif.addr, ETH_ALEN); + 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. + * + * @gate_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, *fskb, *tmp; + struct sk_buff_head failq; + unsigned long flags; + + if (WARN_ON(gate_mpath == from_mpath)) + return; + if (WARN_ON(!gate_mpath->next_hop)) + return; + + __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); + + skb_queue_walk_safe(&failq, fskb, tmp) { + if (skb_queue_len(&gate_mpath->frame_queue) >= + MESH_FRAME_QUEUE_LEN) { + mpath_dbg(gate_mpath->sdata, "mpath queue full!\n"); + break; + } + + skb = skb_copy(fskb, GFP_ATOMIC); + if (WARN_ON(!skb)) + break; + + prepare_for_gate(skb, gate_mpath->dst, gate_mpath); + skb_queue_tail(&gate_mpath->frame_queue, skb); + + if (copy) + continue; + + __skb_unlink(fskb, &failq); + kfree_skb(fskb); + } + + mpath_dbg(gate_mpath->sdata, "Mpath queue for gate %pM has %d frames\n", + gate_mpath->dst, skb_queue_len(&gate_mpath->frame_queue)); + + 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); +} + + +static struct mesh_path *mpath_lookup(struct mesh_table *tbl, const u8 *dst, + struct ieee80211_sub_if_data *sdata) +{ + struct mesh_path *mpath; + + mpath = rhashtable_lookup(&tbl->rhead, dst, mesh_rht_params); + + if (mpath && mpath_expired(mpath)) { + spin_lock_bh(&mpath->state_lock); + mpath->flags &= ~MESH_PATH_ACTIVE; + spin_unlock_bh(&mpath->state_lock); + } + return mpath; +} + +/** + * mesh_path_lookup - look up a path in the mesh path table + * @sdata: local subif + * @dst: hardware address (ETH_ALEN length) of destination + * + * 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(struct ieee80211_sub_if_data *sdata, const u8 *dst) +{ + return mpath_lookup(&sdata->u.mesh.mesh_paths, dst, sdata); +} + +struct mesh_path * +mpp_path_lookup(struct ieee80211_sub_if_data *sdata, const u8 *dst) +{ + return mpath_lookup(&sdata->u.mesh.mpp_paths, dst, sdata); +} + +static struct mesh_path * +__mesh_path_lookup_by_idx(struct mesh_table *tbl, int idx) +{ + int i = 0; + struct mesh_path *mpath; + + hlist_for_each_entry_rcu(mpath, &tbl->walk_head, walk_list) { + if (i++ == idx) + break; + } + + if (!mpath) + return NULL; + + if (mpath_expired(mpath)) { + spin_lock_bh(&mpath->state_lock); + mpath->flags &= ~MESH_PATH_ACTIVE; + spin_unlock_bh(&mpath->state_lock); + } + return mpath; +} + +/** + * 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(struct ieee80211_sub_if_data *sdata, int idx) +{ + return __mesh_path_lookup_by_idx(&sdata->u.mesh.mesh_paths, idx); +} + +/** + * mpp_path_lookup_by_idx - look up a path in the proxy path table by its index + * @idx: index + * @sdata: local subif, or NULL for all entries + * + * Returns: pointer to the proxy path structure, or NULL if not found. + * + * Locking: must be called within a read rcu section. + */ +struct mesh_path * +mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx) +{ + return __mesh_path_lookup_by_idx(&sdata->u.mesh.mpp_paths, idx); +} + +/** + * 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) +{ + struct mesh_table *tbl; + int err; + + rcu_read_lock(); + tbl = &mpath->sdata->u.mesh.mesh_paths; + + spin_lock_bh(&mpath->state_lock); + if (mpath->is_gate) { + err = -EEXIST; + spin_unlock_bh(&mpath->state_lock); + goto err_rcu; + } + mpath->is_gate = true; + mpath->sdata->u.mesh.num_gates++; + + spin_lock(&tbl->gates_lock); + hlist_add_head_rcu(&mpath->gate_list, &tbl->known_gates); + spin_unlock(&tbl->gates_lock); + + spin_unlock_bh(&mpath->state_lock); + + mpath_dbg(mpath->sdata, + "Mesh path: Recorded new gate: %pM. %d known gates\n", + mpath->dst, mpath->sdata->u.mesh.num_gates); + err = 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 + */ +static void mesh_gate_del(struct mesh_table *tbl, struct mesh_path *mpath) +{ + lockdep_assert_held(&mpath->state_lock); + if (!mpath->is_gate) + return; + + mpath->is_gate = false; + spin_lock_bh(&tbl->gates_lock); + hlist_del_rcu(&mpath->gate_list); + mpath->sdata->u.mesh.num_gates--; + spin_unlock_bh(&tbl->gates_lock); + + mpath_dbg(mpath->sdata, + "Mesh path: Deleted gate: %pM. %d known gates\n", + mpath->dst, mpath->sdata->u.mesh.num_gates); +} + +/** + * 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; +} + +static +struct mesh_path *mesh_path_new(struct ieee80211_sub_if_data *sdata, + const u8 *dst, gfp_t gfp_flags) +{ + struct mesh_path *new_mpath; + + new_mpath = kzalloc(sizeof(struct mesh_path), gfp_flags); + if (!new_mpath) + return NULL; + + memcpy(new_mpath->dst, dst, ETH_ALEN); + eth_broadcast_addr(new_mpath->rann_snd_addr); + new_mpath->is_root = false; + new_mpath->sdata = sdata; + new_mpath->flags = 0; + skb_queue_head_init(&new_mpath->frame_queue); + new_mpath->exp_time = jiffies; + spin_lock_init(&new_mpath->state_lock); + timer_setup(&new_mpath->timer, mesh_path_timer, 0); + + return new_mpath; +} + +static void mesh_fast_tx_entry_free(struct mesh_tx_cache *cache, + struct ieee80211_mesh_fast_tx *entry) +{ + hlist_del_rcu(&entry->walk_list); + rhashtable_remove_fast(&cache->rht, &entry->rhash, fast_tx_rht_params); + kfree_rcu(entry, fast_tx.rcu_head); +} + +struct ieee80211_mesh_fast_tx * +mesh_fast_tx_get(struct ieee80211_sub_if_data *sdata, const u8 *addr) +{ + struct ieee80211_mesh_fast_tx *entry; + struct mesh_tx_cache *cache; + + cache = &sdata->u.mesh.tx_cache; + entry = rhashtable_lookup(&cache->rht, addr, fast_tx_rht_params); + if (!entry) + return NULL; + + if (!(entry->mpath->flags & MESH_PATH_ACTIVE) || + mpath_expired(entry->mpath)) { + spin_lock_bh(&cache->walk_lock); + entry = rhashtable_lookup(&cache->rht, addr, fast_tx_rht_params); + if (entry) + mesh_fast_tx_entry_free(cache, entry); + spin_unlock_bh(&cache->walk_lock); + return NULL; + } + + mesh_path_refresh(sdata, entry->mpath, NULL); + if (entry->mppath) + entry->mppath->exp_time = jiffies; + entry->timestamp = jiffies; + + return entry; +} + +void mesh_fast_tx_cache(struct ieee80211_sub_if_data *sdata, + struct sk_buff *skb, struct mesh_path *mpath) +{ + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + struct ieee80211_mesh_fast_tx *entry, *prev; + struct ieee80211_mesh_fast_tx build = {}; + struct ieee80211s_hdr *meshhdr; + struct mesh_tx_cache *cache; + struct ieee80211_key *key; + struct mesh_path *mppath; + struct sta_info *sta; + u8 *qc; + + if (sdata->noack_map || + !ieee80211_is_data_qos(hdr->frame_control)) + return; + + build.fast_tx.hdr_len = ieee80211_hdrlen(hdr->frame_control); + meshhdr = (struct ieee80211s_hdr *)(skb->data + build.fast_tx.hdr_len); + build.hdrlen = ieee80211_get_mesh_hdrlen(meshhdr); + + cache = &sdata->u.mesh.tx_cache; + if (atomic_read(&cache->rht.nelems) >= MESH_FAST_TX_CACHE_MAX_SIZE) + return; + + sta = rcu_dereference(mpath->next_hop); + if (!sta) + return; + + if ((meshhdr->flags & MESH_FLAGS_AE) == MESH_FLAGS_AE_A5_A6) { + /* This is required to keep the mppath alive */ + mppath = mpp_path_lookup(sdata, meshhdr->eaddr1); + if (!mppath) + return; + build.mppath = mppath; + } else if (ieee80211_has_a4(hdr->frame_control)) { + mppath = mpath; + } else { + return; + } + + /* rate limit, in case fast xmit can't be enabled */ + if (mppath->fast_tx_check == jiffies) + return; + + mppath->fast_tx_check = jiffies; + + /* + * Same use of the sta lock as in ieee80211_check_fast_xmit, in order + * to protect against concurrent sta key updates. + */ + spin_lock_bh(&sta->lock); + key = rcu_access_pointer(sta->ptk[sta->ptk_idx]); + if (!key) + key = rcu_access_pointer(sdata->default_unicast_key); + build.fast_tx.key = key; + + if (key) { + bool gen_iv, iv_spc; + + gen_iv = key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV; + iv_spc = key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE; + + if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) || + (key->flags & KEY_FLAG_TAINTED)) + goto unlock_sta; + + switch (key->conf.cipher) { + case WLAN_CIPHER_SUITE_CCMP: + case WLAN_CIPHER_SUITE_CCMP_256: + if (gen_iv) + build.fast_tx.pn_offs = build.fast_tx.hdr_len; + if (gen_iv || iv_spc) + build.fast_tx.hdr_len += IEEE80211_CCMP_HDR_LEN; + break; + case WLAN_CIPHER_SUITE_GCMP: + case WLAN_CIPHER_SUITE_GCMP_256: + if (gen_iv) + build.fast_tx.pn_offs = build.fast_tx.hdr_len; + if (gen_iv || iv_spc) + build.fast_tx.hdr_len += IEEE80211_GCMP_HDR_LEN; + break; + default: + goto unlock_sta; + } + } + + memcpy(build.addr_key, mppath->dst, ETH_ALEN); + build.timestamp = jiffies; + build.fast_tx.band = info->band; + build.fast_tx.da_offs = offsetof(struct ieee80211_hdr, addr3); + build.fast_tx.sa_offs = offsetof(struct ieee80211_hdr, addr4); + build.mpath = mpath; + memcpy(build.hdr, meshhdr, build.hdrlen); + memcpy(build.hdr + build.hdrlen, rfc1042_header, sizeof(rfc1042_header)); + build.hdrlen += sizeof(rfc1042_header); + memcpy(build.fast_tx.hdr, hdr, build.fast_tx.hdr_len); + + hdr = (struct ieee80211_hdr *)build.fast_tx.hdr; + if (build.fast_tx.key) + hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PROTECTED); + + qc = ieee80211_get_qos_ctl(hdr); + qc[1] |= IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8; + + entry = kmemdup(&build, sizeof(build), GFP_ATOMIC); + if (!entry) + goto unlock_sta; + + spin_lock(&cache->walk_lock); + prev = rhashtable_lookup_get_insert_fast(&cache->rht, + &entry->rhash, + fast_tx_rht_params); + if (unlikely(IS_ERR(prev))) { + kfree(entry); + goto unlock_cache; + } + + /* + * replace any previous entry in the hash table, in case we're + * replacing it with a different type (e.g. mpath -> mpp) + */ + if (unlikely(prev)) { + rhashtable_replace_fast(&cache->rht, &prev->rhash, + &entry->rhash, fast_tx_rht_params); + hlist_del_rcu(&prev->walk_list); + kfree_rcu(prev, fast_tx.rcu_head); + } + + hlist_add_head(&entry->walk_list, &cache->walk_head); + +unlock_cache: + spin_unlock(&cache->walk_lock); +unlock_sta: + spin_unlock_bh(&sta->lock); +} + +void mesh_fast_tx_gc(struct ieee80211_sub_if_data *sdata) +{ + unsigned long timeout = msecs_to_jiffies(MESH_FAST_TX_CACHE_TIMEOUT); + struct mesh_tx_cache *cache; + struct ieee80211_mesh_fast_tx *entry; + struct hlist_node *n; + + cache = &sdata->u.mesh.tx_cache; + if (atomic_read(&cache->rht.nelems) < MESH_FAST_TX_CACHE_THRESHOLD_SIZE) + return; + + spin_lock_bh(&cache->walk_lock); + hlist_for_each_entry_safe(entry, n, &cache->walk_head, walk_list) + if (!time_is_after_jiffies(entry->timestamp + timeout)) + mesh_fast_tx_entry_free(cache, entry); + spin_unlock_bh(&cache->walk_lock); +} + +void mesh_fast_tx_flush_mpath(struct mesh_path *mpath) +{ + struct ieee80211_sub_if_data *sdata = mpath->sdata; + struct mesh_tx_cache *cache = &sdata->u.mesh.tx_cache; + struct ieee80211_mesh_fast_tx *entry; + struct hlist_node *n; + + cache = &sdata->u.mesh.tx_cache; + spin_lock_bh(&cache->walk_lock); + hlist_for_each_entry_safe(entry, n, &cache->walk_head, walk_list) + if (entry->mpath == mpath) + mesh_fast_tx_entry_free(cache, entry); + spin_unlock_bh(&cache->walk_lock); +} + +void mesh_fast_tx_flush_sta(struct ieee80211_sub_if_data *sdata, + struct sta_info *sta) +{ + struct mesh_tx_cache *cache = &sdata->u.mesh.tx_cache; + struct ieee80211_mesh_fast_tx *entry; + struct hlist_node *n; + + cache = &sdata->u.mesh.tx_cache; + spin_lock_bh(&cache->walk_lock); + hlist_for_each_entry_safe(entry, n, &cache->walk_head, walk_list) + if (rcu_access_pointer(entry->mpath->next_hop) == sta) + mesh_fast_tx_entry_free(cache, entry); + spin_unlock_bh(&cache->walk_lock); +} + +void mesh_fast_tx_flush_addr(struct ieee80211_sub_if_data *sdata, + const u8 *addr) +{ + struct mesh_tx_cache *cache = &sdata->u.mesh.tx_cache; + struct ieee80211_mesh_fast_tx *entry; + + cache = &sdata->u.mesh.tx_cache; + spin_lock_bh(&cache->walk_lock); + entry = rhashtable_lookup_fast(&cache->rht, addr, fast_tx_rht_params); + if (entry) + mesh_fast_tx_entry_free(cache, entry); + spin_unlock_bh(&cache->walk_lock); +} + +/** + * mesh_path_add - allocate and add a new path to the mesh path table + * @dst: 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 + */ +struct mesh_path *mesh_path_add(struct ieee80211_sub_if_data *sdata, + const u8 *dst) +{ + struct mesh_table *tbl; + struct mesh_path *mpath, *new_mpath; + + if (ether_addr_equal(dst, sdata->vif.addr)) + /* never add ourselves as neighbours */ + return ERR_PTR(-ENOTSUPP); + + if (is_multicast_ether_addr(dst)) + return ERR_PTR(-ENOTSUPP); + + if (atomic_add_unless(&sdata->u.mesh.mpaths, 1, MESH_MAX_MPATHS) == 0) + return ERR_PTR(-ENOSPC); + + new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC); + if (!new_mpath) + return ERR_PTR(-ENOMEM); + + tbl = &sdata->u.mesh.mesh_paths; + spin_lock_bh(&tbl->walk_lock); + mpath = rhashtable_lookup_get_insert_fast(&tbl->rhead, + &new_mpath->rhash, + mesh_rht_params); + if (!mpath) + hlist_add_head(&new_mpath->walk_list, &tbl->walk_head); + spin_unlock_bh(&tbl->walk_lock); + + if (mpath) { + kfree(new_mpath); + + if (IS_ERR(mpath)) + return mpath; + + new_mpath = mpath; + } + + sdata->u.mesh.mesh_paths_generation++; + return new_mpath; +} + +int mpp_path_add(struct ieee80211_sub_if_data *sdata, + const u8 *dst, const u8 *mpp) +{ + struct mesh_table *tbl; + struct mesh_path *new_mpath; + int ret; + + if (ether_addr_equal(dst, sdata->vif.addr)) + /* never add ourselves as neighbours */ + return -ENOTSUPP; + + if (is_multicast_ether_addr(dst)) + return -ENOTSUPP; + + new_mpath = mesh_path_new(sdata, dst, GFP_ATOMIC); + + if (!new_mpath) + return -ENOMEM; + + memcpy(new_mpath->mpp, mpp, ETH_ALEN); + tbl = &sdata->u.mesh.mpp_paths; + + spin_lock_bh(&tbl->walk_lock); + ret = rhashtable_lookup_insert_fast(&tbl->rhead, + &new_mpath->rhash, + mesh_rht_params); + if (!ret) + hlist_add_head_rcu(&new_mpath->walk_list, &tbl->walk_head); + spin_unlock_bh(&tbl->walk_lock); + + if (ret) + kfree(new_mpath); + else + mesh_fast_tx_flush_addr(sdata, dst); + + sdata->u.mesh.mpp_paths_generation++; + return ret; +} + + +/** + * 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 ieee80211_sub_if_data *sdata = sta->sdata; + struct mesh_table *tbl = &sdata->u.mesh.mesh_paths; + static const u8 bcast[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; + struct mesh_path *mpath; + + rcu_read_lock(); + hlist_for_each_entry_rcu(mpath, &tbl->walk_head, walk_list) { + if (rcu_access_pointer(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, + sdata->u.mesh.mshcfg.element_ttl, + mpath->dst, mpath->sn, + WLAN_REASON_MESH_PATH_DEST_UNREACHABLE, bcast); + } + } + rcu_read_unlock(); +} + +static void mesh_path_free_rcu(struct mesh_table *tbl, + struct mesh_path *mpath) +{ + struct ieee80211_sub_if_data *sdata = mpath->sdata; + + spin_lock_bh(&mpath->state_lock); + mpath->flags |= MESH_PATH_RESOLVING | MESH_PATH_DELETED; + mesh_gate_del(tbl, mpath); + spin_unlock_bh(&mpath->state_lock); + timer_shutdown_sync(&mpath->timer); + atomic_dec(&sdata->u.mesh.mpaths); + atomic_dec(&tbl->entries); + mesh_path_flush_pending(mpath); + kfree_rcu(mpath, rcu); +} + +static void __mesh_path_del(struct mesh_table *tbl, struct mesh_path *mpath) +{ + hlist_del_rcu(&mpath->walk_list); + rhashtable_remove_fast(&tbl->rhead, &mpath->rhash, mesh_rht_params); + if (tbl == &mpath->sdata->u.mesh.mpp_paths) + mesh_fast_tx_flush_addr(mpath->sdata, mpath->dst); + else + mesh_fast_tx_flush_mpath(mpath); + mesh_path_free_rcu(tbl, mpath); +} + +/** + * 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 ieee80211_sub_if_data *sdata = sta->sdata; + struct mesh_table *tbl = &sdata->u.mesh.mesh_paths; + struct mesh_path *mpath; + struct hlist_node *n; + + spin_lock_bh(&tbl->walk_lock); + hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) { + if (rcu_access_pointer(mpath->next_hop) == sta) + __mesh_path_del(tbl, mpath); + } + spin_unlock_bh(&tbl->walk_lock); +} + +static void mpp_flush_by_proxy(struct ieee80211_sub_if_data *sdata, + const u8 *proxy) +{ + struct mesh_table *tbl = &sdata->u.mesh.mpp_paths; + struct mesh_path *mpath; + struct hlist_node *n; + + spin_lock_bh(&tbl->walk_lock); + hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) { + if (ether_addr_equal(mpath->mpp, proxy)) + __mesh_path_del(tbl, mpath); + } + spin_unlock_bh(&tbl->walk_lock); +} + +static void table_flush_by_iface(struct mesh_table *tbl) +{ + struct mesh_path *mpath; + struct hlist_node *n; + + spin_lock_bh(&tbl->walk_lock); + hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) { + __mesh_path_del(tbl, mpath); + } + spin_unlock_bh(&tbl->walk_lock); +} + +/** + * 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) +{ + table_flush_by_iface(&sdata->u.mesh.mesh_paths); + table_flush_by_iface(&sdata->u.mesh.mpp_paths); +} + +/** + * table_path_del - delete a path from the mesh or mpp table + * + * @tbl: mesh or mpp path table + * @sdata: local subif + * @addr: dst address (ETH_ALEN length) + * + * Returns: 0 if successful + */ +static int table_path_del(struct mesh_table *tbl, + struct ieee80211_sub_if_data *sdata, + const u8 *addr) +{ + struct mesh_path *mpath; + + spin_lock_bh(&tbl->walk_lock); + mpath = rhashtable_lookup_fast(&tbl->rhead, addr, mesh_rht_params); + if (!mpath) { + spin_unlock_bh(&tbl->walk_lock); + return -ENXIO; + } + + __mesh_path_del(tbl, mpath); + spin_unlock_bh(&tbl->walk_lock); + return 0; +} + + +/** + * 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(struct ieee80211_sub_if_data *sdata, const u8 *addr) +{ + int err; + + /* flush relevant mpp entries first */ + mpp_flush_by_proxy(sdata, addr); + + err = table_path_del(&sdata->u.mesh.mesh_paths, sdata, addr); + sdata->u.mesh.mesh_paths_generation++; + 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 mesh_table *tbl; + struct mesh_path *from_mpath = mpath; + struct mesh_path *gate; + bool copy = false; + + tbl = &sdata->u.mesh.mesh_paths; + + rcu_read_lock(); + hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) { + if (gate->flags & MESH_PATH_ACTIVE) { + mpath_dbg(sdata, "Forwarding to %pM\n", gate->dst); + mesh_path_move_to_queue(gate, from_mpath, copy); + from_mpath = gate; + copy = true; + } else { + mpath_dbg(sdata, + "Not forwarding to %pM (flags %#x)\n", + gate->dst, gate->flags); + } + } + + hlist_for_each_entry_rcu(gate, &tbl->known_gates, gate_list) { + mpath_dbg(sdata, "Sending to %pM\n", gate->dst); + mesh_path_tx_pending(gate); + } + rcu_read_unlock(); + + 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 + * + * Locking: the function must me called within a rcu_read_lock region + */ +void mesh_path_discard_frame(struct ieee80211_sub_if_data *sdata, + struct sk_buff *skb) +{ + ieee80211_free_txskb(&sdata->local->hw, 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(mpath->sdata, skb); +} + +/** + * 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_SN_VALID; + mesh_path_activate(mpath); + mesh_fast_tx_flush_mpath(mpath); + spin_unlock_bh(&mpath->state_lock); + ewma_mesh_fail_avg_init(&next_hop->mesh->fail_avg); + /* init it at a low value - 0 start is tricky */ + ewma_mesh_fail_avg_add(&next_hop->mesh->fail_avg, 1); + mesh_path_tx_pending(mpath); +} + +void mesh_pathtbl_init(struct ieee80211_sub_if_data *sdata) +{ + mesh_table_init(&sdata->u.mesh.mesh_paths); + mesh_table_init(&sdata->u.mesh.mpp_paths); + mesh_fast_tx_init(sdata); +} + +static +void mesh_path_tbl_expire(struct ieee80211_sub_if_data *sdata, + struct mesh_table *tbl) +{ + struct mesh_path *mpath; + struct hlist_node *n; + + spin_lock_bh(&tbl->walk_lock); + hlist_for_each_entry_safe(mpath, n, &tbl->walk_head, walk_list) { + if ((!(mpath->flags & MESH_PATH_RESOLVING)) && + (!(mpath->flags & MESH_PATH_FIXED)) && + time_after(jiffies, mpath->exp_time + MESH_PATH_EXPIRE)) + __mesh_path_del(tbl, mpath); + } + spin_unlock_bh(&tbl->walk_lock); +} + +void mesh_path_expire(struct ieee80211_sub_if_data *sdata) +{ + mesh_path_tbl_expire(sdata, &sdata->u.mesh.mesh_paths); + mesh_path_tbl_expire(sdata, &sdata->u.mesh.mpp_paths); +} + +void mesh_pathtbl_unregister(struct ieee80211_sub_if_data *sdata) +{ + mesh_fast_tx_deinit(sdata); + mesh_table_free(&sdata->u.mesh.mesh_paths); + mesh_table_free(&sdata->u.mesh.mpp_paths); +} |