ibss.c revision 1cd8e88e17729f57a9c7f751103e522596bb5de2
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 ieee80211_mgmt *mgmt; 48 u8 *pos; 49 struct ieee80211_supported_band *sband; 50 struct cfg80211_bss *bss; 51 u32 bss_change; 52 u8 supp_rates[IEEE80211_MAX_SUPP_RATES]; 53 struct cfg80211_chan_def chandef; 54 struct beacon_data *presp; 55 int frame_len; 56 57 lockdep_assert_held(&ifibss->mtx); 58 59 /* Reset own TSF to allow time synchronization work. */ 60 drv_reset_tsf(local, sdata); 61 62 if (!ether_addr_equal(ifibss->bssid, bssid)) 63 sta_info_flush(sdata); 64 65 /* if merging, indicate to driver that we leave the old IBSS */ 66 if (sdata->vif.bss_conf.ibss_joined) { 67 sdata->vif.bss_conf.ibss_joined = false; 68 sdata->vif.bss_conf.ibss_creator = false; 69 sdata->vif.bss_conf.enable_beacon = false; 70 netif_carrier_off(sdata->dev); 71 ieee80211_bss_info_change_notify(sdata, 72 BSS_CHANGED_IBSS | 73 BSS_CHANGED_BEACON_ENABLED); 74 } 75 76 presp = rcu_dereference_protected(ifibss->presp, 77 lockdep_is_held(&ifibss->mtx)); 78 rcu_assign_pointer(ifibss->presp, NULL); 79 if (presp) 80 kfree_rcu(presp, rcu_head); 81 82 sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0; 83 84 cfg80211_chandef_create(&chandef, chan, ifibss->channel_type); 85 if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) { 86 chandef.width = NL80211_CHAN_WIDTH_20; 87 chandef.center_freq1 = chan->center_freq; 88 } 89 90 ieee80211_vif_release_channel(sdata); 91 if (ieee80211_vif_use_channel(sdata, &chandef, 92 ifibss->fixed_channel ? 93 IEEE80211_CHANCTX_SHARED : 94 IEEE80211_CHANCTX_EXCLUSIVE)) { 95 sdata_info(sdata, "Failed to join IBSS, no channel context\n"); 96 return; 97 } 98 99 memcpy(ifibss->bssid, bssid, ETH_ALEN); 100 101 sband = local->hw.wiphy->bands[chan->band]; 102 103 /* Build IBSS probe response */ 104 frame_len = sizeof(struct ieee80211_hdr_3addr) + 105 12 /* struct ieee80211_mgmt.u.beacon */ + 106 2 + IEEE80211_MAX_SSID_LEN /* max SSID */ + 107 2 + 8 /* max Supported Rates */ + 108 3 /* max DS params */ + 109 4 /* IBSS params */ + 110 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 111 2 + sizeof(struct ieee80211_ht_cap) + 112 2 + sizeof(struct ieee80211_ht_operation) + 113 ifibss->ie_len; 114 presp = kzalloc(sizeof(*presp) + frame_len, GFP_KERNEL); 115 if (!presp) 116 return; 117 118 presp->head = (void *)(presp + 1); 119 120 mgmt = (void *) presp->head; 121 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 122 IEEE80211_STYPE_PROBE_RESP); 123 eth_broadcast_addr(mgmt->da); 124 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 125 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN); 126 mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int); 127 mgmt->u.beacon.timestamp = cpu_to_le64(tsf); 128 mgmt->u.beacon.capab_info = cpu_to_le16(capability); 129 130 pos = (u8 *)mgmt + offsetof(struct ieee80211_mgmt, u.beacon.variable); 131 132 *pos++ = WLAN_EID_SSID; 133 *pos++ = ifibss->ssid_len; 134 memcpy(pos, ifibss->ssid, ifibss->ssid_len); 135 pos += ifibss->ssid_len; 136 137 rates = min_t(int, 8, sband->n_bitrates); 138 *pos++ = WLAN_EID_SUPP_RATES; 139 *pos++ = rates; 140 for (i = 0; i < rates; i++) { 141 int rate = sband->bitrates[i].bitrate; 142 u8 basic = 0; 143 if (basic_rates & BIT(i)) 144 basic = 0x80; 145 *pos++ = basic | (u8) (rate / 5); 146 } 147 148 if (sband->band == IEEE80211_BAND_2GHZ) { 149 *pos++ = WLAN_EID_DS_PARAMS; 150 *pos++ = 1; 151 *pos++ = ieee80211_frequency_to_channel(chan->center_freq); 152 } 153 154 *pos++ = WLAN_EID_IBSS_PARAMS; 155 *pos++ = 2; 156 /* FIX: set ATIM window based on scan results */ 157 *pos++ = 0; 158 *pos++ = 0; 159 160 if (sband->n_bitrates > 8) { 161 *pos++ = WLAN_EID_EXT_SUPP_RATES; 162 *pos++ = sband->n_bitrates - 8; 163 for (i = 8; i < sband->n_bitrates; i++) { 164 int rate = sband->bitrates[i].bitrate; 165 u8 basic = 0; 166 if (basic_rates & BIT(i)) 167 basic = 0x80; 168 *pos++ = basic | (u8) (rate / 5); 169 } 170 } 171 172 if (ifibss->ie_len) { 173 memcpy(pos, ifibss->ie, ifibss->ie_len); 174 pos += ifibss->ie_len; 175 } 176 177 /* add HT capability and information IEs */ 178 if (chandef.width != NL80211_CHAN_WIDTH_20_NOHT && 179 sband->ht_cap.ht_supported) { 180 pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, 181 sband->ht_cap.cap); 182 /* 183 * Note: According to 802.11n-2009 9.13.3.1, HT Protection 184 * field and RIFS Mode are reserved in IBSS mode, therefore 185 * keep them at 0 186 */ 187 pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap, 188 &chandef, 0); 189 } 190 191 if (local->hw.queues >= IEEE80211_NUM_ACS) { 192 *pos++ = WLAN_EID_VENDOR_SPECIFIC; 193 *pos++ = 7; /* len */ 194 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */ 195 *pos++ = 0x50; 196 *pos++ = 0xf2; 197 *pos++ = 2; /* WME */ 198 *pos++ = 0; /* WME info */ 199 *pos++ = 1; /* WME ver */ 200 *pos++ = 0; /* U-APSD no in use */ 201 } 202 203 presp->head_len = pos - presp->head; 204 if (WARN_ON(presp->head_len > frame_len)) 205 return; 206 207 rcu_assign_pointer(ifibss->presp, presp); 208 209 sdata->vif.bss_conf.enable_beacon = true; 210 sdata->vif.bss_conf.beacon_int = beacon_int; 211 sdata->vif.bss_conf.basic_rates = basic_rates; 212 bss_change = BSS_CHANGED_BEACON_INT; 213 bss_change |= ieee80211_reset_erp_info(sdata); 214 bss_change |= BSS_CHANGED_BSSID; 215 bss_change |= BSS_CHANGED_BEACON; 216 bss_change |= BSS_CHANGED_BEACON_ENABLED; 217 bss_change |= BSS_CHANGED_BASIC_RATES; 218 bss_change |= BSS_CHANGED_HT; 219 bss_change |= BSS_CHANGED_IBSS; 220 221 /* 222 * In 5 GHz/802.11a, we can always use short slot time. 223 * (IEEE 802.11-2012 18.3.8.7) 224 * 225 * In 2.4GHz, we must always use long slots in IBSS for compatibility 226 * reasons. 227 * (IEEE 802.11-2012 19.4.5) 228 * 229 * HT follows these specifications (IEEE 802.11-2012 20.3.18) 230 */ 231 sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ; 232 bss_change |= BSS_CHANGED_ERP_SLOT; 233 234 sdata->vif.bss_conf.ibss_joined = true; 235 sdata->vif.bss_conf.ibss_creator = creator; 236 ieee80211_bss_info_change_notify(sdata, bss_change); 237 238 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 239 240 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 241 mod_timer(&ifibss->timer, 242 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 243 244 bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan, 245 mgmt, presp->head_len, 0, GFP_KERNEL); 246 cfg80211_put_bss(local->hw.wiphy, bss); 247 netif_carrier_on(sdata->dev); 248 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 249} 250 251static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 252 struct ieee80211_bss *bss) 253{ 254 struct cfg80211_bss *cbss = 255 container_of((void *)bss, struct cfg80211_bss, priv); 256 struct ieee80211_supported_band *sband; 257 u32 basic_rates; 258 int i, j; 259 u16 beacon_int = cbss->beacon_interval; 260 const struct cfg80211_bss_ies *ies; 261 u64 tsf; 262 263 lockdep_assert_held(&sdata->u.ibss.mtx); 264 265 if (beacon_int < 10) 266 beacon_int = 10; 267 268 sband = sdata->local->hw.wiphy->bands[cbss->channel->band]; 269 270 basic_rates = 0; 271 272 for (i = 0; i < bss->supp_rates_len; i++) { 273 int rate = (bss->supp_rates[i] & 0x7f) * 5; 274 bool is_basic = !!(bss->supp_rates[i] & 0x80); 275 276 for (j = 0; j < sband->n_bitrates; j++) { 277 if (sband->bitrates[j].bitrate == rate) { 278 if (is_basic) 279 basic_rates |= BIT(j); 280 break; 281 } 282 } 283 } 284 285 rcu_read_lock(); 286 ies = rcu_dereference(cbss->ies); 287 tsf = ies->tsf; 288 rcu_read_unlock(); 289 290 __ieee80211_sta_join_ibss(sdata, cbss->bssid, 291 beacon_int, 292 cbss->channel, 293 basic_rates, 294 cbss->capability, 295 tsf, false); 296} 297 298static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta, 299 bool auth) 300 __acquires(RCU) 301{ 302 struct ieee80211_sub_if_data *sdata = sta->sdata; 303 u8 addr[ETH_ALEN]; 304 305 memcpy(addr, sta->sta.addr, ETH_ALEN); 306 307 ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr); 308 309 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 310 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 311 /* authorize the station only if the network is not RSN protected. If 312 * not wait for the userspace to authorize it */ 313 if (!sta->sdata->u.ibss.control_port) 314 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 315 316 rate_control_rate_init(sta); 317 318 /* If it fails, maybe we raced another insertion? */ 319 if (sta_info_insert_rcu(sta)) 320 return sta_info_get(sdata, addr); 321 if (auth && !sdata->u.ibss.auth_frame_registrations) { 322 ibss_dbg(sdata, 323 "TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n", 324 sdata->vif.addr, addr, sdata->u.ibss.bssid); 325 ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, 0, NULL, 0, 326 addr, sdata->u.ibss.bssid, NULL, 0, 0, 0); 327 } 328 return sta; 329} 330 331static struct sta_info * 332ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 333 const u8 *bssid, const u8 *addr, 334 u32 supp_rates, bool auth) 335 __acquires(RCU) 336{ 337 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 338 struct ieee80211_local *local = sdata->local; 339 struct sta_info *sta; 340 struct ieee80211_chanctx_conf *chanctx_conf; 341 int band; 342 343 /* 344 * XXX: Consider removing the least recently used entry and 345 * allow new one to be added. 346 */ 347 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 348 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 349 sdata->name, addr); 350 rcu_read_lock(); 351 return NULL; 352 } 353 354 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) { 355 rcu_read_lock(); 356 return NULL; 357 } 358 359 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) { 360 rcu_read_lock(); 361 return NULL; 362 } 363 364 rcu_read_lock(); 365 chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf); 366 if (WARN_ON_ONCE(!chanctx_conf)) 367 return NULL; 368 band = chanctx_conf->def.chan->band; 369 rcu_read_unlock(); 370 371 sta = sta_info_alloc(sdata, addr, GFP_KERNEL); 372 if (!sta) { 373 rcu_read_lock(); 374 return NULL; 375 } 376 377 sta->last_rx = jiffies; 378 379 /* make sure mandatory rates are always added */ 380 sta->sta.supp_rates[band] = supp_rates | 381 ieee80211_mandatory_rates(local, band); 382 383 return ieee80211_ibss_finish_sta(sta, auth); 384} 385 386static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata, 387 struct ieee80211_mgmt *mgmt, 388 size_t len) 389{ 390 u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code); 391 392 if (len < IEEE80211_DEAUTH_FRAME_LEN) 393 return; 394 395 ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n", 396 mgmt->sa, mgmt->da, mgmt->bssid, reason); 397 sta_info_destroy_addr(sdata, mgmt->sa); 398} 399 400static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, 401 struct ieee80211_mgmt *mgmt, 402 size_t len) 403{ 404 u16 auth_alg, auth_transaction; 405 struct sta_info *sta; 406 u8 deauth_frame_buf[IEEE80211_DEAUTH_FRAME_LEN]; 407 408 lockdep_assert_held(&sdata->u.ibss.mtx); 409 410 if (len < 24 + 6) 411 return; 412 413 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 414 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 415 416 ibss_dbg(sdata, 417 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n", 418 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction); 419 420 if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1) 421 return; 422 423 sta_info_destroy_addr(sdata, mgmt->sa); 424 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false); 425 rcu_read_unlock(); 426 427 /* 428 * if we have any problem in allocating the new station, we reply with a 429 * DEAUTH frame to tell the other end that we had a problem 430 */ 431 if (!sta) { 432 ieee80211_send_deauth_disassoc(sdata, sdata->u.ibss.bssid, 433 IEEE80211_STYPE_DEAUTH, 434 WLAN_REASON_UNSPECIFIED, true, 435 deauth_frame_buf); 436 return; 437 } 438 439 /* 440 * IEEE 802.11 standard does not require authentication in IBSS 441 * networks and most implementations do not seem to use it. 442 * However, try to reply to authentication attempts if someone 443 * has actually implemented this. 444 */ 445 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0, 446 mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0); 447} 448 449static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 450 struct ieee80211_mgmt *mgmt, size_t len, 451 struct ieee80211_rx_status *rx_status, 452 struct ieee802_11_elems *elems) 453{ 454 struct ieee80211_local *local = sdata->local; 455 int freq; 456 struct cfg80211_bss *cbss; 457 struct ieee80211_bss *bss; 458 struct sta_info *sta; 459 struct ieee80211_channel *channel; 460 u64 beacon_timestamp, rx_timestamp; 461 u32 supp_rates = 0; 462 enum ieee80211_band band = rx_status->band; 463 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 464 bool rates_updated = false; 465 466 if (elems->ds_params) 467 freq = ieee80211_channel_to_frequency(elems->ds_params[0], 468 band); 469 else 470 freq = rx_status->freq; 471 472 channel = ieee80211_get_channel(local->hw.wiphy, freq); 473 474 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 475 return; 476 477 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && 478 ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) { 479 480 rcu_read_lock(); 481 sta = sta_info_get(sdata, mgmt->sa); 482 483 if (elems->supp_rates) { 484 supp_rates = ieee80211_sta_get_rates(local, elems, 485 band, NULL); 486 if (sta) { 487 u32 prev_rates; 488 489 prev_rates = sta->sta.supp_rates[band]; 490 /* make sure mandatory rates are always added */ 491 sta->sta.supp_rates[band] = supp_rates | 492 ieee80211_mandatory_rates(local, band); 493 494 if (sta->sta.supp_rates[band] != prev_rates) { 495 ibss_dbg(sdata, 496 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n", 497 sta->sta.addr, prev_rates, 498 sta->sta.supp_rates[band]); 499 rates_updated = true; 500 } 501 } else { 502 rcu_read_unlock(); 503 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, 504 mgmt->sa, supp_rates, true); 505 } 506 } 507 508 if (sta && elems->wmm_info) 509 set_sta_flag(sta, WLAN_STA_WME); 510 511 if (sta && elems->ht_operation && elems->ht_cap_elem && 512 sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) { 513 /* we both use HT */ 514 struct ieee80211_ht_cap htcap_ie; 515 struct cfg80211_chan_def chandef; 516 517 ieee80211_ht_oper_to_chandef(channel, 518 elems->ht_operation, 519 &chandef); 520 521 memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie)); 522 523 /* 524 * fall back to HT20 if we don't use or use 525 * the other extension channel 526 */ 527 if (cfg80211_get_chandef_type(&chandef) != 528 sdata->u.ibss.channel_type) 529 htcap_ie.cap_info &= 530 cpu_to_le16(~IEEE80211_HT_CAP_SUP_WIDTH_20_40); 531 532 rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap( 533 sdata, sband, &htcap_ie, sta); 534 } 535 536 if (sta && rates_updated) { 537 drv_sta_rc_update(local, sdata, &sta->sta, 538 IEEE80211_RC_SUPP_RATES_CHANGED); 539 rate_control_rate_init(sta); 540 } 541 542 rcu_read_unlock(); 543 } 544 545 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 546 channel); 547 if (!bss) 548 return; 549 550 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 551 552 /* same for beacon and probe response */ 553 beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp); 554 555 /* check if we need to merge IBSS */ 556 557 /* we use a fixed BSSID */ 558 if (sdata->u.ibss.fixed_bssid) 559 goto put_bss; 560 561 /* not an IBSS */ 562 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 563 goto put_bss; 564 565 /* different channel */ 566 if (sdata->u.ibss.fixed_channel && 567 sdata->u.ibss.channel != cbss->channel) 568 goto put_bss; 569 570 /* different SSID */ 571 if (elems->ssid_len != sdata->u.ibss.ssid_len || 572 memcmp(elems->ssid, sdata->u.ibss.ssid, 573 sdata->u.ibss.ssid_len)) 574 goto put_bss; 575 576 /* same BSSID */ 577 if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid)) 578 goto put_bss; 579 580 if (ieee80211_have_rx_timestamp(rx_status)) { 581 /* time when timestamp field was received */ 582 rx_timestamp = 583 ieee80211_calculate_rx_timestamp(local, rx_status, 584 len + FCS_LEN, 24); 585 } else { 586 /* 587 * second best option: get current TSF 588 * (will return -1 if not supported) 589 */ 590 rx_timestamp = drv_get_tsf(local, sdata); 591 } 592 593 ibss_dbg(sdata, 594 "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 595 mgmt->sa, mgmt->bssid, 596 (unsigned long long)rx_timestamp, 597 (unsigned long long)beacon_timestamp, 598 (unsigned long long)(rx_timestamp - beacon_timestamp), 599 jiffies); 600 601 if (beacon_timestamp > rx_timestamp) { 602 ibss_dbg(sdata, 603 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n", 604 mgmt->bssid); 605 ieee80211_sta_join_ibss(sdata, bss); 606 supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL); 607 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 608 supp_rates, true); 609 rcu_read_unlock(); 610 } 611 612 put_bss: 613 ieee80211_rx_bss_put(local, bss); 614} 615 616void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata, 617 const u8 *bssid, const u8 *addr, 618 u32 supp_rates) 619{ 620 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 621 struct ieee80211_local *local = sdata->local; 622 struct sta_info *sta; 623 struct ieee80211_chanctx_conf *chanctx_conf; 624 int band; 625 626 /* 627 * XXX: Consider removing the least recently used entry and 628 * allow new one to be added. 629 */ 630 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 631 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 632 sdata->name, addr); 633 return; 634 } 635 636 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 637 return; 638 639 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) 640 return; 641 642 rcu_read_lock(); 643 chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf); 644 if (WARN_ON_ONCE(!chanctx_conf)) { 645 rcu_read_unlock(); 646 return; 647 } 648 band = chanctx_conf->def.chan->band; 649 rcu_read_unlock(); 650 651 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC); 652 if (!sta) 653 return; 654 655 sta->last_rx = jiffies; 656 657 /* make sure mandatory rates are always added */ 658 sta->sta.supp_rates[band] = supp_rates | 659 ieee80211_mandatory_rates(local, band); 660 661 spin_lock(&ifibss->incomplete_lock); 662 list_add(&sta->list, &ifibss->incomplete_stations); 663 spin_unlock(&ifibss->incomplete_lock); 664 ieee80211_queue_work(&local->hw, &sdata->work); 665} 666 667static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 668{ 669 struct ieee80211_local *local = sdata->local; 670 int active = 0; 671 struct sta_info *sta; 672 673 lockdep_assert_held(&sdata->u.ibss.mtx); 674 675 rcu_read_lock(); 676 677 list_for_each_entry_rcu(sta, &local->sta_list, list) { 678 if (sta->sdata == sdata && 679 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 680 jiffies)) { 681 active++; 682 break; 683 } 684 } 685 686 rcu_read_unlock(); 687 688 return active; 689} 690 691/* 692 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 693 */ 694 695static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 696{ 697 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 698 699 lockdep_assert_held(&ifibss->mtx); 700 701 mod_timer(&ifibss->timer, 702 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 703 704 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 705 706 if (time_before(jiffies, ifibss->last_scan_completed + 707 IEEE80211_IBSS_MERGE_INTERVAL)) 708 return; 709 710 if (ieee80211_sta_active_ibss(sdata)) 711 return; 712 713 if (ifibss->fixed_channel) 714 return; 715 716 sdata_info(sdata, 717 "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n"); 718 719 ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len, 720 NULL); 721} 722 723static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 724{ 725 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 726 u8 bssid[ETH_ALEN]; 727 u16 capability; 728 int i; 729 730 lockdep_assert_held(&ifibss->mtx); 731 732 if (ifibss->fixed_bssid) { 733 memcpy(bssid, ifibss->bssid, ETH_ALEN); 734 } else { 735 /* Generate random, not broadcast, locally administered BSSID. Mix in 736 * own MAC address to make sure that devices that do not have proper 737 * random number generator get different BSSID. */ 738 get_random_bytes(bssid, ETH_ALEN); 739 for (i = 0; i < ETH_ALEN; i++) 740 bssid[i] ^= sdata->vif.addr[i]; 741 bssid[0] &= ~0x01; 742 bssid[0] |= 0x02; 743 } 744 745 sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid); 746 747 capability = WLAN_CAPABILITY_IBSS; 748 749 if (ifibss->privacy) 750 capability |= WLAN_CAPABILITY_PRIVACY; 751 else 752 sdata->drop_unencrypted = 0; 753 754 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 755 ifibss->channel, ifibss->basic_rates, 756 capability, 0, true); 757} 758 759/* 760 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 761 */ 762 763static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 764{ 765 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 766 struct ieee80211_local *local = sdata->local; 767 struct cfg80211_bss *cbss; 768 struct ieee80211_channel *chan = NULL; 769 const u8 *bssid = NULL; 770 int active_ibss; 771 u16 capability; 772 773 lockdep_assert_held(&ifibss->mtx); 774 775 active_ibss = ieee80211_sta_active_ibss(sdata); 776 ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss); 777 778 if (active_ibss) 779 return; 780 781 capability = WLAN_CAPABILITY_IBSS; 782 if (ifibss->privacy) 783 capability |= WLAN_CAPABILITY_PRIVACY; 784 if (ifibss->fixed_bssid) 785 bssid = ifibss->bssid; 786 if (ifibss->fixed_channel) 787 chan = ifibss->channel; 788 if (!is_zero_ether_addr(ifibss->bssid)) 789 bssid = ifibss->bssid; 790 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 791 ifibss->ssid, ifibss->ssid_len, 792 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 793 capability); 794 795 if (cbss) { 796 struct ieee80211_bss *bss; 797 798 bss = (void *)cbss->priv; 799 ibss_dbg(sdata, 800 "sta_find_ibss: selected %pM current %pM\n", 801 cbss->bssid, ifibss->bssid); 802 sdata_info(sdata, 803 "Selected IBSS BSSID %pM based on configured SSID\n", 804 cbss->bssid); 805 806 ieee80211_sta_join_ibss(sdata, bss); 807 ieee80211_rx_bss_put(local, bss); 808 return; 809 } 810 811 ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n"); 812 813 /* Selected IBSS not found in current scan results - try to scan */ 814 if (time_after(jiffies, ifibss->last_scan_completed + 815 IEEE80211_SCAN_INTERVAL)) { 816 sdata_info(sdata, "Trigger new scan to find an IBSS to join\n"); 817 818 ieee80211_request_ibss_scan(sdata, ifibss->ssid, 819 ifibss->ssid_len, chan); 820 } else { 821 int interval = IEEE80211_SCAN_INTERVAL; 822 823 if (time_after(jiffies, ifibss->ibss_join_req + 824 IEEE80211_IBSS_JOIN_TIMEOUT)) 825 ieee80211_sta_create_ibss(sdata); 826 827 mod_timer(&ifibss->timer, 828 round_jiffies(jiffies + interval)); 829 } 830} 831 832static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 833 struct sk_buff *req) 834{ 835 struct ieee80211_mgmt *mgmt = (void *)req->data; 836 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 837 struct ieee80211_local *local = sdata->local; 838 int tx_last_beacon, len = req->len; 839 struct sk_buff *skb; 840 struct beacon_data *presp; 841 u8 *pos, *end; 842 843 lockdep_assert_held(&ifibss->mtx); 844 845 presp = rcu_dereference_protected(ifibss->presp, 846 lockdep_is_held(&ifibss->mtx)); 847 848 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 849 len < 24 + 2 || !presp) 850 return; 851 852 tx_last_beacon = drv_tx_last_beacon(local); 853 854 ibss_dbg(sdata, 855 "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n", 856 mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon); 857 858 if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da)) 859 return; 860 861 if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) && 862 !is_broadcast_ether_addr(mgmt->bssid)) 863 return; 864 865 end = ((u8 *) mgmt) + len; 866 pos = mgmt->u.probe_req.variable; 867 if (pos[0] != WLAN_EID_SSID || 868 pos + 2 + pos[1] > end) { 869 ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n", 870 mgmt->sa); 871 return; 872 } 873 if (pos[1] != 0 && 874 (pos[1] != ifibss->ssid_len || 875 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 876 /* Ignore ProbeReq for foreign SSID */ 877 return; 878 } 879 880 /* Reply with ProbeResp */ 881 skb = dev_alloc_skb(local->tx_headroom + presp->head_len); 882 if (!skb) 883 return; 884 885 skb_reserve(skb, local->tx_headroom); 886 memcpy(skb_put(skb, presp->head_len), presp->head, presp->head_len); 887 888 memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN); 889 ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa); 890 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 891 ieee80211_tx_skb(sdata, skb); 892} 893 894static 895void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata, 896 struct ieee80211_mgmt *mgmt, size_t len, 897 struct ieee80211_rx_status *rx_status) 898{ 899 size_t baselen; 900 struct ieee802_11_elems elems; 901 902 BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) != 903 offsetof(typeof(mgmt->u.beacon), variable)); 904 905 /* 906 * either beacon or probe_resp but the variable field is at the 907 * same offset 908 */ 909 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 910 if (baselen > len) 911 return; 912 913 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 914 &elems); 915 916 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems); 917} 918 919void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 920 struct sk_buff *skb) 921{ 922 struct ieee80211_rx_status *rx_status; 923 struct ieee80211_mgmt *mgmt; 924 u16 fc; 925 926 rx_status = IEEE80211_SKB_RXCB(skb); 927 mgmt = (struct ieee80211_mgmt *) skb->data; 928 fc = le16_to_cpu(mgmt->frame_control); 929 930 mutex_lock(&sdata->u.ibss.mtx); 931 932 if (!sdata->u.ibss.ssid_len) 933 goto mgmt_out; /* not ready to merge yet */ 934 935 switch (fc & IEEE80211_FCTL_STYPE) { 936 case IEEE80211_STYPE_PROBE_REQ: 937 ieee80211_rx_mgmt_probe_req(sdata, skb); 938 break; 939 case IEEE80211_STYPE_PROBE_RESP: 940 case IEEE80211_STYPE_BEACON: 941 ieee80211_rx_mgmt_probe_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 956void 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 1000static void ieee80211_ibss_timer(unsigned long data) 1001{ 1002 struct ieee80211_sub_if_data *sdata = 1003 (struct ieee80211_sub_if_data *) data; 1004 1005 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1006} 1007 1008void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 1009{ 1010 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1011 1012 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 1013 (unsigned long) sdata); 1014 mutex_init(&ifibss->mtx); 1015 INIT_LIST_HEAD(&ifibss->incomplete_stations); 1016 spin_lock_init(&ifibss->incomplete_lock); 1017} 1018 1019/* scan finished notification */ 1020void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 1021{ 1022 struct ieee80211_sub_if_data *sdata; 1023 1024 mutex_lock(&local->iflist_mtx); 1025 list_for_each_entry(sdata, &local->interfaces, list) { 1026 if (!ieee80211_sdata_running(sdata)) 1027 continue; 1028 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 1029 continue; 1030 sdata->u.ibss.last_scan_completed = jiffies; 1031 ieee80211_queue_work(&local->hw, &sdata->work); 1032 } 1033 mutex_unlock(&local->iflist_mtx); 1034} 1035 1036int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 1037 struct cfg80211_ibss_params *params) 1038{ 1039 u32 changed = 0; 1040 1041 mutex_lock(&sdata->u.ibss.mtx); 1042 1043 if (params->bssid) { 1044 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 1045 sdata->u.ibss.fixed_bssid = true; 1046 } else 1047 sdata->u.ibss.fixed_bssid = false; 1048 1049 sdata->u.ibss.privacy = params->privacy; 1050 sdata->u.ibss.control_port = params->control_port; 1051 sdata->u.ibss.basic_rates = params->basic_rates; 1052 memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate, 1053 sizeof(params->mcast_rate)); 1054 1055 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 1056 1057 sdata->u.ibss.channel = params->chandef.chan; 1058 sdata->u.ibss.channel_type = 1059 cfg80211_get_chandef_type(¶ms->chandef); 1060 sdata->u.ibss.fixed_channel = params->channel_fixed; 1061 1062 if (params->ie) { 1063 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 1064 GFP_KERNEL); 1065 if (sdata->u.ibss.ie) 1066 sdata->u.ibss.ie_len = params->ie_len; 1067 } 1068 1069 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1070 sdata->u.ibss.ibss_join_req = jiffies; 1071 1072 memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len); 1073 sdata->u.ibss.ssid_len = params->ssid_len; 1074 1075 mutex_unlock(&sdata->u.ibss.mtx); 1076 1077 /* 1078 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is 1079 * reserved, but an HT STA shall protect HT transmissions as though 1080 * the HT Protection field were set to non-HT mixed mode. 1081 * 1082 * In an IBSS, the RIFS Mode field of the HT Operation element is 1083 * also reserved, but an HT STA shall operate as though this field 1084 * were set to 1. 1085 */ 1086 1087 sdata->vif.bss_conf.ht_operation_mode |= 1088 IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED 1089 | IEEE80211_HT_PARAM_RIFS_MODE; 1090 1091 changed |= BSS_CHANGED_HT; 1092 ieee80211_bss_info_change_notify(sdata, changed); 1093 1094 sdata->smps_mode = IEEE80211_SMPS_OFF; 1095 sdata->needed_rx_chains = sdata->local->rx_chains; 1096 1097 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1098 1099 return 0; 1100} 1101 1102int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 1103{ 1104 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1105 struct ieee80211_local *local = sdata->local; 1106 struct cfg80211_bss *cbss; 1107 u16 capability; 1108 int active_ibss; 1109 struct sta_info *sta; 1110 struct beacon_data *presp; 1111 1112 mutex_lock(&sdata->u.ibss.mtx); 1113 1114 active_ibss = ieee80211_sta_active_ibss(sdata); 1115 1116 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) { 1117 capability = WLAN_CAPABILITY_IBSS; 1118 1119 if (ifibss->privacy) 1120 capability |= WLAN_CAPABILITY_PRIVACY; 1121 1122 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel, 1123 ifibss->bssid, ifibss->ssid, 1124 ifibss->ssid_len, WLAN_CAPABILITY_IBSS | 1125 WLAN_CAPABILITY_PRIVACY, 1126 capability); 1127 1128 if (cbss) { 1129 cfg80211_unlink_bss(local->hw.wiphy, cbss); 1130 cfg80211_put_bss(local->hw.wiphy, cbss); 1131 } 1132 } 1133 1134 ifibss->state = IEEE80211_IBSS_MLME_SEARCH; 1135 memset(ifibss->bssid, 0, ETH_ALEN); 1136 ifibss->ssid_len = 0; 1137 1138 sta_info_flush(sdata); 1139 1140 spin_lock_bh(&ifibss->incomplete_lock); 1141 while (!list_empty(&ifibss->incomplete_stations)) { 1142 sta = list_first_entry(&ifibss->incomplete_stations, 1143 struct sta_info, list); 1144 list_del(&sta->list); 1145 spin_unlock_bh(&ifibss->incomplete_lock); 1146 1147 sta_info_free(local, sta); 1148 spin_lock_bh(&ifibss->incomplete_lock); 1149 } 1150 spin_unlock_bh(&ifibss->incomplete_lock); 1151 1152 netif_carrier_off(sdata->dev); 1153 1154 /* remove beacon */ 1155 kfree(sdata->u.ibss.ie); 1156 presp = rcu_dereference_protected(ifibss->presp, 1157 lockdep_is_held(&sdata->u.ibss.mtx)); 1158 RCU_INIT_POINTER(sdata->u.ibss.presp, NULL); 1159 sdata->vif.bss_conf.ibss_joined = false; 1160 sdata->vif.bss_conf.ibss_creator = false; 1161 sdata->vif.bss_conf.enable_beacon = false; 1162 clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state); 1163 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | 1164 BSS_CHANGED_IBSS); 1165 synchronize_rcu(); 1166 kfree(presp); 1167 1168 skb_queue_purge(&sdata->skb_queue); 1169 1170 del_timer_sync(&sdata->u.ibss.timer); 1171 1172 mutex_unlock(&sdata->u.ibss.mtx); 1173 1174 return 0; 1175} 1176