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_GET_LLID(p) (p + 2) 17 #define PLINK_GET_PLID(p) (p + 4) 18 19 #define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \ 20 jiffies + HZ * t / 1000)) 21 22 enum plink_event { 23 PLINK_UNDEFINED, 24 OPN_ACPT, 25 OPN_RJCT, 26 OPN_IGNR, 27 CNF_ACPT, 28 CNF_RJCT, 29 CNF_IGNR, 30 CLS_ACPT, 31 CLS_IGNR 32 }; 33 34 static const char * const mplstates[] = { 35 [NL80211_PLINK_LISTEN] = "LISTEN", 36 [NL80211_PLINK_OPN_SNT] = "OPN-SNT", 37 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD", 38 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD", 39 [NL80211_PLINK_ESTAB] = "ESTAB", 40 [NL80211_PLINK_HOLDING] = "HOLDING", 41 [NL80211_PLINK_BLOCKED] = "BLOCKED" 42 }; 43 44 static const char * const mplevents[] = { 45 [PLINK_UNDEFINED] = "NONE", 46 [OPN_ACPT] = "OPN_ACPT", 47 [OPN_RJCT] = "OPN_RJCT", 48 [OPN_IGNR] = "OPN_IGNR", 49 [CNF_ACPT] = "CNF_ACPT", 50 [CNF_RJCT] = "CNF_RJCT", 51 [CNF_IGNR] = "CNF_IGNR", 52 [CLS_ACPT] = "CLS_ACPT", 53 [CLS_IGNR] = "CLS_IGNR" 54 }; 55 56 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 57 enum ieee80211_self_protected_actioncode action, 58 u8 *da, u16 llid, u16 plid, u16 reason); 59 60 61 /* We only need a valid sta if user configured a minimum rssi_threshold. */ 62 static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata, 63 struct sta_info *sta) 64 { 65 s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold; 66 return rssi_threshold == 0 || 67 (sta && (s8) -ewma_read(&sta->avg_signal) > 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->lock 76 */ 77 static inline void mesh_plink_fsm_restart(struct sta_info *sta) 78 { 79 sta->plink_state = NL80211_PLINK_LISTEN; 80 sta->llid = sta->plid = sta->reason = 0; 81 sta->plink_retries = 0; 82 } 83 84 /* 85 * mesh_set_short_slot_time - enable / disable ERP short slot time. 86 * 87 * The standard indirectly mandates mesh STAs to turn off short slot time by 88 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we 89 * can't be sneaky about it. Enable short slot time if all mesh STAs in the 90 * MBSS support ERP rates. 91 * 92 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change. 93 */ 94 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata) 95 { 96 struct ieee80211_local *local = sdata->local; 97 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 98 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 99 struct sta_info *sta; 100 u32 erp_rates = 0, changed = 0; 101 int i; 102 bool short_slot = false; 103 104 if (band == IEEE80211_BAND_5GHZ) { 105 /* (IEEE 802.11-2012 19.4.5) */ 106 short_slot = true; 107 goto out; 108 } else if (band != IEEE80211_BAND_2GHZ || 109 (band == IEEE80211_BAND_2GHZ && 110 local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE)) 111 goto out; 112 113 for (i = 0; i < sband->n_bitrates; i++) 114 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G) 115 erp_rates |= BIT(i); 116 117 if (!erp_rates) 118 goto out; 119 120 rcu_read_lock(); 121 list_for_each_entry_rcu(sta, &local->sta_list, list) { 122 if (sdata != sta->sdata || 123 sta->plink_state != NL80211_PLINK_ESTAB) 124 continue; 125 126 short_slot = false; 127 if (erp_rates & sta->sta.supp_rates[band]) 128 short_slot = true; 129 else 130 break; 131 } 132 rcu_read_unlock(); 133 134 out: 135 if (sdata->vif.bss_conf.use_short_slot != short_slot) { 136 sdata->vif.bss_conf.use_short_slot = short_slot; 137 changed = BSS_CHANGED_ERP_SLOT; 138 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n", 139 sdata->vif.addr, short_slot); 140 } 141 return changed; 142 } 143 144 /** 145 * mesh_set_ht_prot_mode - set correct HT protection mode 146 * 147 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT 148 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT 149 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is 150 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode 151 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one 152 * HT20 peer is present. Otherwise no-protection mode is selected. 153 */ 154 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) 155 { 156 struct ieee80211_local *local = sdata->local; 157 struct sta_info *sta; 158 u16 ht_opmode; 159 bool non_ht_sta = false, ht20_sta = false; 160 161 switch (sdata->vif.bss_conf.chandef.width) { 162 case NL80211_CHAN_WIDTH_20_NOHT: 163 case NL80211_CHAN_WIDTH_5: 164 case NL80211_CHAN_WIDTH_10: 165 return 0; 166 default: 167 break; 168 } 169 170 rcu_read_lock(); 171 list_for_each_entry_rcu(sta, &local->sta_list, list) { 172 if (sdata != sta->sdata || 173 sta->plink_state != NL80211_PLINK_ESTAB) 174 continue; 175 176 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20) 177 continue; 178 179 if (!sta->sta.ht_cap.ht_supported) { 180 mpl_dbg(sdata, "nonHT sta (%pM) is present\n", 181 sta->sta.addr); 182 non_ht_sta = true; 183 break; 184 } 185 186 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); 187 ht20_sta = true; 188 } 189 rcu_read_unlock(); 190 191 if (non_ht_sta) 192 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; 193 else if (ht20_sta && 194 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20) 195 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; 196 else 197 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; 198 199 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) 200 return 0; 201 202 sdata->vif.bss_conf.ht_operation_mode = ht_opmode; 203 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; 204 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); 205 return BSS_CHANGED_HT; 206 } 207 208 /** 209 * __mesh_plink_deactivate - deactivate mesh peer link 210 * 211 * @sta: mesh peer link to deactivate 212 * 213 * All mesh paths with this peer as next hop will be flushed 214 * Returns beacon changed flag if the beacon content changed. 215 * 216 * Locking: the caller must hold sta->lock 217 */ 218 static u32 __mesh_plink_deactivate(struct sta_info *sta) 219 { 220 struct ieee80211_sub_if_data *sdata = sta->sdata; 221 u32 changed = 0; 222 223 if (sta->plink_state == NL80211_PLINK_ESTAB) 224 changed = mesh_plink_dec_estab_count(sdata); 225 sta->plink_state = NL80211_PLINK_BLOCKED; 226 mesh_path_flush_by_nexthop(sta); 227 228 ieee80211_mps_sta_status_update(sta); 229 changed |= ieee80211_mps_set_sta_local_pm(sta, 230 NL80211_MESH_POWER_UNKNOWN); 231 232 return changed; 233 } 234 235 /** 236 * mesh_plink_deactivate - deactivate mesh peer link 237 * 238 * @sta: mesh peer link to deactivate 239 * 240 * All mesh paths with this peer as next hop will be flushed 241 */ 242 u32 mesh_plink_deactivate(struct sta_info *sta) 243 { 244 struct ieee80211_sub_if_data *sdata = sta->sdata; 245 u32 changed; 246 247 spin_lock_bh(&sta->lock); 248 changed = __mesh_plink_deactivate(sta); 249 sta->reason = WLAN_REASON_MESH_PEER_CANCELED; 250 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, 251 sta->sta.addr, sta->llid, sta->plid, 252 sta->reason); 253 spin_unlock_bh(&sta->lock); 254 255 return changed; 256 } 257 258 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 259 enum ieee80211_self_protected_actioncode action, 260 u8 *da, u16 llid, u16 plid, u16 reason) 261 { 262 struct ieee80211_local *local = sdata->local; 263 struct sk_buff *skb; 264 struct ieee80211_tx_info *info; 265 struct ieee80211_mgmt *mgmt; 266 bool include_plid = false; 267 u16 peering_proto = 0; 268 u8 *pos, ie_len = 4; 269 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) + 270 sizeof(mgmt->u.action.u.self_prot); 271 int err = -ENOMEM; 272 273 skb = dev_alloc_skb(local->tx_headroom + 274 hdr_len + 275 2 + /* capability info */ 276 2 + /* AID */ 277 2 + 8 + /* supported rates */ 278 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 279 2 + sdata->u.mesh.mesh_id_len + 280 2 + sizeof(struct ieee80211_meshconf_ie) + 281 2 + sizeof(struct ieee80211_ht_cap) + 282 2 + sizeof(struct ieee80211_ht_operation) + 283 2 + 8 + /* peering IE */ 284 sdata->u.mesh.ie_len); 285 if (!skb) 286 return err; 287 info = IEEE80211_SKB_CB(skb); 288 skb_reserve(skb, local->tx_headroom); 289 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len); 290 memset(mgmt, 0, hdr_len); 291 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 292 IEEE80211_STYPE_ACTION); 293 memcpy(mgmt->da, da, ETH_ALEN); 294 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 295 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 296 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; 297 mgmt->u.action.u.self_prot.action_code = action; 298 299 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 300 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 301 302 /* capability info */ 303 pos = skb_put(skb, 2); 304 memset(pos, 0, 2); 305 if (action == WLAN_SP_MESH_PEERING_CONFIRM) { 306 /* AID */ 307 pos = skb_put(skb, 2); 308 put_unaligned_le16(plid, pos + 2); 309 } 310 if (ieee80211_add_srates_ie(sdata, skb, true, band) || 311 ieee80211_add_ext_srates_ie(sdata, skb, true, band) || 312 mesh_add_rsn_ie(sdata, skb) || 313 mesh_add_meshid_ie(sdata, skb) || 314 mesh_add_meshconf_ie(sdata, skb)) 315 goto free; 316 } else { /* WLAN_SP_MESH_PEERING_CLOSE */ 317 info->flags |= IEEE80211_TX_CTL_NO_ACK; 318 if (mesh_add_meshid_ie(sdata, skb)) 319 goto free; 320 } 321 322 /* Add Mesh Peering Management element */ 323 switch (action) { 324 case WLAN_SP_MESH_PEERING_OPEN: 325 break; 326 case WLAN_SP_MESH_PEERING_CONFIRM: 327 ie_len += 2; 328 include_plid = true; 329 break; 330 case WLAN_SP_MESH_PEERING_CLOSE: 331 if (plid) { 332 ie_len += 2; 333 include_plid = true; 334 } 335 ie_len += 2; /* reason code */ 336 break; 337 default: 338 err = -EINVAL; 339 goto free; 340 } 341 342 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) 343 goto free; 344 345 pos = skb_put(skb, 2 + ie_len); 346 *pos++ = WLAN_EID_PEER_MGMT; 347 *pos++ = ie_len; 348 memcpy(pos, &peering_proto, 2); 349 pos += 2; 350 put_unaligned_le16(llid, pos); 351 pos += 2; 352 if (include_plid) { 353 put_unaligned_le16(plid, pos); 354 pos += 2; 355 } 356 if (action == WLAN_SP_MESH_PEERING_CLOSE) { 357 put_unaligned_le16(reason, pos); 358 pos += 2; 359 } 360 361 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 362 if (mesh_add_ht_cap_ie(sdata, skb) || 363 mesh_add_ht_oper_ie(sdata, skb)) 364 goto free; 365 } 366 367 if (mesh_add_vendor_ies(sdata, skb)) 368 goto free; 369 370 ieee80211_tx_skb(sdata, skb); 371 return 0; 372 free: 373 kfree_skb(skb); 374 return err; 375 } 376 377 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 378 struct sta_info *sta, 379 struct ieee802_11_elems *elems, bool insert) 380 { 381 struct ieee80211_local *local = sdata->local; 382 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 383 struct ieee80211_supported_band *sband; 384 u32 rates, basic_rates = 0, changed = 0; 385 386 sband = local->hw.wiphy->bands[band]; 387 rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates); 388 389 spin_lock_bh(&sta->lock); 390 sta->last_rx = jiffies; 391 392 /* rates and capabilities don't change during peering */ 393 if (sta->plink_state == NL80211_PLINK_ESTAB) 394 goto out; 395 396 if (sta->sta.supp_rates[band] != rates) 397 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 398 sta->sta.supp_rates[band] = rates; 399 400 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 401 elems->ht_cap_elem, sta)) 402 changed |= IEEE80211_RC_BW_CHANGED; 403 404 /* HT peer is operating 20MHz-only */ 405 if (elems->ht_operation && 406 !(elems->ht_operation->ht_param & 407 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 408 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) 409 changed |= IEEE80211_RC_BW_CHANGED; 410 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; 411 } 412 413 if (insert) 414 rate_control_rate_init(sta); 415 else 416 rate_control_rate_update(local, sband, sta, changed); 417 out: 418 spin_unlock_bh(&sta->lock); 419 } 420 421 static struct sta_info * 422 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 423 { 424 struct sta_info *sta; 425 426 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 427 return NULL; 428 429 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 430 if (!sta) 431 return NULL; 432 433 sta->plink_state = NL80211_PLINK_LISTEN; 434 435 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 436 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 437 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 438 439 set_sta_flag(sta, WLAN_STA_WME); 440 sta->sta.wme = true; 441 442 return sta; 443 } 444 445 static struct sta_info * 446 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 447 struct ieee802_11_elems *elems) 448 { 449 struct sta_info *sta = NULL; 450 451 /* Userspace handles station allocation */ 452 if (sdata->u.mesh.user_mpm || 453 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) 454 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 455 elems->ie_start, 456 elems->total_len, 457 GFP_KERNEL); 458 else 459 sta = __mesh_sta_info_alloc(sdata, addr); 460 461 return sta; 462 } 463 464 /* 465 * mesh_sta_info_get - return mesh sta info entry for @addr. 466 * 467 * @sdata: local meshif 468 * @addr: peer's address 469 * @elems: IEs from beacon or mesh peering frame. 470 * 471 * Return existing or newly allocated sta_info under RCU read lock. 472 * (re)initialize with given IEs. 473 */ 474 static struct sta_info * 475 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 476 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU) 477 { 478 struct sta_info *sta = NULL; 479 480 rcu_read_lock(); 481 sta = sta_info_get(sdata, addr); 482 if (sta) { 483 mesh_sta_info_init(sdata, sta, elems, false); 484 } else { 485 rcu_read_unlock(); 486 /* can't run atomic */ 487 sta = mesh_sta_info_alloc(sdata, addr, elems); 488 if (!sta) { 489 rcu_read_lock(); 490 return NULL; 491 } 492 493 mesh_sta_info_init(sdata, sta, elems, true); 494 495 if (sta_info_insert_rcu(sta)) 496 return NULL; 497 } 498 499 return sta; 500 } 501 502 /* 503 * mesh_neighbour_update - update or initialize new mesh neighbor. 504 * 505 * @sdata: local meshif 506 * @addr: peer's address 507 * @elems: IEs from beacon or mesh peering frame 508 * 509 * Initiates peering if appropriate. 510 */ 511 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 512 u8 *hw_addr, 513 struct ieee802_11_elems *elems) 514 { 515 struct sta_info *sta; 516 u32 changed = 0; 517 518 sta = mesh_sta_info_get(sdata, hw_addr, elems); 519 if (!sta) 520 goto out; 521 522 if (mesh_peer_accepts_plinks(elems) && 523 sta->plink_state == NL80211_PLINK_LISTEN && 524 sdata->u.mesh.accepting_plinks && 525 sdata->u.mesh.mshcfg.auto_open_plinks && 526 rssi_threshold_check(sdata, sta)) 527 changed = mesh_plink_open(sta); 528 529 ieee80211_mps_frame_release(sta, elems); 530 out: 531 rcu_read_unlock(); 532 ieee80211_mbss_info_change_notify(sdata, changed); 533 } 534 535 static void mesh_plink_timer(unsigned long data) 536 { 537 struct sta_info *sta; 538 u16 reason = 0; 539 struct ieee80211_sub_if_data *sdata; 540 struct mesh_config *mshcfg; 541 enum ieee80211_self_protected_actioncode action = 0; 542 543 /* 544 * This STA is valid because sta_info_destroy() will 545 * del_timer_sync() this timer after having made sure 546 * it cannot be readded (by deleting the plink.) 547 */ 548 sta = (struct sta_info *) data; 549 550 if (sta->sdata->local->quiescing) 551 return; 552 553 spin_lock_bh(&sta->lock); 554 if (sta->ignore_plink_timer) { 555 sta->ignore_plink_timer = false; 556 spin_unlock_bh(&sta->lock); 557 return; 558 } 559 mpl_dbg(sta->sdata, 560 "Mesh plink timer for %pM fired on state %s\n", 561 sta->sta.addr, mplstates[sta->plink_state]); 562 sdata = sta->sdata; 563 mshcfg = &sdata->u.mesh.mshcfg; 564 565 switch (sta->plink_state) { 566 case NL80211_PLINK_OPN_RCVD: 567 case NL80211_PLINK_OPN_SNT: 568 /* retry timer */ 569 if (sta->plink_retries < mshcfg->dot11MeshMaxRetries) { 570 u32 rand; 571 mpl_dbg(sta->sdata, 572 "Mesh plink for %pM (retry, timeout): %d %d\n", 573 sta->sta.addr, sta->plink_retries, 574 sta->plink_timeout); 575 get_random_bytes(&rand, sizeof(u32)); 576 sta->plink_timeout = sta->plink_timeout + 577 rand % sta->plink_timeout; 578 ++sta->plink_retries; 579 mod_plink_timer(sta, sta->plink_timeout); 580 action = WLAN_SP_MESH_PEERING_OPEN; 581 break; 582 } 583 reason = WLAN_REASON_MESH_MAX_RETRIES; 584 /* fall through on else */ 585 case NL80211_PLINK_CNF_RCVD: 586 /* confirm timer */ 587 if (!reason) 588 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 589 sta->plink_state = NL80211_PLINK_HOLDING; 590 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 591 action = WLAN_SP_MESH_PEERING_CLOSE; 592 break; 593 case NL80211_PLINK_HOLDING: 594 /* holding timer */ 595 del_timer(&sta->plink_timer); 596 mesh_plink_fsm_restart(sta); 597 break; 598 default: 599 break; 600 } 601 spin_unlock_bh(&sta->lock); 602 if (action) 603 mesh_plink_frame_tx(sdata, action, sta->sta.addr, 604 sta->llid, sta->plid, reason); 605 } 606 607 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout) 608 { 609 sta->plink_timer.expires = jiffies + (HZ * timeout / 1000); 610 sta->plink_timer.data = (unsigned long) sta; 611 sta->plink_timer.function = mesh_plink_timer; 612 sta->plink_timeout = timeout; 613 add_timer(&sta->plink_timer); 614 } 615 616 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 617 u16 llid) 618 { 619 struct ieee80211_local *local = sdata->local; 620 bool in_use = false; 621 struct sta_info *sta; 622 623 rcu_read_lock(); 624 list_for_each_entry_rcu(sta, &local->sta_list, list) { 625 if (!memcmp(&sta->llid, &llid, sizeof(llid))) { 626 in_use = true; 627 break; 628 } 629 } 630 rcu_read_unlock(); 631 632 return in_use; 633 } 634 635 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 636 { 637 u16 llid; 638 639 do { 640 get_random_bytes(&llid, sizeof(llid)); 641 /* for mesh PS we still only have the AID range for TIM bits */ 642 llid = (llid % IEEE80211_MAX_AID) + 1; 643 } while (llid_in_use(sdata, llid)); 644 645 return llid; 646 } 647 648 u32 mesh_plink_open(struct sta_info *sta) 649 { 650 struct ieee80211_sub_if_data *sdata = sta->sdata; 651 u32 changed; 652 653 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 654 return 0; 655 656 spin_lock_bh(&sta->lock); 657 sta->llid = mesh_get_new_llid(sdata); 658 if (sta->plink_state != NL80211_PLINK_LISTEN && 659 sta->plink_state != NL80211_PLINK_BLOCKED) { 660 spin_unlock_bh(&sta->lock); 661 return 0; 662 } 663 sta->plink_state = NL80211_PLINK_OPN_SNT; 664 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 665 spin_unlock_bh(&sta->lock); 666 mpl_dbg(sdata, 667 "Mesh plink: starting establishment with %pM\n", 668 sta->sta.addr); 669 670 /* set the non-peer mode to active during peering */ 671 changed = ieee80211_mps_local_status_update(sdata); 672 673 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN, 674 sta->sta.addr, sta->llid, 0, 0); 675 return changed; 676 } 677 678 u32 mesh_plink_block(struct sta_info *sta) 679 { 680 u32 changed; 681 682 spin_lock_bh(&sta->lock); 683 changed = __mesh_plink_deactivate(sta); 684 sta->plink_state = NL80211_PLINK_BLOCKED; 685 spin_unlock_bh(&sta->lock); 686 687 return changed; 688 } 689 690 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 691 struct sta_info *sta, 692 enum plink_event event) 693 { 694 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 695 696 u16 reason = (event == CLS_ACPT) ? 697 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 698 699 sta->reason = reason; 700 sta->plink_state = NL80211_PLINK_HOLDING; 701 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 702 } 703 704 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 705 struct sta_info *sta) 706 { 707 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 708 u32 changed = 0; 709 710 del_timer(&sta->plink_timer); 711 sta->plink_state = NL80211_PLINK_ESTAB; 712 changed |= mesh_plink_inc_estab_count(sdata); 713 changed |= mesh_set_ht_prot_mode(sdata); 714 changed |= mesh_set_short_slot_time(sdata); 715 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 716 ieee80211_mps_sta_status_update(sta); 717 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 718 return changed; 719 } 720 721 /** 722 * mesh_plink_fsm - step @sta MPM based on @event 723 * 724 * @sdata: interface 725 * @sta: mesh neighbor 726 * @event: peering event 727 * 728 * Return: changed MBSS flags 729 */ 730 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 731 struct sta_info *sta, enum plink_event event) 732 { 733 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 734 enum ieee80211_self_protected_actioncode action = 0; 735 u32 changed = 0; 736 737 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 738 mplstates[sta->plink_state], mplevents[event]); 739 740 spin_lock_bh(&sta->lock); 741 switch (sta->plink_state) { 742 case NL80211_PLINK_LISTEN: 743 switch (event) { 744 case CLS_ACPT: 745 mesh_plink_fsm_restart(sta); 746 break; 747 case OPN_ACPT: 748 sta->plink_state = NL80211_PLINK_OPN_RCVD; 749 sta->llid = mesh_get_new_llid(sdata); 750 mesh_plink_timer_set(sta, 751 mshcfg->dot11MeshRetryTimeout); 752 753 /* set the non-peer mode to active during peering */ 754 changed |= ieee80211_mps_local_status_update(sdata); 755 action = WLAN_SP_MESH_PEERING_OPEN; 756 break; 757 default: 758 break; 759 } 760 break; 761 case NL80211_PLINK_OPN_SNT: 762 switch (event) { 763 case OPN_RJCT: 764 case CNF_RJCT: 765 case CLS_ACPT: 766 mesh_plink_close(sdata, sta, event); 767 action = WLAN_SP_MESH_PEERING_CLOSE; 768 break; 769 case OPN_ACPT: 770 /* retry timer is left untouched */ 771 sta->plink_state = NL80211_PLINK_OPN_RCVD; 772 action = WLAN_SP_MESH_PEERING_CONFIRM; 773 break; 774 case CNF_ACPT: 775 sta->plink_state = NL80211_PLINK_CNF_RCVD; 776 if (!mod_plink_timer(sta, 777 mshcfg->dot11MeshConfirmTimeout)) 778 sta->ignore_plink_timer = true; 779 break; 780 default: 781 break; 782 } 783 break; 784 case NL80211_PLINK_OPN_RCVD: 785 switch (event) { 786 case OPN_RJCT: 787 case CNF_RJCT: 788 case CLS_ACPT: 789 mesh_plink_close(sdata, sta, event); 790 action = WLAN_SP_MESH_PEERING_CLOSE; 791 break; 792 case OPN_ACPT: 793 action = WLAN_SP_MESH_PEERING_CONFIRM; 794 break; 795 case CNF_ACPT: 796 changed |= mesh_plink_establish(sdata, sta); 797 break; 798 default: 799 break; 800 } 801 break; 802 case NL80211_PLINK_CNF_RCVD: 803 switch (event) { 804 case OPN_RJCT: 805 case CNF_RJCT: 806 case CLS_ACPT: 807 mesh_plink_close(sdata, sta, event); 808 action = WLAN_SP_MESH_PEERING_CLOSE; 809 break; 810 case OPN_ACPT: 811 changed |= mesh_plink_establish(sdata, sta); 812 action = WLAN_SP_MESH_PEERING_CONFIRM; 813 break; 814 default: 815 break; 816 } 817 break; 818 case NL80211_PLINK_ESTAB: 819 switch (event) { 820 case CLS_ACPT: 821 changed |= __mesh_plink_deactivate(sta); 822 changed |= mesh_set_ht_prot_mode(sdata); 823 changed |= mesh_set_short_slot_time(sdata); 824 mesh_plink_close(sdata, sta, event); 825 action = WLAN_SP_MESH_PEERING_CLOSE; 826 break; 827 case OPN_ACPT: 828 action = WLAN_SP_MESH_PEERING_CONFIRM; 829 break; 830 default: 831 break; 832 } 833 break; 834 case NL80211_PLINK_HOLDING: 835 switch (event) { 836 case CLS_ACPT: 837 if (del_timer(&sta->plink_timer)) 838 sta->ignore_plink_timer = 1; 839 mesh_plink_fsm_restart(sta); 840 break; 841 case OPN_ACPT: 842 case CNF_ACPT: 843 case OPN_RJCT: 844 case CNF_RJCT: 845 action = WLAN_SP_MESH_PEERING_CLOSE; 846 break; 847 default: 848 break; 849 } 850 break; 851 default: 852 /* should not get here, PLINK_BLOCKED is dealt with at the 853 * beginning of the function 854 */ 855 break; 856 } 857 spin_unlock_bh(&sta->lock); 858 if (action) { 859 mesh_plink_frame_tx(sdata, action, sta->sta.addr, 860 sta->llid, sta->plid, sta->reason); 861 862 /* also send confirm in open case */ 863 if (action == WLAN_SP_MESH_PEERING_OPEN) { 864 mesh_plink_frame_tx(sdata, 865 WLAN_SP_MESH_PEERING_CONFIRM, 866 sta->sta.addr, sta->llid, 867 sta->plid, 0); 868 } 869 } 870 871 return changed; 872 } 873 874 /* 875 * mesh_plink_get_event - get correct MPM event 876 * 877 * @sdata: interface 878 * @sta: peer, leave NULL if processing a frame from a new suitable peer 879 * @elems: peering management IEs 880 * @ftype: frame type 881 * @llid: peer's peer link ID 882 * @plid: peer's local link ID 883 * 884 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 885 * an error. 886 */ 887 static enum plink_event 888 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 889 struct sta_info *sta, 890 struct ieee802_11_elems *elems, 891 enum ieee80211_self_protected_actioncode ftype, 892 u16 llid, u16 plid) 893 { 894 enum plink_event event = PLINK_UNDEFINED; 895 u8 ie_len = elems->peering_len; 896 bool matches_local; 897 898 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 899 mesh_matches_local(sdata, elems)); 900 901 /* deny open request from non-matching peer */ 902 if (!matches_local && !sta) { 903 event = OPN_RJCT; 904 goto out; 905 } 906 907 if (!sta) { 908 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 909 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 910 goto out; 911 } 912 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 913 if (!mesh_plink_free_count(sdata)) { 914 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 915 goto out; 916 } 917 } else { 918 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 919 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 920 goto out; 921 } 922 if (sta->plink_state == NL80211_PLINK_BLOCKED) 923 goto out; 924 } 925 926 /* new matching peer */ 927 if (!sta) { 928 event = OPN_ACPT; 929 goto out; 930 } 931 932 switch (ftype) { 933 case WLAN_SP_MESH_PEERING_OPEN: 934 if (!matches_local) 935 event = OPN_RJCT; 936 if (!mesh_plink_free_count(sdata) || 937 (sta->plid && sta->plid != plid)) 938 event = OPN_IGNR; 939 else 940 event = OPN_ACPT; 941 break; 942 case WLAN_SP_MESH_PEERING_CONFIRM: 943 if (!matches_local) 944 event = CNF_RJCT; 945 if (!mesh_plink_free_count(sdata) || 946 (sta->llid != llid || sta->plid != plid)) 947 event = CNF_IGNR; 948 else 949 event = CNF_ACPT; 950 break; 951 case WLAN_SP_MESH_PEERING_CLOSE: 952 if (sta->plink_state == NL80211_PLINK_ESTAB) 953 /* Do not check for llid or plid. This does not 954 * follow the standard but since multiple plinks 955 * per sta are not supported, it is necessary in 956 * order to avoid a livelock when MP A sees an 957 * establish peer link to MP B but MP B does not 958 * see it. This can be caused by a timeout in 959 * B's peer link establishment or B beign 960 * restarted. 961 */ 962 event = CLS_ACPT; 963 else if (sta->plid != plid) 964 event = CLS_IGNR; 965 else if (ie_len == 8 && sta->llid != llid) 966 event = CLS_IGNR; 967 else 968 event = CLS_ACPT; 969 break; 970 default: 971 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 972 break; 973 } 974 975 out: 976 return event; 977 } 978 979 static void 980 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 981 struct ieee80211_mgmt *mgmt, 982 struct ieee802_11_elems *elems) 983 { 984 985 struct sta_info *sta; 986 enum plink_event event; 987 enum ieee80211_self_protected_actioncode ftype; 988 u32 changed = 0; 989 u8 ie_len = elems->peering_len; 990 __le16 _plid, _llid; 991 u16 plid, llid = 0; 992 993 if (!elems->peering) { 994 mpl_dbg(sdata, 995 "Mesh plink: missing necessary peer link ie\n"); 996 return; 997 } 998 999 if (elems->rsn_len && 1000 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1001 mpl_dbg(sdata, 1002 "Mesh plink: can't establish link with secure peer\n"); 1003 return; 1004 } 1005 1006 ftype = mgmt->u.action.u.self_prot.action_code; 1007 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1008 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1009 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1010 && ie_len != 8)) { 1011 mpl_dbg(sdata, 1012 "Mesh plink: incorrect plink ie length %d %d\n", 1013 ftype, ie_len); 1014 return; 1015 } 1016 1017 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1018 (!elems->mesh_id || !elems->mesh_config)) { 1019 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1020 return; 1021 } 1022 /* Note the lines below are correct, the llid in the frame is the plid 1023 * from the point of view of this host. 1024 */ 1025 memcpy(&_plid, PLINK_GET_LLID(elems->peering), sizeof(__le16)); 1026 plid = le16_to_cpu(_plid); 1027 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1028 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) { 1029 memcpy(&_llid, PLINK_GET_PLID(elems->peering), sizeof(__le16)); 1030 llid = le16_to_cpu(_llid); 1031 } 1032 1033 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1034 rcu_read_lock(); 1035 1036 sta = sta_info_get(sdata, mgmt->sa); 1037 1038 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1039 !rssi_threshold_check(sdata, sta)) { 1040 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1041 mgmt->sa); 1042 goto unlock_rcu; 1043 } 1044 1045 /* Now we will figure out the appropriate event... */ 1046 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1047 1048 if (event == OPN_ACPT) { 1049 rcu_read_unlock(); 1050 /* allocate sta entry if necessary and update info */ 1051 sta = mesh_sta_info_get(sdata, mgmt->sa, elems); 1052 if (!sta) { 1053 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1054 goto unlock_rcu; 1055 } 1056 sta->plid = plid; 1057 } else if (!sta && event == OPN_RJCT) { 1058 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, 1059 mgmt->sa, 0, plid, 1060 WLAN_REASON_MESH_CONFIG); 1061 goto unlock_rcu; 1062 } else if (!sta || event == PLINK_UNDEFINED) { 1063 /* something went wrong */ 1064 goto unlock_rcu; 1065 } 1066 1067 changed |= mesh_plink_fsm(sdata, sta, event); 1068 1069 unlock_rcu: 1070 rcu_read_unlock(); 1071 1072 if (changed) 1073 ieee80211_mbss_info_change_notify(sdata, changed); 1074 } 1075 1076 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1077 struct ieee80211_mgmt *mgmt, size_t len, 1078 struct ieee80211_rx_status *rx_status) 1079 { 1080 struct ieee802_11_elems elems; 1081 size_t baselen; 1082 u8 *baseaddr; 1083 1084 /* need action_code, aux */ 1085 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1086 return; 1087 1088 if (sdata->u.mesh.user_mpm) 1089 /* userspace must register for these */ 1090 return; 1091 1092 if (is_multicast_ether_addr(mgmt->da)) { 1093 mpl_dbg(sdata, 1094 "Mesh plink: ignore frame from multicast address\n"); 1095 return; 1096 } 1097 1098 baseaddr = mgmt->u.action.u.self_prot.variable; 1099 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1100 if (mgmt->u.action.u.self_prot.action_code == 1101 WLAN_SP_MESH_PEERING_CONFIRM) { 1102 baseaddr += 4; 1103 baselen += 4; 1104 } 1105 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems); 1106 mesh_process_plink_frame(sdata, mgmt, &elems); 1107 } 1108