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 "wps_supplicant.h"
  24 #include "p2p_supplicant.h"
  25 #include "p2p/p2p.h"
  26 #include "notify.h"
  27 #include "bss.h"
  28 #include "scan.h"
  29
  30
  31 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
  32 {
  33         struct wpa_ssid *ssid;
  34         union wpa_event_data data;
  35
  36         ssid = wpa_supplicant_get_ssid(wpa_s);
  37         if (ssid == NULL)
  38                 return;
  39
  40         if (wpa_s->current_ssid == NULL) {
  41                 wpa_s->current_ssid = ssid;
  42                 if (wpa_s->current_ssid != NULL)
  43                         wpas_notify_network_changed(wpa_s);
  44         }
  45         wpa_supplicant_initiate_eapol(wpa_s);
  46         wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
  47                 "network - generating associated event");
  48         os_memset(&data, 0, sizeof(data));
  49         wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
  50 }
  51
  52
  53 #ifdef CONFIG_WPS
  54 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
  55                            enum wps_request_type *req_type)
  56 {
  57         struct wpa_ssid *ssid;
  58         int wps = 0;
  59
  60         for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
  61                 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
  62                         continue;
  63
  64                 wps = 1;
  65                 *req_type = wpas_wps_get_req_type(ssid);
  66                 if (!ssid->eap.phase1)
  67                         continue;
  68
  69                 if (os_strstr(ssid->eap.phase1, "pbc=1"))
  70                         return 2;
  71         }
  72
  73 #ifdef CONFIG_P2P
  74         wpa_s->wps->dev.p2p = 1;
  75         if (!wps) {
  76                 wps = 1;
  77                 *req_type = WPS_REQ_ENROLLEE_INFO;
  78         }
  79 #endif /* CONFIG_P2P */
  80
  81         return wps;
  82 }
  83 #endif /* CONFIG_WPS */
  84
  85
  86 int wpa_supplicant_enabled_networks(struct wpa_config *conf)
  87 {
  88         struct wpa_ssid *ssid = conf->ssid;
  89         int count = 0;
  90         while (ssid) {
  91                 if (!ssid->disabled)
  92                         count++;
  93                 ssid = ssid->next;
  94         }
  95         return count;
  96 }
  97
  98
  99 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
 100                                      struct wpa_ssid *ssid)
 101 {
 102         while (ssid) {
 103                 if (!ssid->disabled)
 104                         break;
 105                 ssid = ssid->next;
 106         }
 107
 108         /* ap_scan=2 mode - try to associate with each SSID. */
 109         if (ssid == NULL) {
 110                 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
 111                         "end of scan list - go back to beginning");
 112                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 113                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 114                 return;
 115         }
 116         if (ssid->next) {
 117                 /* Continue from the next SSID on the next attempt. */
 118                 wpa_s->prev_scan_ssid = ssid;
 119         } else {
 120                 /* Start from the beginning of the SSID list. */
 121                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 122         }
 123         wpa_supplicant_associate(wpa_s, NULL, ssid);
 124 }
 125
 126
 127 static int int_array_len(const int *a)
 128 {
 129         int i;
 130         for (i = 0; a && a[i]; i++)
 131                 ;
 132         return i;
 133 }
 134
 135
 136 static void int_array_concat(int **res, const int *a)
 137 {
 138         int reslen, alen, i;
 139         int *n;
 140
 141         reslen = int_array_len(*res);
 142         alen = int_array_len(a);
 143
 144         n = os_realloc(*res, (reslen + alen + 1) * sizeof(int));
 145         if (n == NULL) {
 146                 os_free(*res);
 147                 *res = NULL;
 148                 return;
 149         }
 150         for (i = 0; i <= alen; i++)
 151                 n[reslen + i] = a[i];
 152         *res = n;
 153 }
 154
 155
 156 static int freq_cmp(const void *a, const void *b)
 157 {
 158         int _a = *(int *) a;
 159         int _b = *(int *) b;
 160
 161         if (_a == 0)
 162                 return 1;
 163         if (_b == 0)
 164                 return -1;
 165         return _a - _b;
 166 }
 167
 168
 169 static void int_array_sort_unique(int *a)
 170 {
 171         int alen;
 172         int i, j;
 173
 174         if (a == NULL)
 175                 return;
 176
 177         alen = int_array_len(a);
 178         qsort(a, alen, sizeof(int), freq_cmp);
 179
 180         i = 0;
 181         j = 1;
 182         while (a[i] && a[j]) {
 183                 if (a[i] == a[j]) {
 184                         j++;
 185                         continue;
 186                 }
 187                 a[++i] = a[j++];
 188         }
 189         if (a[i])
 190                 i++;
 191         a[i] = 0;
 192 }
 193
 194
 195 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 196                                 struct wpa_driver_scan_params *params)
 197 {
 198         int ret;
 199
 200         wpa_supplicant_notify_scanning(wpa_s, 1);
 201
 202         ret = wpa_drv_scan(wpa_s, params);
 203         if (ret) {
 204                 wpa_supplicant_notify_scanning(wpa_s, 0);
 205                 wpas_notify_scan_done(wpa_s, 0);
 206         } else
 207                 wpa_s->scan_runs++;
 208
 209         return ret;
 210 }
 211
 212
 213 static void
 214 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 215 {
 216         struct wpa_supplicant *wpa_s = eloop_ctx;
 217
 218         wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
 219
 220         if (wpa_supplicant_req_sched_scan(wpa_s))
 221                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 222 }
 223
 224
 225 static void
 226 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 227 {
 228         struct wpa_supplicant *wpa_s = eloop_ctx;
 229
 230         wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
 231
 232         wpa_s->sched_scan_timed_out = 1;
 233         wpa_supplicant_cancel_sched_scan(wpa_s);
 234 }
 235
 236
 237 static int
 238 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
 239                                 struct wpa_driver_scan_params *params,
 240                                 int interval)
 241 {
 242         int ret;
 243
 244         wpa_supplicant_notify_scanning(wpa_s, 1);
 245         ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
 246         if (ret)
 247                 wpa_supplicant_notify_scanning(wpa_s, 0);
 248         else
 249                 wpa_s->sched_scanning = 1;
 250
 251         return ret;
 252 }
 253
 254
 255 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
 256 {
 257         int ret;
 258
 259         ret = wpa_drv_stop_sched_scan(wpa_s);
 260         if (ret) {
 261                 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
 262                 /* TODO: what to do if stopping fails? */
 263                 return -1;
 264         }
 265
 266         return ret;
 267 }
 268
 269
 270 static struct wpa_driver_scan_filter *
 271 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 272 {
 273         struct wpa_driver_scan_filter *ssids;
 274         struct wpa_ssid *ssid;
 275         size_t count;
 276
 277         *num_ssids = 0;
 278         if (!conf->filter_ssids)
 279                 return NULL;
 280
 281         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 282                 if (ssid->ssid && ssid->ssid_len)
 283                         count++;
 284         }
 285         if (count == 0)
 286                 return NULL;
 287         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 288         if (ssids == NULL)
 289                 return NULL;
 290
 291         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 292                 if (!ssid->ssid || !ssid->ssid_len)
 293                         continue;
 294                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 295                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 296                 (*num_ssids)++;
 297         }
 298
 299         return ssids;
 300 }
 301
 302
 303 static void wpa_supplicant_optimize_freqs(
 304         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 305 {
 306 #ifdef CONFIG_P2P
 307         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 308             wpa_s->go_params) {
 309                 /* Optimize provisioning state scan based on GO information */
 310                 if (wpa_s->p2p_in_provisioning < 5 &&
 311                     wpa_s->go_params->freq > 0) {
 312                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 313                                 "preferred frequency %d MHz",
 314                                 wpa_s->go_params->freq);
 315                         params->freqs = os_zalloc(2 * sizeof(int));
 316                         if (params->freqs)
 317                                 params->freqs[0] = wpa_s->go_params->freq;
 318                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 319                            wpa_s->go_params->freq_list[0]) {
 320                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 321                                 "channels");
 322                         int_array_concat(&params->freqs,
 323                                          wpa_s->go_params->freq_list);
 324                         if (params->freqs)
 325                                 int_array_sort_unique(params->freqs);
 326                 }
 327                 wpa_s->p2p_in_provisioning++;
 328         }
 329 #endif /* CONFIG_P2P */
 330
 331 #ifdef CONFIG_WPS
 332         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 333                 /*
 334                  * Optimize post-provisioning scan based on channel used
 335                  * during provisioning.
 336                  */
 337                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 338                         "that was used during provisioning", wpa_s->wps_freq);
 339                 params->freqs = os_zalloc(2 * sizeof(int));
 340                 if (params->freqs)
 341                         params->freqs[0] = wpa_s->wps_freq;
 342                 wpa_s->after_wps--;
 343         }
 344
 345 #endif /* CONFIG_WPS */
 346 }
 347
 348
 349 #ifdef CONFIG_INTERWORKING
 350 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
 351                                            struct wpabuf *buf)
 352 {
 353         if (wpa_s->conf->interworking == 0)
 354                 return;
 355
 356         wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
 357         wpabuf_put_u8(buf, 4);
 358         wpabuf_put_u8(buf, 0x00);
 359         wpabuf_put_u8(buf, 0x00);
 360         wpabuf_put_u8(buf, 0x00);
 361         wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
 362
 363         wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
 364         wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
 365                       1 + ETH_ALEN);
 366         wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
 367         /* No Venue Info */
 368         if (!is_zero_ether_addr(wpa_s->conf->hessid))
 369                 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
 370 }
 371 #endif /* CONFIG_INTERWORKING */
 372
 373
 374 static struct wpabuf *
 375 wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s,
 376                          struct wpa_driver_scan_params *params)
 377 {
 378         struct wpabuf *extra_ie = NULL;
 379 #ifdef CONFIG_WPS
 380         int wps = 0;
 381         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 382 #endif /* CONFIG_WPS */
 383
 384 #ifdef CONFIG_INTERWORKING
 385         if (wpa_s->conf->interworking &&
 386             wpabuf_resize(&extra_ie, 100) == 0)
 387                 wpas_add_interworking_elements(wpa_s, extra_ie);
 388 #endif /* CONFIG_INTERWORKING */
 389
 390 #ifdef CONFIG_WPS
 391         wps = wpas_wps_in_use(wpa_s, &req_type);
 392
 393         if (wps) {
 394                 struct wpabuf *wps_ie;
 395                 wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
 396                                                 wpa_s->wps->uuid, req_type,
 397                                                 0, NULL);
 398                 if (wps_ie) {
 399                         if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
 400                                 wpabuf_put_buf(extra_ie, wps_ie);
 401                         wpabuf_free(wps_ie);
 402                 }
 403         }
 404
 405 #ifdef CONFIG_P2P
 406         if (wps) {
 407                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 408                 if (wpabuf_resize(&extra_ie, ielen) == 0)
 409                         wpas_p2p_scan_ie(wpa_s, extra_ie);
 410         }
 411 #endif /* CONFIG_P2P */
 412
 413 #endif /* CONFIG_WPS */
 414
 415         return extra_ie;
 416 }
 417
 418
 419 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 420 {
 421         struct wpa_supplicant *wpa_s = eloop_ctx;
 422         struct wpa_ssid *ssid;
 423         int scan_req = 0, ret;
 424         struct wpabuf *extra_ie;
 425         struct wpa_driver_scan_params params;
 426         size_t max_ssids;
 427         enum wpa_states prev_state;
 428
 429         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 430                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 431                 return;
 432         }
 433
 434         if (wpa_s->disconnected && !wpa_s->scan_req) {
 435                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 436                 return;
 437         }
 438
 439         if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
 440             !wpa_s->scan_req) {
 441                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 442                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 443                 return;
 444         }
 445
 446         if (wpa_s->conf->ap_scan != 0 &&
 447             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 448                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 449                         "overriding ap_scan configuration");
 450                 wpa_s->conf->ap_scan = 0;
 451                 wpas_notify_ap_scan_changed(wpa_s);
 452         }
 453
 454         if (wpa_s->conf->ap_scan == 0) {
 455                 wpa_supplicant_gen_assoc_event(wpa_s);
 456                 return;
 457         }
 458
 459 #ifdef CONFIG_P2P
 460         if (wpas_p2p_in_progress(wpa_s)) {
 461                 if (wpa_s->wpa_state == WPA_SCANNING) {
 462                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 463                                 "while P2P operation is in progress");
 464                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 465                 } else {
 466                         wpa_dbg(wpa_s, MSG_DEBUG, "Do not request scan while "
 467                                 "P2P operation is in progress");
 468                 }
 469                 return;
 470         }
 471 #endif /* CONFIG_P2P */
 472
 473         if (wpa_s->conf->ap_scan == 2)
 474                 max_ssids = 1;
 475         else {
 476                 max_ssids = wpa_s->max_scan_ssids;
 477                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 478                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 479         }
 480
 481         scan_req = wpa_s->scan_req;
 482         wpa_s->scan_req = 0;
 483
 484         os_memset(&params, 0, sizeof(params));
 485
 486         prev_state = wpa_s->wpa_state;
 487         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 488             wpa_s->wpa_state == WPA_INACTIVE)
 489                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 490
 491         if (scan_req != 2 && wpa_s->connect_without_scan) {
 492                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 493                         if (ssid == wpa_s->connect_without_scan)
 494                                 break;
 495                 }
 496                 wpa_s->connect_without_scan = NULL;
 497                 if (ssid) {
 498                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 499                                    "without scan step");
 500                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 501                         return;
 502                 }
 503         }
 504
 505         /* Find the starting point from which to continue scanning */
 506         ssid = wpa_s->conf->ssid;
 507         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 508                 while (ssid) {
 509                         if (ssid == wpa_s->prev_scan_ssid) {
 510                                 ssid = ssid->next;
 511                                 break;
 512                         }
 513                         ssid = ssid->next;
 514                 }
 515         }
 516
 517         if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
 518                 wpa_s->connect_without_scan = NULL;
 519                 wpa_supplicant_assoc_try(wpa_s, ssid);
 520                 return;
 521         } else if (wpa_s->conf->ap_scan == 2) {
 522                 /*
 523                  * User-initiated scan request in ap_scan == 2; scan with
 524                  * wildcard SSID.
 525                  */
 526                 ssid = NULL;
 527         } else {
 528                 struct wpa_ssid *start = ssid, *tssid;
 529                 int freqs_set = 0;
 530                 if (ssid == NULL && max_ssids > 1)
 531                         ssid = wpa_s->conf->ssid;
 532                 while (ssid) {
 533                         if (!ssid->disabled && ssid->scan_ssid) {
 534                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 535                                                   ssid->ssid, ssid->ssid_len);
 536                                 params.ssids[params.num_ssids].ssid =
 537                                         ssid->ssid;
 538                                 params.ssids[params.num_ssids].ssid_len =
 539                                         ssid->ssid_len;
 540                                 params.num_ssids++;
 541                                 if (params.num_ssids + 1 >= max_ssids)
 542                                         break;
 543                         }
 544                         ssid = ssid->next;
 545                         if (ssid == start)
 546                                 break;
 547                         if (ssid == NULL && max_ssids > 1 &&
 548                             start != wpa_s->conf->ssid)
 549                                 ssid = wpa_s->conf->ssid;
 550                 }
 551
 552                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 553                         if (tssid->disabled)
 554                                 continue;
 555                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 556                                 int_array_concat(&params.freqs,
 557                                                  tssid->scan_freq);
 558                         } else {
 559                                 os_free(params.freqs);
 560                                 params.freqs = NULL;
 561                         }
 562                         freqs_set = 1;
 563                 }
 564                 int_array_sort_unique(params.freqs);
 565         }
 566
 567         if (ssid) {
 568                 wpa_s->prev_scan_ssid = ssid;
 569                 if (max_ssids > 1) {
 570                         wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 571                                 "the scan request");
 572                         params.num_ssids++;
 573                 }
 574                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for specific "
 575                         "SSID(s)");
 576         } else {
 577                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 578                 params.num_ssids++;
 579                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 580                         "SSID");
 581         }
 582
 583         wpa_supplicant_optimize_freqs(wpa_s, &params);
 584         extra_ie = wpa_supplicant_extra_ies(wpa_s, &params);
 585
 586         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 587                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 588                         "generated frequency list");
 589                 params.freqs = wpa_s->next_scan_freqs;
 590         } else
 591                 os_free(wpa_s->next_scan_freqs);
 592         wpa_s->next_scan_freqs = NULL;
 593
 594         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 595                 wpa_s->conf, &params.num_filter_ssids);
 596         if (extra_ie) {
 597                 params.extra_ies = wpabuf_head(extra_ie);
 598                 params.extra_ies_len = wpabuf_len(extra_ie);
 599         }
 600
 601         ret = wpa_supplicant_trigger_scan(wpa_s, &params);
 602
 603         wpabuf_free(extra_ie);
 604         os_free(params.freqs);
 605         os_free(params.filter_ssids);
 606
 607         if (ret) {
 608                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 609                 if (prev_state != wpa_s->wpa_state)
 610                         wpa_supplicant_set_state(wpa_s, prev_state);
 611                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 612         }
 613 }
 614
 615
 616 /**
 617  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 618  * @wpa_s: Pointer to wpa_supplicant data
 619  * @sec: Number of seconds after which to scan
 620  * @usec: Number of microseconds after which to scan
 621  *
 622  * This function is used to schedule a scan for neighboring access points after
 623  * the specified time.
 624  */
 625 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 626 {
 627         /* If there's at least one network that should be specifically scanned
 628          * then don't cancel the scan and reschedule.  Some drivers do
 629          * background scanning which generates frequent scan results, and that
 630          * causes the specific SSID scan to get continually pushed back and
 631          * never happen, which causes hidden APs to never get probe-scanned.
 632          */
 633         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 634             wpa_s->conf->ap_scan == 1) {
 635                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 636
 637                 while (ssid) {
 638                         if (!ssid->disabled && ssid->scan_ssid)
 639                                 break;
 640                         ssid = ssid->next;
 641                 }
 642                 if (ssid) {
 643                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 644                                 "ensure that specific SSID scans occur");
 645                         return;
 646                 }
 647         }
 648
 649         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 650                 sec, usec);
 651         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 652         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 653 }
 654
 655
 656 /**
 657  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 658  * @wpa_s: Pointer to wpa_supplicant data
 659  * @sec: Number of seconds after which to scan
 660  * @usec: Number of microseconds after which to scan
 661  *
 662  * This function is used to schedule periodic scans for neighboring
 663  * access points after the specified time.
 664  */
 665 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 666                                       int sec, int usec)
 667 {
 668         if (!wpa_s->sched_scan_supported)
 669                 return -1;
 670
 671         eloop_register_timeout(sec, usec,
 672                                wpa_supplicant_delayed_sched_scan_timeout,
 673                                wpa_s, NULL);
 674
 675         return 0;
 676 }
 677
 678
 679 /**
 680  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 681  * @wpa_s: Pointer to wpa_supplicant data
 682  *
 683  * This function is used to schedule periodic scans for neighboring
 684  * access points repeating the scan continuously.
 685  */
 686 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 687 {
 688         struct wpa_driver_scan_params params;
 689         enum wpa_states prev_state;
 690         struct wpa_ssid *ssid;
 691         struct wpabuf *wps_ie = NULL;
 692         int ret;
 693         unsigned int max_sched_scan_ssids;
 694
 695         if (!wpa_s->sched_scan_supported)
 696                 return -1;
 697
 698         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 699                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 700         else
 701                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 702
 703         if (wpa_s->sched_scanning)
 704                 return 0;
 705
 706         os_memset(&params, 0, sizeof(params));
 707
 708         /* If we can't allocate space for the filters, we just don't filter */
 709         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
 710                                         sizeof(struct wpa_driver_scan_filter));
 711
 712         prev_state = wpa_s->wpa_state;
 713         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 714             wpa_s->wpa_state == WPA_INACTIVE)
 715                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 716
 717         /* Find the starting point from which to continue scanning */
 718         ssid = wpa_s->conf->ssid;
 719         if (wpa_s->prev_sched_ssid) {
 720                 while (ssid) {
 721                         if (ssid == wpa_s->prev_sched_ssid) {
 722                                 ssid = ssid->next;
 723                                 break;
 724                         }
 725                         ssid = ssid->next;
 726                 }
 727         }
 728
 729         if (!ssid || !wpa_s->prev_sched_ssid) {
 730                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
 731
 732                 wpa_s->sched_scan_interval = 2;
 733                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
 734                 wpa_s->first_sched_scan = 1;
 735                 ssid = wpa_s->conf->ssid;
 736                 wpa_s->prev_sched_ssid = ssid;
 737         }
 738
 739         while (ssid) {
 740                 if (ssid->disabled) {
 741                         wpa_s->prev_sched_ssid = ssid;
 742                         ssid = ssid->next;
 743                         continue;
 744                 }
 745
 746                 if (params.filter_ssids && ssid->ssid && ssid->ssid_len) {
 747                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
 748                                   ssid->ssid, ssid->ssid_len);
 749                         params.filter_ssids[params.num_filter_ssids].ssid_len =
 750                                 ssid->ssid_len;
 751                         params.num_filter_ssids++;
 752                 }
 753
 754                 if (ssid->scan_ssid) {
 755                         params.ssids[params.num_ssids].ssid =
 756                                 ssid->ssid;
 757                         params.ssids[params.num_ssids].ssid_len =
 758                                 ssid->ssid_len;
 759                         params.num_ssids++;
 760                         if (params.num_ssids >= max_sched_scan_ssids) {
 761                                 wpa_s->prev_sched_ssid = ssid;
 762                                 break;
 763                         }
 764                 }
 765
 766                 if (params.num_filter_ssids >= wpa_s->max_match_sets)
 767                         break;
 768                 wpa_s->prev_sched_ssid = ssid;
 769                 ssid = ssid->next;
 770         }
 771
 772         if (!params.num_ssids) {
 773                 os_free(params.filter_ssids);
 774                 return 0;
 775         }
 776
 777         if (wpa_s->wps)
 778                 wps_ie = wpa_supplicant_extra_ies(wpa_s, &params);
 779
 780         wpa_dbg(wpa_s, MSG_DEBUG,
 781                 "Starting sched scan: interval %d timeout %d",
 782                 wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
 783
 784         ret = wpa_supplicant_start_sched_scan(wpa_s, &params,
 785                                               wpa_s->sched_scan_interval);
 786         wpabuf_free(wps_ie);
 787         os_free(params.filter_ssids);
 788         if (ret) {
 789                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
 790                 if (prev_state != wpa_s->wpa_state)
 791                         wpa_supplicant_set_state(wpa_s, prev_state);
 792                 return ret;
 793         }
 794
 795         /* If we have more SSIDs to scan, add a timeout so we scan them too */
 796         if (ssid || !wpa_s->first_sched_scan) {
 797                 wpa_s->sched_scan_timed_out = 0;
 798                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
 799                                        wpa_supplicant_sched_scan_timeout,
 800                                        wpa_s, NULL);
 801                 wpa_s->first_sched_scan = 0;
 802                 wpa_s->sched_scan_timeout /= 2;
 803                 wpa_s->sched_scan_interval *= 2;
 804         }
 805
 806         return 0;
 807 }
 808
 809
 810 /**
 811  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 812  * @wpa_s: Pointer to wpa_supplicant data
 813  *
 814  * This function is used to cancel a scan request scheduled with
 815  * wpa_supplicant_req_scan().
 816  */
 817 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
 818 {
 819         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
 820         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 821 }
 822
 823
 824 /**
 825  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
 826  * @wpa_s: Pointer to wpa_supplicant data
 827  *
 828  * This function is used to stop a periodic scheduled scan.
 829  */
 830 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
 831 {
 832         if (!wpa_s->sched_scanning)
 833                 return;
 834
 835         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
 836         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
 837         wpa_supplicant_stop_sched_scan(wpa_s);
 838 }
 839
 840
 841 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
 842                                     int scanning)
 843 {
 844         if (wpa_s->scanning != scanning) {
 845                 wpa_s->scanning = scanning;
 846                 wpas_notify_scanning(wpa_s);
 847         }
 848 }
 849
 850
 851 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
 852 {
 853         int rate = 0;
 854         const u8 *ie;
 855         int i;
 856
 857         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
 858         for (i = 0; ie && i < ie[1]; i++) {
 859                 if ((ie[i + 2] & 0x7f) > rate)
 860                         rate = ie[i + 2] & 0x7f;
 861         }
 862
 863         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
 864         for (i = 0; ie && i < ie[1]; i++) {
 865                 if ((ie[i + 2] & 0x7f) > rate)
 866                         rate = ie[i + 2] & 0x7f;
 867         }
 868
 869         return rate;
 870 }
 871
 872
 873 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
 874 {
 875         const u8 *end, *pos;
 876
 877         pos = (const u8 *) (res + 1);
 878         end = pos + res->ie_len;
 879
 880         while (pos + 1 < end) {
 881                 if (pos + 2 + pos[1] > end)
 882                         break;
 883                 if (pos[0] == ie)
 884                         return pos;
 885                 pos += 2 + pos[1];
 886         }
 887
 888         return NULL;
 889 }
 890
 891
 892 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
 893                                   u32 vendor_type)
 894 {
 895         const u8 *end, *pos;
 896
 897         pos = (const u8 *) (res + 1);
 898         end = pos + res->ie_len;
 899
 900         while (pos + 1 < end) {
 901                 if (pos + 2 + pos[1] > end)
 902                         break;
 903                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 904                     vendor_type == WPA_GET_BE32(&pos[2]))
 905                         return pos;
 906                 pos += 2 + pos[1];
 907         }
 908
 909         return NULL;
 910 }
 911
 912
 913 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
 914                                              u32 vendor_type)
 915 {
 916         struct wpabuf *buf;
 917         const u8 *end, *pos;
 918
 919         buf = wpabuf_alloc(res->ie_len);
 920         if (buf == NULL)
 921                 return NULL;
 922
 923         pos = (const u8 *) (res + 1);
 924         end = pos + res->ie_len;
 925
 926         while (pos + 1 < end) {
 927                 if (pos + 2 + pos[1] > end)
 928                         break;
 929                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 930                     vendor_type == WPA_GET_BE32(&pos[2]))
 931                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
 932                 pos += 2 + pos[1];
 933         }
 934
 935         if (wpabuf_len(buf) == 0) {
 936                 wpabuf_free(buf);
 937                 buf = NULL;
 938         }
 939
 940         return buf;
 941 }
 942
 943
 944 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
 945         const struct wpa_scan_res *res, u32 vendor_type)
 946 {
 947         struct wpabuf *buf;
 948         const u8 *end, *pos;
 949
 950         if (res->beacon_ie_len == 0)
 951                 return NULL;
 952         buf = wpabuf_alloc(res->beacon_ie_len);
 953         if (buf == NULL)
 954                 return NULL;
 955
 956         pos = (const u8 *) (res + 1);
 957         pos += res->ie_len;
 958         end = pos + res->beacon_ie_len;
 959
 960         while (pos + 1 < end) {
 961                 if (pos + 2 + pos[1] > end)
 962                         break;
 963                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 964                     vendor_type == WPA_GET_BE32(&pos[2]))
 965                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
 966                 pos += 2 + pos[1];
 967         }
 968
 969         if (wpabuf_len(buf) == 0) {
 970                 wpabuf_free(buf);
 971                 buf = NULL;
 972         }
 973
 974         return buf;
 975 }
 976
 977
 978 /* Compare function for sorting scan results. Return >0 if @b is considered
 979  * better. */
 980 static int wpa_scan_result_compar(const void *a, const void *b)
 981 {
 982         struct wpa_scan_res **_wa = (void *) a;
 983         struct wpa_scan_res **_wb = (void *) b;
 984         struct wpa_scan_res *wa = *_wa;
 985         struct wpa_scan_res *wb = *_wb;
 986         int wpa_a, wpa_b, maxrate_a, maxrate_b;
 987
 988         /* WPA/WPA2 support preferred */
 989         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
 990                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
 991         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
 992                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
 993
 994         if (wpa_b && !wpa_a)
 995                 return 1;
 996         if (!wpa_b && wpa_a)
 997                 return -1;
 998
 999         /* privacy support preferred */
1000         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1001             (wb->caps & IEEE80211_CAP_PRIVACY))
1002                 return 1;
1003         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1004             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1005                 return -1;
1006
1007         /* best/max rate preferred if signal level close enough XXX */
1008         if ((wa->level && wb->level && abs(wb->level - wa->level) < 5) ||
1009             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1010                 maxrate_a = wpa_scan_get_max_rate(wa);
1011                 maxrate_b = wpa_scan_get_max_rate(wb);
1012                 if (maxrate_a != maxrate_b)
1013                         return maxrate_b - maxrate_a;
1014         }
1015
1016         /* use freq for channel preference */
1017
1018         /* all things being equal, use signal level; if signal levels are
1019          * identical, use quality values since some drivers may only report
1020          * that value and leave the signal level zero */
1021         if (wb->level == wa->level)
1022                 return wb->qual - wa->qual;
1023         return wb->level - wa->level;
1024 }
1025
1026
1027 #ifdef CONFIG_WPS
1028 /* Compare function for sorting scan results when searching a WPS AP for
1029  * provisioning. Return >0 if @b is considered better. */
1030 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1031 {
1032         struct wpa_scan_res **_wa = (void *) a;
1033         struct wpa_scan_res **_wb = (void *) b;
1034         struct wpa_scan_res *wa = *_wa;
1035         struct wpa_scan_res *wb = *_wb;
1036         int uses_wps_a, uses_wps_b;
1037         struct wpabuf *wps_a, *wps_b;
1038         int res;
1039
1040         /* Optimization - check WPS IE existence before allocated memory and
1041          * doing full reassembly. */
1042         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1043         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1044         if (uses_wps_a && !uses_wps_b)
1045                 return -1;
1046         if (!uses_wps_a && uses_wps_b)
1047                 return 1;
1048
1049         if (uses_wps_a && uses_wps_b) {
1050                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1051                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1052                 res = wps_ap_priority_compar(wps_a, wps_b);
1053                 wpabuf_free(wps_a);
1054                 wpabuf_free(wps_b);
1055                 if (res)
1056                         return res;
1057         }
1058
1059         /*
1060          * Do not use current AP security policy as a sorting criteria during
1061          * WPS provisioning step since the AP may get reconfigured at the
1062          * completion of provisioning.
1063          */
1064
1065         /* all things being equal, use signal level; if signal levels are
1066          * identical, use quality values since some drivers may only report
1067          * that value and leave the signal level zero */
1068         if (wb->level == wa->level)
1069                 return wb->qual - wa->qual;
1070         return wb->level - wa->level;
1071 }
1072 #endif /* CONFIG_WPS */
1073
1074
1075 /**
1076  * wpa_supplicant_get_scan_results - Get scan results
1077  * @wpa_s: Pointer to wpa_supplicant data
1078  * @info: Information about what was scanned or %NULL if not available
1079  * @new_scan: Whether a new scan was performed
1080  * Returns: Scan results, %NULL on failure
1081  *
1082  * This function request the current scan results from the driver and updates
1083  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1084  * results with wpa_scan_results_free().
1085  */
1086 struct wpa_scan_results *
1087 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1088                                 struct scan_info *info, int new_scan)
1089 {
1090         struct wpa_scan_results *scan_res;
1091         size_t i;
1092         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1093
1094         scan_res = wpa_drv_get_scan_results2(wpa_s);
1095         if (scan_res == NULL) {
1096                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1097                 return NULL;
1098         }
1099
1100 #ifdef CONFIG_WPS
1101         if (wpas_wps_in_progress(wpa_s)) {
1102                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1103                         "provisioning rules");
1104                 compar = wpa_scan_result_wps_compar;
1105         }
1106 #endif /* CONFIG_WPS */
1107
1108         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1109               compar);
1110
1111         wpa_bss_update_start(wpa_s);
1112         for (i = 0; i < scan_res->num; i++)
1113                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1114         wpa_bss_update_end(wpa_s, info, new_scan);
1115
1116         return scan_res;
1117 }
1118
1119
1120 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1121 {
1122         struct wpa_scan_results *scan_res;
1123         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1124         if (scan_res == NULL)
1125                 return -1;
1126         wpa_scan_results_free(scan_res);
1127
1128         return 0;
1129 }