ibss.c revision 499f42bb03a9bd8a23f73e7c3886f70f52e7edc5
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 ibss_vdbg("TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n", 285 sdata->vif.addr, sdata->u.ibss.bssid, addr); 286 ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, NULL, 0, 287 addr, sdata->u.ibss.bssid, NULL, 0, 0); 288 } 289 return sta; 290} 291 292static struct sta_info * 293ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 294 const u8 *bssid, const u8 *addr, 295 u32 supp_rates, bool auth) 296 __acquires(RCU) 297{ 298 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 299 struct ieee80211_local *local = sdata->local; 300 struct sta_info *sta; 301 int band = local->hw.conf.channel->band; 302 303 /* 304 * XXX: Consider removing the least recently used entry and 305 * allow new one to be added. 306 */ 307 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 308 net_dbg_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 309 sdata->name, addr); 310 rcu_read_lock(); 311 return NULL; 312 } 313 314 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) { 315 rcu_read_lock(); 316 return NULL; 317 } 318 319 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) { 320 rcu_read_lock(); 321 return NULL; 322 } 323 324 sta = sta_info_alloc(sdata, addr, GFP_KERNEL); 325 if (!sta) { 326 rcu_read_lock(); 327 return NULL; 328 } 329 330 sta->last_rx = jiffies; 331 332 /* make sure mandatory rates are always added */ 333 sta->sta.supp_rates[band] = supp_rates | 334 ieee80211_mandatory_rates(local, band); 335 336 return ieee80211_ibss_finish_sta(sta, auth); 337} 338 339static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, 340 struct ieee80211_mgmt *mgmt, 341 size_t len) 342{ 343 u16 auth_alg, auth_transaction; 344 345 lockdep_assert_held(&sdata->u.ibss.mtx); 346 347 if (len < 24 + 6) 348 return; 349 350 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 351 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 352 353 if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1) 354 return; 355 ibss_vdbg("%s: RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n", 356 sdata->name, mgmt->sa, mgmt->da, mgmt->bssid, 357 auth_transaction); 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 ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) { 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, NULL); 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 ibss_vdbg("%s: updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n", 421 sdata->name, sta->sta.addr, 422 prev_rates, 423 sta->sta.supp_rates[band]); 424 rates_updated = true; 425 } 426 } else { 427 rcu_read_unlock(); 428 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, 429 mgmt->sa, supp_rates, true); 430 } 431 } 432 433 if (sta && elems->wmm_info) 434 set_sta_flag(sta, WLAN_STA_WME); 435 436 if (sta && elems->ht_operation && elems->ht_cap_elem && 437 sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) { 438 /* we both use HT */ 439 struct ieee80211_sta_ht_cap sta_ht_cap_new; 440 enum nl80211_channel_type channel_type = 441 ieee80211_ht_oper_to_channel_type( 442 elems->ht_operation); 443 444 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 445 elems->ht_cap_elem, 446 &sta_ht_cap_new); 447 448 /* 449 * fall back to HT20 if we don't use or use 450 * the other extension channel 451 */ 452 if (!(channel_type == NL80211_CHAN_HT40MINUS || 453 channel_type == NL80211_CHAN_HT40PLUS) || 454 channel_type != sdata->u.ibss.channel_type) 455 sta_ht_cap_new.cap &= 456 ~IEEE80211_HT_CAP_SUP_WIDTH_20_40; 457 458 if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new, 459 sizeof(sta_ht_cap_new))) { 460 memcpy(&sta->sta.ht_cap, &sta_ht_cap_new, 461 sizeof(sta_ht_cap_new)); 462 rates_updated = true; 463 } 464 } 465 466 if (sta && rates_updated) 467 rate_control_rate_init(sta); 468 469 rcu_read_unlock(); 470 } 471 472 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 473 channel, beacon); 474 if (!bss) 475 return; 476 477 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 478 479 /* was just updated in ieee80211_bss_info_update */ 480 beacon_timestamp = cbss->tsf; 481 482 /* check if we need to merge IBSS */ 483 484 /* we use a fixed BSSID */ 485 if (sdata->u.ibss.fixed_bssid) 486 goto put_bss; 487 488 /* not an IBSS */ 489 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 490 goto put_bss; 491 492 /* different channel */ 493 if (cbss->channel != local->oper_channel) 494 goto put_bss; 495 496 /* different SSID */ 497 if (elems->ssid_len != sdata->u.ibss.ssid_len || 498 memcmp(elems->ssid, sdata->u.ibss.ssid, 499 sdata->u.ibss.ssid_len)) 500 goto put_bss; 501 502 /* same BSSID */ 503 if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid)) 504 goto put_bss; 505 506 if (rx_status->flag & RX_FLAG_MACTIME_MPDU) { 507 /* 508 * For correct IBSS merging we need mactime; since mactime is 509 * defined as the time the first data symbol of the frame hits 510 * the PHY, and the timestamp of the beacon is defined as "the 511 * time that the data symbol containing the first bit of the 512 * timestamp is transmitted to the PHY plus the transmitting 513 * STA's delays through its local PHY from the MAC-PHY 514 * interface to its interface with the WM" (802.11 11.1.2) 515 * - equals the time this bit arrives at the receiver - we have 516 * to take into account the offset between the two. 517 * 518 * E.g. at 1 MBit that means mactime is 192 usec earlier 519 * (=24 bytes * 8 usecs/byte) than the beacon timestamp. 520 */ 521 int rate; 522 523 if (rx_status->flag & RX_FLAG_HT) 524 rate = 65; /* TODO: HT rates */ 525 else 526 rate = local->hw.wiphy->bands[band]-> 527 bitrates[rx_status->rate_idx].bitrate; 528 529 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate); 530 } else { 531 /* 532 * second best option: get current TSF 533 * (will return -1 if not supported) 534 */ 535 rx_timestamp = drv_get_tsf(local, sdata); 536 } 537 538 ibss_vdbg("RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 539 mgmt->sa, mgmt->bssid, 540 (unsigned long long)rx_timestamp, 541 (unsigned long long)beacon_timestamp, 542 (unsigned long long)(rx_timestamp - beacon_timestamp), 543 jiffies); 544 545 if (beacon_timestamp > rx_timestamp) { 546 ibss_vdbg("%s: beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n", 547 sdata->name, mgmt->bssid); 548 ieee80211_sta_join_ibss(sdata, bss); 549 supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL); 550 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 551 supp_rates, true); 552 rcu_read_unlock(); 553 } 554 555 put_bss: 556 ieee80211_rx_bss_put(local, bss); 557} 558 559void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata, 560 const u8 *bssid, const u8 *addr, 561 u32 supp_rates) 562{ 563 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 564 struct ieee80211_local *local = sdata->local; 565 struct sta_info *sta; 566 int band = local->hw.conf.channel->band; 567 568 /* 569 * XXX: Consider removing the least recently used entry and 570 * allow new one to be added. 571 */ 572 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 573 net_dbg_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 574 sdata->name, addr); 575 return; 576 } 577 578 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 579 return; 580 581 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) 582 return; 583 584 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC); 585 if (!sta) 586 return; 587 588 sta->last_rx = jiffies; 589 590 /* make sure mandatory rates are always added */ 591 sta->sta.supp_rates[band] = supp_rates | 592 ieee80211_mandatory_rates(local, band); 593 594 spin_lock(&ifibss->incomplete_lock); 595 list_add(&sta->list, &ifibss->incomplete_stations); 596 spin_unlock(&ifibss->incomplete_lock); 597 ieee80211_queue_work(&local->hw, &sdata->work); 598} 599 600static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 601{ 602 struct ieee80211_local *local = sdata->local; 603 int active = 0; 604 struct sta_info *sta; 605 606 lockdep_assert_held(&sdata->u.ibss.mtx); 607 608 rcu_read_lock(); 609 610 list_for_each_entry_rcu(sta, &local->sta_list, list) { 611 if (sta->sdata == sdata && 612 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 613 jiffies)) { 614 active++; 615 break; 616 } 617 } 618 619 rcu_read_unlock(); 620 621 return active; 622} 623 624/* 625 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 626 */ 627 628static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 629{ 630 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 631 632 lockdep_assert_held(&ifibss->mtx); 633 634 mod_timer(&ifibss->timer, 635 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 636 637 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 638 639 if (time_before(jiffies, ifibss->last_scan_completed + 640 IEEE80211_IBSS_MERGE_INTERVAL)) 641 return; 642 643 if (ieee80211_sta_active_ibss(sdata)) 644 return; 645 646 if (ifibss->fixed_channel) 647 return; 648 649 pr_debug("%s: No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n", 650 sdata->name); 651 652 ieee80211_request_internal_scan(sdata, 653 ifibss->ssid, ifibss->ssid_len, NULL); 654} 655 656static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 657{ 658 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 659 u8 bssid[ETH_ALEN]; 660 u16 capability; 661 int i; 662 663 lockdep_assert_held(&ifibss->mtx); 664 665 if (ifibss->fixed_bssid) { 666 memcpy(bssid, ifibss->bssid, ETH_ALEN); 667 } else { 668 /* Generate random, not broadcast, locally administered BSSID. Mix in 669 * own MAC address to make sure that devices that do not have proper 670 * random number generator get different BSSID. */ 671 get_random_bytes(bssid, ETH_ALEN); 672 for (i = 0; i < ETH_ALEN; i++) 673 bssid[i] ^= sdata->vif.addr[i]; 674 bssid[0] &= ~0x01; 675 bssid[0] |= 0x02; 676 } 677 678 pr_debug("%s: Creating new IBSS network, BSSID %pM\n", 679 sdata->name, bssid); 680 681 capability = WLAN_CAPABILITY_IBSS; 682 683 if (ifibss->privacy) 684 capability |= WLAN_CAPABILITY_PRIVACY; 685 else 686 sdata->drop_unencrypted = 0; 687 688 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 689 ifibss->channel, ifibss->basic_rates, 690 capability, 0); 691} 692 693/* 694 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 695 */ 696 697static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 698{ 699 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 700 struct ieee80211_local *local = sdata->local; 701 struct cfg80211_bss *cbss; 702 struct ieee80211_channel *chan = NULL; 703 const u8 *bssid = NULL; 704 int active_ibss; 705 u16 capability; 706 707 lockdep_assert_held(&ifibss->mtx); 708 709 active_ibss = ieee80211_sta_active_ibss(sdata); 710 ibss_vdbg("%s: sta_find_ibss (active_ibss=%d)\n", 711 sdata->name, active_ibss); 712 713 if (active_ibss) 714 return; 715 716 capability = WLAN_CAPABILITY_IBSS; 717 if (ifibss->privacy) 718 capability |= WLAN_CAPABILITY_PRIVACY; 719 if (ifibss->fixed_bssid) 720 bssid = ifibss->bssid; 721 if (ifibss->fixed_channel) 722 chan = ifibss->channel; 723 if (!is_zero_ether_addr(ifibss->bssid)) 724 bssid = ifibss->bssid; 725 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 726 ifibss->ssid, ifibss->ssid_len, 727 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 728 capability); 729 730 if (cbss) { 731 struct ieee80211_bss *bss; 732 733 bss = (void *)cbss->priv; 734 ibss_vdbg(" sta_find_ibss: selected %pM current %pM\n", 735 cbss->bssid, ifibss->bssid); 736 pr_debug("%s: Selected IBSS BSSID %pM 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 ibss_vdbg(" did not try to join ibss\n"); 745 746 /* Selected IBSS not found in current scan results - try to scan */ 747 if (time_after(jiffies, ifibss->last_scan_completed + 748 IEEE80211_SCAN_INTERVAL)) { 749 pr_debug("%s: Trigger new scan to find an IBSS to join\n", 750 sdata->name); 751 752 ieee80211_request_internal_scan(sdata, 753 ifibss->ssid, ifibss->ssid_len, 754 ifibss->fixed_channel ? ifibss->channel : NULL); 755 } else { 756 int interval = IEEE80211_SCAN_INTERVAL; 757 758 if (time_after(jiffies, ifibss->ibss_join_req + 759 IEEE80211_IBSS_JOIN_TIMEOUT)) { 760 if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) { 761 ieee80211_sta_create_ibss(sdata); 762 return; 763 } 764 pr_debug("%s: IBSS not allowed on %d MHz\n", 765 sdata->name, 766 local->hw.conf.channel->center_freq); 767 768 /* No IBSS found - decrease scan interval and continue 769 * scanning. */ 770 interval = IEEE80211_SCAN_INTERVAL_SLOW; 771 } 772 773 mod_timer(&ifibss->timer, 774 round_jiffies(jiffies + interval)); 775 } 776} 777 778static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 779 struct sk_buff *req) 780{ 781 struct ieee80211_mgmt *mgmt = (void *)req->data; 782 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 783 struct ieee80211_local *local = sdata->local; 784 int tx_last_beacon, len = req->len; 785 struct sk_buff *skb; 786 struct ieee80211_mgmt *resp; 787 struct sk_buff *presp; 788 u8 *pos, *end; 789 790 lockdep_assert_held(&ifibss->mtx); 791 792 presp = rcu_dereference_protected(ifibss->presp, 793 lockdep_is_held(&ifibss->mtx)); 794 795 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 796 len < 24 + 2 || !presp) 797 return; 798 799 tx_last_beacon = drv_tx_last_beacon(local); 800 801 ibss_vdbg("%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n", 802 sdata->name, mgmt->sa, mgmt->da, 803 mgmt->bssid, tx_last_beacon); 804 805 if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da)) 806 return; 807 808 if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) && 809 !is_broadcast_ether_addr(mgmt->bssid)) 810 return; 811 812 end = ((u8 *) mgmt) + len; 813 pos = mgmt->u.probe_req.variable; 814 if (pos[0] != WLAN_EID_SSID || 815 pos + 2 + pos[1] > end) { 816 ibss_vdbg("%s: Invalid SSID IE in ProbeReq from %pM\n", 817 sdata->name, mgmt->sa); 818 return; 819 } 820 if (pos[1] != 0 && 821 (pos[1] != ifibss->ssid_len || 822 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 823 /* Ignore ProbeReq for foreign SSID */ 824 return; 825 } 826 827 /* Reply with ProbeResp */ 828 skb = skb_copy(presp, GFP_KERNEL); 829 if (!skb) 830 return; 831 832 resp = (struct ieee80211_mgmt *) skb->data; 833 memcpy(resp->da, mgmt->sa, ETH_ALEN); 834 ibss_vdbg("%s: Sending ProbeResp to %pM\n", sdata->name, resp->da); 835 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 836 ieee80211_tx_skb(sdata, skb); 837} 838 839static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, 840 struct ieee80211_mgmt *mgmt, 841 size_t len, 842 struct ieee80211_rx_status *rx_status) 843{ 844 size_t baselen; 845 struct ieee802_11_elems elems; 846 847 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 848 if (baselen > len) 849 return; 850 851 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 852 &elems); 853 854 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false); 855} 856 857static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, 858 struct ieee80211_mgmt *mgmt, 859 size_t len, 860 struct ieee80211_rx_status *rx_status) 861{ 862 size_t baselen; 863 struct ieee802_11_elems elems; 864 865 /* Process beacon from the current BSS */ 866 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt; 867 if (baselen > len) 868 return; 869 870 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems); 871 872 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); 873} 874 875void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 876 struct sk_buff *skb) 877{ 878 struct ieee80211_rx_status *rx_status; 879 struct ieee80211_mgmt *mgmt; 880 u16 fc; 881 882 rx_status = IEEE80211_SKB_RXCB(skb); 883 mgmt = (struct ieee80211_mgmt *) skb->data; 884 fc = le16_to_cpu(mgmt->frame_control); 885 886 mutex_lock(&sdata->u.ibss.mtx); 887 888 if (!sdata->u.ibss.ssid_len) 889 goto mgmt_out; /* not ready to merge yet */ 890 891 switch (fc & IEEE80211_FCTL_STYPE) { 892 case IEEE80211_STYPE_PROBE_REQ: 893 ieee80211_rx_mgmt_probe_req(sdata, skb); 894 break; 895 case IEEE80211_STYPE_PROBE_RESP: 896 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, 897 rx_status); 898 break; 899 case IEEE80211_STYPE_BEACON: 900 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, 901 rx_status); 902 break; 903 case IEEE80211_STYPE_AUTH: 904 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 905 break; 906 } 907 908 mgmt_out: 909 mutex_unlock(&sdata->u.ibss.mtx); 910} 911 912void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata) 913{ 914 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 915 struct sta_info *sta; 916 917 mutex_lock(&ifibss->mtx); 918 919 /* 920 * Work could be scheduled after scan or similar 921 * when we aren't even joined (or trying) with a 922 * network. 923 */ 924 if (!ifibss->ssid_len) 925 goto out; 926 927 spin_lock_bh(&ifibss->incomplete_lock); 928 while (!list_empty(&ifibss->incomplete_stations)) { 929 sta = list_first_entry(&ifibss->incomplete_stations, 930 struct sta_info, list); 931 list_del(&sta->list); 932 spin_unlock_bh(&ifibss->incomplete_lock); 933 934 ieee80211_ibss_finish_sta(sta, true); 935 rcu_read_unlock(); 936 spin_lock_bh(&ifibss->incomplete_lock); 937 } 938 spin_unlock_bh(&ifibss->incomplete_lock); 939 940 switch (ifibss->state) { 941 case IEEE80211_IBSS_MLME_SEARCH: 942 ieee80211_sta_find_ibss(sdata); 943 break; 944 case IEEE80211_IBSS_MLME_JOINED: 945 ieee80211_sta_merge_ibss(sdata); 946 break; 947 default: 948 WARN_ON(1); 949 break; 950 } 951 952 out: 953 mutex_unlock(&ifibss->mtx); 954} 955 956static void ieee80211_ibss_timer(unsigned long data) 957{ 958 struct ieee80211_sub_if_data *sdata = 959 (struct ieee80211_sub_if_data *) data; 960 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 961 struct ieee80211_local *local = sdata->local; 962 963 if (local->quiescing) { 964 ifibss->timer_running = true; 965 return; 966 } 967 968 ieee80211_queue_work(&local->hw, &sdata->work); 969} 970 971#ifdef CONFIG_PM 972void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata) 973{ 974 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 975 976 if (del_timer_sync(&ifibss->timer)) 977 ifibss->timer_running = true; 978} 979 980void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata) 981{ 982 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 983 984 if (ifibss->timer_running) { 985 add_timer(&ifibss->timer); 986 ifibss->timer_running = false; 987 } 988} 989#endif 990 991void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 992{ 993 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 994 995 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 996 (unsigned long) sdata); 997 mutex_init(&ifibss->mtx); 998 INIT_LIST_HEAD(&ifibss->incomplete_stations); 999 spin_lock_init(&ifibss->incomplete_lock); 1000} 1001 1002/* scan finished notification */ 1003void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 1004{ 1005 struct ieee80211_sub_if_data *sdata; 1006 1007 mutex_lock(&local->iflist_mtx); 1008 list_for_each_entry(sdata, &local->interfaces, list) { 1009 if (!ieee80211_sdata_running(sdata)) 1010 continue; 1011 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 1012 continue; 1013 sdata->u.ibss.last_scan_completed = jiffies; 1014 ieee80211_queue_work(&local->hw, &sdata->work); 1015 } 1016 mutex_unlock(&local->iflist_mtx); 1017} 1018 1019int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 1020 struct cfg80211_ibss_params *params) 1021{ 1022 struct sk_buff *skb; 1023 u32 changed = 0; 1024 1025 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom + 1026 sizeof(struct ieee80211_hdr_3addr) + 1027 12 /* struct ieee80211_mgmt.u.beacon */ + 1028 2 + IEEE80211_MAX_SSID_LEN /* max SSID */ + 1029 2 + 8 /* max Supported Rates */ + 1030 3 /* max DS params */ + 1031 4 /* IBSS params */ + 1032 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 1033 2 + sizeof(struct ieee80211_ht_cap) + 1034 2 + sizeof(struct ieee80211_ht_operation) + 1035 params->ie_len); 1036 if (!skb) 1037 return -ENOMEM; 1038 1039 mutex_lock(&sdata->u.ibss.mtx); 1040 1041 if (params->bssid) { 1042 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 1043 sdata->u.ibss.fixed_bssid = true; 1044 } else 1045 sdata->u.ibss.fixed_bssid = false; 1046 1047 sdata->u.ibss.privacy = params->privacy; 1048 sdata->u.ibss.control_port = params->control_port; 1049 sdata->u.ibss.basic_rates = params->basic_rates; 1050 memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate, 1051 sizeof(params->mcast_rate)); 1052 1053 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 1054 1055 sdata->u.ibss.channel = params->channel; 1056 sdata->u.ibss.channel_type = params->channel_type; 1057 sdata->u.ibss.fixed_channel = params->channel_fixed; 1058 1059 /* fix ourselves to that channel now already */ 1060 if (params->channel_fixed) { 1061 sdata->local->oper_channel = params->channel; 1062 if (!ieee80211_set_channel_type(sdata->local, sdata, 1063 params->channel_type)) { 1064 mutex_unlock(&sdata->u.ibss.mtx); 1065 kfree_skb(skb); 1066 return -EINVAL; 1067 } 1068 } 1069 1070 if (params->ie) { 1071 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 1072 GFP_KERNEL); 1073 if (sdata->u.ibss.ie) 1074 sdata->u.ibss.ie_len = params->ie_len; 1075 } 1076 1077 sdata->u.ibss.skb = skb; 1078 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1079 sdata->u.ibss.ibss_join_req = jiffies; 1080 1081 memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN); 1082 sdata->u.ibss.ssid_len = params->ssid_len; 1083 1084 mutex_unlock(&sdata->u.ibss.mtx); 1085 1086 mutex_lock(&sdata->local->mtx); 1087 ieee80211_recalc_idle(sdata->local); 1088 mutex_unlock(&sdata->local->mtx); 1089 1090 /* 1091 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is 1092 * reserved, but an HT STA shall protect HT transmissions as though 1093 * the HT Protection field were set to non-HT mixed mode. 1094 * 1095 * In an IBSS, the RIFS Mode field of the HT Operation element is 1096 * also reserved, but an HT STA shall operate as though this field 1097 * were set to 1. 1098 */ 1099 1100 sdata->vif.bss_conf.ht_operation_mode |= 1101 IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED 1102 | IEEE80211_HT_PARAM_RIFS_MODE; 1103 1104 changed |= BSS_CHANGED_HT; 1105 ieee80211_bss_info_change_notify(sdata, changed); 1106 1107 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1108 1109 return 0; 1110} 1111 1112int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 1113{ 1114 struct sk_buff *skb; 1115 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1116 struct ieee80211_local *local = sdata->local; 1117 struct cfg80211_bss *cbss; 1118 u16 capability; 1119 int active_ibss; 1120 struct sta_info *sta; 1121 1122 mutex_lock(&sdata->u.ibss.mtx); 1123 1124 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1125 memset(sdata->u.ibss.bssid, 0, ETH_ALEN); 1126 sdata->u.ibss.ssid_len = 0; 1127 1128 active_ibss = ieee80211_sta_active_ibss(sdata); 1129 1130 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) { 1131 capability = WLAN_CAPABILITY_IBSS; 1132 1133 if (ifibss->privacy) 1134 capability |= WLAN_CAPABILITY_PRIVACY; 1135 1136 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel, 1137 ifibss->bssid, ifibss->ssid, 1138 ifibss->ssid_len, WLAN_CAPABILITY_IBSS | 1139 WLAN_CAPABILITY_PRIVACY, 1140 capability); 1141 1142 if (cbss) { 1143 cfg80211_unlink_bss(local->hw.wiphy, cbss); 1144 cfg80211_put_bss(cbss); 1145 } 1146 } 1147 1148 sta_info_flush(sdata->local, sdata); 1149 1150 spin_lock_bh(&ifibss->incomplete_lock); 1151 while (!list_empty(&ifibss->incomplete_stations)) { 1152 sta = list_first_entry(&ifibss->incomplete_stations, 1153 struct sta_info, list); 1154 list_del(&sta->list); 1155 spin_unlock_bh(&ifibss->incomplete_lock); 1156 1157 sta_info_free(local, sta); 1158 spin_lock_bh(&ifibss->incomplete_lock); 1159 } 1160 spin_unlock_bh(&ifibss->incomplete_lock); 1161 1162 netif_carrier_off(sdata->dev); 1163 1164 /* remove beacon */ 1165 kfree(sdata->u.ibss.ie); 1166 skb = rcu_dereference_protected(sdata->u.ibss.presp, 1167 lockdep_is_held(&sdata->u.ibss.mtx)); 1168 RCU_INIT_POINTER(sdata->u.ibss.presp, NULL); 1169 sdata->vif.bss_conf.ibss_joined = false; 1170 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | 1171 BSS_CHANGED_IBSS); 1172 synchronize_rcu(); 1173 kfree_skb(skb); 1174 1175 skb_queue_purge(&sdata->skb_queue); 1176 1177 del_timer_sync(&sdata->u.ibss.timer); 1178 1179 mutex_unlock(&sdata->u.ibss.mtx); 1180 1181 mutex_lock(&local->mtx); 1182 ieee80211_recalc_idle(sdata->local); 1183 mutex_unlock(&local->mtx); 1184 1185 return 0; 1186} 1187