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 #ifndef ANDROID_P2P
 269         wpa_supplicant_notify_scanning(wpa_s, 1);
 270 #endif
 271         ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
 272         if (ret)
 273                 wpa_supplicant_notify_scanning(wpa_s, 0);
 274         else {
 275                 wpa_s->sched_scanning = 1;
 276 #ifdef ANDROID_P2P
 277                 wpa_supplicant_notify_scanning(wpa_s, 1);
 278 #endif
 279         }
 280
 281         return ret;
 282 }
 283
 284
 285 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
 286 {
 287         int ret;
 288
 289         ret = wpa_drv_stop_sched_scan(wpa_s);
 290         if (ret) {
 291                 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
 292                 /* TODO: what to do if stopping fails? */
 293                 return -1;
 294         }
 295
 296         return ret;
 297 }
 298
 299
 300 static struct wpa_driver_scan_filter *
 301 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 302 {
 303         struct wpa_driver_scan_filter *ssids;
 304         struct wpa_ssid *ssid;
 305         size_t count;
 306
 307         *num_ssids = 0;
 308         if (!conf->filter_ssids)
 309                 return NULL;
 310
 311         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 312                 if (ssid->ssid && ssid->ssid_len)
 313                         count++;
 314         }
 315         if (count == 0)
 316                 return NULL;
 317         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 318         if (ssids == NULL)
 319                 return NULL;
 320
 321         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 322                 if (!ssid->ssid || !ssid->ssid_len)
 323                         continue;
 324                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 325                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 326                 (*num_ssids)++;
 327         }
 328
 329         return ssids;
 330 }
 331
 332
 333 static void wpa_supplicant_optimize_freqs(
 334         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 335 {
 336 #ifdef CONFIG_P2P
 337         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 338             wpa_s->go_params) {
 339                 /* Optimize provisioning state scan based on GO information */
 340                 if (wpa_s->p2p_in_provisioning < 5 &&
 341                     wpa_s->go_params->freq > 0) {
 342                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 343                                 "preferred frequency %d MHz",
 344                                 wpa_s->go_params->freq);
 345                         params->freqs = os_zalloc(2 * sizeof(int));
 346                         if (params->freqs)
 347                                 params->freqs[0] = wpa_s->go_params->freq;
 348                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 349                            wpa_s->go_params->freq_list[0]) {
 350                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 351                                 "channels");
 352                         int_array_concat(&params->freqs,
 353                                          wpa_s->go_params->freq_list);
 354                         if (params->freqs)
 355                                 int_array_sort_unique(params->freqs);
 356                 }
 357                 wpa_s->p2p_in_provisioning++;
 358         }
 359 #endif /* CONFIG_P2P */
 360
 361 #ifdef CONFIG_WPS
 362         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 363                 /*
 364                  * Optimize post-provisioning scan based on channel used
 365                  * during provisioning.
 366                  */
 367                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 368                         "that was used during provisioning", wpa_s->wps_freq);
 369                 params->freqs = os_zalloc(2 * sizeof(int));
 370                 if (params->freqs)
 371                         params->freqs[0] = wpa_s->wps_freq;
 372                 wpa_s->after_wps--;
 373         }
 374
 375         if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
 376         {
 377                 /* Optimize provisioning scan based on already known channel */
 378                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
 379                         wpa_s->wps_freq);
 380                 params->freqs = os_zalloc(2 * sizeof(int));
 381                 if (params->freqs)
 382                         params->freqs[0] = wpa_s->wps_freq;
 383                 wpa_s->known_wps_freq = 0; /* only do this once */
 384         }
 385 #endif /* CONFIG_WPS */
 386 }
 387
 388
 389 #ifdef CONFIG_INTERWORKING
 390 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
 391                                            struct wpabuf *buf)
 392 {
 393         if (wpa_s->conf->interworking == 0)
 394                 return;
 395
 396         wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
 397         wpabuf_put_u8(buf, 4);
 398         wpabuf_put_u8(buf, 0x00);
 399         wpabuf_put_u8(buf, 0x00);
 400         wpabuf_put_u8(buf, 0x00);
 401         wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
 402
 403         wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
 404         wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
 405                       1 + ETH_ALEN);
 406         wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
 407         /* No Venue Info */
 408         if (!is_zero_ether_addr(wpa_s->conf->hessid))
 409                 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
 410 }
 411 #endif /* CONFIG_INTERWORKING */
 412
 413
 414 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
 415 {
 416         struct wpabuf *extra_ie = NULL;
 417 #ifdef CONFIG_WPS
 418         int wps = 0;
 419         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 420 #endif /* CONFIG_WPS */
 421
 422 #ifdef CONFIG_INTERWORKING
 423         if (wpa_s->conf->interworking &&
 424             wpabuf_resize(&extra_ie, 100) == 0)
 425                 wpas_add_interworking_elements(wpa_s, extra_ie);
 426 #endif /* CONFIG_INTERWORKING */
 427
 428 #ifdef CONFIG_WPS
 429         wps = wpas_wps_in_use(wpa_s, &req_type);
 430
 431         if (wps) {
 432                 struct wpabuf *wps_ie;
 433                 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
 434                                                 DEV_PW_DEFAULT,
 435                                                 &wpa_s->wps->dev,
 436                                                 wpa_s->wps->uuid, req_type,
 437                                                 0, NULL);
 438                 if (wps_ie) {
 439                         if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
 440                                 wpabuf_put_buf(extra_ie, wps_ie);
 441                         wpabuf_free(wps_ie);
 442                 }
 443         }
 444
 445 #ifdef CONFIG_P2P
 446         if (wps) {
 447                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 448                 if (wpabuf_resize(&extra_ie, ielen) == 0)
 449                         wpas_p2p_scan_ie(wpa_s, extra_ie);
 450         }
 451 #endif /* CONFIG_P2P */
 452
 453 #endif /* CONFIG_WPS */
 454
 455         return extra_ie;
 456 }
 457
 458
 459 #ifdef CONFIG_P2P
 460
 461 /*
 462  * Check whether there are any enabled networks or credentials that could be
 463  * used for a non-P2P connection.
 464  */
 465 static int non_p2p_network_enabled(struct wpa_supplicant *wpa_s)
 466 {
 467         struct wpa_ssid *ssid;
 468
 469         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 470                 if (wpas_network_disabled(wpa_s, ssid))
 471                         continue;
 472                 if (!ssid->p2p_group)
 473                         return 1;
 474         }
 475
 476         if (wpa_s->conf->cred && wpa_s->conf->interworking &&
 477             wpa_s->conf->auto_interworking)
 478                 return 1;
 479
 480         return 0;
 481 }
 482
 483
 484 /*
 485  * Find the operating frequency of any other virtual interface that is using
 486  * the same radio concurrently.
 487  */
 488 static int shared_vif_oper_freq(struct wpa_supplicant *wpa_s)
 489 {
 490         const char *rn, *rn2;
 491         struct wpa_supplicant *ifs;
 492         u8 bssid[ETH_ALEN];
 493
 494         if (!wpa_s->driver->get_radio_name)
 495                 return -1;
 496
 497         rn = wpa_s->driver->get_radio_name(wpa_s->drv_priv);
 498         if (rn == NULL || rn[0] == '\0')
 499                 return -1;
 500
 501         for (ifs = wpa_s->global->ifaces; ifs; ifs = ifs->next) {
 502                 if (ifs == wpa_s || !ifs->driver->get_radio_name)
 503                         continue;
 504
 505                 rn2 = ifs->driver->get_radio_name(ifs->drv_priv);
 506                 if (!rn2 || os_strcmp(rn, rn2) != 0)
 507                         continue;
 508
 509                 if (ifs->current_ssid == NULL || ifs->assoc_freq == 0)
 510                         continue;
 511
 512                 if (ifs->current_ssid->mode == WPAS_MODE_AP ||
 513                     ifs->current_ssid->mode == WPAS_MODE_P2P_GO)
 514                         return ifs->current_ssid->frequency;
 515                 if (wpa_drv_get_bssid(ifs, bssid) == 0)
 516                         return ifs->assoc_freq;
 517         }
 518
 519         return 0;
 520 }
 521
 522 #endif /* CONFIG_P2P */
 523
 524
 525 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 526 {
 527         struct wpa_supplicant *wpa_s = eloop_ctx;
 528         struct wpa_ssid *ssid;
 529         enum scan_req_type scan_req = NORMAL_SCAN_REQ;
 530         int ret;
 531         struct wpabuf *extra_ie = NULL;
 532         struct wpa_driver_scan_params params;
 533         struct wpa_driver_scan_params *scan_params;
 534         size_t max_ssids;
 535         enum wpa_states prev_state;
 536
 537         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 538                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 539                 return;
 540         }
 541
 542         if (wpa_s->disconnected && wpa_s->scan_req == NORMAL_SCAN_REQ) {
 543                 wpa_dbg(wpa_s, MSG_DEBUG, "Disconnected - do not scan");
 544                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 545                 return;
 546         }
 547 #ifdef ANDROID
 548         if (wpa_s->scanning) {
 549                 /* If we are already in scanning state, we shall ignore this new scan request*/
 550                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - already scanning");
 551                 return;
 552         }
 553 #endif
 554         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 555             wpa_s->scan_req == NORMAL_SCAN_REQ) {
 556                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 557                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 558 #ifdef CONFIG_P2P
 559                 wpa_s->sta_scan_pending = 0;
 560 #endif /* CONFIG_P2P */
 561                 return;
 562         }
 563
 564         if (wpa_s->conf->ap_scan != 0 &&
 565             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 566                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 567                         "overriding ap_scan configuration");
 568                 wpa_s->conf->ap_scan = 0;
 569                 wpas_notify_ap_scan_changed(wpa_s);
 570         }
 571
 572         if (wpa_s->conf->ap_scan == 0) {
 573                 wpa_supplicant_gen_assoc_event(wpa_s);
 574                 return;
 575         }
 576
 577 #ifdef CONFIG_P2P
 578         if (wpas_p2p_in_progress(wpa_s)) {
 579                 if (wpa_s->sta_scan_pending &&
 580                     wpas_p2p_in_progress(wpa_s) == 2 &&
 581                     wpa_s->global->p2p_cb_on_scan_complete) {
 582                         wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
 583                                 "mode scan during P2P search");
 584                 } else {
 585                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 586                                 "while P2P operation is in progress");
 587                         wpa_s->sta_scan_pending = 1;
 588                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 589                         return;
 590                 }
 591         }
 592 #endif /* CONFIG_P2P */
 593
 594         if (wpa_s->conf->ap_scan == 2)
 595                 max_ssids = 1;
 596         else {
 597                 max_ssids = wpa_s->max_scan_ssids;
 598                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 599                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 600         }
 601
 602         scan_req = wpa_s->scan_req;
 603         wpa_s->scan_req = NORMAL_SCAN_REQ;
 604
 605         os_memset(&params, 0, sizeof(params));
 606
 607         prev_state = wpa_s->wpa_state;
 608         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 609             wpa_s->wpa_state == WPA_INACTIVE)
 610                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 611
 612         /*
 613          * If autoscan has set its own scanning parameters
 614          */
 615         if (wpa_s->autoscan_params != NULL) {
 616                 scan_params = wpa_s->autoscan_params;
 617                 goto scan;
 618         }
 619
 620         if (scan_req != MANUAL_SCAN_REQ && wpa_s->connect_without_scan) {
 621                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 622                         if (ssid == wpa_s->connect_without_scan)
 623                                 break;
 624                 }
 625                 wpa_s->connect_without_scan = NULL;
 626                 if (ssid) {
 627                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 628                                    "without scan step");
 629                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 630                         return;
 631                 }
 632         }
 633
 634 #ifdef CONFIG_P2P
 635         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 636             wpa_s->go_params) {
 637                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
 638                            "P2P group formation");
 639                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 640                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 641                 params.num_ssids = 1;
 642                 goto ssid_list_set;
 643         }
 644 #endif /* CONFIG_P2P */
 645
 646         /* Find the starting point from which to continue scanning */
 647         ssid = wpa_s->conf->ssid;
 648         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 649                 while (ssid) {
 650                         if (ssid == wpa_s->prev_scan_ssid) {
 651                                 ssid = ssid->next;
 652                                 break;
 653                         }
 654                         ssid = ssid->next;
 655                 }
 656         }
 657
 658         if (scan_req != MANUAL_SCAN_REQ && wpa_s->conf->ap_scan == 2) {
 659                 wpa_s->connect_without_scan = NULL;
 660                 wpa_s->prev_scan_wildcard = 0;
 661                 wpa_supplicant_assoc_try(wpa_s, ssid);
 662                 return;
 663 #ifndef ANDROID
 664         } else if (wpa_s->conf->ap_scan == 2) {
 665                 /*
 666                  * User-initiated scan request in ap_scan == 2; scan with
 667                  * wildcard SSID.
 668                  */
 669                 ssid = NULL;
 670 #endif
 671         } else {
 672                 struct wpa_ssid *start = ssid, *tssid;
 673                 int freqs_set = 0;
 674                 if (ssid == NULL && max_ssids > 1)
 675                         ssid = wpa_s->conf->ssid;
 676                 while (ssid) {
 677                         if (!wpas_network_disabled(wpa_s, ssid) &&
 678                             ssid->scan_ssid) {
 679                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 680                                                   ssid->ssid, ssid->ssid_len);
 681                                 params.ssids[params.num_ssids].ssid =
 682                                         ssid->ssid;
 683                                 params.ssids[params.num_ssids].ssid_len =
 684                                         ssid->ssid_len;
 685                                 params.num_ssids++;
 686                                 if (params.num_ssids + 1 >= max_ssids)
 687                                         break;
 688                         }
 689                         ssid = ssid->next;
 690                         if (ssid == start)
 691                                 break;
 692                         if (ssid == NULL && max_ssids > 1 &&
 693                             start != wpa_s->conf->ssid)
 694                                 ssid = wpa_s->conf->ssid;
 695                 }
 696
 697                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 698                         if (wpas_network_disabled(wpa_s, tssid))
 699                                 continue;
 700                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 701                                 int_array_concat(&params.freqs,
 702                                                  tssid->scan_freq);
 703                         } else {
 704                                 os_free(params.freqs);
 705                                 params.freqs = NULL;
 706                         }
 707                         freqs_set = 1;
 708                 }
 709                 int_array_sort_unique(params.freqs);
 710         }
 711
 712         if (ssid && max_ssids == 1) {
 713                 /*
 714                  * If the driver is limited to 1 SSID at a time interleave
 715                  * wildcard SSID scans with specific SSID scans to avoid
 716                  * waiting a long time for a wildcard scan.
 717                  */
 718                 if (!wpa_s->prev_scan_wildcard) {
 719                         params.ssids[0].ssid = NULL;
 720                         params.ssids[0].ssid_len = 0;
 721                         wpa_s->prev_scan_wildcard = 1;
 722                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 723                                 "wildcard SSID (Interleave with specific)");
 724                 } else {
 725                         wpa_s->prev_scan_ssid = ssid;
 726                         wpa_s->prev_scan_wildcard = 0;
 727                         wpa_dbg(wpa_s, MSG_DEBUG,
 728                                 "Starting AP scan for specific SSID: %s",
 729                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 730                 }
 731         } else if (ssid) {
 732                 /* max_ssids > 1 */
 733
 734                 wpa_s->prev_scan_ssid = ssid;
 735                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 736                         "the scan request");
 737                 params.num_ssids++;
 738         } else {
 739                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 740                 params.num_ssids++;
 741                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 742                         "SSID");
 743         }
 744 #ifdef CONFIG_P2P
 745 ssid_list_set:
 746 #endif /* CONFIG_P2P */
 747
 748         wpa_supplicant_optimize_freqs(wpa_s, &params);
 749         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 750
 751 #ifdef CONFIG_HS20
 752         if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 7) == 0)
 753                 wpas_hs20_add_indication(extra_ie);
 754 #endif /* CONFIG_HS20 */
 755
 756         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 757                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 758                         "generated frequency list");
 759                 params.freqs = wpa_s->next_scan_freqs;
 760         } else
 761                 os_free(wpa_s->next_scan_freqs);
 762         wpa_s->next_scan_freqs = NULL;
 763
 764         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 765                 wpa_s->conf, &params.num_filter_ssids);
 766         if (extra_ie) {
 767                 params.extra_ies = wpabuf_head(extra_ie);
 768                 params.extra_ies_len = wpabuf_len(extra_ie);
 769         }
 770
 771 #ifdef CONFIG_P2P
 772         if (wpa_s->p2p_in_provisioning ||
 773             (wpa_s->show_group_started && wpa_s->go_params)) {
 774                 /*
 775                  * The interface may not yet be in P2P mode, so we have to
 776                  * explicitly request P2P probe to disable CCK rates.
 777                  */
 778                 params.p2p_probe = 1;
 779         }
 780 #endif /* CONFIG_P2P */
 781
 782         scan_params = &params;
 783
 784 scan:
 785 #ifdef CONFIG_P2P
 786         /*
 787          * If the driver does not support multi-channel concurrency and a
 788          * virtual interface that shares the same radio with the wpa_s interface
 789          * is operating there may not be need to scan other channels apart from
 790          * the current operating channel on the other virtual interface. Filter
 791          * out other channels in case we are trying to find a connection for a
 792          * station interface when we are not configured to prefer station
 793          * connection and a concurrent operation is already in process.
 794          */
 795         if (wpa_s->scan_for_connection && scan_req == NORMAL_SCAN_REQ &&
 796             !scan_params->freqs && !params.freqs &&
 797             wpas_is_p2p_prioritized(wpa_s) &&
 798             !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_MULTI_CHANNEL_CONCURRENT) &&
 799             wpa_s->p2p_group_interface == NOT_P2P_GROUP_INTERFACE &&
 800             non_p2p_network_enabled(wpa_s)) {
 801                 int freq = shared_vif_oper_freq(wpa_s);
 802                 if (freq > 0) {
 803                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only the current "
 804                                 "operating channel (%d MHz) since driver does "
 805                                 "not support multi-channel concurrency", freq);
 806                         params.freqs = os_zalloc(sizeof(int) * 2);
 807                         if (params.freqs)
 808                                 params.freqs[0] = freq;
 809                         scan_params->freqs = params.freqs;
 810                 }
 811         }
 812 #endif /* CONFIG_P2P */
 813
 814         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 815
 816         wpabuf_free(extra_ie);
 817         os_free(params.freqs);
 818         os_free(params.filter_ssids);
 819
 820         if (ret) {
 821                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 822                 if (prev_state != wpa_s->wpa_state)
 823                         wpa_supplicant_set_state(wpa_s, prev_state);
 824                 /* Restore scan_req since we will try to scan again */
 825                 wpa_s->scan_req = scan_req;
 826                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 827         } else {
 828                 wpa_s->scan_for_connection = 0;
 829         }
 830 }
 831
 832
 833 void wpa_supplicant_update_scan_int(struct wpa_supplicant *wpa_s, int sec)
 834 {
 835         struct os_time remaining, new_int;
 836         int cancelled;
 837
 838         cancelled = eloop_cancel_timeout_one(wpa_supplicant_scan, wpa_s, NULL,
 839                                              &remaining);
 840
 841         new_int.sec = sec;
 842         new_int.usec = 0;
 843         if (cancelled && os_time_before(&remaining, &new_int)) {
 844                 new_int.sec = remaining.sec;
 845                 new_int.usec = remaining.usec;
 846         }
 847
 848         eloop_register_timeout(new_int.sec, new_int.usec, wpa_supplicant_scan,
 849                                wpa_s, NULL);
 850         wpa_s->scan_interval = sec;
 851 }
 852
 853
 854 /**
 855  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 856  * @wpa_s: Pointer to wpa_supplicant data
 857  * @sec: Number of seconds after which to scan
 858  * @usec: Number of microseconds after which to scan
 859  *
 860  * This function is used to schedule a scan for neighboring access points after
 861  * the specified time.
 862  */
 863 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 864 {
 865 #ifndef ANDROID
 866         /* If there's at least one network that should be specifically scanned
 867          * then don't cancel the scan and reschedule.  Some drivers do
 868          * background scanning which generates frequent scan results, and that
 869          * causes the specific SSID scan to get continually pushed back and
 870          * never happen, which causes hidden APs to never get probe-scanned.
 871          */
 872         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 873             wpa_s->conf->ap_scan == 1) {
 874                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 875
 876                 while (ssid) {
 877                         if (!wpas_network_disabled(wpa_s, ssid) &&
 878                             ssid->scan_ssid)
 879                                 break;
 880                         ssid = ssid->next;
 881                 }
 882                 if (ssid) {
 883                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 884                                 "ensure that specific SSID scans occur");
 885                         return;
 886                 }
 887         }
 888 #endif
 889         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 890                 sec, usec);
 891         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 892         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 893 }
 894
 895
 896 /**
 897  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 898  * @wpa_s: Pointer to wpa_supplicant data
 899  * @sec: Number of seconds after which to scan
 900  * @usec: Number of microseconds after which to scan
 901  * Returns: 0 on success or -1 otherwise
 902  *
 903  * This function is used to schedule periodic scans for neighboring
 904  * access points after the specified time.
 905  */
 906 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 907                                       int sec, int usec)
 908 {
 909         if (!wpa_s->sched_scan_supported)
 910                 return -1;
 911
 912         eloop_register_timeout(sec, usec,
 913                                wpa_supplicant_delayed_sched_scan_timeout,
 914                                wpa_s, NULL);
 915
 916         return 0;
 917 }
 918
 919
 920 /**
 921  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 922  * @wpa_s: Pointer to wpa_supplicant data
 923  * Returns: 0 is sched_scan was started or -1 otherwise
 924  *
 925  * This function is used to schedule periodic scans for neighboring
 926  * access points repeating the scan continuously.
 927  */
 928 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 929 {
 930         struct wpa_driver_scan_params params;
 931         struct wpa_driver_scan_params *scan_params;
 932         enum wpa_states prev_state;
 933         struct wpa_ssid *ssid = NULL;
 934         struct wpabuf *extra_ie = NULL;
 935         int ret;
 936         unsigned int max_sched_scan_ssids;
 937         int wildcard = 0;
 938         int need_ssids;
 939
 940         if (!wpa_s->sched_scan_supported)
 941                 return -1;
 942
 943         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 944                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 945         else
 946                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 947         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 948                 return -1;
 949
 950         if (wpa_s->sched_scanning) {
 951                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 952                 return 0;
 953         }
 954
 955         need_ssids = 0;
 956         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 957                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 958                         /* Use wildcard SSID to find this network */
 959                         wildcard = 1;
 960                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 961                            ssid->ssid_len)
 962                         need_ssids++;
 963
 964 #ifdef CONFIG_WPS
 965                 if (!wpas_network_disabled(wpa_s, ssid) &&
 966                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
 967                         /*
 968                          * Normal scan is more reliable and faster for WPS
 969                          * operations and since these are for short periods of
 970                          * time, the benefit of trying to use sched_scan would
 971                          * be limited.
 972                          */
 973                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 974                                 "sched_scan for WPS");
 975                         return -1;
 976                 }
 977 #endif /* CONFIG_WPS */
 978         }
 979         if (wildcard)
 980                 need_ssids++;
 981
 982         if (wpa_s->normal_scans < 3 &&
 983             (need_ssids <= wpa_s->max_scan_ssids ||
 984              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
 985                 /*
 986                  * When normal scan can speed up operations, use that for the
 987                  * first operations before starting the sched_scan to allow
 988                  * user space sleep more. We do this only if the normal scan
 989                  * has functionality that is suitable for this or if the
 990                  * sched_scan does not have better support for multiple SSIDs.
 991                  */
 992                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 993                         "sched_scan for initial scans (normal_scans=%d)",
 994                         wpa_s->normal_scans);
 995                 return -1;
 996         }
 997
 998         os_memset(&params, 0, sizeof(params));
 999
1000         /* If we can't allocate space for the filters, we just don't filter */
1001         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
1002                                         sizeof(struct wpa_driver_scan_filter));
1003
1004         prev_state = wpa_s->wpa_state;
1005 #ifndef ANDROID_P2P
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 #endif
1010
1011         if (wpa_s->autoscan_params != NULL) {
1012                 scan_params = wpa_s->autoscan_params;
1013                 goto scan;
1014         }
1015
1016         /* Find the starting point from which to continue scanning */
1017         ssid = wpa_s->conf->ssid;
1018         if (wpa_s->prev_sched_ssid) {
1019                 while (ssid) {
1020                         if (ssid == wpa_s->prev_sched_ssid) {
1021                                 ssid = ssid->next;
1022                                 break;
1023                         }
1024                         ssid = ssid->next;
1025                 }
1026         }
1027
1028         if (!ssid || !wpa_s->prev_sched_ssid) {
1029                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
1030
1031                 if (wpa_s->sched_scan_interval == 0)
1032                         wpa_s->sched_scan_interval = 10;
1033                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
1034                 wpa_s->first_sched_scan = 1;
1035                 ssid = wpa_s->conf->ssid;
1036                 wpa_s->prev_sched_ssid = ssid;
1037         }
1038
1039         if (wildcard) {
1040                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
1041                 params.num_ssids++;
1042         }
1043
1044         while (ssid) {
1045                 if (wpas_network_disabled(wpa_s, ssid))
1046                         goto next;
1047
1048                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
1049                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
1050                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
1051                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1052                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
1053                                   ssid->ssid, ssid->ssid_len);
1054                         params.filter_ssids[params.num_filter_ssids].ssid_len =
1055                                 ssid->ssid_len;
1056                         params.num_filter_ssids++;
1057                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
1058                 {
1059                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
1060                                 "filter for sched_scan - drop filter");
1061                         os_free(params.filter_ssids);
1062                         params.filter_ssids = NULL;
1063                         params.num_filter_ssids = 0;
1064                 }
1065
1066                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
1067                         if (params.num_ssids == max_sched_scan_ssids)
1068                                 break; /* only room for broadcast SSID */
1069                         wpa_dbg(wpa_s, MSG_DEBUG,
1070                                 "add to active scan ssid: %s",
1071                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
1072                         params.ssids[params.num_ssids].ssid =
1073                                 ssid->ssid;
1074                         params.ssids[params.num_ssids].ssid_len =
1075                                 ssid->ssid_len;
1076                         params.num_ssids++;
1077                         if (params.num_ssids >= max_sched_scan_ssids) {
1078                                 wpa_s->prev_sched_ssid = ssid;
1079                                 do {
1080                                         ssid = ssid->next;
1081                                 } while (ssid &&
1082                                          (wpas_network_disabled(wpa_s, ssid) ||
1083                                           !ssid->scan_ssid));
1084                                 break;
1085                         }
1086                 }
1087
1088         next:
1089                 wpa_s->prev_sched_ssid = ssid;
1090                 ssid = ssid->next;
1091         }
1092
1093         if (params.num_filter_ssids == 0) {
1094                 os_free(params.filter_ssids);
1095                 params.filter_ssids = NULL;
1096         }
1097
1098         extra_ie = wpa_supplicant_extra_ies(wpa_s);
1099         if (extra_ie) {
1100                 params.extra_ies = wpabuf_head(extra_ie);
1101                 params.extra_ies_len = wpabuf_len(extra_ie);
1102         }
1103
1104         scan_params = &params;
1105
1106 scan:
1107         if (ssid || !wpa_s->first_sched_scan) {
1108                 wpa_dbg(wpa_s, MSG_DEBUG,
1109                         "Starting sched scan: interval %d timeout %d",
1110                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
1111         } else {
1112                 wpa_dbg(wpa_s, MSG_DEBUG,
1113                         "Starting sched scan: interval %d (no timeout)",
1114                         wpa_s->sched_scan_interval);
1115         }
1116
1117         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
1118                                               wpa_s->sched_scan_interval);
1119         wpabuf_free(extra_ie);
1120         os_free(params.filter_ssids);
1121         if (ret) {
1122                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
1123                 if (prev_state != wpa_s->wpa_state)
1124                         wpa_supplicant_set_state(wpa_s, prev_state);
1125                 return ret;
1126         }
1127
1128         /* If we have more SSIDs to scan, add a timeout so we scan them too */
1129         if (ssid || !wpa_s->first_sched_scan) {
1130                 wpa_s->sched_scan_timed_out = 0;
1131                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
1132                                        wpa_supplicant_sched_scan_timeout,
1133                                        wpa_s, NULL);
1134                 wpa_s->first_sched_scan = 0;
1135                 wpa_s->sched_scan_timeout /= 2;
1136                 wpa_s->sched_scan_interval *= 2;
1137         }
1138
1139         return 0;
1140 }
1141
1142
1143 /**
1144  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
1145  * @wpa_s: Pointer to wpa_supplicant data
1146  *
1147  * This function is used to cancel a scan request scheduled with
1148  * wpa_supplicant_req_scan().
1149  */
1150 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
1151 {
1152         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
1153         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
1154 #ifdef ANDROID
1155         wpa_supplicant_notify_scanning(wpa_s, 0);
1156 #endif
1157 }
1158
1159
1160 /**
1161  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
1162  * @wpa_s: Pointer to wpa_supplicant data
1163  *
1164  * This function is used to stop a periodic scheduled scan.
1165  */
1166 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
1167 {
1168         if (!wpa_s->sched_scanning)
1169                 return;
1170
1171         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1172         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1173         wpa_supplicant_stop_sched_scan(wpa_s);
1174 }
1175
1176
1177 /**
1178  * wpa_supplicant_notify_scanning - Indicate possible scan state change
1179  * @wpa_s: Pointer to wpa_supplicant data
1180  * @scanning: Whether scanning is currently in progress
1181  *
1182  * This function is to generate scanning notifycations. It is called whenever
1183  * there may have been a change in scanning (scan started, completed, stopped).
1184  * wpas_notify_scanning() is called whenever the scanning state changed from the
1185  * previously notified state.
1186  */
1187 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1188                                     int scanning)
1189 {
1190         if (wpa_s->scanning != scanning) {
1191 #ifdef ANDROID_P2P
1192                 if(!wpa_s->sched_scanning)
1193                         wpa_s->scanning = scanning;
1194 #else
1195                 wpa_s->scanning = scanning;
1196 #endif
1197                 wpas_notify_scanning(wpa_s);
1198         }
1199 }
1200
1201
1202 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1203 {
1204         int rate = 0;
1205         const u8 *ie;
1206         int i;
1207
1208         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1209         for (i = 0; ie && i < ie[1]; i++) {
1210                 if ((ie[i + 2] & 0x7f) > rate)
1211                         rate = ie[i + 2] & 0x7f;
1212         }
1213
1214         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1215         for (i = 0; ie && i < ie[1]; i++) {
1216                 if ((ie[i + 2] & 0x7f) > rate)
1217                         rate = ie[i + 2] & 0x7f;
1218         }
1219
1220         return rate;
1221 }
1222
1223
1224 /**
1225  * wpa_scan_get_ie - Fetch a specified information element from a scan result
1226  * @res: Scan result entry
1227  * @ie: Information element identitifier (WLAN_EID_*)
1228  * Returns: Pointer to the information element (id field) or %NULL if not found
1229  *
1230  * This function returns the first matching information element in the scan
1231  * result.
1232  */
1233 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1234 {
1235         const u8 *end, *pos;
1236
1237         pos = (const u8 *) (res + 1);
1238         end = pos + res->ie_len;
1239
1240         while (pos + 1 < end) {
1241                 if (pos + 2 + pos[1] > end)
1242                         break;
1243                 if (pos[0] == ie)
1244                         return pos;
1245                 pos += 2 + pos[1];
1246         }
1247
1248         return NULL;
1249 }
1250
1251
1252 /**
1253  * wpa_scan_get_vendor_ie - Fetch vendor information element from a scan result
1254  * @res: Scan result entry
1255  * @vendor_type: Vendor type (four octets starting the IE payload)
1256  * Returns: Pointer to the information element (id field) or %NULL if not found
1257  *
1258  * This function returns the first matching information element in the scan
1259  * result.
1260  */
1261 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1262                                   u32 vendor_type)
1263 {
1264         const u8 *end, *pos;
1265
1266         pos = (const u8 *) (res + 1);
1267         end = pos + res->ie_len;
1268
1269         while (pos + 1 < end) {
1270                 if (pos + 2 + pos[1] > end)
1271                         break;
1272                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1273                     vendor_type == WPA_GET_BE32(&pos[2]))
1274                         return pos;
1275                 pos += 2 + pos[1];
1276         }
1277
1278         return NULL;
1279 }
1280
1281
1282 /**
1283  * wpa_scan_get_vendor_ie_multi - Fetch vendor IE data from a scan result
1284  * @res: Scan result entry
1285  * @vendor_type: Vendor type (four octets starting the IE payload)
1286  * Returns: Pointer to the information element payload or %NULL if not found
1287  *
1288  * This function returns concatenated payload of possibly fragmented vendor
1289  * specific information elements in the scan result. The caller is responsible
1290  * for freeing the returned buffer.
1291  */
1292 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1293                                              u32 vendor_type)
1294 {
1295         struct wpabuf *buf;
1296         const u8 *end, *pos;
1297
1298         buf = wpabuf_alloc(res->ie_len);
1299         if (buf == NULL)
1300                 return NULL;
1301
1302         pos = (const u8 *) (res + 1);
1303         end = pos + res->ie_len;
1304
1305         while (pos + 1 < end) {
1306                 if (pos + 2 + pos[1] > end)
1307                         break;
1308                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1309                     vendor_type == WPA_GET_BE32(&pos[2]))
1310                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1311                 pos += 2 + pos[1];
1312         }
1313
1314         if (wpabuf_len(buf) == 0) {
1315                 wpabuf_free(buf);
1316                 buf = NULL;
1317         }
1318
1319         return buf;
1320 }
1321
1322
1323 /*
1324  * Channels with a great SNR can operate at full rate. What is a great SNR?
1325  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1326  * rule of thumb is that any SNR above 20 is good." This one
1327  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1328  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1329  * conservative value.
1330  */
1331 #define GREAT_SNR 30
1332
1333 /* Compare function for sorting scan results. Return >0 if @b is considered
1334  * better. */
1335 static int wpa_scan_result_compar(const void *a, const void *b)
1336 {
1337 #define IS_5GHZ(n) (n > 4000)
1338 #define MIN(a,b) a < b ? a : b
1339         struct wpa_scan_res **_wa = (void *) a;
1340         struct wpa_scan_res **_wb = (void *) b;
1341         struct wpa_scan_res *wa = *_wa;
1342         struct wpa_scan_res *wb = *_wb;
1343         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1344         int snr_a, snr_b;
1345
1346         /* WPA/WPA2 support preferred */
1347         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1348                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1349         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1350                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1351
1352         if (wpa_b && !wpa_a)
1353                 return 1;
1354         if (!wpa_b && wpa_a)
1355                 return -1;
1356
1357         /* privacy support preferred */
1358         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1359             (wb->caps & IEEE80211_CAP_PRIVACY))
1360                 return 1;
1361         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1362             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1363                 return -1;
1364
1365         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1366             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1367                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1368                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1369         } else {
1370                 /* Not suitable information to calculate SNR, so use level */
1371                 snr_a = wa->level;
1372                 snr_b = wb->level;
1373         }
1374
1375         /* best/max rate preferred if SNR close enough */
1376         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1377             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1378                 maxrate_a = wpa_scan_get_max_rate(wa);
1379                 maxrate_b = wpa_scan_get_max_rate(wb);
1380                 if (maxrate_a != maxrate_b)
1381                         return maxrate_b - maxrate_a;
1382                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1383                         return IS_5GHZ(wa->freq) ? -1 : 1;
1384         }
1385
1386         /* use freq for channel preference */
1387
1388         /* all things being equal, use SNR; if SNRs are
1389          * identical, use quality values since some drivers may only report
1390          * that value and leave the signal level zero */
1391         if (snr_b == snr_a)
1392                 return wb->qual - wa->qual;
1393         return snr_b - snr_a;
1394 #undef MIN
1395 #undef IS_5GHZ
1396 }
1397
1398
1399 #ifdef CONFIG_WPS
1400 /* Compare function for sorting scan results when searching a WPS AP for
1401  * provisioning. Return >0 if @b is considered better. */
1402 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1403 {
1404         struct wpa_scan_res **_wa = (void *) a;
1405         struct wpa_scan_res **_wb = (void *) b;
1406         struct wpa_scan_res *wa = *_wa;
1407         struct wpa_scan_res *wb = *_wb;
1408         int uses_wps_a, uses_wps_b;
1409         struct wpabuf *wps_a, *wps_b;
1410         int res;
1411
1412         /* Optimization - check WPS IE existence before allocated memory and
1413          * doing full reassembly. */
1414         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1415         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1416         if (uses_wps_a && !uses_wps_b)
1417                 return -1;
1418         if (!uses_wps_a && uses_wps_b)
1419                 return 1;
1420
1421         if (uses_wps_a && uses_wps_b) {
1422                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1423                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1424                 res = wps_ap_priority_compar(wps_a, wps_b);
1425                 wpabuf_free(wps_a);
1426                 wpabuf_free(wps_b);
1427                 if (res)
1428                         return res;
1429         }
1430
1431         /*
1432          * Do not use current AP security policy as a sorting criteria during
1433          * WPS provisioning step since the AP may get reconfigured at the
1434          * completion of provisioning.
1435          */
1436
1437         /* all things being equal, use signal level; if signal levels are
1438          * identical, use quality values since some drivers may only report
1439          * that value and leave the signal level zero */
1440         if (wb->level == wa->level)
1441                 return wb->qual - wa->qual;
1442         return wb->level - wa->level;
1443 }
1444 #endif /* CONFIG_WPS */
1445
1446
1447 static void dump_scan_res(struct wpa_scan_results *scan_res)
1448 {
1449 #ifndef CONFIG_NO_STDOUT_DEBUG
1450         size_t i;
1451
1452         if (scan_res->res == NULL || scan_res->num == 0)
1453                 return;
1454
1455         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1456
1457         for (i = 0; i < scan_res->num; i++) {
1458                 struct wpa_scan_res *r = scan_res->res[i];
1459                 u8 *pos;
1460                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1461                     == WPA_SCAN_LEVEL_DBM) {
1462                         int snr = r->level - r->noise;
1463                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1464                                    "noise=%d level=%d snr=%d%s flags=0x%x "
1465                                    "age=%u",
1466                                    MAC2STR(r->bssid), r->freq, r->qual,
1467                                    r->noise, r->level, snr,
1468                                    snr >= GREAT_SNR ? "*" : "", r->flags,
1469                                    r->age);
1470                 } else {
1471                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1472                                    "noise=%d level=%d flags=0x%x age=%u",
1473                                    MAC2STR(r->bssid), r->freq, r->qual,
1474                                    r->noise, r->level, r->flags, r->age);
1475                 }
1476                 pos = (u8 *) (r + 1);
1477                 if (r->ie_len)
1478                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1479                 pos += r->ie_len;
1480                 if (r->beacon_ie_len)
1481                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1482                                     pos, r->beacon_ie_len);
1483         }
1484 #endif /* CONFIG_NO_STDOUT_DEBUG */
1485 }
1486
1487
1488 /**
1489  * wpa_supplicant_filter_bssid_match - Is the specified BSSID allowed
1490  * @wpa_s: Pointer to wpa_supplicant data
1491  * @bssid: BSSID to check
1492  * Returns: 0 if the BSSID is filtered or 1 if not
1493  *
1494  * This function is used to filter out specific BSSIDs from scan reslts mainly
1495  * for testing purposes (SET bssid_filter ctrl_iface command).
1496  */
1497 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1498                                       const u8 *bssid)
1499 {
1500         size_t i;
1501
1502         if (wpa_s->bssid_filter == NULL)
1503                 return 1;
1504
1505         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1506                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1507                               ETH_ALEN) == 0)
1508                         return 1;
1509         }
1510
1511         return 0;
1512 }
1513
1514
1515 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1516                             struct wpa_scan_results *res)
1517 {
1518         size_t i, j;
1519
1520         if (wpa_s->bssid_filter == NULL)
1521                 return;
1522
1523         for (i = 0, j = 0; i < res->num; i++) {
1524                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1525                                                       res->res[i]->bssid)) {
1526                         res->res[j++] = res->res[i];
1527                 } else {
1528                         os_free(res->res[i]);
1529                         res->res[i] = NULL;
1530                 }
1531         }
1532
1533         if (res->num != j) {
1534                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1535                            (int) (res->num - j));
1536                 res->num = j;
1537         }
1538 }
1539
1540
1541 /**
1542  * wpa_supplicant_get_scan_results - Get scan results
1543  * @wpa_s: Pointer to wpa_supplicant data
1544  * @info: Information about what was scanned or %NULL if not available
1545  * @new_scan: Whether a new scan was performed
1546  * Returns: Scan results, %NULL on failure
1547  *
1548  * This function request the current scan results from the driver and updates
1549  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1550  * results with wpa_scan_results_free().
1551  */
1552 struct wpa_scan_results *
1553 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1554                                 struct scan_info *info, int new_scan)
1555 {
1556         struct wpa_scan_results *scan_res;
1557         size_t i;
1558         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1559
1560         scan_res = wpa_drv_get_scan_results2(wpa_s);
1561         if (scan_res == NULL) {
1562                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1563                 return NULL;
1564         }
1565         if (scan_res->fetch_time.sec == 0) {
1566                 /*
1567                  * Make sure we have a valid timestamp if the driver wrapper
1568                  * does not set this.
1569                  */
1570                 os_get_time(&scan_res->fetch_time);
1571         }
1572         filter_scan_res(wpa_s, scan_res);
1573
1574 #ifdef CONFIG_WPS
1575         if (wpas_wps_in_progress(wpa_s)) {
1576                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1577                         "provisioning rules");
1578                 compar = wpa_scan_result_wps_compar;
1579         }
1580 #endif /* CONFIG_WPS */
1581
1582         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1583               compar);
1584         dump_scan_res(scan_res);
1585
1586         wpa_bss_update_start(wpa_s);
1587         for (i = 0; i < scan_res->num; i++)
1588                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i],
1589                                         &scan_res->fetch_time);
1590         wpa_bss_update_end(wpa_s, info, new_scan);
1591
1592         return scan_res;
1593 }
1594
1595
1596 /**
1597  * wpa_supplicant_update_scan_results - Update scan results from the driver
1598  * @wpa_s: Pointer to wpa_supplicant data
1599  * Returns: 0 on success, -1 on failure
1600  *
1601  * This function updates the BSS table within wpa_supplicant based on the
1602  * currently available scan results from the driver without requesting a new
1603  * scan. This is used in cases where the driver indicates an association
1604  * (including roaming within ESS) and wpa_supplicant does not yet have the
1605  * needed information to complete the connection (e.g., to perform validation
1606  * steps in 4-way handshake).
1607  */
1608 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1609 {
1610         struct wpa_scan_results *scan_res;
1611         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1612         if (scan_res == NULL)
1613                 return -1;
1614         wpa_scan_results_free(scan_res);
1615
1616         return 0;
1617 }
1618
1619
1620 /**
1621  * scan_only_handler - Reports scan results
1622  */
1623 void scan_only_handler(struct wpa_supplicant *wpa_s,
1624                        struct wpa_scan_results *scan_res)
1625 {
1626         wpa_dbg(wpa_s, MSG_DEBUG, "Scan-only results received");
1627         wpa_msg_ctrl(wpa_s, MSG_INFO, WPA_EVENT_SCAN_RESULTS);
1628         wpas_notify_scan_results(wpa_s);
1629         wpas_notify_scan_done(wpa_s, 1);
1630 }