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 if (len < 24 + 6) 47 return; 48 49 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 50 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 51 status_code = le16_to_cpu(mgmt->u.auth.status_code); 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 /* Reset own TSF to allow time synchronization work. */ 82 drv_reset_tsf(local); 83 84 skb = ifibss->skb; 85 rcu_assign_pointer(ifibss->presp, NULL); 86 synchronize_rcu(); 87 skb->data = skb->head; 88 skb->len = 0; 89 skb_reset_tail_pointer(skb); 90 skb_reserve(skb, sdata->local->hw.extra_tx_headroom); 91 92 if (memcmp(ifibss->bssid, bssid, ETH_ALEN)) 93 sta_info_flush(sdata->local, sdata); 94 95 /* if merging, indicate to driver that we leave the old IBSS */ 96 if (sdata->vif.bss_conf.ibss_joined) { 97 sdata->vif.bss_conf.ibss_joined = false; 98 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS); 99 } 100 101 memcpy(ifibss->bssid, bssid, ETH_ALEN); 102 103 sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0; 104 105 local->oper_channel = chan; 106 WARN_ON(!ieee80211_set_channel_type(local, sdata, NL80211_CHAN_NO_HT)); 107 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 108 109 sband = local->hw.wiphy->bands[chan->band]; 110 111 /* build supported rates array */ 112 pos = supp_rates; 113 for (i = 0; i < sband->n_bitrates; i++) { 114 int rate = sband->bitrates[i].bitrate; 115 u8 basic = 0; 116 if (basic_rates & BIT(i)) 117 basic = 0x80; 118 *pos++ = basic | (u8) (rate / 5); 119 } 120 121 /* Build IBSS probe response */ 122 mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon)); 123 memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon)); 124 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 125 IEEE80211_STYPE_PROBE_RESP); 126 memset(mgmt->da, 0xff, ETH_ALEN); 127 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 128 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN); 129 mgmt->u.beacon.beacon_int = cpu_to_le16(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 = sband->n_bitrates; 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(chan->center_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 (sband->n_bitrates > 8) { 161 rates = sband->n_bitrates - 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 if (ifibss->ie_len) 169 memcpy(skb_put(skb, ifibss->ie_len), 170 ifibss->ie, ifibss->ie_len); 171 172 rcu_assign_pointer(ifibss->presp, skb); 173 174 sdata->vif.bss_conf.beacon_int = beacon_int; 175 bss_change = BSS_CHANGED_BEACON_INT; 176 bss_change |= ieee80211_reset_erp_info(sdata); 177 bss_change |= BSS_CHANGED_BSSID; 178 bss_change |= BSS_CHANGED_BEACON; 179 bss_change |= BSS_CHANGED_BEACON_ENABLED; 180 bss_change |= BSS_CHANGED_IBSS; 181 sdata->vif.bss_conf.ibss_joined = true; 182 ieee80211_bss_info_change_notify(sdata, bss_change); 183 184 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 185 186 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 187 mod_timer(&ifibss->timer, 188 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 189 190 bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel, 191 mgmt, skb->len, 0, GFP_KERNEL); 192 cfg80211_put_bss(bss); 193 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 194 } 195 196 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 197 struct ieee80211_bss *bss) 198 { 199 struct cfg80211_bss *cbss = 200 container_of((void *)bss, struct cfg80211_bss, priv); 201 struct ieee80211_supported_band *sband; 202 u32 basic_rates; 203 int i, j; 204 u16 beacon_int = cbss->beacon_interval; 205 206 if (beacon_int < 10) 207 beacon_int = 10; 208 209 sband = sdata->local->hw.wiphy->bands[cbss->channel->band]; 210 211 basic_rates = 0; 212 213 for (i = 0; i < bss->supp_rates_len; i++) { 214 int rate = (bss->supp_rates[i] & 0x7f) * 5; 215 bool is_basic = !!(bss->supp_rates[i] & 0x80); 216 217 for (j = 0; j < sband->n_bitrates; j++) { 218 if (sband->bitrates[j].bitrate == rate) { 219 if (is_basic) 220 basic_rates |= BIT(j); 221 break; 222 } 223 } 224 } 225 226 __ieee80211_sta_join_ibss(sdata, cbss->bssid, 227 beacon_int, 228 cbss->channel, 229 basic_rates, 230 cbss->capability, 231 cbss->tsf); 232 } 233 234 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 235 struct ieee80211_mgmt *mgmt, 236 size_t len, 237 struct ieee80211_rx_status *rx_status, 238 struct ieee802_11_elems *elems, 239 bool beacon) 240 { 241 struct ieee80211_local *local = sdata->local; 242 int freq; 243 struct cfg80211_bss *cbss; 244 struct ieee80211_bss *bss; 245 struct sta_info *sta; 246 struct ieee80211_channel *channel; 247 u64 beacon_timestamp, rx_timestamp; 248 u32 supp_rates = 0; 249 enum ieee80211_band band = rx_status->band; 250 251 if (elems->ds_params && elems->ds_params_len == 1) 252 freq = ieee80211_channel_to_frequency(elems->ds_params[0]); 253 else 254 freq = rx_status->freq; 255 256 channel = ieee80211_get_channel(local->hw.wiphy, freq); 257 258 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 259 return; 260 261 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates && 262 memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) { 263 supp_rates = ieee80211_sta_get_rates(local, elems, band); 264 265 rcu_read_lock(); 266 267 sta = sta_info_get(sdata, mgmt->sa); 268 if (sta) { 269 u32 prev_rates; 270 271 prev_rates = sta->sta.supp_rates[band]; 272 /* make sure mandatory rates are always added */ 273 sta->sta.supp_rates[band] = supp_rates | 274 ieee80211_mandatory_rates(local, band); 275 276 if (sta->sta.supp_rates[band] != prev_rates) { 277 #ifdef CONFIG_MAC80211_IBSS_DEBUG 278 printk(KERN_DEBUG "%s: updated supp_rates set " 279 "for %pM based on beacon/probe_response " 280 "(0x%x -> 0x%x)\n", 281 sdata->name, sta->sta.addr, 282 prev_rates, sta->sta.supp_rates[band]); 283 #endif 284 rate_control_rate_init(sta); 285 } 286 rcu_read_unlock(); 287 } else { 288 rcu_read_unlock(); 289 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 290 supp_rates, GFP_KERNEL); 291 } 292 } 293 294 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 295 channel, beacon); 296 if (!bss) 297 return; 298 299 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 300 301 /* was just updated in ieee80211_bss_info_update */ 302 beacon_timestamp = cbss->tsf; 303 304 /* check if we need to merge IBSS */ 305 306 /* we use a fixed BSSID */ 307 if (sdata->u.ibss.fixed_bssid) 308 goto put_bss; 309 310 /* not an IBSS */ 311 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 312 goto put_bss; 313 314 /* different channel */ 315 if (cbss->channel != local->oper_channel) 316 goto put_bss; 317 318 /* different SSID */ 319 if (elems->ssid_len != sdata->u.ibss.ssid_len || 320 memcmp(elems->ssid, sdata->u.ibss.ssid, 321 sdata->u.ibss.ssid_len)) 322 goto put_bss; 323 324 /* same BSSID */ 325 if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) 326 goto put_bss; 327 328 if (rx_status->flag & RX_FLAG_TSFT) { 329 /* 330 * For correct IBSS merging we need mactime; since mactime is 331 * defined as the time the first data symbol of the frame hits 332 * the PHY, and the timestamp of the beacon is defined as "the 333 * time that the data symbol containing the first bit of the 334 * timestamp is transmitted to the PHY plus the transmitting 335 * STA's delays through its local PHY from the MAC-PHY 336 * interface to its interface with the WM" (802.11 11.1.2) 337 * - equals the time this bit arrives at the receiver - we have 338 * to take into account the offset between the two. 339 * 340 * E.g. at 1 MBit that means mactime is 192 usec earlier 341 * (=24 bytes * 8 usecs/byte) than the beacon timestamp. 342 */ 343 int rate; 344 345 if (rx_status->flag & RX_FLAG_HT) 346 rate = 65; /* TODO: HT rates */ 347 else 348 rate = local->hw.wiphy->bands[band]-> 349 bitrates[rx_status->rate_idx].bitrate; 350 351 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate); 352 } else { 353 /* 354 * second best option: get current TSF 355 * (will return -1 if not supported) 356 */ 357 rx_timestamp = drv_get_tsf(local); 358 } 359 360 #ifdef CONFIG_MAC80211_IBSS_DEBUG 361 printk(KERN_DEBUG "RX beacon SA=%pM BSSID=" 362 "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 363 mgmt->sa, mgmt->bssid, 364 (unsigned long long)rx_timestamp, 365 (unsigned long long)beacon_timestamp, 366 (unsigned long long)(rx_timestamp - beacon_timestamp), 367 jiffies); 368 #endif 369 370 /* give slow hardware some time to do the TSF sync */ 371 if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY) 372 goto put_bss; 373 374 if (beacon_timestamp > rx_timestamp) { 375 #ifdef CONFIG_MAC80211_IBSS_DEBUG 376 printk(KERN_DEBUG "%s: beacon TSF higher than " 377 "local TSF - IBSS merge with BSSID %pM\n", 378 sdata->name, mgmt->bssid); 379 #endif 380 ieee80211_sta_join_ibss(sdata, bss); 381 supp_rates = ieee80211_sta_get_rates(local, elems, band); 382 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 383 supp_rates, GFP_KERNEL); 384 } 385 386 put_bss: 387 ieee80211_rx_bss_put(local, bss); 388 } 389 390 /* 391 * Add a new IBSS station, will also be called by the RX code when, 392 * in IBSS mode, receiving a frame from a yet-unknown station, hence 393 * must be callable in atomic context. 394 */ 395 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 396 u8 *bssid,u8 *addr, u32 supp_rates, 397 gfp_t gfp) 398 { 399 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 400 struct ieee80211_local *local = sdata->local; 401 struct sta_info *sta; 402 int band = local->hw.conf.channel->band; 403 404 /* 405 * XXX: Consider removing the least recently used entry and 406 * allow new one to be added. 407 */ 408 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 409 if (net_ratelimit()) 410 printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n", 411 sdata->name, addr); 412 return NULL; 413 } 414 415 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 416 return NULL; 417 418 if (compare_ether_addr(bssid, sdata->u.ibss.bssid)) 419 return NULL; 420 421 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG 422 printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n", 423 wiphy_name(local->hw.wiphy), addr, sdata->name); 424 #endif 425 426 sta = sta_info_alloc(sdata, addr, gfp); 427 if (!sta) 428 return NULL; 429 430 set_sta_flags(sta, WLAN_STA_AUTHORIZED); 431 432 /* make sure mandatory rates are always added */ 433 sta->sta.supp_rates[band] = supp_rates | 434 ieee80211_mandatory_rates(local, band); 435 436 rate_control_rate_init(sta); 437 438 /* If it fails, maybe we raced another insertion? */ 439 if (sta_info_insert(sta)) 440 return sta_info_get(sdata, addr); 441 return sta; 442 } 443 444 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 445 { 446 struct ieee80211_local *local = sdata->local; 447 int active = 0; 448 struct sta_info *sta; 449 450 rcu_read_lock(); 451 452 list_for_each_entry_rcu(sta, &local->sta_list, list) { 453 if (sta->sdata == sdata && 454 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 455 jiffies)) { 456 active++; 457 break; 458 } 459 } 460 461 rcu_read_unlock(); 462 463 return active; 464 } 465 466 /* 467 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 468 */ 469 470 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 471 { 472 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 473 474 mod_timer(&ifibss->timer, 475 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 476 477 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 478 479 if (time_before(jiffies, ifibss->last_scan_completed + 480 IEEE80211_IBSS_MERGE_INTERVAL)) 481 return; 482 483 if (ieee80211_sta_active_ibss(sdata)) 484 return; 485 486 if (ifibss->fixed_channel) 487 return; 488 489 printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other " 490 "IBSS networks with same SSID (merge)\n", sdata->name); 491 492 ieee80211_request_internal_scan(sdata, 493 ifibss->ssid, ifibss->ssid_len, 494 ifibss->fixed_channel ? ifibss->channel : NULL); 495 } 496 497 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 498 { 499 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 500 struct ieee80211_local *local = sdata->local; 501 struct ieee80211_supported_band *sband; 502 u8 bssid[ETH_ALEN]; 503 u16 capability; 504 int i; 505 506 if (ifibss->fixed_bssid) { 507 memcpy(bssid, ifibss->bssid, ETH_ALEN); 508 } else { 509 /* Generate random, not broadcast, locally administered BSSID. Mix in 510 * own MAC address to make sure that devices that do not have proper 511 * random number generator get different BSSID. */ 512 get_random_bytes(bssid, ETH_ALEN); 513 for (i = 0; i < ETH_ALEN; i++) 514 bssid[i] ^= sdata->vif.addr[i]; 515 bssid[0] &= ~0x01; 516 bssid[0] |= 0x02; 517 } 518 519 printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n", 520 sdata->name, bssid); 521 522 sband = local->hw.wiphy->bands[ifibss->channel->band]; 523 524 capability = WLAN_CAPABILITY_IBSS; 525 526 if (ifibss->privacy) 527 capability |= WLAN_CAPABILITY_PRIVACY; 528 else 529 sdata->drop_unencrypted = 0; 530 531 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 532 ifibss->channel, 3, /* first two are basic */ 533 capability, 0); 534 } 535 536 /* 537 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 538 */ 539 540 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 541 { 542 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 543 struct ieee80211_local *local = sdata->local; 544 struct cfg80211_bss *cbss; 545 struct ieee80211_channel *chan = NULL; 546 const u8 *bssid = NULL; 547 int active_ibss; 548 u16 capability; 549 550 active_ibss = ieee80211_sta_active_ibss(sdata); 551 #ifdef CONFIG_MAC80211_IBSS_DEBUG 552 printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n", 553 sdata->name, active_ibss); 554 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 555 556 if (active_ibss) 557 return; 558 559 capability = WLAN_CAPABILITY_IBSS; 560 if (ifibss->privacy) 561 capability |= WLAN_CAPABILITY_PRIVACY; 562 if (ifibss->fixed_bssid) 563 bssid = ifibss->bssid; 564 if (ifibss->fixed_channel) 565 chan = ifibss->channel; 566 if (!is_zero_ether_addr(ifibss->bssid)) 567 bssid = ifibss->bssid; 568 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 569 ifibss->ssid, ifibss->ssid_len, 570 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 571 capability); 572 573 if (cbss) { 574 struct ieee80211_bss *bss; 575 576 bss = (void *)cbss->priv; 577 #ifdef CONFIG_MAC80211_IBSS_DEBUG 578 printk(KERN_DEBUG " sta_find_ibss: selected %pM current " 579 "%pM\n", cbss->bssid, ifibss->bssid); 580 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 581 582 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM" 583 " based on configured SSID\n", 584 sdata->name, cbss->bssid); 585 586 ieee80211_sta_join_ibss(sdata, bss); 587 ieee80211_rx_bss_put(local, bss); 588 return; 589 } 590 591 #ifdef CONFIG_MAC80211_IBSS_DEBUG 592 printk(KERN_DEBUG " did not try to join ibss\n"); 593 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 594 595 /* Selected IBSS not found in current scan results - try to scan */ 596 if (time_after(jiffies, ifibss->last_scan_completed + 597 IEEE80211_SCAN_INTERVAL)) { 598 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to " 599 "join\n", sdata->name); 600 601 ieee80211_request_internal_scan(sdata, 602 ifibss->ssid, ifibss->ssid_len, 603 ifibss->fixed_channel ? ifibss->channel : NULL); 604 } else { 605 int interval = IEEE80211_SCAN_INTERVAL; 606 607 if (time_after(jiffies, ifibss->ibss_join_req + 608 IEEE80211_IBSS_JOIN_TIMEOUT)) { 609 if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) { 610 ieee80211_sta_create_ibss(sdata); 611 return; 612 } 613 printk(KERN_DEBUG "%s: IBSS not allowed on" 614 " %d MHz\n", sdata->name, 615 local->hw.conf.channel->center_freq); 616 617 /* No IBSS found - decrease scan interval and continue 618 * scanning. */ 619 interval = IEEE80211_SCAN_INTERVAL_SLOW; 620 } 621 622 mod_timer(&ifibss->timer, 623 round_jiffies(jiffies + interval)); 624 } 625 } 626 627 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 628 struct ieee80211_mgmt *mgmt, 629 size_t len) 630 { 631 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 632 struct ieee80211_local *local = sdata->local; 633 int tx_last_beacon; 634 struct sk_buff *skb; 635 struct ieee80211_mgmt *resp; 636 u8 *pos, *end; 637 638 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 639 len < 24 + 2 || !ifibss->presp) 640 return; 641 642 tx_last_beacon = drv_tx_last_beacon(local); 643 644 #ifdef CONFIG_MAC80211_IBSS_DEBUG 645 printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM" 646 " (tx_last_beacon=%d)\n", 647 sdata->name, mgmt->sa, mgmt->da, 648 mgmt->bssid, tx_last_beacon); 649 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 650 651 if (!tx_last_beacon) 652 return; 653 654 if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 && 655 memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0) 656 return; 657 658 end = ((u8 *) mgmt) + len; 659 pos = mgmt->u.probe_req.variable; 660 if (pos[0] != WLAN_EID_SSID || 661 pos + 2 + pos[1] > end) { 662 #ifdef CONFIG_MAC80211_IBSS_DEBUG 663 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq " 664 "from %pM\n", 665 sdata->name, mgmt->sa); 666 #endif 667 return; 668 } 669 if (pos[1] != 0 && 670 (pos[1] != ifibss->ssid_len || 671 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 672 /* Ignore ProbeReq for foreign SSID */ 673 return; 674 } 675 676 /* Reply with ProbeResp */ 677 skb = skb_copy(ifibss->presp, GFP_KERNEL); 678 if (!skb) 679 return; 680 681 resp = (struct ieee80211_mgmt *) skb->data; 682 memcpy(resp->da, mgmt->sa, ETH_ALEN); 683 #ifdef CONFIG_MAC80211_IBSS_DEBUG 684 printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n", 685 sdata->name, resp->da); 686 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 687 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 688 ieee80211_tx_skb(sdata, skb); 689 } 690 691 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, 692 struct ieee80211_mgmt *mgmt, 693 size_t len, 694 struct ieee80211_rx_status *rx_status) 695 { 696 size_t baselen; 697 struct ieee802_11_elems elems; 698 699 if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN)) 700 return; /* ignore ProbeResp to foreign address */ 701 702 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 703 if (baselen > len) 704 return; 705 706 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 707 &elems); 708 709 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false); 710 } 711 712 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, 713 struct ieee80211_mgmt *mgmt, 714 size_t len, 715 struct ieee80211_rx_status *rx_status) 716 { 717 size_t baselen; 718 struct ieee802_11_elems elems; 719 720 /* Process beacon from the current BSS */ 721 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt; 722 if (baselen > len) 723 return; 724 725 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems); 726 727 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); 728 } 729 730 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 731 struct sk_buff *skb) 732 { 733 struct ieee80211_rx_status *rx_status; 734 struct ieee80211_mgmt *mgmt; 735 u16 fc; 736 737 rx_status = IEEE80211_SKB_RXCB(skb); 738 mgmt = (struct ieee80211_mgmt *) skb->data; 739 fc = le16_to_cpu(mgmt->frame_control); 740 741 switch (fc & IEEE80211_FCTL_STYPE) { 742 case IEEE80211_STYPE_PROBE_REQ: 743 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len); 744 break; 745 case IEEE80211_STYPE_PROBE_RESP: 746 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, 747 rx_status); 748 break; 749 case IEEE80211_STYPE_BEACON: 750 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, 751 rx_status); 752 break; 753 case IEEE80211_STYPE_AUTH: 754 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 755 break; 756 } 757 758 kfree_skb(skb); 759 } 760 761 static void ieee80211_ibss_work(struct work_struct *work) 762 { 763 struct ieee80211_sub_if_data *sdata = 764 container_of(work, struct ieee80211_sub_if_data, u.ibss.work); 765 struct ieee80211_local *local = sdata->local; 766 struct ieee80211_if_ibss *ifibss; 767 struct sk_buff *skb; 768 769 if (WARN_ON(local->suspended)) 770 return; 771 772 if (!ieee80211_sdata_running(sdata)) 773 return; 774 775 if (local->scanning) 776 return; 777 778 if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC)) 779 return; 780 ifibss = &sdata->u.ibss; 781 782 while ((skb = skb_dequeue(&ifibss->skb_queue))) 783 ieee80211_ibss_rx_queued_mgmt(sdata, skb); 784 785 if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request)) 786 return; 787 788 switch (ifibss->state) { 789 case IEEE80211_IBSS_MLME_SEARCH: 790 ieee80211_sta_find_ibss(sdata); 791 break; 792 case IEEE80211_IBSS_MLME_JOINED: 793 ieee80211_sta_merge_ibss(sdata); 794 break; 795 default: 796 WARN_ON(1); 797 break; 798 } 799 } 800 801 static void ieee80211_ibss_timer(unsigned long data) 802 { 803 struct ieee80211_sub_if_data *sdata = 804 (struct ieee80211_sub_if_data *) data; 805 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 806 struct ieee80211_local *local = sdata->local; 807 808 if (local->quiescing) { 809 ifibss->timer_running = true; 810 return; 811 } 812 813 set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request); 814 ieee80211_queue_work(&local->hw, &ifibss->work); 815 } 816 817 #ifdef CONFIG_PM 818 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata) 819 { 820 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 821 822 cancel_work_sync(&ifibss->work); 823 if (del_timer_sync(&ifibss->timer)) 824 ifibss->timer_running = true; 825 } 826 827 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata) 828 { 829 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 830 831 if (ifibss->timer_running) { 832 add_timer(&ifibss->timer); 833 ifibss->timer_running = false; 834 } 835 } 836 #endif 837 838 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 839 { 840 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 841 842 INIT_WORK(&ifibss->work, ieee80211_ibss_work); 843 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 844 (unsigned long) sdata); 845 skb_queue_head_init(&ifibss->skb_queue); 846 } 847 848 /* scan finished notification */ 849 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 850 { 851 struct ieee80211_sub_if_data *sdata; 852 853 mutex_lock(&local->iflist_mtx); 854 list_for_each_entry(sdata, &local->interfaces, list) { 855 if (!ieee80211_sdata_running(sdata)) 856 continue; 857 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 858 continue; 859 if (!sdata->u.ibss.ssid_len) 860 continue; 861 sdata->u.ibss.last_scan_completed = jiffies; 862 mod_timer(&sdata->u.ibss.timer, 0); 863 } 864 mutex_unlock(&local->iflist_mtx); 865 } 866 867 ieee80211_rx_result 868 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) 869 { 870 struct ieee80211_local *local = sdata->local; 871 struct ieee80211_mgmt *mgmt; 872 u16 fc; 873 874 if (skb->len < 24) 875 return RX_DROP_MONITOR; 876 877 mgmt = (struct ieee80211_mgmt *) skb->data; 878 fc = le16_to_cpu(mgmt->frame_control); 879 880 switch (fc & IEEE80211_FCTL_STYPE) { 881 case IEEE80211_STYPE_PROBE_RESP: 882 case IEEE80211_STYPE_BEACON: 883 case IEEE80211_STYPE_PROBE_REQ: 884 case IEEE80211_STYPE_AUTH: 885 skb_queue_tail(&sdata->u.ibss.skb_queue, skb); 886 ieee80211_queue_work(&local->hw, &sdata->u.ibss.work); 887 return RX_QUEUED; 888 } 889 890 return RX_DROP_MONITOR; 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 if (params->bssid) { 899 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 900 sdata->u.ibss.fixed_bssid = true; 901 } else 902 sdata->u.ibss.fixed_bssid = false; 903 904 sdata->u.ibss.privacy = params->privacy; 905 906 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 907 908 sdata->u.ibss.channel = params->channel; 909 sdata->u.ibss.fixed_channel = params->channel_fixed; 910 911 /* fix ourselves to that channel now already */ 912 if (params->channel_fixed) { 913 sdata->local->oper_channel = params->channel; 914 WARN_ON(!ieee80211_set_channel_type(sdata->local, sdata, 915 NL80211_CHAN_NO_HT)); 916 } 917 918 if (params->ie) { 919 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 920 GFP_KERNEL); 921 if (sdata->u.ibss.ie) 922 sdata->u.ibss.ie_len = params->ie_len; 923 } 924 925 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom + 926 36 /* bitrates */ + 927 34 /* SSID */ + 928 3 /* DS params */ + 929 4 /* IBSS params */ + 930 params->ie_len); 931 if (!skb) 932 return -ENOMEM; 933 934 sdata->u.ibss.skb = skb; 935 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 936 sdata->u.ibss.ibss_join_req = jiffies; 937 938 memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN); 939 940 /* 941 * The ssid_len setting below is used to see whether 942 * we are active, and we need all other settings 943 * before that may get visible. 944 */ 945 mb(); 946 947 sdata->u.ibss.ssid_len = params->ssid_len; 948 949 ieee80211_recalc_idle(sdata->local); 950 951 set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request); 952 ieee80211_queue_work(&sdata->local->hw, &sdata->u.ibss.work); 953 954 return 0; 955 } 956 957 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 958 { 959 struct sk_buff *skb; 960 961 del_timer_sync(&sdata->u.ibss.timer); 962 clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request); 963 cancel_work_sync(&sdata->u.ibss.work); 964 clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request); 965 966 sta_info_flush(sdata->local, sdata); 967 968 /* remove beacon */ 969 kfree(sdata->u.ibss.ie); 970 skb = sdata->u.ibss.presp; 971 rcu_assign_pointer(sdata->u.ibss.presp, NULL); 972 sdata->vif.bss_conf.ibss_joined = false; 973 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | 974 BSS_CHANGED_IBSS); 975 synchronize_rcu(); 976 kfree_skb(skb); 977 978 skb_queue_purge(&sdata->u.ibss.skb_queue); 979 memset(sdata->u.ibss.bssid, 0, ETH_ALEN); 980 sdata->u.ibss.ssid_len = 0; 981 982 ieee80211_recalc_idle(sdata->local); 983 984 return 0; 985 } 986