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->plink_lock 76 */ 77 static inline void mesh_plink_fsm_restart(struct sta_info *sta) 78 { 79 lockdep_assert_held(&sta->plink_lock); 80 sta->plink_state = NL80211_PLINK_LISTEN; 81 sta->llid = sta->plid = sta->reason = 0; 82 sta->plink_retries = 0; 83 } 84 85 /* 86 * mesh_set_short_slot_time - enable / disable ERP short slot time. 87 * 88 * The standard indirectly mandates mesh STAs to turn off short slot time by 89 * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we 90 * can't be sneaky about it. Enable short slot time if all mesh STAs in the 91 * MBSS support ERP rates. 92 * 93 * Returns BSS_CHANGED_ERP_SLOT or 0 for no change. 94 */ 95 static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata) 96 { 97 struct ieee80211_local *local = sdata->local; 98 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 99 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 100 struct sta_info *sta; 101 u32 erp_rates = 0, changed = 0; 102 int i; 103 bool short_slot = false; 104 105 if (band == IEEE80211_BAND_5GHZ) { 106 /* (IEEE 802.11-2012 19.4.5) */ 107 short_slot = true; 108 goto out; 109 } else if (band != IEEE80211_BAND_2GHZ || 110 (band == IEEE80211_BAND_2GHZ && 111 local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE)) 112 goto out; 113 114 for (i = 0; i < sband->n_bitrates; i++) 115 if (sband->bitrates[i].flags & IEEE80211_RATE_ERP_G) 116 erp_rates |= BIT(i); 117 118 if (!erp_rates) 119 goto out; 120 121 rcu_read_lock(); 122 list_for_each_entry_rcu(sta, &local->sta_list, list) { 123 if (sdata != sta->sdata || 124 sta->plink_state != NL80211_PLINK_ESTAB) 125 continue; 126 127 short_slot = false; 128 if (erp_rates & sta->sta.supp_rates[band]) 129 short_slot = true; 130 else 131 break; 132 } 133 rcu_read_unlock(); 134 135 out: 136 if (sdata->vif.bss_conf.use_short_slot != short_slot) { 137 sdata->vif.bss_conf.use_short_slot = short_slot; 138 changed = BSS_CHANGED_ERP_SLOT; 139 mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n", 140 sdata->vif.addr, short_slot); 141 } 142 return changed; 143 } 144 145 /** 146 * mesh_set_ht_prot_mode - set correct HT protection mode 147 * 148 * Section 9.23.3.5 of IEEE 80211-2012 describes the protection rules for HT 149 * mesh STA in a MBSS. Three HT protection modes are supported for now, non-HT 150 * mixed mode, 20MHz-protection and no-protection mode. non-HT mixed mode is 151 * selected if any non-HT peers are present in our MBSS. 20MHz-protection mode 152 * is selected if all peers in our 20/40MHz MBSS support HT and atleast one 153 * HT20 peer is present. Otherwise no-protection mode is selected. 154 */ 155 static u32 mesh_set_ht_prot_mode(struct ieee80211_sub_if_data *sdata) 156 { 157 struct ieee80211_local *local = sdata->local; 158 struct sta_info *sta; 159 u16 ht_opmode; 160 bool non_ht_sta = false, ht20_sta = false; 161 162 switch (sdata->vif.bss_conf.chandef.width) { 163 case NL80211_CHAN_WIDTH_20_NOHT: 164 case NL80211_CHAN_WIDTH_5: 165 case NL80211_CHAN_WIDTH_10: 166 return 0; 167 default: 168 break; 169 } 170 171 rcu_read_lock(); 172 list_for_each_entry_rcu(sta, &local->sta_list, list) { 173 if (sdata != sta->sdata || 174 sta->plink_state != NL80211_PLINK_ESTAB) 175 continue; 176 177 if (sta->sta.bandwidth > IEEE80211_STA_RX_BW_20) 178 continue; 179 180 if (!sta->sta.ht_cap.ht_supported) { 181 mpl_dbg(sdata, "nonHT sta (%pM) is present\n", 182 sta->sta.addr); 183 non_ht_sta = true; 184 break; 185 } 186 187 mpl_dbg(sdata, "HT20 sta (%pM) is present\n", sta->sta.addr); 188 ht20_sta = true; 189 } 190 rcu_read_unlock(); 191 192 if (non_ht_sta) 193 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED; 194 else if (ht20_sta && 195 sdata->vif.bss_conf.chandef.width > NL80211_CHAN_WIDTH_20) 196 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_20MHZ; 197 else 198 ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONE; 199 200 if (sdata->vif.bss_conf.ht_operation_mode == ht_opmode) 201 return 0; 202 203 sdata->vif.bss_conf.ht_operation_mode = ht_opmode; 204 sdata->u.mesh.mshcfg.ht_opmode = ht_opmode; 205 mpl_dbg(sdata, "selected new HT protection mode %d\n", ht_opmode); 206 return BSS_CHANGED_HT; 207 } 208 209 /** 210 * __mesh_plink_deactivate - deactivate mesh peer link 211 * 212 * @sta: mesh peer link to deactivate 213 * 214 * All mesh paths with this peer as next hop will be flushed 215 * Returns beacon changed flag if the beacon content changed. 216 * 217 * Locking: the caller must hold sta->plink_lock 218 */ 219 static u32 __mesh_plink_deactivate(struct sta_info *sta) 220 { 221 struct ieee80211_sub_if_data *sdata = sta->sdata; 222 u32 changed = 0; 223 224 lockdep_assert_held(&sta->plink_lock); 225 226 if (sta->plink_state == NL80211_PLINK_ESTAB) 227 changed = mesh_plink_dec_estab_count(sdata); 228 sta->plink_state = NL80211_PLINK_BLOCKED; 229 mesh_path_flush_by_nexthop(sta); 230 231 ieee80211_mps_sta_status_update(sta); 232 changed |= ieee80211_mps_set_sta_local_pm(sta, 233 NL80211_MESH_POWER_UNKNOWN); 234 235 return changed; 236 } 237 238 /** 239 * mesh_plink_deactivate - deactivate mesh peer link 240 * 241 * @sta: mesh peer link to deactivate 242 * 243 * All mesh paths with this peer as next hop will be flushed 244 */ 245 u32 mesh_plink_deactivate(struct sta_info *sta) 246 { 247 struct ieee80211_sub_if_data *sdata = sta->sdata; 248 u32 changed; 249 250 spin_lock_bh(&sta->plink_lock); 251 changed = __mesh_plink_deactivate(sta); 252 sta->reason = WLAN_REASON_MESH_PEER_CANCELED; 253 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, 254 sta->sta.addr, sta->llid, sta->plid, 255 sta->reason); 256 spin_unlock_bh(&sta->plink_lock); 257 258 return changed; 259 } 260 261 static int mesh_plink_frame_tx(struct ieee80211_sub_if_data *sdata, 262 enum ieee80211_self_protected_actioncode action, 263 u8 *da, u16 llid, u16 plid, u16 reason) 264 { 265 struct ieee80211_local *local = sdata->local; 266 struct sk_buff *skb; 267 struct ieee80211_tx_info *info; 268 struct ieee80211_mgmt *mgmt; 269 bool include_plid = false; 270 u16 peering_proto = 0; 271 u8 *pos, ie_len = 4; 272 int hdr_len = offsetof(struct ieee80211_mgmt, u.action.u.self_prot) + 273 sizeof(mgmt->u.action.u.self_prot); 274 int err = -ENOMEM; 275 276 skb = dev_alloc_skb(local->tx_headroom + 277 hdr_len + 278 2 + /* capability info */ 279 2 + /* AID */ 280 2 + 8 + /* supported rates */ 281 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 282 2 + sdata->u.mesh.mesh_id_len + 283 2 + sizeof(struct ieee80211_meshconf_ie) + 284 2 + sizeof(struct ieee80211_ht_cap) + 285 2 + sizeof(struct ieee80211_ht_operation) + 286 2 + 8 + /* peering IE */ 287 sdata->u.mesh.ie_len); 288 if (!skb) 289 return err; 290 info = IEEE80211_SKB_CB(skb); 291 skb_reserve(skb, local->tx_headroom); 292 mgmt = (struct ieee80211_mgmt *) skb_put(skb, hdr_len); 293 memset(mgmt, 0, hdr_len); 294 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 295 IEEE80211_STYPE_ACTION); 296 memcpy(mgmt->da, da, ETH_ALEN); 297 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 298 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN); 299 mgmt->u.action.category = WLAN_CATEGORY_SELF_PROTECTED; 300 mgmt->u.action.u.self_prot.action_code = action; 301 302 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 303 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 304 305 /* capability info */ 306 pos = skb_put(skb, 2); 307 memset(pos, 0, 2); 308 if (action == WLAN_SP_MESH_PEERING_CONFIRM) { 309 /* AID */ 310 pos = skb_put(skb, 2); 311 put_unaligned_le16(plid, pos + 2); 312 } 313 if (ieee80211_add_srates_ie(sdata, skb, true, band) || 314 ieee80211_add_ext_srates_ie(sdata, skb, true, band) || 315 mesh_add_rsn_ie(sdata, skb) || 316 mesh_add_meshid_ie(sdata, skb) || 317 mesh_add_meshconf_ie(sdata, skb)) 318 goto free; 319 } else { /* WLAN_SP_MESH_PEERING_CLOSE */ 320 info->flags |= IEEE80211_TX_CTL_NO_ACK; 321 if (mesh_add_meshid_ie(sdata, skb)) 322 goto free; 323 } 324 325 /* Add Mesh Peering Management element */ 326 switch (action) { 327 case WLAN_SP_MESH_PEERING_OPEN: 328 break; 329 case WLAN_SP_MESH_PEERING_CONFIRM: 330 ie_len += 2; 331 include_plid = true; 332 break; 333 case WLAN_SP_MESH_PEERING_CLOSE: 334 if (plid) { 335 ie_len += 2; 336 include_plid = true; 337 } 338 ie_len += 2; /* reason code */ 339 break; 340 default: 341 err = -EINVAL; 342 goto free; 343 } 344 345 if (WARN_ON(skb_tailroom(skb) < 2 + ie_len)) 346 goto free; 347 348 pos = skb_put(skb, 2 + ie_len); 349 *pos++ = WLAN_EID_PEER_MGMT; 350 *pos++ = ie_len; 351 memcpy(pos, &peering_proto, 2); 352 pos += 2; 353 put_unaligned_le16(llid, pos); 354 pos += 2; 355 if (include_plid) { 356 put_unaligned_le16(plid, pos); 357 pos += 2; 358 } 359 if (action == WLAN_SP_MESH_PEERING_CLOSE) { 360 put_unaligned_le16(reason, pos); 361 pos += 2; 362 } 363 364 if (action != WLAN_SP_MESH_PEERING_CLOSE) { 365 if (mesh_add_ht_cap_ie(sdata, skb) || 366 mesh_add_ht_oper_ie(sdata, skb)) 367 goto free; 368 } 369 370 if (mesh_add_vendor_ies(sdata, skb)) 371 goto free; 372 373 ieee80211_tx_skb(sdata, skb); 374 return 0; 375 free: 376 kfree_skb(skb); 377 return err; 378 } 379 380 static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 381 struct sta_info *sta, 382 struct ieee802_11_elems *elems, bool insert) 383 { 384 struct ieee80211_local *local = sdata->local; 385 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 386 struct ieee80211_supported_band *sband; 387 u32 rates, basic_rates = 0, changed = 0; 388 enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth; 389 390 sband = local->hw.wiphy->bands[band]; 391 rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates); 392 393 spin_lock_bh(&sta->plink_lock); 394 sta->last_rx = jiffies; 395 396 /* rates and capabilities don't change during peering */ 397 if (sta->plink_state == NL80211_PLINK_ESTAB) 398 goto out; 399 400 if (sta->sta.supp_rates[band] != rates) 401 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 402 sta->sta.supp_rates[band] = rates; 403 404 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 405 elems->ht_cap_elem, sta)) 406 changed |= IEEE80211_RC_BW_CHANGED; 407 408 if (bw != sta->sta.bandwidth) 409 changed |= IEEE80211_RC_BW_CHANGED; 410 411 /* HT peer is operating 20MHz-only */ 412 if (elems->ht_operation && 413 !(elems->ht_operation->ht_param & 414 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 415 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) 416 changed |= IEEE80211_RC_BW_CHANGED; 417 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; 418 } 419 420 if (insert) 421 rate_control_rate_init(sta); 422 else 423 rate_control_rate_update(local, sband, sta, changed); 424 out: 425 spin_unlock_bh(&sta->plink_lock); 426 } 427 428 static struct sta_info * 429 __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 430 { 431 struct sta_info *sta; 432 433 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 434 return NULL; 435 436 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 437 if (!sta) 438 return NULL; 439 440 sta->plink_state = NL80211_PLINK_LISTEN; 441 sta->sta.wme = true; 442 443 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 444 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 445 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 446 447 return sta; 448 } 449 450 static struct sta_info * 451 mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 452 struct ieee802_11_elems *elems) 453 { 454 struct sta_info *sta = NULL; 455 456 /* Userspace handles station allocation */ 457 if (sdata->u.mesh.user_mpm || 458 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) 459 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 460 elems->ie_start, 461 elems->total_len, 462 GFP_KERNEL); 463 else 464 sta = __mesh_sta_info_alloc(sdata, addr); 465 466 return sta; 467 } 468 469 /* 470 * mesh_sta_info_get - return mesh sta info entry for @addr. 471 * 472 * @sdata: local meshif 473 * @addr: peer's address 474 * @elems: IEs from beacon or mesh peering frame. 475 * 476 * Return existing or newly allocated sta_info under RCU read lock. 477 * (re)initialize with given IEs. 478 */ 479 static struct sta_info * 480 mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 481 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU) 482 { 483 struct sta_info *sta = NULL; 484 485 rcu_read_lock(); 486 sta = sta_info_get(sdata, addr); 487 if (sta) { 488 mesh_sta_info_init(sdata, sta, elems, false); 489 } else { 490 rcu_read_unlock(); 491 /* can't run atomic */ 492 sta = mesh_sta_info_alloc(sdata, addr, elems); 493 if (!sta) { 494 rcu_read_lock(); 495 return NULL; 496 } 497 498 mesh_sta_info_init(sdata, sta, elems, true); 499 500 if (sta_info_insert_rcu(sta)) 501 return NULL; 502 } 503 504 return sta; 505 } 506 507 /* 508 * mesh_neighbour_update - update or initialize new mesh neighbor. 509 * 510 * @sdata: local meshif 511 * @addr: peer's address 512 * @elems: IEs from beacon or mesh peering frame 513 * 514 * Initiates peering if appropriate. 515 */ 516 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 517 u8 *hw_addr, 518 struct ieee802_11_elems *elems) 519 { 520 struct sta_info *sta; 521 u32 changed = 0; 522 523 sta = mesh_sta_info_get(sdata, hw_addr, elems); 524 if (!sta) 525 goto out; 526 527 if (mesh_peer_accepts_plinks(elems) && 528 sta->plink_state == NL80211_PLINK_LISTEN && 529 sdata->u.mesh.accepting_plinks && 530 sdata->u.mesh.mshcfg.auto_open_plinks && 531 rssi_threshold_check(sdata, sta)) 532 changed = mesh_plink_open(sta); 533 534 ieee80211_mps_frame_release(sta, elems); 535 out: 536 rcu_read_unlock(); 537 ieee80211_mbss_info_change_notify(sdata, changed); 538 } 539 540 static void mesh_plink_timer(unsigned long data) 541 { 542 struct sta_info *sta; 543 u16 reason = 0; 544 struct ieee80211_sub_if_data *sdata; 545 struct mesh_config *mshcfg; 546 enum ieee80211_self_protected_actioncode action = 0; 547 548 /* 549 * This STA is valid because sta_info_destroy() will 550 * del_timer_sync() this timer after having made sure 551 * it cannot be readded (by deleting the plink.) 552 */ 553 sta = (struct sta_info *) data; 554 555 if (sta->sdata->local->quiescing) 556 return; 557 558 spin_lock_bh(&sta->plink_lock); 559 560 /* If a timer fires just before a state transition on another CPU, 561 * we may have already extended the timeout and changed state by the 562 * time we've acquired the lock and arrived here. In that case, 563 * skip this timer and wait for the new one. 564 */ 565 if (time_before(jiffies, sta->plink_timer.expires)) { 566 mpl_dbg(sta->sdata, 567 "Ignoring timer for %pM in state %s (timer adjusted)", 568 sta->sta.addr, mplstates[sta->plink_state]); 569 spin_unlock_bh(&sta->plink_lock); 570 return; 571 } 572 573 /* del_timer() and handler may race when entering these states */ 574 if (sta->plink_state == NL80211_PLINK_LISTEN || 575 sta->plink_state == NL80211_PLINK_ESTAB) { 576 mpl_dbg(sta->sdata, 577 "Ignoring timer for %pM in state %s (timer deleted)", 578 sta->sta.addr, mplstates[sta->plink_state]); 579 spin_unlock_bh(&sta->plink_lock); 580 return; 581 } 582 583 mpl_dbg(sta->sdata, 584 "Mesh plink timer for %pM fired on state %s\n", 585 sta->sta.addr, mplstates[sta->plink_state]); 586 sdata = sta->sdata; 587 mshcfg = &sdata->u.mesh.mshcfg; 588 589 switch (sta->plink_state) { 590 case NL80211_PLINK_OPN_RCVD: 591 case NL80211_PLINK_OPN_SNT: 592 /* retry timer */ 593 if (sta->plink_retries < mshcfg->dot11MeshMaxRetries) { 594 u32 rand; 595 mpl_dbg(sta->sdata, 596 "Mesh plink for %pM (retry, timeout): %d %d\n", 597 sta->sta.addr, sta->plink_retries, 598 sta->plink_timeout); 599 get_random_bytes(&rand, sizeof(u32)); 600 sta->plink_timeout = sta->plink_timeout + 601 rand % sta->plink_timeout; 602 ++sta->plink_retries; 603 mod_plink_timer(sta, sta->plink_timeout); 604 action = WLAN_SP_MESH_PEERING_OPEN; 605 break; 606 } 607 reason = WLAN_REASON_MESH_MAX_RETRIES; 608 /* fall through on else */ 609 case NL80211_PLINK_CNF_RCVD: 610 /* confirm timer */ 611 if (!reason) 612 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 613 sta->plink_state = NL80211_PLINK_HOLDING; 614 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 615 action = WLAN_SP_MESH_PEERING_CLOSE; 616 break; 617 case NL80211_PLINK_HOLDING: 618 /* holding timer */ 619 del_timer(&sta->plink_timer); 620 mesh_plink_fsm_restart(sta); 621 break; 622 default: 623 break; 624 } 625 spin_unlock_bh(&sta->plink_lock); 626 if (action) 627 mesh_plink_frame_tx(sdata, action, sta->sta.addr, 628 sta->llid, sta->plid, reason); 629 } 630 631 static inline void mesh_plink_timer_set(struct sta_info *sta, u32 timeout) 632 { 633 sta->plink_timer.expires = jiffies + msecs_to_jiffies(timeout); 634 sta->plink_timer.data = (unsigned long) sta; 635 sta->plink_timer.function = mesh_plink_timer; 636 sta->plink_timeout = timeout; 637 add_timer(&sta->plink_timer); 638 } 639 640 static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 641 u16 llid) 642 { 643 struct ieee80211_local *local = sdata->local; 644 bool in_use = false; 645 struct sta_info *sta; 646 647 rcu_read_lock(); 648 list_for_each_entry_rcu(sta, &local->sta_list, list) { 649 if (!memcmp(&sta->llid, &llid, sizeof(llid))) { 650 in_use = true; 651 break; 652 } 653 } 654 rcu_read_unlock(); 655 656 return in_use; 657 } 658 659 static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 660 { 661 u16 llid; 662 663 do { 664 get_random_bytes(&llid, sizeof(llid)); 665 /* for mesh PS we still only have the AID range for TIM bits */ 666 llid = (llid % IEEE80211_MAX_AID) + 1; 667 } while (llid_in_use(sdata, llid)); 668 669 return llid; 670 } 671 672 u32 mesh_plink_open(struct sta_info *sta) 673 { 674 struct ieee80211_sub_if_data *sdata = sta->sdata; 675 u32 changed; 676 677 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 678 return 0; 679 680 spin_lock_bh(&sta->plink_lock); 681 sta->llid = mesh_get_new_llid(sdata); 682 if (sta->plink_state != NL80211_PLINK_LISTEN && 683 sta->plink_state != NL80211_PLINK_BLOCKED) { 684 spin_unlock_bh(&sta->plink_lock); 685 return 0; 686 } 687 sta->plink_state = NL80211_PLINK_OPN_SNT; 688 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 689 spin_unlock_bh(&sta->plink_lock); 690 mpl_dbg(sdata, 691 "Mesh plink: starting establishment with %pM\n", 692 sta->sta.addr); 693 694 /* set the non-peer mode to active during peering */ 695 changed = ieee80211_mps_local_status_update(sdata); 696 697 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN, 698 sta->sta.addr, sta->llid, 0, 0); 699 return changed; 700 } 701 702 u32 mesh_plink_block(struct sta_info *sta) 703 { 704 u32 changed; 705 706 spin_lock_bh(&sta->plink_lock); 707 changed = __mesh_plink_deactivate(sta); 708 sta->plink_state = NL80211_PLINK_BLOCKED; 709 spin_unlock_bh(&sta->plink_lock); 710 711 return changed; 712 } 713 714 static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 715 struct sta_info *sta, 716 enum plink_event event) 717 { 718 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 719 720 u16 reason = (event == CLS_ACPT) ? 721 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 722 723 sta->reason = reason; 724 sta->plink_state = NL80211_PLINK_HOLDING; 725 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 726 } 727 728 static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 729 struct sta_info *sta) 730 { 731 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 732 u32 changed = 0; 733 734 del_timer(&sta->plink_timer); 735 sta->plink_state = NL80211_PLINK_ESTAB; 736 changed |= mesh_plink_inc_estab_count(sdata); 737 changed |= mesh_set_ht_prot_mode(sdata); 738 changed |= mesh_set_short_slot_time(sdata); 739 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 740 ieee80211_mps_sta_status_update(sta); 741 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 742 return changed; 743 } 744 745 /** 746 * mesh_plink_fsm - step @sta MPM based on @event 747 * 748 * @sdata: interface 749 * @sta: mesh neighbor 750 * @event: peering event 751 * 752 * Return: changed MBSS flags 753 */ 754 static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 755 struct sta_info *sta, enum plink_event event) 756 { 757 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 758 enum ieee80211_self_protected_actioncode action = 0; 759 u32 changed = 0; 760 761 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 762 mplstates[sta->plink_state], mplevents[event]); 763 764 spin_lock_bh(&sta->plink_lock); 765 switch (sta->plink_state) { 766 case NL80211_PLINK_LISTEN: 767 switch (event) { 768 case CLS_ACPT: 769 mesh_plink_fsm_restart(sta); 770 break; 771 case OPN_ACPT: 772 sta->plink_state = NL80211_PLINK_OPN_RCVD; 773 sta->llid = mesh_get_new_llid(sdata); 774 mesh_plink_timer_set(sta, 775 mshcfg->dot11MeshRetryTimeout); 776 777 /* set the non-peer mode to active during peering */ 778 changed |= ieee80211_mps_local_status_update(sdata); 779 action = WLAN_SP_MESH_PEERING_OPEN; 780 break; 781 default: 782 break; 783 } 784 break; 785 case NL80211_PLINK_OPN_SNT: 786 switch (event) { 787 case OPN_RJCT: 788 case CNF_RJCT: 789 case CLS_ACPT: 790 mesh_plink_close(sdata, sta, event); 791 action = WLAN_SP_MESH_PEERING_CLOSE; 792 break; 793 case OPN_ACPT: 794 /* retry timer is left untouched */ 795 sta->plink_state = NL80211_PLINK_OPN_RCVD; 796 action = WLAN_SP_MESH_PEERING_CONFIRM; 797 break; 798 case CNF_ACPT: 799 sta->plink_state = NL80211_PLINK_CNF_RCVD; 800 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 801 break; 802 default: 803 break; 804 } 805 break; 806 case NL80211_PLINK_OPN_RCVD: 807 switch (event) { 808 case OPN_RJCT: 809 case CNF_RJCT: 810 case CLS_ACPT: 811 mesh_plink_close(sdata, sta, event); 812 action = WLAN_SP_MESH_PEERING_CLOSE; 813 break; 814 case OPN_ACPT: 815 action = WLAN_SP_MESH_PEERING_CONFIRM; 816 break; 817 case CNF_ACPT: 818 changed |= mesh_plink_establish(sdata, sta); 819 break; 820 default: 821 break; 822 } 823 break; 824 case NL80211_PLINK_CNF_RCVD: 825 switch (event) { 826 case OPN_RJCT: 827 case CNF_RJCT: 828 case CLS_ACPT: 829 mesh_plink_close(sdata, sta, event); 830 action = WLAN_SP_MESH_PEERING_CLOSE; 831 break; 832 case OPN_ACPT: 833 changed |= mesh_plink_establish(sdata, sta); 834 action = WLAN_SP_MESH_PEERING_CONFIRM; 835 break; 836 default: 837 break; 838 } 839 break; 840 case NL80211_PLINK_ESTAB: 841 switch (event) { 842 case CLS_ACPT: 843 changed |= __mesh_plink_deactivate(sta); 844 changed |= mesh_set_ht_prot_mode(sdata); 845 changed |= mesh_set_short_slot_time(sdata); 846 mesh_plink_close(sdata, sta, event); 847 action = WLAN_SP_MESH_PEERING_CLOSE; 848 break; 849 case OPN_ACPT: 850 action = WLAN_SP_MESH_PEERING_CONFIRM; 851 break; 852 default: 853 break; 854 } 855 break; 856 case NL80211_PLINK_HOLDING: 857 switch (event) { 858 case CLS_ACPT: 859 del_timer(&sta->plink_timer); 860 mesh_plink_fsm_restart(sta); 861 break; 862 case OPN_ACPT: 863 case CNF_ACPT: 864 case OPN_RJCT: 865 case CNF_RJCT: 866 action = WLAN_SP_MESH_PEERING_CLOSE; 867 break; 868 default: 869 break; 870 } 871 break; 872 default: 873 /* should not get here, PLINK_BLOCKED is dealt with at the 874 * beginning of the function 875 */ 876 break; 877 } 878 spin_unlock_bh(&sta->plink_lock); 879 if (action) { 880 mesh_plink_frame_tx(sdata, action, sta->sta.addr, 881 sta->llid, sta->plid, sta->reason); 882 883 /* also send confirm in open case */ 884 if (action == WLAN_SP_MESH_PEERING_OPEN) { 885 mesh_plink_frame_tx(sdata, 886 WLAN_SP_MESH_PEERING_CONFIRM, 887 sta->sta.addr, sta->llid, 888 sta->plid, 0); 889 } 890 } 891 892 return changed; 893 } 894 895 /* 896 * mesh_plink_get_event - get correct MPM event 897 * 898 * @sdata: interface 899 * @sta: peer, leave NULL if processing a frame from a new suitable peer 900 * @elems: peering management IEs 901 * @ftype: frame type 902 * @llid: peer's peer link ID 903 * @plid: peer's local link ID 904 * 905 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 906 * an error. 907 */ 908 static enum plink_event 909 mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 910 struct sta_info *sta, 911 struct ieee802_11_elems *elems, 912 enum ieee80211_self_protected_actioncode ftype, 913 u16 llid, u16 plid) 914 { 915 enum plink_event event = PLINK_UNDEFINED; 916 u8 ie_len = elems->peering_len; 917 bool matches_local; 918 919 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 920 mesh_matches_local(sdata, elems)); 921 922 /* deny open request from non-matching peer */ 923 if (!matches_local && !sta) { 924 event = OPN_RJCT; 925 goto out; 926 } 927 928 if (!sta) { 929 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 930 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 931 goto out; 932 } 933 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 934 if (!mesh_plink_free_count(sdata)) { 935 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 936 goto out; 937 } 938 } else { 939 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 940 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 941 goto out; 942 } 943 if (sta->plink_state == NL80211_PLINK_BLOCKED) 944 goto out; 945 } 946 947 /* new matching peer */ 948 if (!sta) { 949 event = OPN_ACPT; 950 goto out; 951 } 952 953 switch (ftype) { 954 case WLAN_SP_MESH_PEERING_OPEN: 955 if (!matches_local) 956 event = OPN_RJCT; 957 if (!mesh_plink_free_count(sdata) || 958 (sta->plid && sta->plid != plid)) 959 event = OPN_IGNR; 960 else 961 event = OPN_ACPT; 962 break; 963 case WLAN_SP_MESH_PEERING_CONFIRM: 964 if (!matches_local) 965 event = CNF_RJCT; 966 if (!mesh_plink_free_count(sdata) || 967 sta->llid != llid || 968 (sta->plid && sta->plid != plid)) 969 event = CNF_IGNR; 970 else 971 event = CNF_ACPT; 972 break; 973 case WLAN_SP_MESH_PEERING_CLOSE: 974 if (sta->plink_state == NL80211_PLINK_ESTAB) 975 /* Do not check for llid or plid. This does not 976 * follow the standard but since multiple plinks 977 * per sta are not supported, it is necessary in 978 * order to avoid a livelock when MP A sees an 979 * establish peer link to MP B but MP B does not 980 * see it. This can be caused by a timeout in 981 * B's peer link establishment or B beign 982 * restarted. 983 */ 984 event = CLS_ACPT; 985 else if (sta->plid != plid) 986 event = CLS_IGNR; 987 else if (ie_len == 8 && sta->llid != llid) 988 event = CLS_IGNR; 989 else 990 event = CLS_ACPT; 991 break; 992 default: 993 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 994 break; 995 } 996 997 out: 998 return event; 999 } 1000 1001 static void 1002 mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 1003 struct ieee80211_mgmt *mgmt, 1004 struct ieee802_11_elems *elems) 1005 { 1006 1007 struct sta_info *sta; 1008 enum plink_event event; 1009 enum ieee80211_self_protected_actioncode ftype; 1010 u32 changed = 0; 1011 u8 ie_len = elems->peering_len; 1012 u16 plid, llid = 0; 1013 1014 if (!elems->peering) { 1015 mpl_dbg(sdata, 1016 "Mesh plink: missing necessary peer link ie\n"); 1017 return; 1018 } 1019 1020 if (elems->rsn_len && 1021 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1022 mpl_dbg(sdata, 1023 "Mesh plink: can't establish link with secure peer\n"); 1024 return; 1025 } 1026 1027 ftype = mgmt->u.action.u.self_prot.action_code; 1028 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1029 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1030 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1031 && ie_len != 8)) { 1032 mpl_dbg(sdata, 1033 "Mesh plink: incorrect plink ie length %d %d\n", 1034 ftype, ie_len); 1035 return; 1036 } 1037 1038 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1039 (!elems->mesh_id || !elems->mesh_config)) { 1040 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1041 return; 1042 } 1043 /* Note the lines below are correct, the llid in the frame is the plid 1044 * from the point of view of this host. 1045 */ 1046 plid = get_unaligned_le16(PLINK_GET_LLID(elems->peering)); 1047 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1048 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) 1049 llid = get_unaligned_le16(PLINK_GET_PLID(elems->peering)); 1050 1051 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1052 rcu_read_lock(); 1053 1054 sta = sta_info_get(sdata, mgmt->sa); 1055 1056 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1057 !rssi_threshold_check(sdata, sta)) { 1058 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1059 mgmt->sa); 1060 goto unlock_rcu; 1061 } 1062 1063 /* Now we will figure out the appropriate event... */ 1064 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1065 1066 if (event == OPN_ACPT) { 1067 rcu_read_unlock(); 1068 /* allocate sta entry if necessary and update info */ 1069 sta = mesh_sta_info_get(sdata, mgmt->sa, elems); 1070 if (!sta) { 1071 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1072 goto unlock_rcu; 1073 } 1074 sta->plid = plid; 1075 } else if (!sta && event == OPN_RJCT) { 1076 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, 1077 mgmt->sa, 0, plid, 1078 WLAN_REASON_MESH_CONFIG); 1079 goto unlock_rcu; 1080 } else if (!sta || event == PLINK_UNDEFINED) { 1081 /* something went wrong */ 1082 goto unlock_rcu; 1083 } 1084 1085 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1086 if (!sta->plid && event == CNF_ACPT) 1087 sta->plid = plid; 1088 1089 changed |= mesh_plink_fsm(sdata, sta, event); 1090 1091 unlock_rcu: 1092 rcu_read_unlock(); 1093 1094 if (changed) 1095 ieee80211_mbss_info_change_notify(sdata, changed); 1096 } 1097 1098 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1099 struct ieee80211_mgmt *mgmt, size_t len, 1100 struct ieee80211_rx_status *rx_status) 1101 { 1102 struct ieee802_11_elems elems; 1103 size_t baselen; 1104 u8 *baseaddr; 1105 1106 /* need action_code, aux */ 1107 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1108 return; 1109 1110 if (sdata->u.mesh.user_mpm) 1111 /* userspace must register for these */ 1112 return; 1113 1114 if (is_multicast_ether_addr(mgmt->da)) { 1115 mpl_dbg(sdata, 1116 "Mesh plink: ignore frame from multicast address\n"); 1117 return; 1118 } 1119 1120 baseaddr = mgmt->u.action.u.self_prot.variable; 1121 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1122 if (mgmt->u.action.u.self_prot.action_code == 1123 WLAN_SP_MESH_PEERING_CONFIRM) { 1124 baseaddr += 4; 1125 baselen += 4; 1126 } 1127 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems); 1128 mesh_process_plink_frame(sdata, mgmt, &elems); 1129 } 1130