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 enum nl80211_band band = ieee80211_get_sdata_band(sdata); 99 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 100 struct sta_info *sta; 101 u32 erp_rates = 0, changed = 0; 102 int i; 103 bool short_slot = false; 104 105 if (band == NL80211_BAND_5GHZ) { 106 /* (IEEE 802.11-2012 19.4.5) */ 107 short_slot = true; 108 goto out; 109 } else if (band != NL80211_BAND_2GHZ) 110 goto out; 111 112 for (i = 0; i < sband->n_bitrates; i++) 113 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G) 114 erp_rates |= BIT(i); 115 116 if (!erp_rates) 117 goto out; 118 119 rcu_read_lock(); 120 list_for_each_entry_rcu(sta, &local->sta_list, list) { 121 if (sdata != sta->sdata || 122 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 123 continue; 124 125 short_slot = false; 126 if (erp_rates & sta->sta.supp_rates[band]) 127 short_slot = true; 128 else 129 break; 130 } 131 rcu_read_unlock(); 132 133 out: 134 if (sdata->vif.bss_conf.use_short_slot != short_slot) { 135 sdata->vif.bss_conf.use_short_slot = short_slot; 136 changed = BSS_CHANGED_ERP_SLOT; 137 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n", 138 sdata->vif.addr, short_slot); 139 } 140 return changed; 141 } 142 143 /** 144 * mesh_set_ht_prot_mode - set correct HT protection mode 145 * 146 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT 147 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT 148 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is 149 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode 150 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one 151 * HT20 peer is present. Otherwise no-protection mode is selected. 152 */ 153 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) 154 { 155 struct ieee80211_local *local = sdata->local; 156 struct sta_info *sta; 157 u16 ht_opmode; 158 bool non_ht_sta = false, ht20_sta = false; 159 160 switch (sdata->vif.bss_conf.chandef.width) { 161 case NL80211_CHAN_WIDTH_20_NOHT: 162 case NL80211_CHAN_WIDTH_5: 163 case NL80211_CHAN_WIDTH_10: 164 return 0; 165 default: 166 break; 167 } 168 169 rcu_read_lock(); 170 list_for_each_entry_rcu(sta, &local->sta_list, list) { 171 if (sdata != sta->sdata || 172 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 173 continue; 174 175 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20) 176 continue; 177 178 if (!sta->sta.ht_cap.ht_supported) { 179 mpl_dbg(sdata, "nonHT sta (%pM) is present\n", 180 sta->sta.addr); 181 non_ht_sta = true; 182 break; 183 } 184 185 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); 186 ht20_sta = true; 187 } 188 rcu_read_unlock(); 189 190 if (non_ht_sta) 191 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; 192 else if (ht20_sta && 193 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20) 194 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; 195 else 196 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; 197 198 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) 199 return 0; 200 201 sdata->vif.bss_conf.ht_operation_mode = ht_opmode; 202 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; 203 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); 204 return BSS_CHANGED_HT; 205 } 206 207 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 208 struct sta_info *sta, 209 enum ieee80211_self_protected_actioncode action, 210 u8 *da, u16 llid, u16 plid, u16 reason) 211 { 212 struct ieee80211_local *local = sdata->local; 213 struct sk_buff *skb; 214 struct ieee80211_tx_info *info; 215 struct ieee80211_mgmt *mgmt; 216 bool include_plid = false; 217 u16 peering_proto = 0; 218 u8 *pos, ie_len = 4; 219 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) + 220 sizeof(mgmt->u.action.u.self_prot); 221 int err = -ENOMEM; 222 223 skb = dev_alloc_skb(local->tx_headroom + 224 hdr_len + 225 2 + /* capability info */ 226 2 + /* AID */ 227 2 + 8 + /* supported rates */ 228 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 229 2 + sdata->u.mesh.mesh_id_len + 230 2 + sizeof(struct ieee80211_meshconf_ie) + 231 2 + sizeof(struct ieee80211_ht_cap) + 232 2 + sizeof(struct ieee80211_ht_operation) + 233 2 + sizeof(struct ieee80211_vht_cap) + 234 2 + sizeof(struct ieee80211_vht_operation) + 235 2 + 8 + /* peering IE */ 236 sdata->u.mesh.ie_len); 237 if (!skb) 238 return err; 239 info = IEEE80211_SKB_CB(skb); 240 skb_reserve(skb, local->tx_headroom); 241 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len); 242 memset(mgmt, 0, hdr_len); 243 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 244 IEEE80211_STYPE_ACTION); 245 memcpy(mgmt->da, da, ETH_ALEN); 246 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 247 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 248 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; 249 mgmt->u.action.u.self_prot.action_code = action; 250 251 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 252 enum nl80211_band band = ieee80211_get_sdata_band(sdata); 253 254 /* capability info */ 255 pos = skb_put(skb, 2); 256 memset(pos, 0, 2); 257 if (action == WLAN_SP_MESH_PEERING_CONFIRM) { 258 /* AID */ 259 pos = skb_put(skb, 2); 260 put_unaligned_le16(sta->sta.aid, pos); 261 } 262 if (ieee80211_add_srates_ie(sdata, skb, true, band) || 263 ieee80211_add_ext_srates_ie(sdata, skb, true, band) || 264 mesh_add_rsn_ie(sdata, skb) || 265 mesh_add_meshid_ie(sdata, skb) || 266 mesh_add_meshconf_ie(sdata, skb)) 267 goto free; 268 } else { /* WLAN_SP_MESH_PEERING_CLOSE */ 269 info->flags |= IEEE80211_TX_CTL_NO_ACK; 270 if (mesh_add_meshid_ie(sdata, skb)) 271 goto free; 272 } 273 274 /* Add Mesh Peering Management element */ 275 switch (action) { 276 case WLAN_SP_MESH_PEERING_OPEN: 277 break; 278 case WLAN_SP_MESH_PEERING_CONFIRM: 279 ie_len += 2; 280 include_plid = true; 281 break; 282 case WLAN_SP_MESH_PEERING_CLOSE: 283 if (plid) { 284 ie_len += 2; 285 include_plid = true; 286 } 287 ie_len += 2; /* reason code */ 288 break; 289 default: 290 err = -EINVAL; 291 goto free; 292 } 293 294 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) 295 goto free; 296 297 pos = skb_put(skb, 2 + ie_len); 298 *pos++ = WLAN_EID_PEER_MGMT; 299 *pos++ = ie_len; 300 memcpy(pos, &peering_proto, 2); 301 pos += 2; 302 put_unaligned_le16(llid, pos); 303 pos += 2; 304 if (include_plid) { 305 put_unaligned_le16(plid, pos); 306 pos += 2; 307 } 308 if (action == WLAN_SP_MESH_PEERING_CLOSE) { 309 put_unaligned_le16(reason, pos); 310 pos += 2; 311 } 312 313 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 314 if (mesh_add_ht_cap_ie(sdata, skb) || 315 mesh_add_ht_oper_ie(sdata, skb) || 316 mesh_add_vht_cap_ie(sdata, skb) || 317 mesh_add_vht_oper_ie(sdata, skb)) 318 goto free; 319 } 320 321 if (mesh_add_vendor_ies(sdata, skb)) 322 goto free; 323 324 ieee80211_tx_skb(sdata, skb); 325 return 0; 326 free: 327 kfree_skb(skb); 328 return err; 329 } 330 331 /** 332 * __mesh_plink_deactivate - deactivate mesh peer link 333 * 334 * @sta: mesh peer link to deactivate 335 * 336 * Mesh paths with this peer as next hop should be flushed 337 * by the caller outside of plink_lock. 338 * 339 * Returns beacon changed flag if the beacon content changed. 340 * 341 * Locking: the caller must hold sta->mesh->plink_lock 342 */ 343 static u32 __mesh_plink_deactivate(struct sta_info *sta) 344 { 345 struct ieee80211_sub_if_data *sdata = sta->sdata; 346 u32 changed = 0; 347 348 lockdep_assert_held(&sta->mesh->plink_lock); 349 350 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 351 changed = mesh_plink_dec_estab_count(sdata); 352 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 353 354 ieee80211_mps_sta_status_update(sta); 355 changed |= ieee80211_mps_set_sta_local_pm(sta, 356 NL80211_MESH_POWER_UNKNOWN); 357 358 return changed; 359 } 360 361 /** 362 * mesh_plink_deactivate - deactivate mesh peer link 363 * 364 * @sta: mesh peer link to deactivate 365 * 366 * All mesh paths with this peer as next hop will be flushed 367 */ 368 u32 mesh_plink_deactivate(struct sta_info *sta) 369 { 370 struct ieee80211_sub_if_data *sdata = sta->sdata; 371 u32 changed; 372 373 spin_lock_bh(&sta->mesh->plink_lock); 374 changed = __mesh_plink_deactivate(sta); 375 376 if (!sdata->u.mesh.user_mpm) { 377 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED; 378 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE, 379 sta->sta.addr, sta->mesh->llid, 380 sta->mesh->plid, sta->mesh->reason); 381 } 382 spin_unlock_bh(&sta->mesh->plink_lock); 383 if (!sdata->u.mesh.user_mpm) 384 del_timer_sync(&sta->mesh->plink_timer); 385 mesh_path_flush_by_nexthop(sta); 386 387 /* make sure no readers can access nexthop sta from here on */ 388 synchronize_net(); 389 390 return changed; 391 } 392 393 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 394 struct sta_info *sta, 395 struct ieee802_11_elems *elems, bool insert) 396 { 397 struct ieee80211_local *local = sdata->local; 398 enum nl80211_band band = ieee80211_get_sdata_band(sdata); 399 struct ieee80211_supported_band *sband; 400 u32 rates, basic_rates = 0, changed = 0; 401 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth; 402 403 sband = local->hw.wiphy->bands[band]; 404 rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates); 405 406 spin_lock_bh(&sta->mesh->plink_lock); 407 sta->rx_stats.last_rx = jiffies; 408 409 /* rates and capabilities don't change during peering */ 410 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB && 411 sta->mesh->processed_beacon) 412 goto out; 413 sta->mesh->processed_beacon = true; 414 415 if (sta->sta.supp_rates[band] != rates) 416 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 417 sta->sta.supp_rates[band] = rates; 418 419 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 420 elems->ht_cap_elem, sta)) 421 changed |= IEEE80211_RC_BW_CHANGED; 422 423 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband, 424 elems->vht_cap_elem, sta); 425 426 if (bw != sta->sta.bandwidth) 427 changed |= IEEE80211_RC_BW_CHANGED; 428 429 /* HT peer is operating 20MHz-only */ 430 if (elems->ht_operation && 431 !(elems->ht_operation->ht_param & 432 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 433 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) 434 changed |= IEEE80211_RC_BW_CHANGED; 435 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; 436 } 437 438 if (insert) 439 rate_control_rate_init(sta); 440 else 441 rate_control_rate_update(local, sband, sta, changed); 442 out: 443 spin_unlock_bh(&sta->mesh->plink_lock); 444 } 445 446 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) 447 { 448 struct sta_info *sta; 449 unsigned long *aid_map; 450 int aid; 451 452 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1), 453 sizeof(*aid_map), GFP_KERNEL); 454 if (!aid_map) 455 return -ENOMEM; 456 457 /* reserve aid 0 for mcast indication */ 458 __set_bit(0, aid_map); 459 460 rcu_read_lock(); 461 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) 462 __set_bit(sta->sta.aid, aid_map); 463 rcu_read_unlock(); 464 465 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); 466 kfree(aid_map); 467 468 if (aid > IEEE80211_MAX_AID) 469 return -ENOBUFS; 470 471 return aid; 472 } 473 474 static struct sta_info * 475 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 476 { 477 struct sta_info *sta; 478 int aid; 479 480 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 481 return NULL; 482 483 aid = mesh_allocate_aid(sdata); 484 if (aid < 0) 485 return NULL; 486 487 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 488 if (!sta) 489 return NULL; 490 491 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 492 sta->sta.wme = true; 493 sta->sta.aid = aid; 494 495 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 496 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 497 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 498 499 return sta; 500 } 501 502 static struct sta_info * 503 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 504 struct ieee802_11_elems *elems) 505 { 506 struct sta_info *sta = NULL; 507 508 /* Userspace handles station allocation */ 509 if (sdata->u.mesh.user_mpm || 510 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) { 511 if (mesh_peer_accepts_plinks(elems) && 512 mesh_plink_availables(sdata)) 513 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 514 elems->ie_start, 515 elems->total_len, 516 GFP_KERNEL); 517 } else 518 sta = __mesh_sta_info_alloc(sdata, addr); 519 520 return sta; 521 } 522 523 /* 524 * mesh_sta_info_get - return mesh sta info entry for @addr. 525 * 526 * @sdata: local meshif 527 * @addr: peer's address 528 * @elems: IEs from beacon or mesh peering frame. 529 * 530 * Return existing or newly allocated sta_info under RCU read lock. 531 * (re)initialize with given IEs. 532 */ 533 static struct sta_info * 534 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 535 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU) 536 { 537 struct sta_info *sta = NULL; 538 539 rcu_read_lock(); 540 sta = sta_info_get(sdata, addr); 541 if (sta) { 542 mesh_sta_info_init(sdata, sta, elems, false); 543 } else { 544 rcu_read_unlock(); 545 /* can't run atomic */ 546 sta = mesh_sta_info_alloc(sdata, addr, elems); 547 if (!sta) { 548 rcu_read_lock(); 549 return NULL; 550 } 551 552 mesh_sta_info_init(sdata, sta, elems, true); 553 554 if (sta_info_insert_rcu(sta)) 555 return NULL; 556 } 557 558 return sta; 559 } 560 561 /* 562 * mesh_neighbour_update - update or initialize new mesh neighbor. 563 * 564 * @sdata: local meshif 565 * @addr: peer's address 566 * @elems: IEs from beacon or mesh peering frame 567 * 568 * Initiates peering if appropriate. 569 */ 570 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 571 u8 *hw_addr, 572 struct ieee802_11_elems *elems) 573 { 574 struct sta_info *sta; 575 u32 changed = 0; 576 577 sta = mesh_sta_info_get(sdata, hw_addr, elems); 578 if (!sta) 579 goto out; 580 581 if (mesh_peer_accepts_plinks(elems) && 582 sta->mesh->plink_state == NL80211_PLINK_LISTEN && 583 sdata->u.mesh.accepting_plinks && 584 sdata->u.mesh.mshcfg.auto_open_plinks && 585 rssi_threshold_check(sdata, sta)) 586 changed = mesh_plink_open(sta); 587 588 ieee80211_mps_frame_release(sta, elems); 589 out: 590 rcu_read_unlock(); 591 ieee80211_mbss_info_change_notify(sdata, changed); 592 } 593 594 static void mesh_plink_timer(unsigned long data) 595 { 596 struct sta_info *sta; 597 u16 reason = 0; 598 struct ieee80211_sub_if_data *sdata; 599 struct mesh_config *mshcfg; 600 enum ieee80211_self_protected_actioncode action = 0; 601 602 /* 603 * This STA is valid because sta_info_destroy() will 604 * del_timer_sync() this timer after having made sure 605 * it cannot be readded (by deleting the plink.) 606 */ 607 sta = (struct sta_info *) data; 608 609 if (sta->sdata->local->quiescing) 610 return; 611 612 spin_lock_bh(&sta->mesh->plink_lock); 613 614 /* If a timer fires just before a state transition on another CPU, 615 * we may have already extended the timeout and changed state by the 616 * time we've acquired the lock and arrived here. In that case, 617 * skip this timer and wait for the new one. 618 */ 619 if (time_before(jiffies, sta->mesh->plink_timer.expires)) { 620 mpl_dbg(sta->sdata, 621 "Ignoring timer for %pM in state %s (timer adjusted)", 622 sta->sta.addr, mplstates[sta->mesh->plink_state]); 623 spin_unlock_bh(&sta->mesh->plink_lock); 624 return; 625 } 626 627 /* del_timer() and handler may race when entering these states */ 628 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || 629 sta->mesh->plink_state == NL80211_PLINK_ESTAB) { 630 mpl_dbg(sta->sdata, 631 "Ignoring timer for %pM in state %s (timer deleted)", 632 sta->sta.addr, mplstates[sta->mesh->plink_state]); 633 spin_unlock_bh(&sta->mesh->plink_lock); 634 return; 635 } 636 637 mpl_dbg(sta->sdata, 638 "Mesh plink timer for %pM fired on state %s\n", 639 sta->sta.addr, mplstates[sta->mesh->plink_state]); 640 sdata = sta->sdata; 641 mshcfg = &sdata->u.mesh.mshcfg; 642 643 switch (sta->mesh->plink_state) { 644 case NL80211_PLINK_OPN_RCVD: 645 case NL80211_PLINK_OPN_SNT: 646 /* retry timer */ 647 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { 648 u32 rand; 649 mpl_dbg(sta->sdata, 650 "Mesh plink for %pM (retry, timeout): %d %d\n", 651 sta->sta.addr, sta->mesh->plink_retries, 652 sta->mesh->plink_timeout); 653 get_random_bytes(&rand, sizeof(u32)); 654 sta->mesh->plink_timeout = sta->mesh->plink_timeout + 655 rand % sta->mesh->plink_timeout; 656 ++sta->mesh->plink_retries; 657 mod_plink_timer(sta, sta->mesh->plink_timeout); 658 action = WLAN_SP_MESH_PEERING_OPEN; 659 break; 660 } 661 reason = WLAN_REASON_MESH_MAX_RETRIES; 662 /* fall through on else */ 663 case NL80211_PLINK_CNF_RCVD: 664 /* confirm timer */ 665 if (!reason) 666 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 667 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 668 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 669 action = WLAN_SP_MESH_PEERING_CLOSE; 670 break; 671 case NL80211_PLINK_HOLDING: 672 /* holding timer */ 673 del_timer(&sta->mesh->plink_timer); 674 mesh_plink_fsm_restart(sta); 675 break; 676 default: 677 break; 678 } 679 spin_unlock_bh(&sta->mesh->plink_lock); 680 if (action) 681 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 682 sta->mesh->llid, sta->mesh->plid, reason); 683 } 684 685 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 686 { 687 sta->mesh->plink_timer.expires = jiffies + msecs_to_jiffies(timeout); 688 sta->mesh->plink_timer.data = (unsigned long) sta; 689 sta->mesh->plink_timer.function = mesh_plink_timer; 690 sta->mesh->plink_timeout = timeout; 691 add_timer(&sta->mesh->plink_timer); 692 } 693 694 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 695 u16 llid) 696 { 697 struct ieee80211_local *local = sdata->local; 698 bool in_use = false; 699 struct sta_info *sta; 700 701 rcu_read_lock(); 702 list_for_each_entry_rcu(sta, &local->sta_list, list) { 703 if (sdata != sta->sdata) 704 continue; 705 706 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { 707 in_use = true; 708 break; 709 } 710 } 711 rcu_read_unlock(); 712 713 return in_use; 714 } 715 716 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 717 { 718 u16 llid; 719 720 do { 721 get_random_bytes(&llid, sizeof(llid)); 722 } while (llid_in_use(sdata, llid)); 723 724 return llid; 725 } 726 727 u32 mesh_plink_open(struct sta_info *sta) 728 { 729 struct ieee80211_sub_if_data *sdata = sta->sdata; 730 u32 changed; 731 732 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 733 return 0; 734 735 spin_lock_bh(&sta->mesh->plink_lock); 736 sta->mesh->llid = mesh_get_new_llid(sdata); 737 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && 738 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { 739 spin_unlock_bh(&sta->mesh->plink_lock); 740 return 0; 741 } 742 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; 743 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 744 spin_unlock_bh(&sta->mesh->plink_lock); 745 mpl_dbg(sdata, 746 "Mesh plink: starting establishment with %pM\n", 747 sta->sta.addr); 748 749 /* set the non-peer mode to active during peering */ 750 changed = ieee80211_mps_local_status_update(sdata); 751 752 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, 753 sta->sta.addr, sta->mesh->llid, 0, 0); 754 return changed; 755 } 756 757 u32 mesh_plink_block(struct sta_info *sta) 758 { 759 u32 changed; 760 761 spin_lock_bh(&sta->mesh->plink_lock); 762 changed = __mesh_plink_deactivate(sta); 763 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 764 spin_unlock_bh(&sta->mesh->plink_lock); 765 mesh_path_flush_by_nexthop(sta); 766 767 return changed; 768 } 769 770 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 771 struct sta_info *sta, 772 enum plink_event event) 773 { 774 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 775 u16 reason = (event == CLS_ACPT) ? 776 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 777 778 sta->mesh->reason = reason; 779 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 780 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 781 } 782 783 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 784 struct sta_info *sta) 785 { 786 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 787 u32 changed = 0; 788 789 del_timer(&sta->mesh->plink_timer); 790 sta->mesh->plink_state = NL80211_PLINK_ESTAB; 791 changed |= mesh_plink_inc_estab_count(sdata); 792 changed |= mesh_set_ht_prot_mode(sdata); 793 changed |= mesh_set_short_slot_time(sdata); 794 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 795 ieee80211_mps_sta_status_update(sta); 796 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 797 return changed; 798 } 799 800 /** 801 * mesh_plink_fsm - step @sta MPM based on @event 802 * 803 * @sdata: interface 804 * @sta: mesh neighbor 805 * @event: peering event 806 * 807 * Return: changed MBSS flags 808 */ 809 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 810 struct sta_info *sta, enum plink_event event) 811 { 812 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 813 enum ieee80211_self_protected_actioncode action = 0; 814 u32 changed = 0; 815 bool flush = false; 816 817 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 818 mplstates[sta->mesh->plink_state], mplevents[event]); 819 820 spin_lock_bh(&sta->mesh->plink_lock); 821 switch (sta->mesh->plink_state) { 822 case NL80211_PLINK_LISTEN: 823 switch (event) { 824 case CLS_ACPT: 825 mesh_plink_fsm_restart(sta); 826 break; 827 case OPN_ACPT: 828 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 829 sta->mesh->llid = mesh_get_new_llid(sdata); 830 mesh_plink_timer_set(sta, 831 mshcfg->dot11MeshRetryTimeout); 832 833 /* set the non-peer mode to active during peering */ 834 changed |= ieee80211_mps_local_status_update(sdata); 835 action = WLAN_SP_MESH_PEERING_OPEN; 836 break; 837 default: 838 break; 839 } 840 break; 841 case NL80211_PLINK_OPN_SNT: 842 switch (event) { 843 case OPN_RJCT: 844 case CNF_RJCT: 845 case CLS_ACPT: 846 mesh_plink_close(sdata, sta, event); 847 action = WLAN_SP_MESH_PEERING_CLOSE; 848 break; 849 case OPN_ACPT: 850 /* retry timer is left untouched */ 851 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 852 action = WLAN_SP_MESH_PEERING_CONFIRM; 853 break; 854 case CNF_ACPT: 855 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; 856 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 857 break; 858 default: 859 break; 860 } 861 break; 862 case NL80211_PLINK_OPN_RCVD: 863 switch (event) { 864 case OPN_RJCT: 865 case CNF_RJCT: 866 case CLS_ACPT: 867 mesh_plink_close(sdata, sta, event); 868 action = WLAN_SP_MESH_PEERING_CLOSE; 869 break; 870 case OPN_ACPT: 871 action = WLAN_SP_MESH_PEERING_CONFIRM; 872 break; 873 case CNF_ACPT: 874 changed |= mesh_plink_establish(sdata, sta); 875 break; 876 default: 877 break; 878 } 879 break; 880 case NL80211_PLINK_CNF_RCVD: 881 switch (event) { 882 case OPN_RJCT: 883 case CNF_RJCT: 884 case CLS_ACPT: 885 mesh_plink_close(sdata, sta, event); 886 action = WLAN_SP_MESH_PEERING_CLOSE; 887 break; 888 case OPN_ACPT: 889 changed |= mesh_plink_establish(sdata, sta); 890 action = WLAN_SP_MESH_PEERING_CONFIRM; 891 break; 892 default: 893 break; 894 } 895 break; 896 case NL80211_PLINK_ESTAB: 897 switch (event) { 898 case CLS_ACPT: 899 changed |= __mesh_plink_deactivate(sta); 900 changed |= mesh_set_ht_prot_mode(sdata); 901 changed |= mesh_set_short_slot_time(sdata); 902 mesh_plink_close(sdata, sta, event); 903 action = WLAN_SP_MESH_PEERING_CLOSE; 904 flush = true; 905 break; 906 case OPN_ACPT: 907 action = WLAN_SP_MESH_PEERING_CONFIRM; 908 break; 909 default: 910 break; 911 } 912 break; 913 case NL80211_PLINK_HOLDING: 914 switch (event) { 915 case CLS_ACPT: 916 del_timer(&sta->mesh->plink_timer); 917 mesh_plink_fsm_restart(sta); 918 break; 919 case OPN_ACPT: 920 case CNF_ACPT: 921 case OPN_RJCT: 922 case CNF_RJCT: 923 action = WLAN_SP_MESH_PEERING_CLOSE; 924 break; 925 default: 926 break; 927 } 928 break; 929 default: 930 /* should not get here, PLINK_BLOCKED is dealt with at the 931 * beginning of the function 932 */ 933 break; 934 } 935 spin_unlock_bh(&sta->mesh->plink_lock); 936 if (flush) 937 mesh_path_flush_by_nexthop(sta); 938 if (action) { 939 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 940 sta->mesh->llid, sta->mesh->plid, 941 sta->mesh->reason); 942 943 /* also send confirm in open case */ 944 if (action == WLAN_SP_MESH_PEERING_OPEN) { 945 mesh_plink_frame_tx(sdata, sta, 946 WLAN_SP_MESH_PEERING_CONFIRM, 947 sta->sta.addr, sta->mesh->llid, 948 sta->mesh->plid, 0); 949 } 950 } 951 952 return changed; 953 } 954 955 /* 956 * mesh_plink_get_event - get correct MPM event 957 * 958 * @sdata: interface 959 * @sta: peer, leave NULL if processing a frame from a new suitable peer 960 * @elems: peering management IEs 961 * @ftype: frame type 962 * @llid: peer's peer link ID 963 * @plid: peer's local link ID 964 * 965 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 966 * an error. 967 */ 968 static enum plink_event 969 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 970 struct sta_info *sta, 971 struct ieee802_11_elems *elems, 972 enum ieee80211_self_protected_actioncode ftype, 973 u16 llid, u16 plid) 974 { 975 enum plink_event event = PLINK_UNDEFINED; 976 u8 ie_len = elems->peering_len; 977 bool matches_local; 978 979 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 980 mesh_matches_local(sdata, elems)); 981 982 /* deny open request from non-matching peer */ 983 if (!matches_local && !sta) { 984 event = OPN_RJCT; 985 goto out; 986 } 987 988 if (!sta) { 989 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 990 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 991 goto out; 992 } 993 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 994 if (!mesh_plink_free_count(sdata)) { 995 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 996 goto out; 997 } 998 999 /* new matching peer */ 1000 event = OPN_ACPT; 1001 goto out; 1002 } else { 1003 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 1004 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 1005 goto out; 1006 } 1007 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) 1008 goto out; 1009 } 1010 1011 switch (ftype) { 1012 case WLAN_SP_MESH_PEERING_OPEN: 1013 if (!matches_local) 1014 event = OPN_RJCT; 1015 if (!mesh_plink_free_count(sdata) || 1016 (sta->mesh->plid && sta->mesh->plid != plid)) 1017 event = OPN_IGNR; 1018 else 1019 event = OPN_ACPT; 1020 break; 1021 case WLAN_SP_MESH_PEERING_CONFIRM: 1022 if (!matches_local) 1023 event = CNF_RJCT; 1024 if (!mesh_plink_free_count(sdata) || 1025 sta->mesh->llid != llid || 1026 (sta->mesh->plid && sta->mesh->plid != plid)) 1027 event = CNF_IGNR; 1028 else 1029 event = CNF_ACPT; 1030 break; 1031 case WLAN_SP_MESH_PEERING_CLOSE: 1032 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 1033 /* Do not check for llid or plid. This does not 1034 * follow the standard but since multiple plinks 1035 * per sta are not supported, it is necessary in 1036 * order to avoid a livelock when MP A sees an 1037 * establish peer link to MP B but MP B does not 1038 * see it. This can be caused by a timeout in 1039 * B's peer link establishment or B beign 1040 * restarted. 1041 */ 1042 event = CLS_ACPT; 1043 else if (sta->mesh->plid != plid) 1044 event = CLS_IGNR; 1045 else if (ie_len == 8 && sta->mesh->llid != llid) 1046 event = CLS_IGNR; 1047 else 1048 event = CLS_ACPT; 1049 break; 1050 default: 1051 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 1052 break; 1053 } 1054 1055 out: 1056 return event; 1057 } 1058 1059 static void 1060 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1061 struct ieee80211_mgmt *mgmt, 1062 struct ieee802_11_elems *elems) 1063 { 1064 1065 struct sta_info *sta; 1066 enum plink_event event; 1067 enum ieee80211_self_protected_actioncode ftype; 1068 u32 changed = 0; 1069 u8 ie_len = elems->peering_len; 1070 u16 plid, llid = 0; 1071 1072 if (!elems->peering) { 1073 mpl_dbg(sdata, 1074 "Mesh plink: missing necessary peer link ie\n"); 1075 return; 1076 } 1077 1078 if (elems->rsn_len && 1079 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1080 mpl_dbg(sdata, 1081 "Mesh plink: can't establish link with secure peer\n"); 1082 return; 1083 } 1084 1085 ftype = mgmt->u.action.u.self_prot.action_code; 1086 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1087 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1088 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1089 && ie_len != 8)) { 1090 mpl_dbg(sdata, 1091 "Mesh plink: incorrect plink ie length %d %d\n", 1092 ftype, ie_len); 1093 return; 1094 } 1095 1096 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1097 (!elems->mesh_id || !elems->mesh_config)) { 1098 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1099 return; 1100 } 1101 /* Note the lines below are correct, the llid in the frame is the plid 1102 * from the point of view of this host. 1103 */ 1104 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1105 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1106 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1107 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1108 1109 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1110 rcu_read_lock(); 1111 1112 sta = sta_info_get(sdata, mgmt->sa); 1113 1114 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1115 !rssi_threshold_check(sdata, sta)) { 1116 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1117 mgmt->sa); 1118 goto unlock_rcu; 1119 } 1120 1121 /* Now we will figure out the appropriate event... */ 1122 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1123 1124 if (event == OPN_ACPT) { 1125 rcu_read_unlock(); 1126 /* allocate sta entry if necessary and update info */ 1127 sta = mesh_sta_info_get(sdata, mgmt->sa, elems); 1128 if (!sta) { 1129 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1130 goto unlock_rcu; 1131 } 1132 sta->mesh->plid = plid; 1133 } else if (!sta && event == OPN_RJCT) { 1134 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, 1135 mgmt->sa, 0, plid, 1136 WLAN_REASON_MESH_CONFIG); 1137 goto unlock_rcu; 1138 } else if (!sta || event == PLINK_UNDEFINED) { 1139 /* something went wrong */ 1140 goto unlock_rcu; 1141 } 1142 1143 if (event == CNF_ACPT) { 1144 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1145 if (!sta->mesh->plid) 1146 sta->mesh->plid = plid; 1147 1148 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); 1149 } 1150 1151 changed |= mesh_plink_fsm(sdata, sta, event); 1152 1153 unlock_rcu: 1154 rcu_read_unlock(); 1155 1156 if (changed) 1157 ieee80211_mbss_info_change_notify(sdata, changed); 1158 } 1159 1160 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1161 struct ieee80211_mgmt *mgmt, size_t len, 1162 struct ieee80211_rx_status *rx_status) 1163 { 1164 struct ieee802_11_elems elems; 1165 size_t baselen; 1166 u8 *baseaddr; 1167 1168 /* need action_code, aux */ 1169 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1170 return; 1171 1172 if (sdata->u.mesh.user_mpm) 1173 /* userspace must register for these */ 1174 return; 1175 1176 if (is_multicast_ether_addr(mgmt->da)) { 1177 mpl_dbg(sdata, 1178 "Mesh plink: ignore frame from multicast address\n"); 1179 return; 1180 } 1181 1182 baseaddr = mgmt->u.action.u.self_prot.variable; 1183 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1184 if (mgmt->u.action.u.self_prot.action_code == 1185 WLAN_SP_MESH_PEERING_CONFIRM) { 1186 baseaddr += 4; 1187 baselen += 4; 1188 1189 if (baselen > len) 1190 return; 1191 } 1192 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems); 1193 mesh_process_plink_frame(sdata, mgmt, &elems); 1194 } 1195