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