1 /* 2 * Copyright (c) 2008, 2009 open80211s Ltd. 3 * Author: Luis Carlos Cobo <luisca@cozybit.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 */ 9 #include <linux/gfp.h> 10 #include <linux/kernel.h> 11 #include <linux/random.h> 12 #include <linux/rculist.h> 13 14 #include "ieee80211_i.h" 15 #include "rate.h" 16 #include "mesh.h" 17 18 #define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2) 19 #define PLINK_GET_LLID(p) (p + 2) 20 #define PLINK_GET_PLID(p) (p + 4) 21 22 #define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \ 23 jiffies + msecs_to_jiffies(t))) 24 25 enum plink_event { 26 PLINK_UNDEFINED, 27 OPN_ACPT, 28 OPN_RJCT, 29 OPN_IGNR, 30 CNF_ACPT, 31 CNF_RJCT, 32 CNF_IGNR, 33 CLS_ACPT, 34 CLS_IGNR 35 }; 36 37 static const char * const mplstates[] = { 38 [NL80211_PLINK_LISTEN] = "LISTEN", 39 [NL80211_PLINK_OPN_SNT] = "OPN-SNT", 40 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD", 41 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD", 42 [NL80211_PLINK_ESTAB] = "ESTAB", 43 [NL80211_PLINK_HOLDING] = "HOLDING", 44 [NL80211_PLINK_BLOCKED] = "BLOCKED" 45 }; 46 47 static const char * const mplevents[] = { 48 [PLINK_UNDEFINED] = "NONE", 49 [OPN_ACPT] = "OPN_ACPT", 50 [OPN_RJCT] = "OPN_RJCT", 51 [OPN_IGNR] = "OPN_IGNR", 52 [CNF_ACPT] = "CNF_ACPT", 53 [CNF_RJCT] = "CNF_RJCT", 54 [CNF_IGNR] = "CNF_IGNR", 55 [CLS_ACPT] = "CLS_ACPT", 56 [CLS_IGNR] = "CLS_IGNR" 57 }; 58 59 /* We only need a valid sta if user configured a minimum rssi_threshold. */ 60 static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata, 61 struct sta_info *sta) 62 { 63 s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold; 64 return rssi_threshold == 0 || 65 (sta && 66 (s8)-ewma_signal_read(&sta->rx_stats_avg.signal) > 67 rssi_threshold); 68 } 69 70 /** 71 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine 72 * 73 * @sta: mesh peer link to restart 74 * 75 * Locking: this function must be called holding sta->mesh->plink_lock 76 */ 77 static inline void mesh_plink_fsm_restart(struct sta_info *sta) 78 { 79 lockdep_assert_held(&sta->mesh->plink_lock); 80 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 81 sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0; 82 sta->mesh->plink_retries = 0; 83 } 84 85 /* 86 * mesh_set_short_slot_time - enable / disable ERP short slot time. 87 * 88 * The standard indirectly mandates mesh STAs to turn off short slot time by 89 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we 90 * can't be sneaky about it. Enable short slot time if all mesh STAs in the 91 * MBSS support ERP rates. 92 * 93 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change. 94 */ 95 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata) 96 { 97 struct ieee80211_local *local = sdata->local; 98 struct ieee80211_supported_band *sband; 99 struct sta_info *sta; 100 u32 erp_rates = 0, changed = 0; 101 int i; 102 bool short_slot = false; 103 104 sband = ieee80211_get_sband(sdata); 105 if (!sband) 106 return changed; 107 108 if (sband->band == NL80211_BAND_5GHZ) { 109 /* (IEEE 802.11-2012 19.4.5) */ 110 short_slot = true; 111 goto out; 112 } else if (sband->band != NL80211_BAND_2GHZ) { 113 goto out; 114 } 115 116 for (i = 0; i < sband->n_bitrates; i++) 117 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G) 118 erp_rates |= BIT(i); 119 120 if (!erp_rates) 121 goto out; 122 123 rcu_read_lock(); 124 list_for_each_entry_rcu(sta, &local->sta_list, list) { 125 if (sdata != sta->sdata || 126 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 127 continue; 128 129 short_slot = false; 130 if (erp_rates & sta->sta.supp_rates[sband->band]) 131 short_slot = true; 132 else 133 break; 134 } 135 rcu_read_unlock(); 136 137 out: 138 if (sdata->vif.bss_conf.use_short_slot != short_slot) { 139 sdata->vif.bss_conf.use_short_slot = short_slot; 140 changed = BSS_CHANGED_ERP_SLOT; 141 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n", 142 sdata->vif.addr, short_slot); 143 } 144 return changed; 145 } 146 147 /** 148 * mesh_set_ht_prot_mode - set correct HT protection mode 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 atleast one 155 * HT20 peer is present. Otherwise no-protection mode is selected. 156 */ 157 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) 158 { 159 struct ieee80211_local *local = sdata->local; 160 struct sta_info *sta; 161 u16 ht_opmode; 162 bool non_ht_sta = false, ht20_sta = false; 163 164 switch (sdata->vif.bss_conf.chandef.width) { 165 case NL80211_CHAN_WIDTH_20_NOHT: 166 case NL80211_CHAN_WIDTH_5: 167 case NL80211_CHAN_WIDTH_10: 168 return 0; 169 default: 170 break; 171 } 172 173 rcu_read_lock(); 174 list_for_each_entry_rcu(sta, &local->sta_list, list) { 175 if (sdata != sta->sdata || 176 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 177 continue; 178 179 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20) 180 continue; 181 182 if (!sta->sta.ht_cap.ht_supported) { 183 mpl_dbg(sdata, "nonHT sta (%pM) is present\n", 184 sta->sta.addr); 185 non_ht_sta = true; 186 break; 187 } 188 189 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); 190 ht20_sta = true; 191 } 192 rcu_read_unlock(); 193 194 if (non_ht_sta) 195 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; 196 else if (ht20_sta && 197 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20) 198 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; 199 else 200 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; 201 202 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) 203 return 0; 204 205 sdata->vif.bss_conf.ht_operation_mode = ht_opmode; 206 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; 207 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); 208 return BSS_CHANGED_HT; 209 } 210 211 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 212 struct sta_info *sta, 213 enum ieee80211_self_protected_actioncode action, 214 u8 *da, u16 llid, u16 plid, u16 reason) 215 { 216 struct ieee80211_local *local = sdata->local; 217 struct sk_buff *skb; 218 struct ieee80211_tx_info *info; 219 struct ieee80211_mgmt *mgmt; 220 bool include_plid = false; 221 u16 peering_proto = 0; 222 u8 *pos, ie_len = 4; 223 int hdr_len = offsetofend(struct ieee80211_mgmt, u.action.u.self_prot); 224 int err = -ENOMEM; 225 226 skb = dev_alloc_skb(local->tx_headroom + 227 hdr_len + 228 2 + /* capability info */ 229 2 + /* AID */ 230 2 + 8 + /* supported rates */ 231 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 232 2 + sdata->u.mesh.mesh_id_len + 233 2 + sizeof(struct ieee80211_meshconf_ie) + 234 2 + sizeof(struct ieee80211_ht_cap) + 235 2 + sizeof(struct ieee80211_ht_operation) + 236 2 + sizeof(struct ieee80211_vht_cap) + 237 2 + sizeof(struct ieee80211_vht_operation) + 238 2 + 8 + /* peering IE */ 239 sdata->u.mesh.ie_len); 240 if (!skb) 241 return err; 242 info = IEEE80211_SKB_CB(skb); 243 skb_reserve(skb, local->tx_headroom); 244 mgmt = skb_put_zero(skb, hdr_len); 245 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 246 IEEE80211_STYPE_ACTION); 247 memcpy(mgmt->da, da, ETH_ALEN); 248 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 249 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 250 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; 251 mgmt->u.action.u.self_prot.action_code = action; 252 253 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 254 struct ieee80211_supported_band *sband; 255 enum nl80211_band band; 256 257 sband = ieee80211_get_sband(sdata); 258 if (!sband) { 259 err = -EINVAL; 260 goto free; 261 } 262 band = sband->band; 263 264 /* capability info */ 265 pos = skb_put_zero(skb, 2); 266 if (action == WLAN_SP_MESH_PEERING_CONFIRM) { 267 /* AID */ 268 pos = skb_put(skb, 2); 269 put_unaligned_le16(sta->sta.aid, pos); 270 } 271 if (ieee80211_add_srates_ie(sdata, skb, true, band) || 272 ieee80211_add_ext_srates_ie(sdata, skb, true, band) || 273 mesh_add_rsn_ie(sdata, skb) || 274 mesh_add_meshid_ie(sdata, skb) || 275 mesh_add_meshconf_ie(sdata, skb)) 276 goto free; 277 } else { /* WLAN_SP_MESH_PEERING_CLOSE */ 278 info->flags |= IEEE80211_TX_CTL_NO_ACK; 279 if (mesh_add_meshid_ie(sdata, skb)) 280 goto free; 281 } 282 283 /* Add Mesh Peering Management element */ 284 switch (action) { 285 case WLAN_SP_MESH_PEERING_OPEN: 286 break; 287 case WLAN_SP_MESH_PEERING_CONFIRM: 288 ie_len += 2; 289 include_plid = true; 290 break; 291 case WLAN_SP_MESH_PEERING_CLOSE: 292 if (plid) { 293 ie_len += 2; 294 include_plid = true; 295 } 296 ie_len += 2; /* reason code */ 297 break; 298 default: 299 err = -EINVAL; 300 goto free; 301 } 302 303 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) 304 goto free; 305 306 pos = skb_put(skb, 2 + ie_len); 307 *pos++ = WLAN_EID_PEER_MGMT; 308 *pos++ = ie_len; 309 memcpy(pos, &peering_proto, 2); 310 pos += 2; 311 put_unaligned_le16(llid, pos); 312 pos += 2; 313 if (include_plid) { 314 put_unaligned_le16(plid, pos); 315 pos += 2; 316 } 317 if (action == WLAN_SP_MESH_PEERING_CLOSE) { 318 put_unaligned_le16(reason, pos); 319 pos += 2; 320 } 321 322 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 323 if (mesh_add_ht_cap_ie(sdata, skb) || 324 mesh_add_ht_oper_ie(sdata, skb) || 325 mesh_add_vht_cap_ie(sdata, skb) || 326 mesh_add_vht_oper_ie(sdata, skb)) 327 goto free; 328 } 329 330 if (mesh_add_vendor_ies(sdata, skb)) 331 goto free; 332 333 ieee80211_tx_skb(sdata, skb); 334 return 0; 335 free: 336 kfree_skb(skb); 337 return err; 338 } 339 340 /** 341 * __mesh_plink_deactivate - deactivate mesh peer link 342 * 343 * @sta: mesh peer link to deactivate 344 * 345 * Mesh paths with this peer as next hop should be flushed 346 * by the caller outside of plink_lock. 347 * 348 * Returns beacon changed flag if the beacon content changed. 349 * 350 * Locking: the caller must hold sta->mesh->plink_lock 351 */ 352 static u32 __mesh_plink_deactivate(struct sta_info *sta) 353 { 354 struct ieee80211_sub_if_data *sdata = sta->sdata; 355 u32 changed = 0; 356 357 lockdep_assert_held(&sta->mesh->plink_lock); 358 359 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 360 changed = mesh_plink_dec_estab_count(sdata); 361 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 362 363 ieee80211_mps_sta_status_update(sta); 364 changed |= ieee80211_mps_set_sta_local_pm(sta, 365 NL80211_MESH_POWER_UNKNOWN); 366 367 return changed; 368 } 369 370 /** 371 * mesh_plink_deactivate - deactivate mesh peer link 372 * 373 * @sta: mesh peer link to deactivate 374 * 375 * All mesh paths with this peer as next hop will be flushed 376 */ 377 u32 mesh_plink_deactivate(struct sta_info *sta) 378 { 379 struct ieee80211_sub_if_data *sdata = sta->sdata; 380 u32 changed; 381 382 spin_lock_bh(&sta->mesh->plink_lock); 383 changed = __mesh_plink_deactivate(sta); 384 385 if (!sdata->u.mesh.user_mpm) { 386 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED; 387 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE, 388 sta->sta.addr, sta->mesh->llid, 389 sta->mesh->plid, sta->mesh->reason); 390 } 391 spin_unlock_bh(&sta->mesh->plink_lock); 392 if (!sdata->u.mesh.user_mpm) 393 del_timer_sync(&sta->mesh->plink_timer); 394 mesh_path_flush_by_nexthop(sta); 395 396 /* make sure no readers can access nexthop sta from here on */ 397 synchronize_net(); 398 399 return changed; 400 } 401 402 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 403 struct sta_info *sta, 404 struct ieee802_11_elems *elems) 405 { 406 struct ieee80211_local *local = sdata->local; 407 struct ieee80211_supported_band *sband; 408 u32 rates, basic_rates = 0, changed = 0; 409 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth; 410 411 sband = ieee80211_get_sband(sdata); 412 if (!sband) 413 return; 414 415 rates = ieee80211_sta_get_rates(sdata, elems, sband->band, 416 &basic_rates); 417 418 spin_lock_bh(&sta->mesh->plink_lock); 419 sta->rx_stats.last_rx = jiffies; 420 421 /* rates and capabilities don't change during peering */ 422 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB && 423 sta->mesh->processed_beacon) 424 goto out; 425 sta->mesh->processed_beacon = true; 426 427 if (sta->sta.supp_rates[sband->band] != rates) 428 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 429 sta->sta.supp_rates[sband->band] = rates; 430 431 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 432 elems->ht_cap_elem, sta)) 433 changed |= IEEE80211_RC_BW_CHANGED; 434 435 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband, 436 elems->vht_cap_elem, sta); 437 438 if (bw != sta->sta.bandwidth) 439 changed |= IEEE80211_RC_BW_CHANGED; 440 441 /* HT peer is operating 20MHz-only */ 442 if (elems->ht_operation && 443 !(elems->ht_operation->ht_param & 444 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 445 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) 446 changed |= IEEE80211_RC_BW_CHANGED; 447 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; 448 } 449 450 if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) 451 rate_control_rate_init(sta); 452 else 453 rate_control_rate_update(local, sband, sta, changed); 454 out: 455 spin_unlock_bh(&sta->mesh->plink_lock); 456 } 457 458 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) 459 { 460 struct sta_info *sta; 461 unsigned long *aid_map; 462 int aid; 463 464 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1), 465 sizeof(*aid_map), GFP_KERNEL); 466 if (!aid_map) 467 return -ENOMEM; 468 469 /* reserve aid 0 for mcast indication */ 470 __set_bit(0, aid_map); 471 472 rcu_read_lock(); 473 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) 474 __set_bit(sta->sta.aid, aid_map); 475 rcu_read_unlock(); 476 477 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); 478 kfree(aid_map); 479 480 if (aid > IEEE80211_MAX_AID) 481 return -ENOBUFS; 482 483 return aid; 484 } 485 486 static struct sta_info * 487 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 488 { 489 struct sta_info *sta; 490 int aid; 491 492 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 493 return NULL; 494 495 aid = mesh_allocate_aid(sdata); 496 if (aid < 0) 497 return NULL; 498 499 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 500 if (!sta) 501 return NULL; 502 503 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 504 sta->sta.wme = true; 505 sta->sta.aid = aid; 506 507 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 508 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 509 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 510 511 return sta; 512 } 513 514 static struct sta_info * 515 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 516 struct ieee802_11_elems *elems, 517 struct ieee80211_rx_status *rx_status) 518 { 519 struct sta_info *sta = NULL; 520 521 /* Userspace handles station allocation */ 522 if (sdata->u.mesh.user_mpm || 523 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) { 524 if (mesh_peer_accepts_plinks(elems) && 525 mesh_plink_availables(sdata)) { 526 int sig = 0; 527 528 if (ieee80211_hw_check(&sdata->local->hw, SIGNAL_DBM)) 529 sig = rx_status->signal; 530 531 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 532 elems->ie_start, 533 elems->total_len, 534 sig, GFP_KERNEL); 535 } 536 } else 537 sta = __mesh_sta_info_alloc(sdata, addr); 538 539 return sta; 540 } 541 542 /* 543 * mesh_sta_info_get - return mesh sta info entry for @addr. 544 * 545 * @sdata: local meshif 546 * @addr: peer's address 547 * @elems: IEs from beacon or mesh peering frame. 548 * @rx_status: rx status for the frame for signal reporting 549 * 550 * Return existing or newly allocated sta_info under RCU read lock. 551 * (re)initialize with given IEs. 552 */ 553 static struct sta_info * 554 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 555 u8 *addr, struct ieee802_11_elems *elems, 556 struct ieee80211_rx_status *rx_status) __acquires(RCU) 557 { 558 struct sta_info *sta = NULL; 559 560 rcu_read_lock(); 561 sta = sta_info_get(sdata, addr); 562 if (sta) { 563 mesh_sta_info_init(sdata, sta, elems); 564 } else { 565 rcu_read_unlock(); 566 /* can't run atomic */ 567 sta = mesh_sta_info_alloc(sdata, addr, elems, rx_status); 568 if (!sta) { 569 rcu_read_lock(); 570 return NULL; 571 } 572 573 mesh_sta_info_init(sdata, sta, elems); 574 575 if (sta_info_insert_rcu(sta)) 576 return NULL; 577 } 578 579 return sta; 580 } 581 582 /* 583 * mesh_neighbour_update - update or initialize new mesh neighbor. 584 * 585 * @sdata: local meshif 586 * @addr: peer's address 587 * @elems: IEs from beacon or mesh peering frame 588 * @rx_status: rx status for the frame for signal reporting 589 * 590 * Initiates peering if appropriate. 591 */ 592 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 593 u8 *hw_addr, 594 struct ieee802_11_elems *elems, 595 struct ieee80211_rx_status *rx_status) 596 { 597 struct sta_info *sta; 598 u32 changed = 0; 599 600 sta = mesh_sta_info_get(sdata, hw_addr, elems, rx_status); 601 if (!sta) 602 goto out; 603 604 sta->mesh->connected_to_gate = elems->mesh_config->meshconf_form & 605 IEEE80211_MESHCONF_FORM_CONNECTED_TO_GATE; 606 607 if (mesh_peer_accepts_plinks(elems) && 608 sta->mesh->plink_state == NL80211_PLINK_LISTEN && 609 sdata->u.mesh.accepting_plinks && 610 sdata->u.mesh.mshcfg.auto_open_plinks && 611 rssi_threshold_check(sdata, sta)) 612 changed = mesh_plink_open(sta); 613 614 ieee80211_mps_frame_release(sta, elems); 615 out: 616 rcu_read_unlock(); 617 ieee80211_mbss_info_change_notify(sdata, changed); 618 } 619 620 void mesh_plink_timer(struct timer_list *t) 621 { 622 struct mesh_sta *mesh = from_timer(mesh, t, plink_timer); 623 struct sta_info *sta; 624 u16 reason = 0; 625 struct ieee80211_sub_if_data *sdata; 626 struct mesh_config *mshcfg; 627 enum ieee80211_self_protected_actioncode action = 0; 628 629 /* 630 * This STA is valid because sta_info_destroy() will 631 * del_timer_sync() this timer after having made sure 632 * it cannot be readded (by deleting the plink.) 633 */ 634 sta = mesh->plink_sta; 635 636 if (sta->sdata->local->quiescing) 637 return; 638 639 spin_lock_bh(&sta->mesh->plink_lock); 640 641 /* If a timer fires just before a state transition on another CPU, 642 * we may have already extended the timeout and changed state by the 643 * time we've acquired the lock and arrived here. In that case, 644 * skip this timer and wait for the new one. 645 */ 646 if (time_before(jiffies, sta->mesh->plink_timer.expires)) { 647 mpl_dbg(sta->sdata, 648 "Ignoring timer for %pM in state %s (timer adjusted)", 649 sta->sta.addr, mplstates[sta->mesh->plink_state]); 650 spin_unlock_bh(&sta->mesh->plink_lock); 651 return; 652 } 653 654 /* del_timer() and handler may race when entering these states */ 655 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || 656 sta->mesh->plink_state == NL80211_PLINK_ESTAB) { 657 mpl_dbg(sta->sdata, 658 "Ignoring timer for %pM in state %s (timer deleted)", 659 sta->sta.addr, mplstates[sta->mesh->plink_state]); 660 spin_unlock_bh(&sta->mesh->plink_lock); 661 return; 662 } 663 664 mpl_dbg(sta->sdata, 665 "Mesh plink timer for %pM fired on state %s\n", 666 sta->sta.addr, mplstates[sta->mesh->plink_state]); 667 sdata = sta->sdata; 668 mshcfg = &sdata->u.mesh.mshcfg; 669 670 switch (sta->mesh->plink_state) { 671 case NL80211_PLINK_OPN_RCVD: 672 case NL80211_PLINK_OPN_SNT: 673 /* retry timer */ 674 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { 675 u32 rand; 676 mpl_dbg(sta->sdata, 677 "Mesh plink for %pM (retry, timeout): %d %d\n", 678 sta->sta.addr, sta->mesh->plink_retries, 679 sta->mesh->plink_timeout); 680 get_random_bytes(&rand, sizeof(u32)); 681 sta->mesh->plink_timeout = sta->mesh->plink_timeout + 682 rand % sta->mesh->plink_timeout; 683 ++sta->mesh->plink_retries; 684 mod_plink_timer(sta, sta->mesh->plink_timeout); 685 action = WLAN_SP_MESH_PEERING_OPEN; 686 break; 687 } 688 reason = WLAN_REASON_MESH_MAX_RETRIES; 689 /* fall through */ 690 case NL80211_PLINK_CNF_RCVD: 691 /* confirm timer */ 692 if (!reason) 693 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 694 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 695 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 696 action = WLAN_SP_MESH_PEERING_CLOSE; 697 break; 698 case NL80211_PLINK_HOLDING: 699 /* holding timer */ 700 del_timer(&sta->mesh->plink_timer); 701 mesh_plink_fsm_restart(sta); 702 break; 703 default: 704 break; 705 } 706 spin_unlock_bh(&sta->mesh->plink_lock); 707 if (action) 708 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 709 sta->mesh->llid, sta->mesh->plid, reason); 710 } 711 712 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 713 { 714 sta->mesh->plink_timeout = timeout; 715 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout)); 716 } 717 718 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 719 u16 llid) 720 { 721 struct ieee80211_local *local = sdata->local; 722 bool in_use = false; 723 struct sta_info *sta; 724 725 rcu_read_lock(); 726 list_for_each_entry_rcu(sta, &local->sta_list, list) { 727 if (sdata != sta->sdata) 728 continue; 729 730 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { 731 in_use = true; 732 break; 733 } 734 } 735 rcu_read_unlock(); 736 737 return in_use; 738 } 739 740 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 741 { 742 u16 llid; 743 744 do { 745 get_random_bytes(&llid, sizeof(llid)); 746 } while (llid_in_use(sdata, llid)); 747 748 return llid; 749 } 750 751 u32 mesh_plink_open(struct sta_info *sta) 752 { 753 struct ieee80211_sub_if_data *sdata = sta->sdata; 754 u32 changed; 755 756 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 757 return 0; 758 759 spin_lock_bh(&sta->mesh->plink_lock); 760 sta->mesh->llid = mesh_get_new_llid(sdata); 761 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && 762 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { 763 spin_unlock_bh(&sta->mesh->plink_lock); 764 return 0; 765 } 766 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; 767 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 768 spin_unlock_bh(&sta->mesh->plink_lock); 769 mpl_dbg(sdata, 770 "Mesh plink: starting establishment with %pM\n", 771 sta->sta.addr); 772 773 /* set the non-peer mode to active during peering */ 774 changed = ieee80211_mps_local_status_update(sdata); 775 776 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, 777 sta->sta.addr, sta->mesh->llid, 0, 0); 778 return changed; 779 } 780 781 u32 mesh_plink_block(struct sta_info *sta) 782 { 783 u32 changed; 784 785 spin_lock_bh(&sta->mesh->plink_lock); 786 changed = __mesh_plink_deactivate(sta); 787 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 788 spin_unlock_bh(&sta->mesh->plink_lock); 789 mesh_path_flush_by_nexthop(sta); 790 791 return changed; 792 } 793 794 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 795 struct sta_info *sta, 796 enum plink_event event) 797 { 798 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 799 u16 reason = (event == CLS_ACPT) ? 800 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 801 802 sta->mesh->reason = reason; 803 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 804 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 805 } 806 807 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 808 struct sta_info *sta) 809 { 810 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 811 u32 changed = 0; 812 813 del_timer(&sta->mesh->plink_timer); 814 sta->mesh->plink_state = NL80211_PLINK_ESTAB; 815 changed |= mesh_plink_inc_estab_count(sdata); 816 changed |= mesh_set_ht_prot_mode(sdata); 817 changed |= mesh_set_short_slot_time(sdata); 818 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 819 ieee80211_mps_sta_status_update(sta); 820 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 821 return changed; 822 } 823 824 /** 825 * mesh_plink_fsm - step @sta MPM based on @event 826 * 827 * @sdata: interface 828 * @sta: mesh neighbor 829 * @event: peering event 830 * 831 * Return: changed MBSS flags 832 */ 833 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 834 struct sta_info *sta, enum plink_event event) 835 { 836 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 837 enum ieee80211_self_protected_actioncode action = 0; 838 u32 changed = 0; 839 bool flush = false; 840 841 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 842 mplstates[sta->mesh->plink_state], mplevents[event]); 843 844 spin_lock_bh(&sta->mesh->plink_lock); 845 switch (sta->mesh->plink_state) { 846 case NL80211_PLINK_LISTEN: 847 switch (event) { 848 case CLS_ACPT: 849 mesh_plink_fsm_restart(sta); 850 break; 851 case OPN_ACPT: 852 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 853 sta->mesh->llid = mesh_get_new_llid(sdata); 854 mesh_plink_timer_set(sta, 855 mshcfg->dot11MeshRetryTimeout); 856 857 /* set the non-peer mode to active during peering */ 858 changed |= ieee80211_mps_local_status_update(sdata); 859 action = WLAN_SP_MESH_PEERING_OPEN; 860 break; 861 default: 862 break; 863 } 864 break; 865 case NL80211_PLINK_OPN_SNT: 866 switch (event) { 867 case OPN_RJCT: 868 case CNF_RJCT: 869 case CLS_ACPT: 870 mesh_plink_close(sdata, sta, event); 871 action = WLAN_SP_MESH_PEERING_CLOSE; 872 break; 873 case OPN_ACPT: 874 /* retry timer is left untouched */ 875 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 876 action = WLAN_SP_MESH_PEERING_CONFIRM; 877 break; 878 case CNF_ACPT: 879 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; 880 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 881 break; 882 default: 883 break; 884 } 885 break; 886 case NL80211_PLINK_OPN_RCVD: 887 switch (event) { 888 case OPN_RJCT: 889 case CNF_RJCT: 890 case CLS_ACPT: 891 mesh_plink_close(sdata, sta, event); 892 action = WLAN_SP_MESH_PEERING_CLOSE; 893 break; 894 case OPN_ACPT: 895 action = WLAN_SP_MESH_PEERING_CONFIRM; 896 break; 897 case CNF_ACPT: 898 changed |= mesh_plink_establish(sdata, sta); 899 break; 900 default: 901 break; 902 } 903 break; 904 case NL80211_PLINK_CNF_RCVD: 905 switch (event) { 906 case OPN_RJCT: 907 case CNF_RJCT: 908 case CLS_ACPT: 909 mesh_plink_close(sdata, sta, event); 910 action = WLAN_SP_MESH_PEERING_CLOSE; 911 break; 912 case OPN_ACPT: 913 changed |= mesh_plink_establish(sdata, sta); 914 action = WLAN_SP_MESH_PEERING_CONFIRM; 915 break; 916 default: 917 break; 918 } 919 break; 920 case NL80211_PLINK_ESTAB: 921 switch (event) { 922 case CLS_ACPT: 923 changed |= __mesh_plink_deactivate(sta); 924 changed |= mesh_set_ht_prot_mode(sdata); 925 changed |= mesh_set_short_slot_time(sdata); 926 mesh_plink_close(sdata, sta, event); 927 action = WLAN_SP_MESH_PEERING_CLOSE; 928 flush = true; 929 break; 930 case OPN_ACPT: 931 action = WLAN_SP_MESH_PEERING_CONFIRM; 932 break; 933 default: 934 break; 935 } 936 break; 937 case NL80211_PLINK_HOLDING: 938 switch (event) { 939 case CLS_ACPT: 940 del_timer(&sta->mesh->plink_timer); 941 mesh_plink_fsm_restart(sta); 942 break; 943 case OPN_ACPT: 944 case CNF_ACPT: 945 case OPN_RJCT: 946 case CNF_RJCT: 947 action = WLAN_SP_MESH_PEERING_CLOSE; 948 break; 949 default: 950 break; 951 } 952 break; 953 default: 954 /* should not get here, PLINK_BLOCKED is dealt with at the 955 * beginning of the function 956 */ 957 break; 958 } 959 spin_unlock_bh(&sta->mesh->plink_lock); 960 if (flush) 961 mesh_path_flush_by_nexthop(sta); 962 if (action) { 963 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 964 sta->mesh->llid, sta->mesh->plid, 965 sta->mesh->reason); 966 967 /* also send confirm in open case */ 968 if (action == WLAN_SP_MESH_PEERING_OPEN) { 969 mesh_plink_frame_tx(sdata, sta, 970 WLAN_SP_MESH_PEERING_CONFIRM, 971 sta->sta.addr, sta->mesh->llid, 972 sta->mesh->plid, 0); 973 } 974 } 975 976 return changed; 977 } 978 979 /* 980 * mesh_plink_get_event - get correct MPM event 981 * 982 * @sdata: interface 983 * @sta: peer, leave NULL if processing a frame from a new suitable peer 984 * @elems: peering management IEs 985 * @ftype: frame type 986 * @llid: peer's peer link ID 987 * @plid: peer's local link ID 988 * 989 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 990 * an error. 991 */ 992 static enum plink_event 993 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 994 struct sta_info *sta, 995 struct ieee802_11_elems *elems, 996 enum ieee80211_self_protected_actioncode ftype, 997 u16 llid, u16 plid) 998 { 999 enum plink_event event = PLINK_UNDEFINED; 1000 u8 ie_len = elems->peering_len; 1001 bool matches_local; 1002 1003 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 1004 mesh_matches_local(sdata, elems)); 1005 1006 /* deny open request from non-matching peer */ 1007 if (!matches_local && !sta) { 1008 event = OPN_RJCT; 1009 goto out; 1010 } 1011 1012 if (!sta) { 1013 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 1014 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 1015 goto out; 1016 } 1017 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 1018 if (!mesh_plink_free_count(sdata)) { 1019 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 1020 goto out; 1021 } 1022 1023 /* new matching peer */ 1024 event = OPN_ACPT; 1025 goto out; 1026 } else { 1027 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 1028 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 1029 goto out; 1030 } 1031 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) 1032 goto out; 1033 } 1034 1035 switch (ftype) { 1036 case WLAN_SP_MESH_PEERING_OPEN: 1037 if (!matches_local) 1038 event = OPN_RJCT; 1039 if (!mesh_plink_free_count(sdata) || 1040 (sta->mesh->plid && sta->mesh->plid != plid)) 1041 event = OPN_IGNR; 1042 else 1043 event = OPN_ACPT; 1044 break; 1045 case WLAN_SP_MESH_PEERING_CONFIRM: 1046 if (!matches_local) 1047 event = CNF_RJCT; 1048 if (!mesh_plink_free_count(sdata) || 1049 sta->mesh->llid != llid || 1050 (sta->mesh->plid && sta->mesh->plid != plid)) 1051 event = CNF_IGNR; 1052 else 1053 event = CNF_ACPT; 1054 break; 1055 case WLAN_SP_MESH_PEERING_CLOSE: 1056 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 1057 /* Do not check for llid or plid. This does not 1058 * follow the standard but since multiple plinks 1059 * per sta are not supported, it is necessary in 1060 * order to avoid a livelock when MP A sees an 1061 * establish peer link to MP B but MP B does not 1062 * see it. This can be caused by a timeout in 1063 * B's peer link establishment or B beign 1064 * restarted. 1065 */ 1066 event = CLS_ACPT; 1067 else if (sta->mesh->plid != plid) 1068 event = CLS_IGNR; 1069 else if (ie_len == 8 && sta->mesh->llid != llid) 1070 event = CLS_IGNR; 1071 else 1072 event = CLS_ACPT; 1073 break; 1074 default: 1075 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 1076 break; 1077 } 1078 1079 out: 1080 return event; 1081 } 1082 1083 static void 1084 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1085 struct ieee80211_mgmt *mgmt, 1086 struct ieee802_11_elems *elems, 1087 struct ieee80211_rx_status *rx_status) 1088 { 1089 1090 struct sta_info *sta; 1091 enum plink_event event; 1092 enum ieee80211_self_protected_actioncode ftype; 1093 u32 changed = 0; 1094 u8 ie_len = elems->peering_len; 1095 u16 plid, llid = 0; 1096 1097 if (!elems->peering) { 1098 mpl_dbg(sdata, 1099 "Mesh plink: missing necessary peer link ie\n"); 1100 return; 1101 } 1102 1103 if (elems->rsn_len && 1104 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1105 mpl_dbg(sdata, 1106 "Mesh plink: can't establish link with secure peer\n"); 1107 return; 1108 } 1109 1110 ftype = mgmt->u.action.u.self_prot.action_code; 1111 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1112 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1113 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1114 && ie_len != 8)) { 1115 mpl_dbg(sdata, 1116 "Mesh plink: incorrect plink ie length %d %d\n", 1117 ftype, ie_len); 1118 return; 1119 } 1120 1121 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1122 (!elems->mesh_id || !elems->mesh_config)) { 1123 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1124 return; 1125 } 1126 /* Note the lines below are correct, the llid in the frame is the plid 1127 * from the point of view of this host. 1128 */ 1129 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1130 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1131 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1132 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1133 1134 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1135 rcu_read_lock(); 1136 1137 sta = sta_info_get(sdata, mgmt->sa); 1138 1139 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1140 !rssi_threshold_check(sdata, sta)) { 1141 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1142 mgmt->sa); 1143 goto unlock_rcu; 1144 } 1145 1146 /* Now we will figure out the appropriate event... */ 1147 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1148 1149 if (event == OPN_ACPT) { 1150 rcu_read_unlock(); 1151 /* allocate sta entry if necessary and update info */ 1152 sta = mesh_sta_info_get(sdata, mgmt->sa, elems, rx_status); 1153 if (!sta) { 1154 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1155 goto unlock_rcu; 1156 } 1157 sta->mesh->plid = plid; 1158 } else if (!sta && event == OPN_RJCT) { 1159 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, 1160 mgmt->sa, 0, plid, 1161 WLAN_REASON_MESH_CONFIG); 1162 goto unlock_rcu; 1163 } else if (!sta || event == PLINK_UNDEFINED) { 1164 /* something went wrong */ 1165 goto unlock_rcu; 1166 } 1167 1168 if (event == CNF_ACPT) { 1169 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1170 if (!sta->mesh->plid) 1171 sta->mesh->plid = plid; 1172 1173 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); 1174 } 1175 1176 changed |= mesh_plink_fsm(sdata, sta, event); 1177 1178 unlock_rcu: 1179 rcu_read_unlock(); 1180 1181 if (changed) 1182 ieee80211_mbss_info_change_notify(sdata, changed); 1183 } 1184 1185 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1186 struct ieee80211_mgmt *mgmt, size_t len, 1187 struct ieee80211_rx_status *rx_status) 1188 { 1189 struct ieee802_11_elems elems; 1190 size_t baselen; 1191 u8 *baseaddr; 1192 1193 /* need action_code, aux */ 1194 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1195 return; 1196 1197 if (sdata->u.mesh.user_mpm) 1198 /* userspace must register for these */ 1199 return; 1200 1201 if (is_multicast_ether_addr(mgmt->da)) { 1202 mpl_dbg(sdata, 1203 "Mesh plink: ignore frame from multicast address\n"); 1204 return; 1205 } 1206 1207 baseaddr = mgmt->u.action.u.self_prot.variable; 1208 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1209 if (mgmt->u.action.u.self_prot.action_code == 1210 WLAN_SP_MESH_PEERING_CONFIRM) { 1211 baseaddr += 4; 1212 baselen += 4; 1213 1214 if (baselen > len) 1215 return; 1216 } 1217 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems); 1218 mesh_process_plink_frame(sdata, mgmt, &elems, rx_status); 1219 } 1220