ibss.c revision 83d5cc012441531ab0bf6f99881958e964e9cf11
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 39static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 40 const u8 *bssid, const int beacon_int, 41 struct ieee80211_channel *chan, 42 const u32 basic_rates, 43 const u16 capability, u64 tsf) 44{ 45 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 46 struct ieee80211_local *local = sdata->local; 47 int rates, i; 48 struct sk_buff *skb; 49 struct ieee80211_mgmt *mgmt; 50 u8 *pos; 51 struct ieee80211_supported_band *sband; 52 struct cfg80211_bss *bss; 53 u32 bss_change; 54 u8 supp_rates[IEEE80211_MAX_SUPP_RATES]; 55 enum nl80211_channel_type channel_type; 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 skb = ifibss->skb; 63 RCU_INIT_POINTER(ifibss->presp, NULL); 64 synchronize_rcu(); 65 skb->data = skb->head; 66 skb->len = 0; 67 skb_reset_tail_pointer(skb); 68 skb_reserve(skb, sdata->local->hw.extra_tx_headroom); 69 70 if (memcmp(ifibss->bssid, bssid, ETH_ALEN)) 71 sta_info_flush(sdata->local, sdata); 72 73 /* if merging, indicate to driver that we leave the old IBSS */ 74 if (sdata->vif.bss_conf.ibss_joined) { 75 sdata->vif.bss_conf.ibss_joined = false; 76 netif_carrier_off(sdata->dev); 77 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS); 78 } 79 80 memcpy(ifibss->bssid, bssid, ETH_ALEN); 81 82 sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0; 83 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_info)); 164 pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, 165 sband->ht_cap.cap); 166 pos = ieee80211_ie_build_ht_info(pos, 167 &sband->ht_cap, 168 chan, 169 channel_type); 170 } 171 172 if (local->hw.queues >= 4) { 173 pos = skb_put(skb, 9); 174 *pos++ = WLAN_EID_VENDOR_SPECIFIC; 175 *pos++ = 7; /* len */ 176 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */ 177 *pos++ = 0x50; 178 *pos++ = 0xf2; 179 *pos++ = 2; /* WME */ 180 *pos++ = 0; /* WME info */ 181 *pos++ = 1; /* WME ver */ 182 *pos++ = 0; /* U-APSD no in use */ 183 } 184 185 rcu_assign_pointer(ifibss->presp, skb); 186 187 sdata->vif.bss_conf.beacon_int = beacon_int; 188 sdata->vif.bss_conf.basic_rates = basic_rates; 189 bss_change = BSS_CHANGED_BEACON_INT; 190 bss_change |= ieee80211_reset_erp_info(sdata); 191 bss_change |= BSS_CHANGED_BSSID; 192 bss_change |= BSS_CHANGED_BEACON; 193 bss_change |= BSS_CHANGED_BEACON_ENABLED; 194 bss_change |= BSS_CHANGED_BASIC_RATES; 195 bss_change |= BSS_CHANGED_HT; 196 bss_change |= BSS_CHANGED_IBSS; 197 sdata->vif.bss_conf.ibss_joined = true; 198 ieee80211_bss_info_change_notify(sdata, bss_change); 199 200 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 201 202 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 203 mod_timer(&ifibss->timer, 204 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 205 206 bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel, 207 mgmt, skb->len, 0, GFP_KERNEL); 208 cfg80211_put_bss(bss); 209 netif_carrier_on(sdata->dev); 210 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 211} 212 213static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 214 struct ieee80211_bss *bss) 215{ 216 struct cfg80211_bss *cbss = 217 container_of((void *)bss, struct cfg80211_bss, priv); 218 struct ieee80211_supported_band *sband; 219 u32 basic_rates; 220 int i, j; 221 u16 beacon_int = cbss->beacon_interval; 222 223 lockdep_assert_held(&sdata->u.ibss.mtx); 224 225 if (beacon_int < 10) 226 beacon_int = 10; 227 228 sband = sdata->local->hw.wiphy->bands[cbss->channel->band]; 229 230 basic_rates = 0; 231 232 for (i = 0; i < bss->supp_rates_len; i++) { 233 int rate = (bss->supp_rates[i] & 0x7f) * 5; 234 bool is_basic = !!(bss->supp_rates[i] & 0x80); 235 236 for (j = 0; j < sband->n_bitrates; j++) { 237 if (sband->bitrates[j].bitrate == rate) { 238 if (is_basic) 239 basic_rates |= BIT(j); 240 break; 241 } 242 } 243 } 244 245 __ieee80211_sta_join_ibss(sdata, cbss->bssid, 246 beacon_int, 247 cbss->channel, 248 basic_rates, 249 cbss->capability, 250 cbss->tsf); 251} 252 253static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta, 254 bool auth) 255 __acquires(RCU) 256{ 257 struct ieee80211_sub_if_data *sdata = sta->sdata; 258 u8 addr[ETH_ALEN]; 259 260 memcpy(addr, sta->sta.addr, ETH_ALEN); 261 262#ifdef CONFIG_MAC80211_VERBOSE_DEBUG 263 wiphy_debug(sdata->local->hw.wiphy, 264 "Adding new IBSS station %pM (dev=%s)\n", 265 addr, sdata->name); 266#endif 267 268 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 269 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 270 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 271 272 rate_control_rate_init(sta); 273 274 /* If it fails, maybe we raced another insertion? */ 275 if (sta_info_insert_rcu(sta)) 276 return sta_info_get(sdata, addr); 277 if (auth) { 278#ifdef CONFIG_MAC80211_IBSS_DEBUG 279 printk(KERN_DEBUG "TX Auth SA=%pM DA=%pM BSSID=%pM" 280 "(auth_transaction=1)\n", sdata->vif.addr, 281 sdata->u.ibss.bssid, addr); 282#endif 283 ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, NULL, 0, 284 addr, sdata->u.ibss.bssid, NULL, 0, 0); 285 } 286 return sta; 287} 288 289static struct sta_info * 290ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 291 const u8 *bssid, const u8 *addr, 292 u32 supp_rates, bool auth) 293 __acquires(RCU) 294{ 295 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 296 struct ieee80211_local *local = sdata->local; 297 struct sta_info *sta; 298 int band = local->hw.conf.channel->band; 299 300 /* 301 * XXX: Consider removing the least recently used entry and 302 * allow new one to be added. 303 */ 304 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 305 if (net_ratelimit()) 306 printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n", 307 sdata->name, addr); 308 rcu_read_lock(); 309 return NULL; 310 } 311 312 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) { 313 rcu_read_lock(); 314 return NULL; 315 } 316 317 if (compare_ether_addr(bssid, sdata->u.ibss.bssid)) { 318 rcu_read_lock(); 319 return NULL; 320 } 321 322 sta = sta_info_alloc(sdata, addr, GFP_KERNEL); 323 if (!sta) { 324 rcu_read_lock(); 325 return NULL; 326 } 327 328 sta->last_rx = jiffies; 329 330 /* make sure mandatory rates are always added */ 331 sta->sta.supp_rates[band] = supp_rates | 332 ieee80211_mandatory_rates(local, band); 333 334 return ieee80211_ibss_finish_sta(sta, auth); 335} 336 337static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, 338 struct ieee80211_mgmt *mgmt, 339 size_t len) 340{ 341 u16 auth_alg, auth_transaction; 342 343 lockdep_assert_held(&sdata->u.ibss.mtx); 344 345 if (len < 24 + 6) 346 return; 347 348 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 349 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 350 351 if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1) 352 return; 353#ifdef CONFIG_MAC80211_IBSS_DEBUG 354 printk(KERN_DEBUG "%s: RX Auth SA=%pM DA=%pM BSSID=%pM." 355 "(auth_transaction=%d)\n", 356 sdata->name, mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction); 357#endif 358 sta_info_destroy_addr(sdata, mgmt->sa); 359 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false); 360 rcu_read_unlock(); 361 362 /* 363 * IEEE 802.11 standard does not require authentication in IBSS 364 * networks and most implementations do not seem to use it. 365 * However, try to reply to authentication attempts if someone 366 * has actually implemented this. 367 */ 368 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0, 369 mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0); 370} 371 372static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 373 struct ieee80211_mgmt *mgmt, 374 size_t len, 375 struct ieee80211_rx_status *rx_status, 376 struct ieee802_11_elems *elems, 377 bool beacon) 378{ 379 struct ieee80211_local *local = sdata->local; 380 int freq; 381 struct cfg80211_bss *cbss; 382 struct ieee80211_bss *bss; 383 struct sta_info *sta; 384 struct ieee80211_channel *channel; 385 u64 beacon_timestamp, rx_timestamp; 386 u32 supp_rates = 0; 387 enum ieee80211_band band = rx_status->band; 388 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 389 bool rates_updated = false; 390 391 if (elems->ds_params && elems->ds_params_len == 1) 392 freq = ieee80211_channel_to_frequency(elems->ds_params[0], 393 band); 394 else 395 freq = rx_status->freq; 396 397 channel = ieee80211_get_channel(local->hw.wiphy, freq); 398 399 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 400 return; 401 402 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && 403 memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) { 404 405 rcu_read_lock(); 406 sta = sta_info_get(sdata, mgmt->sa); 407 408 if (elems->supp_rates) { 409 supp_rates = ieee80211_sta_get_rates(local, elems, 410 band); 411 if (sta) { 412 u32 prev_rates; 413 414 prev_rates = sta->sta.supp_rates[band]; 415 /* make sure mandatory rates are always added */ 416 sta->sta.supp_rates[band] = supp_rates | 417 ieee80211_mandatory_rates(local, band); 418 419 if (sta->sta.supp_rates[band] != prev_rates) { 420#ifdef CONFIG_MAC80211_IBSS_DEBUG 421 printk(KERN_DEBUG 422 "%s: updated supp_rates set " 423 "for %pM based on beacon" 424 "/probe_resp (0x%x -> 0x%x)\n", 425 sdata->name, sta->sta.addr, 426 prev_rates, 427 sta->sta.supp_rates[band]); 428#endif 429 rates_updated = true; 430 } 431 } else { 432 rcu_read_unlock(); 433 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, 434 mgmt->sa, supp_rates, true); 435 } 436 } 437 438 if (sta && elems->wmm_info) 439 set_sta_flag(sta, WLAN_STA_WME); 440 441 if (sta && elems->ht_info_elem && elems->ht_cap_elem && 442 sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) { 443 /* we both use HT */ 444 struct ieee80211_sta_ht_cap sta_ht_cap_new; 445 enum nl80211_channel_type channel_type = 446 ieee80211_ht_info_to_channel_type( 447 elems->ht_info_elem); 448 449 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 450 elems->ht_cap_elem, 451 &sta_ht_cap_new); 452 453 /* 454 * fall back to HT20 if we don't use or use 455 * the other extension channel 456 */ 457 if ((channel_type == NL80211_CHAN_HT40MINUS || 458 channel_type == NL80211_CHAN_HT40PLUS) && 459 channel_type != sdata->u.ibss.channel_type) 460 sta_ht_cap_new.cap &= 461 ~IEEE80211_HT_CAP_SUP_WIDTH_20_40; 462 463 if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new, 464 sizeof(sta_ht_cap_new))) { 465 memcpy(&sta->sta.ht_cap, &sta_ht_cap_new, 466 sizeof(sta_ht_cap_new)); 467 rates_updated = true; 468 } 469 } 470 471 if (sta && rates_updated) 472 rate_control_rate_init(sta); 473 474 rcu_read_unlock(); 475 } 476 477 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 478 channel, beacon); 479 if (!bss) 480 return; 481 482 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 483 484 /* was just updated in ieee80211_bss_info_update */ 485 beacon_timestamp = cbss->tsf; 486 487 /* check if we need to merge IBSS */ 488 489 /* we use a fixed BSSID */ 490 if (sdata->u.ibss.fixed_bssid) 491 goto put_bss; 492 493 /* not an IBSS */ 494 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 495 goto put_bss; 496 497 /* different channel */ 498 if (cbss->channel != local->oper_channel) 499 goto put_bss; 500 501 /* different SSID */ 502 if (elems->ssid_len != sdata->u.ibss.ssid_len || 503 memcmp(elems->ssid, sdata->u.ibss.ssid, 504 sdata->u.ibss.ssid_len)) 505 goto put_bss; 506 507 /* same BSSID */ 508 if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) 509 goto put_bss; 510 511 if (rx_status->flag & RX_FLAG_MACTIME_MPDU) { 512 /* 513 * For correct IBSS merging we need mactime; since mactime is 514 * defined as the time the first data symbol of the frame hits 515 * the PHY, and the timestamp of the beacon is defined as "the 516 * time that the data symbol containing the first bit of the 517 * timestamp is transmitted to the PHY plus the transmitting 518 * STA's delays through its local PHY from the MAC-PHY 519 * interface to its interface with the WM" (802.11 11.1.2) 520 * - equals the time this bit arrives at the receiver - we have 521 * to take into account the offset between the two. 522 * 523 * E.g. at 1 MBit that means mactime is 192 usec earlier 524 * (=24 bytes * 8 usecs/byte) than the beacon timestamp. 525 */ 526 int rate; 527 528 if (rx_status->flag & RX_FLAG_HT) 529 rate = 65; /* TODO: HT rates */ 530 else 531 rate = local->hw.wiphy->bands[band]-> 532 bitrates[rx_status->rate_idx].bitrate; 533 534 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate); 535 } else { 536 /* 537 * second best option: get current TSF 538 * (will return -1 if not supported) 539 */ 540 rx_timestamp = drv_get_tsf(local, sdata); 541 } 542 543#ifdef CONFIG_MAC80211_IBSS_DEBUG 544 printk(KERN_DEBUG "RX beacon SA=%pM BSSID=" 545 "%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 printk(KERN_DEBUG "%s: beacon TSF higher than " 556 "local TSF - IBSS merge with BSSID %pM\n", 557 sdata->name, mgmt->bssid); 558#endif 559 ieee80211_sta_join_ibss(sdata, bss); 560 supp_rates = ieee80211_sta_get_rates(local, elems, band); 561 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 562 supp_rates, true); 563 rcu_read_unlock(); 564 } 565 566 put_bss: 567 ieee80211_rx_bss_put(local, bss); 568} 569 570void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata, 571 const u8 *bssid, const u8 *addr, 572 u32 supp_rates) 573{ 574 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 575 struct ieee80211_local *local = sdata->local; 576 struct sta_info *sta; 577 int band = local->hw.conf.channel->band; 578 579 /* 580 * XXX: Consider removing the least recently used entry and 581 * allow new one to be added. 582 */ 583 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 584 if (net_ratelimit()) 585 printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n", 586 sdata->name, addr); 587 return; 588 } 589 590 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 591 return; 592 593 if (compare_ether_addr(bssid, sdata->u.ibss.bssid)) 594 return; 595 596 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC); 597 if (!sta) 598 return; 599 600 sta->last_rx = jiffies; 601 602 /* make sure mandatory rates are always added */ 603 sta->sta.supp_rates[band] = supp_rates | 604 ieee80211_mandatory_rates(local, band); 605 606 spin_lock(&ifibss->incomplete_lock); 607 list_add(&sta->list, &ifibss->incomplete_stations); 608 spin_unlock(&ifibss->incomplete_lock); 609 ieee80211_queue_work(&local->hw, &sdata->work); 610} 611 612static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 613{ 614 struct ieee80211_local *local = sdata->local; 615 int active = 0; 616 struct sta_info *sta; 617 618 lockdep_assert_held(&sdata->u.ibss.mtx); 619 620 rcu_read_lock(); 621 622 list_for_each_entry_rcu(sta, &local->sta_list, list) { 623 if (sta->sdata == sdata && 624 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 625 jiffies)) { 626 active++; 627 break; 628 } 629 } 630 631 rcu_read_unlock(); 632 633 return active; 634} 635 636/* 637 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 638 */ 639 640static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 641{ 642 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 643 644 lockdep_assert_held(&ifibss->mtx); 645 646 mod_timer(&ifibss->timer, 647 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 648 649 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 650 651 if (time_before(jiffies, ifibss->last_scan_completed + 652 IEEE80211_IBSS_MERGE_INTERVAL)) 653 return; 654 655 if (ieee80211_sta_active_ibss(sdata)) 656 return; 657 658 if (ifibss->fixed_channel) 659 return; 660 661 printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other " 662 "IBSS networks with same SSID (merge)\n", sdata->name); 663 664 ieee80211_request_internal_scan(sdata, 665 ifibss->ssid, ifibss->ssid_len, NULL); 666} 667 668static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 669{ 670 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 671 u8 bssid[ETH_ALEN]; 672 u16 capability; 673 int i; 674 675 lockdep_assert_held(&ifibss->mtx); 676 677 if (ifibss->fixed_bssid) { 678 memcpy(bssid, ifibss->bssid, ETH_ALEN); 679 } else { 680 /* Generate random, not broadcast, locally administered BSSID. Mix in 681 * own MAC address to make sure that devices that do not have proper 682 * random number generator get different BSSID. */ 683 get_random_bytes(bssid, ETH_ALEN); 684 for (i = 0; i < ETH_ALEN; i++) 685 bssid[i] ^= sdata->vif.addr[i]; 686 bssid[0] &= ~0x01; 687 bssid[0] |= 0x02; 688 } 689 690 printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n", 691 sdata->name, bssid); 692 693 capability = WLAN_CAPABILITY_IBSS; 694 695 if (ifibss->privacy) 696 capability |= WLAN_CAPABILITY_PRIVACY; 697 else 698 sdata->drop_unencrypted = 0; 699 700 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 701 ifibss->channel, ifibss->basic_rates, 702 capability, 0); 703} 704 705/* 706 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 707 */ 708 709static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 710{ 711 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 712 struct ieee80211_local *local = sdata->local; 713 struct cfg80211_bss *cbss; 714 struct ieee80211_channel *chan = NULL; 715 const u8 *bssid = NULL; 716 int active_ibss; 717 u16 capability; 718 719 lockdep_assert_held(&ifibss->mtx); 720 721 active_ibss = ieee80211_sta_active_ibss(sdata); 722#ifdef CONFIG_MAC80211_IBSS_DEBUG 723 printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n", 724 sdata->name, active_ibss); 725#endif /* CONFIG_MAC80211_IBSS_DEBUG */ 726 727 if (active_ibss) 728 return; 729 730 capability = WLAN_CAPABILITY_IBSS; 731 if (ifibss->privacy) 732 capability |= WLAN_CAPABILITY_PRIVACY; 733 if (ifibss->fixed_bssid) 734 bssid = ifibss->bssid; 735 if (ifibss->fixed_channel) 736 chan = ifibss->channel; 737 if (!is_zero_ether_addr(ifibss->bssid)) 738 bssid = ifibss->bssid; 739 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 740 ifibss->ssid, ifibss->ssid_len, 741 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 742 capability); 743 744 if (cbss) { 745 struct ieee80211_bss *bss; 746 747 bss = (void *)cbss->priv; 748#ifdef CONFIG_MAC80211_IBSS_DEBUG 749 printk(KERN_DEBUG " sta_find_ibss: selected %pM current " 750 "%pM\n", cbss->bssid, ifibss->bssid); 751#endif /* CONFIG_MAC80211_IBSS_DEBUG */ 752 753 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM" 754 " based on configured SSID\n", 755 sdata->name, cbss->bssid); 756 757 ieee80211_sta_join_ibss(sdata, bss); 758 ieee80211_rx_bss_put(local, bss); 759 return; 760 } 761 762#ifdef CONFIG_MAC80211_IBSS_DEBUG 763 printk(KERN_DEBUG " did not try to join ibss\n"); 764#endif /* CONFIG_MAC80211_IBSS_DEBUG */ 765 766 /* Selected IBSS not found in current scan results - try to scan */ 767 if (time_after(jiffies, ifibss->last_scan_completed + 768 IEEE80211_SCAN_INTERVAL)) { 769 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to " 770 "join\n", sdata->name); 771 772 ieee80211_request_internal_scan(sdata, 773 ifibss->ssid, ifibss->ssid_len, 774 ifibss->fixed_channel ? ifibss->channel : NULL); 775 } else { 776 int interval = IEEE80211_SCAN_INTERVAL; 777 778 if (time_after(jiffies, ifibss->ibss_join_req + 779 IEEE80211_IBSS_JOIN_TIMEOUT)) { 780 if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) { 781 ieee80211_sta_create_ibss(sdata); 782 return; 783 } 784 printk(KERN_DEBUG "%s: IBSS not allowed on" 785 " %d MHz\n", sdata->name, 786 local->hw.conf.channel->center_freq); 787 788 /* No IBSS found - decrease scan interval and continue 789 * scanning. */ 790 interval = IEEE80211_SCAN_INTERVAL_SLOW; 791 } 792 793 mod_timer(&ifibss->timer, 794 round_jiffies(jiffies + interval)); 795 } 796} 797 798static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 799 struct sk_buff *req) 800{ 801 struct ieee80211_mgmt *mgmt = (void *)req->data; 802 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 803 struct ieee80211_local *local = sdata->local; 804 int tx_last_beacon, len = req->len; 805 struct sk_buff *skb; 806 struct ieee80211_mgmt *resp; 807 struct sk_buff *presp; 808 u8 *pos, *end; 809 810 lockdep_assert_held(&ifibss->mtx); 811 812 presp = rcu_dereference_protected(ifibss->presp, 813 lockdep_is_held(&ifibss->mtx)); 814 815 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 816 len < 24 + 2 || !presp) 817 return; 818 819 tx_last_beacon = drv_tx_last_beacon(local); 820 821#ifdef CONFIG_MAC80211_IBSS_DEBUG 822 printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM" 823 " (tx_last_beacon=%d)\n", 824 sdata->name, mgmt->sa, mgmt->da, 825 mgmt->bssid, tx_last_beacon); 826#endif /* CONFIG_MAC80211_IBSS_DEBUG */ 827 828 if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da)) 829 return; 830 831 if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 && 832 memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0) 833 return; 834 835 end = ((u8 *) mgmt) + len; 836 pos = mgmt->u.probe_req.variable; 837 if (pos[0] != WLAN_EID_SSID || 838 pos + 2 + pos[1] > end) { 839#ifdef CONFIG_MAC80211_IBSS_DEBUG 840 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq " 841 "from %pM\n", 842 sdata->name, mgmt->sa); 843#endif 844 return; 845 } 846 if (pos[1] != 0 && 847 (pos[1] != ifibss->ssid_len || 848 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 849 /* Ignore ProbeReq for foreign SSID */ 850 return; 851 } 852 853 /* Reply with ProbeResp */ 854 skb = skb_copy(presp, GFP_KERNEL); 855 if (!skb) 856 return; 857 858 resp = (struct ieee80211_mgmt *) skb->data; 859 memcpy(resp->da, mgmt->sa, ETH_ALEN); 860#ifdef CONFIG_MAC80211_IBSS_DEBUG 861 printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n", 862 sdata->name, resp->da); 863#endif /* CONFIG_MAC80211_IBSS_DEBUG */ 864 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 865 ieee80211_tx_skb(sdata, skb); 866} 867 868static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, 869 struct ieee80211_mgmt *mgmt, 870 size_t len, 871 struct ieee80211_rx_status *rx_status) 872{ 873 size_t baselen; 874 struct ieee802_11_elems elems; 875 876 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 877 if (baselen > len) 878 return; 879 880 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 881 &elems); 882 883 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false); 884} 885 886static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, 887 struct ieee80211_mgmt *mgmt, 888 size_t len, 889 struct ieee80211_rx_status *rx_status) 890{ 891 size_t baselen; 892 struct ieee802_11_elems elems; 893 894 /* Process beacon from the current BSS */ 895 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt; 896 if (baselen > len) 897 return; 898 899 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems); 900 901 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); 902} 903 904void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 905 struct sk_buff *skb) 906{ 907 struct ieee80211_rx_status *rx_status; 908 struct ieee80211_mgmt *mgmt; 909 u16 fc; 910 911 rx_status = IEEE80211_SKB_RXCB(skb); 912 mgmt = (struct ieee80211_mgmt *) skb->data; 913 fc = le16_to_cpu(mgmt->frame_control); 914 915 mutex_lock(&sdata->u.ibss.mtx); 916 917 if (!sdata->u.ibss.ssid_len) 918 goto mgmt_out; /* not ready to merge yet */ 919 920 switch (fc & IEEE80211_FCTL_STYPE) { 921 case IEEE80211_STYPE_PROBE_REQ: 922 ieee80211_rx_mgmt_probe_req(sdata, skb); 923 break; 924 case IEEE80211_STYPE_PROBE_RESP: 925 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, 926 rx_status); 927 break; 928 case IEEE80211_STYPE_BEACON: 929 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, 930 rx_status); 931 break; 932 case IEEE80211_STYPE_AUTH: 933 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 934 break; 935 } 936 937 mgmt_out: 938 mutex_unlock(&sdata->u.ibss.mtx); 939} 940 941void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata) 942{ 943 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 944 struct sta_info *sta; 945 946 mutex_lock(&ifibss->mtx); 947 948 /* 949 * Work could be scheduled after scan or similar 950 * when we aren't even joined (or trying) with a 951 * network. 952 */ 953 if (!ifibss->ssid_len) 954 goto out; 955 956 spin_lock_bh(&ifibss->incomplete_lock); 957 while (!list_empty(&ifibss->incomplete_stations)) { 958 sta = list_first_entry(&ifibss->incomplete_stations, 959 struct sta_info, list); 960 list_del(&sta->list); 961 spin_unlock_bh(&ifibss->incomplete_lock); 962 963 ieee80211_ibss_finish_sta(sta, true); 964 rcu_read_unlock(); 965 spin_lock_bh(&ifibss->incomplete_lock); 966 } 967 spin_unlock_bh(&ifibss->incomplete_lock); 968 969 switch (ifibss->state) { 970 case IEEE80211_IBSS_MLME_SEARCH: 971 ieee80211_sta_find_ibss(sdata); 972 break; 973 case IEEE80211_IBSS_MLME_JOINED: 974 ieee80211_sta_merge_ibss(sdata); 975 break; 976 default: 977 WARN_ON(1); 978 break; 979 } 980 981 out: 982 mutex_unlock(&ifibss->mtx); 983} 984 985static void ieee80211_ibss_timer(unsigned long data) 986{ 987 struct ieee80211_sub_if_data *sdata = 988 (struct ieee80211_sub_if_data *) data; 989 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 990 struct ieee80211_local *local = sdata->local; 991 992 if (local->quiescing) { 993 ifibss->timer_running = true; 994 return; 995 } 996 997 ieee80211_queue_work(&local->hw, &sdata->work); 998} 999 1000#ifdef CONFIG_PM 1001void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata) 1002{ 1003 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1004 1005 if (del_timer_sync(&ifibss->timer)) 1006 ifibss->timer_running = true; 1007} 1008 1009void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata) 1010{ 1011 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1012 1013 if (ifibss->timer_running) { 1014 add_timer(&ifibss->timer); 1015 ifibss->timer_running = false; 1016 } 1017} 1018#endif 1019 1020void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 1021{ 1022 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1023 1024 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 1025 (unsigned long) sdata); 1026 mutex_init(&ifibss->mtx); 1027 INIT_LIST_HEAD(&ifibss->incomplete_stations); 1028 spin_lock_init(&ifibss->incomplete_lock); 1029} 1030 1031/* scan finished notification */ 1032void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 1033{ 1034 struct ieee80211_sub_if_data *sdata; 1035 1036 mutex_lock(&local->iflist_mtx); 1037 list_for_each_entry(sdata, &local->interfaces, list) { 1038 if (!ieee80211_sdata_running(sdata)) 1039 continue; 1040 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 1041 continue; 1042 sdata->u.ibss.last_scan_completed = jiffies; 1043 ieee80211_queue_work(&local->hw, &sdata->work); 1044 } 1045 mutex_unlock(&local->iflist_mtx); 1046} 1047 1048int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 1049 struct cfg80211_ibss_params *params) 1050{ 1051 struct sk_buff *skb; 1052 u32 changed = 0; 1053 1054 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom + 1055 sizeof(struct ieee80211_hdr_3addr) + 1056 12 /* struct ieee80211_mgmt.u.beacon */ + 1057 2 + IEEE80211_MAX_SSID_LEN /* max SSID */ + 1058 2 + 8 /* max Supported Rates */ + 1059 3 /* max DS params */ + 1060 4 /* IBSS params */ + 1061 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 1062 2 + sizeof(struct ieee80211_ht_cap) + 1063 2 + sizeof(struct ieee80211_ht_info) + 1064 params->ie_len); 1065 if (!skb) 1066 return -ENOMEM; 1067 1068 mutex_lock(&sdata->u.ibss.mtx); 1069 1070 if (params->bssid) { 1071 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 1072 sdata->u.ibss.fixed_bssid = true; 1073 } else 1074 sdata->u.ibss.fixed_bssid = false; 1075 1076 sdata->u.ibss.privacy = params->privacy; 1077 sdata->u.ibss.basic_rates = params->basic_rates; 1078 memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate, 1079 sizeof(params->mcast_rate)); 1080 1081 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 1082 1083 sdata->u.ibss.channel = params->channel; 1084 sdata->u.ibss.channel_type = params->channel_type; 1085 sdata->u.ibss.fixed_channel = params->channel_fixed; 1086 1087 /* fix ourselves to that channel now already */ 1088 if (params->channel_fixed) { 1089 sdata->local->oper_channel = params->channel; 1090 if (!ieee80211_set_channel_type(sdata->local, sdata, 1091 params->channel_type)) { 1092 mutex_unlock(&sdata->u.ibss.mtx); 1093 kfree_skb(skb); 1094 return -EINVAL; 1095 } 1096 } 1097 1098 if (params->ie) { 1099 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 1100 GFP_KERNEL); 1101 if (sdata->u.ibss.ie) 1102 sdata->u.ibss.ie_len = params->ie_len; 1103 } 1104 1105 sdata->u.ibss.skb = skb; 1106 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1107 sdata->u.ibss.ibss_join_req = jiffies; 1108 1109 memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN); 1110 sdata->u.ibss.ssid_len = params->ssid_len; 1111 1112 mutex_unlock(&sdata->u.ibss.mtx); 1113 1114 mutex_lock(&sdata->local->mtx); 1115 ieee80211_recalc_idle(sdata->local); 1116 mutex_unlock(&sdata->local->mtx); 1117 1118 /* 1119 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is 1120 * reserved, but an HT STA shall protect HT transmissions as though 1121 * the HT Protection field were set to non-HT mixed mode. 1122 * 1123 * In an IBSS, the RIFS Mode field of the HT Operation element is 1124 * also reserved, but an HT STA shall operate as though this field 1125 * were set to 1. 1126 */ 1127 1128 sdata->vif.bss_conf.ht_operation_mode |= 1129 IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED 1130 | IEEE80211_HT_PARAM_RIFS_MODE; 1131 1132 changed |= BSS_CHANGED_HT; 1133 ieee80211_bss_info_change_notify(sdata, changed); 1134 1135 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1136 1137 return 0; 1138} 1139 1140int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 1141{ 1142 struct sk_buff *skb; 1143 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1144 struct ieee80211_local *local = sdata->local; 1145 struct cfg80211_bss *cbss; 1146 u16 capability; 1147 int active_ibss; 1148 struct sta_info *sta; 1149 1150 mutex_lock(&sdata->u.ibss.mtx); 1151 1152 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1153 memset(sdata->u.ibss.bssid, 0, ETH_ALEN); 1154 sdata->u.ibss.ssid_len = 0; 1155 1156 active_ibss = ieee80211_sta_active_ibss(sdata); 1157 1158 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) { 1159 capability = WLAN_CAPABILITY_IBSS; 1160 1161 if (ifibss->privacy) 1162 capability |= WLAN_CAPABILITY_PRIVACY; 1163 1164 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel, 1165 ifibss->bssid, ifibss->ssid, 1166 ifibss->ssid_len, WLAN_CAPABILITY_IBSS | 1167 WLAN_CAPABILITY_PRIVACY, 1168 capability); 1169 1170 if (cbss) { 1171 cfg80211_unlink_bss(local->hw.wiphy, cbss); 1172 cfg80211_put_bss(cbss); 1173 } 1174 } 1175 1176 sta_info_flush(sdata->local, sdata); 1177 1178 spin_lock_bh(&ifibss->incomplete_lock); 1179 while (!list_empty(&ifibss->incomplete_stations)) { 1180 sta = list_first_entry(&ifibss->incomplete_stations, 1181 struct sta_info, list); 1182 list_del(&sta->list); 1183 spin_unlock_bh(&ifibss->incomplete_lock); 1184 1185 sta_info_free(local, sta); 1186 spin_lock_bh(&ifibss->incomplete_lock); 1187 } 1188 spin_unlock_bh(&ifibss->incomplete_lock); 1189 1190 netif_carrier_off(sdata->dev); 1191 1192 /* remove beacon */ 1193 kfree(sdata->u.ibss.ie); 1194 skb = rcu_dereference_protected(sdata->u.ibss.presp, 1195 lockdep_is_held(&sdata->u.ibss.mtx)); 1196 RCU_INIT_POINTER(sdata->u.ibss.presp, NULL); 1197 sdata->vif.bss_conf.ibss_joined = false; 1198 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | 1199 BSS_CHANGED_IBSS); 1200 synchronize_rcu(); 1201 kfree_skb(skb); 1202 1203 skb_queue_purge(&sdata->skb_queue); 1204 1205 del_timer_sync(&sdata->u.ibss.timer); 1206 1207 mutex_unlock(&sdata->u.ibss.mtx); 1208 1209 mutex_lock(&local->mtx); 1210 ieee80211_recalc_idle(sdata->local); 1211 mutex_unlock(&local->mtx); 1212 1213 return 0; 1214} 1215