/* * 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 <asm/unaligned.h> #include "ieee80211_i.h" #include "mesh.h" #define IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ) #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ) #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); } static void ieee80211_mesh_housekeeping_timer(unsigned long data) { struct ieee80211_sub_if_data *sdata = (void *) data; struct ieee80211_local *local = sdata->local; struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; ifmsh->housekeeping = true; queue_work(local->hw.workqueue, &ifmsh->work); } /** * mesh_matches_local - check if the config of a mesh point matches ours * * @ie: information elements of a management frame from the mesh peer * @sdata: local mesh subif * * 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 ieee80211_sub_if_data *sdata) { struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; /* * 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 (ifmsh->mesh_id_len == ie->mesh_id_len && memcmp(ifmsh->mesh_id, ie->mesh_id, ie->mesh_id_len) == 0 && memcmp(ifmsh->mesh_pp_id, ie->mesh_config + PP_OFFSET, 4) == 0 && memcmp(ifmsh->mesh_pm_id, ie->mesh_config + PM_OFFSET, 4) == 0 && memcmp(ifmsh->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 */ bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie) { 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.mesh.accepting_plinks) ieee80211_mesh_housekeeping_timer((unsigned long) sdata); } void mesh_ids_set_default(struct ieee80211_if_mesh *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 ieee80211_sub_if_data *sdata) { int i; sdata->u.mesh.rmc = kmalloc(sizeof(struct mesh_rmc), GFP_KERNEL); if (!sdata->u.mesh.rmc) return -ENOMEM; sdata->u.mesh.rmc->idx_mask = RMC_BUCKETS - 1; for (i = 0; i < RMC_BUCKETS; i++) INIT_LIST_HEAD(&sdata->u.mesh.rmc->bucket[i].list); return 0; } void mesh_rmc_free(struct ieee80211_sub_if_data *sdata) { struct mesh_rmc *rmc = sdata->u.mesh.rmc; struct rmc_entry *p, *n; int i; if (!sdata->u.mesh.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.mesh.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 ieee80211_sub_if_data *sdata) { struct mesh_rmc *rmc = sdata->u.mesh.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 = le32_to_cpu(mesh_hdr->seqnum) & 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 ieee80211_sub_if_data *sdata) { struct ieee80211_local *local = sdata->local; 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.mesh.mesh_id_len); *pos++ = WLAN_EID_MESH_ID; *pos++ = sdata->u.mesh.mesh_id_len; if (sdata->u.mesh.mesh_id_len) memcpy(pos, sdata->u.mesh.mesh_id, sdata->u.mesh.mesh_id_len); pos = skb_put(skb, 21); *pos++ = WLAN_EID_MESH_CONFIG; *pos++ = IEEE80211_MESH_CONFIG_LEN; /* Version */ *pos++ = 1; /* Active path selection protocol ID */ memcpy(pos, sdata->u.mesh.mesh_pp_id, 4); pos += 4; /* Active path selection metric ID */ memcpy(pos, sdata->u.mesh.mesh_pm_id, 4); pos += 4; /* Congestion control mode identifier */ memcpy(pos, sdata->u.mesh.mesh_cc_id, 4); pos += 4; /* Channel precedence: * Not running simple channel unification protocol */ memset(pos, 0x00, 4); pos += 4; /* Mesh capability */ sdata->u.mesh.accepting_plinks = mesh_plink_availables(sdata); *pos++ = sdata->u.mesh.accepting_plinks ? ACCEPT_PLINKS : 0x00; *pos++ = 0x00; return; } 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; } 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; } static void __mesh_table_free(struct mesh_table *tbl) { kfree(tbl->hash_buckets); kfree(tbl->hashwlock); kfree(tbl); } 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]); } __mesh_table_free(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_mesh *ifmsh = &sdata->u.mesh; struct ieee80211_local *local = sdata->local; queue_work(local->hw.workqueue, &ifmsh->work); } struct mesh_table *mesh_table_grow(struct mesh_table *tbl) { struct mesh_table *newtbl; struct hlist_head *oldhash; struct hlist_node *p, *q; int i; if (atomic_read(&tbl->entries) < tbl->mean_chain_len * (tbl->hash_mask + 1)) goto endgrow; newtbl = mesh_table_alloc(tbl->size_order + 1); if (!newtbl) 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]) if (tbl->copy_node(p, newtbl) < 0) goto errcopy; return newtbl; errcopy: for (i = 0; i <= newtbl->hash_mask; i++) { hlist_for_each_safe(p, q, &newtbl->hash_buckets[i]) tbl->free_node(p, 0); } __mesh_table_free(newtbl); endgrow: return NULL; } /** * 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.mesh.mshcfg.dot11MeshTTL; put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum); sdata->u.mesh.mesh_seqnum++; return 6; } static void ieee80211_mesh_housekeeping(struct ieee80211_sub_if_data *sdata, struct ieee80211_if_mesh *ifmsh) { bool free_plinks; #ifdef CONFIG_MAC80211_VERBOSE_DEBUG printk(KERN_DEBUG "%s: running mesh housekeeping\n", sdata->dev->name); #endif ieee80211_sta_expire(sdata, IEEE80211_MESH_PEER_INACTIVITY_LIMIT); mesh_path_expire(sdata); free_plinks = mesh_plink_availables(sdata); if (free_plinks != sdata->u.mesh.accepting_plinks) ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON); ifmsh->housekeeping = false; mod_timer(&ifmsh->housekeeping_timer, round_jiffies(jiffies + IEEE80211_MESH_HOUSEKEEPING_INTERVAL)); } void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata) { struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; struct ieee80211_local *local = sdata->local; ifmsh->housekeeping = true; queue_work(local->hw.workqueue, &ifmsh->work); ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON); } void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata) { del_timer_sync(&sdata->u.mesh.housekeeping_timer); /* * If the timer fired while we waited for it, it will have * requeued the work. Now the work will be running again * but will not rearm the timer again because it checks * whether the interface is running, which, at this point, * it no longer is. */ cancel_work_sync(&sdata->u.mesh.work); /* * When we get here, the interface is marked down. * Call synchronize_rcu() to wait for the RX path * should it be using the interface and enqueuing * frames at this very time on another CPU. */ synchronize_rcu(); skb_queue_purge(&sdata->u.mesh.skb_queue); } static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata, u16 stype, struct ieee80211_mgmt *mgmt, size_t len, struct ieee80211_rx_status *rx_status) { struct ieee80211_local *local = sdata->local; struct ieee802_11_elems elems; struct ieee80211_channel *channel; u64 supp_rates = 0; size_t baselen; int freq; enum ieee80211_band band = rx_status->band; /* ignore ProbeResp to foreign address */ if (stype == IEEE80211_STYPE_PROBE_RESP && compare_ether_addr(mgmt->da, sdata->dev->dev_addr)) return; baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; if (baselen > len) return; ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, &elems); if (elems.ds_params && elems.ds_params_len == 1) freq = ieee80211_channel_to_frequency(elems.ds_params[0]); else freq = rx_status->freq; channel = ieee80211_get_channel(local->hw.wiphy, freq); if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) return; if (elems.mesh_id && elems.mesh_config && mesh_matches_local(&elems, sdata)) { supp_rates = ieee80211_sta_get_rates(local, &elems, band); mesh_neighbour_update(mgmt->sa, supp_rates, sdata, mesh_peer_accepts_plinks(&elems)); } } static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt, size_t len, struct ieee80211_rx_status *rx_status) { switch (mgmt->u.action.category) { case PLINK_CATEGORY: mesh_rx_plink_frame(sdata, mgmt, len, rx_status); break; case MESH_PATH_SEL_CATEGORY: mesh_rx_path_sel_frame(sdata, mgmt, len); break; } } static void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) { struct ieee80211_rx_status *rx_status; struct ieee80211_if_mesh *ifmsh; struct ieee80211_mgmt *mgmt; u16 stype; ifmsh = &sdata->u.mesh; rx_status = (struct ieee80211_rx_status *) skb->cb; mgmt = (struct ieee80211_mgmt *) skb->data; stype = le16_to_cpu(mgmt->frame_control) & IEEE80211_FCTL_STYPE; switch (stype) { case IEEE80211_STYPE_PROBE_RESP: case IEEE80211_STYPE_BEACON: ieee80211_mesh_rx_bcn_presp(sdata, stype, mgmt, skb->len, rx_status); break; case IEEE80211_STYPE_ACTION: ieee80211_mesh_rx_mgmt_action(sdata, mgmt, skb->len, rx_status); break; } kfree_skb(skb); } static void ieee80211_mesh_work(struct work_struct *work) { struct ieee80211_sub_if_data *sdata = container_of(work, struct ieee80211_sub_if_data, u.mesh.work); struct ieee80211_local *local = sdata->local; struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; struct sk_buff *skb; if (!netif_running(sdata->dev)) return; if (local->sw_scanning || local->hw_scanning) return; while ((skb = skb_dequeue(&ifmsh->skb_queue))) ieee80211_mesh_rx_queued_mgmt(sdata, skb); if (ifmsh->preq_queue_len && time_after(jiffies, ifmsh->last_preq + msecs_to_jiffies(ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval))) mesh_path_start_discovery(sdata); if (ifmsh->housekeeping) ieee80211_mesh_housekeeping(sdata, ifmsh); } void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) { struct ieee80211_sub_if_data *sdata; rcu_read_lock(); list_for_each_entry_rcu(sdata, &local->interfaces, list) if (ieee80211_vif_is_mesh(&sdata->vif)) queue_work(local->hw.workqueue, &sdata->u.mesh.work); rcu_read_unlock(); } void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata) { struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; INIT_WORK(&ifmsh->work, ieee80211_mesh_work); setup_timer(&ifmsh->housekeeping_timer, ieee80211_mesh_housekeeping_timer, (unsigned long) sdata); skb_queue_head_init(&sdata->u.mesh.skb_queue); ifmsh->mshcfg.dot11MeshRetryTimeout = MESH_RET_T; ifmsh->mshcfg.dot11MeshConfirmTimeout = MESH_CONF_T; ifmsh->mshcfg.dot11MeshHoldingTimeout = MESH_HOLD_T; ifmsh->mshcfg.dot11MeshMaxRetries = MESH_MAX_RETR; ifmsh->mshcfg.dot11MeshTTL = MESH_TTL; ifmsh->mshcfg.auto_open_plinks = true; ifmsh->mshcfg.dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS; ifmsh->mshcfg.dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT; ifmsh->mshcfg.dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT; ifmsh->mshcfg.dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME; ifmsh->mshcfg.dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES; ifmsh->mshcfg.path_refresh_time = MESH_PATH_REFRESH_TIME; ifmsh->mshcfg.min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT; ifmsh->accepting_plinks = true; ifmsh->preq_id = 0; ifmsh->dsn = 0; atomic_set(&ifmsh->mpaths, 0); mesh_rmc_init(sdata); ifmsh->last_preq = jiffies; /* Allocate all mesh structures when creating the first mesh interface. */ if (!mesh_allocated) ieee80211s_init(); mesh_ids_set_default(ifmsh); setup_timer(&ifmsh->mesh_path_timer, ieee80211_mesh_path_timer, (unsigned long) sdata); INIT_LIST_HEAD(&ifmsh->preq_queue.list); spin_lock_init(&ifmsh->mesh_preq_queue_lock); } ieee80211_rx_result ieee80211_mesh_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb, struct ieee80211_rx_status *rx_status) { struct ieee80211_local *local = sdata->local; struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; struct ieee80211_mgmt *mgmt; u16 fc; if (skb->len < 24) return RX_DROP_MONITOR; mgmt = (struct ieee80211_mgmt *) skb->data; fc = le16_to_cpu(mgmt->frame_control); switch (fc & IEEE80211_FCTL_STYPE) { case IEEE80211_STYPE_PROBE_RESP: case IEEE80211_STYPE_BEACON: case IEEE80211_STYPE_ACTION: memcpy(skb->cb, rx_status, sizeof(*rx_status)); skb_queue_tail(&ifmsh->skb_queue, skb); queue_work(local->hw.workqueue, &ifmsh->work); return RX_QUEUED; } return RX_CONTINUE; }