ibss.c revision 75a423f493ffdf741acae27bf179cd560f7813d7
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 37static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 38 const u8 *bssid, const int beacon_int, 39 struct cfg80211_chan_def *req_chandef, 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 ieee80211_channel *chan; 55 struct beacon_data *presp; 56 int frame_len; 57 58 sdata_assert_lock(sdata); 59 60 /* Reset own TSF to allow time synchronization work. */ 61 drv_reset_tsf(local, sdata); 62 63 if (!ether_addr_equal(ifibss->bssid, bssid)) 64 sta_info_flush(sdata); 65 66 /* if merging, indicate to driver that we leave the old IBSS */ 67 if (sdata->vif.bss_conf.ibss_joined) { 68 sdata->vif.bss_conf.ibss_joined = false; 69 sdata->vif.bss_conf.ibss_creator = false; 70 sdata->vif.bss_conf.enable_beacon = false; 71 netif_carrier_off(sdata->dev); 72 ieee80211_bss_info_change_notify(sdata, 73 BSS_CHANGED_IBSS | 74 BSS_CHANGED_BEACON_ENABLED); 75 } 76 77 presp = rcu_dereference_protected(ifibss->presp, 78 lockdep_is_held(&sdata->wdev.mtx)); 79 rcu_assign_pointer(ifibss->presp, NULL); 80 if (presp) 81 kfree_rcu(presp, rcu_head); 82 83 sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0; 84 85 /* make a copy of the chandef, it could be modified below. */ 86 chandef = *req_chandef; 87 chan = chandef.chan; 88 if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) { 89 chandef.width = NL80211_CHAN_WIDTH_20; 90 chandef.center_freq1 = chan->center_freq; 91 } 92 93 ieee80211_vif_release_channel(sdata); 94 if (ieee80211_vif_use_channel(sdata, &chandef, 95 ifibss->fixed_channel ? 96 IEEE80211_CHANCTX_SHARED : 97 IEEE80211_CHANCTX_EXCLUSIVE)) { 98 sdata_info(sdata, "Failed to join IBSS, no channel context\n"); 99 return; 100 } 101 102 memcpy(ifibss->bssid, bssid, ETH_ALEN); 103 104 sband = local->hw.wiphy->bands[chan->band]; 105 106 /* Build IBSS probe response */ 107 frame_len = sizeof(struct ieee80211_hdr_3addr) + 108 12 /* struct ieee80211_mgmt.u.beacon */ + 109 2 + IEEE80211_MAX_SSID_LEN /* max SSID */ + 110 2 + 8 /* max Supported Rates */ + 111 3 /* max DS params */ + 112 4 /* IBSS params */ + 113 2 + (IEEE80211_MAX_SUPP_RATES - 8) + 114 2 + sizeof(struct ieee80211_ht_cap) + 115 2 + sizeof(struct ieee80211_ht_operation) + 116 ifibss->ie_len; 117 presp = kzalloc(sizeof(*presp) + frame_len, GFP_KERNEL); 118 if (!presp) 119 return; 120 121 presp->head = (void *)(presp + 1); 122 123 mgmt = (void *) presp->head; 124 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT | 125 IEEE80211_STYPE_PROBE_RESP); 126 eth_broadcast_addr(mgmt->da); 127 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN); 128 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN); 129 mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int); 130 mgmt->u.beacon.timestamp = cpu_to_le64(tsf); 131 mgmt->u.beacon.capab_info = cpu_to_le16(capability); 132 133 pos = (u8 *)mgmt + offsetof(struct ieee80211_mgmt, u.beacon.variable); 134 135 *pos++ = WLAN_EID_SSID; 136 *pos++ = ifibss->ssid_len; 137 memcpy(pos, ifibss->ssid, ifibss->ssid_len); 138 pos += ifibss->ssid_len; 139 140 rates = min_t(int, 8, sband->n_bitrates); 141 *pos++ = WLAN_EID_SUPP_RATES; 142 *pos++ = rates; 143 for (i = 0; i < rates; i++) { 144 int rate = sband->bitrates[i].bitrate; 145 u8 basic = 0; 146 if (basic_rates & BIT(i)) 147 basic = 0x80; 148 *pos++ = basic | (u8) (rate / 5); 149 } 150 151 if (sband->band == IEEE80211_BAND_2GHZ) { 152 *pos++ = WLAN_EID_DS_PARAMS; 153 *pos++ = 1; 154 *pos++ = ieee80211_frequency_to_channel(chan->center_freq); 155 } 156 157 *pos++ = WLAN_EID_IBSS_PARAMS; 158 *pos++ = 2; 159 /* FIX: set ATIM window based on scan results */ 160 *pos++ = 0; 161 *pos++ = 0; 162 163 if (sband->n_bitrates > 8) { 164 *pos++ = WLAN_EID_EXT_SUPP_RATES; 165 *pos++ = sband->n_bitrates - 8; 166 for (i = 8; i < sband->n_bitrates; i++) { 167 int rate = sband->bitrates[i].bitrate; 168 u8 basic = 0; 169 if (basic_rates & BIT(i)) 170 basic = 0x80; 171 *pos++ = basic | (u8) (rate / 5); 172 } 173 } 174 175 if (ifibss->ie_len) { 176 memcpy(pos, ifibss->ie, ifibss->ie_len); 177 pos += ifibss->ie_len; 178 } 179 180 /* add HT capability and information IEs */ 181 if (chandef.width != NL80211_CHAN_WIDTH_20_NOHT && 182 chandef.width != NL80211_CHAN_WIDTH_5 && 183 chandef.width != NL80211_CHAN_WIDTH_10 && 184 sband->ht_cap.ht_supported) { 185 pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap, 186 sband->ht_cap.cap); 187 /* 188 * Note: According to 802.11n-2009 9.13.3.1, HT Protection 189 * field and RIFS Mode are reserved in IBSS mode, therefore 190 * keep them at 0 191 */ 192 pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap, 193 &chandef, 0); 194 } 195 196 if (local->hw.queues >= IEEE80211_NUM_ACS) { 197 *pos++ = WLAN_EID_VENDOR_SPECIFIC; 198 *pos++ = 7; /* len */ 199 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */ 200 *pos++ = 0x50; 201 *pos++ = 0xf2; 202 *pos++ = 2; /* WME */ 203 *pos++ = 0; /* WME info */ 204 *pos++ = 1; /* WME ver */ 205 *pos++ = 0; /* U-APSD no in use */ 206 } 207 208 presp->head_len = pos - presp->head; 209 if (WARN_ON(presp->head_len > frame_len)) 210 return; 211 212 rcu_assign_pointer(ifibss->presp, presp); 213 214 sdata->vif.bss_conf.enable_beacon = true; 215 sdata->vif.bss_conf.beacon_int = beacon_int; 216 sdata->vif.bss_conf.basic_rates = basic_rates; 217 sdata->vif.bss_conf.ssid_len = ifibss->ssid_len; 218 memcpy(sdata->vif.bss_conf.ssid, ifibss->ssid, ifibss->ssid_len); 219 bss_change = BSS_CHANGED_BEACON_INT; 220 bss_change |= ieee80211_reset_erp_info(sdata); 221 bss_change |= BSS_CHANGED_BSSID; 222 bss_change |= BSS_CHANGED_BEACON; 223 bss_change |= BSS_CHANGED_BEACON_ENABLED; 224 bss_change |= BSS_CHANGED_BASIC_RATES; 225 bss_change |= BSS_CHANGED_HT; 226 bss_change |= BSS_CHANGED_IBSS; 227 bss_change |= BSS_CHANGED_SSID; 228 229 /* 230 * In 5 GHz/802.11a, we can always use short slot time. 231 * (IEEE 802.11-2012 18.3.8.7) 232 * 233 * In 2.4GHz, we must always use long slots in IBSS for compatibility 234 * reasons. 235 * (IEEE 802.11-2012 19.4.5) 236 * 237 * HT follows these specifications (IEEE 802.11-2012 20.3.18) 238 */ 239 sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ; 240 bss_change |= BSS_CHANGED_ERP_SLOT; 241 242 sdata->vif.bss_conf.ibss_joined = true; 243 sdata->vif.bss_conf.ibss_creator = creator; 244 ieee80211_bss_info_change_notify(sdata, bss_change); 245 246 ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates); 247 248 ifibss->state = IEEE80211_IBSS_MLME_JOINED; 249 mod_timer(&ifibss->timer, 250 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 251 252 bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan, 253 mgmt, presp->head_len, 0, GFP_KERNEL); 254 cfg80211_put_bss(local->hw.wiphy, bss); 255 netif_carrier_on(sdata->dev); 256 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL); 257} 258 259static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 260 struct ieee80211_bss *bss) 261{ 262 struct cfg80211_bss *cbss = 263 container_of((void *)bss, struct cfg80211_bss, priv); 264 struct ieee80211_supported_band *sband; 265 struct cfg80211_chan_def chandef; 266 u32 basic_rates; 267 int i, j; 268 u16 beacon_int = cbss->beacon_interval; 269 const struct cfg80211_bss_ies *ies; 270 enum nl80211_channel_type chan_type; 271 u64 tsf; 272 273 sdata_assert_lock(sdata); 274 275 if (beacon_int < 10) 276 beacon_int = 10; 277 278 switch (sdata->u.ibss.chandef.width) { 279 case NL80211_CHAN_WIDTH_20_NOHT: 280 case NL80211_CHAN_WIDTH_20: 281 case NL80211_CHAN_WIDTH_40: 282 chan_type = cfg80211_get_chandef_type(&sdata->u.ibss.chandef); 283 cfg80211_chandef_create(&chandef, cbss->channel, chan_type); 284 break; 285 case NL80211_CHAN_WIDTH_5: 286 case NL80211_CHAN_WIDTH_10: 287 cfg80211_chandef_create(&chandef, cbss->channel, 288 NL80211_CHAN_WIDTH_20_NOHT); 289 chandef.width = sdata->u.ibss.chandef.width; 290 break; 291 default: 292 /* fall back to 20 MHz for unsupported modes */ 293 cfg80211_chandef_create(&chandef, cbss->channel, 294 NL80211_CHAN_WIDTH_20_NOHT); 295 break; 296 } 297 298 sband = sdata->local->hw.wiphy->bands[cbss->channel->band]; 299 300 basic_rates = 0; 301 302 for (i = 0; i < bss->supp_rates_len; i++) { 303 int rate = (bss->supp_rates[i] & 0x7f) * 5; 304 bool is_basic = !!(bss->supp_rates[i] & 0x80); 305 306 for (j = 0; j < sband->n_bitrates; j++) { 307 if (sband->bitrates[j].bitrate == rate) { 308 if (is_basic) 309 basic_rates |= BIT(j); 310 break; 311 } 312 } 313 } 314 315 rcu_read_lock(); 316 ies = rcu_dereference(cbss->ies); 317 tsf = ies->tsf; 318 rcu_read_unlock(); 319 320 __ieee80211_sta_join_ibss(sdata, cbss->bssid, 321 beacon_int, 322 &chandef, 323 basic_rates, 324 cbss->capability, 325 tsf, false); 326} 327 328static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta) 329 __acquires(RCU) 330{ 331 struct ieee80211_sub_if_data *sdata = sta->sdata; 332 u8 addr[ETH_ALEN]; 333 334 memcpy(addr, sta->sta.addr, ETH_ALEN); 335 336 ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr); 337 338 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH); 339 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC); 340 /* authorize the station only if the network is not RSN protected. If 341 * not wait for the userspace to authorize it */ 342 if (!sta->sdata->u.ibss.control_port) 343 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED); 344 345 rate_control_rate_init(sta); 346 347 /* If it fails, maybe we raced another insertion? */ 348 if (sta_info_insert_rcu(sta)) 349 return sta_info_get(sdata, addr); 350 return sta; 351} 352 353static struct sta_info * 354ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, const u8 *bssid, 355 const u8 *addr, u32 supp_rates) 356 __acquires(RCU) 357{ 358 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 359 struct ieee80211_local *local = sdata->local; 360 struct sta_info *sta; 361 struct ieee80211_chanctx_conf *chanctx_conf; 362 struct ieee80211_supported_band *sband; 363 int band; 364 365 /* 366 * XXX: Consider removing the least recently used entry and 367 * allow new one to be added. 368 */ 369 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 370 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 371 sdata->name, addr); 372 rcu_read_lock(); 373 return NULL; 374 } 375 376 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) { 377 rcu_read_lock(); 378 return NULL; 379 } 380 381 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) { 382 rcu_read_lock(); 383 return NULL; 384 } 385 386 rcu_read_lock(); 387 chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf); 388 if (WARN_ON_ONCE(!chanctx_conf)) 389 return NULL; 390 band = chanctx_conf->def.chan->band; 391 rcu_read_unlock(); 392 393 sta = sta_info_alloc(sdata, addr, GFP_KERNEL); 394 if (!sta) { 395 rcu_read_lock(); 396 return NULL; 397 } 398 399 sta->last_rx = jiffies; 400 401 /* make sure mandatory rates are always added */ 402 sband = local->hw.wiphy->bands[band]; 403 sta->sta.supp_rates[band] = supp_rates | 404 ieee80211_mandatory_rates(sband); 405 406 return ieee80211_ibss_finish_sta(sta); 407} 408 409static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata, 410 struct ieee80211_mgmt *mgmt, 411 size_t len) 412{ 413 u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code); 414 415 if (len < IEEE80211_DEAUTH_FRAME_LEN) 416 return; 417 418 ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n", 419 mgmt->sa, mgmt->da, mgmt->bssid, reason); 420 sta_info_destroy_addr(sdata, mgmt->sa); 421} 422 423static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, 424 struct ieee80211_mgmt *mgmt, 425 size_t len) 426{ 427 u16 auth_alg, auth_transaction; 428 429 sdata_assert_lock(sdata); 430 431 if (len < 24 + 6) 432 return; 433 434 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); 435 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); 436 437 ibss_dbg(sdata, 438 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n", 439 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction); 440 441 if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1) 442 return; 443 444 /* 445 * IEEE 802.11 standard does not require authentication in IBSS 446 * networks and most implementations do not seem to use it. 447 * However, try to reply to authentication attempts if someone 448 * has actually implemented this. 449 */ 450 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0, 451 mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0); 452} 453 454static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, 455 struct ieee80211_mgmt *mgmt, size_t len, 456 struct ieee80211_rx_status *rx_status, 457 struct ieee802_11_elems *elems) 458{ 459 struct ieee80211_local *local = sdata->local; 460 int freq; 461 struct cfg80211_bss *cbss; 462 struct ieee80211_bss *bss; 463 struct sta_info *sta; 464 struct ieee80211_channel *channel; 465 u64 beacon_timestamp, rx_timestamp; 466 u32 supp_rates = 0; 467 enum ieee80211_band band = rx_status->band; 468 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band]; 469 bool rates_updated = false; 470 471 if (elems->ds_params) 472 freq = ieee80211_channel_to_frequency(elems->ds_params[0], 473 band); 474 else 475 freq = rx_status->freq; 476 477 channel = ieee80211_get_channel(local->hw.wiphy, freq); 478 479 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED) 480 return; 481 482 if (sdata->vif.type == NL80211_IFTYPE_ADHOC && 483 ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) { 484 485 rcu_read_lock(); 486 sta = sta_info_get(sdata, mgmt->sa); 487 488 if (elems->supp_rates) { 489 supp_rates = ieee80211_sta_get_rates(local, elems, 490 band, NULL); 491 if (sta) { 492 u32 prev_rates; 493 494 prev_rates = sta->sta.supp_rates[band]; 495 /* make sure mandatory rates are always added */ 496 sta->sta.supp_rates[band] = supp_rates | 497 ieee80211_mandatory_rates(sband); 498 499 if (sta->sta.supp_rates[band] != prev_rates) { 500 ibss_dbg(sdata, 501 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n", 502 sta->sta.addr, prev_rates, 503 sta->sta.supp_rates[band]); 504 rates_updated = true; 505 } 506 } else { 507 rcu_read_unlock(); 508 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, 509 mgmt->sa, supp_rates); 510 } 511 } 512 513 if (sta && elems->wmm_info) 514 set_sta_flag(sta, WLAN_STA_WME); 515 516 if (sta && elems->ht_operation && elems->ht_cap_elem && 517 sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20_NOHT && 518 sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_5 && 519 sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_10) { 520 /* we both use HT */ 521 struct ieee80211_ht_cap htcap_ie; 522 struct cfg80211_chan_def chandef; 523 524 ieee80211_ht_oper_to_chandef(channel, 525 elems->ht_operation, 526 &chandef); 527 528 memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie)); 529 530 /* 531 * fall back to HT20 if we don't use or use 532 * the other extension channel 533 */ 534 if (chandef.center_freq1 != 535 sdata->u.ibss.chandef.center_freq1) 536 htcap_ie.cap_info &= 537 cpu_to_le16(~IEEE80211_HT_CAP_SUP_WIDTH_20_40); 538 539 rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap( 540 sdata, sband, &htcap_ie, sta); 541 } 542 543 if (sta && rates_updated) { 544 drv_sta_rc_update(local, sdata, &sta->sta, 545 IEEE80211_RC_SUPP_RATES_CHANGED); 546 rate_control_rate_init(sta); 547 } 548 549 rcu_read_unlock(); 550 } 551 552 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems, 553 channel); 554 if (!bss) 555 return; 556 557 cbss = container_of((void *)bss, struct cfg80211_bss, priv); 558 559 /* same for beacon and probe response */ 560 beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp); 561 562 /* check if we need to merge IBSS */ 563 564 /* we use a fixed BSSID */ 565 if (sdata->u.ibss.fixed_bssid) 566 goto put_bss; 567 568 /* not an IBSS */ 569 if (!(cbss->capability & WLAN_CAPABILITY_IBSS)) 570 goto put_bss; 571 572 /* different channel */ 573 if (sdata->u.ibss.fixed_channel && 574 sdata->u.ibss.chandef.chan != cbss->channel) 575 goto put_bss; 576 577 /* different SSID */ 578 if (elems->ssid_len != sdata->u.ibss.ssid_len || 579 memcmp(elems->ssid, sdata->u.ibss.ssid, 580 sdata->u.ibss.ssid_len)) 581 goto put_bss; 582 583 /* same BSSID */ 584 if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid)) 585 goto put_bss; 586 587 if (ieee80211_have_rx_timestamp(rx_status)) { 588 /* time when timestamp field was received */ 589 rx_timestamp = 590 ieee80211_calculate_rx_timestamp(local, rx_status, 591 len + FCS_LEN, 24); 592 } else { 593 /* 594 * second best option: get current TSF 595 * (will return -1 if not supported) 596 */ 597 rx_timestamp = drv_get_tsf(local, sdata); 598 } 599 600 ibss_dbg(sdata, 601 "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", 602 mgmt->sa, mgmt->bssid, 603 (unsigned long long)rx_timestamp, 604 (unsigned long long)beacon_timestamp, 605 (unsigned long long)(rx_timestamp - beacon_timestamp), 606 jiffies); 607 608 if (beacon_timestamp > rx_timestamp) { 609 ibss_dbg(sdata, 610 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n", 611 mgmt->bssid); 612 ieee80211_sta_join_ibss(sdata, bss); 613 supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL); 614 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 615 supp_rates); 616 rcu_read_unlock(); 617 } 618 619 put_bss: 620 ieee80211_rx_bss_put(local, bss); 621} 622 623void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata, 624 const u8 *bssid, const u8 *addr, 625 u32 supp_rates) 626{ 627 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 628 struct ieee80211_local *local = sdata->local; 629 struct sta_info *sta; 630 struct ieee80211_chanctx_conf *chanctx_conf; 631 struct ieee80211_supported_band *sband; 632 int band; 633 634 /* 635 * XXX: Consider removing the least recently used entry and 636 * allow new one to be added. 637 */ 638 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) { 639 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n", 640 sdata->name, addr); 641 return; 642 } 643 644 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) 645 return; 646 647 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) 648 return; 649 650 rcu_read_lock(); 651 chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf); 652 if (WARN_ON_ONCE(!chanctx_conf)) { 653 rcu_read_unlock(); 654 return; 655 } 656 band = chanctx_conf->def.chan->band; 657 rcu_read_unlock(); 658 659 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC); 660 if (!sta) 661 return; 662 663 sta->last_rx = jiffies; 664 665 /* make sure mandatory rates are always added */ 666 sband = local->hw.wiphy->bands[band]; 667 sta->sta.supp_rates[band] = supp_rates | 668 ieee80211_mandatory_rates(sband); 669 670 spin_lock(&ifibss->incomplete_lock); 671 list_add(&sta->list, &ifibss->incomplete_stations); 672 spin_unlock(&ifibss->incomplete_lock); 673 ieee80211_queue_work(&local->hw, &sdata->work); 674} 675 676static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata) 677{ 678 struct ieee80211_local *local = sdata->local; 679 int active = 0; 680 struct sta_info *sta; 681 682 sdata_assert_lock(sdata); 683 684 rcu_read_lock(); 685 686 list_for_each_entry_rcu(sta, &local->sta_list, list) { 687 if (sta->sdata == sdata && 688 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL, 689 jiffies)) { 690 active++; 691 break; 692 } 693 } 694 695 rcu_read_unlock(); 696 697 return active; 698} 699 700/* 701 * This function is called with state == IEEE80211_IBSS_MLME_JOINED 702 */ 703 704static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata) 705{ 706 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 707 708 sdata_assert_lock(sdata); 709 710 mod_timer(&ifibss->timer, 711 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL)); 712 713 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT); 714 715 if (time_before(jiffies, ifibss->last_scan_completed + 716 IEEE80211_IBSS_MERGE_INTERVAL)) 717 return; 718 719 if (ieee80211_sta_active_ibss(sdata)) 720 return; 721 722 if (ifibss->fixed_channel) 723 return; 724 725 sdata_info(sdata, 726 "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n"); 727 728 ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len, 729 NULL); 730} 731 732static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata) 733{ 734 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 735 u8 bssid[ETH_ALEN]; 736 u16 capability; 737 int i; 738 739 sdata_assert_lock(sdata); 740 741 if (ifibss->fixed_bssid) { 742 memcpy(bssid, ifibss->bssid, ETH_ALEN); 743 } else { 744 /* Generate random, not broadcast, locally administered BSSID. Mix in 745 * own MAC address to make sure that devices that do not have proper 746 * random number generator get different BSSID. */ 747 get_random_bytes(bssid, ETH_ALEN); 748 for (i = 0; i < ETH_ALEN; i++) 749 bssid[i] ^= sdata->vif.addr[i]; 750 bssid[0] &= ~0x01; 751 bssid[0] |= 0x02; 752 } 753 754 sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid); 755 756 capability = WLAN_CAPABILITY_IBSS; 757 758 if (ifibss->privacy) 759 capability |= WLAN_CAPABILITY_PRIVACY; 760 else 761 sdata->drop_unencrypted = 0; 762 763 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int, 764 &ifibss->chandef, ifibss->basic_rates, 765 capability, 0, true); 766} 767 768/* 769 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH 770 */ 771 772static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata) 773{ 774 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 775 struct ieee80211_local *local = sdata->local; 776 struct cfg80211_bss *cbss; 777 struct ieee80211_channel *chan = NULL; 778 const u8 *bssid = NULL; 779 int active_ibss; 780 u16 capability; 781 782 sdata_assert_lock(sdata); 783 784 active_ibss = ieee80211_sta_active_ibss(sdata); 785 ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss); 786 787 if (active_ibss) 788 return; 789 790 capability = WLAN_CAPABILITY_IBSS; 791 if (ifibss->privacy) 792 capability |= WLAN_CAPABILITY_PRIVACY; 793 if (ifibss->fixed_bssid) 794 bssid = ifibss->bssid; 795 if (ifibss->fixed_channel) 796 chan = ifibss->chandef.chan; 797 if (!is_zero_ether_addr(ifibss->bssid)) 798 bssid = ifibss->bssid; 799 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid, 800 ifibss->ssid, ifibss->ssid_len, 801 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY, 802 capability); 803 804 if (cbss) { 805 struct ieee80211_bss *bss; 806 807 bss = (void *)cbss->priv; 808 ibss_dbg(sdata, 809 "sta_find_ibss: selected %pM current %pM\n", 810 cbss->bssid, ifibss->bssid); 811 sdata_info(sdata, 812 "Selected IBSS BSSID %pM based on configured SSID\n", 813 cbss->bssid); 814 815 ieee80211_sta_join_ibss(sdata, bss); 816 ieee80211_rx_bss_put(local, bss); 817 return; 818 } 819 820 ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n"); 821 822 /* Selected IBSS not found in current scan results - try to scan */ 823 if (time_after(jiffies, ifibss->last_scan_completed + 824 IEEE80211_SCAN_INTERVAL)) { 825 sdata_info(sdata, "Trigger new scan to find an IBSS to join\n"); 826 827 ieee80211_request_ibss_scan(sdata, ifibss->ssid, 828 ifibss->ssid_len, chan); 829 } else { 830 int interval = IEEE80211_SCAN_INTERVAL; 831 832 if (time_after(jiffies, ifibss->ibss_join_req + 833 IEEE80211_IBSS_JOIN_TIMEOUT)) 834 ieee80211_sta_create_ibss(sdata); 835 836 mod_timer(&ifibss->timer, 837 round_jiffies(jiffies + interval)); 838 } 839} 840 841static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, 842 struct sk_buff *req) 843{ 844 struct ieee80211_mgmt *mgmt = (void *)req->data; 845 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 846 struct ieee80211_local *local = sdata->local; 847 int tx_last_beacon, len = req->len; 848 struct sk_buff *skb; 849 struct beacon_data *presp; 850 u8 *pos, *end; 851 852 sdata_assert_lock(sdata); 853 854 presp = rcu_dereference_protected(ifibss->presp, 855 lockdep_is_held(&sdata->wdev.mtx)); 856 857 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED || 858 len < 24 + 2 || !presp) 859 return; 860 861 tx_last_beacon = drv_tx_last_beacon(local); 862 863 ibss_dbg(sdata, 864 "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n", 865 mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon); 866 867 if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da)) 868 return; 869 870 if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) && 871 !is_broadcast_ether_addr(mgmt->bssid)) 872 return; 873 874 end = ((u8 *) mgmt) + len; 875 pos = mgmt->u.probe_req.variable; 876 if (pos[0] != WLAN_EID_SSID || 877 pos + 2 + pos[1] > end) { 878 ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n", 879 mgmt->sa); 880 return; 881 } 882 if (pos[1] != 0 && 883 (pos[1] != ifibss->ssid_len || 884 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) { 885 /* Ignore ProbeReq for foreign SSID */ 886 return; 887 } 888 889 /* Reply with ProbeResp */ 890 skb = dev_alloc_skb(local->tx_headroom + presp->head_len); 891 if (!skb) 892 return; 893 894 skb_reserve(skb, local->tx_headroom); 895 memcpy(skb_put(skb, presp->head_len), presp->head, presp->head_len); 896 897 memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN); 898 ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa); 899 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT; 900 ieee80211_tx_skb(sdata, skb); 901} 902 903static 904void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata, 905 struct ieee80211_mgmt *mgmt, size_t len, 906 struct ieee80211_rx_status *rx_status) 907{ 908 size_t baselen; 909 struct ieee802_11_elems elems; 910 911 BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) != 912 offsetof(typeof(mgmt->u.beacon), variable)); 913 914 /* 915 * either beacon or probe_resp but the variable field is at the 916 * same offset 917 */ 918 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt; 919 if (baselen > len) 920 return; 921 922 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen, 923 false, &elems); 924 925 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems); 926} 927 928void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, 929 struct sk_buff *skb) 930{ 931 struct ieee80211_rx_status *rx_status; 932 struct ieee80211_mgmt *mgmt; 933 u16 fc; 934 935 rx_status = IEEE80211_SKB_RXCB(skb); 936 mgmt = (struct ieee80211_mgmt *) skb->data; 937 fc = le16_to_cpu(mgmt->frame_control); 938 939 sdata_lock(sdata); 940 941 if (!sdata->u.ibss.ssid_len) 942 goto mgmt_out; /* not ready to merge yet */ 943 944 switch (fc & IEEE80211_FCTL_STYPE) { 945 case IEEE80211_STYPE_PROBE_REQ: 946 ieee80211_rx_mgmt_probe_req(sdata, skb); 947 break; 948 case IEEE80211_STYPE_PROBE_RESP: 949 case IEEE80211_STYPE_BEACON: 950 ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len, 951 rx_status); 952 break; 953 case IEEE80211_STYPE_AUTH: 954 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len); 955 break; 956 case IEEE80211_STYPE_DEAUTH: 957 ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len); 958 break; 959 } 960 961 mgmt_out: 962 sdata_unlock(sdata); 963} 964 965void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata) 966{ 967 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 968 struct sta_info *sta; 969 970 sdata_lock(sdata); 971 972 /* 973 * Work could be scheduled after scan or similar 974 * when we aren't even joined (or trying) with a 975 * network. 976 */ 977 if (!ifibss->ssid_len) 978 goto out; 979 980 spin_lock_bh(&ifibss->incomplete_lock); 981 while (!list_empty(&ifibss->incomplete_stations)) { 982 sta = list_first_entry(&ifibss->incomplete_stations, 983 struct sta_info, list); 984 list_del(&sta->list); 985 spin_unlock_bh(&ifibss->incomplete_lock); 986 987 ieee80211_ibss_finish_sta(sta); 988 rcu_read_unlock(); 989 spin_lock_bh(&ifibss->incomplete_lock); 990 } 991 spin_unlock_bh(&ifibss->incomplete_lock); 992 993 switch (ifibss->state) { 994 case IEEE80211_IBSS_MLME_SEARCH: 995 ieee80211_sta_find_ibss(sdata); 996 break; 997 case IEEE80211_IBSS_MLME_JOINED: 998 ieee80211_sta_merge_ibss(sdata); 999 break; 1000 default: 1001 WARN_ON(1); 1002 break; 1003 } 1004 1005 out: 1006 sdata_unlock(sdata); 1007} 1008 1009static void ieee80211_ibss_timer(unsigned long data) 1010{ 1011 struct ieee80211_sub_if_data *sdata = 1012 (struct ieee80211_sub_if_data *) data; 1013 1014 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1015} 1016 1017void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata) 1018{ 1019 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1020 1021 setup_timer(&ifibss->timer, ieee80211_ibss_timer, 1022 (unsigned long) sdata); 1023 INIT_LIST_HEAD(&ifibss->incomplete_stations); 1024 spin_lock_init(&ifibss->incomplete_lock); 1025} 1026 1027/* scan finished notification */ 1028void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local) 1029{ 1030 struct ieee80211_sub_if_data *sdata; 1031 1032 mutex_lock(&local->iflist_mtx); 1033 list_for_each_entry(sdata, &local->interfaces, list) { 1034 if (!ieee80211_sdata_running(sdata)) 1035 continue; 1036 if (sdata->vif.type != NL80211_IFTYPE_ADHOC) 1037 continue; 1038 sdata->u.ibss.last_scan_completed = jiffies; 1039 ieee80211_queue_work(&local->hw, &sdata->work); 1040 } 1041 mutex_unlock(&local->iflist_mtx); 1042} 1043 1044int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 1045 struct cfg80211_ibss_params *params) 1046{ 1047 u32 changed = 0; 1048 1049 if (params->bssid) { 1050 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN); 1051 sdata->u.ibss.fixed_bssid = true; 1052 } else 1053 sdata->u.ibss.fixed_bssid = false; 1054 1055 sdata->u.ibss.privacy = params->privacy; 1056 sdata->u.ibss.control_port = params->control_port; 1057 sdata->u.ibss.basic_rates = params->basic_rates; 1058 memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate, 1059 sizeof(params->mcast_rate)); 1060 1061 sdata->vif.bss_conf.beacon_int = params->beacon_interval; 1062 1063 sdata->u.ibss.chandef = params->chandef; 1064 sdata->u.ibss.fixed_channel = params->channel_fixed; 1065 1066 if (params->ie) { 1067 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len, 1068 GFP_KERNEL); 1069 if (sdata->u.ibss.ie) 1070 sdata->u.ibss.ie_len = params->ie_len; 1071 } 1072 1073 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH; 1074 sdata->u.ibss.ibss_join_req = jiffies; 1075 1076 memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len); 1077 sdata->u.ibss.ssid_len = params->ssid_len; 1078 1079 /* 1080 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is 1081 * reserved, but an HT STA shall protect HT transmissions as though 1082 * the HT Protection field were set to non-HT mixed mode. 1083 * 1084 * In an IBSS, the RIFS Mode field of the HT Operation element is 1085 * also reserved, but an HT STA shall operate as though this field 1086 * were set to 1. 1087 */ 1088 1089 sdata->vif.bss_conf.ht_operation_mode |= 1090 IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED 1091 | IEEE80211_HT_PARAM_RIFS_MODE; 1092 1093 changed |= BSS_CHANGED_HT; 1094 ieee80211_bss_info_change_notify(sdata, changed); 1095 1096 sdata->smps_mode = IEEE80211_SMPS_OFF; 1097 sdata->needed_rx_chains = sdata->local->rx_chains; 1098 1099 ieee80211_queue_work(&sdata->local->hw, &sdata->work); 1100 1101 return 0; 1102} 1103 1104int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata) 1105{ 1106 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss; 1107 struct ieee80211_local *local = sdata->local; 1108 struct cfg80211_bss *cbss; 1109 u16 capability; 1110 int active_ibss; 1111 struct sta_info *sta; 1112 struct beacon_data *presp; 1113 1114 active_ibss = ieee80211_sta_active_ibss(sdata); 1115 1116 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) { 1117 capability = WLAN_CAPABILITY_IBSS; 1118 1119 if (ifibss->privacy) 1120 capability |= WLAN_CAPABILITY_PRIVACY; 1121 1122 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->chandef.chan, 1123 ifibss->bssid, ifibss->ssid, 1124 ifibss->ssid_len, WLAN_CAPABILITY_IBSS | 1125 WLAN_CAPABILITY_PRIVACY, 1126 capability); 1127 1128 if (cbss) { 1129 cfg80211_unlink_bss(local->hw.wiphy, cbss); 1130 cfg80211_put_bss(local->hw.wiphy, cbss); 1131 } 1132 } 1133 1134 ifibss->state = IEEE80211_IBSS_MLME_SEARCH; 1135 memset(ifibss->bssid, 0, ETH_ALEN); 1136 ifibss->ssid_len = 0; 1137 1138 sta_info_flush(sdata); 1139 1140 spin_lock_bh(&ifibss->incomplete_lock); 1141 while (!list_empty(&ifibss->incomplete_stations)) { 1142 sta = list_first_entry(&ifibss->incomplete_stations, 1143 struct sta_info, list); 1144 list_del(&sta->list); 1145 spin_unlock_bh(&ifibss->incomplete_lock); 1146 1147 sta_info_free(local, sta); 1148 spin_lock_bh(&ifibss->incomplete_lock); 1149 } 1150 spin_unlock_bh(&ifibss->incomplete_lock); 1151 1152 netif_carrier_off(sdata->dev); 1153 1154 /* remove beacon */ 1155 kfree(sdata->u.ibss.ie); 1156 presp = rcu_dereference_protected(ifibss->presp, 1157 lockdep_is_held(&sdata->wdev.mtx)); 1158 RCU_INIT_POINTER(sdata->u.ibss.presp, NULL); 1159 sdata->vif.bss_conf.ibss_joined = false; 1160 sdata->vif.bss_conf.ibss_creator = false; 1161 sdata->vif.bss_conf.enable_beacon = false; 1162 sdata->vif.bss_conf.ssid_len = 0; 1163 clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state); 1164 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED | 1165 BSS_CHANGED_IBSS); 1166 ieee80211_vif_release_channel(sdata); 1167 synchronize_rcu(); 1168 kfree(presp); 1169 1170 skb_queue_purge(&sdata->skb_queue); 1171 1172 del_timer_sync(&sdata->u.ibss.timer); 1173 1174 return 0; 1175} 1176