1 /* 2 * IBSS mode implementation 3 * Copyright 2003-2008, Jouni Malinen <j@w1.fi> 4 * Copyright 2004, Instant802 Networks, Inc. 5 * Copyright 2005, Devicescape Software, Inc. 6 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> 7 * Copyright 2007, Michael Wu <flamingice@sourmilk.net> 8 * Copyright 2009, Johannes Berg <johannes@sipsolutions.net> 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 */ 14 15 #include <linux/delay.h> 16 #include <linux/slab.h> 17 #include <linux/if_ether.h> 18 #include <linux/skbuff.h> 19 #include <linux/if_arp.h> 20 #include <linux/etherdevice.h> 21 #include <linux/rtnetlink.h> 22 #include <net/mac80211.h> 23 #include <asm/unaligned.h> 24 25 #include "ieee80211_i.h" 26 #include "driver-ops.h" 27 #include "rate.h" 28 29 #define IEEE80211_SCAN_INTERVAL (2 * HZ) 30 #define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ) 31 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ) 32 33 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ) 34 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ) 35 36 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128 37 38 39 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, 40 struct ieee80211_mgmt *mgmt, 41 size_t len) 42 { 43 u16 auth_alg, auth_transaction; 44 45 lockdep_assert_held(&sdata->u.ibss.mtx); 46 47 if (len < 24 + 6) 48 return; 49 50 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 51 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 52 53 /* 54 * IEEE 802.11 standard does not require authentication in IBSS 55 * networks and most implementations do not seem to use it. 56 * However, try to reply to authentication attempts if someone 57 * has actually implemented this. 58 */ 59 if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1) 60 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0, 61 sdata->u.ibss.bssid, NULL, 0, 0); 62 } 63 64 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 65 const u8 *bssid, const int beacon_int, 66 struct ieee80211_channel *chan, 67 const u32 basic_rates, 68 const u16 capability, u64 tsf) 69 { 70 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 71 struct ieee80211_local *local = sdata->local; 72 int rates, i; 73 struct sk_buff *skb; 74 struct ieee80211_mgmt *mgmt; 75 u8 *pos; 76 struct ieee80211_supported_band *sband; 77 struct cfg80211_bss *bss; 78 u32 bss_change; 79 u8 supp_rates[IEEE80211_MAX_SUPP_RATES]; 80 81 lockdep_assert_held(&ifibss->mtx); 82 83 /* Reset own TSF to allow time synchronization work. */ 84 drv_reset_tsf(local); 85 86 skb = ifibss->skb; 87 rcu_assign_pointer(ifibss->presp, NULL); 88 synchronize_rcu(); 89 skb->data = skb->head; 90 skb->len = 0; 91 skb_reset_tail_pointer(skb); 92 skb_reserve(skb, sdata->local->hw.extra_tx_headroom); 93 94 if (memcmp(ifibss->bssid, bssid, ETH_ALEN)) 95 sta_info_flush(sdata->local, sdata); 96 97 /* if merging, indicate to driver that we leave the old IBSS */ 98 if (sdata->vif.bss_conf.ibss_joined) { 99 sdata->vif.bss_conf.ibss_joined = false; 100 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS); 101 } 102 103 memcpy(ifibss->bssid, bssid, ETH_ALEN); 104 105 sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0; 106 107 local->oper_channel = chan; 108 WARN_ON(!ieee80211_set_channel_type(local, sdata, NL80211_CHAN_NO_HT)); 109 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 110 111 sband = local->hw.wiphy->bands[chan->band]; 112 113 /* build supported rates array */ 114 pos = supp_rates; 115 for (i = 0; i < sband->n_bitrates; i++) { 116 int rate = sband->bitrates[i].bitrate; 117 u8 basic = 0; 118 if (basic_rates & BIT(i)) 119 basic = 0x80; 120 *pos++ = basic | (u8) (rate / 5); 121 } 122 123 /* Build IBSS probe response */ 124 mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon)); 125 memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon)); 126 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 127 IEEE80211_STYPE_PROBE_RESP); 128 memset(mgmt->da, 0xff, ETH_ALEN); 129 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 130 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN); 131 mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int); 132 mgmt->u.beacon.timestamp = cpu_to_le64(tsf); 133 mgmt->u.beacon.capab_info = cpu_to_le16(capability); 134 135 pos = skb_put(skb, 2 + ifibss->ssid_len); 136 *pos++ = WLAN_EID_SSID; 137 *pos++ = ifibss->ssid_len; 138 memcpy(pos, ifibss->ssid, ifibss->ssid_len); 139 140 rates = sband->n_bitrates; 141 if (rates > 8) 142 rates = 8; 143 pos = skb_put(skb, 2 + rates); 144 *pos++ = WLAN_EID_SUPP_RATES; 145 *pos++ = rates; 146 memcpy(pos, supp_rates, rates); 147 148 if (sband->band == IEEE80211_BAND_2GHZ) { 149 pos = skb_put(skb, 2 + 1); 150 *pos++ = WLAN_EID_DS_PARAMS; 151 *pos++ = 1; 152 *pos++ = ieee80211_frequency_to_channel(chan->center_freq); 153 } 154 155 pos = skb_put(skb, 2 + 2); 156 *pos++ = WLAN_EID_IBSS_PARAMS; 157 *pos++ = 2; 158 /* FIX: set ATIM window based on scan results */ 159 *pos++ = 0; 160 *pos++ = 0; 161 162 if (sband->n_bitrates > 8) { 163 rates = sband->n_bitrates - 8; 164 pos = skb_put(skb, 2 + rates); 165 *pos++ = WLAN_EID_EXT_SUPP_RATES; 166 *pos++ = rates; 167 memcpy(pos, &supp_rates[8], rates); 168 } 169 170 if (ifibss->ie_len) 171 memcpy(skb_put(skb, ifibss->ie_len), 172 ifibss->ie, ifibss->ie_len); 173 174 if (local->hw.queues >= 4) { 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_IBSS; 198 sdata->vif.bss_conf.ibss_joined = true; 199 ieee80211_bss_info_change_notify(sdata, bss_change); 200 201 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 202 203 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 204 mod_timer(&ifibss->timer, 205 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 206 207 bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel, 208 mgmt, skb->len, 0, GFP_KERNEL); 209 cfg80211_put_bss(bss); 210 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 211 } 212 213 static 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 } 252 253 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 254 struct ieee80211_mgmt *mgmt, 255 size_t len, 256 struct ieee80211_rx_status *rx_status, 257 struct ieee802_11_elems *elems, 258 bool beacon) 259 { 260 struct ieee80211_local *local = sdata->local; 261 int freq; 262 struct cfg80211_bss *cbss; 263 struct ieee80211_bss *bss; 264 struct sta_info *sta; 265 struct ieee80211_channel *channel; 266 u64 beacon_timestamp, rx_timestamp; 267 u32 supp_rates = 0; 268 enum ieee80211_band band = rx_status->band; 269 270 if (elems->ds_params && elems->ds_params_len == 1) 271 freq = ieee80211_channel_to_frequency(elems->ds_params[0], 272 band); 273 else 274 freq = rx_status->freq; 275 276 channel = ieee80211_get_channel(local->hw.wiphy, freq); 277 278 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 279 return; 280 281 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && 282 memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) { 283 284 rcu_read_lock(); 285 sta = sta_info_get(sdata, mgmt->sa); 286 287 if (elems->supp_rates) { 288 supp_rates = ieee80211_sta_get_rates(local, elems, 289 band); 290 if (sta) { 291 u32 prev_rates; 292 293 prev_rates = sta->sta.supp_rates[band]; 294 /* make sure mandatory rates are always added */ 295 sta->sta.supp_rates[band] = supp_rates | 296 ieee80211_mandatory_rates(local, band); 297 298 if (sta->sta.supp_rates[band] != prev_rates) { 299 #ifdef CONFIG_MAC80211_IBSS_DEBUG 300 printk(KERN_DEBUG 301 "%s: updated supp_rates set " 302 "for %pM based on beacon" 303 "/probe_resp (0x%x -> 0x%x)\n", 304 sdata->name, sta->sta.addr, 305 prev_rates, 306 sta->sta.supp_rates[band]); 307 #endif 308 rate_control_rate_init(sta); 309 } 310 } else 311 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, 312 mgmt->sa, supp_rates, 313 GFP_ATOMIC); 314 } 315 316 if (sta && elems->wmm_info) 317 set_sta_flags(sta, WLAN_STA_WME); 318 319 rcu_read_unlock(); 320 } 321 322 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 323 channel, beacon); 324 if (!bss) 325 return; 326 327 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 328 329 /* was just updated in ieee80211_bss_info_update */ 330 beacon_timestamp = cbss->tsf; 331 332 /* check if we need to merge IBSS */ 333 334 /* we use a fixed BSSID */ 335 if (sdata->u.ibss.fixed_bssid) 336 goto put_bss; 337 338 /* not an IBSS */ 339 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 340 goto put_bss; 341 342 /* different channel */ 343 if (cbss->channel != local->oper_channel) 344 goto put_bss; 345 346 /* different SSID */ 347 if (elems->ssid_len != sdata->u.ibss.ssid_len || 348 memcmp(elems->ssid, sdata->u.ibss.ssid, 349 sdata->u.ibss.ssid_len)) 350 goto put_bss; 351 352 /* same BSSID */ 353 if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) 354 goto put_bss; 355 356 if (rx_status->flag & RX_FLAG_MACTIME_MPDU) { 357 /* 358 * For correct IBSS merging we need mactime; since mactime is 359 * defined as the time the first data symbol of the frame hits 360 * the PHY, and the timestamp of the beacon is defined as "the 361 * time that the data symbol containing the first bit of the 362 * timestamp is transmitted to the PHY plus the transmitting 363 * STA's delays through its local PHY from the MAC-PHY 364 * interface to its interface with the WM" (802.11 11.1.2) 365 * - equals the time this bit arrives at the receiver - we have 366 * to take into account the offset between the two. 367 * 368 * E.g. at 1 MBit that means mactime is 192 usec earlier 369 * (=24 bytes * 8 usecs/byte) than the beacon timestamp. 370 */ 371 int rate; 372 373 if (rx_status->flag & RX_FLAG_HT) 374 rate = 65; /* TODO: HT rates */ 375 else 376 rate = local->hw.wiphy->bands[band]-> 377 bitrates[rx_status->rate_idx].bitrate; 378 379 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate); 380 } else { 381 /* 382 * second best option: get current TSF 383 * (will return -1 if not supported) 384 */ 385 rx_timestamp = drv_get_tsf(local); 386 } 387 388 #ifdef CONFIG_MAC80211_IBSS_DEBUG 389 printk(KERN_DEBUG "RX beacon SA=%pM BSSID=" 390 "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 391 mgmt->sa, mgmt->bssid, 392 (unsigned long long)rx_timestamp, 393 (unsigned long long)beacon_timestamp, 394 (unsigned long long)(rx_timestamp - beacon_timestamp), 395 jiffies); 396 #endif 397 398 if (beacon_timestamp > rx_timestamp) { 399 #ifdef CONFIG_MAC80211_IBSS_DEBUG 400 printk(KERN_DEBUG "%s: beacon TSF higher than " 401 "local TSF - IBSS merge with BSSID %pM\n", 402 sdata->name, mgmt->bssid); 403 #endif 404 ieee80211_sta_join_ibss(sdata, bss); 405 supp_rates = ieee80211_sta_get_rates(local, elems, band); 406 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 407 supp_rates, GFP_KERNEL); 408 } 409 410 put_bss: 411 ieee80211_rx_bss_put(local, bss); 412 } 413 414 /* 415 * Add a new IBSS station, will also be called by the RX code when, 416 * in IBSS mode, receiving a frame from a yet-unknown station, hence 417 * must be callable in atomic context. 418 */ 419 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 420 u8 *bssid,u8 *addr, u32 supp_rates, 421 gfp_t gfp) 422 { 423 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 424 struct ieee80211_local *local = sdata->local; 425 struct sta_info *sta; 426 int band = local->hw.conf.channel->band; 427 428 /* 429 * XXX: Consider removing the least recently used entry and 430 * allow new one to be added. 431 */ 432 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 433 if (net_ratelimit()) 434 printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n", 435 sdata->name, addr); 436 return NULL; 437 } 438 439 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 440 return NULL; 441 442 if (compare_ether_addr(bssid, sdata->u.ibss.bssid)) 443 return NULL; 444 445 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG 446 wiphy_debug(local->hw.wiphy, "Adding new IBSS station %pM (dev=%s)\n", 447 addr, sdata->name); 448 #endif 449 450 sta = sta_info_alloc(sdata, addr, gfp); 451 if (!sta) 452 return NULL; 453 454 sta->last_rx = jiffies; 455 set_sta_flags(sta, WLAN_STA_AUTHORIZED); 456 457 /* make sure mandatory rates are always added */ 458 sta->sta.supp_rates[band] = supp_rates | 459 ieee80211_mandatory_rates(local, band); 460 461 rate_control_rate_init(sta); 462 463 /* If it fails, maybe we raced another insertion? */ 464 if (sta_info_insert(sta)) 465 return sta_info_get(sdata, addr); 466 return sta; 467 } 468 469 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 470 { 471 struct ieee80211_local *local = sdata->local; 472 int active = 0; 473 struct sta_info *sta; 474 475 lockdep_assert_held(&sdata->u.ibss.mtx); 476 477 rcu_read_lock(); 478 479 list_for_each_entry_rcu(sta, &local->sta_list, list) { 480 if (sta->sdata == sdata && 481 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 482 jiffies)) { 483 active++; 484 break; 485 } 486 } 487 488 rcu_read_unlock(); 489 490 return active; 491 } 492 493 /* 494 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 495 */ 496 497 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 498 { 499 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 500 501 lockdep_assert_held(&ifibss->mtx); 502 503 mod_timer(&ifibss->timer, 504 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 505 506 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 507 508 if (time_before(jiffies, ifibss->last_scan_completed + 509 IEEE80211_IBSS_MERGE_INTERVAL)) 510 return; 511 512 if (ieee80211_sta_active_ibss(sdata)) 513 return; 514 515 if (ifibss->fixed_channel) 516 return; 517 518 printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other " 519 "IBSS networks with same SSID (merge)\n", sdata->name); 520 521 ieee80211_request_internal_scan(sdata, 522 ifibss->ssid, ifibss->ssid_len, 523 ifibss->fixed_channel ? ifibss->channel : NULL); 524 } 525 526 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 527 { 528 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 529 u8 bssid[ETH_ALEN]; 530 u16 capability; 531 int i; 532 533 lockdep_assert_held(&ifibss->mtx); 534 535 if (ifibss->fixed_bssid) { 536 memcpy(bssid, ifibss->bssid, ETH_ALEN); 537 } else { 538 /* Generate random, not broadcast, locally administered BSSID. Mix in 539 * own MAC address to make sure that devices that do not have proper 540 * random number generator get different BSSID. */ 541 get_random_bytes(bssid, ETH_ALEN); 542 for (i = 0; i < ETH_ALEN; i++) 543 bssid[i] ^= sdata->vif.addr[i]; 544 bssid[0] &= ~0x01; 545 bssid[0] |= 0x02; 546 } 547 548 printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n", 549 sdata->name, bssid); 550 551 capability = WLAN_CAPABILITY_IBSS; 552 553 if (ifibss->privacy) 554 capability |= WLAN_CAPABILITY_PRIVACY; 555 else 556 sdata->drop_unencrypted = 0; 557 558 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 559 ifibss->channel, ifibss->basic_rates, 560 capability, 0); 561 } 562 563 /* 564 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 565 */ 566 567 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 568 { 569 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 570 struct ieee80211_local *local = sdata->local; 571 struct cfg80211_bss *cbss; 572 struct ieee80211_channel *chan = NULL; 573 const u8 *bssid = NULL; 574 int active_ibss; 575 u16 capability; 576 577 lockdep_assert_held(&ifibss->mtx); 578 579 active_ibss = ieee80211_sta_active_ibss(sdata); 580 #ifdef CONFIG_MAC80211_IBSS_DEBUG 581 printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n", 582 sdata->name, active_ibss); 583 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 584 585 if (active_ibss) 586 return; 587 588 capability = WLAN_CAPABILITY_IBSS; 589 if (ifibss->privacy) 590 capability |= WLAN_CAPABILITY_PRIVACY; 591 if (ifibss->fixed_bssid) 592 bssid = ifibss->bssid; 593 if (ifibss->fixed_channel) 594 chan = ifibss->channel; 595 if (!is_zero_ether_addr(ifibss->bssid)) 596 bssid = ifibss->bssid; 597 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 598 ifibss->ssid, ifibss->ssid_len, 599 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 600 capability); 601 602 if (cbss) { 603 struct ieee80211_bss *bss; 604 605 bss = (void *)cbss->priv; 606 #ifdef CONFIG_MAC80211_IBSS_DEBUG 607 printk(KERN_DEBUG " sta_find_ibss: selected %pM current " 608 "%pM\n", cbss->bssid, ifibss->bssid); 609 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 610 611 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM" 612 " based on configured SSID\n", 613 sdata->name, cbss->bssid); 614 615 ieee80211_sta_join_ibss(sdata, bss); 616 ieee80211_rx_bss_put(local, bss); 617 return; 618 } 619 620 #ifdef CONFIG_MAC80211_IBSS_DEBUG 621 printk(KERN_DEBUG " did not try to join ibss\n"); 622 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 623 624 /* Selected IBSS not found in current scan results - try to scan */ 625 if (time_after(jiffies, ifibss->last_scan_completed + 626 IEEE80211_SCAN_INTERVAL)) { 627 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to " 628 "join\n", sdata->name); 629 630 ieee80211_request_internal_scan(sdata, 631 ifibss->ssid, ifibss->ssid_len, 632 ifibss->fixed_channel ? ifibss->channel : NULL); 633 } else { 634 int interval = IEEE80211_SCAN_INTERVAL; 635 636 if (time_after(jiffies, ifibss->ibss_join_req + 637 IEEE80211_IBSS_JOIN_TIMEOUT)) { 638 if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) { 639 ieee80211_sta_create_ibss(sdata); 640 return; 641 } 642 printk(KERN_DEBUG "%s: IBSS not allowed on" 643 " %d MHz\n", sdata->name, 644 local->hw.conf.channel->center_freq); 645 646 /* No IBSS found - decrease scan interval and continue 647 * scanning. */ 648 interval = IEEE80211_SCAN_INTERVAL_SLOW; 649 } 650 651 mod_timer(&ifibss->timer, 652 round_jiffies(jiffies + interval)); 653 } 654 } 655 656 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 657 struct sk_buff *req) 658 { 659 struct ieee80211_mgmt *mgmt = (void *)req->data; 660 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 661 struct ieee80211_local *local = sdata->local; 662 int tx_last_beacon, len = req->len; 663 struct sk_buff *skb; 664 struct ieee80211_mgmt *resp; 665 struct sk_buff *presp; 666 u8 *pos, *end; 667 668 lockdep_assert_held(&ifibss->mtx); 669 670 presp = rcu_dereference_protected(ifibss->presp, 671 lockdep_is_held(&ifibss->mtx)); 672 673 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 674 len < 24 + 2 || !presp) 675 return; 676 677 tx_last_beacon = drv_tx_last_beacon(local); 678 679 #ifdef CONFIG_MAC80211_IBSS_DEBUG 680 printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM" 681 " (tx_last_beacon=%d)\n", 682 sdata->name, mgmt->sa, mgmt->da, 683 mgmt->bssid, tx_last_beacon); 684 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 685 686 if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da)) 687 return; 688 689 if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 && 690 memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0) 691 return; 692 693 end = ((u8 *) mgmt) + len; 694 pos = mgmt->u.probe_req.variable; 695 if (pos[0] != WLAN_EID_SSID || 696 pos + 2 + pos[1] > end) { 697 #ifdef CONFIG_MAC80211_IBSS_DEBUG 698 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq " 699 "from %pM\n", 700 sdata->name, mgmt->sa); 701 #endif 702 return; 703 } 704 if (pos[1] != 0 && 705 (pos[1] != ifibss->ssid_len || 706 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 707 /* Ignore ProbeReq for foreign SSID */ 708 return; 709 } 710 711 /* Reply with ProbeResp */ 712 skb = skb_copy(presp, GFP_KERNEL); 713 if (!skb) 714 return; 715 716 resp = (struct ieee80211_mgmt *) skb->data; 717 memcpy(resp->da, mgmt->sa, ETH_ALEN); 718 #ifdef CONFIG_MAC80211_IBSS_DEBUG 719 printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n", 720 sdata->name, resp->da); 721 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 722 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 723 ieee80211_tx_skb(sdata, skb); 724 } 725 726 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, 727 struct ieee80211_mgmt *mgmt, 728 size_t len, 729 struct ieee80211_rx_status *rx_status) 730 { 731 size_t baselen; 732 struct ieee802_11_elems elems; 733 734 if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN)) 735 return; /* ignore ProbeResp to foreign address */ 736 737 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 738 if (baselen > len) 739 return; 740 741 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 742 &elems); 743 744 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false); 745 } 746 747 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, 748 struct ieee80211_mgmt *mgmt, 749 size_t len, 750 struct ieee80211_rx_status *rx_status) 751 { 752 size_t baselen; 753 struct ieee802_11_elems elems; 754 755 /* Process beacon from the current BSS */ 756 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt; 757 if (baselen > len) 758 return; 759 760 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems); 761 762 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); 763 } 764 765 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 766 struct sk_buff *skb) 767 { 768 struct ieee80211_rx_status *rx_status; 769 struct ieee80211_mgmt *mgmt; 770 u16 fc; 771 772 rx_status = IEEE80211_SKB_RXCB(skb); 773 mgmt = (struct ieee80211_mgmt *) skb->data; 774 fc = le16_to_cpu(mgmt->frame_control); 775 776 mutex_lock(&sdata->u.ibss.mtx); 777 778 if (!sdata->u.ibss.ssid_len) 779 goto mgmt_out; /* not ready to merge yet */ 780 781 switch (fc & IEEE80211_FCTL_STYPE) { 782 case IEEE80211_STYPE_PROBE_REQ: 783 ieee80211_rx_mgmt_probe_req(sdata, skb); 784 break; 785 case IEEE80211_STYPE_PROBE_RESP: 786 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, 787 rx_status); 788 break; 789 case IEEE80211_STYPE_BEACON: 790 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, 791 rx_status); 792 break; 793 case IEEE80211_STYPE_AUTH: 794 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 795 break; 796 } 797 798 mgmt_out: 799 mutex_unlock(&sdata->u.ibss.mtx); 800 } 801 802 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata) 803 { 804 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 805 806 mutex_lock(&ifibss->mtx); 807 808 /* 809 * Work could be scheduled after scan or similar 810 * when we aren't even joined (or trying) with a 811 * network. 812 */ 813 if (!ifibss->ssid_len) 814 goto out; 815 816 switch (ifibss->state) { 817 case IEEE80211_IBSS_MLME_SEARCH: 818 ieee80211_sta_find_ibss(sdata); 819 break; 820 case IEEE80211_IBSS_MLME_JOINED: 821 ieee80211_sta_merge_ibss(sdata); 822 break; 823 default: 824 WARN_ON(1); 825 break; 826 } 827 828 out: 829 mutex_unlock(&ifibss->mtx); 830 } 831 832 static void ieee80211_ibss_timer(unsigned long data) 833 { 834 struct ieee80211_sub_if_data *sdata = 835 (struct ieee80211_sub_if_data *) data; 836 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 837 struct ieee80211_local *local = sdata->local; 838 839 if (local->quiescing) { 840 ifibss->timer_running = true; 841 return; 842 } 843 844 ieee80211_queue_work(&local->hw, &sdata->work); 845 } 846 847 #ifdef CONFIG_PM 848 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata) 849 { 850 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 851 852 if (del_timer_sync(&ifibss->timer)) 853 ifibss->timer_running = true; 854 } 855 856 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata) 857 { 858 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 859 860 if (ifibss->timer_running) { 861 add_timer(&ifibss->timer); 862 ifibss->timer_running = false; 863 } 864 } 865 #endif 866 867 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 868 { 869 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 870 871 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 872 (unsigned long) sdata); 873 mutex_init(&ifibss->mtx); 874 } 875 876 /* scan finished notification */ 877 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 878 { 879 struct ieee80211_sub_if_data *sdata; 880 881 mutex_lock(&local->iflist_mtx); 882 list_for_each_entry(sdata, &local->interfaces, list) { 883 if (!ieee80211_sdata_running(sdata)) 884 continue; 885 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 886 continue; 887 sdata->u.ibss.last_scan_completed = jiffies; 888 ieee80211_queue_work(&local->hw, &sdata->work); 889 } 890 mutex_unlock(&local->iflist_mtx); 891 } 892 893 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 894 struct cfg80211_ibss_params *params) 895 { 896 struct sk_buff *skb; 897 898 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom + 899 36 /* bitrates */ + 900 34 /* SSID */ + 901 3 /* DS params */ + 902 4 /* IBSS params */ + 903 params->ie_len); 904 if (!skb) 905 return -ENOMEM; 906 907 mutex_lock(&sdata->u.ibss.mtx); 908 909 if (params->bssid) { 910 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 911 sdata->u.ibss.fixed_bssid = true; 912 } else 913 sdata->u.ibss.fixed_bssid = false; 914 915 sdata->u.ibss.privacy = params->privacy; 916 sdata->u.ibss.basic_rates = params->basic_rates; 917 memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate, 918 sizeof(params->mcast_rate)); 919 920 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 921 922 sdata->u.ibss.channel = params->channel; 923 sdata->u.ibss.fixed_channel = params->channel_fixed; 924 925 /* fix ourselves to that channel now already */ 926 if (params->channel_fixed) { 927 sdata->local->oper_channel = params->channel; 928 WARN_ON(!ieee80211_set_channel_type(sdata->local, sdata, 929 NL80211_CHAN_NO_HT)); 930 } 931 932 if (params->ie) { 933 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 934 GFP_KERNEL); 935 if (sdata->u.ibss.ie) 936 sdata->u.ibss.ie_len = params->ie_len; 937 } 938 939 sdata->u.ibss.skb = skb; 940 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 941 sdata->u.ibss.ibss_join_req = jiffies; 942 943 memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN); 944 sdata->u.ibss.ssid_len = params->ssid_len; 945 946 mutex_unlock(&sdata->u.ibss.mtx); 947 948 mutex_lock(&sdata->local->mtx); 949 ieee80211_recalc_idle(sdata->local); 950 mutex_unlock(&sdata->local->mtx); 951 952 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 953 954 return 0; 955 } 956 957 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 958 { 959 struct sk_buff *skb; 960 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 961 struct ieee80211_local *local = sdata->local; 962 struct cfg80211_bss *cbss; 963 u16 capability; 964 int active_ibss; 965 966 mutex_lock(&sdata->u.ibss.mtx); 967 968 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 969 memset(sdata->u.ibss.bssid, 0, ETH_ALEN); 970 sdata->u.ibss.ssid_len = 0; 971 972 active_ibss = ieee80211_sta_active_ibss(sdata); 973 974 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) { 975 capability = WLAN_CAPABILITY_IBSS; 976 977 if (ifibss->privacy) 978 capability |= WLAN_CAPABILITY_PRIVACY; 979 980 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel, 981 ifibss->bssid, ifibss->ssid, 982 ifibss->ssid_len, WLAN_CAPABILITY_IBSS | 983 WLAN_CAPABILITY_PRIVACY, 984 capability); 985 986 if (cbss) { 987 cfg80211_unlink_bss(local->hw.wiphy, cbss); 988 cfg80211_put_bss(cbss); 989 } 990 } 991 992 sta_info_flush(sdata->local, sdata); 993 994 /* remove beacon */ 995 kfree(sdata->u.ibss.ie); 996 skb = rcu_dereference_protected(sdata->u.ibss.presp, 997 lockdep_is_held(&sdata->u.ibss.mtx)); 998 rcu_assign_pointer(sdata->u.ibss.presp, NULL); 999 sdata->vif.bss_conf.ibss_joined = false; 1000 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | 1001 BSS_CHANGED_IBSS); 1002 synchronize_rcu(); 1003 kfree_skb(skb); 1004 1005 skb_queue_purge(&sdata->skb_queue); 1006 1007 del_timer_sync(&sdata->u.ibss.timer); 1008 1009 mutex_unlock(&sdata->u.ibss.mtx); 1010 1011 mutex_lock(&local->mtx); 1012 ieee80211_recalc_idle(sdata->local); 1013 mutex_unlock(&local->mtx); 1014 1015 return 0; 1016 } 1017