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 + msecs_to_jiffies(t))) 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 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth; 386 387 sband = local->hw.wiphy->bands[band]; 388 rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates); 389 390 spin_lock_bh(&sta->lock); 391 sta->last_rx = jiffies; 392 393 /* rates and capabilities don't change during peering */ 394 if (sta->plink_state == NL80211_PLINK_ESTAB) 395 goto out; 396 397 if (sta->sta.supp_rates[band] != rates) 398 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 399 sta->sta.supp_rates[band] = rates; 400 401 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 402 elems->ht_cap_elem, sta)) 403 changed |= IEEE80211_RC_BW_CHANGED; 404 405 if (bw != sta->sta.bandwidth) 406 changed |= IEEE80211_RC_BW_CHANGED; 407 408 /* HT peer is operating 20MHz-only */ 409 if (elems->ht_operation && 410 !(elems->ht_operation->ht_param & 411 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 412 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) 413 changed |= IEEE80211_RC_BW_CHANGED; 414 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; 415 } 416 417 if (insert) 418 rate_control_rate_init(sta); 419 else 420 rate_control_rate_update(local, sband, sta, changed); 421 out: 422 spin_unlock_bh(&sta->lock); 423 } 424 425 static struct sta_info * 426 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 427 { 428 struct sta_info *sta; 429 430 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 431 return NULL; 432 433 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 434 if (!sta) 435 return NULL; 436 437 sta->plink_state = NL80211_PLINK_LISTEN; 438 sta->sta.wme = true; 439 440 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 441 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 442 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 443 444 return sta; 445 } 446 447 static struct sta_info * 448 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 449 struct ieee802_11_elems *elems) 450 { 451 struct sta_info *sta = NULL; 452 453 /* Userspace handles station allocation */ 454 if (sdata->u.mesh.user_mpm || 455 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) 456 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 457 elems->ie_start, 458 elems->total_len, 459 GFP_KERNEL); 460 else 461 sta = __mesh_sta_info_alloc(sdata, addr); 462 463 return sta; 464 } 465 466 /* 467 * mesh_sta_info_get - return mesh sta info entry for @addr. 468 * 469 * @sdata: local meshif 470 * @addr: peer's address 471 * @elems: IEs from beacon or mesh peering frame. 472 * 473 * Return existing or newly allocated sta_info under RCU read lock. 474 * (re)initialize with given IEs. 475 */ 476 static struct sta_info * 477 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 478 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU) 479 { 480 struct sta_info *sta = NULL; 481 482 rcu_read_lock(); 483 sta = sta_info_get(sdata, addr); 484 if (sta) { 485 mesh_sta_info_init(sdata, sta, elems, false); 486 } else { 487 rcu_read_unlock(); 488 /* can't run atomic */ 489 sta = mesh_sta_info_alloc(sdata, addr, elems); 490 if (!sta) { 491 rcu_read_lock(); 492 return NULL; 493 } 494 495 mesh_sta_info_init(sdata, sta, elems, true); 496 497 if (sta_info_insert_rcu(sta)) 498 return NULL; 499 } 500 501 return sta; 502 } 503 504 /* 505 * mesh_neighbour_update - update or initialize new mesh neighbor. 506 * 507 * @sdata: local meshif 508 * @addr: peer's address 509 * @elems: IEs from beacon or mesh peering frame 510 * 511 * Initiates peering if appropriate. 512 */ 513 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 514 u8 *hw_addr, 515 struct ieee802_11_elems *elems) 516 { 517 struct sta_info *sta; 518 u32 changed = 0; 519 520 sta = mesh_sta_info_get(sdata, hw_addr, elems); 521 if (!sta) 522 goto out; 523 524 if (mesh_peer_accepts_plinks(elems) && 525 sta->plink_state == NL80211_PLINK_LISTEN && 526 sdata->u.mesh.accepting_plinks && 527 sdata->u.mesh.mshcfg.auto_open_plinks && 528 rssi_threshold_check(sdata, sta)) 529 changed = mesh_plink_open(sta); 530 531 ieee80211_mps_frame_release(sta, elems); 532 out: 533 rcu_read_unlock(); 534 ieee80211_mbss_info_change_notify(sdata, changed); 535 } 536 537 static void mesh_plink_timer(unsigned long data) 538 { 539 struct sta_info *sta; 540 u16 reason = 0; 541 struct ieee80211_sub_if_data *sdata; 542 struct mesh_config *mshcfg; 543 enum ieee80211_self_protected_actioncode action = 0; 544 545 /* 546 * This STA is valid because sta_info_destroy() will 547 * del_timer_sync() this timer after having made sure 548 * it cannot be readded (by deleting the plink.) 549 */ 550 sta = (struct sta_info *) data; 551 552 if (sta->sdata->local->quiescing) 553 return; 554 555 spin_lock_bh(&sta->lock); 556 557 /* If a timer fires just before a state transition on another CPU, 558 * we may have already extended the timeout and changed state by the 559 * time we've acquired the lock and arrived here. In that case, 560 * skip this timer and wait for the new one. 561 */ 562 if (time_before(jiffies, sta->plink_timer.expires)) { 563 mpl_dbg(sta->sdata, 564 "Ignoring timer for %pM in state %s (timer adjusted)", 565 sta->sta.addr, mplstates[sta->plink_state]); 566 spin_unlock_bh(&sta->lock); 567 return; 568 } 569 570 /* del_timer() and handler may race when entering these states */ 571 if (sta->plink_state == NL80211_PLINK_LISTEN || 572 sta->plink_state == NL80211_PLINK_ESTAB) { 573 mpl_dbg(sta->sdata, 574 "Ignoring timer for %pM in state %s (timer deleted)", 575 sta->sta.addr, mplstates[sta->plink_state]); 576 spin_unlock_bh(&sta->lock); 577 return; 578 } 579 580 mpl_dbg(sta->sdata, 581 "Mesh plink timer for %pM fired on state %s\n", 582 sta->sta.addr, mplstates[sta->plink_state]); 583 sdata = sta->sdata; 584 mshcfg = &sdata->u.mesh.mshcfg; 585 586 switch (sta->plink_state) { 587 case NL80211_PLINK_OPN_RCVD: 588 case NL80211_PLINK_OPN_SNT: 589 /* retry timer */ 590 if (sta->plink_retries < mshcfg->dot11MeshMaxRetries) { 591 u32 rand; 592 mpl_dbg(sta->sdata, 593 "Mesh plink for %pM (retry, timeout): %d %d\n", 594 sta->sta.addr, sta->plink_retries, 595 sta->plink_timeout); 596 get_random_bytes(&rand, sizeof(u32)); 597 sta->plink_timeout = sta->plink_timeout + 598 rand % sta->plink_timeout; 599 ++sta->plink_retries; 600 mod_plink_timer(sta, sta->plink_timeout); 601 action = WLAN_SP_MESH_PEERING_OPEN; 602 break; 603 } 604 reason = WLAN_REASON_MESH_MAX_RETRIES; 605 /* fall through on else */ 606 case NL80211_PLINK_CNF_RCVD: 607 /* confirm timer */ 608 if (!reason) 609 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 610 sta->plink_state = NL80211_PLINK_HOLDING; 611 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 612 action = WLAN_SP_MESH_PEERING_CLOSE; 613 break; 614 case NL80211_PLINK_HOLDING: 615 /* holding timer */ 616 del_timer(&sta->plink_timer); 617 mesh_plink_fsm_restart(sta); 618 break; 619 default: 620 break; 621 } 622 spin_unlock_bh(&sta->lock); 623 if (action) 624 mesh_plink_frame_tx(sdata, action, sta->sta.addr, 625 sta->llid, sta->plid, reason); 626 } 627 628 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 629 { 630 sta->plink_timer.expires = jiffies + msecs_to_jiffies(timeout); 631 sta->plink_timer.data = (unsigned long) sta; 632 sta->plink_timer.function = mesh_plink_timer; 633 sta->plink_timeout = timeout; 634 add_timer(&sta->plink_timer); 635 } 636 637 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 638 u16 llid) 639 { 640 struct ieee80211_local *local = sdata->local; 641 bool in_use = false; 642 struct sta_info *sta; 643 644 rcu_read_lock(); 645 list_for_each_entry_rcu(sta, &local->sta_list, list) { 646 if (!memcmp(&sta->llid, &llid, sizeof(llid))) { 647 in_use = true; 648 break; 649 } 650 } 651 rcu_read_unlock(); 652 653 return in_use; 654 } 655 656 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 657 { 658 u16 llid; 659 660 do { 661 get_random_bytes(&llid, sizeof(llid)); 662 /* for mesh PS we still only have the AID range for TIM bits */ 663 llid = (llid % IEEE80211_MAX_AID) + 1; 664 } while (llid_in_use(sdata, llid)); 665 666 return llid; 667 } 668 669 u32 mesh_plink_open(struct sta_info *sta) 670 { 671 struct ieee80211_sub_if_data *sdata = sta->sdata; 672 u32 changed; 673 674 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 675 return 0; 676 677 spin_lock_bh(&sta->lock); 678 sta->llid = mesh_get_new_llid(sdata); 679 if (sta->plink_state != NL80211_PLINK_LISTEN && 680 sta->plink_state != NL80211_PLINK_BLOCKED) { 681 spin_unlock_bh(&sta->lock); 682 return 0; 683 } 684 sta->plink_state = NL80211_PLINK_OPN_SNT; 685 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 686 spin_unlock_bh(&sta->lock); 687 mpl_dbg(sdata, 688 "Mesh plink: starting establishment with %pM\n", 689 sta->sta.addr); 690 691 /* set the non-peer mode to active during peering */ 692 changed = ieee80211_mps_local_status_update(sdata); 693 694 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN, 695 sta->sta.addr, sta->llid, 0, 0); 696 return changed; 697 } 698 699 u32 mesh_plink_block(struct sta_info *sta) 700 { 701 u32 changed; 702 703 spin_lock_bh(&sta->lock); 704 changed = __mesh_plink_deactivate(sta); 705 sta->plink_state = NL80211_PLINK_BLOCKED; 706 spin_unlock_bh(&sta->lock); 707 708 return changed; 709 } 710 711 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 712 struct sta_info *sta, 713 enum plink_event event) 714 { 715 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 716 717 u16 reason = (event == CLS_ACPT) ? 718 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 719 720 sta->reason = reason; 721 sta->plink_state = NL80211_PLINK_HOLDING; 722 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 723 } 724 725 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 726 struct sta_info *sta) 727 { 728 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 729 u32 changed = 0; 730 731 del_timer(&sta->plink_timer); 732 sta->plink_state = NL80211_PLINK_ESTAB; 733 changed |= mesh_plink_inc_estab_count(sdata); 734 changed |= mesh_set_ht_prot_mode(sdata); 735 changed |= mesh_set_short_slot_time(sdata); 736 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 737 ieee80211_mps_sta_status_update(sta); 738 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 739 return changed; 740 } 741 742 /** 743 * mesh_plink_fsm - step @sta MPM based on @event 744 * 745 * @sdata: interface 746 * @sta: mesh neighbor 747 * @event: peering event 748 * 749 * Return: changed MBSS flags 750 */ 751 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 752 struct sta_info *sta, enum plink_event event) 753 { 754 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 755 enum ieee80211_self_protected_actioncode action = 0; 756 u32 changed = 0; 757 758 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 759 mplstates[sta->plink_state], mplevents[event]); 760 761 spin_lock_bh(&sta->lock); 762 switch (sta->plink_state) { 763 case NL80211_PLINK_LISTEN: 764 switch (event) { 765 case CLS_ACPT: 766 mesh_plink_fsm_restart(sta); 767 break; 768 case OPN_ACPT: 769 sta->plink_state = NL80211_PLINK_OPN_RCVD; 770 sta->llid = mesh_get_new_llid(sdata); 771 mesh_plink_timer_set(sta, 772 mshcfg->dot11MeshRetryTimeout); 773 774 /* set the non-peer mode to active during peering */ 775 changed |= ieee80211_mps_local_status_update(sdata); 776 action = WLAN_SP_MESH_PEERING_OPEN; 777 break; 778 default: 779 break; 780 } 781 break; 782 case NL80211_PLINK_OPN_SNT: 783 switch (event) { 784 case OPN_RJCT: 785 case CNF_RJCT: 786 case CLS_ACPT: 787 mesh_plink_close(sdata, sta, event); 788 action = WLAN_SP_MESH_PEERING_CLOSE; 789 break; 790 case OPN_ACPT: 791 /* retry timer is left untouched */ 792 sta->plink_state = NL80211_PLINK_OPN_RCVD; 793 action = WLAN_SP_MESH_PEERING_CONFIRM; 794 break; 795 case CNF_ACPT: 796 sta->plink_state = NL80211_PLINK_CNF_RCVD; 797 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 798 break; 799 default: 800 break; 801 } 802 break; 803 case NL80211_PLINK_OPN_RCVD: 804 switch (event) { 805 case OPN_RJCT: 806 case CNF_RJCT: 807 case CLS_ACPT: 808 mesh_plink_close(sdata, sta, event); 809 action = WLAN_SP_MESH_PEERING_CLOSE; 810 break; 811 case OPN_ACPT: 812 action = WLAN_SP_MESH_PEERING_CONFIRM; 813 break; 814 case CNF_ACPT: 815 changed |= mesh_plink_establish(sdata, sta); 816 break; 817 default: 818 break; 819 } 820 break; 821 case NL80211_PLINK_CNF_RCVD: 822 switch (event) { 823 case OPN_RJCT: 824 case CNF_RJCT: 825 case CLS_ACPT: 826 mesh_plink_close(sdata, sta, event); 827 action = WLAN_SP_MESH_PEERING_CLOSE; 828 break; 829 case OPN_ACPT: 830 changed |= mesh_plink_establish(sdata, sta); 831 action = WLAN_SP_MESH_PEERING_CONFIRM; 832 break; 833 default: 834 break; 835 } 836 break; 837 case NL80211_PLINK_ESTAB: 838 switch (event) { 839 case CLS_ACPT: 840 changed |= __mesh_plink_deactivate(sta); 841 changed |= mesh_set_ht_prot_mode(sdata); 842 changed |= mesh_set_short_slot_time(sdata); 843 mesh_plink_close(sdata, sta, event); 844 action = WLAN_SP_MESH_PEERING_CLOSE; 845 break; 846 case OPN_ACPT: 847 action = WLAN_SP_MESH_PEERING_CONFIRM; 848 break; 849 default: 850 break; 851 } 852 break; 853 case NL80211_PLINK_HOLDING: 854 switch (event) { 855 case CLS_ACPT: 856 del_timer(&sta->plink_timer); 857 mesh_plink_fsm_restart(sta); 858 break; 859 case OPN_ACPT: 860 case CNF_ACPT: 861 case OPN_RJCT: 862 case CNF_RJCT: 863 action = WLAN_SP_MESH_PEERING_CLOSE; 864 break; 865 default: 866 break; 867 } 868 break; 869 default: 870 /* should not get here, PLINK_BLOCKED is dealt with at the 871 * beginning of the function 872 */ 873 break; 874 } 875 spin_unlock_bh(&sta->lock); 876 if (action) { 877 mesh_plink_frame_tx(sdata, action, sta->sta.addr, 878 sta->llid, sta->plid, sta->reason); 879 880 /* also send confirm in open case */ 881 if (action == WLAN_SP_MESH_PEERING_OPEN) { 882 mesh_plink_frame_tx(sdata, 883 WLAN_SP_MESH_PEERING_CONFIRM, 884 sta->sta.addr, sta->llid, 885 sta->plid, 0); 886 } 887 } 888 889 return changed; 890 } 891 892 /* 893 * mesh_plink_get_event - get correct MPM event 894 * 895 * @sdata: interface 896 * @sta: peer, leave NULL if processing a frame from a new suitable peer 897 * @elems: peering management IEs 898 * @ftype: frame type 899 * @llid: peer's peer link ID 900 * @plid: peer's local link ID 901 * 902 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 903 * an error. 904 */ 905 static enum plink_event 906 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 907 struct sta_info *sta, 908 struct ieee802_11_elems *elems, 909 enum ieee80211_self_protected_actioncode ftype, 910 u16 llid, u16 plid) 911 { 912 enum plink_event event = PLINK_UNDEFINED; 913 u8 ie_len = elems->peering_len; 914 bool matches_local; 915 916 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 917 mesh_matches_local(sdata, elems)); 918 919 /* deny open request from non-matching peer */ 920 if (!matches_local && !sta) { 921 event = OPN_RJCT; 922 goto out; 923 } 924 925 if (!sta) { 926 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 927 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 928 goto out; 929 } 930 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 931 if (!mesh_plink_free_count(sdata)) { 932 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 933 goto out; 934 } 935 } else { 936 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 937 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 938 goto out; 939 } 940 if (sta->plink_state == NL80211_PLINK_BLOCKED) 941 goto out; 942 } 943 944 /* new matching peer */ 945 if (!sta) { 946 event = OPN_ACPT; 947 goto out; 948 } 949 950 switch (ftype) { 951 case WLAN_SP_MESH_PEERING_OPEN: 952 if (!matches_local) 953 event = OPN_RJCT; 954 if (!mesh_plink_free_count(sdata) || 955 (sta->plid && sta->plid != plid)) 956 event = OPN_IGNR; 957 else 958 event = OPN_ACPT; 959 break; 960 case WLAN_SP_MESH_PEERING_CONFIRM: 961 if (!matches_local) 962 event = CNF_RJCT; 963 if (!mesh_plink_free_count(sdata) || 964 sta->llid != llid || 965 (sta->plid && sta->plid != plid)) 966 event = CNF_IGNR; 967 else 968 event = CNF_ACPT; 969 break; 970 case WLAN_SP_MESH_PEERING_CLOSE: 971 if (sta->plink_state == NL80211_PLINK_ESTAB) 972 /* Do not check for llid or plid. This does not 973 * follow the standard but since multiple plinks 974 * per sta are not supported, it is necessary in 975 * order to avoid a livelock when MP A sees an 976 * establish peer link to MP B but MP B does not 977 * see it. This can be caused by a timeout in 978 * B's peer link establishment or B beign 979 * restarted. 980 */ 981 event = CLS_ACPT; 982 else if (sta->plid != plid) 983 event = CLS_IGNR; 984 else if (ie_len == 8 && sta->llid != llid) 985 event = CLS_IGNR; 986 else 987 event = CLS_ACPT; 988 break; 989 default: 990 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 991 break; 992 } 993 994 out: 995 return event; 996 } 997 998 static void 999 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1000 struct ieee80211_mgmt *mgmt, 1001 struct ieee802_11_elems *elems) 1002 { 1003 1004 struct sta_info *sta; 1005 enum plink_event event; 1006 enum ieee80211_self_protected_actioncode ftype; 1007 u32 changed = 0; 1008 u8 ie_len = elems->peering_len; 1009 u16 plid, llid = 0; 1010 1011 if (!elems->peering) { 1012 mpl_dbg(sdata, 1013 "Mesh plink: missing necessary peer link ie\n"); 1014 return; 1015 } 1016 1017 if (elems->rsn_len && 1018 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1019 mpl_dbg(sdata, 1020 "Mesh plink: can't establish link with secure peer\n"); 1021 return; 1022 } 1023 1024 ftype = mgmt->u.action.u.self_prot.action_code; 1025 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1026 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1027 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1028 && ie_len != 8)) { 1029 mpl_dbg(sdata, 1030 "Mesh plink: incorrect plink ie length %d %d\n", 1031 ftype, ie_len); 1032 return; 1033 } 1034 1035 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1036 (!elems->mesh_id || !elems->mesh_config)) { 1037 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1038 return; 1039 } 1040 /* Note the lines below are correct, the llid in the frame is the plid 1041 * from the point of view of this host. 1042 */ 1043 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1044 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1045 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1046 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1047 1048 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1049 rcu_read_lock(); 1050 1051 sta = sta_info_get(sdata, mgmt->sa); 1052 1053 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1054 !rssi_threshold_check(sdata, sta)) { 1055 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1056 mgmt->sa); 1057 goto unlock_rcu; 1058 } 1059 1060 /* Now we will figure out the appropriate event... */ 1061 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1062 1063 if (event == OPN_ACPT) { 1064 rcu_read_unlock(); 1065 /* allocate sta entry if necessary and update info */ 1066 sta = mesh_sta_info_get(sdata, mgmt->sa, elems); 1067 if (!sta) { 1068 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1069 goto unlock_rcu; 1070 } 1071 sta->plid = plid; 1072 } else if (!sta && event == OPN_RJCT) { 1073 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, 1074 mgmt->sa, 0, plid, 1075 WLAN_REASON_MESH_CONFIG); 1076 goto unlock_rcu; 1077 } else if (!sta || event == PLINK_UNDEFINED) { 1078 /* something went wrong */ 1079 goto unlock_rcu; 1080 } 1081 1082 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1083 if (!sta->plid && event == CNF_ACPT) 1084 sta->plid = plid; 1085 1086 changed |= mesh_plink_fsm(sdata, sta, event); 1087 1088 unlock_rcu: 1089 rcu_read_unlock(); 1090 1091 if (changed) 1092 ieee80211_mbss_info_change_notify(sdata, changed); 1093 } 1094 1095 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1096 struct ieee80211_mgmt *mgmt, size_t len, 1097 struct ieee80211_rx_status *rx_status) 1098 { 1099 struct ieee802_11_elems elems; 1100 size_t baselen; 1101 u8 *baseaddr; 1102 1103 /* need action_code, aux */ 1104 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1105 return; 1106 1107 if (sdata->u.mesh.user_mpm) 1108 /* userspace must register for these */ 1109 return; 1110 1111 if (is_multicast_ether_addr(mgmt->da)) { 1112 mpl_dbg(sdata, 1113 "Mesh plink: ignore frame from multicast address\n"); 1114 return; 1115 } 1116 1117 baseaddr = mgmt->u.action.u.self_prot.variable; 1118 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1119 if (mgmt->u.action.u.self_prot.action_code == 1120 WLAN_SP_MESH_PEERING_CONFIRM) { 1121 baseaddr += 4; 1122 baselen += 4; 1123 } 1124 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems); 1125 mesh_process_plink_frame(sdata, mgmt, &elems); 1126 } 1127