1 /* 2 * Copyright (c) 2008, 2009 open80211s Ltd. 3 * Copyright (C) 2019 Intel Corporation 4 * Author: Luis Carlos Cobo <luisca@cozybit.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 #include <linux/gfp.h> 11 #include <linux/kernel.h> 12 #include <linux/random.h> 13 #include <linux/rculist.h> 14 15 #include "ieee80211_i.h" 16 #include "rate.h" 17 #include "mesh.h" 18 19 #define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2) 20 #define PLINK_GET_LLID(p) (p + 2) 21 #define PLINK_GET_PLID(p) (p + 4) 22 23 #define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \ 24 jiffies + msecs_to_jiffies(t))) 25 26 enum plink_event { 27 PLINK_UNDEFINED, 28 OPN_ACPT, 29 OPN_RJCT, 30 OPN_IGNR, 31 CNF_ACPT, 32 CNF_RJCT, 33 CNF_IGNR, 34 CLS_ACPT, 35 CLS_IGNR 36 }; 37 38 static const char * const mplstates[] = { 39 [NL80211_PLINK_LISTEN] = "LISTEN", 40 [NL80211_PLINK_OPN_SNT] = "OPN-SNT", 41 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD", 42 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD", 43 [NL80211_PLINK_ESTAB] = "ESTAB", 44 [NL80211_PLINK_HOLDING] = "HOLDING", 45 [NL80211_PLINK_BLOCKED] = "BLOCKED" 46 }; 47 48 static const char * const mplevents[] = { 49 [PLINK_UNDEFINED] = "NONE", 50 [OPN_ACPT] = "OPN_ACPT", 51 [OPN_RJCT] = "OPN_RJCT", 52 [OPN_IGNR] = "OPN_IGNR", 53 [CNF_ACPT] = "CNF_ACPT", 54 [CNF_RJCT] = "CNF_RJCT", 55 [CNF_IGNR] = "CNF_IGNR", 56 [CLS_ACPT] = "CLS_ACPT", 57 [CLS_IGNR] = "CLS_IGNR" 58 }; 59 60 /* We only need a valid sta if user configured a minimum rssi_threshold. */ 61 static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata, 62 struct sta_info *sta) 63 { 64 s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold; 65 return rssi_threshold == 0 || 66 (sta && 67 (s8)-ewma_signal_read(&sta->rx_stats_avg.signal) > 68 rssi_threshold); 69 } 70 71 /** 72 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine 73 * 74 * @sta: mesh peer link to restart 75 * 76 * Locking: this function must be called holding sta->mesh->plink_lock 77 */ 78 static inline void mesh_plink_fsm_restart(struct sta_info *sta) 79 { 80 lockdep_assert_held(&sta->mesh->plink_lock); 81 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 82 sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0; 83 sta->mesh->plink_retries = 0; 84 } 85 86 /* 87 * mesh_set_short_slot_time - enable / disable ERP short slot time. 88 * 89 * The standard indirectly mandates mesh STAs to turn off short slot time by 90 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we 91 * can't be sneaky about it. Enable short slot time if all mesh STAs in the 92 * MBSS support ERP rates. 93 * 94 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change. 95 */ 96 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata) 97 { 98 struct ieee80211_local *local = sdata->local; 99 struct ieee80211_supported_band *sband; 100 struct sta_info *sta; 101 u32 erp_rates = 0, changed = 0; 102 int i; 103 bool short_slot = false; 104 105 sband = ieee80211_get_sband(sdata); 106 if (!sband) 107 return changed; 108 109 if (sband->band == NL80211_BAND_5GHZ) { 110 /* (IEEE 802.11-2012 19.4.5) */ 111 short_slot = true; 112 goto out; 113 } else if (sband->band != NL80211_BAND_2GHZ) { 114 goto out; 115 } 116 117 for (i = 0; i < sband->n_bitrates; i++) 118 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G) 119 erp_rates |= BIT(i); 120 121 if (!erp_rates) 122 goto out; 123 124 rcu_read_lock(); 125 list_for_each_entry_rcu(sta, &local->sta_list, list) { 126 if (sdata != sta->sdata || 127 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 128 continue; 129 130 short_slot = false; 131 if (erp_rates & sta->sta.supp_rates[sband->band]) 132 short_slot = true; 133 else 134 break; 135 } 136 rcu_read_unlock(); 137 138 out: 139 if (sdata->vif.bss_conf.use_short_slot != short_slot) { 140 sdata->vif.bss_conf.use_short_slot = short_slot; 141 changed = BSS_CHANGED_ERP_SLOT; 142 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n", 143 sdata->vif.addr, short_slot); 144 } 145 return changed; 146 } 147 148 /** 149 * mesh_set_ht_prot_mode - set correct HT protection mode 150 * 151 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT 152 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT 153 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is 154 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode 155 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one 156 * HT20 peer is present. Otherwise no-protection mode is selected. 157 */ 158 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) 159 { 160 struct ieee80211_local *local = sdata->local; 161 struct sta_info *sta; 162 u16 ht_opmode; 163 bool non_ht_sta = false, ht20_sta = false; 164 165 switch (sdata->vif.bss_conf.chandef.width) { 166 case NL80211_CHAN_WIDTH_20_NOHT: 167 case NL80211_CHAN_WIDTH_5: 168 case NL80211_CHAN_WIDTH_10: 169 return 0; 170 default: 171 break; 172 } 173 174 rcu_read_lock(); 175 list_for_each_entry_rcu(sta, &local->sta_list, list) { 176 if (sdata != sta->sdata || 177 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 178 continue; 179 180 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20) 181 continue; 182 183 if (!sta->sta.ht_cap.ht_supported) { 184 mpl_dbg(sdata, "nonHT sta (%pM) is present\n", 185 sta->sta.addr); 186 non_ht_sta = true; 187 break; 188 } 189 190 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); 191 ht20_sta = true; 192 } 193 rcu_read_unlock(); 194 195 if (non_ht_sta) 196 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; 197 else if (ht20_sta && 198 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20) 199 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; 200 else 201 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; 202 203 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) 204 return 0; 205 206 sdata->vif.bss_conf.ht_operation_mode = ht_opmode; 207 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; 208 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); 209 return BSS_CHANGED_HT; 210 } 211 212 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 213 struct sta_info *sta, 214 enum ieee80211_self_protected_actioncode action, 215 u8 *da, u16 llid, u16 plid, u16 reason) 216 { 217 struct ieee80211_local *local = sdata->local; 218 struct sk_buff *skb; 219 struct ieee80211_tx_info *info; 220 struct ieee80211_mgmt *mgmt; 221 bool include_plid = false; 222 u16 peering_proto = 0; 223 u8 *pos, ie_len = 4; 224 int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot); 225 int err = -ENOMEM; 226 227 skb = dev_alloc_skb(local->tx_headroom + 228 hdr_len + 229 2 + /* capability info */ 230 2 + /* AID */ 231 2 + 8 + /* supported rates */ 232 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 233 2 + sdata->u.mesh.mesh_id_len + 234 2 + sizeof(struct ieee80211_meshconf_ie) + 235 2 + sizeof(struct ieee80211_ht_cap) + 236 2 + sizeof(struct ieee80211_ht_operation) + 237 2 + sizeof(struct ieee80211_vht_cap) + 238 2 + sizeof(struct ieee80211_vht_operation) + 239 2 + 8 + /* peering IE */ 240 sdata->u.mesh.ie_len); 241 if (!skb) 242 return err; 243 info = IEEE80211_SKB_CB(skb); 244 skb_reserve(skb, local->tx_headroom); 245 mgmt = skb_put_zero(skb, hdr_len); 246 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 247 IEEE80211_STYPE_ACTION); 248 memcpy(mgmt->da, da, ETH_ALEN); 249 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 250 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 251 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; 252 mgmt->u.action.u.self_prot.action_code = action; 253 254 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 255 struct ieee80211_supported_band *sband; 256 enum nl80211_band band; 257 258 sband = ieee80211_get_sband(sdata); 259 if (!sband) { 260 err = -EINVAL; 261 goto free; 262 } 263 band = sband->band; 264 265 /* capability info */ 266 pos = skb_put_zero(skb, 2); 267 if (action == WLAN_SP_MESH_PEERING_CONFIRM) { 268 /* AID */ 269 pos = skb_put(skb, 2); 270 put_unaligned_le16(sta->sta.aid, pos); 271 } 272 if (ieee80211_add_srates_ie(sdata, skb, true, band) || 273 ieee80211_add_ext_srates_ie(sdata, skb, true, band) || 274 mesh_add_rsn_ie(sdata, skb) || 275 mesh_add_meshid_ie(sdata, skb) || 276 mesh_add_meshconf_ie(sdata, skb)) 277 goto free; 278 } else { /* WLAN_SP_MESH_PEERING_CLOSE */ 279 info->flags |= IEEE80211_TX_CTL_NO_ACK; 280 if (mesh_add_meshid_ie(sdata, skb)) 281 goto free; 282 } 283 284 /* Add Mesh Peering Management element */ 285 switch (action) { 286 case WLAN_SP_MESH_PEERING_OPEN: 287 break; 288 case WLAN_SP_MESH_PEERING_CONFIRM: 289 ie_len += 2; 290 include_plid = true; 291 break; 292 case WLAN_SP_MESH_PEERING_CLOSE: 293 if (plid) { 294 ie_len += 2; 295 include_plid = true; 296 } 297 ie_len += 2; /* reason code */ 298 break; 299 default: 300 err = -EINVAL; 301 goto free; 302 } 303 304 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) 305 goto free; 306 307 pos = skb_put(skb, 2 + ie_len); 308 *pos++ = WLAN_EID_PEER_MGMT; 309 *pos++ = ie_len; 310 memcpy(pos, &peering_proto, 2); 311 pos += 2; 312 put_unaligned_le16(llid, pos); 313 pos += 2; 314 if (include_plid) { 315 put_unaligned_le16(plid, pos); 316 pos += 2; 317 } 318 if (action == WLAN_SP_MESH_PEERING_CLOSE) { 319 put_unaligned_le16(reason, pos); 320 pos += 2; 321 } 322 323 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 324 if (mesh_add_ht_cap_ie(sdata, skb) || 325 mesh_add_ht_oper_ie(sdata, skb) || 326 mesh_add_vht_cap_ie(sdata, skb) || 327 mesh_add_vht_oper_ie(sdata, skb)) 328 goto free; 329 } 330 331 if (mesh_add_vendor_ies(sdata, skb)) 332 goto free; 333 334 ieee80211_tx_skb(sdata, skb); 335 return 0; 336 free: 337 kfree_skb(skb); 338 return err; 339 } 340 341 /** 342 * __mesh_plink_deactivate - deactivate mesh peer link 343 * 344 * @sta: mesh peer link to deactivate 345 * 346 * Mesh paths with this peer as next hop should be flushed 347 * by the caller outside of plink_lock. 348 * 349 * Returns beacon changed flag if the beacon content changed. 350 * 351 * Locking: the caller must hold sta->mesh->plink_lock 352 */ 353 static u32 __mesh_plink_deactivate(struct sta_info *sta) 354 { 355 struct ieee80211_sub_if_data *sdata = sta->sdata; 356 u32 changed = 0; 357 358 lockdep_assert_held(&sta->mesh->plink_lock); 359 360 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 361 changed = mesh_plink_dec_estab_count(sdata); 362 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 363 364 ieee80211_mps_sta_status_update(sta); 365 changed |= ieee80211_mps_set_sta_local_pm(sta, 366 NL80211_MESH_POWER_UNKNOWN); 367 368 return changed; 369 } 370 371 /** 372 * mesh_plink_deactivate - deactivate mesh peer link 373 * 374 * @sta: mesh peer link to deactivate 375 * 376 * All mesh paths with this peer as next hop will be flushed 377 */ 378 u32 mesh_plink_deactivate(struct sta_info *sta) 379 { 380 struct ieee80211_sub_if_data *sdata = sta->sdata; 381 u32 changed; 382 383 spin_lock_bh(&sta->mesh->plink_lock); 384 changed = __mesh_plink_deactivate(sta); 385 386 if (!sdata->u.mesh.user_mpm) { 387 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED; 388 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE, 389 sta->sta.addr, sta->mesh->llid, 390 sta->mesh->plid, sta->mesh->reason); 391 } 392 spin_unlock_bh(&sta->mesh->plink_lock); 393 if (!sdata->u.mesh.user_mpm) 394 del_timer_sync(&sta->mesh->plink_timer); 395 mesh_path_flush_by_nexthop(sta); 396 397 /* make sure no readers can access nexthop sta from here on */ 398 synchronize_net(); 399 400 return changed; 401 } 402 403 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 404 struct sta_info *sta, 405 struct ieee802_11_elems *elems) 406 { 407 struct ieee80211_local *local = sdata->local; 408 struct ieee80211_supported_band *sband; 409 u32 rates, basic_rates = 0, changed = 0; 410 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth; 411 412 sband = ieee80211_get_sband(sdata); 413 if (!sband) 414 return; 415 416 rates = ieee80211_sta_get_rates(sdata, elems, sband->band, 417 &basic_rates); 418 419 spin_lock_bh(&sta->mesh->plink_lock); 420 sta->rx_stats.last_rx = jiffies; 421 422 /* rates and capabilities don't change during peering */ 423 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB && 424 sta->mesh->processed_beacon) 425 goto out; 426 sta->mesh->processed_beacon = true; 427 428 if (sta->sta.supp_rates[sband->band] != rates) 429 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 430 sta->sta.supp_rates[sband->band] = rates; 431 432 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 433 elems->ht_cap_elem, sta)) 434 changed |= IEEE80211_RC_BW_CHANGED; 435 436 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband, 437 elems->vht_cap_elem, sta); 438 439 if (bw != sta->sta.bandwidth) 440 changed |= IEEE80211_RC_BW_CHANGED; 441 442 /* HT peer is operating 20MHz-only */ 443 if (elems->ht_operation && 444 !(elems->ht_operation->ht_param & 445 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 446 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) 447 changed |= IEEE80211_RC_BW_CHANGED; 448 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; 449 } 450 451 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) 452 rate_control_rate_init(sta); 453 else 454 rate_control_rate_update(local, sband, sta, changed); 455 out: 456 spin_unlock_bh(&sta->mesh->plink_lock); 457 } 458 459 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) 460 { 461 struct sta_info *sta; 462 unsigned long *aid_map; 463 int aid; 464 465 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1), 466 sizeof(*aid_map), GFP_KERNEL); 467 if (!aid_map) 468 return -ENOMEM; 469 470 /* reserve aid 0 for mcast indication */ 471 __set_bit(0, aid_map); 472 473 rcu_read_lock(); 474 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) 475 __set_bit(sta->sta.aid, aid_map); 476 rcu_read_unlock(); 477 478 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); 479 kfree(aid_map); 480 481 if (aid > IEEE80211_MAX_AID) 482 return -ENOBUFS; 483 484 return aid; 485 } 486 487 static struct sta_info * 488 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 489 { 490 struct sta_info *sta; 491 int aid; 492 493 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 494 return NULL; 495 496 aid = mesh_allocate_aid(sdata); 497 if (aid < 0) 498 return NULL; 499 500 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 501 if (!sta) 502 return NULL; 503 504 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 505 sta->sta.wme = true; 506 sta->sta.aid = aid; 507 508 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 509 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 510 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 511 512 return sta; 513 } 514 515 static struct sta_info * 516 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 517 struct ieee802_11_elems *elems, 518 struct ieee80211_rx_status *rx_status) 519 { 520 struct sta_info *sta = NULL; 521 522 /* Userspace handles station allocation */ 523 if (sdata->u.mesh.user_mpm || 524 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) { 525 if (mesh_peer_accepts_plinks(elems) && 526 mesh_plink_availables(sdata)) { 527 int sig = 0; 528 529 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM)) 530 sig = rx_status->signal; 531 532 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 533 elems->ie_start, 534 elems->total_len, 535 sig, GFP_KERNEL); 536 } 537 } else 538 sta = __mesh_sta_info_alloc(sdata, addr); 539 540 return sta; 541 } 542 543 /* 544 * mesh_sta_info_get - return mesh sta info entry for @addr. 545 * 546 * @sdata: local meshif 547 * @addr: peer's address 548 * @elems: IEs from beacon or mesh peering frame. 549 * @rx_status: rx status for the frame for signal reporting 550 * 551 * Return existing or newly allocated sta_info under RCU read lock. 552 * (re)initialize with given IEs. 553 */ 554 static struct sta_info * 555 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 556 u8 *addr, struct ieee802_11_elems *elems, 557 struct ieee80211_rx_status *rx_status) __acquires(RCU) 558 { 559 struct sta_info *sta = NULL; 560 561 rcu_read_lock(); 562 sta = sta_info_get(sdata, addr); 563 if (sta) { 564 mesh_sta_info_init(sdata, sta, elems); 565 } else { 566 rcu_read_unlock(); 567 /* can't run atomic */ 568 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status); 569 if (!sta) { 570 rcu_read_lock(); 571 return NULL; 572 } 573 574 mesh_sta_info_init(sdata, sta, elems); 575 576 if (sta_info_insert_rcu(sta)) 577 return NULL; 578 } 579 580 return sta; 581 } 582 583 /* 584 * mesh_neighbour_update - update or initialize new mesh neighbor. 585 * 586 * @sdata: local meshif 587 * @addr: peer's address 588 * @elems: IEs from beacon or mesh peering frame 589 * @rx_status: rx status for the frame for signal reporting 590 * 591 * Initiates peering if appropriate. 592 */ 593 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 594 u8 *hw_addr, 595 struct ieee802_11_elems *elems, 596 struct ieee80211_rx_status *rx_status) 597 { 598 struct sta_info *sta; 599 u32 changed = 0; 600 601 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status); 602 if (!sta) 603 goto out; 604 605 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form & 606 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE; 607 608 if (mesh_peer_accepts_plinks(elems) && 609 sta->mesh->plink_state == NL80211_PLINK_LISTEN && 610 sdata->u.mesh.accepting_plinks && 611 sdata->u.mesh.mshcfg.auto_open_plinks && 612 rssi_threshold_check(sdata, sta)) 613 changed = mesh_plink_open(sta); 614 615 ieee80211_mps_frame_release(sta, elems); 616 out: 617 rcu_read_unlock(); 618 ieee80211_mbss_info_change_notify(sdata, changed); 619 } 620 621 void mesh_plink_timer(struct timer_list *t) 622 { 623 struct mesh_sta *mesh = from_timer(mesh, t, plink_timer); 624 struct sta_info *sta; 625 u16 reason = 0; 626 struct ieee80211_sub_if_data *sdata; 627 struct mesh_config *mshcfg; 628 enum ieee80211_self_protected_actioncode action = 0; 629 630 /* 631 * This STA is valid because sta_info_destroy() will 632 * del_timer_sync() this timer after having made sure 633 * it cannot be readded (by deleting the plink.) 634 */ 635 sta = mesh->plink_sta; 636 637 if (sta->sdata->local->quiescing) 638 return; 639 640 spin_lock_bh(&sta->mesh->plink_lock); 641 642 /* If a timer fires just before a state transition on another CPU, 643 * we may have already extended the timeout and changed state by the 644 * time we've acquired the lock and arrived here. In that case, 645 * skip this timer and wait for the new one. 646 */ 647 if (time_before(jiffies, sta->mesh->plink_timer.expires)) { 648 mpl_dbg(sta->sdata, 649 "Ignoring timer for %pM in state %s (timer adjusted)", 650 sta->sta.addr, mplstates[sta->mesh->plink_state]); 651 spin_unlock_bh(&sta->mesh->plink_lock); 652 return; 653 } 654 655 /* del_timer() and handler may race when entering these states */ 656 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || 657 sta->mesh->plink_state == NL80211_PLINK_ESTAB) { 658 mpl_dbg(sta->sdata, 659 "Ignoring timer for %pM in state %s (timer deleted)", 660 sta->sta.addr, mplstates[sta->mesh->plink_state]); 661 spin_unlock_bh(&sta->mesh->plink_lock); 662 return; 663 } 664 665 mpl_dbg(sta->sdata, 666 "Mesh plink timer for %pM fired on state %s\n", 667 sta->sta.addr, mplstates[sta->mesh->plink_state]); 668 sdata = sta->sdata; 669 mshcfg = &sdata->u.mesh.mshcfg; 670 671 switch (sta->mesh->plink_state) { 672 case NL80211_PLINK_OPN_RCVD: 673 case NL80211_PLINK_OPN_SNT: 674 /* retry timer */ 675 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { 676 u32 rand; 677 mpl_dbg(sta->sdata, 678 "Mesh plink for %pM (retry, timeout): %d %d\n", 679 sta->sta.addr, sta->mesh->plink_retries, 680 sta->mesh->plink_timeout); 681 get_random_bytes(&rand, sizeof(u32)); 682 sta->mesh->plink_timeout = sta->mesh->plink_timeout + 683 rand % sta->mesh->plink_timeout; 684 ++sta->mesh->plink_retries; 685 mod_plink_timer(sta, sta->mesh->plink_timeout); 686 action = WLAN_SP_MESH_PEERING_OPEN; 687 break; 688 } 689 reason = WLAN_REASON_MESH_MAX_RETRIES; 690 /* fall through */ 691 case NL80211_PLINK_CNF_RCVD: 692 /* confirm timer */ 693 if (!reason) 694 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 695 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 696 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 697 action = WLAN_SP_MESH_PEERING_CLOSE; 698 break; 699 case NL80211_PLINK_HOLDING: 700 /* holding timer */ 701 del_timer(&sta->mesh->plink_timer); 702 mesh_plink_fsm_restart(sta); 703 break; 704 default: 705 break; 706 } 707 spin_unlock_bh(&sta->mesh->plink_lock); 708 if (action) 709 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 710 sta->mesh->llid, sta->mesh->plid, reason); 711 } 712 713 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 714 { 715 sta->mesh->plink_timeout = timeout; 716 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout)); 717 } 718 719 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 720 u16 llid) 721 { 722 struct ieee80211_local *local = sdata->local; 723 bool in_use = false; 724 struct sta_info *sta; 725 726 rcu_read_lock(); 727 list_for_each_entry_rcu(sta, &local->sta_list, list) { 728 if (sdata != sta->sdata) 729 continue; 730 731 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { 732 in_use = true; 733 break; 734 } 735 } 736 rcu_read_unlock(); 737 738 return in_use; 739 } 740 741 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 742 { 743 u16 llid; 744 745 do { 746 get_random_bytes(&llid, sizeof(llid)); 747 } while (llid_in_use(sdata, llid)); 748 749 return llid; 750 } 751 752 u32 mesh_plink_open(struct sta_info *sta) 753 { 754 struct ieee80211_sub_if_data *sdata = sta->sdata; 755 u32 changed; 756 757 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 758 return 0; 759 760 spin_lock_bh(&sta->mesh->plink_lock); 761 sta->mesh->llid = mesh_get_new_llid(sdata); 762 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && 763 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { 764 spin_unlock_bh(&sta->mesh->plink_lock); 765 return 0; 766 } 767 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; 768 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 769 spin_unlock_bh(&sta->mesh->plink_lock); 770 mpl_dbg(sdata, 771 "Mesh plink: starting establishment with %pM\n", 772 sta->sta.addr); 773 774 /* set the non-peer mode to active during peering */ 775 changed = ieee80211_mps_local_status_update(sdata); 776 777 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, 778 sta->sta.addr, sta->mesh->llid, 0, 0); 779 return changed; 780 } 781 782 u32 mesh_plink_block(struct sta_info *sta) 783 { 784 u32 changed; 785 786 spin_lock_bh(&sta->mesh->plink_lock); 787 changed = __mesh_plink_deactivate(sta); 788 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 789 spin_unlock_bh(&sta->mesh->plink_lock); 790 mesh_path_flush_by_nexthop(sta); 791 792 return changed; 793 } 794 795 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 796 struct sta_info *sta, 797 enum plink_event event) 798 { 799 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 800 u16 reason = (event == CLS_ACPT) ? 801 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 802 803 sta->mesh->reason = reason; 804 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 805 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 806 } 807 808 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 809 struct sta_info *sta) 810 { 811 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 812 u32 changed = 0; 813 814 del_timer(&sta->mesh->plink_timer); 815 sta->mesh->plink_state = NL80211_PLINK_ESTAB; 816 changed |= mesh_plink_inc_estab_count(sdata); 817 changed |= mesh_set_ht_prot_mode(sdata); 818 changed |= mesh_set_short_slot_time(sdata); 819 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 820 ieee80211_mps_sta_status_update(sta); 821 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 822 return changed; 823 } 824 825 /** 826 * mesh_plink_fsm - step @sta MPM based on @event 827 * 828 * @sdata: interface 829 * @sta: mesh neighbor 830 * @event: peering event 831 * 832 * Return: changed MBSS flags 833 */ 834 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 835 struct sta_info *sta, enum plink_event event) 836 { 837 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 838 enum ieee80211_self_protected_actioncode action = 0; 839 u32 changed = 0; 840 bool flush = false; 841 842 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 843 mplstates[sta->mesh->plink_state], mplevents[event]); 844 845 spin_lock_bh(&sta->mesh->plink_lock); 846 switch (sta->mesh->plink_state) { 847 case NL80211_PLINK_LISTEN: 848 switch (event) { 849 case CLS_ACPT: 850 mesh_plink_fsm_restart(sta); 851 break; 852 case OPN_ACPT: 853 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 854 sta->mesh->llid = mesh_get_new_llid(sdata); 855 mesh_plink_timer_set(sta, 856 mshcfg->dot11MeshRetryTimeout); 857 858 /* set the non-peer mode to active during peering */ 859 changed |= ieee80211_mps_local_status_update(sdata); 860 action = WLAN_SP_MESH_PEERING_OPEN; 861 break; 862 default: 863 break; 864 } 865 break; 866 case NL80211_PLINK_OPN_SNT: 867 switch (event) { 868 case OPN_RJCT: 869 case CNF_RJCT: 870 case CLS_ACPT: 871 mesh_plink_close(sdata, sta, event); 872 action = WLAN_SP_MESH_PEERING_CLOSE; 873 break; 874 case OPN_ACPT: 875 /* retry timer is left untouched */ 876 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 877 action = WLAN_SP_MESH_PEERING_CONFIRM; 878 break; 879 case CNF_ACPT: 880 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; 881 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 882 break; 883 default: 884 break; 885 } 886 break; 887 case NL80211_PLINK_OPN_RCVD: 888 switch (event) { 889 case OPN_RJCT: 890 case CNF_RJCT: 891 case CLS_ACPT: 892 mesh_plink_close(sdata, sta, event); 893 action = WLAN_SP_MESH_PEERING_CLOSE; 894 break; 895 case OPN_ACPT: 896 action = WLAN_SP_MESH_PEERING_CONFIRM; 897 break; 898 case CNF_ACPT: 899 changed |= mesh_plink_establish(sdata, sta); 900 break; 901 default: 902 break; 903 } 904 break; 905 case NL80211_PLINK_CNF_RCVD: 906 switch (event) { 907 case OPN_RJCT: 908 case CNF_RJCT: 909 case CLS_ACPT: 910 mesh_plink_close(sdata, sta, event); 911 action = WLAN_SP_MESH_PEERING_CLOSE; 912 break; 913 case OPN_ACPT: 914 changed |= mesh_plink_establish(sdata, sta); 915 action = WLAN_SP_MESH_PEERING_CONFIRM; 916 break; 917 default: 918 break; 919 } 920 break; 921 case NL80211_PLINK_ESTAB: 922 switch (event) { 923 case CLS_ACPT: 924 changed |= __mesh_plink_deactivate(sta); 925 changed |= mesh_set_ht_prot_mode(sdata); 926 changed |= mesh_set_short_slot_time(sdata); 927 mesh_plink_close(sdata, sta, event); 928 action = WLAN_SP_MESH_PEERING_CLOSE; 929 flush = true; 930 break; 931 case OPN_ACPT: 932 action = WLAN_SP_MESH_PEERING_CONFIRM; 933 break; 934 default: 935 break; 936 } 937 break; 938 case NL80211_PLINK_HOLDING: 939 switch (event) { 940 case CLS_ACPT: 941 del_timer(&sta->mesh->plink_timer); 942 mesh_plink_fsm_restart(sta); 943 break; 944 case OPN_ACPT: 945 case CNF_ACPT: 946 case OPN_RJCT: 947 case CNF_RJCT: 948 action = WLAN_SP_MESH_PEERING_CLOSE; 949 break; 950 default: 951 break; 952 } 953 break; 954 default: 955 /* should not get here, PLINK_BLOCKED is dealt with at the 956 * beginning of the function 957 */ 958 break; 959 } 960 spin_unlock_bh(&sta->mesh->plink_lock); 961 if (flush) 962 mesh_path_flush_by_nexthop(sta); 963 if (action) { 964 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 965 sta->mesh->llid, sta->mesh->plid, 966 sta->mesh->reason); 967 968 /* also send confirm in open case */ 969 if (action == WLAN_SP_MESH_PEERING_OPEN) { 970 mesh_plink_frame_tx(sdata, sta, 971 WLAN_SP_MESH_PEERING_CONFIRM, 972 sta->sta.addr, sta->mesh->llid, 973 sta->mesh->plid, 0); 974 } 975 } 976 977 return changed; 978 } 979 980 /* 981 * mesh_plink_get_event - get correct MPM event 982 * 983 * @sdata: interface 984 * @sta: peer, leave NULL if processing a frame from a new suitable peer 985 * @elems: peering management IEs 986 * @ftype: frame type 987 * @llid: peer's peer link ID 988 * @plid: peer's local link ID 989 * 990 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 991 * an error. 992 */ 993 static enum plink_event 994 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 995 struct sta_info *sta, 996 struct ieee802_11_elems *elems, 997 enum ieee80211_self_protected_actioncode ftype, 998 u16 llid, u16 plid) 999 { 1000 enum plink_event event = PLINK_UNDEFINED; 1001 u8 ie_len = elems->peering_len; 1002 bool matches_local; 1003 1004 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 1005 mesh_matches_local(sdata, elems)); 1006 1007 /* deny open request from non-matching peer */ 1008 if (!matches_local && !sta) { 1009 event = OPN_RJCT; 1010 goto out; 1011 } 1012 1013 if (!sta) { 1014 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 1015 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 1016 goto out; 1017 } 1018 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 1019 if (!mesh_plink_free_count(sdata)) { 1020 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 1021 goto out; 1022 } 1023 1024 /* new matching peer */ 1025 event = OPN_ACPT; 1026 goto out; 1027 } else { 1028 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 1029 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 1030 goto out; 1031 } 1032 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) 1033 goto out; 1034 } 1035 1036 switch (ftype) { 1037 case WLAN_SP_MESH_PEERING_OPEN: 1038 if (!matches_local) 1039 event = OPN_RJCT; 1040 if (!mesh_plink_free_count(sdata) || 1041 (sta->mesh->plid && sta->mesh->plid != plid)) 1042 event = OPN_IGNR; 1043 else 1044 event = OPN_ACPT; 1045 break; 1046 case WLAN_SP_MESH_PEERING_CONFIRM: 1047 if (!matches_local) 1048 event = CNF_RJCT; 1049 if (!mesh_plink_free_count(sdata) || 1050 sta->mesh->llid != llid || 1051 (sta->mesh->plid && sta->mesh->plid != plid)) 1052 event = CNF_IGNR; 1053 else 1054 event = CNF_ACPT; 1055 break; 1056 case WLAN_SP_MESH_PEERING_CLOSE: 1057 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 1058 /* Do not check for llid or plid. This does not 1059 * follow the standard but since multiple plinks 1060 * per sta are not supported, it is necessary in 1061 * order to avoid a livelock when MP A sees an 1062 * establish peer link to MP B but MP B does not 1063 * see it. This can be caused by a timeout in 1064 * B's peer link establishment or B beign 1065 * restarted. 1066 */ 1067 event = CLS_ACPT; 1068 else if (sta->mesh->plid != plid) 1069 event = CLS_IGNR; 1070 else if (ie_len == 8 && sta->mesh->llid != llid) 1071 event = CLS_IGNR; 1072 else 1073 event = CLS_ACPT; 1074 break; 1075 default: 1076 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 1077 break; 1078 } 1079 1080 out: 1081 return event; 1082 } 1083 1084 static void 1085 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1086 struct ieee80211_mgmt *mgmt, 1087 struct ieee802_11_elems *elems, 1088 struct ieee80211_rx_status *rx_status) 1089 { 1090 1091 struct sta_info *sta; 1092 enum plink_event event; 1093 enum ieee80211_self_protected_actioncode ftype; 1094 u32 changed = 0; 1095 u8 ie_len = elems->peering_len; 1096 u16 plid, llid = 0; 1097 1098 if (!elems->peering) { 1099 mpl_dbg(sdata, 1100 "Mesh plink: missing necessary peer link ie\n"); 1101 return; 1102 } 1103 1104 if (elems->rsn_len && 1105 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1106 mpl_dbg(sdata, 1107 "Mesh plink: can't establish link with secure peer\n"); 1108 return; 1109 } 1110 1111 ftype = mgmt->u.action.u.self_prot.action_code; 1112 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1113 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1114 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1115 && ie_len != 8)) { 1116 mpl_dbg(sdata, 1117 "Mesh plink: incorrect plink ie length %d %d\n", 1118 ftype, ie_len); 1119 return; 1120 } 1121 1122 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1123 (!elems->mesh_id || !elems->mesh_config)) { 1124 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1125 return; 1126 } 1127 /* Note the lines below are correct, the llid in the frame is the plid 1128 * from the point of view of this host. 1129 */ 1130 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1131 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1132 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1133 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1134 1135 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1136 rcu_read_lock(); 1137 1138 sta = sta_info_get(sdata, mgmt->sa); 1139 1140 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1141 !rssi_threshold_check(sdata, sta)) { 1142 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1143 mgmt->sa); 1144 goto unlock_rcu; 1145 } 1146 1147 /* Now we will figure out the appropriate event... */ 1148 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1149 1150 if (event == OPN_ACPT) { 1151 rcu_read_unlock(); 1152 /* allocate sta entry if necessary and update info */ 1153 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status); 1154 if (!sta) { 1155 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1156 goto unlock_rcu; 1157 } 1158 sta->mesh->plid = plid; 1159 } else if (!sta && event == OPN_RJCT) { 1160 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, 1161 mgmt->sa, 0, plid, 1162 WLAN_REASON_MESH_CONFIG); 1163 goto unlock_rcu; 1164 } else if (!sta || event == PLINK_UNDEFINED) { 1165 /* something went wrong */ 1166 goto unlock_rcu; 1167 } 1168 1169 if (event == CNF_ACPT) { 1170 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1171 if (!sta->mesh->plid) 1172 sta->mesh->plid = plid; 1173 1174 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); 1175 } 1176 1177 changed |= mesh_plink_fsm(sdata, sta, event); 1178 1179 unlock_rcu: 1180 rcu_read_unlock(); 1181 1182 if (changed) 1183 ieee80211_mbss_info_change_notify(sdata, changed); 1184 } 1185 1186 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1187 struct ieee80211_mgmt *mgmt, size_t len, 1188 struct ieee80211_rx_status *rx_status) 1189 { 1190 struct ieee802_11_elems elems; 1191 size_t baselen; 1192 u8 *baseaddr; 1193 1194 /* need action_code, aux */ 1195 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1196 return; 1197 1198 if (sdata->u.mesh.user_mpm) 1199 /* userspace must register for these */ 1200 return; 1201 1202 if (is_multicast_ether_addr(mgmt->da)) { 1203 mpl_dbg(sdata, 1204 "Mesh plink: ignore frame from multicast address\n"); 1205 return; 1206 } 1207 1208 baseaddr = mgmt->u.action.u.self_prot.variable; 1209 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1210 if (mgmt->u.action.u.self_prot.action_code == 1211 WLAN_SP_MESH_PEERING_CONFIRM) { 1212 baseaddr += 4; 1213 baselen += 4; 1214 1215 if (baselen > len) 1216 return; 1217 } 1218 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems, 1219 mgmt->bssid, NULL); 1220 mesh_process_plink_frame(sdata, mgmt, &elems, rx_status); 1221 } 1222