1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008, 2009 open80211s Ltd. 4 * Copyright (C) 2019, 2021 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 * @sdata: the (mesh) interface to handle 148 * 149 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT 150 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT 151 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is 152 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode 153 * is selected if all peers in our 20/40MHz MBSS support HT and at least one 154 * HT20 peer is present. Otherwise no-protection mode is selected. 155 */ 156 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) 157 { 158 struct ieee80211_local *local = sdata->local; 159 struct sta_info *sta; 160 u16 ht_opmode; 161 bool non_ht_sta = false, ht20_sta = false; 162 163 switch (sdata->vif.bss_conf.chandef.width) { 164 case NL80211_CHAN_WIDTH_20_NOHT: 165 case NL80211_CHAN_WIDTH_5: 166 case NL80211_CHAN_WIDTH_10: 167 return 0; 168 default: 169 break; 170 } 171 172 rcu_read_lock(); 173 list_for_each_entry_rcu(sta, &local->sta_list, list) { 174 if (sdata != sta->sdata || 175 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 176 continue; 177 178 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20) 179 continue; 180 181 if (!sta->sta.ht_cap.ht_supported) { 182 mpl_dbg(sdata, "nonHT sta (%pM) is present\n", 183 sta->sta.addr); 184 non_ht_sta = true; 185 break; 186 } 187 188 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); 189 ht20_sta = true; 190 } 191 rcu_read_unlock(); 192 193 if (non_ht_sta) 194 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; 195 else if (ht20_sta && 196 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20) 197 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; 198 else 199 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; 200 201 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) 202 return 0; 203 204 sdata->vif.bss_conf.ht_operation_mode = ht_opmode; 205 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; 206 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); 207 return BSS_CHANGED_HT; 208 } 209 210 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 211 struct sta_info *sta, 212 enum ieee80211_self_protected_actioncode action, 213 u8 *da, u16 llid, u16 plid, u16 reason) 214 { 215 struct ieee80211_local *local = sdata->local; 216 struct sk_buff *skb; 217 struct ieee80211_tx_info *info; 218 struct ieee80211_mgmt *mgmt; 219 bool include_plid = false; 220 u16 peering_proto = 0; 221 u8 *pos, ie_len = 4; 222 u8 ie_len_he_cap; 223 int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot); 224 int err = -ENOMEM; 225 226 ie_len_he_cap = ieee80211_ie_len_he_cap(sdata, 227 NL80211_IFTYPE_MESH_POINT); 228 skb = dev_alloc_skb(local->tx_headroom + 229 hdr_len + 230 2 + /* capability info */ 231 2 + /* AID */ 232 2 + 8 + /* supported rates */ 233 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 234 2 + sdata->u.mesh.mesh_id_len + 235 2 + sizeof(struct ieee80211_meshconf_ie) + 236 2 + sizeof(struct ieee80211_ht_cap) + 237 2 + sizeof(struct ieee80211_ht_operation) + 238 2 + sizeof(struct ieee80211_vht_cap) + 239 2 + sizeof(struct ieee80211_vht_operation) + 240 ie_len_he_cap + 241 2 + 1 + sizeof(struct ieee80211_he_operation) + 242 sizeof(struct ieee80211_he_6ghz_oper) + 243 2 + 1 + sizeof(struct ieee80211_he_6ghz_capa) + 244 2 + 8 + /* peering IE */ 245 sdata->u.mesh.ie_len); 246 if (!skb) 247 return err; 248 info = IEEE80211_SKB_CB(skb); 249 skb_reserve(skb, local->tx_headroom); 250 mgmt = skb_put_zero(skb, hdr_len); 251 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 252 IEEE80211_STYPE_ACTION); 253 memcpy(mgmt->da, da, ETH_ALEN); 254 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 255 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 256 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; 257 mgmt->u.action.u.self_prot.action_code = action; 258 259 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 260 struct ieee80211_supported_band *sband; 261 enum nl80211_band band; 262 263 sband = ieee80211_get_sband(sdata); 264 if (!sband) { 265 err = -EINVAL; 266 goto free; 267 } 268 band = sband->band; 269 270 /* capability info */ 271 pos = skb_put_zero(skb, 2); 272 if (action == WLAN_SP_MESH_PEERING_CONFIRM) { 273 /* AID */ 274 pos = skb_put(skb, 2); 275 put_unaligned_le16(sta->sta.aid, pos); 276 } 277 if (ieee80211_add_srates_ie(sdata, skb, true, band) || 278 ieee80211_add_ext_srates_ie(sdata, skb, true, band) || 279 mesh_add_rsn_ie(sdata, skb) || 280 mesh_add_meshid_ie(sdata, skb) || 281 mesh_add_meshconf_ie(sdata, skb)) 282 goto free; 283 } else { /* WLAN_SP_MESH_PEERING_CLOSE */ 284 info->flags |= IEEE80211_TX_CTL_NO_ACK; 285 if (mesh_add_meshid_ie(sdata, skb)) 286 goto free; 287 } 288 289 /* Add Mesh Peering Management element */ 290 switch (action) { 291 case WLAN_SP_MESH_PEERING_OPEN: 292 break; 293 case WLAN_SP_MESH_PEERING_CONFIRM: 294 ie_len += 2; 295 include_plid = true; 296 break; 297 case WLAN_SP_MESH_PEERING_CLOSE: 298 if (plid) { 299 ie_len += 2; 300 include_plid = true; 301 } 302 ie_len += 2; /* reason code */ 303 break; 304 default: 305 err = -EINVAL; 306 goto free; 307 } 308 309 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) 310 goto free; 311 312 pos = skb_put(skb, 2 + ie_len); 313 *pos++ = WLAN_EID_PEER_MGMT; 314 *pos++ = ie_len; 315 memcpy(pos, &peering_proto, 2); 316 pos += 2; 317 put_unaligned_le16(llid, pos); 318 pos += 2; 319 if (include_plid) { 320 put_unaligned_le16(plid, pos); 321 pos += 2; 322 } 323 if (action == WLAN_SP_MESH_PEERING_CLOSE) { 324 put_unaligned_le16(reason, pos); 325 pos += 2; 326 } 327 328 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 329 if (mesh_add_ht_cap_ie(sdata, skb) || 330 mesh_add_ht_oper_ie(sdata, skb) || 331 mesh_add_vht_cap_ie(sdata, skb) || 332 mesh_add_vht_oper_ie(sdata, skb) || 333 mesh_add_he_cap_ie(sdata, skb, ie_len_he_cap) || 334 mesh_add_he_oper_ie(sdata, skb) || 335 mesh_add_he_6ghz_cap_ie(sdata, skb)) 336 goto free; 337 } 338 339 if (mesh_add_vendor_ies(sdata, skb)) 340 goto free; 341 342 ieee80211_tx_skb(sdata, skb); 343 return 0; 344 free: 345 kfree_skb(skb); 346 return err; 347 } 348 349 /** 350 * __mesh_plink_deactivate - deactivate mesh peer link 351 * 352 * @sta: mesh peer link to deactivate 353 * 354 * Mesh paths with this peer as next hop should be flushed 355 * by the caller outside of plink_lock. 356 * 357 * Returns beacon changed flag if the beacon content changed. 358 * 359 * Locking: the caller must hold sta->mesh->plink_lock 360 */ 361 static u32 __mesh_plink_deactivate(struct sta_info *sta) 362 { 363 struct ieee80211_sub_if_data *sdata = sta->sdata; 364 u32 changed = 0; 365 366 lockdep_assert_held(&sta->mesh->plink_lock); 367 368 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 369 changed = mesh_plink_dec_estab_count(sdata); 370 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 371 372 ieee80211_mps_sta_status_update(sta); 373 changed |= ieee80211_mps_set_sta_local_pm(sta, 374 NL80211_MESH_POWER_UNKNOWN); 375 376 return changed; 377 } 378 379 /** 380 * mesh_plink_deactivate - deactivate mesh peer link 381 * 382 * @sta: mesh peer link to deactivate 383 * 384 * All mesh paths with this peer as next hop will be flushed 385 */ 386 u32 mesh_plink_deactivate(struct sta_info *sta) 387 { 388 struct ieee80211_sub_if_data *sdata = sta->sdata; 389 u32 changed; 390 391 spin_lock_bh(&sta->mesh->plink_lock); 392 changed = __mesh_plink_deactivate(sta); 393 394 if (!sdata->u.mesh.user_mpm) { 395 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED; 396 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE, 397 sta->sta.addr, sta->mesh->llid, 398 sta->mesh->plid, sta->mesh->reason); 399 } 400 spin_unlock_bh(&sta->mesh->plink_lock); 401 if (!sdata->u.mesh.user_mpm) 402 del_timer_sync(&sta->mesh->plink_timer); 403 mesh_path_flush_by_nexthop(sta); 404 405 /* make sure no readers can access nexthop sta from here on */ 406 synchronize_net(); 407 408 return changed; 409 } 410 411 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 412 struct sta_info *sta, 413 struct ieee802_11_elems *elems) 414 { 415 struct ieee80211_local *local = sdata->local; 416 struct ieee80211_supported_band *sband; 417 u32 rates, basic_rates = 0, changed = 0; 418 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth; 419 420 sband = ieee80211_get_sband(sdata); 421 if (!sband) 422 return; 423 424 rates = ieee80211_sta_get_rates(sdata, elems, sband->band, 425 &basic_rates); 426 427 spin_lock_bh(&sta->mesh->plink_lock); 428 sta->rx_stats.last_rx = jiffies; 429 430 /* rates and capabilities don't change during peering */ 431 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB && 432 sta->mesh->processed_beacon) 433 goto out; 434 sta->mesh->processed_beacon = true; 435 436 if (sta->sta.supp_rates[sband->band] != rates) 437 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 438 sta->sta.supp_rates[sband->band] = rates; 439 440 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 441 elems->ht_cap_elem, sta)) 442 changed |= IEEE80211_RC_BW_CHANGED; 443 444 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband, 445 elems->vht_cap_elem, sta); 446 447 ieee80211_he_cap_ie_to_sta_he_cap(sdata, sband, elems->he_cap, 448 elems->he_cap_len, 449 elems->he_6ghz_capa, 450 sta); 451 452 if (bw != sta->sta.bandwidth) 453 changed |= IEEE80211_RC_BW_CHANGED; 454 455 /* HT peer is operating 20MHz-only */ 456 if (elems->ht_operation && 457 !(elems->ht_operation->ht_param & 458 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 459 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) 460 changed |= IEEE80211_RC_BW_CHANGED; 461 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; 462 } 463 464 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) 465 rate_control_rate_init(sta); 466 else 467 rate_control_rate_update(local, sband, sta, changed); 468 out: 469 spin_unlock_bh(&sta->mesh->plink_lock); 470 } 471 472 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) 473 { 474 struct sta_info *sta; 475 unsigned long *aid_map; 476 int aid; 477 478 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1), 479 sizeof(*aid_map), GFP_KERNEL); 480 if (!aid_map) 481 return -ENOMEM; 482 483 /* reserve aid 0 for mcast indication */ 484 __set_bit(0, aid_map); 485 486 rcu_read_lock(); 487 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) 488 __set_bit(sta->sta.aid, aid_map); 489 rcu_read_unlock(); 490 491 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); 492 kfree(aid_map); 493 494 if (aid > IEEE80211_MAX_AID) 495 return -ENOBUFS; 496 497 return aid; 498 } 499 500 static struct sta_info * 501 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 502 { 503 struct sta_info *sta; 504 int aid; 505 506 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 507 return NULL; 508 509 aid = mesh_allocate_aid(sdata); 510 if (aid < 0) 511 return NULL; 512 513 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 514 if (!sta) 515 return NULL; 516 517 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 518 sta->sta.wme = true; 519 sta->sta.aid = aid; 520 521 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 522 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 523 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 524 525 return sta; 526 } 527 528 static struct sta_info * 529 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 530 struct ieee802_11_elems *elems, 531 struct ieee80211_rx_status *rx_status) 532 { 533 struct sta_info *sta = NULL; 534 535 /* Userspace handles station allocation */ 536 if (sdata->u.mesh.user_mpm || 537 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) { 538 if (mesh_peer_accepts_plinks(elems) && 539 mesh_plink_availables(sdata)) { 540 int sig = 0; 541 542 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM)) 543 sig = rx_status->signal; 544 545 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 546 elems->ie_start, 547 elems->total_len, 548 sig, GFP_KERNEL); 549 } 550 } else 551 sta = __mesh_sta_info_alloc(sdata, addr); 552 553 return sta; 554 } 555 556 /* 557 * mesh_sta_info_get - return mesh sta info entry for @addr. 558 * 559 * @sdata: local meshif 560 * @addr: peer's address 561 * @elems: IEs from beacon or mesh peering frame. 562 * @rx_status: rx status for the frame for signal reporting 563 * 564 * Return existing or newly allocated sta_info under RCU read lock. 565 * (re)initialize with given IEs. 566 */ 567 static struct sta_info * 568 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 569 u8 *addr, struct ieee802_11_elems *elems, 570 struct ieee80211_rx_status *rx_status) __acquires(RCU) 571 { 572 struct sta_info *sta = NULL; 573 574 rcu_read_lock(); 575 sta = sta_info_get(sdata, addr); 576 if (sta) { 577 mesh_sta_info_init(sdata, sta, elems); 578 } else { 579 rcu_read_unlock(); 580 /* can't run atomic */ 581 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status); 582 if (!sta) { 583 rcu_read_lock(); 584 return NULL; 585 } 586 587 mesh_sta_info_init(sdata, sta, elems); 588 589 if (sta_info_insert_rcu(sta)) 590 return NULL; 591 } 592 593 return sta; 594 } 595 596 /* 597 * mesh_neighbour_update - update or initialize new mesh neighbor. 598 * 599 * @sdata: local meshif 600 * @addr: peer's address 601 * @elems: IEs from beacon or mesh peering frame 602 * @rx_status: rx status for the frame for signal reporting 603 * 604 * Initiates peering if appropriate. 605 */ 606 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 607 u8 *hw_addr, 608 struct ieee802_11_elems *elems, 609 struct ieee80211_rx_status *rx_status) 610 { 611 struct sta_info *sta; 612 u32 changed = 0; 613 614 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status); 615 if (!sta) 616 goto out; 617 618 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form & 619 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE; 620 621 if (mesh_peer_accepts_plinks(elems) && 622 sta->mesh->plink_state == NL80211_PLINK_LISTEN && 623 sdata->u.mesh.accepting_plinks && 624 sdata->u.mesh.mshcfg.auto_open_plinks && 625 rssi_threshold_check(sdata, sta)) 626 changed = mesh_plink_open(sta); 627 628 ieee80211_mps_frame_release(sta, elems); 629 out: 630 rcu_read_unlock(); 631 ieee80211_mbss_info_change_notify(sdata, changed); 632 } 633 634 void mesh_plink_timer(struct timer_list *t) 635 { 636 struct mesh_sta *mesh = from_timer(mesh, t, plink_timer); 637 struct sta_info *sta; 638 u16 reason = 0; 639 struct ieee80211_sub_if_data *sdata; 640 struct mesh_config *mshcfg; 641 enum ieee80211_self_protected_actioncode action = 0; 642 643 /* 644 * This STA is valid because sta_info_destroy() will 645 * del_timer_sync() this timer after having made sure 646 * it cannot be readded (by deleting the plink.) 647 */ 648 sta = mesh->plink_sta; 649 650 if (sta->sdata->local->quiescing) 651 return; 652 653 spin_lock_bh(&sta->mesh->plink_lock); 654 655 /* If a timer fires just before a state transition on another CPU, 656 * we may have already extended the timeout and changed state by the 657 * time we've acquired the lock and arrived here. In that case, 658 * skip this timer and wait for the new one. 659 */ 660 if (time_before(jiffies, sta->mesh->plink_timer.expires)) { 661 mpl_dbg(sta->sdata, 662 "Ignoring timer for %pM in state %s (timer adjusted)", 663 sta->sta.addr, mplstates[sta->mesh->plink_state]); 664 spin_unlock_bh(&sta->mesh->plink_lock); 665 return; 666 } 667 668 /* del_timer() and handler may race when entering these states */ 669 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || 670 sta->mesh->plink_state == NL80211_PLINK_ESTAB) { 671 mpl_dbg(sta->sdata, 672 "Ignoring timer for %pM in state %s (timer deleted)", 673 sta->sta.addr, mplstates[sta->mesh->plink_state]); 674 spin_unlock_bh(&sta->mesh->plink_lock); 675 return; 676 } 677 678 mpl_dbg(sta->sdata, 679 "Mesh plink timer for %pM fired on state %s\n", 680 sta->sta.addr, mplstates[sta->mesh->plink_state]); 681 sdata = sta->sdata; 682 mshcfg = &sdata->u.mesh.mshcfg; 683 684 switch (sta->mesh->plink_state) { 685 case NL80211_PLINK_OPN_RCVD: 686 case NL80211_PLINK_OPN_SNT: 687 /* retry timer */ 688 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { 689 u32 rand; 690 mpl_dbg(sta->sdata, 691 "Mesh plink for %pM (retry, timeout): %d %d\n", 692 sta->sta.addr, sta->mesh->plink_retries, 693 sta->mesh->plink_timeout); 694 get_random_bytes(&rand, sizeof(u32)); 695 sta->mesh->plink_timeout = sta->mesh->plink_timeout + 696 rand % sta->mesh->plink_timeout; 697 ++sta->mesh->plink_retries; 698 mod_plink_timer(sta, sta->mesh->plink_timeout); 699 action = WLAN_SP_MESH_PEERING_OPEN; 700 break; 701 } 702 reason = WLAN_REASON_MESH_MAX_RETRIES; 703 fallthrough; 704 case NL80211_PLINK_CNF_RCVD: 705 /* confirm timer */ 706 if (!reason) 707 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 708 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 709 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 710 action = WLAN_SP_MESH_PEERING_CLOSE; 711 break; 712 case NL80211_PLINK_HOLDING: 713 /* holding timer */ 714 del_timer(&sta->mesh->plink_timer); 715 mesh_plink_fsm_restart(sta); 716 break; 717 default: 718 break; 719 } 720 spin_unlock_bh(&sta->mesh->plink_lock); 721 if (action) 722 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 723 sta->mesh->llid, sta->mesh->plid, reason); 724 } 725 726 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 727 { 728 sta->mesh->plink_timeout = timeout; 729 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout)); 730 } 731 732 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 733 u16 llid) 734 { 735 struct ieee80211_local *local = sdata->local; 736 bool in_use = false; 737 struct sta_info *sta; 738 739 rcu_read_lock(); 740 list_for_each_entry_rcu(sta, &local->sta_list, list) { 741 if (sdata != sta->sdata) 742 continue; 743 744 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { 745 in_use = true; 746 break; 747 } 748 } 749 rcu_read_unlock(); 750 751 return in_use; 752 } 753 754 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 755 { 756 u16 llid; 757 758 do { 759 get_random_bytes(&llid, sizeof(llid)); 760 } while (llid_in_use(sdata, llid)); 761 762 return llid; 763 } 764 765 u32 mesh_plink_open(struct sta_info *sta) 766 { 767 struct ieee80211_sub_if_data *sdata = sta->sdata; 768 u32 changed; 769 770 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 771 return 0; 772 773 spin_lock_bh(&sta->mesh->plink_lock); 774 sta->mesh->llid = mesh_get_new_llid(sdata); 775 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && 776 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { 777 spin_unlock_bh(&sta->mesh->plink_lock); 778 return 0; 779 } 780 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; 781 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 782 spin_unlock_bh(&sta->mesh->plink_lock); 783 mpl_dbg(sdata, 784 "Mesh plink: starting establishment with %pM\n", 785 sta->sta.addr); 786 787 /* set the non-peer mode to active during peering */ 788 changed = ieee80211_mps_local_status_update(sdata); 789 790 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, 791 sta->sta.addr, sta->mesh->llid, 0, 0); 792 return changed; 793 } 794 795 u32 mesh_plink_block(struct sta_info *sta) 796 { 797 u32 changed; 798 799 spin_lock_bh(&sta->mesh->plink_lock); 800 changed = __mesh_plink_deactivate(sta); 801 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 802 spin_unlock_bh(&sta->mesh->plink_lock); 803 mesh_path_flush_by_nexthop(sta); 804 805 return changed; 806 } 807 808 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 809 struct sta_info *sta, 810 enum plink_event event) 811 { 812 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 813 u16 reason = (event == CLS_ACPT) ? 814 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 815 816 sta->mesh->reason = reason; 817 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 818 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 819 } 820 821 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 822 struct sta_info *sta) 823 { 824 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 825 u32 changed = 0; 826 827 del_timer(&sta->mesh->plink_timer); 828 sta->mesh->plink_state = NL80211_PLINK_ESTAB; 829 changed |= mesh_plink_inc_estab_count(sdata); 830 changed |= mesh_set_ht_prot_mode(sdata); 831 changed |= mesh_set_short_slot_time(sdata); 832 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 833 ieee80211_mps_sta_status_update(sta); 834 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 835 return changed; 836 } 837 838 /** 839 * mesh_plink_fsm - step @sta MPM based on @event 840 * 841 * @sdata: interface 842 * @sta: mesh neighbor 843 * @event: peering event 844 * 845 * Return: changed MBSS flags 846 */ 847 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 848 struct sta_info *sta, enum plink_event event) 849 { 850 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 851 enum ieee80211_self_protected_actioncode action = 0; 852 u32 changed = 0; 853 bool flush = false; 854 855 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 856 mplstates[sta->mesh->plink_state], mplevents[event]); 857 858 spin_lock_bh(&sta->mesh->plink_lock); 859 switch (sta->mesh->plink_state) { 860 case NL80211_PLINK_LISTEN: 861 switch (event) { 862 case CLS_ACPT: 863 mesh_plink_fsm_restart(sta); 864 break; 865 case OPN_ACPT: 866 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 867 sta->mesh->llid = mesh_get_new_llid(sdata); 868 mesh_plink_timer_set(sta, 869 mshcfg->dot11MeshRetryTimeout); 870 871 /* set the non-peer mode to active during peering */ 872 changed |= ieee80211_mps_local_status_update(sdata); 873 action = WLAN_SP_MESH_PEERING_OPEN; 874 break; 875 default: 876 break; 877 } 878 break; 879 case NL80211_PLINK_OPN_SNT: 880 switch (event) { 881 case OPN_RJCT: 882 case CNF_RJCT: 883 case CLS_ACPT: 884 mesh_plink_close(sdata, sta, event); 885 action = WLAN_SP_MESH_PEERING_CLOSE; 886 break; 887 case OPN_ACPT: 888 /* retry timer is left untouched */ 889 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 890 action = WLAN_SP_MESH_PEERING_CONFIRM; 891 break; 892 case CNF_ACPT: 893 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; 894 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 895 break; 896 default: 897 break; 898 } 899 break; 900 case NL80211_PLINK_OPN_RCVD: 901 switch (event) { 902 case OPN_RJCT: 903 case CNF_RJCT: 904 case CLS_ACPT: 905 mesh_plink_close(sdata, sta, event); 906 action = WLAN_SP_MESH_PEERING_CLOSE; 907 break; 908 case OPN_ACPT: 909 action = WLAN_SP_MESH_PEERING_CONFIRM; 910 break; 911 case CNF_ACPT: 912 changed |= mesh_plink_establish(sdata, sta); 913 break; 914 default: 915 break; 916 } 917 break; 918 case NL80211_PLINK_CNF_RCVD: 919 switch (event) { 920 case OPN_RJCT: 921 case CNF_RJCT: 922 case CLS_ACPT: 923 mesh_plink_close(sdata, sta, event); 924 action = WLAN_SP_MESH_PEERING_CLOSE; 925 break; 926 case OPN_ACPT: 927 changed |= mesh_plink_establish(sdata, sta); 928 action = WLAN_SP_MESH_PEERING_CONFIRM; 929 break; 930 default: 931 break; 932 } 933 break; 934 case NL80211_PLINK_ESTAB: 935 switch (event) { 936 case CLS_ACPT: 937 changed |= __mesh_plink_deactivate(sta); 938 changed |= mesh_set_ht_prot_mode(sdata); 939 changed |= mesh_set_short_slot_time(sdata); 940 mesh_plink_close(sdata, sta, event); 941 action = WLAN_SP_MESH_PEERING_CLOSE; 942 flush = true; 943 break; 944 case OPN_ACPT: 945 action = WLAN_SP_MESH_PEERING_CONFIRM; 946 break; 947 default: 948 break; 949 } 950 break; 951 case NL80211_PLINK_HOLDING: 952 switch (event) { 953 case CLS_ACPT: 954 del_timer(&sta->mesh->plink_timer); 955 mesh_plink_fsm_restart(sta); 956 break; 957 case OPN_ACPT: 958 case CNF_ACPT: 959 case OPN_RJCT: 960 case CNF_RJCT: 961 action = WLAN_SP_MESH_PEERING_CLOSE; 962 break; 963 default: 964 break; 965 } 966 break; 967 default: 968 /* should not get here, PLINK_BLOCKED is dealt with at the 969 * beginning of the function 970 */ 971 break; 972 } 973 spin_unlock_bh(&sta->mesh->plink_lock); 974 if (flush) 975 mesh_path_flush_by_nexthop(sta); 976 if (action) { 977 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 978 sta->mesh->llid, sta->mesh->plid, 979 sta->mesh->reason); 980 981 /* also send confirm in open case */ 982 if (action == WLAN_SP_MESH_PEERING_OPEN) { 983 mesh_plink_frame_tx(sdata, sta, 984 WLAN_SP_MESH_PEERING_CONFIRM, 985 sta->sta.addr, sta->mesh->llid, 986 sta->mesh->plid, 0); 987 } 988 } 989 990 return changed; 991 } 992 993 /* 994 * mesh_plink_get_event - get correct MPM event 995 * 996 * @sdata: interface 997 * @sta: peer, leave NULL if processing a frame from a new suitable peer 998 * @elems: peering management IEs 999 * @ftype: frame type 1000 * @llid: peer's peer link ID 1001 * @plid: peer's local link ID 1002 * 1003 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 1004 * an error. 1005 */ 1006 static enum plink_event 1007 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 1008 struct sta_info *sta, 1009 struct ieee802_11_elems *elems, 1010 enum ieee80211_self_protected_actioncode ftype, 1011 u16 llid, u16 plid) 1012 { 1013 enum plink_event event = PLINK_UNDEFINED; 1014 u8 ie_len = elems->peering_len; 1015 bool matches_local; 1016 1017 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 1018 mesh_matches_local(sdata, elems)); 1019 1020 /* deny open request from non-matching peer */ 1021 if (!matches_local && !sta) { 1022 event = OPN_RJCT; 1023 goto out; 1024 } 1025 1026 if (!sta) { 1027 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 1028 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 1029 goto out; 1030 } 1031 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 1032 if (!mesh_plink_free_count(sdata)) { 1033 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 1034 goto out; 1035 } 1036 1037 /* new matching peer */ 1038 event = OPN_ACPT; 1039 goto out; 1040 } else { 1041 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 1042 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 1043 goto out; 1044 } 1045 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) 1046 goto out; 1047 } 1048 1049 switch (ftype) { 1050 case WLAN_SP_MESH_PEERING_OPEN: 1051 if (!matches_local) 1052 event = OPN_RJCT; 1053 if (!mesh_plink_free_count(sdata) || 1054 (sta->mesh->plid && sta->mesh->plid != plid)) 1055 event = OPN_IGNR; 1056 else 1057 event = OPN_ACPT; 1058 break; 1059 case WLAN_SP_MESH_PEERING_CONFIRM: 1060 if (!matches_local) 1061 event = CNF_RJCT; 1062 if (!mesh_plink_free_count(sdata) || 1063 sta->mesh->llid != llid || 1064 (sta->mesh->plid && sta->mesh->plid != plid)) 1065 event = CNF_IGNR; 1066 else 1067 event = CNF_ACPT; 1068 break; 1069 case WLAN_SP_MESH_PEERING_CLOSE: 1070 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 1071 /* Do not check for llid or plid. This does not 1072 * follow the standard but since multiple plinks 1073 * per sta are not supported, it is necessary in 1074 * order to avoid a livelock when MP A sees an 1075 * establish peer link to MP B but MP B does not 1076 * see it. This can be caused by a timeout in 1077 * B's peer link establishment or B beign 1078 * restarted. 1079 */ 1080 event = CLS_ACPT; 1081 else if (sta->mesh->plid != plid) 1082 event = CLS_IGNR; 1083 else if (ie_len == 8 && sta->mesh->llid != llid) 1084 event = CLS_IGNR; 1085 else 1086 event = CLS_ACPT; 1087 break; 1088 default: 1089 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 1090 break; 1091 } 1092 1093 out: 1094 return event; 1095 } 1096 1097 static void 1098 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1099 struct ieee80211_mgmt *mgmt, 1100 struct ieee802_11_elems *elems, 1101 struct ieee80211_rx_status *rx_status) 1102 { 1103 1104 struct sta_info *sta; 1105 enum plink_event event; 1106 enum ieee80211_self_protected_actioncode ftype; 1107 u32 changed = 0; 1108 u8 ie_len = elems->peering_len; 1109 u16 plid, llid = 0; 1110 1111 if (!elems->peering) { 1112 mpl_dbg(sdata, 1113 "Mesh plink: missing necessary peer link ie\n"); 1114 return; 1115 } 1116 1117 if (elems->rsn_len && 1118 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1119 mpl_dbg(sdata, 1120 "Mesh plink: can't establish link with secure peer\n"); 1121 return; 1122 } 1123 1124 ftype = mgmt->u.action.u.self_prot.action_code; 1125 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1126 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1127 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1128 && ie_len != 8)) { 1129 mpl_dbg(sdata, 1130 "Mesh plink: incorrect plink ie length %d %d\n", 1131 ftype, ie_len); 1132 return; 1133 } 1134 1135 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1136 (!elems->mesh_id || !elems->mesh_config)) { 1137 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1138 return; 1139 } 1140 /* Note the lines below are correct, the llid in the frame is the plid 1141 * from the point of view of this host. 1142 */ 1143 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1144 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1145 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1146 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1147 1148 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1149 rcu_read_lock(); 1150 1151 sta = sta_info_get(sdata, mgmt->sa); 1152 1153 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1154 !rssi_threshold_check(sdata, sta)) { 1155 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1156 mgmt->sa); 1157 goto unlock_rcu; 1158 } 1159 1160 /* Now we will figure out the appropriate event... */ 1161 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1162 1163 if (event == OPN_ACPT) { 1164 rcu_read_unlock(); 1165 /* allocate sta entry if necessary and update info */ 1166 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status); 1167 if (!sta) { 1168 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1169 goto unlock_rcu; 1170 } 1171 sta->mesh->plid = plid; 1172 } else if (!sta && event == OPN_RJCT) { 1173 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, 1174 mgmt->sa, 0, plid, 1175 WLAN_REASON_MESH_CONFIG); 1176 goto unlock_rcu; 1177 } else if (!sta || event == PLINK_UNDEFINED) { 1178 /* something went wrong */ 1179 goto unlock_rcu; 1180 } 1181 1182 if (event == CNF_ACPT) { 1183 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1184 if (!sta->mesh->plid) 1185 sta->mesh->plid = plid; 1186 1187 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); 1188 } 1189 1190 changed |= mesh_plink_fsm(sdata, sta, event); 1191 1192 unlock_rcu: 1193 rcu_read_unlock(); 1194 1195 if (changed) 1196 ieee80211_mbss_info_change_notify(sdata, changed); 1197 } 1198 1199 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1200 struct ieee80211_mgmt *mgmt, size_t len, 1201 struct ieee80211_rx_status *rx_status) 1202 { 1203 struct ieee802_11_elems *elems; 1204 size_t baselen; 1205 u8 *baseaddr; 1206 1207 /* need action_code, aux */ 1208 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1209 return; 1210 1211 if (sdata->u.mesh.user_mpm) 1212 /* userspace must register for these */ 1213 return; 1214 1215 if (is_multicast_ether_addr(mgmt->da)) { 1216 mpl_dbg(sdata, 1217 "Mesh plink: ignore frame from multicast address\n"); 1218 return; 1219 } 1220 1221 baseaddr = mgmt->u.action.u.self_prot.variable; 1222 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1223 if (mgmt->u.action.u.self_prot.action_code == 1224 WLAN_SP_MESH_PEERING_CONFIRM) { 1225 baseaddr += 4; 1226 baselen += 4; 1227 1228 if (baselen > len) 1229 return; 1230 } 1231 elems = ieee802_11_parse_elems(baseaddr, len - baselen, true, 1232 mgmt->bssid, NULL); 1233 mesh_process_plink_frame(sdata, mgmt, elems, rx_status); 1234 kfree(elems); 1235 } 1236