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/if_ether.h> 17 #include <linux/skbuff.h> 18 #include <linux/if_arp.h> 19 #include <linux/etherdevice.h> 20 #include <linux/rtnetlink.h> 21 #include <net/mac80211.h> 22 #include <asm/unaligned.h> 23 24 #include "ieee80211_i.h" 25 #include "rate.h" 26 27 #define IEEE80211_SCAN_INTERVAL (2 * HZ) 28 #define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ) 29 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ) 30 31 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ) 32 #define IEEE80211_IBSS_MERGE_DELAY 0x400000 33 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ) 34 35 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128 36 37 38 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, 39 struct ieee80211_mgmt *mgmt, 40 size_t len) 41 { 42 u16 auth_alg, auth_transaction, status_code; 43 44 if (len < 24 + 6) 45 return; 46 47 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 48 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 49 status_code = le16_to_cpu(mgmt->u.auth.status_code); 50 51 /* 52 * IEEE 802.11 standard does not require authentication in IBSS 53 * networks and most implementations do not seem to use it. 54 * However, try to reply to authentication attempts if someone 55 * has actually implemented this. 56 */ 57 if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1) 58 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0, 59 sdata->u.ibss.bssid, 0); 60 } 61 62 static int __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 63 const u8 *bssid, const int beacon_int, 64 const int freq, 65 const size_t supp_rates_len, 66 const u8 *supp_rates, 67 const u16 capability, u64 tsf) 68 { 69 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 70 struct ieee80211_local *local = sdata->local; 71 int res = 0, rates, i, j; 72 struct sk_buff *skb; 73 struct ieee80211_mgmt *mgmt; 74 u8 *pos; 75 struct ieee80211_supported_band *sband; 76 union iwreq_data wrqu; 77 78 if (local->ops->reset_tsf) { 79 /* Reset own TSF to allow time synchronization work. */ 80 local->ops->reset_tsf(local_to_hw(local)); 81 } 82 83 if ((ifibss->flags & IEEE80211_IBSS_PREV_BSSID_SET) && 84 memcmp(ifibss->bssid, bssid, ETH_ALEN) == 0) 85 return res; 86 87 skb = dev_alloc_skb(local->hw.extra_tx_headroom + 400); 88 if (!skb) { 89 printk(KERN_DEBUG "%s: failed to allocate buffer for probe " 90 "response\n", sdata->dev->name); 91 return -ENOMEM; 92 } 93 94 if (!(ifibss->flags & IEEE80211_IBSS_PREV_BSSID_SET)) { 95 /* Remove possible STA entries from other IBSS networks. */ 96 sta_info_flush_delayed(sdata); 97 } 98 99 memcpy(ifibss->bssid, bssid, ETH_ALEN); 100 res = ieee80211_if_config(sdata, IEEE80211_IFCC_BSSID); 101 if (res) 102 return res; 103 104 local->hw.conf.beacon_int = beacon_int >= 10 ? beacon_int : 10; 105 106 sdata->drop_unencrypted = capability & 107 WLAN_CAPABILITY_PRIVACY ? 1 : 0; 108 109 res = ieee80211_set_freq(sdata, freq); 110 111 if (res) 112 return res; 113 114 sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; 115 116 /* Build IBSS probe response */ 117 118 skb_reserve(skb, local->hw.extra_tx_headroom); 119 120 mgmt = (struct ieee80211_mgmt *) 121 skb_put(skb, 24 + sizeof(mgmt->u.beacon)); 122 memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon)); 123 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 124 IEEE80211_STYPE_PROBE_RESP); 125 memset(mgmt->da, 0xff, ETH_ALEN); 126 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN); 127 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN); 128 mgmt->u.beacon.beacon_int = 129 cpu_to_le16(local->hw.conf.beacon_int); 130 mgmt->u.beacon.timestamp = cpu_to_le64(tsf); 131 mgmt->u.beacon.capab_info = cpu_to_le16(capability); 132 133 pos = skb_put(skb, 2 + ifibss->ssid_len); 134 *pos++ = WLAN_EID_SSID; 135 *pos++ = ifibss->ssid_len; 136 memcpy(pos, ifibss->ssid, ifibss->ssid_len); 137 138 rates = supp_rates_len; 139 if (rates > 8) 140 rates = 8; 141 pos = skb_put(skb, 2 + rates); 142 *pos++ = WLAN_EID_SUPP_RATES; 143 *pos++ = rates; 144 memcpy(pos, supp_rates, rates); 145 146 if (sband->band == IEEE80211_BAND_2GHZ) { 147 pos = skb_put(skb, 2 + 1); 148 *pos++ = WLAN_EID_DS_PARAMS; 149 *pos++ = 1; 150 *pos++ = ieee80211_frequency_to_channel(freq); 151 } 152 153 pos = skb_put(skb, 2 + 2); 154 *pos++ = WLAN_EID_IBSS_PARAMS; 155 *pos++ = 2; 156 /* FIX: set ATIM window based on scan results */ 157 *pos++ = 0; 158 *pos++ = 0; 159 160 if (supp_rates_len > 8) { 161 rates = supp_rates_len - 8; 162 pos = skb_put(skb, 2 + rates); 163 *pos++ = WLAN_EID_EXT_SUPP_RATES; 164 *pos++ = rates; 165 memcpy(pos, &supp_rates[8], rates); 166 } 167 168 ifibss->probe_resp = skb; 169 170 ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON | 171 IEEE80211_IFCC_BEACON_ENABLED); 172 173 174 rates = 0; 175 for (i = 0; i < supp_rates_len; i++) { 176 int bitrate = (supp_rates[i] & 0x7f) * 5; 177 for (j = 0; j < sband->n_bitrates; j++) 178 if (sband->bitrates[j].bitrate == bitrate) 179 rates |= BIT(j); 180 } 181 182 ieee80211_sta_def_wmm_params(sdata, supp_rates_len, supp_rates); 183 184 ifibss->flags |= IEEE80211_IBSS_PREV_BSSID_SET; 185 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 186 mod_timer(&ifibss->timer, jiffies + IEEE80211_IBSS_MERGE_INTERVAL); 187 188 memset(&wrqu, 0, sizeof(wrqu)); 189 memcpy(wrqu.ap_addr.sa_data, bssid, ETH_ALEN); 190 wireless_send_event(sdata->dev, SIOCGIWAP, &wrqu, NULL); 191 192 return res; 193 } 194 195 static int ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 196 struct ieee80211_bss *bss) 197 { 198 return __ieee80211_sta_join_ibss(sdata, 199 bss->cbss.bssid, 200 bss->cbss.beacon_interval, 201 bss->cbss.channel->center_freq, 202 bss->supp_rates_len, bss->supp_rates, 203 bss->cbss.capability, 204 bss->cbss.tsf); 205 } 206 207 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 208 struct ieee80211_mgmt *mgmt, 209 size_t len, 210 struct ieee80211_rx_status *rx_status, 211 struct ieee802_11_elems *elems, 212 bool beacon) 213 { 214 struct ieee80211_local *local = sdata->local; 215 int freq; 216 struct ieee80211_bss *bss; 217 struct sta_info *sta; 218 struct ieee80211_channel *channel; 219 u64 beacon_timestamp, rx_timestamp; 220 u32 supp_rates = 0; 221 enum ieee80211_band band = rx_status->band; 222 223 if (elems->ds_params && elems->ds_params_len == 1) 224 freq = ieee80211_channel_to_frequency(elems->ds_params[0]); 225 else 226 freq = rx_status->freq; 227 228 channel = ieee80211_get_channel(local->hw.wiphy, freq); 229 230 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 231 return; 232 233 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates && 234 memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) { 235 supp_rates = ieee80211_sta_get_rates(local, elems, band); 236 237 rcu_read_lock(); 238 239 sta = sta_info_get(local, mgmt->sa); 240 if (sta) { 241 u32 prev_rates; 242 243 prev_rates = sta->sta.supp_rates[band]; 244 /* make sure mandatory rates are always added */ 245 sta->sta.supp_rates[band] = supp_rates | 246 ieee80211_mandatory_rates(local, band); 247 248 #ifdef CONFIG_MAC80211_IBSS_DEBUG 249 if (sta->sta.supp_rates[band] != prev_rates) 250 printk(KERN_DEBUG "%s: updated supp_rates set " 251 "for %pM based on beacon info (0x%llx | " 252 "0x%llx -> 0x%llx)\n", 253 sdata->dev->name, 254 sta->sta.addr, 255 (unsigned long long) prev_rates, 256 (unsigned long long) supp_rates, 257 (unsigned long long) sta->sta.supp_rates[band]); 258 #endif 259 } else 260 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates); 261 262 rcu_read_unlock(); 263 } 264 265 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 266 channel, beacon); 267 if (!bss) 268 return; 269 270 /* was just updated in ieee80211_bss_info_update */ 271 beacon_timestamp = bss->cbss.tsf; 272 273 /* check if we need to merge IBSS */ 274 275 /* merge only on beacons (???) */ 276 if (!beacon) 277 goto put_bss; 278 279 /* we use a fixed BSSID */ 280 if (sdata->u.ibss.flags & IEEE80211_IBSS_BSSID_SET) 281 goto put_bss; 282 283 /* not an IBSS */ 284 if (!(bss->cbss.capability & WLAN_CAPABILITY_IBSS)) 285 goto put_bss; 286 287 /* different channel */ 288 if (bss->cbss.channel != local->oper_channel) 289 goto put_bss; 290 291 /* different SSID */ 292 if (elems->ssid_len != sdata->u.ibss.ssid_len || 293 memcmp(elems->ssid, sdata->u.ibss.ssid, 294 sdata->u.ibss.ssid_len)) 295 goto put_bss; 296 297 /* same BSSID */ 298 if (memcmp(bss->cbss.bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) 299 goto put_bss; 300 301 if (rx_status->flag & RX_FLAG_TSFT) { 302 /* 303 * For correct IBSS merging we need mactime; since mactime is 304 * defined as the time the first data symbol of the frame hits 305 * the PHY, and the timestamp of the beacon is defined as "the 306 * time that the data symbol containing the first bit of the 307 * timestamp is transmitted to the PHY plus the transmitting 308 * STA's delays through its local PHY from the MAC-PHY 309 * interface to its interface with the WM" (802.11 11.1.2) 310 * - equals the time this bit arrives at the receiver - we have 311 * to take into account the offset between the two. 312 * 313 * E.g. at 1 MBit that means mactime is 192 usec earlier 314 * (=24 bytes * 8 usecs/byte) than the beacon timestamp. 315 */ 316 int rate; 317 318 if (rx_status->flag & RX_FLAG_HT) 319 rate = 65; /* TODO: HT rates */ 320 else 321 rate = local->hw.wiphy->bands[band]-> 322 bitrates[rx_status->rate_idx].bitrate; 323 324 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate); 325 } else if (local && local->ops && local->ops->get_tsf) 326 /* second best option: get current TSF */ 327 rx_timestamp = local->ops->get_tsf(local_to_hw(local)); 328 else 329 /* can't merge without knowing the TSF */ 330 rx_timestamp = -1LLU; 331 332 #ifdef CONFIG_MAC80211_IBSS_DEBUG 333 printk(KERN_DEBUG "RX beacon SA=%pM BSSID=" 334 "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 335 mgmt->sa, mgmt->bssid, 336 (unsigned long long)rx_timestamp, 337 (unsigned long long)beacon_timestamp, 338 (unsigned long long)(rx_timestamp - beacon_timestamp), 339 jiffies); 340 #endif 341 342 /* give slow hardware some time to do the TSF sync */ 343 if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY) 344 goto put_bss; 345 346 if (beacon_timestamp > rx_timestamp) { 347 #ifdef CONFIG_MAC80211_IBSS_DEBUG 348 printk(KERN_DEBUG "%s: beacon TSF higher than " 349 "local TSF - IBSS merge with BSSID %pM\n", 350 sdata->dev->name, mgmt->bssid); 351 #endif 352 ieee80211_sta_join_ibss(sdata, bss); 353 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates); 354 } 355 356 put_bss: 357 ieee80211_rx_bss_put(local, bss); 358 } 359 360 /* 361 * Add a new IBSS station, will also be called by the RX code when, 362 * in IBSS mode, receiving a frame from a yet-unknown station, hence 363 * must be callable in atomic context. 364 */ 365 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 366 u8 *bssid,u8 *addr, u32 supp_rates) 367 { 368 struct ieee80211_local *local = sdata->local; 369 struct sta_info *sta; 370 int band = local->hw.conf.channel->band; 371 372 /* TODO: Could consider removing the least recently used entry and 373 * allow new one to be added. */ 374 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 375 if (net_ratelimit()) { 376 printk(KERN_DEBUG "%s: No room for a new IBSS STA " 377 "entry %pM\n", sdata->dev->name, addr); 378 } 379 return NULL; 380 } 381 382 if (compare_ether_addr(bssid, sdata->u.ibss.bssid)) 383 return NULL; 384 385 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG 386 printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n", 387 wiphy_name(local->hw.wiphy), addr, sdata->dev->name); 388 #endif 389 390 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC); 391 if (!sta) 392 return NULL; 393 394 set_sta_flags(sta, WLAN_STA_AUTHORIZED); 395 396 /* make sure mandatory rates are always added */ 397 sta->sta.supp_rates[band] = supp_rates | 398 ieee80211_mandatory_rates(local, band); 399 400 rate_control_rate_init(sta); 401 402 if (sta_info_insert(sta)) 403 return NULL; 404 405 return sta; 406 } 407 408 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 409 { 410 struct ieee80211_local *local = sdata->local; 411 int active = 0; 412 struct sta_info *sta; 413 414 rcu_read_lock(); 415 416 list_for_each_entry_rcu(sta, &local->sta_list, list) { 417 if (sta->sdata == sdata && 418 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 419 jiffies)) { 420 active++; 421 break; 422 } 423 } 424 425 rcu_read_unlock(); 426 427 return active; 428 } 429 430 431 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 432 { 433 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 434 435 mod_timer(&ifibss->timer, jiffies + IEEE80211_IBSS_MERGE_INTERVAL); 436 437 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 438 if (ieee80211_sta_active_ibss(sdata)) 439 return; 440 441 if ((ifibss->flags & IEEE80211_IBSS_BSSID_SET) && 442 (!(ifibss->flags & IEEE80211_IBSS_AUTO_CHANNEL_SEL))) 443 return; 444 445 printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other " 446 "IBSS networks with same SSID (merge)\n", sdata->dev->name); 447 448 /* XXX maybe racy? */ 449 if (sdata->local->scan_req) 450 return; 451 452 memcpy(sdata->local->int_scan_req.ssids[0].ssid, 453 ifibss->ssid, IEEE80211_MAX_SSID_LEN); 454 sdata->local->int_scan_req.ssids[0].ssid_len = ifibss->ssid_len; 455 ieee80211_request_scan(sdata, &sdata->local->int_scan_req); 456 } 457 458 static int ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 459 { 460 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 461 struct ieee80211_local *local = sdata->local; 462 struct ieee80211_supported_band *sband; 463 u8 *pos; 464 u8 bssid[ETH_ALEN]; 465 u8 supp_rates[IEEE80211_MAX_SUPP_RATES]; 466 u16 capability; 467 int i; 468 469 if (ifibss->flags & IEEE80211_IBSS_BSSID_SET) { 470 memcpy(bssid, ifibss->bssid, ETH_ALEN); 471 } else { 472 /* Generate random, not broadcast, locally administered BSSID. Mix in 473 * own MAC address to make sure that devices that do not have proper 474 * random number generator get different BSSID. */ 475 get_random_bytes(bssid, ETH_ALEN); 476 for (i = 0; i < ETH_ALEN; i++) 477 bssid[i] ^= sdata->dev->dev_addr[i]; 478 bssid[0] &= ~0x01; 479 bssid[0] |= 0x02; 480 } 481 482 printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n", 483 sdata->dev->name, bssid); 484 485 sband = local->hw.wiphy->bands[local->hw.conf.channel->band]; 486 487 if (local->hw.conf.beacon_int == 0) 488 local->hw.conf.beacon_int = 100; 489 490 capability = WLAN_CAPABILITY_IBSS; 491 492 if (sdata->default_key) 493 capability |= WLAN_CAPABILITY_PRIVACY; 494 else 495 sdata->drop_unencrypted = 0; 496 497 pos = supp_rates; 498 for (i = 0; i < sband->n_bitrates; i++) { 499 int rate = sband->bitrates[i].bitrate; 500 *pos++ = (u8) (rate / 5); 501 } 502 503 return __ieee80211_sta_join_ibss(sdata, 504 bssid, local->hw.conf.beacon_int, 505 local->hw.conf.channel->center_freq, 506 sband->n_bitrates, supp_rates, 507 capability, 0); 508 } 509 510 static int ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 511 { 512 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 513 struct ieee80211_local *local = sdata->local; 514 struct ieee80211_bss *bss; 515 const u8 *bssid = NULL; 516 int active_ibss; 517 518 if (ifibss->ssid_len == 0) 519 return -EINVAL; 520 521 active_ibss = ieee80211_sta_active_ibss(sdata); 522 #ifdef CONFIG_MAC80211_IBSS_DEBUG 523 printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n", 524 sdata->dev->name, active_ibss); 525 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 526 527 if (active_ibss) 528 return 0; 529 530 if (ifibss->flags & IEEE80211_IBSS_BSSID_SET) 531 bssid = ifibss->bssid; 532 bss = (void *)cfg80211_get_bss(local->hw.wiphy, NULL, bssid, 533 ifibss->ssid, ifibss->ssid_len, 534 WLAN_CAPABILITY_IBSS, 535 WLAN_CAPABILITY_IBSS); 536 537 #ifdef CONFIG_MAC80211_IBSS_DEBUG 538 if (bss) 539 printk(KERN_DEBUG " sta_find_ibss: selected %pM current " 540 "%pM\n", bss->cbss.bssid, ifibss->bssid); 541 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 542 543 if (bss && 544 (!(ifibss->flags & IEEE80211_IBSS_PREV_BSSID_SET) || 545 memcmp(ifibss->bssid, bss->cbss.bssid, ETH_ALEN))) { 546 int ret; 547 548 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM" 549 " based on configured SSID\n", 550 sdata->dev->name, bss->cbss.bssid); 551 552 ret = ieee80211_sta_join_ibss(sdata, bss); 553 ieee80211_rx_bss_put(local, bss); 554 return ret; 555 } else if (bss) 556 ieee80211_rx_bss_put(local, bss); 557 558 #ifdef CONFIG_MAC80211_IBSS_DEBUG 559 printk(KERN_DEBUG " did not try to join ibss\n"); 560 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 561 562 /* Selected IBSS not found in current scan results - try to scan */ 563 if (ifibss->state == IEEE80211_IBSS_MLME_JOINED && 564 !ieee80211_sta_active_ibss(sdata)) { 565 mod_timer(&ifibss->timer, jiffies + 566 IEEE80211_IBSS_MERGE_INTERVAL); 567 } else if (time_after(jiffies, local->last_scan_completed + 568 IEEE80211_SCAN_INTERVAL)) { 569 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to " 570 "join\n", sdata->dev->name); 571 572 /* XXX maybe racy? */ 573 if (local->scan_req) 574 return -EBUSY; 575 576 memcpy(local->int_scan_req.ssids[0].ssid, 577 ifibss->ssid, IEEE80211_MAX_SSID_LEN); 578 local->int_scan_req.ssids[0].ssid_len = ifibss->ssid_len; 579 return ieee80211_request_scan(sdata, &local->int_scan_req); 580 } else if (ifibss->state != IEEE80211_IBSS_MLME_JOINED) { 581 int interval = IEEE80211_SCAN_INTERVAL; 582 583 if (time_after(jiffies, ifibss->ibss_join_req + 584 IEEE80211_IBSS_JOIN_TIMEOUT)) { 585 if (!(local->oper_channel->flags & 586 IEEE80211_CHAN_NO_IBSS)) 587 return ieee80211_sta_create_ibss(sdata); 588 printk(KERN_DEBUG "%s: IBSS not allowed on" 589 " %d MHz\n", sdata->dev->name, 590 local->hw.conf.channel->center_freq); 591 592 /* No IBSS found - decrease scan interval and continue 593 * scanning. */ 594 interval = IEEE80211_SCAN_INTERVAL_SLOW; 595 } 596 597 ifibss->state = IEEE80211_IBSS_MLME_SEARCH; 598 mod_timer(&ifibss->timer, jiffies + interval); 599 return 0; 600 } 601 602 return 0; 603 } 604 605 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 606 struct ieee80211_mgmt *mgmt, 607 size_t len) 608 { 609 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 610 struct ieee80211_local *local = sdata->local; 611 int tx_last_beacon; 612 struct sk_buff *skb; 613 struct ieee80211_mgmt *resp; 614 u8 *pos, *end; 615 616 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 617 len < 24 + 2 || !ifibss->probe_resp) 618 return; 619 620 if (local->ops->tx_last_beacon) 621 tx_last_beacon = local->ops->tx_last_beacon(local_to_hw(local)); 622 else 623 tx_last_beacon = 1; 624 625 #ifdef CONFIG_MAC80211_IBSS_DEBUG 626 printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM" 627 " (tx_last_beacon=%d)\n", 628 sdata->dev->name, mgmt->sa, mgmt->da, 629 mgmt->bssid, tx_last_beacon); 630 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 631 632 if (!tx_last_beacon) 633 return; 634 635 if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 && 636 memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0) 637 return; 638 639 end = ((u8 *) mgmt) + len; 640 pos = mgmt->u.probe_req.variable; 641 if (pos[0] != WLAN_EID_SSID || 642 pos + 2 + pos[1] > end) { 643 #ifdef CONFIG_MAC80211_IBSS_DEBUG 644 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq " 645 "from %pM\n", 646 sdata->dev->name, mgmt->sa); 647 #endif 648 return; 649 } 650 if (pos[1] != 0 && 651 (pos[1] != ifibss->ssid_len || 652 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len) != 0)) { 653 /* Ignore ProbeReq for foreign SSID */ 654 return; 655 } 656 657 /* Reply with ProbeResp */ 658 skb = skb_copy(ifibss->probe_resp, GFP_KERNEL); 659 if (!skb) 660 return; 661 662 resp = (struct ieee80211_mgmt *) skb->data; 663 memcpy(resp->da, mgmt->sa, ETH_ALEN); 664 #ifdef CONFIG_MAC80211_IBSS_DEBUG 665 printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n", 666 sdata->dev->name, resp->da); 667 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 668 ieee80211_tx_skb(sdata, skb, 0); 669 } 670 671 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, 672 struct ieee80211_mgmt *mgmt, 673 size_t len, 674 struct ieee80211_rx_status *rx_status) 675 { 676 size_t baselen; 677 struct ieee802_11_elems elems; 678 679 if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN)) 680 return; /* ignore ProbeResp to foreign address */ 681 682 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 683 if (baselen > len) 684 return; 685 686 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 687 &elems); 688 689 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false); 690 } 691 692 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, 693 struct ieee80211_mgmt *mgmt, 694 size_t len, 695 struct ieee80211_rx_status *rx_status) 696 { 697 size_t baselen; 698 struct ieee802_11_elems elems; 699 700 /* Process beacon from the current BSS */ 701 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt; 702 if (baselen > len) 703 return; 704 705 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems); 706 707 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); 708 } 709 710 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 711 struct sk_buff *skb) 712 { 713 struct ieee80211_rx_status *rx_status; 714 struct ieee80211_mgmt *mgmt; 715 u16 fc; 716 717 rx_status = (struct ieee80211_rx_status *) skb->cb; 718 mgmt = (struct ieee80211_mgmt *) skb->data; 719 fc = le16_to_cpu(mgmt->frame_control); 720 721 switch (fc & IEEE80211_FCTL_STYPE) { 722 case IEEE80211_STYPE_PROBE_REQ: 723 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len); 724 break; 725 case IEEE80211_STYPE_PROBE_RESP: 726 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, 727 rx_status); 728 break; 729 case IEEE80211_STYPE_BEACON: 730 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, 731 rx_status); 732 break; 733 case IEEE80211_STYPE_AUTH: 734 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 735 break; 736 } 737 738 kfree_skb(skb); 739 } 740 741 static void ieee80211_ibss_work(struct work_struct *work) 742 { 743 struct ieee80211_sub_if_data *sdata = 744 container_of(work, struct ieee80211_sub_if_data, u.ibss.work); 745 struct ieee80211_local *local = sdata->local; 746 struct ieee80211_if_ibss *ifibss; 747 struct sk_buff *skb; 748 749 if (!netif_running(sdata->dev)) 750 return; 751 752 if (local->sw_scanning || local->hw_scanning) 753 return; 754 755 if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC)) 756 return; 757 ifibss = &sdata->u.ibss; 758 759 while ((skb = skb_dequeue(&ifibss->skb_queue))) 760 ieee80211_ibss_rx_queued_mgmt(sdata, skb); 761 762 if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request)) 763 return; 764 765 switch (ifibss->state) { 766 case IEEE80211_IBSS_MLME_SEARCH: 767 ieee80211_sta_find_ibss(sdata); 768 break; 769 case IEEE80211_IBSS_MLME_JOINED: 770 ieee80211_sta_merge_ibss(sdata); 771 break; 772 default: 773 WARN_ON(1); 774 break; 775 } 776 } 777 778 static void ieee80211_ibss_timer(unsigned long data) 779 { 780 struct ieee80211_sub_if_data *sdata = 781 (struct ieee80211_sub_if_data *) data; 782 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 783 struct ieee80211_local *local = sdata->local; 784 785 set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request); 786 queue_work(local->hw.workqueue, &ifibss->work); 787 } 788 789 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 790 { 791 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 792 793 INIT_WORK(&ifibss->work, ieee80211_ibss_work); 794 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 795 (unsigned long) sdata); 796 skb_queue_head_init(&ifibss->skb_queue); 797 798 ifibss->flags |= IEEE80211_IBSS_AUTO_BSSID_SEL | 799 IEEE80211_IBSS_AUTO_CHANNEL_SEL; 800 } 801 802 int ieee80211_ibss_commit(struct ieee80211_sub_if_data *sdata) 803 { 804 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 805 806 ifibss->flags &= ~IEEE80211_IBSS_PREV_BSSID_SET; 807 808 if (ifibss->ssid_len) 809 ifibss->flags |= IEEE80211_IBSS_SSID_SET; 810 else 811 ifibss->flags &= ~IEEE80211_IBSS_SSID_SET; 812 813 ifibss->ibss_join_req = jiffies; 814 ifibss->state = IEEE80211_IBSS_MLME_SEARCH; 815 set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request); 816 817 return 0; 818 } 819 820 int ieee80211_ibss_set_ssid(struct ieee80211_sub_if_data *sdata, char *ssid, size_t len) 821 { 822 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 823 824 if (len > IEEE80211_MAX_SSID_LEN) 825 return -EINVAL; 826 827 if (ifibss->ssid_len != len || memcmp(ifibss->ssid, ssid, len) != 0) { 828 memset(ifibss->ssid, 0, sizeof(ifibss->ssid)); 829 memcpy(ifibss->ssid, ssid, len); 830 ifibss->ssid_len = len; 831 } 832 833 return ieee80211_ibss_commit(sdata); 834 } 835 836 int ieee80211_ibss_get_ssid(struct ieee80211_sub_if_data *sdata, char *ssid, size_t *len) 837 { 838 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 839 840 memcpy(ssid, ifibss->ssid, ifibss->ssid_len); 841 *len = ifibss->ssid_len; 842 843 return 0; 844 } 845 846 int ieee80211_ibss_set_bssid(struct ieee80211_sub_if_data *sdata, u8 *bssid) 847 { 848 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 849 850 if (is_valid_ether_addr(bssid)) { 851 memcpy(ifibss->bssid, bssid, ETH_ALEN); 852 ifibss->flags |= IEEE80211_IBSS_BSSID_SET; 853 } else { 854 memset(ifibss->bssid, 0, ETH_ALEN); 855 ifibss->flags &= ~IEEE80211_IBSS_BSSID_SET; 856 } 857 858 if (netif_running(sdata->dev)) { 859 if (ieee80211_if_config(sdata, IEEE80211_IFCC_BSSID)) { 860 printk(KERN_DEBUG "%s: Failed to config new BSSID to " 861 "the low-level driver\n", sdata->dev->name); 862 } 863 } 864 865 return ieee80211_ibss_commit(sdata); 866 } 867 868 /* scan finished notification */ 869 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 870 { 871 struct ieee80211_sub_if_data *sdata = local->scan_sdata; 872 struct ieee80211_if_ibss *ifibss; 873 874 if (sdata && sdata->vif.type == NL80211_IFTYPE_ADHOC) { 875 ifibss = &sdata->u.ibss; 876 if ((!(ifibss->flags & IEEE80211_IBSS_PREV_BSSID_SET)) || 877 !ieee80211_sta_active_ibss(sdata)) 878 ieee80211_sta_find_ibss(sdata); 879 } 880 } 881 882 ieee80211_rx_result 883 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb, 884 struct ieee80211_rx_status *rx_status) 885 { 886 struct ieee80211_local *local = sdata->local; 887 struct ieee80211_mgmt *mgmt; 888 u16 fc; 889 890 if (skb->len < 24) 891 return RX_DROP_MONITOR; 892 893 mgmt = (struct ieee80211_mgmt *) skb->data; 894 fc = le16_to_cpu(mgmt->frame_control); 895 896 switch (fc & IEEE80211_FCTL_STYPE) { 897 case IEEE80211_STYPE_PROBE_RESP: 898 case IEEE80211_STYPE_BEACON: 899 memcpy(skb->cb, rx_status, sizeof(*rx_status)); 900 case IEEE80211_STYPE_PROBE_REQ: 901 case IEEE80211_STYPE_AUTH: 902 skb_queue_tail(&sdata->u.ibss.skb_queue, skb); 903 queue_work(local->hw.workqueue, &sdata->u.ibss.work); 904 return RX_QUEUED; 905 } 906 907 return RX_DROP_MONITOR; 908 } 909