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 /* We only need a valid sta if user configured a minimum rssi_threshold. */ 23 #define rssi_threshold_check(sta, sdata) \ 24 (sdata->u.mesh.mshcfg.rssi_threshold == 0 ||\ 25 (sta && (s8) -ewma_read(&sta->avg_signal) > \ 26 sdata->u.mesh.mshcfg.rssi_threshold)) 27 28 enum plink_event { 29 PLINK_UNDEFINED, 30 OPN_ACPT, 31 OPN_RJCT, 32 OPN_IGNR, 33 CNF_ACPT, 34 CNF_RJCT, 35 CNF_IGNR, 36 CLS_ACPT, 37 CLS_IGNR 38 }; 39 40 static const char * const mplstates[] = { 41 [NL80211_PLINK_LISTEN] = "LISTEN", 42 [NL80211_PLINK_OPN_SNT] = "OPN-SNT", 43 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD", 44 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD", 45 [NL80211_PLINK_ESTAB] = "ESTAB", 46 [NL80211_PLINK_HOLDING] = "HOLDING", 47 [NL80211_PLINK_BLOCKED] = "BLOCKED" 48 }; 49 50 static const char * const mplevents[] = { 51 [PLINK_UNDEFINED] = "NONE", 52 [OPN_ACPT] = "OPN_ACPT", 53 [OPN_RJCT] = "OPN_RJCT", 54 [OPN_IGNR] = "OPN_IGNR", 55 [CNF_ACPT] = "CNF_ACPT", 56 [CNF_RJCT] = "CNF_RJCT", 57 [CNF_IGNR] = "CNF_IGNR", 58 [CLS_ACPT] = "CLS_ACPT", 59 [CLS_IGNR] = "CLS_IGNR" 60 }; 61 62 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 63 enum ieee80211_self_protected_actioncode action, 64 u8 *da, __le16 llid, __le16 plid, __le16 reason); 65 66 /** 67 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine 68 * 69 * @sta: mesh peer link to restart 70 * 71 * Locking: this function must be called holding sta->lock 72 */ 73 static inline void mesh_plink_fsm_restart(struct sta_info *sta) 74 { 75 sta->plink_state = NL80211_PLINK_LISTEN; 76 sta->llid = sta->plid = sta->reason = 0; 77 sta->plink_retries = 0; 78 } 79 80 /* 81 * mesh_set_short_slot_time - enable / disable ERP short slot time. 82 * 83 * The standard indirectly mandates mesh STAs to turn off short slot time by 84 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we 85 * can't be sneaky about it. Enable short slot time if all mesh STAs in the 86 * MBSS support ERP rates. 87 * 88 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change. 89 */ 90 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata) 91 { 92 struct ieee80211_local *local = sdata->local; 93 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 94 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 95 struct sta_info *sta; 96 u32 erp_rates = 0, changed = 0; 97 int i; 98 bool short_slot = false; 99 100 if (band == IEEE80211_BAND_5GHZ) { 101 /* (IEEE 802.11-2012 19.4.5) */ 102 short_slot = true; 103 goto out; 104 } else if (band != IEEE80211_BAND_2GHZ || 105 (band == IEEE80211_BAND_2GHZ && 106 local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE)) 107 goto out; 108 109 for (i = 0; i < sband->n_bitrates; i++) 110 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G) 111 erp_rates |= BIT(i); 112 113 if (!erp_rates) 114 goto out; 115 116 rcu_read_lock(); 117 list_for_each_entry_rcu(sta, &local->sta_list, list) { 118 if (sdata != sta->sdata || 119 sta->plink_state != NL80211_PLINK_ESTAB) 120 continue; 121 122 short_slot = false; 123 if (erp_rates & sta->sta.supp_rates[band]) 124 short_slot = true; 125 else 126 break; 127 } 128 rcu_read_unlock(); 129 130 out: 131 if (sdata->vif.bss_conf.use_short_slot != short_slot) { 132 sdata->vif.bss_conf.use_short_slot = short_slot; 133 changed = BSS_CHANGED_ERP_SLOT; 134 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n", 135 sdata->vif.addr, short_slot); 136 } 137 return changed; 138 } 139 140 /** 141 * mesh_set_ht_prot_mode - set correct HT protection mode 142 * 143 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT 144 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT 145 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is 146 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode 147 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one 148 * HT20 peer is present. Otherwise no-protection mode is selected. 149 */ 150 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) 151 { 152 struct ieee80211_local *local = sdata->local; 153 struct sta_info *sta; 154 u16 ht_opmode; 155 bool non_ht_sta = false, ht20_sta = false; 156 157 switch (sdata->vif.bss_conf.chandef.width) { 158 case NL80211_CHAN_WIDTH_20_NOHT: 159 case NL80211_CHAN_WIDTH_5: 160 case NL80211_CHAN_WIDTH_10: 161 return 0; 162 default: 163 break; 164 } 165 166 rcu_read_lock(); 167 list_for_each_entry_rcu(sta, &local->sta_list, list) { 168 if (sdata != sta->sdata || 169 sta->plink_state != NL80211_PLINK_ESTAB) 170 continue; 171 172 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20) 173 continue; 174 175 if (!sta->sta.ht_cap.ht_supported) { 176 mpl_dbg(sdata, "nonHT sta (%pM) is present\n", 177 sta->sta.addr); 178 non_ht_sta = true; 179 break; 180 } 181 182 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); 183 ht20_sta = true; 184 } 185 rcu_read_unlock(); 186 187 if (non_ht_sta) 188 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; 189 else if (ht20_sta && 190 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20) 191 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; 192 else 193 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; 194 195 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) 196 return 0; 197 198 sdata->vif.bss_conf.ht_operation_mode = ht_opmode; 199 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; 200 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); 201 return BSS_CHANGED_HT; 202 } 203 204 /** 205 * __mesh_plink_deactivate - deactivate mesh peer link 206 * 207 * @sta: mesh peer link to deactivate 208 * 209 * All mesh paths with this peer as next hop will be flushed 210 * Returns beacon changed flag if the beacon content changed. 211 * 212 * Locking: the caller must hold sta->lock 213 */ 214 static u32 __mesh_plink_deactivate(struct sta_info *sta) 215 { 216 struct ieee80211_sub_if_data *sdata = sta->sdata; 217 u32 changed = 0; 218 219 if (sta->plink_state == NL80211_PLINK_ESTAB) 220 changed = mesh_plink_dec_estab_count(sdata); 221 sta->plink_state = NL80211_PLINK_BLOCKED; 222 mesh_path_flush_by_nexthop(sta); 223 224 ieee80211_mps_sta_status_update(sta); 225 changed |= ieee80211_mps_local_status_update(sdata); 226 227 return changed; 228 } 229 230 /** 231 * mesh_plink_deactivate - deactivate mesh peer link 232 * 233 * @sta: mesh peer link to deactivate 234 * 235 * All mesh paths with this peer as next hop will be flushed 236 */ 237 u32 mesh_plink_deactivate(struct sta_info *sta) 238 { 239 struct ieee80211_sub_if_data *sdata = sta->sdata; 240 u32 changed; 241 242 spin_lock_bh(&sta->lock); 243 changed = __mesh_plink_deactivate(sta); 244 sta->reason = cpu_to_le16(WLAN_REASON_MESH_PEER_CANCELED); 245 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, 246 sta->sta.addr, sta->llid, sta->plid, 247 sta->reason); 248 spin_unlock_bh(&sta->lock); 249 250 return changed; 251 } 252 253 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 254 enum ieee80211_self_protected_actioncode action, 255 u8 *da, __le16 llid, __le16 plid, __le16 reason) 256 { 257 struct ieee80211_local *local = sdata->local; 258 struct sk_buff *skb; 259 struct ieee80211_tx_info *info; 260 struct ieee80211_mgmt *mgmt; 261 bool include_plid = false; 262 u16 peering_proto = 0; 263 u8 *pos, ie_len = 4; 264 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) + 265 sizeof(mgmt->u.action.u.self_prot); 266 int err = -ENOMEM; 267 268 skb = dev_alloc_skb(local->tx_headroom + 269 hdr_len + 270 2 + /* capability info */ 271 2 + /* AID */ 272 2 + 8 + /* supported rates */ 273 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 274 2 + sdata->u.mesh.mesh_id_len + 275 2 + sizeof(struct ieee80211_meshconf_ie) + 276 2 + sizeof(struct ieee80211_ht_cap) + 277 2 + sizeof(struct ieee80211_ht_operation) + 278 2 + 8 + /* peering IE */ 279 sdata->u.mesh.ie_len); 280 if (!skb) 281 return -1; 282 info = IEEE80211_SKB_CB(skb); 283 skb_reserve(skb, local->tx_headroom); 284 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len); 285 memset(mgmt, 0, hdr_len); 286 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 287 IEEE80211_STYPE_ACTION); 288 memcpy(mgmt->da, da, ETH_ALEN); 289 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 290 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 291 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; 292 mgmt->u.action.u.self_prot.action_code = action; 293 294 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 295 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 296 297 /* capability info */ 298 pos = skb_put(skb, 2); 299 memset(pos, 0, 2); 300 if (action == WLAN_SP_MESH_PEERING_CONFIRM) { 301 /* AID */ 302 pos = skb_put(skb, 2); 303 memcpy(pos + 2, &plid, 2); 304 } 305 if (ieee80211_add_srates_ie(sdata, skb, true, band) || 306 ieee80211_add_ext_srates_ie(sdata, skb, true, band) || 307 mesh_add_rsn_ie(sdata, skb) || 308 mesh_add_meshid_ie(sdata, skb) || 309 mesh_add_meshconf_ie(sdata, skb)) 310 goto free; 311 } else { /* WLAN_SP_MESH_PEERING_CLOSE */ 312 info->flags |= IEEE80211_TX_CTL_NO_ACK; 313 if (mesh_add_meshid_ie(sdata, skb)) 314 goto free; 315 } 316 317 /* Add Mesh Peering Management element */ 318 switch (action) { 319 case WLAN_SP_MESH_PEERING_OPEN: 320 break; 321 case WLAN_SP_MESH_PEERING_CONFIRM: 322 ie_len += 2; 323 include_plid = true; 324 break; 325 case WLAN_SP_MESH_PEERING_CLOSE: 326 if (plid) { 327 ie_len += 2; 328 include_plid = true; 329 } 330 ie_len += 2; /* reason code */ 331 break; 332 default: 333 err = -EINVAL; 334 goto free; 335 } 336 337 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) 338 goto free; 339 340 pos = skb_put(skb, 2 + ie_len); 341 *pos++ = WLAN_EID_PEER_MGMT; 342 *pos++ = ie_len; 343 memcpy(pos, &peering_proto, 2); 344 pos += 2; 345 memcpy(pos, &llid, 2); 346 pos += 2; 347 if (include_plid) { 348 memcpy(pos, &plid, 2); 349 pos += 2; 350 } 351 if (action == WLAN_SP_MESH_PEERING_CLOSE) { 352 memcpy(pos, &reason, 2); 353 pos += 2; 354 } 355 356 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 357 if (mesh_add_ht_cap_ie(sdata, skb) || 358 mesh_add_ht_oper_ie(sdata, skb)) 359 goto free; 360 } 361 362 if (mesh_add_vendor_ies(sdata, skb)) 363 goto free; 364 365 ieee80211_tx_skb(sdata, skb); 366 return 0; 367 free: 368 kfree_skb(skb); 369 return err; 370 } 371 372 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 373 struct sta_info *sta, 374 struct ieee802_11_elems *elems, bool insert) 375 { 376 struct ieee80211_local *local = sdata->local; 377 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 378 struct ieee80211_supported_band *sband; 379 u32 rates, basic_rates = 0, changed = 0; 380 381 sband = local->hw.wiphy->bands[band]; 382 rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates); 383 384 spin_lock_bh(&sta->lock); 385 sta->last_rx = jiffies; 386 387 /* rates and capabilities don't change during peering */ 388 if (sta->plink_state == NL80211_PLINK_ESTAB) 389 goto out; 390 391 if (sta->sta.supp_rates[band] != rates) 392 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 393 sta->sta.supp_rates[band] = rates; 394 395 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 396 elems->ht_cap_elem, sta)) 397 changed |= IEEE80211_RC_BW_CHANGED; 398 399 /* HT peer is operating 20MHz-only */ 400 if (elems->ht_operation && 401 !(elems->ht_operation->ht_param & 402 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 403 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) 404 changed |= IEEE80211_RC_BW_CHANGED; 405 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; 406 } 407 408 if (insert) 409 rate_control_rate_init(sta); 410 else 411 rate_control_rate_update(local, sband, sta, changed); 412 out: 413 spin_unlock_bh(&sta->lock); 414 } 415 416 static struct sta_info * 417 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 418 { 419 struct sta_info *sta; 420 421 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 422 return NULL; 423 424 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 425 if (!sta) 426 return NULL; 427 428 sta->plink_state = NL80211_PLINK_LISTEN; 429 430 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 431 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 432 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 433 434 set_sta_flag(sta, WLAN_STA_WME); 435 436 return sta; 437 } 438 439 static struct sta_info * 440 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 441 struct ieee802_11_elems *elems) 442 { 443 struct sta_info *sta = NULL; 444 445 /* Userspace handles station allocation */ 446 if (sdata->u.mesh.user_mpm || 447 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) 448 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 449 elems->ie_start, 450 elems->total_len, 451 GFP_KERNEL); 452 else 453 sta = __mesh_sta_info_alloc(sdata, addr); 454 455 return sta; 456 } 457 458 /* 459 * mesh_sta_info_get - return mesh sta info entry for @addr. 460 * 461 * @sdata: local meshif 462 * @addr: peer's address 463 * @elems: IEs from beacon or mesh peering frame. 464 * 465 * Return existing or newly allocated sta_info under RCU read lock. 466 * (re)initialize with given IEs. 467 */ 468 static struct sta_info * 469 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 470 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU) 471 { 472 struct sta_info *sta = NULL; 473 474 rcu_read_lock(); 475 sta = sta_info_get(sdata, addr); 476 if (sta) { 477 mesh_sta_info_init(sdata, sta, elems, false); 478 } else { 479 rcu_read_unlock(); 480 /* can't run atomic */ 481 sta = mesh_sta_info_alloc(sdata, addr, elems); 482 if (!sta) { 483 rcu_read_lock(); 484 return NULL; 485 } 486 487 mesh_sta_info_init(sdata, sta, elems, true); 488 489 if (sta_info_insert_rcu(sta)) 490 return NULL; 491 } 492 493 return sta; 494 } 495 496 /* 497 * mesh_neighbour_update - update or initialize new mesh neighbor. 498 * 499 * @sdata: local meshif 500 * @addr: peer's address 501 * @elems: IEs from beacon or mesh peering frame 502 * 503 * Initiates peering if appropriate. 504 */ 505 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 506 u8 *hw_addr, 507 struct ieee802_11_elems *elems) 508 { 509 struct sta_info *sta; 510 u32 changed = 0; 511 512 sta = mesh_sta_info_get(sdata, hw_addr, elems); 513 if (!sta) 514 goto out; 515 516 if (mesh_peer_accepts_plinks(elems) && 517 sta->plink_state == NL80211_PLINK_LISTEN && 518 sdata->u.mesh.accepting_plinks && 519 sdata->u.mesh.mshcfg.auto_open_plinks && 520 rssi_threshold_check(sta, sdata)) 521 changed = mesh_plink_open(sta); 522 523 ieee80211_mps_frame_release(sta, elems); 524 out: 525 rcu_read_unlock(); 526 ieee80211_mbss_info_change_notify(sdata, changed); 527 } 528 529 static void mesh_plink_timer(unsigned long data) 530 { 531 struct sta_info *sta; 532 __le16 llid, plid, reason; 533 struct ieee80211_sub_if_data *sdata; 534 struct mesh_config *mshcfg; 535 536 /* 537 * This STA is valid because sta_info_destroy() will 538 * del_timer_sync() this timer after having made sure 539 * it cannot be readded (by deleting the plink.) 540 */ 541 sta = (struct sta_info *) data; 542 543 if (sta->sdata->local->quiescing) 544 return; 545 546 spin_lock_bh(&sta->lock); 547 if (sta->ignore_plink_timer) { 548 sta->ignore_plink_timer = false; 549 spin_unlock_bh(&sta->lock); 550 return; 551 } 552 mpl_dbg(sta->sdata, 553 "Mesh plink timer for %pM fired on state %s\n", 554 sta->sta.addr, mplstates[sta->plink_state]); 555 reason = 0; 556 llid = sta->llid; 557 plid = sta->plid; 558 sdata = sta->sdata; 559 mshcfg = &sdata->u.mesh.mshcfg; 560 561 switch (sta->plink_state) { 562 case NL80211_PLINK_OPN_RCVD: 563 case NL80211_PLINK_OPN_SNT: 564 /* retry timer */ 565 if (sta->plink_retries < mshcfg->dot11MeshMaxRetries) { 566 u32 rand; 567 mpl_dbg(sta->sdata, 568 "Mesh plink for %pM (retry, timeout): %d %d\n", 569 sta->sta.addr, sta->plink_retries, 570 sta->plink_timeout); 571 get_random_bytes(&rand, sizeof(u32)); 572 sta->plink_timeout = sta->plink_timeout + 573 rand % sta->plink_timeout; 574 ++sta->plink_retries; 575 mod_plink_timer(sta, sta->plink_timeout); 576 spin_unlock_bh(&sta->lock); 577 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN, 578 sta->sta.addr, llid, 0, 0); 579 break; 580 } 581 reason = cpu_to_le16(WLAN_REASON_MESH_MAX_RETRIES); 582 /* fall through on else */ 583 case NL80211_PLINK_CNF_RCVD: 584 /* confirm timer */ 585 if (!reason) 586 reason = cpu_to_le16(WLAN_REASON_MESH_CONFIRM_TIMEOUT); 587 sta->plink_state = NL80211_PLINK_HOLDING; 588 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 589 spin_unlock_bh(&sta->lock); 590 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, 591 sta->sta.addr, llid, plid, reason); 592 break; 593 case NL80211_PLINK_HOLDING: 594 /* holding timer */ 595 del_timer(&sta->plink_timer); 596 mesh_plink_fsm_restart(sta); 597 spin_unlock_bh(&sta->lock); 598 break; 599 default: 600 spin_unlock_bh(&sta->lock); 601 break; 602 } 603 } 604 605 static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout) 606 { 607 sta->plink_timer.expires = jiffies + (HZ * timeout / 1000); 608 sta->plink_timer.data = (unsigned long) sta; 609 sta->plink_timer.function = mesh_plink_timer; 610 sta->plink_timeout = timeout; 611 add_timer(&sta->plink_timer); 612 } 613 614 u32 mesh_plink_open(struct sta_info *sta) 615 { 616 __le16 llid; 617 struct ieee80211_sub_if_data *sdata = sta->sdata; 618 u32 changed; 619 620 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 621 return 0; 622 623 spin_lock_bh(&sta->lock); 624 get_random_bytes(&llid, 2); 625 sta->llid = llid; 626 if (sta->plink_state != NL80211_PLINK_LISTEN && 627 sta->plink_state != NL80211_PLINK_BLOCKED) { 628 spin_unlock_bh(&sta->lock); 629 return 0; 630 } 631 sta->plink_state = NL80211_PLINK_OPN_SNT; 632 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 633 spin_unlock_bh(&sta->lock); 634 mpl_dbg(sdata, 635 "Mesh plink: starting establishment with %pM\n", 636 sta->sta.addr); 637 638 /* set the non-peer mode to active during peering */ 639 changed = ieee80211_mps_local_status_update(sdata); 640 641 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN, 642 sta->sta.addr, llid, 0, 0); 643 return changed; 644 } 645 646 u32 mesh_plink_block(struct sta_info *sta) 647 { 648 u32 changed; 649 650 spin_lock_bh(&sta->lock); 651 changed = __mesh_plink_deactivate(sta); 652 sta->plink_state = NL80211_PLINK_BLOCKED; 653 spin_unlock_bh(&sta->lock); 654 655 return changed; 656 } 657 658 659 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 660 struct ieee80211_mgmt *mgmt, size_t len, 661 struct ieee80211_rx_status *rx_status) 662 { 663 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 664 struct ieee802_11_elems elems; 665 struct sta_info *sta; 666 enum plink_event event; 667 enum ieee80211_self_protected_actioncode ftype; 668 size_t baselen; 669 bool matches_local = true; 670 u8 ie_len; 671 u8 *baseaddr; 672 u32 changed = 0; 673 __le16 plid, llid, reason; 674 675 /* need action_code, aux */ 676 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 677 return; 678 679 if (sdata->u.mesh.user_mpm) 680 /* userspace must register for these */ 681 return; 682 683 if (is_multicast_ether_addr(mgmt->da)) { 684 mpl_dbg(sdata, 685 "Mesh plink: ignore frame from multicast address\n"); 686 return; 687 } 688 689 baseaddr = mgmt->u.action.u.self_prot.variable; 690 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 691 if (mgmt->u.action.u.self_prot.action_code == 692 WLAN_SP_MESH_PEERING_CONFIRM) { 693 baseaddr += 4; 694 baselen += 4; 695 } 696 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems); 697 698 if (!elems.peering) { 699 mpl_dbg(sdata, 700 "Mesh plink: missing necessary peer link ie\n"); 701 return; 702 } 703 704 if (elems.rsn_len && 705 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 706 mpl_dbg(sdata, 707 "Mesh plink: can't establish link with secure peer\n"); 708 return; 709 } 710 711 ftype = mgmt->u.action.u.self_prot.action_code; 712 ie_len = elems.peering_len; 713 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 714 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 715 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 716 && ie_len != 8)) { 717 mpl_dbg(sdata, 718 "Mesh plink: incorrect plink ie length %d %d\n", 719 ftype, ie_len); 720 return; 721 } 722 723 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 724 (!elems.mesh_id || !elems.mesh_config)) { 725 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 726 return; 727 } 728 /* Note the lines below are correct, the llid in the frame is the plid 729 * from the point of view of this host. 730 */ 731 memcpy(&plid, PLINK_GET_LLID(elems.peering), 2); 732 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 733 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 734 memcpy(&llid, PLINK_GET_PLID(elems.peering), 2); 735 736 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 737 rcu_read_lock(); 738 739 sta = sta_info_get(sdata, mgmt->sa); 740 if (!sta && ftype != WLAN_SP_MESH_PEERING_OPEN) { 741 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 742 rcu_read_unlock(); 743 return; 744 } 745 746 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 747 !rssi_threshold_check(sta, sdata)) { 748 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 749 mgmt->sa); 750 rcu_read_unlock(); 751 return; 752 } 753 754 if (sta && !test_sta_flag(sta, WLAN_STA_AUTH)) { 755 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 756 rcu_read_unlock(); 757 return; 758 } 759 760 if (sta && sta->plink_state == NL80211_PLINK_BLOCKED) { 761 rcu_read_unlock(); 762 return; 763 } 764 765 /* Now we will figure out the appropriate event... */ 766 event = PLINK_UNDEFINED; 767 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 768 !mesh_matches_local(sdata, &elems)) { 769 matches_local = false; 770 switch (ftype) { 771 case WLAN_SP_MESH_PEERING_OPEN: 772 event = OPN_RJCT; 773 break; 774 case WLAN_SP_MESH_PEERING_CONFIRM: 775 event = CNF_RJCT; 776 break; 777 default: 778 break; 779 } 780 } 781 782 if (!sta && !matches_local) { 783 rcu_read_unlock(); 784 reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG); 785 llid = 0; 786 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, 787 mgmt->sa, llid, plid, reason); 788 return; 789 } else if (!sta) { 790 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 791 if (!mesh_plink_free_count(sdata)) { 792 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 793 rcu_read_unlock(); 794 return; 795 } 796 event = OPN_ACPT; 797 } else if (matches_local) { 798 switch (ftype) { 799 case WLAN_SP_MESH_PEERING_OPEN: 800 if (!mesh_plink_free_count(sdata) || 801 (sta->plid && sta->plid != plid)) 802 event = OPN_IGNR; 803 else 804 event = OPN_ACPT; 805 break; 806 case WLAN_SP_MESH_PEERING_CONFIRM: 807 if (!mesh_plink_free_count(sdata) || 808 (sta->llid != llid || sta->plid != plid)) 809 event = CNF_IGNR; 810 else 811 event = CNF_ACPT; 812 break; 813 case WLAN_SP_MESH_PEERING_CLOSE: 814 if (sta->plink_state == NL80211_PLINK_ESTAB) 815 /* Do not check for llid or plid. This does not 816 * follow the standard but since multiple plinks 817 * per sta are not supported, it is necessary in 818 * order to avoid a livelock when MP A sees an 819 * establish peer link to MP B but MP B does not 820 * see it. This can be caused by a timeout in 821 * B's peer link establishment or B beign 822 * restarted. 823 */ 824 event = CLS_ACPT; 825 else if (sta->plid != plid) 826 event = CLS_IGNR; 827 else if (ie_len == 7 && sta->llid != llid) 828 event = CLS_IGNR; 829 else 830 event = CLS_ACPT; 831 break; 832 default: 833 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 834 rcu_read_unlock(); 835 return; 836 } 837 } 838 839 if (event == OPN_ACPT) { 840 rcu_read_unlock(); 841 /* allocate sta entry if necessary and update info */ 842 sta = mesh_sta_info_get(sdata, mgmt->sa, &elems); 843 if (!sta) { 844 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 845 rcu_read_unlock(); 846 return; 847 } 848 } 849 850 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", mgmt->sa, 851 mplstates[sta->plink_state], mplevents[event]); 852 reason = 0; 853 spin_lock_bh(&sta->lock); 854 switch (sta->plink_state) { 855 /* spin_unlock as soon as state is updated at each case */ 856 case NL80211_PLINK_LISTEN: 857 switch (event) { 858 case CLS_ACPT: 859 mesh_plink_fsm_restart(sta); 860 spin_unlock_bh(&sta->lock); 861 break; 862 case OPN_ACPT: 863 sta->plink_state = NL80211_PLINK_OPN_RCVD; 864 sta->plid = plid; 865 get_random_bytes(&llid, 2); 866 sta->llid = llid; 867 mesh_plink_timer_set(sta, 868 mshcfg->dot11MeshRetryTimeout); 869 870 /* set the non-peer mode to active during peering */ 871 changed |= ieee80211_mps_local_status_update(sdata); 872 873 spin_unlock_bh(&sta->lock); 874 mesh_plink_frame_tx(sdata, 875 WLAN_SP_MESH_PEERING_OPEN, 876 sta->sta.addr, llid, 0, 0); 877 mesh_plink_frame_tx(sdata, 878 WLAN_SP_MESH_PEERING_CONFIRM, 879 sta->sta.addr, llid, plid, 0); 880 break; 881 default: 882 spin_unlock_bh(&sta->lock); 883 break; 884 } 885 break; 886 887 case NL80211_PLINK_OPN_SNT: 888 switch (event) { 889 case OPN_RJCT: 890 case CNF_RJCT: 891 reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG); 892 case CLS_ACPT: 893 if (!reason) 894 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE); 895 sta->reason = reason; 896 sta->plink_state = NL80211_PLINK_HOLDING; 897 if (!mod_plink_timer(sta, 898 mshcfg->dot11MeshHoldingTimeout)) 899 sta->ignore_plink_timer = true; 900 901 llid = sta->llid; 902 spin_unlock_bh(&sta->lock); 903 mesh_plink_frame_tx(sdata, 904 WLAN_SP_MESH_PEERING_CLOSE, 905 sta->sta.addr, llid, plid, reason); 906 break; 907 case OPN_ACPT: 908 /* retry timer is left untouched */ 909 sta->plink_state = NL80211_PLINK_OPN_RCVD; 910 sta->plid = plid; 911 llid = sta->llid; 912 spin_unlock_bh(&sta->lock); 913 mesh_plink_frame_tx(sdata, 914 WLAN_SP_MESH_PEERING_CONFIRM, 915 sta->sta.addr, llid, plid, 0); 916 break; 917 case CNF_ACPT: 918 sta->plink_state = NL80211_PLINK_CNF_RCVD; 919 if (!mod_plink_timer(sta, 920 mshcfg->dot11MeshConfirmTimeout)) 921 sta->ignore_plink_timer = true; 922 923 spin_unlock_bh(&sta->lock); 924 break; 925 default: 926 spin_unlock_bh(&sta->lock); 927 break; 928 } 929 break; 930 931 case NL80211_PLINK_OPN_RCVD: 932 switch (event) { 933 case OPN_RJCT: 934 case CNF_RJCT: 935 reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG); 936 case CLS_ACPT: 937 if (!reason) 938 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE); 939 sta->reason = reason; 940 sta->plink_state = NL80211_PLINK_HOLDING; 941 if (!mod_plink_timer(sta, 942 mshcfg->dot11MeshHoldingTimeout)) 943 sta->ignore_plink_timer = true; 944 945 llid = sta->llid; 946 spin_unlock_bh(&sta->lock); 947 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, 948 sta->sta.addr, llid, plid, reason); 949 break; 950 case OPN_ACPT: 951 llid = sta->llid; 952 spin_unlock_bh(&sta->lock); 953 mesh_plink_frame_tx(sdata, 954 WLAN_SP_MESH_PEERING_CONFIRM, 955 sta->sta.addr, llid, plid, 0); 956 break; 957 case CNF_ACPT: 958 del_timer(&sta->plink_timer); 959 sta->plink_state = NL80211_PLINK_ESTAB; 960 spin_unlock_bh(&sta->lock); 961 changed |= mesh_plink_inc_estab_count(sdata); 962 changed |= mesh_set_ht_prot_mode(sdata); 963 changed |= mesh_set_short_slot_time(sdata); 964 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", 965 sta->sta.addr); 966 ieee80211_mps_sta_status_update(sta); 967 changed |= ieee80211_mps_set_sta_local_pm(sta, 968 mshcfg->power_mode); 969 break; 970 default: 971 spin_unlock_bh(&sta->lock); 972 break; 973 } 974 break; 975 976 case NL80211_PLINK_CNF_RCVD: 977 switch (event) { 978 case OPN_RJCT: 979 case CNF_RJCT: 980 reason = cpu_to_le16(WLAN_REASON_MESH_CONFIG); 981 case CLS_ACPT: 982 if (!reason) 983 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE); 984 sta->reason = reason; 985 sta->plink_state = NL80211_PLINK_HOLDING; 986 if (!mod_plink_timer(sta, 987 mshcfg->dot11MeshHoldingTimeout)) 988 sta->ignore_plink_timer = true; 989 990 llid = sta->llid; 991 spin_unlock_bh(&sta->lock); 992 mesh_plink_frame_tx(sdata, 993 WLAN_SP_MESH_PEERING_CLOSE, 994 sta->sta.addr, llid, plid, reason); 995 break; 996 case OPN_ACPT: 997 del_timer(&sta->plink_timer); 998 sta->plink_state = NL80211_PLINK_ESTAB; 999 spin_unlock_bh(&sta->lock); 1000 changed |= mesh_plink_inc_estab_count(sdata); 1001 changed |= mesh_set_ht_prot_mode(sdata); 1002 changed |= mesh_set_short_slot_time(sdata); 1003 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", 1004 sta->sta.addr); 1005 mesh_plink_frame_tx(sdata, 1006 WLAN_SP_MESH_PEERING_CONFIRM, 1007 sta->sta.addr, llid, plid, 0); 1008 ieee80211_mps_sta_status_update(sta); 1009 changed |= ieee80211_mps_set_sta_local_pm(sta, 1010 mshcfg->power_mode); 1011 break; 1012 default: 1013 spin_unlock_bh(&sta->lock); 1014 break; 1015 } 1016 break; 1017 1018 case NL80211_PLINK_ESTAB: 1019 switch (event) { 1020 case CLS_ACPT: 1021 reason = cpu_to_le16(WLAN_REASON_MESH_CLOSE); 1022 sta->reason = reason; 1023 changed |= __mesh_plink_deactivate(sta); 1024 sta->plink_state = NL80211_PLINK_HOLDING; 1025 llid = sta->llid; 1026 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 1027 spin_unlock_bh(&sta->lock); 1028 changed |= mesh_set_ht_prot_mode(sdata); 1029 changed |= mesh_set_short_slot_time(sdata); 1030 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, 1031 sta->sta.addr, llid, plid, reason); 1032 break; 1033 case OPN_ACPT: 1034 llid = sta->llid; 1035 spin_unlock_bh(&sta->lock); 1036 mesh_plink_frame_tx(sdata, 1037 WLAN_SP_MESH_PEERING_CONFIRM, 1038 sta->sta.addr, llid, plid, 0); 1039 break; 1040 default: 1041 spin_unlock_bh(&sta->lock); 1042 break; 1043 } 1044 break; 1045 case NL80211_PLINK_HOLDING: 1046 switch (event) { 1047 case CLS_ACPT: 1048 if (del_timer(&sta->plink_timer)) 1049 sta->ignore_plink_timer = 1; 1050 mesh_plink_fsm_restart(sta); 1051 spin_unlock_bh(&sta->lock); 1052 break; 1053 case OPN_ACPT: 1054 case CNF_ACPT: 1055 case OPN_RJCT: 1056 case CNF_RJCT: 1057 llid = sta->llid; 1058 reason = sta->reason; 1059 spin_unlock_bh(&sta->lock); 1060 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, 1061 sta->sta.addr, llid, plid, reason); 1062 break; 1063 default: 1064 spin_unlock_bh(&sta->lock); 1065 } 1066 break; 1067 default: 1068 /* should not get here, PLINK_BLOCKED is dealt with at the 1069 * beginning of the function 1070 */ 1071 spin_unlock_bh(&sta->lock); 1072 break; 1073 } 1074 1075 rcu_read_unlock(); 1076 1077 if (changed) 1078 ieee80211_mbss_info_change_notify(sdata, changed); 1079 } 1080