1 /* 2 * IBSS mode implementation 3 * Copyright 2003-2008, Jouni Malinen <j@w1.fi> 4 * Copyright 2004, Instant802 Networks, Inc. 5 * Copyright 2005, Devicescape Software, Inc. 6 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> 7 * Copyright 2007, Michael Wu <flamingice@sourmilk.net> 8 * Copyright 2009, Johannes Berg <johannes@sipsolutions.net> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 */ 14 15 #include <linux/delay.h> 16 #include <linux/slab.h> 17 #include <linux/if_ether.h> 18 #include <linux/skbuff.h> 19 #include <linux/if_arp.h> 20 #include <linux/etherdevice.h> 21 #include <linux/rtnetlink.h> 22 #include <net/mac80211.h> 23 24 #include "ieee80211_i.h" 25 #include "driver-ops.h" 26 #include "rate.h" 27 28 #define IEEE80211_SCAN_INTERVAL (2 * HZ) 29 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ) 30 31 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ) 32 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ) 33 34 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128 35 36 37 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 38 const u8 *bssid, const int beacon_int, 39 struct ieee80211_channel *chan, 40 const u32 basic_rates, 41 const u16 capability, u64 tsf, 42 bool creator) 43 { 44 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 45 struct ieee80211_local *local = sdata->local; 46 int rates, i; 47 struct sk_buff *skb; 48 struct ieee80211_mgmt *mgmt; 49 u8 *pos; 50 struct ieee80211_supported_band *sband; 51 struct cfg80211_bss *bss; 52 u32 bss_change; 53 u8 supp_rates[IEEE80211_MAX_SUPP_RATES]; 54 struct cfg80211_chan_def chandef; 55 56 lockdep_assert_held(&ifibss->mtx); 57 58 /* Reset own TSF to allow time synchronization work. */ 59 drv_reset_tsf(local, sdata); 60 61 skb = ifibss->skb; 62 RCU_INIT_POINTER(ifibss->presp, NULL); 63 synchronize_rcu(); 64 skb->data = skb->head; 65 skb->len = 0; 66 skb_reset_tail_pointer(skb); 67 skb_reserve(skb, sdata->local->hw.extra_tx_headroom); 68 69 if (!ether_addr_equal(ifibss->bssid, bssid)) 70 sta_info_flush(sdata->local, sdata); 71 72 /* if merging, indicate to driver that we leave the old IBSS */ 73 if (sdata->vif.bss_conf.ibss_joined) { 74 sdata->vif.bss_conf.ibss_joined = false; 75 sdata->vif.bss_conf.ibss_creator = false; 76 netif_carrier_off(sdata->dev); 77 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS); 78 } 79 80 sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0; 81 82 cfg80211_chandef_create(&chandef, chan, ifibss->channel_type); 83 if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) { 84 chandef.width = NL80211_CHAN_WIDTH_20; 85 chandef.center_freq1 = chan->center_freq; 86 } 87 88 ieee80211_vif_release_channel(sdata); 89 if (ieee80211_vif_use_channel(sdata, &chandef, 90 ifibss->fixed_channel ? 91 IEEE80211_CHANCTX_SHARED : 92 IEEE80211_CHANCTX_EXCLUSIVE)) { 93 sdata_info(sdata, "Failed to join IBSS, no channel context\n"); 94 return; 95 } 96 97 memcpy(ifibss->bssid, bssid, ETH_ALEN); 98 99 sband = local->hw.wiphy->bands[chan->band]; 100 101 /* build supported rates array */ 102 pos = supp_rates; 103 for (i = 0; i < sband->n_bitrates; i++) { 104 int rate = sband->bitrates[i].bitrate; 105 u8 basic = 0; 106 if (basic_rates & BIT(i)) 107 basic = 0x80; 108 *pos++ = basic | (u8) (rate / 5); 109 } 110 111 /* Build IBSS probe response */ 112 mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon)); 113 memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon)); 114 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 115 IEEE80211_STYPE_PROBE_RESP); 116 eth_broadcast_addr(mgmt->da); 117 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 118 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN); 119 mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int); 120 mgmt->u.beacon.timestamp = cpu_to_le64(tsf); 121 mgmt->u.beacon.capab_info = cpu_to_le16(capability); 122 123 pos = skb_put(skb, 2 + ifibss->ssid_len); 124 *pos++ = WLAN_EID_SSID; 125 *pos++ = ifibss->ssid_len; 126 memcpy(pos, ifibss->ssid, ifibss->ssid_len); 127 128 rates = sband->n_bitrates; 129 if (rates > 8) 130 rates = 8; 131 pos = skb_put(skb, 2 + rates); 132 *pos++ = WLAN_EID_SUPP_RATES; 133 *pos++ = rates; 134 memcpy(pos, supp_rates, rates); 135 136 if (sband->band == IEEE80211_BAND_2GHZ) { 137 pos = skb_put(skb, 2 + 1); 138 *pos++ = WLAN_EID_DS_PARAMS; 139 *pos++ = 1; 140 *pos++ = ieee80211_frequency_to_channel(chan->center_freq); 141 } 142 143 pos = skb_put(skb, 2 + 2); 144 *pos++ = WLAN_EID_IBSS_PARAMS; 145 *pos++ = 2; 146 /* FIX: set ATIM window based on scan results */ 147 *pos++ = 0; 148 *pos++ = 0; 149 150 if (sband->n_bitrates > 8) { 151 rates = sband->n_bitrates - 8; 152 pos = skb_put(skb, 2 + rates); 153 *pos++ = WLAN_EID_EXT_SUPP_RATES; 154 *pos++ = rates; 155 memcpy(pos, &supp_rates[8], rates); 156 } 157 158 if (ifibss->ie_len) 159 memcpy(skb_put(skb, ifibss->ie_len), 160 ifibss->ie, ifibss->ie_len); 161 162 /* add HT capability and information IEs */ 163 if (chandef.width != NL80211_CHAN_WIDTH_20_NOHT && 164 sband->ht_cap.ht_supported) { 165 pos = skb_put(skb, 4 + 166 sizeof(struct ieee80211_ht_cap) + 167 sizeof(struct ieee80211_ht_operation)); 168 pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, 169 sband->ht_cap.cap); 170 /* 171 * Note: According to 802.11n-2009 9.13.3.1, HT Protection 172 * field and RIFS Mode are reserved in IBSS mode, therefore 173 * keep them at 0 174 */ 175 pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap, 176 &chandef, 0); 177 } 178 179 if (local->hw.queues >= IEEE80211_NUM_ACS) { 180 pos = skb_put(skb, 9); 181 *pos++ = WLAN_EID_VENDOR_SPECIFIC; 182 *pos++ = 7; /* len */ 183 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */ 184 *pos++ = 0x50; 185 *pos++ = 0xf2; 186 *pos++ = 2; /* WME */ 187 *pos++ = 0; /* WME info */ 188 *pos++ = 1; /* WME ver */ 189 *pos++ = 0; /* U-APSD no in use */ 190 } 191 192 rcu_assign_pointer(ifibss->presp, skb); 193 194 sdata->vif.bss_conf.beacon_int = beacon_int; 195 sdata->vif.bss_conf.basic_rates = basic_rates; 196 bss_change = BSS_CHANGED_BEACON_INT; 197 bss_change |= ieee80211_reset_erp_info(sdata); 198 bss_change |= BSS_CHANGED_BSSID; 199 bss_change |= BSS_CHANGED_BEACON; 200 bss_change |= BSS_CHANGED_BEACON_ENABLED; 201 bss_change |= BSS_CHANGED_BASIC_RATES; 202 bss_change |= BSS_CHANGED_HT; 203 bss_change |= BSS_CHANGED_IBSS; 204 205 /* 206 * In 5 GHz/802.11a, we can always use short slot time. 207 * (IEEE 802.11-2012 18.3.8.7) 208 * 209 * In 2.4GHz, we must always use long slots in IBSS for compatibility 210 * reasons. 211 * (IEEE 802.11-2012 19.4.5) 212 * 213 * HT follows these specifications (IEEE 802.11-2012 20.3.18) 214 */ 215 sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ; 216 bss_change |= BSS_CHANGED_ERP_SLOT; 217 218 sdata->vif.bss_conf.ibss_joined = true; 219 sdata->vif.bss_conf.ibss_creator = creator; 220 ieee80211_bss_info_change_notify(sdata, bss_change); 221 222 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 223 224 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 225 mod_timer(&ifibss->timer, 226 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 227 228 bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan, 229 mgmt, skb->len, 0, GFP_KERNEL); 230 cfg80211_put_bss(bss); 231 netif_carrier_on(sdata->dev); 232 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 233 } 234 235 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 236 struct ieee80211_bss *bss) 237 { 238 struct cfg80211_bss *cbss = 239 container_of((void *)bss, struct cfg80211_bss, priv); 240 struct ieee80211_supported_band *sband; 241 u32 basic_rates; 242 int i, j; 243 u16 beacon_int = cbss->beacon_interval; 244 245 lockdep_assert_held(&sdata->u.ibss.mtx); 246 247 if (beacon_int < 10) 248 beacon_int = 10; 249 250 sband = sdata->local->hw.wiphy->bands[cbss->channel->band]; 251 252 basic_rates = 0; 253 254 for (i = 0; i < bss->supp_rates_len; i++) { 255 int rate = (bss->supp_rates[i] & 0x7f) * 5; 256 bool is_basic = !!(bss->supp_rates[i] & 0x80); 257 258 for (j = 0; j < sband->n_bitrates; j++) { 259 if (sband->bitrates[j].bitrate == rate) { 260 if (is_basic) 261 basic_rates |= BIT(j); 262 break; 263 } 264 } 265 } 266 267 __ieee80211_sta_join_ibss(sdata, cbss->bssid, 268 beacon_int, 269 cbss->channel, 270 basic_rates, 271 cbss->capability, 272 cbss->tsf, 273 false); 274 } 275 276 static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta, 277 bool auth) 278 __acquires(RCU) 279 { 280 struct ieee80211_sub_if_data *sdata = sta->sdata; 281 u8 addr[ETH_ALEN]; 282 283 memcpy(addr, sta->sta.addr, ETH_ALEN); 284 285 ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr); 286 287 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 288 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 289 /* authorize the station only if the network is not RSN protected. If 290 * not wait for the userspace to authorize it */ 291 if (!sta->sdata->u.ibss.control_port) 292 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 293 294 rate_control_rate_init(sta); 295 296 /* If it fails, maybe we raced another insertion? */ 297 if (sta_info_insert_rcu(sta)) 298 return sta_info_get(sdata, addr); 299 if (auth && !sdata->u.ibss.auth_frame_registrations) { 300 ibss_dbg(sdata, 301 "TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n", 302 sdata->vif.addr, addr, sdata->u.ibss.bssid); 303 ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, 0, NULL, 0, 304 addr, sdata->u.ibss.bssid, NULL, 0, 0); 305 } 306 return sta; 307 } 308 309 static struct sta_info * 310 ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 311 const u8 *bssid, const u8 *addr, 312 u32 supp_rates, bool auth) 313 __acquires(RCU) 314 { 315 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 316 struct ieee80211_local *local = sdata->local; 317 struct sta_info *sta; 318 struct ieee80211_chanctx_conf *chanctx_conf; 319 int band; 320 321 /* 322 * XXX: Consider removing the least recently used entry and 323 * allow new one to be added. 324 */ 325 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 326 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 327 sdata->name, addr); 328 rcu_read_lock(); 329 return NULL; 330 } 331 332 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) { 333 rcu_read_lock(); 334 return NULL; 335 } 336 337 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) { 338 rcu_read_lock(); 339 return NULL; 340 } 341 342 rcu_read_lock(); 343 chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf); 344 if (WARN_ON_ONCE(!chanctx_conf)) 345 return NULL; 346 band = chanctx_conf->def.chan->band; 347 rcu_read_unlock(); 348 349 sta = sta_info_alloc(sdata, addr, GFP_KERNEL); 350 if (!sta) { 351 rcu_read_lock(); 352 return NULL; 353 } 354 355 sta->last_rx = jiffies; 356 357 /* make sure mandatory rates are always added */ 358 sta->sta.supp_rates[band] = supp_rates | 359 ieee80211_mandatory_rates(local, band); 360 361 return ieee80211_ibss_finish_sta(sta, auth); 362 } 363 364 static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata, 365 struct ieee80211_mgmt *mgmt, 366 size_t len) 367 { 368 u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code); 369 370 if (len < IEEE80211_DEAUTH_FRAME_LEN) 371 return; 372 373 ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n", 374 mgmt->sa, mgmt->da, mgmt->bssid, reason); 375 sta_info_destroy_addr(sdata, mgmt->sa); 376 } 377 378 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, 379 struct ieee80211_mgmt *mgmt, 380 size_t len) 381 { 382 u16 auth_alg, auth_transaction; 383 struct sta_info *sta; 384 u8 deauth_frame_buf[IEEE80211_DEAUTH_FRAME_LEN]; 385 386 lockdep_assert_held(&sdata->u.ibss.mtx); 387 388 if (len < 24 + 6) 389 return; 390 391 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 392 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 393 394 ibss_dbg(sdata, 395 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n", 396 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction); 397 398 if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1) 399 return; 400 401 sta_info_destroy_addr(sdata, mgmt->sa); 402 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false); 403 rcu_read_unlock(); 404 405 /* 406 * if we have any problem in allocating the new station, we reply with a 407 * DEAUTH frame to tell the other end that we had a problem 408 */ 409 if (!sta) { 410 ieee80211_send_deauth_disassoc(sdata, sdata->u.ibss.bssid, 411 IEEE80211_STYPE_DEAUTH, 412 WLAN_REASON_UNSPECIFIED, true, 413 deauth_frame_buf); 414 return; 415 } 416 417 /* 418 * IEEE 802.11 standard does not require authentication in IBSS 419 * networks and most implementations do not seem to use it. 420 * However, try to reply to authentication attempts if someone 421 * has actually implemented this. 422 */ 423 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0, 424 mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0); 425 } 426 427 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 428 struct ieee80211_mgmt *mgmt, 429 size_t len, 430 struct ieee80211_rx_status *rx_status, 431 struct ieee802_11_elems *elems, 432 bool beacon) 433 { 434 struct ieee80211_local *local = sdata->local; 435 int freq; 436 struct cfg80211_bss *cbss; 437 struct ieee80211_bss *bss; 438 struct sta_info *sta; 439 struct ieee80211_channel *channel; 440 u64 beacon_timestamp, rx_timestamp; 441 u32 supp_rates = 0; 442 enum ieee80211_band band = rx_status->band; 443 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 444 bool rates_updated = false; 445 446 if (elems->ds_params && elems->ds_params_len == 1) 447 freq = ieee80211_channel_to_frequency(elems->ds_params[0], 448 band); 449 else 450 freq = rx_status->freq; 451 452 channel = ieee80211_get_channel(local->hw.wiphy, freq); 453 454 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 455 return; 456 457 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && 458 ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) { 459 460 rcu_read_lock(); 461 sta = sta_info_get(sdata, mgmt->sa); 462 463 if (elems->supp_rates) { 464 supp_rates = ieee80211_sta_get_rates(local, elems, 465 band, NULL); 466 if (sta) { 467 u32 prev_rates; 468 469 prev_rates = sta->sta.supp_rates[band]; 470 /* make sure mandatory rates are always added */ 471 sta->sta.supp_rates[band] = supp_rates | 472 ieee80211_mandatory_rates(local, band); 473 474 if (sta->sta.supp_rates[band] != prev_rates) { 475 ibss_dbg(sdata, 476 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n", 477 sta->sta.addr, prev_rates, 478 sta->sta.supp_rates[band]); 479 rates_updated = true; 480 } 481 } else { 482 rcu_read_unlock(); 483 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, 484 mgmt->sa, supp_rates, true); 485 } 486 } 487 488 if (sta && elems->wmm_info) 489 set_sta_flag(sta, WLAN_STA_WME); 490 491 if (sta && elems->ht_operation && elems->ht_cap_elem && 492 sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) { 493 /* we both use HT */ 494 struct ieee80211_sta_ht_cap sta_ht_cap_new; 495 struct cfg80211_chan_def chandef; 496 497 ieee80211_ht_oper_to_chandef(channel, 498 elems->ht_operation, 499 &chandef); 500 501 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 502 elems->ht_cap_elem, 503 &sta_ht_cap_new); 504 505 /* 506 * fall back to HT20 if we don't use or use 507 * the other extension channel 508 */ 509 if (chandef.width != NL80211_CHAN_WIDTH_40 || 510 cfg80211_get_chandef_type(&chandef) != 511 sdata->u.ibss.channel_type) 512 sta_ht_cap_new.cap &= 513 ~IEEE80211_HT_CAP_SUP_WIDTH_20_40; 514 515 if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new, 516 sizeof(sta_ht_cap_new))) { 517 memcpy(&sta->sta.ht_cap, &sta_ht_cap_new, 518 sizeof(sta_ht_cap_new)); 519 rates_updated = true; 520 } 521 } 522 523 if (sta && rates_updated) { 524 drv_sta_rc_update(local, sdata, &sta->sta, 525 IEEE80211_RC_SUPP_RATES_CHANGED); 526 rate_control_rate_init(sta); 527 } 528 529 rcu_read_unlock(); 530 } 531 532 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 533 channel, beacon); 534 if (!bss) 535 return; 536 537 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 538 539 /* was just updated in ieee80211_bss_info_update */ 540 beacon_timestamp = cbss->tsf; 541 542 /* check if we need to merge IBSS */ 543 544 /* we use a fixed BSSID */ 545 if (sdata->u.ibss.fixed_bssid) 546 goto put_bss; 547 548 /* not an IBSS */ 549 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 550 goto put_bss; 551 552 /* different channel */ 553 if (sdata->u.ibss.fixed_channel && 554 sdata->u.ibss.channel != cbss->channel) 555 goto put_bss; 556 557 /* different SSID */ 558 if (elems->ssid_len != sdata->u.ibss.ssid_len || 559 memcmp(elems->ssid, sdata->u.ibss.ssid, 560 sdata->u.ibss.ssid_len)) 561 goto put_bss; 562 563 /* same BSSID */ 564 if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid)) 565 goto put_bss; 566 567 if (ieee80211_have_rx_timestamp(rx_status)) { 568 /* time when timestamp field was received */ 569 rx_timestamp = 570 ieee80211_calculate_rx_timestamp(local, rx_status, 571 len + FCS_LEN, 24); 572 } else { 573 /* 574 * second best option: get current TSF 575 * (will return -1 if not supported) 576 */ 577 rx_timestamp = drv_get_tsf(local, sdata); 578 } 579 580 ibss_dbg(sdata, 581 "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 582 mgmt->sa, mgmt->bssid, 583 (unsigned long long)rx_timestamp, 584 (unsigned long long)beacon_timestamp, 585 (unsigned long long)(rx_timestamp - beacon_timestamp), 586 jiffies); 587 588 if (beacon_timestamp > rx_timestamp) { 589 ibss_dbg(sdata, 590 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n", 591 mgmt->bssid); 592 ieee80211_sta_join_ibss(sdata, bss); 593 supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL); 594 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 595 supp_rates, true); 596 rcu_read_unlock(); 597 } 598 599 put_bss: 600 ieee80211_rx_bss_put(local, bss); 601 } 602 603 void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata, 604 const u8 *bssid, const u8 *addr, 605 u32 supp_rates) 606 { 607 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 608 struct ieee80211_local *local = sdata->local; 609 struct sta_info *sta; 610 struct ieee80211_chanctx_conf *chanctx_conf; 611 int band; 612 613 /* 614 * XXX: Consider removing the least recently used entry and 615 * allow new one to be added. 616 */ 617 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 618 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 619 sdata->name, addr); 620 return; 621 } 622 623 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 624 return; 625 626 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) 627 return; 628 629 rcu_read_lock(); 630 chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf); 631 if (WARN_ON_ONCE(!chanctx_conf)) { 632 rcu_read_unlock(); 633 return; 634 } 635 band = chanctx_conf->def.chan->band; 636 rcu_read_unlock(); 637 638 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC); 639 if (!sta) 640 return; 641 642 sta->last_rx = jiffies; 643 644 /* make sure mandatory rates are always added */ 645 sta->sta.supp_rates[band] = supp_rates | 646 ieee80211_mandatory_rates(local, band); 647 648 spin_lock(&ifibss->incomplete_lock); 649 list_add(&sta->list, &ifibss->incomplete_stations); 650 spin_unlock(&ifibss->incomplete_lock); 651 ieee80211_queue_work(&local->hw, &sdata->work); 652 } 653 654 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 655 { 656 struct ieee80211_local *local = sdata->local; 657 int active = 0; 658 struct sta_info *sta; 659 660 lockdep_assert_held(&sdata->u.ibss.mtx); 661 662 rcu_read_lock(); 663 664 list_for_each_entry_rcu(sta, &local->sta_list, list) { 665 if (sta->sdata == sdata && 666 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 667 jiffies)) { 668 active++; 669 break; 670 } 671 } 672 673 rcu_read_unlock(); 674 675 return active; 676 } 677 678 /* 679 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 680 */ 681 682 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 683 { 684 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 685 686 lockdep_assert_held(&ifibss->mtx); 687 688 mod_timer(&ifibss->timer, 689 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 690 691 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 692 693 if (time_before(jiffies, ifibss->last_scan_completed + 694 IEEE80211_IBSS_MERGE_INTERVAL)) 695 return; 696 697 if (ieee80211_sta_active_ibss(sdata)) 698 return; 699 700 if (ifibss->fixed_channel) 701 return; 702 703 sdata_info(sdata, 704 "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n"); 705 706 ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len, 707 NULL); 708 } 709 710 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 711 { 712 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 713 u8 bssid[ETH_ALEN]; 714 u16 capability; 715 int i; 716 717 lockdep_assert_held(&ifibss->mtx); 718 719 if (ifibss->fixed_bssid) { 720 memcpy(bssid, ifibss->bssid, ETH_ALEN); 721 } else { 722 /* Generate random, not broadcast, locally administered BSSID. Mix in 723 * own MAC address to make sure that devices that do not have proper 724 * random number generator get different BSSID. */ 725 get_random_bytes(bssid, ETH_ALEN); 726 for (i = 0; i < ETH_ALEN; i++) 727 bssid[i] ^= sdata->vif.addr[i]; 728 bssid[0] &= ~0x01; 729 bssid[0] |= 0x02; 730 } 731 732 sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid); 733 734 capability = WLAN_CAPABILITY_IBSS; 735 736 if (ifibss->privacy) 737 capability |= WLAN_CAPABILITY_PRIVACY; 738 else 739 sdata->drop_unencrypted = 0; 740 741 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 742 ifibss->channel, ifibss->basic_rates, 743 capability, 0, true); 744 } 745 746 /* 747 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 748 */ 749 750 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 751 { 752 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 753 struct ieee80211_local *local = sdata->local; 754 struct cfg80211_bss *cbss; 755 struct ieee80211_channel *chan = NULL; 756 const u8 *bssid = NULL; 757 int active_ibss; 758 u16 capability; 759 760 lockdep_assert_held(&ifibss->mtx); 761 762 active_ibss = ieee80211_sta_active_ibss(sdata); 763 ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss); 764 765 if (active_ibss) 766 return; 767 768 capability = WLAN_CAPABILITY_IBSS; 769 if (ifibss->privacy) 770 capability |= WLAN_CAPABILITY_PRIVACY; 771 if (ifibss->fixed_bssid) 772 bssid = ifibss->bssid; 773 if (ifibss->fixed_channel) 774 chan = ifibss->channel; 775 if (!is_zero_ether_addr(ifibss->bssid)) 776 bssid = ifibss->bssid; 777 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 778 ifibss->ssid, ifibss->ssid_len, 779 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 780 capability); 781 782 if (cbss) { 783 struct ieee80211_bss *bss; 784 785 bss = (void *)cbss->priv; 786 ibss_dbg(sdata, 787 "sta_find_ibss: selected %pM current %pM\n", 788 cbss->bssid, ifibss->bssid); 789 sdata_info(sdata, 790 "Selected IBSS BSSID %pM based on configured SSID\n", 791 cbss->bssid); 792 793 ieee80211_sta_join_ibss(sdata, bss); 794 ieee80211_rx_bss_put(local, bss); 795 return; 796 } 797 798 ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n"); 799 800 /* Selected IBSS not found in current scan results - try to scan */ 801 if (time_after(jiffies, ifibss->last_scan_completed + 802 IEEE80211_SCAN_INTERVAL)) { 803 sdata_info(sdata, "Trigger new scan to find an IBSS to join\n"); 804 805 ieee80211_request_ibss_scan(sdata, ifibss->ssid, 806 ifibss->ssid_len, chan); 807 } else { 808 int interval = IEEE80211_SCAN_INTERVAL; 809 810 if (time_after(jiffies, ifibss->ibss_join_req + 811 IEEE80211_IBSS_JOIN_TIMEOUT)) 812 ieee80211_sta_create_ibss(sdata); 813 814 mod_timer(&ifibss->timer, 815 round_jiffies(jiffies + interval)); 816 } 817 } 818 819 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 820 struct sk_buff *req) 821 { 822 struct ieee80211_mgmt *mgmt = (void *)req->data; 823 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 824 struct ieee80211_local *local = sdata->local; 825 int tx_last_beacon, len = req->len; 826 struct sk_buff *skb; 827 struct ieee80211_mgmt *resp; 828 struct sk_buff *presp; 829 u8 *pos, *end; 830 831 lockdep_assert_held(&ifibss->mtx); 832 833 presp = rcu_dereference_protected(ifibss->presp, 834 lockdep_is_held(&ifibss->mtx)); 835 836 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 837 len < 24 + 2 || !presp) 838 return; 839 840 tx_last_beacon = drv_tx_last_beacon(local); 841 842 ibss_dbg(sdata, 843 "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n", 844 mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon); 845 846 if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da)) 847 return; 848 849 if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) && 850 !is_broadcast_ether_addr(mgmt->bssid)) 851 return; 852 853 end = ((u8 *) mgmt) + len; 854 pos = mgmt->u.probe_req.variable; 855 if (pos[0] != WLAN_EID_SSID || 856 pos + 2 + pos[1] > end) { 857 ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n", 858 mgmt->sa); 859 return; 860 } 861 if (pos[1] != 0 && 862 (pos[1] != ifibss->ssid_len || 863 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 864 /* Ignore ProbeReq for foreign SSID */ 865 return; 866 } 867 868 /* Reply with ProbeResp */ 869 skb = skb_copy(presp, GFP_KERNEL); 870 if (!skb) 871 return; 872 873 resp = (struct ieee80211_mgmt *) skb->data; 874 memcpy(resp->da, mgmt->sa, ETH_ALEN); 875 ibss_dbg(sdata, "Sending ProbeResp to %pM\n", resp->da); 876 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 877 ieee80211_tx_skb(sdata, skb); 878 } 879 880 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, 881 struct ieee80211_mgmt *mgmt, 882 size_t len, 883 struct ieee80211_rx_status *rx_status) 884 { 885 size_t baselen; 886 struct ieee802_11_elems elems; 887 888 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 889 if (baselen > len) 890 return; 891 892 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 893 &elems); 894 895 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false); 896 } 897 898 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, 899 struct ieee80211_mgmt *mgmt, 900 size_t len, 901 struct ieee80211_rx_status *rx_status) 902 { 903 size_t baselen; 904 struct ieee802_11_elems elems; 905 906 /* Process beacon from the current BSS */ 907 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt; 908 if (baselen > len) 909 return; 910 911 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems); 912 913 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); 914 } 915 916 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 917 struct sk_buff *skb) 918 { 919 struct ieee80211_rx_status *rx_status; 920 struct ieee80211_mgmt *mgmt; 921 u16 fc; 922 923 rx_status = IEEE80211_SKB_RXCB(skb); 924 mgmt = (struct ieee80211_mgmt *) skb->data; 925 fc = le16_to_cpu(mgmt->frame_control); 926 927 mutex_lock(&sdata->u.ibss.mtx); 928 929 if (!sdata->u.ibss.ssid_len) 930 goto mgmt_out; /* not ready to merge yet */ 931 932 switch (fc & IEEE80211_FCTL_STYPE) { 933 case IEEE80211_STYPE_PROBE_REQ: 934 ieee80211_rx_mgmt_probe_req(sdata, skb); 935 break; 936 case IEEE80211_STYPE_PROBE_RESP: 937 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, 938 rx_status); 939 break; 940 case IEEE80211_STYPE_BEACON: 941 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, 942 rx_status); 943 break; 944 case IEEE80211_STYPE_AUTH: 945 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 946 break; 947 case IEEE80211_STYPE_DEAUTH: 948 ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len); 949 break; 950 } 951 952 mgmt_out: 953 mutex_unlock(&sdata->u.ibss.mtx); 954 } 955 956 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata) 957 { 958 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 959 struct sta_info *sta; 960 961 mutex_lock(&ifibss->mtx); 962 963 /* 964 * Work could be scheduled after scan or similar 965 * when we aren't even joined (or trying) with a 966 * network. 967 */ 968 if (!ifibss->ssid_len) 969 goto out; 970 971 spin_lock_bh(&ifibss->incomplete_lock); 972 while (!list_empty(&ifibss->incomplete_stations)) { 973 sta = list_first_entry(&ifibss->incomplete_stations, 974 struct sta_info, list); 975 list_del(&sta->list); 976 spin_unlock_bh(&ifibss->incomplete_lock); 977 978 ieee80211_ibss_finish_sta(sta, true); 979 rcu_read_unlock(); 980 spin_lock_bh(&ifibss->incomplete_lock); 981 } 982 spin_unlock_bh(&ifibss->incomplete_lock); 983 984 switch (ifibss->state) { 985 case IEEE80211_IBSS_MLME_SEARCH: 986 ieee80211_sta_find_ibss(sdata); 987 break; 988 case IEEE80211_IBSS_MLME_JOINED: 989 ieee80211_sta_merge_ibss(sdata); 990 break; 991 default: 992 WARN_ON(1); 993 break; 994 } 995 996 out: 997 mutex_unlock(&ifibss->mtx); 998 } 999 1000 static void ieee80211_ibss_timer(unsigned long data) 1001 { 1002 struct ieee80211_sub_if_data *sdata = 1003 (struct ieee80211_sub_if_data *) data; 1004 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1005 struct ieee80211_local *local = sdata->local; 1006 1007 if (local->quiescing) { 1008 ifibss->timer_running = true; 1009 return; 1010 } 1011 1012 ieee80211_queue_work(&local->hw, &sdata->work); 1013 } 1014 1015 #ifdef CONFIG_PM 1016 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata) 1017 { 1018 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1019 1020 if (del_timer_sync(&ifibss->timer)) 1021 ifibss->timer_running = true; 1022 } 1023 1024 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata) 1025 { 1026 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1027 1028 if (ifibss->timer_running) { 1029 add_timer(&ifibss->timer); 1030 ifibss->timer_running = false; 1031 } 1032 } 1033 #endif 1034 1035 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 1036 { 1037 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1038 1039 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 1040 (unsigned long) sdata); 1041 mutex_init(&ifibss->mtx); 1042 INIT_LIST_HEAD(&ifibss->incomplete_stations); 1043 spin_lock_init(&ifibss->incomplete_lock); 1044 } 1045 1046 /* scan finished notification */ 1047 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 1048 { 1049 struct ieee80211_sub_if_data *sdata; 1050 1051 mutex_lock(&local->iflist_mtx); 1052 list_for_each_entry(sdata, &local->interfaces, list) { 1053 if (!ieee80211_sdata_running(sdata)) 1054 continue; 1055 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 1056 continue; 1057 sdata->u.ibss.last_scan_completed = jiffies; 1058 ieee80211_queue_work(&local->hw, &sdata->work); 1059 } 1060 mutex_unlock(&local->iflist_mtx); 1061 } 1062 1063 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 1064 struct cfg80211_ibss_params *params) 1065 { 1066 struct sk_buff *skb; 1067 u32 changed = 0; 1068 1069 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom + 1070 sizeof(struct ieee80211_hdr_3addr) + 1071 12 /* struct ieee80211_mgmt.u.beacon */ + 1072 2 + IEEE80211_MAX_SSID_LEN /* max SSID */ + 1073 2 + 8 /* max Supported Rates */ + 1074 3 /* max DS params */ + 1075 4 /* IBSS params */ + 1076 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 1077 2 + sizeof(struct ieee80211_ht_cap) + 1078 2 + sizeof(struct ieee80211_ht_operation) + 1079 params->ie_len); 1080 if (!skb) 1081 return -ENOMEM; 1082 1083 mutex_lock(&sdata->u.ibss.mtx); 1084 1085 if (params->bssid) { 1086 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 1087 sdata->u.ibss.fixed_bssid = true; 1088 } else 1089 sdata->u.ibss.fixed_bssid = false; 1090 1091 sdata->u.ibss.privacy = params->privacy; 1092 sdata->u.ibss.control_port = params->control_port; 1093 sdata->u.ibss.basic_rates = params->basic_rates; 1094 memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate, 1095 sizeof(params->mcast_rate)); 1096 1097 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 1098 1099 sdata->u.ibss.channel = params->chandef.chan; 1100 sdata->u.ibss.channel_type = 1101 cfg80211_get_chandef_type(¶ms->chandef); 1102 sdata->u.ibss.fixed_channel = params->channel_fixed; 1103 1104 if (params->ie) { 1105 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 1106 GFP_KERNEL); 1107 if (sdata->u.ibss.ie) 1108 sdata->u.ibss.ie_len = params->ie_len; 1109 } 1110 1111 sdata->u.ibss.skb = skb; 1112 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1113 sdata->u.ibss.ibss_join_req = jiffies; 1114 1115 memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len); 1116 sdata->u.ibss.ssid_len = params->ssid_len; 1117 1118 mutex_unlock(&sdata->u.ibss.mtx); 1119 1120 mutex_lock(&sdata->local->mtx); 1121 ieee80211_recalc_idle(sdata->local); 1122 mutex_unlock(&sdata->local->mtx); 1123 1124 /* 1125 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is 1126 * reserved, but an HT STA shall protect HT transmissions as though 1127 * the HT Protection field were set to non-HT mixed mode. 1128 * 1129 * In an IBSS, the RIFS Mode field of the HT Operation element is 1130 * also reserved, but an HT STA shall operate as though this field 1131 * were set to 1. 1132 */ 1133 1134 sdata->vif.bss_conf.ht_operation_mode |= 1135 IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED 1136 | IEEE80211_HT_PARAM_RIFS_MODE; 1137 1138 changed |= BSS_CHANGED_HT; 1139 ieee80211_bss_info_change_notify(sdata, changed); 1140 1141 sdata->smps_mode = IEEE80211_SMPS_OFF; 1142 sdata->needed_rx_chains = sdata->local->rx_chains; 1143 1144 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1145 1146 return 0; 1147 } 1148 1149 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 1150 { 1151 struct sk_buff *skb; 1152 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1153 struct ieee80211_local *local = sdata->local; 1154 struct cfg80211_bss *cbss; 1155 u16 capability; 1156 int active_ibss; 1157 struct sta_info *sta; 1158 1159 mutex_lock(&sdata->u.ibss.mtx); 1160 1161 active_ibss = ieee80211_sta_active_ibss(sdata); 1162 1163 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) { 1164 capability = WLAN_CAPABILITY_IBSS; 1165 1166 if (ifibss->privacy) 1167 capability |= WLAN_CAPABILITY_PRIVACY; 1168 1169 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel, 1170 ifibss->bssid, ifibss->ssid, 1171 ifibss->ssid_len, WLAN_CAPABILITY_IBSS | 1172 WLAN_CAPABILITY_PRIVACY, 1173 capability); 1174 1175 if (cbss) { 1176 cfg80211_unlink_bss(local->hw.wiphy, cbss); 1177 cfg80211_put_bss(cbss); 1178 } 1179 } 1180 1181 ifibss->state = IEEE80211_IBSS_MLME_SEARCH; 1182 memset(ifibss->bssid, 0, ETH_ALEN); 1183 ifibss->ssid_len = 0; 1184 1185 sta_info_flush(sdata->local, sdata); 1186 1187 spin_lock_bh(&ifibss->incomplete_lock); 1188 while (!list_empty(&ifibss->incomplete_stations)) { 1189 sta = list_first_entry(&ifibss->incomplete_stations, 1190 struct sta_info, list); 1191 list_del(&sta->list); 1192 spin_unlock_bh(&ifibss->incomplete_lock); 1193 1194 sta_info_free(local, sta); 1195 spin_lock_bh(&ifibss->incomplete_lock); 1196 } 1197 spin_unlock_bh(&ifibss->incomplete_lock); 1198 1199 netif_carrier_off(sdata->dev); 1200 1201 /* remove beacon */ 1202 kfree(sdata->u.ibss.ie); 1203 skb = rcu_dereference_protected(sdata->u.ibss.presp, 1204 lockdep_is_held(&sdata->u.ibss.mtx)); 1205 RCU_INIT_POINTER(sdata->u.ibss.presp, NULL); 1206 sdata->vif.bss_conf.ibss_joined = false; 1207 sdata->vif.bss_conf.ibss_creator = false; 1208 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | 1209 BSS_CHANGED_IBSS); 1210 synchronize_rcu(); 1211 kfree_skb(skb); 1212 1213 skb_queue_purge(&sdata->skb_queue); 1214 1215 del_timer_sync(&sdata->u.ibss.timer); 1216 1217 mutex_unlock(&sdata->u.ibss.mtx); 1218 1219 mutex_lock(&local->mtx); 1220 ieee80211_recalc_idle(sdata->local); 1221 mutex_unlock(&local->mtx); 1222 1223 return 0; 1224 } 1225