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 "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_MERGE_DELAY 0x400000 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, status_code; 44 45 if (len < 24 + 6) 46 return; 47 48 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 49 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 50 status_code = le16_to_cpu(mgmt->u.auth.status_code); 51 52 /* 53 * IEEE 802.11 standard does not require authentication in IBSS 54 * networks and most implementations do not seem to use it. 55 * However, try to reply to authentication attempts if someone 56 * has actually implemented this. 57 */ 58 if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1) 59 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0, 60 sdata->u.ibss.bssid, NULL, 0, 0); 61 } 62 63 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 64 const u8 *bssid, const int beacon_int, 65 struct ieee80211_channel *chan, 66 const u32 basic_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 rates, i; 72 struct sk_buff *skb; 73 struct ieee80211_mgmt *mgmt; 74 u8 *pos; 75 struct ieee80211_supported_band *sband; 76 struct cfg80211_bss *bss; 77 u32 bss_change; 78 u8 supp_rates[IEEE80211_MAX_SUPP_RATES]; 79 80 /* Reset own TSF to allow time synchronization work. */ 81 drv_reset_tsf(local); 82 83 skb = ifibss->skb; 84 rcu_assign_pointer(ifibss->presp, NULL); 85 synchronize_rcu(); 86 skb->data = skb->head; 87 skb->len = 0; 88 skb_reset_tail_pointer(skb); 89 skb_reserve(skb, sdata->local->hw.extra_tx_headroom); 90 91 if (memcmp(ifibss->bssid, bssid, ETH_ALEN)) 92 sta_info_flush(sdata->local, sdata); 93 94 memcpy(ifibss->bssid, bssid, ETH_ALEN); 95 96 sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0; 97 98 local->oper_channel = chan; 99 local->oper_channel_type = NL80211_CHAN_NO_HT; 100 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 101 102 sband = local->hw.wiphy->bands[chan->band]; 103 104 /* build supported rates array */ 105 pos = supp_rates; 106 for (i = 0; i < sband->n_bitrates; i++) { 107 int rate = sband->bitrates[i].bitrate; 108 u8 basic = 0; 109 if (basic_rates & BIT(i)) 110 basic = 0x80; 111 *pos++ = basic | (u8) (rate / 5); 112 } 113 114 /* Build IBSS probe response */ 115 mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon)); 116 memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon)); 117 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 118 IEEE80211_STYPE_PROBE_RESP); 119 memset(mgmt->da, 0xff, ETH_ALEN); 120 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN); 121 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN); 122 mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int); 123 mgmt->u.beacon.timestamp = cpu_to_le64(tsf); 124 mgmt->u.beacon.capab_info = cpu_to_le16(capability); 125 126 pos = skb_put(skb, 2 + ifibss->ssid_len); 127 *pos++ = WLAN_EID_SSID; 128 *pos++ = ifibss->ssid_len; 129 memcpy(pos, ifibss->ssid, ifibss->ssid_len); 130 131 rates = sband->n_bitrates; 132 if (rates > 8) 133 rates = 8; 134 pos = skb_put(skb, 2 + rates); 135 *pos++ = WLAN_EID_SUPP_RATES; 136 *pos++ = rates; 137 memcpy(pos, supp_rates, rates); 138 139 if (sband->band == IEEE80211_BAND_2GHZ) { 140 pos = skb_put(skb, 2 + 1); 141 *pos++ = WLAN_EID_DS_PARAMS; 142 *pos++ = 1; 143 *pos++ = ieee80211_frequency_to_channel(chan->center_freq); 144 } 145 146 pos = skb_put(skb, 2 + 2); 147 *pos++ = WLAN_EID_IBSS_PARAMS; 148 *pos++ = 2; 149 /* FIX: set ATIM window based on scan results */ 150 *pos++ = 0; 151 *pos++ = 0; 152 153 if (sband->n_bitrates > 8) { 154 rates = sband->n_bitrates - 8; 155 pos = skb_put(skb, 2 + rates); 156 *pos++ = WLAN_EID_EXT_SUPP_RATES; 157 *pos++ = rates; 158 memcpy(pos, &supp_rates[8], rates); 159 } 160 161 if (ifibss->ie_len) 162 memcpy(skb_put(skb, ifibss->ie_len), 163 ifibss->ie, ifibss->ie_len); 164 165 rcu_assign_pointer(ifibss->presp, skb); 166 167 sdata->vif.bss_conf.beacon_int = beacon_int; 168 bss_change = BSS_CHANGED_BEACON_INT; 169 bss_change |= ieee80211_reset_erp_info(sdata); 170 bss_change |= BSS_CHANGED_BSSID; 171 bss_change |= BSS_CHANGED_BEACON; 172 bss_change |= BSS_CHANGED_BEACON_ENABLED; 173 ieee80211_bss_info_change_notify(sdata, bss_change); 174 175 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 176 177 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 178 mod_timer(&ifibss->timer, 179 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 180 181 bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel, 182 mgmt, skb->len, 0, GFP_KERNEL); 183 cfg80211_put_bss(bss); 184 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 185 } 186 187 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 188 struct ieee80211_bss *bss) 189 { 190 struct ieee80211_supported_band *sband; 191 u32 basic_rates; 192 int i, j; 193 u16 beacon_int = bss->cbss.beacon_interval; 194 195 if (beacon_int < 10) 196 beacon_int = 10; 197 198 sband = sdata->local->hw.wiphy->bands[bss->cbss.channel->band]; 199 200 basic_rates = 0; 201 202 for (i = 0; i < bss->supp_rates_len; i++) { 203 int rate = (bss->supp_rates[i] & 0x7f) * 5; 204 bool is_basic = !!(bss->supp_rates[i] & 0x80); 205 206 for (j = 0; j < sband->n_bitrates; j++) { 207 if (sband->bitrates[j].bitrate == rate) { 208 if (is_basic) 209 basic_rates |= BIT(j); 210 break; 211 } 212 } 213 } 214 215 __ieee80211_sta_join_ibss(sdata, bss->cbss.bssid, 216 beacon_int, 217 bss->cbss.channel, 218 basic_rates, 219 bss->cbss.capability, 220 bss->cbss.tsf); 221 } 222 223 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 224 struct ieee80211_mgmt *mgmt, 225 size_t len, 226 struct ieee80211_rx_status *rx_status, 227 struct ieee802_11_elems *elems, 228 bool beacon) 229 { 230 struct ieee80211_local *local = sdata->local; 231 int freq; 232 struct ieee80211_bss *bss; 233 struct sta_info *sta; 234 struct ieee80211_channel *channel; 235 u64 beacon_timestamp, rx_timestamp; 236 u32 supp_rates = 0; 237 enum ieee80211_band band = rx_status->band; 238 239 if (elems->ds_params && elems->ds_params_len == 1) 240 freq = ieee80211_channel_to_frequency(elems->ds_params[0]); 241 else 242 freq = rx_status->freq; 243 244 channel = ieee80211_get_channel(local->hw.wiphy, freq); 245 246 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 247 return; 248 249 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates && 250 memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) { 251 supp_rates = ieee80211_sta_get_rates(local, elems, band); 252 253 rcu_read_lock(); 254 255 sta = sta_info_get(local, mgmt->sa); 256 if (sta) { 257 u32 prev_rates; 258 259 prev_rates = sta->sta.supp_rates[band]; 260 /* make sure mandatory rates are always added */ 261 sta->sta.supp_rates[band] = supp_rates | 262 ieee80211_mandatory_rates(local, band); 263 264 #ifdef CONFIG_MAC80211_IBSS_DEBUG 265 if (sta->sta.supp_rates[band] != prev_rates) 266 printk(KERN_DEBUG "%s: updated supp_rates set " 267 "for %pM based on beacon info (0x%llx | " 268 "0x%llx -> 0x%llx)\n", 269 sdata->dev->name, 270 sta->sta.addr, 271 (unsigned long long) prev_rates, 272 (unsigned long long) supp_rates, 273 (unsigned long long) sta->sta.supp_rates[band]); 274 #endif 275 } else 276 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates); 277 278 rcu_read_unlock(); 279 } 280 281 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 282 channel, beacon); 283 if (!bss) 284 return; 285 286 /* was just updated in ieee80211_bss_info_update */ 287 beacon_timestamp = bss->cbss.tsf; 288 289 /* check if we need to merge IBSS */ 290 291 /* merge only on beacons (???) */ 292 if (!beacon) 293 goto put_bss; 294 295 /* we use a fixed BSSID */ 296 if (sdata->u.ibss.bssid) 297 goto put_bss; 298 299 /* not an IBSS */ 300 if (!(bss->cbss.capability & WLAN_CAPABILITY_IBSS)) 301 goto put_bss; 302 303 /* different channel */ 304 if (bss->cbss.channel != local->oper_channel) 305 goto put_bss; 306 307 /* different SSID */ 308 if (elems->ssid_len != sdata->u.ibss.ssid_len || 309 memcmp(elems->ssid, sdata->u.ibss.ssid, 310 sdata->u.ibss.ssid_len)) 311 goto put_bss; 312 313 /* same BSSID */ 314 if (memcmp(bss->cbss.bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) 315 goto put_bss; 316 317 if (rx_status->flag & RX_FLAG_TSFT) { 318 /* 319 * For correct IBSS merging we need mactime; since mactime is 320 * defined as the time the first data symbol of the frame hits 321 * the PHY, and the timestamp of the beacon is defined as "the 322 * time that the data symbol containing the first bit of the 323 * timestamp is transmitted to the PHY plus the transmitting 324 * STA's delays through its local PHY from the MAC-PHY 325 * interface to its interface with the WM" (802.11 11.1.2) 326 * - equals the time this bit arrives at the receiver - we have 327 * to take into account the offset between the two. 328 * 329 * E.g. at 1 MBit that means mactime is 192 usec earlier 330 * (=24 bytes * 8 usecs/byte) than the beacon timestamp. 331 */ 332 int rate; 333 334 if (rx_status->flag & RX_FLAG_HT) 335 rate = 65; /* TODO: HT rates */ 336 else 337 rate = local->hw.wiphy->bands[band]-> 338 bitrates[rx_status->rate_idx].bitrate; 339 340 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate); 341 } else { 342 /* 343 * second best option: get current TSF 344 * (will return -1 if not supported) 345 */ 346 rx_timestamp = drv_get_tsf(local); 347 } 348 349 #ifdef CONFIG_MAC80211_IBSS_DEBUG 350 printk(KERN_DEBUG "RX beacon SA=%pM BSSID=" 351 "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 352 mgmt->sa, mgmt->bssid, 353 (unsigned long long)rx_timestamp, 354 (unsigned long long)beacon_timestamp, 355 (unsigned long long)(rx_timestamp - beacon_timestamp), 356 jiffies); 357 #endif 358 359 /* give slow hardware some time to do the TSF sync */ 360 if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY) 361 goto put_bss; 362 363 if (beacon_timestamp > rx_timestamp) { 364 #ifdef CONFIG_MAC80211_IBSS_DEBUG 365 printk(KERN_DEBUG "%s: beacon TSF higher than " 366 "local TSF - IBSS merge with BSSID %pM\n", 367 sdata->dev->name, mgmt->bssid); 368 #endif 369 ieee80211_sta_join_ibss(sdata, bss); 370 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates); 371 } 372 373 put_bss: 374 ieee80211_rx_bss_put(local, bss); 375 } 376 377 /* 378 * Add a new IBSS station, will also be called by the RX code when, 379 * in IBSS mode, receiving a frame from a yet-unknown station, hence 380 * must be callable in atomic context. 381 */ 382 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 383 u8 *bssid,u8 *addr, u32 supp_rates) 384 { 385 struct ieee80211_local *local = sdata->local; 386 struct sta_info *sta; 387 int band = local->hw.conf.channel->band; 388 389 /* 390 * XXX: Consider removing the least recently used entry and 391 * allow new one to be added. 392 */ 393 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 394 if (net_ratelimit()) 395 printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n", 396 sdata->dev->name, addr); 397 return NULL; 398 } 399 400 if (compare_ether_addr(bssid, sdata->u.ibss.bssid)) 401 return NULL; 402 403 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG 404 printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n", 405 wiphy_name(local->hw.wiphy), addr, sdata->dev->name); 406 #endif 407 408 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC); 409 if (!sta) 410 return NULL; 411 412 set_sta_flags(sta, WLAN_STA_AUTHORIZED); 413 414 /* make sure mandatory rates are always added */ 415 sta->sta.supp_rates[band] = supp_rates | 416 ieee80211_mandatory_rates(local, band); 417 418 rate_control_rate_init(sta); 419 420 if (sta_info_insert(sta)) 421 return NULL; 422 423 return sta; 424 } 425 426 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 427 { 428 struct ieee80211_local *local = sdata->local; 429 int active = 0; 430 struct sta_info *sta; 431 432 rcu_read_lock(); 433 434 list_for_each_entry_rcu(sta, &local->sta_list, list) { 435 if (sta->sdata == sdata && 436 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 437 jiffies)) { 438 active++; 439 break; 440 } 441 } 442 443 rcu_read_unlock(); 444 445 return active; 446 } 447 448 449 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 450 { 451 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 452 453 mod_timer(&ifibss->timer, 454 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 455 456 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 457 458 if (time_before(jiffies, ifibss->last_scan_completed + 459 IEEE80211_IBSS_MERGE_INTERVAL)) 460 return; 461 462 if (ieee80211_sta_active_ibss(sdata)) 463 return; 464 465 if (ifibss->fixed_channel) 466 return; 467 468 printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other " 469 "IBSS networks with same SSID (merge)\n", sdata->dev->name); 470 471 ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len); 472 } 473 474 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 475 { 476 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 477 struct ieee80211_local *local = sdata->local; 478 struct ieee80211_supported_band *sband; 479 u8 bssid[ETH_ALEN]; 480 u16 capability; 481 int i; 482 483 if (ifibss->fixed_bssid) { 484 memcpy(bssid, ifibss->bssid, ETH_ALEN); 485 } else { 486 /* Generate random, not broadcast, locally administered BSSID. Mix in 487 * own MAC address to make sure that devices that do not have proper 488 * random number generator get different BSSID. */ 489 get_random_bytes(bssid, ETH_ALEN); 490 for (i = 0; i < ETH_ALEN; i++) 491 bssid[i] ^= sdata->dev->dev_addr[i]; 492 bssid[0] &= ~0x01; 493 bssid[0] |= 0x02; 494 } 495 496 printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n", 497 sdata->dev->name, bssid); 498 499 sband = local->hw.wiphy->bands[ifibss->channel->band]; 500 501 capability = WLAN_CAPABILITY_IBSS; 502 503 if (ifibss->privacy) 504 capability |= WLAN_CAPABILITY_PRIVACY; 505 else 506 sdata->drop_unencrypted = 0; 507 508 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 509 ifibss->channel, 3, /* first two are basic */ 510 capability, 0); 511 } 512 513 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 514 { 515 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 516 struct ieee80211_local *local = sdata->local; 517 struct ieee80211_bss *bss; 518 struct ieee80211_channel *chan = NULL; 519 const u8 *bssid = NULL; 520 int active_ibss; 521 u16 capability; 522 523 active_ibss = ieee80211_sta_active_ibss(sdata); 524 #ifdef CONFIG_MAC80211_IBSS_DEBUG 525 printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n", 526 sdata->dev->name, active_ibss); 527 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 528 529 if (active_ibss) 530 return; 531 532 capability = WLAN_CAPABILITY_IBSS; 533 if (ifibss->privacy) 534 capability |= WLAN_CAPABILITY_PRIVACY; 535 if (ifibss->fixed_bssid) 536 bssid = ifibss->bssid; 537 if (ifibss->fixed_channel) 538 chan = ifibss->channel; 539 if (!is_zero_ether_addr(ifibss->bssid)) 540 bssid = ifibss->bssid; 541 bss = (void *)cfg80211_get_bss(local->hw.wiphy, chan, bssid, 542 ifibss->ssid, ifibss->ssid_len, 543 WLAN_CAPABILITY_IBSS | 544 WLAN_CAPABILITY_PRIVACY, 545 capability); 546 547 if (bss) { 548 #ifdef CONFIG_MAC80211_IBSS_DEBUG 549 printk(KERN_DEBUG " sta_find_ibss: selected %pM current " 550 "%pM\n", bss->cbss.bssid, ifibss->bssid); 551 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 552 553 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM" 554 " based on configured SSID\n", 555 sdata->dev->name, bss->cbss.bssid); 556 557 ieee80211_sta_join_ibss(sdata, bss); 558 ieee80211_rx_bss_put(local, bss); 559 return; 560 } 561 562 #ifdef CONFIG_MAC80211_IBSS_DEBUG 563 printk(KERN_DEBUG " did not try to join ibss\n"); 564 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 565 566 /* Selected IBSS not found in current scan results - try to scan */ 567 if (ifibss->state == IEEE80211_IBSS_MLME_JOINED && 568 !ieee80211_sta_active_ibss(sdata)) { 569 mod_timer(&ifibss->timer, 570 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 571 } else if (time_after(jiffies, ifibss->last_scan_completed + 572 IEEE80211_SCAN_INTERVAL)) { 573 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to " 574 "join\n", sdata->dev->name); 575 576 ieee80211_request_internal_scan(sdata, ifibss->ssid, 577 ifibss->ssid_len); 578 } else if (ifibss->state != IEEE80211_IBSS_MLME_JOINED) { 579 int interval = IEEE80211_SCAN_INTERVAL; 580 581 if (time_after(jiffies, ifibss->ibss_join_req + 582 IEEE80211_IBSS_JOIN_TIMEOUT)) { 583 if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) { 584 ieee80211_sta_create_ibss(sdata); 585 return; 586 } 587 printk(KERN_DEBUG "%s: IBSS not allowed on" 588 " %d MHz\n", sdata->dev->name, 589 local->hw.conf.channel->center_freq); 590 591 /* No IBSS found - decrease scan interval and continue 592 * scanning. */ 593 interval = IEEE80211_SCAN_INTERVAL_SLOW; 594 } 595 596 ifibss->state = IEEE80211_IBSS_MLME_SEARCH; 597 mod_timer(&ifibss->timer, 598 round_jiffies(jiffies + interval)); 599 } 600 } 601 602 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 603 struct ieee80211_mgmt *mgmt, 604 size_t len) 605 { 606 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 607 struct ieee80211_local *local = sdata->local; 608 int tx_last_beacon; 609 struct sk_buff *skb; 610 struct ieee80211_mgmt *resp; 611 u8 *pos, *end; 612 613 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 614 len < 24 + 2 || !ifibss->presp) 615 return; 616 617 tx_last_beacon = drv_tx_last_beacon(local); 618 619 #ifdef CONFIG_MAC80211_IBSS_DEBUG 620 printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM" 621 " (tx_last_beacon=%d)\n", 622 sdata->dev->name, mgmt->sa, mgmt->da, 623 mgmt->bssid, tx_last_beacon); 624 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 625 626 if (!tx_last_beacon) 627 return; 628 629 if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 && 630 memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0) 631 return; 632 633 end = ((u8 *) mgmt) + len; 634 pos = mgmt->u.probe_req.variable; 635 if (pos[0] != WLAN_EID_SSID || 636 pos + 2 + pos[1] > end) { 637 #ifdef CONFIG_MAC80211_IBSS_DEBUG 638 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq " 639 "from %pM\n", 640 sdata->dev->name, mgmt->sa); 641 #endif 642 return; 643 } 644 if (pos[1] != 0 && 645 (pos[1] != ifibss->ssid_len || 646 !memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 647 /* Ignore ProbeReq for foreign SSID */ 648 return; 649 } 650 651 /* Reply with ProbeResp */ 652 skb = skb_copy(ifibss->presp, GFP_KERNEL); 653 if (!skb) 654 return; 655 656 resp = (struct ieee80211_mgmt *) skb->data; 657 memcpy(resp->da, mgmt->sa, ETH_ALEN); 658 #ifdef CONFIG_MAC80211_IBSS_DEBUG 659 printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n", 660 sdata->dev->name, resp->da); 661 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 662 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 663 ieee80211_tx_skb(sdata, skb); 664 } 665 666 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, 667 struct ieee80211_mgmt *mgmt, 668 size_t len, 669 struct ieee80211_rx_status *rx_status) 670 { 671 size_t baselen; 672 struct ieee802_11_elems elems; 673 674 if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN)) 675 return; /* ignore ProbeResp to foreign address */ 676 677 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 678 if (baselen > len) 679 return; 680 681 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 682 &elems); 683 684 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false); 685 } 686 687 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, 688 struct ieee80211_mgmt *mgmt, 689 size_t len, 690 struct ieee80211_rx_status *rx_status) 691 { 692 size_t baselen; 693 struct ieee802_11_elems elems; 694 695 /* Process beacon from the current BSS */ 696 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt; 697 if (baselen > len) 698 return; 699 700 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems); 701 702 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); 703 } 704 705 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 706 struct sk_buff *skb) 707 { 708 struct ieee80211_rx_status *rx_status; 709 struct ieee80211_mgmt *mgmt; 710 u16 fc; 711 712 rx_status = IEEE80211_SKB_RXCB(skb); 713 mgmt = (struct ieee80211_mgmt *) skb->data; 714 fc = le16_to_cpu(mgmt->frame_control); 715 716 switch (fc & IEEE80211_FCTL_STYPE) { 717 case IEEE80211_STYPE_PROBE_REQ: 718 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len); 719 break; 720 case IEEE80211_STYPE_PROBE_RESP: 721 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, 722 rx_status); 723 break; 724 case IEEE80211_STYPE_BEACON: 725 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, 726 rx_status); 727 break; 728 case IEEE80211_STYPE_AUTH: 729 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 730 break; 731 } 732 733 kfree_skb(skb); 734 } 735 736 static void ieee80211_ibss_work(struct work_struct *work) 737 { 738 struct ieee80211_sub_if_data *sdata = 739 container_of(work, struct ieee80211_sub_if_data, u.ibss.work); 740 struct ieee80211_local *local = sdata->local; 741 struct ieee80211_if_ibss *ifibss; 742 struct sk_buff *skb; 743 744 if (WARN_ON(local->suspended)) 745 return; 746 747 if (!netif_running(sdata->dev)) 748 return; 749 750 if (local->scanning) 751 return; 752 753 if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC)) 754 return; 755 ifibss = &sdata->u.ibss; 756 757 while ((skb = skb_dequeue(&ifibss->skb_queue))) 758 ieee80211_ibss_rx_queued_mgmt(sdata, skb); 759 760 if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request)) 761 return; 762 763 switch (ifibss->state) { 764 case IEEE80211_IBSS_MLME_SEARCH: 765 ieee80211_sta_find_ibss(sdata); 766 break; 767 case IEEE80211_IBSS_MLME_JOINED: 768 ieee80211_sta_merge_ibss(sdata); 769 break; 770 default: 771 WARN_ON(1); 772 break; 773 } 774 } 775 776 static void ieee80211_ibss_timer(unsigned long data) 777 { 778 struct ieee80211_sub_if_data *sdata = 779 (struct ieee80211_sub_if_data *) data; 780 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 781 struct ieee80211_local *local = sdata->local; 782 783 if (local->quiescing) { 784 ifibss->timer_running = true; 785 return; 786 } 787 788 set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request); 789 ieee80211_queue_work(&local->hw, &ifibss->work); 790 } 791 792 #ifdef CONFIG_PM 793 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata) 794 { 795 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 796 797 cancel_work_sync(&ifibss->work); 798 if (del_timer_sync(&ifibss->timer)) 799 ifibss->timer_running = true; 800 } 801 802 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata) 803 { 804 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 805 806 if (ifibss->timer_running) { 807 add_timer(&ifibss->timer); 808 ifibss->timer_running = false; 809 } 810 } 811 #endif 812 813 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 814 { 815 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 816 817 INIT_WORK(&ifibss->work, ieee80211_ibss_work); 818 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 819 (unsigned long) sdata); 820 skb_queue_head_init(&ifibss->skb_queue); 821 } 822 823 /* scan finished notification */ 824 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 825 { 826 struct ieee80211_sub_if_data *sdata; 827 828 mutex_lock(&local->iflist_mtx); 829 list_for_each_entry(sdata, &local->interfaces, list) { 830 if (!netif_running(sdata->dev)) 831 continue; 832 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 833 continue; 834 if (!sdata->u.ibss.ssid_len) 835 continue; 836 sdata->u.ibss.last_scan_completed = jiffies; 837 mod_timer(&sdata->u.ibss.timer, 0); 838 } 839 mutex_unlock(&local->iflist_mtx); 840 } 841 842 ieee80211_rx_result 843 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) 844 { 845 struct ieee80211_local *local = sdata->local; 846 struct ieee80211_mgmt *mgmt; 847 u16 fc; 848 849 if (skb->len < 24) 850 return RX_DROP_MONITOR; 851 852 mgmt = (struct ieee80211_mgmt *) skb->data; 853 fc = le16_to_cpu(mgmt->frame_control); 854 855 switch (fc & IEEE80211_FCTL_STYPE) { 856 case IEEE80211_STYPE_PROBE_RESP: 857 case IEEE80211_STYPE_BEACON: 858 case IEEE80211_STYPE_PROBE_REQ: 859 case IEEE80211_STYPE_AUTH: 860 skb_queue_tail(&sdata->u.ibss.skb_queue, skb); 861 ieee80211_queue_work(&local->hw, &sdata->u.ibss.work); 862 return RX_QUEUED; 863 } 864 865 return RX_DROP_MONITOR; 866 } 867 868 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 869 struct cfg80211_ibss_params *params) 870 { 871 struct sk_buff *skb; 872 873 if (params->bssid) { 874 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 875 sdata->u.ibss.fixed_bssid = true; 876 } else 877 sdata->u.ibss.fixed_bssid = false; 878 879 sdata->u.ibss.privacy = params->privacy; 880 881 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 882 883 sdata->u.ibss.channel = params->channel; 884 sdata->u.ibss.fixed_channel = params->channel_fixed; 885 886 if (params->ie) { 887 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 888 GFP_KERNEL); 889 if (sdata->u.ibss.ie) 890 sdata->u.ibss.ie_len = params->ie_len; 891 } 892 893 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom + 894 36 /* bitrates */ + 895 34 /* SSID */ + 896 3 /* DS params */ + 897 4 /* IBSS params */ + 898 params->ie_len); 899 if (!skb) 900 return -ENOMEM; 901 902 sdata->u.ibss.skb = skb; 903 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 904 sdata->u.ibss.ibss_join_req = jiffies; 905 906 memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN); 907 908 /* 909 * The ssid_len setting below is used to see whether 910 * we are active, and we need all other settings 911 * before that may get visible. 912 */ 913 mb(); 914 915 sdata->u.ibss.ssid_len = params->ssid_len; 916 917 ieee80211_recalc_idle(sdata->local); 918 919 set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request); 920 ieee80211_queue_work(&sdata->local->hw, &sdata->u.ibss.work); 921 922 return 0; 923 } 924 925 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 926 { 927 struct sk_buff *skb; 928 929 del_timer_sync(&sdata->u.ibss.timer); 930 clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request); 931 cancel_work_sync(&sdata->u.ibss.work); 932 clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request); 933 934 sta_info_flush(sdata->local, sdata); 935 936 /* remove beacon */ 937 kfree(sdata->u.ibss.ie); 938 skb = sdata->u.ibss.presp; 939 rcu_assign_pointer(sdata->u.ibss.presp, NULL); 940 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED); 941 synchronize_rcu(); 942 kfree_skb(skb); 943 944 skb_queue_purge(&sdata->u.ibss.skb_queue); 945 memset(sdata->u.ibss.bssid, 0, ETH_ALEN); 946 sdata->u.ibss.ssid_len = 0; 947 948 ieee80211_recalc_idle(sdata->local); 949 950 return 0; 951 } 952