ibss.c revision 452a6d22615bb8262a932b362f41fc5d89f03293
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 (!cfg80211_can_beacon_sec_chan(local->hw.wiphy, chan, channel_type)) 86 channel_type = NL80211_CHAN_HT20; 87 if (!ieee80211_set_channel_type(local, sdata, channel_type)) { 88 /* can only fail due to HT40+/- mismatch */ 89 channel_type = NL80211_CHAN_HT20; 90 WARN_ON(!ieee80211_set_channel_type(local, sdata, 91 NL80211_CHAN_HT20)); 92 } 93 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 94 95 sband = local->hw.wiphy->bands[chan->band]; 96 97 /* build supported rates array */ 98 pos = supp_rates; 99 for (i = 0; i < sband->n_bitrates; i++) { 100 int rate = sband->bitrates[i].bitrate; 101 u8 basic = 0; 102 if (basic_rates & BIT(i)) 103 basic = 0x80; 104 *pos++ = basic | (u8) (rate / 5); 105 } 106 107 /* Build IBSS probe response */ 108 mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon)); 109 memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon)); 110 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 111 IEEE80211_STYPE_PROBE_RESP); 112 memset(mgmt->da, 0xff, ETH_ALEN); 113 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 114 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN); 115 mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int); 116 mgmt->u.beacon.timestamp = cpu_to_le64(tsf); 117 mgmt->u.beacon.capab_info = cpu_to_le16(capability); 118 119 pos = skb_put(skb, 2 + ifibss->ssid_len); 120 *pos++ = WLAN_EID_SSID; 121 *pos++ = ifibss->ssid_len; 122 memcpy(pos, ifibss->ssid, ifibss->ssid_len); 123 124 rates = sband->n_bitrates; 125 if (rates > 8) 126 rates = 8; 127 pos = skb_put(skb, 2 + rates); 128 *pos++ = WLAN_EID_SUPP_RATES; 129 *pos++ = rates; 130 memcpy(pos, supp_rates, rates); 131 132 if (sband->band == IEEE80211_BAND_2GHZ) { 133 pos = skb_put(skb, 2 + 1); 134 *pos++ = WLAN_EID_DS_PARAMS; 135 *pos++ = 1; 136 *pos++ = ieee80211_frequency_to_channel(chan->center_freq); 137 } 138 139 pos = skb_put(skb, 2 + 2); 140 *pos++ = WLAN_EID_IBSS_PARAMS; 141 *pos++ = 2; 142 /* FIX: set ATIM window based on scan results */ 143 *pos++ = 0; 144 *pos++ = 0; 145 146 if (sband->n_bitrates > 8) { 147 rates = sband->n_bitrates - 8; 148 pos = skb_put(skb, 2 + rates); 149 *pos++ = WLAN_EID_EXT_SUPP_RATES; 150 *pos++ = rates; 151 memcpy(pos, &supp_rates[8], rates); 152 } 153 154 if (ifibss->ie_len) 155 memcpy(skb_put(skb, ifibss->ie_len), 156 ifibss->ie, ifibss->ie_len); 157 158 /* add HT capability and information IEs */ 159 if (channel_type && sband->ht_cap.ht_supported) { 160 pos = skb_put(skb, 4 + 161 sizeof(struct ieee80211_ht_cap) + 162 sizeof(struct ieee80211_ht_operation)); 163 pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, 164 sband->ht_cap.cap); 165 /* 166 * Note: According to 802.11n-2009 9.13.3.1, HT Protection 167 * field and RIFS Mode are reserved in IBSS mode, therefore 168 * keep them at 0 169 */ 170 pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap, 171 chan, channel_type, 0); 172 } 173 174 if (local->hw.queues >= IEEE80211_NUM_ACS) { 175 pos = skb_put(skb, 9); 176 *pos++ = WLAN_EID_VENDOR_SPECIFIC; 177 *pos++ = 7; /* len */ 178 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */ 179 *pos++ = 0x50; 180 *pos++ = 0xf2; 181 *pos++ = 2; /* WME */ 182 *pos++ = 0; /* WME info */ 183 *pos++ = 1; /* WME ver */ 184 *pos++ = 0; /* U-APSD no in use */ 185 } 186 187 rcu_assign_pointer(ifibss->presp, skb); 188 189 sdata->vif.bss_conf.beacon_int = beacon_int; 190 sdata->vif.bss_conf.basic_rates = basic_rates; 191 bss_change = BSS_CHANGED_BEACON_INT; 192 bss_change |= ieee80211_reset_erp_info(sdata); 193 bss_change |= BSS_CHANGED_BSSID; 194 bss_change |= BSS_CHANGED_BEACON; 195 bss_change |= BSS_CHANGED_BEACON_ENABLED; 196 bss_change |= BSS_CHANGED_BASIC_RATES; 197 bss_change |= BSS_CHANGED_HT; 198 bss_change |= BSS_CHANGED_IBSS; 199 sdata->vif.bss_conf.ibss_joined = true; 200 ieee80211_bss_info_change_notify(sdata, bss_change); 201 202 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 203 204 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 205 mod_timer(&ifibss->timer, 206 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 207 208 bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel, 209 mgmt, skb->len, 0, GFP_KERNEL); 210 cfg80211_put_bss(bss); 211 netif_carrier_on(sdata->dev); 212 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 213} 214 215static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 216 struct ieee80211_bss *bss) 217{ 218 struct cfg80211_bss *cbss = 219 container_of((void *)bss, struct cfg80211_bss, priv); 220 struct ieee80211_supported_band *sband; 221 u32 basic_rates; 222 int i, j; 223 u16 beacon_int = cbss->beacon_interval; 224 225 lockdep_assert_held(&sdata->u.ibss.mtx); 226 227 if (beacon_int < 10) 228 beacon_int = 10; 229 230 sband = sdata->local->hw.wiphy->bands[cbss->channel->band]; 231 232 basic_rates = 0; 233 234 for (i = 0; i < bss->supp_rates_len; i++) { 235 int rate = (bss->supp_rates[i] & 0x7f) * 5; 236 bool is_basic = !!(bss->supp_rates[i] & 0x80); 237 238 for (j = 0; j < sband->n_bitrates; j++) { 239 if (sband->bitrates[j].bitrate == rate) { 240 if (is_basic) 241 basic_rates |= BIT(j); 242 break; 243 } 244 } 245 } 246 247 __ieee80211_sta_join_ibss(sdata, cbss->bssid, 248 beacon_int, 249 cbss->channel, 250 basic_rates, 251 cbss->capability, 252 cbss->tsf); 253} 254 255static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta, 256 bool auth) 257 __acquires(RCU) 258{ 259 struct ieee80211_sub_if_data *sdata = sta->sdata; 260 u8 addr[ETH_ALEN]; 261 262 memcpy(addr, sta->sta.addr, ETH_ALEN); 263 264#ifdef CONFIG_MAC80211_VERBOSE_DEBUG 265 wiphy_debug(sdata->local->hw.wiphy, 266 "Adding new IBSS station %pM (dev=%s)\n", 267 addr, sdata->name); 268#endif 269 270 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 271 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 272 /* authorize the station only if the network is not RSN protected. If 273 * not wait for the userspace to authorize it */ 274 if (!sta->sdata->u.ibss.control_port) 275 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 276 277 rate_control_rate_init(sta); 278 279 /* If it fails, maybe we raced another insertion? */ 280 if (sta_info_insert_rcu(sta)) 281 return sta_info_get(sdata, addr); 282 if (auth && !sdata->u.ibss.auth_frame_registrations) { 283 ibss_vdbg("TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n", 284 sdata->vif.addr, sdata->u.ibss.bssid, addr); 285 ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, NULL, 0, 286 addr, sdata->u.ibss.bssid, NULL, 0, 0); 287 } 288 return sta; 289} 290 291static struct sta_info * 292ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 293 const u8 *bssid, const u8 *addr, 294 u32 supp_rates, bool auth) 295 __acquires(RCU) 296{ 297 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 298 struct ieee80211_local *local = sdata->local; 299 struct sta_info *sta; 300 int band = local->hw.conf.channel->band; 301 302 /* 303 * XXX: Consider removing the least recently used entry and 304 * allow new one to be added. 305 */ 306 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 307 net_dbg_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 308 sdata->name, addr); 309 rcu_read_lock(); 310 return NULL; 311 } 312 313 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) { 314 rcu_read_lock(); 315 return NULL; 316 } 317 318 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) { 319 rcu_read_lock(); 320 return NULL; 321 } 322 323 sta = sta_info_alloc(sdata, addr, GFP_KERNEL); 324 if (!sta) { 325 rcu_read_lock(); 326 return NULL; 327 } 328 329 sta->last_rx = jiffies; 330 331 /* make sure mandatory rates are always added */ 332 sta->sta.supp_rates[band] = supp_rates | 333 ieee80211_mandatory_rates(local, band); 334 335 return ieee80211_ibss_finish_sta(sta, auth); 336} 337 338static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, 339 struct ieee80211_mgmt *mgmt, 340 size_t len) 341{ 342 u16 auth_alg, auth_transaction; 343 344 lockdep_assert_held(&sdata->u.ibss.mtx); 345 346 if (len < 24 + 6) 347 return; 348 349 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 350 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 351 352 if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1) 353 return; 354 ibss_vdbg("%s: RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n", 355 sdata->name, mgmt->sa, mgmt->da, mgmt->bssid, 356 auth_transaction); 357 sta_info_destroy_addr(sdata, mgmt->sa); 358 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false); 359 rcu_read_unlock(); 360 361 /* 362 * IEEE 802.11 standard does not require authentication in IBSS 363 * networks and most implementations do not seem to use it. 364 * However, try to reply to authentication attempts if someone 365 * has actually implemented this. 366 */ 367 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0, 368 mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0); 369} 370 371static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 372 struct ieee80211_mgmt *mgmt, 373 size_t len, 374 struct ieee80211_rx_status *rx_status, 375 struct ieee802_11_elems *elems, 376 bool beacon) 377{ 378 struct ieee80211_local *local = sdata->local; 379 int freq; 380 struct cfg80211_bss *cbss; 381 struct ieee80211_bss *bss; 382 struct sta_info *sta; 383 struct ieee80211_channel *channel; 384 u64 beacon_timestamp, rx_timestamp; 385 u32 supp_rates = 0; 386 enum ieee80211_band band = rx_status->band; 387 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 388 bool rates_updated = false; 389 390 if (elems->ds_params && elems->ds_params_len == 1) 391 freq = ieee80211_channel_to_frequency(elems->ds_params[0], 392 band); 393 else 394 freq = rx_status->freq; 395 396 channel = ieee80211_get_channel(local->hw.wiphy, freq); 397 398 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 399 return; 400 401 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && 402 ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) { 403 404 rcu_read_lock(); 405 sta = sta_info_get(sdata, mgmt->sa); 406 407 if (elems->supp_rates) { 408 supp_rates = ieee80211_sta_get_rates(local, elems, 409 band, NULL); 410 if (sta) { 411 u32 prev_rates; 412 413 prev_rates = sta->sta.supp_rates[band]; 414 /* make sure mandatory rates are always added */ 415 sta->sta.supp_rates[band] = supp_rates | 416 ieee80211_mandatory_rates(local, band); 417 418 if (sta->sta.supp_rates[band] != prev_rates) { 419 ibss_vdbg("%s: updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n", 420 sdata->name, sta->sta.addr, 421 prev_rates, 422 sta->sta.supp_rates[band]); 423 rates_updated = true; 424 } 425 } else { 426 rcu_read_unlock(); 427 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, 428 mgmt->sa, supp_rates, true); 429 } 430 } 431 432 if (sta && elems->wmm_info) 433 set_sta_flag(sta, WLAN_STA_WME); 434 435 if (sta && elems->ht_operation && elems->ht_cap_elem && 436 sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) { 437 /* we both use HT */ 438 struct ieee80211_sta_ht_cap sta_ht_cap_new; 439 enum nl80211_channel_type channel_type = 440 ieee80211_ht_oper_to_channel_type( 441 elems->ht_operation); 442 443 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 444 elems->ht_cap_elem, 445 &sta_ht_cap_new); 446 447 /* 448 * fall back to HT20 if we don't use or use 449 * the other extension channel 450 */ 451 if (!(channel_type == NL80211_CHAN_HT40MINUS || 452 channel_type == NL80211_CHAN_HT40PLUS) || 453 channel_type != sdata->u.ibss.channel_type) 454 sta_ht_cap_new.cap &= 455 ~IEEE80211_HT_CAP_SUP_WIDTH_20_40; 456 457 if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new, 458 sizeof(sta_ht_cap_new))) { 459 memcpy(&sta->sta.ht_cap, &sta_ht_cap_new, 460 sizeof(sta_ht_cap_new)); 461 rates_updated = true; 462 } 463 } 464 465 if (sta && rates_updated) 466 rate_control_rate_init(sta); 467 468 rcu_read_unlock(); 469 } 470 471 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 472 channel, beacon); 473 if (!bss) 474 return; 475 476 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 477 478 /* was just updated in ieee80211_bss_info_update */ 479 beacon_timestamp = cbss->tsf; 480 481 /* check if we need to merge IBSS */ 482 483 /* we use a fixed BSSID */ 484 if (sdata->u.ibss.fixed_bssid) 485 goto put_bss; 486 487 /* not an IBSS */ 488 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 489 goto put_bss; 490 491 /* different channel */ 492 if (cbss->channel != local->oper_channel) 493 goto put_bss; 494 495 /* different SSID */ 496 if (elems->ssid_len != sdata->u.ibss.ssid_len || 497 memcmp(elems->ssid, sdata->u.ibss.ssid, 498 sdata->u.ibss.ssid_len)) 499 goto put_bss; 500 501 /* same BSSID */ 502 if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid)) 503 goto put_bss; 504 505 if (rx_status->flag & RX_FLAG_MACTIME_MPDU) { 506 /* 507 * For correct IBSS merging we need mactime; since mactime is 508 * defined as the time the first data symbol of the frame hits 509 * the PHY, and the timestamp of the beacon is defined as "the 510 * time that the data symbol containing the first bit of the 511 * timestamp is transmitted to the PHY plus the transmitting 512 * STA's delays through its local PHY from the MAC-PHY 513 * interface to its interface with the WM" (802.11 11.1.2) 514 * - equals the time this bit arrives at the receiver - we have 515 * to take into account the offset between the two. 516 * 517 * E.g. at 1 MBit that means mactime is 192 usec earlier 518 * (=24 bytes * 8 usecs/byte) than the beacon timestamp. 519 */ 520 int rate; 521 522 if (rx_status->flag & RX_FLAG_HT) 523 rate = 65; /* TODO: HT rates */ 524 else 525 rate = local->hw.wiphy->bands[band]-> 526 bitrates[rx_status->rate_idx].bitrate; 527 528 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate); 529 } else { 530 /* 531 * second best option: get current TSF 532 * (will return -1 if not supported) 533 */ 534 rx_timestamp = drv_get_tsf(local, sdata); 535 } 536 537 ibss_vdbg("RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 538 mgmt->sa, mgmt->bssid, 539 (unsigned long long)rx_timestamp, 540 (unsigned long long)beacon_timestamp, 541 (unsigned long long)(rx_timestamp - beacon_timestamp), 542 jiffies); 543 544 if (beacon_timestamp > rx_timestamp) { 545 ibss_vdbg("%s: beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n", 546 sdata->name, mgmt->bssid); 547 ieee80211_sta_join_ibss(sdata, bss); 548 supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL); 549 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 550 supp_rates, true); 551 rcu_read_unlock(); 552 } 553 554 put_bss: 555 ieee80211_rx_bss_put(local, bss); 556} 557 558void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata, 559 const u8 *bssid, const u8 *addr, 560 u32 supp_rates) 561{ 562 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 563 struct ieee80211_local *local = sdata->local; 564 struct sta_info *sta; 565 int band = local->hw.conf.channel->band; 566 567 /* 568 * XXX: Consider removing the least recently used entry and 569 * allow new one to be added. 570 */ 571 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 572 net_dbg_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 573 sdata->name, addr); 574 return; 575 } 576 577 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 578 return; 579 580 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) 581 return; 582 583 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC); 584 if (!sta) 585 return; 586 587 sta->last_rx = jiffies; 588 589 /* make sure mandatory rates are always added */ 590 sta->sta.supp_rates[band] = supp_rates | 591 ieee80211_mandatory_rates(local, band); 592 593 spin_lock(&ifibss->incomplete_lock); 594 list_add(&sta->list, &ifibss->incomplete_stations); 595 spin_unlock(&ifibss->incomplete_lock); 596 ieee80211_queue_work(&local->hw, &sdata->work); 597} 598 599static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 600{ 601 struct ieee80211_local *local = sdata->local; 602 int active = 0; 603 struct sta_info *sta; 604 605 lockdep_assert_held(&sdata->u.ibss.mtx); 606 607 rcu_read_lock(); 608 609 list_for_each_entry_rcu(sta, &local->sta_list, list) { 610 if (sta->sdata == sdata && 611 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 612 jiffies)) { 613 active++; 614 break; 615 } 616 } 617 618 rcu_read_unlock(); 619 620 return active; 621} 622 623/* 624 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 625 */ 626 627static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 628{ 629 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 630 631 lockdep_assert_held(&ifibss->mtx); 632 633 mod_timer(&ifibss->timer, 634 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 635 636 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 637 638 if (time_before(jiffies, ifibss->last_scan_completed + 639 IEEE80211_IBSS_MERGE_INTERVAL)) 640 return; 641 642 if (ieee80211_sta_active_ibss(sdata)) 643 return; 644 645 if (ifibss->fixed_channel) 646 return; 647 648 pr_debug("%s: No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n", 649 sdata->name); 650 651 ieee80211_request_internal_scan(sdata, 652 ifibss->ssid, ifibss->ssid_len, NULL); 653} 654 655static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 656{ 657 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 658 u8 bssid[ETH_ALEN]; 659 u16 capability; 660 int i; 661 662 lockdep_assert_held(&ifibss->mtx); 663 664 if (ifibss->fixed_bssid) { 665 memcpy(bssid, ifibss->bssid, ETH_ALEN); 666 } else { 667 /* Generate random, not broadcast, locally administered BSSID. Mix in 668 * own MAC address to make sure that devices that do not have proper 669 * random number generator get different BSSID. */ 670 get_random_bytes(bssid, ETH_ALEN); 671 for (i = 0; i < ETH_ALEN; i++) 672 bssid[i] ^= sdata->vif.addr[i]; 673 bssid[0] &= ~0x01; 674 bssid[0] |= 0x02; 675 } 676 677 pr_debug("%s: Creating new IBSS network, BSSID %pM\n", 678 sdata->name, bssid); 679 680 capability = WLAN_CAPABILITY_IBSS; 681 682 if (ifibss->privacy) 683 capability |= WLAN_CAPABILITY_PRIVACY; 684 else 685 sdata->drop_unencrypted = 0; 686 687 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 688 ifibss->channel, ifibss->basic_rates, 689 capability, 0); 690} 691 692/* 693 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 694 */ 695 696static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 697{ 698 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 699 struct ieee80211_local *local = sdata->local; 700 struct cfg80211_bss *cbss; 701 struct ieee80211_channel *chan = NULL; 702 const u8 *bssid = NULL; 703 int active_ibss; 704 u16 capability; 705 706 lockdep_assert_held(&ifibss->mtx); 707 708 active_ibss = ieee80211_sta_active_ibss(sdata); 709 ibss_vdbg("%s: sta_find_ibss (active_ibss=%d)\n", 710 sdata->name, active_ibss); 711 712 if (active_ibss) 713 return; 714 715 capability = WLAN_CAPABILITY_IBSS; 716 if (ifibss->privacy) 717 capability |= WLAN_CAPABILITY_PRIVACY; 718 if (ifibss->fixed_bssid) 719 bssid = ifibss->bssid; 720 if (ifibss->fixed_channel) 721 chan = ifibss->channel; 722 if (!is_zero_ether_addr(ifibss->bssid)) 723 bssid = ifibss->bssid; 724 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 725 ifibss->ssid, ifibss->ssid_len, 726 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 727 capability); 728 729 if (cbss) { 730 struct ieee80211_bss *bss; 731 732 bss = (void *)cbss->priv; 733 ibss_vdbg(" sta_find_ibss: selected %pM current %pM\n", 734 cbss->bssid, ifibss->bssid); 735 pr_debug("%s: Selected IBSS BSSID %pM based on configured SSID\n", 736 sdata->name, cbss->bssid); 737 738 ieee80211_sta_join_ibss(sdata, bss); 739 ieee80211_rx_bss_put(local, bss); 740 return; 741 } 742 743 ibss_vdbg(" did not try to join ibss\n"); 744 745 /* Selected IBSS not found in current scan results - try to scan */ 746 if (time_after(jiffies, ifibss->last_scan_completed + 747 IEEE80211_SCAN_INTERVAL)) { 748 pr_debug("%s: Trigger new scan to find an IBSS to join\n", 749 sdata->name); 750 751 ieee80211_request_internal_scan(sdata, 752 ifibss->ssid, ifibss->ssid_len, 753 ifibss->fixed_channel ? ifibss->channel : NULL); 754 } else { 755 int interval = IEEE80211_SCAN_INTERVAL; 756 757 if (time_after(jiffies, ifibss->ibss_join_req + 758 IEEE80211_IBSS_JOIN_TIMEOUT)) { 759 if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) { 760 ieee80211_sta_create_ibss(sdata); 761 return; 762 } 763 pr_debug("%s: IBSS not allowed on %d MHz\n", 764 sdata->name, 765 local->hw.conf.channel->center_freq); 766 767 /* No IBSS found - decrease scan interval and continue 768 * scanning. */ 769 interval = IEEE80211_SCAN_INTERVAL_SLOW; 770 } 771 772 mod_timer(&ifibss->timer, 773 round_jiffies(jiffies + interval)); 774 } 775} 776 777static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 778 struct sk_buff *req) 779{ 780 struct ieee80211_mgmt *mgmt = (void *)req->data; 781 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 782 struct ieee80211_local *local = sdata->local; 783 int tx_last_beacon, len = req->len; 784 struct sk_buff *skb; 785 struct ieee80211_mgmt *resp; 786 struct sk_buff *presp; 787 u8 *pos, *end; 788 789 lockdep_assert_held(&ifibss->mtx); 790 791 presp = rcu_dereference_protected(ifibss->presp, 792 lockdep_is_held(&ifibss->mtx)); 793 794 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 795 len < 24 + 2 || !presp) 796 return; 797 798 tx_last_beacon = drv_tx_last_beacon(local); 799 800 ibss_vdbg("%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n", 801 sdata->name, mgmt->sa, mgmt->da, 802 mgmt->bssid, tx_last_beacon); 803 804 if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da)) 805 return; 806 807 if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) && 808 !is_broadcast_ether_addr(mgmt->bssid)) 809 return; 810 811 end = ((u8 *) mgmt) + len; 812 pos = mgmt->u.probe_req.variable; 813 if (pos[0] != WLAN_EID_SSID || 814 pos + 2 + pos[1] > end) { 815 ibss_vdbg("%s: Invalid SSID IE in ProbeReq from %pM\n", 816 sdata->name, mgmt->sa); 817 return; 818 } 819 if (pos[1] != 0 && 820 (pos[1] != ifibss->ssid_len || 821 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 822 /* Ignore ProbeReq for foreign SSID */ 823 return; 824 } 825 826 /* Reply with ProbeResp */ 827 skb = skb_copy(presp, GFP_KERNEL); 828 if (!skb) 829 return; 830 831 resp = (struct ieee80211_mgmt *) skb->data; 832 memcpy(resp->da, mgmt->sa, ETH_ALEN); 833 ibss_vdbg("%s: Sending ProbeResp to %pM\n", sdata->name, resp->da); 834 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 835 ieee80211_tx_skb(sdata, skb); 836} 837 838static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, 839 struct ieee80211_mgmt *mgmt, 840 size_t len, 841 struct ieee80211_rx_status *rx_status) 842{ 843 size_t baselen; 844 struct ieee802_11_elems elems; 845 846 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 847 if (baselen > len) 848 return; 849 850 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 851 &elems); 852 853 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false); 854} 855 856static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, 857 struct ieee80211_mgmt *mgmt, 858 size_t len, 859 struct ieee80211_rx_status *rx_status) 860{ 861 size_t baselen; 862 struct ieee802_11_elems elems; 863 864 /* Process beacon from the current BSS */ 865 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt; 866 if (baselen > len) 867 return; 868 869 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems); 870 871 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); 872} 873 874void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 875 struct sk_buff *skb) 876{ 877 struct ieee80211_rx_status *rx_status; 878 struct ieee80211_mgmt *mgmt; 879 u16 fc; 880 881 rx_status = IEEE80211_SKB_RXCB(skb); 882 mgmt = (struct ieee80211_mgmt *) skb->data; 883 fc = le16_to_cpu(mgmt->frame_control); 884 885 mutex_lock(&sdata->u.ibss.mtx); 886 887 if (!sdata->u.ibss.ssid_len) 888 goto mgmt_out; /* not ready to merge yet */ 889 890 switch (fc & IEEE80211_FCTL_STYPE) { 891 case IEEE80211_STYPE_PROBE_REQ: 892 ieee80211_rx_mgmt_probe_req(sdata, skb); 893 break; 894 case IEEE80211_STYPE_PROBE_RESP: 895 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, 896 rx_status); 897 break; 898 case IEEE80211_STYPE_BEACON: 899 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, 900 rx_status); 901 break; 902 case IEEE80211_STYPE_AUTH: 903 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 904 break; 905 } 906 907 mgmt_out: 908 mutex_unlock(&sdata->u.ibss.mtx); 909} 910 911void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata) 912{ 913 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 914 struct sta_info *sta; 915 916 mutex_lock(&ifibss->mtx); 917 918 /* 919 * Work could be scheduled after scan or similar 920 * when we aren't even joined (or trying) with a 921 * network. 922 */ 923 if (!ifibss->ssid_len) 924 goto out; 925 926 spin_lock_bh(&ifibss->incomplete_lock); 927 while (!list_empty(&ifibss->incomplete_stations)) { 928 sta = list_first_entry(&ifibss->incomplete_stations, 929 struct sta_info, list); 930 list_del(&sta->list); 931 spin_unlock_bh(&ifibss->incomplete_lock); 932 933 ieee80211_ibss_finish_sta(sta, true); 934 rcu_read_unlock(); 935 spin_lock_bh(&ifibss->incomplete_lock); 936 } 937 spin_unlock_bh(&ifibss->incomplete_lock); 938 939 switch (ifibss->state) { 940 case IEEE80211_IBSS_MLME_SEARCH: 941 ieee80211_sta_find_ibss(sdata); 942 break; 943 case IEEE80211_IBSS_MLME_JOINED: 944 ieee80211_sta_merge_ibss(sdata); 945 break; 946 default: 947 WARN_ON(1); 948 break; 949 } 950 951 out: 952 mutex_unlock(&ifibss->mtx); 953} 954 955static void ieee80211_ibss_timer(unsigned long data) 956{ 957 struct ieee80211_sub_if_data *sdata = 958 (struct ieee80211_sub_if_data *) data; 959 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 960 struct ieee80211_local *local = sdata->local; 961 962 if (local->quiescing) { 963 ifibss->timer_running = true; 964 return; 965 } 966 967 ieee80211_queue_work(&local->hw, &sdata->work); 968} 969 970#ifdef CONFIG_PM 971void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata) 972{ 973 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 974 975 if (del_timer_sync(&ifibss->timer)) 976 ifibss->timer_running = true; 977} 978 979void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata) 980{ 981 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 982 983 if (ifibss->timer_running) { 984 add_timer(&ifibss->timer); 985 ifibss->timer_running = false; 986 } 987} 988#endif 989 990void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 991{ 992 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 993 994 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 995 (unsigned long) sdata); 996 mutex_init(&ifibss->mtx); 997 INIT_LIST_HEAD(&ifibss->incomplete_stations); 998 spin_lock_init(&ifibss->incomplete_lock); 999} 1000 1001/* scan finished notification */ 1002void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 1003{ 1004 struct ieee80211_sub_if_data *sdata; 1005 1006 mutex_lock(&local->iflist_mtx); 1007 list_for_each_entry(sdata, &local->interfaces, list) { 1008 if (!ieee80211_sdata_running(sdata)) 1009 continue; 1010 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 1011 continue; 1012 sdata->u.ibss.last_scan_completed = jiffies; 1013 ieee80211_queue_work(&local->hw, &sdata->work); 1014 } 1015 mutex_unlock(&local->iflist_mtx); 1016} 1017 1018int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 1019 struct cfg80211_ibss_params *params) 1020{ 1021 struct sk_buff *skb; 1022 u32 changed = 0; 1023 1024 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom + 1025 sizeof(struct ieee80211_hdr_3addr) + 1026 12 /* struct ieee80211_mgmt.u.beacon */ + 1027 2 + IEEE80211_MAX_SSID_LEN /* max SSID */ + 1028 2 + 8 /* max Supported Rates */ + 1029 3 /* max DS params */ + 1030 4 /* IBSS params */ + 1031 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 1032 2 + sizeof(struct ieee80211_ht_cap) + 1033 2 + sizeof(struct ieee80211_ht_operation) + 1034 params->ie_len); 1035 if (!skb) 1036 return -ENOMEM; 1037 1038 mutex_lock(&sdata->u.ibss.mtx); 1039 1040 if (params->bssid) { 1041 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 1042 sdata->u.ibss.fixed_bssid = true; 1043 } else 1044 sdata->u.ibss.fixed_bssid = false; 1045 1046 sdata->u.ibss.privacy = params->privacy; 1047 sdata->u.ibss.control_port = params->control_port; 1048 sdata->u.ibss.basic_rates = params->basic_rates; 1049 memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate, 1050 sizeof(params->mcast_rate)); 1051 1052 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 1053 1054 sdata->u.ibss.channel = params->channel; 1055 sdata->u.ibss.channel_type = params->channel_type; 1056 sdata->u.ibss.fixed_channel = params->channel_fixed; 1057 1058 /* fix ourselves to that channel now already */ 1059 if (params->channel_fixed) { 1060 sdata->local->oper_channel = params->channel; 1061 if (!ieee80211_set_channel_type(sdata->local, sdata, 1062 params->channel_type)) { 1063 mutex_unlock(&sdata->u.ibss.mtx); 1064 kfree_skb(skb); 1065 return -EINVAL; 1066 } 1067 } 1068 1069 if (params->ie) { 1070 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 1071 GFP_KERNEL); 1072 if (sdata->u.ibss.ie) 1073 sdata->u.ibss.ie_len = params->ie_len; 1074 } 1075 1076 sdata->u.ibss.skb = skb; 1077 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1078 sdata->u.ibss.ibss_join_req = jiffies; 1079 1080 memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN); 1081 sdata->u.ibss.ssid_len = params->ssid_len; 1082 1083 mutex_unlock(&sdata->u.ibss.mtx); 1084 1085 mutex_lock(&sdata->local->mtx); 1086 ieee80211_recalc_idle(sdata->local); 1087 mutex_unlock(&sdata->local->mtx); 1088 1089 /* 1090 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is 1091 * reserved, but an HT STA shall protect HT transmissions as though 1092 * the HT Protection field were set to non-HT mixed mode. 1093 * 1094 * In an IBSS, the RIFS Mode field of the HT Operation element is 1095 * also reserved, but an HT STA shall operate as though this field 1096 * were set to 1. 1097 */ 1098 1099 sdata->vif.bss_conf.ht_operation_mode |= 1100 IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED 1101 | IEEE80211_HT_PARAM_RIFS_MODE; 1102 1103 changed |= BSS_CHANGED_HT; 1104 ieee80211_bss_info_change_notify(sdata, changed); 1105 1106 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1107 1108 return 0; 1109} 1110 1111int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 1112{ 1113 struct sk_buff *skb; 1114 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1115 struct ieee80211_local *local = sdata->local; 1116 struct cfg80211_bss *cbss; 1117 u16 capability; 1118 int active_ibss; 1119 struct sta_info *sta; 1120 1121 mutex_lock(&sdata->u.ibss.mtx); 1122 1123 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1124 memset(sdata->u.ibss.bssid, 0, ETH_ALEN); 1125 sdata->u.ibss.ssid_len = 0; 1126 1127 active_ibss = ieee80211_sta_active_ibss(sdata); 1128 1129 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) { 1130 capability = WLAN_CAPABILITY_IBSS; 1131 1132 if (ifibss->privacy) 1133 capability |= WLAN_CAPABILITY_PRIVACY; 1134 1135 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel, 1136 ifibss->bssid, ifibss->ssid, 1137 ifibss->ssid_len, WLAN_CAPABILITY_IBSS | 1138 WLAN_CAPABILITY_PRIVACY, 1139 capability); 1140 1141 if (cbss) { 1142 cfg80211_unlink_bss(local->hw.wiphy, cbss); 1143 cfg80211_put_bss(cbss); 1144 } 1145 } 1146 1147 sta_info_flush(sdata->local, sdata); 1148 1149 spin_lock_bh(&ifibss->incomplete_lock); 1150 while (!list_empty(&ifibss->incomplete_stations)) { 1151 sta = list_first_entry(&ifibss->incomplete_stations, 1152 struct sta_info, list); 1153 list_del(&sta->list); 1154 spin_unlock_bh(&ifibss->incomplete_lock); 1155 1156 sta_info_free(local, sta); 1157 spin_lock_bh(&ifibss->incomplete_lock); 1158 } 1159 spin_unlock_bh(&ifibss->incomplete_lock); 1160 1161 netif_carrier_off(sdata->dev); 1162 1163 /* remove beacon */ 1164 kfree(sdata->u.ibss.ie); 1165 skb = rcu_dereference_protected(sdata->u.ibss.presp, 1166 lockdep_is_held(&sdata->u.ibss.mtx)); 1167 RCU_INIT_POINTER(sdata->u.ibss.presp, NULL); 1168 sdata->vif.bss_conf.ibss_joined = false; 1169 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | 1170 BSS_CHANGED_IBSS); 1171 synchronize_rcu(); 1172 kfree_skb(skb); 1173 1174 skb_queue_purge(&sdata->skb_queue); 1175 1176 del_timer_sync(&sdata->u.ibss.timer); 1177 1178 mutex_unlock(&sdata->u.ibss.mtx); 1179 1180 mutex_lock(&local->mtx); 1181 ieee80211_recalc_idle(sdata->local); 1182 mutex_unlock(&local->mtx); 1183 1184 return 0; 1185} 1186