/* * 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/gfp.h> #include <linux/kernel.h> #include <linux/random.h> #include "ieee80211_i.h" #include "rate.h" #include "mesh.h" #define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2) #define PLINK_GET_LLID(p) (p + 2) #define PLINK_GET_PLID(p) (p + 4) #define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \ jiffies + msecs_to_jiffies(t))) enum plink_event { PLINK_UNDEFINED, OPN_ACPT, OPN_RJCT, OPN_IGNR, CNF_ACPT, CNF_RJCT, CNF_IGNR, CLS_ACPT, CLS_IGNR }; static const char * const mplstates[] = { [NL80211_PLINK_LISTEN] = "LISTEN", [NL80211_PLINK_OPN_SNT] = "OPN-SNT", [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD", [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD", [NL80211_PLINK_ESTAB] = "ESTAB", [NL80211_PLINK_HOLDING] = "HOLDING", [NL80211_PLINK_BLOCKED] = "BLOCKED" }; static const char * const mplevents[] = { [PLINK_UNDEFINED] = "NONE", [OPN_ACPT] = "OPN_ACPT", [OPN_RJCT] = "OPN_RJCT", [OPN_IGNR] = "OPN_IGNR", [CNF_ACPT] = "CNF_ACPT", [CNF_RJCT] = "CNF_RJCT", [CNF_IGNR] = "CNF_IGNR", [CLS_ACPT] = "CLS_ACPT", [CLS_IGNR] = "CLS_IGNR" }; /* We only need a valid sta if user configured a minimum rssi_threshold. */ static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata, struct sta_info *sta) { s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold; return rssi_threshold == 0 || (sta && (s8)-ewma_signal_read(&sta->rx_stats_avg.signal) > rssi_threshold); } /** * mesh_plink_fsm_restart - restart a mesh peer link finite state machine * * @sta: mesh peer link to restart * * Locking: this function must be called holding sta->mesh->plink_lock */ static inline void mesh_plink_fsm_restart(struct sta_info *sta) { lockdep_assert_held(&sta->mesh->plink_lock); sta->mesh->plink_state = NL80211_PLINK_LISTEN; sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0; sta->mesh->plink_retries = 0; } /* * mesh_set_short_slot_time - enable / disable ERP short slot time. * * The standard indirectly mandates mesh STAs to turn off short slot time by * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we * can't be sneaky about it. Enable short slot time if all mesh STAs in the * MBSS support ERP rates. * * Returns BSS_CHANGED_ERP_SLOT or 0 for no change. */ static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata) { struct ieee80211_local *local = sdata->local; enum nl80211_band band = ieee80211_get_sdata_band(sdata); struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; struct sta_info *sta; u32 erp_rates = 0, changed = 0; int i; bool short_slot = false; if (band == NL80211_BAND_5GHZ) { /* (IEEE 802.11-2012 19.4.5) */ short_slot = true; goto out; } else if (band != NL80211_BAND_2GHZ) goto out; for (i = 0; i < sband->n_bitrates; i++) if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G) erp_rates |= BIT(i); if (!erp_rates) goto out; rcu_read_lock(); list_for_each_entry_rcu(sta, &local->sta_list, list) { if (sdata != sta->sdata || sta->mesh->plink_state != NL80211_PLINK_ESTAB) continue; short_slot = false; if (erp_rates & sta->sta.supp_rates[band]) short_slot = true; else break; } rcu_read_unlock(); out: if (sdata->vif.bss_conf.use_short_slot != short_slot) { sdata->vif.bss_conf.use_short_slot = short_slot; changed = BSS_CHANGED_ERP_SLOT; mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n", sdata->vif.addr, short_slot); } return changed; } /** * mesh_set_ht_prot_mode - set correct HT protection mode * * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode * is selected if all peers in our 20/40MHz MBSS support HT and atleast one * HT20 peer is present. Otherwise no-protection mode is selected. */ static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) { struct ieee80211_local *local = sdata->local; struct sta_info *sta; u16 ht_opmode; bool non_ht_sta = false, ht20_sta = false; switch (sdata->vif.bss_conf.chandef.width) { case NL80211_CHAN_WIDTH_20_NOHT: case NL80211_CHAN_WIDTH_5: case NL80211_CHAN_WIDTH_10: return 0; default: break; } rcu_read_lock(); list_for_each_entry_rcu(sta, &local->sta_list, list) { if (sdata != sta->sdata || sta->mesh->plink_state != NL80211_PLINK_ESTAB) continue; if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20) continue; if (!sta->sta.ht_cap.ht_supported) { mpl_dbg(sdata, "nonHT sta (%pM) is present\n", sta->sta.addr); non_ht_sta = true; break; } mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); ht20_sta = true; } rcu_read_unlock(); if (non_ht_sta) ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; else if (ht20_sta && sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20) ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; else ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) return 0; sdata->vif.bss_conf.ht_operation_mode = ht_opmode; sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); return BSS_CHANGED_HT; } static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, struct sta_info *sta, enum ieee80211_self_protected_actioncode action, u8 *da, u16 llid, u16 plid, u16 reason) { struct ieee80211_local *local = sdata->local; struct sk_buff *skb; struct ieee80211_tx_info *info; struct ieee80211_mgmt *mgmt; bool include_plid = false; u16 peering_proto = 0; u8 *pos, ie_len = 4; int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) + sizeof(mgmt->u.action.u.self_prot); int err = -ENOMEM; skb = dev_alloc_skb(local->tx_headroom + hdr_len + 2 + /* capability info */ 2 + /* AID */ 2 + 8 + /* supported rates */ 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 2 + sdata->u.mesh.mesh_id_len + 2 + sizeof(struct ieee80211_meshconf_ie) + 2 + sizeof(struct ieee80211_ht_cap) + 2 + sizeof(struct ieee80211_ht_operation) + 2 + sizeof(struct ieee80211_vht_cap) + 2 + sizeof(struct ieee80211_vht_operation) + 2 + 8 + /* peering IE */ sdata->u.mesh.ie_len); if (!skb) return err; info = IEEE80211_SKB_CB(skb); skb_reserve(skb, local->tx_headroom); mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len); memset(mgmt, 0, hdr_len); mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_ACTION); memcpy(mgmt->da, da, ETH_ALEN); memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; mgmt->u.action.u.self_prot.action_code = action; if (action != WLAN_SP_MESH_PEERING_CLOSE) { enum nl80211_band band = ieee80211_get_sdata_band(sdata); /* capability info */ pos = skb_put(skb, 2); memset(pos, 0, 2); if (action == WLAN_SP_MESH_PEERING_CONFIRM) { /* AID */ pos = skb_put(skb, 2); put_unaligned_le16(sta->sta.aid, pos); } if (ieee80211_add_srates_ie(sdata, skb, true, band) || ieee80211_add_ext_srates_ie(sdata, skb, true, band) || mesh_add_rsn_ie(sdata, skb) || mesh_add_meshid_ie(sdata, skb) || mesh_add_meshconf_ie(sdata, skb)) goto free; } else { /* WLAN_SP_MESH_PEERING_CLOSE */ info->flags |= IEEE80211_TX_CTL_NO_ACK; if (mesh_add_meshid_ie(sdata, skb)) goto free; } /* Add Mesh Peering Management element */ switch (action) { case WLAN_SP_MESH_PEERING_OPEN: break; case WLAN_SP_MESH_PEERING_CONFIRM: ie_len += 2; include_plid = true; break; case WLAN_SP_MESH_PEERING_CLOSE: if (plid) { ie_len += 2; include_plid = true; } ie_len += 2; /* reason code */ break; default: err = -EINVAL; goto free; } if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) goto free; pos = skb_put(skb, 2 + ie_len); *pos++ = WLAN_EID_PEER_MGMT; *pos++ = ie_len; memcpy(pos, &peering_proto, 2); pos += 2; put_unaligned_le16(llid, pos); pos += 2; if (include_plid) { put_unaligned_le16(plid, pos); pos += 2; } if (action == WLAN_SP_MESH_PEERING_CLOSE) { put_unaligned_le16(reason, pos); pos += 2; } if (action != WLAN_SP_MESH_PEERING_CLOSE) { if (mesh_add_ht_cap_ie(sdata, skb) || mesh_add_ht_oper_ie(sdata, skb) || mesh_add_vht_cap_ie(sdata, skb) || mesh_add_vht_oper_ie(sdata, skb)) goto free; } if (mesh_add_vendor_ies(sdata, skb)) goto free; ieee80211_tx_skb(sdata, skb); return 0; free: kfree_skb(skb); return err; } /** * __mesh_plink_deactivate - deactivate mesh peer link * * @sta: mesh peer link to deactivate * * Mesh paths with this peer as next hop should be flushed * by the caller outside of plink_lock. * * Returns beacon changed flag if the beacon content changed. * * Locking: the caller must hold sta->mesh->plink_lock */ static u32 __mesh_plink_deactivate(struct sta_info *sta) { struct ieee80211_sub_if_data *sdata = sta->sdata; u32 changed = 0; lockdep_assert_held(&sta->mesh->plink_lock); if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) changed = mesh_plink_dec_estab_count(sdata); sta->mesh->plink_state = NL80211_PLINK_BLOCKED; ieee80211_mps_sta_status_update(sta); changed |= ieee80211_mps_set_sta_local_pm(sta, NL80211_MESH_POWER_UNKNOWN); return changed; } /** * mesh_plink_deactivate - deactivate mesh peer link * * @sta: mesh peer link to deactivate * * All mesh paths with this peer as next hop will be flushed */ u32 mesh_plink_deactivate(struct sta_info *sta) { struct ieee80211_sub_if_data *sdata = sta->sdata; u32 changed; spin_lock_bh(&sta->mesh->plink_lock); changed = __mesh_plink_deactivate(sta); if (!sdata->u.mesh.user_mpm) { sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED; mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE, sta->sta.addr, sta->mesh->llid, sta->mesh->plid, sta->mesh->reason); } spin_unlock_bh(&sta->mesh->plink_lock); if (!sdata->u.mesh.user_mpm) del_timer_sync(&sta->mesh->plink_timer); mesh_path_flush_by_nexthop(sta); /* make sure no readers can access nexthop sta from here on */ synchronize_net(); return changed; } static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, struct sta_info *sta, struct ieee802_11_elems *elems, bool insert) { struct ieee80211_local *local = sdata->local; enum nl80211_band band = ieee80211_get_sdata_band(sdata); struct ieee80211_supported_band *sband; u32 rates, basic_rates = 0, changed = 0; enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth; sband = local->hw.wiphy->bands[band]; rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates); spin_lock_bh(&sta->mesh->plink_lock); sta->rx_stats.last_rx = jiffies; /* rates and capabilities don't change during peering */ if (sta->mesh->plink_state == NL80211_PLINK_ESTAB && sta->mesh->processed_beacon) goto out; sta->mesh->processed_beacon = true; if (sta->sta.supp_rates[band] != rates) changed |= IEEE80211_RC_SUPP_RATES_CHANGED; sta->sta.supp_rates[band] = rates; if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, elems->ht_cap_elem, sta)) changed |= IEEE80211_RC_BW_CHANGED; ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband, elems->vht_cap_elem, sta); if (bw != sta->sta.bandwidth) changed |= IEEE80211_RC_BW_CHANGED; /* HT peer is operating 20MHz-only */ if (elems->ht_operation && !(elems->ht_operation->ht_param & IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) changed |= IEEE80211_RC_BW_CHANGED; sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; } if (insert) rate_control_rate_init(sta); else rate_control_rate_update(local, sband, sta, changed); out: spin_unlock_bh(&sta->mesh->plink_lock); } static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) { struct sta_info *sta; unsigned long *aid_map; int aid; aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1), sizeof(*aid_map), GFP_KERNEL); if (!aid_map) return -ENOMEM; /* reserve aid 0 for mcast indication */ __set_bit(0, aid_map); rcu_read_lock(); list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) __set_bit(sta->sta.aid, aid_map); rcu_read_unlock(); aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); kfree(aid_map); if (aid > IEEE80211_MAX_AID) return -ENOBUFS; return aid; } static struct sta_info * __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) { struct sta_info *sta; int aid; if (sdata->local->num_sta >= MESH_MAX_PLINKS) return NULL; aid = mesh_allocate_aid(sdata); if (aid < 0) return NULL; sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); if (!sta) return NULL; sta->mesh->plink_state = NL80211_PLINK_LISTEN; sta->sta.wme = true; sta->sta.aid = aid; sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); return sta; } static struct sta_info * mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, struct ieee802_11_elems *elems) { struct sta_info *sta = NULL; /* Userspace handles station allocation */ if (sdata->u.mesh.user_mpm || sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) { if (mesh_peer_accepts_plinks(elems) && mesh_plink_availables(sdata)) cfg80211_notify_new_peer_candidate(sdata->dev, addr, elems->ie_start, elems->total_len, GFP_KERNEL); } else sta = __mesh_sta_info_alloc(sdata, addr); return sta; } /* * mesh_sta_info_get - return mesh sta info entry for @addr. * * @sdata: local meshif * @addr: peer's address * @elems: IEs from beacon or mesh peering frame. * * Return existing or newly allocated sta_info under RCU read lock. * (re)initialize with given IEs. */ static struct sta_info * mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU) { struct sta_info *sta = NULL; rcu_read_lock(); sta = sta_info_get(sdata, addr); if (sta) { mesh_sta_info_init(sdata, sta, elems, false); } else { rcu_read_unlock(); /* can't run atomic */ sta = mesh_sta_info_alloc(sdata, addr, elems); if (!sta) { rcu_read_lock(); return NULL; } mesh_sta_info_init(sdata, sta, elems, true); if (sta_info_insert_rcu(sta)) return NULL; } return sta; } /* * mesh_neighbour_update - update or initialize new mesh neighbor. * * @sdata: local meshif * @addr: peer's address * @elems: IEs from beacon or mesh peering frame * * Initiates peering if appropriate. */ void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, u8 *hw_addr, struct ieee802_11_elems *elems) { struct sta_info *sta; u32 changed = 0; sta = mesh_sta_info_get(sdata, hw_addr, elems); if (!sta) goto out; if (mesh_peer_accepts_plinks(elems) && sta->mesh->plink_state == NL80211_PLINK_LISTEN && sdata->u.mesh.accepting_plinks && sdata->u.mesh.mshcfg.auto_open_plinks && rssi_threshold_check(sdata, sta)) changed = mesh_plink_open(sta); ieee80211_mps_frame_release(sta, elems); out: rcu_read_unlock(); ieee80211_mbss_info_change_notify(sdata, changed); } static void mesh_plink_timer(unsigned long data) { struct sta_info *sta; u16 reason = 0; struct ieee80211_sub_if_data *sdata; struct mesh_config *mshcfg; enum ieee80211_self_protected_actioncode action = 0; /* * This STA is valid because sta_info_destroy() will * del_timer_sync() this timer after having made sure * it cannot be readded (by deleting the plink.) */ sta = (struct sta_info *) data; if (sta->sdata->local->quiescing) return; spin_lock_bh(&sta->mesh->plink_lock); /* If a timer fires just before a state transition on another CPU, * we may have already extended the timeout and changed state by the * time we've acquired the lock and arrived here. In that case, * skip this timer and wait for the new one. */ if (time_before(jiffies, sta->mesh->plink_timer.expires)) { mpl_dbg(sta->sdata, "Ignoring timer for %pM in state %s (timer adjusted)", sta->sta.addr, mplstates[sta->mesh->plink_state]); spin_unlock_bh(&sta->mesh->plink_lock); return; } /* del_timer() and handler may race when entering these states */ if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || sta->mesh->plink_state == NL80211_PLINK_ESTAB) { mpl_dbg(sta->sdata, "Ignoring timer for %pM in state %s (timer deleted)", sta->sta.addr, mplstates[sta->mesh->plink_state]); spin_unlock_bh(&sta->mesh->plink_lock); return; } mpl_dbg(sta->sdata, "Mesh plink timer for %pM fired on state %s\n", sta->sta.addr, mplstates[sta->mesh->plink_state]); sdata = sta->sdata; mshcfg = &sdata->u.mesh.mshcfg; switch (sta->mesh->plink_state) { case NL80211_PLINK_OPN_RCVD: case NL80211_PLINK_OPN_SNT: /* retry timer */ if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { u32 rand; mpl_dbg(sta->sdata, "Mesh plink for %pM (retry, timeout): %d %d\n", sta->sta.addr, sta->mesh->plink_retries, sta->mesh->plink_timeout); get_random_bytes(&rand, sizeof(u32)); sta->mesh->plink_timeout = sta->mesh->plink_timeout + rand % sta->mesh->plink_timeout; ++sta->mesh->plink_retries; mod_plink_timer(sta, sta->mesh->plink_timeout); action = WLAN_SP_MESH_PEERING_OPEN; break; } reason = WLAN_REASON_MESH_MAX_RETRIES; /* fall through on else */ case NL80211_PLINK_CNF_RCVD: /* confirm timer */ if (!reason) reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; sta->mesh->plink_state = NL80211_PLINK_HOLDING; mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); action = WLAN_SP_MESH_PEERING_CLOSE; break; case NL80211_PLINK_HOLDING: /* holding timer */ del_timer(&sta->mesh->plink_timer); mesh_plink_fsm_restart(sta); break; default: break; } spin_unlock_bh(&sta->mesh->plink_lock); if (action) mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, sta->mesh->llid, sta->mesh->plid, reason); } static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) { sta->mesh->plink_timer.expires = jiffies + msecs_to_jiffies(timeout); sta->mesh->plink_timer.data = (unsigned long) sta; sta->mesh->plink_timer.function = mesh_plink_timer; sta->mesh->plink_timeout = timeout; add_timer(&sta->mesh->plink_timer); } static bool llid_in_use(struct ieee80211_sub_if_data *sdata, u16 llid) { struct ieee80211_local *local = sdata->local; bool in_use = false; struct sta_info *sta; rcu_read_lock(); list_for_each_entry_rcu(sta, &local->sta_list, list) { if (sdata != sta->sdata) continue; if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { in_use = true; break; } } rcu_read_unlock(); return in_use; } static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) { u16 llid; do { get_random_bytes(&llid, sizeof(llid)); } while (llid_in_use(sdata, llid)); return llid; } u32 mesh_plink_open(struct sta_info *sta) { struct ieee80211_sub_if_data *sdata = sta->sdata; u32 changed; if (!test_sta_flag(sta, WLAN_STA_AUTH)) return 0; spin_lock_bh(&sta->mesh->plink_lock); sta->mesh->llid = mesh_get_new_llid(sdata); if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { spin_unlock_bh(&sta->mesh->plink_lock); return 0; } sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); spin_unlock_bh(&sta->mesh->plink_lock); mpl_dbg(sdata, "Mesh plink: starting establishment with %pM\n", sta->sta.addr); /* set the non-peer mode to active during peering */ changed = ieee80211_mps_local_status_update(sdata); mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, sta->sta.addr, sta->mesh->llid, 0, 0); return changed; } u32 mesh_plink_block(struct sta_info *sta) { u32 changed; spin_lock_bh(&sta->mesh->plink_lock); changed = __mesh_plink_deactivate(sta); sta->mesh->plink_state = NL80211_PLINK_BLOCKED; spin_unlock_bh(&sta->mesh->plink_lock); mesh_path_flush_by_nexthop(sta); return changed; } static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, struct sta_info *sta, enum plink_event event) { struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; u16 reason = (event == CLS_ACPT) ? WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; sta->mesh->reason = reason; sta->mesh->plink_state = NL80211_PLINK_HOLDING; mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); } static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, struct sta_info *sta) { struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; u32 changed = 0; del_timer(&sta->mesh->plink_timer); sta->mesh->plink_state = NL80211_PLINK_ESTAB; changed |= mesh_plink_inc_estab_count(sdata); changed |= mesh_set_ht_prot_mode(sdata); changed |= mesh_set_short_slot_time(sdata); mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); ieee80211_mps_sta_status_update(sta); changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); return changed; } /** * mesh_plink_fsm - step @sta MPM based on @event * * @sdata: interface * @sta: mesh neighbor * @event: peering event * * Return: changed MBSS flags */ static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, struct sta_info *sta, enum plink_event event) { struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; enum ieee80211_self_protected_actioncode action = 0; u32 changed = 0; bool flush = false; mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, mplstates[sta->mesh->plink_state], mplevents[event]); spin_lock_bh(&sta->mesh->plink_lock); switch (sta->mesh->plink_state) { case NL80211_PLINK_LISTEN: switch (event) { case CLS_ACPT: mesh_plink_fsm_restart(sta); break; case OPN_ACPT: sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; sta->mesh->llid = mesh_get_new_llid(sdata); mesh_plink_timer_set(sta, mshcfg->dot11MeshRetryTimeout); /* set the non-peer mode to active during peering */ changed |= ieee80211_mps_local_status_update(sdata); action = WLAN_SP_MESH_PEERING_OPEN; break; default: break; } break; case NL80211_PLINK_OPN_SNT: switch (event) { case OPN_RJCT: case CNF_RJCT: case CLS_ACPT: mesh_plink_close(sdata, sta, event); action = WLAN_SP_MESH_PEERING_CLOSE; break; case OPN_ACPT: /* retry timer is left untouched */ sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; action = WLAN_SP_MESH_PEERING_CONFIRM; break; case CNF_ACPT: sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); break; default: break; } break; case NL80211_PLINK_OPN_RCVD: switch (event) { case OPN_RJCT: case CNF_RJCT: case CLS_ACPT: mesh_plink_close(sdata, sta, event); action = WLAN_SP_MESH_PEERING_CLOSE; break; case OPN_ACPT: action = WLAN_SP_MESH_PEERING_CONFIRM; break; case CNF_ACPT: changed |= mesh_plink_establish(sdata, sta); break; default: break; } break; case NL80211_PLINK_CNF_RCVD: switch (event) { case OPN_RJCT: case CNF_RJCT: case CLS_ACPT: mesh_plink_close(sdata, sta, event); action = WLAN_SP_MESH_PEERING_CLOSE; break; case OPN_ACPT: changed |= mesh_plink_establish(sdata, sta); action = WLAN_SP_MESH_PEERING_CONFIRM; break; default: break; } break; case NL80211_PLINK_ESTAB: switch (event) { case CLS_ACPT: changed |= __mesh_plink_deactivate(sta); changed |= mesh_set_ht_prot_mode(sdata); changed |= mesh_set_short_slot_time(sdata); mesh_plink_close(sdata, sta, event); action = WLAN_SP_MESH_PEERING_CLOSE; flush = true; break; case OPN_ACPT: action = WLAN_SP_MESH_PEERING_CONFIRM; break; default: break; } break; case NL80211_PLINK_HOLDING: switch (event) { case CLS_ACPT: del_timer(&sta->mesh->plink_timer); mesh_plink_fsm_restart(sta); break; case OPN_ACPT: case CNF_ACPT: case OPN_RJCT: case CNF_RJCT: action = WLAN_SP_MESH_PEERING_CLOSE; break; default: break; } break; default: /* should not get here, PLINK_BLOCKED is dealt with at the * beginning of the function */ break; } spin_unlock_bh(&sta->mesh->plink_lock); if (flush) mesh_path_flush_by_nexthop(sta); if (action) { mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, sta->mesh->llid, sta->mesh->plid, sta->mesh->reason); /* also send confirm in open case */ if (action == WLAN_SP_MESH_PEERING_OPEN) { mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CONFIRM, sta->sta.addr, sta->mesh->llid, sta->mesh->plid, 0); } } return changed; } /* * mesh_plink_get_event - get correct MPM event * * @sdata: interface * @sta: peer, leave NULL if processing a frame from a new suitable peer * @elems: peering management IEs * @ftype: frame type * @llid: peer's peer link ID * @plid: peer's local link ID * * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as * an error. */ static enum plink_event mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, struct sta_info *sta, struct ieee802_11_elems *elems, enum ieee80211_self_protected_actioncode ftype, u16 llid, u16 plid) { enum plink_event event = PLINK_UNDEFINED; u8 ie_len = elems->peering_len; bool matches_local; matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || mesh_matches_local(sdata, elems)); /* deny open request from non-matching peer */ if (!matches_local && !sta) { event = OPN_RJCT; goto out; } if (!sta) { if (ftype != WLAN_SP_MESH_PEERING_OPEN) { mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); goto out; } /* ftype == WLAN_SP_MESH_PEERING_OPEN */ if (!mesh_plink_free_count(sdata)) { mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); goto out; } /* new matching peer */ event = OPN_ACPT; goto out; } else { if (!test_sta_flag(sta, WLAN_STA_AUTH)) { mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); goto out; } if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) goto out; } switch (ftype) { case WLAN_SP_MESH_PEERING_OPEN: if (!matches_local) event = OPN_RJCT; if (!mesh_plink_free_count(sdata) || (sta->mesh->plid && sta->mesh->plid != plid)) event = OPN_IGNR; else event = OPN_ACPT; break; case WLAN_SP_MESH_PEERING_CONFIRM: if (!matches_local) event = CNF_RJCT; if (!mesh_plink_free_count(sdata) || sta->mesh->llid != llid || (sta->mesh->plid && sta->mesh->plid != plid)) event = CNF_IGNR; else event = CNF_ACPT; break; case WLAN_SP_MESH_PEERING_CLOSE: if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) /* Do not check for llid or plid. This does not * follow the standard but since multiple plinks * per sta are not supported, it is necessary in * order to avoid a livelock when MP A sees an * establish peer link to MP B but MP B does not * see it. This can be caused by a timeout in * B's peer link establishment or B beign * restarted. */ event = CLS_ACPT; else if (sta->mesh->plid != plid) event = CLS_IGNR; else if (ie_len == 8 && sta->mesh->llid != llid) event = CLS_IGNR; else event = CLS_ACPT; break; default: mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); break; } out: return event; } static void mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt, struct ieee802_11_elems *elems) { struct sta_info *sta; enum plink_event event; enum ieee80211_self_protected_actioncode ftype; u32 changed = 0; u8 ie_len = elems->peering_len; u16 plid, llid = 0; if (!elems->peering) { mpl_dbg(sdata, "Mesh plink: missing necessary peer link ie\n"); return; } if (elems->rsn_len && sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { mpl_dbg(sdata, "Mesh plink: can't establish link with secure peer\n"); return; } ftype = mgmt->u.action.u.self_prot.action_code; if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 && ie_len != 8)) { mpl_dbg(sdata, "Mesh plink: incorrect plink ie length %d %d\n", ftype, ie_len); return; } if (ftype != WLAN_SP_MESH_PEERING_CLOSE && (!elems->mesh_id || !elems->mesh_config)) { mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); return; } /* Note the lines below are correct, the llid in the frame is the plid * from the point of view of this host. */ plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); /* WARNING: Only for sta pointer, is dropped & re-acquired */ rcu_read_lock(); sta = sta_info_get(sdata, mgmt->sa); if (ftype == WLAN_SP_MESH_PEERING_OPEN && !rssi_threshold_check(sdata, sta)) { mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", mgmt->sa); goto unlock_rcu; } /* Now we will figure out the appropriate event... */ event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); if (event == OPN_ACPT) { rcu_read_unlock(); /* allocate sta entry if necessary and update info */ sta = mesh_sta_info_get(sdata, mgmt->sa, elems); if (!sta) { mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); goto unlock_rcu; } sta->mesh->plid = plid; } else if (!sta && event == OPN_RJCT) { mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, mgmt->sa, 0, plid, WLAN_REASON_MESH_CONFIG); goto unlock_rcu; } else if (!sta || event == PLINK_UNDEFINED) { /* something went wrong */ goto unlock_rcu; } if (event == CNF_ACPT) { /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ if (!sta->mesh->plid) sta->mesh->plid = plid; sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); } changed |= mesh_plink_fsm(sdata, sta, event); unlock_rcu: rcu_read_unlock(); if (changed) ieee80211_mbss_info_change_notify(sdata, changed); } void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt, size_t len, struct ieee80211_rx_status *rx_status) { struct ieee802_11_elems elems; size_t baselen; u8 *baseaddr; /* need action_code, aux */ if (len < IEEE80211_MIN_ACTION_SIZE + 3) return; if (sdata->u.mesh.user_mpm) /* userspace must register for these */ return; if (is_multicast_ether_addr(mgmt->da)) { mpl_dbg(sdata, "Mesh plink: ignore frame from multicast address\n"); return; } baseaddr = mgmt->u.action.u.self_prot.variable; baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; if (mgmt->u.action.u.self_prot.action_code == WLAN_SP_MESH_PEERING_CONFIRM) { baseaddr += 4; baselen += 4; if (baselen > len) return; } ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems); mesh_process_plink_frame(sdata, mgmt, &elems); }