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Diffstat (limited to '')
| -rw-r--r-- | net/mac80211/mesh.c | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c new file mode 100644 index 000000000000..594a3356a508 --- /dev/null +++ b/net/mac80211/mesh.c @@ -0,0 +1,449 @@ +/* + * Copyright (c) 2008 open80211s Ltd. + * Authors: Luis Carlos Cobo <luisca@cozybit.com> + * Javier Cardona <javier@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 "ieee80211_i.h" +#include "mesh.h" + +#define PP_OFFSET 1 /* Path Selection Protocol */ +#define PM_OFFSET 5 /* Path Selection Metric */ +#define CC_OFFSET 9 /* Congestion Control Mode */ +#define CAPAB_OFFSET 17 +#define ACCEPT_PLINKS 0x80 + +int mesh_allocated; +static struct kmem_cache *rm_cache; + +void ieee80211s_init(void) +{ + mesh_pathtbl_init(); + mesh_allocated = 1; + rm_cache = kmem_cache_create("mesh_rmc", sizeof(struct rmc_entry), + 0, 0, NULL); +} + +void ieee80211s_stop(void) +{ + mesh_pathtbl_unregister(); + kmem_cache_destroy(rm_cache); +} + +/** + * mesh_matches_local - check if the config of a mesh point matches ours + * + * @ie: information elements of a management frame from the mesh peer + * @dev: local mesh interface + * + * This function checks if the mesh configuration of a mesh point matches the + * local mesh configuration, i.e. if both nodes belong to the same mesh network. + */ +bool mesh_matches_local(struct ieee802_11_elems *ie, struct net_device *dev) +{ + struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); + struct ieee80211_if_sta *sta = &sdata->u.sta; + + /* + * As support for each feature is added, check for matching + * - On mesh config capabilities + * - Power Save Support En + * - Sync support enabled + * - Sync support active + * - Sync support required from peer + * - MDA enabled + * - Power management control on fc + */ + if (sta->mesh_id_len == ie->mesh_id_len && + memcmp(sta->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 && + memcmp(sta->mesh_pp_id, ie->mesh_config + PP_OFFSET, 4) == 0 && + memcmp(sta->mesh_pm_id, ie->mesh_config + PM_OFFSET, 4) == 0 && + memcmp(sta->mesh_cc_id, ie->mesh_config + CC_OFFSET, 4) == 0) + return true; + + return false; +} + +/** + * mesh_peer_accepts_plinks - check if an mp is willing to establish peer links + * + * @ie: information elements of a management frame from the mesh peer + * @dev: local mesh interface + */ +bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie, + struct net_device *dev) +{ + return (*(ie->mesh_config + CAPAB_OFFSET) & ACCEPT_PLINKS) != 0; +} + +/** + * mesh_accept_plinks_update: update accepting_plink in local mesh beacons + * + * @sdata: mesh interface in which mesh beacons are going to be updated + */ +void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata) +{ + bool free_plinks; + + /* In case mesh_plink_free_count > 0 and mesh_plinktbl_capacity == 0, + * the mesh interface might be able to establish plinks with peers that + * are already on the table but are not on PLINK_ESTAB state. However, + * in general the mesh interface is not accepting peer link requests + * from new peers, and that must be reflected in the beacon + */ + free_plinks = mesh_plink_availables(sdata); + + if (free_plinks != sdata->u.sta.accepting_plinks) + ieee80211_sta_timer((unsigned long) sdata); +} + +void mesh_ids_set_default(struct ieee80211_if_sta *sta) +{ + u8 def_id[4] = {0x00, 0x0F, 0xAC, 0xff}; + + memcpy(sta->mesh_pp_id, def_id, 4); + memcpy(sta->mesh_pm_id, def_id, 4); + memcpy(sta->mesh_cc_id, def_id, 4); +} + +int mesh_rmc_init(struct net_device *dev) +{ + struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); + int i; + + sdata->u.sta.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL); + if (!sdata->u.sta.rmc) + return -ENOMEM; + sdata->u.sta.rmc->idx_mask = RMC_BUCKETS - 1; + for (i = 0; i < RMC_BUCKETS; i++) + INIT_LIST_HEAD(&sdata->u.sta.rmc->bucket[i].list); + return 0; +} + +void mesh_rmc_free(struct net_device *dev) +{ + struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); + struct mesh_rmc *rmc = sdata->u.sta.rmc; + struct rmc_entry *p, *n; + int i; + + if (!sdata->u.sta.rmc) + return; + + for (i = 0; i < RMC_BUCKETS; i++) + list_for_each_entry_safe(p, n, &rmc->bucket[i].list, list) { + list_del(&p->list); + kmem_cache_free(rm_cache, p); + } + + kfree(rmc); + sdata->u.sta.rmc = NULL; +} + +/** + * mesh_rmc_check - Check frame in recent multicast cache and add if absent. + * + * @sa: source address + * @mesh_hdr: mesh_header + * + * Returns: 0 if the frame is not in the cache, nonzero otherwise. + * + * Checks using the source address and the mesh sequence number if we have + * received this frame lately. If the frame is not in the cache, it is added to + * it. + */ +int mesh_rmc_check(u8 *sa, struct ieee80211s_hdr *mesh_hdr, + struct net_device *dev) +{ + struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); + struct mesh_rmc *rmc = sdata->u.sta.rmc; + u32 seqnum = 0; + int entries = 0; + u8 idx; + struct rmc_entry *p, *n; + + /* Don't care about endianness since only match matters */ + memcpy(&seqnum, mesh_hdr->seqnum, sizeof(mesh_hdr->seqnum)); + idx = mesh_hdr->seqnum[0] & rmc->idx_mask; + list_for_each_entry_safe(p, n, &rmc->bucket[idx].list, list) { + ++entries; + if (time_after(jiffies, p->exp_time) || + (entries == RMC_QUEUE_MAX_LEN)) { + list_del(&p->list); + kmem_cache_free(rm_cache, p); + --entries; + } else if ((seqnum == p->seqnum) + && (memcmp(sa, p->sa, ETH_ALEN) == 0)) + return -1; + } + + p = kmem_cache_alloc(rm_cache, GFP_ATOMIC); + if (!p) { + printk(KERN_DEBUG "o11s: could not allocate RMC entry\n"); + return 0; + } + p->seqnum = seqnum; + p->exp_time = jiffies + RMC_TIMEOUT; + memcpy(p->sa, sa, ETH_ALEN); + list_add(&p->list, &rmc->bucket[idx].list); + return 0; +} + +void mesh_mgmt_ies_add(struct sk_buff *skb, struct net_device *dev) +{ + struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr); + struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); + struct ieee80211_supported_band *sband; + u8 *pos; + int len, i, rate; + + sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; + len = sband->n_bitrates; + if (len > 8) + len = 8; + pos = skb_put(skb, len + 2); + *pos++ = WLAN_EID_SUPP_RATES; + *pos++ = len; + for (i = 0; i < len; i++) { + rate = sband->bitrates[i].bitrate; + *pos++ = (u8) (rate / 5); + } + + if (sband->n_bitrates > len) { + pos = skb_put(skb, sband->n_bitrates - len + 2); + *pos++ = WLAN_EID_EXT_SUPP_RATES; + *pos++ = sband->n_bitrates - len; + for (i = len; i < sband->n_bitrates; i++) { + rate = sband->bitrates[i].bitrate; + *pos++ = (u8) (rate / 5); + } + } + + pos = skb_put(skb, 2 + sdata->u.sta.mesh_id_len); + *pos++ = WLAN_EID_MESH_ID; + *pos++ = sdata->u.sta.mesh_id_len; + if (sdata->u.sta.mesh_id_len) + memcpy(pos, sdata->u.sta.mesh_id, sdata->u.sta.mesh_id_len); + + pos = skb_put(skb, 21); + *pos++ = WLAN_EID_MESH_CONFIG; + *pos++ = MESH_CFG_LEN; + /* Version */ + *pos++ = 1; + + /* Active path selection protocol ID */ + memcpy(pos, sdata->u.sta.mesh_pp_id, 4); + pos += 4; + + /* Active path selection metric ID */ + memcpy(pos, sdata->u.sta.mesh_pm_id, 4); + pos += 4; + + /* Congestion control mode identifier */ + memcpy(pos, sdata->u.sta.mesh_cc_id, 4); + pos += 4; + + /* Channel precedence: + * Not running simple channel unification protocol + */ + memset(pos, 0x00, 4); + pos += 4; + + /* Mesh capability */ + sdata->u.sta.accepting_plinks = mesh_plink_availables(sdata); + *pos++ = sdata->u.sta.accepting_plinks ? ACCEPT_PLINKS : 0x00; + *pos++ = 0x00; + + return; +} + +u32 mesh_table_hash(u8 *addr, struct net_device *dev, struct mesh_table *tbl) +{ + /* Use last four bytes of hw addr and interface index as hash index */ + return jhash_2words(*(u32 *)(addr+2), dev->ifindex, tbl->hash_rnd) + & tbl->hash_mask; +} + +u8 mesh_id_hash(u8 *mesh_id, int mesh_id_len) +{ + if (!mesh_id_len) + return 1; + else if (mesh_id_len == 1) + return (u8) mesh_id[0]; + else + return (u8) (mesh_id[0] + 2 * mesh_id[1]); +} + +struct mesh_table *mesh_table_alloc(int size_order) +{ + int i; + struct mesh_table *newtbl; + + newtbl = kmalloc(sizeof(struct mesh_table), GFP_KERNEL); + if (!newtbl) + return NULL; + + newtbl->hash_buckets = kzalloc(sizeof(struct hlist_head) * + (1 << size_order), GFP_KERNEL); + + if (!newtbl->hash_buckets) { + kfree(newtbl); + return NULL; + } + + newtbl->hashwlock = kmalloc(sizeof(spinlock_t) * + (1 << size_order), GFP_KERNEL); + 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; +} + +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(&tbl->hashwlock[i]); + hlist_for_each_safe(p, q, &mesh_hash[i]) { + tbl->free_node(p, free_leafs); + atomic_dec(&tbl->entries); + } + spin_unlock(&tbl->hashwlock[i]); + } + kfree(tbl->hash_buckets); + kfree(tbl->hashwlock); + kfree(tbl); +} + +static void ieee80211_mesh_path_timer(unsigned long data) +{ + struct ieee80211_sub_if_data *sdata = + (struct ieee80211_sub_if_data *) data; + struct ieee80211_if_sta *ifsta = &sdata->u.sta; + struct ieee80211_local *local = wdev_priv(&sdata->wdev); + + queue_work(local->hw.workqueue, &ifsta->work); +} + +struct mesh_table *mesh_table_grow(struct mesh_table *tbl) +{ + struct mesh_table *newtbl; + struct hlist_head *oldhash; + struct hlist_node *p; + int err = 0; + int i; + + if (atomic_read(&tbl->entries) + < tbl->mean_chain_len * (tbl->hash_mask + 1)) { + err = -EPERM; + goto endgrow; + } + + newtbl = mesh_table_alloc(tbl->size_order + 1); + if (!newtbl) { + err = -ENOMEM; + goto endgrow; + } + + newtbl->free_node = tbl->free_node; + newtbl->mean_chain_len = tbl->mean_chain_len; + newtbl->copy_node = tbl->copy_node; + atomic_set(&newtbl->entries, atomic_read(&tbl->entries)); + + oldhash = tbl->hash_buckets; + for (i = 0; i <= tbl->hash_mask; i++) + hlist_for_each(p, &oldhash[i]) + tbl->copy_node(p, newtbl); + +endgrow: + if (err) + return NULL; + else + return newtbl; +} + +/** + * ieee80211_new_mesh_header - create a new mesh header + * @meshhdr: uninitialized mesh header + * @sdata: mesh interface to be used + * + * Return the header length. + */ +int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr, + struct ieee80211_sub_if_data *sdata) +{ + meshhdr->flags = 0; + meshhdr->ttl = sdata->u.sta.mshcfg.dot11MeshTTL; + + meshhdr->seqnum[0] = sdata->u.sta.mesh_seqnum[0]++; + meshhdr->seqnum[1] = sdata->u.sta.mesh_seqnum[1]; + meshhdr->seqnum[2] = sdata->u.sta.mesh_seqnum[2]; + + if (sdata->u.sta.mesh_seqnum[0] == 0) { + sdata->u.sta.mesh_seqnum[1]++; + if (sdata->u.sta.mesh_seqnum[1] == 0) + sdata->u.sta.mesh_seqnum[2]++; + } + + return 5; +} + +void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata) +{ + struct ieee80211_if_sta *ifsta = &sdata->u.sta; + + ifsta->mshcfg.dot11MeshRetryTimeout = MESH_RET_T; + ifsta->mshcfg.dot11MeshConfirmTimeout = MESH_CONF_T; + ifsta->mshcfg.dot11MeshHoldingTimeout = MESH_HOLD_T; + ifsta->mshcfg.dot11MeshMaxRetries = MESH_MAX_RETR; + ifsta->mshcfg.dot11MeshTTL = MESH_TTL; + ifsta->mshcfg.auto_open_plinks = true; + ifsta->mshcfg.dot11MeshMaxPeerLinks = + MESH_MAX_ESTAB_PLINKS; + ifsta->mshcfg.dot11MeshHWMPactivePathTimeout = + MESH_PATH_TIMEOUT; + ifsta->mshcfg.dot11MeshHWMPpreqMinInterval = + MESH_PREQ_MIN_INT; + ifsta->mshcfg.dot11MeshHWMPnetDiameterTraversalTime = + MESH_DIAM_TRAVERSAL_TIME; + ifsta->mshcfg.dot11MeshHWMPmaxPREQretries = + MESH_MAX_PREQ_RETRIES; + ifsta->mshcfg.path_refresh_time = + MESH_PATH_REFRESH_TIME; + ifsta->mshcfg.min_discovery_timeout = + MESH_MIN_DISCOVERY_TIMEOUT; + ifsta->accepting_plinks = true; + ifsta->preq_id = 0; + ifsta->dsn = 0; + atomic_set(&ifsta->mpaths, 0); + mesh_rmc_init(sdata->dev); + ifsta->last_preq = jiffies; + /* Allocate all mesh structures when creating the first mesh interface. */ + if (!mesh_allocated) + ieee80211s_init(); + mesh_ids_set_default(ifsta); + setup_timer(&ifsta->mesh_path_timer, + ieee80211_mesh_path_timer, + (unsigned long) sdata); + INIT_LIST_HEAD(&ifsta->preq_queue.list); + spin_lock_init(&ifsta->mesh_preq_queue_lock); +} |