wpa_supplicant/scan.c

   1 /*
   2  * WPA Supplicant - Scanning
   3  * Copyright (c) 2003-2012, Jouni Malinen <j@w1.fi>
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "utils/includes.h"
  10
  11 #include "utils/common.h"
  12 #include "utils/eloop.h"
  13 #include "common/ieee802_11_defs.h"
  14 #include "common/wpa_ctrl.h"
  15 #include "config.h"
  16 #include "wpa_supplicant_i.h"
  17 #include "driver_i.h"
  18 #include "wps_supplicant.h"
  19 #include "p2p_supplicant.h"
  20 #include "p2p/p2p.h"
  21 #include "hs20_supplicant.h"
  22 #include "notify.h"
  23 #include "bss.h"
  24 #include "gas_query.h"
  25 #include "scan.h"
  26
  27
  28 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
  29 {
  30         struct wpa_ssid *ssid;
  31         union wpa_event_data data;
  32
  33         ssid = wpa_supplicant_get_ssid(wpa_s);
  34         if (ssid == NULL)
  35                 return;
  36
  37         if (wpa_s->current_ssid == NULL) {
  38                 wpa_s->current_ssid = ssid;
  39                 if (wpa_s->current_ssid != NULL)
  40                         wpas_notify_network_changed(wpa_s);
  41         }
  42         wpa_supplicant_initiate_eapol(wpa_s);
  43         wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
  44                 "network - generating associated event");
  45         os_memset(&data, 0, sizeof(data));
  46         wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
  47 }
  48
  49
  50 #ifdef CONFIG_WPS
  51 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
  52                            enum wps_request_type *req_type)
  53 {
  54         struct wpa_ssid *ssid;
  55         int wps = 0;
  56
  57         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
  58                 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
  59                         continue;
  60
  61                 wps = 1;
  62                 *req_type = wpas_wps_get_req_type(ssid);
  63                 if (!ssid->eap.phase1)
  64                         continue;
  65
  66                 if (os_strstr(ssid->eap.phase1, "pbc=1"))
  67                         return 2;
  68         }
  69
  70 #ifdef CONFIG_P2P
  71         if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p &&
  72             !wpa_s->conf->p2p_disabled) {
  73                 wpa_s->wps->dev.p2p = 1;
  74                 if (!wps) {
  75                         wps = 1;
  76                         *req_type = WPS_REQ_ENROLLEE_INFO;
  77                 }
  78         }
  79 #endif /* CONFIG_P2P */
  80
  81         return wps;
  82 }
  83 #endif /* CONFIG_WPS */
  84
  85
  86 /**
  87  * wpa_supplicant_enabled_networks - Check whether there are enabled networks
  88  * @wpa_s: Pointer to wpa_supplicant data
  89  * Returns: 0 if no networks are enabled, >0 if networks are enabled
  90  *
  91  * This function is used to figure out whether any networks (or Interworking
  92  * with enabled credentials and auto_interworking) are present in the current
  93  * configuration.
  94  */
  95 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
  96 {
  97         struct wpa_ssid *ssid = wpa_s->conf->ssid;
  98         int count = 0, disabled = 0;
  99         while (ssid) {
 100                 if (!wpas_network_disabled(wpa_s, ssid))
 101                         count++;
 102                 else
 103                         disabled++;
 104                 ssid = ssid->next;
 105         }
 106         if (wpa_s->conf->cred && wpa_s->conf->interworking &&
 107             wpa_s->conf->auto_interworking)
 108                 count++;
 109         if (count == 0 && disabled > 0) {
 110                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks (%d disabled "
 111                         "networks)", disabled);
 112         }
 113         return count;
 114 }
 115
 116
 117 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
 118                                      struct wpa_ssid *ssid)
 119 {
 120         while (ssid) {
 121                 if (!wpas_network_disabled(wpa_s, ssid))
 122                         break;
 123                 ssid = ssid->next;
 124         }
 125
 126         /* ap_scan=2 mode - try to associate with each SSID. */
 127         if (ssid == NULL) {
 128                 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
 129                         "end of scan list - go back to beginning");
 130                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 131                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 132                 return;
 133         }
 134         if (ssid->next) {
 135                 /* Continue from the next SSID on the next attempt. */
 136                 wpa_s->prev_scan_ssid = ssid;
 137         } else {
 138                 /* Start from the beginning of the SSID list. */
 139                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 140         }
 141         wpa_supplicant_associate(wpa_s, NULL, ssid);
 142 }
 143
 144
 145 /**
 146  * wpa_supplicant_trigger_scan - Request driver to start a scan
 147  * @wpa_s: Pointer to wpa_supplicant data
 148  * @params: Scan parameters
 149  * Returns: 0 on success, -1 on failure
 150  */
 151 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 152                                 struct wpa_driver_scan_params *params)
 153 {
 154         int ret;
 155
 156         wpa_supplicant_notify_scanning(wpa_s, 1);
 157
 158         ret = wpa_drv_scan(wpa_s, params);
 159         if (ret) {
 160                 wpa_supplicant_notify_scanning(wpa_s, 0);
 161                 wpas_notify_scan_done(wpa_s, 0);
 162         } else {
 163                 os_get_reltime(&wpa_s->scan_trigger_time);
 164                 wpa_s->scan_runs++;
 165                 wpa_s->normal_scans++;
 166                 wpa_s->own_scan_requested = 1;
 167         }
 168
 169         return ret;
 170 }
 171
 172
 173 static void
 174 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 175 {
 176         struct wpa_supplicant *wpa_s = eloop_ctx;
 177
 178         wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
 179
 180         if (wpa_supplicant_req_sched_scan(wpa_s))
 181                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 182 }
 183
 184
 185 static void
 186 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 187 {
 188         struct wpa_supplicant *wpa_s = eloop_ctx;
 189
 190         wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
 191
 192         wpa_s->sched_scan_timed_out = 1;
 193         wpa_supplicant_cancel_sched_scan(wpa_s);
 194 }
 195
 196
 197 int wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
 198                                     struct wpa_driver_scan_params *params,
 199                                     int interval)
 200 {
 201         int ret;
 202
 203         wpa_supplicant_notify_scanning(wpa_s, 1);
 204         ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
 205         if (ret)
 206                 wpa_supplicant_notify_scanning(wpa_s, 0);
 207         else
 208                 wpa_s->sched_scanning = 1;
 209
 210         return ret;
 211 }
 212
 213
 214 int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
 215 {
 216         int ret;
 217
 218         ret = wpa_drv_stop_sched_scan(wpa_s);
 219         if (ret) {
 220                 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
 221                 /* TODO: what to do if stopping fails? */
 222                 return -1;
 223         }
 224
 225         return ret;
 226 }
 227
 228
 229 static struct wpa_driver_scan_filter *
 230 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 231 {
 232         struct wpa_driver_scan_filter *ssids;
 233         struct wpa_ssid *ssid;
 234         size_t count;
 235
 236         *num_ssids = 0;
 237         if (!conf->filter_ssids)
 238                 return NULL;
 239
 240         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 241                 if (ssid->ssid && ssid->ssid_len)
 242                         count++;
 243         }
 244         if (count == 0)
 245                 return NULL;
 246         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 247         if (ssids == NULL)
 248                 return NULL;
 249
 250         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 251                 if (!ssid->ssid || !ssid->ssid_len)
 252                         continue;
 253                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 254                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 255                 (*num_ssids)++;
 256         }
 257
 258         return ssids;
 259 }
 260
 261
 262 static void wpa_supplicant_optimize_freqs(
 263         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 264 {
 265 #ifdef CONFIG_P2P
 266         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 267             wpa_s->go_params) {
 268                 /* Optimize provisioning state scan based on GO information */
 269                 if (wpa_s->p2p_in_provisioning < 5 &&
 270                     wpa_s->go_params->freq > 0) {
 271                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 272                                 "preferred frequency %d MHz",
 273                                 wpa_s->go_params->freq);
 274                         params->freqs = os_zalloc(2 * sizeof(int));
 275                         if (params->freqs)
 276                                 params->freqs[0] = wpa_s->go_params->freq;
 277                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 278                            wpa_s->go_params->freq_list[0]) {
 279                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 280                                 "channels");
 281                         int_array_concat(&params->freqs,
 282                                          wpa_s->go_params->freq_list);
 283                         if (params->freqs)
 284                                 int_array_sort_unique(params->freqs);
 285                 }
 286                 wpa_s->p2p_in_provisioning++;
 287         }
 288 #endif /* CONFIG_P2P */
 289
 290 #ifdef CONFIG_WPS
 291         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 292                 /*
 293                  * Optimize post-provisioning scan based on channel used
 294                  * during provisioning.
 295                  */
 296                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 297                         "that was used during provisioning", wpa_s->wps_freq);
 298                 params->freqs = os_zalloc(2 * sizeof(int));
 299                 if (params->freqs)
 300                         params->freqs[0] = wpa_s->wps_freq;
 301                 wpa_s->after_wps--;
 302         } else if (wpa_s->after_wps)
 303                 wpa_s->after_wps--;
 304
 305         if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
 306         {
 307                 /* Optimize provisioning scan based on already known channel */
 308                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
 309                         wpa_s->wps_freq);
 310                 params->freqs = os_zalloc(2 * sizeof(int));
 311                 if (params->freqs)
 312                         params->freqs[0] = wpa_s->wps_freq;
 313                 wpa_s->known_wps_freq = 0; /* only do this once */
 314         }
 315 #endif /* CONFIG_WPS */
 316 }
 317
 318
 319 #ifdef CONFIG_INTERWORKING
 320 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
 321                                            struct wpabuf *buf)
 322 {
 323         if (wpa_s->conf->interworking == 0)
 324                 return;
 325
 326         wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
 327         wpabuf_put_u8(buf, 4);
 328         wpabuf_put_u8(buf, 0x00);
 329         wpabuf_put_u8(buf, 0x00);
 330         wpabuf_put_u8(buf, 0x00);
 331         wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
 332
 333         wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
 334         wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
 335                       1 + ETH_ALEN);
 336         wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
 337         /* No Venue Info */
 338         if (!is_zero_ether_addr(wpa_s->conf->hessid))
 339                 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
 340 }
 341 #endif /* CONFIG_INTERWORKING */
 342
 343
 344 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
 345 {
 346         struct wpabuf *extra_ie = NULL;
 347 #ifdef CONFIG_WPS
 348         int wps = 0;
 349         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 350 #endif /* CONFIG_WPS */
 351
 352 #ifdef CONFIG_INTERWORKING
 353         if (wpa_s->conf->interworking &&
 354             wpabuf_resize(&extra_ie, 100) == 0)
 355                 wpas_add_interworking_elements(wpa_s, extra_ie);
 356 #endif /* CONFIG_INTERWORKING */
 357
 358 #ifdef CONFIG_WPS
 359         wps = wpas_wps_in_use(wpa_s, &req_type);
 360
 361         if (wps) {
 362                 struct wpabuf *wps_ie;
 363                 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
 364                                                 DEV_PW_DEFAULT,
 365                                                 &wpa_s->wps->dev,
 366                                                 wpa_s->wps->uuid, req_type,
 367                                                 0, NULL);
 368                 if (wps_ie) {
 369                         if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
 370                                 wpabuf_put_buf(extra_ie, wps_ie);
 371                         wpabuf_free(wps_ie);
 372                 }
 373         }
 374
 375 #ifdef CONFIG_P2P
 376         if (wps) {
 377                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 378                 if (wpabuf_resize(&extra_ie, ielen) == 0)
 379                         wpas_p2p_scan_ie(wpa_s, extra_ie);
 380         }
 381 #endif /* CONFIG_P2P */
 382
 383 #endif /* CONFIG_WPS */
 384
 385 #ifdef CONFIG_HS20
 386         if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 7) == 0)
 387                 wpas_hs20_add_indication(extra_ie);
 388 #endif /* CONFIG_HS20 */
 389
 390         return extra_ie;
 391 }
 392
 393
 394 #ifdef CONFIG_P2P
 395
 396 /*
 397  * Check whether there are any enabled networks or credentials that could be
 398  * used for a non-P2P connection.
 399  */
 400 static int non_p2p_network_enabled(struct wpa_supplicant *wpa_s)
 401 {
 402         struct wpa_ssid *ssid;
 403
 404         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 405                 if (wpas_network_disabled(wpa_s, ssid))
 406                         continue;
 407                 if (!ssid->p2p_group)
 408                         return 1;
 409         }
 410
 411         if (wpa_s->conf->cred && wpa_s->conf->interworking &&
 412             wpa_s->conf->auto_interworking)
 413                 return 1;
 414
 415         return 0;
 416 }
 417
 418 #endif /* CONFIG_P2P */
 419
 420
 421 static struct hostapd_hw_modes * get_mode(struct hostapd_hw_modes *modes,
 422                                           u16 num_modes,
 423                                           enum hostapd_hw_mode mode)
 424 {
 425         u16 i;
 426
 427         for (i = 0; i < num_modes; i++) {
 428                 if (modes[i].mode == mode)
 429                         return &modes[i];
 430         }
 431
 432         return NULL;
 433 }
 434
 435
 436 static void wpa_setband_scan_freqs_list(struct wpa_supplicant *wpa_s,
 437                                         enum hostapd_hw_mode band,
 438                                         struct wpa_driver_scan_params *params)
 439 {
 440         /* Include only supported channels for the specified band */
 441         struct hostapd_hw_modes *mode;
 442         int count, i;
 443
 444         mode = get_mode(wpa_s->hw.modes, wpa_s->hw.num_modes, band);
 445         if (mode == NULL) {
 446                 /* No channels supported in this band - use empty list */
 447                 params->freqs = os_zalloc(sizeof(int));
 448                 return;
 449         }
 450
 451         params->freqs = os_zalloc((mode->num_channels + 1) * sizeof(int));
 452         if (params->freqs == NULL)
 453                 return;
 454         for (count = 0, i = 0; i < mode->num_channels; i++) {
 455                 if (mode->channels[i].flag & HOSTAPD_CHAN_DISABLED)
 456                         continue;
 457                 params->freqs[count++] = mode->channels[i].freq;
 458         }
 459 }
 460
 461
 462 static void wpa_setband_scan_freqs(struct wpa_supplicant *wpa_s,
 463                                    struct wpa_driver_scan_params *params)
 464 {
 465         if (wpa_s->hw.modes == NULL)
 466                 return; /* unknown what channels the driver supports */
 467         if (params->freqs)
 468                 return; /* already using a limited channel set */
 469         if (wpa_s->setband == WPA_SETBAND_5G)
 470                 wpa_setband_scan_freqs_list(wpa_s, HOSTAPD_MODE_IEEE80211A,
 471                                             params);
 472         else if (wpa_s->setband == WPA_SETBAND_2G)
 473                 wpa_setband_scan_freqs_list(wpa_s, HOSTAPD_MODE_IEEE80211G,
 474                                             params);
 475 }
 476
 477
 478 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 479 {
 480         struct wpa_supplicant *wpa_s = eloop_ctx;
 481         struct wpa_ssid *ssid;
 482         int ret;
 483         struct wpabuf *extra_ie = NULL;
 484         struct wpa_driver_scan_params params;
 485         struct wpa_driver_scan_params *scan_params;
 486         size_t max_ssids;
 487         enum wpa_states prev_state;
 488
 489         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 490                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 491                 wpas_p2p_continue_after_scan(wpa_s);
 492                 return;
 493         }
 494
 495         if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) {
 496                 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
 497                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 498                 wpas_p2p_continue_after_scan(wpa_s);
 499                 return;
 500         }
 501
 502         if (wpa_s->scanning) {
 503                 /*
 504                  * If we are already in scanning state, we shall reschedule the
 505                  * the incoming scan request.
 506                  */
 507                 wpa_dbg(wpa_s, MSG_DEBUG, "Already scanning - Reschedule the incoming scan req");
 508                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 509                 return;
 510         }
 511
 512         if (wpa_s->external_scan_running) {
 513                 struct os_reltime now, diff;
 514                 os_get_reltime(&now);
 515                 os_reltime_sub(&now, &wpa_s->scan_start_time, &diff);
 516                 if (diff.sec < 30) {
 517                         wpa_dbg(wpa_s, MSG_DEBUG, "Externally triggered scan running - Reschedule the incoming scan req");
 518                         wpa_supplicant_req_scan(wpa_s, 1, 0);
 519                         return;
 520                 }
 521         }
 522
 523         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 524             wpa_s->scan_req == NORMAL_SCAN_REQ) {
 525                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 526                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 527                 wpas_p2p_continue_after_scan(wpa_s);
 528                 return;
 529         }
 530
 531         if (wpa_s->conf->ap_scan != 0 &&
 532             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 533                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 534                         "overriding ap_scan configuration");
 535                 wpa_s->conf->ap_scan = 0;
 536                 wpas_notify_ap_scan_changed(wpa_s);
 537         }
 538
 539         if (wpa_s->conf->ap_scan == 0) {
 540                 wpa_supplicant_gen_assoc_event(wpa_s);
 541                 return;
 542         }
 543
 544 #ifdef CONFIG_P2P
 545         if (wpas_p2p_in_progress(wpa_s) || wpas_wpa_is_in_progress(wpa_s, 0)) {
 546                 if (wpa_s->sta_scan_pending &&
 547                     wpas_p2p_in_progress(wpa_s) == 2 &&
 548                     wpa_s->global->p2p_cb_on_scan_complete) {
 549                         wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
 550                                 "mode scan during P2P search");
 551                 } else {
 552                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 553                                 "while P2P operation is in progress");
 554                         wpa_s->sta_scan_pending = 1;
 555                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 556                         return;
 557                 }
 558         }
 559 #endif /* CONFIG_P2P */
 560
 561 #ifdef CONFIG_GAS
 562         if (gas_query_in_progress(wpa_s->gas)) {
 563                 wpa_dbg(wpa_s, MSG_DEBUG, "Delay scan while GAS query is in progress");
 564                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 565                 return;
 566         }
 567 #endif /* CONFIG_GAS */
 568
 569         if (wpa_s->conf->ap_scan == 2)
 570                 max_ssids = 1;
 571         else {
 572                 max_ssids = wpa_s->max_scan_ssids;
 573                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 574                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 575         }
 576
 577         wpa_s->last_scan_req = wpa_s->scan_req;
 578         wpa_s->scan_req = NORMAL_SCAN_REQ;
 579
 580         os_memset(&params, 0, sizeof(params));
 581
 582         prev_state = wpa_s->wpa_state;
 583         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 584             wpa_s->wpa_state == WPA_INACTIVE)
 585                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 586
 587         /*
 588          * If autoscan has set its own scanning parameters
 589          */
 590         if (wpa_s->autoscan_params != NULL) {
 591                 scan_params = wpa_s->autoscan_params;
 592                 goto scan;
 593         }
 594
 595         if (wpa_s->last_scan_req != MANUAL_SCAN_REQ &&
 596             wpa_s->connect_without_scan) {
 597                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 598                         if (ssid == wpa_s->connect_without_scan)
 599                                 break;
 600                 }
 601                 wpa_s->connect_without_scan = NULL;
 602                 if (ssid) {
 603                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 604                                    "without scan step");
 605                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 606                         return;
 607                 }
 608         }
 609
 610 #ifdef CONFIG_P2P
 611         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 612             wpa_s->go_params) {
 613                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during P2P group formation (p2p_in_provisioning=%d show_group_started=%d)",
 614                            wpa_s->p2p_in_provisioning,
 615                            wpa_s->show_group_started);
 616                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 617                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 618                 params.num_ssids = 1;
 619                 goto ssid_list_set;
 620         }
 621 #endif /* CONFIG_P2P */
 622
 623         /* Find the starting point from which to continue scanning */
 624         ssid = wpa_s->conf->ssid;
 625         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 626                 while (ssid) {
 627                         if (ssid == wpa_s->prev_scan_ssid) {
 628                                 ssid = ssid->next;
 629                                 break;
 630                         }
 631                         ssid = ssid->next;
 632                 }
 633         }
 634
 635         if (wpa_s->last_scan_req != MANUAL_SCAN_REQ &&
 636             wpa_s->conf->ap_scan == 2) {
 637                 wpa_s->connect_without_scan = NULL;
 638                 wpa_s->prev_scan_wildcard = 0;
 639                 wpa_supplicant_assoc_try(wpa_s, ssid);
 640                 return;
 641         } else if (wpa_s->conf->ap_scan == 2) {
 642                 /*
 643                  * User-initiated scan request in ap_scan == 2; scan with
 644                  * wildcard SSID.
 645                  */
 646                 ssid = NULL;
 647         } else {
 648                 struct wpa_ssid *start = ssid, *tssid;
 649                 int freqs_set = 0;
 650                 if (ssid == NULL && max_ssids > 1)
 651                         ssid = wpa_s->conf->ssid;
 652                 while (ssid) {
 653                         if (!wpas_network_disabled(wpa_s, ssid) &&
 654                             ssid->scan_ssid) {
 655                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 656                                                   ssid->ssid, ssid->ssid_len);
 657                                 params.ssids[params.num_ssids].ssid =
 658                                         ssid->ssid;
 659                                 params.ssids[params.num_ssids].ssid_len =
 660                                         ssid->ssid_len;
 661                                 params.num_ssids++;
 662                                 if (params.num_ssids + 1 >= max_ssids)
 663                                         break;
 664                         }
 665                         ssid = ssid->next;
 666                         if (ssid == start)
 667                                 break;
 668                         if (ssid == NULL && max_ssids > 1 &&
 669                             start != wpa_s->conf->ssid)
 670                                 ssid = wpa_s->conf->ssid;
 671                 }
 672
 673                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 674                         if (wpas_network_disabled(wpa_s, tssid))
 675                                 continue;
 676                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 677                                 int_array_concat(&params.freqs,
 678                                                  tssid->scan_freq);
 679                         } else {
 680                                 os_free(params.freqs);
 681                                 params.freqs = NULL;
 682                         }
 683                         freqs_set = 1;
 684                 }
 685                 int_array_sort_unique(params.freqs);
 686         }
 687
 688         if (ssid && max_ssids == 1) {
 689                 /*
 690                  * If the driver is limited to 1 SSID at a time interleave
 691                  * wildcard SSID scans with specific SSID scans to avoid
 692                  * waiting a long time for a wildcard scan.
 693                  */
 694                 if (!wpa_s->prev_scan_wildcard) {
 695                         params.ssids[0].ssid = NULL;
 696                         params.ssids[0].ssid_len = 0;
 697                         wpa_s->prev_scan_wildcard = 1;
 698                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 699                                 "wildcard SSID (Interleave with specific)");
 700                 } else {
 701                         wpa_s->prev_scan_ssid = ssid;
 702                         wpa_s->prev_scan_wildcard = 0;
 703                         wpa_dbg(wpa_s, MSG_DEBUG,
 704                                 "Starting AP scan for specific SSID: %s",
 705                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 706                 }
 707         } else if (ssid) {
 708                 /* max_ssids > 1 */
 709
 710                 wpa_s->prev_scan_ssid = ssid;
 711                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 712                         "the scan request");
 713                 params.num_ssids++;
 714         } else if (wpa_s->last_scan_req == MANUAL_SCAN_REQ &&
 715                    wpa_s->manual_scan_passive && params.num_ssids == 0) {
 716                 wpa_dbg(wpa_s, MSG_DEBUG, "Use passive scan based on manual request");
 717         } else {
 718                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 719                 params.num_ssids++;
 720                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 721                         "SSID");
 722         }
 723 #ifdef CONFIG_P2P
 724 ssid_list_set:
 725 #endif /* CONFIG_P2P */
 726
 727         wpa_supplicant_optimize_freqs(wpa_s, &params);
 728         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 729
 730         if (wpa_s->last_scan_req == MANUAL_SCAN_REQ && params.freqs == NULL &&
 731             wpa_s->manual_scan_freqs) {
 732                 wpa_dbg(wpa_s, MSG_DEBUG, "Limit manual scan to specified channels");
 733                 params.freqs = wpa_s->manual_scan_freqs;
 734                 wpa_s->manual_scan_freqs = NULL;
 735         }
 736
 737         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 738                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 739                         "generated frequency list");
 740                 params.freqs = wpa_s->next_scan_freqs;
 741         } else
 742                 os_free(wpa_s->next_scan_freqs);
 743         wpa_s->next_scan_freqs = NULL;
 744         wpa_setband_scan_freqs(wpa_s, &params);
 745
 746         /* See if user specified frequencies. If so, scan only those. */
 747         if (wpa_s->conf->freq_list && !params.freqs) {
 748                 wpa_dbg(wpa_s, MSG_DEBUG,
 749                         "Optimize scan based on conf->freq_list");
 750                 int_array_concat(&params.freqs, wpa_s->conf->freq_list);
 751         }
 752
 753         /* Use current associated channel? */
 754         if (wpa_s->conf->scan_cur_freq && !params.freqs) {
 755                 unsigned int num = wpa_s->num_multichan_concurrent;
 756
 757                 params.freqs = os_calloc(num + 1, sizeof(int));
 758                 if (params.freqs) {
 759                         num = get_shared_radio_freqs(wpa_s, params.freqs, num);
 760                         if (num > 0) {
 761                                 wpa_dbg(wpa_s, MSG_DEBUG, "Scan only the "
 762                                         "current operating channels since "
 763                                         "scan_cur_freq is enabled");
 764                         } else {
 765                                 os_free(params.freqs);
 766                                 params.freqs = NULL;
 767                         }
 768                 }
 769         }
 770
 771         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 772                 wpa_s->conf, &params.num_filter_ssids);
 773         if (extra_ie) {
 774                 params.extra_ies = wpabuf_head(extra_ie);
 775                 params.extra_ies_len = wpabuf_len(extra_ie);
 776         }
 777
 778 #ifdef CONFIG_P2P
 779         if (wpa_s->p2p_in_provisioning ||
 780             (wpa_s->show_group_started && wpa_s->go_params)) {
 781                 /*
 782                  * The interface may not yet be in P2P mode, so we have to
 783                  * explicitly request P2P probe to disable CCK rates.
 784                  */
 785                 params.p2p_probe = 1;
 786         }
 787 #endif /* CONFIG_P2P */
 788
 789         scan_params = &params;
 790
 791 scan:
 792 #ifdef CONFIG_P2P
 793         /*
 794          * If the driver does not support multi-channel concurrency and a
 795          * virtual interface that shares the same radio with the wpa_s interface
 796          * is operating there may not be need to scan other channels apart from
 797          * the current operating channel on the other virtual interface. Filter
 798          * out other channels in case we are trying to find a connection for a
 799          * station interface when we are not configured to prefer station
 800          * connection and a concurrent operation is already in process.
 801          */
 802         if (wpa_s->scan_for_connection &&
 803             wpa_s->last_scan_req == NORMAL_SCAN_REQ &&
 804             !scan_params->freqs && !params.freqs &&
 805             wpas_is_p2p_prioritized(wpa_s) &&
 806             wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
 807             non_p2p_network_enabled(wpa_s)) {
 808                 unsigned int num = wpa_s->num_multichan_concurrent;
 809
 810                 params.freqs = os_calloc(num + 1, sizeof(int));
 811                 if (params.freqs) {
 812                         num = get_shared_radio_freqs(wpa_s, params.freqs, num);
 813                         if (num > 0 && num == wpa_s->num_multichan_concurrent) {
 814                                 wpa_dbg(wpa_s, MSG_DEBUG, "Scan only the current operating channels since all channels are already used");
 815                         } else {
 816                                 os_free(params.freqs);
 817                                 params.freqs = NULL;
 818                         }
 819                 }
 820         }
 821 #endif /* CONFIG_P2P */
 822
 823         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 824
 825         if (ret && wpa_s->last_scan_req == MANUAL_SCAN_REQ && params.freqs &&
 826             !wpa_s->manual_scan_freqs) {
 827                 /* Restore manual_scan_freqs for the next attempt */
 828                 wpa_s->manual_scan_freqs = params.freqs;
 829                 params.freqs = NULL;
 830         }
 831
 832         wpabuf_free(extra_ie);
 833         os_free(params.freqs);
 834         os_free(params.filter_ssids);
 835
 836         if (ret) {
 837                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 838                 if (prev_state != wpa_s->wpa_state)
 839                         wpa_supplicant_set_state(wpa_s, prev_state);
 840                 /* Restore scan_req since we will try to scan again */
 841                 wpa_s->scan_req = wpa_s->last_scan_req;
 842                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 843         } else {
 844                 wpa_s->scan_for_connection = 0;
 845         }
 846 }
 847
 848
 849 void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec)
 850 {
 851         struct os_reltime remaining, new_int;
 852         int cancelled;
 853
 854         cancelled = eloop_cancel_timeout_one(wpa_supplicant_scan, wpa_s, NULL,
 855                                              &remaining);
 856
 857         new_int.sec = sec;
 858         new_int.usec = 0;
 859         if (cancelled && os_reltime_before(&remaining, &new_int)) {
 860                 new_int.sec = remaining.sec;
 861                 new_int.usec = remaining.usec;
 862         }
 863
 864         if (cancelled) {
 865                 eloop_register_timeout(new_int.sec, new_int.usec,
 866                                        wpa_supplicant_scan, wpa_s, NULL);
 867         }
 868         wpa_s->scan_interval = sec;
 869 }
 870
 871
 872 /**
 873  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 874  * @wpa_s: Pointer to wpa_supplicant data
 875  * @sec: Number of seconds after which to scan
 876  * @usec: Number of microseconds after which to scan
 877  *
 878  * This function is used to schedule a scan for neighboring access points after
 879  * the specified time.
 880  */
 881 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 882 {
 883         if (eloop_deplete_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL))
 884         {
 885                 wpa_dbg(wpa_s, MSG_DEBUG, "Rescheduling scan request: %d sec %d usec",
 886                         sec, usec);
 887                 return;
 888         }
 889
 890         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 891                 sec, usec);
 892         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 893         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 894 }
 895
 896
 897 /**
 898  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 899  * @wpa_s: Pointer to wpa_supplicant data
 900  * @sec: Number of seconds after which to scan
 901  * @usec: Number of microseconds after which to scan
 902  * Returns: 0 on success or -1 otherwise
 903  *
 904  * This function is used to schedule periodic scans for neighboring
 905  * access points after the specified time.
 906  */
 907 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 908                                       int sec, int usec)
 909 {
 910         if (!wpa_s->sched_scan_supported)
 911                 return -1;
 912
 913         eloop_register_timeout(sec, usec,
 914                                wpa_supplicant_delayed_sched_scan_timeout,
 915                                wpa_s, NULL);
 916
 917         return 0;
 918 }
 919
 920
 921 /**
 922  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 923  * @wpa_s: Pointer to wpa_supplicant data
 924  * Returns: 0 is sched_scan was started or -1 otherwise
 925  *
 926  * This function is used to schedule periodic scans for neighboring
 927  * access points repeating the scan continuously.
 928  */
 929 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 930 {
 931         struct wpa_driver_scan_params params;
 932         struct wpa_driver_scan_params *scan_params;
 933         enum wpa_states prev_state;
 934         struct wpa_ssid *ssid = NULL;
 935         struct wpabuf *extra_ie = NULL;
 936         int ret;
 937         unsigned int max_sched_scan_ssids;
 938         int wildcard = 0;
 939         int need_ssids;
 940
 941         if (!wpa_s->sched_scan_supported)
 942                 return -1;
 943
 944         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 945                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 946         else
 947                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 948         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 949                 return -1;
 950
 951         if (wpa_s->sched_scanning) {
 952                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 953                 return 0;
 954         }
 955
 956         need_ssids = 0;
 957         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 958                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 959                         /* Use wildcard SSID to find this network */
 960                         wildcard = 1;
 961                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 962                            ssid->ssid_len)
 963                         need_ssids++;
 964
 965 #ifdef CONFIG_WPS
 966                 if (!wpas_network_disabled(wpa_s, ssid) &&
 967                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
 968                         /*
 969                          * Normal scan is more reliable and faster for WPS
 970                          * operations and since these are for short periods of
 971                          * time, the benefit of trying to use sched_scan would
 972                          * be limited.
 973                          */
 974                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 975                                 "sched_scan for WPS");
 976                         return -1;
 977                 }
 978 #endif /* CONFIG_WPS */
 979         }
 980         if (wildcard)
 981                 need_ssids++;
 982
 983         if (wpa_s->normal_scans < 3 &&
 984             (need_ssids <= wpa_s->max_scan_ssids ||
 985              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
 986                 /*
 987                  * When normal scan can speed up operations, use that for the
 988                  * first operations before starting the sched_scan to allow
 989                  * user space sleep more. We do this only if the normal scan
 990                  * has functionality that is suitable for this or if the
 991                  * sched_scan does not have better support for multiple SSIDs.
 992                  */
 993                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 994                         "sched_scan for initial scans (normal_scans=%d)",
 995                         wpa_s->normal_scans);
 996                 return -1;
 997         }
 998
 999         os_memset(&params, 0, sizeof(params));
1000
1001         /* If we can't allocate space for the filters, we just don't filter */
1002         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
1003                                         sizeof(struct wpa_driver_scan_filter));
1004
1005         prev_state = wpa_s->wpa_state;
1006         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
1007             wpa_s->wpa_state == WPA_INACTIVE)
1008                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
1009
1010         if (wpa_s->autoscan_params != NULL) {
1011                 scan_params = wpa_s->autoscan_params;
1012                 goto scan;
1013         }
1014
1015         /* Find the starting point from which to continue scanning */
1016         ssid = wpa_s->conf->ssid;
1017         if (wpa_s->prev_sched_ssid) {
1018                 while (ssid) {
1019                         if (ssid == wpa_s->prev_sched_ssid) {
1020                                 ssid = ssid->next;
1021                                 break;
1022                         }
1023                         ssid = ssid->next;
1024                 }
1025         }
1026
1027         if (!ssid || !wpa_s->prev_sched_ssid) {
1028                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
1029                 if (wpa_s->conf->sched_scan_interval)
1030                         wpa_s->sched_scan_interval =
1031                                 wpa_s->conf->sched_scan_interval;
1032                 if (wpa_s->sched_scan_interval == 0)
1033                         wpa_s->sched_scan_interval = 10;
1034                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1035                 wpa_s->first_sched_scan = 1;
1036                 ssid = wpa_s->conf->ssid;
1037                 wpa_s->prev_sched_ssid = ssid;
1038         }
1039
1040         if (wildcard) {
1041                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1042                 params.num_ssids++;
1043         }
1044
1045         while (ssid) {
1046                 if (wpas_network_disabled(wpa_s, ssid))
1047                         goto next;
1048
1049                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1050                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1051                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1052                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1053                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1054                                   ssid->ssid, ssid->ssid_len);
1055                         params.filter_ssids[params.num_filter_ssids].ssid_len =
1056                                 ssid->ssid_len;
1057                         params.num_filter_ssids++;
1058                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1059                 {
1060                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1061                                 "filter for sched_scan - drop filter");
1062                         os_free(params.filter_ssids);
1063                         params.filter_ssids = NULL;
1064                         params.num_filter_ssids = 0;
1065                 }
1066
1067                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1068                         if (params.num_ssids == max_sched_scan_ssids)
1069                                 break; /* only room for broadcast SSID */
1070                         wpa_dbg(wpa_s, MSG_DEBUG,
1071                                 "add to active scan ssid: %s",
1072                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1073                         params.ssids[params.num_ssids].ssid =
1074                                 ssid->ssid;
1075                         params.ssids[params.num_ssids].ssid_len =
1076                                 ssid->ssid_len;
1077                         params.num_ssids++;
1078                         if (params.num_ssids >= max_sched_scan_ssids) {
1079                                 wpa_s->prev_sched_ssid = ssid;
1080                                 do {
1081                                         ssid = ssid->next;
1082                                 } while (ssid &&
1083                                          (wpas_network_disabled(wpa_s, ssid) ||
1084                                           !ssid->scan_ssid));
1085                                 break;
1086                         }
1087                 }
1088
1089         next:
1090                 wpa_s->prev_sched_ssid = ssid;
1091                 ssid = ssid->next;
1092         }
1093
1094         if (params.num_filter_ssids == 0) {
1095                 os_free(params.filter_ssids);
1096                 params.filter_ssids = NULL;
1097         }
1098
1099         extra_ie = wpa_supplicant_extra_ies(wpa_s);
1100         if (extra_ie) {
1101                 params.extra_ies = wpabuf_head(extra_ie);
1102                 params.extra_ies_len = wpabuf_len(extra_ie);
1103         }
1104
1105         scan_params = &params;
1106
1107 scan:
1108         if (ssid || !wpa_s->first_sched_scan) {
1109                 wpa_dbg(wpa_s, MSG_DEBUG,
1110                         "Starting sched scan: interval %d timeout %d",
1111                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1112         } else {
1113                 wpa_dbg(wpa_s, MSG_DEBUG,
1114                         "Starting sched scan: interval %d (no timeout)",
1115                         wpa_s->sched_scan_interval);
1116         }
1117
1118         wpa_setband_scan_freqs(wpa_s, scan_params);
1119
1120         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1121                                               wpa_s->sched_scan_interval);
1122         wpabuf_free(extra_ie);
1123         os_free(params.filter_ssids);
1124         if (ret) {
1125                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1126                 if (prev_state != wpa_s->wpa_state)
1127                         wpa_supplicant_set_state(wpa_s, prev_state);
1128                 return ret;
1129         }
1130
1131         /* If we have more SSIDs to scan, add a timeout so we scan them too */
1132         if (ssid || !wpa_s->first_sched_scan) {
1133                 wpa_s->sched_scan_timed_out = 0;
1134                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1135                                        wpa_supplicant_sched_scan_timeout,
1136                                        wpa_s, NULL);
1137                 wpa_s->first_sched_scan = 0;
1138                 wpa_s->sched_scan_timeout /= 2;
1139                 wpa_s->sched_scan_interval *= 2;
1140                 if (wpa_s->sched_scan_timeout < wpa_s->sched_scan_interval) {
1141                         wpa_s->sched_scan_interval = 10;
1142                         wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1143                 }
1144         }
1145
1146         /* If there is no more ssids, start next time from the beginning */
1147         if (!ssid)
1148                 wpa_s->prev_sched_ssid = NULL;
1149
1150         return 0;
1151 }
1152
1153
1154 /**
1155  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1156  * @wpa_s: Pointer to wpa_supplicant data
1157  *
1158  * This function is used to cancel a scan request scheduled with
1159  * wpa_supplicant_req_scan().
1160  */
1161 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1162 {
1163         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1164         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1165         wpas_p2p_continue_after_scan(wpa_s);
1166 }
1167
1168
1169 /**
1170  * wpa_supplicant_cancel_delayed_sched_scan - Stop a delayed scheduled scan
1171  * @wpa_s: Pointer to wpa_supplicant data
1172  *
1173  * This function is used to stop a delayed scheduled scan.
1174  */
1175 void wpa_supplicant_cancel_delayed_sched_scan(struct wpa_supplicant *wpa_s)
1176 {
1177         if (!wpa_s->sched_scan_supported)
1178                 return;
1179
1180         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling delayed sched scan");
1181         eloop_cancel_timeout(wpa_supplicant_delayed_sched_scan_timeout,
1182                              wpa_s, NULL);
1183 }
1184
1185
1186 /**
1187  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1188  * @wpa_s: Pointer to wpa_supplicant data
1189  *
1190  * This function is used to stop a periodic scheduled scan.
1191  */
1192 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1193 {
1194         if (!wpa_s->sched_scanning)
1195                 return;
1196
1197         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1198         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1199         wpa_supplicant_stop_sched_scan(wpa_s);
1200 }
1201
1202
1203 /**
1204  * wpa_supplicant_notify_scanning - Indicate possible scan state change
1205  * @wpa_s: Pointer to wpa_supplicant data
1206  * @scanning: Whether scanning is currently in progress
1207  *
1208  * This function is to generate scanning notifycations. It is called whenever
1209  * there may have been a change in scanning (scan started, completed, stopped).
1210  * wpas_notify_scanning() is called whenever the scanning state changed from the
1211  * previously notified state.
1212  */
1213 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1214                                     int scanning)
1215 {
1216         if (wpa_s->scanning != scanning) {
1217                 wpa_s->scanning = scanning;
1218                 wpas_notify_scanning(wpa_s);
1219         }
1220 }
1221
1222
1223 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1224 {
1225         int rate = 0;
1226         const u8 *ie;
1227         int i;
1228
1229         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1230         for (i = 0; ie && i < ie[1]; i++) {
1231                 if ((ie[i + 2] & 0x7f) > rate)
1232                         rate = ie[i + 2] & 0x7f;
1233         }
1234
1235         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1236         for (i = 0; ie && i < ie[1]; i++) {
1237                 if ((ie[i + 2] & 0x7f) > rate)
1238                         rate = ie[i + 2] & 0x7f;
1239         }
1240
1241         return rate;
1242 }
1243
1244
1245 /**
1246  * wpa_scan_get_ie - Fetch a specified information element from a scan result
1247  * @res: Scan result entry
1248  * @ie: Information element identitifier (WLAN_EID_*)
1249  * Returns: Pointer to the information element (id field) or %NULL if not found
1250  *
1251  * This function returns the first matching information element in the scan
1252  * result.
1253  */
1254 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1255 {
1256         const u8 *end, *pos;
1257
1258         pos = (const u8 *) (res + 1);
1259         end = pos + res->ie_len;
1260
1261         while (pos + 1 < end) {
1262                 if (pos + 2 + pos[1] > end)
1263                         break;
1264                 if (pos[0] == ie)
1265                         return pos;
1266                 pos += 2 + pos[1];
1267         }
1268
1269         return NULL;
1270 }
1271
1272
1273 /**
1274  * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1275  * @res: Scan result entry
1276  * @vendor_type: Vendor type (four octets starting the IE payload)
1277  * Returns: Pointer to the information element (id field) or %NULL if not found
1278  *
1279  * This function returns the first matching information element in the scan
1280  * result.
1281  */
1282 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1283                                   u32 vendor_type)
1284 {
1285         const u8 *end, *pos;
1286
1287         pos = (const u8 *) (res + 1);
1288         end = pos + res->ie_len;
1289
1290         while (pos + 1 < end) {
1291                 if (pos + 2 + pos[1] > end)
1292                         break;
1293                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1294                     vendor_type == WPA_GET_BE32(&pos[2]))
1295                         return pos;
1296                 pos += 2 + pos[1];
1297         }
1298
1299         return NULL;
1300 }
1301
1302
1303 /**
1304  * wpa_scan_get_vendor_ie_beacon - Fetch vendor information from a scan result
1305  * @res: Scan result entry
1306  * @vendor_type: Vendor type (four octets starting the IE payload)
1307  * Returns: Pointer to the information element (id field) or %NULL if not found
1308  *
1309  * This function returns the first matching information element in the scan
1310  * result.
1311  *
1312  * This function is like wpa_scan_get_vendor_ie(), but uses IE buffer only
1313  * from Beacon frames instead of either Beacon or Probe Response frames.
1314  */
1315 const u8 * wpa_scan_get_vendor_ie_beacon(const struct wpa_scan_res *res,
1316                                          u32 vendor_type)
1317 {
1318         const u8 *end, *pos;
1319
1320         if (res->beacon_ie_len == 0)
1321                 return NULL;
1322
1323         pos = (const u8 *) (res + 1);
1324         pos += res->ie_len;
1325         end = pos + res->beacon_ie_len;
1326
1327         while (pos + 1 < end) {
1328                 if (pos + 2 + pos[1] > end)
1329                         break;
1330                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1331                     vendor_type == WPA_GET_BE32(&pos[2]))
1332                         return pos;
1333                 pos += 2 + pos[1];
1334         }
1335
1336         return NULL;
1337 }
1338
1339
1340 /**
1341  * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1342  * @res: Scan result entry
1343  * @vendor_type: Vendor type (four octets starting the IE payload)
1344  * Returns: Pointer to the information element payload or %NULL if not found
1345  *
1346  * This function returns concatenated payload of possibly fragmented vendor
1347  * specific information elements in the scan result. The caller is responsible
1348  * for freeing the returned buffer.
1349  */
1350 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1351                                              u32 vendor_type)
1352 {
1353         struct wpabuf *buf;
1354         const u8 *end, *pos;
1355
1356         buf = wpabuf_alloc(res->ie_len);
1357         if (buf == NULL)
1358                 return NULL;
1359
1360         pos = (const u8 *) (res + 1);
1361         end = pos + res->ie_len;
1362
1363         while (pos + 1 < end) {
1364                 if (pos + 2 + pos[1] > end)
1365                         break;
1366                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1367                     vendor_type == WPA_GET_BE32(&pos[2]))
1368                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1369                 pos += 2 + pos[1];
1370         }
1371
1372         if (wpabuf_len(buf) == 0) {
1373                 wpabuf_free(buf);
1374                 buf = NULL;
1375         }
1376
1377         return buf;
1378 }
1379
1380
1381 /*
1382  * Channels with a great SNR can operate at full rate. What is a great SNR?
1383  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1384  * rule of thumb is that any SNR above 20 is good." This one
1385  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1386  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1387  * conservative value.
1388  */
1389 #define GREAT_SNR 30
1390
1391 /* Compare function for sorting scan results. Return >0 if @b is considered
1392  * better. */
1393 static int wpa_scan_result_compar(const void *a, const void *b)
1394 {
1395 #define IS_5GHZ(n) (n > 4000)
1396 #define MIN(a,b) a < b ? a : b
1397         struct wpa_scan_res **_wa = (void *) a;
1398         struct wpa_scan_res **_wb = (void *) b;
1399         struct wpa_scan_res *wa = *_wa;
1400         struct wpa_scan_res *wb = *_wb;
1401         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1402         int snr_a, snr_b;
1403
1404         /* WPA/WPA2 support preferred */
1405         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1406                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1407         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1408                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1409
1410         if (wpa_b && !wpa_a)
1411                 return 1;
1412         if (!wpa_b && wpa_a)
1413                 return -1;
1414
1415         /* privacy support preferred */
1416         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1417             (wb->caps & IEEE80211_CAP_PRIVACY))
1418                 return 1;
1419         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1420             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1421                 return -1;
1422
1423         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1424             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1425                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1426                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1427         } else {
1428                 /* Not suitable information to calculate SNR, so use level */
1429                 snr_a = wa->level;
1430                 snr_b = wb->level;
1431         }
1432
1433         /* best/max rate preferred if SNR close enough */
1434         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1435             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1436                 maxrate_a = wpa_scan_get_max_rate(wa);
1437                 maxrate_b = wpa_scan_get_max_rate(wb);
1438                 if (maxrate_a != maxrate_b)
1439                         return maxrate_b - maxrate_a;
1440                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1441                         return IS_5GHZ(wa->freq) ? -1 : 1;
1442         }
1443
1444         /* use freq for channel preference */
1445
1446         /* all things being equal, use SNR; if SNRs are
1447          * identical, use quality values since some drivers may only report
1448          * that value and leave the signal level zero */
1449         if (snr_b == snr_a)
1450                 return wb->qual - wa->qual;
1451         return snr_b - snr_a;
1452 #undef MIN
1453 #undef IS_5GHZ
1454 }
1455
1456
1457 #ifdef CONFIG_WPS
1458 /* Compare function for sorting scan results when searching a WPS AP for
1459  * provisioning. Return >0 if @b is considered better. */
1460 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1461 {
1462         struct wpa_scan_res **_wa = (void *) a;
1463         struct wpa_scan_res **_wb = (void *) b;
1464         struct wpa_scan_res *wa = *_wa;
1465         struct wpa_scan_res *wb = *_wb;
1466         int uses_wps_a, uses_wps_b;
1467         struct wpabuf *wps_a, *wps_b;
1468         int res;
1469
1470         /* Optimization - check WPS IE existence before allocated memory and
1471          * doing full reassembly. */
1472         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1473         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1474         if (uses_wps_a && !uses_wps_b)
1475                 return -1;
1476         if (!uses_wps_a && uses_wps_b)
1477                 return 1;
1478
1479         if (uses_wps_a && uses_wps_b) {
1480                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1481                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1482                 res = wps_ap_priority_compar(wps_a, wps_b);
1483                 wpabuf_free(wps_a);
1484                 wpabuf_free(wps_b);
1485                 if (res)
1486                         return res;
1487         }
1488
1489         /*
1490          * Do not use current AP security policy as a sorting criteria during
1491          * WPS provisioning step since the AP may get reconfigured at the
1492          * completion of provisioning.
1493          */
1494
1495         /* all things being equal, use signal level; if signal levels are
1496          * identical, use quality values since some drivers may only report
1497          * that value and leave the signal level zero */
1498         if (wb->level == wa->level)
1499                 return wb->qual - wa->qual;
1500         return wb->level - wa->level;
1501 }
1502 #endif /* CONFIG_WPS */
1503
1504
1505 static void dump_scan_res(struct wpa_scan_results *scan_res)
1506 {
1507 #ifndef CONFIG_NO_STDOUT_DEBUG
1508         size_t i;
1509
1510         if (scan_res->res == NULL || scan_res->num == 0)
1511                 return;
1512
1513         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1514
1515         for (i = 0; i < scan_res->num; i++) {
1516                 struct wpa_scan_res *r = scan_res->res[i];
1517                 u8 *pos;
1518                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1519                     == WPA_SCAN_LEVEL_DBM) {
1520                         int snr = r->level - r->noise;
1521                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1522                                    "noise=%d level=%d snr=%d%s flags=0x%x "
1523                                    "age=%u",
1524                                    MAC2STR(r->bssid), r->freq, r->qual,
1525                                    r->noise, r->level, snr,
1526                                    snr >= GREAT_SNR ? "*" : "", r->flags,
1527                                    r->age);
1528                 } else {
1529                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1530                                    "noise=%d level=%d flags=0x%x age=%u",
1531                                    MAC2STR(r->bssid), r->freq, r->qual,
1532                                    r->noise, r->level, r->flags, r->age);
1533                 }
1534                 pos = (u8 *) (r + 1);
1535                 if (r->ie_len)
1536                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1537                 pos += r->ie_len;
1538                 if (r->beacon_ie_len)
1539                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1540                                     pos, r->beacon_ie_len);
1541         }
1542 #endif /* CONFIG_NO_STDOUT_DEBUG */
1543 }
1544
1545
1546 /**
1547  * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1548  * @wpa_s: Pointer to wpa_supplicant data
1549  * @bssid: BSSID to check
1550  * Returns: 0 if the BSSID is filtered or 1 if not
1551  *
1552  * This function is used to filter out specific BSSIDs from scan reslts mainly
1553  * for testing purposes (SET bssid_filter ctrl_iface command).
1554  */
1555 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1556                                       const u8 *bssid)
1557 {
1558         size_t i;
1559
1560         if (wpa_s->bssid_filter == NULL)
1561                 return 1;
1562
1563         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1564                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1565                               ETH_ALEN) == 0)
1566                         return 1;
1567         }
1568
1569         return 0;
1570 }
1571
1572
1573 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1574                             struct wpa_scan_results *res)
1575 {
1576         size_t i, j;
1577
1578         if (wpa_s->bssid_filter == NULL)
1579                 return;
1580
1581         for (i = 0, j = 0; i < res->num; i++) {
1582                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1583                                                       res->res[i]->bssid)) {
1584                         res->res[j++] = res->res[i];
1585                 } else {
1586                         os_free(res->res[i]);
1587                         res->res[i] = NULL;
1588                 }
1589         }
1590
1591         if (res->num != j) {
1592                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1593                            (int) (res->num - j));
1594                 res->num = j;
1595         }
1596 }
1597
1598
1599 /**
1600  * wpa_supplicant_get_scan_results - Get scan results
1601  * @wpa_s: Pointer to wpa_supplicant data
1602  * @info: Information about what was scanned or %NULL if not available
1603  * @new_scan: Whether a new scan was performed
1604  * Returns: Scan results, %NULL on failure
1605  *
1606  * This function request the current scan results from the driver and updates
1607  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1608  * results with wpa_scan_results_free().
1609  */
1610 struct wpa_scan_results *
1611 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1612                                 struct scan_info *info, int new_scan)
1613 {
1614         struct wpa_scan_results *scan_res;
1615         size_t i;
1616         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1617
1618         scan_res = wpa_drv_get_scan_results2(wpa_s);
1619         if (scan_res == NULL) {
1620                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1621                 return NULL;
1622         }
1623         if (scan_res->fetch_time.sec == 0) {
1624                 /*
1625                  * Make sure we have a valid timestamp if the driver wrapper
1626                  * does not set this.
1627                  */
1628                 os_get_reltime(&scan_res->fetch_time);
1629         }
1630         filter_scan_res(wpa_s, scan_res);
1631
1632 #ifdef CONFIG_WPS
1633         if (wpas_wps_in_progress(wpa_s)) {
1634                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1635                         "provisioning rules");
1636                 compar = wpa_scan_result_wps_compar;
1637         }
1638 #endif /* CONFIG_WPS */
1639
1640         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1641               compar);
1642         dump_scan_res(scan_res);
1643
1644         wpa_bss_update_start(wpa_s);
1645         for (i = 0; i < scan_res->num; i++)
1646                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i],
1647                                         &scan_res->fetch_time);
1648         wpa_bss_update_end(wpa_s, info, new_scan);
1649
1650         return scan_res;
1651 }
1652
1653
1654 /**
1655  * wpa_supplicant_update_scan_results - Update scan results from the driver
1656  * @wpa_s: Pointer to wpa_supplicant data
1657  * Returns: 0 on success, -1 on failure
1658  *
1659  * This function updates the BSS table within wpa_supplicant based on the
1660  * currently available scan results from the driver without requesting a new
1661  * scan. This is used in cases where the driver indicates an association
1662  * (including roaming within ESS) and wpa_supplicant does not yet have the
1663  * needed information to complete the connection (e.g., to perform validation
1664  * steps in 4-way handshake).
1665  */
1666 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1667 {
1668         struct wpa_scan_results *scan_res;
1669         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1670         if (scan_res == NULL)
1671                 return -1;
1672         wpa_scan_results_free(scan_res);
1673
1674         return 0;
1675 }
1676
1677
1678 /**
1679  * scan_only_handler - Reports scan results
1680  */
1681 void scan_only_handler(struct wpa_supplicant *wpa_s,
1682                        struct wpa_scan_results *scan_res)
1683 {
1684         wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
1685         if (wpa_s->last_scan_req == MANUAL_SCAN_REQ &&
1686             wpa_s->manual_scan_use_id && wpa_s->own_scan_running) {
1687                 wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS "id=%u",
1688                              wpa_s->manual_scan_id);
1689                 wpa_s->manual_scan_use_id = 0;
1690         } else {
1691                 wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
1692         }
1693         wpas_notify_scan_results(wpa_s);
1694         wpas_notify_scan_done(wpa_s, 1);
1695 }
1696
1697
1698 int wpas_scan_scheduled(struct wpa_supplicant *wpa_s)
1699 {
1700         return eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL);
1701 }