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 "ieee80211_i.h" 13 #include "rate.h" 14 #include "mesh.h" 15 16 #define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2) 17 #define PLINK_GET_LLID(p) (p + 2) 18 #define PLINK_GET_PLID(p) (p + 4) 19 20 #define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \ 21 jiffies + msecs_to_jiffies(t))) 22 23 enum plink_event { 24 PLINK_UNDEFINED, 25 OPN_ACPT, 26 OPN_RJCT, 27 OPN_IGNR, 28 CNF_ACPT, 29 CNF_RJCT, 30 CNF_IGNR, 31 CLS_ACPT, 32 CLS_IGNR 33 }; 34 35 static const char * const mplstates[] = { 36 [NL80211_PLINK_LISTEN] = "LISTEN", 37 [NL80211_PLINK_OPN_SNT] = "OPN-SNT", 38 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD", 39 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD", 40 [NL80211_PLINK_ESTAB] = "ESTAB", 41 [NL80211_PLINK_HOLDING] = "HOLDING", 42 [NL80211_PLINK_BLOCKED] = "BLOCKED" 43 }; 44 45 static const char * const mplevents[] = { 46 [PLINK_UNDEFINED] = "NONE", 47 [OPN_ACPT] = "OPN_ACPT", 48 [OPN_RJCT] = "OPN_RJCT", 49 [OPN_IGNR] = "OPN_IGNR", 50 [CNF_ACPT] = "CNF_ACPT", 51 [CNF_RJCT] = "CNF_RJCT", 52 [CNF_IGNR] = "CNF_IGNR", 53 [CLS_ACPT] = "CLS_ACPT", 54 [CLS_IGNR] = "CLS_IGNR" 55 }; 56 57 /* We only need a valid sta if user configured a minimum rssi_threshold. */ 58 static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata, 59 struct sta_info *sta) 60 { 61 s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold; 62 return rssi_threshold == 0 || 63 (sta && (s8) -ewma_signal_read(&sta->avg_signal) > rssi_threshold); 64 } 65 66 /** 67 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine 68 * 69 * @sta: mesh peer link to restart 70 * 71 * Locking: this function must be called holding sta->mesh->plink_lock 72 */ 73 static inline void mesh_plink_fsm_restart(struct sta_info *sta) 74 { 75 lockdep_assert_held(&sta->mesh->plink_lock); 76 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 77 sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0; 78 sta->mesh->plink_retries = 0; 79 } 80 81 /* 82 * mesh_set_short_slot_time - enable / disable ERP short slot time. 83 * 84 * The standard indirectly mandates mesh STAs to turn off short slot time by 85 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we 86 * can't be sneaky about it. Enable short slot time if all mesh STAs in the 87 * MBSS support ERP rates. 88 * 89 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change. 90 */ 91 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata) 92 { 93 struct ieee80211_local *local = sdata->local; 94 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 95 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 96 struct sta_info *sta; 97 u32 erp_rates = 0, changed = 0; 98 int i; 99 bool short_slot = false; 100 101 if (band == IEEE80211_BAND_5GHZ) { 102 /* (IEEE 802.11-2012 19.4.5) */ 103 short_slot = true; 104 goto out; 105 } else if (band != IEEE80211_BAND_2GHZ) 106 goto out; 107 108 for (i = 0; i < sband->n_bitrates; i++) 109 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G) 110 erp_rates |= BIT(i); 111 112 if (!erp_rates) 113 goto out; 114 115 rcu_read_lock(); 116 list_for_each_entry_rcu(sta, &local->sta_list, list) { 117 if (sdata != sta->sdata || 118 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 119 continue; 120 121 short_slot = false; 122 if (erp_rates & sta->sta.supp_rates[band]) 123 short_slot = true; 124 else 125 break; 126 } 127 rcu_read_unlock(); 128 129 out: 130 if (sdata->vif.bss_conf.use_short_slot != short_slot) { 131 sdata->vif.bss_conf.use_short_slot = short_slot; 132 changed = BSS_CHANGED_ERP_SLOT; 133 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n", 134 sdata->vif.addr, short_slot); 135 } 136 return changed; 137 } 138 139 /** 140 * mesh_set_ht_prot_mode - set correct HT protection mode 141 * 142 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT 143 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT 144 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is 145 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode 146 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one 147 * HT20 peer is present. Otherwise no-protection mode is selected. 148 */ 149 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) 150 { 151 struct ieee80211_local *local = sdata->local; 152 struct sta_info *sta; 153 u16 ht_opmode; 154 bool non_ht_sta = false, ht20_sta = false; 155 156 switch (sdata->vif.bss_conf.chandef.width) { 157 case NL80211_CHAN_WIDTH_20_NOHT: 158 case NL80211_CHAN_WIDTH_5: 159 case NL80211_CHAN_WIDTH_10: 160 return 0; 161 default: 162 break; 163 } 164 165 rcu_read_lock(); 166 list_for_each_entry_rcu(sta, &local->sta_list, list) { 167 if (sdata != sta->sdata || 168 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 169 continue; 170 171 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20) 172 continue; 173 174 if (!sta->sta.ht_cap.ht_supported) { 175 mpl_dbg(sdata, "nonHT sta (%pM) is present\n", 176 sta->sta.addr); 177 non_ht_sta = true; 178 break; 179 } 180 181 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); 182 ht20_sta = true; 183 } 184 rcu_read_unlock(); 185 186 if (non_ht_sta) 187 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; 188 else if (ht20_sta && 189 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20) 190 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; 191 else 192 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; 193 194 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) 195 return 0; 196 197 sdata->vif.bss_conf.ht_operation_mode = ht_opmode; 198 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; 199 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); 200 return BSS_CHANGED_HT; 201 } 202 203 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 204 struct sta_info *sta, 205 enum ieee80211_self_protected_actioncode action, 206 u8 *da, u16 llid, u16 plid, u16 reason) 207 { 208 struct ieee80211_local *local = sdata->local; 209 struct sk_buff *skb; 210 struct ieee80211_tx_info *info; 211 struct ieee80211_mgmt *mgmt; 212 bool include_plid = false; 213 u16 peering_proto = 0; 214 u8 *pos, ie_len = 4; 215 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) + 216 sizeof(mgmt->u.action.u.self_prot); 217 int err = -ENOMEM; 218 219 skb = dev_alloc_skb(local->tx_headroom + 220 hdr_len + 221 2 + /* capability info */ 222 2 + /* AID */ 223 2 + 8 + /* supported rates */ 224 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 225 2 + sdata->u.mesh.mesh_id_len + 226 2 + sizeof(struct ieee80211_meshconf_ie) + 227 2 + sizeof(struct ieee80211_ht_cap) + 228 2 + sizeof(struct ieee80211_ht_operation) + 229 2 + 8 + /* peering IE */ 230 sdata->u.mesh.ie_len); 231 if (!skb) 232 return err; 233 info = IEEE80211_SKB_CB(skb); 234 skb_reserve(skb, local->tx_headroom); 235 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len); 236 memset(mgmt, 0, hdr_len); 237 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 238 IEEE80211_STYPE_ACTION); 239 memcpy(mgmt->da, da, ETH_ALEN); 240 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 241 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 242 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; 243 mgmt->u.action.u.self_prot.action_code = action; 244 245 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 246 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 247 248 /* capability info */ 249 pos = skb_put(skb, 2); 250 memset(pos, 0, 2); 251 if (action == WLAN_SP_MESH_PEERING_CONFIRM) { 252 /* AID */ 253 pos = skb_put(skb, 2); 254 put_unaligned_le16(sta->sta.aid, pos); 255 } 256 if (ieee80211_add_srates_ie(sdata, skb, true, band) || 257 ieee80211_add_ext_srates_ie(sdata, skb, true, band) || 258 mesh_add_rsn_ie(sdata, skb) || 259 mesh_add_meshid_ie(sdata, skb) || 260 mesh_add_meshconf_ie(sdata, skb)) 261 goto free; 262 } else { /* WLAN_SP_MESH_PEERING_CLOSE */ 263 info->flags |= IEEE80211_TX_CTL_NO_ACK; 264 if (mesh_add_meshid_ie(sdata, skb)) 265 goto free; 266 } 267 268 /* Add Mesh Peering Management element */ 269 switch (action) { 270 case WLAN_SP_MESH_PEERING_OPEN: 271 break; 272 case WLAN_SP_MESH_PEERING_CONFIRM: 273 ie_len += 2; 274 include_plid = true; 275 break; 276 case WLAN_SP_MESH_PEERING_CLOSE: 277 if (plid) { 278 ie_len += 2; 279 include_plid = true; 280 } 281 ie_len += 2; /* reason code */ 282 break; 283 default: 284 err = -EINVAL; 285 goto free; 286 } 287 288 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) 289 goto free; 290 291 pos = skb_put(skb, 2 + ie_len); 292 *pos++ = WLAN_EID_PEER_MGMT; 293 *pos++ = ie_len; 294 memcpy(pos, &peering_proto, 2); 295 pos += 2; 296 put_unaligned_le16(llid, pos); 297 pos += 2; 298 if (include_plid) { 299 put_unaligned_le16(plid, pos); 300 pos += 2; 301 } 302 if (action == WLAN_SP_MESH_PEERING_CLOSE) { 303 put_unaligned_le16(reason, pos); 304 pos += 2; 305 } 306 307 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 308 if (mesh_add_ht_cap_ie(sdata, skb) || 309 mesh_add_ht_oper_ie(sdata, skb)) 310 goto free; 311 } 312 313 if (mesh_add_vendor_ies(sdata, skb)) 314 goto free; 315 316 ieee80211_tx_skb(sdata, skb); 317 return 0; 318 free: 319 kfree_skb(skb); 320 return err; 321 } 322 323 /** 324 * __mesh_plink_deactivate - deactivate mesh peer link 325 * 326 * @sta: mesh peer link to deactivate 327 * 328 * All mesh paths with this peer as next hop will be flushed 329 * Returns beacon changed flag if the beacon content changed. 330 * 331 * Locking: the caller must hold sta->mesh->plink_lock 332 */ 333 static u32 __mesh_plink_deactivate(struct sta_info *sta) 334 { 335 struct ieee80211_sub_if_data *sdata = sta->sdata; 336 u32 changed = 0; 337 338 lockdep_assert_held(&sta->mesh->plink_lock); 339 340 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 341 changed = mesh_plink_dec_estab_count(sdata); 342 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 343 mesh_path_flush_by_nexthop(sta); 344 345 ieee80211_mps_sta_status_update(sta); 346 changed |= ieee80211_mps_set_sta_local_pm(sta, 347 NL80211_MESH_POWER_UNKNOWN); 348 349 return changed; 350 } 351 352 /** 353 * mesh_plink_deactivate - deactivate mesh peer link 354 * 355 * @sta: mesh peer link to deactivate 356 * 357 * All mesh paths with this peer as next hop will be flushed 358 */ 359 u32 mesh_plink_deactivate(struct sta_info *sta) 360 { 361 struct ieee80211_sub_if_data *sdata = sta->sdata; 362 u32 changed; 363 364 spin_lock_bh(&sta->mesh->plink_lock); 365 changed = __mesh_plink_deactivate(sta); 366 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED; 367 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE, 368 sta->sta.addr, sta->mesh->llid, sta->mesh->plid, 369 sta->mesh->reason); 370 spin_unlock_bh(&sta->mesh->plink_lock); 371 372 return changed; 373 } 374 375 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 376 struct sta_info *sta, 377 struct ieee802_11_elems *elems, bool insert) 378 { 379 struct ieee80211_local *local = sdata->local; 380 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 381 struct ieee80211_supported_band *sband; 382 u32 rates, basic_rates = 0, changed = 0; 383 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth; 384 385 sband = local->hw.wiphy->bands[band]; 386 rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates); 387 388 spin_lock_bh(&sta->mesh->plink_lock); 389 sta->last_rx = jiffies; 390 391 /* rates and capabilities don't change during peering */ 392 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB && 393 sta->mesh->processed_beacon) 394 goto out; 395 sta->mesh->processed_beacon = true; 396 397 if (sta->sta.supp_rates[band] != rates) 398 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 399 sta->sta.supp_rates[band] = rates; 400 401 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 402 elems->ht_cap_elem, sta)) 403 changed |= IEEE80211_RC_BW_CHANGED; 404 405 if (bw != sta->sta.bandwidth) 406 changed |= IEEE80211_RC_BW_CHANGED; 407 408 /* HT peer is operating 20MHz-only */ 409 if (elems->ht_operation && 410 !(elems->ht_operation->ht_param & 411 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 412 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) 413 changed |= IEEE80211_RC_BW_CHANGED; 414 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; 415 } 416 417 if (insert) 418 rate_control_rate_init(sta); 419 else 420 rate_control_rate_update(local, sband, sta, changed); 421 out: 422 spin_unlock_bh(&sta->mesh->plink_lock); 423 } 424 425 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) 426 { 427 struct sta_info *sta; 428 unsigned long *aid_map; 429 int aid; 430 431 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1), 432 sizeof(*aid_map), GFP_KERNEL); 433 if (!aid_map) 434 return -ENOMEM; 435 436 /* reserve aid 0 for mcast indication */ 437 __set_bit(0, aid_map); 438 439 rcu_read_lock(); 440 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) 441 __set_bit(sta->sta.aid, aid_map); 442 rcu_read_unlock(); 443 444 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); 445 kfree(aid_map); 446 447 if (aid > IEEE80211_MAX_AID) 448 return -ENOBUFS; 449 450 return aid; 451 } 452 453 static struct sta_info * 454 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 455 { 456 struct sta_info *sta; 457 int aid; 458 459 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 460 return NULL; 461 462 aid = mesh_allocate_aid(sdata); 463 if (aid < 0) 464 return NULL; 465 466 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 467 if (!sta) 468 return NULL; 469 470 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 471 sta->sta.wme = true; 472 sta->sta.aid = aid; 473 474 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 475 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 476 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 477 478 return sta; 479 } 480 481 static struct sta_info * 482 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 483 struct ieee802_11_elems *elems) 484 { 485 struct sta_info *sta = NULL; 486 487 /* Userspace handles station allocation */ 488 if (sdata->u.mesh.user_mpm || 489 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) 490 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 491 elems->ie_start, 492 elems->total_len, 493 GFP_KERNEL); 494 else 495 sta = __mesh_sta_info_alloc(sdata, addr); 496 497 return sta; 498 } 499 500 /* 501 * mesh_sta_info_get - return mesh sta info entry for @addr. 502 * 503 * @sdata: local meshif 504 * @addr: peer's address 505 * @elems: IEs from beacon or mesh peering frame. 506 * 507 * Return existing or newly allocated sta_info under RCU read lock. 508 * (re)initialize with given IEs. 509 */ 510 static struct sta_info * 511 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 512 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU) 513 { 514 struct sta_info *sta = NULL; 515 516 rcu_read_lock(); 517 sta = sta_info_get(sdata, addr); 518 if (sta) { 519 mesh_sta_info_init(sdata, sta, elems, false); 520 } else { 521 rcu_read_unlock(); 522 /* can't run atomic */ 523 sta = mesh_sta_info_alloc(sdata, addr, elems); 524 if (!sta) { 525 rcu_read_lock(); 526 return NULL; 527 } 528 529 mesh_sta_info_init(sdata, sta, elems, true); 530 531 if (sta_info_insert_rcu(sta)) 532 return NULL; 533 } 534 535 return sta; 536 } 537 538 /* 539 * mesh_neighbour_update - update or initialize new mesh neighbor. 540 * 541 * @sdata: local meshif 542 * @addr: peer's address 543 * @elems: IEs from beacon or mesh peering frame 544 * 545 * Initiates peering if appropriate. 546 */ 547 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 548 u8 *hw_addr, 549 struct ieee802_11_elems *elems) 550 { 551 struct sta_info *sta; 552 u32 changed = 0; 553 554 sta = mesh_sta_info_get(sdata, hw_addr, elems); 555 if (!sta) 556 goto out; 557 558 if (mesh_peer_accepts_plinks(elems) && 559 sta->mesh->plink_state == NL80211_PLINK_LISTEN && 560 sdata->u.mesh.accepting_plinks && 561 sdata->u.mesh.mshcfg.auto_open_plinks && 562 rssi_threshold_check(sdata, sta)) 563 changed = mesh_plink_open(sta); 564 565 ieee80211_mps_frame_release(sta, elems); 566 out: 567 rcu_read_unlock(); 568 ieee80211_mbss_info_change_notify(sdata, changed); 569 } 570 571 static void mesh_plink_timer(unsigned long data) 572 { 573 struct sta_info *sta; 574 u16 reason = 0; 575 struct ieee80211_sub_if_data *sdata; 576 struct mesh_config *mshcfg; 577 enum ieee80211_self_protected_actioncode action = 0; 578 579 /* 580 * This STA is valid because sta_info_destroy() will 581 * del_timer_sync() this timer after having made sure 582 * it cannot be readded (by deleting the plink.) 583 */ 584 sta = (struct sta_info *) data; 585 586 if (sta->sdata->local->quiescing) 587 return; 588 589 spin_lock_bh(&sta->mesh->plink_lock); 590 591 /* If a timer fires just before a state transition on another CPU, 592 * we may have already extended the timeout and changed state by the 593 * time we've acquired the lock and arrived here. In that case, 594 * skip this timer and wait for the new one. 595 */ 596 if (time_before(jiffies, sta->mesh->plink_timer.expires)) { 597 mpl_dbg(sta->sdata, 598 "Ignoring timer for %pM in state %s (timer adjusted)", 599 sta->sta.addr, mplstates[sta->mesh->plink_state]); 600 spin_unlock_bh(&sta->mesh->plink_lock); 601 return; 602 } 603 604 /* del_timer() and handler may race when entering these states */ 605 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || 606 sta->mesh->plink_state == NL80211_PLINK_ESTAB) { 607 mpl_dbg(sta->sdata, 608 "Ignoring timer for %pM in state %s (timer deleted)", 609 sta->sta.addr, mplstates[sta->mesh->plink_state]); 610 spin_unlock_bh(&sta->mesh->plink_lock); 611 return; 612 } 613 614 mpl_dbg(sta->sdata, 615 "Mesh plink timer for %pM fired on state %s\n", 616 sta->sta.addr, mplstates[sta->mesh->plink_state]); 617 sdata = sta->sdata; 618 mshcfg = &sdata->u.mesh.mshcfg; 619 620 switch (sta->mesh->plink_state) { 621 case NL80211_PLINK_OPN_RCVD: 622 case NL80211_PLINK_OPN_SNT: 623 /* retry timer */ 624 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { 625 u32 rand; 626 mpl_dbg(sta->sdata, 627 "Mesh plink for %pM (retry, timeout): %d %d\n", 628 sta->sta.addr, sta->mesh->plink_retries, 629 sta->mesh->plink_timeout); 630 get_random_bytes(&rand, sizeof(u32)); 631 sta->mesh->plink_timeout = sta->mesh->plink_timeout + 632 rand % sta->mesh->plink_timeout; 633 ++sta->mesh->plink_retries; 634 mod_plink_timer(sta, sta->mesh->plink_timeout); 635 action = WLAN_SP_MESH_PEERING_OPEN; 636 break; 637 } 638 reason = WLAN_REASON_MESH_MAX_RETRIES; 639 /* fall through on else */ 640 case NL80211_PLINK_CNF_RCVD: 641 /* confirm timer */ 642 if (!reason) 643 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 644 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 645 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 646 action = WLAN_SP_MESH_PEERING_CLOSE; 647 break; 648 case NL80211_PLINK_HOLDING: 649 /* holding timer */ 650 del_timer(&sta->mesh->plink_timer); 651 mesh_plink_fsm_restart(sta); 652 break; 653 default: 654 break; 655 } 656 spin_unlock_bh(&sta->mesh->plink_lock); 657 if (action) 658 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 659 sta->mesh->llid, sta->mesh->plid, reason); 660 } 661 662 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 663 { 664 sta->mesh->plink_timer.expires = jiffies + msecs_to_jiffies(timeout); 665 sta->mesh->plink_timer.data = (unsigned long) sta; 666 sta->mesh->plink_timer.function = mesh_plink_timer; 667 sta->mesh->plink_timeout = timeout; 668 add_timer(&sta->mesh->plink_timer); 669 } 670 671 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 672 u16 llid) 673 { 674 struct ieee80211_local *local = sdata->local; 675 bool in_use = false; 676 struct sta_info *sta; 677 678 rcu_read_lock(); 679 list_for_each_entry_rcu(sta, &local->sta_list, list) { 680 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { 681 in_use = true; 682 break; 683 } 684 } 685 rcu_read_unlock(); 686 687 return in_use; 688 } 689 690 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 691 { 692 u16 llid; 693 694 do { 695 get_random_bytes(&llid, sizeof(llid)); 696 } while (llid_in_use(sdata, llid)); 697 698 return llid; 699 } 700 701 u32 mesh_plink_open(struct sta_info *sta) 702 { 703 struct ieee80211_sub_if_data *sdata = sta->sdata; 704 u32 changed; 705 706 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 707 return 0; 708 709 spin_lock_bh(&sta->mesh->plink_lock); 710 sta->mesh->llid = mesh_get_new_llid(sdata); 711 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && 712 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { 713 spin_unlock_bh(&sta->mesh->plink_lock); 714 return 0; 715 } 716 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; 717 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 718 spin_unlock_bh(&sta->mesh->plink_lock); 719 mpl_dbg(sdata, 720 "Mesh plink: starting establishment with %pM\n", 721 sta->sta.addr); 722 723 /* set the non-peer mode to active during peering */ 724 changed = ieee80211_mps_local_status_update(sdata); 725 726 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, 727 sta->sta.addr, sta->mesh->llid, 0, 0); 728 return changed; 729 } 730 731 u32 mesh_plink_block(struct sta_info *sta) 732 { 733 u32 changed; 734 735 spin_lock_bh(&sta->mesh->plink_lock); 736 changed = __mesh_plink_deactivate(sta); 737 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 738 spin_unlock_bh(&sta->mesh->plink_lock); 739 740 return changed; 741 } 742 743 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 744 struct sta_info *sta, 745 enum plink_event event) 746 { 747 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 748 u16 reason = (event == CLS_ACPT) ? 749 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 750 751 sta->mesh->reason = reason; 752 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 753 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 754 } 755 756 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 757 struct sta_info *sta) 758 { 759 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 760 u32 changed = 0; 761 762 del_timer(&sta->mesh->plink_timer); 763 sta->mesh->plink_state = NL80211_PLINK_ESTAB; 764 changed |= mesh_plink_inc_estab_count(sdata); 765 changed |= mesh_set_ht_prot_mode(sdata); 766 changed |= mesh_set_short_slot_time(sdata); 767 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 768 ieee80211_mps_sta_status_update(sta); 769 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 770 return changed; 771 } 772 773 /** 774 * mesh_plink_fsm - step @sta MPM based on @event 775 * 776 * @sdata: interface 777 * @sta: mesh neighbor 778 * @event: peering event 779 * 780 * Return: changed MBSS flags 781 */ 782 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 783 struct sta_info *sta, enum plink_event event) 784 { 785 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 786 enum ieee80211_self_protected_actioncode action = 0; 787 u32 changed = 0; 788 789 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 790 mplstates[sta->mesh->plink_state], mplevents[event]); 791 792 spin_lock_bh(&sta->mesh->plink_lock); 793 switch (sta->mesh->plink_state) { 794 case NL80211_PLINK_LISTEN: 795 switch (event) { 796 case CLS_ACPT: 797 mesh_plink_fsm_restart(sta); 798 break; 799 case OPN_ACPT: 800 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 801 sta->mesh->llid = mesh_get_new_llid(sdata); 802 mesh_plink_timer_set(sta, 803 mshcfg->dot11MeshRetryTimeout); 804 805 /* set the non-peer mode to active during peering */ 806 changed |= ieee80211_mps_local_status_update(sdata); 807 action = WLAN_SP_MESH_PEERING_OPEN; 808 break; 809 default: 810 break; 811 } 812 break; 813 case NL80211_PLINK_OPN_SNT: 814 switch (event) { 815 case OPN_RJCT: 816 case CNF_RJCT: 817 case CLS_ACPT: 818 mesh_plink_close(sdata, sta, event); 819 action = WLAN_SP_MESH_PEERING_CLOSE; 820 break; 821 case OPN_ACPT: 822 /* retry timer is left untouched */ 823 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 824 action = WLAN_SP_MESH_PEERING_CONFIRM; 825 break; 826 case CNF_ACPT: 827 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; 828 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 829 break; 830 default: 831 break; 832 } 833 break; 834 case NL80211_PLINK_OPN_RCVD: 835 switch (event) { 836 case OPN_RJCT: 837 case CNF_RJCT: 838 case CLS_ACPT: 839 mesh_plink_close(sdata, sta, event); 840 action = WLAN_SP_MESH_PEERING_CLOSE; 841 break; 842 case OPN_ACPT: 843 action = WLAN_SP_MESH_PEERING_CONFIRM; 844 break; 845 case CNF_ACPT: 846 changed |= mesh_plink_establish(sdata, sta); 847 break; 848 default: 849 break; 850 } 851 break; 852 case NL80211_PLINK_CNF_RCVD: 853 switch (event) { 854 case OPN_RJCT: 855 case CNF_RJCT: 856 case CLS_ACPT: 857 mesh_plink_close(sdata, sta, event); 858 action = WLAN_SP_MESH_PEERING_CLOSE; 859 break; 860 case OPN_ACPT: 861 changed |= mesh_plink_establish(sdata, sta); 862 action = WLAN_SP_MESH_PEERING_CONFIRM; 863 break; 864 default: 865 break; 866 } 867 break; 868 case NL80211_PLINK_ESTAB: 869 switch (event) { 870 case CLS_ACPT: 871 changed |= __mesh_plink_deactivate(sta); 872 changed |= mesh_set_ht_prot_mode(sdata); 873 changed |= mesh_set_short_slot_time(sdata); 874 mesh_plink_close(sdata, sta, event); 875 action = WLAN_SP_MESH_PEERING_CLOSE; 876 break; 877 case OPN_ACPT: 878 action = WLAN_SP_MESH_PEERING_CONFIRM; 879 break; 880 default: 881 break; 882 } 883 break; 884 case NL80211_PLINK_HOLDING: 885 switch (event) { 886 case CLS_ACPT: 887 del_timer(&sta->mesh->plink_timer); 888 mesh_plink_fsm_restart(sta); 889 break; 890 case OPN_ACPT: 891 case CNF_ACPT: 892 case OPN_RJCT: 893 case CNF_RJCT: 894 action = WLAN_SP_MESH_PEERING_CLOSE; 895 break; 896 default: 897 break; 898 } 899 break; 900 default: 901 /* should not get here, PLINK_BLOCKED is dealt with at the 902 * beginning of the function 903 */ 904 break; 905 } 906 spin_unlock_bh(&sta->mesh->plink_lock); 907 if (action) { 908 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 909 sta->mesh->llid, sta->mesh->plid, 910 sta->mesh->reason); 911 912 /* also send confirm in open case */ 913 if (action == WLAN_SP_MESH_PEERING_OPEN) { 914 mesh_plink_frame_tx(sdata, sta, 915 WLAN_SP_MESH_PEERING_CONFIRM, 916 sta->sta.addr, sta->mesh->llid, 917 sta->mesh->plid, 0); 918 } 919 } 920 921 return changed; 922 } 923 924 /* 925 * mesh_plink_get_event - get correct MPM event 926 * 927 * @sdata: interface 928 * @sta: peer, leave NULL if processing a frame from a new suitable peer 929 * @elems: peering management IEs 930 * @ftype: frame type 931 * @llid: peer's peer link ID 932 * @plid: peer's local link ID 933 * 934 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 935 * an error. 936 */ 937 static enum plink_event 938 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 939 struct sta_info *sta, 940 struct ieee802_11_elems *elems, 941 enum ieee80211_self_protected_actioncode ftype, 942 u16 llid, u16 plid) 943 { 944 enum plink_event event = PLINK_UNDEFINED; 945 u8 ie_len = elems->peering_len; 946 bool matches_local; 947 948 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 949 mesh_matches_local(sdata, elems)); 950 951 /* deny open request from non-matching peer */ 952 if (!matches_local && !sta) { 953 event = OPN_RJCT; 954 goto out; 955 } 956 957 if (!sta) { 958 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 959 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 960 goto out; 961 } 962 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 963 if (!mesh_plink_free_count(sdata)) { 964 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 965 goto out; 966 } 967 } else { 968 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 969 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 970 goto out; 971 } 972 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) 973 goto out; 974 } 975 976 /* new matching peer */ 977 if (!sta) { 978 event = OPN_ACPT; 979 goto out; 980 } 981 982 switch (ftype) { 983 case WLAN_SP_MESH_PEERING_OPEN: 984 if (!matches_local) 985 event = OPN_RJCT; 986 if (!mesh_plink_free_count(sdata) || 987 (sta->mesh->plid && sta->mesh->plid != plid)) 988 event = OPN_IGNR; 989 else 990 event = OPN_ACPT; 991 break; 992 case WLAN_SP_MESH_PEERING_CONFIRM: 993 if (!matches_local) 994 event = CNF_RJCT; 995 if (!mesh_plink_free_count(sdata) || 996 sta->mesh->llid != llid || 997 (sta->mesh->plid && sta->mesh->plid != plid)) 998 event = CNF_IGNR; 999 else 1000 event = CNF_ACPT; 1001 break; 1002 case WLAN_SP_MESH_PEERING_CLOSE: 1003 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 1004 /* Do not check for llid or plid. This does not 1005 * follow the standard but since multiple plinks 1006 * per sta are not supported, it is necessary in 1007 * order to avoid a livelock when MP A sees an 1008 * establish peer link to MP B but MP B does not 1009 * see it. This can be caused by a timeout in 1010 * B's peer link establishment or B beign 1011 * restarted. 1012 */ 1013 event = CLS_ACPT; 1014 else if (sta->mesh->plid != plid) 1015 event = CLS_IGNR; 1016 else if (ie_len == 8 && sta->mesh->llid != llid) 1017 event = CLS_IGNR; 1018 else 1019 event = CLS_ACPT; 1020 break; 1021 default: 1022 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 1023 break; 1024 } 1025 1026 out: 1027 return event; 1028 } 1029 1030 static void 1031 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1032 struct ieee80211_mgmt *mgmt, 1033 struct ieee802_11_elems *elems) 1034 { 1035 1036 struct sta_info *sta; 1037 enum plink_event event; 1038 enum ieee80211_self_protected_actioncode ftype; 1039 u32 changed = 0; 1040 u8 ie_len = elems->peering_len; 1041 u16 plid, llid = 0; 1042 1043 if (!elems->peering) { 1044 mpl_dbg(sdata, 1045 "Mesh plink: missing necessary peer link ie\n"); 1046 return; 1047 } 1048 1049 if (elems->rsn_len && 1050 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1051 mpl_dbg(sdata, 1052 "Mesh plink: can't establish link with secure peer\n"); 1053 return; 1054 } 1055 1056 ftype = mgmt->u.action.u.self_prot.action_code; 1057 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1058 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1059 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1060 && ie_len != 8)) { 1061 mpl_dbg(sdata, 1062 "Mesh plink: incorrect plink ie length %d %d\n", 1063 ftype, ie_len); 1064 return; 1065 } 1066 1067 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1068 (!elems->mesh_id || !elems->mesh_config)) { 1069 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1070 return; 1071 } 1072 /* Note the lines below are correct, the llid in the frame is the plid 1073 * from the point of view of this host. 1074 */ 1075 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1076 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1077 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1078 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1079 1080 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1081 rcu_read_lock(); 1082 1083 sta = sta_info_get(sdata, mgmt->sa); 1084 1085 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1086 !rssi_threshold_check(sdata, sta)) { 1087 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1088 mgmt->sa); 1089 goto unlock_rcu; 1090 } 1091 1092 /* Now we will figure out the appropriate event... */ 1093 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1094 1095 if (event == OPN_ACPT) { 1096 rcu_read_unlock(); 1097 /* allocate sta entry if necessary and update info */ 1098 sta = mesh_sta_info_get(sdata, mgmt->sa, elems); 1099 if (!sta) { 1100 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1101 goto unlock_rcu; 1102 } 1103 sta->mesh->plid = plid; 1104 } else if (!sta && event == OPN_RJCT) { 1105 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, 1106 mgmt->sa, 0, plid, 1107 WLAN_REASON_MESH_CONFIG); 1108 goto unlock_rcu; 1109 } else if (!sta || event == PLINK_UNDEFINED) { 1110 /* something went wrong */ 1111 goto unlock_rcu; 1112 } 1113 1114 if (event == CNF_ACPT) { 1115 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1116 if (!sta->mesh->plid) 1117 sta->mesh->plid = plid; 1118 1119 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); 1120 } 1121 1122 changed |= mesh_plink_fsm(sdata, sta, event); 1123 1124 unlock_rcu: 1125 rcu_read_unlock(); 1126 1127 if (changed) 1128 ieee80211_mbss_info_change_notify(sdata, changed); 1129 } 1130 1131 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1132 struct ieee80211_mgmt *mgmt, size_t len, 1133 struct ieee80211_rx_status *rx_status) 1134 { 1135 struct ieee802_11_elems elems; 1136 size_t baselen; 1137 u8 *baseaddr; 1138 1139 /* need action_code, aux */ 1140 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1141 return; 1142 1143 if (sdata->u.mesh.user_mpm) 1144 /* userspace must register for these */ 1145 return; 1146 1147 if (is_multicast_ether_addr(mgmt->da)) { 1148 mpl_dbg(sdata, 1149 "Mesh plink: ignore frame from multicast address\n"); 1150 return; 1151 } 1152 1153 baseaddr = mgmt->u.action.u.self_prot.variable; 1154 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1155 if (mgmt->u.action.u.self_prot.action_code == 1156 WLAN_SP_MESH_PEERING_CONFIRM) { 1157 baseaddr += 4; 1158 baselen += 4; 1159 1160 if (baselen > len) 1161 return; 1162 } 1163 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems); 1164 mesh_process_plink_frame(sdata, mgmt, &elems); 1165 } 1166