ibss.c revision 2514ec86531481713036081e93a353bbd02e542b
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 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_INACTIVITY_LIMIT (60 * HZ) 34 35#define IEEE80211_IBSS_MAX_STA_ENTRIES 128 36 37 38static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 39 const u8 *bssid, const int beacon_int, 40 struct ieee80211_channel *chan, 41 const u32 basic_rates, 42 const u16 capability, u64 tsf) 43{ 44 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 45 struct ieee80211_local *local = sdata->local; 46 int rates, i; 47 struct sk_buff *skb; 48 struct ieee80211_mgmt *mgmt; 49 u8 *pos; 50 struct ieee80211_supported_band *sband; 51 struct cfg80211_bss *bss; 52 u32 bss_change; 53 u8 supp_rates[IEEE80211_MAX_SUPP_RATES]; 54 enum nl80211_channel_type channel_type; 55 56 lockdep_assert_held(&ifibss->mtx); 57 58 /* Reset own TSF to allow time synchronization work. */ 59 drv_reset_tsf(local, sdata); 60 61 skb = ifibss->skb; 62 RCU_INIT_POINTER(ifibss->presp, NULL); 63 synchronize_rcu(); 64 skb->data = skb->head; 65 skb->len = 0; 66 skb_reset_tail_pointer(skb); 67 skb_reserve(skb, sdata->local->hw.extra_tx_headroom); 68 69 if (!ether_addr_equal(ifibss->bssid, bssid)) 70 sta_info_flush(sdata->local, sdata); 71 72 /* if merging, indicate to driver that we leave the old IBSS */ 73 if (sdata->vif.bss_conf.ibss_joined) { 74 sdata->vif.bss_conf.ibss_joined = false; 75 netif_carrier_off(sdata->dev); 76 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS); 77 } 78 79 memcpy(ifibss->bssid, bssid, ETH_ALEN); 80 81 sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0; 82 83 local->oper_channel = chan; 84 channel_type = ifibss->channel_type; 85 if (!cfg80211_can_beacon_sec_chan(local->hw.wiphy, chan, channel_type)) 86 channel_type = NL80211_CHAN_HT20; 87 if (!ieee80211_set_channel_type(local, sdata, channel_type)) { 88 /* can only fail due to HT40+/- mismatch */ 89 channel_type = NL80211_CHAN_HT20; 90 WARN_ON(!ieee80211_set_channel_type(local, sdata, 91 NL80211_CHAN_HT20)); 92 } 93 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL); 94 95 sband = local->hw.wiphy->bands[chan->band]; 96 97 /* build supported rates array */ 98 pos = supp_rates; 99 for (i = 0; i < sband->n_bitrates; i++) { 100 int rate = sband->bitrates[i].bitrate; 101 u8 basic = 0; 102 if (basic_rates & BIT(i)) 103 basic = 0x80; 104 *pos++ = basic | (u8) (rate / 5); 105 } 106 107 /* Build IBSS probe response */ 108 mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon)); 109 memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon)); 110 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 111 IEEE80211_STYPE_PROBE_RESP); 112 eth_broadcast_addr(mgmt->da); 113 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 114 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN); 115 mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int); 116 mgmt->u.beacon.timestamp = cpu_to_le64(tsf); 117 mgmt->u.beacon.capab_info = cpu_to_le16(capability); 118 119 pos = skb_put(skb, 2 + ifibss->ssid_len); 120 *pos++ = WLAN_EID_SSID; 121 *pos++ = ifibss->ssid_len; 122 memcpy(pos, ifibss->ssid, ifibss->ssid_len); 123 124 rates = sband->n_bitrates; 125 if (rates > 8) 126 rates = 8; 127 pos = skb_put(skb, 2 + rates); 128 *pos++ = WLAN_EID_SUPP_RATES; 129 *pos++ = rates; 130 memcpy(pos, supp_rates, rates); 131 132 if (sband->band == IEEE80211_BAND_2GHZ) { 133 pos = skb_put(skb, 2 + 1); 134 *pos++ = WLAN_EID_DS_PARAMS; 135 *pos++ = 1; 136 *pos++ = ieee80211_frequency_to_channel(chan->center_freq); 137 } 138 139 pos = skb_put(skb, 2 + 2); 140 *pos++ = WLAN_EID_IBSS_PARAMS; 141 *pos++ = 2; 142 /* FIX: set ATIM window based on scan results */ 143 *pos++ = 0; 144 *pos++ = 0; 145 146 if (sband->n_bitrates > 8) { 147 rates = sband->n_bitrates - 8; 148 pos = skb_put(skb, 2 + rates); 149 *pos++ = WLAN_EID_EXT_SUPP_RATES; 150 *pos++ = rates; 151 memcpy(pos, &supp_rates[8], rates); 152 } 153 154 if (ifibss->ie_len) 155 memcpy(skb_put(skb, ifibss->ie_len), 156 ifibss->ie, ifibss->ie_len); 157 158 /* add HT capability and information IEs */ 159 if (channel_type && sband->ht_cap.ht_supported) { 160 pos = skb_put(skb, 4 + 161 sizeof(struct ieee80211_ht_cap) + 162 sizeof(struct ieee80211_ht_operation)); 163 pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, 164 sband->ht_cap.cap); 165 /* 166 * Note: According to 802.11n-2009 9.13.3.1, HT Protection 167 * field and RIFS Mode are reserved in IBSS mode, therefore 168 * keep them at 0 169 */ 170 pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap, 171 chan, channel_type, 0); 172 } 173 174 if (local->hw.queues >= IEEE80211_NUM_ACS) { 175 pos = skb_put(skb, 9); 176 *pos++ = WLAN_EID_VENDOR_SPECIFIC; 177 *pos++ = 7; /* len */ 178 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */ 179 *pos++ = 0x50; 180 *pos++ = 0xf2; 181 *pos++ = 2; /* WME */ 182 *pos++ = 0; /* WME info */ 183 *pos++ = 1; /* WME ver */ 184 *pos++ = 0; /* U-APSD no in use */ 185 } 186 187 rcu_assign_pointer(ifibss->presp, skb); 188 189 sdata->vif.bss_conf.beacon_int = beacon_int; 190 sdata->vif.bss_conf.basic_rates = basic_rates; 191 bss_change = BSS_CHANGED_BEACON_INT; 192 bss_change |= ieee80211_reset_erp_info(sdata); 193 bss_change |= BSS_CHANGED_BSSID; 194 bss_change |= BSS_CHANGED_BEACON; 195 bss_change |= BSS_CHANGED_BEACON_ENABLED; 196 bss_change |= BSS_CHANGED_BASIC_RATES; 197 bss_change |= BSS_CHANGED_HT; 198 bss_change |= BSS_CHANGED_IBSS; 199 sdata->vif.bss_conf.ibss_joined = true; 200 ieee80211_bss_info_change_notify(sdata, bss_change); 201 202 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 203 204 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 205 mod_timer(&ifibss->timer, 206 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 207 208 bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan, 209 mgmt, skb->len, 0, GFP_KERNEL); 210 cfg80211_put_bss(bss); 211 netif_carrier_on(sdata->dev); 212 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 213} 214 215static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 216 struct ieee80211_bss *bss) 217{ 218 struct cfg80211_bss *cbss = 219 container_of((void *)bss, struct cfg80211_bss, priv); 220 struct ieee80211_supported_band *sband; 221 u32 basic_rates; 222 int i, j; 223 u16 beacon_int = cbss->beacon_interval; 224 225 lockdep_assert_held(&sdata->u.ibss.mtx); 226 227 if (beacon_int < 10) 228 beacon_int = 10; 229 230 sband = sdata->local->hw.wiphy->bands[cbss->channel->band]; 231 232 basic_rates = 0; 233 234 for (i = 0; i < bss->supp_rates_len; i++) { 235 int rate = (bss->supp_rates[i] & 0x7f) * 5; 236 bool is_basic = !!(bss->supp_rates[i] & 0x80); 237 238 for (j = 0; j < sband->n_bitrates; j++) { 239 if (sband->bitrates[j].bitrate == rate) { 240 if (is_basic) 241 basic_rates |= BIT(j); 242 break; 243 } 244 } 245 } 246 247 __ieee80211_sta_join_ibss(sdata, cbss->bssid, 248 beacon_int, 249 cbss->channel, 250 basic_rates, 251 cbss->capability, 252 cbss->tsf); 253} 254 255static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta, 256 bool auth) 257 __acquires(RCU) 258{ 259 struct ieee80211_sub_if_data *sdata = sta->sdata; 260 u8 addr[ETH_ALEN]; 261 262 memcpy(addr, sta->sta.addr, ETH_ALEN); 263 264 ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr); 265 266 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 267 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 268 /* authorize the station only if the network is not RSN protected. If 269 * not wait for the userspace to authorize it */ 270 if (!sta->sdata->u.ibss.control_port) 271 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 272 273 rate_control_rate_init(sta); 274 275 /* If it fails, maybe we raced another insertion? */ 276 if (sta_info_insert_rcu(sta)) 277 return sta_info_get(sdata, addr); 278 if (auth && !sdata->u.ibss.auth_frame_registrations) { 279 ibss_dbg(sdata, 280 "TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n", 281 sdata->vif.addr, addr, sdata->u.ibss.bssid); 282 ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, NULL, 0, 283 addr, sdata->u.ibss.bssid, NULL, 0, 0); 284 } 285 return sta; 286} 287 288static struct sta_info * 289ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, 290 const u8 *bssid, const u8 *addr, 291 u32 supp_rates, bool auth) 292 __acquires(RCU) 293{ 294 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 295 struct ieee80211_local *local = sdata->local; 296 struct sta_info *sta; 297 int band = local->oper_channel->band; 298 299 /* 300 * XXX: Consider removing the least recently used entry and 301 * allow new one to be added. 302 */ 303 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 304 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 305 sdata->name, addr); 306 rcu_read_lock(); 307 return NULL; 308 } 309 310 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) { 311 rcu_read_lock(); 312 return NULL; 313 } 314 315 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) { 316 rcu_read_lock(); 317 return NULL; 318 } 319 320 sta = sta_info_alloc(sdata, addr, GFP_KERNEL); 321 if (!sta) { 322 rcu_read_lock(); 323 return NULL; 324 } 325 326 sta->last_rx = jiffies; 327 328 /* make sure mandatory rates are always added */ 329 sta->sta.supp_rates[band] = supp_rates | 330 ieee80211_mandatory_rates(local, band); 331 332 return ieee80211_ibss_finish_sta(sta, auth); 333} 334 335static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata, 336 struct ieee80211_mgmt *mgmt, 337 size_t len) 338{ 339 u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code); 340 341 if (len < IEEE80211_DEAUTH_FRAME_LEN) 342 return; 343 344 ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n", 345 mgmt->sa, mgmt->da, mgmt->bssid, reason); 346 sta_info_destroy_addr(sdata, mgmt->sa); 347} 348 349static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, 350 struct ieee80211_mgmt *mgmt, 351 size_t len) 352{ 353 u16 auth_alg, auth_transaction; 354 struct sta_info *sta; 355 u8 deauth_frame_buf[IEEE80211_DEAUTH_FRAME_LEN]; 356 357 lockdep_assert_held(&sdata->u.ibss.mtx); 358 359 if (len < 24 + 6) 360 return; 361 362 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 363 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 364 365 if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1) 366 return; 367 ibss_dbg(sdata, 368 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n", 369 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction); 370 sta_info_destroy_addr(sdata, mgmt->sa); 371 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false); 372 rcu_read_unlock(); 373 374 /* 375 * if we have any problem in allocating the new station, we reply with a 376 * DEAUTH frame to tell the other end that we had a problem 377 */ 378 if (!sta) { 379 ieee80211_send_deauth_disassoc(sdata, sdata->u.ibss.bssid, 380 IEEE80211_STYPE_DEAUTH, 381 WLAN_REASON_UNSPECIFIED, true, 382 deauth_frame_buf); 383 return; 384 } 385 386 /* 387 * IEEE 802.11 standard does not require authentication in IBSS 388 * networks and most implementations do not seem to use it. 389 * However, try to reply to authentication attempts if someone 390 * has actually implemented this. 391 */ 392 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0, 393 mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0); 394} 395 396static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 397 struct ieee80211_mgmt *mgmt, 398 size_t len, 399 struct ieee80211_rx_status *rx_status, 400 struct ieee802_11_elems *elems, 401 bool beacon) 402{ 403 struct ieee80211_local *local = sdata->local; 404 int freq; 405 struct cfg80211_bss *cbss; 406 struct ieee80211_bss *bss; 407 struct sta_info *sta; 408 struct ieee80211_channel *channel; 409 u64 beacon_timestamp, rx_timestamp; 410 u32 supp_rates = 0; 411 enum ieee80211_band band = rx_status->band; 412 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 413 bool rates_updated = false; 414 415 if (elems->ds_params && elems->ds_params_len == 1) 416 freq = ieee80211_channel_to_frequency(elems->ds_params[0], 417 band); 418 else 419 freq = rx_status->freq; 420 421 channel = ieee80211_get_channel(local->hw.wiphy, freq); 422 423 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 424 return; 425 426 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && 427 ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) { 428 429 rcu_read_lock(); 430 sta = sta_info_get(sdata, mgmt->sa); 431 432 if (elems->supp_rates) { 433 supp_rates = ieee80211_sta_get_rates(local, elems, 434 band, NULL); 435 if (sta) { 436 u32 prev_rates; 437 438 prev_rates = sta->sta.supp_rates[band]; 439 /* make sure mandatory rates are always added */ 440 sta->sta.supp_rates[band] = supp_rates | 441 ieee80211_mandatory_rates(local, band); 442 443 if (sta->sta.supp_rates[band] != prev_rates) { 444 ibss_dbg(sdata, 445 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n", 446 sta->sta.addr, prev_rates, 447 sta->sta.supp_rates[band]); 448 rates_updated = true; 449 } 450 } else { 451 rcu_read_unlock(); 452 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, 453 mgmt->sa, supp_rates, true); 454 } 455 } 456 457 if (sta && elems->wmm_info) 458 set_sta_flag(sta, WLAN_STA_WME); 459 460 if (sta && elems->ht_operation && elems->ht_cap_elem && 461 sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) { 462 /* we both use HT */ 463 struct ieee80211_sta_ht_cap sta_ht_cap_new; 464 enum nl80211_channel_type channel_type = 465 ieee80211_ht_oper_to_channel_type( 466 elems->ht_operation); 467 468 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband, 469 elems->ht_cap_elem, 470 &sta_ht_cap_new); 471 472 /* 473 * fall back to HT20 if we don't use or use 474 * the other extension channel 475 */ 476 if (!(channel_type == NL80211_CHAN_HT40MINUS || 477 channel_type == NL80211_CHAN_HT40PLUS) || 478 channel_type != sdata->u.ibss.channel_type) 479 sta_ht_cap_new.cap &= 480 ~IEEE80211_HT_CAP_SUP_WIDTH_20_40; 481 482 if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new, 483 sizeof(sta_ht_cap_new))) { 484 memcpy(&sta->sta.ht_cap, &sta_ht_cap_new, 485 sizeof(sta_ht_cap_new)); 486 rates_updated = true; 487 } 488 } 489 490 if (sta && rates_updated) { 491 drv_sta_rc_update(local, sdata, &sta->sta, 492 IEEE80211_RC_SUPP_RATES_CHANGED); 493 rate_control_rate_init(sta); 494 } 495 496 rcu_read_unlock(); 497 } 498 499 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 500 channel, beacon); 501 if (!bss) 502 return; 503 504 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 505 506 /* was just updated in ieee80211_bss_info_update */ 507 beacon_timestamp = cbss->tsf; 508 509 /* check if we need to merge IBSS */ 510 511 /* we use a fixed BSSID */ 512 if (sdata->u.ibss.fixed_bssid) 513 goto put_bss; 514 515 /* not an IBSS */ 516 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 517 goto put_bss; 518 519 /* different channel */ 520 if (cbss->channel != local->oper_channel) 521 goto put_bss; 522 523 /* different SSID */ 524 if (elems->ssid_len != sdata->u.ibss.ssid_len || 525 memcmp(elems->ssid, sdata->u.ibss.ssid, 526 sdata->u.ibss.ssid_len)) 527 goto put_bss; 528 529 /* same BSSID */ 530 if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid)) 531 goto put_bss; 532 533 if (rx_status->flag & RX_FLAG_MACTIME_MPDU) { 534 /* 535 * For correct IBSS merging we need mactime; since mactime is 536 * defined as the time the first data symbol of the frame hits 537 * the PHY, and the timestamp of the beacon is defined as "the 538 * time that the data symbol containing the first bit of the 539 * timestamp is transmitted to the PHY plus the transmitting 540 * STA's delays through its local PHY from the MAC-PHY 541 * interface to its interface with the WM" (802.11 11.1.2) 542 * - equals the time this bit arrives at the receiver - we have 543 * to take into account the offset between the two. 544 * 545 * E.g. at 1 MBit that means mactime is 192 usec earlier 546 * (=24 bytes * 8 usecs/byte) than the beacon timestamp. 547 */ 548 int rate; 549 550 if (rx_status->flag & RX_FLAG_HT) 551 rate = 65; /* TODO: HT rates */ 552 else 553 rate = local->hw.wiphy->bands[band]-> 554 bitrates[rx_status->rate_idx].bitrate; 555 556 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate); 557 } else { 558 /* 559 * second best option: get current TSF 560 * (will return -1 if not supported) 561 */ 562 rx_timestamp = drv_get_tsf(local, sdata); 563 } 564 565 ibss_dbg(sdata, 566 "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 567 mgmt->sa, mgmt->bssid, 568 (unsigned long long)rx_timestamp, 569 (unsigned long long)beacon_timestamp, 570 (unsigned long long)(rx_timestamp - beacon_timestamp), 571 jiffies); 572 573 if (beacon_timestamp > rx_timestamp) { 574 ibss_dbg(sdata, 575 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n", 576 mgmt->bssid); 577 ieee80211_sta_join_ibss(sdata, bss); 578 supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL); 579 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 580 supp_rates, true); 581 rcu_read_unlock(); 582 } 583 584 put_bss: 585 ieee80211_rx_bss_put(local, bss); 586} 587 588void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata, 589 const u8 *bssid, const u8 *addr, 590 u32 supp_rates) 591{ 592 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 593 struct ieee80211_local *local = sdata->local; 594 struct sta_info *sta; 595 int band = local->oper_channel->band; 596 597 /* 598 * XXX: Consider removing the least recently used entry and 599 * allow new one to be added. 600 */ 601 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 602 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 603 sdata->name, addr); 604 return; 605 } 606 607 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 608 return; 609 610 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) 611 return; 612 613 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC); 614 if (!sta) 615 return; 616 617 sta->last_rx = jiffies; 618 619 /* make sure mandatory rates are always added */ 620 sta->sta.supp_rates[band] = supp_rates | 621 ieee80211_mandatory_rates(local, band); 622 623 spin_lock(&ifibss->incomplete_lock); 624 list_add(&sta->list, &ifibss->incomplete_stations); 625 spin_unlock(&ifibss->incomplete_lock); 626 ieee80211_queue_work(&local->hw, &sdata->work); 627} 628 629static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 630{ 631 struct ieee80211_local *local = sdata->local; 632 int active = 0; 633 struct sta_info *sta; 634 635 lockdep_assert_held(&sdata->u.ibss.mtx); 636 637 rcu_read_lock(); 638 639 list_for_each_entry_rcu(sta, &local->sta_list, list) { 640 if (sta->sdata == sdata && 641 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 642 jiffies)) { 643 active++; 644 break; 645 } 646 } 647 648 rcu_read_unlock(); 649 650 return active; 651} 652 653/* 654 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 655 */ 656 657static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 658{ 659 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 660 661 lockdep_assert_held(&ifibss->mtx); 662 663 mod_timer(&ifibss->timer, 664 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 665 666 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 667 668 if (time_before(jiffies, ifibss->last_scan_completed + 669 IEEE80211_IBSS_MERGE_INTERVAL)) 670 return; 671 672 if (ieee80211_sta_active_ibss(sdata)) 673 return; 674 675 if (ifibss->fixed_channel) 676 return; 677 678 sdata_info(sdata, 679 "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n"); 680 681 ieee80211_request_internal_scan(sdata, 682 ifibss->ssid, ifibss->ssid_len, NULL); 683} 684 685static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 686{ 687 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 688 u8 bssid[ETH_ALEN]; 689 u16 capability; 690 int i; 691 692 lockdep_assert_held(&ifibss->mtx); 693 694 if (ifibss->fixed_bssid) { 695 memcpy(bssid, ifibss->bssid, ETH_ALEN); 696 } else { 697 /* Generate random, not broadcast, locally administered BSSID. Mix in 698 * own MAC address to make sure that devices that do not have proper 699 * random number generator get different BSSID. */ 700 get_random_bytes(bssid, ETH_ALEN); 701 for (i = 0; i < ETH_ALEN; i++) 702 bssid[i] ^= sdata->vif.addr[i]; 703 bssid[0] &= ~0x01; 704 bssid[0] |= 0x02; 705 } 706 707 sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid); 708 709 capability = WLAN_CAPABILITY_IBSS; 710 711 if (ifibss->privacy) 712 capability |= WLAN_CAPABILITY_PRIVACY; 713 else 714 sdata->drop_unencrypted = 0; 715 716 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 717 ifibss->channel, ifibss->basic_rates, 718 capability, 0); 719} 720 721/* 722 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 723 */ 724 725static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 726{ 727 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 728 struct ieee80211_local *local = sdata->local; 729 struct cfg80211_bss *cbss; 730 struct ieee80211_channel *chan = NULL; 731 const u8 *bssid = NULL; 732 int active_ibss; 733 u16 capability; 734 735 lockdep_assert_held(&ifibss->mtx); 736 737 active_ibss = ieee80211_sta_active_ibss(sdata); 738 ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss); 739 740 if (active_ibss) 741 return; 742 743 capability = WLAN_CAPABILITY_IBSS; 744 if (ifibss->privacy) 745 capability |= WLAN_CAPABILITY_PRIVACY; 746 if (ifibss->fixed_bssid) 747 bssid = ifibss->bssid; 748 if (ifibss->fixed_channel) 749 chan = ifibss->channel; 750 if (!is_zero_ether_addr(ifibss->bssid)) 751 bssid = ifibss->bssid; 752 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 753 ifibss->ssid, ifibss->ssid_len, 754 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 755 capability); 756 757 if (cbss) { 758 struct ieee80211_bss *bss; 759 760 bss = (void *)cbss->priv; 761 ibss_dbg(sdata, 762 "sta_find_ibss: selected %pM current %pM\n", 763 cbss->bssid, ifibss->bssid); 764 sdata_info(sdata, 765 "Selected IBSS BSSID %pM based on configured SSID\n", 766 cbss->bssid); 767 768 ieee80211_sta_join_ibss(sdata, bss); 769 ieee80211_rx_bss_put(local, bss); 770 return; 771 } 772 773 ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n"); 774 775 /* Selected IBSS not found in current scan results - try to scan */ 776 if (time_after(jiffies, ifibss->last_scan_completed + 777 IEEE80211_SCAN_INTERVAL)) { 778 sdata_info(sdata, "Trigger new scan to find an IBSS to join\n"); 779 780 ieee80211_request_internal_scan(sdata, 781 ifibss->ssid, ifibss->ssid_len, 782 ifibss->fixed_channel ? ifibss->channel : NULL); 783 } else { 784 int interval = IEEE80211_SCAN_INTERVAL; 785 786 if (time_after(jiffies, ifibss->ibss_join_req + 787 IEEE80211_IBSS_JOIN_TIMEOUT)) { 788 if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) { 789 ieee80211_sta_create_ibss(sdata); 790 return; 791 } 792 sdata_info(sdata, "IBSS not allowed on %d MHz\n", 793 local->oper_channel->center_freq); 794 795 /* No IBSS found - decrease scan interval and continue 796 * scanning. */ 797 interval = IEEE80211_SCAN_INTERVAL_SLOW; 798 } 799 800 mod_timer(&ifibss->timer, 801 round_jiffies(jiffies + interval)); 802 } 803} 804 805static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 806 struct sk_buff *req) 807{ 808 struct ieee80211_mgmt *mgmt = (void *)req->data; 809 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 810 struct ieee80211_local *local = sdata->local; 811 int tx_last_beacon, len = req->len; 812 struct sk_buff *skb; 813 struct ieee80211_mgmt *resp; 814 struct sk_buff *presp; 815 u8 *pos, *end; 816 817 lockdep_assert_held(&ifibss->mtx); 818 819 presp = rcu_dereference_protected(ifibss->presp, 820 lockdep_is_held(&ifibss->mtx)); 821 822 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 823 len < 24 + 2 || !presp) 824 return; 825 826 tx_last_beacon = drv_tx_last_beacon(local); 827 828 ibss_dbg(sdata, 829 "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n", 830 mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon); 831 832 if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da)) 833 return; 834 835 if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) && 836 !is_broadcast_ether_addr(mgmt->bssid)) 837 return; 838 839 end = ((u8 *) mgmt) + len; 840 pos = mgmt->u.probe_req.variable; 841 if (pos[0] != WLAN_EID_SSID || 842 pos + 2 + pos[1] > end) { 843 ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n", 844 mgmt->sa); 845 return; 846 } 847 if (pos[1] != 0 && 848 (pos[1] != ifibss->ssid_len || 849 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 850 /* Ignore ProbeReq for foreign SSID */ 851 return; 852 } 853 854 /* Reply with ProbeResp */ 855 skb = skb_copy(presp, GFP_KERNEL); 856 if (!skb) 857 return; 858 859 resp = (struct ieee80211_mgmt *) skb->data; 860 memcpy(resp->da, mgmt->sa, ETH_ALEN); 861 ibss_dbg(sdata, "Sending ProbeResp to %pM\n", resp->da); 862 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 863 ieee80211_tx_skb(sdata, skb); 864} 865 866static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, 867 struct ieee80211_mgmt *mgmt, 868 size_t len, 869 struct ieee80211_rx_status *rx_status) 870{ 871 size_t baselen; 872 struct ieee802_11_elems elems; 873 874 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 875 if (baselen > len) 876 return; 877 878 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 879 &elems); 880 881 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false); 882} 883 884static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, 885 struct ieee80211_mgmt *mgmt, 886 size_t len, 887 struct ieee80211_rx_status *rx_status) 888{ 889 size_t baselen; 890 struct ieee802_11_elems elems; 891 892 /* Process beacon from the current BSS */ 893 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt; 894 if (baselen > len) 895 return; 896 897 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems); 898 899 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); 900} 901 902void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 903 struct sk_buff *skb) 904{ 905 struct ieee80211_rx_status *rx_status; 906 struct ieee80211_mgmt *mgmt; 907 u16 fc; 908 909 rx_status = IEEE80211_SKB_RXCB(skb); 910 mgmt = (struct ieee80211_mgmt *) skb->data; 911 fc = le16_to_cpu(mgmt->frame_control); 912 913 mutex_lock(&sdata->u.ibss.mtx); 914 915 if (!sdata->u.ibss.ssid_len) 916 goto mgmt_out; /* not ready to merge yet */ 917 918 switch (fc & IEEE80211_FCTL_STYPE) { 919 case IEEE80211_STYPE_PROBE_REQ: 920 ieee80211_rx_mgmt_probe_req(sdata, skb); 921 break; 922 case IEEE80211_STYPE_PROBE_RESP: 923 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, 924 rx_status); 925 break; 926 case IEEE80211_STYPE_BEACON: 927 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, 928 rx_status); 929 break; 930 case IEEE80211_STYPE_AUTH: 931 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 932 break; 933 case IEEE80211_STYPE_DEAUTH: 934 ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len); 935 break; 936 } 937 938 mgmt_out: 939 mutex_unlock(&sdata->u.ibss.mtx); 940} 941 942void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata) 943{ 944 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 945 struct sta_info *sta; 946 947 mutex_lock(&ifibss->mtx); 948 949 /* 950 * Work could be scheduled after scan or similar 951 * when we aren't even joined (or trying) with a 952 * network. 953 */ 954 if (!ifibss->ssid_len) 955 goto out; 956 957 spin_lock_bh(&ifibss->incomplete_lock); 958 while (!list_empty(&ifibss->incomplete_stations)) { 959 sta = list_first_entry(&ifibss->incomplete_stations, 960 struct sta_info, list); 961 list_del(&sta->list); 962 spin_unlock_bh(&ifibss->incomplete_lock); 963 964 ieee80211_ibss_finish_sta(sta, true); 965 rcu_read_unlock(); 966 spin_lock_bh(&ifibss->incomplete_lock); 967 } 968 spin_unlock_bh(&ifibss->incomplete_lock); 969 970 switch (ifibss->state) { 971 case IEEE80211_IBSS_MLME_SEARCH: 972 ieee80211_sta_find_ibss(sdata); 973 break; 974 case IEEE80211_IBSS_MLME_JOINED: 975 ieee80211_sta_merge_ibss(sdata); 976 break; 977 default: 978 WARN_ON(1); 979 break; 980 } 981 982 out: 983 mutex_unlock(&ifibss->mtx); 984} 985 986static void ieee80211_ibss_timer(unsigned long data) 987{ 988 struct ieee80211_sub_if_data *sdata = 989 (struct ieee80211_sub_if_data *) data; 990 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 991 struct ieee80211_local *local = sdata->local; 992 993 if (local->quiescing) { 994 ifibss->timer_running = true; 995 return; 996 } 997 998 ieee80211_queue_work(&local->hw, &sdata->work); 999} 1000 1001#ifdef CONFIG_PM 1002void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata) 1003{ 1004 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1005 1006 if (del_timer_sync(&ifibss->timer)) 1007 ifibss->timer_running = true; 1008} 1009 1010void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata) 1011{ 1012 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1013 1014 if (ifibss->timer_running) { 1015 add_timer(&ifibss->timer); 1016 ifibss->timer_running = false; 1017 } 1018} 1019#endif 1020 1021void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 1022{ 1023 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1024 1025 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 1026 (unsigned long) sdata); 1027 mutex_init(&ifibss->mtx); 1028 INIT_LIST_HEAD(&ifibss->incomplete_stations); 1029 spin_lock_init(&ifibss->incomplete_lock); 1030} 1031 1032/* scan finished notification */ 1033void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 1034{ 1035 struct ieee80211_sub_if_data *sdata; 1036 1037 mutex_lock(&local->iflist_mtx); 1038 list_for_each_entry(sdata, &local->interfaces, list) { 1039 if (!ieee80211_sdata_running(sdata)) 1040 continue; 1041 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 1042 continue; 1043 sdata->u.ibss.last_scan_completed = jiffies; 1044 ieee80211_queue_work(&local->hw, &sdata->work); 1045 } 1046 mutex_unlock(&local->iflist_mtx); 1047} 1048 1049int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 1050 struct cfg80211_ibss_params *params) 1051{ 1052 struct sk_buff *skb; 1053 u32 changed = 0; 1054 1055 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom + 1056 sizeof(struct ieee80211_hdr_3addr) + 1057 12 /* struct ieee80211_mgmt.u.beacon */ + 1058 2 + IEEE80211_MAX_SSID_LEN /* max SSID */ + 1059 2 + 8 /* max Supported Rates */ + 1060 3 /* max DS params */ + 1061 4 /* IBSS params */ + 1062 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 1063 2 + sizeof(struct ieee80211_ht_cap) + 1064 2 + sizeof(struct ieee80211_ht_operation) + 1065 params->ie_len); 1066 if (!skb) 1067 return -ENOMEM; 1068 1069 mutex_lock(&sdata->u.ibss.mtx); 1070 1071 if (params->bssid) { 1072 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 1073 sdata->u.ibss.fixed_bssid = true; 1074 } else 1075 sdata->u.ibss.fixed_bssid = false; 1076 1077 sdata->u.ibss.privacy = params->privacy; 1078 sdata->u.ibss.control_port = params->control_port; 1079 sdata->u.ibss.basic_rates = params->basic_rates; 1080 memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate, 1081 sizeof(params->mcast_rate)); 1082 1083 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 1084 1085 sdata->u.ibss.channel = params->channel; 1086 sdata->u.ibss.channel_type = params->channel_type; 1087 sdata->u.ibss.fixed_channel = params->channel_fixed; 1088 1089 /* fix ourselves to that channel now already */ 1090 if (params->channel_fixed) { 1091 sdata->local->oper_channel = params->channel; 1092 if (!ieee80211_set_channel_type(sdata->local, sdata, 1093 params->channel_type)) { 1094 mutex_unlock(&sdata->u.ibss.mtx); 1095 kfree_skb(skb); 1096 return -EINVAL; 1097 } 1098 } 1099 1100 if (params->ie) { 1101 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 1102 GFP_KERNEL); 1103 if (sdata->u.ibss.ie) 1104 sdata->u.ibss.ie_len = params->ie_len; 1105 } 1106 1107 sdata->u.ibss.skb = skb; 1108 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1109 sdata->u.ibss.ibss_join_req = jiffies; 1110 1111 memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN); 1112 sdata->u.ibss.ssid_len = params->ssid_len; 1113 1114 mutex_unlock(&sdata->u.ibss.mtx); 1115 1116 mutex_lock(&sdata->local->mtx); 1117 ieee80211_recalc_idle(sdata->local); 1118 mutex_unlock(&sdata->local->mtx); 1119 1120 /* 1121 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is 1122 * reserved, but an HT STA shall protect HT transmissions as though 1123 * the HT Protection field were set to non-HT mixed mode. 1124 * 1125 * In an IBSS, the RIFS Mode field of the HT Operation element is 1126 * also reserved, but an HT STA shall operate as though this field 1127 * were set to 1. 1128 */ 1129 1130 sdata->vif.bss_conf.ht_operation_mode |= 1131 IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED 1132 | IEEE80211_HT_PARAM_RIFS_MODE; 1133 1134 changed |= BSS_CHANGED_HT; 1135 ieee80211_bss_info_change_notify(sdata, changed); 1136 1137 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1138 1139 return 0; 1140} 1141 1142int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 1143{ 1144 struct sk_buff *skb; 1145 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1146 struct ieee80211_local *local = sdata->local; 1147 struct cfg80211_bss *cbss; 1148 u16 capability; 1149 int active_ibss; 1150 struct sta_info *sta; 1151 1152 mutex_lock(&sdata->u.ibss.mtx); 1153 1154 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1155 memset(sdata->u.ibss.bssid, 0, ETH_ALEN); 1156 sdata->u.ibss.ssid_len = 0; 1157 1158 active_ibss = ieee80211_sta_active_ibss(sdata); 1159 1160 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) { 1161 capability = WLAN_CAPABILITY_IBSS; 1162 1163 if (ifibss->privacy) 1164 capability |= WLAN_CAPABILITY_PRIVACY; 1165 1166 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel, 1167 ifibss->bssid, ifibss->ssid, 1168 ifibss->ssid_len, WLAN_CAPABILITY_IBSS | 1169 WLAN_CAPABILITY_PRIVACY, 1170 capability); 1171 1172 if (cbss) { 1173 cfg80211_unlink_bss(local->hw.wiphy, cbss); 1174 cfg80211_put_bss(cbss); 1175 } 1176 } 1177 1178 sta_info_flush(sdata->local, sdata); 1179 1180 spin_lock_bh(&ifibss->incomplete_lock); 1181 while (!list_empty(&ifibss->incomplete_stations)) { 1182 sta = list_first_entry(&ifibss->incomplete_stations, 1183 struct sta_info, list); 1184 list_del(&sta->list); 1185 spin_unlock_bh(&ifibss->incomplete_lock); 1186 1187 sta_info_free(local, sta); 1188 spin_lock_bh(&ifibss->incomplete_lock); 1189 } 1190 spin_unlock_bh(&ifibss->incomplete_lock); 1191 1192 netif_carrier_off(sdata->dev); 1193 1194 /* remove beacon */ 1195 kfree(sdata->u.ibss.ie); 1196 skb = rcu_dereference_protected(sdata->u.ibss.presp, 1197 lockdep_is_held(&sdata->u.ibss.mtx)); 1198 RCU_INIT_POINTER(sdata->u.ibss.presp, NULL); 1199 sdata->vif.bss_conf.ibss_joined = false; 1200 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | 1201 BSS_CHANGED_IBSS); 1202 synchronize_rcu(); 1203 kfree_skb(skb); 1204 1205 skb_queue_purge(&sdata->skb_queue); 1206 1207 del_timer_sync(&sdata->u.ibss.timer); 1208 1209 mutex_unlock(&sdata->u.ibss.mtx); 1210 1211 mutex_lock(&local->mtx); 1212 ieee80211_recalc_idle(sdata->local); 1213 mutex_unlock(&local->mtx); 1214 1215 return 0; 1216} 1217