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 "scan.h"
  25
  26
  27 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
  28 {
  29         struct wpa_ssid *ssid;
  30         union wpa_event_data data;
  31
  32         ssid = wpa_supplicant_get_ssid(wpa_s);
  33         if (ssid == NULL)
  34                 return;
  35
  36         if (wpa_s->current_ssid == NULL) {
  37                 wpa_s->current_ssid = ssid;
  38                 if (wpa_s->current_ssid != NULL)
  39                         wpas_notify_network_changed(wpa_s);
  40         }
  41         wpa_supplicant_initiate_eapol(wpa_s);
  42         wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
  43                 "network - generating associated event");
  44         os_memset(&data, 0, sizeof(data));
  45         wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
  46 }
  47
  48
  49 #ifdef CONFIG_WPS
  50 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
  51                            enum wps_request_type *req_type)
  52 {
  53         struct wpa_ssid *ssid;
  54         int wps = 0;
  55
  56         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
  57                 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
  58                         continue;
  59
  60                 wps = 1;
  61                 *req_type = wpas_wps_get_req_type(ssid);
  62                 if (!ssid->eap.phase1)
  63                         continue;
  64
  65                 if (os_strstr(ssid->eap.phase1, "pbc=1"))
  66                         return 2;
  67         }
  68
  69 #ifdef CONFIG_P2P
  70         if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p &&
  71             !wpa_s->conf->p2p_disabled) {
  72                 wpa_s->wps->dev.p2p = 1;
  73                 if (!wps) {
  74                         wps = 1;
  75                         *req_type = WPS_REQ_ENROLLEE_INFO;
  76                 }
  77         }
  78 #endif /* CONFIG_P2P */
  79
  80         return wps;
  81 }
  82 #endif /* CONFIG_WPS */
  83
  84
  85 /**
  86  * wpa_supplicant_enabled_networks - Check whether there are enabled networks
  87  * @wpa_s: Pointer to wpa_supplicant data
  88  * Returns: 0 if no networks are enabled, >0 if networks are enabled
  89  *
  90  * This function is used to figure out whether any networks (or Interworking
  91  * with enabled credentials and auto_interworking) are present in the current
  92  * configuration.
  93  */
  94 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
  95 {
  96         struct wpa_ssid *ssid = wpa_s->conf->ssid;
  97         int count = 0, disabled = 0;
  98         while (ssid) {
  99                 if (!wpas_network_disabled(wpa_s, ssid))
 100                         count++;
 101                 else
 102                         disabled++;
 103                 ssid = ssid->next;
 104         }
 105         if (wpa_s->conf->cred && wpa_s->conf->interworking &&
 106             wpa_s->conf->auto_interworking)
 107                 count++;
 108         if (count == 0 && disabled > 0) {
 109                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks (%d disabled "
 110                         "networks)", disabled);
 111         }
 112         return count;
 113 }
 114
 115
 116 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
 117                                      struct wpa_ssid *ssid)
 118 {
 119         while (ssid) {
 120                 if (!wpas_network_disabled(wpa_s, ssid))
 121                         break;
 122                 ssid = ssid->next;
 123         }
 124
 125         /* ap_scan=2 mode - try to associate with each SSID. */
 126         if (ssid == NULL) {
 127                 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
 128                         "end of scan list - go back to beginning");
 129                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 130                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 131                 return;
 132         }
 133         if (ssid->next) {
 134                 /* Continue from the next SSID on the next attempt. */
 135                 wpa_s->prev_scan_ssid = ssid;
 136         } else {
 137                 /* Start from the beginning of the SSID list. */
 138                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 139         }
 140         wpa_supplicant_associate(wpa_s, NULL, ssid);
 141 }
 142
 143
 144 static int int_array_len(const int *a)
 145 {
 146         int i;
 147         for (i = 0; a && a[i]; i++)
 148                 ;
 149         return i;
 150 }
 151
 152
 153 static void int_array_concat(int **res, const int *a)
 154 {
 155         int reslen, alen, i;
 156         int *n;
 157
 158         reslen = int_array_len(*res);
 159         alen = int_array_len(a);
 160
 161         n = os_realloc_array(*res, reslen + alen + 1, sizeof(int));
 162         if (n == NULL) {
 163                 os_free(*res);
 164                 *res = NULL;
 165                 return;
 166         }
 167         for (i = 0; i <= alen; i++)
 168                 n[reslen + i] = a[i];
 169         *res = n;
 170 }
 171
 172
 173 static int freq_cmp(const void *a, const void *b)
 174 {
 175         int _a = *(int *) a;
 176         int _b = *(int *) b;
 177
 178         if (_a == 0)
 179                 return 1;
 180         if (_b == 0)
 181                 return -1;
 182         return _a - _b;
 183 }
 184
 185
 186 static void int_array_sort_unique(int *a)
 187 {
 188         int alen;
 189         int i, j;
 190
 191         if (a == NULL)
 192                 return;
 193
 194         alen = int_array_len(a);
 195         qsort(a, alen, sizeof(int), freq_cmp);
 196
 197         i = 0;
 198         j = 1;
 199         while (a[i] && a[j]) {
 200                 if (a[i] == a[j]) {
 201                         j++;
 202                         continue;
 203                 }
 204                 a[++i] = a[j++];
 205         }
 206         if (a[i])
 207                 i++;
 208         a[i] = 0;
 209 }
 210
 211
 212 /**
 213  * wpa_supplicant_trigger_scan - Request driver to start a scan
 214  * @wpa_s: Pointer to wpa_supplicant data
 215  * @params: Scan parameters
 216  * Returns: 0 on success, -1 on failure
 217  */
 218 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 219                                 struct wpa_driver_scan_params *params)
 220 {
 221         int ret;
 222
 223         wpa_supplicant_notify_scanning(wpa_s, 1);
 224
 225         ret = wpa_drv_scan(wpa_s, params);
 226         if (ret) {
 227                 wpa_supplicant_notify_scanning(wpa_s, 0);
 228                 wpas_notify_scan_done(wpa_s, 0);
 229         } else {
 230                 wpa_s->scan_runs++;
 231                 wpa_s->normal_scans++;
 232         }
 233
 234         return ret;
 235 }
 236
 237
 238 static void
 239 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 240 {
 241         struct wpa_supplicant *wpa_s = eloop_ctx;
 242
 243         wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
 244
 245         if (wpa_supplicant_req_sched_scan(wpa_s))
 246                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 247 }
 248
 249
 250 static void
 251 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 252 {
 253         struct wpa_supplicant *wpa_s = eloop_ctx;
 254
 255         wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
 256
 257         wpa_s->sched_scan_timed_out = 1;
 258         wpa_supplicant_cancel_sched_scan(wpa_s);
 259 }
 260
 261
 262 static int
 263 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
 264                                 struct wpa_driver_scan_params *params,
 265                                 int interval)
 266 {
 267         int ret;
 268
 269         wpa_supplicant_notify_scanning(wpa_s, 1);
 270         ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
 271         if (ret)
 272                 wpa_supplicant_notify_scanning(wpa_s, 0);
 273         else
 274                 wpa_s->sched_scanning = 1;
 275
 276         return ret;
 277 }
 278
 279
 280 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
 281 {
 282         int ret;
 283
 284         ret = wpa_drv_stop_sched_scan(wpa_s);
 285         if (ret) {
 286                 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
 287                 /* TODO: what to do if stopping fails? */
 288                 return -1;
 289         }
 290
 291         return ret;
 292 }
 293
 294
 295 static struct wpa_driver_scan_filter *
 296 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 297 {
 298         struct wpa_driver_scan_filter *ssids;
 299         struct wpa_ssid *ssid;
 300         size_t count;
 301
 302         *num_ssids = 0;
 303         if (!conf->filter_ssids)
 304                 return NULL;
 305
 306         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 307                 if (ssid->ssid && ssid->ssid_len)
 308                         count++;
 309         }
 310         if (count == 0)
 311                 return NULL;
 312         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 313         if (ssids == NULL)
 314                 return NULL;
 315
 316         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 317                 if (!ssid->ssid || !ssid->ssid_len)
 318                         continue;
 319                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 320                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 321                 (*num_ssids)++;
 322         }
 323
 324         return ssids;
 325 }
 326
 327
 328 static void wpa_supplicant_optimize_freqs(
 329         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 330 {
 331 #ifdef CONFIG_P2P
 332         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 333             wpa_s->go_params) {
 334                 /* Optimize provisioning state scan based on GO information */
 335                 if (wpa_s->p2p_in_provisioning < 5 &&
 336                     wpa_s->go_params->freq > 0) {
 337                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 338                                 "preferred frequency %d MHz",
 339                                 wpa_s->go_params->freq);
 340                         params->freqs = os_zalloc(2 * sizeof(int));
 341                         if (params->freqs)
 342                                 params->freqs[0] = wpa_s->go_params->freq;
 343                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 344                            wpa_s->go_params->freq_list[0]) {
 345                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 346                                 "channels");
 347                         int_array_concat(&params->freqs,
 348                                          wpa_s->go_params->freq_list);
 349                         if (params->freqs)
 350                                 int_array_sort_unique(params->freqs);
 351                 }
 352                 wpa_s->p2p_in_provisioning++;
 353         }
 354 #endif /* CONFIG_P2P */
 355
 356 #ifdef CONFIG_WPS
 357         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 358                 /*
 359                  * Optimize post-provisioning scan based on channel used
 360                  * during provisioning.
 361                  */
 362                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 363                         "that was used during provisioning", wpa_s->wps_freq);
 364                 params->freqs = os_zalloc(2 * sizeof(int));
 365                 if (params->freqs)
 366                         params->freqs[0] = wpa_s->wps_freq;
 367                 wpa_s->after_wps--;
 368         }
 369
 370         if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
 371         {
 372                 /* Optimize provisioning scan based on already known channel */
 373                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
 374                         wpa_s->wps_freq);
 375                 params->freqs = os_zalloc(2 * sizeof(int));
 376                 if (params->freqs)
 377                         params->freqs[0] = wpa_s->wps_freq;
 378                 wpa_s->known_wps_freq = 0; /* only do this once */
 379         }
 380 #endif /* CONFIG_WPS */
 381 }
 382
 383
 384 #ifdef CONFIG_INTERWORKING
 385 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
 386                                            struct wpabuf *buf)
 387 {
 388         if (wpa_s->conf->interworking == 0)
 389                 return;
 390
 391         wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
 392         wpabuf_put_u8(buf, 4);
 393         wpabuf_put_u8(buf, 0x00);
 394         wpabuf_put_u8(buf, 0x00);
 395         wpabuf_put_u8(buf, 0x00);
 396         wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
 397
 398         wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
 399         wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
 400                       1 + ETH_ALEN);
 401         wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
 402         /* No Venue Info */
 403         if (!is_zero_ether_addr(wpa_s->conf->hessid))
 404                 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
 405 }
 406 #endif /* CONFIG_INTERWORKING */
 407
 408
 409 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
 410 {
 411         struct wpabuf *extra_ie = NULL;
 412 #ifdef CONFIG_WPS
 413         int wps = 0;
 414         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 415 #endif /* CONFIG_WPS */
 416
 417 #ifdef CONFIG_INTERWORKING
 418         if (wpa_s->conf->interworking &&
 419             wpabuf_resize(&extra_ie, 100) == 0)
 420                 wpas_add_interworking_elements(wpa_s, extra_ie);
 421 #endif /* CONFIG_INTERWORKING */
 422
 423 #ifdef CONFIG_WPS
 424         wps = wpas_wps_in_use(wpa_s, &req_type);
 425
 426         if (wps) {
 427                 struct wpabuf *wps_ie;
 428                 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
 429                                                 DEV_PW_DEFAULT,
 430                                                 &wpa_s->wps->dev,
 431                                                 wpa_s->wps->uuid, req_type,
 432                                                 0, NULL);
 433                 if (wps_ie) {
 434                         if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
 435                                 wpabuf_put_buf(extra_ie, wps_ie);
 436                         wpabuf_free(wps_ie);
 437                 }
 438         }
 439
 440 #ifdef CONFIG_P2P
 441         if (wps) {
 442                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 443                 if (wpabuf_resize(&extra_ie, ielen) == 0)
 444                         wpas_p2p_scan_ie(wpa_s, extra_ie);
 445         }
 446 #endif /* CONFIG_P2P */
 447
 448 #endif /* CONFIG_WPS */
 449
 450         return extra_ie;
 451 }
 452
 453
 454 #ifdef CONFIG_P2P
 455
 456 /*
 457  * Check whether there are any enabled networks or credentials that could be
 458  * used for a non-P2P connection.
 459  */
 460 static int non_p2p_network_enabled(struct wpa_supplicant *wpa_s)
 461 {
 462         struct wpa_ssid *ssid;
 463
 464         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 465                 if (wpas_network_disabled(wpa_s, ssid))
 466                         continue;
 467                 if (!ssid->p2p_group)
 468                         return 1;
 469         }
 470
 471         if (wpa_s->conf->cred && wpa_s->conf->interworking &&
 472             wpa_s->conf->auto_interworking)
 473                 return 1;
 474
 475         return 0;
 476 }
 477
 478
 479 /*
 480  * Find the operating frequency of any other virtual interface that is using
 481  * the same radio concurrently.
 482  */
 483 static int shared_vif_oper_freq(struct wpa_supplicant *wpa_s)
 484 {
 485         const char *rn, *rn2;
 486         struct wpa_supplicant *ifs;
 487         u8 bssid[ETH_ALEN];
 488
 489         if (!wpa_s->driver->get_radio_name)
 490                 return -1;
 491
 492         rn = wpa_s->driver->get_radio_name(wpa_s->drv_priv);
 493         if (rn == NULL || rn[0] == '\0')
 494                 return -1;
 495
 496         for (ifs = wpa_s->global->ifaces; ifs; ifs = ifs->next) {
 497                 if (ifs == wpa_s || !ifs->driver->get_radio_name)
 498                         continue;
 499
 500                 rn2 = ifs->driver->get_radio_name(ifs->drv_priv);
 501                 if (!rn2 || os_strcmp(rn, rn2) != 0)
 502                         continue;
 503
 504                 if (ifs->current_ssid == NULL || ifs->assoc_freq == 0)
 505                         continue;
 506
 507                 if (ifs->current_ssid->mode == WPAS_MODE_AP ||
 508                     ifs->current_ssid->mode == WPAS_MODE_P2P_GO)
 509                         return ifs->current_ssid->frequency;
 510                 if (wpa_drv_get_bssid(ifs, bssid) == 0)
 511                         return ifs->assoc_freq;
 512         }
 513
 514         return 0;
 515 }
 516
 517 #endif /* CONFIG_P2P */
 518
 519
 520 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 521 {
 522         struct wpa_supplicant *wpa_s = eloop_ctx;
 523         struct wpa_ssid *ssid;
 524         enum scan_req_type scan_req = NORMAL_SCAN_REQ;
 525         int ret;
 526         struct wpabuf *extra_ie = NULL;
 527         struct wpa_driver_scan_params params;
 528         struct wpa_driver_scan_params *scan_params;
 529         size_t max_ssids;
 530         enum wpa_states prev_state;
 531
 532         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 533                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 534                 return;
 535         }
 536
 537         if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) {
 538                 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
 539                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 540                 return;
 541         }
 542
 543         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 544             wpa_s->scan_req == NORMAL_SCAN_REQ) {
 545                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 546                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 547 #ifdef CONFIG_P2P
 548                 wpa_s->sta_scan_pending = 0;
 549 #endif /* CONFIG_P2P */
 550                 return;
 551         }
 552
 553         if (wpa_s->conf->ap_scan != 0 &&
 554             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 555                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 556                         "overriding ap_scan configuration");
 557                 wpa_s->conf->ap_scan = 0;
 558                 wpas_notify_ap_scan_changed(wpa_s);
 559         }
 560
 561         if (wpa_s->conf->ap_scan == 0) {
 562                 wpa_supplicant_gen_assoc_event(wpa_s);
 563                 return;
 564         }
 565
 566 #ifdef CONFIG_P2P
 567         if (wpas_p2p_in_progress(wpa_s)) {
 568                 if (wpa_s->sta_scan_pending &&
 569                     wpas_p2p_in_progress(wpa_s) == 2 &&
 570                     wpa_s->global->p2p_cb_on_scan_complete) {
 571                         wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
 572                                 "mode scan during P2P search");
 573                 } else {
 574                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 575                                 "while P2P operation is in progress");
 576                         wpa_s->sta_scan_pending = 1;
 577                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 578                         return;
 579                 }
 580         }
 581 #endif /* CONFIG_P2P */
 582
 583         if (wpa_s->conf->ap_scan == 2)
 584                 max_ssids = 1;
 585         else {
 586                 max_ssids = wpa_s->max_scan_ssids;
 587                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 588                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 589         }
 590
 591         scan_req = wpa_s->scan_req;
 592         wpa_s->scan_req = NORMAL_SCAN_REQ;
 593
 594         os_memset(&params, 0, sizeof(params));
 595
 596         prev_state = wpa_s->wpa_state;
 597         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 598             wpa_s->wpa_state == WPA_INACTIVE)
 599                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 600
 601         /*
 602          * If autoscan has set its own scanning parameters
 603          */
 604         if (wpa_s->autoscan_params != NULL) {
 605                 scan_params = wpa_s->autoscan_params;
 606                 goto scan;
 607         }
 608
 609         if (scan_req != MANUAL_SCAN_REQ && wpa_s->connect_without_scan) {
 610                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 611                         if (ssid == wpa_s->connect_without_scan)
 612                                 break;
 613                 }
 614                 wpa_s->connect_without_scan = NULL;
 615                 if (ssid) {
 616                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 617                                    "without scan step");
 618                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 619                         return;
 620                 }
 621         }
 622
 623 #ifdef CONFIG_P2P
 624         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 625             wpa_s->go_params) {
 626                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
 627                            "P2P group formation");
 628                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 629                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 630                 params.num_ssids = 1;
 631                 goto ssid_list_set;
 632         }
 633 #endif /* CONFIG_P2P */
 634
 635         /* Find the starting point from which to continue scanning */
 636         ssid = wpa_s->conf->ssid;
 637         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 638                 while (ssid) {
 639                         if (ssid == wpa_s->prev_scan_ssid) {
 640                                 ssid = ssid->next;
 641                                 break;
 642                         }
 643                         ssid = ssid->next;
 644                 }
 645         }
 646
 647         if (scan_req != MANUAL_SCAN_REQ && wpa_s->conf->ap_scan == 2) {
 648                 wpa_s->connect_without_scan = NULL;
 649                 wpa_s->prev_scan_wildcard = 0;
 650                 wpa_supplicant_assoc_try(wpa_s, ssid);
 651                 return;
 652         } else if (wpa_s->conf->ap_scan == 2) {
 653                 /*
 654                  * User-initiated scan request in ap_scan == 2; scan with
 655                  * wildcard SSID.
 656                  */
 657                 ssid = NULL;
 658         } else {
 659                 struct wpa_ssid *start = ssid, *tssid;
 660                 int freqs_set = 0;
 661                 if (ssid == NULL && max_ssids > 1)
 662                         ssid = wpa_s->conf->ssid;
 663                 while (ssid) {
 664                         if (!wpas_network_disabled(wpa_s, ssid) &&
 665                             ssid->scan_ssid) {
 666                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 667                                                   ssid->ssid, ssid->ssid_len);
 668                                 params.ssids[params.num_ssids].ssid =
 669                                         ssid->ssid;
 670                                 params.ssids[params.num_ssids].ssid_len =
 671                                         ssid->ssid_len;
 672                                 params.num_ssids++;
 673                                 if (params.num_ssids + 1 >= max_ssids)
 674                                         break;
 675                         }
 676                         ssid = ssid->next;
 677                         if (ssid == start)
 678                                 break;
 679                         if (ssid == NULL && max_ssids > 1 &&
 680                             start != wpa_s->conf->ssid)
 681                                 ssid = wpa_s->conf->ssid;
 682                 }
 683
 684                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 685                         if (wpas_network_disabled(wpa_s, tssid))
 686                                 continue;
 687                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 688                                 int_array_concat(&params.freqs,
 689                                                  tssid->scan_freq);
 690                         } else {
 691                                 os_free(params.freqs);
 692                                 params.freqs = NULL;
 693                         }
 694                         freqs_set = 1;
 695                 }
 696                 int_array_sort_unique(params.freqs);
 697         }
 698
 699         if (ssid && max_ssids == 1) {
 700                 /*
 701                  * If the driver is limited to 1 SSID at a time interleave
 702                  * wildcard SSID scans with specific SSID scans to avoid
 703                  * waiting a long time for a wildcard scan.
 704                  */
 705                 if (!wpa_s->prev_scan_wildcard) {
 706                         params.ssids[0].ssid = NULL;
 707                         params.ssids[0].ssid_len = 0;
 708                         wpa_s->prev_scan_wildcard = 1;
 709                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 710                                 "wildcard SSID (Interleave with specific)");
 711                 } else {
 712                         wpa_s->prev_scan_ssid = ssid;
 713                         wpa_s->prev_scan_wildcard = 0;
 714                         wpa_dbg(wpa_s, MSG_DEBUG,
 715                                 "Starting AP scan for specific SSID: %s",
 716                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 717                 }
 718         } else if (ssid) {
 719                 /* max_ssids > 1 */
 720
 721                 wpa_s->prev_scan_ssid = ssid;
 722                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 723                         "the scan request");
 724                 params.num_ssids++;
 725         } else {
 726                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 727                 params.num_ssids++;
 728                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 729                         "SSID");
 730         }
 731 #ifdef CONFIG_P2P
 732 ssid_list_set:
 733 #endif /* CONFIG_P2P */
 734
 735         wpa_supplicant_optimize_freqs(wpa_s, &params);
 736         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 737
 738 #ifdef CONFIG_HS20
 739         if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 7) == 0)
 740                 wpas_hs20_add_indication(extra_ie);
 741 #endif /* CONFIG_HS20 */
 742
 743         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 744                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 745                         "generated frequency list");
 746                 params.freqs = wpa_s->next_scan_freqs;
 747         } else
 748                 os_free(wpa_s->next_scan_freqs);
 749         wpa_s->next_scan_freqs = NULL;
 750
 751         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 752                 wpa_s->conf, &params.num_filter_ssids);
 753         if (extra_ie) {
 754                 params.extra_ies = wpabuf_head(extra_ie);
 755                 params.extra_ies_len = wpabuf_len(extra_ie);
 756         }
 757
 758 #ifdef CONFIG_P2P
 759         if (wpa_s->p2p_in_provisioning ||
 760             (wpa_s->show_group_started && wpa_s->go_params)) {
 761                 /*
 762                  * The interface may not yet be in P2P mode, so we have to
 763                  * explicitly request P2P probe to disable CCK rates.
 764                  */
 765                 params.p2p_probe = 1;
 766         }
 767 #endif /* CONFIG_P2P */
 768
 769         scan_params = &params;
 770
 771 scan:
 772 #ifdef CONFIG_P2P
 773         /*
 774          * If the driver does not support multi-channel concurrency and a
 775          * virtual interface that shares the same radio with the wpa_s interface
 776          * is operating there may not be need to scan other channels apart from
 777          * the current operating channel on the other virtual interface. Filter
 778          * out other channels in case we are trying to find a connection for a
 779          * station interface when we are not configured to prefer station
 780          * connection and a concurrent operation is already in process.
 781          */
 782         if (wpa_s->scan_for_connection && scan_req == NORMAL_SCAN_REQ &&
 783             !scan_params->freqs && !params.freqs &&
 784             wpas_is_p2p_prioritized(wpa_s) &&
 785             !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_MULTI_CHANNEL_CONCURRENT) &&
 786             wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
 787             non_p2p_network_enabled(wpa_s)) {
 788                 int freq = shared_vif_oper_freq(wpa_s);
 789                 if (freq > 0) {
 790                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only the current "
 791                                 "operating channel (%d MHz) since driver does "
 792                                 "not support multi-channel concurrency", freq);
 793                         params.freqs = os_zalloc(sizeof(int) * 2);
 794                         if (params.freqs)
 795                                 params.freqs[0] = freq;
 796                         scan_params->freqs = params.freqs;
 797                 }
 798         }
 799 #endif /* CONFIG_P2P */
 800
 801         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 802
 803         wpabuf_free(extra_ie);
 804         os_free(params.freqs);
 805         os_free(params.filter_ssids);
 806
 807         if (ret) {
 808                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 809                 if (prev_state != wpa_s->wpa_state)
 810                         wpa_supplicant_set_state(wpa_s, prev_state);
 811                 /* Restore scan_req since we will try to scan again */
 812                 wpa_s->scan_req = scan_req;
 813                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 814         } else {
 815                 wpa_s->scan_for_connection = 0;
 816         }
 817 }
 818
 819
 820 void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec)
 821 {
 822         struct os_time remaining, new_int;
 823         int cancelled;
 824
 825         cancelled = eloop_cancel_timeout_one(wpa_supplicant_scan, wpa_s, NULL,
 826                                              &remaining);
 827
 828         new_int.sec = sec;
 829         new_int.usec = 0;
 830         if (cancelled && os_time_before(&remaining, &new_int)) {
 831                 new_int.sec = remaining.sec;
 832                 new_int.usec = remaining.usec;
 833         }
 834
 835         eloop_register_timeout(new_int.sec, new_int.usec, wpa_supplicant_scan,
 836                                wpa_s, NULL);
 837         wpa_s->scan_interval = sec;
 838 }
 839
 840
 841 /**
 842  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 843  * @wpa_s: Pointer to wpa_supplicant data
 844  * @sec: Number of seconds after which to scan
 845  * @usec: Number of microseconds after which to scan
 846  *
 847  * This function is used to schedule a scan for neighboring access points after
 848  * the specified time.
 849  */
 850 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 851 {
 852         /* If there's at least one network that should be specifically scanned
 853          * then don't cancel the scan and reschedule.  Some drivers do
 854          * background scanning which generates frequent scan results, and that
 855          * causes the specific SSID scan to get continually pushed back and
 856          * never happen, which causes hidden APs to never get probe-scanned.
 857          */
 858         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 859             wpa_s->conf->ap_scan == 1) {
 860                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 861
 862                 while (ssid) {
 863                         if (!wpas_network_disabled(wpa_s, ssid) &&
 864                             ssid->scan_ssid)
 865                                 break;
 866                         ssid = ssid->next;
 867                 }
 868                 if (ssid) {
 869                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 870                                 "ensure that specific SSID scans occur");
 871                         return;
 872                 }
 873         }
 874
 875         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 876                 sec, usec);
 877         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 878         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 879 }
 880
 881
 882 /**
 883  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 884  * @wpa_s: Pointer to wpa_supplicant data
 885  * @sec: Number of seconds after which to scan
 886  * @usec: Number of microseconds after which to scan
 887  * Returns: 0 on success or -1 otherwise
 888  *
 889  * This function is used to schedule periodic scans for neighboring
 890  * access points after the specified time.
 891  */
 892 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 893                                       int sec, int usec)
 894 {
 895         if (!wpa_s->sched_scan_supported)
 896                 return -1;
 897
 898         eloop_register_timeout(sec, usec,
 899                                wpa_supplicant_delayed_sched_scan_timeout,
 900                                wpa_s, NULL);
 901
 902         return 0;
 903 }
 904
 905
 906 /**
 907  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 908  * @wpa_s: Pointer to wpa_supplicant data
 909  * Returns: 0 is sched_scan was started or -1 otherwise
 910  *
 911  * This function is used to schedule periodic scans for neighboring
 912  * access points repeating the scan continuously.
 913  */
 914 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 915 {
 916         struct wpa_driver_scan_params params;
 917         struct wpa_driver_scan_params *scan_params;
 918         enum wpa_states prev_state;
 919         struct wpa_ssid *ssid = NULL;
 920         struct wpabuf *extra_ie = NULL;
 921         int ret;
 922         unsigned int max_sched_scan_ssids;
 923         int wildcard = 0;
 924         int need_ssids;
 925
 926         if (!wpa_s->sched_scan_supported)
 927                 return -1;
 928
 929         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 930                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 931         else
 932                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 933         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 934                 return -1;
 935
 936         if (wpa_s->sched_scanning) {
 937                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 938                 return 0;
 939         }
 940
 941         need_ssids = 0;
 942         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 943                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 944                         /* Use wildcard SSID to find this network */
 945                         wildcard = 1;
 946                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 947                            ssid->ssid_len)
 948                         need_ssids++;
 949
 950 #ifdef CONFIG_WPS
 951                 if (!wpas_network_disabled(wpa_s, ssid) &&
 952                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
 953                         /*
 954                          * Normal scan is more reliable and faster for WPS
 955                          * operations and since these are for short periods of
 956                          * time, the benefit of trying to use sched_scan would
 957                          * be limited.
 958                          */
 959                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 960                                 "sched_scan for WPS");
 961                         return -1;
 962                 }
 963 #endif /* CONFIG_WPS */
 964         }
 965         if (wildcard)
 966                 need_ssids++;
 967
 968         if (wpa_s->normal_scans < 3 &&
 969             (need_ssids <= wpa_s->max_scan_ssids ||
 970              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
 971                 /*
 972                  * When normal scan can speed up operations, use that for the
 973                  * first operations before starting the sched_scan to allow
 974                  * user space sleep more. We do this only if the normal scan
 975                  * has functionality that is suitable for this or if the
 976                  * sched_scan does not have better support for multiple SSIDs.
 977                  */
 978                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 979                         "sched_scan for initial scans (normal_scans=%d)",
 980                         wpa_s->normal_scans);
 981                 return -1;
 982         }
 983
 984         os_memset(&params, 0, sizeof(params));
 985
 986         /* If we can't allocate space for the filters, we just don't filter */
 987         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
 988                                         sizeof(struct wpa_driver_scan_filter));
 989
 990         prev_state = wpa_s->wpa_state;
 991         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 992             wpa_s->wpa_state == WPA_INACTIVE)
 993                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 994
 995         if (wpa_s->autoscan_params != NULL) {
 996                 scan_params = wpa_s->autoscan_params;
 997                 goto scan;
 998         }
 999
1000         /* Find the starting point from which to continue scanning */
1001         ssid = wpa_s->conf->ssid;
1002         if (wpa_s->prev_sched_ssid) {
1003                 while (ssid) {
1004                         if (ssid == wpa_s->prev_sched_ssid) {
1005                                 ssid = ssid->next;
1006                                 break;
1007                         }
1008                         ssid = ssid->next;
1009                 }
1010         }
1011
1012         if (!ssid || !wpa_s->prev_sched_ssid) {
1013                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
1014
1015                 if (wpa_s->sched_scan_interval == 0)
1016                         wpa_s->sched_scan_interval = 10;
1017                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1018                 wpa_s->first_sched_scan = 1;
1019                 ssid = wpa_s->conf->ssid;
1020                 wpa_s->prev_sched_ssid = ssid;
1021         }
1022
1023         if (wildcard) {
1024                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1025                 params.num_ssids++;
1026         }
1027
1028         while (ssid) {
1029                 if (wpas_network_disabled(wpa_s, ssid))
1030                         goto next;
1031
1032                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1033                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1034                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1035                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1036                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1037                                   ssid->ssid, ssid->ssid_len);
1038                         params.filter_ssids[params.num_filter_ssids].ssid_len =
1039                                 ssid->ssid_len;
1040                         params.num_filter_ssids++;
1041                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1042                 {
1043                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1044                                 "filter for sched_scan - drop filter");
1045                         os_free(params.filter_ssids);
1046                         params.filter_ssids = NULL;
1047                         params.num_filter_ssids = 0;
1048                 }
1049
1050                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1051                         if (params.num_ssids == max_sched_scan_ssids)
1052                                 break; /* only room for broadcast SSID */
1053                         wpa_dbg(wpa_s, MSG_DEBUG,
1054                                 "add to active scan ssid: %s",
1055                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1056                         params.ssids[params.num_ssids].ssid =
1057                                 ssid->ssid;
1058                         params.ssids[params.num_ssids].ssid_len =
1059                                 ssid->ssid_len;
1060                         params.num_ssids++;
1061                         if (params.num_ssids >= max_sched_scan_ssids) {
1062                                 wpa_s->prev_sched_ssid = ssid;
1063                                 do {
1064                                         ssid = ssid->next;
1065                                 } while (ssid &&
1066                                          (wpas_network_disabled(wpa_s, ssid) ||
1067                                           !ssid->scan_ssid));
1068                                 break;
1069                         }
1070                 }
1071
1072         next:
1073                 wpa_s->prev_sched_ssid = ssid;
1074                 ssid = ssid->next;
1075         }
1076
1077         if (params.num_filter_ssids == 0) {
1078                 os_free(params.filter_ssids);
1079                 params.filter_ssids = NULL;
1080         }
1081
1082         extra_ie = wpa_supplicant_extra_ies(wpa_s);
1083         if (extra_ie) {
1084                 params.extra_ies = wpabuf_head(extra_ie);
1085                 params.extra_ies_len = wpabuf_len(extra_ie);
1086         }
1087
1088         scan_params = &params;
1089
1090 scan:
1091         if (ssid || !wpa_s->first_sched_scan) {
1092                 wpa_dbg(wpa_s, MSG_DEBUG,
1093                         "Starting sched scan: interval %d timeout %d",
1094                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1095         } else {
1096                 wpa_dbg(wpa_s, MSG_DEBUG,
1097                         "Starting sched scan: interval %d (no timeout)",
1098                         wpa_s->sched_scan_interval);
1099         }
1100
1101         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1102                                               wpa_s->sched_scan_interval);
1103         wpabuf_free(extra_ie);
1104         os_free(params.filter_ssids);
1105         if (ret) {
1106                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1107                 if (prev_state != wpa_s->wpa_state)
1108                         wpa_supplicant_set_state(wpa_s, prev_state);
1109                 return ret;
1110         }
1111
1112         /* If we have more SSIDs to scan, add a timeout so we scan them too */
1113         if (ssid || !wpa_s->first_sched_scan) {
1114                 wpa_s->sched_scan_timed_out = 0;
1115                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1116                                        wpa_supplicant_sched_scan_timeout,
1117                                        wpa_s, NULL);
1118                 wpa_s->first_sched_scan = 0;
1119                 wpa_s->sched_scan_timeout /= 2;
1120                 wpa_s->sched_scan_interval *= 2;
1121                 if (wpa_s->sched_scan_timeout < wpa_s->sched_scan_interval) {
1122                         wpa_s->sched_scan_interval = 10;
1123                         wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1124                 }
1125         }
1126
1127         return 0;
1128 }
1129
1130
1131 /**
1132  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1133  * @wpa_s: Pointer to wpa_supplicant data
1134  *
1135  * This function is used to cancel a scan request scheduled with
1136  * wpa_supplicant_req_scan().
1137  */
1138 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1139 {
1140         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1141         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1142 }
1143
1144
1145 /**
1146  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1147  * @wpa_s: Pointer to wpa_supplicant data
1148  *
1149  * This function is used to stop a periodic scheduled scan.
1150  */
1151 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1152 {
1153         if (!wpa_s->sched_scanning)
1154                 return;
1155
1156         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1157         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1158         wpa_supplicant_stop_sched_scan(wpa_s);
1159 }
1160
1161
1162 /**
1163  * wpa_supplicant_notify_scanning - Indicate possible scan state change
1164  * @wpa_s: Pointer to wpa_supplicant data
1165  * @scanning: Whether scanning is currently in progress
1166  *
1167  * This function is to generate scanning notifycations. It is called whenever
1168  * there may have been a change in scanning (scan started, completed, stopped).
1169  * wpas_notify_scanning() is called whenever the scanning state changed from the
1170  * previously notified state.
1171  */
1172 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1173                                     int scanning)
1174 {
1175         if (wpa_s->scanning != scanning) {
1176                 wpa_s->scanning = scanning;
1177                 wpas_notify_scanning(wpa_s);
1178         }
1179 }
1180
1181
1182 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1183 {
1184         int rate = 0;
1185         const u8 *ie;
1186         int i;
1187
1188         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1189         for (i = 0; ie && i < ie[1]; i++) {
1190                 if ((ie[i + 2] & 0x7f) > rate)
1191                         rate = ie[i + 2] & 0x7f;
1192         }
1193
1194         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1195         for (i = 0; ie && i < ie[1]; i++) {
1196                 if ((ie[i + 2] & 0x7f) > rate)
1197                         rate = ie[i + 2] & 0x7f;
1198         }
1199
1200         return rate;
1201 }
1202
1203
1204 /**
1205  * wpa_scan_get_ie - Fetch a specified information element from a scan result
1206  * @res: Scan result entry
1207  * @ie: Information element identitifier (WLAN_EID_*)
1208  * Returns: Pointer to the information element (id field) or %NULL if not found
1209  *
1210  * This function returns the first matching information element in the scan
1211  * result.
1212  */
1213 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1214 {
1215         const u8 *end, *pos;
1216
1217         pos = (const u8 *) (res + 1);
1218         end = pos + res->ie_len;
1219
1220         while (pos + 1 < end) {
1221                 if (pos + 2 + pos[1] > end)
1222                         break;
1223                 if (pos[0] == ie)
1224                         return pos;
1225                 pos += 2 + pos[1];
1226         }
1227
1228         return NULL;
1229 }
1230
1231
1232 /**
1233  * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1234  * @res: Scan result entry
1235  * @vendor_type: Vendor type (four octets starting the IE payload)
1236  * Returns: Pointer to the information element (id field) or %NULL if not found
1237  *
1238  * This function returns the first matching information element in the scan
1239  * result.
1240  */
1241 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1242                                   u32 vendor_type)
1243 {
1244         const u8 *end, *pos;
1245
1246         pos = (const u8 *) (res + 1);
1247         end = pos + res->ie_len;
1248
1249         while (pos + 1 < end) {
1250                 if (pos + 2 + pos[1] > end)
1251                         break;
1252                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1253                     vendor_type == WPA_GET_BE32(&pos[2]))
1254                         return pos;
1255                 pos += 2 + pos[1];
1256         }
1257
1258         return NULL;
1259 }
1260
1261
1262 /**
1263  * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1264  * @res: Scan result entry
1265  * @vendor_type: Vendor type (four octets starting the IE payload)
1266  * Returns: Pointer to the information element payload or %NULL if not found
1267  *
1268  * This function returns concatenated payload of possibly fragmented vendor
1269  * specific information elements in the scan result. The caller is responsible
1270  * for freeing the returned buffer.
1271  */
1272 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1273                                              u32 vendor_type)
1274 {
1275         struct wpabuf *buf;
1276         const u8 *end, *pos;
1277
1278         buf = wpabuf_alloc(res->ie_len);
1279         if (buf == NULL)
1280                 return NULL;
1281
1282         pos = (const u8 *) (res + 1);
1283         end = pos + res->ie_len;
1284
1285         while (pos + 1 < end) {
1286                 if (pos + 2 + pos[1] > end)
1287                         break;
1288                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1289                     vendor_type == WPA_GET_BE32(&pos[2]))
1290                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1291                 pos += 2 + pos[1];
1292         }
1293
1294         if (wpabuf_len(buf) == 0) {
1295                 wpabuf_free(buf);
1296                 buf = NULL;
1297         }
1298
1299         return buf;
1300 }
1301
1302
1303 /*
1304  * Channels with a great SNR can operate at full rate. What is a great SNR?
1305  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1306  * rule of thumb is that any SNR above 20 is good." This one
1307  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1308  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1309  * conservative value.
1310  */
1311 #define GREAT_SNR 30
1312
1313 /* Compare function for sorting scan results. Return >0 if @b is considered
1314  * better. */
1315 static int wpa_scan_result_compar(const void *a, const void *b)
1316 {
1317 #define IS_5GHZ(n) (n > 4000)
1318 #define MIN(a,b) a < b ? a : b
1319         struct wpa_scan_res **_wa = (void *) a;
1320         struct wpa_scan_res **_wb = (void *) b;
1321         struct wpa_scan_res *wa = *_wa;
1322         struct wpa_scan_res *wb = *_wb;
1323         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1324         int snr_a, snr_b;
1325
1326         /* WPA/WPA2 support preferred */
1327         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1328                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1329         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1330                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1331
1332         if (wpa_b && !wpa_a)
1333                 return 1;
1334         if (!wpa_b && wpa_a)
1335                 return -1;
1336
1337         /* privacy support preferred */
1338         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1339             (wb->caps & IEEE80211_CAP_PRIVACY))
1340                 return 1;
1341         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1342             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1343                 return -1;
1344
1345         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1346             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1347                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1348                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1349         } else {
1350                 /* Not suitable information to calculate SNR, so use level */
1351                 snr_a = wa->level;
1352                 snr_b = wb->level;
1353         }
1354
1355         /* best/max rate preferred if SNR close enough */
1356         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1357             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1358                 maxrate_a = wpa_scan_get_max_rate(wa);
1359                 maxrate_b = wpa_scan_get_max_rate(wb);
1360                 if (maxrate_a != maxrate_b)
1361                         return maxrate_b - maxrate_a;
1362                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1363                         return IS_5GHZ(wa->freq) ? -1 : 1;
1364         }
1365
1366         /* use freq for channel preference */
1367
1368         /* all things being equal, use SNR; if SNRs are
1369          * identical, use quality values since some drivers may only report
1370          * that value and leave the signal level zero */
1371         if (snr_b == snr_a)
1372                 return wb->qual - wa->qual;
1373         return snr_b - snr_a;
1374 #undef MIN
1375 #undef IS_5GHZ
1376 }
1377
1378
1379 #ifdef CONFIG_WPS
1380 /* Compare function for sorting scan results when searching a WPS AP for
1381  * provisioning. Return >0 if @b is considered better. */
1382 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1383 {
1384         struct wpa_scan_res **_wa = (void *) a;
1385         struct wpa_scan_res **_wb = (void *) b;
1386         struct wpa_scan_res *wa = *_wa;
1387         struct wpa_scan_res *wb = *_wb;
1388         int uses_wps_a, uses_wps_b;
1389         struct wpabuf *wps_a, *wps_b;
1390         int res;
1391
1392         /* Optimization - check WPS IE existence before allocated memory and
1393          * doing full reassembly. */
1394         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1395         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1396         if (uses_wps_a && !uses_wps_b)
1397                 return -1;
1398         if (!uses_wps_a && uses_wps_b)
1399                 return 1;
1400
1401         if (uses_wps_a && uses_wps_b) {
1402                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1403                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1404                 res = wps_ap_priority_compar(wps_a, wps_b);
1405                 wpabuf_free(wps_a);
1406                 wpabuf_free(wps_b);
1407                 if (res)
1408                         return res;
1409         }
1410
1411         /*
1412          * Do not use current AP security policy as a sorting criteria during
1413          * WPS provisioning step since the AP may get reconfigured at the
1414          * completion of provisioning.
1415          */
1416
1417         /* all things being equal, use signal level; if signal levels are
1418          * identical, use quality values since some drivers may only report
1419          * that value and leave the signal level zero */
1420         if (wb->level == wa->level)
1421                 return wb->qual - wa->qual;
1422         return wb->level - wa->level;
1423 }
1424 #endif /* CONFIG_WPS */
1425
1426
1427 static void dump_scan_res(struct wpa_scan_results *scan_res)
1428 {
1429 #ifndef CONFIG_NO_STDOUT_DEBUG
1430         size_t i;
1431
1432         if (scan_res->res == NULL || scan_res->num == 0)
1433                 return;
1434
1435         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1436
1437         for (i = 0; i < scan_res->num; i++) {
1438                 struct wpa_scan_res *r = scan_res->res[i];
1439                 u8 *pos;
1440                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1441                     == WPA_SCAN_LEVEL_DBM) {
1442                         int snr = r->level - r->noise;
1443                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1444                                    "noise=%d level=%d snr=%d%s flags=0x%x "
1445                                    "age=%u",
1446                                    MAC2STR(r->bssid), r->freq, r->qual,
1447                                    r->noise, r->level, snr,
1448                                    snr >= GREAT_SNR ? "*" : "", r->flags,
1449                                    r->age);
1450                 } else {
1451                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1452                                    "noise=%d level=%d flags=0x%x age=%u",
1453                                    MAC2STR(r->bssid), r->freq, r->qual,
1454                                    r->noise, r->level, r->flags, r->age);
1455                 }
1456                 pos = (u8 *) (r + 1);
1457                 if (r->ie_len)
1458                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1459                 pos += r->ie_len;
1460                 if (r->beacon_ie_len)
1461                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1462                                     pos, r->beacon_ie_len);
1463         }
1464 #endif /* CONFIG_NO_STDOUT_DEBUG */
1465 }
1466
1467
1468 /**
1469  * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1470  * @wpa_s: Pointer to wpa_supplicant data
1471  * @bssid: BSSID to check
1472  * Returns: 0 if the BSSID is filtered or 1 if not
1473  *
1474  * This function is used to filter out specific BSSIDs from scan reslts mainly
1475  * for testing purposes (SET bssid_filter ctrl_iface command).
1476  */
1477 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1478                                       const u8 *bssid)
1479 {
1480         size_t i;
1481
1482         if (wpa_s->bssid_filter == NULL)
1483                 return 1;
1484
1485         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1486                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1487                               ETH_ALEN) == 0)
1488                         return 1;
1489         }
1490
1491         return 0;
1492 }
1493
1494
1495 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1496                             struct wpa_scan_results *res)
1497 {
1498         size_t i, j;
1499
1500         if (wpa_s->bssid_filter == NULL)
1501                 return;
1502
1503         for (i = 0, j = 0; i < res->num; i++) {
1504                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1505                                                       res->res[i]->bssid)) {
1506                         res->res[j++] = res->res[i];
1507                 } else {
1508                         os_free(res->res[i]);
1509                         res->res[i] = NULL;
1510                 }
1511         }
1512
1513         if (res->num != j) {
1514                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1515                            (int) (res->num - j));
1516                 res->num = j;
1517         }
1518 }
1519
1520
1521 /**
1522  * wpa_supplicant_get_scan_results - Get scan results
1523  * @wpa_s: Pointer to wpa_supplicant data
1524  * @info: Information about what was scanned or %NULL if not available
1525  * @new_scan: Whether a new scan was performed
1526  * Returns: Scan results, %NULL on failure
1527  *
1528  * This function request the current scan results from the driver and updates
1529  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1530  * results with wpa_scan_results_free().
1531  */
1532 struct wpa_scan_results *
1533 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1534                                 struct scan_info *info, int new_scan)
1535 {
1536         struct wpa_scan_results *scan_res;
1537         size_t i;
1538         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1539
1540         scan_res = wpa_drv_get_scan_results2(wpa_s);
1541         if (scan_res == NULL) {
1542                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1543                 return NULL;
1544         }
1545         if (scan_res->fetch_time.sec == 0) {
1546                 /*
1547                  * Make sure we have a valid timestamp if the driver wrapper
1548                  * does not set this.
1549                  */
1550                 os_get_time(&scan_res->fetch_time);
1551         }
1552         filter_scan_res(wpa_s, scan_res);
1553
1554 #ifdef CONFIG_WPS
1555         if (wpas_wps_in_progress(wpa_s)) {
1556                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1557                         "provisioning rules");
1558                 compar = wpa_scan_result_wps_compar;
1559         }
1560 #endif /* CONFIG_WPS */
1561
1562         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1563               compar);
1564         dump_scan_res(scan_res);
1565
1566         wpa_bss_update_start(wpa_s);
1567         for (i = 0; i < scan_res->num; i++)
1568                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i],
1569                                         &scan_res->fetch_time);
1570         wpa_bss_update_end(wpa_s, info, new_scan);
1571
1572         return scan_res;
1573 }
1574
1575
1576 /**
1577  * wpa_supplicant_update_scan_results - Update scan results from the driver
1578  * @wpa_s: Pointer to wpa_supplicant data
1579  * Returns: 0 on success, -1 on failure
1580  *
1581  * This function updates the BSS table within wpa_supplicant based on the
1582  * currently available scan results from the driver without requesting a new
1583  * scan. This is used in cases where the driver indicates an association
1584  * (including roaming within ESS) and wpa_supplicant does not yet have the
1585  * needed information to complete the connection (e.g., to perform validation
1586  * steps in 4-way handshake).
1587  */
1588 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1589 {
1590         struct wpa_scan_results *scan_res;
1591         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1592         if (scan_res == NULL)
1593                 return -1;
1594         wpa_scan_results_free(scan_res);
1595
1596         return 0;
1597 }
1598
1599
1600 /**
1601  * scan_only_handler - Reports scan results
1602  */
1603 void scan_only_handler(struct wpa_supplicant *wpa_s,
1604                        struct wpa_scan_results *scan_res)
1605 {
1606         wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
1607         wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
1608         wpas_notify_scan_results(wpa_s);
1609         wpas_notify_scan_done(wpa_s, 1);
1610 }