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 * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
 384 {
 385         struct wpabuf *extra_ie = NULL;
 386 #ifdef CONFIG_WPS
 387         int wps = 0;
 388         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 389 #endif /* CONFIG_WPS */
 390
 391 #ifdef CONFIG_INTERWORKING
 392         if (wpa_s->conf->interworking &&
 393             wpabuf_resize(&extra_ie, 100) == 0)
 394                 wpas_add_interworking_elements(wpa_s, extra_ie);
 395 #endif /* CONFIG_INTERWORKING */
 396
 397 #ifdef CONFIG_WPS
 398         wps = wpas_wps_in_use(wpa_s, &req_type);
 399
 400         if (wps) {
 401                 struct wpabuf *wps_ie;
 402                 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
 403                                                 DEV_PW_DEFAULT,
 404                                                 &wpa_s->wps->dev,
 405                                                 wpa_s->wps->uuid, req_type,
 406                                                 0, NULL);
 407                 if (wps_ie) {
 408                         if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
 409                                 wpabuf_put_buf(extra_ie, wps_ie);
 410                         wpabuf_free(wps_ie);
 411                 }
 412         }
 413
 414 #ifdef CONFIG_P2P
 415         if (wps) {
 416                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 417                 if (wpabuf_resize(&extra_ie, ielen) == 0)
 418                         wpas_p2p_scan_ie(wpa_s, extra_ie);
 419         }
 420 #endif /* CONFIG_P2P */
 421
 422 #endif /* CONFIG_WPS */
 423
 424         return extra_ie;
 425 }
 426
 427
 428 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 429 {
 430         struct wpa_supplicant *wpa_s = eloop_ctx;
 431         struct wpa_ssid *ssid;
 432         int scan_req = 0, ret;
 433         struct wpabuf *extra_ie = NULL;
 434         struct wpa_driver_scan_params params;
 435         struct wpa_driver_scan_params *scan_params;
 436         size_t max_ssids;
 437         enum wpa_states prev_state;
 438
 439         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 440                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 441                 return;
 442         }
 443
 444         if (wpa_s->disconnected && !wpa_s->scan_req) {
 445                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 446                 return;
 447         }
 448
 449         if (!wpa_supplicant_enabled_networks(wpa_s) &&
 450             !wpa_s->scan_req) {
 451                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 452                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 453                 return;
 454         }
 455
 456         if (wpa_s->conf->ap_scan != 0 &&
 457             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 458                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 459                         "overriding ap_scan configuration");
 460                 wpa_s->conf->ap_scan = 0;
 461                 wpas_notify_ap_scan_changed(wpa_s);
 462         }
 463
 464         if (wpa_s->conf->ap_scan == 0) {
 465                 wpa_supplicant_gen_assoc_event(wpa_s);
 466                 return;
 467         }
 468
 469 #ifdef CONFIG_P2P
 470         if (wpas_p2p_in_progress(wpa_s)) {
 471                 if (wpa_s->wpa_state == WPA_SCANNING) {
 472                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 473                                 "while P2P operation is in progress");
 474                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 475                 } else {
 476                         wpa_dbg(wpa_s, MSG_DEBUG, "Do not request scan while "
 477                                 "P2P operation is in progress");
 478                 }
 479                 return;
 480         }
 481 #endif /* CONFIG_P2P */
 482
 483         if (wpa_s->conf->ap_scan == 2)
 484                 max_ssids = 1;
 485         else {
 486                 max_ssids = wpa_s->max_scan_ssids;
 487                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 488                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 489         }
 490
 491         scan_req = wpa_s->scan_req;
 492         wpa_s->scan_req = 0;
 493
 494         os_memset(&params, 0, sizeof(params));
 495
 496         prev_state = wpa_s->wpa_state;
 497         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 498             wpa_s->wpa_state == WPA_INACTIVE)
 499                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 500
 501         /*
 502          * If autoscan has set its own scanning parameters
 503          */
 504         if (wpa_s->autoscan_params != NULL) {
 505                 scan_params = wpa_s->autoscan_params;
 506                 goto scan;
 507         }
 508
 509         if (scan_req != 2 && wpa_s->connect_without_scan) {
 510                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 511                         if (ssid == wpa_s->connect_without_scan)
 512                                 break;
 513                 }
 514                 wpa_s->connect_without_scan = NULL;
 515                 if (ssid) {
 516                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 517                                    "without scan step");
 518                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 519                         return;
 520                 }
 521         }
 522
 523 #ifdef CONFIG_P2P
 524         if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 525             wpa_s->go_params) {
 526                 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
 527                            "P2P group formation");
 528                 params.ssids[0].ssid = wpa_s->go_params->ssid;
 529                 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
 530                 params.num_ssids = 1;
 531                 goto ssid_list_set;
 532         }
 533 #endif /* CONFIG_P2P */
 534
 535         /* Find the starting point from which to continue scanning */
 536         ssid = wpa_s->conf->ssid;
 537         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 538                 while (ssid) {
 539                         if (ssid == wpa_s->prev_scan_ssid) {
 540                                 ssid = ssid->next;
 541                                 break;
 542                         }
 543                         ssid = ssid->next;
 544                 }
 545         }
 546
 547         if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
 548                 wpa_s->connect_without_scan = NULL;
 549                 wpa_s->prev_scan_wildcard = 0;
 550                 wpa_supplicant_assoc_try(wpa_s, ssid);
 551                 return;
 552         } else if (wpa_s->conf->ap_scan == 2) {
 553                 /*
 554                  * User-initiated scan request in ap_scan == 2; scan with
 555                  * wildcard SSID.
 556                  */
 557                 ssid = NULL;
 558         } else {
 559                 struct wpa_ssid *start = ssid, *tssid;
 560                 int freqs_set = 0;
 561                 if (ssid == NULL && max_ssids > 1)
 562                         ssid = wpa_s->conf->ssid;
 563                 while (ssid) {
 564                         if (!wpas_network_disabled(wpa_s, ssid) &&
 565                             ssid->scan_ssid) {
 566                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 567                                                   ssid->ssid, ssid->ssid_len);
 568                                 params.ssids[params.num_ssids].ssid =
 569                                         ssid->ssid;
 570                                 params.ssids[params.num_ssids].ssid_len =
 571                                         ssid->ssid_len;
 572                                 params.num_ssids++;
 573                                 if (params.num_ssids + 1 >= max_ssids)
 574                                         break;
 575                         }
 576                         ssid = ssid->next;
 577                         if (ssid == start)
 578                                 break;
 579                         if (ssid == NULL && max_ssids > 1 &&
 580                             start != wpa_s->conf->ssid)
 581                                 ssid = wpa_s->conf->ssid;
 582                 }
 583
 584                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 585                         if (wpas_network_disabled(wpa_s, tssid))
 586                                 continue;
 587                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 588                                 int_array_concat(&params.freqs,
 589                                                  tssid->scan_freq);
 590                         } else {
 591                                 os_free(params.freqs);
 592                                 params.freqs = NULL;
 593                         }
 594                         freqs_set = 1;
 595                 }
 596                 int_array_sort_unique(params.freqs);
 597         }
 598
 599         if (ssid && max_ssids == 1) {
 600                 /*
 601                  * If the driver is limited to 1 SSID at a time interleave
 602                  * wildcard SSID scans with specific SSID scans to avoid
 603                  * waiting a long time for a wildcard scan.
 604                  */
 605                 if (!wpa_s->prev_scan_wildcard) {
 606                         params.ssids[0].ssid = NULL;
 607                         params.ssids[0].ssid_len = 0;
 608                         wpa_s->prev_scan_wildcard = 1;
 609                         wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
 610                                 "wildcard SSID (Interleave with specific)");
 611                 } else {
 612                         wpa_s->prev_scan_ssid = ssid;
 613                         wpa_s->prev_scan_wildcard = 0;
 614                         wpa_dbg(wpa_s, MSG_DEBUG,
 615                                 "Starting AP scan for specific SSID: %s",
 616                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 617                 }
 618         } else if (ssid) {
 619                 /* max_ssids > 1 */
 620
 621                 wpa_s->prev_scan_ssid = ssid;
 622                 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 623                         "the scan request");
 624                 params.num_ssids++;
 625         } else {
 626                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 627                 params.num_ssids++;
 628                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 629                         "SSID");
 630         }
 631 #ifdef CONFIG_P2P
 632 ssid_list_set:
 633 #endif /* CONFIG_P2P */
 634
 635         wpa_supplicant_optimize_freqs(wpa_s, &params);
 636         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 637
 638 #ifdef CONFIG_HS20
 639         if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 6) == 0)
 640                 wpas_hs20_add_indication(extra_ie);
 641 #endif /* CONFIG_HS20 */
 642
 643         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 644                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 645                         "generated frequency list");
 646                 params.freqs = wpa_s->next_scan_freqs;
 647         } else
 648                 os_free(wpa_s->next_scan_freqs);
 649         wpa_s->next_scan_freqs = NULL;
 650
 651         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 652                 wpa_s->conf, &params.num_filter_ssids);
 653         if (extra_ie) {
 654                 params.extra_ies = wpabuf_head(extra_ie);
 655                 params.extra_ies_len = wpabuf_len(extra_ie);
 656         }
 657
 658 #ifdef CONFIG_P2P
 659         if (wpa_s->p2p_in_provisioning ||
 660             (wpa_s->show_group_started && wpa_s->go_params)) {
 661                 /*
 662                  * The interface may not yet be in P2P mode, so we have to
 663                  * explicitly request P2P probe to disable CCK rates.
 664                  */
 665                 params.p2p_probe = 1;
 666         }
 667 #endif /* CONFIG_P2P */
 668
 669         scan_params = &params;
 670
 671 scan:
 672         ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
 673
 674         wpabuf_free(extra_ie);
 675         os_free(params.freqs);
 676         os_free(params.filter_ssids);
 677
 678         if (ret) {
 679                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 680                 if (prev_state != wpa_s->wpa_state)
 681                         wpa_supplicant_set_state(wpa_s, prev_state);
 682                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 683         }
 684 }
 685
 686
 687 /**
 688  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 689  * @wpa_s: Pointer to wpa_supplicant data
 690  * @sec: Number of seconds after which to scan
 691  * @usec: Number of microseconds after which to scan
 692  *
 693  * This function is used to schedule a scan for neighboring access points after
 694  * the specified time.
 695  */
 696 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 697 {
 698         /* If there's at least one network that should be specifically scanned
 699          * then don't cancel the scan and reschedule.  Some drivers do
 700          * background scanning which generates frequent scan results, and that
 701          * causes the specific SSID scan to get continually pushed back and
 702          * never happen, which causes hidden APs to never get probe-scanned.
 703          */
 704         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 705             wpa_s->conf->ap_scan == 1) {
 706                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 707
 708                 while (ssid) {
 709                         if (!wpas_network_disabled(wpa_s, ssid) &&
 710                             ssid->scan_ssid)
 711                                 break;
 712                         ssid = ssid->next;
 713                 }
 714                 if (ssid) {
 715                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 716                                 "ensure that specific SSID scans occur");
 717                         return;
 718                 }
 719         }
 720
 721         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 722                 sec, usec);
 723         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 724         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 725 }
 726
 727
 728 /**
 729  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 730  * @wpa_s: Pointer to wpa_supplicant data
 731  * @sec: Number of seconds after which to scan
 732  * @usec: Number of microseconds after which to scan
 733  *
 734  * This function is used to schedule periodic scans for neighboring
 735  * access points after the specified time.
 736  */
 737 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 738                                       int sec, int usec)
 739 {
 740         if (!wpa_s->sched_scan_supported)
 741                 return -1;
 742
 743         eloop_register_timeout(sec, usec,
 744                                wpa_supplicant_delayed_sched_scan_timeout,
 745                                wpa_s, NULL);
 746
 747         return 0;
 748 }
 749
 750
 751 /**
 752  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 753  * @wpa_s: Pointer to wpa_supplicant data
 754  *
 755  * This function is used to schedule periodic scans for neighboring
 756  * access points repeating the scan continuously.
 757  */
 758 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 759 {
 760         struct wpa_driver_scan_params params;
 761         struct wpa_driver_scan_params *scan_params;
 762         enum wpa_states prev_state;
 763         struct wpa_ssid *ssid = NULL;
 764         struct wpabuf *extra_ie = NULL;
 765         int ret;
 766         unsigned int max_sched_scan_ssids;
 767         int wildcard = 0;
 768         int need_ssids;
 769
 770         if (!wpa_s->sched_scan_supported)
 771                 return -1;
 772
 773         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 774                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 775         else
 776                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 777         if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
 778                 return -1;
 779
 780         if (wpa_s->sched_scanning) {
 781                 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
 782                 return 0;
 783         }
 784
 785         need_ssids = 0;
 786         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 787                 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
 788                         /* Use wildcard SSID to find this network */
 789                         wildcard = 1;
 790                 } else if (!wpas_network_disabled(wpa_s, ssid) &&
 791                            ssid->ssid_len)
 792                         need_ssids++;
 793
 794 #ifdef CONFIG_WPS
 795                 if (!wpas_network_disabled(wpa_s, ssid) &&
 796                     ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
 797                         /*
 798                          * Normal scan is more reliable and faster for WPS
 799                          * operations and since these are for short periods of
 800                          * time, the benefit of trying to use sched_scan would
 801                          * be limited.
 802                          */
 803                         wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 804                                 "sched_scan for WPS");
 805                         return -1;
 806                 }
 807 #endif /* CONFIG_WPS */
 808         }
 809         if (wildcard)
 810                 need_ssids++;
 811
 812         if (wpa_s->normal_scans < 3 &&
 813             (need_ssids <= wpa_s->max_scan_ssids ||
 814              wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
 815                 /*
 816                  * When normal scan can speed up operations, use that for the
 817                  * first operations before starting the sched_scan to allow
 818                  * user space sleep more. We do this only if the normal scan
 819                  * has functionality that is suitable for this or if the
 820                  * sched_scan does not have better support for multiple SSIDs.
 821                  */
 822                 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
 823                         "sched_scan for initial scans (normal_scans=%d)",
 824                         wpa_s->normal_scans);
 825                 return -1;
 826         }
 827
 828         os_memset(&params, 0, sizeof(params));
 829
 830         /* If we can't allocate space for the filters, we just don't filter */
 831         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
 832                                         sizeof(struct wpa_driver_scan_filter));
 833
 834         prev_state = wpa_s->wpa_state;
 835         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 836             wpa_s->wpa_state == WPA_INACTIVE)
 837                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 838
 839         if (wpa_s->autoscan_params != NULL) {
 840                 scan_params = wpa_s->autoscan_params;
 841                 goto scan;
 842         }
 843
 844         /* Find the starting point from which to continue scanning */
 845         ssid = wpa_s->conf->ssid;
 846         if (wpa_s->prev_sched_ssid) {
 847                 while (ssid) {
 848                         if (ssid == wpa_s->prev_sched_ssid) {
 849                                 ssid = ssid->next;
 850                                 break;
 851                         }
 852                         ssid = ssid->next;
 853                 }
 854         }
 855
 856         if (!ssid || !wpa_s->prev_sched_ssid) {
 857                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
 858
 859                 if (wpa_s->sched_scan_interval == 0)
 860                         wpa_s->sched_scan_interval = 10;
 861                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
 862                 wpa_s->first_sched_scan = 1;
 863                 ssid = wpa_s->conf->ssid;
 864                 wpa_s->prev_sched_ssid = ssid;
 865         }
 866
 867         if (wildcard) {
 868                 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
 869                 params.num_ssids++;
 870         }
 871
 872         while (ssid) {
 873                 if (wpas_network_disabled(wpa_s, ssid))
 874                         goto next;
 875
 876                 if (params.num_filter_ssids < wpa_s->max_match_sets &&
 877                     params.filter_ssids && ssid->ssid && ssid->ssid_len) {
 878                         wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
 879                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 880                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
 881                                   ssid->ssid, ssid->ssid_len);
 882                         params.filter_ssids[params.num_filter_ssids].ssid_len =
 883                                 ssid->ssid_len;
 884                         params.num_filter_ssids++;
 885                 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
 886                 {
 887                         wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
 888                                 "filter for sched_scan - drop filter");
 889                         os_free(params.filter_ssids);
 890                         params.filter_ssids = NULL;
 891                         params.num_filter_ssids = 0;
 892                 }
 893
 894                 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
 895                         if (params.num_ssids == max_sched_scan_ssids)
 896                                 break; /* only room for broadcast SSID */
 897                         wpa_dbg(wpa_s, MSG_DEBUG,
 898                                 "add to active scan ssid: %s",
 899                                 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
 900                         params.ssids[params.num_ssids].ssid =
 901                                 ssid->ssid;
 902                         params.ssids[params.num_ssids].ssid_len =
 903                                 ssid->ssid_len;
 904                         params.num_ssids++;
 905                         if (params.num_ssids >= max_sched_scan_ssids) {
 906                                 wpa_s->prev_sched_ssid = ssid;
 907                                 do {
 908                                         ssid = ssid->next;
 909                                 } while (ssid &&
 910                                          (wpas_network_disabled(wpa_s, ssid) ||
 911                                           !ssid->scan_ssid));
 912                                 break;
 913                         }
 914                 }
 915
 916         next:
 917                 wpa_s->prev_sched_ssid = ssid;
 918                 ssid = ssid->next;
 919         }
 920
 921         if (params.num_filter_ssids == 0) {
 922                 os_free(params.filter_ssids);
 923                 params.filter_ssids = NULL;
 924         }
 925
 926         extra_ie = wpa_supplicant_extra_ies(wpa_s);
 927         if (extra_ie) {
 928                 params.extra_ies = wpabuf_head(extra_ie);
 929                 params.extra_ies_len = wpabuf_len(extra_ie);
 930         }
 931
 932         scan_params = &params;
 933
 934 scan:
 935         if (ssid || !wpa_s->first_sched_scan) {
 936                 wpa_dbg(wpa_s, MSG_DEBUG,
 937                         "Starting sched scan: interval %d timeout %d",
 938                         wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
 939         } else {
 940                 wpa_dbg(wpa_s, MSG_DEBUG,
 941                         "Starting sched scan: interval %d (no timeout)",
 942                         wpa_s->sched_scan_interval);
 943         }
 944
 945         ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
 946                                               wpa_s->sched_scan_interval);
 947         wpabuf_free(extra_ie);
 948         os_free(params.filter_ssids);
 949         if (ret) {
 950                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
 951                 if (prev_state != wpa_s->wpa_state)
 952                         wpa_supplicant_set_state(wpa_s, prev_state);
 953                 return ret;
 954         }
 955
 956         /* If we have more SSIDs to scan, add a timeout so we scan them too */
 957         if (ssid || !wpa_s->first_sched_scan) {
 958                 wpa_s->sched_scan_timed_out = 0;
 959                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
 960                                        wpa_supplicant_sched_scan_timeout,
 961                                        wpa_s, NULL);
 962                 wpa_s->first_sched_scan = 0;
 963                 wpa_s->sched_scan_timeout /= 2;
 964                 wpa_s->sched_scan_interval *= 2;
 965         }
 966
 967         return 0;
 968 }
 969
 970
 971 /**
 972  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 973  * @wpa_s: Pointer to wpa_supplicant data
 974  *
 975  * This function is used to cancel a scan request scheduled with
 976  * wpa_supplicant_req_scan().
 977  */
 978 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
 979 {
 980         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
 981         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 982 }
 983
 984
 985 /**
 986  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
 987  * @wpa_s: Pointer to wpa_supplicant data
 988  *
 989  * This function is used to stop a periodic scheduled scan.
 990  */
 991 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
 992 {
 993         if (!wpa_s->sched_scanning)
 994                 return;
 995
 996         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
 997         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
 998         wpa_supplicant_stop_sched_scan(wpa_s);
 999 }
1000
1001
1002 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1003                                     int scanning)
1004 {
1005         if (wpa_s->scanning != scanning) {
1006                 wpa_s->scanning = scanning;
1007                 wpas_notify_scanning(wpa_s);
1008         }
1009 }
1010
1011
1012 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1013 {
1014         int rate = 0;
1015         const u8 *ie;
1016         int i;
1017
1018         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1019         for (i = 0; ie && i < ie[1]; i++) {
1020                 if ((ie[i + 2] & 0x7f) > rate)
1021                         rate = ie[i + 2] & 0x7f;
1022         }
1023
1024         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1025         for (i = 0; ie && i < ie[1]; i++) {
1026                 if ((ie[i + 2] & 0x7f) > rate)
1027                         rate = ie[i + 2] & 0x7f;
1028         }
1029
1030         return rate;
1031 }
1032
1033
1034 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1035 {
1036         const u8 *end, *pos;
1037
1038         pos = (const u8 *) (res + 1);
1039         end = pos + res->ie_len;
1040
1041         while (pos + 1 < end) {
1042                 if (pos + 2 + pos[1] > end)
1043                         break;
1044                 if (pos[0] == ie)
1045                         return pos;
1046                 pos += 2 + pos[1];
1047         }
1048
1049         return NULL;
1050 }
1051
1052
1053 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1054                                   u32 vendor_type)
1055 {
1056         const u8 *end, *pos;
1057
1058         pos = (const u8 *) (res + 1);
1059         end = pos + res->ie_len;
1060
1061         while (pos + 1 < end) {
1062                 if (pos + 2 + pos[1] > end)
1063                         break;
1064                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1065                     vendor_type == WPA_GET_BE32(&pos[2]))
1066                         return pos;
1067                 pos += 2 + pos[1];
1068         }
1069
1070         return NULL;
1071 }
1072
1073
1074 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1075                                              u32 vendor_type)
1076 {
1077         struct wpabuf *buf;
1078         const u8 *end, *pos;
1079
1080         buf = wpabuf_alloc(res->ie_len);
1081         if (buf == NULL)
1082                 return NULL;
1083
1084         pos = (const u8 *) (res + 1);
1085         end = pos + res->ie_len;
1086
1087         while (pos + 1 < end) {
1088                 if (pos + 2 + pos[1] > end)
1089                         break;
1090                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1091                     vendor_type == WPA_GET_BE32(&pos[2]))
1092                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1093                 pos += 2 + pos[1];
1094         }
1095
1096         if (wpabuf_len(buf) == 0) {
1097                 wpabuf_free(buf);
1098                 buf = NULL;
1099         }
1100
1101         return buf;
1102 }
1103
1104
1105 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
1106         const struct wpa_scan_res *res, u32 vendor_type)
1107 {
1108         struct wpabuf *buf;
1109         const u8 *end, *pos;
1110
1111         if (res->beacon_ie_len == 0)
1112                 return NULL;
1113         buf = wpabuf_alloc(res->beacon_ie_len);
1114         if (buf == NULL)
1115                 return NULL;
1116
1117         pos = (const u8 *) (res + 1);
1118         pos += res->ie_len;
1119         end = pos + res->beacon_ie_len;
1120
1121         while (pos + 1 < end) {
1122                 if (pos + 2 + pos[1] > end)
1123                         break;
1124                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1125                     vendor_type == WPA_GET_BE32(&pos[2]))
1126                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1127                 pos += 2 + pos[1];
1128         }
1129
1130         if (wpabuf_len(buf) == 0) {
1131                 wpabuf_free(buf);
1132                 buf = NULL;
1133         }
1134
1135         return buf;
1136 }
1137
1138
1139 /*
1140  * Channels with a great SNR can operate at full rate. What is a great SNR?
1141  * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1142  * rule of thumb is that any SNR above 20 is good." This one
1143  * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1144  * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1145  * conservative value.
1146  */
1147 #define GREAT_SNR 30
1148
1149 /* Compare function for sorting scan results. Return >0 if @b is considered
1150  * better. */
1151 static int wpa_scan_result_compar(const void *a, const void *b)
1152 {
1153 #define IS_5GHZ(n) (n > 4000)
1154 #define MIN(a,b) a < b ? a : b
1155         struct wpa_scan_res **_wa = (void *) a;
1156         struct wpa_scan_res **_wb = (void *) b;
1157         struct wpa_scan_res *wa = *_wa;
1158         struct wpa_scan_res *wb = *_wb;
1159         int wpa_a, wpa_b, maxrate_a, maxrate_b;
1160         int snr_a, snr_b;
1161
1162         /* WPA/WPA2 support preferred */
1163         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1164                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1165         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1166                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1167
1168         if (wpa_b && !wpa_a)
1169                 return 1;
1170         if (!wpa_b && wpa_a)
1171                 return -1;
1172
1173         /* privacy support preferred */
1174         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1175             (wb->caps & IEEE80211_CAP_PRIVACY))
1176                 return 1;
1177         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1178             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1179                 return -1;
1180
1181         if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1182             !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1183                 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1184                 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1185         } else {
1186                 /* Not suitable information to calculate SNR, so use level */
1187                 snr_a = wa->level;
1188                 snr_b = wb->level;
1189         }
1190
1191         /* best/max rate preferred if SNR close enough */
1192         if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1193             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1194                 maxrate_a = wpa_scan_get_max_rate(wa);
1195                 maxrate_b = wpa_scan_get_max_rate(wb);
1196                 if (maxrate_a != maxrate_b)
1197                         return maxrate_b - maxrate_a;
1198                 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1199                         return IS_5GHZ(wa->freq) ? -1 : 1;
1200         }
1201
1202         /* use freq for channel preference */
1203
1204         /* all things being equal, use SNR; if SNRs are
1205          * identical, use quality values since some drivers may only report
1206          * that value and leave the signal level zero */
1207         if (snr_b == snr_a)
1208                 return wb->qual - wa->qual;
1209         return snr_b - snr_a;
1210 #undef MIN
1211 #undef IS_5GHZ
1212 }
1213
1214
1215 #ifdef CONFIG_WPS
1216 /* Compare function for sorting scan results when searching a WPS AP for
1217  * provisioning. Return >0 if @b is considered better. */
1218 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1219 {
1220         struct wpa_scan_res **_wa = (void *) a;
1221         struct wpa_scan_res **_wb = (void *) b;
1222         struct wpa_scan_res *wa = *_wa;
1223         struct wpa_scan_res *wb = *_wb;
1224         int uses_wps_a, uses_wps_b;
1225         struct wpabuf *wps_a, *wps_b;
1226         int res;
1227
1228         /* Optimization - check WPS IE existence before allocated memory and
1229          * doing full reassembly. */
1230         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1231         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1232         if (uses_wps_a && !uses_wps_b)
1233                 return -1;
1234         if (!uses_wps_a && uses_wps_b)
1235                 return 1;
1236
1237         if (uses_wps_a && uses_wps_b) {
1238                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1239                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1240                 res = wps_ap_priority_compar(wps_a, wps_b);
1241                 wpabuf_free(wps_a);
1242                 wpabuf_free(wps_b);
1243                 if (res)
1244                         return res;
1245         }
1246
1247         /*
1248          * Do not use current AP security policy as a sorting criteria during
1249          * WPS provisioning step since the AP may get reconfigured at the
1250          * completion of provisioning.
1251          */
1252
1253         /* all things being equal, use signal level; if signal levels are
1254          * identical, use quality values since some drivers may only report
1255          * that value and leave the signal level zero */
1256         if (wb->level == wa->level)
1257                 return wb->qual - wa->qual;
1258         return wb->level - wa->level;
1259 }
1260 #endif /* CONFIG_WPS */
1261
1262
1263 static void dump_scan_res(struct wpa_scan_results *scan_res)
1264 {
1265 #ifndef CONFIG_NO_STDOUT_DEBUG
1266         size_t i;
1267
1268         if (scan_res->res == NULL || scan_res->num == 0)
1269                 return;
1270
1271         wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1272
1273         for (i = 0; i < scan_res->num; i++) {
1274                 struct wpa_scan_res *r = scan_res->res[i];
1275                 u8 *pos;
1276                 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1277                     == WPA_SCAN_LEVEL_DBM) {
1278                         int snr = r->level - r->noise;
1279                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1280                                    "noise=%d level=%d snr=%d%s flags=0x%x",
1281                                    MAC2STR(r->bssid), r->freq, r->qual,
1282                                    r->noise, r->level, snr,
1283                                    snr >= GREAT_SNR ? "*" : "", r->flags);
1284                 } else {
1285                         wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1286                                    "noise=%d level=%d flags=0x%x",
1287                                    MAC2STR(r->bssid), r->freq, r->qual,
1288                                    r->noise, r->level, r->flags);
1289                 }
1290                 pos = (u8 *) (r + 1);
1291                 if (r->ie_len)
1292                         wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1293                 pos += r->ie_len;
1294                 if (r->beacon_ie_len)
1295                         wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1296                                     pos, r->beacon_ie_len);
1297         }
1298 #endif /* CONFIG_NO_STDOUT_DEBUG */
1299 }
1300
1301
1302 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1303                                       const u8 *bssid)
1304 {
1305         size_t i;
1306
1307         if (wpa_s->bssid_filter == NULL)
1308                 return 1;
1309
1310         for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1311                 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1312                               ETH_ALEN) == 0)
1313                         return 1;
1314         }
1315
1316         return 0;
1317 }
1318
1319
1320 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1321                             struct wpa_scan_results *res)
1322 {
1323         size_t i, j;
1324
1325         if (wpa_s->bssid_filter == NULL)
1326                 return;
1327
1328         for (i = 0, j = 0; i < res->num; i++) {
1329                 if (wpa_supplicant_filter_bssid_match(wpa_s,
1330                                                       res->res[i]->bssid)) {
1331                         res->res[j++] = res->res[i];
1332                 } else {
1333                         os_free(res->res[i]);
1334                         res->res[i] = NULL;
1335                 }
1336         }
1337
1338         if (res->num != j) {
1339                 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1340                            (int) (res->num - j));
1341                 res->num = j;
1342         }
1343 }
1344
1345
1346 /**
1347  * wpa_supplicant_get_scan_results - Get scan results
1348  * @wpa_s: Pointer to wpa_supplicant data
1349  * @info: Information about what was scanned or %NULL if not available
1350  * @new_scan: Whether a new scan was performed
1351  * Returns: Scan results, %NULL on failure
1352  *
1353  * This function request the current scan results from the driver and updates
1354  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1355  * results with wpa_scan_results_free().
1356  */
1357 struct wpa_scan_results *
1358 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1359                                 struct scan_info *info, int new_scan)
1360 {
1361         struct wpa_scan_results *scan_res;
1362         size_t i;
1363         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1364
1365         scan_res = wpa_drv_get_scan_results2(wpa_s);
1366         if (scan_res == NULL) {
1367                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1368                 return NULL;
1369         }
1370         filter_scan_res(wpa_s, scan_res);
1371
1372 #ifdef CONFIG_WPS
1373         if (wpas_wps_in_progress(wpa_s)) {
1374                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1375                         "provisioning rules");
1376                 compar = wpa_scan_result_wps_compar;
1377         }
1378 #endif /* CONFIG_WPS */
1379
1380         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1381               compar);
1382         dump_scan_res(scan_res);
1383
1384         wpa_bss_update_start(wpa_s);
1385         for (i = 0; i < scan_res->num; i++)
1386                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1387         wpa_bss_update_end(wpa_s, info, new_scan);
1388
1389         return scan_res;
1390 }
1391
1392
1393 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1394 {
1395         struct wpa_scan_results *scan_res;
1396         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1397         if (scan_res == NULL)
1398                 return -1;
1399         wpa_scan_results_free(scan_res);
1400
1401         return 0;
1402 }