mesh_plink.c revision 6c6fa49649dc826b7ef81314324fe55cf1d0d954
1/* 2 * Copyright (c) 2008, 2009 open80211s Ltd. 3 * Author: Luis Carlos Cobo <luisca@cozybit.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 */ 9#include <linux/gfp.h> 10#include <linux/kernel.h> 11#include <linux/random.h> 12#include "ieee80211_i.h" 13#include "rate.h" 14#include "mesh.h" 15 16#define PLINK_GET_LLID(p) (p + 2) 17#define PLINK_GET_PLID(p) (p + 4) 18 19#define mod_plink_timer(s, t) (mod_timer(&s->plink_timer, \ 20 jiffies + HZ * t / 1000)) 21 22enum 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 34static 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 44static 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 56static 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. */ 62static 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 */ 77static 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 */ 94static 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 134out: 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 */ 154static 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 */ 218static 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 */ 242u32 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 258static 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; 372free: 373 kfree_skb(skb); 374 return err; 375} 376 377static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata, 378 struct sta_info *sta, 379 struct ieee802_11_elems *elems, bool insert) 380{ 381 struct ieee80211_local *local = sdata->local; 382 enum ieee80211_band band = ieee80211_get_sdata_band(sdata); 383 struct ieee80211_supported_band *sband; 384 u32 rates, basic_rates = 0, changed = 0; 385 386 sband = local->hw.wiphy->bands[band]; 387 rates = ieee80211_sta_get_rates(sdata, elems, band, &basic_rates); 388 389 spin_lock_bh(&sta->lock); 390 sta->last_rx = jiffies; 391 392 /* rates and capabilities don't change during peering */ 393 if (sta->plink_state == NL80211_PLINK_ESTAB) 394 goto out; 395 396 if (sta->sta.supp_rates[band] != rates) 397 changed |= IEEE80211_RC_SUPP_RATES_CHANGED; 398 sta->sta.supp_rates[band] = rates; 399 400 if (ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 401 elems->ht_cap_elem, sta)) 402 changed |= IEEE80211_RC_BW_CHANGED; 403 404 /* HT peer is operating 20MHz-only */ 405 if (elems->ht_operation && 406 !(elems->ht_operation->ht_param & 407 IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) { 408 if (sta->sta.bandwidth != IEEE80211_STA_RX_BW_20) 409 changed |= IEEE80211_RC_BW_CHANGED; 410 sta->sta.bandwidth = IEEE80211_STA_RX_BW_20; 411 } 412 413 if (insert) 414 rate_control_rate_init(sta); 415 else 416 rate_control_rate_update(local, sband, sta, changed); 417out: 418 spin_unlock_bh(&sta->lock); 419} 420 421static struct sta_info * 422__mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr) 423{ 424 struct sta_info *sta; 425 426 if (sdata->local->num_sta >= MESH_MAX_PLINKS) 427 return NULL; 428 429 sta = sta_info_alloc(sdata, hw_addr, GFP_KERNEL); 430 if (!sta) 431 return NULL; 432 433 sta->plink_state = NL80211_PLINK_LISTEN; 434 435 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 436 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 437 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 438 439 set_sta_flag(sta, WLAN_STA_WME); 440 sta->sta.wme = true; 441 442 return sta; 443} 444 445static struct sta_info * 446mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *addr, 447 struct ieee802_11_elems *elems) 448{ 449 struct sta_info *sta = NULL; 450 451 /* Userspace handles station allocation */ 452 if (sdata->u.mesh.user_mpm || 453 sdata->u.mesh.security & IEEE80211_MESH_SEC_AUTHED) 454 cfg80211_notify_new_peer_candidate(sdata->dev, addr, 455 elems->ie_start, 456 elems->total_len, 457 GFP_KERNEL); 458 else 459 sta = __mesh_sta_info_alloc(sdata, addr); 460 461 return sta; 462} 463 464/* 465 * mesh_sta_info_get - return mesh sta info entry for @addr. 466 * 467 * @sdata: local meshif 468 * @addr: peer's address 469 * @elems: IEs from beacon or mesh peering frame. 470 * 471 * Return existing or newly allocated sta_info under RCU read lock. 472 * (re)initialize with given IEs. 473 */ 474static struct sta_info * 475mesh_sta_info_get(struct ieee80211_sub_if_data *sdata, 476 u8 *addr, struct ieee802_11_elems *elems) __acquires(RCU) 477{ 478 struct sta_info *sta = NULL; 479 480 rcu_read_lock(); 481 sta = sta_info_get(sdata, addr); 482 if (sta) { 483 mesh_sta_info_init(sdata, sta, elems, false); 484 } else { 485 rcu_read_unlock(); 486 /* can't run atomic */ 487 sta = mesh_sta_info_alloc(sdata, addr, elems); 488 if (!sta) { 489 rcu_read_lock(); 490 return NULL; 491 } 492 493 mesh_sta_info_init(sdata, sta, elems, true); 494 495 if (sta_info_insert_rcu(sta)) 496 return NULL; 497 } 498 499 return sta; 500} 501 502/* 503 * mesh_neighbour_update - update or initialize new mesh neighbor. 504 * 505 * @sdata: local meshif 506 * @addr: peer's address 507 * @elems: IEs from beacon or mesh peering frame 508 * 509 * Initiates peering if appropriate. 510 */ 511void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata, 512 u8 *hw_addr, 513 struct ieee802_11_elems *elems) 514{ 515 struct sta_info *sta; 516 u32 changed = 0; 517 518 sta = mesh_sta_info_get(sdata, hw_addr, elems); 519 if (!sta) 520 goto out; 521 522 if (mesh_peer_accepts_plinks(elems) && 523 sta->plink_state == NL80211_PLINK_LISTEN && 524 sdata->u.mesh.accepting_plinks && 525 sdata->u.mesh.mshcfg.auto_open_plinks && 526 rssi_threshold_check(sdata, sta)) 527 changed = mesh_plink_open(sta); 528 529 ieee80211_mps_frame_release(sta, elems); 530out: 531 rcu_read_unlock(); 532 ieee80211_mbss_info_change_notify(sdata, changed); 533} 534 535static void mesh_plink_timer(unsigned long data) 536{ 537 struct sta_info *sta; 538 u16 reason = 0; 539 struct ieee80211_sub_if_data *sdata; 540 struct mesh_config *mshcfg; 541 enum ieee80211_self_protected_actioncode action = 0; 542 543 /* 544 * This STA is valid because sta_info_destroy() will 545 * del_timer_sync() this timer after having made sure 546 * it cannot be readded (by deleting the plink.) 547 */ 548 sta = (struct sta_info *) data; 549 550 if (sta->sdata->local->quiescing) 551 return; 552 553 spin_lock_bh(&sta->lock); 554 555 /* If a timer fires just before a state transition on another CPU, 556 * we may have already extended the timeout and changed state by the 557 * time we've acquired the lock and arrived here. In that case, 558 * skip this timer and wait for the new one. 559 */ 560 if (time_before(jiffies, sta->plink_timer.expires)) { 561 mpl_dbg(sta->sdata, 562 "Ignoring timer for %pM in state %s (timer adjusted)", 563 sta->sta.addr, mplstates[sta->plink_state]); 564 spin_unlock_bh(&sta->lock); 565 return; 566 } 567 568 /* del_timer() and handler may race when entering these states */ 569 if (sta->plink_state == NL80211_PLINK_LISTEN || 570 sta->plink_state == NL80211_PLINK_ESTAB) { 571 mpl_dbg(sta->sdata, 572 "Ignoring timer for %pM in state %s (timer deleted)", 573 sta->sta.addr, mplstates[sta->plink_state]); 574 spin_unlock_bh(&sta->lock); 575 return; 576 } 577 578 mpl_dbg(sta->sdata, 579 "Mesh plink timer for %pM fired on state %s\n", 580 sta->sta.addr, mplstates[sta->plink_state]); 581 sdata = sta->sdata; 582 mshcfg = &sdata->u.mesh.mshcfg; 583 584 switch (sta->plink_state) { 585 case NL80211_PLINK_OPN_RCVD: 586 case NL80211_PLINK_OPN_SNT: 587 /* retry timer */ 588 if (sta->plink_retries < mshcfg->dot11MeshMaxRetries) { 589 u32 rand; 590 mpl_dbg(sta->sdata, 591 "Mesh plink for %pM (retry, timeout): %d %d\n", 592 sta->sta.addr, sta->plink_retries, 593 sta->plink_timeout); 594 get_random_bytes(&rand, sizeof(u32)); 595 sta->plink_timeout = sta->plink_timeout + 596 rand % sta->plink_timeout; 597 ++sta->plink_retries; 598 mod_plink_timer(sta, sta->plink_timeout); 599 action = WLAN_SP_MESH_PEERING_OPEN; 600 break; 601 } 602 reason = WLAN_REASON_MESH_MAX_RETRIES; 603 /* fall through on else */ 604 case NL80211_PLINK_CNF_RCVD: 605 /* confirm timer */ 606 if (!reason) 607 reason = WLAN_REASON_MESH_CONFIRM_TIMEOUT; 608 sta->plink_state = NL80211_PLINK_HOLDING; 609 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 610 action = WLAN_SP_MESH_PEERING_CLOSE; 611 break; 612 case NL80211_PLINK_HOLDING: 613 /* holding timer */ 614 del_timer(&sta->plink_timer); 615 mesh_plink_fsm_restart(sta); 616 break; 617 default: 618 break; 619 } 620 spin_unlock_bh(&sta->lock); 621 if (action) 622 mesh_plink_frame_tx(sdata, action, sta->sta.addr, 623 sta->llid, sta->plid, reason); 624} 625 626static inline void mesh_plink_timer_set(struct sta_info *sta, int timeout) 627{ 628 sta->plink_timer.expires = jiffies + (HZ * timeout / 1000); 629 sta->plink_timer.data = (unsigned long) sta; 630 sta->plink_timer.function = mesh_plink_timer; 631 sta->plink_timeout = timeout; 632 add_timer(&sta->plink_timer); 633} 634 635static bool llid_in_use(struct ieee80211_sub_if_data *sdata, 636 u16 llid) 637{ 638 struct ieee80211_local *local = sdata->local; 639 bool in_use = false; 640 struct sta_info *sta; 641 642 rcu_read_lock(); 643 list_for_each_entry_rcu(sta, &local->sta_list, list) { 644 if (!memcmp(&sta->llid, &llid, sizeof(llid))) { 645 in_use = true; 646 break; 647 } 648 } 649 rcu_read_unlock(); 650 651 return in_use; 652} 653 654static u16 mesh_get_new_llid(struct ieee80211_sub_if_data *sdata) 655{ 656 u16 llid; 657 658 do { 659 get_random_bytes(&llid, sizeof(llid)); 660 /* for mesh PS we still only have the AID range for TIM bits */ 661 llid = (llid % IEEE80211_MAX_AID) + 1; 662 } while (llid_in_use(sdata, llid)); 663 664 return llid; 665} 666 667u32 mesh_plink_open(struct sta_info *sta) 668{ 669 struct ieee80211_sub_if_data *sdata = sta->sdata; 670 u32 changed; 671 672 if (!test_sta_flag(sta, WLAN_STA_AUTH)) 673 return 0; 674 675 spin_lock_bh(&sta->lock); 676 sta->llid = mesh_get_new_llid(sdata); 677 if (sta->plink_state != NL80211_PLINK_LISTEN && 678 sta->plink_state != NL80211_PLINK_BLOCKED) { 679 spin_unlock_bh(&sta->lock); 680 return 0; 681 } 682 sta->plink_state = NL80211_PLINK_OPN_SNT; 683 mesh_plink_timer_set(sta, sdata->u.mesh.mshcfg.dot11MeshRetryTimeout); 684 spin_unlock_bh(&sta->lock); 685 mpl_dbg(sdata, 686 "Mesh plink: starting establishment with %pM\n", 687 sta->sta.addr); 688 689 /* set the non-peer mode to active during peering */ 690 changed = ieee80211_mps_local_status_update(sdata); 691 692 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_OPEN, 693 sta->sta.addr, sta->llid, 0, 0); 694 return changed; 695} 696 697u32 mesh_plink_block(struct sta_info *sta) 698{ 699 u32 changed; 700 701 spin_lock_bh(&sta->lock); 702 changed = __mesh_plink_deactivate(sta); 703 sta->plink_state = NL80211_PLINK_BLOCKED; 704 spin_unlock_bh(&sta->lock); 705 706 return changed; 707} 708 709static void mesh_plink_close(struct ieee80211_sub_if_data *sdata, 710 struct sta_info *sta, 711 enum plink_event event) 712{ 713 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 714 715 u16 reason = (event == CLS_ACPT) ? 716 WLAN_REASON_MESH_CLOSE : WLAN_REASON_MESH_CONFIG; 717 718 sta->reason = reason; 719 sta->plink_state = NL80211_PLINK_HOLDING; 720 mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); 721} 722 723static u32 mesh_plink_establish(struct ieee80211_sub_if_data *sdata, 724 struct sta_info *sta) 725{ 726 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 727 u32 changed = 0; 728 729 del_timer(&sta->plink_timer); 730 sta->plink_state = NL80211_PLINK_ESTAB; 731 changed |= mesh_plink_inc_estab_count(sdata); 732 changed |= mesh_set_ht_prot_mode(sdata); 733 changed |= mesh_set_short_slot_time(sdata); 734 mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); 735 ieee80211_mps_sta_status_update(sta); 736 changed |= ieee80211_mps_set_sta_local_pm(sta, mshcfg->power_mode); 737 return changed; 738} 739 740/** 741 * mesh_plink_fsm - step @sta MPM based on @event 742 * 743 * @sdata: interface 744 * @sta: mesh neighbor 745 * @event: peering event 746 * 747 * Return: changed MBSS flags 748 */ 749static u32 mesh_plink_fsm(struct ieee80211_sub_if_data *sdata, 750 struct sta_info *sta, enum plink_event event) 751{ 752 struct mesh_config *mshcfg = &sdata->u.mesh.mshcfg; 753 enum ieee80211_self_protected_actioncode action = 0; 754 u32 changed = 0; 755 756 mpl_dbg(sdata, "peer %pM in state %s got event %s\n", sta->sta.addr, 757 mplstates[sta->plink_state], mplevents[event]); 758 759 spin_lock_bh(&sta->lock); 760 switch (sta->plink_state) { 761 case NL80211_PLINK_LISTEN: 762 switch (event) { 763 case CLS_ACPT: 764 mesh_plink_fsm_restart(sta); 765 break; 766 case OPN_ACPT: 767 sta->plink_state = NL80211_PLINK_OPN_RCVD; 768 sta->llid = mesh_get_new_llid(sdata); 769 mesh_plink_timer_set(sta, 770 mshcfg->dot11MeshRetryTimeout); 771 772 /* set the non-peer mode to active during peering */ 773 changed |= ieee80211_mps_local_status_update(sdata); 774 action = WLAN_SP_MESH_PEERING_OPEN; 775 break; 776 default: 777 break; 778 } 779 break; 780 case NL80211_PLINK_OPN_SNT: 781 switch (event) { 782 case OPN_RJCT: 783 case CNF_RJCT: 784 case CLS_ACPT: 785 mesh_plink_close(sdata, sta, event); 786 action = WLAN_SP_MESH_PEERING_CLOSE; 787 break; 788 case OPN_ACPT: 789 /* retry timer is left untouched */ 790 sta->plink_state = NL80211_PLINK_OPN_RCVD; 791 action = WLAN_SP_MESH_PEERING_CONFIRM; 792 break; 793 case CNF_ACPT: 794 sta->plink_state = NL80211_PLINK_CNF_RCVD; 795 mod_plink_timer(sta, mshcfg->dot11MeshConfirmTimeout); 796 break; 797 default: 798 break; 799 } 800 break; 801 case NL80211_PLINK_OPN_RCVD: 802 switch (event) { 803 case OPN_RJCT: 804 case CNF_RJCT: 805 case CLS_ACPT: 806 mesh_plink_close(sdata, sta, event); 807 action = WLAN_SP_MESH_PEERING_CLOSE; 808 break; 809 case OPN_ACPT: 810 action = WLAN_SP_MESH_PEERING_CONFIRM; 811 break; 812 case CNF_ACPT: 813 changed |= mesh_plink_establish(sdata, sta); 814 break; 815 default: 816 break; 817 } 818 break; 819 case NL80211_PLINK_CNF_RCVD: 820 switch (event) { 821 case OPN_RJCT: 822 case CNF_RJCT: 823 case CLS_ACPT: 824 mesh_plink_close(sdata, sta, event); 825 action = WLAN_SP_MESH_PEERING_CLOSE; 826 break; 827 case OPN_ACPT: 828 changed |= mesh_plink_establish(sdata, sta); 829 action = WLAN_SP_MESH_PEERING_CONFIRM; 830 break; 831 default: 832 break; 833 } 834 break; 835 case NL80211_PLINK_ESTAB: 836 switch (event) { 837 case CLS_ACPT: 838 changed |= __mesh_plink_deactivate(sta); 839 changed |= mesh_set_ht_prot_mode(sdata); 840 changed |= mesh_set_short_slot_time(sdata); 841 mesh_plink_close(sdata, sta, event); 842 action = WLAN_SP_MESH_PEERING_CLOSE; 843 break; 844 case OPN_ACPT: 845 action = WLAN_SP_MESH_PEERING_CONFIRM; 846 break; 847 default: 848 break; 849 } 850 break; 851 case NL80211_PLINK_HOLDING: 852 switch (event) { 853 case CLS_ACPT: 854 del_timer(&sta->plink_timer); 855 mesh_plink_fsm_restart(sta); 856 break; 857 case OPN_ACPT: 858 case CNF_ACPT: 859 case OPN_RJCT: 860 case CNF_RJCT: 861 action = WLAN_SP_MESH_PEERING_CLOSE; 862 break; 863 default: 864 break; 865 } 866 break; 867 default: 868 /* should not get here, PLINK_BLOCKED is dealt with at the 869 * beginning of the function 870 */ 871 break; 872 } 873 spin_unlock_bh(&sta->lock); 874 if (action) { 875 mesh_plink_frame_tx(sdata, action, sta->sta.addr, 876 sta->llid, sta->plid, sta->reason); 877 878 /* also send confirm in open case */ 879 if (action == WLAN_SP_MESH_PEERING_OPEN) { 880 mesh_plink_frame_tx(sdata, 881 WLAN_SP_MESH_PEERING_CONFIRM, 882 sta->sta.addr, sta->llid, 883 sta->plid, 0); 884 } 885 } 886 887 return changed; 888} 889 890/* 891 * mesh_plink_get_event - get correct MPM event 892 * 893 * @sdata: interface 894 * @sta: peer, leave NULL if processing a frame from a new suitable peer 895 * @elems: peering management IEs 896 * @ftype: frame type 897 * @llid: peer's peer link ID 898 * @plid: peer's local link ID 899 * 900 * Return: new peering event for @sta, but PLINK_UNDEFINED should be treated as 901 * an error. 902 */ 903static enum plink_event 904mesh_plink_get_event(struct ieee80211_sub_if_data *sdata, 905 struct sta_info *sta, 906 struct ieee802_11_elems *elems, 907 enum ieee80211_self_protected_actioncode ftype, 908 u16 llid, u16 plid) 909{ 910 enum plink_event event = PLINK_UNDEFINED; 911 u8 ie_len = elems->peering_len; 912 bool matches_local; 913 914 matches_local = (ftype == WLAN_SP_MESH_PEERING_CLOSE || 915 mesh_matches_local(sdata, elems)); 916 917 /* deny open request from non-matching peer */ 918 if (!matches_local && !sta) { 919 event = OPN_RJCT; 920 goto out; 921 } 922 923 if (!sta) { 924 if (ftype != WLAN_SP_MESH_PEERING_OPEN) { 925 mpl_dbg(sdata, "Mesh plink: cls or cnf from unknown peer\n"); 926 goto out; 927 } 928 /* ftype == WLAN_SP_MESH_PEERING_OPEN */ 929 if (!mesh_plink_free_count(sdata)) { 930 mpl_dbg(sdata, "Mesh plink error: no more free plinks\n"); 931 goto out; 932 } 933 } else { 934 if (!test_sta_flag(sta, WLAN_STA_AUTH)) { 935 mpl_dbg(sdata, "Mesh plink: Action frame from non-authed peer\n"); 936 goto out; 937 } 938 if (sta->plink_state == NL80211_PLINK_BLOCKED) 939 goto out; 940 } 941 942 /* new matching peer */ 943 if (!sta) { 944 event = OPN_ACPT; 945 goto out; 946 } 947 948 switch (ftype) { 949 case WLAN_SP_MESH_PEERING_OPEN: 950 if (!matches_local) 951 event = OPN_RJCT; 952 if (!mesh_plink_free_count(sdata) || 953 (sta->plid && sta->plid != plid)) 954 event = OPN_IGNR; 955 else 956 event = OPN_ACPT; 957 break; 958 case WLAN_SP_MESH_PEERING_CONFIRM: 959 if (!matches_local) 960 event = CNF_RJCT; 961 if (!mesh_plink_free_count(sdata) || 962 sta->llid != llid || 963 (sta->plid && sta->plid != plid)) 964 event = CNF_IGNR; 965 else 966 event = CNF_ACPT; 967 break; 968 case WLAN_SP_MESH_PEERING_CLOSE: 969 if (sta->plink_state == NL80211_PLINK_ESTAB) 970 /* Do not check for llid or plid. This does not 971 * follow the standard but since multiple plinks 972 * per sta are not supported, it is necessary in 973 * order to avoid a livelock when MP A sees an 974 * establish peer link to MP B but MP B does not 975 * see it. This can be caused by a timeout in 976 * B's peer link establishment or B beign 977 * restarted. 978 */ 979 event = CLS_ACPT; 980 else if (sta->plid != plid) 981 event = CLS_IGNR; 982 else if (ie_len == 8 && sta->llid != llid) 983 event = CLS_IGNR; 984 else 985 event = CLS_ACPT; 986 break; 987 default: 988 mpl_dbg(sdata, "Mesh plink: unknown frame subtype\n"); 989 break; 990 } 991 992out: 993 return event; 994} 995 996static void 997mesh_process_plink_frame(struct ieee80211_sub_if_data *sdata, 998 struct ieee80211_mgmt *mgmt, 999 struct ieee802_11_elems *elems) 1000{ 1001 1002 struct sta_info *sta; 1003 enum plink_event event; 1004 enum ieee80211_self_protected_actioncode ftype; 1005 u32 changed = 0; 1006 u8 ie_len = elems->peering_len; 1007 __le16 _plid, _llid; 1008 u16 plid, llid = 0; 1009 1010 if (!elems->peering) { 1011 mpl_dbg(sdata, 1012 "Mesh plink: missing necessary peer link ie\n"); 1013 return; 1014 } 1015 1016 if (elems->rsn_len && 1017 sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) { 1018 mpl_dbg(sdata, 1019 "Mesh plink: can't establish link with secure peer\n"); 1020 return; 1021 } 1022 1023 ftype = mgmt->u.action.u.self_prot.action_code; 1024 if ((ftype == WLAN_SP_MESH_PEERING_OPEN && ie_len != 4) || 1025 (ftype == WLAN_SP_MESH_PEERING_CONFIRM && ie_len != 6) || 1026 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len != 6 1027 && ie_len != 8)) { 1028 mpl_dbg(sdata, 1029 "Mesh plink: incorrect plink ie length %d %d\n", 1030 ftype, ie_len); 1031 return; 1032 } 1033 1034 if (ftype != WLAN_SP_MESH_PEERING_CLOSE && 1035 (!elems->mesh_id || !elems->mesh_config)) { 1036 mpl_dbg(sdata, "Mesh plink: missing necessary ie\n"); 1037 return; 1038 } 1039 /* Note the lines below are correct, the llid in the frame is the plid 1040 * from the point of view of this host. 1041 */ 1042 memcpy(&_plid, PLINK_GET_LLID(elems->peering), sizeof(__le16)); 1043 plid = le16_to_cpu(_plid); 1044 if (ftype == WLAN_SP_MESH_PEERING_CONFIRM || 1045 (ftype == WLAN_SP_MESH_PEERING_CLOSE && ie_len == 8)) { 1046 memcpy(&_llid, PLINK_GET_PLID(elems->peering), sizeof(__le16)); 1047 llid = le16_to_cpu(_llid); 1048 } 1049 1050 /* WARNING: Only for sta pointer, is dropped & re-acquired */ 1051 rcu_read_lock(); 1052 1053 sta = sta_info_get(sdata, mgmt->sa); 1054 1055 if (ftype == WLAN_SP_MESH_PEERING_OPEN && 1056 !rssi_threshold_check(sdata, sta)) { 1057 mpl_dbg(sdata, "Mesh plink: %pM does not meet rssi threshold\n", 1058 mgmt->sa); 1059 goto unlock_rcu; 1060 } 1061 1062 /* Now we will figure out the appropriate event... */ 1063 event = mesh_plink_get_event(sdata, sta, elems, ftype, llid, plid); 1064 1065 if (event == OPN_ACPT) { 1066 rcu_read_unlock(); 1067 /* allocate sta entry if necessary and update info */ 1068 sta = mesh_sta_info_get(sdata, mgmt->sa, elems); 1069 if (!sta) { 1070 mpl_dbg(sdata, "Mesh plink: failed to init peer!\n"); 1071 goto unlock_rcu; 1072 } 1073 sta->plid = plid; 1074 } else if (!sta && event == OPN_RJCT) { 1075 mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, 1076 mgmt->sa, 0, plid, 1077 WLAN_REASON_MESH_CONFIG); 1078 goto unlock_rcu; 1079 } else if (!sta || event == PLINK_UNDEFINED) { 1080 /* something went wrong */ 1081 goto unlock_rcu; 1082 } 1083 1084 /* 802.11-2012 13.3.7.2 - update plid on CNF if not set */ 1085 if (!sta->plid && event == CNF_ACPT) 1086 sta->plid = plid; 1087 1088 changed |= mesh_plink_fsm(sdata, sta, event); 1089 1090unlock_rcu: 1091 rcu_read_unlock(); 1092 1093 if (changed) 1094 ieee80211_mbss_info_change_notify(sdata, changed); 1095} 1096 1097void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 1098 struct ieee80211_mgmt *mgmt, size_t len, 1099 struct ieee80211_rx_status *rx_status) 1100{ 1101 struct ieee802_11_elems elems; 1102 size_t baselen; 1103 u8 *baseaddr; 1104 1105 /* need action_code, aux */ 1106 if (len < IEEE80211_MIN_ACTION_SIZE + 3) 1107 return; 1108 1109 if (sdata->u.mesh.user_mpm) 1110 /* userspace must register for these */ 1111 return; 1112 1113 if (is_multicast_ether_addr(mgmt->da)) { 1114 mpl_dbg(sdata, 1115 "Mesh plink: ignore frame from multicast address\n"); 1116 return; 1117 } 1118 1119 baseaddr = mgmt->u.action.u.self_prot.variable; 1120 baselen = (u8 *) mgmt->u.action.u.self_prot.variable - (u8 *) mgmt; 1121 if (mgmt->u.action.u.self_prot.action_code == 1122 WLAN_SP_MESH_PEERING_CONFIRM) { 1123 baseaddr += 4; 1124 baselen += 4; 1125 } 1126 ieee802_11_parse_elems(baseaddr, len - baselen, true, &elems); 1127 mesh_process_plink_frame(sdata, mgmt, &elems); 1128} 1129