1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008, 2009 open80211s Ltd. 4 * Copyright (C) 2019, 2021-2024 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 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 struct ieee80211_local *local = sdata->local; 219 struct sk_buff *skb; 220 struct ieee80211_tx_info *info; 221 struct ieee80211_mgmt *mgmt; 222 bool include_plid = false; 223 u16 peering_proto = 0; 224 u8 *pos, ie_len = 4; 225 u8 ie_len_he_cap, ie_len_eht_cap; 226 int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot); 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.u.self_prot.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, 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 elems->vht_cap_elem, NULL, 460 &sta->deflink); 461 462 ieee80211_he_cap_ie_to_sta_he_cap(sdata, sband, elems->he_cap, 463 elems->he_cap_len, 464 elems->he_6ghz_capa, 465 &sta->deflink); 466 467 ieee80211_eht_cap_ie_to_sta_eht_cap(sdata, sband, elems->he_cap, 468 elems->he_cap_len, 469 elems->eht_cap, elems->eht_cap_len, 470 &sta->deflink); 471 472 if (bw != sta->sta.deflink.bandwidth) 473 changed |= IEEE80211_RC_BW_CHANGED; 474 475 /* HT peer is operating 20MHz-only */ 476 if (elems->ht_operation && 477 !(elems->ht_operation->ht_param & 478 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 479 if (sta->sta.deflink.bandwidth != IEEE80211_STA_RX_BW_20) 480 changed |= IEEE80211_RC_BW_CHANGED; 481 sta->sta.deflink.bandwidth = IEEE80211_STA_RX_BW_20; 482 } 483 484 /* FIXME: this check is wrong without SW rate control */ 485 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) 486 rate_control_rate_init(&sta->deflink); 487 else 488 rate_control_rate_update(local, sband, &sta->deflink, changed); 489 out: 490 spin_unlock_bh(&sta->mesh->plink_lock); 491 } 492 493 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) 494 { 495 struct sta_info *sta; 496 unsigned long *aid_map; 497 int aid; 498 499 aid_map = bitmap_zalloc(IEEE80211_MAX_AID + 1, GFP_KERNEL); 500 if (!aid_map) 501 return -ENOMEM; 502 503 /* reserve aid 0 for mcast indication */ 504 __set_bit(0, aid_map); 505 506 rcu_read_lock(); 507 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) 508 __set_bit(sta->sta.aid, aid_map); 509 rcu_read_unlock(); 510 511 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); 512 bitmap_free(aid_map); 513 514 if (aid > IEEE80211_MAX_AID) 515 return -ENOBUFS; 516 517 return aid; 518 } 519 520 static struct sta_info * 521 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 522 { 523 struct sta_info *sta; 524 int aid; 525 526 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 527 return NULL; 528 529 aid = mesh_allocate_aid(sdata); 530 if (aid < 0) 531 return NULL; 532 533 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 534 if (!sta) 535 return NULL; 536 537 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 538 sta->sta.wme = true; 539 sta->sta.aid = aid; 540 541 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 542 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 543 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 544 545 return sta; 546 } 547 548 static struct sta_info * 549 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 550 struct ieee802_11_elems *elems, 551 struct ieee80211_rx_status *rx_status) 552 { 553 struct sta_info *sta = NULL; 554 555 /* Userspace handles station allocation */ 556 if (sdata->u.mesh.user_mpm || 557 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) { 558 if (mesh_peer_accepts_plinks(elems) && 559 mesh_plink_availables(sdata)) { 560 int sig = 0; 561 562 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM)) 563 sig = rx_status->signal; 564 565 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 566 elems->ie_start, 567 elems->total_len, 568 sig, GFP_KERNEL); 569 } 570 } else 571 sta = __mesh_sta_info_alloc(sdata, addr); 572 573 return sta; 574 } 575 576 /* 577 * mesh_sta_info_get - return mesh sta info entry for @addr. 578 * 579 * @sdata: local meshif 580 * @addr: peer's address 581 * @elems: IEs from beacon or mesh peering frame. 582 * @rx_status: rx status for the frame for signal reporting 583 * 584 * Return existing or newly allocated sta_info under RCU read lock. 585 * (re)initialize with given IEs. 586 */ 587 static struct sta_info * 588 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 589 u8 *addr, struct ieee802_11_elems *elems, 590 struct ieee80211_rx_status *rx_status) __acquires(RCU) 591 { 592 struct sta_info *sta = NULL; 593 594 rcu_read_lock(); 595 sta = sta_info_get(sdata, addr); 596 if (sta) { 597 mesh_sta_info_init(sdata, sta, elems); 598 } else { 599 rcu_read_unlock(); 600 /* can't run atomic */ 601 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status); 602 if (!sta) { 603 rcu_read_lock(); 604 return NULL; 605 } 606 607 mesh_sta_info_init(sdata, sta, elems); 608 609 if (sta_info_insert_rcu(sta)) 610 return NULL; 611 } 612 613 return sta; 614 } 615 616 /* 617 * mesh_neighbour_update - update or initialize new mesh neighbor. 618 * 619 * @sdata: local meshif 620 * @addr: peer's address 621 * @elems: IEs from beacon or mesh peering frame 622 * @rx_status: rx status for the frame for signal reporting 623 * 624 * Initiates peering if appropriate. 625 */ 626 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 627 u8 *hw_addr, 628 struct ieee802_11_elems *elems, 629 struct ieee80211_rx_status *rx_status) 630 { 631 struct sta_info *sta; 632 u64 changed = 0; 633 634 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status); 635 if (!sta) 636 goto out; 637 638 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form & 639 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE; 640 641 if (mesh_peer_accepts_plinks(elems) && 642 sta->mesh->plink_state == NL80211_PLINK_LISTEN && 643 sdata->u.mesh.accepting_plinks && 644 sdata->u.mesh.mshcfg.auto_open_plinks && 645 rssi_threshold_check(sdata, sta)) 646 changed = mesh_plink_open(sta); 647 648 ieee80211_mps_frame_release(sta, elems); 649 out: 650 rcu_read_unlock(); 651 ieee80211_mbss_info_change_notify(sdata, changed); 652 } 653 654 void mesh_plink_timer(struct timer_list *t) 655 { 656 struct mesh_sta *mesh = timer_container_of(mesh, t, plink_timer); 657 struct sta_info *sta; 658 u16 reason = 0; 659 struct ieee80211_sub_if_data *sdata; 660 struct mesh_config *mshcfg; 661 enum ieee80211_self_protected_actioncode action = 0; 662 663 /* 664 * This STA is valid because sta_info_destroy() will 665 * timer_delete_sync() this timer after having made sure 666 * it cannot be re-added (by deleting the plink.) 667 */ 668 sta = mesh->plink_sta; 669 670 if (sta->sdata->local->quiescing) 671 return; 672 673 spin_lock_bh(&sta->mesh->plink_lock); 674 675 /* If a timer fires just before a state transition on another CPU, 676 * we may have already extended the timeout and changed state by the 677 * time we've acquired the lock and arrived here. In that case, 678 * skip this timer and wait for the new one. 679 */ 680 if (time_before(jiffies, sta->mesh->plink_timer.expires)) { 681 mpl_dbg(sta->sdata, 682 "Ignoring timer for %pM in state %s (timer adjusted)", 683 sta->sta.addr, mplstates[sta->mesh->plink_state]); 684 spin_unlock_bh(&sta->mesh->plink_lock); 685 return; 686 } 687 688 /* timer_delete() and handler may race when entering these states */ 689 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || 690 sta->mesh->plink_state == NL80211_PLINK_ESTAB) { 691 mpl_dbg(sta->sdata, 692 "Ignoring timer for %pM in state %s (timer deleted)", 693 sta->sta.addr, mplstates[sta->mesh->plink_state]); 694 spin_unlock_bh(&sta->mesh->plink_lock); 695 return; 696 } 697 698 mpl_dbg(sta->sdata, 699 "Mesh plink timer for %pM fired on state %s\n", 700 sta->sta.addr, mplstates[sta->mesh->plink_state]); 701 sdata = sta->sdata; 702 mshcfg = &sdata->u.mesh.mshcfg; 703 704 switch (sta->mesh->plink_state) { 705 case NL80211_PLINK_OPN_RCVD: 706 case NL80211_PLINK_OPN_SNT: 707 /* retry timer */ 708 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { 709 u32 rand; 710 mpl_dbg(sta->sdata, 711 "Mesh plink for %pM (retry, timeout): %d %d\n", 712 sta->sta.addr, sta->mesh->plink_retries, 713 sta->mesh->plink_timeout); 714 get_random_bytes(&rand, sizeof(u32)); 715 sta->mesh->plink_timeout = sta->mesh->plink_timeout + 716 rand % sta->mesh->plink_timeout; 717 ++sta->mesh->plink_retries; 718 mod_plink_timer(sta, sta->mesh->plink_timeout); 719 action = WLAN_SP_MESH_PEERING_OPEN; 720 break; 721 } 722 reason = WLAN_REASON_MESH_MAX_RETRIES; 723 fallthrough; 724 case NL80211_PLINK_CNF_RCVD: 725 /* confirm timer */ 726 if (!reason) 727 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 728 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 729 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 730 action = WLAN_SP_MESH_PEERING_CLOSE; 731 break; 732 case NL80211_PLINK_HOLDING: 733 /* holding timer */ 734 timer_delete(&sta->mesh->plink_timer); 735 mesh_plink_fsm_restart(sta); 736 break; 737 default: 738 break; 739 } 740 spin_unlock_bh(&sta->mesh->plink_lock); 741 if (action) 742 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 743 sta->mesh->llid, sta->mesh->plid, reason); 744 } 745 746 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 747 { 748 sta->mesh->plink_timeout = timeout; 749 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout)); 750 } 751 752 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 753 u16 llid) 754 { 755 struct ieee80211_local *local = sdata->local; 756 bool in_use = false; 757 struct sta_info *sta; 758 759 rcu_read_lock(); 760 list_for_each_entry_rcu(sta, &local->sta_list, list) { 761 if (sdata != sta->sdata) 762 continue; 763 764 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { 765 in_use = true; 766 break; 767 } 768 } 769 rcu_read_unlock(); 770 771 return in_use; 772 } 773 774 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 775 { 776 u16 llid; 777 778 do { 779 get_random_bytes(&llid, sizeof(llid)); 780 } while (llid_in_use(sdata, llid)); 781 782 return llid; 783 } 784 785 u64 mesh_plink_open(struct sta_info *sta) 786 { 787 struct ieee80211_sub_if_data *sdata = sta->sdata; 788 u64 changed; 789 790 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 791 return 0; 792 793 spin_lock_bh(&sta->mesh->plink_lock); 794 sta->mesh->llid = mesh_get_new_llid(sdata); 795 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && 796 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { 797 spin_unlock_bh(&sta->mesh->plink_lock); 798 return 0; 799 } 800 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; 801 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 802 spin_unlock_bh(&sta->mesh->plink_lock); 803 mpl_dbg(sdata, 804 "Mesh plink: starting establishment with %pM\n", 805 sta->sta.addr); 806 807 /* set the non-peer mode to active during peering */ 808 changed = ieee80211_mps_local_status_update(sdata); 809 810 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, 811 sta->sta.addr, sta->mesh->llid, 0, 0); 812 return changed; 813 } 814 815 u64 mesh_plink_block(struct sta_info *sta) 816 { 817 u64 changed; 818 819 spin_lock_bh(&sta->mesh->plink_lock); 820 changed = __mesh_plink_deactivate(sta); 821 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 822 spin_unlock_bh(&sta->mesh->plink_lock); 823 mesh_path_flush_by_nexthop(sta); 824 825 return changed; 826 } 827 828 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 829 struct sta_info *sta, 830 enum plink_event event) 831 { 832 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 833 u16 reason = (event == CLS_ACPT) ? 834 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 835 836 sta->mesh->reason = reason; 837 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 838 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 839 } 840 841 static u64 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 842 struct sta_info *sta) 843 { 844 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 845 u64 changed = 0; 846 847 timer_delete(&sta->mesh->plink_timer); 848 sta->mesh->plink_state = NL80211_PLINK_ESTAB; 849 changed |= mesh_plink_inc_estab_count(sdata); 850 changed |= mesh_set_ht_prot_mode(sdata); 851 changed |= mesh_set_short_slot_time(sdata); 852 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 853 ieee80211_mps_sta_status_update(sta); 854 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 855 return changed; 856 } 857 858 /** 859 * mesh_plink_fsm - step @sta MPM based on @event 860 * 861 * @sdata: interface 862 * @sta: mesh neighbor 863 * @event: peering event 864 * 865 * Return: changed MBSS flags 866 */ 867 static u64 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 868 struct sta_info *sta, enum plink_event event) 869 { 870 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 871 enum ieee80211_self_protected_actioncode action = 0; 872 u64 changed = 0; 873 bool flush = false; 874 875 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 876 mplstates[sta->mesh->plink_state], mplevents[event]); 877 878 spin_lock_bh(&sta->mesh->plink_lock); 879 switch (sta->mesh->plink_state) { 880 case NL80211_PLINK_LISTEN: 881 switch (event) { 882 case CLS_ACPT: 883 mesh_plink_fsm_restart(sta); 884 break; 885 case OPN_ACPT: 886 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 887 sta->mesh->llid = mesh_get_new_llid(sdata); 888 mesh_plink_timer_set(sta, 889 mshcfg->dot11MeshRetryTimeout); 890 891 /* set the non-peer mode to active during peering */ 892 changed |= ieee80211_mps_local_status_update(sdata); 893 action = WLAN_SP_MESH_PEERING_OPEN; 894 break; 895 default: 896 break; 897 } 898 break; 899 case NL80211_PLINK_OPN_SNT: 900 switch (event) { 901 case OPN_RJCT: 902 case CNF_RJCT: 903 case CLS_ACPT: 904 mesh_plink_close(sdata, sta, event); 905 action = WLAN_SP_MESH_PEERING_CLOSE; 906 break; 907 case OPN_ACPT: 908 /* retry timer is left untouched */ 909 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 910 action = WLAN_SP_MESH_PEERING_CONFIRM; 911 break; 912 case CNF_ACPT: 913 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; 914 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 915 break; 916 default: 917 break; 918 } 919 break; 920 case NL80211_PLINK_OPN_RCVD: 921 switch (event) { 922 case OPN_RJCT: 923 case CNF_RJCT: 924 case CLS_ACPT: 925 mesh_plink_close(sdata, sta, event); 926 action = WLAN_SP_MESH_PEERING_CLOSE; 927 break; 928 case OPN_ACPT: 929 action = WLAN_SP_MESH_PEERING_CONFIRM; 930 break; 931 case CNF_ACPT: 932 changed |= mesh_plink_establish(sdata, sta); 933 break; 934 default: 935 break; 936 } 937 break; 938 case NL80211_PLINK_CNF_RCVD: 939 switch (event) { 940 case OPN_RJCT: 941 case CNF_RJCT: 942 case CLS_ACPT: 943 mesh_plink_close(sdata, sta, event); 944 action = WLAN_SP_MESH_PEERING_CLOSE; 945 break; 946 case OPN_ACPT: 947 changed |= mesh_plink_establish(sdata, sta); 948 action = WLAN_SP_MESH_PEERING_CONFIRM; 949 break; 950 default: 951 break; 952 } 953 break; 954 case NL80211_PLINK_ESTAB: 955 switch (event) { 956 case CLS_ACPT: 957 changed |= __mesh_plink_deactivate(sta); 958 changed |= mesh_set_ht_prot_mode(sdata); 959 changed |= mesh_set_short_slot_time(sdata); 960 mesh_plink_close(sdata, sta, event); 961 action = WLAN_SP_MESH_PEERING_CLOSE; 962 flush = true; 963 break; 964 case OPN_ACPT: 965 action = WLAN_SP_MESH_PEERING_CONFIRM; 966 break; 967 default: 968 break; 969 } 970 break; 971 case NL80211_PLINK_HOLDING: 972 switch (event) { 973 case CLS_ACPT: 974 timer_delete(&sta->mesh->plink_timer); 975 mesh_plink_fsm_restart(sta); 976 break; 977 case OPN_ACPT: 978 case CNF_ACPT: 979 case OPN_RJCT: 980 case CNF_RJCT: 981 action = WLAN_SP_MESH_PEERING_CLOSE; 982 break; 983 default: 984 break; 985 } 986 break; 987 default: 988 /* should not get here, PLINK_BLOCKED is dealt with at the 989 * beginning of the function 990 */ 991 break; 992 } 993 spin_unlock_bh(&sta->mesh->plink_lock); 994 if (flush) 995 mesh_path_flush_by_nexthop(sta); 996 if (action) { 997 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 998 sta->mesh->llid, sta->mesh->plid, 999 sta->mesh->reason); 1000 1001 /* also send confirm in open case */ 1002 if (action == WLAN_SP_MESH_PEERING_OPEN) { 1003 mesh_plink_frame_tx(sdata, sta, 1004 WLAN_SP_MESH_PEERING_CONFIRM, 1005 sta->sta.addr, sta->mesh->llid, 1006 sta->mesh->plid, 0); 1007 } 1008 } 1009 1010 return changed; 1011 } 1012 1013 /* 1014 * mesh_plink_get_event - get correct MPM event 1015 * 1016 * @sdata: interface 1017 * @sta: peer, leave NULL if processing a frame from a new suitable peer 1018 * @elems: peering management IEs 1019 * @ftype: frame type 1020 * @llid: peer's peer link ID 1021 * @plid: peer's local link ID 1022 * 1023 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 1024 * an error. 1025 */ 1026 static enum plink_event 1027 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 1028 struct sta_info *sta, 1029 struct ieee802_11_elems *elems, 1030 enum ieee80211_self_protected_actioncode ftype, 1031 u16 llid, u16 plid) 1032 { 1033 enum plink_event event = PLINK_UNDEFINED; 1034 u8 ie_len = elems->peering_len; 1035 bool matches_local; 1036 1037 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 1038 mesh_matches_local(sdata, elems)); 1039 1040 /* deny open request from non-matching peer */ 1041 if (!matches_local && !sta) { 1042 event = OPN_RJCT; 1043 goto out; 1044 } 1045 1046 if (!sta) { 1047 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 1048 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 1049 goto out; 1050 } 1051 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 1052 if (!mesh_plink_free_count(sdata)) { 1053 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 1054 goto out; 1055 } 1056 1057 /* new matching peer */ 1058 event = OPN_ACPT; 1059 goto out; 1060 } else { 1061 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 1062 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 1063 goto out; 1064 } 1065 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) 1066 goto out; 1067 } 1068 1069 switch (ftype) { 1070 case WLAN_SP_MESH_PEERING_OPEN: 1071 if (!matches_local) 1072 event = OPN_RJCT; 1073 else if (!mesh_plink_free_count(sdata) || 1074 (sta->mesh->plid && sta->mesh->plid != plid)) 1075 event = OPN_IGNR; 1076 else 1077 event = OPN_ACPT; 1078 break; 1079 case WLAN_SP_MESH_PEERING_CONFIRM: 1080 if (!matches_local) 1081 event = CNF_RJCT; 1082 else if (!mesh_plink_free_count(sdata) || 1083 sta->mesh->llid != llid || 1084 (sta->mesh->plid && sta->mesh->plid != plid)) 1085 event = CNF_IGNR; 1086 else 1087 event = CNF_ACPT; 1088 break; 1089 case WLAN_SP_MESH_PEERING_CLOSE: 1090 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 1091 /* Do not check for llid or plid. This does not 1092 * follow the standard but since multiple plinks 1093 * per sta are not supported, it is necessary in 1094 * order to avoid a livelock when MP A sees an 1095 * establish peer link to MP B but MP B does not 1096 * see it. This can be caused by a timeout in 1097 * B's peer link establishment or B beign 1098 * restarted. 1099 */ 1100 event = CLS_ACPT; 1101 else if (sta->mesh->plid != plid) 1102 event = CLS_IGNR; 1103 else if (ie_len == 8 && sta->mesh->llid != llid) 1104 event = CLS_IGNR; 1105 else 1106 event = CLS_ACPT; 1107 break; 1108 default: 1109 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 1110 break; 1111 } 1112 1113 out: 1114 return event; 1115 } 1116 1117 static void 1118 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1119 struct ieee80211_mgmt *mgmt, 1120 struct ieee802_11_elems *elems, 1121 struct ieee80211_rx_status *rx_status) 1122 { 1123 1124 struct sta_info *sta; 1125 enum plink_event event; 1126 enum ieee80211_self_protected_actioncode ftype; 1127 u64 changed = 0; 1128 u8 ie_len = elems->peering_len; 1129 u16 plid, llid = 0; 1130 1131 if (!elems->peering) { 1132 mpl_dbg(sdata, 1133 "Mesh plink: missing necessary peer link ie\n"); 1134 return; 1135 } 1136 1137 if (elems->rsn_len && 1138 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1139 mpl_dbg(sdata, 1140 "Mesh plink: can't establish link with secure peer\n"); 1141 return; 1142 } 1143 1144 ftype = mgmt->u.action.u.self_prot.action_code; 1145 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1146 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1147 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1148 && ie_len != 8)) { 1149 mpl_dbg(sdata, 1150 "Mesh plink: incorrect plink ie length %d %d\n", 1151 ftype, ie_len); 1152 return; 1153 } 1154 1155 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1156 (!elems->mesh_id || !elems->mesh_config)) { 1157 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1158 return; 1159 } 1160 /* Note the lines below are correct, the llid in the frame is the plid 1161 * from the point of view of this host. 1162 */ 1163 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1164 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1165 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1166 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1167 1168 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1169 rcu_read_lock(); 1170 1171 sta = sta_info_get(sdata, mgmt->sa); 1172 1173 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1174 !rssi_threshold_check(sdata, sta)) { 1175 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1176 mgmt->sa); 1177 goto unlock_rcu; 1178 } 1179 1180 /* Now we will figure out the appropriate event... */ 1181 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1182 1183 if (event == OPN_ACPT) { 1184 rcu_read_unlock(); 1185 /* allocate sta entry if necessary and update info */ 1186 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status); 1187 if (!sta) { 1188 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1189 goto unlock_rcu; 1190 } 1191 sta->mesh->plid = plid; 1192 } else if (!sta && event == OPN_RJCT) { 1193 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, 1194 mgmt->sa, 0, plid, 1195 WLAN_REASON_MESH_CONFIG); 1196 goto unlock_rcu; 1197 } else if (!sta || event == PLINK_UNDEFINED) { 1198 /* something went wrong */ 1199 goto unlock_rcu; 1200 } 1201 1202 if (event == CNF_ACPT) { 1203 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1204 if (!sta->mesh->plid) 1205 sta->mesh->plid = plid; 1206 1207 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); 1208 } 1209 1210 changed |= mesh_plink_fsm(sdata, sta, event); 1211 1212 unlock_rcu: 1213 rcu_read_unlock(); 1214 1215 if (changed) 1216 ieee80211_mbss_info_change_notify(sdata, changed); 1217 } 1218 1219 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1220 struct ieee80211_mgmt *mgmt, size_t len, 1221 struct ieee80211_rx_status *rx_status) 1222 { 1223 struct ieee802_11_elems *elems; 1224 size_t baselen; 1225 u8 *baseaddr; 1226 1227 /* need action_code, aux */ 1228 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1229 return; 1230 1231 if (sdata->u.mesh.user_mpm) 1232 /* userspace must register for these */ 1233 return; 1234 1235 if (is_multicast_ether_addr(mgmt->da)) { 1236 mpl_dbg(sdata, 1237 "Mesh plink: ignore frame from multicast address\n"); 1238 return; 1239 } 1240 1241 baseaddr = mgmt->u.action.u.self_prot.variable; 1242 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1243 if (mgmt->u.action.u.self_prot.action_code == 1244 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, true, NULL); 1252 if (elems) { 1253 mesh_process_plink_frame(sdata, mgmt, elems, rx_status); 1254 kfree(elems); 1255 } 1256 } 1257