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_IBSS_JOIN_TIMEOUT (7 * HZ) 30 31 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ) 32 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ) 33 34 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128 35 36 37 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 38 const u8 *bssid, const int beacon_int, 39 struct ieee80211_channel *chan, 40 const u32 basic_rates, 41 const u16 capability, u64 tsf, 42 bool creator) 43 { 44 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 45 struct ieee80211_local *local = sdata->local; 46 int rates, i; 47 struct ieee80211_mgmt *mgmt; 48 u8 *pos; 49 struct ieee80211_supported_band *sband; 50 struct cfg80211_bss *bss; 51 u32 bss_change; 52 u8 supp_rates[IEEE80211_MAX_SUPP_RATES]; 53 struct cfg80211_chan_def chandef; 54 struct beacon_data *presp; 55 int frame_len; 56 57 sdata_assert_lock(sdata); 58 59 /* Reset own TSF to allow time synchronization work. */ 60 drv_reset_tsf(local, sdata); 61 62 if (!ether_addr_equal(ifibss->bssid, bssid)) 63 sta_info_flush(sdata); 64 65 /* if merging, indicate to driver that we leave the old IBSS */ 66 if (sdata->vif.bss_conf.ibss_joined) { 67 sdata->vif.bss_conf.ibss_joined = false; 68 sdata->vif.bss_conf.ibss_creator = false; 69 sdata->vif.bss_conf.enable_beacon = false; 70 netif_carrier_off(sdata->dev); 71 ieee80211_bss_info_change_notify(sdata, 72 BSS_CHANGED_IBSS | 73 BSS_CHANGED_BEACON_ENABLED); 74 } 75 76 presp = rcu_dereference_protected(ifibss->presp, 77 lockdep_is_held(&sdata->wdev.mtx)); 78 rcu_assign_pointer(ifibss->presp, NULL); 79 if (presp) 80 kfree_rcu(presp, rcu_head); 81 82 sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0; 83 84 chandef = ifibss->chandef; 85 if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) { 86 chandef.width = NL80211_CHAN_WIDTH_20; 87 chandef.center_freq1 = chan->center_freq; 88 } 89 90 ieee80211_vif_release_channel(sdata); 91 if (ieee80211_vif_use_channel(sdata, &chandef, 92 ifibss->fixed_channel ? 93 IEEE80211_CHANCTX_SHARED : 94 IEEE80211_CHANCTX_EXCLUSIVE)) { 95 sdata_info(sdata, "Failed to join IBSS, no channel context\n"); 96 return; 97 } 98 99 memcpy(ifibss->bssid, bssid, ETH_ALEN); 100 101 sband = local->hw.wiphy->bands[chan->band]; 102 103 /* Build IBSS probe response */ 104 frame_len = sizeof(struct ieee80211_hdr_3addr) + 105 12 /* struct ieee80211_mgmt.u.beacon */ + 106 2 + IEEE80211_MAX_SSID_LEN /* max SSID */ + 107 2 + 8 /* max Supported Rates */ + 108 3 /* max DS params */ + 109 4 /* IBSS params */ + 110 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 111 2 + sizeof(struct ieee80211_ht_cap) + 112 2 + sizeof(struct ieee80211_ht_operation) + 113 ifibss->ie_len; 114 presp = kzalloc(sizeof(*presp) + frame_len, GFP_KERNEL); 115 if (!presp) 116 return; 117 118 presp->head = (void *)(presp + 1); 119 120 mgmt = (void *) presp->head; 121 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 122 IEEE80211_STYPE_PROBE_RESP); 123 eth_broadcast_addr(mgmt->da); 124 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 125 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN); 126 mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int); 127 mgmt->u.beacon.timestamp = cpu_to_le64(tsf); 128 mgmt->u.beacon.capab_info = cpu_to_le16(capability); 129 130 pos = (u8 *)mgmt + offsetof(struct ieee80211_mgmt, u.beacon.variable); 131 132 *pos++ = WLAN_EID_SSID; 133 *pos++ = ifibss->ssid_len; 134 memcpy(pos, ifibss->ssid, ifibss->ssid_len); 135 pos += ifibss->ssid_len; 136 137 rates = min_t(int, 8, sband->n_bitrates); 138 *pos++ = WLAN_EID_SUPP_RATES; 139 *pos++ = rates; 140 for (i = 0; i < rates; i++) { 141 int rate = sband->bitrates[i].bitrate; 142 u8 basic = 0; 143 if (basic_rates & BIT(i)) 144 basic = 0x80; 145 *pos++ = basic | (u8) (rate / 5); 146 } 147 148 if (sband->band == IEEE80211_BAND_2GHZ) { 149 *pos++ = WLAN_EID_DS_PARAMS; 150 *pos++ = 1; 151 *pos++ = ieee80211_frequency_to_channel(chan->center_freq); 152 } 153 154 *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 *pos++ = WLAN_EID_EXT_SUPP_RATES; 162 *pos++ = sband->n_bitrates - 8; 163 for (i = 8; i < sband->n_bitrates; i++) { 164 int rate = sband->bitrates[i].bitrate; 165 u8 basic = 0; 166 if (basic_rates & BIT(i)) 167 basic = 0x80; 168 *pos++ = basic | (u8) (rate / 5); 169 } 170 } 171 172 if (ifibss->ie_len) { 173 memcpy(pos, ifibss->ie, ifibss->ie_len); 174 pos += ifibss->ie_len; 175 } 176 177 /* add HT capability and information IEs */ 178 if (chandef.width != NL80211_CHAN_WIDTH_20_NOHT && 179 chandef.width != NL80211_CHAN_WIDTH_5 && 180 chandef.width != NL80211_CHAN_WIDTH_10 && 181 sband->ht_cap.ht_supported) { 182 pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, 183 sband->ht_cap.cap); 184 /* 185 * Note: According to 802.11n-2009 9.13.3.1, HT Protection 186 * field and RIFS Mode are reserved in IBSS mode, therefore 187 * keep them at 0 188 */ 189 pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap, 190 &chandef, 0); 191 } 192 193 if (local->hw.queues >= IEEE80211_NUM_ACS) { 194 *pos++ = WLAN_EID_VENDOR_SPECIFIC; 195 *pos++ = 7; /* len */ 196 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */ 197 *pos++ = 0x50; 198 *pos++ = 0xf2; 199 *pos++ = 2; /* WME */ 200 *pos++ = 0; /* WME info */ 201 *pos++ = 1; /* WME ver */ 202 *pos++ = 0; /* U-APSD no in use */ 203 } 204 205 presp->head_len = pos - presp->head; 206 if (WARN_ON(presp->head_len > frame_len)) 207 return; 208 209 rcu_assign_pointer(ifibss->presp, presp); 210 211 sdata->vif.bss_conf.enable_beacon = true; 212 sdata->vif.bss_conf.beacon_int = beacon_int; 213 sdata->vif.bss_conf.basic_rates = basic_rates; 214 sdata->vif.bss_conf.ssid_len = ifibss->ssid_len; 215 memcpy(sdata->vif.bss_conf.ssid, ifibss->ssid, ifibss->ssid_len); 216 bss_change = BSS_CHANGED_BEACON_INT; 217 bss_change |= ieee80211_reset_erp_info(sdata); 218 bss_change |= BSS_CHANGED_BSSID; 219 bss_change |= BSS_CHANGED_BEACON; 220 bss_change |= BSS_CHANGED_BEACON_ENABLED; 221 bss_change |= BSS_CHANGED_BASIC_RATES; 222 bss_change |= BSS_CHANGED_HT; 223 bss_change |= BSS_CHANGED_IBSS; 224 bss_change |= BSS_CHANGED_SSID; 225 226 /* 227 * In 5 GHz/802.11a, we can always use short slot time. 228 * (IEEE 802.11-2012 18.3.8.7) 229 * 230 * In 2.4GHz, we must always use long slots in IBSS for compatibility 231 * reasons. 232 * (IEEE 802.11-2012 19.4.5) 233 * 234 * HT follows these specifications (IEEE 802.11-2012 20.3.18) 235 */ 236 sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ; 237 bss_change |= BSS_CHANGED_ERP_SLOT; 238 239 sdata->vif.bss_conf.ibss_joined = true; 240 sdata->vif.bss_conf.ibss_creator = creator; 241 ieee80211_bss_info_change_notify(sdata, bss_change); 242 243 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 244 245 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 246 mod_timer(&ifibss->timer, 247 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 248 249 bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan, 250 mgmt, presp->head_len, 0, GFP_KERNEL); 251 cfg80211_put_bss(local->hw.wiphy, bss); 252 netif_carrier_on(sdata->dev); 253 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 254 } 255 256 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 257 struct ieee80211_bss *bss) 258 { 259 struct cfg80211_bss *cbss = 260 container_of((void *)bss, struct cfg80211_bss, priv); 261 struct ieee80211_supported_band *sband; 262 u32 basic_rates; 263 int i, j; 264 u16 beacon_int = cbss->beacon_interval; 265 const struct cfg80211_bss_ies *ies; 266 u64 tsf; 267 268 sdata_assert_lock(sdata); 269 270 if (beacon_int < 10) 271 beacon_int = 10; 272 273 sband = sdata->local->hw.wiphy->bands[cbss->channel->band]; 274 275 basic_rates = 0; 276 277 for (i = 0; i < bss->supp_rates_len; i++) { 278 int rate = (bss->supp_rates[i] & 0x7f) * 5; 279 bool is_basic = !!(bss->supp_rates[i] & 0x80); 280 281 for (j = 0; j < sband->n_bitrates; j++) { 282 if (sband->bitrates[j].bitrate == rate) { 283 if (is_basic) 284 basic_rates |= BIT(j); 285 break; 286 } 287 } 288 } 289 290 rcu_read_lock(); 291 ies = rcu_dereference(cbss->ies); 292 tsf = ies->tsf; 293 rcu_read_unlock(); 294 295 __ieee80211_sta_join_ibss(sdata, cbss->bssid, 296 beacon_int, 297 cbss->channel, 298 basic_rates, 299 cbss->capability, 300 tsf, false); 301 } 302 303 static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta) 304 __acquires(RCU) 305 { 306 struct ieee80211_sub_if_data *sdata = sta->sdata; 307 u8 addr[ETH_ALEN]; 308 309 memcpy(addr, sta->sta.addr, ETH_ALEN); 310 311 ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr); 312 313 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 314 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 315 /* authorize the station only if the network is not RSN protected. If 316 * not wait for the userspace to authorize it */ 317 if (!sta->sdata->u.ibss.control_port) 318 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 319 320 rate_control_rate_init(sta); 321 322 /* If it fails, maybe we raced another insertion? */ 323 if (sta_info_insert_rcu(sta)) 324 return sta_info_get(sdata, addr); 325 return sta; 326 } 327 328 static struct sta_info * 329 ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, const u8 *bssid, 330 const u8 *addr, u32 supp_rates) 331 __acquires(RCU) 332 { 333 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 334 struct ieee80211_local *local = sdata->local; 335 struct sta_info *sta; 336 struct ieee80211_chanctx_conf *chanctx_conf; 337 struct ieee80211_supported_band *sband; 338 int band; 339 340 /* 341 * XXX: Consider removing the least recently used entry and 342 * allow new one to be added. 343 */ 344 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 345 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 346 sdata->name, addr); 347 rcu_read_lock(); 348 return NULL; 349 } 350 351 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) { 352 rcu_read_lock(); 353 return NULL; 354 } 355 356 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) { 357 rcu_read_lock(); 358 return NULL; 359 } 360 361 rcu_read_lock(); 362 chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf); 363 if (WARN_ON_ONCE(!chanctx_conf)) 364 return NULL; 365 band = chanctx_conf->def.chan->band; 366 rcu_read_unlock(); 367 368 sta = sta_info_alloc(sdata, addr, GFP_KERNEL); 369 if (!sta) { 370 rcu_read_lock(); 371 return NULL; 372 } 373 374 sta->last_rx = jiffies; 375 376 /* make sure mandatory rates are always added */ 377 sband = local->hw.wiphy->bands[band]; 378 sta->sta.supp_rates[band] = supp_rates | 379 ieee80211_mandatory_rates(sband); 380 381 return ieee80211_ibss_finish_sta(sta); 382 } 383 384 static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata, 385 struct ieee80211_mgmt *mgmt, 386 size_t len) 387 { 388 u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code); 389 390 if (len < IEEE80211_DEAUTH_FRAME_LEN) 391 return; 392 393 ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n", 394 mgmt->sa, mgmt->da, mgmt->bssid, reason); 395 sta_info_destroy_addr(sdata, mgmt->sa); 396 } 397 398 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, 399 struct ieee80211_mgmt *mgmt, 400 size_t len) 401 { 402 u16 auth_alg, auth_transaction; 403 404 sdata_assert_lock(sdata); 405 406 if (len < 24 + 6) 407 return; 408 409 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 410 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 411 412 ibss_dbg(sdata, 413 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n", 414 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction); 415 416 if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1) 417 return; 418 419 /* 420 * IEEE 802.11 standard does not require authentication in IBSS 421 * networks and most implementations do not seem to use it. 422 * However, try to reply to authentication attempts if someone 423 * has actually implemented this. 424 */ 425 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0, 426 mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0); 427 } 428 429 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 430 struct ieee80211_mgmt *mgmt, size_t len, 431 struct ieee80211_rx_status *rx_status, 432 struct ieee802_11_elems *elems) 433 { 434 struct ieee80211_local *local = sdata->local; 435 int freq; 436 struct cfg80211_bss *cbss; 437 struct ieee80211_bss *bss; 438 struct sta_info *sta; 439 struct ieee80211_channel *channel; 440 u64 beacon_timestamp, rx_timestamp; 441 u32 supp_rates = 0; 442 enum ieee80211_band band = rx_status->band; 443 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 444 bool rates_updated = false; 445 446 if (elems->ds_params) 447 freq = ieee80211_channel_to_frequency(elems->ds_params[0], 448 band); 449 else 450 freq = rx_status->freq; 451 452 channel = ieee80211_get_channel(local->hw.wiphy, freq); 453 454 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 455 return; 456 457 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && 458 ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) { 459 460 rcu_read_lock(); 461 sta = sta_info_get(sdata, mgmt->sa); 462 463 if (elems->supp_rates) { 464 supp_rates = ieee80211_sta_get_rates(local, elems, 465 band, NULL); 466 if (sta) { 467 u32 prev_rates; 468 469 prev_rates = sta->sta.supp_rates[band]; 470 /* make sure mandatory rates are always added */ 471 sta->sta.supp_rates[band] = supp_rates | 472 ieee80211_mandatory_rates(sband); 473 474 if (sta->sta.supp_rates[band] != prev_rates) { 475 ibss_dbg(sdata, 476 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n", 477 sta->sta.addr, prev_rates, 478 sta->sta.supp_rates[band]); 479 rates_updated = true; 480 } 481 } else { 482 rcu_read_unlock(); 483 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, 484 mgmt->sa, supp_rates); 485 } 486 } 487 488 if (sta && elems->wmm_info) 489 set_sta_flag(sta, WLAN_STA_WME); 490 491 if (sta && elems->ht_operation && elems->ht_cap_elem && 492 sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20_NOHT && 493 sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_5 && 494 sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_10) { 495 /* we both use HT */ 496 struct ieee80211_ht_cap htcap_ie; 497 struct cfg80211_chan_def chandef; 498 499 ieee80211_ht_oper_to_chandef(channel, 500 elems->ht_operation, 501 &chandef); 502 503 memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie)); 504 505 /* 506 * fall back to HT20 if we don't use or use 507 * the other extension channel 508 */ 509 if (chandef.center_freq1 != 510 sdata->u.ibss.chandef.center_freq1) 511 htcap_ie.cap_info &= 512 cpu_to_le16(~IEEE80211_HT_CAP_SUP_WIDTH_20_40); 513 514 rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap( 515 sdata, sband, &htcap_ie, sta); 516 } 517 518 if (sta && rates_updated) { 519 drv_sta_rc_update(local, sdata, &sta->sta, 520 IEEE80211_RC_SUPP_RATES_CHANGED); 521 rate_control_rate_init(sta); 522 } 523 524 rcu_read_unlock(); 525 } 526 527 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 528 channel); 529 if (!bss) 530 return; 531 532 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 533 534 /* same for beacon and probe response */ 535 beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp); 536 537 /* check if we need to merge IBSS */ 538 539 /* we use a fixed BSSID */ 540 if (sdata->u.ibss.fixed_bssid) 541 goto put_bss; 542 543 /* not an IBSS */ 544 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 545 goto put_bss; 546 547 /* different channel */ 548 if (sdata->u.ibss.fixed_channel && 549 sdata->u.ibss.chandef.chan != cbss->channel) 550 goto put_bss; 551 552 /* different SSID */ 553 if (elems->ssid_len != sdata->u.ibss.ssid_len || 554 memcmp(elems->ssid, sdata->u.ibss.ssid, 555 sdata->u.ibss.ssid_len)) 556 goto put_bss; 557 558 /* same BSSID */ 559 if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid)) 560 goto put_bss; 561 562 if (ieee80211_have_rx_timestamp(rx_status)) { 563 /* time when timestamp field was received */ 564 rx_timestamp = 565 ieee80211_calculate_rx_timestamp(local, rx_status, 566 len + FCS_LEN, 24); 567 } else { 568 /* 569 * second best option: get current TSF 570 * (will return -1 if not supported) 571 */ 572 rx_timestamp = drv_get_tsf(local, sdata); 573 } 574 575 ibss_dbg(sdata, 576 "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 577 mgmt->sa, mgmt->bssid, 578 (unsigned long long)rx_timestamp, 579 (unsigned long long)beacon_timestamp, 580 (unsigned long long)(rx_timestamp - beacon_timestamp), 581 jiffies); 582 583 if (beacon_timestamp > rx_timestamp) { 584 ibss_dbg(sdata, 585 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n", 586 mgmt->bssid); 587 ieee80211_sta_join_ibss(sdata, bss); 588 supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL); 589 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 590 supp_rates); 591 rcu_read_unlock(); 592 } 593 594 put_bss: 595 ieee80211_rx_bss_put(local, bss); 596 } 597 598 void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata, 599 const u8 *bssid, const u8 *addr, 600 u32 supp_rates) 601 { 602 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 603 struct ieee80211_local *local = sdata->local; 604 struct sta_info *sta; 605 struct ieee80211_chanctx_conf *chanctx_conf; 606 struct ieee80211_supported_band *sband; 607 int band; 608 609 /* 610 * XXX: Consider removing the least recently used entry and 611 * allow new one to be added. 612 */ 613 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 614 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 615 sdata->name, addr); 616 return; 617 } 618 619 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 620 return; 621 622 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) 623 return; 624 625 rcu_read_lock(); 626 chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf); 627 if (WARN_ON_ONCE(!chanctx_conf)) { 628 rcu_read_unlock(); 629 return; 630 } 631 band = chanctx_conf->def.chan->band; 632 rcu_read_unlock(); 633 634 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC); 635 if (!sta) 636 return; 637 638 sta->last_rx = jiffies; 639 640 /* make sure mandatory rates are always added */ 641 sband = local->hw.wiphy->bands[band]; 642 sta->sta.supp_rates[band] = supp_rates | 643 ieee80211_mandatory_rates(sband); 644 645 spin_lock(&ifibss->incomplete_lock); 646 list_add(&sta->list, &ifibss->incomplete_stations); 647 spin_unlock(&ifibss->incomplete_lock); 648 ieee80211_queue_work(&local->hw, &sdata->work); 649 } 650 651 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 652 { 653 struct ieee80211_local *local = sdata->local; 654 int active = 0; 655 struct sta_info *sta; 656 657 sdata_assert_lock(sdata); 658 659 rcu_read_lock(); 660 661 list_for_each_entry_rcu(sta, &local->sta_list, list) { 662 if (sta->sdata == sdata && 663 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 664 jiffies)) { 665 active++; 666 break; 667 } 668 } 669 670 rcu_read_unlock(); 671 672 return active; 673 } 674 675 /* 676 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 677 */ 678 679 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 680 { 681 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 682 683 sdata_assert_lock(sdata); 684 685 mod_timer(&ifibss->timer, 686 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 687 688 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 689 690 if (time_before(jiffies, ifibss->last_scan_completed + 691 IEEE80211_IBSS_MERGE_INTERVAL)) 692 return; 693 694 if (ieee80211_sta_active_ibss(sdata)) 695 return; 696 697 if (ifibss->fixed_channel) 698 return; 699 700 sdata_info(sdata, 701 "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n"); 702 703 ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len, 704 NULL); 705 } 706 707 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 708 { 709 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 710 u8 bssid[ETH_ALEN]; 711 u16 capability; 712 int i; 713 714 sdata_assert_lock(sdata); 715 716 if (ifibss->fixed_bssid) { 717 memcpy(bssid, ifibss->bssid, ETH_ALEN); 718 } else { 719 /* Generate random, not broadcast, locally administered BSSID. Mix in 720 * own MAC address to make sure that devices that do not have proper 721 * random number generator get different BSSID. */ 722 get_random_bytes(bssid, ETH_ALEN); 723 for (i = 0; i < ETH_ALEN; i++) 724 bssid[i] ^= sdata->vif.addr[i]; 725 bssid[0] &= ~0x01; 726 bssid[0] |= 0x02; 727 } 728 729 sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid); 730 731 capability = WLAN_CAPABILITY_IBSS; 732 733 if (ifibss->privacy) 734 capability |= WLAN_CAPABILITY_PRIVACY; 735 else 736 sdata->drop_unencrypted = 0; 737 738 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 739 ifibss->chandef.chan, ifibss->basic_rates, 740 capability, 0, true); 741 } 742 743 /* 744 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 745 */ 746 747 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 748 { 749 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 750 struct ieee80211_local *local = sdata->local; 751 struct cfg80211_bss *cbss; 752 struct ieee80211_channel *chan = NULL; 753 const u8 *bssid = NULL; 754 int active_ibss; 755 u16 capability; 756 757 sdata_assert_lock(sdata); 758 759 active_ibss = ieee80211_sta_active_ibss(sdata); 760 ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss); 761 762 if (active_ibss) 763 return; 764 765 capability = WLAN_CAPABILITY_IBSS; 766 if (ifibss->privacy) 767 capability |= WLAN_CAPABILITY_PRIVACY; 768 if (ifibss->fixed_bssid) 769 bssid = ifibss->bssid; 770 if (ifibss->fixed_channel) 771 chan = ifibss->chandef.chan; 772 if (!is_zero_ether_addr(ifibss->bssid)) 773 bssid = ifibss->bssid; 774 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 775 ifibss->ssid, ifibss->ssid_len, 776 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 777 capability); 778 779 if (cbss) { 780 struct ieee80211_bss *bss; 781 782 bss = (void *)cbss->priv; 783 ibss_dbg(sdata, 784 "sta_find_ibss: selected %pM current %pM\n", 785 cbss->bssid, ifibss->bssid); 786 sdata_info(sdata, 787 "Selected IBSS BSSID %pM based on configured SSID\n", 788 cbss->bssid); 789 790 ieee80211_sta_join_ibss(sdata, bss); 791 ieee80211_rx_bss_put(local, bss); 792 return; 793 } 794 795 ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n"); 796 797 /* Selected IBSS not found in current scan results - try to scan */ 798 if (time_after(jiffies, ifibss->last_scan_completed + 799 IEEE80211_SCAN_INTERVAL)) { 800 sdata_info(sdata, "Trigger new scan to find an IBSS to join\n"); 801 802 ieee80211_request_ibss_scan(sdata, ifibss->ssid, 803 ifibss->ssid_len, chan); 804 } else { 805 int interval = IEEE80211_SCAN_INTERVAL; 806 807 if (time_after(jiffies, ifibss->ibss_join_req + 808 IEEE80211_IBSS_JOIN_TIMEOUT)) 809 ieee80211_sta_create_ibss(sdata); 810 811 mod_timer(&ifibss->timer, 812 round_jiffies(jiffies + interval)); 813 } 814 } 815 816 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 817 struct sk_buff *req) 818 { 819 struct ieee80211_mgmt *mgmt = (void *)req->data; 820 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 821 struct ieee80211_local *local = sdata->local; 822 int tx_last_beacon, len = req->len; 823 struct sk_buff *skb; 824 struct beacon_data *presp; 825 u8 *pos, *end; 826 827 sdata_assert_lock(sdata); 828 829 presp = rcu_dereference_protected(ifibss->presp, 830 lockdep_is_held(&sdata->wdev.mtx)); 831 832 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 833 len < 24 + 2 || !presp) 834 return; 835 836 tx_last_beacon = drv_tx_last_beacon(local); 837 838 ibss_dbg(sdata, 839 "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n", 840 mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon); 841 842 if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da)) 843 return; 844 845 if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) && 846 !is_broadcast_ether_addr(mgmt->bssid)) 847 return; 848 849 end = ((u8 *) mgmt) + len; 850 pos = mgmt->u.probe_req.variable; 851 if (pos[0] != WLAN_EID_SSID || 852 pos + 2 + pos[1] > end) { 853 ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n", 854 mgmt->sa); 855 return; 856 } 857 if (pos[1] != 0 && 858 (pos[1] != ifibss->ssid_len || 859 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 860 /* Ignore ProbeReq for foreign SSID */ 861 return; 862 } 863 864 /* Reply with ProbeResp */ 865 skb = dev_alloc_skb(local->tx_headroom + presp->head_len); 866 if (!skb) 867 return; 868 869 skb_reserve(skb, local->tx_headroom); 870 memcpy(skb_put(skb, presp->head_len), presp->head, presp->head_len); 871 872 memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN); 873 ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa); 874 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 875 ieee80211_tx_skb(sdata, skb); 876 } 877 878 static 879 void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata, 880 struct ieee80211_mgmt *mgmt, size_t len, 881 struct ieee80211_rx_status *rx_status) 882 { 883 size_t baselen; 884 struct ieee802_11_elems elems; 885 886 BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) != 887 offsetof(typeof(mgmt->u.beacon), variable)); 888 889 /* 890 * either beacon or probe_resp but the variable field is at the 891 * same offset 892 */ 893 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 894 if (baselen > len) 895 return; 896 897 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 898 false, &elems); 899 900 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems); 901 } 902 903 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 904 struct sk_buff *skb) 905 { 906 struct ieee80211_rx_status *rx_status; 907 struct ieee80211_mgmt *mgmt; 908 u16 fc; 909 910 rx_status = IEEE80211_SKB_RXCB(skb); 911 mgmt = (struct ieee80211_mgmt *) skb->data; 912 fc = le16_to_cpu(mgmt->frame_control); 913 914 sdata_lock(sdata); 915 916 if (!sdata->u.ibss.ssid_len) 917 goto mgmt_out; /* not ready to merge yet */ 918 919 switch (fc & IEEE80211_FCTL_STYPE) { 920 case IEEE80211_STYPE_PROBE_REQ: 921 ieee80211_rx_mgmt_probe_req(sdata, skb); 922 break; 923 case IEEE80211_STYPE_PROBE_RESP: 924 case IEEE80211_STYPE_BEACON: 925 ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len, 926 rx_status); 927 break; 928 case IEEE80211_STYPE_AUTH: 929 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 930 break; 931 case IEEE80211_STYPE_DEAUTH: 932 ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len); 933 break; 934 } 935 936 mgmt_out: 937 sdata_unlock(sdata); 938 } 939 940 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata) 941 { 942 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 943 struct sta_info *sta; 944 945 sdata_lock(sdata); 946 947 /* 948 * Work could be scheduled after scan or similar 949 * when we aren't even joined (or trying) with a 950 * network. 951 */ 952 if (!ifibss->ssid_len) 953 goto out; 954 955 spin_lock_bh(&ifibss->incomplete_lock); 956 while (!list_empty(&ifibss->incomplete_stations)) { 957 sta = list_first_entry(&ifibss->incomplete_stations, 958 struct sta_info, list); 959 list_del(&sta->list); 960 spin_unlock_bh(&ifibss->incomplete_lock); 961 962 ieee80211_ibss_finish_sta(sta); 963 rcu_read_unlock(); 964 spin_lock_bh(&ifibss->incomplete_lock); 965 } 966 spin_unlock_bh(&ifibss->incomplete_lock); 967 968 switch (ifibss->state) { 969 case IEEE80211_IBSS_MLME_SEARCH: 970 ieee80211_sta_find_ibss(sdata); 971 break; 972 case IEEE80211_IBSS_MLME_JOINED: 973 ieee80211_sta_merge_ibss(sdata); 974 break; 975 default: 976 WARN_ON(1); 977 break; 978 } 979 980 out: 981 sdata_unlock(sdata); 982 } 983 984 static void ieee80211_ibss_timer(unsigned long data) 985 { 986 struct ieee80211_sub_if_data *sdata = 987 (struct ieee80211_sub_if_data *) data; 988 989 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 990 } 991 992 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 993 { 994 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 995 996 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 997 (unsigned long) sdata); 998 INIT_LIST_HEAD(&ifibss->incomplete_stations); 999 spin_lock_init(&ifibss->incomplete_lock); 1000 } 1001 1002 /* scan finished notification */ 1003 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 1004 { 1005 struct ieee80211_sub_if_data *sdata; 1006 1007 mutex_lock(&local->iflist_mtx); 1008 list_for_each_entry(sdata, &local->interfaces, list) { 1009 if (!ieee80211_sdata_running(sdata)) 1010 continue; 1011 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 1012 continue; 1013 sdata->u.ibss.last_scan_completed = jiffies; 1014 ieee80211_queue_work(&local->hw, &sdata->work); 1015 } 1016 mutex_unlock(&local->iflist_mtx); 1017 } 1018 1019 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 1020 struct cfg80211_ibss_params *params) 1021 { 1022 u32 changed = 0; 1023 1024 if (params->bssid) { 1025 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 1026 sdata->u.ibss.fixed_bssid = true; 1027 } else 1028 sdata->u.ibss.fixed_bssid = false; 1029 1030 sdata->u.ibss.privacy = params->privacy; 1031 sdata->u.ibss.control_port = params->control_port; 1032 sdata->u.ibss.basic_rates = params->basic_rates; 1033 memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate, 1034 sizeof(params->mcast_rate)); 1035 1036 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 1037 1038 sdata->u.ibss.chandef = params->chandef; 1039 sdata->u.ibss.fixed_channel = params->channel_fixed; 1040 1041 if (params->ie) { 1042 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 1043 GFP_KERNEL); 1044 if (sdata->u.ibss.ie) 1045 sdata->u.ibss.ie_len = params->ie_len; 1046 } 1047 1048 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1049 sdata->u.ibss.ibss_join_req = jiffies; 1050 1051 memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len); 1052 sdata->u.ibss.ssid_len = params->ssid_len; 1053 1054 /* 1055 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is 1056 * reserved, but an HT STA shall protect HT transmissions as though 1057 * the HT Protection field were set to non-HT mixed mode. 1058 * 1059 * In an IBSS, the RIFS Mode field of the HT Operation element is 1060 * also reserved, but an HT STA shall operate as though this field 1061 * were set to 1. 1062 */ 1063 1064 sdata->vif.bss_conf.ht_operation_mode |= 1065 IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED 1066 | IEEE80211_HT_PARAM_RIFS_MODE; 1067 1068 changed |= BSS_CHANGED_HT; 1069 ieee80211_bss_info_change_notify(sdata, changed); 1070 1071 sdata->smps_mode = IEEE80211_SMPS_OFF; 1072 sdata->needed_rx_chains = sdata->local->rx_chains; 1073 1074 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1075 1076 return 0; 1077 } 1078 1079 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 1080 { 1081 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1082 struct ieee80211_local *local = sdata->local; 1083 struct cfg80211_bss *cbss; 1084 u16 capability; 1085 int active_ibss; 1086 struct sta_info *sta; 1087 struct beacon_data *presp; 1088 1089 active_ibss = ieee80211_sta_active_ibss(sdata); 1090 1091 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) { 1092 capability = WLAN_CAPABILITY_IBSS; 1093 1094 if (ifibss->privacy) 1095 capability |= WLAN_CAPABILITY_PRIVACY; 1096 1097 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->chandef.chan, 1098 ifibss->bssid, ifibss->ssid, 1099 ifibss->ssid_len, WLAN_CAPABILITY_IBSS | 1100 WLAN_CAPABILITY_PRIVACY, 1101 capability); 1102 1103 if (cbss) { 1104 cfg80211_unlink_bss(local->hw.wiphy, cbss); 1105 cfg80211_put_bss(local->hw.wiphy, cbss); 1106 } 1107 } 1108 1109 ifibss->state = IEEE80211_IBSS_MLME_SEARCH; 1110 memset(ifibss->bssid, 0, ETH_ALEN); 1111 ifibss->ssid_len = 0; 1112 1113 sta_info_flush(sdata); 1114 1115 spin_lock_bh(&ifibss->incomplete_lock); 1116 while (!list_empty(&ifibss->incomplete_stations)) { 1117 sta = list_first_entry(&ifibss->incomplete_stations, 1118 struct sta_info, list); 1119 list_del(&sta->list); 1120 spin_unlock_bh(&ifibss->incomplete_lock); 1121 1122 sta_info_free(local, sta); 1123 spin_lock_bh(&ifibss->incomplete_lock); 1124 } 1125 spin_unlock_bh(&ifibss->incomplete_lock); 1126 1127 netif_carrier_off(sdata->dev); 1128 1129 /* remove beacon */ 1130 kfree(sdata->u.ibss.ie); 1131 presp = rcu_dereference_protected(ifibss->presp, 1132 lockdep_is_held(&sdata->wdev.mtx)); 1133 RCU_INIT_POINTER(sdata->u.ibss.presp, NULL); 1134 sdata->vif.bss_conf.ibss_joined = false; 1135 sdata->vif.bss_conf.ibss_creator = false; 1136 sdata->vif.bss_conf.enable_beacon = false; 1137 sdata->vif.bss_conf.ssid_len = 0; 1138 clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state); 1139 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | 1140 BSS_CHANGED_IBSS); 1141 synchronize_rcu(); 1142 kfree(presp); 1143 1144 skb_queue_purge(&sdata->skb_queue); 1145 1146 del_timer_sync(&sdata->u.ibss.timer); 1147 1148 return 0; 1149 } 1150