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_MERGE_DELAY 0x400000 35 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ) 36 37 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128 38 39 40 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, 41 struct ieee80211_mgmt *mgmt, 42 size_t len) 43 { 44 u16 auth_alg, auth_transaction, status_code; 45 46 lockdep_assert_held(&sdata->u.ibss.mtx); 47 48 if (len < 24 + 6) 49 return; 50 51 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 52 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 53 status_code = le16_to_cpu(mgmt->u.auth.status_code); 54 55 /* 56 * IEEE 802.11 standard does not require authentication in IBSS 57 * networks and most implementations do not seem to use it. 58 * However, try to reply to authentication attempts if someone 59 * has actually implemented this. 60 */ 61 if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1) 62 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0, 63 sdata->u.ibss.bssid, NULL, 0, 0); 64 } 65 66 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 67 const u8 *bssid, const int beacon_int, 68 struct ieee80211_channel *chan, 69 const u32 basic_rates, 70 const u16 capability, u64 tsf) 71 { 72 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 73 struct ieee80211_local *local = sdata->local; 74 int rates, i; 75 struct sk_buff *skb; 76 struct ieee80211_mgmt *mgmt; 77 u8 *pos; 78 struct ieee80211_supported_band *sband; 79 struct cfg80211_bss *bss; 80 u32 bss_change; 81 u8 supp_rates[IEEE80211_MAX_SUPP_RATES]; 82 83 lockdep_assert_held(&ifibss->mtx); 84 85 /* Reset own TSF to allow time synchronization work. */ 86 drv_reset_tsf(local); 87 88 skb = ifibss->skb; 89 rcu_assign_pointer(ifibss->presp, NULL); 90 synchronize_rcu(); 91 skb->data = skb->head; 92 skb->len = 0; 93 skb_reset_tail_pointer(skb); 94 skb_reserve(skb, sdata->local->hw.extra_tx_headroom); 95 96 if (memcmp(ifibss->bssid, bssid, ETH_ALEN)) 97 sta_info_flush(sdata->local, sdata); 98 99 /* if merging, indicate to driver that we leave the old IBSS */ 100 if (sdata->vif.bss_conf.ibss_joined) { 101 sdata->vif.bss_conf.ibss_joined = false; 102 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS); 103 } 104 105 memcpy(ifibss->bssid, bssid, ETH_ALEN); 106 107 sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0; 108 109 local->oper_channel = chan; 110 WARN_ON(!ieee80211_set_channel_type(local, sdata, NL80211_CHAN_NO_HT)); 111 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 112 113 sband = local->hw.wiphy->bands[chan->band]; 114 115 /* build supported rates array */ 116 pos = supp_rates; 117 for (i = 0; i < sband->n_bitrates; i++) { 118 int rate = sband->bitrates[i].bitrate; 119 u8 basic = 0; 120 if (basic_rates & BIT(i)) 121 basic = 0x80; 122 *pos++ = basic | (u8) (rate / 5); 123 } 124 125 /* Build IBSS probe response */ 126 mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon)); 127 memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon)); 128 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 129 IEEE80211_STYPE_PROBE_RESP); 130 memset(mgmt->da, 0xff, ETH_ALEN); 131 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 132 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN); 133 mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int); 134 mgmt->u.beacon.timestamp = cpu_to_le64(tsf); 135 mgmt->u.beacon.capab_info = cpu_to_le16(capability); 136 137 pos = skb_put(skb, 2 + ifibss->ssid_len); 138 *pos++ = WLAN_EID_SSID; 139 *pos++ = ifibss->ssid_len; 140 memcpy(pos, ifibss->ssid, ifibss->ssid_len); 141 142 rates = sband->n_bitrates; 143 if (rates > 8) 144 rates = 8; 145 pos = skb_put(skb, 2 + rates); 146 *pos++ = WLAN_EID_SUPP_RATES; 147 *pos++ = rates; 148 memcpy(pos, supp_rates, rates); 149 150 if (sband->band == IEEE80211_BAND_2GHZ) { 151 pos = skb_put(skb, 2 + 1); 152 *pos++ = WLAN_EID_DS_PARAMS; 153 *pos++ = 1; 154 *pos++ = ieee80211_frequency_to_channel(chan->center_freq); 155 } 156 157 pos = skb_put(skb, 2 + 2); 158 *pos++ = WLAN_EID_IBSS_PARAMS; 159 *pos++ = 2; 160 /* FIX: set ATIM window based on scan results */ 161 *pos++ = 0; 162 *pos++ = 0; 163 164 if (sband->n_bitrates > 8) { 165 rates = sband->n_bitrates - 8; 166 pos = skb_put(skb, 2 + rates); 167 *pos++ = WLAN_EID_EXT_SUPP_RATES; 168 *pos++ = rates; 169 memcpy(pos, &supp_rates[8], rates); 170 } 171 172 if (ifibss->ie_len) 173 memcpy(skb_put(skb, ifibss->ie_len), 174 ifibss->ie, ifibss->ie_len); 175 176 rcu_assign_pointer(ifibss->presp, skb); 177 178 sdata->vif.bss_conf.beacon_int = beacon_int; 179 sdata->vif.bss_conf.basic_rates = basic_rates; 180 bss_change = BSS_CHANGED_BEACON_INT; 181 bss_change |= ieee80211_reset_erp_info(sdata); 182 bss_change |= BSS_CHANGED_BSSID; 183 bss_change |= BSS_CHANGED_BEACON; 184 bss_change |= BSS_CHANGED_BEACON_ENABLED; 185 bss_change |= BSS_CHANGED_BASIC_RATES; 186 bss_change |= BSS_CHANGED_IBSS; 187 sdata->vif.bss_conf.ibss_joined = true; 188 ieee80211_bss_info_change_notify(sdata, bss_change); 189 190 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 191 192 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 193 mod_timer(&ifibss->timer, 194 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 195 196 bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel, 197 mgmt, skb->len, 0, GFP_KERNEL); 198 cfg80211_put_bss(bss); 199 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 200 } 201 202 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 203 struct ieee80211_bss *bss) 204 { 205 struct cfg80211_bss *cbss = 206 container_of((void *)bss, struct cfg80211_bss, priv); 207 struct ieee80211_supported_band *sband; 208 u32 basic_rates; 209 int i, j; 210 u16 beacon_int = cbss->beacon_interval; 211 212 lockdep_assert_held(&sdata->u.ibss.mtx); 213 214 if (beacon_int < 10) 215 beacon_int = 10; 216 217 sband = sdata->local->hw.wiphy->bands[cbss->channel->band]; 218 219 basic_rates = 0; 220 221 for (i = 0; i < bss->supp_rates_len; i++) { 222 int rate = (bss->supp_rates[i] & 0x7f) * 5; 223 bool is_basic = !!(bss->supp_rates[i] & 0x80); 224 225 for (j = 0; j < sband->n_bitrates; j++) { 226 if (sband->bitrates[j].bitrate == rate) { 227 if (is_basic) 228 basic_rates |= BIT(j); 229 break; 230 } 231 } 232 } 233 234 __ieee80211_sta_join_ibss(sdata, cbss->bssid, 235 beacon_int, 236 cbss->channel, 237 basic_rates, 238 cbss->capability, 239 cbss->tsf); 240 } 241 242 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 243 struct ieee80211_mgmt *mgmt, 244 size_t len, 245 struct ieee80211_rx_status *rx_status, 246 struct ieee802_11_elems *elems, 247 bool beacon) 248 { 249 struct ieee80211_local *local = sdata->local; 250 int freq; 251 struct cfg80211_bss *cbss; 252 struct ieee80211_bss *bss; 253 struct sta_info *sta; 254 struct ieee80211_channel *channel; 255 u64 beacon_timestamp, rx_timestamp; 256 u32 supp_rates = 0; 257 enum ieee80211_band band = rx_status->band; 258 259 if (elems->ds_params && elems->ds_params_len == 1) 260 freq = ieee80211_channel_to_frequency(elems->ds_params[0]); 261 else 262 freq = rx_status->freq; 263 264 channel = ieee80211_get_channel(local->hw.wiphy, freq); 265 266 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 267 return; 268 269 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates && 270 memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) { 271 supp_rates = ieee80211_sta_get_rates(local, elems, band); 272 273 rcu_read_lock(); 274 275 sta = sta_info_get(sdata, mgmt->sa); 276 if (sta) { 277 u32 prev_rates; 278 279 prev_rates = sta->sta.supp_rates[band]; 280 /* make sure mandatory rates are always added */ 281 sta->sta.supp_rates[band] = supp_rates | 282 ieee80211_mandatory_rates(local, band); 283 284 if (sta->sta.supp_rates[band] != prev_rates) { 285 #ifdef CONFIG_MAC80211_IBSS_DEBUG 286 printk(KERN_DEBUG "%s: updated supp_rates set " 287 "for %pM based on beacon/probe_response " 288 "(0x%x -> 0x%x)\n", 289 sdata->name, sta->sta.addr, 290 prev_rates, sta->sta.supp_rates[band]); 291 #endif 292 rate_control_rate_init(sta); 293 } 294 rcu_read_unlock(); 295 } else { 296 rcu_read_unlock(); 297 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 298 supp_rates, GFP_KERNEL); 299 } 300 } 301 302 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 303 channel, beacon); 304 if (!bss) 305 return; 306 307 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 308 309 /* was just updated in ieee80211_bss_info_update */ 310 beacon_timestamp = cbss->tsf; 311 312 /* check if we need to merge IBSS */ 313 314 /* we use a fixed BSSID */ 315 if (sdata->u.ibss.fixed_bssid) 316 goto put_bss; 317 318 /* not an IBSS */ 319 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 320 goto put_bss; 321 322 /* different channel */ 323 if (cbss->channel != local->oper_channel) 324 goto put_bss; 325 326 /* different SSID */ 327 if (elems->ssid_len != sdata->u.ibss.ssid_len || 328 memcmp(elems->ssid, sdata->u.ibss.ssid, 329 sdata->u.ibss.ssid_len)) 330 goto put_bss; 331 332 /* same BSSID */ 333 if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) 334 goto put_bss; 335 336 if (rx_status->flag & RX_FLAG_TSFT) { 337 /* 338 * For correct IBSS merging we need mactime; since mactime is 339 * defined as the time the first data symbol of the frame hits 340 * the PHY, and the timestamp of the beacon is defined as "the 341 * time that the data symbol containing the first bit of the 342 * timestamp is transmitted to the PHY plus the transmitting 343 * STA's delays through its local PHY from the MAC-PHY 344 * interface to its interface with the WM" (802.11 11.1.2) 345 * - equals the time this bit arrives at the receiver - we have 346 * to take into account the offset between the two. 347 * 348 * E.g. at 1 MBit that means mactime is 192 usec earlier 349 * (=24 bytes * 8 usecs/byte) than the beacon timestamp. 350 */ 351 int rate; 352 353 if (rx_status->flag & RX_FLAG_HT) 354 rate = 65; /* TODO: HT rates */ 355 else 356 rate = local->hw.wiphy->bands[band]-> 357 bitrates[rx_status->rate_idx].bitrate; 358 359 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate); 360 } else { 361 /* 362 * second best option: get current TSF 363 * (will return -1 if not supported) 364 */ 365 rx_timestamp = drv_get_tsf(local); 366 } 367 368 #ifdef CONFIG_MAC80211_IBSS_DEBUG 369 printk(KERN_DEBUG "RX beacon SA=%pM BSSID=" 370 "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 371 mgmt->sa, mgmt->bssid, 372 (unsigned long long)rx_timestamp, 373 (unsigned long long)beacon_timestamp, 374 (unsigned long long)(rx_timestamp - beacon_timestamp), 375 jiffies); 376 #endif 377 378 /* give slow hardware some time to do the TSF sync */ 379 if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY) 380 goto put_bss; 381 382 if (beacon_timestamp > rx_timestamp) { 383 #ifdef CONFIG_MAC80211_IBSS_DEBUG 384 printk(KERN_DEBUG "%s: beacon TSF higher than " 385 "local TSF - IBSS merge with BSSID %pM\n", 386 sdata->name, mgmt->bssid); 387 #endif 388 ieee80211_sta_join_ibss(sdata, bss); 389 supp_rates = ieee80211_sta_get_rates(local, elems, band); 390 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 391 supp_rates, GFP_KERNEL); 392 } 393 394 put_bss: 395 ieee80211_rx_bss_put(local, bss); 396 } 397 398 /* 399 * Add a new IBSS station, will also be called by the RX code when, 400 * in IBSS mode, receiving a frame from a yet-unknown station, hence 401 * must be callable in atomic context. 402 */ 403 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 404 u8 *bssid,u8 *addr, u32 supp_rates, 405 gfp_t gfp) 406 { 407 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 408 struct ieee80211_local *local = sdata->local; 409 struct sta_info *sta; 410 int band = local->hw.conf.channel->band; 411 412 /* 413 * XXX: Consider removing the least recently used entry and 414 * allow new one to be added. 415 */ 416 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 417 if (net_ratelimit()) 418 printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n", 419 sdata->name, addr); 420 return NULL; 421 } 422 423 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 424 return NULL; 425 426 if (compare_ether_addr(bssid, sdata->u.ibss.bssid)) 427 return NULL; 428 429 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG 430 printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n", 431 wiphy_name(local->hw.wiphy), addr, sdata->name); 432 #endif 433 434 sta = sta_info_alloc(sdata, addr, gfp); 435 if (!sta) 436 return NULL; 437 438 set_sta_flags(sta, WLAN_STA_AUTHORIZED); 439 440 /* make sure mandatory rates are always added */ 441 sta->sta.supp_rates[band] = supp_rates | 442 ieee80211_mandatory_rates(local, band); 443 444 rate_control_rate_init(sta); 445 446 /* If it fails, maybe we raced another insertion? */ 447 if (sta_info_insert(sta)) 448 return sta_info_get(sdata, addr); 449 return sta; 450 } 451 452 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 453 { 454 struct ieee80211_local *local = sdata->local; 455 int active = 0; 456 struct sta_info *sta; 457 458 lockdep_assert_held(&sdata->u.ibss.mtx); 459 460 rcu_read_lock(); 461 462 list_for_each_entry_rcu(sta, &local->sta_list, list) { 463 if (sta->sdata == sdata && 464 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 465 jiffies)) { 466 active++; 467 break; 468 } 469 } 470 471 rcu_read_unlock(); 472 473 return active; 474 } 475 476 /* 477 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 478 */ 479 480 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 481 { 482 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 483 484 lockdep_assert_held(&ifibss->mtx); 485 486 mod_timer(&ifibss->timer, 487 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 488 489 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 490 491 if (time_before(jiffies, ifibss->last_scan_completed + 492 IEEE80211_IBSS_MERGE_INTERVAL)) 493 return; 494 495 if (ieee80211_sta_active_ibss(sdata)) 496 return; 497 498 if (ifibss->fixed_channel) 499 return; 500 501 printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other " 502 "IBSS networks with same SSID (merge)\n", sdata->name); 503 504 ieee80211_request_internal_scan(sdata, 505 ifibss->ssid, ifibss->ssid_len, 506 ifibss->fixed_channel ? ifibss->channel : NULL); 507 } 508 509 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 510 { 511 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 512 struct ieee80211_local *local = sdata->local; 513 struct ieee80211_supported_band *sband; 514 u8 bssid[ETH_ALEN]; 515 u16 capability; 516 int i; 517 518 lockdep_assert_held(&ifibss->mtx); 519 520 if (ifibss->fixed_bssid) { 521 memcpy(bssid, ifibss->bssid, ETH_ALEN); 522 } else { 523 /* Generate random, not broadcast, locally administered BSSID. Mix in 524 * own MAC address to make sure that devices that do not have proper 525 * random number generator get different BSSID. */ 526 get_random_bytes(bssid, ETH_ALEN); 527 for (i = 0; i < ETH_ALEN; i++) 528 bssid[i] ^= sdata->vif.addr[i]; 529 bssid[0] &= ~0x01; 530 bssid[0] |= 0x02; 531 } 532 533 printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n", 534 sdata->name, bssid); 535 536 sband = local->hw.wiphy->bands[ifibss->channel->band]; 537 538 capability = WLAN_CAPABILITY_IBSS; 539 540 if (ifibss->privacy) 541 capability |= WLAN_CAPABILITY_PRIVACY; 542 else 543 sdata->drop_unencrypted = 0; 544 545 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 546 ifibss->channel, ifibss->basic_rates, 547 capability, 0); 548 } 549 550 /* 551 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 552 */ 553 554 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 555 { 556 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 557 struct ieee80211_local *local = sdata->local; 558 struct cfg80211_bss *cbss; 559 struct ieee80211_channel *chan = NULL; 560 const u8 *bssid = NULL; 561 int active_ibss; 562 u16 capability; 563 564 lockdep_assert_held(&ifibss->mtx); 565 566 active_ibss = ieee80211_sta_active_ibss(sdata); 567 #ifdef CONFIG_MAC80211_IBSS_DEBUG 568 printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n", 569 sdata->name, active_ibss); 570 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 571 572 if (active_ibss) 573 return; 574 575 capability = WLAN_CAPABILITY_IBSS; 576 if (ifibss->privacy) 577 capability |= WLAN_CAPABILITY_PRIVACY; 578 if (ifibss->fixed_bssid) 579 bssid = ifibss->bssid; 580 if (ifibss->fixed_channel) 581 chan = ifibss->channel; 582 if (!is_zero_ether_addr(ifibss->bssid)) 583 bssid = ifibss->bssid; 584 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 585 ifibss->ssid, ifibss->ssid_len, 586 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 587 capability); 588 589 if (cbss) { 590 struct ieee80211_bss *bss; 591 592 bss = (void *)cbss->priv; 593 #ifdef CONFIG_MAC80211_IBSS_DEBUG 594 printk(KERN_DEBUG " sta_find_ibss: selected %pM current " 595 "%pM\n", cbss->bssid, ifibss->bssid); 596 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 597 598 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM" 599 " based on configured SSID\n", 600 sdata->name, cbss->bssid); 601 602 ieee80211_sta_join_ibss(sdata, bss); 603 ieee80211_rx_bss_put(local, bss); 604 return; 605 } 606 607 #ifdef CONFIG_MAC80211_IBSS_DEBUG 608 printk(KERN_DEBUG " did not try to join ibss\n"); 609 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 610 611 /* Selected IBSS not found in current scan results - try to scan */ 612 if (time_after(jiffies, ifibss->last_scan_completed + 613 IEEE80211_SCAN_INTERVAL)) { 614 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to " 615 "join\n", sdata->name); 616 617 ieee80211_request_internal_scan(sdata, 618 ifibss->ssid, ifibss->ssid_len, 619 ifibss->fixed_channel ? ifibss->channel : NULL); 620 } else { 621 int interval = IEEE80211_SCAN_INTERVAL; 622 623 if (time_after(jiffies, ifibss->ibss_join_req + 624 IEEE80211_IBSS_JOIN_TIMEOUT)) { 625 if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) { 626 ieee80211_sta_create_ibss(sdata); 627 return; 628 } 629 printk(KERN_DEBUG "%s: IBSS not allowed on" 630 " %d MHz\n", sdata->name, 631 local->hw.conf.channel->center_freq); 632 633 /* No IBSS found - decrease scan interval and continue 634 * scanning. */ 635 interval = IEEE80211_SCAN_INTERVAL_SLOW; 636 } 637 638 mod_timer(&ifibss->timer, 639 round_jiffies(jiffies + interval)); 640 } 641 } 642 643 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 644 struct ieee80211_mgmt *mgmt, 645 size_t len) 646 { 647 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 648 struct ieee80211_local *local = sdata->local; 649 int tx_last_beacon; 650 struct sk_buff *skb; 651 struct ieee80211_mgmt *resp; 652 u8 *pos, *end; 653 654 lockdep_assert_held(&ifibss->mtx); 655 656 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 657 len < 24 + 2 || !ifibss->presp) 658 return; 659 660 tx_last_beacon = drv_tx_last_beacon(local); 661 662 #ifdef CONFIG_MAC80211_IBSS_DEBUG 663 printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM" 664 " (tx_last_beacon=%d)\n", 665 sdata->name, mgmt->sa, mgmt->da, 666 mgmt->bssid, tx_last_beacon); 667 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 668 669 if (!tx_last_beacon) 670 return; 671 672 if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 && 673 memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0) 674 return; 675 676 end = ((u8 *) mgmt) + len; 677 pos = mgmt->u.probe_req.variable; 678 if (pos[0] != WLAN_EID_SSID || 679 pos + 2 + pos[1] > end) { 680 #ifdef CONFIG_MAC80211_IBSS_DEBUG 681 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq " 682 "from %pM\n", 683 sdata->name, mgmt->sa); 684 #endif 685 return; 686 } 687 if (pos[1] != 0 && 688 (pos[1] != ifibss->ssid_len || 689 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 690 /* Ignore ProbeReq for foreign SSID */ 691 return; 692 } 693 694 /* Reply with ProbeResp */ 695 skb = skb_copy(ifibss->presp, GFP_KERNEL); 696 if (!skb) 697 return; 698 699 resp = (struct ieee80211_mgmt *) skb->data; 700 memcpy(resp->da, mgmt->sa, ETH_ALEN); 701 #ifdef CONFIG_MAC80211_IBSS_DEBUG 702 printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n", 703 sdata->name, resp->da); 704 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 705 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 706 ieee80211_tx_skb(sdata, skb); 707 } 708 709 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, 710 struct ieee80211_mgmt *mgmt, 711 size_t len, 712 struct ieee80211_rx_status *rx_status) 713 { 714 size_t baselen; 715 struct ieee802_11_elems elems; 716 717 if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN)) 718 return; /* ignore ProbeResp to foreign address */ 719 720 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 721 if (baselen > len) 722 return; 723 724 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 725 &elems); 726 727 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false); 728 } 729 730 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, 731 struct ieee80211_mgmt *mgmt, 732 size_t len, 733 struct ieee80211_rx_status *rx_status) 734 { 735 size_t baselen; 736 struct ieee802_11_elems elems; 737 738 /* Process beacon from the current BSS */ 739 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt; 740 if (baselen > len) 741 return; 742 743 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems); 744 745 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); 746 } 747 748 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 749 struct sk_buff *skb) 750 { 751 struct ieee80211_rx_status *rx_status; 752 struct ieee80211_mgmt *mgmt; 753 u16 fc; 754 755 rx_status = IEEE80211_SKB_RXCB(skb); 756 mgmt = (struct ieee80211_mgmt *) skb->data; 757 fc = le16_to_cpu(mgmt->frame_control); 758 759 mutex_lock(&sdata->u.ibss.mtx); 760 761 switch (fc & IEEE80211_FCTL_STYPE) { 762 case IEEE80211_STYPE_PROBE_REQ: 763 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len); 764 break; 765 case IEEE80211_STYPE_PROBE_RESP: 766 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, 767 rx_status); 768 break; 769 case IEEE80211_STYPE_BEACON: 770 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, 771 rx_status); 772 break; 773 case IEEE80211_STYPE_AUTH: 774 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 775 break; 776 } 777 778 mutex_unlock(&sdata->u.ibss.mtx); 779 } 780 781 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata) 782 { 783 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 784 785 mutex_lock(&ifibss->mtx); 786 787 /* 788 * Work could be scheduled after scan or similar 789 * when we aren't even joined (or trying) with a 790 * network. 791 */ 792 if (!ifibss->ssid_len) 793 goto out; 794 795 switch (ifibss->state) { 796 case IEEE80211_IBSS_MLME_SEARCH: 797 ieee80211_sta_find_ibss(sdata); 798 break; 799 case IEEE80211_IBSS_MLME_JOINED: 800 ieee80211_sta_merge_ibss(sdata); 801 break; 802 default: 803 WARN_ON(1); 804 break; 805 } 806 807 out: 808 mutex_unlock(&ifibss->mtx); 809 } 810 811 static void ieee80211_ibss_timer(unsigned long data) 812 { 813 struct ieee80211_sub_if_data *sdata = 814 (struct ieee80211_sub_if_data *) data; 815 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 816 struct ieee80211_local *local = sdata->local; 817 818 if (local->quiescing) { 819 ifibss->timer_running = true; 820 return; 821 } 822 823 ieee80211_queue_work(&local->hw, &sdata->work); 824 } 825 826 #ifdef CONFIG_PM 827 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata) 828 { 829 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 830 831 if (del_timer_sync(&ifibss->timer)) 832 ifibss->timer_running = true; 833 } 834 835 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata) 836 { 837 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 838 839 if (ifibss->timer_running) { 840 add_timer(&ifibss->timer); 841 ifibss->timer_running = false; 842 } 843 } 844 #endif 845 846 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 847 { 848 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 849 850 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 851 (unsigned long) sdata); 852 mutex_init(&ifibss->mtx); 853 } 854 855 /* scan finished notification */ 856 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 857 { 858 struct ieee80211_sub_if_data *sdata; 859 860 mutex_lock(&local->iflist_mtx); 861 list_for_each_entry(sdata, &local->interfaces, list) { 862 if (!ieee80211_sdata_running(sdata)) 863 continue; 864 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 865 continue; 866 sdata->u.ibss.last_scan_completed = jiffies; 867 ieee80211_queue_work(&local->hw, &sdata->work); 868 } 869 mutex_unlock(&local->iflist_mtx); 870 } 871 872 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 873 struct cfg80211_ibss_params *params) 874 { 875 struct sk_buff *skb; 876 877 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom + 878 36 /* bitrates */ + 879 34 /* SSID */ + 880 3 /* DS params */ + 881 4 /* IBSS params */ + 882 params->ie_len); 883 if (!skb) 884 return -ENOMEM; 885 886 mutex_lock(&sdata->u.ibss.mtx); 887 888 if (params->bssid) { 889 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 890 sdata->u.ibss.fixed_bssid = true; 891 } else 892 sdata->u.ibss.fixed_bssid = false; 893 894 sdata->u.ibss.privacy = params->privacy; 895 sdata->u.ibss.basic_rates = params->basic_rates; 896 897 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 898 899 sdata->u.ibss.channel = params->channel; 900 sdata->u.ibss.fixed_channel = params->channel_fixed; 901 902 /* fix ourselves to that channel now already */ 903 if (params->channel_fixed) { 904 sdata->local->oper_channel = params->channel; 905 WARN_ON(!ieee80211_set_channel_type(sdata->local, sdata, 906 NL80211_CHAN_NO_HT)); 907 } 908 909 if (params->ie) { 910 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 911 GFP_KERNEL); 912 if (sdata->u.ibss.ie) 913 sdata->u.ibss.ie_len = params->ie_len; 914 } 915 916 sdata->u.ibss.skb = skb; 917 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 918 sdata->u.ibss.ibss_join_req = jiffies; 919 920 memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN); 921 sdata->u.ibss.ssid_len = params->ssid_len; 922 923 ieee80211_recalc_idle(sdata->local); 924 925 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 926 927 mutex_unlock(&sdata->u.ibss.mtx); 928 929 return 0; 930 } 931 932 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 933 { 934 struct sk_buff *skb; 935 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 936 struct ieee80211_local *local = sdata->local; 937 struct cfg80211_bss *cbss; 938 u16 capability; 939 int active_ibss; 940 941 mutex_lock(&sdata->u.ibss.mtx); 942 943 active_ibss = ieee80211_sta_active_ibss(sdata); 944 945 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) { 946 capability = WLAN_CAPABILITY_IBSS; 947 948 if (ifibss->privacy) 949 capability |= WLAN_CAPABILITY_PRIVACY; 950 951 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel, 952 ifibss->bssid, ifibss->ssid, 953 ifibss->ssid_len, WLAN_CAPABILITY_IBSS | 954 WLAN_CAPABILITY_PRIVACY, 955 capability); 956 957 if (cbss) { 958 cfg80211_unlink_bss(local->hw.wiphy, cbss); 959 cfg80211_put_bss(cbss); 960 } 961 } 962 963 sta_info_flush(sdata->local, sdata); 964 965 /* remove beacon */ 966 kfree(sdata->u.ibss.ie); 967 skb = sdata->u.ibss.presp; 968 rcu_assign_pointer(sdata->u.ibss.presp, NULL); 969 sdata->vif.bss_conf.ibss_joined = false; 970 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | 971 BSS_CHANGED_IBSS); 972 synchronize_rcu(); 973 kfree_skb(skb); 974 975 skb_queue_purge(&sdata->skb_queue); 976 memset(sdata->u.ibss.bssid, 0, ETH_ALEN); 977 sdata->u.ibss.ssid_len = 0; 978 979 del_timer_sync(&sdata->u.ibss.timer); 980 981 mutex_unlock(&sdata->u.ibss.mtx); 982 983 ieee80211_recalc_idle(sdata->local); 984 985 return 0; 986 } 987