1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008, 2009 open80211s Ltd. 4 * Copyright (C) 2019, 2021-2022 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->deflink.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.deflink.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.deflink.bandwidth > IEEE80211_STA_RX_BW_20) 179 continue; 180 181 if (!sta->sta.deflink.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.deflink.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->deflink.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.deflink.supp_rates[sband->band] != rates) 437 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 438 sta->sta.deflink.supp_rates[sband->band] = rates; 439 440 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 441 elems->ht_cap_elem, 442 &sta->deflink)) 443 changed |= IEEE80211_RC_BW_CHANGED; 444 445 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband, 446 elems->vht_cap_elem, 447 &sta->deflink); 448 449 ieee80211_he_cap_ie_to_sta_he_cap(sdata, sband, elems->he_cap, 450 elems->he_cap_len, 451 elems->he_6ghz_capa, 452 &sta->deflink); 453 454 if (bw != sta->sta.deflink.bandwidth) 455 changed |= IEEE80211_RC_BW_CHANGED; 456 457 /* HT peer is operating 20MHz-only */ 458 if (elems->ht_operation && 459 !(elems->ht_operation->ht_param & 460 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 461 if (sta->sta.deflink.bandwidth != IEEE80211_STA_RX_BW_20) 462 changed |= IEEE80211_RC_BW_CHANGED; 463 sta->sta.deflink.bandwidth = IEEE80211_STA_RX_BW_20; 464 } 465 466 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) 467 rate_control_rate_init(sta); 468 else 469 rate_control_rate_update(local, sband, sta, 0, changed); 470 out: 471 spin_unlock_bh(&sta->mesh->plink_lock); 472 } 473 474 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) 475 { 476 struct sta_info *sta; 477 unsigned long *aid_map; 478 int aid; 479 480 aid_map = bitmap_zalloc(IEEE80211_MAX_AID + 1, GFP_KERNEL); 481 if (!aid_map) 482 return -ENOMEM; 483 484 /* reserve aid 0 for mcast indication */ 485 __set_bit(0, aid_map); 486 487 rcu_read_lock(); 488 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) 489 __set_bit(sta->sta.aid, aid_map); 490 rcu_read_unlock(); 491 492 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); 493 bitmap_free(aid_map); 494 495 if (aid > IEEE80211_MAX_AID) 496 return -ENOBUFS; 497 498 return aid; 499 } 500 501 static struct sta_info * 502 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 503 { 504 struct sta_info *sta; 505 int aid; 506 507 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 508 return NULL; 509 510 aid = mesh_allocate_aid(sdata); 511 if (aid < 0) 512 return NULL; 513 514 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 515 if (!sta) 516 return NULL; 517 518 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 519 sta->sta.wme = true; 520 sta->sta.aid = aid; 521 522 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 523 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 524 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 525 526 return sta; 527 } 528 529 static struct sta_info * 530 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 531 struct ieee802_11_elems *elems, 532 struct ieee80211_rx_status *rx_status) 533 { 534 struct sta_info *sta = NULL; 535 536 /* Userspace handles station allocation */ 537 if (sdata->u.mesh.user_mpm || 538 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) { 539 if (mesh_peer_accepts_plinks(elems) && 540 mesh_plink_availables(sdata)) { 541 int sig = 0; 542 543 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM)) 544 sig = rx_status->signal; 545 546 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 547 elems->ie_start, 548 elems->total_len, 549 sig, GFP_KERNEL); 550 } 551 } else 552 sta = __mesh_sta_info_alloc(sdata, addr); 553 554 return sta; 555 } 556 557 /* 558 * mesh_sta_info_get - return mesh sta info entry for @addr. 559 * 560 * @sdata: local meshif 561 * @addr: peer's address 562 * @elems: IEs from beacon or mesh peering frame. 563 * @rx_status: rx status for the frame for signal reporting 564 * 565 * Return existing or newly allocated sta_info under RCU read lock. 566 * (re)initialize with given IEs. 567 */ 568 static struct sta_info * 569 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 570 u8 *addr, struct ieee802_11_elems *elems, 571 struct ieee80211_rx_status *rx_status) __acquires(RCU) 572 { 573 struct sta_info *sta = NULL; 574 575 rcu_read_lock(); 576 sta = sta_info_get(sdata, addr); 577 if (sta) { 578 mesh_sta_info_init(sdata, sta, elems); 579 } else { 580 rcu_read_unlock(); 581 /* can't run atomic */ 582 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status); 583 if (!sta) { 584 rcu_read_lock(); 585 return NULL; 586 } 587 588 mesh_sta_info_init(sdata, sta, elems); 589 590 if (sta_info_insert_rcu(sta)) 591 return NULL; 592 } 593 594 return sta; 595 } 596 597 /* 598 * mesh_neighbour_update - update or initialize new mesh neighbor. 599 * 600 * @sdata: local meshif 601 * @addr: peer's address 602 * @elems: IEs from beacon or mesh peering frame 603 * @rx_status: rx status for the frame for signal reporting 604 * 605 * Initiates peering if appropriate. 606 */ 607 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 608 u8 *hw_addr, 609 struct ieee802_11_elems *elems, 610 struct ieee80211_rx_status *rx_status) 611 { 612 struct sta_info *sta; 613 u32 changed = 0; 614 615 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status); 616 if (!sta) 617 goto out; 618 619 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form & 620 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE; 621 622 if (mesh_peer_accepts_plinks(elems) && 623 sta->mesh->plink_state == NL80211_PLINK_LISTEN && 624 sdata->u.mesh.accepting_plinks && 625 sdata->u.mesh.mshcfg.auto_open_plinks && 626 rssi_threshold_check(sdata, sta)) 627 changed = mesh_plink_open(sta); 628 629 ieee80211_mps_frame_release(sta, elems); 630 out: 631 rcu_read_unlock(); 632 ieee80211_mbss_info_change_notify(sdata, changed); 633 } 634 635 void mesh_plink_timer(struct timer_list *t) 636 { 637 struct mesh_sta *mesh = from_timer(mesh, t, plink_timer); 638 struct sta_info *sta; 639 u16 reason = 0; 640 struct ieee80211_sub_if_data *sdata; 641 struct mesh_config *mshcfg; 642 enum ieee80211_self_protected_actioncode action = 0; 643 644 /* 645 * This STA is valid because sta_info_destroy() will 646 * del_timer_sync() this timer after having made sure 647 * it cannot be readded (by deleting the plink.) 648 */ 649 sta = mesh->plink_sta; 650 651 if (sta->sdata->local->quiescing) 652 return; 653 654 spin_lock_bh(&sta->mesh->plink_lock); 655 656 /* If a timer fires just before a state transition on another CPU, 657 * we may have already extended the timeout and changed state by the 658 * time we've acquired the lock and arrived here. In that case, 659 * skip this timer and wait for the new one. 660 */ 661 if (time_before(jiffies, sta->mesh->plink_timer.expires)) { 662 mpl_dbg(sta->sdata, 663 "Ignoring timer for %pM in state %s (timer adjusted)", 664 sta->sta.addr, mplstates[sta->mesh->plink_state]); 665 spin_unlock_bh(&sta->mesh->plink_lock); 666 return; 667 } 668 669 /* del_timer() and handler may race when entering these states */ 670 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || 671 sta->mesh->plink_state == NL80211_PLINK_ESTAB) { 672 mpl_dbg(sta->sdata, 673 "Ignoring timer for %pM in state %s (timer deleted)", 674 sta->sta.addr, mplstates[sta->mesh->plink_state]); 675 spin_unlock_bh(&sta->mesh->plink_lock); 676 return; 677 } 678 679 mpl_dbg(sta->sdata, 680 "Mesh plink timer for %pM fired on state %s\n", 681 sta->sta.addr, mplstates[sta->mesh->plink_state]); 682 sdata = sta->sdata; 683 mshcfg = &sdata->u.mesh.mshcfg; 684 685 switch (sta->mesh->plink_state) { 686 case NL80211_PLINK_OPN_RCVD: 687 case NL80211_PLINK_OPN_SNT: 688 /* retry timer */ 689 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { 690 u32 rand; 691 mpl_dbg(sta->sdata, 692 "Mesh plink for %pM (retry, timeout): %d %d\n", 693 sta->sta.addr, sta->mesh->plink_retries, 694 sta->mesh->plink_timeout); 695 get_random_bytes(&rand, sizeof(u32)); 696 sta->mesh->plink_timeout = sta->mesh->plink_timeout + 697 rand % sta->mesh->plink_timeout; 698 ++sta->mesh->plink_retries; 699 mod_plink_timer(sta, sta->mesh->plink_timeout); 700 action = WLAN_SP_MESH_PEERING_OPEN; 701 break; 702 } 703 reason = WLAN_REASON_MESH_MAX_RETRIES; 704 fallthrough; 705 case NL80211_PLINK_CNF_RCVD: 706 /* confirm timer */ 707 if (!reason) 708 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 709 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 710 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 711 action = WLAN_SP_MESH_PEERING_CLOSE; 712 break; 713 case NL80211_PLINK_HOLDING: 714 /* holding timer */ 715 del_timer(&sta->mesh->plink_timer); 716 mesh_plink_fsm_restart(sta); 717 break; 718 default: 719 break; 720 } 721 spin_unlock_bh(&sta->mesh->plink_lock); 722 if (action) 723 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 724 sta->mesh->llid, sta->mesh->plid, reason); 725 } 726 727 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 728 { 729 sta->mesh->plink_timeout = timeout; 730 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout)); 731 } 732 733 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 734 u16 llid) 735 { 736 struct ieee80211_local *local = sdata->local; 737 bool in_use = false; 738 struct sta_info *sta; 739 740 rcu_read_lock(); 741 list_for_each_entry_rcu(sta, &local->sta_list, list) { 742 if (sdata != sta->sdata) 743 continue; 744 745 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { 746 in_use = true; 747 break; 748 } 749 } 750 rcu_read_unlock(); 751 752 return in_use; 753 } 754 755 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 756 { 757 u16 llid; 758 759 do { 760 get_random_bytes(&llid, sizeof(llid)); 761 } while (llid_in_use(sdata, llid)); 762 763 return llid; 764 } 765 766 u32 mesh_plink_open(struct sta_info *sta) 767 { 768 struct ieee80211_sub_if_data *sdata = sta->sdata; 769 u32 changed; 770 771 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 772 return 0; 773 774 spin_lock_bh(&sta->mesh->plink_lock); 775 sta->mesh->llid = mesh_get_new_llid(sdata); 776 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && 777 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { 778 spin_unlock_bh(&sta->mesh->plink_lock); 779 return 0; 780 } 781 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; 782 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 783 spin_unlock_bh(&sta->mesh->plink_lock); 784 mpl_dbg(sdata, 785 "Mesh plink: starting establishment with %pM\n", 786 sta->sta.addr); 787 788 /* set the non-peer mode to active during peering */ 789 changed = ieee80211_mps_local_status_update(sdata); 790 791 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, 792 sta->sta.addr, sta->mesh->llid, 0, 0); 793 return changed; 794 } 795 796 u32 mesh_plink_block(struct sta_info *sta) 797 { 798 u32 changed; 799 800 spin_lock_bh(&sta->mesh->plink_lock); 801 changed = __mesh_plink_deactivate(sta); 802 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 803 spin_unlock_bh(&sta->mesh->plink_lock); 804 mesh_path_flush_by_nexthop(sta); 805 806 return changed; 807 } 808 809 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 810 struct sta_info *sta, 811 enum plink_event event) 812 { 813 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 814 u16 reason = (event == CLS_ACPT) ? 815 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 816 817 sta->mesh->reason = reason; 818 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 819 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 820 } 821 822 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 823 struct sta_info *sta) 824 { 825 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 826 u32 changed = 0; 827 828 del_timer(&sta->mesh->plink_timer); 829 sta->mesh->plink_state = NL80211_PLINK_ESTAB; 830 changed |= mesh_plink_inc_estab_count(sdata); 831 changed |= mesh_set_ht_prot_mode(sdata); 832 changed |= mesh_set_short_slot_time(sdata); 833 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 834 ieee80211_mps_sta_status_update(sta); 835 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 836 return changed; 837 } 838 839 /** 840 * mesh_plink_fsm - step @sta MPM based on @event 841 * 842 * @sdata: interface 843 * @sta: mesh neighbor 844 * @event: peering event 845 * 846 * Return: changed MBSS flags 847 */ 848 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 849 struct sta_info *sta, enum plink_event event) 850 { 851 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 852 enum ieee80211_self_protected_actioncode action = 0; 853 u32 changed = 0; 854 bool flush = false; 855 856 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 857 mplstates[sta->mesh->plink_state], mplevents[event]); 858 859 spin_lock_bh(&sta->mesh->plink_lock); 860 switch (sta->mesh->plink_state) { 861 case NL80211_PLINK_LISTEN: 862 switch (event) { 863 case CLS_ACPT: 864 mesh_plink_fsm_restart(sta); 865 break; 866 case OPN_ACPT: 867 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 868 sta->mesh->llid = mesh_get_new_llid(sdata); 869 mesh_plink_timer_set(sta, 870 mshcfg->dot11MeshRetryTimeout); 871 872 /* set the non-peer mode to active during peering */ 873 changed |= ieee80211_mps_local_status_update(sdata); 874 action = WLAN_SP_MESH_PEERING_OPEN; 875 break; 876 default: 877 break; 878 } 879 break; 880 case NL80211_PLINK_OPN_SNT: 881 switch (event) { 882 case OPN_RJCT: 883 case CNF_RJCT: 884 case CLS_ACPT: 885 mesh_plink_close(sdata, sta, event); 886 action = WLAN_SP_MESH_PEERING_CLOSE; 887 break; 888 case OPN_ACPT: 889 /* retry timer is left untouched */ 890 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 891 action = WLAN_SP_MESH_PEERING_CONFIRM; 892 break; 893 case CNF_ACPT: 894 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; 895 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 896 break; 897 default: 898 break; 899 } 900 break; 901 case NL80211_PLINK_OPN_RCVD: 902 switch (event) { 903 case OPN_RJCT: 904 case CNF_RJCT: 905 case CLS_ACPT: 906 mesh_plink_close(sdata, sta, event); 907 action = WLAN_SP_MESH_PEERING_CLOSE; 908 break; 909 case OPN_ACPT: 910 action = WLAN_SP_MESH_PEERING_CONFIRM; 911 break; 912 case CNF_ACPT: 913 changed |= mesh_plink_establish(sdata, sta); 914 break; 915 default: 916 break; 917 } 918 break; 919 case NL80211_PLINK_CNF_RCVD: 920 switch (event) { 921 case OPN_RJCT: 922 case CNF_RJCT: 923 case CLS_ACPT: 924 mesh_plink_close(sdata, sta, event); 925 action = WLAN_SP_MESH_PEERING_CLOSE; 926 break; 927 case OPN_ACPT: 928 changed |= mesh_plink_establish(sdata, sta); 929 action = WLAN_SP_MESH_PEERING_CONFIRM; 930 break; 931 default: 932 break; 933 } 934 break; 935 case NL80211_PLINK_ESTAB: 936 switch (event) { 937 case CLS_ACPT: 938 changed |= __mesh_plink_deactivate(sta); 939 changed |= mesh_set_ht_prot_mode(sdata); 940 changed |= mesh_set_short_slot_time(sdata); 941 mesh_plink_close(sdata, sta, event); 942 action = WLAN_SP_MESH_PEERING_CLOSE; 943 flush = true; 944 break; 945 case OPN_ACPT: 946 action = WLAN_SP_MESH_PEERING_CONFIRM; 947 break; 948 default: 949 break; 950 } 951 break; 952 case NL80211_PLINK_HOLDING: 953 switch (event) { 954 case CLS_ACPT: 955 del_timer(&sta->mesh->plink_timer); 956 mesh_plink_fsm_restart(sta); 957 break; 958 case OPN_ACPT: 959 case CNF_ACPT: 960 case OPN_RJCT: 961 case CNF_RJCT: 962 action = WLAN_SP_MESH_PEERING_CLOSE; 963 break; 964 default: 965 break; 966 } 967 break; 968 default: 969 /* should not get here, PLINK_BLOCKED is dealt with at the 970 * beginning of the function 971 */ 972 break; 973 } 974 spin_unlock_bh(&sta->mesh->plink_lock); 975 if (flush) 976 mesh_path_flush_by_nexthop(sta); 977 if (action) { 978 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 979 sta->mesh->llid, sta->mesh->plid, 980 sta->mesh->reason); 981 982 /* also send confirm in open case */ 983 if (action == WLAN_SP_MESH_PEERING_OPEN) { 984 mesh_plink_frame_tx(sdata, sta, 985 WLAN_SP_MESH_PEERING_CONFIRM, 986 sta->sta.addr, sta->mesh->llid, 987 sta->mesh->plid, 0); 988 } 989 } 990 991 return changed; 992 } 993 994 /* 995 * mesh_plink_get_event - get correct MPM event 996 * 997 * @sdata: interface 998 * @sta: peer, leave NULL if processing a frame from a new suitable peer 999 * @elems: peering management IEs 1000 * @ftype: frame type 1001 * @llid: peer's peer link ID 1002 * @plid: peer's local link ID 1003 * 1004 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 1005 * an error. 1006 */ 1007 static enum plink_event 1008 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 1009 struct sta_info *sta, 1010 struct ieee802_11_elems *elems, 1011 enum ieee80211_self_protected_actioncode ftype, 1012 u16 llid, u16 plid) 1013 { 1014 enum plink_event event = PLINK_UNDEFINED; 1015 u8 ie_len = elems->peering_len; 1016 bool matches_local; 1017 1018 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 1019 mesh_matches_local(sdata, elems)); 1020 1021 /* deny open request from non-matching peer */ 1022 if (!matches_local && !sta) { 1023 event = OPN_RJCT; 1024 goto out; 1025 } 1026 1027 if (!sta) { 1028 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 1029 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 1030 goto out; 1031 } 1032 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 1033 if (!mesh_plink_free_count(sdata)) { 1034 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 1035 goto out; 1036 } 1037 1038 /* new matching peer */ 1039 event = OPN_ACPT; 1040 goto out; 1041 } else { 1042 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 1043 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 1044 goto out; 1045 } 1046 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) 1047 goto out; 1048 } 1049 1050 switch (ftype) { 1051 case WLAN_SP_MESH_PEERING_OPEN: 1052 if (!matches_local) 1053 event = OPN_RJCT; 1054 if (!mesh_plink_free_count(sdata) || 1055 (sta->mesh->plid && sta->mesh->plid != plid)) 1056 event = OPN_IGNR; 1057 else 1058 event = OPN_ACPT; 1059 break; 1060 case WLAN_SP_MESH_PEERING_CONFIRM: 1061 if (!matches_local) 1062 event = CNF_RJCT; 1063 if (!mesh_plink_free_count(sdata) || 1064 sta->mesh->llid != llid || 1065 (sta->mesh->plid && sta->mesh->plid != plid)) 1066 event = CNF_IGNR; 1067 else 1068 event = CNF_ACPT; 1069 break; 1070 case WLAN_SP_MESH_PEERING_CLOSE: 1071 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 1072 /* Do not check for llid or plid. This does not 1073 * follow the standard but since multiple plinks 1074 * per sta are not supported, it is necessary in 1075 * order to avoid a livelock when MP A sees an 1076 * establish peer link to MP B but MP B does not 1077 * see it. This can be caused by a timeout in 1078 * B's peer link establishment or B beign 1079 * restarted. 1080 */ 1081 event = CLS_ACPT; 1082 else if (sta->mesh->plid != plid) 1083 event = CLS_IGNR; 1084 else if (ie_len == 8 && sta->mesh->llid != llid) 1085 event = CLS_IGNR; 1086 else 1087 event = CLS_ACPT; 1088 break; 1089 default: 1090 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 1091 break; 1092 } 1093 1094 out: 1095 return event; 1096 } 1097 1098 static void 1099 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1100 struct ieee80211_mgmt *mgmt, 1101 struct ieee802_11_elems *elems, 1102 struct ieee80211_rx_status *rx_status) 1103 { 1104 1105 struct sta_info *sta; 1106 enum plink_event event; 1107 enum ieee80211_self_protected_actioncode ftype; 1108 u32 changed = 0; 1109 u8 ie_len = elems->peering_len; 1110 u16 plid, llid = 0; 1111 1112 if (!elems->peering) { 1113 mpl_dbg(sdata, 1114 "Mesh plink: missing necessary peer link ie\n"); 1115 return; 1116 } 1117 1118 if (elems->rsn_len && 1119 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1120 mpl_dbg(sdata, 1121 "Mesh plink: can't establish link with secure peer\n"); 1122 return; 1123 } 1124 1125 ftype = mgmt->u.action.u.self_prot.action_code; 1126 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1127 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1128 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1129 && ie_len != 8)) { 1130 mpl_dbg(sdata, 1131 "Mesh plink: incorrect plink ie length %d %d\n", 1132 ftype, ie_len); 1133 return; 1134 } 1135 1136 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1137 (!elems->mesh_id || !elems->mesh_config)) { 1138 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1139 return; 1140 } 1141 /* Note the lines below are correct, the llid in the frame is the plid 1142 * from the point of view of this host. 1143 */ 1144 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1145 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1146 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1147 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1148 1149 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1150 rcu_read_lock(); 1151 1152 sta = sta_info_get(sdata, mgmt->sa); 1153 1154 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1155 !rssi_threshold_check(sdata, sta)) { 1156 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1157 mgmt->sa); 1158 goto unlock_rcu; 1159 } 1160 1161 /* Now we will figure out the appropriate event... */ 1162 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1163 1164 if (event == OPN_ACPT) { 1165 rcu_read_unlock(); 1166 /* allocate sta entry if necessary and update info */ 1167 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status); 1168 if (!sta) { 1169 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1170 goto unlock_rcu; 1171 } 1172 sta->mesh->plid = plid; 1173 } else if (!sta && event == OPN_RJCT) { 1174 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, 1175 mgmt->sa, 0, plid, 1176 WLAN_REASON_MESH_CONFIG); 1177 goto unlock_rcu; 1178 } else if (!sta || event == PLINK_UNDEFINED) { 1179 /* something went wrong */ 1180 goto unlock_rcu; 1181 } 1182 1183 if (event == CNF_ACPT) { 1184 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1185 if (!sta->mesh->plid) 1186 sta->mesh->plid = plid; 1187 1188 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); 1189 } 1190 1191 changed |= mesh_plink_fsm(sdata, sta, event); 1192 1193 unlock_rcu: 1194 rcu_read_unlock(); 1195 1196 if (changed) 1197 ieee80211_mbss_info_change_notify(sdata, changed); 1198 } 1199 1200 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1201 struct ieee80211_mgmt *mgmt, size_t len, 1202 struct ieee80211_rx_status *rx_status) 1203 { 1204 struct ieee802_11_elems *elems; 1205 size_t baselen; 1206 u8 *baseaddr; 1207 1208 /* need action_code, aux */ 1209 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1210 return; 1211 1212 if (sdata->u.mesh.user_mpm) 1213 /* userspace must register for these */ 1214 return; 1215 1216 if (is_multicast_ether_addr(mgmt->da)) { 1217 mpl_dbg(sdata, 1218 "Mesh plink: ignore frame from multicast address\n"); 1219 return; 1220 } 1221 1222 baseaddr = mgmt->u.action.u.self_prot.variable; 1223 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1224 if (mgmt->u.action.u.self_prot.action_code == 1225 WLAN_SP_MESH_PEERING_CONFIRM) { 1226 baseaddr += 4; 1227 baselen += 4; 1228 1229 if (baselen > len) 1230 return; 1231 } 1232 elems = ieee802_11_parse_elems(baseaddr, len - baselen, true, NULL); 1233 mesh_process_plink_frame(sdata, mgmt, elems, rx_status); 1234 kfree(elems); 1235 } 1236