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 && 64 (s8)-ewma_signal_read(&sta->rx_stats.avg_signal) > 65 rssi_threshold); 66 } 67 68 /** 69 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine 70 * 71 * @sta: mesh peer link to restart 72 * 73 * Locking: this function must be called holding sta->mesh->plink_lock 74 */ 75 static inline void mesh_plink_fsm_restart(struct sta_info *sta) 76 { 77 lockdep_assert_held(&sta->mesh->plink_lock); 78 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 79 sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0; 80 sta->mesh->plink_retries = 0; 81 } 82 83 /* 84 * mesh_set_short_slot_time - enable / disable ERP short slot time. 85 * 86 * The standard indirectly mandates mesh STAs to turn off short slot time by 87 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we 88 * can't be sneaky about it. Enable short slot time if all mesh STAs in the 89 * MBSS support ERP rates. 90 * 91 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change. 92 */ 93 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata) 94 { 95 struct ieee80211_local *local = sdata->local; 96 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 97 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 98 struct sta_info *sta; 99 u32 erp_rates = 0, changed = 0; 100 int i; 101 bool short_slot = false; 102 103 if (band == IEEE80211_BAND_5GHZ) { 104 /* (IEEE 802.11-2012 19.4.5) */ 105 short_slot = true; 106 goto out; 107 } else if (band != IEEE80211_BAND_2GHZ) 108 goto out; 109 110 for (i = 0; i < sband->n_bitrates; i++) 111 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G) 112 erp_rates |= BIT(i); 113 114 if (!erp_rates) 115 goto out; 116 117 rcu_read_lock(); 118 list_for_each_entry_rcu(sta, &local->sta_list, list) { 119 if (sdata != sta->sdata || 120 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 121 continue; 122 123 short_slot = false; 124 if (erp_rates & sta->sta.supp_rates[band]) 125 short_slot = true; 126 else 127 break; 128 } 129 rcu_read_unlock(); 130 131 out: 132 if (sdata->vif.bss_conf.use_short_slot != short_slot) { 133 sdata->vif.bss_conf.use_short_slot = short_slot; 134 changed = BSS_CHANGED_ERP_SLOT; 135 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n", 136 sdata->vif.addr, short_slot); 137 } 138 return changed; 139 } 140 141 /** 142 * mesh_set_ht_prot_mode - set correct HT protection mode 143 * 144 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT 145 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT 146 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is 147 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode 148 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one 149 * HT20 peer is present. Otherwise no-protection mode is selected. 150 */ 151 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) 152 { 153 struct ieee80211_local *local = sdata->local; 154 struct sta_info *sta; 155 u16 ht_opmode; 156 bool non_ht_sta = false, ht20_sta = false; 157 158 switch (sdata->vif.bss_conf.chandef.width) { 159 case NL80211_CHAN_WIDTH_20_NOHT: 160 case NL80211_CHAN_WIDTH_5: 161 case NL80211_CHAN_WIDTH_10: 162 return 0; 163 default: 164 break; 165 } 166 167 rcu_read_lock(); 168 list_for_each_entry_rcu(sta, &local->sta_list, list) { 169 if (sdata != sta->sdata || 170 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 171 continue; 172 173 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20) 174 continue; 175 176 if (!sta->sta.ht_cap.ht_supported) { 177 mpl_dbg(sdata, "nonHT sta (%pM) is present\n", 178 sta->sta.addr); 179 non_ht_sta = true; 180 break; 181 } 182 183 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); 184 ht20_sta = true; 185 } 186 rcu_read_unlock(); 187 188 if (non_ht_sta) 189 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; 190 else if (ht20_sta && 191 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20) 192 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; 193 else 194 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; 195 196 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) 197 return 0; 198 199 sdata->vif.bss_conf.ht_operation_mode = ht_opmode; 200 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; 201 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); 202 return BSS_CHANGED_HT; 203 } 204 205 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 206 struct sta_info *sta, 207 enum ieee80211_self_protected_actioncode action, 208 u8 *da, u16 llid, u16 plid, u16 reason) 209 { 210 struct ieee80211_local *local = sdata->local; 211 struct sk_buff *skb; 212 struct ieee80211_tx_info *info; 213 struct ieee80211_mgmt *mgmt; 214 bool include_plid = false; 215 u16 peering_proto = 0; 216 u8 *pos, ie_len = 4; 217 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) + 218 sizeof(mgmt->u.action.u.self_prot); 219 int err = -ENOMEM; 220 221 skb = dev_alloc_skb(local->tx_headroom + 222 hdr_len + 223 2 + /* capability info */ 224 2 + /* AID */ 225 2 + 8 + /* supported rates */ 226 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 227 2 + sdata->u.mesh.mesh_id_len + 228 2 + sizeof(struct ieee80211_meshconf_ie) + 229 2 + sizeof(struct ieee80211_ht_cap) + 230 2 + sizeof(struct ieee80211_ht_operation) + 231 2 + sizeof(struct ieee80211_vht_cap) + 232 2 + sizeof(struct ieee80211_vht_operation) + 233 2 + 8 + /* peering IE */ 234 sdata->u.mesh.ie_len); 235 if (!skb) 236 return err; 237 info = IEEE80211_SKB_CB(skb); 238 skb_reserve(skb, local->tx_headroom); 239 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len); 240 memset(mgmt, 0, hdr_len); 241 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 242 IEEE80211_STYPE_ACTION); 243 memcpy(mgmt->da, da, ETH_ALEN); 244 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 245 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 246 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; 247 mgmt->u.action.u.self_prot.action_code = action; 248 249 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 250 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 251 252 /* capability info */ 253 pos = skb_put(skb, 2); 254 memset(pos, 0, 2); 255 if (action == WLAN_SP_MESH_PEERING_CONFIRM) { 256 /* AID */ 257 pos = skb_put(skb, 2); 258 put_unaligned_le16(sta->sta.aid, pos); 259 } 260 if (ieee80211_add_srates_ie(sdata, skb, true, band) || 261 ieee80211_add_ext_srates_ie(sdata, skb, true, band) || 262 mesh_add_rsn_ie(sdata, skb) || 263 mesh_add_meshid_ie(sdata, skb) || 264 mesh_add_meshconf_ie(sdata, skb)) 265 goto free; 266 } else { /* WLAN_SP_MESH_PEERING_CLOSE */ 267 info->flags |= IEEE80211_TX_CTL_NO_ACK; 268 if (mesh_add_meshid_ie(sdata, skb)) 269 goto free; 270 } 271 272 /* Add Mesh Peering Management element */ 273 switch (action) { 274 case WLAN_SP_MESH_PEERING_OPEN: 275 break; 276 case WLAN_SP_MESH_PEERING_CONFIRM: 277 ie_len += 2; 278 include_plid = true; 279 break; 280 case WLAN_SP_MESH_PEERING_CLOSE: 281 if (plid) { 282 ie_len += 2; 283 include_plid = true; 284 } 285 ie_len += 2; /* reason code */ 286 break; 287 default: 288 err = -EINVAL; 289 goto free; 290 } 291 292 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) 293 goto free; 294 295 pos = skb_put(skb, 2 + ie_len); 296 *pos++ = WLAN_EID_PEER_MGMT; 297 *pos++ = ie_len; 298 memcpy(pos, &peering_proto, 2); 299 pos += 2; 300 put_unaligned_le16(llid, pos); 301 pos += 2; 302 if (include_plid) { 303 put_unaligned_le16(plid, pos); 304 pos += 2; 305 } 306 if (action == WLAN_SP_MESH_PEERING_CLOSE) { 307 put_unaligned_le16(reason, pos); 308 pos += 2; 309 } 310 311 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 312 if (mesh_add_ht_cap_ie(sdata, skb) || 313 mesh_add_ht_oper_ie(sdata, skb) || 314 mesh_add_vht_cap_ie(sdata, skb) || 315 mesh_add_vht_oper_ie(sdata, skb)) 316 goto free; 317 } 318 319 if (mesh_add_vendor_ies(sdata, skb)) 320 goto free; 321 322 ieee80211_tx_skb(sdata, skb); 323 return 0; 324 free: 325 kfree_skb(skb); 326 return err; 327 } 328 329 /** 330 * __mesh_plink_deactivate - deactivate mesh peer link 331 * 332 * @sta: mesh peer link to deactivate 333 * 334 * All mesh paths with this peer as next hop will be flushed 335 * Returns beacon changed flag if the beacon content changed. 336 * 337 * Locking: the caller must hold sta->mesh->plink_lock 338 */ 339 static u32 __mesh_plink_deactivate(struct sta_info *sta) 340 { 341 struct ieee80211_sub_if_data *sdata = sta->sdata; 342 u32 changed = 0; 343 344 lockdep_assert_held(&sta->mesh->plink_lock); 345 346 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 347 changed = mesh_plink_dec_estab_count(sdata); 348 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 349 mesh_path_flush_by_nexthop(sta); 350 351 ieee80211_mps_sta_status_update(sta); 352 changed |= ieee80211_mps_set_sta_local_pm(sta, 353 NL80211_MESH_POWER_UNKNOWN); 354 355 return changed; 356 } 357 358 /** 359 * mesh_plink_deactivate - deactivate mesh peer link 360 * 361 * @sta: mesh peer link to deactivate 362 * 363 * All mesh paths with this peer as next hop will be flushed 364 */ 365 u32 mesh_plink_deactivate(struct sta_info *sta) 366 { 367 struct ieee80211_sub_if_data *sdata = sta->sdata; 368 u32 changed; 369 370 spin_lock_bh(&sta->mesh->plink_lock); 371 changed = __mesh_plink_deactivate(sta); 372 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED; 373 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE, 374 sta->sta.addr, sta->mesh->llid, sta->mesh->plid, 375 sta->mesh->reason); 376 spin_unlock_bh(&sta->mesh->plink_lock); 377 378 return changed; 379 } 380 381 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 382 struct sta_info *sta, 383 struct ieee802_11_elems *elems, bool insert) 384 { 385 struct ieee80211_local *local = sdata->local; 386 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 387 struct ieee80211_supported_band *sband; 388 u32 rates, basic_rates = 0, changed = 0; 389 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth; 390 391 sband = local->hw.wiphy->bands[band]; 392 rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates); 393 394 spin_lock_bh(&sta->mesh->plink_lock); 395 sta->rx_stats.last_rx = jiffies; 396 397 /* rates and capabilities don't change during peering */ 398 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB && 399 sta->mesh->processed_beacon) 400 goto out; 401 sta->mesh->processed_beacon = true; 402 403 if (sta->sta.supp_rates[band] != rates) 404 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 405 sta->sta.supp_rates[band] = rates; 406 407 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 408 elems->ht_cap_elem, sta)) 409 changed |= IEEE80211_RC_BW_CHANGED; 410 411 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband, 412 elems->vht_cap_elem, sta); 413 414 if (bw != sta->sta.bandwidth) 415 changed |= IEEE80211_RC_BW_CHANGED; 416 417 /* HT peer is operating 20MHz-only */ 418 if (elems->ht_operation && 419 !(elems->ht_operation->ht_param & 420 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 421 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) 422 changed |= IEEE80211_RC_BW_CHANGED; 423 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; 424 } 425 426 if (insert) 427 rate_control_rate_init(sta); 428 else 429 rate_control_rate_update(local, sband, sta, changed); 430 out: 431 spin_unlock_bh(&sta->mesh->plink_lock); 432 } 433 434 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) 435 { 436 struct sta_info *sta; 437 unsigned long *aid_map; 438 int aid; 439 440 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1), 441 sizeof(*aid_map), GFP_KERNEL); 442 if (!aid_map) 443 return -ENOMEM; 444 445 /* reserve aid 0 for mcast indication */ 446 __set_bit(0, aid_map); 447 448 rcu_read_lock(); 449 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) 450 __set_bit(sta->sta.aid, aid_map); 451 rcu_read_unlock(); 452 453 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); 454 kfree(aid_map); 455 456 if (aid > IEEE80211_MAX_AID) 457 return -ENOBUFS; 458 459 return aid; 460 } 461 462 static struct sta_info * 463 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 464 { 465 struct sta_info *sta; 466 int aid; 467 468 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 469 return NULL; 470 471 aid = mesh_allocate_aid(sdata); 472 if (aid < 0) 473 return NULL; 474 475 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 476 if (!sta) 477 return NULL; 478 479 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 480 sta->sta.wme = true; 481 sta->sta.aid = aid; 482 483 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 484 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 485 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 486 487 return sta; 488 } 489 490 static struct sta_info * 491 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 492 struct ieee802_11_elems *elems) 493 { 494 struct sta_info *sta = NULL; 495 496 /* Userspace handles station allocation */ 497 if (sdata->u.mesh.user_mpm || 498 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) 499 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 500 elems->ie_start, 501 elems->total_len, 502 GFP_KERNEL); 503 else 504 sta = __mesh_sta_info_alloc(sdata, addr); 505 506 return sta; 507 } 508 509 /* 510 * mesh_sta_info_get - return mesh sta info entry for @addr. 511 * 512 * @sdata: local meshif 513 * @addr: peer's address 514 * @elems: IEs from beacon or mesh peering frame. 515 * 516 * Return existing or newly allocated sta_info under RCU read lock. 517 * (re)initialize with given IEs. 518 */ 519 static struct sta_info * 520 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 521 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU) 522 { 523 struct sta_info *sta = NULL; 524 525 rcu_read_lock(); 526 sta = sta_info_get(sdata, addr); 527 if (sta) { 528 mesh_sta_info_init(sdata, sta, elems, false); 529 } else { 530 rcu_read_unlock(); 531 /* can't run atomic */ 532 sta = mesh_sta_info_alloc(sdata, addr, elems); 533 if (!sta) { 534 rcu_read_lock(); 535 return NULL; 536 } 537 538 mesh_sta_info_init(sdata, sta, elems, true); 539 540 if (sta_info_insert_rcu(sta)) 541 return NULL; 542 } 543 544 return sta; 545 } 546 547 /* 548 * mesh_neighbour_update - update or initialize new mesh neighbor. 549 * 550 * @sdata: local meshif 551 * @addr: peer's address 552 * @elems: IEs from beacon or mesh peering frame 553 * 554 * Initiates peering if appropriate. 555 */ 556 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 557 u8 *hw_addr, 558 struct ieee802_11_elems *elems) 559 { 560 struct sta_info *sta; 561 u32 changed = 0; 562 563 sta = mesh_sta_info_get(sdata, hw_addr, elems); 564 if (!sta) 565 goto out; 566 567 if (mesh_peer_accepts_plinks(elems) && 568 sta->mesh->plink_state == NL80211_PLINK_LISTEN && 569 sdata->u.mesh.accepting_plinks && 570 sdata->u.mesh.mshcfg.auto_open_plinks && 571 rssi_threshold_check(sdata, sta)) 572 changed = mesh_plink_open(sta); 573 574 ieee80211_mps_frame_release(sta, elems); 575 out: 576 rcu_read_unlock(); 577 ieee80211_mbss_info_change_notify(sdata, changed); 578 } 579 580 static void mesh_plink_timer(unsigned long data) 581 { 582 struct sta_info *sta; 583 u16 reason = 0; 584 struct ieee80211_sub_if_data *sdata; 585 struct mesh_config *mshcfg; 586 enum ieee80211_self_protected_actioncode action = 0; 587 588 /* 589 * This STA is valid because sta_info_destroy() will 590 * del_timer_sync() this timer after having made sure 591 * it cannot be readded (by deleting the plink.) 592 */ 593 sta = (struct sta_info *) data; 594 595 if (sta->sdata->local->quiescing) 596 return; 597 598 spin_lock_bh(&sta->mesh->plink_lock); 599 600 /* If a timer fires just before a state transition on another CPU, 601 * we may have already extended the timeout and changed state by the 602 * time we've acquired the lock and arrived here. In that case, 603 * skip this timer and wait for the new one. 604 */ 605 if (time_before(jiffies, sta->mesh->plink_timer.expires)) { 606 mpl_dbg(sta->sdata, 607 "Ignoring timer for %pM in state %s (timer adjusted)", 608 sta->sta.addr, mplstates[sta->mesh->plink_state]); 609 spin_unlock_bh(&sta->mesh->plink_lock); 610 return; 611 } 612 613 /* del_timer() and handler may race when entering these states */ 614 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || 615 sta->mesh->plink_state == NL80211_PLINK_ESTAB) { 616 mpl_dbg(sta->sdata, 617 "Ignoring timer for %pM in state %s (timer deleted)", 618 sta->sta.addr, mplstates[sta->mesh->plink_state]); 619 spin_unlock_bh(&sta->mesh->plink_lock); 620 return; 621 } 622 623 mpl_dbg(sta->sdata, 624 "Mesh plink timer for %pM fired on state %s\n", 625 sta->sta.addr, mplstates[sta->mesh->plink_state]); 626 sdata = sta->sdata; 627 mshcfg = &sdata->u.mesh.mshcfg; 628 629 switch (sta->mesh->plink_state) { 630 case NL80211_PLINK_OPN_RCVD: 631 case NL80211_PLINK_OPN_SNT: 632 /* retry timer */ 633 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { 634 u32 rand; 635 mpl_dbg(sta->sdata, 636 "Mesh plink for %pM (retry, timeout): %d %d\n", 637 sta->sta.addr, sta->mesh->plink_retries, 638 sta->mesh->plink_timeout); 639 get_random_bytes(&rand, sizeof(u32)); 640 sta->mesh->plink_timeout = sta->mesh->plink_timeout + 641 rand % sta->mesh->plink_timeout; 642 ++sta->mesh->plink_retries; 643 mod_plink_timer(sta, sta->mesh->plink_timeout); 644 action = WLAN_SP_MESH_PEERING_OPEN; 645 break; 646 } 647 reason = WLAN_REASON_MESH_MAX_RETRIES; 648 /* fall through on else */ 649 case NL80211_PLINK_CNF_RCVD: 650 /* confirm timer */ 651 if (!reason) 652 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 653 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 654 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 655 action = WLAN_SP_MESH_PEERING_CLOSE; 656 break; 657 case NL80211_PLINK_HOLDING: 658 /* holding timer */ 659 del_timer(&sta->mesh->plink_timer); 660 mesh_plink_fsm_restart(sta); 661 break; 662 default: 663 break; 664 } 665 spin_unlock_bh(&sta->mesh->plink_lock); 666 if (action) 667 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 668 sta->mesh->llid, sta->mesh->plid, reason); 669 } 670 671 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 672 { 673 sta->mesh->plink_timer.expires = jiffies + msecs_to_jiffies(timeout); 674 sta->mesh->plink_timer.data = (unsigned long) sta; 675 sta->mesh->plink_timer.function = mesh_plink_timer; 676 sta->mesh->plink_timeout = timeout; 677 add_timer(&sta->mesh->plink_timer); 678 } 679 680 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 681 u16 llid) 682 { 683 struct ieee80211_local *local = sdata->local; 684 bool in_use = false; 685 struct sta_info *sta; 686 687 rcu_read_lock(); 688 list_for_each_entry_rcu(sta, &local->sta_list, list) { 689 if (sdata != sta->sdata) 690 continue; 691 692 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { 693 in_use = true; 694 break; 695 } 696 } 697 rcu_read_unlock(); 698 699 return in_use; 700 } 701 702 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 703 { 704 u16 llid; 705 706 do { 707 get_random_bytes(&llid, sizeof(llid)); 708 } while (llid_in_use(sdata, llid)); 709 710 return llid; 711 } 712 713 u32 mesh_plink_open(struct sta_info *sta) 714 { 715 struct ieee80211_sub_if_data *sdata = sta->sdata; 716 u32 changed; 717 718 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 719 return 0; 720 721 spin_lock_bh(&sta->mesh->plink_lock); 722 sta->mesh->llid = mesh_get_new_llid(sdata); 723 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && 724 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { 725 spin_unlock_bh(&sta->mesh->plink_lock); 726 return 0; 727 } 728 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; 729 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 730 spin_unlock_bh(&sta->mesh->plink_lock); 731 mpl_dbg(sdata, 732 "Mesh plink: starting establishment with %pM\n", 733 sta->sta.addr); 734 735 /* set the non-peer mode to active during peering */ 736 changed = ieee80211_mps_local_status_update(sdata); 737 738 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, 739 sta->sta.addr, sta->mesh->llid, 0, 0); 740 return changed; 741 } 742 743 u32 mesh_plink_block(struct sta_info *sta) 744 { 745 u32 changed; 746 747 spin_lock_bh(&sta->mesh->plink_lock); 748 changed = __mesh_plink_deactivate(sta); 749 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 750 spin_unlock_bh(&sta->mesh->plink_lock); 751 752 return changed; 753 } 754 755 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 756 struct sta_info *sta, 757 enum plink_event event) 758 { 759 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 760 u16 reason = (event == CLS_ACPT) ? 761 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 762 763 sta->mesh->reason = reason; 764 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 765 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 766 } 767 768 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 769 struct sta_info *sta) 770 { 771 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 772 u32 changed = 0; 773 774 del_timer(&sta->mesh->plink_timer); 775 sta->mesh->plink_state = NL80211_PLINK_ESTAB; 776 changed |= mesh_plink_inc_estab_count(sdata); 777 changed |= mesh_set_ht_prot_mode(sdata); 778 changed |= mesh_set_short_slot_time(sdata); 779 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 780 ieee80211_mps_sta_status_update(sta); 781 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 782 return changed; 783 } 784 785 /** 786 * mesh_plink_fsm - step @sta MPM based on @event 787 * 788 * @sdata: interface 789 * @sta: mesh neighbor 790 * @event: peering event 791 * 792 * Return: changed MBSS flags 793 */ 794 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 795 struct sta_info *sta, enum plink_event event) 796 { 797 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 798 enum ieee80211_self_protected_actioncode action = 0; 799 u32 changed = 0; 800 801 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 802 mplstates[sta->mesh->plink_state], mplevents[event]); 803 804 spin_lock_bh(&sta->mesh->plink_lock); 805 switch (sta->mesh->plink_state) { 806 case NL80211_PLINK_LISTEN: 807 switch (event) { 808 case CLS_ACPT: 809 mesh_plink_fsm_restart(sta); 810 break; 811 case OPN_ACPT: 812 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 813 sta->mesh->llid = mesh_get_new_llid(sdata); 814 mesh_plink_timer_set(sta, 815 mshcfg->dot11MeshRetryTimeout); 816 817 /* set the non-peer mode to active during peering */ 818 changed |= ieee80211_mps_local_status_update(sdata); 819 action = WLAN_SP_MESH_PEERING_OPEN; 820 break; 821 default: 822 break; 823 } 824 break; 825 case NL80211_PLINK_OPN_SNT: 826 switch (event) { 827 case OPN_RJCT: 828 case CNF_RJCT: 829 case CLS_ACPT: 830 mesh_plink_close(sdata, sta, event); 831 action = WLAN_SP_MESH_PEERING_CLOSE; 832 break; 833 case OPN_ACPT: 834 /* retry timer is left untouched */ 835 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 836 action = WLAN_SP_MESH_PEERING_CONFIRM; 837 break; 838 case CNF_ACPT: 839 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; 840 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 841 break; 842 default: 843 break; 844 } 845 break; 846 case NL80211_PLINK_OPN_RCVD: 847 switch (event) { 848 case OPN_RJCT: 849 case CNF_RJCT: 850 case CLS_ACPT: 851 mesh_plink_close(sdata, sta, event); 852 action = WLAN_SP_MESH_PEERING_CLOSE; 853 break; 854 case OPN_ACPT: 855 action = WLAN_SP_MESH_PEERING_CONFIRM; 856 break; 857 case CNF_ACPT: 858 changed |= mesh_plink_establish(sdata, sta); 859 break; 860 default: 861 break; 862 } 863 break; 864 case NL80211_PLINK_CNF_RCVD: 865 switch (event) { 866 case OPN_RJCT: 867 case CNF_RJCT: 868 case CLS_ACPT: 869 mesh_plink_close(sdata, sta, event); 870 action = WLAN_SP_MESH_PEERING_CLOSE; 871 break; 872 case OPN_ACPT: 873 changed |= mesh_plink_establish(sdata, sta); 874 action = WLAN_SP_MESH_PEERING_CONFIRM; 875 break; 876 default: 877 break; 878 } 879 break; 880 case NL80211_PLINK_ESTAB: 881 switch (event) { 882 case CLS_ACPT: 883 changed |= __mesh_plink_deactivate(sta); 884 changed |= mesh_set_ht_prot_mode(sdata); 885 changed |= mesh_set_short_slot_time(sdata); 886 mesh_plink_close(sdata, sta, event); 887 action = WLAN_SP_MESH_PEERING_CLOSE; 888 break; 889 case OPN_ACPT: 890 action = WLAN_SP_MESH_PEERING_CONFIRM; 891 break; 892 default: 893 break; 894 } 895 break; 896 case NL80211_PLINK_HOLDING: 897 switch (event) { 898 case CLS_ACPT: 899 del_timer(&sta->mesh->plink_timer); 900 mesh_plink_fsm_restart(sta); 901 break; 902 case OPN_ACPT: 903 case CNF_ACPT: 904 case OPN_RJCT: 905 case CNF_RJCT: 906 action = WLAN_SP_MESH_PEERING_CLOSE; 907 break; 908 default: 909 break; 910 } 911 break; 912 default: 913 /* should not get here, PLINK_BLOCKED is dealt with at the 914 * beginning of the function 915 */ 916 break; 917 } 918 spin_unlock_bh(&sta->mesh->plink_lock); 919 if (action) { 920 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 921 sta->mesh->llid, sta->mesh->plid, 922 sta->mesh->reason); 923 924 /* also send confirm in open case */ 925 if (action == WLAN_SP_MESH_PEERING_OPEN) { 926 mesh_plink_frame_tx(sdata, sta, 927 WLAN_SP_MESH_PEERING_CONFIRM, 928 sta->sta.addr, sta->mesh->llid, 929 sta->mesh->plid, 0); 930 } 931 } 932 933 return changed; 934 } 935 936 /* 937 * mesh_plink_get_event - get correct MPM event 938 * 939 * @sdata: interface 940 * @sta: peer, leave NULL if processing a frame from a new suitable peer 941 * @elems: peering management IEs 942 * @ftype: frame type 943 * @llid: peer's peer link ID 944 * @plid: peer's local link ID 945 * 946 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 947 * an error. 948 */ 949 static enum plink_event 950 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 951 struct sta_info *sta, 952 struct ieee802_11_elems *elems, 953 enum ieee80211_self_protected_actioncode ftype, 954 u16 llid, u16 plid) 955 { 956 enum plink_event event = PLINK_UNDEFINED; 957 u8 ie_len = elems->peering_len; 958 bool matches_local; 959 960 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 961 mesh_matches_local(sdata, elems)); 962 963 /* deny open request from non-matching peer */ 964 if (!matches_local && !sta) { 965 event = OPN_RJCT; 966 goto out; 967 } 968 969 if (!sta) { 970 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 971 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 972 goto out; 973 } 974 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 975 if (!mesh_plink_free_count(sdata)) { 976 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 977 goto out; 978 } 979 } else { 980 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 981 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 982 goto out; 983 } 984 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) 985 goto out; 986 } 987 988 /* new matching peer */ 989 if (!sta) { 990 event = OPN_ACPT; 991 goto out; 992 } 993 994 switch (ftype) { 995 case WLAN_SP_MESH_PEERING_OPEN: 996 if (!matches_local) 997 event = OPN_RJCT; 998 if (!mesh_plink_free_count(sdata) || 999 (sta->mesh->plid && sta->mesh->plid != plid)) 1000 event = OPN_IGNR; 1001 else 1002 event = OPN_ACPT; 1003 break; 1004 case WLAN_SP_MESH_PEERING_CONFIRM: 1005 if (!matches_local) 1006 event = CNF_RJCT; 1007 if (!mesh_plink_free_count(sdata) || 1008 sta->mesh->llid != llid || 1009 (sta->mesh->plid && sta->mesh->plid != plid)) 1010 event = CNF_IGNR; 1011 else 1012 event = CNF_ACPT; 1013 break; 1014 case WLAN_SP_MESH_PEERING_CLOSE: 1015 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 1016 /* Do not check for llid or plid. This does not 1017 * follow the standard but since multiple plinks 1018 * per sta are not supported, it is necessary in 1019 * order to avoid a livelock when MP A sees an 1020 * establish peer link to MP B but MP B does not 1021 * see it. This can be caused by a timeout in 1022 * B's peer link establishment or B beign 1023 * restarted. 1024 */ 1025 event = CLS_ACPT; 1026 else if (sta->mesh->plid != plid) 1027 event = CLS_IGNR; 1028 else if (ie_len == 8 && sta->mesh->llid != llid) 1029 event = CLS_IGNR; 1030 else 1031 event = CLS_ACPT; 1032 break; 1033 default: 1034 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 1035 break; 1036 } 1037 1038 out: 1039 return event; 1040 } 1041 1042 static void 1043 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1044 struct ieee80211_mgmt *mgmt, 1045 struct ieee802_11_elems *elems) 1046 { 1047 1048 struct sta_info *sta; 1049 enum plink_event event; 1050 enum ieee80211_self_protected_actioncode ftype; 1051 u32 changed = 0; 1052 u8 ie_len = elems->peering_len; 1053 u16 plid, llid = 0; 1054 1055 if (!elems->peering) { 1056 mpl_dbg(sdata, 1057 "Mesh plink: missing necessary peer link ie\n"); 1058 return; 1059 } 1060 1061 if (elems->rsn_len && 1062 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1063 mpl_dbg(sdata, 1064 "Mesh plink: can't establish link with secure peer\n"); 1065 return; 1066 } 1067 1068 ftype = mgmt->u.action.u.self_prot.action_code; 1069 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1070 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1071 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1072 && ie_len != 8)) { 1073 mpl_dbg(sdata, 1074 "Mesh plink: incorrect plink ie length %d %d\n", 1075 ftype, ie_len); 1076 return; 1077 } 1078 1079 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1080 (!elems->mesh_id || !elems->mesh_config)) { 1081 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1082 return; 1083 } 1084 /* Note the lines below are correct, the llid in the frame is the plid 1085 * from the point of view of this host. 1086 */ 1087 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1088 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1089 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1090 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1091 1092 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1093 rcu_read_lock(); 1094 1095 sta = sta_info_get(sdata, mgmt->sa); 1096 1097 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1098 !rssi_threshold_check(sdata, sta)) { 1099 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1100 mgmt->sa); 1101 goto unlock_rcu; 1102 } 1103 1104 /* Now we will figure out the appropriate event... */ 1105 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1106 1107 if (event == OPN_ACPT) { 1108 rcu_read_unlock(); 1109 /* allocate sta entry if necessary and update info */ 1110 sta = mesh_sta_info_get(sdata, mgmt->sa, elems); 1111 if (!sta) { 1112 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1113 goto unlock_rcu; 1114 } 1115 sta->mesh->plid = plid; 1116 } else if (!sta && event == OPN_RJCT) { 1117 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, 1118 mgmt->sa, 0, plid, 1119 WLAN_REASON_MESH_CONFIG); 1120 goto unlock_rcu; 1121 } else if (!sta || event == PLINK_UNDEFINED) { 1122 /* something went wrong */ 1123 goto unlock_rcu; 1124 } 1125 1126 if (event == CNF_ACPT) { 1127 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1128 if (!sta->mesh->plid) 1129 sta->mesh->plid = plid; 1130 1131 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); 1132 } 1133 1134 changed |= mesh_plink_fsm(sdata, sta, event); 1135 1136 unlock_rcu: 1137 rcu_read_unlock(); 1138 1139 if (changed) 1140 ieee80211_mbss_info_change_notify(sdata, changed); 1141 } 1142 1143 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1144 struct ieee80211_mgmt *mgmt, size_t len, 1145 struct ieee80211_rx_status *rx_status) 1146 { 1147 struct ieee802_11_elems elems; 1148 size_t baselen; 1149 u8 *baseaddr; 1150 1151 /* need action_code, aux */ 1152 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1153 return; 1154 1155 if (sdata->u.mesh.user_mpm) 1156 /* userspace must register for these */ 1157 return; 1158 1159 if (is_multicast_ether_addr(mgmt->da)) { 1160 mpl_dbg(sdata, 1161 "Mesh plink: ignore frame from multicast address\n"); 1162 return; 1163 } 1164 1165 baseaddr = mgmt->u.action.u.self_prot.variable; 1166 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1167 if (mgmt->u.action.u.self_prot.action_code == 1168 WLAN_SP_MESH_PEERING_CONFIRM) { 1169 baseaddr += 4; 1170 baselen += 4; 1171 1172 if (baselen > len) 1173 return; 1174 } 1175 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems); 1176 mesh_process_plink_frame(sdata, mgmt, &elems); 1177 } 1178