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 #include <asm/unaligned.h> 24 25 #include "ieee80211_i.h" 26 #include "driver-ops.h" 27 #include "rate.h" 28 29 #define IEEE80211_SCAN_INTERVAL (2 * HZ) 30 #define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ) 31 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ) 32 33 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ) 34 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ) 35 36 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128 37 38 39 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, 40 struct ieee80211_mgmt *mgmt, 41 size_t len) 42 { 43 u16 auth_alg, auth_transaction; 44 45 lockdep_assert_held(&sdata->u.ibss.mtx); 46 47 if (len < 24 + 6) 48 return; 49 50 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 51 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 52 53 /* 54 * IEEE 802.11 standard does not require authentication in IBSS 55 * networks and most implementations do not seem to use it. 56 * However, try to reply to authentication attempts if someone 57 * has actually implemented this. 58 */ 59 if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1) 60 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0, 61 sdata->u.ibss.bssid, NULL, 0, 0); 62 } 63 64 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 65 const u8 *bssid, const int beacon_int, 66 struct ieee80211_channel *chan, 67 const u32 basic_rates, 68 const u16 capability, u64 tsf) 69 { 70 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 71 struct ieee80211_local *local = sdata->local; 72 int rates, i; 73 struct sk_buff *skb; 74 struct ieee80211_mgmt *mgmt; 75 u8 *pos; 76 struct ieee80211_supported_band *sband; 77 struct cfg80211_bss *bss; 78 u32 bss_change; 79 u8 supp_rates[IEEE80211_MAX_SUPP_RATES]; 80 enum nl80211_channel_type channel_type; 81 82 lockdep_assert_held(&ifibss->mtx); 83 84 /* Reset own TSF to allow time synchronization work. */ 85 drv_reset_tsf(local, sdata); 86 87 skb = ifibss->skb; 88 RCU_INIT_POINTER(ifibss->presp, NULL); 89 synchronize_rcu(); 90 skb->data = skb->head; 91 skb->len = 0; 92 skb_reset_tail_pointer(skb); 93 skb_reserve(skb, sdata->local->hw.extra_tx_headroom); 94 95 if (memcmp(ifibss->bssid, bssid, ETH_ALEN)) 96 sta_info_flush(sdata->local, sdata); 97 98 /* if merging, indicate to driver that we leave the old IBSS */ 99 if (sdata->vif.bss_conf.ibss_joined) { 100 sdata->vif.bss_conf.ibss_joined = false; 101 netif_carrier_off(sdata->dev); 102 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS); 103 } 104 105 memcpy(ifibss->bssid, bssid, ETH_ALEN); 106 107 sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0; 108 109 local->oper_channel = chan; 110 channel_type = ifibss->channel_type; 111 if (channel_type > NL80211_CHAN_HT20 && 112 !cfg80211_can_beacon_sec_chan(local->hw.wiphy, chan, channel_type)) 113 channel_type = NL80211_CHAN_HT20; 114 if (!ieee80211_set_channel_type(local, sdata, channel_type)) { 115 /* can only fail due to HT40+/- mismatch */ 116 channel_type = NL80211_CHAN_HT20; 117 WARN_ON(!ieee80211_set_channel_type(local, sdata, 118 NL80211_CHAN_HT20)); 119 } 120 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 121 122 sband = local->hw.wiphy->bands[chan->band]; 123 124 /* build supported rates array */ 125 pos = supp_rates; 126 for (i = 0; i < sband->n_bitrates; i++) { 127 int rate = sband->bitrates[i].bitrate; 128 u8 basic = 0; 129 if (basic_rates & BIT(i)) 130 basic = 0x80; 131 *pos++ = basic | (u8) (rate / 5); 132 } 133 134 /* Build IBSS probe response */ 135 mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon)); 136 memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon)); 137 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 138 IEEE80211_STYPE_PROBE_RESP); 139 memset(mgmt->da, 0xff, ETH_ALEN); 140 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 141 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN); 142 mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int); 143 mgmt->u.beacon.timestamp = cpu_to_le64(tsf); 144 mgmt->u.beacon.capab_info = cpu_to_le16(capability); 145 146 pos = skb_put(skb, 2 + ifibss->ssid_len); 147 *pos++ = WLAN_EID_SSID; 148 *pos++ = ifibss->ssid_len; 149 memcpy(pos, ifibss->ssid, ifibss->ssid_len); 150 151 rates = sband->n_bitrates; 152 if (rates > 8) 153 rates = 8; 154 pos = skb_put(skb, 2 + rates); 155 *pos++ = WLAN_EID_SUPP_RATES; 156 *pos++ = rates; 157 memcpy(pos, supp_rates, rates); 158 159 if (sband->band == IEEE80211_BAND_2GHZ) { 160 pos = skb_put(skb, 2 + 1); 161 *pos++ = WLAN_EID_DS_PARAMS; 162 *pos++ = 1; 163 *pos++ = ieee80211_frequency_to_channel(chan->center_freq); 164 } 165 166 pos = skb_put(skb, 2 + 2); 167 *pos++ = WLAN_EID_IBSS_PARAMS; 168 *pos++ = 2; 169 /* FIX: set ATIM window based on scan results */ 170 *pos++ = 0; 171 *pos++ = 0; 172 173 if (sband->n_bitrates > 8) { 174 rates = sband->n_bitrates - 8; 175 pos = skb_put(skb, 2 + rates); 176 *pos++ = WLAN_EID_EXT_SUPP_RATES; 177 *pos++ = rates; 178 memcpy(pos, &supp_rates[8], rates); 179 } 180 181 if (ifibss->ie_len) 182 memcpy(skb_put(skb, ifibss->ie_len), 183 ifibss->ie, ifibss->ie_len); 184 185 /* add HT capability and information IEs */ 186 if (channel_type && sband->ht_cap.ht_supported) { 187 pos = skb_put(skb, 4 + 188 sizeof(struct ieee80211_ht_cap) + 189 sizeof(struct ieee80211_ht_info)); 190 pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, 191 sband->ht_cap.cap); 192 pos = ieee80211_ie_build_ht_info(pos, 193 &sband->ht_cap, 194 chan, 195 channel_type); 196 } 197 198 if (local->hw.queues >= 4) { 199 pos = skb_put(skb, 9); 200 *pos++ = WLAN_EID_VENDOR_SPECIFIC; 201 *pos++ = 7; /* len */ 202 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */ 203 *pos++ = 0x50; 204 *pos++ = 0xf2; 205 *pos++ = 2; /* WME */ 206 *pos++ = 0; /* WME info */ 207 *pos++ = 1; /* WME ver */ 208 *pos++ = 0; /* U-APSD no in use */ 209 } 210 211 rcu_assign_pointer(ifibss->presp, skb); 212 213 sdata->vif.bss_conf.beacon_int = beacon_int; 214 sdata->vif.bss_conf.basic_rates = basic_rates; 215 bss_change = BSS_CHANGED_BEACON_INT; 216 bss_change |= ieee80211_reset_erp_info(sdata); 217 bss_change |= BSS_CHANGED_BSSID; 218 bss_change |= BSS_CHANGED_BEACON; 219 bss_change |= BSS_CHANGED_BEACON_ENABLED; 220 bss_change |= BSS_CHANGED_BASIC_RATES; 221 bss_change |= BSS_CHANGED_HT; 222 bss_change |= BSS_CHANGED_IBSS; 223 sdata->vif.bss_conf.ibss_joined = true; 224 ieee80211_bss_info_change_notify(sdata, bss_change); 225 226 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 227 228 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 229 mod_timer(&ifibss->timer, 230 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 231 232 bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel, 233 mgmt, skb->len, 0, GFP_KERNEL); 234 cfg80211_put_bss(bss); 235 netif_carrier_on(sdata->dev); 236 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 237 } 238 239 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 240 struct ieee80211_bss *bss) 241 { 242 struct cfg80211_bss *cbss = 243 container_of((void *)bss, struct cfg80211_bss, priv); 244 struct ieee80211_supported_band *sband; 245 u32 basic_rates; 246 int i, j; 247 u16 beacon_int = cbss->beacon_interval; 248 249 lockdep_assert_held(&sdata->u.ibss.mtx); 250 251 if (beacon_int < 10) 252 beacon_int = 10; 253 254 sband = sdata->local->hw.wiphy->bands[cbss->channel->band]; 255 256 basic_rates = 0; 257 258 for (i = 0; i < bss->supp_rates_len; i++) { 259 int rate = (bss->supp_rates[i] & 0x7f) * 5; 260 bool is_basic = !!(bss->supp_rates[i] & 0x80); 261 262 for (j = 0; j < sband->n_bitrates; j++) { 263 if (sband->bitrates[j].bitrate == rate) { 264 if (is_basic) 265 basic_rates |= BIT(j); 266 break; 267 } 268 } 269 } 270 271 __ieee80211_sta_join_ibss(sdata, cbss->bssid, 272 beacon_int, 273 cbss->channel, 274 basic_rates, 275 cbss->capability, 276 cbss->tsf); 277 } 278 279 static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta) 280 __acquires(RCU) 281 { 282 struct ieee80211_sub_if_data *sdata = sta->sdata; 283 u8 addr[ETH_ALEN]; 284 285 memcpy(addr, sta->sta.addr, ETH_ALEN); 286 287 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG 288 wiphy_debug(sdata->local->hw.wiphy, 289 "Adding new IBSS station %pM (dev=%s)\n", 290 addr, sdata->name); 291 #endif 292 293 sta_info_move_state(sta, IEEE80211_STA_AUTH); 294 sta_info_move_state(sta, IEEE80211_STA_ASSOC); 295 sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED); 296 297 rate_control_rate_init(sta); 298 299 /* If it fails, maybe we raced another insertion? */ 300 if (sta_info_insert_rcu(sta)) 301 return sta_info_get(sdata, addr); 302 return sta; 303 } 304 305 static struct sta_info * 306 ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 307 const u8 *bssid, const u8 *addr, 308 u32 supp_rates) 309 __acquires(RCU) 310 { 311 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 312 struct ieee80211_local *local = sdata->local; 313 struct sta_info *sta; 314 int band = local->hw.conf.channel->band; 315 316 /* 317 * XXX: Consider removing the least recently used entry and 318 * allow new one to be added. 319 */ 320 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 321 if (net_ratelimit()) 322 printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n", 323 sdata->name, addr); 324 rcu_read_lock(); 325 return NULL; 326 } 327 328 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) { 329 rcu_read_lock(); 330 return NULL; 331 } 332 333 if (compare_ether_addr(bssid, sdata->u.ibss.bssid)) { 334 rcu_read_lock(); 335 return NULL; 336 } 337 338 sta = sta_info_alloc(sdata, addr, GFP_KERNEL); 339 if (!sta) { 340 rcu_read_lock(); 341 return NULL; 342 } 343 344 sta->last_rx = jiffies; 345 346 /* make sure mandatory rates are always added */ 347 sta->sta.supp_rates[band] = supp_rates | 348 ieee80211_mandatory_rates(local, band); 349 350 return ieee80211_ibss_finish_sta(sta); 351 } 352 353 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 354 struct ieee80211_mgmt *mgmt, 355 size_t len, 356 struct ieee80211_rx_status *rx_status, 357 struct ieee802_11_elems *elems, 358 bool beacon) 359 { 360 struct ieee80211_local *local = sdata->local; 361 int freq; 362 struct cfg80211_bss *cbss; 363 struct ieee80211_bss *bss; 364 struct sta_info *sta; 365 struct ieee80211_channel *channel; 366 u64 beacon_timestamp, rx_timestamp; 367 u32 supp_rates = 0; 368 enum ieee80211_band band = rx_status->band; 369 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 370 bool rates_updated = false; 371 372 if (elems->ds_params && elems->ds_params_len == 1) 373 freq = ieee80211_channel_to_frequency(elems->ds_params[0], 374 band); 375 else 376 freq = rx_status->freq; 377 378 channel = ieee80211_get_channel(local->hw.wiphy, freq); 379 380 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 381 return; 382 383 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && 384 memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) { 385 386 rcu_read_lock(); 387 sta = sta_info_get(sdata, mgmt->sa); 388 389 if (elems->supp_rates) { 390 supp_rates = ieee80211_sta_get_rates(local, elems, 391 band); 392 if (sta) { 393 u32 prev_rates; 394 395 prev_rates = sta->sta.supp_rates[band]; 396 /* make sure mandatory rates are always added */ 397 sta->sta.supp_rates[band] = supp_rates | 398 ieee80211_mandatory_rates(local, band); 399 400 if (sta->sta.supp_rates[band] != prev_rates) { 401 #ifdef CONFIG_MAC80211_IBSS_DEBUG 402 printk(KERN_DEBUG 403 "%s: updated supp_rates set " 404 "for %pM based on beacon" 405 "/probe_resp (0x%x -> 0x%x)\n", 406 sdata->name, sta->sta.addr, 407 prev_rates, 408 sta->sta.supp_rates[band]); 409 #endif 410 rates_updated = true; 411 } 412 } else { 413 rcu_read_unlock(); 414 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, 415 mgmt->sa, supp_rates); 416 } 417 } 418 419 if (sta && elems->wmm_info) 420 set_sta_flag(sta, WLAN_STA_WME); 421 422 if (sta && elems->ht_info_elem && elems->ht_cap_elem && 423 sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) { 424 /* we both use HT */ 425 struct ieee80211_sta_ht_cap sta_ht_cap_new; 426 enum nl80211_channel_type channel_type = 427 ieee80211_ht_info_to_channel_type( 428 elems->ht_info_elem); 429 430 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 431 elems->ht_cap_elem, 432 &sta_ht_cap_new); 433 434 /* 435 * fall back to HT20 if we don't use or use 436 * the other extension channel 437 */ 438 if ((channel_type == NL80211_CHAN_HT40MINUS || 439 channel_type == NL80211_CHAN_HT40PLUS) && 440 channel_type != sdata->u.ibss.channel_type) 441 sta_ht_cap_new.cap &= 442 ~IEEE80211_HT_CAP_SUP_WIDTH_20_40; 443 444 if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new, 445 sizeof(sta_ht_cap_new))) { 446 memcpy(&sta->sta.ht_cap, &sta_ht_cap_new, 447 sizeof(sta_ht_cap_new)); 448 rates_updated = true; 449 } 450 } 451 452 if (sta && rates_updated) 453 rate_control_rate_init(sta); 454 455 rcu_read_unlock(); 456 } 457 458 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 459 channel, beacon); 460 if (!bss) 461 return; 462 463 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 464 465 /* was just updated in ieee80211_bss_info_update */ 466 beacon_timestamp = cbss->tsf; 467 468 /* check if we need to merge IBSS */ 469 470 /* we use a fixed BSSID */ 471 if (sdata->u.ibss.fixed_bssid) 472 goto put_bss; 473 474 /* not an IBSS */ 475 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 476 goto put_bss; 477 478 /* different channel */ 479 if (cbss->channel != local->oper_channel) 480 goto put_bss; 481 482 /* different SSID */ 483 if (elems->ssid_len != sdata->u.ibss.ssid_len || 484 memcmp(elems->ssid, sdata->u.ibss.ssid, 485 sdata->u.ibss.ssid_len)) 486 goto put_bss; 487 488 /* same BSSID */ 489 if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) 490 goto put_bss; 491 492 if (rx_status->flag & RX_FLAG_MACTIME_MPDU) { 493 /* 494 * For correct IBSS merging we need mactime; since mactime is 495 * defined as the time the first data symbol of the frame hits 496 * the PHY, and the timestamp of the beacon is defined as "the 497 * time that the data symbol containing the first bit of the 498 * timestamp is transmitted to the PHY plus the transmitting 499 * STA's delays through its local PHY from the MAC-PHY 500 * interface to its interface with the WM" (802.11 11.1.2) 501 * - equals the time this bit arrives at the receiver - we have 502 * to take into account the offset between the two. 503 * 504 * E.g. at 1 MBit that means mactime is 192 usec earlier 505 * (=24 bytes * 8 usecs/byte) than the beacon timestamp. 506 */ 507 int rate; 508 509 if (rx_status->flag & RX_FLAG_HT) 510 rate = 65; /* TODO: HT rates */ 511 else 512 rate = local->hw.wiphy->bands[band]-> 513 bitrates[rx_status->rate_idx].bitrate; 514 515 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate); 516 } else { 517 /* 518 * second best option: get current TSF 519 * (will return -1 if not supported) 520 */ 521 rx_timestamp = drv_get_tsf(local, sdata); 522 } 523 524 #ifdef CONFIG_MAC80211_IBSS_DEBUG 525 printk(KERN_DEBUG "RX beacon SA=%pM BSSID=" 526 "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 527 mgmt->sa, mgmt->bssid, 528 (unsigned long long)rx_timestamp, 529 (unsigned long long)beacon_timestamp, 530 (unsigned long long)(rx_timestamp - beacon_timestamp), 531 jiffies); 532 #endif 533 534 if (beacon_timestamp > rx_timestamp) { 535 #ifdef CONFIG_MAC80211_IBSS_DEBUG 536 printk(KERN_DEBUG "%s: beacon TSF higher than " 537 "local TSF - IBSS merge with BSSID %pM\n", 538 sdata->name, mgmt->bssid); 539 #endif 540 ieee80211_sta_join_ibss(sdata, bss); 541 supp_rates = ieee80211_sta_get_rates(local, elems, band); 542 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 543 supp_rates); 544 rcu_read_unlock(); 545 } 546 547 put_bss: 548 ieee80211_rx_bss_put(local, bss); 549 } 550 551 void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata, 552 const u8 *bssid, const u8 *addr, 553 u32 supp_rates) 554 { 555 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 556 struct ieee80211_local *local = sdata->local; 557 struct sta_info *sta; 558 int band = local->hw.conf.channel->band; 559 560 /* 561 * XXX: Consider removing the least recently used entry and 562 * allow new one to be added. 563 */ 564 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 565 if (net_ratelimit()) 566 printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n", 567 sdata->name, addr); 568 return; 569 } 570 571 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 572 return; 573 574 if (compare_ether_addr(bssid, sdata->u.ibss.bssid)) 575 return; 576 577 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC); 578 if (!sta) 579 return; 580 581 sta->last_rx = jiffies; 582 583 /* make sure mandatory rates are always added */ 584 sta->sta.supp_rates[band] = supp_rates | 585 ieee80211_mandatory_rates(local, band); 586 587 spin_lock(&ifibss->incomplete_lock); 588 list_add(&sta->list, &ifibss->incomplete_stations); 589 spin_unlock(&ifibss->incomplete_lock); 590 ieee80211_queue_work(&local->hw, &sdata->work); 591 } 592 593 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 594 { 595 struct ieee80211_local *local = sdata->local; 596 int active = 0; 597 struct sta_info *sta; 598 599 lockdep_assert_held(&sdata->u.ibss.mtx); 600 601 rcu_read_lock(); 602 603 list_for_each_entry_rcu(sta, &local->sta_list, list) { 604 if (sta->sdata == sdata && 605 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 606 jiffies)) { 607 active++; 608 break; 609 } 610 } 611 612 rcu_read_unlock(); 613 614 return active; 615 } 616 617 /* 618 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 619 */ 620 621 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 622 { 623 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 624 625 lockdep_assert_held(&ifibss->mtx); 626 627 mod_timer(&ifibss->timer, 628 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 629 630 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 631 632 if (time_before(jiffies, ifibss->last_scan_completed + 633 IEEE80211_IBSS_MERGE_INTERVAL)) 634 return; 635 636 if (ieee80211_sta_active_ibss(sdata)) 637 return; 638 639 if (ifibss->fixed_channel) 640 return; 641 642 printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other " 643 "IBSS networks with same SSID (merge)\n", sdata->name); 644 645 ieee80211_request_internal_scan(sdata, 646 ifibss->ssid, ifibss->ssid_len, 647 ifibss->fixed_channel ? ifibss->channel : NULL); 648 } 649 650 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 651 { 652 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 653 u8 bssid[ETH_ALEN]; 654 u16 capability; 655 int i; 656 657 lockdep_assert_held(&ifibss->mtx); 658 659 if (ifibss->fixed_bssid) { 660 memcpy(bssid, ifibss->bssid, ETH_ALEN); 661 } else { 662 /* Generate random, not broadcast, locally administered BSSID. Mix in 663 * own MAC address to make sure that devices that do not have proper 664 * random number generator get different BSSID. */ 665 get_random_bytes(bssid, ETH_ALEN); 666 for (i = 0; i < ETH_ALEN; i++) 667 bssid[i] ^= sdata->vif.addr[i]; 668 bssid[0] &= ~0x01; 669 bssid[0] |= 0x02; 670 } 671 672 printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n", 673 sdata->name, bssid); 674 675 capability = WLAN_CAPABILITY_IBSS; 676 677 if (ifibss->privacy) 678 capability |= WLAN_CAPABILITY_PRIVACY; 679 else 680 sdata->drop_unencrypted = 0; 681 682 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 683 ifibss->channel, ifibss->basic_rates, 684 capability, 0); 685 } 686 687 /* 688 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 689 */ 690 691 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 692 { 693 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 694 struct ieee80211_local *local = sdata->local; 695 struct cfg80211_bss *cbss; 696 struct ieee80211_channel *chan = NULL; 697 const u8 *bssid = NULL; 698 int active_ibss; 699 u16 capability; 700 701 lockdep_assert_held(&ifibss->mtx); 702 703 active_ibss = ieee80211_sta_active_ibss(sdata); 704 #ifdef CONFIG_MAC80211_IBSS_DEBUG 705 printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n", 706 sdata->name, active_ibss); 707 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 708 709 if (active_ibss) 710 return; 711 712 capability = WLAN_CAPABILITY_IBSS; 713 if (ifibss->privacy) 714 capability |= WLAN_CAPABILITY_PRIVACY; 715 if (ifibss->fixed_bssid) 716 bssid = ifibss->bssid; 717 if (ifibss->fixed_channel) 718 chan = ifibss->channel; 719 if (!is_zero_ether_addr(ifibss->bssid)) 720 bssid = ifibss->bssid; 721 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 722 ifibss->ssid, ifibss->ssid_len, 723 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 724 capability); 725 726 if (cbss) { 727 struct ieee80211_bss *bss; 728 729 bss = (void *)cbss->priv; 730 #ifdef CONFIG_MAC80211_IBSS_DEBUG 731 printk(KERN_DEBUG " sta_find_ibss: selected %pM current " 732 "%pM\n", cbss->bssid, ifibss->bssid); 733 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 734 735 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM" 736 " based on configured SSID\n", 737 sdata->name, cbss->bssid); 738 739 ieee80211_sta_join_ibss(sdata, bss); 740 ieee80211_rx_bss_put(local, bss); 741 return; 742 } 743 744 #ifdef CONFIG_MAC80211_IBSS_DEBUG 745 printk(KERN_DEBUG " did not try to join ibss\n"); 746 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 747 748 /* Selected IBSS not found in current scan results - try to scan */ 749 if (time_after(jiffies, ifibss->last_scan_completed + 750 IEEE80211_SCAN_INTERVAL)) { 751 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to " 752 "join\n", sdata->name); 753 754 ieee80211_request_internal_scan(sdata, 755 ifibss->ssid, ifibss->ssid_len, 756 ifibss->fixed_channel ? ifibss->channel : NULL); 757 } else { 758 int interval = IEEE80211_SCAN_INTERVAL; 759 760 if (time_after(jiffies, ifibss->ibss_join_req + 761 IEEE80211_IBSS_JOIN_TIMEOUT)) { 762 if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) { 763 ieee80211_sta_create_ibss(sdata); 764 return; 765 } 766 printk(KERN_DEBUG "%s: IBSS not allowed on" 767 " %d MHz\n", sdata->name, 768 local->hw.conf.channel->center_freq); 769 770 /* No IBSS found - decrease scan interval and continue 771 * scanning. */ 772 interval = IEEE80211_SCAN_INTERVAL_SLOW; 773 } 774 775 mod_timer(&ifibss->timer, 776 round_jiffies(jiffies + interval)); 777 } 778 } 779 780 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 781 struct sk_buff *req) 782 { 783 struct ieee80211_mgmt *mgmt = (void *)req->data; 784 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 785 struct ieee80211_local *local = sdata->local; 786 int tx_last_beacon, len = req->len; 787 struct sk_buff *skb; 788 struct ieee80211_mgmt *resp; 789 struct sk_buff *presp; 790 u8 *pos, *end; 791 792 lockdep_assert_held(&ifibss->mtx); 793 794 presp = rcu_dereference_protected(ifibss->presp, 795 lockdep_is_held(&ifibss->mtx)); 796 797 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 798 len < 24 + 2 || !presp) 799 return; 800 801 tx_last_beacon = drv_tx_last_beacon(local); 802 803 #ifdef CONFIG_MAC80211_IBSS_DEBUG 804 printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM" 805 " (tx_last_beacon=%d)\n", 806 sdata->name, mgmt->sa, mgmt->da, 807 mgmt->bssid, tx_last_beacon); 808 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 809 810 if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da)) 811 return; 812 813 if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 && 814 memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0) 815 return; 816 817 end = ((u8 *) mgmt) + len; 818 pos = mgmt->u.probe_req.variable; 819 if (pos[0] != WLAN_EID_SSID || 820 pos + 2 + pos[1] > end) { 821 #ifdef CONFIG_MAC80211_IBSS_DEBUG 822 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq " 823 "from %pM\n", 824 sdata->name, mgmt->sa); 825 #endif 826 return; 827 } 828 if (pos[1] != 0 && 829 (pos[1] != ifibss->ssid_len || 830 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 831 /* Ignore ProbeReq for foreign SSID */ 832 return; 833 } 834 835 /* Reply with ProbeResp */ 836 skb = skb_copy(presp, GFP_KERNEL); 837 if (!skb) 838 return; 839 840 resp = (struct ieee80211_mgmt *) skb->data; 841 memcpy(resp->da, mgmt->sa, ETH_ALEN); 842 #ifdef CONFIG_MAC80211_IBSS_DEBUG 843 printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n", 844 sdata->name, resp->da); 845 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 846 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 847 ieee80211_tx_skb(sdata, skb); 848 } 849 850 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, 851 struct ieee80211_mgmt *mgmt, 852 size_t len, 853 struct ieee80211_rx_status *rx_status) 854 { 855 size_t baselen; 856 struct ieee802_11_elems elems; 857 858 if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN)) 859 return; /* ignore ProbeResp to foreign address */ 860 861 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 862 if (baselen > len) 863 return; 864 865 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 866 &elems); 867 868 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false); 869 } 870 871 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, 872 struct ieee80211_mgmt *mgmt, 873 size_t len, 874 struct ieee80211_rx_status *rx_status) 875 { 876 size_t baselen; 877 struct ieee802_11_elems elems; 878 879 /* Process beacon from the current BSS */ 880 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt; 881 if (baselen > len) 882 return; 883 884 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems); 885 886 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); 887 } 888 889 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 890 struct sk_buff *skb) 891 { 892 struct ieee80211_rx_status *rx_status; 893 struct ieee80211_mgmt *mgmt; 894 u16 fc; 895 896 rx_status = IEEE80211_SKB_RXCB(skb); 897 mgmt = (struct ieee80211_mgmt *) skb->data; 898 fc = le16_to_cpu(mgmt->frame_control); 899 900 mutex_lock(&sdata->u.ibss.mtx); 901 902 if (!sdata->u.ibss.ssid_len) 903 goto mgmt_out; /* not ready to merge yet */ 904 905 switch (fc & IEEE80211_FCTL_STYPE) { 906 case IEEE80211_STYPE_PROBE_REQ: 907 ieee80211_rx_mgmt_probe_req(sdata, skb); 908 break; 909 case IEEE80211_STYPE_PROBE_RESP: 910 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, 911 rx_status); 912 break; 913 case IEEE80211_STYPE_BEACON: 914 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, 915 rx_status); 916 break; 917 case IEEE80211_STYPE_AUTH: 918 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 919 break; 920 } 921 922 mgmt_out: 923 mutex_unlock(&sdata->u.ibss.mtx); 924 } 925 926 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata) 927 { 928 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 929 struct sta_info *sta; 930 931 mutex_lock(&ifibss->mtx); 932 933 /* 934 * Work could be scheduled after scan or similar 935 * when we aren't even joined (or trying) with a 936 * network. 937 */ 938 if (!ifibss->ssid_len) 939 goto out; 940 941 spin_lock_bh(&ifibss->incomplete_lock); 942 while (!list_empty(&ifibss->incomplete_stations)) { 943 sta = list_first_entry(&ifibss->incomplete_stations, 944 struct sta_info, list); 945 list_del(&sta->list); 946 spin_unlock_bh(&ifibss->incomplete_lock); 947 948 ieee80211_ibss_finish_sta(sta); 949 rcu_read_unlock(); 950 spin_lock_bh(&ifibss->incomplete_lock); 951 } 952 spin_unlock_bh(&ifibss->incomplete_lock); 953 954 switch (ifibss->state) { 955 case IEEE80211_IBSS_MLME_SEARCH: 956 ieee80211_sta_find_ibss(sdata); 957 break; 958 case IEEE80211_IBSS_MLME_JOINED: 959 ieee80211_sta_merge_ibss(sdata); 960 break; 961 default: 962 WARN_ON(1); 963 break; 964 } 965 966 out: 967 mutex_unlock(&ifibss->mtx); 968 } 969 970 static void ieee80211_ibss_timer(unsigned long data) 971 { 972 struct ieee80211_sub_if_data *sdata = 973 (struct ieee80211_sub_if_data *) data; 974 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 975 struct ieee80211_local *local = sdata->local; 976 977 if (local->quiescing) { 978 ifibss->timer_running = true; 979 return; 980 } 981 982 ieee80211_queue_work(&local->hw, &sdata->work); 983 } 984 985 #ifdef CONFIG_PM 986 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata) 987 { 988 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 989 990 if (del_timer_sync(&ifibss->timer)) 991 ifibss->timer_running = true; 992 } 993 994 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata) 995 { 996 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 997 998 if (ifibss->timer_running) { 999 add_timer(&ifibss->timer); 1000 ifibss->timer_running = false; 1001 } 1002 } 1003 #endif 1004 1005 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 1006 { 1007 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1008 1009 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 1010 (unsigned long) sdata); 1011 mutex_init(&ifibss->mtx); 1012 INIT_LIST_HEAD(&ifibss->incomplete_stations); 1013 spin_lock_init(&ifibss->incomplete_lock); 1014 } 1015 1016 /* scan finished notification */ 1017 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 1018 { 1019 struct ieee80211_sub_if_data *sdata; 1020 1021 mutex_lock(&local->iflist_mtx); 1022 list_for_each_entry(sdata, &local->interfaces, list) { 1023 if (!ieee80211_sdata_running(sdata)) 1024 continue; 1025 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 1026 continue; 1027 sdata->u.ibss.last_scan_completed = jiffies; 1028 ieee80211_queue_work(&local->hw, &sdata->work); 1029 } 1030 mutex_unlock(&local->iflist_mtx); 1031 } 1032 1033 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 1034 struct cfg80211_ibss_params *params) 1035 { 1036 struct sk_buff *skb; 1037 u32 changed = 0; 1038 1039 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom + 1040 sizeof(struct ieee80211_hdr_3addr) + 1041 12 /* struct ieee80211_mgmt.u.beacon */ + 1042 2 + IEEE80211_MAX_SSID_LEN /* max SSID */ + 1043 2 + 8 /* max Supported Rates */ + 1044 3 /* max DS params */ + 1045 4 /* IBSS params */ + 1046 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 1047 2 + sizeof(struct ieee80211_ht_cap) + 1048 2 + sizeof(struct ieee80211_ht_info) + 1049 params->ie_len); 1050 if (!skb) 1051 return -ENOMEM; 1052 1053 mutex_lock(&sdata->u.ibss.mtx); 1054 1055 if (params->bssid) { 1056 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 1057 sdata->u.ibss.fixed_bssid = true; 1058 } else 1059 sdata->u.ibss.fixed_bssid = false; 1060 1061 sdata->u.ibss.privacy = params->privacy; 1062 sdata->u.ibss.basic_rates = params->basic_rates; 1063 memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate, 1064 sizeof(params->mcast_rate)); 1065 1066 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 1067 1068 sdata->u.ibss.channel = params->channel; 1069 sdata->u.ibss.channel_type = params->channel_type; 1070 sdata->u.ibss.fixed_channel = params->channel_fixed; 1071 1072 /* fix ourselves to that channel now already */ 1073 if (params->channel_fixed) { 1074 sdata->local->oper_channel = params->channel; 1075 if (!ieee80211_set_channel_type(sdata->local, sdata, 1076 params->channel_type)) { 1077 mutex_unlock(&sdata->u.ibss.mtx); 1078 kfree_skb(skb); 1079 return -EINVAL; 1080 } 1081 } 1082 1083 if (params->ie) { 1084 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 1085 GFP_KERNEL); 1086 if (sdata->u.ibss.ie) 1087 sdata->u.ibss.ie_len = params->ie_len; 1088 } 1089 1090 sdata->u.ibss.skb = skb; 1091 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1092 sdata->u.ibss.ibss_join_req = jiffies; 1093 1094 memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN); 1095 sdata->u.ibss.ssid_len = params->ssid_len; 1096 1097 mutex_unlock(&sdata->u.ibss.mtx); 1098 1099 mutex_lock(&sdata->local->mtx); 1100 ieee80211_recalc_idle(sdata->local); 1101 mutex_unlock(&sdata->local->mtx); 1102 1103 /* 1104 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is 1105 * reserved, but an HT STA shall protect HT transmissions as though 1106 * the HT Protection field were set to non-HT mixed mode. 1107 * 1108 * In an IBSS, the RIFS Mode field of the HT Operation element is 1109 * also reserved, but an HT STA shall operate as though this field 1110 * were set to 1. 1111 */ 1112 1113 sdata->vif.bss_conf.ht_operation_mode |= 1114 IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED 1115 | IEEE80211_HT_PARAM_RIFS_MODE; 1116 1117 changed |= BSS_CHANGED_HT; 1118 ieee80211_bss_info_change_notify(sdata, changed); 1119 1120 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1121 1122 return 0; 1123 } 1124 1125 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 1126 { 1127 struct sk_buff *skb; 1128 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1129 struct ieee80211_local *local = sdata->local; 1130 struct cfg80211_bss *cbss; 1131 u16 capability; 1132 int active_ibss; 1133 struct sta_info *sta; 1134 1135 mutex_lock(&sdata->u.ibss.mtx); 1136 1137 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1138 memset(sdata->u.ibss.bssid, 0, ETH_ALEN); 1139 sdata->u.ibss.ssid_len = 0; 1140 1141 active_ibss = ieee80211_sta_active_ibss(sdata); 1142 1143 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) { 1144 capability = WLAN_CAPABILITY_IBSS; 1145 1146 if (ifibss->privacy) 1147 capability |= WLAN_CAPABILITY_PRIVACY; 1148 1149 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel, 1150 ifibss->bssid, ifibss->ssid, 1151 ifibss->ssid_len, WLAN_CAPABILITY_IBSS | 1152 WLAN_CAPABILITY_PRIVACY, 1153 capability); 1154 1155 if (cbss) { 1156 cfg80211_unlink_bss(local->hw.wiphy, cbss); 1157 cfg80211_put_bss(cbss); 1158 } 1159 } 1160 1161 sta_info_flush(sdata->local, sdata); 1162 1163 spin_lock_bh(&ifibss->incomplete_lock); 1164 while (!list_empty(&ifibss->incomplete_stations)) { 1165 sta = list_first_entry(&ifibss->incomplete_stations, 1166 struct sta_info, list); 1167 list_del(&sta->list); 1168 spin_unlock_bh(&ifibss->incomplete_lock); 1169 1170 sta_info_free(local, sta); 1171 spin_lock_bh(&ifibss->incomplete_lock); 1172 } 1173 spin_unlock_bh(&ifibss->incomplete_lock); 1174 1175 netif_carrier_off(sdata->dev); 1176 1177 /* remove beacon */ 1178 kfree(sdata->u.ibss.ie); 1179 skb = rcu_dereference_protected(sdata->u.ibss.presp, 1180 lockdep_is_held(&sdata->u.ibss.mtx)); 1181 RCU_INIT_POINTER(sdata->u.ibss.presp, NULL); 1182 sdata->vif.bss_conf.ibss_joined = false; 1183 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | 1184 BSS_CHANGED_IBSS); 1185 synchronize_rcu(); 1186 kfree_skb(skb); 1187 1188 skb_queue_purge(&sdata->skb_queue); 1189 1190 del_timer_sync(&sdata->u.ibss.timer); 1191 1192 mutex_unlock(&sdata->u.ibss.mtx); 1193 1194 mutex_lock(&local->mtx); 1195 ieee80211_recalc_idle(sdata->local); 1196 mutex_unlock(&local->mtx); 1197 1198 return 0; 1199 } 1200