1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008, 2009 open80211s Ltd. 4 * Copyright (C) 2019 Intel Corporation 5 * Author: Luis Carlos Cobo <luisca@cozybit.com> 6 */ 7 #include <linux/gfp.h> 8 #include <linux/kernel.h> 9 #include <linux/random.h> 10 #include <linux/rculist.h> 11 12 #include "ieee80211_i.h" 13 #include "rate.h" 14 #include "mesh.h" 15 16 #define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2) 17 #define PLINK_GET_LLID(p) (p + 2) 18 #define PLINK_GET_PLID(p) (p + 4) 19 20 #define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \ 21 jiffies + msecs_to_jiffies(t))) 22 23 enum plink_event { 24 PLINK_UNDEFINED, 25 OPN_ACPT, 26 OPN_RJCT, 27 OPN_IGNR, 28 CNF_ACPT, 29 CNF_RJCT, 30 CNF_IGNR, 31 CLS_ACPT, 32 CLS_IGNR 33 }; 34 35 static const char * const mplstates[] = { 36 [NL80211_PLINK_LISTEN] = "LISTEN", 37 [NL80211_PLINK_OPN_SNT] = "OPN-SNT", 38 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD", 39 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD", 40 [NL80211_PLINK_ESTAB] = "ESTAB", 41 [NL80211_PLINK_HOLDING] = "HOLDING", 42 [NL80211_PLINK_BLOCKED] = "BLOCKED" 43 }; 44 45 static const char * const mplevents[] = { 46 [PLINK_UNDEFINED] = "NONE", 47 [OPN_ACPT] = "OPN_ACPT", 48 [OPN_RJCT] = "OPN_RJCT", 49 [OPN_IGNR] = "OPN_IGNR", 50 [CNF_ACPT] = "CNF_ACPT", 51 [CNF_RJCT] = "CNF_RJCT", 52 [CNF_IGNR] = "CNF_IGNR", 53 [CLS_ACPT] = "CLS_ACPT", 54 [CLS_IGNR] = "CLS_IGNR" 55 }; 56 57 /* We only need a valid sta if user configured a minimum rssi_threshold. */ 58 static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata, 59 struct sta_info *sta) 60 { 61 s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold; 62 return rssi_threshold == 0 || 63 (sta && 64 (s8)-ewma_signal_read(&sta->rx_stats_avg.signal) > 65 rssi_threshold); 66 } 67 68 /** 69 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine 70 * 71 * @sta: mesh peer link to restart 72 * 73 * Locking: this function must be called holding sta->mesh->plink_lock 74 */ 75 static inline void mesh_plink_fsm_restart(struct sta_info *sta) 76 { 77 lockdep_assert_held(&sta->mesh->plink_lock); 78 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 79 sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0; 80 sta->mesh->plink_retries = 0; 81 } 82 83 /* 84 * mesh_set_short_slot_time - enable / disable ERP short slot time. 85 * 86 * The standard indirectly mandates mesh STAs to turn off short slot time by 87 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we 88 * can't be sneaky about it. Enable short slot time if all mesh STAs in the 89 * MBSS support ERP rates. 90 * 91 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change. 92 */ 93 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata) 94 { 95 struct ieee80211_local *local = sdata->local; 96 struct ieee80211_supported_band *sband; 97 struct sta_info *sta; 98 u32 erp_rates = 0, changed = 0; 99 int i; 100 bool short_slot = false; 101 102 sband = ieee80211_get_sband(sdata); 103 if (!sband) 104 return changed; 105 106 if (sband->band == NL80211_BAND_5GHZ) { 107 /* (IEEE 802.11-2012 19.4.5) */ 108 short_slot = true; 109 goto out; 110 } else if (sband->band != NL80211_BAND_2GHZ) { 111 goto out; 112 } 113 114 for (i = 0; i < sband->n_bitrates; i++) 115 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G) 116 erp_rates |= BIT(i); 117 118 if (!erp_rates) 119 goto out; 120 121 rcu_read_lock(); 122 list_for_each_entry_rcu(sta, &local->sta_list, list) { 123 if (sdata != sta->sdata || 124 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 125 continue; 126 127 short_slot = false; 128 if (erp_rates & sta->sta.supp_rates[sband->band]) 129 short_slot = true; 130 else 131 break; 132 } 133 rcu_read_unlock(); 134 135 out: 136 if (sdata->vif.bss_conf.use_short_slot != short_slot) { 137 sdata->vif.bss_conf.use_short_slot = short_slot; 138 changed = BSS_CHANGED_ERP_SLOT; 139 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n", 140 sdata->vif.addr, short_slot); 141 } 142 return changed; 143 } 144 145 /** 146 * mesh_set_ht_prot_mode - set correct HT protection mode 147 * 148 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT 149 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT 150 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is 151 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode 152 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one 153 * HT20 peer is present. Otherwise no-protection mode is selected. 154 */ 155 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) 156 { 157 struct ieee80211_local *local = sdata->local; 158 struct sta_info *sta; 159 u16 ht_opmode; 160 bool non_ht_sta = false, ht20_sta = false; 161 162 switch (sdata->vif.bss_conf.chandef.width) { 163 case NL80211_CHAN_WIDTH_20_NOHT: 164 case NL80211_CHAN_WIDTH_5: 165 case NL80211_CHAN_WIDTH_10: 166 return 0; 167 default: 168 break; 169 } 170 171 rcu_read_lock(); 172 list_for_each_entry_rcu(sta, &local->sta_list, list) { 173 if (sdata != sta->sdata || 174 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 175 continue; 176 177 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20) 178 continue; 179 180 if (!sta->sta.ht_cap.ht_supported) { 181 mpl_dbg(sdata, "nonHT sta (%pM) is present\n", 182 sta->sta.addr); 183 non_ht_sta = true; 184 break; 185 } 186 187 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); 188 ht20_sta = true; 189 } 190 rcu_read_unlock(); 191 192 if (non_ht_sta) 193 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; 194 else if (ht20_sta && 195 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20) 196 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; 197 else 198 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; 199 200 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) 201 return 0; 202 203 sdata->vif.bss_conf.ht_operation_mode = ht_opmode; 204 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; 205 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); 206 return BSS_CHANGED_HT; 207 } 208 209 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 210 struct sta_info *sta, 211 enum ieee80211_self_protected_actioncode action, 212 u8 *da, u16 llid, u16 plid, u16 reason) 213 { 214 struct ieee80211_local *local = sdata->local; 215 struct sk_buff *skb; 216 struct ieee80211_tx_info *info; 217 struct ieee80211_mgmt *mgmt; 218 bool include_plid = false; 219 u16 peering_proto = 0; 220 u8 *pos, ie_len = 4; 221 u8 ie_len_he_cap; 222 int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot); 223 int err = -ENOMEM; 224 225 ie_len_he_cap = ieee80211_ie_len_he_cap(sdata, 226 NL80211_IFTYPE_MESH_POINT); 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 ie_len_he_cap + 240 2 + 1 + sizeof(struct ieee80211_he_operation) + 241 sizeof(struct ieee80211_he_6ghz_oper) + 242 2 + 1 + sizeof(struct ieee80211_he_6ghz_capa) + 243 2 + 8 + /* peering IE */ 244 sdata->u.mesh.ie_len); 245 if (!skb) 246 return err; 247 info = IEEE80211_SKB_CB(skb); 248 skb_reserve(skb, local->tx_headroom); 249 mgmt = skb_put_zero(skb, hdr_len); 250 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 251 IEEE80211_STYPE_ACTION); 252 memcpy(mgmt->da, da, ETH_ALEN); 253 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 254 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 255 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; 256 mgmt->u.action.u.self_prot.action_code = action; 257 258 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 259 struct ieee80211_supported_band *sband; 260 enum nl80211_band band; 261 262 sband = ieee80211_get_sband(sdata); 263 if (!sband) { 264 err = -EINVAL; 265 goto free; 266 } 267 band = sband->band; 268 269 /* capability info */ 270 pos = skb_put_zero(skb, 2); 271 if (action == WLAN_SP_MESH_PEERING_CONFIRM) { 272 /* AID */ 273 pos = skb_put(skb, 2); 274 put_unaligned_le16(sta->sta.aid, pos); 275 } 276 if (ieee80211_add_srates_ie(sdata, skb, true, band) || 277 ieee80211_add_ext_srates_ie(sdata, skb, true, band) || 278 mesh_add_rsn_ie(sdata, skb) || 279 mesh_add_meshid_ie(sdata, skb) || 280 mesh_add_meshconf_ie(sdata, skb)) 281 goto free; 282 } else { /* WLAN_SP_MESH_PEERING_CLOSE */ 283 info->flags |= IEEE80211_TX_CTL_NO_ACK; 284 if (mesh_add_meshid_ie(sdata, skb)) 285 goto free; 286 } 287 288 /* Add Mesh Peering Management element */ 289 switch (action) { 290 case WLAN_SP_MESH_PEERING_OPEN: 291 break; 292 case WLAN_SP_MESH_PEERING_CONFIRM: 293 ie_len += 2; 294 include_plid = true; 295 break; 296 case WLAN_SP_MESH_PEERING_CLOSE: 297 if (plid) { 298 ie_len += 2; 299 include_plid = true; 300 } 301 ie_len += 2; /* reason code */ 302 break; 303 default: 304 err = -EINVAL; 305 goto free; 306 } 307 308 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) 309 goto free; 310 311 pos = skb_put(skb, 2 + ie_len); 312 *pos++ = WLAN_EID_PEER_MGMT; 313 *pos++ = ie_len; 314 memcpy(pos, &peering_proto, 2); 315 pos += 2; 316 put_unaligned_le16(llid, pos); 317 pos += 2; 318 if (include_plid) { 319 put_unaligned_le16(plid, pos); 320 pos += 2; 321 } 322 if (action == WLAN_SP_MESH_PEERING_CLOSE) { 323 put_unaligned_le16(reason, pos); 324 pos += 2; 325 } 326 327 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 328 if (mesh_add_ht_cap_ie(sdata, skb) || 329 mesh_add_ht_oper_ie(sdata, skb) || 330 mesh_add_vht_cap_ie(sdata, skb) || 331 mesh_add_vht_oper_ie(sdata, skb) || 332 mesh_add_he_cap_ie(sdata, skb, ie_len_he_cap) || 333 mesh_add_he_oper_ie(sdata, skb) || 334 mesh_add_he_6ghz_cap_ie(sdata, skb)) 335 goto free; 336 } 337 338 if (mesh_add_vendor_ies(sdata, skb)) 339 goto free; 340 341 ieee80211_tx_skb(sdata, skb); 342 return 0; 343 free: 344 kfree_skb(skb); 345 return err; 346 } 347 348 /** 349 * __mesh_plink_deactivate - deactivate mesh peer link 350 * 351 * @sta: mesh peer link to deactivate 352 * 353 * Mesh paths with this peer as next hop should be flushed 354 * by the caller outside of plink_lock. 355 * 356 * Returns beacon changed flag if the beacon content changed. 357 * 358 * Locking: the caller must hold sta->mesh->plink_lock 359 */ 360 static u32 __mesh_plink_deactivate(struct sta_info *sta) 361 { 362 struct ieee80211_sub_if_data *sdata = sta->sdata; 363 u32 changed = 0; 364 365 lockdep_assert_held(&sta->mesh->plink_lock); 366 367 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 368 changed = mesh_plink_dec_estab_count(sdata); 369 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 370 371 ieee80211_mps_sta_status_update(sta); 372 changed |= ieee80211_mps_set_sta_local_pm(sta, 373 NL80211_MESH_POWER_UNKNOWN); 374 375 return changed; 376 } 377 378 /** 379 * mesh_plink_deactivate - deactivate mesh peer link 380 * 381 * @sta: mesh peer link to deactivate 382 * 383 * All mesh paths with this peer as next hop will be flushed 384 */ 385 u32 mesh_plink_deactivate(struct sta_info *sta) 386 { 387 struct ieee80211_sub_if_data *sdata = sta->sdata; 388 u32 changed; 389 390 spin_lock_bh(&sta->mesh->plink_lock); 391 changed = __mesh_plink_deactivate(sta); 392 393 if (!sdata->u.mesh.user_mpm) { 394 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED; 395 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE, 396 sta->sta.addr, sta->mesh->llid, 397 sta->mesh->plid, sta->mesh->reason); 398 } 399 spin_unlock_bh(&sta->mesh->plink_lock); 400 if (!sdata->u.mesh.user_mpm) 401 del_timer_sync(&sta->mesh->plink_timer); 402 mesh_path_flush_by_nexthop(sta); 403 404 /* make sure no readers can access nexthop sta from here on */ 405 synchronize_net(); 406 407 return changed; 408 } 409 410 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 411 struct sta_info *sta, 412 struct ieee802_11_elems *elems) 413 { 414 struct ieee80211_local *local = sdata->local; 415 struct ieee80211_supported_band *sband; 416 u32 rates, basic_rates = 0, changed = 0; 417 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth; 418 419 sband = ieee80211_get_sband(sdata); 420 if (!sband) 421 return; 422 423 rates = ieee80211_sta_get_rates(sdata, elems, sband->band, 424 &basic_rates); 425 426 spin_lock_bh(&sta->mesh->plink_lock); 427 sta->rx_stats.last_rx = jiffies; 428 429 /* rates and capabilities don't change during peering */ 430 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB && 431 sta->mesh->processed_beacon) 432 goto out; 433 sta->mesh->processed_beacon = true; 434 435 if (sta->sta.supp_rates[sband->band] != rates) 436 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 437 sta->sta.supp_rates[sband->band] = rates; 438 439 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 440 elems->ht_cap_elem, sta)) 441 changed |= IEEE80211_RC_BW_CHANGED; 442 443 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband, 444 elems->vht_cap_elem, sta); 445 446 ieee80211_he_cap_ie_to_sta_he_cap(sdata, sband, elems->he_cap, 447 elems->he_cap_len, 448 elems->he_6ghz_capa, 449 sta); 450 451 if (bw != sta->sta.bandwidth) 452 changed |= IEEE80211_RC_BW_CHANGED; 453 454 /* HT peer is operating 20MHz-only */ 455 if (elems->ht_operation && 456 !(elems->ht_operation->ht_param & 457 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 458 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) 459 changed |= IEEE80211_RC_BW_CHANGED; 460 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; 461 } 462 463 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) 464 rate_control_rate_init(sta); 465 else 466 rate_control_rate_update(local, sband, sta, changed); 467 out: 468 spin_unlock_bh(&sta->mesh->plink_lock); 469 } 470 471 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) 472 { 473 struct sta_info *sta; 474 unsigned long *aid_map; 475 int aid; 476 477 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1), 478 sizeof(*aid_map), GFP_KERNEL); 479 if (!aid_map) 480 return -ENOMEM; 481 482 /* reserve aid 0 for mcast indication */ 483 __set_bit(0, aid_map); 484 485 rcu_read_lock(); 486 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) 487 __set_bit(sta->sta.aid, aid_map); 488 rcu_read_unlock(); 489 490 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); 491 kfree(aid_map); 492 493 if (aid > IEEE80211_MAX_AID) 494 return -ENOBUFS; 495 496 return aid; 497 } 498 499 static struct sta_info * 500 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 501 { 502 struct sta_info *sta; 503 int aid; 504 505 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 506 return NULL; 507 508 aid = mesh_allocate_aid(sdata); 509 if (aid < 0) 510 return NULL; 511 512 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 513 if (!sta) 514 return NULL; 515 516 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 517 sta->sta.wme = true; 518 sta->sta.aid = aid; 519 520 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 521 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 522 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 523 524 return sta; 525 } 526 527 static struct sta_info * 528 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 529 struct ieee802_11_elems *elems, 530 struct ieee80211_rx_status *rx_status) 531 { 532 struct sta_info *sta = NULL; 533 534 /* Userspace handles station allocation */ 535 if (sdata->u.mesh.user_mpm || 536 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) { 537 if (mesh_peer_accepts_plinks(elems) && 538 mesh_plink_availables(sdata)) { 539 int sig = 0; 540 541 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM)) 542 sig = rx_status->signal; 543 544 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 545 elems->ie_start, 546 elems->total_len, 547 sig, GFP_KERNEL); 548 } 549 } else 550 sta = __mesh_sta_info_alloc(sdata, addr); 551 552 return sta; 553 } 554 555 /* 556 * mesh_sta_info_get - return mesh sta info entry for @addr. 557 * 558 * @sdata: local meshif 559 * @addr: peer's address 560 * @elems: IEs from beacon or mesh peering frame. 561 * @rx_status: rx status for the frame for signal reporting 562 * 563 * Return existing or newly allocated sta_info under RCU read lock. 564 * (re)initialize with given IEs. 565 */ 566 static struct sta_info * 567 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 568 u8 *addr, struct ieee802_11_elems *elems, 569 struct ieee80211_rx_status *rx_status) __acquires(RCU) 570 { 571 struct sta_info *sta = NULL; 572 573 rcu_read_lock(); 574 sta = sta_info_get(sdata, addr); 575 if (sta) { 576 mesh_sta_info_init(sdata, sta, elems); 577 } else { 578 rcu_read_unlock(); 579 /* can't run atomic */ 580 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status); 581 if (!sta) { 582 rcu_read_lock(); 583 return NULL; 584 } 585 586 mesh_sta_info_init(sdata, sta, elems); 587 588 if (sta_info_insert_rcu(sta)) 589 return NULL; 590 } 591 592 return sta; 593 } 594 595 /* 596 * mesh_neighbour_update - update or initialize new mesh neighbor. 597 * 598 * @sdata: local meshif 599 * @addr: peer's address 600 * @elems: IEs from beacon or mesh peering frame 601 * @rx_status: rx status for the frame for signal reporting 602 * 603 * Initiates peering if appropriate. 604 */ 605 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 606 u8 *hw_addr, 607 struct ieee802_11_elems *elems, 608 struct ieee80211_rx_status *rx_status) 609 { 610 struct sta_info *sta; 611 u32 changed = 0; 612 613 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status); 614 if (!sta) 615 goto out; 616 617 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form & 618 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE; 619 620 if (mesh_peer_accepts_plinks(elems) && 621 sta->mesh->plink_state == NL80211_PLINK_LISTEN && 622 sdata->u.mesh.accepting_plinks && 623 sdata->u.mesh.mshcfg.auto_open_plinks && 624 rssi_threshold_check(sdata, sta)) 625 changed = mesh_plink_open(sta); 626 627 ieee80211_mps_frame_release(sta, elems); 628 out: 629 rcu_read_unlock(); 630 ieee80211_mbss_info_change_notify(sdata, changed); 631 } 632 633 void mesh_plink_timer(struct timer_list *t) 634 { 635 struct mesh_sta *mesh = from_timer(mesh, t, plink_timer); 636 struct sta_info *sta; 637 u16 reason = 0; 638 struct ieee80211_sub_if_data *sdata; 639 struct mesh_config *mshcfg; 640 enum ieee80211_self_protected_actioncode action = 0; 641 642 /* 643 * This STA is valid because sta_info_destroy() will 644 * del_timer_sync() this timer after having made sure 645 * it cannot be readded (by deleting the plink.) 646 */ 647 sta = mesh->plink_sta; 648 649 if (sta->sdata->local->quiescing) 650 return; 651 652 spin_lock_bh(&sta->mesh->plink_lock); 653 654 /* If a timer fires just before a state transition on another CPU, 655 * we may have already extended the timeout and changed state by the 656 * time we've acquired the lock and arrived here. In that case, 657 * skip this timer and wait for the new one. 658 */ 659 if (time_before(jiffies, sta->mesh->plink_timer.expires)) { 660 mpl_dbg(sta->sdata, 661 "Ignoring timer for %pM in state %s (timer adjusted)", 662 sta->sta.addr, mplstates[sta->mesh->plink_state]); 663 spin_unlock_bh(&sta->mesh->plink_lock); 664 return; 665 } 666 667 /* del_timer() and handler may race when entering these states */ 668 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || 669 sta->mesh->plink_state == NL80211_PLINK_ESTAB) { 670 mpl_dbg(sta->sdata, 671 "Ignoring timer for %pM in state %s (timer deleted)", 672 sta->sta.addr, mplstates[sta->mesh->plink_state]); 673 spin_unlock_bh(&sta->mesh->plink_lock); 674 return; 675 } 676 677 mpl_dbg(sta->sdata, 678 "Mesh plink timer for %pM fired on state %s\n", 679 sta->sta.addr, mplstates[sta->mesh->plink_state]); 680 sdata = sta->sdata; 681 mshcfg = &sdata->u.mesh.mshcfg; 682 683 switch (sta->mesh->plink_state) { 684 case NL80211_PLINK_OPN_RCVD: 685 case NL80211_PLINK_OPN_SNT: 686 /* retry timer */ 687 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { 688 u32 rand; 689 mpl_dbg(sta->sdata, 690 "Mesh plink for %pM (retry, timeout): %d %d\n", 691 sta->sta.addr, sta->mesh->plink_retries, 692 sta->mesh->plink_timeout); 693 get_random_bytes(&rand, sizeof(u32)); 694 sta->mesh->plink_timeout = sta->mesh->plink_timeout + 695 rand % sta->mesh->plink_timeout; 696 ++sta->mesh->plink_retries; 697 mod_plink_timer(sta, sta->mesh->plink_timeout); 698 action = WLAN_SP_MESH_PEERING_OPEN; 699 break; 700 } 701 reason = WLAN_REASON_MESH_MAX_RETRIES; 702 fallthrough; 703 case NL80211_PLINK_CNF_RCVD: 704 /* confirm timer */ 705 if (!reason) 706 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 707 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 708 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 709 action = WLAN_SP_MESH_PEERING_CLOSE; 710 break; 711 case NL80211_PLINK_HOLDING: 712 /* holding timer */ 713 del_timer(&sta->mesh->plink_timer); 714 mesh_plink_fsm_restart(sta); 715 break; 716 default: 717 break; 718 } 719 spin_unlock_bh(&sta->mesh->plink_lock); 720 if (action) 721 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 722 sta->mesh->llid, sta->mesh->plid, reason); 723 } 724 725 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 726 { 727 sta->mesh->plink_timeout = timeout; 728 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout)); 729 } 730 731 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 732 u16 llid) 733 { 734 struct ieee80211_local *local = sdata->local; 735 bool in_use = false; 736 struct sta_info *sta; 737 738 rcu_read_lock(); 739 list_for_each_entry_rcu(sta, &local->sta_list, list) { 740 if (sdata != sta->sdata) 741 continue; 742 743 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { 744 in_use = true; 745 break; 746 } 747 } 748 rcu_read_unlock(); 749 750 return in_use; 751 } 752 753 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 754 { 755 u16 llid; 756 757 do { 758 get_random_bytes(&llid, sizeof(llid)); 759 } while (llid_in_use(sdata, llid)); 760 761 return llid; 762 } 763 764 u32 mesh_plink_open(struct sta_info *sta) 765 { 766 struct ieee80211_sub_if_data *sdata = sta->sdata; 767 u32 changed; 768 769 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 770 return 0; 771 772 spin_lock_bh(&sta->mesh->plink_lock); 773 sta->mesh->llid = mesh_get_new_llid(sdata); 774 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && 775 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { 776 spin_unlock_bh(&sta->mesh->plink_lock); 777 return 0; 778 } 779 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; 780 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 781 spin_unlock_bh(&sta->mesh->plink_lock); 782 mpl_dbg(sdata, 783 "Mesh plink: starting establishment with %pM\n", 784 sta->sta.addr); 785 786 /* set the non-peer mode to active during peering */ 787 changed = ieee80211_mps_local_status_update(sdata); 788 789 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, 790 sta->sta.addr, sta->mesh->llid, 0, 0); 791 return changed; 792 } 793 794 u32 mesh_plink_block(struct sta_info *sta) 795 { 796 u32 changed; 797 798 spin_lock_bh(&sta->mesh->plink_lock); 799 changed = __mesh_plink_deactivate(sta); 800 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 801 spin_unlock_bh(&sta->mesh->plink_lock); 802 mesh_path_flush_by_nexthop(sta); 803 804 return changed; 805 } 806 807 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 808 struct sta_info *sta, 809 enum plink_event event) 810 { 811 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 812 u16 reason = (event == CLS_ACPT) ? 813 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 814 815 sta->mesh->reason = reason; 816 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 817 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 818 } 819 820 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 821 struct sta_info *sta) 822 { 823 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 824 u32 changed = 0; 825 826 del_timer(&sta->mesh->plink_timer); 827 sta->mesh->plink_state = NL80211_PLINK_ESTAB; 828 changed |= mesh_plink_inc_estab_count(sdata); 829 changed |= mesh_set_ht_prot_mode(sdata); 830 changed |= mesh_set_short_slot_time(sdata); 831 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 832 ieee80211_mps_sta_status_update(sta); 833 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 834 return changed; 835 } 836 837 /** 838 * mesh_plink_fsm - step @sta MPM based on @event 839 * 840 * @sdata: interface 841 * @sta: mesh neighbor 842 * @event: peering event 843 * 844 * Return: changed MBSS flags 845 */ 846 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 847 struct sta_info *sta, enum plink_event event) 848 { 849 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 850 enum ieee80211_self_protected_actioncode action = 0; 851 u32 changed = 0; 852 bool flush = false; 853 854 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 855 mplstates[sta->mesh->plink_state], mplevents[event]); 856 857 spin_lock_bh(&sta->mesh->plink_lock); 858 switch (sta->mesh->plink_state) { 859 case NL80211_PLINK_LISTEN: 860 switch (event) { 861 case CLS_ACPT: 862 mesh_plink_fsm_restart(sta); 863 break; 864 case OPN_ACPT: 865 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 866 sta->mesh->llid = mesh_get_new_llid(sdata); 867 mesh_plink_timer_set(sta, 868 mshcfg->dot11MeshRetryTimeout); 869 870 /* set the non-peer mode to active during peering */ 871 changed |= ieee80211_mps_local_status_update(sdata); 872 action = WLAN_SP_MESH_PEERING_OPEN; 873 break; 874 default: 875 break; 876 } 877 break; 878 case NL80211_PLINK_OPN_SNT: 879 switch (event) { 880 case OPN_RJCT: 881 case CNF_RJCT: 882 case CLS_ACPT: 883 mesh_plink_close(sdata, sta, event); 884 action = WLAN_SP_MESH_PEERING_CLOSE; 885 break; 886 case OPN_ACPT: 887 /* retry timer is left untouched */ 888 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 889 action = WLAN_SP_MESH_PEERING_CONFIRM; 890 break; 891 case CNF_ACPT: 892 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; 893 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 894 break; 895 default: 896 break; 897 } 898 break; 899 case NL80211_PLINK_OPN_RCVD: 900 switch (event) { 901 case OPN_RJCT: 902 case CNF_RJCT: 903 case CLS_ACPT: 904 mesh_plink_close(sdata, sta, event); 905 action = WLAN_SP_MESH_PEERING_CLOSE; 906 break; 907 case OPN_ACPT: 908 action = WLAN_SP_MESH_PEERING_CONFIRM; 909 break; 910 case CNF_ACPT: 911 changed |= mesh_plink_establish(sdata, sta); 912 break; 913 default: 914 break; 915 } 916 break; 917 case NL80211_PLINK_CNF_RCVD: 918 switch (event) { 919 case OPN_RJCT: 920 case CNF_RJCT: 921 case CLS_ACPT: 922 mesh_plink_close(sdata, sta, event); 923 action = WLAN_SP_MESH_PEERING_CLOSE; 924 break; 925 case OPN_ACPT: 926 changed |= mesh_plink_establish(sdata, sta); 927 action = WLAN_SP_MESH_PEERING_CONFIRM; 928 break; 929 default: 930 break; 931 } 932 break; 933 case NL80211_PLINK_ESTAB: 934 switch (event) { 935 case CLS_ACPT: 936 changed |= __mesh_plink_deactivate(sta); 937 changed |= mesh_set_ht_prot_mode(sdata); 938 changed |= mesh_set_short_slot_time(sdata); 939 mesh_plink_close(sdata, sta, event); 940 action = WLAN_SP_MESH_PEERING_CLOSE; 941 flush = true; 942 break; 943 case OPN_ACPT: 944 action = WLAN_SP_MESH_PEERING_CONFIRM; 945 break; 946 default: 947 break; 948 } 949 break; 950 case NL80211_PLINK_HOLDING: 951 switch (event) { 952 case CLS_ACPT: 953 del_timer(&sta->mesh->plink_timer); 954 mesh_plink_fsm_restart(sta); 955 break; 956 case OPN_ACPT: 957 case CNF_ACPT: 958 case OPN_RJCT: 959 case CNF_RJCT: 960 action = WLAN_SP_MESH_PEERING_CLOSE; 961 break; 962 default: 963 break; 964 } 965 break; 966 default: 967 /* should not get here, PLINK_BLOCKED is dealt with at the 968 * beginning of the function 969 */ 970 break; 971 } 972 spin_unlock_bh(&sta->mesh->plink_lock); 973 if (flush) 974 mesh_path_flush_by_nexthop(sta); 975 if (action) { 976 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 977 sta->mesh->llid, sta->mesh->plid, 978 sta->mesh->reason); 979 980 /* also send confirm in open case */ 981 if (action == WLAN_SP_MESH_PEERING_OPEN) { 982 mesh_plink_frame_tx(sdata, sta, 983 WLAN_SP_MESH_PEERING_CONFIRM, 984 sta->sta.addr, sta->mesh->llid, 985 sta->mesh->plid, 0); 986 } 987 } 988 989 return changed; 990 } 991 992 /* 993 * mesh_plink_get_event - get correct MPM event 994 * 995 * @sdata: interface 996 * @sta: peer, leave NULL if processing a frame from a new suitable peer 997 * @elems: peering management IEs 998 * @ftype: frame type 999 * @llid: peer's peer link ID 1000 * @plid: peer's local link ID 1001 * 1002 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 1003 * an error. 1004 */ 1005 static enum plink_event 1006 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 1007 struct sta_info *sta, 1008 struct ieee802_11_elems *elems, 1009 enum ieee80211_self_protected_actioncode ftype, 1010 u16 llid, u16 plid) 1011 { 1012 enum plink_event event = PLINK_UNDEFINED; 1013 u8 ie_len = elems->peering_len; 1014 bool matches_local; 1015 1016 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 1017 mesh_matches_local(sdata, elems)); 1018 1019 /* deny open request from non-matching peer */ 1020 if (!matches_local && !sta) { 1021 event = OPN_RJCT; 1022 goto out; 1023 } 1024 1025 if (!sta) { 1026 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 1027 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 1028 goto out; 1029 } 1030 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 1031 if (!mesh_plink_free_count(sdata)) { 1032 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 1033 goto out; 1034 } 1035 1036 /* new matching peer */ 1037 event = OPN_ACPT; 1038 goto out; 1039 } else { 1040 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 1041 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 1042 goto out; 1043 } 1044 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) 1045 goto out; 1046 } 1047 1048 switch (ftype) { 1049 case WLAN_SP_MESH_PEERING_OPEN: 1050 if (!matches_local) 1051 event = OPN_RJCT; 1052 if (!mesh_plink_free_count(sdata) || 1053 (sta->mesh->plid && sta->mesh->plid != plid)) 1054 event = OPN_IGNR; 1055 else 1056 event = OPN_ACPT; 1057 break; 1058 case WLAN_SP_MESH_PEERING_CONFIRM: 1059 if (!matches_local) 1060 event = CNF_RJCT; 1061 if (!mesh_plink_free_count(sdata) || 1062 sta->mesh->llid != llid || 1063 (sta->mesh->plid && sta->mesh->plid != plid)) 1064 event = CNF_IGNR; 1065 else 1066 event = CNF_ACPT; 1067 break; 1068 case WLAN_SP_MESH_PEERING_CLOSE: 1069 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 1070 /* Do not check for llid or plid. This does not 1071 * follow the standard but since multiple plinks 1072 * per sta are not supported, it is necessary in 1073 * order to avoid a livelock when MP A sees an 1074 * establish peer link to MP B but MP B does not 1075 * see it. This can be caused by a timeout in 1076 * B's peer link establishment or B beign 1077 * restarted. 1078 */ 1079 event = CLS_ACPT; 1080 else if (sta->mesh->plid != plid) 1081 event = CLS_IGNR; 1082 else if (ie_len == 8 && sta->mesh->llid != llid) 1083 event = CLS_IGNR; 1084 else 1085 event = CLS_ACPT; 1086 break; 1087 default: 1088 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 1089 break; 1090 } 1091 1092 out: 1093 return event; 1094 } 1095 1096 static void 1097 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1098 struct ieee80211_mgmt *mgmt, 1099 struct ieee802_11_elems *elems, 1100 struct ieee80211_rx_status *rx_status) 1101 { 1102 1103 struct sta_info *sta; 1104 enum plink_event event; 1105 enum ieee80211_self_protected_actioncode ftype; 1106 u32 changed = 0; 1107 u8 ie_len = elems->peering_len; 1108 u16 plid, llid = 0; 1109 1110 if (!elems->peering) { 1111 mpl_dbg(sdata, 1112 "Mesh plink: missing necessary peer link ie\n"); 1113 return; 1114 } 1115 1116 if (elems->rsn_len && 1117 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1118 mpl_dbg(sdata, 1119 "Mesh plink: can't establish link with secure peer\n"); 1120 return; 1121 } 1122 1123 ftype = mgmt->u.action.u.self_prot.action_code; 1124 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1125 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1126 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1127 && ie_len != 8)) { 1128 mpl_dbg(sdata, 1129 "Mesh plink: incorrect plink ie length %d %d\n", 1130 ftype, ie_len); 1131 return; 1132 } 1133 1134 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1135 (!elems->mesh_id || !elems->mesh_config)) { 1136 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1137 return; 1138 } 1139 /* Note the lines below are correct, the llid in the frame is the plid 1140 * from the point of view of this host. 1141 */ 1142 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1143 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1144 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1145 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1146 1147 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1148 rcu_read_lock(); 1149 1150 sta = sta_info_get(sdata, mgmt->sa); 1151 1152 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1153 !rssi_threshold_check(sdata, sta)) { 1154 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1155 mgmt->sa); 1156 goto unlock_rcu; 1157 } 1158 1159 /* Now we will figure out the appropriate event... */ 1160 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1161 1162 if (event == OPN_ACPT) { 1163 rcu_read_unlock(); 1164 /* allocate sta entry if necessary and update info */ 1165 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status); 1166 if (!sta) { 1167 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1168 goto unlock_rcu; 1169 } 1170 sta->mesh->plid = plid; 1171 } else if (!sta && event == OPN_RJCT) { 1172 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, 1173 mgmt->sa, 0, plid, 1174 WLAN_REASON_MESH_CONFIG); 1175 goto unlock_rcu; 1176 } else if (!sta || event == PLINK_UNDEFINED) { 1177 /* something went wrong */ 1178 goto unlock_rcu; 1179 } 1180 1181 if (event == CNF_ACPT) { 1182 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1183 if (!sta->mesh->plid) 1184 sta->mesh->plid = plid; 1185 1186 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); 1187 } 1188 1189 changed |= mesh_plink_fsm(sdata, sta, event); 1190 1191 unlock_rcu: 1192 rcu_read_unlock(); 1193 1194 if (changed) 1195 ieee80211_mbss_info_change_notify(sdata, changed); 1196 } 1197 1198 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1199 struct ieee80211_mgmt *mgmt, size_t len, 1200 struct ieee80211_rx_status *rx_status) 1201 { 1202 struct ieee802_11_elems elems; 1203 size_t baselen; 1204 u8 *baseaddr; 1205 1206 /* need action_code, aux */ 1207 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1208 return; 1209 1210 if (sdata->u.mesh.user_mpm) 1211 /* userspace must register for these */ 1212 return; 1213 1214 if (is_multicast_ether_addr(mgmt->da)) { 1215 mpl_dbg(sdata, 1216 "Mesh plink: ignore frame from multicast address\n"); 1217 return; 1218 } 1219 1220 baseaddr = mgmt->u.action.u.self_prot.variable; 1221 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1222 if (mgmt->u.action.u.self_prot.action_code == 1223 WLAN_SP_MESH_PEERING_CONFIRM) { 1224 baseaddr += 4; 1225 baselen += 4; 1226 1227 if (baselen > len) 1228 return; 1229 } 1230 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems, 1231 mgmt->bssid, NULL); 1232 mesh_process_plink_frame(sdata, mgmt, &elems, rx_status); 1233 } 1234