ibss.c revision d6a83228823fc0cc8d79d95c9f0bf568b7317862
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 37static 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); 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.enable_beacon = true; 195 sdata->vif.bss_conf.beacon_int = beacon_int; 196 sdata->vif.bss_conf.basic_rates = basic_rates; 197 bss_change = BSS_CHANGED_BEACON_INT; 198 bss_change |= ieee80211_reset_erp_info(sdata); 199 bss_change |= BSS_CHANGED_BSSID; 200 bss_change |= BSS_CHANGED_BEACON; 201 bss_change |= BSS_CHANGED_BEACON_ENABLED; 202 bss_change |= BSS_CHANGED_BASIC_RATES; 203 bss_change |= BSS_CHANGED_HT; 204 bss_change |= BSS_CHANGED_IBSS; 205 206 /* 207 * In 5 GHz/802.11a, we can always use short slot time. 208 * (IEEE 802.11-2012 18.3.8.7) 209 * 210 * In 2.4GHz, we must always use long slots in IBSS for compatibility 211 * reasons. 212 * (IEEE 802.11-2012 19.4.5) 213 * 214 * HT follows these specifications (IEEE 802.11-2012 20.3.18) 215 */ 216 sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ; 217 bss_change |= BSS_CHANGED_ERP_SLOT; 218 219 sdata->vif.bss_conf.ibss_joined = true; 220 sdata->vif.bss_conf.ibss_creator = creator; 221 ieee80211_bss_info_change_notify(sdata, bss_change); 222 223 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 224 225 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 226 mod_timer(&ifibss->timer, 227 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 228 229 bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan, 230 mgmt, skb->len, 0, GFP_KERNEL); 231 cfg80211_put_bss(bss); 232 netif_carrier_on(sdata->dev); 233 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 234} 235 236static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 237 struct ieee80211_bss *bss) 238{ 239 struct cfg80211_bss *cbss = 240 container_of((void *)bss, struct cfg80211_bss, priv); 241 struct ieee80211_supported_band *sband; 242 u32 basic_rates; 243 int i, j; 244 u16 beacon_int = cbss->beacon_interval; 245 246 lockdep_assert_held(&sdata->u.ibss.mtx); 247 248 if (beacon_int < 10) 249 beacon_int = 10; 250 251 sband = sdata->local->hw.wiphy->bands[cbss->channel->band]; 252 253 basic_rates = 0; 254 255 for (i = 0; i < bss->supp_rates_len; i++) { 256 int rate = (bss->supp_rates[i] & 0x7f) * 5; 257 bool is_basic = !!(bss->supp_rates[i] & 0x80); 258 259 for (j = 0; j < sband->n_bitrates; j++) { 260 if (sband->bitrates[j].bitrate == rate) { 261 if (is_basic) 262 basic_rates |= BIT(j); 263 break; 264 } 265 } 266 } 267 268 __ieee80211_sta_join_ibss(sdata, cbss->bssid, 269 beacon_int, 270 cbss->channel, 271 basic_rates, 272 cbss->capability, 273 cbss->tsf, 274 false); 275} 276 277static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta, 278 bool auth) 279 __acquires(RCU) 280{ 281 struct ieee80211_sub_if_data *sdata = sta->sdata; 282 u8 addr[ETH_ALEN]; 283 284 memcpy(addr, sta->sta.addr, ETH_ALEN); 285 286 ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr); 287 288 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 289 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 290 /* authorize the station only if the network is not RSN protected. If 291 * not wait for the userspace to authorize it */ 292 if (!sta->sdata->u.ibss.control_port) 293 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 294 295 rate_control_rate_init(sta); 296 297 /* If it fails, maybe we raced another insertion? */ 298 if (sta_info_insert_rcu(sta)) 299 return sta_info_get(sdata, addr); 300 if (auth && !sdata->u.ibss.auth_frame_registrations) { 301 ibss_dbg(sdata, 302 "TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n", 303 sdata->vif.addr, addr, sdata->u.ibss.bssid); 304 ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, 0, NULL, 0, 305 addr, sdata->u.ibss.bssid, NULL, 0, 0); 306 } 307 return sta; 308} 309 310static struct sta_info * 311ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 312 const u8 *bssid, const u8 *addr, 313 u32 supp_rates, bool auth) 314 __acquires(RCU) 315{ 316 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 317 struct ieee80211_local *local = sdata->local; 318 struct sta_info *sta; 319 struct ieee80211_chanctx_conf *chanctx_conf; 320 int band; 321 322 /* 323 * XXX: Consider removing the least recently used entry and 324 * allow new one to be added. 325 */ 326 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 327 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 328 sdata->name, addr); 329 rcu_read_lock(); 330 return NULL; 331 } 332 333 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) { 334 rcu_read_lock(); 335 return NULL; 336 } 337 338 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) { 339 rcu_read_lock(); 340 return NULL; 341 } 342 343 rcu_read_lock(); 344 chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf); 345 if (WARN_ON_ONCE(!chanctx_conf)) 346 return NULL; 347 band = chanctx_conf->def.chan->band; 348 rcu_read_unlock(); 349 350 sta = sta_info_alloc(sdata, addr, GFP_KERNEL); 351 if (!sta) { 352 rcu_read_lock(); 353 return NULL; 354 } 355 356 sta->last_rx = jiffies; 357 358 /* make sure mandatory rates are always added */ 359 sta->sta.supp_rates[band] = supp_rates | 360 ieee80211_mandatory_rates(local, band); 361 362 return ieee80211_ibss_finish_sta(sta, auth); 363} 364 365static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata, 366 struct ieee80211_mgmt *mgmt, 367 size_t len) 368{ 369 u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code); 370 371 if (len < IEEE80211_DEAUTH_FRAME_LEN) 372 return; 373 374 ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n", 375 mgmt->sa, mgmt->da, mgmt->bssid, reason); 376 sta_info_destroy_addr(sdata, mgmt->sa); 377} 378 379static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, 380 struct ieee80211_mgmt *mgmt, 381 size_t len) 382{ 383 u16 auth_alg, auth_transaction; 384 struct sta_info *sta; 385 u8 deauth_frame_buf[IEEE80211_DEAUTH_FRAME_LEN]; 386 387 lockdep_assert_held(&sdata->u.ibss.mtx); 388 389 if (len < 24 + 6) 390 return; 391 392 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 393 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 394 395 ibss_dbg(sdata, 396 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n", 397 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction); 398 399 if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1) 400 return; 401 402 sta_info_destroy_addr(sdata, mgmt->sa); 403 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false); 404 rcu_read_unlock(); 405 406 /* 407 * if we have any problem in allocating the new station, we reply with a 408 * DEAUTH frame to tell the other end that we had a problem 409 */ 410 if (!sta) { 411 ieee80211_send_deauth_disassoc(sdata, sdata->u.ibss.bssid, 412 IEEE80211_STYPE_DEAUTH, 413 WLAN_REASON_UNSPECIFIED, true, 414 deauth_frame_buf); 415 return; 416 } 417 418 /* 419 * IEEE 802.11 standard does not require authentication in IBSS 420 * networks and most implementations do not seem to use it. 421 * However, try to reply to authentication attempts if someone 422 * has actually implemented this. 423 */ 424 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0, 425 mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0); 426} 427 428static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 429 struct ieee80211_mgmt *mgmt, size_t len, 430 struct ieee80211_rx_status *rx_status, 431 struct ieee802_11_elems *elems) 432{ 433 struct ieee80211_local *local = sdata->local; 434 int freq; 435 struct cfg80211_bss *cbss; 436 struct ieee80211_bss *bss; 437 struct sta_info *sta; 438 struct ieee80211_channel *channel; 439 u64 beacon_timestamp, rx_timestamp; 440 u32 supp_rates = 0; 441 enum ieee80211_band band = rx_status->band; 442 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 443 bool rates_updated = false; 444 445 if (elems->ds_params && elems->ds_params_len == 1) 446 freq = ieee80211_channel_to_frequency(elems->ds_params[0], 447 band); 448 else 449 freq = rx_status->freq; 450 451 channel = ieee80211_get_channel(local->hw.wiphy, freq); 452 453 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 454 return; 455 456 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && 457 ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) { 458 459 rcu_read_lock(); 460 sta = sta_info_get(sdata, mgmt->sa); 461 462 if (elems->supp_rates) { 463 supp_rates = ieee80211_sta_get_rates(local, elems, 464 band, NULL); 465 if (sta) { 466 u32 prev_rates; 467 468 prev_rates = sta->sta.supp_rates[band]; 469 /* make sure mandatory rates are always added */ 470 sta->sta.supp_rates[band] = supp_rates | 471 ieee80211_mandatory_rates(local, band); 472 473 if (sta->sta.supp_rates[band] != prev_rates) { 474 ibss_dbg(sdata, 475 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n", 476 sta->sta.addr, prev_rates, 477 sta->sta.supp_rates[band]); 478 rates_updated = true; 479 } 480 } else { 481 rcu_read_unlock(); 482 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, 483 mgmt->sa, supp_rates, true); 484 } 485 } 486 487 if (sta && elems->wmm_info) 488 set_sta_flag(sta, WLAN_STA_WME); 489 490 if (sta && elems->ht_operation && elems->ht_cap_elem && 491 sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) { 492 /* we both use HT */ 493 struct ieee80211_sta_ht_cap sta_ht_cap_new; 494 struct cfg80211_chan_def chandef; 495 496 ieee80211_ht_oper_to_chandef(channel, 497 elems->ht_operation, 498 &chandef); 499 500 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 501 elems->ht_cap_elem, 502 &sta_ht_cap_new); 503 504 /* 505 * fall back to HT20 if we don't use or use 506 * the other extension channel 507 */ 508 if (chandef.width != NL80211_CHAN_WIDTH_40 || 509 cfg80211_get_chandef_type(&chandef) != 510 sdata->u.ibss.channel_type) 511 sta_ht_cap_new.cap &= 512 ~IEEE80211_HT_CAP_SUP_WIDTH_20_40; 513 514 if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new, 515 sizeof(sta_ht_cap_new))) { 516 memcpy(&sta->sta.ht_cap, &sta_ht_cap_new, 517 sizeof(sta_ht_cap_new)); 518 rates_updated = true; 519 } 520 } 521 522 if (sta && rates_updated) { 523 drv_sta_rc_update(local, sdata, &sta->sta, 524 IEEE80211_RC_SUPP_RATES_CHANGED); 525 rate_control_rate_init(sta); 526 } 527 528 rcu_read_unlock(); 529 } 530 531 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 532 channel); 533 if (!bss) 534 return; 535 536 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 537 538 /* was just updated in ieee80211_bss_info_update */ 539 beacon_timestamp = cbss->tsf; 540 541 /* check if we need to merge IBSS */ 542 543 /* we use a fixed BSSID */ 544 if (sdata->u.ibss.fixed_bssid) 545 goto put_bss; 546 547 /* not an IBSS */ 548 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 549 goto put_bss; 550 551 /* different channel */ 552 if (sdata->u.ibss.fixed_channel && 553 sdata->u.ibss.channel != cbss->channel) 554 goto put_bss; 555 556 /* different SSID */ 557 if (elems->ssid_len != sdata->u.ibss.ssid_len || 558 memcmp(elems->ssid, sdata->u.ibss.ssid, 559 sdata->u.ibss.ssid_len)) 560 goto put_bss; 561 562 /* same BSSID */ 563 if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid)) 564 goto put_bss; 565 566 if (ieee80211_have_rx_timestamp(rx_status)) { 567 /* time when timestamp field was received */ 568 rx_timestamp = 569 ieee80211_calculate_rx_timestamp(local, rx_status, 570 len + FCS_LEN, 24); 571 } else { 572 /* 573 * second best option: get current TSF 574 * (will return -1 if not supported) 575 */ 576 rx_timestamp = drv_get_tsf(local, sdata); 577 } 578 579 ibss_dbg(sdata, 580 "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 581 mgmt->sa, mgmt->bssid, 582 (unsigned long long)rx_timestamp, 583 (unsigned long long)beacon_timestamp, 584 (unsigned long long)(rx_timestamp - beacon_timestamp), 585 jiffies); 586 587 if (beacon_timestamp > rx_timestamp) { 588 ibss_dbg(sdata, 589 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n", 590 mgmt->bssid); 591 ieee80211_sta_join_ibss(sdata, bss); 592 supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL); 593 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 594 supp_rates, true); 595 rcu_read_unlock(); 596 } 597 598 put_bss: 599 ieee80211_rx_bss_put(local, bss); 600} 601 602void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata, 603 const u8 *bssid, const u8 *addr, 604 u32 supp_rates) 605{ 606 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 607 struct ieee80211_local *local = sdata->local; 608 struct sta_info *sta; 609 struct ieee80211_chanctx_conf *chanctx_conf; 610 int band; 611 612 /* 613 * XXX: Consider removing the least recently used entry and 614 * allow new one to be added. 615 */ 616 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 617 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 618 sdata->name, addr); 619 return; 620 } 621 622 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 623 return; 624 625 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) 626 return; 627 628 rcu_read_lock(); 629 chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf); 630 if (WARN_ON_ONCE(!chanctx_conf)) { 631 rcu_read_unlock(); 632 return; 633 } 634 band = chanctx_conf->def.chan->band; 635 rcu_read_unlock(); 636 637 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC); 638 if (!sta) 639 return; 640 641 sta->last_rx = jiffies; 642 643 /* make sure mandatory rates are always added */ 644 sta->sta.supp_rates[band] = supp_rates | 645 ieee80211_mandatory_rates(local, band); 646 647 spin_lock(&ifibss->incomplete_lock); 648 list_add(&sta->list, &ifibss->incomplete_stations); 649 spin_unlock(&ifibss->incomplete_lock); 650 ieee80211_queue_work(&local->hw, &sdata->work); 651} 652 653static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 654{ 655 struct ieee80211_local *local = sdata->local; 656 int active = 0; 657 struct sta_info *sta; 658 659 lockdep_assert_held(&sdata->u.ibss.mtx); 660 661 rcu_read_lock(); 662 663 list_for_each_entry_rcu(sta, &local->sta_list, list) { 664 if (sta->sdata == sdata && 665 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 666 jiffies)) { 667 active++; 668 break; 669 } 670 } 671 672 rcu_read_unlock(); 673 674 return active; 675} 676 677/* 678 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 679 */ 680 681static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 682{ 683 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 684 685 lockdep_assert_held(&ifibss->mtx); 686 687 mod_timer(&ifibss->timer, 688 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 689 690 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 691 692 if (time_before(jiffies, ifibss->last_scan_completed + 693 IEEE80211_IBSS_MERGE_INTERVAL)) 694 return; 695 696 if (ieee80211_sta_active_ibss(sdata)) 697 return; 698 699 if (ifibss->fixed_channel) 700 return; 701 702 sdata_info(sdata, 703 "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n"); 704 705 ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len, 706 NULL); 707} 708 709static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 710{ 711 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 712 u8 bssid[ETH_ALEN]; 713 u16 capability; 714 int i; 715 716 lockdep_assert_held(&ifibss->mtx); 717 718 if (ifibss->fixed_bssid) { 719 memcpy(bssid, ifibss->bssid, ETH_ALEN); 720 } else { 721 /* Generate random, not broadcast, locally administered BSSID. Mix in 722 * own MAC address to make sure that devices that do not have proper 723 * random number generator get different BSSID. */ 724 get_random_bytes(bssid, ETH_ALEN); 725 for (i = 0; i < ETH_ALEN; i++) 726 bssid[i] ^= sdata->vif.addr[i]; 727 bssid[0] &= ~0x01; 728 bssid[0] |= 0x02; 729 } 730 731 sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid); 732 733 capability = WLAN_CAPABILITY_IBSS; 734 735 if (ifibss->privacy) 736 capability |= WLAN_CAPABILITY_PRIVACY; 737 else 738 sdata->drop_unencrypted = 0; 739 740 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 741 ifibss->channel, ifibss->basic_rates, 742 capability, 0, true); 743} 744 745/* 746 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 747 */ 748 749static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 750{ 751 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 752 struct ieee80211_local *local = sdata->local; 753 struct cfg80211_bss *cbss; 754 struct ieee80211_channel *chan = NULL; 755 const u8 *bssid = NULL; 756 int active_ibss; 757 u16 capability; 758 759 lockdep_assert_held(&ifibss->mtx); 760 761 active_ibss = ieee80211_sta_active_ibss(sdata); 762 ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss); 763 764 if (active_ibss) 765 return; 766 767 capability = WLAN_CAPABILITY_IBSS; 768 if (ifibss->privacy) 769 capability |= WLAN_CAPABILITY_PRIVACY; 770 if (ifibss->fixed_bssid) 771 bssid = ifibss->bssid; 772 if (ifibss->fixed_channel) 773 chan = ifibss->channel; 774 if (!is_zero_ether_addr(ifibss->bssid)) 775 bssid = ifibss->bssid; 776 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 777 ifibss->ssid, ifibss->ssid_len, 778 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 779 capability); 780 781 if (cbss) { 782 struct ieee80211_bss *bss; 783 784 bss = (void *)cbss->priv; 785 ibss_dbg(sdata, 786 "sta_find_ibss: selected %pM current %pM\n", 787 cbss->bssid, ifibss->bssid); 788 sdata_info(sdata, 789 "Selected IBSS BSSID %pM based on configured SSID\n", 790 cbss->bssid); 791 792 ieee80211_sta_join_ibss(sdata, bss); 793 ieee80211_rx_bss_put(local, bss); 794 return; 795 } 796 797 ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n"); 798 799 /* Selected IBSS not found in current scan results - try to scan */ 800 if (time_after(jiffies, ifibss->last_scan_completed + 801 IEEE80211_SCAN_INTERVAL)) { 802 sdata_info(sdata, "Trigger new scan to find an IBSS to join\n"); 803 804 ieee80211_request_ibss_scan(sdata, ifibss->ssid, 805 ifibss->ssid_len, chan); 806 } else { 807 int interval = IEEE80211_SCAN_INTERVAL; 808 809 if (time_after(jiffies, ifibss->ibss_join_req + 810 IEEE80211_IBSS_JOIN_TIMEOUT)) 811 ieee80211_sta_create_ibss(sdata); 812 813 mod_timer(&ifibss->timer, 814 round_jiffies(jiffies + interval)); 815 } 816} 817 818static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 819 struct sk_buff *req) 820{ 821 struct ieee80211_mgmt *mgmt = (void *)req->data; 822 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 823 struct ieee80211_local *local = sdata->local; 824 int tx_last_beacon, len = req->len; 825 struct sk_buff *skb; 826 struct ieee80211_mgmt *resp; 827 struct sk_buff *presp; 828 u8 *pos, *end; 829 830 lockdep_assert_held(&ifibss->mtx); 831 832 presp = rcu_dereference_protected(ifibss->presp, 833 lockdep_is_held(&ifibss->mtx)); 834 835 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 836 len < 24 + 2 || !presp) 837 return; 838 839 tx_last_beacon = drv_tx_last_beacon(local); 840 841 ibss_dbg(sdata, 842 "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n", 843 mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon); 844 845 if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da)) 846 return; 847 848 if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) && 849 !is_broadcast_ether_addr(mgmt->bssid)) 850 return; 851 852 end = ((u8 *) mgmt) + len; 853 pos = mgmt->u.probe_req.variable; 854 if (pos[0] != WLAN_EID_SSID || 855 pos + 2 + pos[1] > end) { 856 ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n", 857 mgmt->sa); 858 return; 859 } 860 if (pos[1] != 0 && 861 (pos[1] != ifibss->ssid_len || 862 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 863 /* Ignore ProbeReq for foreign SSID */ 864 return; 865 } 866 867 /* Reply with ProbeResp */ 868 skb = skb_copy(presp, GFP_KERNEL); 869 if (!skb) 870 return; 871 872 resp = (struct ieee80211_mgmt *) skb->data; 873 memcpy(resp->da, mgmt->sa, ETH_ALEN); 874 ibss_dbg(sdata, "Sending ProbeResp to %pM\n", resp->da); 875 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 876 ieee80211_tx_skb(sdata, skb); 877} 878 879static 880void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata, 881 struct ieee80211_mgmt *mgmt, size_t len, 882 struct ieee80211_rx_status *rx_status) 883{ 884 size_t baselen; 885 struct ieee802_11_elems elems; 886 887 BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) != 888 offsetof(typeof(mgmt->u.beacon), variable)); 889 890 /* 891 * either beacon or probe_resp but the variable field is at the 892 * same offset 893 */ 894 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 895 if (baselen > len) 896 return; 897 898 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 899 &elems); 900 901 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems); 902} 903 904void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 905 struct sk_buff *skb) 906{ 907 struct ieee80211_rx_status *rx_status; 908 struct ieee80211_mgmt *mgmt; 909 u16 fc; 910 911 rx_status = IEEE80211_SKB_RXCB(skb); 912 mgmt = (struct ieee80211_mgmt *) skb->data; 913 fc = le16_to_cpu(mgmt->frame_control); 914 915 mutex_lock(&sdata->u.ibss.mtx); 916 917 if (!sdata->u.ibss.ssid_len) 918 goto mgmt_out; /* not ready to merge yet */ 919 920 switch (fc & IEEE80211_FCTL_STYPE) { 921 case IEEE80211_STYPE_PROBE_REQ: 922 ieee80211_rx_mgmt_probe_req(sdata, skb); 923 break; 924 case IEEE80211_STYPE_PROBE_RESP: 925 case IEEE80211_STYPE_BEACON: 926 ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len, 927 rx_status); 928 break; 929 case IEEE80211_STYPE_AUTH: 930 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 931 break; 932 case IEEE80211_STYPE_DEAUTH: 933 ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len); 934 break; 935 } 936 937 mgmt_out: 938 mutex_unlock(&sdata->u.ibss.mtx); 939} 940 941void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata) 942{ 943 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 944 struct sta_info *sta; 945 946 mutex_lock(&ifibss->mtx); 947 948 /* 949 * Work could be scheduled after scan or similar 950 * when we aren't even joined (or trying) with a 951 * network. 952 */ 953 if (!ifibss->ssid_len) 954 goto out; 955 956 spin_lock_bh(&ifibss->incomplete_lock); 957 while (!list_empty(&ifibss->incomplete_stations)) { 958 sta = list_first_entry(&ifibss->incomplete_stations, 959 struct sta_info, list); 960 list_del(&sta->list); 961 spin_unlock_bh(&ifibss->incomplete_lock); 962 963 ieee80211_ibss_finish_sta(sta, true); 964 rcu_read_unlock(); 965 spin_lock_bh(&ifibss->incomplete_lock); 966 } 967 spin_unlock_bh(&ifibss->incomplete_lock); 968 969 switch (ifibss->state) { 970 case IEEE80211_IBSS_MLME_SEARCH: 971 ieee80211_sta_find_ibss(sdata); 972 break; 973 case IEEE80211_IBSS_MLME_JOINED: 974 ieee80211_sta_merge_ibss(sdata); 975 break; 976 default: 977 WARN_ON(1); 978 break; 979 } 980 981 out: 982 mutex_unlock(&ifibss->mtx); 983} 984 985static void ieee80211_ibss_timer(unsigned long data) 986{ 987 struct ieee80211_sub_if_data *sdata = 988 (struct ieee80211_sub_if_data *) data; 989 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 990 struct ieee80211_local *local = sdata->local; 991 992 if (local->quiescing) { 993 ifibss->timer_running = true; 994 return; 995 } 996 997 ieee80211_queue_work(&local->hw, &sdata->work); 998} 999 1000#ifdef CONFIG_PM 1001void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata) 1002{ 1003 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1004 1005 if (del_timer_sync(&ifibss->timer)) 1006 ifibss->timer_running = true; 1007} 1008 1009void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata) 1010{ 1011 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1012 1013 if (ifibss->timer_running) { 1014 add_timer(&ifibss->timer); 1015 ifibss->timer_running = false; 1016 } 1017} 1018#endif 1019 1020void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 1021{ 1022 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1023 1024 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 1025 (unsigned long) sdata); 1026 mutex_init(&ifibss->mtx); 1027 INIT_LIST_HEAD(&ifibss->incomplete_stations); 1028 spin_lock_init(&ifibss->incomplete_lock); 1029} 1030 1031/* scan finished notification */ 1032void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 1033{ 1034 struct ieee80211_sub_if_data *sdata; 1035 1036 mutex_lock(&local->iflist_mtx); 1037 list_for_each_entry(sdata, &local->interfaces, list) { 1038 if (!ieee80211_sdata_running(sdata)) 1039 continue; 1040 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 1041 continue; 1042 sdata->u.ibss.last_scan_completed = jiffies; 1043 ieee80211_queue_work(&local->hw, &sdata->work); 1044 } 1045 mutex_unlock(&local->iflist_mtx); 1046} 1047 1048int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 1049 struct cfg80211_ibss_params *params) 1050{ 1051 struct sk_buff *skb; 1052 u32 changed = 0; 1053 1054 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom + 1055 sizeof(struct ieee80211_hdr_3addr) + 1056 12 /* struct ieee80211_mgmt.u.beacon */ + 1057 2 + IEEE80211_MAX_SSID_LEN /* max SSID */ + 1058 2 + 8 /* max Supported Rates */ + 1059 3 /* max DS params */ + 1060 4 /* IBSS params */ + 1061 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 1062 2 + sizeof(struct ieee80211_ht_cap) + 1063 2 + sizeof(struct ieee80211_ht_operation) + 1064 params->ie_len); 1065 if (!skb) 1066 return -ENOMEM; 1067 1068 mutex_lock(&sdata->u.ibss.mtx); 1069 1070 if (params->bssid) { 1071 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 1072 sdata->u.ibss.fixed_bssid = true; 1073 } else 1074 sdata->u.ibss.fixed_bssid = false; 1075 1076 sdata->u.ibss.privacy = params->privacy; 1077 sdata->u.ibss.control_port = params->control_port; 1078 sdata->u.ibss.basic_rates = params->basic_rates; 1079 memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate, 1080 sizeof(params->mcast_rate)); 1081 1082 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 1083 1084 sdata->u.ibss.channel = params->chandef.chan; 1085 sdata->u.ibss.channel_type = 1086 cfg80211_get_chandef_type(¶ms->chandef); 1087 sdata->u.ibss.fixed_channel = params->channel_fixed; 1088 1089 if (params->ie) { 1090 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 1091 GFP_KERNEL); 1092 if (sdata->u.ibss.ie) 1093 sdata->u.ibss.ie_len = params->ie_len; 1094 } 1095 1096 sdata->u.ibss.skb = skb; 1097 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1098 sdata->u.ibss.ibss_join_req = jiffies; 1099 1100 memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len); 1101 sdata->u.ibss.ssid_len = params->ssid_len; 1102 1103 mutex_unlock(&sdata->u.ibss.mtx); 1104 1105 mutex_lock(&sdata->local->mtx); 1106 ieee80211_recalc_idle(sdata->local); 1107 mutex_unlock(&sdata->local->mtx); 1108 1109 /* 1110 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is 1111 * reserved, but an HT STA shall protect HT transmissions as though 1112 * the HT Protection field were set to non-HT mixed mode. 1113 * 1114 * In an IBSS, the RIFS Mode field of the HT Operation element is 1115 * also reserved, but an HT STA shall operate as though this field 1116 * were set to 1. 1117 */ 1118 1119 sdata->vif.bss_conf.ht_operation_mode |= 1120 IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED 1121 | IEEE80211_HT_PARAM_RIFS_MODE; 1122 1123 changed |= BSS_CHANGED_HT; 1124 ieee80211_bss_info_change_notify(sdata, changed); 1125 1126 sdata->smps_mode = IEEE80211_SMPS_OFF; 1127 sdata->needed_rx_chains = sdata->local->rx_chains; 1128 1129 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1130 1131 return 0; 1132} 1133 1134int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 1135{ 1136 struct sk_buff *skb; 1137 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1138 struct ieee80211_local *local = sdata->local; 1139 struct cfg80211_bss *cbss; 1140 u16 capability; 1141 int active_ibss; 1142 struct sta_info *sta; 1143 1144 mutex_lock(&sdata->u.ibss.mtx); 1145 1146 active_ibss = ieee80211_sta_active_ibss(sdata); 1147 1148 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) { 1149 capability = WLAN_CAPABILITY_IBSS; 1150 1151 if (ifibss->privacy) 1152 capability |= WLAN_CAPABILITY_PRIVACY; 1153 1154 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel, 1155 ifibss->bssid, ifibss->ssid, 1156 ifibss->ssid_len, WLAN_CAPABILITY_IBSS | 1157 WLAN_CAPABILITY_PRIVACY, 1158 capability); 1159 1160 if (cbss) { 1161 cfg80211_unlink_bss(local->hw.wiphy, cbss); 1162 cfg80211_put_bss(cbss); 1163 } 1164 } 1165 1166 ifibss->state = IEEE80211_IBSS_MLME_SEARCH; 1167 memset(ifibss->bssid, 0, ETH_ALEN); 1168 ifibss->ssid_len = 0; 1169 1170 sta_info_flush(sdata); 1171 1172 spin_lock_bh(&ifibss->incomplete_lock); 1173 while (!list_empty(&ifibss->incomplete_stations)) { 1174 sta = list_first_entry(&ifibss->incomplete_stations, 1175 struct sta_info, list); 1176 list_del(&sta->list); 1177 spin_unlock_bh(&ifibss->incomplete_lock); 1178 1179 sta_info_free(local, sta); 1180 spin_lock_bh(&ifibss->incomplete_lock); 1181 } 1182 spin_unlock_bh(&ifibss->incomplete_lock); 1183 1184 netif_carrier_off(sdata->dev); 1185 1186 /* remove beacon */ 1187 kfree(sdata->u.ibss.ie); 1188 skb = rcu_dereference_protected(sdata->u.ibss.presp, 1189 lockdep_is_held(&sdata->u.ibss.mtx)); 1190 RCU_INIT_POINTER(sdata->u.ibss.presp, NULL); 1191 sdata->vif.bss_conf.ibss_joined = false; 1192 sdata->vif.bss_conf.ibss_creator = false; 1193 sdata->vif.bss_conf.enable_beacon = false; 1194 clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state); 1195 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | 1196 BSS_CHANGED_IBSS); 1197 synchronize_rcu(); 1198 kfree_skb(skb); 1199 1200 skb_queue_purge(&sdata->skb_queue); 1201 1202 del_timer_sync(&sdata->u.ibss.timer); 1203 1204 mutex_unlock(&sdata->u.ibss.mtx); 1205 1206 mutex_lock(&local->mtx); 1207 ieee80211_recalc_idle(sdata->local); 1208 mutex_unlock(&local->mtx); 1209 1210 return 0; 1211} 1212