1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008, 2009 open80211s Ltd. 4 * Copyright (C) 2019, 2021-2026 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.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 u64 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; 99 u64 changed = 0; 100 int i; 101 bool short_slot = false; 102 103 sband = ieee80211_get_sband(sdata); 104 if (!sband) 105 return changed; 106 107 if (sband->band == NL80211_BAND_5GHZ) { 108 /* (IEEE 802.11-2012 19.4.5) */ 109 short_slot = true; 110 goto out; 111 } else if (sband->band != NL80211_BAND_2GHZ) { 112 goto out; 113 } 114 115 for (i = 0; i < sband->n_bitrates; i++) 116 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G) 117 erp_rates |= BIT(i); 118 119 if (!erp_rates) 120 goto out; 121 122 rcu_read_lock(); 123 list_for_each_entry_rcu(sta, &local->sta_list, list) { 124 if (sdata != sta->sdata || 125 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 126 continue; 127 128 short_slot = false; 129 if (erp_rates & sta->sta.deflink.supp_rates[sband->band]) 130 short_slot = true; 131 else 132 break; 133 } 134 rcu_read_unlock(); 135 136 out: 137 if (sdata->vif.bss_conf.use_short_slot != short_slot) { 138 sdata->vif.bss_conf.use_short_slot = short_slot; 139 changed = BSS_CHANGED_ERP_SLOT; 140 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n", 141 sdata->vif.addr, short_slot); 142 } 143 return changed; 144 } 145 146 /** 147 * mesh_set_ht_prot_mode - set correct HT protection mode 148 * @sdata: the (mesh) interface to handle 149 * 150 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT 151 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT 152 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is 153 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode 154 * is selected if all peers in our 20/40MHz MBSS support HT and at least one 155 * HT20 peer is present. Otherwise no-protection mode is selected. 156 * 157 * Returns: BSS_CHANGED_HT or 0 for no change 158 */ 159 static u64 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) 160 { 161 struct ieee80211_local *local = sdata->local; 162 struct sta_info *sta; 163 u16 ht_opmode; 164 bool non_ht_sta = false, ht20_sta = false; 165 166 switch (sdata->vif.bss_conf.chanreq.oper.width) { 167 case NL80211_CHAN_WIDTH_20_NOHT: 168 case NL80211_CHAN_WIDTH_5: 169 case NL80211_CHAN_WIDTH_10: 170 return 0; 171 default: 172 break; 173 } 174 175 rcu_read_lock(); 176 list_for_each_entry_rcu(sta, &local->sta_list, list) { 177 if (sdata != sta->sdata || 178 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 179 continue; 180 181 if (sta->sta.deflink.bandwidth > IEEE80211_STA_RX_BW_20) 182 continue; 183 184 if (!sta->sta.deflink.ht_cap.ht_supported) { 185 mpl_dbg(sdata, "nonHT sta (%pM) is present\n", 186 sta->sta.addr); 187 non_ht_sta = true; 188 break; 189 } 190 191 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); 192 ht20_sta = true; 193 } 194 rcu_read_unlock(); 195 196 if (non_ht_sta) 197 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; 198 else if (ht20_sta && 199 sdata->vif.bss_conf.chanreq.oper.width > NL80211_CHAN_WIDTH_20) 200 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; 201 else 202 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; 203 204 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) 205 return 0; 206 207 sdata->vif.bss_conf.ht_operation_mode = ht_opmode; 208 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; 209 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); 210 return BSS_CHANGED_HT; 211 } 212 213 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 214 struct sta_info *sta, 215 enum ieee80211_self_protected_actioncode action, 216 u8 *da, u16 llid, u16 plid, u16 reason) 217 { 218 int hdr_len = IEEE80211_MIN_ACTION_SIZE(self_prot); 219 struct ieee80211_local *local = sdata->local; 220 struct sk_buff *skb; 221 struct ieee80211_tx_info *info; 222 struct ieee80211_mgmt *mgmt; 223 bool include_plid = false; 224 u16 peering_proto = 0; 225 u8 *pos, ie_len = 4; 226 u8 ie_len_he_cap, ie_len_eht_cap; 227 int err = -ENOMEM; 228 229 ie_len_he_cap = ieee80211_ie_len_he_cap(sdata); 230 ie_len_eht_cap = ieee80211_ie_len_eht_cap(sdata); 231 skb = dev_alloc_skb(local->tx_headroom + 232 hdr_len + 233 2 + /* capability info */ 234 2 + /* AID */ 235 2 + 8 + /* supported rates */ 236 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 237 2 + sdata->u.mesh.mesh_id_len + 238 2 + sizeof(struct ieee80211_meshconf_ie) + 239 2 + sizeof(struct ieee80211_ht_cap) + 240 2 + sizeof(struct ieee80211_ht_operation) + 241 2 + sizeof(struct ieee80211_vht_cap) + 242 2 + sizeof(struct ieee80211_vht_operation) + 243 ie_len_he_cap + 244 2 + 1 + sizeof(struct ieee80211_he_operation) + 245 sizeof(struct ieee80211_he_6ghz_oper) + 246 2 + 1 + sizeof(struct ieee80211_he_6ghz_capa) + 247 ie_len_eht_cap + 248 2 + 1 + offsetof(struct ieee80211_eht_operation, optional) + 249 offsetof(struct ieee80211_eht_operation_info, optional) + 250 2 + 8 + /* peering IE */ 251 sdata->u.mesh.ie_len); 252 if (!skb) 253 return err; 254 info = IEEE80211_SKB_CB(skb); 255 skb_reserve(skb, local->tx_headroom); 256 mgmt = skb_put_zero(skb, hdr_len); 257 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 258 IEEE80211_STYPE_ACTION); 259 memcpy(mgmt->da, da, ETH_ALEN); 260 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 261 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 262 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; 263 mgmt->u.action.action_code = action; 264 265 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 266 struct ieee80211_supported_band *sband; 267 u32 basic_rates; 268 269 sband = ieee80211_get_sband(sdata); 270 if (!sband) { 271 err = -EINVAL; 272 goto free; 273 } 274 275 /* capability info */ 276 pos = skb_put_zero(skb, 2); 277 if (action == WLAN_SP_MESH_PEERING_CONFIRM) { 278 /* AID */ 279 pos = skb_put(skb, 2); 280 put_unaligned_le16(sta->sta.aid, pos); 281 } 282 283 basic_rates = sdata->vif.bss_conf.basic_rates; 284 285 if (ieee80211_put_srates_elem(skb, sband, basic_rates, 286 0, WLAN_EID_SUPP_RATES) || 287 ieee80211_put_srates_elem(skb, sband, basic_rates, 288 0, WLAN_EID_EXT_SUPP_RATES) || 289 mesh_add_rsn_ie(sdata, skb) || 290 mesh_add_meshid_ie(sdata, skb) || 291 mesh_add_meshconf_ie(sdata, skb)) 292 goto free; 293 } else { /* WLAN_SP_MESH_PEERING_CLOSE */ 294 info->flags |= IEEE80211_TX_CTL_NO_ACK; 295 if (mesh_add_meshid_ie(sdata, skb)) 296 goto free; 297 } 298 299 /* Add Mesh Peering Management element */ 300 switch (action) { 301 case WLAN_SP_MESH_PEERING_OPEN: 302 break; 303 case WLAN_SP_MESH_PEERING_CONFIRM: 304 ie_len += 2; 305 include_plid = true; 306 break; 307 case WLAN_SP_MESH_PEERING_CLOSE: 308 if (plid) { 309 ie_len += 2; 310 include_plid = true; 311 } 312 ie_len += 2; /* reason code */ 313 break; 314 default: 315 err = -EINVAL; 316 goto free; 317 } 318 319 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) 320 goto free; 321 322 pos = skb_put(skb, 2 + ie_len); 323 *pos++ = WLAN_EID_PEER_MGMT; 324 *pos++ = ie_len; 325 memcpy(pos, &peering_proto, 2); 326 pos += 2; 327 put_unaligned_le16(llid, pos); 328 pos += 2; 329 if (include_plid) { 330 put_unaligned_le16(plid, pos); 331 pos += 2; 332 } 333 if (action == WLAN_SP_MESH_PEERING_CLOSE) { 334 put_unaligned_le16(reason, pos); 335 pos += 2; 336 } 337 338 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 339 if (mesh_add_ht_cap_ie(sdata, skb) || 340 mesh_add_ht_oper_ie(sdata, skb) || 341 mesh_add_vht_cap_ie(sdata, skb) || 342 mesh_add_vht_oper_ie(sdata, skb) || 343 mesh_add_he_cap_ie(sdata, skb, ie_len_he_cap) || 344 mesh_add_he_oper_ie(sdata, skb) || 345 mesh_add_he_6ghz_cap_ie(sdata, skb) || 346 mesh_add_eht_cap_ie(sdata, skb, ie_len_eht_cap) || 347 mesh_add_eht_oper_ie(sdata, skb)) 348 goto free; 349 } 350 351 if (mesh_add_vendor_ies(sdata, skb)) 352 goto free; 353 354 ieee80211_tx_skb(sdata, skb); 355 return 0; 356 free: 357 kfree_skb(skb); 358 return err; 359 } 360 361 /** 362 * __mesh_plink_deactivate - deactivate mesh peer link 363 * 364 * @sta: mesh peer link to deactivate 365 * 366 * Mesh paths with this peer as next hop should be flushed 367 * by the caller outside of plink_lock. 368 * 369 * Returns: beacon changed flag if the beacon content changed. 370 * 371 * Locking: the caller must hold sta->mesh->plink_lock 372 */ 373 static u64 __mesh_plink_deactivate(struct sta_info *sta) 374 { 375 struct ieee80211_sub_if_data *sdata = sta->sdata; 376 u64 changed = 0; 377 378 lockdep_assert_held(&sta->mesh->plink_lock); 379 380 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 381 changed = mesh_plink_dec_estab_count(sdata); 382 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 383 384 ieee80211_mps_sta_status_update(sta); 385 changed |= ieee80211_mps_set_sta_local_pm(sta, 386 NL80211_MESH_POWER_UNKNOWN); 387 388 return changed; 389 } 390 391 /** 392 * mesh_plink_deactivate - deactivate mesh peer link 393 * 394 * @sta: mesh peer link to deactivate 395 * 396 * All mesh paths with this peer as next hop will be flushed 397 * 398 * Returns: beacon changed flag if the beacon content changed. 399 */ 400 u64 mesh_plink_deactivate(struct sta_info *sta) 401 { 402 struct ieee80211_sub_if_data *sdata = sta->sdata; 403 u64 changed; 404 405 spin_lock_bh(&sta->mesh->plink_lock); 406 changed = __mesh_plink_deactivate(sta); 407 408 if (!sdata->u.mesh.user_mpm) { 409 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED; 410 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE, 411 sta->sta.addr, sta->mesh->llid, 412 sta->mesh->plid, sta->mesh->reason); 413 } 414 spin_unlock_bh(&sta->mesh->plink_lock); 415 if (!sdata->u.mesh.user_mpm) 416 timer_delete_sync(&sta->mesh->plink_timer); 417 mesh_path_flush_by_nexthop(sta); 418 419 /* make sure no readers can access nexthop sta from here on */ 420 synchronize_net(); 421 422 return changed; 423 } 424 425 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 426 struct sta_info *sta, 427 struct ieee802_11_elems *elems) 428 { 429 struct ieee80211_local *local = sdata->local; 430 struct ieee80211_supported_band *sband; 431 u32 rates, changed = 0; 432 enum ieee80211_sta_rx_bandwidth bw = sta->sta.deflink.bandwidth; 433 434 sband = ieee80211_get_sband(sdata); 435 if (!sband) 436 return; 437 438 rates = ieee80211_sta_get_rates(sdata, elems, sband->band, NULL); 439 440 spin_lock_bh(&sta->mesh->plink_lock); 441 sta->deflink.rx_stats.last_rx = jiffies; 442 443 /* rates and capabilities don't change during peering */ 444 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB && 445 sta->mesh->processed_beacon) 446 goto out; 447 sta->mesh->processed_beacon = true; 448 449 if (sta->sta.deflink.supp_rates[sband->band] != rates) 450 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 451 sta->sta.deflink.supp_rates[sband->band] = rates; 452 453 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, &sband->ht_cap, 454 elems->ht_cap_elem, 455 &sta->deflink)) 456 changed |= IEEE80211_RC_BW_CHANGED; 457 458 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband, 459 &sband->vht_cap, 460 elems->vht_cap_elem, NULL, 461 &sta->deflink); 462 463 ieee80211_he_cap_ie_to_sta_he_cap(sdata, sband, elems->he_cap, 464 elems->he_cap_len, 465 elems->he_6ghz_capa, 466 &sta->deflink); 467 468 ieee80211_eht_cap_ie_to_sta_eht_cap(sdata, sband, elems->he_cap, 469 elems->he_cap_len, 470 elems->eht_cap, elems->eht_cap_len, 471 &sta->deflink); 472 473 if (bw != sta->sta.deflink.bandwidth) 474 changed |= IEEE80211_RC_BW_CHANGED; 475 476 /* HT peer is operating 20MHz-only */ 477 if (elems->ht_operation && 478 !(elems->ht_operation->ht_param & 479 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 480 if (sta->sta.deflink.bandwidth != IEEE80211_STA_RX_BW_20) 481 changed |= IEEE80211_RC_BW_CHANGED; 482 sta->sta.deflink.bandwidth = IEEE80211_STA_RX_BW_20; 483 } 484 485 /* FIXME: this check is wrong without SW rate control */ 486 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) 487 rate_control_rate_init(&sta->deflink); 488 else 489 rate_control_rate_update(local, sband, &sta->deflink, changed); 490 out: 491 spin_unlock_bh(&sta->mesh->plink_lock); 492 } 493 494 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) 495 { 496 struct sta_info *sta; 497 unsigned long *aid_map; 498 int aid; 499 500 aid_map = bitmap_zalloc(IEEE80211_MAX_AID + 1, GFP_KERNEL); 501 if (!aid_map) 502 return -ENOMEM; 503 504 /* reserve aid 0 for mcast indication */ 505 __set_bit(0, aid_map); 506 507 rcu_read_lock(); 508 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) 509 __set_bit(sta->sta.aid, aid_map); 510 rcu_read_unlock(); 511 512 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); 513 bitmap_free(aid_map); 514 515 if (aid > IEEE80211_MAX_AID) 516 return -ENOBUFS; 517 518 return aid; 519 } 520 521 static struct sta_info * 522 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 523 { 524 struct sta_info *sta; 525 int aid; 526 527 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 528 return NULL; 529 530 aid = mesh_allocate_aid(sdata); 531 if (aid < 0) 532 return NULL; 533 534 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 535 if (!sta) 536 return NULL; 537 538 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 539 sta->sta.wme = true; 540 sta->sta.aid = aid; 541 542 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 543 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 544 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 545 546 return sta; 547 } 548 549 static struct sta_info * 550 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 551 struct ieee802_11_elems *elems, 552 struct ieee80211_rx_status *rx_status) 553 { 554 struct sta_info *sta = NULL; 555 556 /* Userspace handles station allocation */ 557 if (sdata->u.mesh.user_mpm || 558 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) { 559 if (mesh_peer_accepts_plinks(elems) && 560 mesh_plink_availables(sdata)) { 561 int sig = 0; 562 563 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM)) 564 sig = rx_status->signal; 565 566 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 567 elems->ie_start, 568 elems->total_len, 569 sig, GFP_KERNEL); 570 } 571 } else 572 sta = __mesh_sta_info_alloc(sdata, addr); 573 574 return sta; 575 } 576 577 /* 578 * mesh_sta_info_get - return mesh sta info entry for @addr. 579 * 580 * @sdata: local meshif 581 * @addr: peer's address 582 * @elems: IEs from beacon or mesh peering frame. 583 * @rx_status: rx status for the frame for signal reporting 584 * 585 * Return existing or newly allocated sta_info under RCU read lock. 586 * (re)initialize with given IEs. 587 */ 588 static struct sta_info * 589 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 590 u8 *addr, struct ieee802_11_elems *elems, 591 struct ieee80211_rx_status *rx_status) __acquires(RCU) 592 { 593 struct sta_info *sta = NULL; 594 595 rcu_read_lock(); 596 sta = sta_info_get(sdata, addr); 597 if (sta) { 598 mesh_sta_info_init(sdata, sta, elems); 599 } else { 600 rcu_read_unlock(); 601 /* can't run atomic */ 602 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status); 603 if (!sta) { 604 rcu_read_lock(); 605 return NULL; 606 } 607 608 mesh_sta_info_init(sdata, sta, elems); 609 610 if (sta_info_insert_rcu(sta)) 611 return NULL; 612 } 613 614 return sta; 615 } 616 617 /* 618 * mesh_neighbour_update - update or initialize new mesh neighbor. 619 * 620 * @sdata: local meshif 621 * @addr: peer's address 622 * @elems: IEs from beacon or mesh peering frame 623 * @rx_status: rx status for the frame for signal reporting 624 * 625 * Initiates peering if appropriate. 626 */ 627 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 628 u8 *hw_addr, 629 struct ieee802_11_elems *elems, 630 struct ieee80211_rx_status *rx_status) 631 { 632 struct sta_info *sta; 633 u64 changed = 0; 634 635 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status); 636 if (!sta) 637 goto out; 638 639 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form & 640 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE; 641 642 if (mesh_peer_accepts_plinks(elems) && 643 sta->mesh->plink_state == NL80211_PLINK_LISTEN && 644 sdata->u.mesh.accepting_plinks && 645 sdata->u.mesh.mshcfg.auto_open_plinks && 646 rssi_threshold_check(sdata, sta)) 647 changed = mesh_plink_open(sta); 648 649 ieee80211_mps_frame_release(sta, elems); 650 out: 651 rcu_read_unlock(); 652 ieee80211_mbss_info_change_notify(sdata, changed); 653 } 654 655 void mesh_plink_timer(struct timer_list *t) 656 { 657 struct mesh_sta *mesh = timer_container_of(mesh, t, plink_timer); 658 struct sta_info *sta; 659 u16 reason = 0; 660 struct ieee80211_sub_if_data *sdata; 661 struct mesh_config *mshcfg; 662 enum ieee80211_self_protected_actioncode action = 0; 663 664 /* 665 * This STA is valid because sta_info_destroy() will 666 * timer_delete_sync() this timer after having made sure 667 * it cannot be re-added (by deleting the plink.) 668 */ 669 sta = mesh->plink_sta; 670 671 if (sta->sdata->local->quiescing) 672 return; 673 674 spin_lock_bh(&sta->mesh->plink_lock); 675 676 /* If a timer fires just before a state transition on another CPU, 677 * we may have already extended the timeout and changed state by the 678 * time we've acquired the lock and arrived here. In that case, 679 * skip this timer and wait for the new one. 680 */ 681 if (time_before(jiffies, sta->mesh->plink_timer.expires)) { 682 mpl_dbg(sta->sdata, 683 "Ignoring timer for %pM in state %s (timer adjusted)", 684 sta->sta.addr, mplstates[sta->mesh->plink_state]); 685 spin_unlock_bh(&sta->mesh->plink_lock); 686 return; 687 } 688 689 /* timer_delete() and handler may race when entering these states */ 690 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || 691 sta->mesh->plink_state == NL80211_PLINK_ESTAB) { 692 mpl_dbg(sta->sdata, 693 "Ignoring timer for %pM in state %s (timer deleted)", 694 sta->sta.addr, mplstates[sta->mesh->plink_state]); 695 spin_unlock_bh(&sta->mesh->plink_lock); 696 return; 697 } 698 699 mpl_dbg(sta->sdata, 700 "Mesh plink timer for %pM fired on state %s\n", 701 sta->sta.addr, mplstates[sta->mesh->plink_state]); 702 sdata = sta->sdata; 703 mshcfg = &sdata->u.mesh.mshcfg; 704 705 switch (sta->mesh->plink_state) { 706 case NL80211_PLINK_OPN_RCVD: 707 case NL80211_PLINK_OPN_SNT: 708 /* retry timer */ 709 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { 710 u32 rand; 711 mpl_dbg(sta->sdata, 712 "Mesh plink for %pM (retry, timeout): %d %d\n", 713 sta->sta.addr, sta->mesh->plink_retries, 714 sta->mesh->plink_timeout); 715 rand = get_random_u32(); 716 sta->mesh->plink_timeout = sta->mesh->plink_timeout + 717 rand % sta->mesh->plink_timeout; 718 ++sta->mesh->plink_retries; 719 mod_plink_timer(sta, sta->mesh->plink_timeout); 720 action = WLAN_SP_MESH_PEERING_OPEN; 721 break; 722 } 723 reason = WLAN_REASON_MESH_MAX_RETRIES; 724 fallthrough; 725 case NL80211_PLINK_CNF_RCVD: 726 /* confirm timer */ 727 if (!reason) 728 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 729 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 730 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 731 action = WLAN_SP_MESH_PEERING_CLOSE; 732 break; 733 case NL80211_PLINK_HOLDING: 734 /* holding timer */ 735 timer_delete(&sta->mesh->plink_timer); 736 mesh_plink_fsm_restart(sta); 737 break; 738 default: 739 break; 740 } 741 spin_unlock_bh(&sta->mesh->plink_lock); 742 if (action) 743 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 744 sta->mesh->llid, sta->mesh->plid, reason); 745 } 746 747 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 748 { 749 sta->mesh->plink_timeout = timeout; 750 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout)); 751 } 752 753 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 754 u16 llid) 755 { 756 struct ieee80211_local *local = sdata->local; 757 bool in_use = false; 758 struct sta_info *sta; 759 760 rcu_read_lock(); 761 list_for_each_entry_rcu(sta, &local->sta_list, list) { 762 if (sdata != sta->sdata) 763 continue; 764 765 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { 766 in_use = true; 767 break; 768 } 769 } 770 rcu_read_unlock(); 771 772 return in_use; 773 } 774 775 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 776 { 777 u16 llid; 778 779 do { 780 get_random_bytes(&llid, sizeof(llid)); 781 } while (llid_in_use(sdata, llid)); 782 783 return llid; 784 } 785 786 u64 mesh_plink_open(struct sta_info *sta) 787 { 788 struct ieee80211_sub_if_data *sdata = sta->sdata; 789 u64 changed; 790 791 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 792 return 0; 793 794 spin_lock_bh(&sta->mesh->plink_lock); 795 sta->mesh->llid = mesh_get_new_llid(sdata); 796 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && 797 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { 798 spin_unlock_bh(&sta->mesh->plink_lock); 799 return 0; 800 } 801 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; 802 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 803 spin_unlock_bh(&sta->mesh->plink_lock); 804 mpl_dbg(sdata, 805 "Mesh plink: starting establishment with %pM\n", 806 sta->sta.addr); 807 808 /* set the non-peer mode to active during peering */ 809 changed = ieee80211_mps_local_status_update(sdata); 810 811 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, 812 sta->sta.addr, sta->mesh->llid, 0, 0); 813 return changed; 814 } 815 816 u64 mesh_plink_block(struct sta_info *sta) 817 { 818 u64 changed; 819 820 spin_lock_bh(&sta->mesh->plink_lock); 821 changed = __mesh_plink_deactivate(sta); 822 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 823 spin_unlock_bh(&sta->mesh->plink_lock); 824 mesh_path_flush_by_nexthop(sta); 825 826 return changed; 827 } 828 829 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 830 struct sta_info *sta, 831 enum plink_event event) 832 { 833 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 834 u16 reason = (event == CLS_ACPT) ? 835 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 836 837 sta->mesh->reason = reason; 838 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 839 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 840 } 841 842 static u64 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 843 struct sta_info *sta) 844 { 845 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 846 u64 changed = 0; 847 848 timer_delete(&sta->mesh->plink_timer); 849 sta->mesh->plink_state = NL80211_PLINK_ESTAB; 850 changed |= mesh_plink_inc_estab_count(sdata); 851 changed |= mesh_set_ht_prot_mode(sdata); 852 changed |= mesh_set_short_slot_time(sdata); 853 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 854 ieee80211_mps_sta_status_update(sta); 855 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 856 return changed; 857 } 858 859 /** 860 * mesh_plink_fsm - step @sta MPM based on @event 861 * 862 * @sdata: interface 863 * @sta: mesh neighbor 864 * @event: peering event 865 * 866 * Return: changed MBSS flags 867 */ 868 static u64 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 869 struct sta_info *sta, enum plink_event event) 870 { 871 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 872 enum ieee80211_self_protected_actioncode action = 0; 873 u64 changed = 0; 874 bool flush = false; 875 876 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 877 mplstates[sta->mesh->plink_state], mplevents[event]); 878 879 spin_lock_bh(&sta->mesh->plink_lock); 880 switch (sta->mesh->plink_state) { 881 case NL80211_PLINK_LISTEN: 882 switch (event) { 883 case CLS_ACPT: 884 mesh_plink_fsm_restart(sta); 885 break; 886 case OPN_ACPT: 887 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 888 sta->mesh->llid = mesh_get_new_llid(sdata); 889 mesh_plink_timer_set(sta, 890 mshcfg->dot11MeshRetryTimeout); 891 892 /* set the non-peer mode to active during peering */ 893 changed |= ieee80211_mps_local_status_update(sdata); 894 action = WLAN_SP_MESH_PEERING_OPEN; 895 break; 896 default: 897 break; 898 } 899 break; 900 case NL80211_PLINK_OPN_SNT: 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 /* retry timer is left untouched */ 910 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 911 action = WLAN_SP_MESH_PEERING_CONFIRM; 912 break; 913 case CNF_ACPT: 914 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; 915 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 916 break; 917 default: 918 break; 919 } 920 break; 921 case NL80211_PLINK_OPN_RCVD: 922 switch (event) { 923 case OPN_RJCT: 924 case CNF_RJCT: 925 case CLS_ACPT: 926 mesh_plink_close(sdata, sta, event); 927 action = WLAN_SP_MESH_PEERING_CLOSE; 928 break; 929 case OPN_ACPT: 930 action = WLAN_SP_MESH_PEERING_CONFIRM; 931 break; 932 case CNF_ACPT: 933 changed |= mesh_plink_establish(sdata, sta); 934 break; 935 default: 936 break; 937 } 938 break; 939 case NL80211_PLINK_CNF_RCVD: 940 switch (event) { 941 case OPN_RJCT: 942 case CNF_RJCT: 943 case CLS_ACPT: 944 mesh_plink_close(sdata, sta, event); 945 action = WLAN_SP_MESH_PEERING_CLOSE; 946 break; 947 case OPN_ACPT: 948 changed |= mesh_plink_establish(sdata, sta); 949 action = WLAN_SP_MESH_PEERING_CONFIRM; 950 break; 951 default: 952 break; 953 } 954 break; 955 case NL80211_PLINK_ESTAB: 956 switch (event) { 957 case CLS_ACPT: 958 changed |= __mesh_plink_deactivate(sta); 959 changed |= mesh_set_ht_prot_mode(sdata); 960 changed |= mesh_set_short_slot_time(sdata); 961 mesh_plink_close(sdata, sta, event); 962 action = WLAN_SP_MESH_PEERING_CLOSE; 963 flush = true; 964 break; 965 case OPN_ACPT: 966 action = WLAN_SP_MESH_PEERING_CONFIRM; 967 break; 968 default: 969 break; 970 } 971 break; 972 case NL80211_PLINK_HOLDING: 973 switch (event) { 974 case CLS_ACPT: 975 timer_delete(&sta->mesh->plink_timer); 976 mesh_plink_fsm_restart(sta); 977 break; 978 case OPN_ACPT: 979 case CNF_ACPT: 980 case OPN_RJCT: 981 case CNF_RJCT: 982 action = WLAN_SP_MESH_PEERING_CLOSE; 983 break; 984 default: 985 break; 986 } 987 break; 988 default: 989 /* should not get here, PLINK_BLOCKED is dealt with at the 990 * beginning of the function 991 */ 992 break; 993 } 994 spin_unlock_bh(&sta->mesh->plink_lock); 995 if (flush) 996 mesh_path_flush_by_nexthop(sta); 997 if (action) { 998 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 999 sta->mesh->llid, sta->mesh->plid, 1000 sta->mesh->reason); 1001 1002 /* also send confirm in open case */ 1003 if (action == WLAN_SP_MESH_PEERING_OPEN) { 1004 mesh_plink_frame_tx(sdata, sta, 1005 WLAN_SP_MESH_PEERING_CONFIRM, 1006 sta->sta.addr, sta->mesh->llid, 1007 sta->mesh->plid, 0); 1008 } 1009 } 1010 1011 return changed; 1012 } 1013 1014 /* 1015 * mesh_plink_get_event - get correct MPM event 1016 * 1017 * @sdata: interface 1018 * @sta: peer, leave NULL if processing a frame from a new suitable peer 1019 * @elems: peering management IEs 1020 * @ftype: frame type 1021 * @llid: peer's peer link ID 1022 * @plid: peer's local link ID 1023 * 1024 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 1025 * an error. 1026 */ 1027 static enum plink_event 1028 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 1029 struct sta_info *sta, 1030 struct ieee802_11_elems *elems, 1031 enum ieee80211_self_protected_actioncode ftype, 1032 u16 llid, u16 plid) 1033 { 1034 enum plink_event event = PLINK_UNDEFINED; 1035 u8 ie_len = elems->peering_len; 1036 bool matches_local; 1037 1038 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 1039 mesh_matches_local(sdata, elems)); 1040 1041 /* deny open request from non-matching peer */ 1042 if (!matches_local && !sta) { 1043 event = OPN_RJCT; 1044 goto out; 1045 } 1046 1047 if (!sta) { 1048 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 1049 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 1050 goto out; 1051 } 1052 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 1053 if (!mesh_plink_free_count(sdata)) { 1054 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 1055 goto out; 1056 } 1057 1058 /* new matching peer */ 1059 event = OPN_ACPT; 1060 goto out; 1061 } else { 1062 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 1063 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 1064 goto out; 1065 } 1066 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) 1067 goto out; 1068 } 1069 1070 switch (ftype) { 1071 case WLAN_SP_MESH_PEERING_OPEN: 1072 if (!matches_local) 1073 event = OPN_RJCT; 1074 else if (!mesh_plink_free_count(sdata) || 1075 (sta->mesh->plid && sta->mesh->plid != plid)) 1076 event = OPN_IGNR; 1077 else 1078 event = OPN_ACPT; 1079 break; 1080 case WLAN_SP_MESH_PEERING_CONFIRM: 1081 if (!matches_local) 1082 event = CNF_RJCT; 1083 else if (!mesh_plink_free_count(sdata) || 1084 sta->mesh->llid != llid || 1085 (sta->mesh->plid && sta->mesh->plid != plid)) 1086 event = CNF_IGNR; 1087 else 1088 event = CNF_ACPT; 1089 break; 1090 case WLAN_SP_MESH_PEERING_CLOSE: 1091 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 1092 /* Do not check for llid or plid. This does not 1093 * follow the standard but since multiple plinks 1094 * per sta are not supported, it is necessary in 1095 * order to avoid a livelock when MP A sees an 1096 * establish peer link to MP B but MP B does not 1097 * see it. This can be caused by a timeout in 1098 * B's peer link establishment or B beign 1099 * restarted. 1100 */ 1101 event = CLS_ACPT; 1102 else if (sta->mesh->plid != plid) 1103 event = CLS_IGNR; 1104 else if (ie_len == 8 && sta->mesh->llid != llid) 1105 event = CLS_IGNR; 1106 else 1107 event = CLS_ACPT; 1108 break; 1109 default: 1110 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 1111 break; 1112 } 1113 1114 out: 1115 return event; 1116 } 1117 1118 static void 1119 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1120 struct ieee80211_mgmt *mgmt, 1121 struct ieee802_11_elems *elems, 1122 struct ieee80211_rx_status *rx_status) 1123 { 1124 1125 struct sta_info *sta; 1126 enum plink_event event; 1127 enum ieee80211_self_protected_actioncode ftype; 1128 u64 changed = 0; 1129 u8 ie_len = elems->peering_len; 1130 u16 plid, llid = 0; 1131 1132 if (!elems->peering) { 1133 mpl_dbg(sdata, 1134 "Mesh plink: missing necessary peer link ie\n"); 1135 return; 1136 } 1137 1138 if (elems->rsn_len && 1139 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1140 mpl_dbg(sdata, 1141 "Mesh plink: can't establish link with secure peer\n"); 1142 return; 1143 } 1144 1145 ftype = mgmt->u.action.action_code; 1146 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1147 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1148 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1149 && ie_len != 8)) { 1150 mpl_dbg(sdata, 1151 "Mesh plink: incorrect plink ie length %d %d\n", 1152 ftype, ie_len); 1153 return; 1154 } 1155 1156 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1157 (!elems->mesh_id || !elems->mesh_config)) { 1158 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1159 return; 1160 } 1161 /* Note the lines below are correct, the llid in the frame is the plid 1162 * from the point of view of this host. 1163 */ 1164 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1165 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1166 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1167 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1168 1169 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1170 rcu_read_lock(); 1171 1172 sta = sta_info_get(sdata, mgmt->sa); 1173 1174 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1175 !rssi_threshold_check(sdata, sta)) { 1176 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1177 mgmt->sa); 1178 goto unlock_rcu; 1179 } 1180 1181 /* Now we will figure out the appropriate event... */ 1182 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1183 1184 if (event == OPN_ACPT) { 1185 rcu_read_unlock(); 1186 /* allocate sta entry if necessary and update info */ 1187 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status); 1188 if (!sta) { 1189 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1190 goto unlock_rcu; 1191 } 1192 sta->mesh->plid = plid; 1193 } else if (!sta && event == OPN_RJCT) { 1194 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, 1195 mgmt->sa, 0, plid, 1196 WLAN_REASON_MESH_CONFIG); 1197 goto unlock_rcu; 1198 } else if (!sta || event == PLINK_UNDEFINED) { 1199 /* something went wrong */ 1200 goto unlock_rcu; 1201 } 1202 1203 if (event == CNF_ACPT) { 1204 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1205 if (!sta->mesh->plid) 1206 sta->mesh->plid = plid; 1207 1208 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); 1209 } 1210 1211 changed |= mesh_plink_fsm(sdata, sta, event); 1212 1213 unlock_rcu: 1214 rcu_read_unlock(); 1215 1216 if (changed) 1217 ieee80211_mbss_info_change_notify(sdata, changed); 1218 } 1219 1220 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1221 struct ieee80211_mgmt *mgmt, size_t len, 1222 struct ieee80211_rx_status *rx_status) 1223 { 1224 struct ieee802_11_elems *elems; 1225 size_t baselen; 1226 u8 *baseaddr; 1227 1228 /* need aux */ 1229 if (len < IEEE80211_MIN_ACTION_SIZE(self_prot) + 1) 1230 return; 1231 1232 if (sdata->u.mesh.user_mpm) 1233 /* userspace must register for these */ 1234 return; 1235 1236 if (is_multicast_ether_addr(mgmt->da)) { 1237 mpl_dbg(sdata, 1238 "Mesh plink: ignore frame from multicast address\n"); 1239 return; 1240 } 1241 1242 baseaddr = mgmt->u.action.self_prot.variable; 1243 baselen = mgmt->u.action.self_prot.variable - (u8 *)mgmt; 1244 if (mgmt->u.action.action_code == WLAN_SP_MESH_PEERING_CONFIRM) { 1245 baseaddr += 4; 1246 baselen += 4; 1247 1248 if (baselen > len) 1249 return; 1250 } 1251 elems = ieee802_11_parse_elems(baseaddr, len - baselen, 1252 IEEE80211_FTYPE_MGMT | 1253 IEEE80211_STYPE_ACTION, 1254 NULL); 1255 if (elems) { 1256 mesh_process_plink_frame(sdata, mgmt, elems, rx_status); 1257 kfree(elems); 1258 } 1259 } 1260