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