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