1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2008, 2009 open80211s Ltd. 4 * Copyright (C) 2019 Intel Corporation 5 * Author: Luis Carlos Cobo <luisca@cozybit.com> 6 */ 7 #include <linux/gfp.h> 8 #include <linux/kernel.h> 9 #include <linux/random.h> 10 #include <linux/rculist.h> 11 12 #include "ieee80211_i.h" 13 #include "rate.h" 14 #include "mesh.h" 15 16 #define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2) 17 #define PLINK_GET_LLID(p) (p + 2) 18 #define PLINK_GET_PLID(p) (p + 4) 19 20 #define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \ 21 jiffies + msecs_to_jiffies(t))) 22 23 enum plink_event { 24 PLINK_UNDEFINED, 25 OPN_ACPT, 26 OPN_RJCT, 27 OPN_IGNR, 28 CNF_ACPT, 29 CNF_RJCT, 30 CNF_IGNR, 31 CLS_ACPT, 32 CLS_IGNR 33 }; 34 35 static const char * const mplstates[] = { 36 [NL80211_PLINK_LISTEN] = "LISTEN", 37 [NL80211_PLINK_OPN_SNT] = "OPN-SNT", 38 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD", 39 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD", 40 [NL80211_PLINK_ESTAB] = "ESTAB", 41 [NL80211_PLINK_HOLDING] = "HOLDING", 42 [NL80211_PLINK_BLOCKED] = "BLOCKED" 43 }; 44 45 static const char * const mplevents[] = { 46 [PLINK_UNDEFINED] = "NONE", 47 [OPN_ACPT] = "OPN_ACPT", 48 [OPN_RJCT] = "OPN_RJCT", 49 [OPN_IGNR] = "OPN_IGNR", 50 [CNF_ACPT] = "CNF_ACPT", 51 [CNF_RJCT] = "CNF_RJCT", 52 [CNF_IGNR] = "CNF_IGNR", 53 [CLS_ACPT] = "CLS_ACPT", 54 [CLS_IGNR] = "CLS_IGNR" 55 }; 56 57 /* We only need a valid sta if user configured a minimum rssi_threshold. */ 58 static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata, 59 struct sta_info *sta) 60 { 61 s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold; 62 return rssi_threshold == 0 || 63 (sta && 64 (s8)-ewma_signal_read(&sta->rx_stats_avg.signal) > 65 rssi_threshold); 66 } 67 68 /** 69 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine 70 * 71 * @sta: mesh peer link to restart 72 * 73 * Locking: this function must be called holding sta->mesh->plink_lock 74 */ 75 static inline void mesh_plink_fsm_restart(struct sta_info *sta) 76 { 77 lockdep_assert_held(&sta->mesh->plink_lock); 78 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 79 sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0; 80 sta->mesh->plink_retries = 0; 81 } 82 83 /* 84 * mesh_set_short_slot_time - enable / disable ERP short slot time. 85 * 86 * The standard indirectly mandates mesh STAs to turn off short slot time by 87 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we 88 * can't be sneaky about it. Enable short slot time if all mesh STAs in the 89 * MBSS support ERP rates. 90 * 91 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change. 92 */ 93 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata) 94 { 95 struct ieee80211_local *local = sdata->local; 96 struct ieee80211_supported_band *sband; 97 struct sta_info *sta; 98 u32 erp_rates = 0, changed = 0; 99 int i; 100 bool short_slot = false; 101 102 sband = ieee80211_get_sband(sdata); 103 if (!sband) 104 return changed; 105 106 if (sband->band == NL80211_BAND_5GHZ) { 107 /* (IEEE 802.11-2012 19.4.5) */ 108 short_slot = true; 109 goto out; 110 } else if (sband->band != NL80211_BAND_2GHZ) { 111 goto out; 112 } 113 114 for (i = 0; i < sband->n_bitrates; i++) 115 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G) 116 erp_rates |= BIT(i); 117 118 if (!erp_rates) 119 goto out; 120 121 rcu_read_lock(); 122 list_for_each_entry_rcu(sta, &local->sta_list, list) { 123 if (sdata != sta->sdata || 124 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 125 continue; 126 127 short_slot = false; 128 if (erp_rates & sta->sta.supp_rates[sband->band]) 129 short_slot = true; 130 else 131 break; 132 } 133 rcu_read_unlock(); 134 135 out: 136 if (sdata->vif.bss_conf.use_short_slot != short_slot) { 137 sdata->vif.bss_conf.use_short_slot = short_slot; 138 changed = BSS_CHANGED_ERP_SLOT; 139 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n", 140 sdata->vif.addr, short_slot); 141 } 142 return changed; 143 } 144 145 /** 146 * mesh_set_ht_prot_mode - set correct HT protection mode 147 * 148 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT 149 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT 150 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is 151 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode 152 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one 153 * HT20 peer is present. Otherwise no-protection mode is selected. 154 */ 155 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) 156 { 157 struct ieee80211_local *local = sdata->local; 158 struct sta_info *sta; 159 u16 ht_opmode; 160 bool non_ht_sta = false, ht20_sta = false; 161 162 switch (sdata->vif.bss_conf.chandef.width) { 163 case NL80211_CHAN_WIDTH_20_NOHT: 164 case NL80211_CHAN_WIDTH_5: 165 case NL80211_CHAN_WIDTH_10: 166 return 0; 167 default: 168 break; 169 } 170 171 rcu_read_lock(); 172 list_for_each_entry_rcu(sta, &local->sta_list, list) { 173 if (sdata != sta->sdata || 174 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 175 continue; 176 177 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20) 178 continue; 179 180 if (!sta->sta.ht_cap.ht_supported) { 181 mpl_dbg(sdata, "nonHT sta (%pM) is present\n", 182 sta->sta.addr); 183 non_ht_sta = true; 184 break; 185 } 186 187 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); 188 ht20_sta = true; 189 } 190 rcu_read_unlock(); 191 192 if (non_ht_sta) 193 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; 194 else if (ht20_sta && 195 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20) 196 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; 197 else 198 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; 199 200 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) 201 return 0; 202 203 sdata->vif.bss_conf.ht_operation_mode = ht_opmode; 204 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; 205 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); 206 return BSS_CHANGED_HT; 207 } 208 209 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 210 struct sta_info *sta, 211 enum ieee80211_self_protected_actioncode action, 212 u8 *da, u16 llid, u16 plid, u16 reason) 213 { 214 struct ieee80211_local *local = sdata->local; 215 struct sk_buff *skb; 216 struct ieee80211_tx_info *info; 217 struct ieee80211_mgmt *mgmt; 218 bool include_plid = false; 219 u16 peering_proto = 0; 220 u8 *pos, ie_len = 4; 221 int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot); 222 int err = -ENOMEM; 223 224 skb = dev_alloc_skb(local->tx_headroom + 225 hdr_len + 226 2 + /* capability info */ 227 2 + /* AID */ 228 2 + 8 + /* supported rates */ 229 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 230 2 + sdata->u.mesh.mesh_id_len + 231 2 + sizeof(struct ieee80211_meshconf_ie) + 232 2 + sizeof(struct ieee80211_ht_cap) + 233 2 + sizeof(struct ieee80211_ht_operation) + 234 2 + sizeof(struct ieee80211_vht_cap) + 235 2 + sizeof(struct ieee80211_vht_operation) + 236 2 + 8 + /* peering IE */ 237 sdata->u.mesh.ie_len); 238 if (!skb) 239 return err; 240 info = IEEE80211_SKB_CB(skb); 241 skb_reserve(skb, local->tx_headroom); 242 mgmt = skb_put_zero(skb, hdr_len); 243 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 244 IEEE80211_STYPE_ACTION); 245 memcpy(mgmt->da, da, ETH_ALEN); 246 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 247 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 248 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; 249 mgmt->u.action.u.self_prot.action_code = action; 250 251 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 252 struct ieee80211_supported_band *sband; 253 enum nl80211_band band; 254 255 sband = ieee80211_get_sband(sdata); 256 if (!sband) { 257 err = -EINVAL; 258 goto free; 259 } 260 band = sband->band; 261 262 /* capability info */ 263 pos = skb_put_zero(skb, 2); 264 if (action == WLAN_SP_MESH_PEERING_CONFIRM) { 265 /* AID */ 266 pos = skb_put(skb, 2); 267 put_unaligned_le16(sta->sta.aid, pos); 268 } 269 if (ieee80211_add_srates_ie(sdata, skb, true, band) || 270 ieee80211_add_ext_srates_ie(sdata, skb, true, band) || 271 mesh_add_rsn_ie(sdata, skb) || 272 mesh_add_meshid_ie(sdata, skb) || 273 mesh_add_meshconf_ie(sdata, skb)) 274 goto free; 275 } else { /* WLAN_SP_MESH_PEERING_CLOSE */ 276 info->flags |= IEEE80211_TX_CTL_NO_ACK; 277 if (mesh_add_meshid_ie(sdata, skb)) 278 goto free; 279 } 280 281 /* Add Mesh Peering Management element */ 282 switch (action) { 283 case WLAN_SP_MESH_PEERING_OPEN: 284 break; 285 case WLAN_SP_MESH_PEERING_CONFIRM: 286 ie_len += 2; 287 include_plid = true; 288 break; 289 case WLAN_SP_MESH_PEERING_CLOSE: 290 if (plid) { 291 ie_len += 2; 292 include_plid = true; 293 } 294 ie_len += 2; /* reason code */ 295 break; 296 default: 297 err = -EINVAL; 298 goto free; 299 } 300 301 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) 302 goto free; 303 304 pos = skb_put(skb, 2 + ie_len); 305 *pos++ = WLAN_EID_PEER_MGMT; 306 *pos++ = ie_len; 307 memcpy(pos, &peering_proto, 2); 308 pos += 2; 309 put_unaligned_le16(llid, pos); 310 pos += 2; 311 if (include_plid) { 312 put_unaligned_le16(plid, pos); 313 pos += 2; 314 } 315 if (action == WLAN_SP_MESH_PEERING_CLOSE) { 316 put_unaligned_le16(reason, pos); 317 pos += 2; 318 } 319 320 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 321 if (mesh_add_ht_cap_ie(sdata, skb) || 322 mesh_add_ht_oper_ie(sdata, skb) || 323 mesh_add_vht_cap_ie(sdata, skb) || 324 mesh_add_vht_oper_ie(sdata, skb)) 325 goto free; 326 } 327 328 if (mesh_add_vendor_ies(sdata, skb)) 329 goto free; 330 331 ieee80211_tx_skb(sdata, skb); 332 return 0; 333 free: 334 kfree_skb(skb); 335 return err; 336 } 337 338 /** 339 * __mesh_plink_deactivate - deactivate mesh peer link 340 * 341 * @sta: mesh peer link to deactivate 342 * 343 * Mesh paths with this peer as next hop should be flushed 344 * by the caller outside of plink_lock. 345 * 346 * Returns beacon changed flag if the beacon content changed. 347 * 348 * Locking: the caller must hold sta->mesh->plink_lock 349 */ 350 static u32 __mesh_plink_deactivate(struct sta_info *sta) 351 { 352 struct ieee80211_sub_if_data *sdata = sta->sdata; 353 u32 changed = 0; 354 355 lockdep_assert_held(&sta->mesh->plink_lock); 356 357 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 358 changed = mesh_plink_dec_estab_count(sdata); 359 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 360 361 ieee80211_mps_sta_status_update(sta); 362 changed |= ieee80211_mps_set_sta_local_pm(sta, 363 NL80211_MESH_POWER_UNKNOWN); 364 365 return changed; 366 } 367 368 /** 369 * mesh_plink_deactivate - deactivate mesh peer link 370 * 371 * @sta: mesh peer link to deactivate 372 * 373 * All mesh paths with this peer as next hop will be flushed 374 */ 375 u32 mesh_plink_deactivate(struct sta_info *sta) 376 { 377 struct ieee80211_sub_if_data *sdata = sta->sdata; 378 u32 changed; 379 380 spin_lock_bh(&sta->mesh->plink_lock); 381 changed = __mesh_plink_deactivate(sta); 382 383 if (!sdata->u.mesh.user_mpm) { 384 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED; 385 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE, 386 sta->sta.addr, sta->mesh->llid, 387 sta->mesh->plid, sta->mesh->reason); 388 } 389 spin_unlock_bh(&sta->mesh->plink_lock); 390 if (!sdata->u.mesh.user_mpm) 391 del_timer_sync(&sta->mesh->plink_timer); 392 mesh_path_flush_by_nexthop(sta); 393 394 /* make sure no readers can access nexthop sta from here on */ 395 synchronize_net(); 396 397 return changed; 398 } 399 400 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 401 struct sta_info *sta, 402 struct ieee802_11_elems *elems) 403 { 404 struct ieee80211_local *local = sdata->local; 405 struct ieee80211_supported_band *sband; 406 u32 rates, basic_rates = 0, changed = 0; 407 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth; 408 409 sband = ieee80211_get_sband(sdata); 410 if (!sband) 411 return; 412 413 rates = ieee80211_sta_get_rates(sdata, elems, sband->band, 414 &basic_rates); 415 416 spin_lock_bh(&sta->mesh->plink_lock); 417 sta->rx_stats.last_rx = jiffies; 418 419 /* rates and capabilities don't change during peering */ 420 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB && 421 sta->mesh->processed_beacon) 422 goto out; 423 sta->mesh->processed_beacon = true; 424 425 if (sta->sta.supp_rates[sband->band] != rates) 426 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 427 sta->sta.supp_rates[sband->band] = rates; 428 429 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 430 elems->ht_cap_elem, sta)) 431 changed |= IEEE80211_RC_BW_CHANGED; 432 433 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband, 434 elems->vht_cap_elem, sta); 435 436 if (bw != sta->sta.bandwidth) 437 changed |= IEEE80211_RC_BW_CHANGED; 438 439 /* HT peer is operating 20MHz-only */ 440 if (elems->ht_operation && 441 !(elems->ht_operation->ht_param & 442 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 443 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) 444 changed |= IEEE80211_RC_BW_CHANGED; 445 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; 446 } 447 448 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) 449 rate_control_rate_init(sta); 450 else 451 rate_control_rate_update(local, sband, sta, changed); 452 out: 453 spin_unlock_bh(&sta->mesh->plink_lock); 454 } 455 456 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) 457 { 458 struct sta_info *sta; 459 unsigned long *aid_map; 460 int aid; 461 462 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1), 463 sizeof(*aid_map), GFP_KERNEL); 464 if (!aid_map) 465 return -ENOMEM; 466 467 /* reserve aid 0 for mcast indication */ 468 __set_bit(0, aid_map); 469 470 rcu_read_lock(); 471 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) 472 __set_bit(sta->sta.aid, aid_map); 473 rcu_read_unlock(); 474 475 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); 476 kfree(aid_map); 477 478 if (aid > IEEE80211_MAX_AID) 479 return -ENOBUFS; 480 481 return aid; 482 } 483 484 static struct sta_info * 485 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 486 { 487 struct sta_info *sta; 488 int aid; 489 490 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 491 return NULL; 492 493 aid = mesh_allocate_aid(sdata); 494 if (aid < 0) 495 return NULL; 496 497 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 498 if (!sta) 499 return NULL; 500 501 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 502 sta->sta.wme = true; 503 sta->sta.aid = aid; 504 505 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 506 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 507 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 508 509 return sta; 510 } 511 512 static struct sta_info * 513 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 514 struct ieee802_11_elems *elems, 515 struct ieee80211_rx_status *rx_status) 516 { 517 struct sta_info *sta = NULL; 518 519 /* Userspace handles station allocation */ 520 if (sdata->u.mesh.user_mpm || 521 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) { 522 if (mesh_peer_accepts_plinks(elems) && 523 mesh_plink_availables(sdata)) { 524 int sig = 0; 525 526 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM)) 527 sig = rx_status->signal; 528 529 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 530 elems->ie_start, 531 elems->total_len, 532 sig, GFP_KERNEL); 533 } 534 } else 535 sta = __mesh_sta_info_alloc(sdata, addr); 536 537 return sta; 538 } 539 540 /* 541 * mesh_sta_info_get - return mesh sta info entry for @addr. 542 * 543 * @sdata: local meshif 544 * @addr: peer's address 545 * @elems: IEs from beacon or mesh peering frame. 546 * @rx_status: rx status for the frame for signal reporting 547 * 548 * Return existing or newly allocated sta_info under RCU read lock. 549 * (re)initialize with given IEs. 550 */ 551 static struct sta_info * 552 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 553 u8 *addr, struct ieee802_11_elems *elems, 554 struct ieee80211_rx_status *rx_status) __acquires(RCU) 555 { 556 struct sta_info *sta = NULL; 557 558 rcu_read_lock(); 559 sta = sta_info_get(sdata, addr); 560 if (sta) { 561 mesh_sta_info_init(sdata, sta, elems); 562 } else { 563 rcu_read_unlock(); 564 /* can't run atomic */ 565 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status); 566 if (!sta) { 567 rcu_read_lock(); 568 return NULL; 569 } 570 571 mesh_sta_info_init(sdata, sta, elems); 572 573 if (sta_info_insert_rcu(sta)) 574 return NULL; 575 } 576 577 return sta; 578 } 579 580 /* 581 * mesh_neighbour_update - update or initialize new mesh neighbor. 582 * 583 * @sdata: local meshif 584 * @addr: peer's address 585 * @elems: IEs from beacon or mesh peering frame 586 * @rx_status: rx status for the frame for signal reporting 587 * 588 * Initiates peering if appropriate. 589 */ 590 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 591 u8 *hw_addr, 592 struct ieee802_11_elems *elems, 593 struct ieee80211_rx_status *rx_status) 594 { 595 struct sta_info *sta; 596 u32 changed = 0; 597 598 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status); 599 if (!sta) 600 goto out; 601 602 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form & 603 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE; 604 605 if (mesh_peer_accepts_plinks(elems) && 606 sta->mesh->plink_state == NL80211_PLINK_LISTEN && 607 sdata->u.mesh.accepting_plinks && 608 sdata->u.mesh.mshcfg.auto_open_plinks && 609 rssi_threshold_check(sdata, sta)) 610 changed = mesh_plink_open(sta); 611 612 ieee80211_mps_frame_release(sta, elems); 613 out: 614 rcu_read_unlock(); 615 ieee80211_mbss_info_change_notify(sdata, changed); 616 } 617 618 void mesh_plink_timer(struct timer_list *t) 619 { 620 struct mesh_sta *mesh = from_timer(mesh, t, plink_timer); 621 struct sta_info *sta; 622 u16 reason = 0; 623 struct ieee80211_sub_if_data *sdata; 624 struct mesh_config *mshcfg; 625 enum ieee80211_self_protected_actioncode action = 0; 626 627 /* 628 * This STA is valid because sta_info_destroy() will 629 * del_timer_sync() this timer after having made sure 630 * it cannot be readded (by deleting the plink.) 631 */ 632 sta = mesh->plink_sta; 633 634 if (sta->sdata->local->quiescing) 635 return; 636 637 spin_lock_bh(&sta->mesh->plink_lock); 638 639 /* If a timer fires just before a state transition on another CPU, 640 * we may have already extended the timeout and changed state by the 641 * time we've acquired the lock and arrived here. In that case, 642 * skip this timer and wait for the new one. 643 */ 644 if (time_before(jiffies, sta->mesh->plink_timer.expires)) { 645 mpl_dbg(sta->sdata, 646 "Ignoring timer for %pM in state %s (timer adjusted)", 647 sta->sta.addr, mplstates[sta->mesh->plink_state]); 648 spin_unlock_bh(&sta->mesh->plink_lock); 649 return; 650 } 651 652 /* del_timer() and handler may race when entering these states */ 653 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || 654 sta->mesh->plink_state == NL80211_PLINK_ESTAB) { 655 mpl_dbg(sta->sdata, 656 "Ignoring timer for %pM in state %s (timer deleted)", 657 sta->sta.addr, mplstates[sta->mesh->plink_state]); 658 spin_unlock_bh(&sta->mesh->plink_lock); 659 return; 660 } 661 662 mpl_dbg(sta->sdata, 663 "Mesh plink timer for %pM fired on state %s\n", 664 sta->sta.addr, mplstates[sta->mesh->plink_state]); 665 sdata = sta->sdata; 666 mshcfg = &sdata->u.mesh.mshcfg; 667 668 switch (sta->mesh->plink_state) { 669 case NL80211_PLINK_OPN_RCVD: 670 case NL80211_PLINK_OPN_SNT: 671 /* retry timer */ 672 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { 673 u32 rand; 674 mpl_dbg(sta->sdata, 675 "Mesh plink for %pM (retry, timeout): %d %d\n", 676 sta->sta.addr, sta->mesh->plink_retries, 677 sta->mesh->plink_timeout); 678 get_random_bytes(&rand, sizeof(u32)); 679 sta->mesh->plink_timeout = sta->mesh->plink_timeout + 680 rand % sta->mesh->plink_timeout; 681 ++sta->mesh->plink_retries; 682 mod_plink_timer(sta, sta->mesh->plink_timeout); 683 action = WLAN_SP_MESH_PEERING_OPEN; 684 break; 685 } 686 reason = WLAN_REASON_MESH_MAX_RETRIES; 687 /* fall through */ 688 case NL80211_PLINK_CNF_RCVD: 689 /* confirm timer */ 690 if (!reason) 691 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 692 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 693 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 694 action = WLAN_SP_MESH_PEERING_CLOSE; 695 break; 696 case NL80211_PLINK_HOLDING: 697 /* holding timer */ 698 del_timer(&sta->mesh->plink_timer); 699 mesh_plink_fsm_restart(sta); 700 break; 701 default: 702 break; 703 } 704 spin_unlock_bh(&sta->mesh->plink_lock); 705 if (action) 706 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 707 sta->mesh->llid, sta->mesh->plid, reason); 708 } 709 710 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 711 { 712 sta->mesh->plink_timeout = timeout; 713 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout)); 714 } 715 716 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 717 u16 llid) 718 { 719 struct ieee80211_local *local = sdata->local; 720 bool in_use = false; 721 struct sta_info *sta; 722 723 rcu_read_lock(); 724 list_for_each_entry_rcu(sta, &local->sta_list, list) { 725 if (sdata != sta->sdata) 726 continue; 727 728 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { 729 in_use = true; 730 break; 731 } 732 } 733 rcu_read_unlock(); 734 735 return in_use; 736 } 737 738 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 739 { 740 u16 llid; 741 742 do { 743 get_random_bytes(&llid, sizeof(llid)); 744 } while (llid_in_use(sdata, llid)); 745 746 return llid; 747 } 748 749 u32 mesh_plink_open(struct sta_info *sta) 750 { 751 struct ieee80211_sub_if_data *sdata = sta->sdata; 752 u32 changed; 753 754 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 755 return 0; 756 757 spin_lock_bh(&sta->mesh->plink_lock); 758 sta->mesh->llid = mesh_get_new_llid(sdata); 759 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && 760 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { 761 spin_unlock_bh(&sta->mesh->plink_lock); 762 return 0; 763 } 764 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; 765 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 766 spin_unlock_bh(&sta->mesh->plink_lock); 767 mpl_dbg(sdata, 768 "Mesh plink: starting establishment with %pM\n", 769 sta->sta.addr); 770 771 /* set the non-peer mode to active during peering */ 772 changed = ieee80211_mps_local_status_update(sdata); 773 774 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, 775 sta->sta.addr, sta->mesh->llid, 0, 0); 776 return changed; 777 } 778 779 u32 mesh_plink_block(struct sta_info *sta) 780 { 781 u32 changed; 782 783 spin_lock_bh(&sta->mesh->plink_lock); 784 changed = __mesh_plink_deactivate(sta); 785 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 786 spin_unlock_bh(&sta->mesh->plink_lock); 787 mesh_path_flush_by_nexthop(sta); 788 789 return changed; 790 } 791 792 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 793 struct sta_info *sta, 794 enum plink_event event) 795 { 796 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 797 u16 reason = (event == CLS_ACPT) ? 798 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 799 800 sta->mesh->reason = reason; 801 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 802 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 803 } 804 805 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 806 struct sta_info *sta) 807 { 808 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 809 u32 changed = 0; 810 811 del_timer(&sta->mesh->plink_timer); 812 sta->mesh->plink_state = NL80211_PLINK_ESTAB; 813 changed |= mesh_plink_inc_estab_count(sdata); 814 changed |= mesh_set_ht_prot_mode(sdata); 815 changed |= mesh_set_short_slot_time(sdata); 816 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 817 ieee80211_mps_sta_status_update(sta); 818 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 819 return changed; 820 } 821 822 /** 823 * mesh_plink_fsm - step @sta MPM based on @event 824 * 825 * @sdata: interface 826 * @sta: mesh neighbor 827 * @event: peering event 828 * 829 * Return: changed MBSS flags 830 */ 831 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 832 struct sta_info *sta, enum plink_event event) 833 { 834 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 835 enum ieee80211_self_protected_actioncode action = 0; 836 u32 changed = 0; 837 bool flush = false; 838 839 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 840 mplstates[sta->mesh->plink_state], mplevents[event]); 841 842 spin_lock_bh(&sta->mesh->plink_lock); 843 switch (sta->mesh->plink_state) { 844 case NL80211_PLINK_LISTEN: 845 switch (event) { 846 case CLS_ACPT: 847 mesh_plink_fsm_restart(sta); 848 break; 849 case OPN_ACPT: 850 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 851 sta->mesh->llid = mesh_get_new_llid(sdata); 852 mesh_plink_timer_set(sta, 853 mshcfg->dot11MeshRetryTimeout); 854 855 /* set the non-peer mode to active during peering */ 856 changed |= ieee80211_mps_local_status_update(sdata); 857 action = WLAN_SP_MESH_PEERING_OPEN; 858 break; 859 default: 860 break; 861 } 862 break; 863 case NL80211_PLINK_OPN_SNT: 864 switch (event) { 865 case OPN_RJCT: 866 case CNF_RJCT: 867 case CLS_ACPT: 868 mesh_plink_close(sdata, sta, event); 869 action = WLAN_SP_MESH_PEERING_CLOSE; 870 break; 871 case OPN_ACPT: 872 /* retry timer is left untouched */ 873 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 874 action = WLAN_SP_MESH_PEERING_CONFIRM; 875 break; 876 case CNF_ACPT: 877 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; 878 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 879 break; 880 default: 881 break; 882 } 883 break; 884 case NL80211_PLINK_OPN_RCVD: 885 switch (event) { 886 case OPN_RJCT: 887 case CNF_RJCT: 888 case CLS_ACPT: 889 mesh_plink_close(sdata, sta, event); 890 action = WLAN_SP_MESH_PEERING_CLOSE; 891 break; 892 case OPN_ACPT: 893 action = WLAN_SP_MESH_PEERING_CONFIRM; 894 break; 895 case CNF_ACPT: 896 changed |= mesh_plink_establish(sdata, sta); 897 break; 898 default: 899 break; 900 } 901 break; 902 case NL80211_PLINK_CNF_RCVD: 903 switch (event) { 904 case OPN_RJCT: 905 case CNF_RJCT: 906 case CLS_ACPT: 907 mesh_plink_close(sdata, sta, event); 908 action = WLAN_SP_MESH_PEERING_CLOSE; 909 break; 910 case OPN_ACPT: 911 changed |= mesh_plink_establish(sdata, sta); 912 action = WLAN_SP_MESH_PEERING_CONFIRM; 913 break; 914 default: 915 break; 916 } 917 break; 918 case NL80211_PLINK_ESTAB: 919 switch (event) { 920 case CLS_ACPT: 921 changed |= __mesh_plink_deactivate(sta); 922 changed |= mesh_set_ht_prot_mode(sdata); 923 changed |= mesh_set_short_slot_time(sdata); 924 mesh_plink_close(sdata, sta, event); 925 action = WLAN_SP_MESH_PEERING_CLOSE; 926 flush = true; 927 break; 928 case OPN_ACPT: 929 action = WLAN_SP_MESH_PEERING_CONFIRM; 930 break; 931 default: 932 break; 933 } 934 break; 935 case NL80211_PLINK_HOLDING: 936 switch (event) { 937 case CLS_ACPT: 938 del_timer(&sta->mesh->plink_timer); 939 mesh_plink_fsm_restart(sta); 940 break; 941 case OPN_ACPT: 942 case CNF_ACPT: 943 case OPN_RJCT: 944 case CNF_RJCT: 945 action = WLAN_SP_MESH_PEERING_CLOSE; 946 break; 947 default: 948 break; 949 } 950 break; 951 default: 952 /* should not get here, PLINK_BLOCKED is dealt with at the 953 * beginning of the function 954 */ 955 break; 956 } 957 spin_unlock_bh(&sta->mesh->plink_lock); 958 if (flush) 959 mesh_path_flush_by_nexthop(sta); 960 if (action) { 961 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 962 sta->mesh->llid, sta->mesh->plid, 963 sta->mesh->reason); 964 965 /* also send confirm in open case */ 966 if (action == WLAN_SP_MESH_PEERING_OPEN) { 967 mesh_plink_frame_tx(sdata, sta, 968 WLAN_SP_MESH_PEERING_CONFIRM, 969 sta->sta.addr, sta->mesh->llid, 970 sta->mesh->plid, 0); 971 } 972 } 973 974 return changed; 975 } 976 977 /* 978 * mesh_plink_get_event - get correct MPM event 979 * 980 * @sdata: interface 981 * @sta: peer, leave NULL if processing a frame from a new suitable peer 982 * @elems: peering management IEs 983 * @ftype: frame type 984 * @llid: peer's peer link ID 985 * @plid: peer's local link ID 986 * 987 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 988 * an error. 989 */ 990 static enum plink_event 991 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 992 struct sta_info *sta, 993 struct ieee802_11_elems *elems, 994 enum ieee80211_self_protected_actioncode ftype, 995 u16 llid, u16 plid) 996 { 997 enum plink_event event = PLINK_UNDEFINED; 998 u8 ie_len = elems->peering_len; 999 bool matches_local; 1000 1001 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 1002 mesh_matches_local(sdata, elems)); 1003 1004 /* deny open request from non-matching peer */ 1005 if (!matches_local && !sta) { 1006 event = OPN_RJCT; 1007 goto out; 1008 } 1009 1010 if (!sta) { 1011 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 1012 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 1013 goto out; 1014 } 1015 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 1016 if (!mesh_plink_free_count(sdata)) { 1017 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 1018 goto out; 1019 } 1020 1021 /* new matching peer */ 1022 event = OPN_ACPT; 1023 goto out; 1024 } else { 1025 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 1026 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 1027 goto out; 1028 } 1029 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) 1030 goto out; 1031 } 1032 1033 switch (ftype) { 1034 case WLAN_SP_MESH_PEERING_OPEN: 1035 if (!matches_local) 1036 event = OPN_RJCT; 1037 if (!mesh_plink_free_count(sdata) || 1038 (sta->mesh->plid && sta->mesh->plid != plid)) 1039 event = OPN_IGNR; 1040 else 1041 event = OPN_ACPT; 1042 break; 1043 case WLAN_SP_MESH_PEERING_CONFIRM: 1044 if (!matches_local) 1045 event = CNF_RJCT; 1046 if (!mesh_plink_free_count(sdata) || 1047 sta->mesh->llid != llid || 1048 (sta->mesh->plid && sta->mesh->plid != plid)) 1049 event = CNF_IGNR; 1050 else 1051 event = CNF_ACPT; 1052 break; 1053 case WLAN_SP_MESH_PEERING_CLOSE: 1054 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 1055 /* Do not check for llid or plid. This does not 1056 * follow the standard but since multiple plinks 1057 * per sta are not supported, it is necessary in 1058 * order to avoid a livelock when MP A sees an 1059 * establish peer link to MP B but MP B does not 1060 * see it. This can be caused by a timeout in 1061 * B's peer link establishment or B beign 1062 * restarted. 1063 */ 1064 event = CLS_ACPT; 1065 else if (sta->mesh->plid != plid) 1066 event = CLS_IGNR; 1067 else if (ie_len == 8 && sta->mesh->llid != llid) 1068 event = CLS_IGNR; 1069 else 1070 event = CLS_ACPT; 1071 break; 1072 default: 1073 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 1074 break; 1075 } 1076 1077 out: 1078 return event; 1079 } 1080 1081 static void 1082 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1083 struct ieee80211_mgmt *mgmt, 1084 struct ieee802_11_elems *elems, 1085 struct ieee80211_rx_status *rx_status) 1086 { 1087 1088 struct sta_info *sta; 1089 enum plink_event event; 1090 enum ieee80211_self_protected_actioncode ftype; 1091 u32 changed = 0; 1092 u8 ie_len = elems->peering_len; 1093 u16 plid, llid = 0; 1094 1095 if (!elems->peering) { 1096 mpl_dbg(sdata, 1097 "Mesh plink: missing necessary peer link ie\n"); 1098 return; 1099 } 1100 1101 if (elems->rsn_len && 1102 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1103 mpl_dbg(sdata, 1104 "Mesh plink: can't establish link with secure peer\n"); 1105 return; 1106 } 1107 1108 ftype = mgmt->u.action.u.self_prot.action_code; 1109 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1110 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1111 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1112 && ie_len != 8)) { 1113 mpl_dbg(sdata, 1114 "Mesh plink: incorrect plink ie length %d %d\n", 1115 ftype, ie_len); 1116 return; 1117 } 1118 1119 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1120 (!elems->mesh_id || !elems->mesh_config)) { 1121 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1122 return; 1123 } 1124 /* Note the lines below are correct, the llid in the frame is the plid 1125 * from the point of view of this host. 1126 */ 1127 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1128 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1129 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1130 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1131 1132 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1133 rcu_read_lock(); 1134 1135 sta = sta_info_get(sdata, mgmt->sa); 1136 1137 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1138 !rssi_threshold_check(sdata, sta)) { 1139 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1140 mgmt->sa); 1141 goto unlock_rcu; 1142 } 1143 1144 /* Now we will figure out the appropriate event... */ 1145 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1146 1147 if (event == OPN_ACPT) { 1148 rcu_read_unlock(); 1149 /* allocate sta entry if necessary and update info */ 1150 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status); 1151 if (!sta) { 1152 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1153 goto unlock_rcu; 1154 } 1155 sta->mesh->plid = plid; 1156 } else if (!sta && event == OPN_RJCT) { 1157 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, 1158 mgmt->sa, 0, plid, 1159 WLAN_REASON_MESH_CONFIG); 1160 goto unlock_rcu; 1161 } else if (!sta || event == PLINK_UNDEFINED) { 1162 /* something went wrong */ 1163 goto unlock_rcu; 1164 } 1165 1166 if (event == CNF_ACPT) { 1167 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1168 if (!sta->mesh->plid) 1169 sta->mesh->plid = plid; 1170 1171 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); 1172 } 1173 1174 changed |= mesh_plink_fsm(sdata, sta, event); 1175 1176 unlock_rcu: 1177 rcu_read_unlock(); 1178 1179 if (changed) 1180 ieee80211_mbss_info_change_notify(sdata, changed); 1181 } 1182 1183 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1184 struct ieee80211_mgmt *mgmt, size_t len, 1185 struct ieee80211_rx_status *rx_status) 1186 { 1187 struct ieee802_11_elems elems; 1188 size_t baselen; 1189 u8 *baseaddr; 1190 1191 /* need action_code, aux */ 1192 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1193 return; 1194 1195 if (sdata->u.mesh.user_mpm) 1196 /* userspace must register for these */ 1197 return; 1198 1199 if (is_multicast_ether_addr(mgmt->da)) { 1200 mpl_dbg(sdata, 1201 "Mesh plink: ignore frame from multicast address\n"); 1202 return; 1203 } 1204 1205 baseaddr = mgmt->u.action.u.self_prot.variable; 1206 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1207 if (mgmt->u.action.u.self_prot.action_code == 1208 WLAN_SP_MESH_PEERING_CONFIRM) { 1209 baseaddr += 4; 1210 baselen += 4; 1211 1212 if (baselen > len) 1213 return; 1214 } 1215 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems, 1216 mgmt->bssid, NULL); 1217 mesh_process_plink_frame(sdata, mgmt, &elems, rx_status); 1218 } 1219