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, bool insert) 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 (insert) 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 { 518 struct sta_info *sta = NULL; 519 520 /* Userspace handles station allocation */ 521 if (sdata->u.mesh.user_mpm || 522 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) { 523 if (mesh_peer_accepts_plinks(elems) && 524 mesh_plink_availables(sdata)) 525 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 526 elems->ie_start, 527 elems->total_len, 528 GFP_KERNEL); 529 } else 530 sta = __mesh_sta_info_alloc(sdata, addr); 531 532 return sta; 533 } 534 535 /* 536 * mesh_sta_info_get - return mesh sta info entry for @addr. 537 * 538 * @sdata: local meshif 539 * @addr: peer's address 540 * @elems: IEs from beacon or mesh peering frame. 541 * 542 * Return existing or newly allocated sta_info under RCU read lock. 543 * (re)initialize with given IEs. 544 */ 545 static struct sta_info * 546 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 547 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU) 548 { 549 struct sta_info *sta = NULL; 550 551 rcu_read_lock(); 552 sta = sta_info_get(sdata, addr); 553 if (sta) { 554 mesh_sta_info_init(sdata, sta, elems, false); 555 } else { 556 rcu_read_unlock(); 557 /* can't run atomic */ 558 sta = mesh_sta_info_alloc(sdata, addr, elems); 559 if (!sta) { 560 rcu_read_lock(); 561 return NULL; 562 } 563 564 mesh_sta_info_init(sdata, sta, elems, true); 565 566 if (sta_info_insert_rcu(sta)) 567 return NULL; 568 } 569 570 return sta; 571 } 572 573 /* 574 * mesh_neighbour_update - update or initialize new mesh neighbor. 575 * 576 * @sdata: local meshif 577 * @addr: peer's address 578 * @elems: IEs from beacon or mesh peering frame 579 * 580 * Initiates peering if appropriate. 581 */ 582 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 583 u8 *hw_addr, 584 struct ieee802_11_elems *elems) 585 { 586 struct sta_info *sta; 587 u32 changed = 0; 588 589 sta = mesh_sta_info_get(sdata, hw_addr, elems); 590 if (!sta) 591 goto out; 592 593 if (mesh_peer_accepts_plinks(elems) && 594 sta->mesh->plink_state == NL80211_PLINK_LISTEN && 595 sdata->u.mesh.accepting_plinks && 596 sdata->u.mesh.mshcfg.auto_open_plinks && 597 rssi_threshold_check(sdata, sta)) 598 changed = mesh_plink_open(sta); 599 600 ieee80211_mps_frame_release(sta, elems); 601 out: 602 rcu_read_unlock(); 603 ieee80211_mbss_info_change_notify(sdata, changed); 604 } 605 606 void mesh_plink_timer(struct timer_list *t) 607 { 608 struct mesh_sta *mesh = from_timer(mesh, t, plink_timer); 609 struct sta_info *sta; 610 u16 reason = 0; 611 struct ieee80211_sub_if_data *sdata; 612 struct mesh_config *mshcfg; 613 enum ieee80211_self_protected_actioncode action = 0; 614 615 /* 616 * This STA is valid because sta_info_destroy() will 617 * del_timer_sync() this timer after having made sure 618 * it cannot be readded (by deleting the plink.) 619 */ 620 sta = mesh->plink_sta; 621 622 if (sta->sdata->local->quiescing) 623 return; 624 625 spin_lock_bh(&sta->mesh->plink_lock); 626 627 /* If a timer fires just before a state transition on another CPU, 628 * we may have already extended the timeout and changed state by the 629 * time we've acquired the lock and arrived here. In that case, 630 * skip this timer and wait for the new one. 631 */ 632 if (time_before(jiffies, sta->mesh->plink_timer.expires)) { 633 mpl_dbg(sta->sdata, 634 "Ignoring timer for %pM in state %s (timer adjusted)", 635 sta->sta.addr, mplstates[sta->mesh->plink_state]); 636 spin_unlock_bh(&sta->mesh->plink_lock); 637 return; 638 } 639 640 /* del_timer() and handler may race when entering these states */ 641 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || 642 sta->mesh->plink_state == NL80211_PLINK_ESTAB) { 643 mpl_dbg(sta->sdata, 644 "Ignoring timer for %pM in state %s (timer deleted)", 645 sta->sta.addr, mplstates[sta->mesh->plink_state]); 646 spin_unlock_bh(&sta->mesh->plink_lock); 647 return; 648 } 649 650 mpl_dbg(sta->sdata, 651 "Mesh plink timer for %pM fired on state %s\n", 652 sta->sta.addr, mplstates[sta->mesh->plink_state]); 653 sdata = sta->sdata; 654 mshcfg = &sdata->u.mesh.mshcfg; 655 656 switch (sta->mesh->plink_state) { 657 case NL80211_PLINK_OPN_RCVD: 658 case NL80211_PLINK_OPN_SNT: 659 /* retry timer */ 660 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { 661 u32 rand; 662 mpl_dbg(sta->sdata, 663 "Mesh plink for %pM (retry, timeout): %d %d\n", 664 sta->sta.addr, sta->mesh->plink_retries, 665 sta->mesh->plink_timeout); 666 get_random_bytes(&rand, sizeof(u32)); 667 sta->mesh->plink_timeout = sta->mesh->plink_timeout + 668 rand % sta->mesh->plink_timeout; 669 ++sta->mesh->plink_retries; 670 mod_plink_timer(sta, sta->mesh->plink_timeout); 671 action = WLAN_SP_MESH_PEERING_OPEN; 672 break; 673 } 674 reason = WLAN_REASON_MESH_MAX_RETRIES; 675 /* fall through */ 676 case NL80211_PLINK_CNF_RCVD: 677 /* confirm timer */ 678 if (!reason) 679 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 680 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 681 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 682 action = WLAN_SP_MESH_PEERING_CLOSE; 683 break; 684 case NL80211_PLINK_HOLDING: 685 /* holding timer */ 686 del_timer(&sta->mesh->plink_timer); 687 mesh_plink_fsm_restart(sta); 688 break; 689 default: 690 break; 691 } 692 spin_unlock_bh(&sta->mesh->plink_lock); 693 if (action) 694 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 695 sta->mesh->llid, sta->mesh->plid, reason); 696 } 697 698 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 699 { 700 sta->mesh->plink_timeout = timeout; 701 mod_timer(&sta->mesh->plink_timer, jiffies + msecs_to_jiffies(timeout)); 702 } 703 704 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 705 u16 llid) 706 { 707 struct ieee80211_local *local = sdata->local; 708 bool in_use = false; 709 struct sta_info *sta; 710 711 rcu_read_lock(); 712 list_for_each_entry_rcu(sta, &local->sta_list, list) { 713 if (sdata != sta->sdata) 714 continue; 715 716 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { 717 in_use = true; 718 break; 719 } 720 } 721 rcu_read_unlock(); 722 723 return in_use; 724 } 725 726 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 727 { 728 u16 llid; 729 730 do { 731 get_random_bytes(&llid, sizeof(llid)); 732 } while (llid_in_use(sdata, llid)); 733 734 return llid; 735 } 736 737 u32 mesh_plink_open(struct sta_info *sta) 738 { 739 struct ieee80211_sub_if_data *sdata = sta->sdata; 740 u32 changed; 741 742 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 743 return 0; 744 745 spin_lock_bh(&sta->mesh->plink_lock); 746 sta->mesh->llid = mesh_get_new_llid(sdata); 747 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && 748 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { 749 spin_unlock_bh(&sta->mesh->plink_lock); 750 return 0; 751 } 752 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; 753 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 754 spin_unlock_bh(&sta->mesh->plink_lock); 755 mpl_dbg(sdata, 756 "Mesh plink: starting establishment with %pM\n", 757 sta->sta.addr); 758 759 /* set the non-peer mode to active during peering */ 760 changed = ieee80211_mps_local_status_update(sdata); 761 762 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, 763 sta->sta.addr, sta->mesh->llid, 0, 0); 764 return changed; 765 } 766 767 u32 mesh_plink_block(struct sta_info *sta) 768 { 769 u32 changed; 770 771 spin_lock_bh(&sta->mesh->plink_lock); 772 changed = __mesh_plink_deactivate(sta); 773 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 774 spin_unlock_bh(&sta->mesh->plink_lock); 775 mesh_path_flush_by_nexthop(sta); 776 777 return changed; 778 } 779 780 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 781 struct sta_info *sta, 782 enum plink_event event) 783 { 784 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 785 u16 reason = (event == CLS_ACPT) ? 786 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 787 788 sta->mesh->reason = reason; 789 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 790 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 791 } 792 793 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 794 struct sta_info *sta) 795 { 796 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 797 u32 changed = 0; 798 799 del_timer(&sta->mesh->plink_timer); 800 sta->mesh->plink_state = NL80211_PLINK_ESTAB; 801 changed |= mesh_plink_inc_estab_count(sdata); 802 changed |= mesh_set_ht_prot_mode(sdata); 803 changed |= mesh_set_short_slot_time(sdata); 804 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 805 ieee80211_mps_sta_status_update(sta); 806 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 807 return changed; 808 } 809 810 /** 811 * mesh_plink_fsm - step @sta MPM based on @event 812 * 813 * @sdata: interface 814 * @sta: mesh neighbor 815 * @event: peering event 816 * 817 * Return: changed MBSS flags 818 */ 819 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 820 struct sta_info *sta, enum plink_event event) 821 { 822 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 823 enum ieee80211_self_protected_actioncode action = 0; 824 u32 changed = 0; 825 bool flush = false; 826 827 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 828 mplstates[sta->mesh->plink_state], mplevents[event]); 829 830 spin_lock_bh(&sta->mesh->plink_lock); 831 switch (sta->mesh->plink_state) { 832 case NL80211_PLINK_LISTEN: 833 switch (event) { 834 case CLS_ACPT: 835 mesh_plink_fsm_restart(sta); 836 break; 837 case OPN_ACPT: 838 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 839 sta->mesh->llid = mesh_get_new_llid(sdata); 840 mesh_plink_timer_set(sta, 841 mshcfg->dot11MeshRetryTimeout); 842 843 /* set the non-peer mode to active during peering */ 844 changed |= ieee80211_mps_local_status_update(sdata); 845 action = WLAN_SP_MESH_PEERING_OPEN; 846 break; 847 default: 848 break; 849 } 850 break; 851 case NL80211_PLINK_OPN_SNT: 852 switch (event) { 853 case OPN_RJCT: 854 case CNF_RJCT: 855 case CLS_ACPT: 856 mesh_plink_close(sdata, sta, event); 857 action = WLAN_SP_MESH_PEERING_CLOSE; 858 break; 859 case OPN_ACPT: 860 /* retry timer is left untouched */ 861 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 862 action = WLAN_SP_MESH_PEERING_CONFIRM; 863 break; 864 case CNF_ACPT: 865 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; 866 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 867 break; 868 default: 869 break; 870 } 871 break; 872 case NL80211_PLINK_OPN_RCVD: 873 switch (event) { 874 case OPN_RJCT: 875 case CNF_RJCT: 876 case CLS_ACPT: 877 mesh_plink_close(sdata, sta, event); 878 action = WLAN_SP_MESH_PEERING_CLOSE; 879 break; 880 case OPN_ACPT: 881 action = WLAN_SP_MESH_PEERING_CONFIRM; 882 break; 883 case CNF_ACPT: 884 changed |= mesh_plink_establish(sdata, sta); 885 break; 886 default: 887 break; 888 } 889 break; 890 case NL80211_PLINK_CNF_RCVD: 891 switch (event) { 892 case OPN_RJCT: 893 case CNF_RJCT: 894 case CLS_ACPT: 895 mesh_plink_close(sdata, sta, event); 896 action = WLAN_SP_MESH_PEERING_CLOSE; 897 break; 898 case OPN_ACPT: 899 changed |= mesh_plink_establish(sdata, sta); 900 action = WLAN_SP_MESH_PEERING_CONFIRM; 901 break; 902 default: 903 break; 904 } 905 break; 906 case NL80211_PLINK_ESTAB: 907 switch (event) { 908 case CLS_ACPT: 909 changed |= __mesh_plink_deactivate(sta); 910 changed |= mesh_set_ht_prot_mode(sdata); 911 changed |= mesh_set_short_slot_time(sdata); 912 mesh_plink_close(sdata, sta, event); 913 action = WLAN_SP_MESH_PEERING_CLOSE; 914 flush = true; 915 break; 916 case OPN_ACPT: 917 action = WLAN_SP_MESH_PEERING_CONFIRM; 918 break; 919 default: 920 break; 921 } 922 break; 923 case NL80211_PLINK_HOLDING: 924 switch (event) { 925 case CLS_ACPT: 926 del_timer(&sta->mesh->plink_timer); 927 mesh_plink_fsm_restart(sta); 928 break; 929 case OPN_ACPT: 930 case CNF_ACPT: 931 case OPN_RJCT: 932 case CNF_RJCT: 933 action = WLAN_SP_MESH_PEERING_CLOSE; 934 break; 935 default: 936 break; 937 } 938 break; 939 default: 940 /* should not get here, PLINK_BLOCKED is dealt with at the 941 * beginning of the function 942 */ 943 break; 944 } 945 spin_unlock_bh(&sta->mesh->plink_lock); 946 if (flush) 947 mesh_path_flush_by_nexthop(sta); 948 if (action) { 949 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 950 sta->mesh->llid, sta->mesh->plid, 951 sta->mesh->reason); 952 953 /* also send confirm in open case */ 954 if (action == WLAN_SP_MESH_PEERING_OPEN) { 955 mesh_plink_frame_tx(sdata, sta, 956 WLAN_SP_MESH_PEERING_CONFIRM, 957 sta->sta.addr, sta->mesh->llid, 958 sta->mesh->plid, 0); 959 } 960 } 961 962 return changed; 963 } 964 965 /* 966 * mesh_plink_get_event - get correct MPM event 967 * 968 * @sdata: interface 969 * @sta: peer, leave NULL if processing a frame from a new suitable peer 970 * @elems: peering management IEs 971 * @ftype: frame type 972 * @llid: peer's peer link ID 973 * @plid: peer's local link ID 974 * 975 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 976 * an error. 977 */ 978 static enum plink_event 979 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 980 struct sta_info *sta, 981 struct ieee802_11_elems *elems, 982 enum ieee80211_self_protected_actioncode ftype, 983 u16 llid, u16 plid) 984 { 985 enum plink_event event = PLINK_UNDEFINED; 986 u8 ie_len = elems->peering_len; 987 bool matches_local; 988 989 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 990 mesh_matches_local(sdata, elems)); 991 992 /* deny open request from non-matching peer */ 993 if (!matches_local && !sta) { 994 event = OPN_RJCT; 995 goto out; 996 } 997 998 if (!sta) { 999 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 1000 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 1001 goto out; 1002 } 1003 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 1004 if (!mesh_plink_free_count(sdata)) { 1005 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 1006 goto out; 1007 } 1008 1009 /* new matching peer */ 1010 event = OPN_ACPT; 1011 goto out; 1012 } else { 1013 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 1014 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 1015 goto out; 1016 } 1017 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) 1018 goto out; 1019 } 1020 1021 switch (ftype) { 1022 case WLAN_SP_MESH_PEERING_OPEN: 1023 if (!matches_local) 1024 event = OPN_RJCT; 1025 if (!mesh_plink_free_count(sdata) || 1026 (sta->mesh->plid && sta->mesh->plid != plid)) 1027 event = OPN_IGNR; 1028 else 1029 event = OPN_ACPT; 1030 break; 1031 case WLAN_SP_MESH_PEERING_CONFIRM: 1032 if (!matches_local) 1033 event = CNF_RJCT; 1034 if (!mesh_plink_free_count(sdata) || 1035 sta->mesh->llid != llid || 1036 (sta->mesh->plid && sta->mesh->plid != plid)) 1037 event = CNF_IGNR; 1038 else 1039 event = CNF_ACPT; 1040 break; 1041 case WLAN_SP_MESH_PEERING_CLOSE: 1042 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 1043 /* Do not check for llid or plid. This does not 1044 * follow the standard but since multiple plinks 1045 * per sta are not supported, it is necessary in 1046 * order to avoid a livelock when MP A sees an 1047 * establish peer link to MP B but MP B does not 1048 * see it. This can be caused by a timeout in 1049 * B's peer link establishment or B beign 1050 * restarted. 1051 */ 1052 event = CLS_ACPT; 1053 else if (sta->mesh->plid != plid) 1054 event = CLS_IGNR; 1055 else if (ie_len == 8 && sta->mesh->llid != llid) 1056 event = CLS_IGNR; 1057 else 1058 event = CLS_ACPT; 1059 break; 1060 default: 1061 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 1062 break; 1063 } 1064 1065 out: 1066 return event; 1067 } 1068 1069 static void 1070 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1071 struct ieee80211_mgmt *mgmt, 1072 struct ieee802_11_elems *elems) 1073 { 1074 1075 struct sta_info *sta; 1076 enum plink_event event; 1077 enum ieee80211_self_protected_actioncode ftype; 1078 u32 changed = 0; 1079 u8 ie_len = elems->peering_len; 1080 u16 plid, llid = 0; 1081 1082 if (!elems->peering) { 1083 mpl_dbg(sdata, 1084 "Mesh plink: missing necessary peer link ie\n"); 1085 return; 1086 } 1087 1088 if (elems->rsn_len && 1089 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1090 mpl_dbg(sdata, 1091 "Mesh plink: can't establish link with secure peer\n"); 1092 return; 1093 } 1094 1095 ftype = mgmt->u.action.u.self_prot.action_code; 1096 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1097 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1098 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1099 && ie_len != 8)) { 1100 mpl_dbg(sdata, 1101 "Mesh plink: incorrect plink ie length %d %d\n", 1102 ftype, ie_len); 1103 return; 1104 } 1105 1106 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1107 (!elems->mesh_id || !elems->mesh_config)) { 1108 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1109 return; 1110 } 1111 /* Note the lines below are correct, the llid in the frame is the plid 1112 * from the point of view of this host. 1113 */ 1114 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1115 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1116 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1117 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1118 1119 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1120 rcu_read_lock(); 1121 1122 sta = sta_info_get(sdata, mgmt->sa); 1123 1124 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1125 !rssi_threshold_check(sdata, sta)) { 1126 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1127 mgmt->sa); 1128 goto unlock_rcu; 1129 } 1130 1131 /* Now we will figure out the appropriate event... */ 1132 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1133 1134 if (event == OPN_ACPT) { 1135 rcu_read_unlock(); 1136 /* allocate sta entry if necessary and update info */ 1137 sta = mesh_sta_info_get(sdata, mgmt->sa, elems); 1138 if (!sta) { 1139 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1140 goto unlock_rcu; 1141 } 1142 sta->mesh->plid = plid; 1143 } else if (!sta && event == OPN_RJCT) { 1144 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, 1145 mgmt->sa, 0, plid, 1146 WLAN_REASON_MESH_CONFIG); 1147 goto unlock_rcu; 1148 } else if (!sta || event == PLINK_UNDEFINED) { 1149 /* something went wrong */ 1150 goto unlock_rcu; 1151 } 1152 1153 if (event == CNF_ACPT) { 1154 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1155 if (!sta->mesh->plid) 1156 sta->mesh->plid = plid; 1157 1158 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); 1159 } 1160 1161 changed |= mesh_plink_fsm(sdata, sta, event); 1162 1163 unlock_rcu: 1164 rcu_read_unlock(); 1165 1166 if (changed) 1167 ieee80211_mbss_info_change_notify(sdata, changed); 1168 } 1169 1170 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1171 struct ieee80211_mgmt *mgmt, size_t len, 1172 struct ieee80211_rx_status *rx_status) 1173 { 1174 struct ieee802_11_elems elems; 1175 size_t baselen; 1176 u8 *baseaddr; 1177 1178 /* need action_code, aux */ 1179 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1180 return; 1181 1182 if (sdata->u.mesh.user_mpm) 1183 /* userspace must register for these */ 1184 return; 1185 1186 if (is_multicast_ether_addr(mgmt->da)) { 1187 mpl_dbg(sdata, 1188 "Mesh plink: ignore frame from multicast address\n"); 1189 return; 1190 } 1191 1192 baseaddr = mgmt->u.action.u.self_prot.variable; 1193 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1194 if (mgmt->u.action.u.self_prot.action_code == 1195 WLAN_SP_MESH_PEERING_CONFIRM) { 1196 baseaddr += 4; 1197 baselen += 4; 1198 1199 if (baselen > len) 1200 return; 1201 } 1202 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems); 1203 mesh_process_plink_frame(sdata, mgmt, &elems); 1204 } 1205