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); 440 441 return sta; 442 } 443 444 static struct sta_info * 445 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 446 struct ieee802_11_elems *elems) 447 { 448 struct sta_info *sta = NULL; 449 450 /* Userspace handles station allocation */ 451 if (sdata->u.mesh.user_mpm || 452 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) 453 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 454 elems->ie_start, 455 elems->total_len, 456 GFP_KERNEL); 457 else 458 sta = __mesh_sta_info_alloc(sdata, addr); 459 460 return sta; 461 } 462 463 /* 464 * mesh_sta_info_get - return mesh sta info entry for @addr. 465 * 466 * @sdata: local meshif 467 * @addr: peer's address 468 * @elems: IEs from beacon or mesh peering frame. 469 * 470 * Return existing or newly allocated sta_info under RCU read lock. 471 * (re)initialize with given IEs. 472 */ 473 static struct sta_info * 474 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 475 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU) 476 { 477 struct sta_info *sta = NULL; 478 479 rcu_read_lock(); 480 sta = sta_info_get(sdata, addr); 481 if (sta) { 482 mesh_sta_info_init(sdata, sta, elems, false); 483 } else { 484 rcu_read_unlock(); 485 /* can't run atomic */ 486 sta = mesh_sta_info_alloc(sdata, addr, elems); 487 if (!sta) { 488 rcu_read_lock(); 489 return NULL; 490 } 491 492 mesh_sta_info_init(sdata, sta, elems, true); 493 494 if (sta_info_insert_rcu(sta)) 495 return NULL; 496 } 497 498 return sta; 499 } 500 501 /* 502 * mesh_neighbour_update - update or initialize new mesh neighbor. 503 * 504 * @sdata: local meshif 505 * @addr: peer's address 506 * @elems: IEs from beacon or mesh peering frame 507 * 508 * Initiates peering if appropriate. 509 */ 510 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 511 u8 *hw_addr, 512 struct ieee802_11_elems *elems) 513 { 514 struct sta_info *sta; 515 u32 changed = 0; 516 517 sta = mesh_sta_info_get(sdata, hw_addr, elems); 518 if (!sta) 519 goto out; 520 521 if (mesh_peer_accepts_plinks(elems) && 522 sta->plink_state == NL80211_PLINK_LISTEN && 523 sdata->u.mesh.accepting_plinks && 524 sdata->u.mesh.mshcfg.auto_open_plinks && 525 rssi_threshold_check(sdata, sta)) 526 changed = mesh_plink_open(sta); 527 528 ieee80211_mps_frame_release(sta, elems); 529 out: 530 rcu_read_unlock(); 531 ieee80211_mbss_info_change_notify(sdata, changed); 532 } 533 534 static void mesh_plink_timer(unsigned long data) 535 { 536 struct sta_info *sta; 537 u16 reason = 0; 538 struct ieee80211_sub_if_data *sdata; 539 struct mesh_config *mshcfg; 540 enum ieee80211_self_protected_actioncode action = 0; 541 542 /* 543 * This STA is valid because sta_info_destroy() will 544 * del_timer_sync() this timer after having made sure 545 * it cannot be readded (by deleting the plink.) 546 */ 547 sta = (struct sta_info *) data; 548 549 if (sta->sdata->local->quiescing) 550 return; 551 552 spin_lock_bh(&sta->lock); 553 if (sta->ignore_plink_timer) { 554 sta->ignore_plink_timer = false; 555 spin_unlock_bh(&sta->lock); 556 return; 557 } 558 mpl_dbg(sta->sdata, 559 "Mesh plink timer for %pM fired on state %s\n", 560 sta->sta.addr, mplstates[sta->plink_state]); 561 sdata = sta->sdata; 562 mshcfg = &sdata->u.mesh.mshcfg; 563 564 switch (sta->plink_state) { 565 case NL80211_PLINK_OPN_RCVD: 566 case NL80211_PLINK_OPN_SNT: 567 /* retry timer */ 568 if (sta->plink_retries < mshcfg->dot11MeshMaxRetries) { 569 u32 rand; 570 mpl_dbg(sta->sdata, 571 "Mesh plink for %pM (retry, timeout): %d %d\n", 572 sta->sta.addr, sta->plink_retries, 573 sta->plink_timeout); 574 get_random_bytes(&rand, sizeof(u32)); 575 sta->plink_timeout = sta->plink_timeout + 576 rand % sta->plink_timeout; 577 ++sta->plink_retries; 578 mod_plink_timer(sta, sta->plink_timeout); 579 action = WLAN_SP_MESH_PEERING_OPEN; 580 break; 581 } 582 reason = WLAN_REASON_MESH_MAX_RETRIES; 583 /* fall through on else */ 584 case NL80211_PLINK_CNF_RCVD: 585 /* confirm timer */ 586 if (!reason) 587 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 588 sta->plink_state = NL80211_PLINK_HOLDING; 589 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 590 action = WLAN_SP_MESH_PEERING_CLOSE; 591 break; 592 case NL80211_PLINK_HOLDING: 593 /* holding timer */ 594 del_timer(&sta->plink_timer); 595 mesh_plink_fsm_restart(sta); 596 break; 597 default: 598 break; 599 } 600 spin_unlock_bh(&sta->lock); 601 if (action) 602 mesh_plink_frame_tx(sdata, action, sta->sta.addr, 603 sta->llid, sta->plid, reason); 604 } 605 606 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout) 607 { 608 sta->plink_timer.expires = jiffies + (HZ * timeout / 1000); 609 sta->plink_timer.data = (unsigned long) sta; 610 sta->plink_timer.function = mesh_plink_timer; 611 sta->plink_timeout = timeout; 612 add_timer(&sta->plink_timer); 613 } 614 615 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 616 u16 llid) 617 { 618 struct ieee80211_local *local = sdata->local; 619 bool in_use = false; 620 struct sta_info *sta; 621 622 rcu_read_lock(); 623 list_for_each_entry_rcu(sta, &local->sta_list, list) { 624 if (!memcmp(&sta->llid, &llid, sizeof(llid))) { 625 in_use = true; 626 break; 627 } 628 } 629 rcu_read_unlock(); 630 631 return in_use; 632 } 633 634 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 635 { 636 u16 llid; 637 638 do { 639 get_random_bytes(&llid, sizeof(llid)); 640 /* for mesh PS we still only have the AID range for TIM bits */ 641 llid = (llid % IEEE80211_MAX_AID) + 1; 642 } while (llid_in_use(sdata, llid)); 643 644 return llid; 645 } 646 647 u32 mesh_plink_open(struct sta_info *sta) 648 { 649 struct ieee80211_sub_if_data *sdata = sta->sdata; 650 u32 changed; 651 652 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 653 return 0; 654 655 spin_lock_bh(&sta->lock); 656 sta->llid = mesh_get_new_llid(sdata); 657 if (sta->plink_state != NL80211_PLINK_LISTEN && 658 sta->plink_state != NL80211_PLINK_BLOCKED) { 659 spin_unlock_bh(&sta->lock); 660 return 0; 661 } 662 sta->plink_state = NL80211_PLINK_OPN_SNT; 663 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 664 spin_unlock_bh(&sta->lock); 665 mpl_dbg(sdata, 666 "Mesh plink: starting establishment with %pM\n", 667 sta->sta.addr); 668 669 /* set the non-peer mode to active during peering */ 670 changed = ieee80211_mps_local_status_update(sdata); 671 672 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN, 673 sta->sta.addr, sta->llid, 0, 0); 674 return changed; 675 } 676 677 u32 mesh_plink_block(struct sta_info *sta) 678 { 679 u32 changed; 680 681 spin_lock_bh(&sta->lock); 682 changed = __mesh_plink_deactivate(sta); 683 sta->plink_state = NL80211_PLINK_BLOCKED; 684 spin_unlock_bh(&sta->lock); 685 686 return changed; 687 } 688 689 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 690 struct sta_info *sta, 691 enum plink_event event) 692 { 693 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 694 695 u16 reason = (event == CLS_ACPT) ? 696 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 697 698 sta->reason = reason; 699 sta->plink_state = NL80211_PLINK_HOLDING; 700 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 701 } 702 703 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 704 struct sta_info *sta) 705 { 706 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 707 u32 changed = 0; 708 709 del_timer(&sta->plink_timer); 710 sta->plink_state = NL80211_PLINK_ESTAB; 711 changed |= mesh_plink_inc_estab_count(sdata); 712 changed |= mesh_set_ht_prot_mode(sdata); 713 changed |= mesh_set_short_slot_time(sdata); 714 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 715 ieee80211_mps_sta_status_update(sta); 716 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 717 return changed; 718 } 719 720 /** 721 * mesh_plink_fsm - step @sta MPM based on @event 722 * 723 * @sdata: interface 724 * @sta: mesh neighbor 725 * @event: peering event 726 * 727 * Return: changed MBSS flags 728 */ 729 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 730 struct sta_info *sta, enum plink_event event) 731 { 732 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 733 enum ieee80211_self_protected_actioncode action = 0; 734 u32 changed = 0; 735 736 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 737 mplstates[sta->plink_state], mplevents[event]); 738 739 spin_lock_bh(&sta->lock); 740 switch (sta->plink_state) { 741 case NL80211_PLINK_LISTEN: 742 switch (event) { 743 case CLS_ACPT: 744 mesh_plink_fsm_restart(sta); 745 break; 746 case OPN_ACPT: 747 sta->plink_state = NL80211_PLINK_OPN_RCVD; 748 sta->llid = mesh_get_new_llid(sdata); 749 mesh_plink_timer_set(sta, 750 mshcfg->dot11MeshRetryTimeout); 751 752 /* set the non-peer mode to active during peering */ 753 changed |= ieee80211_mps_local_status_update(sdata); 754 action = WLAN_SP_MESH_PEERING_OPEN; 755 break; 756 default: 757 break; 758 } 759 break; 760 case NL80211_PLINK_OPN_SNT: 761 switch (event) { 762 case OPN_RJCT: 763 case CNF_RJCT: 764 case CLS_ACPT: 765 mesh_plink_close(sdata, sta, event); 766 action = WLAN_SP_MESH_PEERING_CLOSE; 767 break; 768 case OPN_ACPT: 769 /* retry timer is left untouched */ 770 sta->plink_state = NL80211_PLINK_OPN_RCVD; 771 action = WLAN_SP_MESH_PEERING_CONFIRM; 772 break; 773 case CNF_ACPT: 774 sta->plink_state = NL80211_PLINK_CNF_RCVD; 775 if (!mod_plink_timer(sta, 776 mshcfg->dot11MeshConfirmTimeout)) 777 sta->ignore_plink_timer = true; 778 break; 779 default: 780 break; 781 } 782 break; 783 case NL80211_PLINK_OPN_RCVD: 784 switch (event) { 785 case OPN_RJCT: 786 case CNF_RJCT: 787 case CLS_ACPT: 788 mesh_plink_close(sdata, sta, event); 789 action = WLAN_SP_MESH_PEERING_CLOSE; 790 break; 791 case OPN_ACPT: 792 action = WLAN_SP_MESH_PEERING_CONFIRM; 793 break; 794 case CNF_ACPT: 795 changed |= mesh_plink_establish(sdata, sta); 796 break; 797 default: 798 break; 799 } 800 break; 801 case NL80211_PLINK_CNF_RCVD: 802 switch (event) { 803 case OPN_RJCT: 804 case CNF_RJCT: 805 case CLS_ACPT: 806 mesh_plink_close(sdata, sta, event); 807 action = WLAN_SP_MESH_PEERING_CLOSE; 808 break; 809 case OPN_ACPT: 810 changed |= mesh_plink_establish(sdata, sta); 811 action = WLAN_SP_MESH_PEERING_CONFIRM; 812 break; 813 default: 814 break; 815 } 816 break; 817 case NL80211_PLINK_ESTAB: 818 switch (event) { 819 case CLS_ACPT: 820 changed |= __mesh_plink_deactivate(sta); 821 changed |= mesh_set_ht_prot_mode(sdata); 822 changed |= mesh_set_short_slot_time(sdata); 823 mesh_plink_close(sdata, sta, event); 824 action = WLAN_SP_MESH_PEERING_CLOSE; 825 break; 826 case OPN_ACPT: 827 action = WLAN_SP_MESH_PEERING_CONFIRM; 828 break; 829 default: 830 break; 831 } 832 break; 833 case NL80211_PLINK_HOLDING: 834 switch (event) { 835 case CLS_ACPT: 836 if (del_timer(&sta->plink_timer)) 837 sta->ignore_plink_timer = 1; 838 mesh_plink_fsm_restart(sta); 839 break; 840 case OPN_ACPT: 841 case CNF_ACPT: 842 case OPN_RJCT: 843 case CNF_RJCT: 844 action = WLAN_SP_MESH_PEERING_CLOSE; 845 break; 846 default: 847 break; 848 } 849 break; 850 default: 851 /* should not get here, PLINK_BLOCKED is dealt with at the 852 * beginning of the function 853 */ 854 break; 855 } 856 spin_unlock_bh(&sta->lock); 857 if (action) { 858 mesh_plink_frame_tx(sdata, action, sta->sta.addr, 859 sta->llid, sta->plid, sta->reason); 860 861 /* also send confirm in open case */ 862 if (action == WLAN_SP_MESH_PEERING_OPEN) { 863 mesh_plink_frame_tx(sdata, 864 WLAN_SP_MESH_PEERING_CONFIRM, 865 sta->sta.addr, sta->llid, 866 sta->plid, 0); 867 } 868 } 869 870 return changed; 871 } 872 873 /* 874 * mesh_plink_get_event - get correct MPM event 875 * 876 * @sdata: interface 877 * @sta: peer, leave NULL if processing a frame from a new suitable peer 878 * @elems: peering management IEs 879 * @ftype: frame type 880 * @llid: peer's peer link ID 881 * @plid: peer's local link ID 882 * 883 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 884 * an error. 885 */ 886 static enum plink_event 887 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 888 struct sta_info *sta, 889 struct ieee802_11_elems *elems, 890 enum ieee80211_self_protected_actioncode ftype, 891 u16 llid, u16 plid) 892 { 893 enum plink_event event = PLINK_UNDEFINED; 894 u8 ie_len = elems->peering_len; 895 bool matches_local; 896 897 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 898 mesh_matches_local(sdata, elems)); 899 900 /* deny open request from non-matching peer */ 901 if (!matches_local && !sta) { 902 event = OPN_RJCT; 903 goto out; 904 } 905 906 if (!sta) { 907 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 908 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 909 goto out; 910 } 911 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 912 if (!mesh_plink_free_count(sdata)) { 913 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 914 goto out; 915 } 916 } else { 917 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 918 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 919 goto out; 920 } 921 if (sta->plink_state == NL80211_PLINK_BLOCKED) 922 goto out; 923 } 924 925 /* new matching peer */ 926 if (!sta) { 927 event = OPN_ACPT; 928 goto out; 929 } 930 931 switch (ftype) { 932 case WLAN_SP_MESH_PEERING_OPEN: 933 if (!matches_local) 934 event = OPN_RJCT; 935 if (!mesh_plink_free_count(sdata) || 936 (sta->plid && sta->plid != plid)) 937 event = OPN_IGNR; 938 else 939 event = OPN_ACPT; 940 break; 941 case WLAN_SP_MESH_PEERING_CONFIRM: 942 if (!matches_local) 943 event = CNF_RJCT; 944 if (!mesh_plink_free_count(sdata) || 945 (sta->llid != llid || sta->plid != plid)) 946 event = CNF_IGNR; 947 else 948 event = CNF_ACPT; 949 break; 950 case WLAN_SP_MESH_PEERING_CLOSE: 951 if (sta->plink_state == NL80211_PLINK_ESTAB) 952 /* Do not check for llid or plid. This does not 953 * follow the standard but since multiple plinks 954 * per sta are not supported, it is necessary in 955 * order to avoid a livelock when MP A sees an 956 * establish peer link to MP B but MP B does not 957 * see it. This can be caused by a timeout in 958 * B's peer link establishment or B beign 959 * restarted. 960 */ 961 event = CLS_ACPT; 962 else if (sta->plid != plid) 963 event = CLS_IGNR; 964 else if (ie_len == 8 && sta->llid != llid) 965 event = CLS_IGNR; 966 else 967 event = CLS_ACPT; 968 break; 969 default: 970 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 971 break; 972 } 973 974 out: 975 return event; 976 } 977 978 static void 979 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 980 struct ieee80211_mgmt *mgmt, 981 struct ieee802_11_elems *elems) 982 { 983 984 struct sta_info *sta; 985 enum plink_event event; 986 enum ieee80211_self_protected_actioncode ftype; 987 u32 changed = 0; 988 u8 ie_len = elems->peering_len; 989 __le16 _plid, _llid; 990 u16 plid, llid = 0; 991 992 if (!elems->peering) { 993 mpl_dbg(sdata, 994 "Mesh plink: missing necessary peer link ie\n"); 995 return; 996 } 997 998 if (elems->rsn_len && 999 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1000 mpl_dbg(sdata, 1001 "Mesh plink: can't establish link with secure peer\n"); 1002 return; 1003 } 1004 1005 ftype = mgmt->u.action.u.self_prot.action_code; 1006 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1007 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1008 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1009 && ie_len != 8)) { 1010 mpl_dbg(sdata, 1011 "Mesh plink: incorrect plink ie length %d %d\n", 1012 ftype, ie_len); 1013 return; 1014 } 1015 1016 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1017 (!elems->mesh_id || !elems->mesh_config)) { 1018 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1019 return; 1020 } 1021 /* Note the lines below are correct, the llid in the frame is the plid 1022 * from the point of view of this host. 1023 */ 1024 memcpy(&_plid, PLINK_GET_LLID(elems->peering), sizeof(__le16)); 1025 plid = le16_to_cpu(_plid); 1026 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1027 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) { 1028 memcpy(&_llid, PLINK_GET_PLID(elems->peering), sizeof(__le16)); 1029 llid = le16_to_cpu(_llid); 1030 } 1031 1032 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1033 rcu_read_lock(); 1034 1035 sta = sta_info_get(sdata, mgmt->sa); 1036 1037 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1038 !rssi_threshold_check(sdata, sta)) { 1039 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1040 mgmt->sa); 1041 goto unlock_rcu; 1042 } 1043 1044 /* Now we will figure out the appropriate event... */ 1045 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1046 1047 if (event == OPN_ACPT) { 1048 rcu_read_unlock(); 1049 /* allocate sta entry if necessary and update info */ 1050 sta = mesh_sta_info_get(sdata, mgmt->sa, elems); 1051 if (!sta) { 1052 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1053 goto unlock_rcu; 1054 } 1055 sta->plid = plid; 1056 } else if (!sta && event == OPN_RJCT) { 1057 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, 1058 mgmt->sa, 0, plid, 1059 WLAN_REASON_MESH_CONFIG); 1060 goto unlock_rcu; 1061 } else if (!sta || event == PLINK_UNDEFINED) { 1062 /* something went wrong */ 1063 goto unlock_rcu; 1064 } 1065 1066 changed |= mesh_plink_fsm(sdata, sta, event); 1067 1068 unlock_rcu: 1069 rcu_read_unlock(); 1070 1071 if (changed) 1072 ieee80211_mbss_info_change_notify(sdata, changed); 1073 } 1074 1075 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1076 struct ieee80211_mgmt *mgmt, size_t len, 1077 struct ieee80211_rx_status *rx_status) 1078 { 1079 struct ieee802_11_elems elems; 1080 size_t baselen; 1081 u8 *baseaddr; 1082 1083 /* need action_code, aux */ 1084 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1085 return; 1086 1087 if (sdata->u.mesh.user_mpm) 1088 /* userspace must register for these */ 1089 return; 1090 1091 if (is_multicast_ether_addr(mgmt->da)) { 1092 mpl_dbg(sdata, 1093 "Mesh plink: ignore frame from multicast address\n"); 1094 return; 1095 } 1096 1097 baseaddr = mgmt->u.action.u.self_prot.variable; 1098 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1099 if (mgmt->u.action.u.self_prot.action_code == 1100 WLAN_SP_MESH_PEERING_CONFIRM) { 1101 baseaddr += 4; 1102 baselen += 4; 1103 } 1104 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems); 1105 mesh_process_plink_frame(sdata, mgmt, &elems); 1106 } 1107