wpa_supplicant/scan.c

   1 /*
   2  * WPA Supplicant - Scanning
   3  * Copyright (c) 2003-2010, 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 "config.h"
  15 #include "wpa_supplicant_i.h"
  16 #include "driver_i.h"
  17 #include "wps_supplicant.h"
  18 #include "p2p_supplicant.h"
  19 #include "p2p/p2p.h"
  20 #include "hs20_supplicant.h"
  21 #include "notify.h"
  22 #include "bss.h"
  23 #include "scan.h"
  24
  25
  26 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
  27 {
  28         struct wpa_ssid *ssid;
  29         union wpa_event_data data;
  30
  31         ssid = wpa_supplicant_get_ssid(wpa_s);
  32         if (ssid == NULL)
  33                 return;
  34
  35         if (wpa_s->current_ssid == NULL) {
  36                 wpa_s->current_ssid = ssid;
  37                 if (wpa_s->current_ssid != NULL)
  38                         wpas_notify_network_changed(wpa_s);
  39         }
  40         wpa_supplicant_initiate_eapol(wpa_s);
  41         wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
  42                 "network - generating associated event");
  43         os_memset(&data, 0, sizeof(data));
  44         wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
  45 }
  46
  47
  48 #ifdef CONFIG_WPS
  49 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
  50                            enum wps_request_type *req_type)
  51 {
  52         struct wpa_ssid *ssid;
  53         int wps = 0;
  54
  55         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
  56                 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
  57                         continue;
  58
  59                 wps = 1;
  60                 *req_type = wpas_wps_get_req_type(ssid);
  61                 if (!ssid->eap.phase1)
  62                         continue;
  63
  64                 if (os_strstr(ssid->eap.phase1, "pbc=1"))
  65                         return 2;
  66         }
  67
  68 #ifdef CONFIG_P2P
  69         if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p) {
  70                 wpa_s->wps->dev.p2p = 1;
  71                 if (!wps) {
  72                         wps = 1;
  73                         *req_type = WPS_REQ_ENROLLEE_INFO;
  74                 }
  75         }
  76 #endif /* CONFIG_P2P */
  77
  78         return wps;
  79 }
  80 #endif /* CONFIG_WPS */
  81
  82
  83 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
  84 {
  85         struct wpa_ssid *ssid = wpa_s->conf->ssid;
  86         int count = 0;
  87         while (ssid) {
  88                 if (!wpas_network_disabled(wpa_s, ssid))
  89                         count++;
  90                 ssid = ssid->next;
  91         }
  92         return count;
  93 }
  94
  95
  96 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
  97                                      struct wpa_ssid *ssid)
  98 {
  99         while (ssid) {
 100                 if (!wpas_network_disabled(wpa_s, ssid))
 101                         break;
 102                 ssid = ssid->next;
 103         }
 104
 105         /* ap_scan=2 mode - try to associate with each SSID. */
 106         if (ssid == NULL) {
 107                 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
 108                         "end of scan list - go back to beginning");
 109                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 110                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 111                 return;
 112         }
 113         if (ssid->next) {
 114                 /* Continue from the next SSID on the next attempt. */
 115                 wpa_s->prev_scan_ssid = ssid;
 116         } else {
 117                 /* Start from the beginning of the SSID list. */
 118                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 119         }
 120         wpa_supplicant_associate(wpa_s, NULL, ssid);
 121 }
 122
 123
 124 static int int_array_len(const int *a)
 125 {
 126         int i;
 127         for (i = 0; a && a[i]; i++)
 128                 ;
 129         return i;
 130 }
 131
 132
 133 static void int_array_concat(int **res, const int *a)
 134 {
 135         int reslen, alen, i;
 136         int *n;
 137
 138         reslen = int_array_len(*res);
 139         alen = int_array_len(a);
 140
 141         n = os_realloc_array(*res, reslen + alen + 1, sizeof(int));
 142         if (n == NULL) {
 143                 os_free(*res);
 144                 *res = NULL;
 145                 return;
 146         }
 147         for (i = 0; i <= alen; i++)
 148                 n[reslen + i] = a[i];
 149         *res = n;
 150 }
 151
 152
 153 static int freq_cmp(const void *a, const void *b)
 154 {
 155         int _a = *(int *) a;
 156         int _b = *(int *) b;
 157
 158         if (_a == 0)
 159                 return 1;
 160         if (_b == 0)
 161                 return -1;
 162         return _a - _b;
 163 }
 164
 165
 166 static void int_array_sort_unique(int *a)
 167 {
 168         int alen;
 169         int i, j;
 170
 171         if (a == NULL)
 172                 return;
 173
 174         alen = int_array_len(a);
 175         qsort(a, alen, sizeof(int), freq_cmp);
 176
 177         i = 0;
 178         j = 1;
 179         while (a[i] && a[j]) {
 180                 if (a[i] == a[j]) {
 181                         j++;
 182                         continue;
 183                 }
 184                 a[++i] = a[j++];
 185         }
 186         if (a[i])
 187                 i++;
 188         a[i] = 0;
 189 }
 190
 191
 192 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 193                                 struct wpa_driver_scan_params *params)
 194 {
 195         int ret;
 196
 197         wpa_supplicant_notify_scanning(wpa_s, 1);
 198
 199         ret = wpa_drv_scan(wpa_s, params);
 200         if (ret) {
 201                 wpa_supplicant_notify_scanning(wpa_s, 0);
 202                 wpas_notify_scan_done(wpa_s, 0);
 203         } else {
 204                 wpa_s->scan_runs++;
 205                 wpa_s->normal_scans++;
 206         }
 207
 208         return ret;
 209 }
 210
 211
 212 static void
 213 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 214 {
 215         struct wpa_supplicant *wpa_s = eloop_ctx;
 216
 217         wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
 218
 219         if (wpa_supplicant_req_sched_scan(wpa_s))
 220                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 221 }
 222
 223
 224 static void
 225 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 226 {
 227         struct wpa_supplicant *wpa_s = eloop_ctx;
 228
 229         wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
 230
 231         wpa_s->sched_scan_timed_out = 1;
 232         wpa_supplicant_cancel_sched_scan(wpa_s);
 233 }
 234
 235
 236 static int
 237 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
 238                                 struct wpa_driver_scan_params *params,
 239                                 int interval)
 240 {
 241         int ret;
 242
 243         wpa_supplicant_notify_scanning(wpa_s, 1);
 244         ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
 245         if (ret)
 246                 wpa_supplicant_notify_scanning(wpa_s, 0);
 247         else
 248                 wpa_s->sched_scanning = 1;
 249
 250         return ret;
 251 }
 252
 253
 254 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
 255 {
 256         int ret;
 257
 258         ret = wpa_drv_stop_sched_scan(wpa_s);
 259         if (ret) {
 260                 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
 261                 /* TODO: what to do if stopping fails? */
 262                 return -1;
 263         }
 264
 265         return ret;
 266 }
 267
 268
 269 static struct wpa_driver_scan_filter *
 270 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 271 {
 272         struct wpa_driver_scan_filter *ssids;
 273         struct wpa_ssid *ssid;
 274         size_t count;
 275
 276         *num_ssids = 0;
 277         if (!conf->filter_ssids)
 278                 return NULL;
 279
 280         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 281                 if (ssid->ssid && ssid->ssid_len)
 282                         count++;
 283         }
 284         if (count == 0)
 285                 return NULL;
 286         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 287         if (ssids == NULL)
 288                 return NULL;
 289
 290         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 291                 if (!ssid->ssid || !ssid->ssid_len)
 292                         continue;
 293                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 294                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 295                 (*num_ssids)++;
 296         }
 297
 298         return ssids;
 299 }
 300
 301
 302 static void wpa_supplicant_optimize_freqs(
 303         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 304 {
 305 #ifdef CONFIG_P2P
 306         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 307             wpa_s->go_params) {
 308                 /* Optimize provisioning state scan based on GO information */
 309                 if (wpa_s->p2p_in_provisioning < 5 &&
 310                     wpa_s->go_params->freq > 0) {
 311                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 312                                 "preferred frequency %d MHz",
 313                                 wpa_s->go_params->freq);
 314                         params->freqs = os_zalloc(2 * sizeof(int));
 315                         if (params->freqs)
 316                                 params->freqs[0] = wpa_s->go_params->freq;
 317                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 318                            wpa_s->go_params->freq_list[0]) {
 319                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 320                                 "channels");
 321                         int_array_concat(&params->freqs,
 322                                          wpa_s->go_params->freq_list);
 323                         if (params->freqs)
 324                                 int_array_sort_unique(params->freqs);
 325                 }
 326                 wpa_s->p2p_in_provisioning++;
 327         }
 328 #endif /* CONFIG_P2P */
 329
 330 #ifdef CONFIG_WPS
 331         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 332                 /*
 333                  * Optimize post-provisioning scan based on channel used
 334                  * during provisioning.
 335                  */
 336                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 337                         "that was used during provisioning", wpa_s->wps_freq);
 338                 params->freqs = os_zalloc(2 * sizeof(int));
 339                 if (params->freqs)
 340                         params->freqs[0] = wpa_s->wps_freq;
 341                 wpa_s->after_wps--;
 342         }
 343
 344         if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
 345         {
 346                 /* Optimize provisioning scan based on already known channel */
 347                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
 348                         wpa_s->wps_freq);
 349                 params->freqs = os_zalloc(2 * sizeof(int));
 350                 if (params->freqs)
 351                         params->freqs[0] = wpa_s->wps_freq;
 352                 wpa_s->known_wps_freq = 0; /* only do this once */
 353         }
 354 #endif /* CONFIG_WPS */
 355 }
 356
 357
 358 #ifdef CONFIG_INTERWORKING
 359 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
 360                                            struct wpabuf *buf)
 361 {
 362         if (wpa_s->conf->interworking == 0)
 363                 return;
 364
 365         wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
 366         wpabuf_put_u8(buf, 4);
 367         wpabuf_put_u8(buf, 0x00);
 368         wpabuf_put_u8(buf, 0x00);
 369         wpabuf_put_u8(buf, 0x00);
 370         wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
 371
 372         wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
 373         wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
 374                       1 + ETH_ALEN);
 375         wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
 376         /* No Venue Info */
 377         if (!is_zero_ether_addr(wpa_s->conf->hessid))
 378                 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
 379 }
 380 #endif /* CONFIG_INTERWORKING */
 381
 382
 383 static struct wpabuf *
 384 wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s,
 385                          struct wpa_driver_scan_params *params)
 386 {
 387         struct wpabuf *extra_ie = NULL;
 388 #ifdef CONFIG_WPS
 389         int wps = 0;
 390         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 391 #endif /* CONFIG_WPS */
 392
 393 #ifdef CONFIG_INTERWORKING
 394         if (wpa_s->conf->interworking &&
 395             wpabuf_resize(&extra_ie, 100) == 0)
 396                 wpas_add_interworking_elements(wpa_s, extra_ie);
 397 #endif /* CONFIG_INTERWORKING */
 398
 399 #ifdef CONFIG_WPS
 400         wps = wpas_wps_in_use(wpa_s, &req_type);
 401
 402         if (wps) {
 403                 struct wpabuf *wps_ie;
 404                 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
 405                                                 DEV_PW_DEFAULT,
 406                                                 &wpa_s->wps->dev,
 407                                                 wpa_s->wps->uuid, req_type,
 408                                                 0, NULL);
 409                 if (wps_ie) {
 410                         if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
 411                                 wpabuf_put_buf(extra_ie, wps_ie);
 412                         wpabuf_free(wps_ie);
 413                 }
 414         }
 415
 416 #ifdef CONFIG_P2P
 417         if (wps) {
 418                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 419                 if (wpabuf_resize(&extra_ie, ielen) == 0)
 420                         wpas_p2p_scan_ie(wpa_s, extra_ie);
 421         }
 422 #endif /* CONFIG_P2P */
 423
 424 #endif /* CONFIG_WPS */
 425
 426         return extra_ie;
 427 }
 428
 429
 430 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 431 {
 432         struct wpa_supplicant *wpa_s = eloop_ctx;
 433         struct wpa_ssid *ssid;
 434         int scan_req = 0, ret;
 435         struct wpabuf *extra_ie = NULL;
 436         struct wpa_driver_scan_params params;
 437         struct wpa_driver_scan_params *scan_params;
 438         size_t max_ssids;
 439         enum wpa_states prev_state;
 440
 441         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 442                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 443                 return;
 444         }
 445
 446         if (wpa_s->disconnected && !wpa_s->scan_req) {
 447                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 448                 return;
 449         }
 450
 451         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 452             !wpa_s->scan_req) {
 453                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 454                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 455                 return;
 456         }
 457
 458         if (wpa_s->conf->ap_scan != 0 &&
 459             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 460                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 461                         "overriding ap_scan configuration");
 462                 wpa_s->conf->ap_scan = 0;
 463                 wpas_notify_ap_scan_changed(wpa_s);
 464         }
 465
 466         if (wpa_s->conf->ap_scan == 0) {
 467                 wpa_supplicant_gen_assoc_event(wpa_s);
 468                 return;
 469         }
 470
 471 #ifdef CONFIG_P2P
 472         if (wpas_p2p_in_progress(wpa_s)) {
 473                 if (wpa_s->wpa_state == WPA_SCANNING) {
 474                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 475                                 "while P2P operation is in progress");
 476                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 477                 } else {
 478                         wpa_dbg(wpa_s, MSG_DEBUG, "Do not request scan while "
 479                                 "P2P operation is in progress");
 480                 }
 481                 return;
 482         }
 483 #endif /* CONFIG_P2P */
 484
 485         if (wpa_s->conf->ap_scan == 2)
 486                 max_ssids = 1;
 487         else {
 488                 max_ssids = wpa_s->max_scan_ssids;
 489                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 490                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 491         }
 492
 493         scan_req = wpa_s->scan_req;
 494         wpa_s->scan_req = 0;
 495
 496         os_memset(&params, 0, sizeof(params));
 497
 498         prev_state = wpa_s->wpa_state;
 499         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 500             wpa_s->wpa_state == WPA_INACTIVE)
 501                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 502
 503         /*
 504          * If autoscan has set its own scanning parameters
 505          */
 506         if (wpa_s->autoscan_params != NULL) {
 507                 scan_params = wpa_s->autoscan_params;
 508                 goto scan;
 509         }
 510
 511         if (scan_req != 2 && wpa_s->connect_without_scan) {
 512                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 513                         if (ssid == wpa_s->connect_without_scan)
 514                                 break;
 515                 }
 516                 wpa_s->connect_without_scan = NULL;
 517                 if (ssid) {
 518                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 519                                    "without scan step");
 520                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 521                         return;
 522                 }
 523         }
 524
 525 #ifdef CONFIG_P2P
 526         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 527             wpa_s->go_params) {
 528                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
 529                            "P2P group formation");
 530                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 531                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 532                 params.num_ssids = 1;
 533                 goto ssid_list_set;
 534         }
 535 #endif /* CONFIG_P2P */
 536
 537         /* Find the starting point from which to continue scanning */
 538         ssid = wpa_s->conf->ssid;
 539         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 540                 while (ssid) {
 541                         if (ssid == wpa_s->prev_scan_ssid) {
 542                                 ssid = ssid->next;
 543                                 break;
 544                         }
 545                         ssid = ssid->next;
 546                 }
 547         }
 548
 549         if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
 550                 wpa_s->connect_without_scan = NULL;
 551                 wpa_s->prev_scan_wildcard = 0;
 552                 wpa_supplicant_assoc_try(wpa_s, ssid);
 553                 return;
 554         } else if (wpa_s->conf->ap_scan == 2) {
 555                 /*
 556                  * User-initiated scan request in ap_scan == 2; scan with
 557                  * wildcard SSID.
 558                  */
 559                 ssid = NULL;
 560         } else {
 561                 struct wpa_ssid *start = ssid, *tssid;
 562                 int freqs_set = 0;
 563                 if (ssid == NULL && max_ssids > 1)
 564                         ssid = wpa_s->conf->ssid;
 565                 while (ssid) {
 566                         if (!wpas_network_disabled(wpa_s, ssid) &&
 567                             ssid->scan_ssid) {
 568                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 569                                                   ssid->ssid, ssid->ssid_len);
 570                                 params.ssids[params.num_ssids].ssid =
 571                                         ssid->ssid;
 572                                 params.ssids[params.num_ssids].ssid_len =
 573                                         ssid->ssid_len;
 574                                 params.num_ssids++;
 575                                 if (params.num_ssids + 1 >= max_ssids)
 576                                         break;
 577                         }
 578                         ssid = ssid->next;
 579                         if (ssid == start)
 580                                 break;
 581                         if (ssid == NULL && max_ssids > 1 &&
 582                             start != wpa_s->conf->ssid)
 583                                 ssid = wpa_s->conf->ssid;
 584                 }
 585
 586                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 587                         if (wpas_network_disabled(wpa_s, tssid))
 588                                 continue;
 589                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 590                                 int_array_concat(&params.freqs,
 591                                                  tssid->scan_freq);
 592                         } else {
 593                                 os_free(params.freqs);
 594                                 params.freqs = NULL;
 595                         }
 596                         freqs_set = 1;
 597                 }
 598                 int_array_sort_unique(params.freqs);
 599         }
 600
 601         if (ssid && max_ssids == 1) {
 602                 /*
 603                  * If the driver is limited to 1 SSID at a time interleave
 604                  * wildcard SSID scans with specific SSID scans to avoid
 605                  * waiting a long time for a wildcard scan.
 606                  */
 607                 if (!wpa_s->prev_scan_wildcard) {
 608                         params.ssids[0].ssid = NULL;
 609                         params.ssids[0].ssid_len = 0;
 610                         wpa_s->prev_scan_wildcard = 1;
 611                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 612                                 "wildcard SSID (Interleave with specific)");
 613                 } else {
 614                         wpa_s->prev_scan_ssid = ssid;
 615                         wpa_s->prev_scan_wildcard = 0;
 616                         wpa_dbg(wpa_s, MSG_DEBUG,
 617                                 "Starting AP scan for specific SSID: %s",
 618                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 619                 }
 620         } else if (ssid) {
 621                 /* max_ssids > 1 */
 622
 623                 wpa_s->prev_scan_ssid = ssid;
 624                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 625                         "the scan request");
 626                 params.num_ssids++;
 627         } else {
 628                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 629                 params.num_ssids++;
 630                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 631                         "SSID");
 632         }
 633 #ifdef CONFIG_P2P
 634 ssid_list_set:
 635 #endif /* CONFIG_P2P */
 636
 637         wpa_supplicant_optimize_freqs(wpa_s, &params);
 638         extra_ie = wpa_supplicant_extra_ies(wpa_s, &params);
 639
 640 #ifdef CONFIG_HS20
 641         if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 6) == 0)
 642                 wpas_hs20_add_indication(extra_ie);
 643 #endif /* CONFIG_HS20 */
 644
 645         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 646                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 647                         "generated frequency list");
 648                 params.freqs = wpa_s->next_scan_freqs;
 649         } else
 650                 os_free(wpa_s->next_scan_freqs);
 651         wpa_s->next_scan_freqs = NULL;
 652
 653         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 654                 wpa_s->conf, &params.num_filter_ssids);
 655         if (extra_ie) {
 656                 params.extra_ies = wpabuf_head(extra_ie);
 657                 params.extra_ies_len = wpabuf_len(extra_ie);
 658         }
 659
 660 #ifdef CONFIG_P2P
 661         if (wpa_s->p2p_in_provisioning ||
 662             (wpa_s->show_group_started && wpa_s->go_params)) {
 663                 /*
 664                  * The interface may not yet be in P2P mode, so we have to
 665                  * explicitly request P2P probe to disable CCK rates.
 666                  */
 667                 params.p2p_probe = 1;
 668         }
 669 #endif /* CONFIG_P2P */
 670
 671         scan_params = &params;
 672
 673 scan:
 674         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 675
 676         wpabuf_free(extra_ie);
 677         os_free(params.freqs);
 678         os_free(params.filter_ssids);
 679
 680         if (ret) {
 681                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 682                 if (prev_state != wpa_s->wpa_state)
 683                         wpa_supplicant_set_state(wpa_s, prev_state);
 684                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 685         }
 686 }
 687
 688
 689 /**
 690  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 691  * @wpa_s: Pointer to wpa_supplicant data
 692  * @sec: Number of seconds after which to scan
 693  * @usec: Number of microseconds after which to scan
 694  *
 695  * This function is used to schedule a scan for neighboring access points after
 696  * the specified time.
 697  */
 698 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 699 {
 700         /* If there's at least one network that should be specifically scanned
 701          * then don't cancel the scan and reschedule.  Some drivers do
 702          * background scanning which generates frequent scan results, and that
 703          * causes the specific SSID scan to get continually pushed back and
 704          * never happen, which causes hidden APs to never get probe-scanned.
 705          */
 706         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 707             wpa_s->conf->ap_scan == 1) {
 708                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 709
 710                 while (ssid) {
 711                         if (!wpas_network_disabled(wpa_s, ssid) &&
 712                             ssid->scan_ssid)
 713                                 break;
 714                         ssid = ssid->next;
 715                 }
 716                 if (ssid) {
 717                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 718                                 "ensure that specific SSID scans occur");
 719                         return;
 720                 }
 721         }
 722
 723         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 724                 sec, usec);
 725         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 726         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 727 }
 728
 729
 730 /**
 731  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 732  * @wpa_s: Pointer to wpa_supplicant data
 733  * @sec: Number of seconds after which to scan
 734  * @usec: Number of microseconds after which to scan
 735  *
 736  * This function is used to schedule periodic scans for neighboring
 737  * access points after the specified time.
 738  */
 739 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 740                                       int sec, int usec)
 741 {
 742         if (!wpa_s->sched_scan_supported)
 743                 return -1;
 744
 745         eloop_register_timeout(sec, usec,
 746                                wpa_supplicant_delayed_sched_scan_timeout,
 747                                wpa_s, NULL);
 748
 749         return 0;
 750 }
 751
 752
 753 /**
 754  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 755  * @wpa_s: Pointer to wpa_supplicant data
 756  *
 757  * This function is used to schedule periodic scans for neighboring
 758  * access points repeating the scan continuously.
 759  */
 760 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 761 {
 762         struct wpa_driver_scan_params params;
 763         struct wpa_driver_scan_params *scan_params;
 764         enum wpa_states prev_state;
 765         struct wpa_ssid *ssid = NULL;
 766         struct wpabuf *wps_ie = NULL;
 767         int ret;
 768         unsigned int max_sched_scan_ssids;
 769         int wildcard = 0;
 770         int need_ssids;
 771
 772         if (!wpa_s->sched_scan_supported)
 773                 return -1;
 774
 775         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 776                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 777         else
 778                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 779         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 780                 return -1;
 781
 782         if (wpa_s->sched_scanning) {
 783                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 784                 return 0;
 785         }
 786
 787         need_ssids = 0;
 788         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 789                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 790                         /* Use wildcard SSID to find this network */
 791                         wildcard = 1;
 792                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 793                            ssid->ssid_len)
 794                         need_ssids++;
 795
 796 #ifdef CONFIG_WPS
 797                 if (!wpas_network_disabled(wpa_s, ssid) &&
 798                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
 799                         /*
 800                          * Normal scan is more reliable and faster for WPS
 801                          * operations and since these are for short periods of
 802                          * time, the benefit of trying to use sched_scan would
 803                          * be limited.
 804                          */
 805                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 806                                 "sched_scan for WPS");
 807                         return -1;
 808                 }
 809 #endif /* CONFIG_WPS */
 810         }
 811         if (wildcard)
 812                 need_ssids++;
 813
 814         if (wpa_s->normal_scans < 3 &&
 815             (need_ssids <= wpa_s->max_scan_ssids ||
 816              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
 817                 /*
 818                  * When normal scan can speed up operations, use that for the
 819                  * first operations before starting the sched_scan to allow
 820                  * user space sleep more. We do this only if the normal scan
 821                  * has functionality that is suitable for this or if the
 822                  * sched_scan does not have better support for multiple SSIDs.
 823                  */
 824                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 825                         "sched_scan for initial scans (normal_scans=%d)",
 826                         wpa_s->normal_scans);
 827                 return -1;
 828         }
 829
 830         os_memset(&params, 0, sizeof(params));
 831
 832         /* If we can't allocate space for the filters, we just don't filter */
 833         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
 834                                         sizeof(struct wpa_driver_scan_filter));
 835
 836         prev_state = wpa_s->wpa_state;
 837         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 838             wpa_s->wpa_state == WPA_INACTIVE)
 839                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 840
 841         if (wpa_s->autoscan_params != NULL) {
 842                 scan_params = wpa_s->autoscan_params;
 843                 goto scan;
 844         }
 845
 846         /* Find the starting point from which to continue scanning */
 847         ssid = wpa_s->conf->ssid;
 848         if (wpa_s->prev_sched_ssid) {
 849                 while (ssid) {
 850                         if (ssid == wpa_s->prev_sched_ssid) {
 851                                 ssid = ssid->next;
 852                                 break;
 853                         }
 854                         ssid = ssid->next;
 855                 }
 856         }
 857
 858         if (!ssid || !wpa_s->prev_sched_ssid) {
 859                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
 860
 861                 if (wpa_s->sched_scan_interval == 0)
 862                         wpa_s->sched_scan_interval = 10;
 863                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
 864                 wpa_s->first_sched_scan = 1;
 865                 ssid = wpa_s->conf->ssid;
 866                 wpa_s->prev_sched_ssid = ssid;
 867         }
 868
 869         if (wildcard) {
 870                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
 871                 params.num_ssids++;
 872         }
 873
 874         while (ssid) {
 875                 if (wpas_network_disabled(wpa_s, ssid))
 876                         goto next;
 877
 878                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
 879                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
 880                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
 881                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 882                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
 883                                   ssid->ssid, ssid->ssid_len);
 884                         params.filter_ssids[params.num_filter_ssids].ssid_len =
 885                                 ssid->ssid_len;
 886                         params.num_filter_ssids++;
 887                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
 888                 {
 889                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
 890                                 "filter for sched_scan - drop filter");
 891                         os_free(params.filter_ssids);
 892                         params.filter_ssids = NULL;
 893                         params.num_filter_ssids = 0;
 894                 }
 895
 896                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
 897                         if (params.num_ssids == max_sched_scan_ssids)
 898                                 break; /* only room for broadcast SSID */
 899                         wpa_dbg(wpa_s, MSG_DEBUG,
 900                                 "add to active scan ssid: %s",
 901                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 902                         params.ssids[params.num_ssids].ssid =
 903                                 ssid->ssid;
 904                         params.ssids[params.num_ssids].ssid_len =
 905                                 ssid->ssid_len;
 906                         params.num_ssids++;
 907                         if (params.num_ssids >= max_sched_scan_ssids) {
 908                                 wpa_s->prev_sched_ssid = ssid;
 909                                 do {
 910                                         ssid = ssid->next;
 911                                 } while (ssid &&
 912                                          (wpas_network_disabled(wpa_s, ssid) ||
 913                                           !ssid->scan_ssid));
 914                                 break;
 915                         }
 916                 }
 917
 918         next:
 919                 wpa_s->prev_sched_ssid = ssid;
 920                 ssid = ssid->next;
 921         }
 922
 923         if (params.num_filter_ssids == 0) {
 924                 os_free(params.filter_ssids);
 925                 params.filter_ssids = NULL;
 926         }
 927
 928         if (wpa_s->wps)
 929                 wps_ie = wpa_supplicant_extra_ies(wpa_s, &params);
 930
 931         scan_params = &params;
 932
 933 scan:
 934         if (ssid || !wpa_s->first_sched_scan) {
 935                 wpa_dbg(wpa_s, MSG_DEBUG,
 936                         "Starting sched scan: interval %d timeout %d",
 937                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
 938         } else {
 939                 wpa_dbg(wpa_s, MSG_DEBUG,
 940                         "Starting sched scan: interval %d (no timeout)",
 941                         wpa_s->sched_scan_interval);
 942         }
 943
 944         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
 945                                               wpa_s->sched_scan_interval);
 946         wpabuf_free(wps_ie);
 947         os_free(params.filter_ssids);
 948         if (ret) {
 949                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
 950                 if (prev_state != wpa_s->wpa_state)
 951                         wpa_supplicant_set_state(wpa_s, prev_state);
 952                 return ret;
 953         }
 954
 955         /* If we have more SSIDs to scan, add a timeout so we scan them too */
 956         if (ssid || !wpa_s->first_sched_scan) {
 957                 wpa_s->sched_scan_timed_out = 0;
 958                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
 959                                        wpa_supplicant_sched_scan_timeout,
 960                                        wpa_s, NULL);
 961                 wpa_s->first_sched_scan = 0;
 962                 wpa_s->sched_scan_timeout /= 2;
 963                 wpa_s->sched_scan_interval *= 2;
 964         }
 965
 966         return 0;
 967 }
 968
 969
 970 /**
 971  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 972  * @wpa_s: Pointer to wpa_supplicant data
 973  *
 974  * This function is used to cancel a scan request scheduled with
 975  * wpa_supplicant_req_scan().
 976  */
 977 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
 978 {
 979         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
 980         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 981 }
 982
 983
 984 /**
 985  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
 986  * @wpa_s: Pointer to wpa_supplicant data
 987  *
 988  * This function is used to stop a periodic scheduled scan.
 989  */
 990 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
 991 {
 992         if (!wpa_s->sched_scanning)
 993                 return;
 994
 995         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
 996         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
 997         wpa_supplicant_stop_sched_scan(wpa_s);
 998 }
 999
1000
1001 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1002                                     int scanning)
1003 {
1004         if (wpa_s->scanning != scanning) {
1005                 wpa_s->scanning = scanning;
1006                 wpas_notify_scanning(wpa_s);
1007         }
1008 }
1009
1010
1011 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1012 {
1013         int rate = 0;
1014         const u8 *ie;
1015         int i;
1016
1017         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1018         for (i = 0; ie && i < ie[1]; i++) {
1019                 if ((ie[i + 2] & 0x7f) > rate)
1020                         rate = ie[i + 2] & 0x7f;
1021         }
1022
1023         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1024         for (i = 0; ie && i < ie[1]; i++) {
1025                 if ((ie[i + 2] & 0x7f) > rate)
1026                         rate = ie[i + 2] & 0x7f;
1027         }
1028
1029         return rate;
1030 }
1031
1032
1033 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1034 {
1035         const u8 *end, *pos;
1036
1037         pos = (const u8 *) (res + 1);
1038         end = pos + res->ie_len;
1039
1040         while (pos + 1 < end) {
1041                 if (pos + 2 + pos[1] > end)
1042                         break;
1043                 if (pos[0] == ie)
1044                         return pos;
1045                 pos += 2 + pos[1];
1046         }
1047
1048         return NULL;
1049 }
1050
1051
1052 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1053                                   u32 vendor_type)
1054 {
1055         const u8 *end, *pos;
1056
1057         pos = (const u8 *) (res + 1);
1058         end = pos + res->ie_len;
1059
1060         while (pos + 1 < end) {
1061                 if (pos + 2 + pos[1] > end)
1062                         break;
1063                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1064                     vendor_type == WPA_GET_BE32(&pos[2]))
1065                         return pos;
1066                 pos += 2 + pos[1];
1067         }
1068
1069         return NULL;
1070 }
1071
1072
1073 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1074                                              u32 vendor_type)
1075 {
1076         struct wpabuf *buf;
1077         const u8 *end, *pos;
1078
1079         buf = wpabuf_alloc(res->ie_len);
1080         if (buf == NULL)
1081                 return NULL;
1082
1083         pos = (const u8 *) (res + 1);
1084         end = pos + res->ie_len;
1085
1086         while (pos + 1 < end) {
1087                 if (pos + 2 + pos[1] > end)
1088                         break;
1089                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1090                     vendor_type == WPA_GET_BE32(&pos[2]))
1091                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1092                 pos += 2 + pos[1];
1093         }
1094
1095         if (wpabuf_len(buf) == 0) {
1096                 wpabuf_free(buf);
1097                 buf = NULL;
1098         }
1099
1100         return buf;
1101 }
1102
1103
1104 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
1105         const struct wpa_scan_res *res, u32 vendor_type)
1106 {
1107         struct wpabuf *buf;
1108         const u8 *end, *pos;
1109
1110         if (res->beacon_ie_len == 0)
1111                 return NULL;
1112         buf = wpabuf_alloc(res->beacon_ie_len);
1113         if (buf == NULL)
1114                 return NULL;
1115
1116         pos = (const u8 *) (res + 1);
1117         pos += res->ie_len;
1118         end = pos + res->beacon_ie_len;
1119
1120         while (pos + 1 < end) {
1121                 if (pos + 2 + pos[1] > end)
1122                         break;
1123                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1124                     vendor_type == WPA_GET_BE32(&pos[2]))
1125                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1126                 pos += 2 + pos[1];
1127         }
1128
1129         if (wpabuf_len(buf) == 0) {
1130                 wpabuf_free(buf);
1131                 buf = NULL;
1132         }
1133
1134         return buf;
1135 }
1136
1137
1138 /*
1139  * Channels with a great SNR can operate at full rate. What is a great SNR?
1140  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1141  * rule of thumb is that any SNR above 20 is good." This one
1142  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1143  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1144  * conservative value.
1145  */
1146 #define GREAT_SNR 30
1147
1148 /* Compare function for sorting scan results. Return >0 if @b is considered
1149  * better. */
1150 static int wpa_scan_result_compar(const void *a, const void *b)
1151 {
1152 #define IS_5GHZ(n) (n > 4000)
1153 #define MIN(a,b) a < b ? a : b
1154         struct wpa_scan_res **_wa = (void *) a;
1155         struct wpa_scan_res **_wb = (void *) b;
1156         struct wpa_scan_res *wa = *_wa;
1157         struct wpa_scan_res *wb = *_wb;
1158         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1159         int snr_a, snr_b;
1160
1161         /* WPA/WPA2 support preferred */
1162         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1163                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1164         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1165                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1166
1167         if (wpa_b && !wpa_a)
1168                 return 1;
1169         if (!wpa_b && wpa_a)
1170                 return -1;
1171
1172         /* privacy support preferred */
1173         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1174             (wb->caps & IEEE80211_CAP_PRIVACY))
1175                 return 1;
1176         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1177             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1178                 return -1;
1179
1180         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1181             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1182                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1183                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1184         } else {
1185                 /* Not suitable information to calculate SNR, so use level */
1186                 snr_a = wa->level;
1187                 snr_b = wb->level;
1188         }
1189
1190         /* best/max rate preferred if SNR close enough */
1191         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1192             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1193                 maxrate_a = wpa_scan_get_max_rate(wa);
1194                 maxrate_b = wpa_scan_get_max_rate(wb);
1195                 if (maxrate_a != maxrate_b)
1196                         return maxrate_b - maxrate_a;
1197                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1198                         return IS_5GHZ(wa->freq) ? -1 : 1;
1199         }
1200
1201         /* use freq for channel preference */
1202
1203         /* all things being equal, use SNR; if SNRs are
1204          * identical, use quality values since some drivers may only report
1205          * that value and leave the signal level zero */
1206         if (snr_b == snr_a)
1207                 return wb->qual - wa->qual;
1208         return snr_b - snr_a;
1209 #undef MIN
1210 #undef IS_5GHZ
1211 }
1212
1213
1214 #ifdef CONFIG_WPS
1215 /* Compare function for sorting scan results when searching a WPS AP for
1216  * provisioning. Return >0 if @b is considered better. */
1217 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1218 {
1219         struct wpa_scan_res **_wa = (void *) a;
1220         struct wpa_scan_res **_wb = (void *) b;
1221         struct wpa_scan_res *wa = *_wa;
1222         struct wpa_scan_res *wb = *_wb;
1223         int uses_wps_a, uses_wps_b;
1224         struct wpabuf *wps_a, *wps_b;
1225         int res;
1226
1227         /* Optimization - check WPS IE existence before allocated memory and
1228          * doing full reassembly. */
1229         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1230         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1231         if (uses_wps_a && !uses_wps_b)
1232                 return -1;
1233         if (!uses_wps_a && uses_wps_b)
1234                 return 1;
1235
1236         if (uses_wps_a && uses_wps_b) {
1237                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1238                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1239                 res = wps_ap_priority_compar(wps_a, wps_b);
1240                 wpabuf_free(wps_a);
1241                 wpabuf_free(wps_b);
1242                 if (res)
1243                         return res;
1244         }
1245
1246         /*
1247          * Do not use current AP security policy as a sorting criteria during
1248          * WPS provisioning step since the AP may get reconfigured at the
1249          * completion of provisioning.
1250          */
1251
1252         /* all things being equal, use signal level; if signal levels are
1253          * identical, use quality values since some drivers may only report
1254          * that value and leave the signal level zero */
1255         if (wb->level == wa->level)
1256                 return wb->qual - wa->qual;
1257         return wb->level - wa->level;
1258 }
1259 #endif /* CONFIG_WPS */
1260
1261
1262 static void dump_scan_res(struct wpa_scan_results *scan_res)
1263 {
1264 #ifndef CONFIG_NO_STDOUT_DEBUG
1265         size_t i;
1266
1267         if (scan_res->res == NULL || scan_res->num == 0)
1268                 return;
1269
1270         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1271
1272         for (i = 0; i < scan_res->num; i++) {
1273                 struct wpa_scan_res *r = scan_res->res[i];
1274                 u8 *pos;
1275                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1276                     == WPA_SCAN_LEVEL_DBM) {
1277                         int snr = r->level - r->noise;
1278                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1279                                    "noise=%d level=%d snr=%d%s flags=0x%x",
1280                                    MAC2STR(r->bssid), r->freq, r->qual,
1281                                    r->noise, r->level, snr,
1282                                    snr >= GREAT_SNR ? "*" : "", r->flags);
1283                 } else {
1284                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1285                                    "noise=%d level=%d flags=0x%x",
1286                                    MAC2STR(r->bssid), r->freq, r->qual,
1287                                    r->noise, r->level, r->flags);
1288                 }
1289                 pos = (u8 *) (r + 1);
1290                 if (r->ie_len)
1291                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1292                 pos += r->ie_len;
1293                 if (r->beacon_ie_len)
1294                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1295                                     pos, r->beacon_ie_len);
1296         }
1297 #endif /* CONFIG_NO_STDOUT_DEBUG */
1298 }
1299
1300
1301 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1302                                       const u8 *bssid)
1303 {
1304         size_t i;
1305
1306         if (wpa_s->bssid_filter == NULL)
1307                 return 1;
1308
1309         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1310                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1311                               ETH_ALEN) == 0)
1312                         return 1;
1313         }
1314
1315         return 0;
1316 }
1317
1318
1319 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1320                             struct wpa_scan_results *res)
1321 {
1322         size_t i, j;
1323
1324         if (wpa_s->bssid_filter == NULL)
1325                 return;
1326
1327         for (i = 0, j = 0; i < res->num; i++) {
1328                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1329                                                       res->res[i]->bssid)) {
1330                         res->res[j++] = res->res[i];
1331                 } else {
1332                         os_free(res->res[i]);
1333                         res->res[i] = NULL;
1334                 }
1335         }
1336
1337         if (res->num != j) {
1338                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1339                            (int) (res->num - j));
1340                 res->num = j;
1341         }
1342 }
1343
1344
1345 /**
1346  * wpa_supplicant_get_scan_results - Get scan results
1347  * @wpa_s: Pointer to wpa_supplicant data
1348  * @info: Information about what was scanned or %NULL if not available
1349  * @new_scan: Whether a new scan was performed
1350  * Returns: Scan results, %NULL on failure
1351  *
1352  * This function request the current scan results from the driver and updates
1353  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1354  * results with wpa_scan_results_free().
1355  */
1356 struct wpa_scan_results *
1357 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1358                                 struct scan_info *info, int new_scan)
1359 {
1360         struct wpa_scan_results *scan_res;
1361         size_t i;
1362         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1363
1364         scan_res = wpa_drv_get_scan_results2(wpa_s);
1365         if (scan_res == NULL) {
1366                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1367                 return NULL;
1368         }
1369         filter_scan_res(wpa_s, scan_res);
1370
1371 #ifdef CONFIG_WPS
1372         if (wpas_wps_in_progress(wpa_s)) {
1373                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1374                         "provisioning rules");
1375                 compar = wpa_scan_result_wps_compar;
1376         }
1377 #endif /* CONFIG_WPS */
1378
1379         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1380               compar);
1381         dump_scan_res(scan_res);
1382
1383         wpa_bss_update_start(wpa_s);
1384         for (i = 0; i < scan_res->num; i++)
1385                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1386         wpa_bss_update_end(wpa_s, info, new_scan);
1387
1388         return scan_res;
1389 }
1390
1391
1392 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1393 {
1394         struct wpa_scan_results *scan_res;
1395         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1396         if (scan_res == NULL)
1397                 return -1;
1398         wpa_scan_results_free(scan_res);
1399
1400         return 0;
1401 }