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 memcpy(ifibss->bssid, bssid, ETH_ALEN); 96 97 sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0; 98 99 local->oper_channel = chan; 100 local->oper_channel_type = NL80211_CHAN_NO_HT; 101 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 102 103 sband = local->hw.wiphy->bands[chan->band]; 104 105 /* build supported rates array */ 106 pos = supp_rates; 107 for (i = 0; i < sband->n_bitrates; i++) { 108 int rate = sband->bitrates[i].bitrate; 109 u8 basic = 0; 110 if (basic_rates & BIT(i)) 111 basic = 0x80; 112 *pos++ = basic | (u8) (rate / 5); 113 } 114 115 /* Build IBSS probe response */ 116 mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon)); 117 memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon)); 118 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 119 IEEE80211_STYPE_PROBE_RESP); 120 memset(mgmt->da, 0xff, ETH_ALEN); 121 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 122 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN); 123 mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int); 124 mgmt->u.beacon.timestamp = cpu_to_le64(tsf); 125 mgmt->u.beacon.capab_info = cpu_to_le16(capability); 126 127 pos = skb_put(skb, 2 + ifibss->ssid_len); 128 *pos++ = WLAN_EID_SSID; 129 *pos++ = ifibss->ssid_len; 130 memcpy(pos, ifibss->ssid, ifibss->ssid_len); 131 132 rates = sband->n_bitrates; 133 if (rates > 8) 134 rates = 8; 135 pos = skb_put(skb, 2 + rates); 136 *pos++ = WLAN_EID_SUPP_RATES; 137 *pos++ = rates; 138 memcpy(pos, supp_rates, rates); 139 140 if (sband->band == IEEE80211_BAND_2GHZ) { 141 pos = skb_put(skb, 2 + 1); 142 *pos++ = WLAN_EID_DS_PARAMS; 143 *pos++ = 1; 144 *pos++ = ieee80211_frequency_to_channel(chan->center_freq); 145 } 146 147 pos = skb_put(skb, 2 + 2); 148 *pos++ = WLAN_EID_IBSS_PARAMS; 149 *pos++ = 2; 150 /* FIX: set ATIM window based on scan results */ 151 *pos++ = 0; 152 *pos++ = 0; 153 154 if (sband->n_bitrates > 8) { 155 rates = sband->n_bitrates - 8; 156 pos = skb_put(skb, 2 + rates); 157 *pos++ = WLAN_EID_EXT_SUPP_RATES; 158 *pos++ = rates; 159 memcpy(pos, &supp_rates[8], rates); 160 } 161 162 if (ifibss->ie_len) 163 memcpy(skb_put(skb, ifibss->ie_len), 164 ifibss->ie, ifibss->ie_len); 165 166 rcu_assign_pointer(ifibss->presp, skb); 167 168 sdata->vif.bss_conf.beacon_int = beacon_int; 169 bss_change = BSS_CHANGED_BEACON_INT; 170 bss_change |= ieee80211_reset_erp_info(sdata); 171 bss_change |= BSS_CHANGED_BSSID; 172 bss_change |= BSS_CHANGED_BEACON; 173 bss_change |= BSS_CHANGED_BEACON_ENABLED; 174 ieee80211_bss_info_change_notify(sdata, bss_change); 175 176 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 177 178 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 179 mod_timer(&ifibss->timer, 180 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 181 182 bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel, 183 mgmt, skb->len, 0, GFP_KERNEL); 184 cfg80211_put_bss(bss); 185 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 186 } 187 188 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 189 struct ieee80211_bss *bss) 190 { 191 struct cfg80211_bss *cbss = 192 container_of((void *)bss, struct cfg80211_bss, priv); 193 struct ieee80211_supported_band *sband; 194 u32 basic_rates; 195 int i, j; 196 u16 beacon_int = cbss->beacon_interval; 197 198 if (beacon_int < 10) 199 beacon_int = 10; 200 201 sband = sdata->local->hw.wiphy->bands[cbss->channel->band]; 202 203 basic_rates = 0; 204 205 for (i = 0; i < bss->supp_rates_len; i++) { 206 int rate = (bss->supp_rates[i] & 0x7f) * 5; 207 bool is_basic = !!(bss->supp_rates[i] & 0x80); 208 209 for (j = 0; j < sband->n_bitrates; j++) { 210 if (sband->bitrates[j].bitrate == rate) { 211 if (is_basic) 212 basic_rates |= BIT(j); 213 break; 214 } 215 } 216 } 217 218 __ieee80211_sta_join_ibss(sdata, cbss->bssid, 219 beacon_int, 220 cbss->channel, 221 basic_rates, 222 cbss->capability, 223 cbss->tsf); 224 } 225 226 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 227 struct ieee80211_mgmt *mgmt, 228 size_t len, 229 struct ieee80211_rx_status *rx_status, 230 struct ieee802_11_elems *elems, 231 bool beacon) 232 { 233 struct ieee80211_local *local = sdata->local; 234 int freq; 235 struct cfg80211_bss *cbss; 236 struct ieee80211_bss *bss; 237 struct sta_info *sta; 238 struct ieee80211_channel *channel; 239 u64 beacon_timestamp, rx_timestamp; 240 u32 supp_rates = 0; 241 enum ieee80211_band band = rx_status->band; 242 243 if (elems->ds_params && elems->ds_params_len == 1) 244 freq = ieee80211_channel_to_frequency(elems->ds_params[0]); 245 else 246 freq = rx_status->freq; 247 248 channel = ieee80211_get_channel(local->hw.wiphy, freq); 249 250 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 251 return; 252 253 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates && 254 memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) { 255 supp_rates = ieee80211_sta_get_rates(local, elems, band); 256 257 rcu_read_lock(); 258 259 sta = sta_info_get(sdata, mgmt->sa); 260 if (sta) { 261 u32 prev_rates; 262 263 prev_rates = sta->sta.supp_rates[band]; 264 /* make sure mandatory rates are always added */ 265 sta->sta.supp_rates[band] = supp_rates | 266 ieee80211_mandatory_rates(local, band); 267 268 #ifdef CONFIG_MAC80211_IBSS_DEBUG 269 if (sta->sta.supp_rates[band] != prev_rates) 270 printk(KERN_DEBUG "%s: updated supp_rates set " 271 "for %pM based on beacon info (0x%llx | " 272 "0x%llx -> 0x%llx)\n", 273 sdata->name, 274 sta->sta.addr, 275 (unsigned long long) prev_rates, 276 (unsigned long long) supp_rates, 277 (unsigned long long) sta->sta.supp_rates[band]); 278 #endif 279 rcu_read_unlock(); 280 } else { 281 rcu_read_unlock(); 282 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 283 supp_rates, GFP_KERNEL); 284 } 285 } 286 287 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 288 channel, beacon); 289 if (!bss) 290 return; 291 292 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 293 294 /* was just updated in ieee80211_bss_info_update */ 295 beacon_timestamp = cbss->tsf; 296 297 /* check if we need to merge IBSS */ 298 299 /* we use a fixed BSSID */ 300 if (sdata->u.ibss.fixed_bssid) 301 goto put_bss; 302 303 /* not an IBSS */ 304 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 305 goto put_bss; 306 307 /* different channel */ 308 if (cbss->channel != local->oper_channel) 309 goto put_bss; 310 311 /* different SSID */ 312 if (elems->ssid_len != sdata->u.ibss.ssid_len || 313 memcmp(elems->ssid, sdata->u.ibss.ssid, 314 sdata->u.ibss.ssid_len)) 315 goto put_bss; 316 317 /* same BSSID */ 318 if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) 319 goto put_bss; 320 321 if (rx_status->flag & RX_FLAG_TSFT) { 322 /* 323 * For correct IBSS merging we need mactime; since mactime is 324 * defined as the time the first data symbol of the frame hits 325 * the PHY, and the timestamp of the beacon is defined as "the 326 * time that the data symbol containing the first bit of the 327 * timestamp is transmitted to the PHY plus the transmitting 328 * STA's delays through its local PHY from the MAC-PHY 329 * interface to its interface with the WM" (802.11 11.1.2) 330 * - equals the time this bit arrives at the receiver - we have 331 * to take into account the offset between the two. 332 * 333 * E.g. at 1 MBit that means mactime is 192 usec earlier 334 * (=24 bytes * 8 usecs/byte) than the beacon timestamp. 335 */ 336 int rate; 337 338 if (rx_status->flag & RX_FLAG_HT) 339 rate = 65; /* TODO: HT rates */ 340 else 341 rate = local->hw.wiphy->bands[band]-> 342 bitrates[rx_status->rate_idx].bitrate; 343 344 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate); 345 } else { 346 /* 347 * second best option: get current TSF 348 * (will return -1 if not supported) 349 */ 350 rx_timestamp = drv_get_tsf(local); 351 } 352 353 #ifdef CONFIG_MAC80211_IBSS_DEBUG 354 printk(KERN_DEBUG "RX beacon SA=%pM BSSID=" 355 "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 356 mgmt->sa, mgmt->bssid, 357 (unsigned long long)rx_timestamp, 358 (unsigned long long)beacon_timestamp, 359 (unsigned long long)(rx_timestamp - beacon_timestamp), 360 jiffies); 361 #endif 362 363 /* give slow hardware some time to do the TSF sync */ 364 if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY) 365 goto put_bss; 366 367 if (beacon_timestamp > rx_timestamp) { 368 #ifdef CONFIG_MAC80211_IBSS_DEBUG 369 printk(KERN_DEBUG "%s: beacon TSF higher than " 370 "local TSF - IBSS merge with BSSID %pM\n", 371 sdata->name, mgmt->bssid); 372 #endif 373 ieee80211_sta_join_ibss(sdata, bss); 374 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 375 supp_rates, GFP_KERNEL); 376 } 377 378 put_bss: 379 ieee80211_rx_bss_put(local, bss); 380 } 381 382 /* 383 * Add a new IBSS station, will also be called by the RX code when, 384 * in IBSS mode, receiving a frame from a yet-unknown station, hence 385 * must be callable in atomic context. 386 */ 387 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 388 u8 *bssid,u8 *addr, u32 supp_rates, 389 gfp_t gfp) 390 { 391 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 392 struct ieee80211_local *local = sdata->local; 393 struct sta_info *sta; 394 int band = local->hw.conf.channel->band; 395 396 /* 397 * XXX: Consider removing the least recently used entry and 398 * allow new one to be added. 399 */ 400 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 401 if (net_ratelimit()) 402 printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n", 403 sdata->name, addr); 404 return NULL; 405 } 406 407 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 408 return NULL; 409 410 if (compare_ether_addr(bssid, sdata->u.ibss.bssid)) 411 return NULL; 412 413 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG 414 printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n", 415 wiphy_name(local->hw.wiphy), addr, sdata->name); 416 #endif 417 418 sta = sta_info_alloc(sdata, addr, gfp); 419 if (!sta) 420 return NULL; 421 422 set_sta_flags(sta, WLAN_STA_AUTHORIZED); 423 424 /* make sure mandatory rates are always added */ 425 sta->sta.supp_rates[band] = supp_rates | 426 ieee80211_mandatory_rates(local, band); 427 428 rate_control_rate_init(sta); 429 430 /* If it fails, maybe we raced another insertion? */ 431 if (sta_info_insert(sta)) 432 return sta_info_get(sdata, addr); 433 return sta; 434 } 435 436 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 437 { 438 struct ieee80211_local *local = sdata->local; 439 int active = 0; 440 struct sta_info *sta; 441 442 rcu_read_lock(); 443 444 list_for_each_entry_rcu(sta, &local->sta_list, list) { 445 if (sta->sdata == sdata && 446 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 447 jiffies)) { 448 active++; 449 break; 450 } 451 } 452 453 rcu_read_unlock(); 454 455 return active; 456 } 457 458 /* 459 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 460 */ 461 462 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 463 { 464 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 465 466 mod_timer(&ifibss->timer, 467 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 468 469 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 470 471 if (time_before(jiffies, ifibss->last_scan_completed + 472 IEEE80211_IBSS_MERGE_INTERVAL)) 473 return; 474 475 if (ieee80211_sta_active_ibss(sdata)) 476 return; 477 478 if (ifibss->fixed_channel) 479 return; 480 481 printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other " 482 "IBSS networks with same SSID (merge)\n", sdata->name); 483 484 ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len); 485 } 486 487 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 488 { 489 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 490 struct ieee80211_local *local = sdata->local; 491 struct ieee80211_supported_band *sband; 492 u8 bssid[ETH_ALEN]; 493 u16 capability; 494 int i; 495 496 if (ifibss->fixed_bssid) { 497 memcpy(bssid, ifibss->bssid, ETH_ALEN); 498 } else { 499 /* Generate random, not broadcast, locally administered BSSID. Mix in 500 * own MAC address to make sure that devices that do not have proper 501 * random number generator get different BSSID. */ 502 get_random_bytes(bssid, ETH_ALEN); 503 for (i = 0; i < ETH_ALEN; i++) 504 bssid[i] ^= sdata->vif.addr[i]; 505 bssid[0] &= ~0x01; 506 bssid[0] |= 0x02; 507 } 508 509 printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n", 510 sdata->name, bssid); 511 512 sband = local->hw.wiphy->bands[ifibss->channel->band]; 513 514 capability = WLAN_CAPABILITY_IBSS; 515 516 if (ifibss->privacy) 517 capability |= WLAN_CAPABILITY_PRIVACY; 518 else 519 sdata->drop_unencrypted = 0; 520 521 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 522 ifibss->channel, 3, /* first two are basic */ 523 capability, 0); 524 } 525 526 /* 527 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 528 */ 529 530 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 531 { 532 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 533 struct ieee80211_local *local = sdata->local; 534 struct cfg80211_bss *cbss; 535 struct ieee80211_channel *chan = NULL; 536 const u8 *bssid = NULL; 537 int active_ibss; 538 u16 capability; 539 540 active_ibss = ieee80211_sta_active_ibss(sdata); 541 #ifdef CONFIG_MAC80211_IBSS_DEBUG 542 printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n", 543 sdata->name, active_ibss); 544 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 545 546 if (active_ibss) 547 return; 548 549 capability = WLAN_CAPABILITY_IBSS; 550 if (ifibss->privacy) 551 capability |= WLAN_CAPABILITY_PRIVACY; 552 if (ifibss->fixed_bssid) 553 bssid = ifibss->bssid; 554 if (ifibss->fixed_channel) 555 chan = ifibss->channel; 556 if (!is_zero_ether_addr(ifibss->bssid)) 557 bssid = ifibss->bssid; 558 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 559 ifibss->ssid, ifibss->ssid_len, 560 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 561 capability); 562 563 if (cbss) { 564 struct ieee80211_bss *bss; 565 566 bss = (void *)cbss->priv; 567 #ifdef CONFIG_MAC80211_IBSS_DEBUG 568 printk(KERN_DEBUG " sta_find_ibss: selected %pM current " 569 "%pM\n", cbss->bssid, ifibss->bssid); 570 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 571 572 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM" 573 " based on configured SSID\n", 574 sdata->name, cbss->bssid); 575 576 ieee80211_sta_join_ibss(sdata, bss); 577 ieee80211_rx_bss_put(local, bss); 578 return; 579 } 580 581 #ifdef CONFIG_MAC80211_IBSS_DEBUG 582 printk(KERN_DEBUG " did not try to join ibss\n"); 583 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 584 585 /* Selected IBSS not found in current scan results - try to scan */ 586 if (time_after(jiffies, ifibss->last_scan_completed + 587 IEEE80211_SCAN_INTERVAL)) { 588 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to " 589 "join\n", sdata->name); 590 591 ieee80211_request_internal_scan(sdata, ifibss->ssid, 592 ifibss->ssid_len); 593 } else { 594 int interval = IEEE80211_SCAN_INTERVAL; 595 596 if (time_after(jiffies, ifibss->ibss_join_req + 597 IEEE80211_IBSS_JOIN_TIMEOUT)) { 598 if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) { 599 ieee80211_sta_create_ibss(sdata); 600 return; 601 } 602 printk(KERN_DEBUG "%s: IBSS not allowed on" 603 " %d MHz\n", sdata->name, 604 local->hw.conf.channel->center_freq); 605 606 /* No IBSS found - decrease scan interval and continue 607 * scanning. */ 608 interval = IEEE80211_SCAN_INTERVAL_SLOW; 609 } 610 611 mod_timer(&ifibss->timer, 612 round_jiffies(jiffies + interval)); 613 } 614 } 615 616 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 617 struct ieee80211_mgmt *mgmt, 618 size_t len) 619 { 620 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 621 struct ieee80211_local *local = sdata->local; 622 int tx_last_beacon; 623 struct sk_buff *skb; 624 struct ieee80211_mgmt *resp; 625 u8 *pos, *end; 626 627 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 628 len < 24 + 2 || !ifibss->presp) 629 return; 630 631 tx_last_beacon = drv_tx_last_beacon(local); 632 633 #ifdef CONFIG_MAC80211_IBSS_DEBUG 634 printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM" 635 " (tx_last_beacon=%d)\n", 636 sdata->name, mgmt->sa, mgmt->da, 637 mgmt->bssid, tx_last_beacon); 638 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 639 640 if (!tx_last_beacon) 641 return; 642 643 if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 && 644 memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0) 645 return; 646 647 end = ((u8 *) mgmt) + len; 648 pos = mgmt->u.probe_req.variable; 649 if (pos[0] != WLAN_EID_SSID || 650 pos + 2 + pos[1] > end) { 651 #ifdef CONFIG_MAC80211_IBSS_DEBUG 652 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq " 653 "from %pM\n", 654 sdata->name, mgmt->sa); 655 #endif 656 return; 657 } 658 if (pos[1] != 0 && 659 (pos[1] != ifibss->ssid_len || 660 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 661 /* Ignore ProbeReq for foreign SSID */ 662 return; 663 } 664 665 /* Reply with ProbeResp */ 666 skb = skb_copy(ifibss->presp, GFP_KERNEL); 667 if (!skb) 668 return; 669 670 resp = (struct ieee80211_mgmt *) skb->data; 671 memcpy(resp->da, mgmt->sa, ETH_ALEN); 672 #ifdef CONFIG_MAC80211_IBSS_DEBUG 673 printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n", 674 sdata->name, resp->da); 675 #endif /* CONFIG_MAC80211_IBSS_DEBUG */ 676 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 677 ieee80211_tx_skb(sdata, skb); 678 } 679 680 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, 681 struct ieee80211_mgmt *mgmt, 682 size_t len, 683 struct ieee80211_rx_status *rx_status) 684 { 685 size_t baselen; 686 struct ieee802_11_elems elems; 687 688 if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN)) 689 return; /* ignore ProbeResp to foreign address */ 690 691 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 692 if (baselen > len) 693 return; 694 695 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 696 &elems); 697 698 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false); 699 } 700 701 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, 702 struct ieee80211_mgmt *mgmt, 703 size_t len, 704 struct ieee80211_rx_status *rx_status) 705 { 706 size_t baselen; 707 struct ieee802_11_elems elems; 708 709 /* Process beacon from the current BSS */ 710 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt; 711 if (baselen > len) 712 return; 713 714 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems); 715 716 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); 717 } 718 719 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 720 struct sk_buff *skb) 721 { 722 struct ieee80211_rx_status *rx_status; 723 struct ieee80211_mgmt *mgmt; 724 u16 fc; 725 726 rx_status = IEEE80211_SKB_RXCB(skb); 727 mgmt = (struct ieee80211_mgmt *) skb->data; 728 fc = le16_to_cpu(mgmt->frame_control); 729 730 switch (fc & IEEE80211_FCTL_STYPE) { 731 case IEEE80211_STYPE_PROBE_REQ: 732 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len); 733 break; 734 case IEEE80211_STYPE_PROBE_RESP: 735 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, 736 rx_status); 737 break; 738 case IEEE80211_STYPE_BEACON: 739 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, 740 rx_status); 741 break; 742 case IEEE80211_STYPE_AUTH: 743 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 744 break; 745 } 746 747 kfree_skb(skb); 748 } 749 750 static void ieee80211_ibss_work(struct work_struct *work) 751 { 752 struct ieee80211_sub_if_data *sdata = 753 container_of(work, struct ieee80211_sub_if_data, u.ibss.work); 754 struct ieee80211_local *local = sdata->local; 755 struct ieee80211_if_ibss *ifibss; 756 struct sk_buff *skb; 757 758 if (WARN_ON(local->suspended)) 759 return; 760 761 if (!ieee80211_sdata_running(sdata)) 762 return; 763 764 if (local->scanning) 765 return; 766 767 if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC)) 768 return; 769 ifibss = &sdata->u.ibss; 770 771 while ((skb = skb_dequeue(&ifibss->skb_queue))) 772 ieee80211_ibss_rx_queued_mgmt(sdata, skb); 773 774 if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request)) 775 return; 776 777 switch (ifibss->state) { 778 case IEEE80211_IBSS_MLME_SEARCH: 779 ieee80211_sta_find_ibss(sdata); 780 break; 781 case IEEE80211_IBSS_MLME_JOINED: 782 ieee80211_sta_merge_ibss(sdata); 783 break; 784 default: 785 WARN_ON(1); 786 break; 787 } 788 } 789 790 static void ieee80211_ibss_timer(unsigned long data) 791 { 792 struct ieee80211_sub_if_data *sdata = 793 (struct ieee80211_sub_if_data *) data; 794 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 795 struct ieee80211_local *local = sdata->local; 796 797 if (local->quiescing) { 798 ifibss->timer_running = true; 799 return; 800 } 801 802 set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request); 803 ieee80211_queue_work(&local->hw, &ifibss->work); 804 } 805 806 #ifdef CONFIG_PM 807 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata) 808 { 809 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 810 811 cancel_work_sync(&ifibss->work); 812 if (del_timer_sync(&ifibss->timer)) 813 ifibss->timer_running = true; 814 } 815 816 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata) 817 { 818 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 819 820 if (ifibss->timer_running) { 821 add_timer(&ifibss->timer); 822 ifibss->timer_running = false; 823 } 824 } 825 #endif 826 827 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 828 { 829 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 830 831 INIT_WORK(&ifibss->work, ieee80211_ibss_work); 832 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 833 (unsigned long) sdata); 834 skb_queue_head_init(&ifibss->skb_queue); 835 } 836 837 /* scan finished notification */ 838 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 839 { 840 struct ieee80211_sub_if_data *sdata; 841 842 mutex_lock(&local->iflist_mtx); 843 list_for_each_entry(sdata, &local->interfaces, list) { 844 if (!ieee80211_sdata_running(sdata)) 845 continue; 846 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 847 continue; 848 if (!sdata->u.ibss.ssid_len) 849 continue; 850 sdata->u.ibss.last_scan_completed = jiffies; 851 mod_timer(&sdata->u.ibss.timer, 0); 852 } 853 mutex_unlock(&local->iflist_mtx); 854 } 855 856 ieee80211_rx_result 857 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) 858 { 859 struct ieee80211_local *local = sdata->local; 860 struct ieee80211_mgmt *mgmt; 861 u16 fc; 862 863 if (skb->len < 24) 864 return RX_DROP_MONITOR; 865 866 mgmt = (struct ieee80211_mgmt *) skb->data; 867 fc = le16_to_cpu(mgmt->frame_control); 868 869 switch (fc & IEEE80211_FCTL_STYPE) { 870 case IEEE80211_STYPE_PROBE_RESP: 871 case IEEE80211_STYPE_BEACON: 872 case IEEE80211_STYPE_PROBE_REQ: 873 case IEEE80211_STYPE_AUTH: 874 skb_queue_tail(&sdata->u.ibss.skb_queue, skb); 875 ieee80211_queue_work(&local->hw, &sdata->u.ibss.work); 876 return RX_QUEUED; 877 } 878 879 return RX_DROP_MONITOR; 880 } 881 882 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 883 struct cfg80211_ibss_params *params) 884 { 885 struct sk_buff *skb; 886 887 if (params->bssid) { 888 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 889 sdata->u.ibss.fixed_bssid = true; 890 } else 891 sdata->u.ibss.fixed_bssid = false; 892 893 sdata->u.ibss.privacy = params->privacy; 894 895 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 896 897 sdata->u.ibss.channel = params->channel; 898 sdata->u.ibss.fixed_channel = params->channel_fixed; 899 900 if (params->ie) { 901 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 902 GFP_KERNEL); 903 if (sdata->u.ibss.ie) 904 sdata->u.ibss.ie_len = params->ie_len; 905 } 906 907 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom + 908 36 /* bitrates */ + 909 34 /* SSID */ + 910 3 /* DS params */ + 911 4 /* IBSS params */ + 912 params->ie_len); 913 if (!skb) 914 return -ENOMEM; 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); 921 922 /* 923 * The ssid_len setting below is used to see whether 924 * we are active, and we need all other settings 925 * before that may get visible. 926 */ 927 mb(); 928 929 sdata->u.ibss.ssid_len = params->ssid_len; 930 931 ieee80211_recalc_idle(sdata->local); 932 933 set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request); 934 ieee80211_queue_work(&sdata->local->hw, &sdata->u.ibss.work); 935 936 return 0; 937 } 938 939 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 940 { 941 struct sk_buff *skb; 942 943 del_timer_sync(&sdata->u.ibss.timer); 944 clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request); 945 cancel_work_sync(&sdata->u.ibss.work); 946 clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request); 947 948 sta_info_flush(sdata->local, sdata); 949 950 /* remove beacon */ 951 kfree(sdata->u.ibss.ie); 952 skb = sdata->u.ibss.presp; 953 rcu_assign_pointer(sdata->u.ibss.presp, NULL); 954 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED); 955 synchronize_rcu(); 956 kfree_skb(skb); 957 958 skb_queue_purge(&sdata->u.ibss.skb_queue); 959 memset(sdata->u.ibss.bssid, 0, ETH_ALEN); 960 sdata->u.ibss.ssid_len = 0; 961 962 ieee80211_recalc_idle(sdata->local); 963 964 return 0; 965 } 966