1 /* 2 * Copyright (c) 2008, 2009 open80211s Ltd. 3 * Author: Luis Carlos Cobo <luisca@cozybit.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 */ 9 #include <linux/gfp.h> 10 #include <linux/kernel.h> 11 #include <linux/random.h> 12 #include "ieee80211_i.h" 13 #include "rate.h" 14 #include "mesh.h" 15 16 #define PLINK_CNF_AID(mgmt) ((mgmt)->u.action.u.self_prot.variable + 2) 17 #define PLINK_GET_LLID(p) (p + 2) 18 #define PLINK_GET_PLID(p) (p + 4) 19 20 #define mod_plink_timer(s, t) (mod_timer(&s->mesh->plink_timer, \ 21 jiffies + msecs_to_jiffies(t))) 22 23 enum plink_event { 24 PLINK_UNDEFINED, 25 OPN_ACPT, 26 OPN_RJCT, 27 OPN_IGNR, 28 CNF_ACPT, 29 CNF_RJCT, 30 CNF_IGNR, 31 CLS_ACPT, 32 CLS_IGNR 33 }; 34 35 static const char * const mplstates[] = { 36 [NL80211_PLINK_LISTEN] = "LISTEN", 37 [NL80211_PLINK_OPN_SNT] = "OPN-SNT", 38 [NL80211_PLINK_OPN_RCVD] = "OPN-RCVD", 39 [NL80211_PLINK_CNF_RCVD] = "CNF_RCVD", 40 [NL80211_PLINK_ESTAB] = "ESTAB", 41 [NL80211_PLINK_HOLDING] = "HOLDING", 42 [NL80211_PLINK_BLOCKED] = "BLOCKED" 43 }; 44 45 static const char * const mplevents[] = { 46 [PLINK_UNDEFINED] = "NONE", 47 [OPN_ACPT] = "OPN_ACPT", 48 [OPN_RJCT] = "OPN_RJCT", 49 [OPN_IGNR] = "OPN_IGNR", 50 [CNF_ACPT] = "CNF_ACPT", 51 [CNF_RJCT] = "CNF_RJCT", 52 [CNF_IGNR] = "CNF_IGNR", 53 [CLS_ACPT] = "CLS_ACPT", 54 [CLS_IGNR] = "CLS_IGNR" 55 }; 56 57 /* We only need a valid sta if user configured a minimum rssi_threshold. */ 58 static bool rssi_threshold_check(struct ieee80211_sub_if_data *sdata, 59 struct sta_info *sta) 60 { 61 s32 rssi_threshold = sdata->u.mesh.mshcfg.rssi_threshold; 62 return rssi_threshold == 0 || 63 (sta && 64 (s8)-ewma_signal_read(&sta->rx_stats_avg.signal) > 65 rssi_threshold); 66 } 67 68 /** 69 * mesh_plink_fsm_restart - restart a mesh peer link finite state machine 70 * 71 * @sta: mesh peer link to restart 72 * 73 * Locking: this function must be called holding sta->mesh->plink_lock 74 */ 75 static inline void mesh_plink_fsm_restart(struct sta_info *sta) 76 { 77 lockdep_assert_held(&sta->mesh->plink_lock); 78 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 79 sta->mesh->llid = sta->mesh->plid = sta->mesh->reason = 0; 80 sta->mesh->plink_retries = 0; 81 } 82 83 /* 84 * mesh_set_short_slot_time - enable / disable ERP short slot time. 85 * 86 * The standard indirectly mandates mesh STAs to turn off short slot time by 87 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we 88 * can't be sneaky about it. Enable short slot time if all mesh STAs in the 89 * MBSS support ERP rates. 90 * 91 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change. 92 */ 93 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata) 94 { 95 struct ieee80211_local *local = sdata->local; 96 enum nl80211_band band = ieee80211_get_sdata_band(sdata); 97 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 98 struct sta_info *sta; 99 u32 erp_rates = 0, changed = 0; 100 int i; 101 bool short_slot = false; 102 103 if (band == NL80211_BAND_5GHZ) { 104 /* (IEEE 802.11-2012 19.4.5) */ 105 short_slot = true; 106 goto out; 107 } else if (band != NL80211_BAND_2GHZ) 108 goto out; 109 110 for (i = 0; i < sband->n_bitrates; i++) 111 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G) 112 erp_rates |= BIT(i); 113 114 if (!erp_rates) 115 goto out; 116 117 rcu_read_lock(); 118 list_for_each_entry_rcu(sta, &local->sta_list, list) { 119 if (sdata != sta->sdata || 120 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 121 continue; 122 123 short_slot = false; 124 if (erp_rates & sta->sta.supp_rates[band]) 125 short_slot = true; 126 else 127 break; 128 } 129 rcu_read_unlock(); 130 131 out: 132 if (sdata->vif.bss_conf.use_short_slot != short_slot) { 133 sdata->vif.bss_conf.use_short_slot = short_slot; 134 changed = BSS_CHANGED_ERP_SLOT; 135 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n", 136 sdata->vif.addr, short_slot); 137 } 138 return changed; 139 } 140 141 /** 142 * mesh_set_ht_prot_mode - set correct HT protection mode 143 * 144 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT 145 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT 146 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is 147 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode 148 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one 149 * HT20 peer is present. Otherwise no-protection mode is selected. 150 */ 151 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) 152 { 153 struct ieee80211_local *local = sdata->local; 154 struct sta_info *sta; 155 u16 ht_opmode; 156 bool non_ht_sta = false, ht20_sta = false; 157 158 switch (sdata->vif.bss_conf.chandef.width) { 159 case NL80211_CHAN_WIDTH_20_NOHT: 160 case NL80211_CHAN_WIDTH_5: 161 case NL80211_CHAN_WIDTH_10: 162 return 0; 163 default: 164 break; 165 } 166 167 rcu_read_lock(); 168 list_for_each_entry_rcu(sta, &local->sta_list, list) { 169 if (sdata != sta->sdata || 170 sta->mesh->plink_state != NL80211_PLINK_ESTAB) 171 continue; 172 173 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20) 174 continue; 175 176 if (!sta->sta.ht_cap.ht_supported) { 177 mpl_dbg(sdata, "nonHT sta (%pM) is present\n", 178 sta->sta.addr); 179 non_ht_sta = true; 180 break; 181 } 182 183 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); 184 ht20_sta = true; 185 } 186 rcu_read_unlock(); 187 188 if (non_ht_sta) 189 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; 190 else if (ht20_sta && 191 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20) 192 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; 193 else 194 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; 195 196 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) 197 return 0; 198 199 sdata->vif.bss_conf.ht_operation_mode = ht_opmode; 200 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; 201 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); 202 return BSS_CHANGED_HT; 203 } 204 205 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 206 struct sta_info *sta, 207 enum ieee80211_self_protected_actioncode action, 208 u8 *da, u16 llid, u16 plid, u16 reason) 209 { 210 struct ieee80211_local *local = sdata->local; 211 struct sk_buff *skb; 212 struct ieee80211_tx_info *info; 213 struct ieee80211_mgmt *mgmt; 214 bool include_plid = false; 215 u16 peering_proto = 0; 216 u8 *pos, ie_len = 4; 217 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) + 218 sizeof(mgmt->u.action.u.self_prot); 219 int err = -ENOMEM; 220 221 skb = dev_alloc_skb(local->tx_headroom + 222 hdr_len + 223 2 + /* capability info */ 224 2 + /* AID */ 225 2 + 8 + /* supported rates */ 226 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 227 2 + sdata->u.mesh.mesh_id_len + 228 2 + sizeof(struct ieee80211_meshconf_ie) + 229 2 + sizeof(struct ieee80211_ht_cap) + 230 2 + sizeof(struct ieee80211_ht_operation) + 231 2 + sizeof(struct ieee80211_vht_cap) + 232 2 + sizeof(struct ieee80211_vht_operation) + 233 2 + 8 + /* peering IE */ 234 sdata->u.mesh.ie_len); 235 if (!skb) 236 return err; 237 info = IEEE80211_SKB_CB(skb); 238 skb_reserve(skb, local->tx_headroom); 239 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len); 240 memset(mgmt, 0, hdr_len); 241 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 242 IEEE80211_STYPE_ACTION); 243 memcpy(mgmt->da, da, ETH_ALEN); 244 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 245 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 246 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; 247 mgmt->u.action.u.self_prot.action_code = action; 248 249 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 250 enum nl80211_band band = ieee80211_get_sdata_band(sdata); 251 252 /* capability info */ 253 pos = skb_put(skb, 2); 254 memset(pos, 0, 2); 255 if (action == WLAN_SP_MESH_PEERING_CONFIRM) { 256 /* AID */ 257 pos = skb_put(skb, 2); 258 put_unaligned_le16(sta->sta.aid, pos); 259 } 260 if (ieee80211_add_srates_ie(sdata, skb, true, band) || 261 ieee80211_add_ext_srates_ie(sdata, skb, true, band) || 262 mesh_add_rsn_ie(sdata, skb) || 263 mesh_add_meshid_ie(sdata, skb) || 264 mesh_add_meshconf_ie(sdata, skb)) 265 goto free; 266 } else { /* WLAN_SP_MESH_PEERING_CLOSE */ 267 info->flags |= IEEE80211_TX_CTL_NO_ACK; 268 if (mesh_add_meshid_ie(sdata, skb)) 269 goto free; 270 } 271 272 /* Add Mesh Peering Management element */ 273 switch (action) { 274 case WLAN_SP_MESH_PEERING_OPEN: 275 break; 276 case WLAN_SP_MESH_PEERING_CONFIRM: 277 ie_len += 2; 278 include_plid = true; 279 break; 280 case WLAN_SP_MESH_PEERING_CLOSE: 281 if (plid) { 282 ie_len += 2; 283 include_plid = true; 284 } 285 ie_len += 2; /* reason code */ 286 break; 287 default: 288 err = -EINVAL; 289 goto free; 290 } 291 292 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) 293 goto free; 294 295 pos = skb_put(skb, 2 + ie_len); 296 *pos++ = WLAN_EID_PEER_MGMT; 297 *pos++ = ie_len; 298 memcpy(pos, &peering_proto, 2); 299 pos += 2; 300 put_unaligned_le16(llid, pos); 301 pos += 2; 302 if (include_plid) { 303 put_unaligned_le16(plid, pos); 304 pos += 2; 305 } 306 if (action == WLAN_SP_MESH_PEERING_CLOSE) { 307 put_unaligned_le16(reason, pos); 308 pos += 2; 309 } 310 311 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 312 if (mesh_add_ht_cap_ie(sdata, skb) || 313 mesh_add_ht_oper_ie(sdata, skb) || 314 mesh_add_vht_cap_ie(sdata, skb) || 315 mesh_add_vht_oper_ie(sdata, skb)) 316 goto free; 317 } 318 319 if (mesh_add_vendor_ies(sdata, skb)) 320 goto free; 321 322 ieee80211_tx_skb(sdata, skb); 323 return 0; 324 free: 325 kfree_skb(skb); 326 return err; 327 } 328 329 /** 330 * __mesh_plink_deactivate - deactivate mesh peer link 331 * 332 * @sta: mesh peer link to deactivate 333 * 334 * Mesh paths with this peer as next hop should be flushed 335 * by the caller outside of plink_lock. 336 * 337 * Returns beacon changed flag if the beacon content changed. 338 * 339 * Locking: the caller must hold sta->mesh->plink_lock 340 */ 341 static u32 __mesh_plink_deactivate(struct sta_info *sta) 342 { 343 struct ieee80211_sub_if_data *sdata = sta->sdata; 344 u32 changed = 0; 345 346 lockdep_assert_held(&sta->mesh->plink_lock); 347 348 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 349 changed = mesh_plink_dec_estab_count(sdata); 350 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 351 352 ieee80211_mps_sta_status_update(sta); 353 changed |= ieee80211_mps_set_sta_local_pm(sta, 354 NL80211_MESH_POWER_UNKNOWN); 355 356 return changed; 357 } 358 359 /** 360 * mesh_plink_deactivate - deactivate mesh peer link 361 * 362 * @sta: mesh peer link to deactivate 363 * 364 * All mesh paths with this peer as next hop will be flushed 365 */ 366 u32 mesh_plink_deactivate(struct sta_info *sta) 367 { 368 struct ieee80211_sub_if_data *sdata = sta->sdata; 369 u32 changed; 370 371 spin_lock_bh(&sta->mesh->plink_lock); 372 changed = __mesh_plink_deactivate(sta); 373 374 if (!sdata->u.mesh.user_mpm) { 375 sta->mesh->reason = WLAN_REASON_MESH_PEER_CANCELED; 376 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_CLOSE, 377 sta->sta.addr, sta->mesh->llid, 378 sta->mesh->plid, sta->mesh->reason); 379 } 380 spin_unlock_bh(&sta->mesh->plink_lock); 381 if (!sdata->u.mesh.user_mpm) 382 del_timer_sync(&sta->mesh->plink_timer); 383 mesh_path_flush_by_nexthop(sta); 384 385 /* make sure no readers can access nexthop sta from here on */ 386 synchronize_net(); 387 388 return changed; 389 } 390 391 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 392 struct sta_info *sta, 393 struct ieee802_11_elems *elems, bool insert) 394 { 395 struct ieee80211_local *local = sdata->local; 396 enum nl80211_band band = ieee80211_get_sdata_band(sdata); 397 struct ieee80211_supported_band *sband; 398 u32 rates, basic_rates = 0, changed = 0; 399 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth; 400 401 sband = local->hw.wiphy->bands[band]; 402 rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates); 403 404 spin_lock_bh(&sta->mesh->plink_lock); 405 sta->rx_stats.last_rx = jiffies; 406 407 /* rates and capabilities don't change during peering */ 408 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB && 409 sta->mesh->processed_beacon) 410 goto out; 411 sta->mesh->processed_beacon = true; 412 413 if (sta->sta.supp_rates[band] != rates) 414 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 415 sta->sta.supp_rates[band] = rates; 416 417 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 418 elems->ht_cap_elem, sta)) 419 changed |= IEEE80211_RC_BW_CHANGED; 420 421 ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband, 422 elems->vht_cap_elem, sta); 423 424 if (bw != sta->sta.bandwidth) 425 changed |= IEEE80211_RC_BW_CHANGED; 426 427 /* HT peer is operating 20MHz-only */ 428 if (elems->ht_operation && 429 !(elems->ht_operation->ht_param & 430 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 431 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) 432 changed |= IEEE80211_RC_BW_CHANGED; 433 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; 434 } 435 436 if (insert) 437 rate_control_rate_init(sta); 438 else 439 rate_control_rate_update(local, sband, sta, changed); 440 out: 441 spin_unlock_bh(&sta->mesh->plink_lock); 442 } 443 444 static int mesh_allocate_aid(struct ieee80211_sub_if_data *sdata) 445 { 446 struct sta_info *sta; 447 unsigned long *aid_map; 448 int aid; 449 450 aid_map = kcalloc(BITS_TO_LONGS(IEEE80211_MAX_AID + 1), 451 sizeof(*aid_map), GFP_KERNEL); 452 if (!aid_map) 453 return -ENOMEM; 454 455 /* reserve aid 0 for mcast indication */ 456 __set_bit(0, aid_map); 457 458 rcu_read_lock(); 459 list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) 460 __set_bit(sta->sta.aid, aid_map); 461 rcu_read_unlock(); 462 463 aid = find_first_zero_bit(aid_map, IEEE80211_MAX_AID + 1); 464 kfree(aid_map); 465 466 if (aid > IEEE80211_MAX_AID) 467 return -ENOBUFS; 468 469 return aid; 470 } 471 472 static struct sta_info * 473 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 474 { 475 struct sta_info *sta; 476 int aid; 477 478 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 479 return NULL; 480 481 aid = mesh_allocate_aid(sdata); 482 if (aid < 0) 483 return NULL; 484 485 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 486 if (!sta) 487 return NULL; 488 489 sta->mesh->plink_state = NL80211_PLINK_LISTEN; 490 sta->sta.wme = true; 491 sta->sta.aid = aid; 492 493 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 494 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 495 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 496 497 return sta; 498 } 499 500 static struct sta_info * 501 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 502 struct ieee802_11_elems *elems) 503 { 504 struct sta_info *sta = NULL; 505 506 /* Userspace handles station allocation */ 507 if (sdata->u.mesh.user_mpm || 508 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) { 509 if (mesh_peer_accepts_plinks(elems) && 510 mesh_plink_availables(sdata)) 511 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 512 elems->ie_start, 513 elems->total_len, 514 GFP_KERNEL); 515 } else 516 sta = __mesh_sta_info_alloc(sdata, addr); 517 518 return sta; 519 } 520 521 /* 522 * mesh_sta_info_get - return mesh sta info entry for @addr. 523 * 524 * @sdata: local meshif 525 * @addr: peer's address 526 * @elems: IEs from beacon or mesh peering frame. 527 * 528 * Return existing or newly allocated sta_info under RCU read lock. 529 * (re)initialize with given IEs. 530 */ 531 static struct sta_info * 532 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 533 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU) 534 { 535 struct sta_info *sta = NULL; 536 537 rcu_read_lock(); 538 sta = sta_info_get(sdata, addr); 539 if (sta) { 540 mesh_sta_info_init(sdata, sta, elems, false); 541 } else { 542 rcu_read_unlock(); 543 /* can't run atomic */ 544 sta = mesh_sta_info_alloc(sdata, addr, elems); 545 if (!sta) { 546 rcu_read_lock(); 547 return NULL; 548 } 549 550 mesh_sta_info_init(sdata, sta, elems, true); 551 552 if (sta_info_insert_rcu(sta)) 553 return NULL; 554 } 555 556 return sta; 557 } 558 559 /* 560 * mesh_neighbour_update - update or initialize new mesh neighbor. 561 * 562 * @sdata: local meshif 563 * @addr: peer's address 564 * @elems: IEs from beacon or mesh peering frame 565 * 566 * Initiates peering if appropriate. 567 */ 568 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 569 u8 *hw_addr, 570 struct ieee802_11_elems *elems) 571 { 572 struct sta_info *sta; 573 u32 changed = 0; 574 575 sta = mesh_sta_info_get(sdata, hw_addr, elems); 576 if (!sta) 577 goto out; 578 579 if (mesh_peer_accepts_plinks(elems) && 580 sta->mesh->plink_state == NL80211_PLINK_LISTEN && 581 sdata->u.mesh.accepting_plinks && 582 sdata->u.mesh.mshcfg.auto_open_plinks && 583 rssi_threshold_check(sdata, sta)) 584 changed = mesh_plink_open(sta); 585 586 ieee80211_mps_frame_release(sta, elems); 587 out: 588 rcu_read_unlock(); 589 ieee80211_mbss_info_change_notify(sdata, changed); 590 } 591 592 static void mesh_plink_timer(unsigned long data) 593 { 594 struct sta_info *sta; 595 u16 reason = 0; 596 struct ieee80211_sub_if_data *sdata; 597 struct mesh_config *mshcfg; 598 enum ieee80211_self_protected_actioncode action = 0; 599 600 /* 601 * This STA is valid because sta_info_destroy() will 602 * del_timer_sync() this timer after having made sure 603 * it cannot be readded (by deleting the plink.) 604 */ 605 sta = (struct sta_info *) data; 606 607 if (sta->sdata->local->quiescing) 608 return; 609 610 spin_lock_bh(&sta->mesh->plink_lock); 611 612 /* If a timer fires just before a state transition on another CPU, 613 * we may have already extended the timeout and changed state by the 614 * time we've acquired the lock and arrived here. In that case, 615 * skip this timer and wait for the new one. 616 */ 617 if (time_before(jiffies, sta->mesh->plink_timer.expires)) { 618 mpl_dbg(sta->sdata, 619 "Ignoring timer for %pM in state %s (timer adjusted)", 620 sta->sta.addr, mplstates[sta->mesh->plink_state]); 621 spin_unlock_bh(&sta->mesh->plink_lock); 622 return; 623 } 624 625 /* del_timer() and handler may race when entering these states */ 626 if (sta->mesh->plink_state == NL80211_PLINK_LISTEN || 627 sta->mesh->plink_state == NL80211_PLINK_ESTAB) { 628 mpl_dbg(sta->sdata, 629 "Ignoring timer for %pM in state %s (timer deleted)", 630 sta->sta.addr, mplstates[sta->mesh->plink_state]); 631 spin_unlock_bh(&sta->mesh->plink_lock); 632 return; 633 } 634 635 mpl_dbg(sta->sdata, 636 "Mesh plink timer for %pM fired on state %s\n", 637 sta->sta.addr, mplstates[sta->mesh->plink_state]); 638 sdata = sta->sdata; 639 mshcfg = &sdata->u.mesh.mshcfg; 640 641 switch (sta->mesh->plink_state) { 642 case NL80211_PLINK_OPN_RCVD: 643 case NL80211_PLINK_OPN_SNT: 644 /* retry timer */ 645 if (sta->mesh->plink_retries < mshcfg->dot11MeshMaxRetries) { 646 u32 rand; 647 mpl_dbg(sta->sdata, 648 "Mesh plink for %pM (retry, timeout): %d %d\n", 649 sta->sta.addr, sta->mesh->plink_retries, 650 sta->mesh->plink_timeout); 651 get_random_bytes(&rand, sizeof(u32)); 652 sta->mesh->plink_timeout = sta->mesh->plink_timeout + 653 rand % sta->mesh->plink_timeout; 654 ++sta->mesh->plink_retries; 655 mod_plink_timer(sta, sta->mesh->plink_timeout); 656 action = WLAN_SP_MESH_PEERING_OPEN; 657 break; 658 } 659 reason = WLAN_REASON_MESH_MAX_RETRIES; 660 /* fall through on else */ 661 case NL80211_PLINK_CNF_RCVD: 662 /* confirm timer */ 663 if (!reason) 664 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 665 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 666 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 667 action = WLAN_SP_MESH_PEERING_CLOSE; 668 break; 669 case NL80211_PLINK_HOLDING: 670 /* holding timer */ 671 del_timer(&sta->mesh->plink_timer); 672 mesh_plink_fsm_restart(sta); 673 break; 674 default: 675 break; 676 } 677 spin_unlock_bh(&sta->mesh->plink_lock); 678 if (action) 679 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 680 sta->mesh->llid, sta->mesh->plid, reason); 681 } 682 683 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 684 { 685 sta->mesh->plink_timer.expires = jiffies + msecs_to_jiffies(timeout); 686 sta->mesh->plink_timer.data = (unsigned long) sta; 687 sta->mesh->plink_timer.function = mesh_plink_timer; 688 sta->mesh->plink_timeout = timeout; 689 add_timer(&sta->mesh->plink_timer); 690 } 691 692 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 693 u16 llid) 694 { 695 struct ieee80211_local *local = sdata->local; 696 bool in_use = false; 697 struct sta_info *sta; 698 699 rcu_read_lock(); 700 list_for_each_entry_rcu(sta, &local->sta_list, list) { 701 if (sdata != sta->sdata) 702 continue; 703 704 if (!memcmp(&sta->mesh->llid, &llid, sizeof(llid))) { 705 in_use = true; 706 break; 707 } 708 } 709 rcu_read_unlock(); 710 711 return in_use; 712 } 713 714 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 715 { 716 u16 llid; 717 718 do { 719 get_random_bytes(&llid, sizeof(llid)); 720 } while (llid_in_use(sdata, llid)); 721 722 return llid; 723 } 724 725 u32 mesh_plink_open(struct sta_info *sta) 726 { 727 struct ieee80211_sub_if_data *sdata = sta->sdata; 728 u32 changed; 729 730 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 731 return 0; 732 733 spin_lock_bh(&sta->mesh->plink_lock); 734 sta->mesh->llid = mesh_get_new_llid(sdata); 735 if (sta->mesh->plink_state != NL80211_PLINK_LISTEN && 736 sta->mesh->plink_state != NL80211_PLINK_BLOCKED) { 737 spin_unlock_bh(&sta->mesh->plink_lock); 738 return 0; 739 } 740 sta->mesh->plink_state = NL80211_PLINK_OPN_SNT; 741 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 742 spin_unlock_bh(&sta->mesh->plink_lock); 743 mpl_dbg(sdata, 744 "Mesh plink: starting establishment with %pM\n", 745 sta->sta.addr); 746 747 /* set the non-peer mode to active during peering */ 748 changed = ieee80211_mps_local_status_update(sdata); 749 750 mesh_plink_frame_tx(sdata, sta, WLAN_SP_MESH_PEERING_OPEN, 751 sta->sta.addr, sta->mesh->llid, 0, 0); 752 return changed; 753 } 754 755 u32 mesh_plink_block(struct sta_info *sta) 756 { 757 u32 changed; 758 759 spin_lock_bh(&sta->mesh->plink_lock); 760 changed = __mesh_plink_deactivate(sta); 761 sta->mesh->plink_state = NL80211_PLINK_BLOCKED; 762 spin_unlock_bh(&sta->mesh->plink_lock); 763 mesh_path_flush_by_nexthop(sta); 764 765 return changed; 766 } 767 768 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 769 struct sta_info *sta, 770 enum plink_event event) 771 { 772 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 773 u16 reason = (event == CLS_ACPT) ? 774 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 775 776 sta->mesh->reason = reason; 777 sta->mesh->plink_state = NL80211_PLINK_HOLDING; 778 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 779 } 780 781 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 782 struct sta_info *sta) 783 { 784 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 785 u32 changed = 0; 786 787 del_timer(&sta->mesh->plink_timer); 788 sta->mesh->plink_state = NL80211_PLINK_ESTAB; 789 changed |= mesh_plink_inc_estab_count(sdata); 790 changed |= mesh_set_ht_prot_mode(sdata); 791 changed |= mesh_set_short_slot_time(sdata); 792 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 793 ieee80211_mps_sta_status_update(sta); 794 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 795 return changed; 796 } 797 798 /** 799 * mesh_plink_fsm - step @sta MPM based on @event 800 * 801 * @sdata: interface 802 * @sta: mesh neighbor 803 * @event: peering event 804 * 805 * Return: changed MBSS flags 806 */ 807 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 808 struct sta_info *sta, enum plink_event event) 809 { 810 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 811 enum ieee80211_self_protected_actioncode action = 0; 812 u32 changed = 0; 813 bool flush = false; 814 815 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 816 mplstates[sta->mesh->plink_state], mplevents[event]); 817 818 spin_lock_bh(&sta->mesh->plink_lock); 819 switch (sta->mesh->plink_state) { 820 case NL80211_PLINK_LISTEN: 821 switch (event) { 822 case CLS_ACPT: 823 mesh_plink_fsm_restart(sta); 824 break; 825 case OPN_ACPT: 826 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 827 sta->mesh->llid = mesh_get_new_llid(sdata); 828 mesh_plink_timer_set(sta, 829 mshcfg->dot11MeshRetryTimeout); 830 831 /* set the non-peer mode to active during peering */ 832 changed |= ieee80211_mps_local_status_update(sdata); 833 action = WLAN_SP_MESH_PEERING_OPEN; 834 break; 835 default: 836 break; 837 } 838 break; 839 case NL80211_PLINK_OPN_SNT: 840 switch (event) { 841 case OPN_RJCT: 842 case CNF_RJCT: 843 case CLS_ACPT: 844 mesh_plink_close(sdata, sta, event); 845 action = WLAN_SP_MESH_PEERING_CLOSE; 846 break; 847 case OPN_ACPT: 848 /* retry timer is left untouched */ 849 sta->mesh->plink_state = NL80211_PLINK_OPN_RCVD; 850 action = WLAN_SP_MESH_PEERING_CONFIRM; 851 break; 852 case CNF_ACPT: 853 sta->mesh->plink_state = NL80211_PLINK_CNF_RCVD; 854 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 855 break; 856 default: 857 break; 858 } 859 break; 860 case NL80211_PLINK_OPN_RCVD: 861 switch (event) { 862 case OPN_RJCT: 863 case CNF_RJCT: 864 case CLS_ACPT: 865 mesh_plink_close(sdata, sta, event); 866 action = WLAN_SP_MESH_PEERING_CLOSE; 867 break; 868 case OPN_ACPT: 869 action = WLAN_SP_MESH_PEERING_CONFIRM; 870 break; 871 case CNF_ACPT: 872 changed |= mesh_plink_establish(sdata, sta); 873 break; 874 default: 875 break; 876 } 877 break; 878 case NL80211_PLINK_CNF_RCVD: 879 switch (event) { 880 case OPN_RJCT: 881 case CNF_RJCT: 882 case CLS_ACPT: 883 mesh_plink_close(sdata, sta, event); 884 action = WLAN_SP_MESH_PEERING_CLOSE; 885 break; 886 case OPN_ACPT: 887 changed |= mesh_plink_establish(sdata, sta); 888 action = WLAN_SP_MESH_PEERING_CONFIRM; 889 break; 890 default: 891 break; 892 } 893 break; 894 case NL80211_PLINK_ESTAB: 895 switch (event) { 896 case CLS_ACPT: 897 changed |= __mesh_plink_deactivate(sta); 898 changed |= mesh_set_ht_prot_mode(sdata); 899 changed |= mesh_set_short_slot_time(sdata); 900 mesh_plink_close(sdata, sta, event); 901 action = WLAN_SP_MESH_PEERING_CLOSE; 902 flush = true; 903 break; 904 case OPN_ACPT: 905 action = WLAN_SP_MESH_PEERING_CONFIRM; 906 break; 907 default: 908 break; 909 } 910 break; 911 case NL80211_PLINK_HOLDING: 912 switch (event) { 913 case CLS_ACPT: 914 del_timer(&sta->mesh->plink_timer); 915 mesh_plink_fsm_restart(sta); 916 break; 917 case OPN_ACPT: 918 case CNF_ACPT: 919 case OPN_RJCT: 920 case CNF_RJCT: 921 action = WLAN_SP_MESH_PEERING_CLOSE; 922 break; 923 default: 924 break; 925 } 926 break; 927 default: 928 /* should not get here, PLINK_BLOCKED is dealt with at the 929 * beginning of the function 930 */ 931 break; 932 } 933 spin_unlock_bh(&sta->mesh->plink_lock); 934 if (flush) 935 mesh_path_flush_by_nexthop(sta); 936 if (action) { 937 mesh_plink_frame_tx(sdata, sta, action, sta->sta.addr, 938 sta->mesh->llid, sta->mesh->plid, 939 sta->mesh->reason); 940 941 /* also send confirm in open case */ 942 if (action == WLAN_SP_MESH_PEERING_OPEN) { 943 mesh_plink_frame_tx(sdata, sta, 944 WLAN_SP_MESH_PEERING_CONFIRM, 945 sta->sta.addr, sta->mesh->llid, 946 sta->mesh->plid, 0); 947 } 948 } 949 950 return changed; 951 } 952 953 /* 954 * mesh_plink_get_event - get correct MPM event 955 * 956 * @sdata: interface 957 * @sta: peer, leave NULL if processing a frame from a new suitable peer 958 * @elems: peering management IEs 959 * @ftype: frame type 960 * @llid: peer's peer link ID 961 * @plid: peer's local link ID 962 * 963 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 964 * an error. 965 */ 966 static enum plink_event 967 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 968 struct sta_info *sta, 969 struct ieee802_11_elems *elems, 970 enum ieee80211_self_protected_actioncode ftype, 971 u16 llid, u16 plid) 972 { 973 enum plink_event event = PLINK_UNDEFINED; 974 u8 ie_len = elems->peering_len; 975 bool matches_local; 976 977 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 978 mesh_matches_local(sdata, elems)); 979 980 /* deny open request from non-matching peer */ 981 if (!matches_local && !sta) { 982 event = OPN_RJCT; 983 goto out; 984 } 985 986 if (!sta) { 987 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 988 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 989 goto out; 990 } 991 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 992 if (!mesh_plink_free_count(sdata)) { 993 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 994 goto out; 995 } 996 997 /* new matching peer */ 998 event = OPN_ACPT; 999 goto out; 1000 } else { 1001 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 1002 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 1003 goto out; 1004 } 1005 if (sta->mesh->plink_state == NL80211_PLINK_BLOCKED) 1006 goto out; 1007 } 1008 1009 switch (ftype) { 1010 case WLAN_SP_MESH_PEERING_OPEN: 1011 if (!matches_local) 1012 event = OPN_RJCT; 1013 if (!mesh_plink_free_count(sdata) || 1014 (sta->mesh->plid && sta->mesh->plid != plid)) 1015 event = OPN_IGNR; 1016 else 1017 event = OPN_ACPT; 1018 break; 1019 case WLAN_SP_MESH_PEERING_CONFIRM: 1020 if (!matches_local) 1021 event = CNF_RJCT; 1022 if (!mesh_plink_free_count(sdata) || 1023 sta->mesh->llid != llid || 1024 (sta->mesh->plid && sta->mesh->plid != plid)) 1025 event = CNF_IGNR; 1026 else 1027 event = CNF_ACPT; 1028 break; 1029 case WLAN_SP_MESH_PEERING_CLOSE: 1030 if (sta->mesh->plink_state == NL80211_PLINK_ESTAB) 1031 /* Do not check for llid or plid. This does not 1032 * follow the standard but since multiple plinks 1033 * per sta are not supported, it is necessary in 1034 * order to avoid a livelock when MP A sees an 1035 * establish peer link to MP B but MP B does not 1036 * see it. This can be caused by a timeout in 1037 * B's peer link establishment or B beign 1038 * restarted. 1039 */ 1040 event = CLS_ACPT; 1041 else if (sta->mesh->plid != plid) 1042 event = CLS_IGNR; 1043 else if (ie_len == 8 && sta->mesh->llid != llid) 1044 event = CLS_IGNR; 1045 else 1046 event = CLS_ACPT; 1047 break; 1048 default: 1049 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 1050 break; 1051 } 1052 1053 out: 1054 return event; 1055 } 1056 1057 static void 1058 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1059 struct ieee80211_mgmt *mgmt, 1060 struct ieee802_11_elems *elems) 1061 { 1062 1063 struct sta_info *sta; 1064 enum plink_event event; 1065 enum ieee80211_self_protected_actioncode ftype; 1066 u32 changed = 0; 1067 u8 ie_len = elems->peering_len; 1068 u16 plid, llid = 0; 1069 1070 if (!elems->peering) { 1071 mpl_dbg(sdata, 1072 "Mesh plink: missing necessary peer link ie\n"); 1073 return; 1074 } 1075 1076 if (elems->rsn_len && 1077 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1078 mpl_dbg(sdata, 1079 "Mesh plink: can't establish link with secure peer\n"); 1080 return; 1081 } 1082 1083 ftype = mgmt->u.action.u.self_prot.action_code; 1084 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1085 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1086 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1087 && ie_len != 8)) { 1088 mpl_dbg(sdata, 1089 "Mesh plink: incorrect plink ie length %d %d\n", 1090 ftype, ie_len); 1091 return; 1092 } 1093 1094 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1095 (!elems->mesh_id || !elems->mesh_config)) { 1096 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1097 return; 1098 } 1099 /* Note the lines below are correct, the llid in the frame is the plid 1100 * from the point of view of this host. 1101 */ 1102 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1103 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1104 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1105 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1106 1107 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1108 rcu_read_lock(); 1109 1110 sta = sta_info_get(sdata, mgmt->sa); 1111 1112 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1113 !rssi_threshold_check(sdata, sta)) { 1114 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1115 mgmt->sa); 1116 goto unlock_rcu; 1117 } 1118 1119 /* Now we will figure out the appropriate event... */ 1120 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1121 1122 if (event == OPN_ACPT) { 1123 rcu_read_unlock(); 1124 /* allocate sta entry if necessary and update info */ 1125 sta = mesh_sta_info_get(sdata, mgmt->sa, elems); 1126 if (!sta) { 1127 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1128 goto unlock_rcu; 1129 } 1130 sta->mesh->plid = plid; 1131 } else if (!sta && event == OPN_RJCT) { 1132 mesh_plink_frame_tx(sdata, NULL, WLAN_SP_MESH_PEERING_CLOSE, 1133 mgmt->sa, 0, plid, 1134 WLAN_REASON_MESH_CONFIG); 1135 goto unlock_rcu; 1136 } else if (!sta || event == PLINK_UNDEFINED) { 1137 /* something went wrong */ 1138 goto unlock_rcu; 1139 } 1140 1141 if (event == CNF_ACPT) { 1142 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1143 if (!sta->mesh->plid) 1144 sta->mesh->plid = plid; 1145 1146 sta->mesh->aid = get_unaligned_le16(PLINK_CNF_AID(mgmt)); 1147 } 1148 1149 changed |= mesh_plink_fsm(sdata, sta, event); 1150 1151 unlock_rcu: 1152 rcu_read_unlock(); 1153 1154 if (changed) 1155 ieee80211_mbss_info_change_notify(sdata, changed); 1156 } 1157 1158 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1159 struct ieee80211_mgmt *mgmt, size_t len, 1160 struct ieee80211_rx_status *rx_status) 1161 { 1162 struct ieee802_11_elems elems; 1163 size_t baselen; 1164 u8 *baseaddr; 1165 1166 /* need action_code, aux */ 1167 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1168 return; 1169 1170 if (sdata->u.mesh.user_mpm) 1171 /* userspace must register for these */ 1172 return; 1173 1174 if (is_multicast_ether_addr(mgmt->da)) { 1175 mpl_dbg(sdata, 1176 "Mesh plink: ignore frame from multicast address\n"); 1177 return; 1178 } 1179 1180 baseaddr = mgmt->u.action.u.self_prot.variable; 1181 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1182 if (mgmt->u.action.u.self_prot.action_code == 1183 WLAN_SP_MESH_PEERING_CONFIRM) { 1184 baseaddr += 4; 1185 baselen += 4; 1186 1187 if (baselen > len) 1188 return; 1189 } 1190 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems); 1191 mesh_process_plink_frame(sdata, mgmt, &elems); 1192 } 1193