wpa_supplicant/scan.c

   1 /*
   2  * WPA Supplicant - Scanning
   3  * Copyright (c) 2003-2010, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "utils/includes.h"
  16
  17 #include "utils/common.h"
  18 #include "utils/eloop.h"
  19 #include "common/ieee802_11_defs.h"
  20 #include "config.h"
  21 #include "wpa_supplicant_i.h"
  22 #include "driver_i.h"
  23 #include "mlme.h"
  24 #include "wps_supplicant.h"
  25 #include "p2p_supplicant.h"
  26 #include "p2p/p2p.h"
  27 #include "notify.h"
  28 #include "bss.h"
  29 #include "scan.h"
  30
  31
  32 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
  33 {
  34         struct wpa_ssid *ssid;
  35         union wpa_event_data data;
  36
  37         ssid = wpa_supplicant_get_ssid(wpa_s);
  38         if (ssid == NULL)
  39                 return;
  40
  41         if (wpa_s->current_ssid == NULL) {
  42                 wpa_s->current_ssid = ssid;
  43                 if (wpa_s->current_ssid != NULL)
  44                         wpas_notify_network_changed(wpa_s);
  45         }
  46         wpa_supplicant_initiate_eapol(wpa_s);
  47         wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
  48                 "network - generating associated event");
  49         os_memset(&data, 0, sizeof(data));
  50         wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
  51 }
  52
  53
  54 #ifdef CONFIG_WPS
  55 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
  56                            enum wps_request_type *req_type)
  57 {
  58         struct wpa_ssid *ssid;
  59         int wps = 0;
  60
  61         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
  62                 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
  63                         continue;
  64
  65                 wps = 1;
  66                 *req_type = wpas_wps_get_req_type(ssid);
  67                 if (!ssid->eap.phase1)
  68                         continue;
  69
  70                 if (os_strstr(ssid->eap.phase1, "pbc=1"))
  71                         return 2;
  72         }
  73
  74 #ifdef CONFIG_P2P
  75         wpa_s->wps->dev.p2p = 1;
  76         if (!wps) {
  77                 wps = 1;
  78                 *req_type = WPS_REQ_ENROLLEE_INFO;
  79         }
  80 #endif /* CONFIG_P2P */
  81
  82         return wps;
  83 }
  84 #endif /* CONFIG_WPS */
  85
  86
  87 int wpa_supplicant_enabled_networks(struct wpa_config *conf)
  88 {
  89         struct wpa_ssid *ssid = conf->ssid;
  90         int count = 0;
  91         while (ssid) {
  92                 if (!ssid->disabled)
  93                         count++;
  94                 ssid = ssid->next;
  95         }
  96         return count;
  97 }
  98
  99
 100 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
 101                                      struct wpa_ssid *ssid)
 102 {
 103         while (ssid) {
 104                 if (!ssid->disabled)
 105                         break;
 106                 ssid = ssid->next;
 107         }
 108
 109         /* ap_scan=2 mode - try to associate with each SSID. */
 110         if (ssid == NULL) {
 111                 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
 112                         "end of scan list - go back to beginning");
 113                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 114                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 115                 return;
 116         }
 117         if (ssid->next) {
 118                 /* Continue from the next SSID on the next attempt. */
 119                 wpa_s->prev_scan_ssid = ssid;
 120         } else {
 121                 /* Start from the beginning of the SSID list. */
 122                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 123         }
 124         wpa_supplicant_associate(wpa_s, NULL, ssid);
 125 }
 126
 127
 128 static int int_array_len(const int *a)
 129 {
 130         int i;
 131         for (i = 0; a && a[i]; i++)
 132                 ;
 133         return i;
 134 }
 135
 136
 137 static void int_array_concat(int **res, const int *a)
 138 {
 139         int reslen, alen, i;
 140         int *n;
 141
 142         reslen = int_array_len(*res);
 143         alen = int_array_len(a);
 144
 145         n = os_realloc(*res, (reslen + alen + 1) * sizeof(int));
 146         if (n == NULL) {
 147                 os_free(*res);
 148                 *res = NULL;
 149                 return;
 150         }
 151         for (i = 0; i <= alen; i++)
 152                 n[reslen + i] = a[i];
 153         *res = n;
 154 }
 155
 156
 157 static int freq_cmp(const void *a, const void *b)
 158 {
 159         int _a = *(int *) a;
 160         int _b = *(int *) b;
 161
 162         if (_a == 0)
 163                 return 1;
 164         if (_b == 0)
 165                 return -1;
 166         return _a - _b;
 167 }
 168
 169
 170 static void int_array_sort_unique(int *a)
 171 {
 172         int alen;
 173         int i, j;
 174
 175         if (a == NULL)
 176                 return;
 177
 178         alen = int_array_len(a);
 179         qsort(a, alen, sizeof(int), freq_cmp);
 180
 181         i = 0;
 182         j = 1;
 183         while (a[i] && a[j]) {
 184                 if (a[i] == a[j]) {
 185                         j++;
 186                         continue;
 187                 }
 188                 a[++i] = a[j++];
 189         }
 190         if (a[i])
 191                 i++;
 192         a[i] = 0;
 193 }
 194
 195
 196 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 197                                 struct wpa_driver_scan_params *params)
 198 {
 199         int ret;
 200
 201         wpa_supplicant_notify_scanning(wpa_s, 1);
 202
 203         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
 204                 ret = ieee80211_sta_req_scan(wpa_s, params);
 205         else
 206                 ret = wpa_drv_scan(wpa_s, params);
 207
 208         if (ret) {
 209                 wpa_supplicant_notify_scanning(wpa_s, 0);
 210                 wpas_notify_scan_done(wpa_s, 0);
 211         } else
 212                 wpa_s->scan_runs++;
 213
 214         return ret;
 215 }
 216
 217
 218 static struct wpa_driver_scan_filter *
 219 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 220 {
 221         struct wpa_driver_scan_filter *ssids;
 222         struct wpa_ssid *ssid;
 223         size_t count;
 224
 225         *num_ssids = 0;
 226         if (!conf->filter_ssids)
 227                 return NULL;
 228
 229         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 230                 if (ssid->ssid && ssid->ssid_len)
 231                         count++;
 232         }
 233         if (count == 0)
 234                 return NULL;
 235         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 236         if (ssids == NULL)
 237                 return NULL;
 238
 239         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 240                 if (!ssid->ssid || !ssid->ssid_len)
 241                         continue;
 242                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 243                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 244                 (*num_ssids)++;
 245         }
 246
 247         return ssids;
 248 }
 249
 250
 251 static void wpa_supplicant_optimize_freqs(
 252         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 253 {
 254 #ifdef CONFIG_P2P
 255         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 256             wpa_s->go_params) {
 257                 /* Optimize provisioning state scan based on GO information */
 258                 if (wpa_s->p2p_in_provisioning < 5 &&
 259                     wpa_s->go_params->freq > 0) {
 260                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 261                                 "preferred frequency %d MHz",
 262                                 wpa_s->go_params->freq);
 263                         params->freqs = os_zalloc(2 * sizeof(int));
 264                         if (params->freqs)
 265                                 params->freqs[0] = wpa_s->go_params->freq;
 266                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 267                            wpa_s->go_params->freq_list[0]) {
 268                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 269                                 "channels");
 270                         int_array_concat(&params->freqs,
 271                                          wpa_s->go_params->freq_list);
 272                         if (params->freqs)
 273                                 int_array_sort_unique(params->freqs);
 274                 }
 275                 wpa_s->p2p_in_provisioning++;
 276         }
 277 #endif /* CONFIG_P2P */
 278
 279 #ifdef CONFIG_WPS
 280         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 281                 /*
 282                  * Optimize post-provisioning scan based on channel used
 283                  * during provisioning.
 284                  */
 285                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 286                         "that was used during provisioning", wpa_s->wps_freq);
 287                 params->freqs = os_zalloc(2 * sizeof(int));
 288                 if (params->freqs)
 289                         params->freqs[0] = wpa_s->wps_freq;
 290                 wpa_s->after_wps--;
 291         }
 292
 293 #endif /* CONFIG_WPS */
 294 }
 295
 296
 297 static struct wpabuf *
 298 wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s,
 299                          struct wpa_driver_scan_params *params)
 300 {
 301         struct wpabuf *wps_ie = NULL;
 302 #ifdef CONFIG_WPS
 303         int wps = 0;
 304         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 305
 306         wps = wpas_wps_in_use(wpa_s, &req_type);
 307
 308         if (wps) {
 309                 wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
 310                                                 wpa_s->wps->uuid, req_type,
 311                                                 0, NULL);
 312                 if (wps_ie) {
 313                         params->extra_ies = wpabuf_head(wps_ie);
 314                         params->extra_ies_len = wpabuf_len(wps_ie);
 315                 }
 316         }
 317
 318 #ifdef CONFIG_P2P
 319         if (wps_ie) {
 320                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 321                 if (wpabuf_resize(&wps_ie, ielen) == 0) {
 322                         wpas_p2p_scan_ie(wpa_s, wps_ie);
 323                         params->extra_ies = wpabuf_head(wps_ie);
 324                         params->extra_ies_len = wpabuf_len(wps_ie);
 325                 }
 326         }
 327 #endif /* CONFIG_P2P */
 328
 329 #endif /* CONFIG_WPS */
 330
 331         return wps_ie;
 332 }
 333
 334
 335 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 336 {
 337         struct wpa_supplicant *wpa_s = eloop_ctx;
 338         struct wpa_ssid *ssid;
 339         int scan_req = 0, ret;
 340         struct wpabuf *wps_ie;
 341         struct wpa_driver_scan_params params;
 342         size_t max_ssids;
 343         enum wpa_states prev_state;
 344
 345         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 346                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 347                 return;
 348         }
 349
 350         if (wpa_s->disconnected && !wpa_s->scan_req) {
 351                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 352                 return;
 353         }
 354
 355         if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
 356             !wpa_s->scan_req) {
 357                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 358                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 359                 return;
 360         }
 361
 362         if (wpa_s->conf->ap_scan != 0 &&
 363             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 364                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 365                         "overriding ap_scan configuration");
 366                 wpa_s->conf->ap_scan = 0;
 367                 wpas_notify_ap_scan_changed(wpa_s);
 368         }
 369
 370         if (wpa_s->conf->ap_scan == 0) {
 371                 wpa_supplicant_gen_assoc_event(wpa_s);
 372                 return;
 373         }
 374
 375 #ifdef CONFIG_P2P
 376         if (wpas_p2p_in_progress(wpa_s)) {
 377                 if (wpa_s->wpa_state == WPA_SCANNING) {
 378                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 379                                 "while P2P operation is in progress");
 380                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 381                 } else {
 382                         wpa_dbg(wpa_s, MSG_DEBUG, "Do not request scan while "
 383                                 "P2P operation is in progress");
 384                 }
 385                 return;
 386         }
 387 #endif /* CONFIG_P2P */
 388
 389         if ((wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) ||
 390             wpa_s->conf->ap_scan == 2)
 391                 max_ssids = 1;
 392         else {
 393                 max_ssids = wpa_s->max_scan_ssids;
 394                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 395                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 396         }
 397
 398         scan_req = wpa_s->scan_req;
 399         wpa_s->scan_req = 0;
 400
 401         os_memset(&params, 0, sizeof(params));
 402
 403         prev_state = wpa_s->wpa_state;
 404         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 405             wpa_s->wpa_state == WPA_INACTIVE)
 406                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 407
 408         if (scan_req != 2 && wpa_s->connect_without_scan) {
 409                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 410                         if (ssid == wpa_s->connect_without_scan)
 411                                 break;
 412                 }
 413                 wpa_s->connect_without_scan = NULL;
 414                 if (ssid) {
 415                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 416                                    "without scan step");
 417                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 418                         return;
 419                 }
 420         }
 421
 422         /* Find the starting point from which to continue scanning */
 423         ssid = wpa_s->conf->ssid;
 424         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 425                 while (ssid) {
 426                         if (ssid == wpa_s->prev_scan_ssid) {
 427                                 ssid = ssid->next;
 428                                 break;
 429                         }
 430                         ssid = ssid->next;
 431                 }
 432         }
 433
 434         if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
 435                 wpa_s->connect_without_scan = NULL;
 436                 wpa_supplicant_assoc_try(wpa_s, ssid);
 437                 return;
 438         } else if (wpa_s->conf->ap_scan == 2) {
 439                 /*
 440                  * User-initiated scan request in ap_scan == 2; scan with
 441                  * wildcard SSID.
 442                  */
 443                 ssid = NULL;
 444         } else {
 445                 struct wpa_ssid *start = ssid, *tssid;
 446                 int freqs_set = 0;
 447                 if (ssid == NULL && max_ssids > 1)
 448                         ssid = wpa_s->conf->ssid;
 449                 while (ssid) {
 450                         if (!ssid->disabled && ssid->scan_ssid) {
 451                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 452                                                   ssid->ssid, ssid->ssid_len);
 453                                 params.ssids[params.num_ssids].ssid =
 454                                         ssid->ssid;
 455                                 params.ssids[params.num_ssids].ssid_len =
 456                                         ssid->ssid_len;
 457                                 params.num_ssids++;
 458                                 if (params.num_ssids + 1 >= max_ssids)
 459                                         break;
 460                         }
 461                         ssid = ssid->next;
 462                         if (ssid == start)
 463                                 break;
 464                         if (ssid == NULL && max_ssids > 1 &&
 465                             start != wpa_s->conf->ssid)
 466                                 ssid = wpa_s->conf->ssid;
 467                 }
 468
 469                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 470                         if (tssid->disabled)
 471                                 continue;
 472                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 473                                 int_array_concat(&params.freqs,
 474                                                  tssid->scan_freq);
 475                         } else {
 476                                 os_free(params.freqs);
 477                                 params.freqs = NULL;
 478                         }
 479                         freqs_set = 1;
 480                 }
 481                 int_array_sort_unique(params.freqs);
 482         }
 483
 484         if (ssid) {
 485                 wpa_s->prev_scan_ssid = ssid;
 486                 if (max_ssids > 1) {
 487                         wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 488                                 "the scan request");
 489                         params.num_ssids++;
 490                 }
 491                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for specific "
 492                         "SSID(s)");
 493         } else {
 494                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 495                 params.num_ssids++;
 496                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 497                         "SSID");
 498         }
 499
 500         wpa_supplicant_optimize_freqs(wpa_s, &params);
 501         wps_ie = wpa_supplicant_extra_ies(wpa_s, &params);
 502
 503         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 504                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 505                         "generated frequency list");
 506                 params.freqs = wpa_s->next_scan_freqs;
 507         } else
 508                 os_free(wpa_s->next_scan_freqs);
 509         wpa_s->next_scan_freqs = NULL;
 510
 511         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 512                 wpa_s->conf, &params.num_filter_ssids);
 513
 514         ret = wpa_supplicant_trigger_scan(wpa_s, &params);
 515
 516         wpabuf_free(wps_ie);
 517         os_free(params.freqs);
 518         os_free(params.filter_ssids);
 519
 520         if (ret) {
 521                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 522                 if (prev_state != wpa_s->wpa_state)
 523                         wpa_supplicant_set_state(wpa_s, prev_state);
 524                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 525         }
 526 }
 527
 528
 529 /**
 530  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 531  * @wpa_s: Pointer to wpa_supplicant data
 532  * @sec: Number of seconds after which to scan
 533  * @usec: Number of microseconds after which to scan
 534  *
 535  * This function is used to schedule a scan for neighboring access points after
 536  * the specified time.
 537  */
 538 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 539 {
 540         /* If there's at least one network that should be specifically scanned
 541          * then don't cancel the scan and reschedule.  Some drivers do
 542          * background scanning which generates frequent scan results, and that
 543          * causes the specific SSID scan to get continually pushed back and
 544          * never happen, which causes hidden APs to never get probe-scanned.
 545          */
 546         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 547             wpa_s->conf->ap_scan == 1) {
 548                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 549
 550                 while (ssid) {
 551                         if (!ssid->disabled && ssid->scan_ssid)
 552                                 break;
 553                         ssid = ssid->next;
 554                 }
 555                 if (ssid) {
 556                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 557                                 "ensure that specific SSID scans occur");
 558                         return;
 559                 }
 560         }
 561
 562         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 563                 sec, usec);
 564         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 565         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 566 }
 567
 568
 569 /**
 570  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 571  * @wpa_s: Pointer to wpa_supplicant data
 572  *
 573  * This function is used to cancel a scan request scheduled with
 574  * wpa_supplicant_req_scan().
 575  */
 576 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
 577 {
 578         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
 579         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 580 }
 581
 582
 583 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
 584                                     int scanning)
 585 {
 586         if (wpa_s->scanning != scanning) {
 587                 wpa_s->scanning = scanning;
 588                 wpas_notify_scanning(wpa_s);
 589         }
 590 }
 591
 592
 593 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
 594 {
 595         int rate = 0;
 596         const u8 *ie;
 597         int i;
 598
 599         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
 600         for (i = 0; ie && i < ie[1]; i++) {
 601                 if ((ie[i + 2] & 0x7f) > rate)
 602                         rate = ie[i + 2] & 0x7f;
 603         }
 604
 605         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
 606         for (i = 0; ie && i < ie[1]; i++) {
 607                 if ((ie[i + 2] & 0x7f) > rate)
 608                         rate = ie[i + 2] & 0x7f;
 609         }
 610
 611         return rate;
 612 }
 613
 614
 615 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
 616 {
 617         const u8 *end, *pos;
 618
 619         pos = (const u8 *) (res + 1);
 620         end = pos + res->ie_len;
 621
 622         while (pos + 1 < end) {
 623                 if (pos + 2 + pos[1] > end)
 624                         break;
 625                 if (pos[0] == ie)
 626                         return pos;
 627                 pos += 2 + pos[1];
 628         }
 629
 630         return NULL;
 631 }
 632
 633
 634 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
 635                                   u32 vendor_type)
 636 {
 637         const u8 *end, *pos;
 638
 639         pos = (const u8 *) (res + 1);
 640         end = pos + res->ie_len;
 641
 642         while (pos + 1 < end) {
 643                 if (pos + 2 + pos[1] > end)
 644                         break;
 645                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 646                     vendor_type == WPA_GET_BE32(&pos[2]))
 647                         return pos;
 648                 pos += 2 + pos[1];
 649         }
 650
 651         return NULL;
 652 }
 653
 654
 655 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
 656                                              u32 vendor_type)
 657 {
 658         struct wpabuf *buf;
 659         const u8 *end, *pos;
 660
 661         buf = wpabuf_alloc(res->ie_len);
 662         if (buf == NULL)
 663                 return NULL;
 664
 665         pos = (const u8 *) (res + 1);
 666         end = pos + res->ie_len;
 667
 668         while (pos + 1 < end) {
 669                 if (pos + 2 + pos[1] > end)
 670                         break;
 671                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 672                     vendor_type == WPA_GET_BE32(&pos[2]))
 673                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
 674                 pos += 2 + pos[1];
 675         }
 676
 677         if (wpabuf_len(buf) == 0) {
 678                 wpabuf_free(buf);
 679                 buf = NULL;
 680         }
 681
 682         return buf;
 683 }
 684
 685
 686 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
 687         const struct wpa_scan_res *res, u32 vendor_type)
 688 {
 689         struct wpabuf *buf;
 690         const u8 *end, *pos;
 691
 692         if (res->beacon_ie_len == 0)
 693                 return NULL;
 694         buf = wpabuf_alloc(res->beacon_ie_len);
 695         if (buf == NULL)
 696                 return NULL;
 697
 698         pos = (const u8 *) (res + 1);
 699         pos += res->ie_len;
 700         end = pos + res->beacon_ie_len;
 701
 702         while (pos + 1 < end) {
 703                 if (pos + 2 + pos[1] > end)
 704                         break;
 705                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 706                     vendor_type == WPA_GET_BE32(&pos[2]))
 707                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
 708                 pos += 2 + pos[1];
 709         }
 710
 711         if (wpabuf_len(buf) == 0) {
 712                 wpabuf_free(buf);
 713                 buf = NULL;
 714         }
 715
 716         return buf;
 717 }
 718
 719
 720 /* Compare function for sorting scan results. Return >0 if @b is considered
 721  * better. */
 722 static int wpa_scan_result_compar(const void *a, const void *b)
 723 {
 724         struct wpa_scan_res **_wa = (void *) a;
 725         struct wpa_scan_res **_wb = (void *) b;
 726         struct wpa_scan_res *wa = *_wa;
 727         struct wpa_scan_res *wb = *_wb;
 728         int wpa_a, wpa_b, maxrate_a, maxrate_b;
 729
 730         /* WPA/WPA2 support preferred */
 731         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
 732                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
 733         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
 734                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
 735
 736         if (wpa_b && !wpa_a)
 737                 return 1;
 738         if (!wpa_b && wpa_a)
 739                 return -1;
 740
 741         /* privacy support preferred */
 742         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
 743             (wb->caps & IEEE80211_CAP_PRIVACY))
 744                 return 1;
 745         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
 746             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
 747                 return -1;
 748
 749         /* best/max rate preferred if signal level close enough XXX */
 750         if ((wa->level && wb->level && abs(wb->level - wa->level) < 5) ||
 751             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
 752                 maxrate_a = wpa_scan_get_max_rate(wa);
 753                 maxrate_b = wpa_scan_get_max_rate(wb);
 754                 if (maxrate_a != maxrate_b)
 755                         return maxrate_b - maxrate_a;
 756         }
 757
 758         /* use freq for channel preference */
 759
 760         /* all things being equal, use signal level; if signal levels are
 761          * identical, use quality values since some drivers may only report
 762          * that value and leave the signal level zero */
 763         if (wb->level == wa->level)
 764                 return wb->qual - wa->qual;
 765         return wb->level - wa->level;
 766 }
 767
 768
 769 #ifdef CONFIG_WPS
 770 /* Compare function for sorting scan results when searching a WPS AP for
 771  * provisioning. Return >0 if @b is considered better. */
 772 static int wpa_scan_result_wps_compar(const void *a, const void *b)
 773 {
 774         struct wpa_scan_res **_wa = (void *) a;
 775         struct wpa_scan_res **_wb = (void *) b;
 776         struct wpa_scan_res *wa = *_wa;
 777         struct wpa_scan_res *wb = *_wb;
 778         int uses_wps_a, uses_wps_b;
 779         struct wpabuf *wps_a, *wps_b;
 780         int res;
 781
 782         /* Optimization - check WPS IE existence before allocated memory and
 783          * doing full reassembly. */
 784         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
 785         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
 786         if (uses_wps_a && !uses_wps_b)
 787                 return -1;
 788         if (!uses_wps_a && uses_wps_b)
 789                 return 1;
 790
 791         if (uses_wps_a && uses_wps_b) {
 792                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
 793                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
 794                 res = wps_ap_priority_compar(wps_a, wps_b);
 795                 wpabuf_free(wps_a);
 796                 wpabuf_free(wps_b);
 797                 if (res)
 798                         return res;
 799         }
 800
 801         /*
 802          * Do not use current AP security policy as a sorting criteria during
 803          * WPS provisioning step since the AP may get reconfigured at the
 804          * completion of provisioning.
 805          */
 806
 807         /* all things being equal, use signal level; if signal levels are
 808          * identical, use quality values since some drivers may only report
 809          * that value and leave the signal level zero */
 810         if (wb->level == wa->level)
 811                 return wb->qual - wa->qual;
 812         return wb->level - wa->level;
 813 }
 814 #endif /* CONFIG_WPS */
 815
 816
 817 /**
 818  * wpa_supplicant_get_scan_results - Get scan results
 819  * @wpa_s: Pointer to wpa_supplicant data
 820  * @info: Information about what was scanned or %NULL if not available
 821  * @new_scan: Whether a new scan was performed
 822  * Returns: Scan results, %NULL on failure
 823  *
 824  * This function request the current scan results from the driver and updates
 825  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
 826  * results with wpa_scan_results_free().
 827  */
 828 struct wpa_scan_results *
 829 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
 830                                 struct scan_info *info, int new_scan)
 831 {
 832         struct wpa_scan_results *scan_res;
 833         size_t i;
 834         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
 835
 836         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
 837                 scan_res = ieee80211_sta_get_scan_results(wpa_s);
 838         else
 839                 scan_res = wpa_drv_get_scan_results2(wpa_s);
 840         if (scan_res == NULL) {
 841                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
 842                 return NULL;
 843         }
 844
 845 #ifdef CONFIG_WPS
 846         if (wpas_wps_in_progress(wpa_s)) {
 847                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
 848                         "provisioning rules");
 849                 compar = wpa_scan_result_wps_compar;
 850         }
 851 #endif /* CONFIG_WPS */
 852
 853         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
 854               compar);
 855
 856         wpa_bss_update_start(wpa_s);
 857         for (i = 0; i < scan_res->num; i++)
 858                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
 859         wpa_bss_update_end(wpa_s, info, new_scan);
 860
 861         return scan_res;
 862 }
 863
 864
 865 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
 866 {
 867         struct wpa_scan_results *scan_res;
 868         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
 869         if (scan_res == NULL)
 870                 return -1;
 871         wpa_scan_results_free(scan_res);
 872
 873         return 0;
 874 }
 875
 876
 877 void wpa_scan_results_free(struct wpa_scan_results *res)
 878 {
 879         size_t i;
 880
 881         if (res == NULL)
 882                 return;
 883
 884         for (i = 0; i < res->num; i++)
 885                 os_free(res->res[i]);
 886         os_free(res->res);
 887         os_free(res);
 888 }