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