ibss.c revision f0d232080fa5d040aaf73a39d127b003cdd2d0ae
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_SCAN_INTERVAL_SLOW (15 * HZ) 30#define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ) 31 32#define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ) 33#define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ) 34 35#define IEEE80211_IBSS_MAX_STA_ENTRIES 128 36 37 38static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 39 const u8 *bssid, const int beacon_int, 40 struct ieee80211_channel *chan, 41 const u32 basic_rates, 42 const u16 capability, u64 tsf) 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 enum nl80211_channel_type channel_type; 55 56 lockdep_assert_held(&ifibss->mtx); 57 58 /* Reset own TSF to allow time synchronization work. */ 59 drv_reset_tsf(local, sdata); 60 61 skb = ifibss->skb; 62 RCU_INIT_POINTER(ifibss->presp, NULL); 63 synchronize_rcu(); 64 skb->data = skb->head; 65 skb->len = 0; 66 skb_reset_tail_pointer(skb); 67 skb_reserve(skb, sdata->local->hw.extra_tx_headroom); 68 69 if (!ether_addr_equal(ifibss->bssid, bssid)) 70 sta_info_flush(sdata->local, sdata); 71 72 /* if merging, indicate to driver that we leave the old IBSS */ 73 if (sdata->vif.bss_conf.ibss_joined) { 74 sdata->vif.bss_conf.ibss_joined = false; 75 netif_carrier_off(sdata->dev); 76 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS); 77 } 78 79 memcpy(ifibss->bssid, bssid, ETH_ALEN); 80 81 sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0; 82 83 local->oper_channel = chan; 84 channel_type = ifibss->channel_type; 85 if (channel_type > NL80211_CHAN_HT20 && 86 !cfg80211_can_beacon_sec_chan(local->hw.wiphy, chan, channel_type)) 87 channel_type = NL80211_CHAN_HT20; 88 if (!ieee80211_set_channel_type(local, sdata, channel_type)) { 89 /* can only fail due to HT40+/- mismatch */ 90 channel_type = NL80211_CHAN_HT20; 91 WARN_ON(!ieee80211_set_channel_type(local, sdata, 92 NL80211_CHAN_HT20)); 93 } 94 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 95 96 sband = local->hw.wiphy->bands[chan->band]; 97 98 /* build supported rates array */ 99 pos = supp_rates; 100 for (i = 0; i < sband->n_bitrates; i++) { 101 int rate = sband->bitrates[i].bitrate; 102 u8 basic = 0; 103 if (basic_rates & BIT(i)) 104 basic = 0x80; 105 *pos++ = basic | (u8) (rate / 5); 106 } 107 108 /* Build IBSS probe response */ 109 mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon)); 110 memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon)); 111 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 112 IEEE80211_STYPE_PROBE_RESP); 113 memset(mgmt->da, 0xff, ETH_ALEN); 114 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 115 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN); 116 mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int); 117 mgmt->u.beacon.timestamp = cpu_to_le64(tsf); 118 mgmt->u.beacon.capab_info = cpu_to_le16(capability); 119 120 pos = skb_put(skb, 2 + ifibss->ssid_len); 121 *pos++ = WLAN_EID_SSID; 122 *pos++ = ifibss->ssid_len; 123 memcpy(pos, ifibss->ssid, ifibss->ssid_len); 124 125 rates = sband->n_bitrates; 126 if (rates > 8) 127 rates = 8; 128 pos = skb_put(skb, 2 + rates); 129 *pos++ = WLAN_EID_SUPP_RATES; 130 *pos++ = rates; 131 memcpy(pos, supp_rates, rates); 132 133 if (sband->band == IEEE80211_BAND_2GHZ) { 134 pos = skb_put(skb, 2 + 1); 135 *pos++ = WLAN_EID_DS_PARAMS; 136 *pos++ = 1; 137 *pos++ = ieee80211_frequency_to_channel(chan->center_freq); 138 } 139 140 pos = skb_put(skb, 2 + 2); 141 *pos++ = WLAN_EID_IBSS_PARAMS; 142 *pos++ = 2; 143 /* FIX: set ATIM window based on scan results */ 144 *pos++ = 0; 145 *pos++ = 0; 146 147 if (sband->n_bitrates > 8) { 148 rates = sband->n_bitrates - 8; 149 pos = skb_put(skb, 2 + rates); 150 *pos++ = WLAN_EID_EXT_SUPP_RATES; 151 *pos++ = rates; 152 memcpy(pos, &supp_rates[8], rates); 153 } 154 155 if (ifibss->ie_len) 156 memcpy(skb_put(skb, ifibss->ie_len), 157 ifibss->ie, ifibss->ie_len); 158 159 /* add HT capability and information IEs */ 160 if (channel_type && sband->ht_cap.ht_supported) { 161 pos = skb_put(skb, 4 + 162 sizeof(struct ieee80211_ht_cap) + 163 sizeof(struct ieee80211_ht_operation)); 164 pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, 165 sband->ht_cap.cap); 166 /* 167 * Note: According to 802.11n-2009 9.13.3.1, HT Protection 168 * field and RIFS Mode are reserved in IBSS mode, therefore 169 * keep them at 0 170 */ 171 pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap, 172 chan, channel_type, 0); 173 } 174 175 if (local->hw.queues >= IEEE80211_NUM_ACS) { 176 pos = skb_put(skb, 9); 177 *pos++ = WLAN_EID_VENDOR_SPECIFIC; 178 *pos++ = 7; /* len */ 179 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */ 180 *pos++ = 0x50; 181 *pos++ = 0xf2; 182 *pos++ = 2; /* WME */ 183 *pos++ = 0; /* WME info */ 184 *pos++ = 1; /* WME ver */ 185 *pos++ = 0; /* U-APSD no in use */ 186 } 187 188 rcu_assign_pointer(ifibss->presp, skb); 189 190 sdata->vif.bss_conf.beacon_int = beacon_int; 191 sdata->vif.bss_conf.basic_rates = basic_rates; 192 bss_change = BSS_CHANGED_BEACON_INT; 193 bss_change |= ieee80211_reset_erp_info(sdata); 194 bss_change |= BSS_CHANGED_BSSID; 195 bss_change |= BSS_CHANGED_BEACON; 196 bss_change |= BSS_CHANGED_BEACON_ENABLED; 197 bss_change |= BSS_CHANGED_BASIC_RATES; 198 bss_change |= BSS_CHANGED_HT; 199 bss_change |= BSS_CHANGED_IBSS; 200 sdata->vif.bss_conf.ibss_joined = true; 201 ieee80211_bss_info_change_notify(sdata, bss_change); 202 203 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 204 205 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 206 mod_timer(&ifibss->timer, 207 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 208 209 bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel, 210 mgmt, skb->len, 0, GFP_KERNEL); 211 cfg80211_put_bss(bss); 212 netif_carrier_on(sdata->dev); 213 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 214} 215 216static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 217 struct ieee80211_bss *bss) 218{ 219 struct cfg80211_bss *cbss = 220 container_of((void *)bss, struct cfg80211_bss, priv); 221 struct ieee80211_supported_band *sband; 222 u32 basic_rates; 223 int i, j; 224 u16 beacon_int = cbss->beacon_interval; 225 226 lockdep_assert_held(&sdata->u.ibss.mtx); 227 228 if (beacon_int < 10) 229 beacon_int = 10; 230 231 sband = sdata->local->hw.wiphy->bands[cbss->channel->band]; 232 233 basic_rates = 0; 234 235 for (i = 0; i < bss->supp_rates_len; i++) { 236 int rate = (bss->supp_rates[i] & 0x7f) * 5; 237 bool is_basic = !!(bss->supp_rates[i] & 0x80); 238 239 for (j = 0; j < sband->n_bitrates; j++) { 240 if (sband->bitrates[j].bitrate == rate) { 241 if (is_basic) 242 basic_rates |= BIT(j); 243 break; 244 } 245 } 246 } 247 248 __ieee80211_sta_join_ibss(sdata, cbss->bssid, 249 beacon_int, 250 cbss->channel, 251 basic_rates, 252 cbss->capability, 253 cbss->tsf); 254} 255 256static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta, 257 bool auth) 258 __acquires(RCU) 259{ 260 struct ieee80211_sub_if_data *sdata = sta->sdata; 261 u8 addr[ETH_ALEN]; 262 263 memcpy(addr, sta->sta.addr, ETH_ALEN); 264 265#ifdef CONFIG_MAC80211_VERBOSE_DEBUG 266 wiphy_debug(sdata->local->hw.wiphy, 267 "Adding new IBSS station %pM (dev=%s)\n", 268 addr, sdata->name); 269#endif 270 271 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 272 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 273 /* authorize the station only if the network is not RSN protected. If 274 * not wait for the userspace to authorize it */ 275 if (!sta->sdata->u.ibss.control_port) 276 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 277 278 rate_control_rate_init(sta); 279 280 /* If it fails, maybe we raced another insertion? */ 281 if (sta_info_insert_rcu(sta)) 282 return sta_info_get(sdata, addr); 283 if (auth) { 284#ifdef CONFIG_MAC80211_IBSS_DEBUG 285 pr_debug("TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n", 286 sdata->vif.addr, sdata->u.ibss.bssid, addr); 287#endif 288 ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, NULL, 0, 289 addr, sdata->u.ibss.bssid, NULL, 0, 0); 290 } 291 return sta; 292} 293 294static struct sta_info * 295ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 296 const u8 *bssid, const u8 *addr, 297 u32 supp_rates, bool auth) 298 __acquires(RCU) 299{ 300 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 301 struct ieee80211_local *local = sdata->local; 302 struct sta_info *sta; 303 int band = local->hw.conf.channel->band; 304 305 /* 306 * XXX: Consider removing the least recently used entry and 307 * allow new one to be added. 308 */ 309 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 310 net_dbg_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 311 sdata->name, addr); 312 rcu_read_lock(); 313 return NULL; 314 } 315 316 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) { 317 rcu_read_lock(); 318 return NULL; 319 } 320 321 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) { 322 rcu_read_lock(); 323 return NULL; 324 } 325 326 sta = sta_info_alloc(sdata, addr, GFP_KERNEL); 327 if (!sta) { 328 rcu_read_lock(); 329 return NULL; 330 } 331 332 sta->last_rx = jiffies; 333 334 /* make sure mandatory rates are always added */ 335 sta->sta.supp_rates[band] = supp_rates | 336 ieee80211_mandatory_rates(local, band); 337 338 return ieee80211_ibss_finish_sta(sta, auth); 339} 340 341static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, 342 struct ieee80211_mgmt *mgmt, 343 size_t len) 344{ 345 u16 auth_alg, auth_transaction; 346 347 lockdep_assert_held(&sdata->u.ibss.mtx); 348 349 if (len < 24 + 6) 350 return; 351 352 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 353 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 354 355 if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1) 356 return; 357#ifdef CONFIG_MAC80211_IBSS_DEBUG 358 pr_debug("%s: RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n", 359 sdata->name, mgmt->sa, mgmt->da, mgmt->bssid, 360 auth_transaction); 361#endif 362 sta_info_destroy_addr(sdata, mgmt->sa); 363 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false); 364 rcu_read_unlock(); 365 366 /* 367 * IEEE 802.11 standard does not require authentication in IBSS 368 * networks and most implementations do not seem to use it. 369 * However, try to reply to authentication attempts if someone 370 * has actually implemented this. 371 */ 372 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0, 373 mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0); 374} 375 376static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 377 struct ieee80211_mgmt *mgmt, 378 size_t len, 379 struct ieee80211_rx_status *rx_status, 380 struct ieee802_11_elems *elems, 381 bool beacon) 382{ 383 struct ieee80211_local *local = sdata->local; 384 int freq; 385 struct cfg80211_bss *cbss; 386 struct ieee80211_bss *bss; 387 struct sta_info *sta; 388 struct ieee80211_channel *channel; 389 u64 beacon_timestamp, rx_timestamp; 390 u32 supp_rates = 0; 391 enum ieee80211_band band = rx_status->band; 392 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 393 bool rates_updated = false; 394 395 if (elems->ds_params && elems->ds_params_len == 1) 396 freq = ieee80211_channel_to_frequency(elems->ds_params[0], 397 band); 398 else 399 freq = rx_status->freq; 400 401 channel = ieee80211_get_channel(local->hw.wiphy, freq); 402 403 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 404 return; 405 406 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && 407 ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) { 408 409 rcu_read_lock(); 410 sta = sta_info_get(sdata, mgmt->sa); 411 412 if (elems->supp_rates) { 413 supp_rates = ieee80211_sta_get_rates(local, elems, 414 band, NULL); 415 if (sta) { 416 u32 prev_rates; 417 418 prev_rates = sta->sta.supp_rates[band]; 419 /* make sure mandatory rates are always added */ 420 sta->sta.supp_rates[band] = supp_rates | 421 ieee80211_mandatory_rates(local, band); 422 423 if (sta->sta.supp_rates[band] != prev_rates) { 424#ifdef CONFIG_MAC80211_IBSS_DEBUG 425 pr_debug("%s: updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n", 426 sdata->name, sta->sta.addr, 427 prev_rates, 428 sta->sta.supp_rates[band]); 429#endif 430 rates_updated = true; 431 } 432 } else { 433 rcu_read_unlock(); 434 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, 435 mgmt->sa, supp_rates, true); 436 } 437 } 438 439 if (sta && elems->wmm_info) 440 set_sta_flag(sta, WLAN_STA_WME); 441 442 if (sta && elems->ht_operation && elems->ht_cap_elem && 443 sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) { 444 /* we both use HT */ 445 struct ieee80211_sta_ht_cap sta_ht_cap_new; 446 enum nl80211_channel_type channel_type = 447 ieee80211_ht_oper_to_channel_type( 448 elems->ht_operation); 449 450 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 451 elems->ht_cap_elem, 452 &sta_ht_cap_new); 453 454 /* 455 * fall back to HT20 if we don't use or use 456 * the other extension channel 457 */ 458 if (!(channel_type == NL80211_CHAN_HT40MINUS || 459 channel_type == NL80211_CHAN_HT40PLUS) || 460 channel_type != sdata->u.ibss.channel_type) 461 sta_ht_cap_new.cap &= 462 ~IEEE80211_HT_CAP_SUP_WIDTH_20_40; 463 464 if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new, 465 sizeof(sta_ht_cap_new))) { 466 memcpy(&sta->sta.ht_cap, &sta_ht_cap_new, 467 sizeof(sta_ht_cap_new)); 468 rates_updated = true; 469 } 470 } 471 472 if (sta && rates_updated) 473 rate_control_rate_init(sta); 474 475 rcu_read_unlock(); 476 } 477 478 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 479 channel, beacon); 480 if (!bss) 481 return; 482 483 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 484 485 /* was just updated in ieee80211_bss_info_update */ 486 beacon_timestamp = cbss->tsf; 487 488 /* check if we need to merge IBSS */ 489 490 /* we use a fixed BSSID */ 491 if (sdata->u.ibss.fixed_bssid) 492 goto put_bss; 493 494 /* not an IBSS */ 495 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 496 goto put_bss; 497 498 /* different channel */ 499 if (cbss->channel != local->oper_channel) 500 goto put_bss; 501 502 /* different SSID */ 503 if (elems->ssid_len != sdata->u.ibss.ssid_len || 504 memcmp(elems->ssid, sdata->u.ibss.ssid, 505 sdata->u.ibss.ssid_len)) 506 goto put_bss; 507 508 /* same BSSID */ 509 if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid)) 510 goto put_bss; 511 512 if (rx_status->flag & RX_FLAG_MACTIME_MPDU) { 513 /* 514 * For correct IBSS merging we need mactime; since mactime is 515 * defined as the time the first data symbol of the frame hits 516 * the PHY, and the timestamp of the beacon is defined as "the 517 * time that the data symbol containing the first bit of the 518 * timestamp is transmitted to the PHY plus the transmitting 519 * STA's delays through its local PHY from the MAC-PHY 520 * interface to its interface with the WM" (802.11 11.1.2) 521 * - equals the time this bit arrives at the receiver - we have 522 * to take into account the offset between the two. 523 * 524 * E.g. at 1 MBit that means mactime is 192 usec earlier 525 * (=24 bytes * 8 usecs/byte) than the beacon timestamp. 526 */ 527 int rate; 528 529 if (rx_status->flag & RX_FLAG_HT) 530 rate = 65; /* TODO: HT rates */ 531 else 532 rate = local->hw.wiphy->bands[band]-> 533 bitrates[rx_status->rate_idx].bitrate; 534 535 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate); 536 } else { 537 /* 538 * second best option: get current TSF 539 * (will return -1 if not supported) 540 */ 541 rx_timestamp = drv_get_tsf(local, sdata); 542 } 543 544#ifdef CONFIG_MAC80211_IBSS_DEBUG 545 pr_debug("RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 546 mgmt->sa, mgmt->bssid, 547 (unsigned long long)rx_timestamp, 548 (unsigned long long)beacon_timestamp, 549 (unsigned long long)(rx_timestamp - beacon_timestamp), 550 jiffies); 551#endif 552 553 if (beacon_timestamp > rx_timestamp) { 554#ifdef CONFIG_MAC80211_IBSS_DEBUG 555 pr_debug("%s: beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n", 556 sdata->name, mgmt->bssid); 557#endif 558 ieee80211_sta_join_ibss(sdata, bss); 559 supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL); 560 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 561 supp_rates, true); 562 rcu_read_unlock(); 563 } 564 565 put_bss: 566 ieee80211_rx_bss_put(local, bss); 567} 568 569void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata, 570 const u8 *bssid, const u8 *addr, 571 u32 supp_rates) 572{ 573 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 574 struct ieee80211_local *local = sdata->local; 575 struct sta_info *sta; 576 int band = local->hw.conf.channel->band; 577 578 /* 579 * XXX: Consider removing the least recently used entry and 580 * allow new one to be added. 581 */ 582 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 583 net_dbg_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 584 sdata->name, addr); 585 return; 586 } 587 588 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 589 return; 590 591 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) 592 return; 593 594 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC); 595 if (!sta) 596 return; 597 598 sta->last_rx = jiffies; 599 600 /* make sure mandatory rates are always added */ 601 sta->sta.supp_rates[band] = supp_rates | 602 ieee80211_mandatory_rates(local, band); 603 604 spin_lock(&ifibss->incomplete_lock); 605 list_add(&sta->list, &ifibss->incomplete_stations); 606 spin_unlock(&ifibss->incomplete_lock); 607 ieee80211_queue_work(&local->hw, &sdata->work); 608} 609 610static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 611{ 612 struct ieee80211_local *local = sdata->local; 613 int active = 0; 614 struct sta_info *sta; 615 616 lockdep_assert_held(&sdata->u.ibss.mtx); 617 618 rcu_read_lock(); 619 620 list_for_each_entry_rcu(sta, &local->sta_list, list) { 621 if (sta->sdata == sdata && 622 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 623 jiffies)) { 624 active++; 625 break; 626 } 627 } 628 629 rcu_read_unlock(); 630 631 return active; 632} 633 634/* 635 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 636 */ 637 638static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 639{ 640 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 641 642 lockdep_assert_held(&ifibss->mtx); 643 644 mod_timer(&ifibss->timer, 645 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 646 647 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 648 649 if (time_before(jiffies, ifibss->last_scan_completed + 650 IEEE80211_IBSS_MERGE_INTERVAL)) 651 return; 652 653 if (ieee80211_sta_active_ibss(sdata)) 654 return; 655 656 if (ifibss->fixed_channel) 657 return; 658 659 pr_debug("%s: No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n", 660 sdata->name); 661 662 ieee80211_request_internal_scan(sdata, 663 ifibss->ssid, ifibss->ssid_len, NULL); 664} 665 666static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 667{ 668 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 669 u8 bssid[ETH_ALEN]; 670 u16 capability; 671 int i; 672 673 lockdep_assert_held(&ifibss->mtx); 674 675 if (ifibss->fixed_bssid) { 676 memcpy(bssid, ifibss->bssid, ETH_ALEN); 677 } else { 678 /* Generate random, not broadcast, locally administered BSSID. Mix in 679 * own MAC address to make sure that devices that do not have proper 680 * random number generator get different BSSID. */ 681 get_random_bytes(bssid, ETH_ALEN); 682 for (i = 0; i < ETH_ALEN; i++) 683 bssid[i] ^= sdata->vif.addr[i]; 684 bssid[0] &= ~0x01; 685 bssid[0] |= 0x02; 686 } 687 688 pr_debug("%s: Creating new IBSS network, BSSID %pM\n", 689 sdata->name, bssid); 690 691 capability = WLAN_CAPABILITY_IBSS; 692 693 if (ifibss->privacy) 694 capability |= WLAN_CAPABILITY_PRIVACY; 695 else 696 sdata->drop_unencrypted = 0; 697 698 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 699 ifibss->channel, ifibss->basic_rates, 700 capability, 0); 701} 702 703/* 704 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 705 */ 706 707static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 708{ 709 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 710 struct ieee80211_local *local = sdata->local; 711 struct cfg80211_bss *cbss; 712 struct ieee80211_channel *chan = NULL; 713 const u8 *bssid = NULL; 714 int active_ibss; 715 u16 capability; 716 717 lockdep_assert_held(&ifibss->mtx); 718 719 active_ibss = ieee80211_sta_active_ibss(sdata); 720#ifdef CONFIG_MAC80211_IBSS_DEBUG 721 pr_debug("%s: sta_find_ibss (active_ibss=%d)\n", 722 sdata->name, active_ibss); 723#endif /* CONFIG_MAC80211_IBSS_DEBUG */ 724 725 if (active_ibss) 726 return; 727 728 capability = WLAN_CAPABILITY_IBSS; 729 if (ifibss->privacy) 730 capability |= WLAN_CAPABILITY_PRIVACY; 731 if (ifibss->fixed_bssid) 732 bssid = ifibss->bssid; 733 if (ifibss->fixed_channel) 734 chan = ifibss->channel; 735 if (!is_zero_ether_addr(ifibss->bssid)) 736 bssid = ifibss->bssid; 737 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 738 ifibss->ssid, ifibss->ssid_len, 739 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 740 capability); 741 742 if (cbss) { 743 struct ieee80211_bss *bss; 744 745 bss = (void *)cbss->priv; 746#ifdef CONFIG_MAC80211_IBSS_DEBUG 747 pr_debug(" sta_find_ibss: selected %pM current %pM\n", 748 cbss->bssid, ifibss->bssid); 749#endif /* CONFIG_MAC80211_IBSS_DEBUG */ 750 751 pr_debug("%s: Selected IBSS BSSID %pM based on configured SSID\n", 752 sdata->name, cbss->bssid); 753 754 ieee80211_sta_join_ibss(sdata, bss); 755 ieee80211_rx_bss_put(local, bss); 756 return; 757 } 758 759#ifdef CONFIG_MAC80211_IBSS_DEBUG 760 pr_debug(" did not try to join ibss\n"); 761#endif /* CONFIG_MAC80211_IBSS_DEBUG */ 762 763 /* Selected IBSS not found in current scan results - try to scan */ 764 if (time_after(jiffies, ifibss->last_scan_completed + 765 IEEE80211_SCAN_INTERVAL)) { 766 pr_debug("%s: Trigger new scan to find an IBSS to join\n", 767 sdata->name); 768 769 ieee80211_request_internal_scan(sdata, 770 ifibss->ssid, ifibss->ssid_len, 771 ifibss->fixed_channel ? ifibss->channel : NULL); 772 } else { 773 int interval = IEEE80211_SCAN_INTERVAL; 774 775 if (time_after(jiffies, ifibss->ibss_join_req + 776 IEEE80211_IBSS_JOIN_TIMEOUT)) { 777 if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) { 778 ieee80211_sta_create_ibss(sdata); 779 return; 780 } 781 pr_debug("%s: IBSS not allowed on %d MHz\n", 782 sdata->name, 783 local->hw.conf.channel->center_freq); 784 785 /* No IBSS found - decrease scan interval and continue 786 * scanning. */ 787 interval = IEEE80211_SCAN_INTERVAL_SLOW; 788 } 789 790 mod_timer(&ifibss->timer, 791 round_jiffies(jiffies + interval)); 792 } 793} 794 795static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 796 struct sk_buff *req) 797{ 798 struct ieee80211_mgmt *mgmt = (void *)req->data; 799 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 800 struct ieee80211_local *local = sdata->local; 801 int tx_last_beacon, len = req->len; 802 struct sk_buff *skb; 803 struct ieee80211_mgmt *resp; 804 struct sk_buff *presp; 805 u8 *pos, *end; 806 807 lockdep_assert_held(&ifibss->mtx); 808 809 presp = rcu_dereference_protected(ifibss->presp, 810 lockdep_is_held(&ifibss->mtx)); 811 812 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 813 len < 24 + 2 || !presp) 814 return; 815 816 tx_last_beacon = drv_tx_last_beacon(local); 817 818#ifdef CONFIG_MAC80211_IBSS_DEBUG 819 pr_debug("%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n", 820 sdata->name, mgmt->sa, mgmt->da, 821 mgmt->bssid, tx_last_beacon); 822#endif /* CONFIG_MAC80211_IBSS_DEBUG */ 823 824 if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da)) 825 return; 826 827 if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) && 828 !is_broadcast_ether_addr(mgmt->bssid)) 829 return; 830 831 end = ((u8 *) mgmt) + len; 832 pos = mgmt->u.probe_req.variable; 833 if (pos[0] != WLAN_EID_SSID || 834 pos + 2 + pos[1] > end) { 835#ifdef CONFIG_MAC80211_IBSS_DEBUG 836 pr_debug("%s: Invalid SSID IE in ProbeReq from %pM\n", 837 sdata->name, mgmt->sa); 838#endif 839 return; 840 } 841 if (pos[1] != 0 && 842 (pos[1] != ifibss->ssid_len || 843 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 844 /* Ignore ProbeReq for foreign SSID */ 845 return; 846 } 847 848 /* Reply with ProbeResp */ 849 skb = skb_copy(presp, GFP_KERNEL); 850 if (!skb) 851 return; 852 853 resp = (struct ieee80211_mgmt *) skb->data; 854 memcpy(resp->da, mgmt->sa, ETH_ALEN); 855#ifdef CONFIG_MAC80211_IBSS_DEBUG 856 pr_debug("%s: Sending ProbeResp to %pM\n", sdata->name, resp->da); 857#endif /* CONFIG_MAC80211_IBSS_DEBUG */ 858 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 859 ieee80211_tx_skb(sdata, skb); 860} 861 862static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, 863 struct ieee80211_mgmt *mgmt, 864 size_t len, 865 struct ieee80211_rx_status *rx_status) 866{ 867 size_t baselen; 868 struct ieee802_11_elems elems; 869 870 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 871 if (baselen > len) 872 return; 873 874 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 875 &elems); 876 877 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false); 878} 879 880static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, 881 struct ieee80211_mgmt *mgmt, 882 size_t len, 883 struct ieee80211_rx_status *rx_status) 884{ 885 size_t baselen; 886 struct ieee802_11_elems elems; 887 888 /* Process beacon from the current BSS */ 889 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt; 890 if (baselen > len) 891 return; 892 893 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems); 894 895 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); 896} 897 898void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 899 struct sk_buff *skb) 900{ 901 struct ieee80211_rx_status *rx_status; 902 struct ieee80211_mgmt *mgmt; 903 u16 fc; 904 905 rx_status = IEEE80211_SKB_RXCB(skb); 906 mgmt = (struct ieee80211_mgmt *) skb->data; 907 fc = le16_to_cpu(mgmt->frame_control); 908 909 mutex_lock(&sdata->u.ibss.mtx); 910 911 if (!sdata->u.ibss.ssid_len) 912 goto mgmt_out; /* not ready to merge yet */ 913 914 switch (fc & IEEE80211_FCTL_STYPE) { 915 case IEEE80211_STYPE_PROBE_REQ: 916 ieee80211_rx_mgmt_probe_req(sdata, skb); 917 break; 918 case IEEE80211_STYPE_PROBE_RESP: 919 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, 920 rx_status); 921 break; 922 case IEEE80211_STYPE_BEACON: 923 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, 924 rx_status); 925 break; 926 case IEEE80211_STYPE_AUTH: 927 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 928 break; 929 } 930 931 mgmt_out: 932 mutex_unlock(&sdata->u.ibss.mtx); 933} 934 935void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata) 936{ 937 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 938 struct sta_info *sta; 939 940 mutex_lock(&ifibss->mtx); 941 942 /* 943 * Work could be scheduled after scan or similar 944 * when we aren't even joined (or trying) with a 945 * network. 946 */ 947 if (!ifibss->ssid_len) 948 goto out; 949 950 spin_lock_bh(&ifibss->incomplete_lock); 951 while (!list_empty(&ifibss->incomplete_stations)) { 952 sta = list_first_entry(&ifibss->incomplete_stations, 953 struct sta_info, list); 954 list_del(&sta->list); 955 spin_unlock_bh(&ifibss->incomplete_lock); 956 957 ieee80211_ibss_finish_sta(sta, true); 958 rcu_read_unlock(); 959 spin_lock_bh(&ifibss->incomplete_lock); 960 } 961 spin_unlock_bh(&ifibss->incomplete_lock); 962 963 switch (ifibss->state) { 964 case IEEE80211_IBSS_MLME_SEARCH: 965 ieee80211_sta_find_ibss(sdata); 966 break; 967 case IEEE80211_IBSS_MLME_JOINED: 968 ieee80211_sta_merge_ibss(sdata); 969 break; 970 default: 971 WARN_ON(1); 972 break; 973 } 974 975 out: 976 mutex_unlock(&ifibss->mtx); 977} 978 979static void ieee80211_ibss_timer(unsigned long data) 980{ 981 struct ieee80211_sub_if_data *sdata = 982 (struct ieee80211_sub_if_data *) data; 983 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 984 struct ieee80211_local *local = sdata->local; 985 986 if (local->quiescing) { 987 ifibss->timer_running = true; 988 return; 989 } 990 991 ieee80211_queue_work(&local->hw, &sdata->work); 992} 993 994#ifdef CONFIG_PM 995void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata) 996{ 997 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 998 999 if (del_timer_sync(&ifibss->timer)) 1000 ifibss->timer_running = true; 1001} 1002 1003void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata) 1004{ 1005 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1006 1007 if (ifibss->timer_running) { 1008 add_timer(&ifibss->timer); 1009 ifibss->timer_running = false; 1010 } 1011} 1012#endif 1013 1014void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 1015{ 1016 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1017 1018 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 1019 (unsigned long) sdata); 1020 mutex_init(&ifibss->mtx); 1021 INIT_LIST_HEAD(&ifibss->incomplete_stations); 1022 spin_lock_init(&ifibss->incomplete_lock); 1023} 1024 1025/* scan finished notification */ 1026void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 1027{ 1028 struct ieee80211_sub_if_data *sdata; 1029 1030 mutex_lock(&local->iflist_mtx); 1031 list_for_each_entry(sdata, &local->interfaces, list) { 1032 if (!ieee80211_sdata_running(sdata)) 1033 continue; 1034 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 1035 continue; 1036 sdata->u.ibss.last_scan_completed = jiffies; 1037 ieee80211_queue_work(&local->hw, &sdata->work); 1038 } 1039 mutex_unlock(&local->iflist_mtx); 1040} 1041 1042int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 1043 struct cfg80211_ibss_params *params) 1044{ 1045 struct sk_buff *skb; 1046 u32 changed = 0; 1047 1048 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom + 1049 sizeof(struct ieee80211_hdr_3addr) + 1050 12 /* struct ieee80211_mgmt.u.beacon */ + 1051 2 + IEEE80211_MAX_SSID_LEN /* max SSID */ + 1052 2 + 8 /* max Supported Rates */ + 1053 3 /* max DS params */ + 1054 4 /* IBSS params */ + 1055 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 1056 2 + sizeof(struct ieee80211_ht_cap) + 1057 2 + sizeof(struct ieee80211_ht_operation) + 1058 params->ie_len); 1059 if (!skb) 1060 return -ENOMEM; 1061 1062 mutex_lock(&sdata->u.ibss.mtx); 1063 1064 if (params->bssid) { 1065 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 1066 sdata->u.ibss.fixed_bssid = true; 1067 } else 1068 sdata->u.ibss.fixed_bssid = false; 1069 1070 sdata->u.ibss.privacy = params->privacy; 1071 sdata->u.ibss.control_port = params->control_port; 1072 sdata->u.ibss.basic_rates = params->basic_rates; 1073 memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate, 1074 sizeof(params->mcast_rate)); 1075 1076 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 1077 1078 sdata->u.ibss.channel = params->channel; 1079 sdata->u.ibss.channel_type = params->channel_type; 1080 sdata->u.ibss.fixed_channel = params->channel_fixed; 1081 1082 /* fix ourselves to that channel now already */ 1083 if (params->channel_fixed) { 1084 sdata->local->oper_channel = params->channel; 1085 if (!ieee80211_set_channel_type(sdata->local, sdata, 1086 params->channel_type)) { 1087 mutex_unlock(&sdata->u.ibss.mtx); 1088 kfree_skb(skb); 1089 return -EINVAL; 1090 } 1091 } 1092 1093 if (params->ie) { 1094 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 1095 GFP_KERNEL); 1096 if (sdata->u.ibss.ie) 1097 sdata->u.ibss.ie_len = params->ie_len; 1098 } 1099 1100 sdata->u.ibss.skb = skb; 1101 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1102 sdata->u.ibss.ibss_join_req = jiffies; 1103 1104 memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN); 1105 sdata->u.ibss.ssid_len = params->ssid_len; 1106 1107 mutex_unlock(&sdata->u.ibss.mtx); 1108 1109 mutex_lock(&sdata->local->mtx); 1110 ieee80211_recalc_idle(sdata->local); 1111 mutex_unlock(&sdata->local->mtx); 1112 1113 /* 1114 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is 1115 * reserved, but an HT STA shall protect HT transmissions as though 1116 * the HT Protection field were set to non-HT mixed mode. 1117 * 1118 * In an IBSS, the RIFS Mode field of the HT Operation element is 1119 * also reserved, but an HT STA shall operate as though this field 1120 * were set to 1. 1121 */ 1122 1123 sdata->vif.bss_conf.ht_operation_mode |= 1124 IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED 1125 | IEEE80211_HT_PARAM_RIFS_MODE; 1126 1127 changed |= BSS_CHANGED_HT; 1128 ieee80211_bss_info_change_notify(sdata, changed); 1129 1130 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1131 1132 return 0; 1133} 1134 1135int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 1136{ 1137 struct sk_buff *skb; 1138 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1139 struct ieee80211_local *local = sdata->local; 1140 struct cfg80211_bss *cbss; 1141 u16 capability; 1142 int active_ibss; 1143 struct sta_info *sta; 1144 1145 mutex_lock(&sdata->u.ibss.mtx); 1146 1147 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1148 memset(sdata->u.ibss.bssid, 0, ETH_ALEN); 1149 sdata->u.ibss.ssid_len = 0; 1150 1151 active_ibss = ieee80211_sta_active_ibss(sdata); 1152 1153 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) { 1154 capability = WLAN_CAPABILITY_IBSS; 1155 1156 if (ifibss->privacy) 1157 capability |= WLAN_CAPABILITY_PRIVACY; 1158 1159 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel, 1160 ifibss->bssid, ifibss->ssid, 1161 ifibss->ssid_len, WLAN_CAPABILITY_IBSS | 1162 WLAN_CAPABILITY_PRIVACY, 1163 capability); 1164 1165 if (cbss) { 1166 cfg80211_unlink_bss(local->hw.wiphy, cbss); 1167 cfg80211_put_bss(cbss); 1168 } 1169 } 1170 1171 sta_info_flush(sdata->local, sdata); 1172 1173 spin_lock_bh(&ifibss->incomplete_lock); 1174 while (!list_empty(&ifibss->incomplete_stations)) { 1175 sta = list_first_entry(&ifibss->incomplete_stations, 1176 struct sta_info, list); 1177 list_del(&sta->list); 1178 spin_unlock_bh(&ifibss->incomplete_lock); 1179 1180 sta_info_free(local, sta); 1181 spin_lock_bh(&ifibss->incomplete_lock); 1182 } 1183 spin_unlock_bh(&ifibss->incomplete_lock); 1184 1185 netif_carrier_off(sdata->dev); 1186 1187 /* remove beacon */ 1188 kfree(sdata->u.ibss.ie); 1189 skb = rcu_dereference_protected(sdata->u.ibss.presp, 1190 lockdep_is_held(&sdata->u.ibss.mtx)); 1191 RCU_INIT_POINTER(sdata->u.ibss.presp, NULL); 1192 sdata->vif.bss_conf.ibss_joined = false; 1193 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | 1194 BSS_CHANGED_IBSS); 1195 synchronize_rcu(); 1196 kfree_skb(skb); 1197 1198 skb_queue_purge(&sdata->skb_queue); 1199 1200 del_timer_sync(&sdata->u.ibss.timer); 1201 1202 mutex_unlock(&sdata->u.ibss.mtx); 1203 1204 mutex_lock(&local->mtx); 1205 ieee80211_recalc_idle(sdata->local); 1206 mutex_unlock(&local->mtx); 1207 1208 return 0; 1209} 1210