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, ie_len_eht_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 ie_len_eht_cap = ieee80211_ie_len_eht_cap(sdata, 229 NL80211_IFTYPE_MESH_POINT); 230 skb = dev_alloc_skb(local->tx_headroom + 231 hdr_len + 232 2 + /* capability info */ 233 2 + /* AID */ 234 2 + 8 + /* supported rates */ 235 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 236 2 + sdata->u.mesh.mesh_id_len + 237 2 + sizeof(struct ieee80211_meshconf_ie) + 238 2 + sizeof(struct ieee80211_ht_cap) + 239 2 + sizeof(struct ieee80211_ht_operation) + 240 2 + sizeof(struct ieee80211_vht_cap) + 241 2 + sizeof(struct ieee80211_vht_operation) + 242 ie_len_he_cap + 243 2 + 1 + sizeof(struct ieee80211_he_operation) + 244 sizeof(struct ieee80211_he_6ghz_oper) + 245 2 + 1 + sizeof(struct ieee80211_he_6ghz_capa) + 246 ie_len_eht_cap + 247 2 + 1 + offsetof(struct ieee80211_eht_operation, optional) + 248 offsetof(struct ieee80211_eht_operation_info, optional) + 249 2 + 8 + /* peering IE */ 250 sdata->u.mesh.ie_len); 251 if (!skb) 252 return err; 253 info = IEEE80211_SKB_CB(skb); 254 skb_reserve(skb, local->tx_headroom); 255 mgmt = skb_put_zero(skb, hdr_len); 256 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 257 IEEE80211_STYPE_ACTION); 258 memcpy(mgmt->da, da, ETH_ALEN); 259 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 260 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 261 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; 262 mgmt->u.action.u.self_prot.action_code = action; 263 264 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 265 struct ieee80211_supported_band *sband; 266 enum nl80211_band band; 267 268 sband = ieee80211_get_sband(sdata); 269 if (!sband) { 270 err = -EINVAL; 271 goto free; 272 } 273 band = sband->band; 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 if (ieee80211_add_srates_ie(sdata, skb, true, band) || 283 ieee80211_add_ext_srates_ie(sdata, skb, true, band) || 284 mesh_add_rsn_ie(sdata, skb) || 285 mesh_add_meshid_ie(sdata, skb) || 286 mesh_add_meshconf_ie(sdata, skb)) 287 goto free; 288 } else { /* WLAN_SP_MESH_PEERING_CLOSE */ 289 info->flags |= IEEE80211_TX_CTL_NO_ACK; 290 if (mesh_add_meshid_ie(sdata, skb)) 291 goto free; 292 } 293 294 /* Add Mesh Peering Management element */ 295 switch (action) { 296 case WLAN_SP_MESH_PEERING_OPEN: 297 break; 298 case WLAN_SP_MESH_PEERING_CONFIRM: 299 ie_len += 2; 300 include_plid = true; 301 break; 302 case WLAN_SP_MESH_PEERING_CLOSE: 303 if (plid) { 304 ie_len += 2; 305 include_plid = true; 306 } 307 ie_len += 2; /* reason code */ 308 break; 309 default: 310 err = -EINVAL; 311 goto free; 312 } 313 314 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) 315 goto free; 316 317 pos = skb_put(skb, 2 + ie_len); 318 *pos++ = WLAN_EID_PEER_MGMT; 319 *pos++ = ie_len; 320 memcpy(pos, &peering_proto, 2); 321 pos += 2; 322 put_unaligned_le16(llid, pos); 323 pos += 2; 324 if (include_plid) { 325 put_unaligned_le16(plid, pos); 326 pos += 2; 327 } 328 if (action == WLAN_SP_MESH_PEERING_CLOSE) { 329 put_unaligned_le16(reason, pos); 330 pos += 2; 331 } 332 333 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 334 if (mesh_add_ht_cap_ie(sdata, skb) || 335 mesh_add_ht_oper_ie(sdata, skb) || 336 mesh_add_vht_cap_ie(sdata, skb) || 337 mesh_add_vht_oper_ie(sdata, skb) || 338 mesh_add_he_cap_ie(sdata, skb, ie_len_he_cap) || 339 mesh_add_he_oper_ie(sdata, skb) || 340 mesh_add_he_6ghz_cap_ie(sdata, skb) || 341 mesh_add_eht_cap_ie(sdata, skb, ie_len_eht_cap) || 342 mesh_add_eht_oper_ie(sdata, skb)) 343 goto free; 344 } 345 346 if (mesh_add_vendor_ies(sdata, skb)) 347 goto free; 348 349 ieee80211_tx_skb(sdata, skb); 350 return 0; 351 free: 352 kfree_skb(skb); 353 return err; 354 } 355 356 /** 357 * __mesh_plink_deactivate - deactivate mesh peer link 358 * 359 * @sta: mesh peer link to deactivate 360 * 361 * Mesh paths with this peer as next hop should be flushed 362 * by the caller outside of plink_lock. 363 * 364 * Returns beacon changed flag if the beacon content changed. 365 * 366 * Locking: the caller must hold sta->mesh->plink_lock 367 */ 368 static u32 __mesh_plink_deactivate(struct sta_info *sta) 369 { 370 struct ieee80211_sub_if_data *sdata = sta->sdata; 371 u32 changed = 0; 372 373 lockdep_assert_held(&sta->mesh->plink_lock); 374 375 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 376 changed = mesh_plink_dec_estab_count(sdata); 377 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 378 379 ieee80211_mps_sta_status_update(sta); 380 changed |= ieee80211_mps_set_sta_local_pm(sta, 381 NL80211_MESH_POWER_UNKNOWN); 382 383 return changed; 384 } 385 386 /** 387 * mesh_plink_deactivate - deactivate mesh peer link 388 * 389 * @sta: mesh peer link to deactivate 390 * 391 * All mesh paths with this peer as next hop will be flushed 392 */ 393 u32 mesh_plink_deactivate(struct sta_info *sta) 394 { 395 struct ieee80211_sub_if_data *sdata = sta->sdata; 396 u32 changed; 397 398 spin_lock_bh(&sta->mesh->plink_lock); 399 changed = __mesh_plink_deactivate(sta); 400 401 if (!sdata->u.mesh.user_mpm) { 402 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED; 403 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE, 404 sta->sta.addr, sta->mesh->llid, 405 sta->mesh->plid, sta->mesh->reason); 406 } 407 spin_unlock_bh(&sta->mesh->plink_lock); 408 if (!sdata->u.mesh.user_mpm) 409 del_timer_sync(&sta->mesh->plink_timer); 410 mesh_path_flush_by_nexthop(sta); 411 412 /* make sure no readers can access nexthop sta from here on */ 413 synchronize_net(); 414 415 return changed; 416 } 417 418 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 419 struct sta_info *sta, 420 struct ieee802_11_elems *elems) 421 { 422 struct ieee80211_local *local = sdata->local; 423 struct ieee80211_supported_band *sband; 424 u32 rates, basic_rates = 0, changed = 0; 425 enum ieee80211_sta_rx_bandwidth bw = sta->sta.deflink.bandwidth; 426 427 sband = ieee80211_get_sband(sdata); 428 if (!sband) 429 return; 430 431 rates = ieee80211_sta_get_rates(sdata, elems, sband->band, 432 &basic_rates); 433 434 spin_lock_bh(&sta->mesh->plink_lock); 435 sta->deflink.rx_stats.last_rx = jiffies; 436 437 /* rates and capabilities don't change during peering */ 438 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB && 439 sta->mesh->processed_beacon) 440 goto out; 441 sta->mesh->processed_beacon = true; 442 443 if (sta->sta.deflink.supp_rates[sband->band] != rates) 444 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 445 sta->sta.deflink.supp_rates[sband->band] = rates; 446 447 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 448 elems->ht_cap_elem, 449 &sta->deflink)) 450 changed |= IEEE80211_RC_BW_CHANGED; 451 452 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband, 453 elems->vht_cap_elem, 454 &sta->deflink); 455 456 ieee80211_he_cap_ie_to_sta_he_cap(sdata, sband, elems->he_cap, 457 elems->he_cap_len, 458 elems->he_6ghz_capa, 459 &sta->deflink); 460 461 ieee80211_eht_cap_ie_to_sta_eht_cap(sdata, sband, elems->he_cap, 462 elems->he_cap_len, 463 elems->eht_cap, elems->eht_cap_len, 464 &sta->deflink); 465 466 if (bw != sta->sta.deflink.bandwidth) 467 changed |= IEEE80211_RC_BW_CHANGED; 468 469 /* HT peer is operating 20MHz-only */ 470 if (elems->ht_operation && 471 !(elems->ht_operation->ht_param & 472 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 473 if (sta->sta.deflink.bandwidth != IEEE80211_STA_RX_BW_20) 474 changed |= IEEE80211_RC_BW_CHANGED; 475 sta->sta.deflink.bandwidth = IEEE80211_STA_RX_BW_20; 476 } 477 478 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) 479 rate_control_rate_init(sta); 480 else 481 rate_control_rate_update(local, sband, sta, 0, changed); 482 out: 483 spin_unlock_bh(&sta->mesh->plink_lock); 484 } 485 486 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) 487 { 488 struct sta_info *sta; 489 unsigned long *aid_map; 490 int aid; 491 492 aid_map = bitmap_zalloc(IEEE80211_MAX_AID + 1, GFP_KERNEL); 493 if (!aid_map) 494 return -ENOMEM; 495 496 /* reserve aid 0 for mcast indication */ 497 __set_bit(0, aid_map); 498 499 rcu_read_lock(); 500 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) 501 __set_bit(sta->sta.aid, aid_map); 502 rcu_read_unlock(); 503 504 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); 505 bitmap_free(aid_map); 506 507 if (aid > IEEE80211_MAX_AID) 508 return -ENOBUFS; 509 510 return aid; 511 } 512 513 static struct sta_info * 514 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 515 { 516 struct sta_info *sta; 517 int aid; 518 519 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 520 return NULL; 521 522 aid = mesh_allocate_aid(sdata); 523 if (aid < 0) 524 return NULL; 525 526 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 527 if (!sta) 528 return NULL; 529 530 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 531 sta->sta.wme = true; 532 sta->sta.aid = aid; 533 534 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 535 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 536 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 537 538 return sta; 539 } 540 541 static struct sta_info * 542 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 543 struct ieee802_11_elems *elems, 544 struct ieee80211_rx_status *rx_status) 545 { 546 struct sta_info *sta = NULL; 547 548 /* Userspace handles station allocation */ 549 if (sdata->u.mesh.user_mpm || 550 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) { 551 if (mesh_peer_accepts_plinks(elems) && 552 mesh_plink_availables(sdata)) { 553 int sig = 0; 554 555 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM)) 556 sig = rx_status->signal; 557 558 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 559 elems->ie_start, 560 elems->total_len, 561 sig, GFP_KERNEL); 562 } 563 } else 564 sta = __mesh_sta_info_alloc(sdata, addr); 565 566 return sta; 567 } 568 569 /* 570 * mesh_sta_info_get - return mesh sta info entry for @addr. 571 * 572 * @sdata: local meshif 573 * @addr: peer's address 574 * @elems: IEs from beacon or mesh peering frame. 575 * @rx_status: rx status for the frame for signal reporting 576 * 577 * Return existing or newly allocated sta_info under RCU read lock. 578 * (re)initialize with given IEs. 579 */ 580 static struct sta_info * 581 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 582 u8 *addr, struct ieee802_11_elems *elems, 583 struct ieee80211_rx_status *rx_status) __acquires(RCU) 584 { 585 struct sta_info *sta = NULL; 586 587 rcu_read_lock(); 588 sta = sta_info_get(sdata, addr); 589 if (sta) { 590 mesh_sta_info_init(sdata, sta, elems); 591 } else { 592 rcu_read_unlock(); 593 /* can't run atomic */ 594 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status); 595 if (!sta) { 596 rcu_read_lock(); 597 return NULL; 598 } 599 600 mesh_sta_info_init(sdata, sta, elems); 601 602 if (sta_info_insert_rcu(sta)) 603 return NULL; 604 } 605 606 return sta; 607 } 608 609 /* 610 * mesh_neighbour_update - update or initialize new mesh neighbor. 611 * 612 * @sdata: local meshif 613 * @addr: peer's address 614 * @elems: IEs from beacon or mesh peering frame 615 * @rx_status: rx status for the frame for signal reporting 616 * 617 * Initiates peering if appropriate. 618 */ 619 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 620 u8 *hw_addr, 621 struct ieee802_11_elems *elems, 622 struct ieee80211_rx_status *rx_status) 623 { 624 struct sta_info *sta; 625 u32 changed = 0; 626 627 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status); 628 if (!sta) 629 goto out; 630 631 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form & 632 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE; 633 634 if (mesh_peer_accepts_plinks(elems) && 635 sta->mesh->plink_state == NL80211_PLINK_LISTEN && 636 sdata->u.mesh.accepting_plinks && 637 sdata->u.mesh.mshcfg.auto_open_plinks && 638 rssi_threshold_check(sdata, sta)) 639 changed = mesh_plink_open(sta); 640 641 ieee80211_mps_frame_release(sta, elems); 642 out: 643 rcu_read_unlock(); 644 ieee80211_mbss_info_change_notify(sdata, changed); 645 } 646 647 void mesh_plink_timer(struct timer_list *t) 648 { 649 struct mesh_sta *mesh = from_timer(mesh, t, plink_timer); 650 struct sta_info *sta; 651 u16 reason = 0; 652 struct ieee80211_sub_if_data *sdata; 653 struct mesh_config *mshcfg; 654 enum ieee80211_self_protected_actioncode action = 0; 655 656 /* 657 * This STA is valid because sta_info_destroy() will 658 * del_timer_sync() this timer after having made sure 659 * it cannot be readded (by deleting the plink.) 660 */ 661 sta = mesh->plink_sta; 662 663 if (sta->sdata->local->quiescing) 664 return; 665 666 spin_lock_bh(&sta->mesh->plink_lock); 667 668 /* If a timer fires just before a state transition on another CPU, 669 * we may have already extended the timeout and changed state by the 670 * time we've acquired the lock and arrived here. In that case, 671 * skip this timer and wait for the new one. 672 */ 673 if (time_before(jiffies, sta->mesh->plink_timer.expires)) { 674 mpl_dbg(sta->sdata, 675 "Ignoring timer for %pM in state %s (timer adjusted)", 676 sta->sta.addr, mplstates[sta->mesh->plink_state]); 677 spin_unlock_bh(&sta->mesh->plink_lock); 678 return; 679 } 680 681 /* del_timer() and handler may race when entering these states */ 682 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || 683 sta->mesh->plink_state == NL80211_PLINK_ESTAB) { 684 mpl_dbg(sta->sdata, 685 "Ignoring timer for %pM in state %s (timer deleted)", 686 sta->sta.addr, mplstates[sta->mesh->plink_state]); 687 spin_unlock_bh(&sta->mesh->plink_lock); 688 return; 689 } 690 691 mpl_dbg(sta->sdata, 692 "Mesh plink timer for %pM fired on state %s\n", 693 sta->sta.addr, mplstates[sta->mesh->plink_state]); 694 sdata = sta->sdata; 695 mshcfg = &sdata->u.mesh.mshcfg; 696 697 switch (sta->mesh->plink_state) { 698 case NL80211_PLINK_OPN_RCVD: 699 case NL80211_PLINK_OPN_SNT: 700 /* retry timer */ 701 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { 702 u32 rand; 703 mpl_dbg(sta->sdata, 704 "Mesh plink for %pM (retry, timeout): %d %d\n", 705 sta->sta.addr, sta->mesh->plink_retries, 706 sta->mesh->plink_timeout); 707 get_random_bytes(&rand, sizeof(u32)); 708 sta->mesh->plink_timeout = sta->mesh->plink_timeout + 709 rand % sta->mesh->plink_timeout; 710 ++sta->mesh->plink_retries; 711 mod_plink_timer(sta, sta->mesh->plink_timeout); 712 action = WLAN_SP_MESH_PEERING_OPEN; 713 break; 714 } 715 reason = WLAN_REASON_MESH_MAX_RETRIES; 716 fallthrough; 717 case NL80211_PLINK_CNF_RCVD: 718 /* confirm timer */ 719 if (!reason) 720 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 721 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 722 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 723 action = WLAN_SP_MESH_PEERING_CLOSE; 724 break; 725 case NL80211_PLINK_HOLDING: 726 /* holding timer */ 727 del_timer(&sta->mesh->plink_timer); 728 mesh_plink_fsm_restart(sta); 729 break; 730 default: 731 break; 732 } 733 spin_unlock_bh(&sta->mesh->plink_lock); 734 if (action) 735 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 736 sta->mesh->llid, sta->mesh->plid, reason); 737 } 738 739 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 740 { 741 sta->mesh->plink_timeout = timeout; 742 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout)); 743 } 744 745 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 746 u16 llid) 747 { 748 struct ieee80211_local *local = sdata->local; 749 bool in_use = false; 750 struct sta_info *sta; 751 752 rcu_read_lock(); 753 list_for_each_entry_rcu(sta, &local->sta_list, list) { 754 if (sdata != sta->sdata) 755 continue; 756 757 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { 758 in_use = true; 759 break; 760 } 761 } 762 rcu_read_unlock(); 763 764 return in_use; 765 } 766 767 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 768 { 769 u16 llid; 770 771 do { 772 get_random_bytes(&llid, sizeof(llid)); 773 } while (llid_in_use(sdata, llid)); 774 775 return llid; 776 } 777 778 u32 mesh_plink_open(struct sta_info *sta) 779 { 780 struct ieee80211_sub_if_data *sdata = sta->sdata; 781 u32 changed; 782 783 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 784 return 0; 785 786 spin_lock_bh(&sta->mesh->plink_lock); 787 sta->mesh->llid = mesh_get_new_llid(sdata); 788 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && 789 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { 790 spin_unlock_bh(&sta->mesh->plink_lock); 791 return 0; 792 } 793 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; 794 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 795 spin_unlock_bh(&sta->mesh->plink_lock); 796 mpl_dbg(sdata, 797 "Mesh plink: starting establishment with %pM\n", 798 sta->sta.addr); 799 800 /* set the non-peer mode to active during peering */ 801 changed = ieee80211_mps_local_status_update(sdata); 802 803 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, 804 sta->sta.addr, sta->mesh->llid, 0, 0); 805 return changed; 806 } 807 808 u32 mesh_plink_block(struct sta_info *sta) 809 { 810 u32 changed; 811 812 spin_lock_bh(&sta->mesh->plink_lock); 813 changed = __mesh_plink_deactivate(sta); 814 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 815 spin_unlock_bh(&sta->mesh->plink_lock); 816 mesh_path_flush_by_nexthop(sta); 817 818 return changed; 819 } 820 821 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 822 struct sta_info *sta, 823 enum plink_event event) 824 { 825 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 826 u16 reason = (event == CLS_ACPT) ? 827 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 828 829 sta->mesh->reason = reason; 830 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 831 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 832 } 833 834 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 835 struct sta_info *sta) 836 { 837 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 838 u32 changed = 0; 839 840 del_timer(&sta->mesh->plink_timer); 841 sta->mesh->plink_state = NL80211_PLINK_ESTAB; 842 changed |= mesh_plink_inc_estab_count(sdata); 843 changed |= mesh_set_ht_prot_mode(sdata); 844 changed |= mesh_set_short_slot_time(sdata); 845 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 846 ieee80211_mps_sta_status_update(sta); 847 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 848 return changed; 849 } 850 851 /** 852 * mesh_plink_fsm - step @sta MPM based on @event 853 * 854 * @sdata: interface 855 * @sta: mesh neighbor 856 * @event: peering event 857 * 858 * Return: changed MBSS flags 859 */ 860 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 861 struct sta_info *sta, enum plink_event event) 862 { 863 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 864 enum ieee80211_self_protected_actioncode action = 0; 865 u32 changed = 0; 866 bool flush = false; 867 868 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 869 mplstates[sta->mesh->plink_state], mplevents[event]); 870 871 spin_lock_bh(&sta->mesh->plink_lock); 872 switch (sta->mesh->plink_state) { 873 case NL80211_PLINK_LISTEN: 874 switch (event) { 875 case CLS_ACPT: 876 mesh_plink_fsm_restart(sta); 877 break; 878 case OPN_ACPT: 879 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 880 sta->mesh->llid = mesh_get_new_llid(sdata); 881 mesh_plink_timer_set(sta, 882 mshcfg->dot11MeshRetryTimeout); 883 884 /* set the non-peer mode to active during peering */ 885 changed |= ieee80211_mps_local_status_update(sdata); 886 action = WLAN_SP_MESH_PEERING_OPEN; 887 break; 888 default: 889 break; 890 } 891 break; 892 case NL80211_PLINK_OPN_SNT: 893 switch (event) { 894 case OPN_RJCT: 895 case CNF_RJCT: 896 case CLS_ACPT: 897 mesh_plink_close(sdata, sta, event); 898 action = WLAN_SP_MESH_PEERING_CLOSE; 899 break; 900 case OPN_ACPT: 901 /* retry timer is left untouched */ 902 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 903 action = WLAN_SP_MESH_PEERING_CONFIRM; 904 break; 905 case CNF_ACPT: 906 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; 907 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 908 break; 909 default: 910 break; 911 } 912 break; 913 case NL80211_PLINK_OPN_RCVD: 914 switch (event) { 915 case OPN_RJCT: 916 case CNF_RJCT: 917 case CLS_ACPT: 918 mesh_plink_close(sdata, sta, event); 919 action = WLAN_SP_MESH_PEERING_CLOSE; 920 break; 921 case OPN_ACPT: 922 action = WLAN_SP_MESH_PEERING_CONFIRM; 923 break; 924 case CNF_ACPT: 925 changed |= mesh_plink_establish(sdata, sta); 926 break; 927 default: 928 break; 929 } 930 break; 931 case NL80211_PLINK_CNF_RCVD: 932 switch (event) { 933 case OPN_RJCT: 934 case CNF_RJCT: 935 case CLS_ACPT: 936 mesh_plink_close(sdata, sta, event); 937 action = WLAN_SP_MESH_PEERING_CLOSE; 938 break; 939 case OPN_ACPT: 940 changed |= mesh_plink_establish(sdata, sta); 941 action = WLAN_SP_MESH_PEERING_CONFIRM; 942 break; 943 default: 944 break; 945 } 946 break; 947 case NL80211_PLINK_ESTAB: 948 switch (event) { 949 case CLS_ACPT: 950 changed |= __mesh_plink_deactivate(sta); 951 changed |= mesh_set_ht_prot_mode(sdata); 952 changed |= mesh_set_short_slot_time(sdata); 953 mesh_plink_close(sdata, sta, event); 954 action = WLAN_SP_MESH_PEERING_CLOSE; 955 flush = true; 956 break; 957 case OPN_ACPT: 958 action = WLAN_SP_MESH_PEERING_CONFIRM; 959 break; 960 default: 961 break; 962 } 963 break; 964 case NL80211_PLINK_HOLDING: 965 switch (event) { 966 case CLS_ACPT: 967 del_timer(&sta->mesh->plink_timer); 968 mesh_plink_fsm_restart(sta); 969 break; 970 case OPN_ACPT: 971 case CNF_ACPT: 972 case OPN_RJCT: 973 case CNF_RJCT: 974 action = WLAN_SP_MESH_PEERING_CLOSE; 975 break; 976 default: 977 break; 978 } 979 break; 980 default: 981 /* should not get here, PLINK_BLOCKED is dealt with at the 982 * beginning of the function 983 */ 984 break; 985 } 986 spin_unlock_bh(&sta->mesh->plink_lock); 987 if (flush) 988 mesh_path_flush_by_nexthop(sta); 989 if (action) { 990 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 991 sta->mesh->llid, sta->mesh->plid, 992 sta->mesh->reason); 993 994 /* also send confirm in open case */ 995 if (action == WLAN_SP_MESH_PEERING_OPEN) { 996 mesh_plink_frame_tx(sdata, sta, 997 WLAN_SP_MESH_PEERING_CONFIRM, 998 sta->sta.addr, sta->mesh->llid, 999 sta->mesh->plid, 0); 1000 } 1001 } 1002 1003 return changed; 1004 } 1005 1006 /* 1007 * mesh_plink_get_event - get correct MPM event 1008 * 1009 * @sdata: interface 1010 * @sta: peer, leave NULL if processing a frame from a new suitable peer 1011 * @elems: peering management IEs 1012 * @ftype: frame type 1013 * @llid: peer's peer link ID 1014 * @plid: peer's local link ID 1015 * 1016 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 1017 * an error. 1018 */ 1019 static enum plink_event 1020 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 1021 struct sta_info *sta, 1022 struct ieee802_11_elems *elems, 1023 enum ieee80211_self_protected_actioncode ftype, 1024 u16 llid, u16 plid) 1025 { 1026 enum plink_event event = PLINK_UNDEFINED; 1027 u8 ie_len = elems->peering_len; 1028 bool matches_local; 1029 1030 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 1031 mesh_matches_local(sdata, elems)); 1032 1033 /* deny open request from non-matching peer */ 1034 if (!matches_local && !sta) { 1035 event = OPN_RJCT; 1036 goto out; 1037 } 1038 1039 if (!sta) { 1040 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 1041 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 1042 goto out; 1043 } 1044 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 1045 if (!mesh_plink_free_count(sdata)) { 1046 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 1047 goto out; 1048 } 1049 1050 /* new matching peer */ 1051 event = OPN_ACPT; 1052 goto out; 1053 } else { 1054 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 1055 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 1056 goto out; 1057 } 1058 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) 1059 goto out; 1060 } 1061 1062 switch (ftype) { 1063 case WLAN_SP_MESH_PEERING_OPEN: 1064 if (!matches_local) 1065 event = OPN_RJCT; 1066 if (!mesh_plink_free_count(sdata) || 1067 (sta->mesh->plid && sta->mesh->plid != plid)) 1068 event = OPN_IGNR; 1069 else 1070 event = OPN_ACPT; 1071 break; 1072 case WLAN_SP_MESH_PEERING_CONFIRM: 1073 if (!matches_local) 1074 event = CNF_RJCT; 1075 if (!mesh_plink_free_count(sdata) || 1076 sta->mesh->llid != llid || 1077 (sta->mesh->plid && sta->mesh->plid != plid)) 1078 event = CNF_IGNR; 1079 else 1080 event = CNF_ACPT; 1081 break; 1082 case WLAN_SP_MESH_PEERING_CLOSE: 1083 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 1084 /* Do not check for llid or plid. This does not 1085 * follow the standard but since multiple plinks 1086 * per sta are not supported, it is necessary in 1087 * order to avoid a livelock when MP A sees an 1088 * establish peer link to MP B but MP B does not 1089 * see it. This can be caused by a timeout in 1090 * B's peer link establishment or B beign 1091 * restarted. 1092 */ 1093 event = CLS_ACPT; 1094 else if (sta->mesh->plid != plid) 1095 event = CLS_IGNR; 1096 else if (ie_len == 8 && sta->mesh->llid != llid) 1097 event = CLS_IGNR; 1098 else 1099 event = CLS_ACPT; 1100 break; 1101 default: 1102 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 1103 break; 1104 } 1105 1106 out: 1107 return event; 1108 } 1109 1110 static void 1111 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1112 struct ieee80211_mgmt *mgmt, 1113 struct ieee802_11_elems *elems, 1114 struct ieee80211_rx_status *rx_status) 1115 { 1116 1117 struct sta_info *sta; 1118 enum plink_event event; 1119 enum ieee80211_self_protected_actioncode ftype; 1120 u32 changed = 0; 1121 u8 ie_len = elems->peering_len; 1122 u16 plid, llid = 0; 1123 1124 if (!elems->peering) { 1125 mpl_dbg(sdata, 1126 "Mesh plink: missing necessary peer link ie\n"); 1127 return; 1128 } 1129 1130 if (elems->rsn_len && 1131 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1132 mpl_dbg(sdata, 1133 "Mesh plink: can't establish link with secure peer\n"); 1134 return; 1135 } 1136 1137 ftype = mgmt->u.action.u.self_prot.action_code; 1138 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1139 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1140 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1141 && ie_len != 8)) { 1142 mpl_dbg(sdata, 1143 "Mesh plink: incorrect plink ie length %d %d\n", 1144 ftype, ie_len); 1145 return; 1146 } 1147 1148 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1149 (!elems->mesh_id || !elems->mesh_config)) { 1150 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1151 return; 1152 } 1153 /* Note the lines below are correct, the llid in the frame is the plid 1154 * from the point of view of this host. 1155 */ 1156 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1157 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1158 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1159 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1160 1161 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1162 rcu_read_lock(); 1163 1164 sta = sta_info_get(sdata, mgmt->sa); 1165 1166 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1167 !rssi_threshold_check(sdata, sta)) { 1168 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1169 mgmt->sa); 1170 goto unlock_rcu; 1171 } 1172 1173 /* Now we will figure out the appropriate event... */ 1174 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1175 1176 if (event == OPN_ACPT) { 1177 rcu_read_unlock(); 1178 /* allocate sta entry if necessary and update info */ 1179 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status); 1180 if (!sta) { 1181 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1182 goto unlock_rcu; 1183 } 1184 sta->mesh->plid = plid; 1185 } else if (!sta && event == OPN_RJCT) { 1186 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, 1187 mgmt->sa, 0, plid, 1188 WLAN_REASON_MESH_CONFIG); 1189 goto unlock_rcu; 1190 } else if (!sta || event == PLINK_UNDEFINED) { 1191 /* something went wrong */ 1192 goto unlock_rcu; 1193 } 1194 1195 if (event == CNF_ACPT) { 1196 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1197 if (!sta->mesh->plid) 1198 sta->mesh->plid = plid; 1199 1200 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); 1201 } 1202 1203 changed |= mesh_plink_fsm(sdata, sta, event); 1204 1205 unlock_rcu: 1206 rcu_read_unlock(); 1207 1208 if (changed) 1209 ieee80211_mbss_info_change_notify(sdata, changed); 1210 } 1211 1212 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1213 struct ieee80211_mgmt *mgmt, size_t len, 1214 struct ieee80211_rx_status *rx_status) 1215 { 1216 struct ieee802_11_elems *elems; 1217 size_t baselen; 1218 u8 *baseaddr; 1219 1220 /* need action_code, aux */ 1221 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1222 return; 1223 1224 if (sdata->u.mesh.user_mpm) 1225 /* userspace must register for these */ 1226 return; 1227 1228 if (is_multicast_ether_addr(mgmt->da)) { 1229 mpl_dbg(sdata, 1230 "Mesh plink: ignore frame from multicast address\n"); 1231 return; 1232 } 1233 1234 baseaddr = mgmt->u.action.u.self_prot.variable; 1235 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1236 if (mgmt->u.action.u.self_prot.action_code == 1237 WLAN_SP_MESH_PEERING_CONFIRM) { 1238 baseaddr += 4; 1239 baselen += 4; 1240 1241 if (baselen > len) 1242 return; 1243 } 1244 elems = ieee802_11_parse_elems(baseaddr, len - baselen, true, NULL); 1245 mesh_process_plink_frame(sdata, mgmt, elems, rx_status); 1246 kfree(elems); 1247 } 1248