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 void
 219 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 220 {
 221         struct wpa_supplicant *wpa_s = eloop_ctx;
 222
 223         wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
 224
 225         if (wpa_supplicant_req_sched_scan(wpa_s))
 226                 wpa_supplicant_req_scan(wpa_s, 0, 0);
 227 }
 228
 229
 230 static void
 231 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 232 {
 233         struct wpa_supplicant *wpa_s = eloop_ctx;
 234
 235         wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
 236
 237         wpa_s->sched_scan_timed_out = 1;
 238         wpa_supplicant_cancel_sched_scan(wpa_s);
 239 }
 240
 241
 242 static int
 243 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
 244                                 struct wpa_driver_scan_params *params,
 245                                 int interval)
 246 {
 247         int ret;
 248
 249         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
 250                 return -1;
 251
 252         wpa_supplicant_notify_scanning(wpa_s, 1);
 253         ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
 254         if (ret)
 255                 wpa_supplicant_notify_scanning(wpa_s, 0);
 256         else
 257                 wpa_s->sched_scanning = 1;
 258
 259         return ret;
 260 }
 261
 262
 263 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
 264 {
 265         int ret;
 266
 267         ret = wpa_drv_stop_sched_scan(wpa_s);
 268         if (ret) {
 269                 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
 270                 /* TODO: what to do if stopping fails? */
 271                 return -1;
 272         }
 273
 274         return ret;
 275 }
 276
 277
 278 static struct wpa_driver_scan_filter *
 279 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 280 {
 281         struct wpa_driver_scan_filter *ssids;
 282         struct wpa_ssid *ssid;
 283         size_t count;
 284
 285         *num_ssids = 0;
 286         if (!conf->filter_ssids)
 287                 return NULL;
 288
 289         for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 290                 if (ssid->ssid && ssid->ssid_len)
 291                         count++;
 292         }
 293         if (count == 0)
 294                 return NULL;
 295         ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 296         if (ssids == NULL)
 297                 return NULL;
 298
 299         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 300                 if (!ssid->ssid || !ssid->ssid_len)
 301                         continue;
 302                 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 303                 ssids[*num_ssids].ssid_len = ssid->ssid_len;
 304                 (*num_ssids)++;
 305         }
 306
 307         return ssids;
 308 }
 309
 310
 311 static void wpa_supplicant_optimize_freqs(
 312         struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
 313 {
 314 #ifdef CONFIG_P2P
 315         if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
 316             wpa_s->go_params) {
 317                 /* Optimize provisioning state scan based on GO information */
 318                 if (wpa_s->p2p_in_provisioning < 5 &&
 319                     wpa_s->go_params->freq > 0) {
 320                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 321                                 "preferred frequency %d MHz",
 322                                 wpa_s->go_params->freq);
 323                         params->freqs = os_zalloc(2 * sizeof(int));
 324                         if (params->freqs)
 325                                 params->freqs[0] = wpa_s->go_params->freq;
 326                 } else if (wpa_s->p2p_in_provisioning < 8 &&
 327                            wpa_s->go_params->freq_list[0]) {
 328                         wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 329                                 "channels");
 330                         int_array_concat(&params->freqs,
 331                                          wpa_s->go_params->freq_list);
 332                         if (params->freqs)
 333                                 int_array_sort_unique(params->freqs);
 334                 }
 335                 wpa_s->p2p_in_provisioning++;
 336         }
 337 #endif /* CONFIG_P2P */
 338
 339 #ifdef CONFIG_WPS
 340         if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 341                 /*
 342                  * Optimize post-provisioning scan based on channel used
 343                  * during provisioning.
 344                  */
 345                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 346                         "that was used during provisioning", wpa_s->wps_freq);
 347                 params->freqs = os_zalloc(2 * sizeof(int));
 348                 if (params->freqs)
 349                         params->freqs[0] = wpa_s->wps_freq;
 350                 wpa_s->after_wps--;
 351         }
 352
 353 #endif /* CONFIG_WPS */
 354 }
 355
 356
 357 #ifdef CONFIG_INTERWORKING
 358 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
 359                                            struct wpabuf *buf)
 360 {
 361         if (wpa_s->conf->interworking == 0)
 362                 return;
 363
 364         wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
 365         wpabuf_put_u8(buf, 4);
 366         wpabuf_put_u8(buf, 0x00);
 367         wpabuf_put_u8(buf, 0x00);
 368         wpabuf_put_u8(buf, 0x00);
 369         wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
 370
 371         wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
 372         wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
 373                       1 + ETH_ALEN);
 374         wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
 375         /* No Venue Info */
 376         if (!is_zero_ether_addr(wpa_s->conf->hessid))
 377                 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
 378 }
 379 #endif /* CONFIG_INTERWORKING */
 380
 381
 382 static struct wpabuf *
 383 wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s,
 384                          struct wpa_driver_scan_params *params)
 385 {
 386         struct wpabuf *extra_ie = NULL;
 387 #ifdef CONFIG_WPS
 388         int wps = 0;
 389         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 390 #endif /* CONFIG_WPS */
 391
 392 #ifdef CONFIG_INTERWORKING
 393         if (wpa_s->conf->interworking &&
 394             wpabuf_resize(&extra_ie, 100) == 0)
 395                 wpas_add_interworking_elements(wpa_s, extra_ie);
 396 #endif /* CONFIG_INTERWORKING */
 397
 398 #ifdef CONFIG_WPS
 399         wps = wpas_wps_in_use(wpa_s, &req_type);
 400
 401         if (wps) {
 402                 struct wpabuf *wps_ie;
 403                 wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
 404                                                 wpa_s->wps->uuid, req_type,
 405                                                 0, NULL);
 406                 if (wps_ie) {
 407                         if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
 408                                 wpabuf_put_buf(extra_ie, wps_ie);
 409                         wpabuf_free(wps_ie);
 410                 }
 411         }
 412
 413 #ifdef CONFIG_P2P
 414         if (wps) {
 415                 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
 416                 if (wpabuf_resize(&extra_ie, ielen) == 0)
 417                         wpas_p2p_scan_ie(wpa_s, extra_ie);
 418         }
 419 #endif /* CONFIG_P2P */
 420
 421 #endif /* CONFIG_WPS */
 422
 423         return extra_ie;
 424 }
 425
 426
 427 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 428 {
 429         struct wpa_supplicant *wpa_s = eloop_ctx;
 430         struct wpa_ssid *ssid;
 431         int scan_req = 0, ret;
 432         struct wpabuf *extra_ie;
 433         struct wpa_driver_scan_params params;
 434         size_t max_ssids;
 435         enum wpa_states prev_state;
 436
 437         if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 438                 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 439                 return;
 440         }
 441
 442         if (wpa_s->disconnected && !wpa_s->scan_req) {
 443                 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 444                 return;
 445         }
 446
 447         if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
 448             !wpa_s->scan_req) {
 449                 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 450                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 451                 return;
 452         }
 453
 454         if (wpa_s->conf->ap_scan != 0 &&
 455             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 456                 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 457                         "overriding ap_scan configuration");
 458                 wpa_s->conf->ap_scan = 0;
 459                 wpas_notify_ap_scan_changed(wpa_s);
 460         }
 461
 462         if (wpa_s->conf->ap_scan == 0) {
 463                 wpa_supplicant_gen_assoc_event(wpa_s);
 464                 return;
 465         }
 466
 467 #ifdef CONFIG_P2P
 468         if (wpas_p2p_in_progress(wpa_s)) {
 469                 if (wpa_s->wpa_state == WPA_SCANNING) {
 470                         wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
 471                                 "while P2P operation is in progress");
 472                         wpa_supplicant_req_scan(wpa_s, 5, 0);
 473                 } else {
 474                         wpa_dbg(wpa_s, MSG_DEBUG, "Do not request scan while "
 475                                 "P2P operation is in progress");
 476                 }
 477                 return;
 478         }
 479 #endif /* CONFIG_P2P */
 480
 481         if ((wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) ||
 482             wpa_s->conf->ap_scan == 2)
 483                 max_ssids = 1;
 484         else {
 485                 max_ssids = wpa_s->max_scan_ssids;
 486                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 487                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 488         }
 489
 490         scan_req = wpa_s->scan_req;
 491         wpa_s->scan_req = 0;
 492
 493         os_memset(&params, 0, sizeof(params));
 494
 495         prev_state = wpa_s->wpa_state;
 496         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 497             wpa_s->wpa_state == WPA_INACTIVE)
 498                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 499
 500         if (scan_req != 2 && wpa_s->connect_without_scan) {
 501                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 502                         if (ssid == wpa_s->connect_without_scan)
 503                                 break;
 504                 }
 505                 wpa_s->connect_without_scan = NULL;
 506                 if (ssid) {
 507                         wpa_printf(MSG_DEBUG, "Start a pre-selected network "
 508                                    "without scan step");
 509                         wpa_supplicant_associate(wpa_s, NULL, ssid);
 510                         return;
 511                 }
 512         }
 513
 514         /* Find the starting point from which to continue scanning */
 515         ssid = wpa_s->conf->ssid;
 516         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 517                 while (ssid) {
 518                         if (ssid == wpa_s->prev_scan_ssid) {
 519                                 ssid = ssid->next;
 520                                 break;
 521                         }
 522                         ssid = ssid->next;
 523                 }
 524         }
 525
 526         if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
 527                 wpa_s->connect_without_scan = NULL;
 528                 wpa_supplicant_assoc_try(wpa_s, ssid);
 529                 return;
 530         } else if (wpa_s->conf->ap_scan == 2) {
 531                 /*
 532                  * User-initiated scan request in ap_scan == 2; scan with
 533                  * wildcard SSID.
 534                  */
 535                 ssid = NULL;
 536         } else {
 537                 struct wpa_ssid *start = ssid, *tssid;
 538                 int freqs_set = 0;
 539                 if (ssid == NULL && max_ssids > 1)
 540                         ssid = wpa_s->conf->ssid;
 541                 while (ssid) {
 542                         if (!ssid->disabled && ssid->scan_ssid) {
 543                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 544                                                   ssid->ssid, ssid->ssid_len);
 545                                 params.ssids[params.num_ssids].ssid =
 546                                         ssid->ssid;
 547                                 params.ssids[params.num_ssids].ssid_len =
 548                                         ssid->ssid_len;
 549                                 params.num_ssids++;
 550                                 if (params.num_ssids + 1 >= max_ssids)
 551                                         break;
 552                         }
 553                         ssid = ssid->next;
 554                         if (ssid == start)
 555                                 break;
 556                         if (ssid == NULL && max_ssids > 1 &&
 557                             start != wpa_s->conf->ssid)
 558                                 ssid = wpa_s->conf->ssid;
 559                 }
 560
 561                 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 562                         if (tssid->disabled)
 563                                 continue;
 564                         if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 565                                 int_array_concat(&params.freqs,
 566                                                  tssid->scan_freq);
 567                         } else {
 568                                 os_free(params.freqs);
 569                                 params.freqs = NULL;
 570                         }
 571                         freqs_set = 1;
 572                 }
 573                 int_array_sort_unique(params.freqs);
 574         }
 575
 576         if (ssid) {
 577                 wpa_s->prev_scan_ssid = ssid;
 578                 if (max_ssids > 1) {
 579                         wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 580                                 "the scan request");
 581                         params.num_ssids++;
 582                 }
 583                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for specific "
 584                         "SSID(s)");
 585         } else {
 586                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 587                 params.num_ssids++;
 588                 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 589                         "SSID");
 590         }
 591
 592         wpa_supplicant_optimize_freqs(wpa_s, &params);
 593         extra_ie = wpa_supplicant_extra_ies(wpa_s, &params);
 594
 595         if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 596                 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 597                         "generated frequency list");
 598                 params.freqs = wpa_s->next_scan_freqs;
 599         } else
 600                 os_free(wpa_s->next_scan_freqs);
 601         wpa_s->next_scan_freqs = NULL;
 602
 603         params.filter_ssids = wpa_supplicant_build_filter_ssids(
 604                 wpa_s->conf, &params.num_filter_ssids);
 605         if (extra_ie) {
 606                 params.extra_ies = wpabuf_head(extra_ie);
 607                 params.extra_ies_len = wpabuf_len(extra_ie);
 608         }
 609
 610         ret = wpa_supplicant_trigger_scan(wpa_s, &params);
 611
 612         wpabuf_free(extra_ie);
 613         os_free(params.freqs);
 614         os_free(params.filter_ssids);
 615
 616         if (ret) {
 617                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 618                 if (prev_state != wpa_s->wpa_state)
 619                         wpa_supplicant_set_state(wpa_s, prev_state);
 620                 wpa_supplicant_req_scan(wpa_s, 1, 0);
 621         }
 622 }
 623
 624
 625 /**
 626  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 627  * @wpa_s: Pointer to wpa_supplicant data
 628  * @sec: Number of seconds after which to scan
 629  * @usec: Number of microseconds after which to scan
 630  *
 631  * This function is used to schedule a scan for neighboring access points after
 632  * the specified time.
 633  */
 634 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 635 {
 636         /* If there's at least one network that should be specifically scanned
 637          * then don't cancel the scan and reschedule.  Some drivers do
 638          * background scanning which generates frequent scan results, and that
 639          * causes the specific SSID scan to get continually pushed back and
 640          * never happen, which causes hidden APs to never get probe-scanned.
 641          */
 642         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 643             wpa_s->conf->ap_scan == 1) {
 644                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 645
 646                 while (ssid) {
 647                         if (!ssid->disabled && ssid->scan_ssid)
 648                                 break;
 649                         ssid = ssid->next;
 650                 }
 651                 if (ssid) {
 652                         wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 653                                 "ensure that specific SSID scans occur");
 654                         return;
 655                 }
 656         }
 657
 658         wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 659                 sec, usec);
 660         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 661         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 662 }
 663
 664
 665 /**
 666  * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
 667  * @wpa_s: Pointer to wpa_supplicant data
 668  * @sec: Number of seconds after which to scan
 669  * @usec: Number of microseconds after which to scan
 670  *
 671  * This function is used to schedule periodic scans for neighboring
 672  * access points after the specified time.
 673  */
 674 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
 675                                       int sec, int usec)
 676 {
 677         if (!wpa_s->sched_scan_supported)
 678                 return -1;
 679
 680         eloop_register_timeout(sec, usec,
 681                                wpa_supplicant_delayed_sched_scan_timeout,
 682                                wpa_s, NULL);
 683
 684         return 0;
 685 }
 686
 687
 688 /**
 689  * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
 690  * @wpa_s: Pointer to wpa_supplicant data
 691  *
 692  * This function is used to schedule periodic scans for neighboring
 693  * access points repeating the scan continuously.
 694  */
 695 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
 696 {
 697         struct wpa_driver_scan_params params;
 698         enum wpa_states prev_state;
 699         struct wpa_ssid *ssid;
 700         struct wpabuf *wps_ie = NULL;
 701         int ret;
 702         unsigned int max_sched_scan_ssids;
 703
 704         if (!wpa_s->sched_scan_supported)
 705                 return -1;
 706
 707         if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
 708                 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
 709         else
 710                 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
 711
 712         if (wpa_s->sched_scanning)
 713                 return 0;
 714
 715         os_memset(&params, 0, sizeof(params));
 716
 717         /* If we can't allocate space for the filters, we just don't filter */
 718         params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
 719                                         sizeof(struct wpa_driver_scan_filter));
 720
 721         prev_state = wpa_s->wpa_state;
 722         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 723             wpa_s->wpa_state == WPA_INACTIVE)
 724                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 725
 726         /* Find the starting point from which to continue scanning */
 727         ssid = wpa_s->conf->ssid;
 728         if (wpa_s->prev_sched_ssid) {
 729                 while (ssid) {
 730                         if (ssid == wpa_s->prev_sched_ssid) {
 731                                 ssid = ssid->next;
 732                                 break;
 733                         }
 734                         ssid = ssid->next;
 735                 }
 736         }
 737
 738         if (!ssid || !wpa_s->prev_sched_ssid) {
 739                 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
 740
 741                 wpa_s->sched_scan_interval = 2;
 742                 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
 743                 wpa_s->first_sched_scan = 1;
 744                 ssid = wpa_s->conf->ssid;
 745                 wpa_s->prev_sched_ssid = ssid;
 746         }
 747
 748         while (ssid) {
 749                 if (ssid->disabled) {
 750                         wpa_s->prev_sched_ssid = ssid;
 751                         ssid = ssid->next;
 752                         continue;
 753                 }
 754
 755                 if (params.filter_ssids && ssid->ssid && ssid->ssid_len) {
 756                         os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
 757                                   ssid->ssid, ssid->ssid_len);
 758                         params.filter_ssids[params.num_filter_ssids].ssid_len =
 759                                 ssid->ssid_len;
 760                         params.num_filter_ssids++;
 761                 }
 762
 763                 if (ssid->scan_ssid) {
 764                         params.ssids[params.num_ssids].ssid =
 765                                 ssid->ssid;
 766                         params.ssids[params.num_ssids].ssid_len =
 767                                 ssid->ssid_len;
 768                         params.num_ssids++;
 769                         if (params.num_ssids >= max_sched_scan_ssids) {
 770                                 wpa_s->prev_sched_ssid = ssid;
 771                                 break;
 772                         }
 773                 }
 774
 775                 if (params.num_filter_ssids >= wpa_s->max_match_sets)
 776                         break;
 777                 wpa_s->prev_sched_ssid = ssid;
 778                 ssid = ssid->next;
 779         }
 780
 781         if (!params.num_ssids) {
 782                 os_free(params.filter_ssids);
 783                 return 0;
 784         }
 785
 786         if (wpa_s->wps)
 787                 wps_ie = wpa_supplicant_extra_ies(wpa_s, &params);
 788
 789         wpa_dbg(wpa_s, MSG_DEBUG,
 790                 "Starting sched scan: interval %d timeout %d",
 791                 wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
 792
 793         ret = wpa_supplicant_start_sched_scan(wpa_s, &params,
 794                                               wpa_s->sched_scan_interval);
 795         wpabuf_free(wps_ie);
 796         os_free(params.filter_ssids);
 797         if (ret) {
 798                 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
 799                 if (prev_state != wpa_s->wpa_state)
 800                         wpa_supplicant_set_state(wpa_s, prev_state);
 801                 return ret;
 802         }
 803
 804         /* If we have more SSIDs to scan, add a timeout so we scan them too */
 805         if (ssid || !wpa_s->first_sched_scan) {
 806                 wpa_s->sched_scan_timed_out = 0;
 807                 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
 808                                        wpa_supplicant_sched_scan_timeout,
 809                                        wpa_s, NULL);
 810                 wpa_s->first_sched_scan = 0;
 811                 wpa_s->sched_scan_timeout /= 2;
 812                 wpa_s->sched_scan_interval *= 2;
 813         }
 814
 815         return 0;
 816 }
 817
 818
 819 /**
 820  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 821  * @wpa_s: Pointer to wpa_supplicant data
 822  *
 823  * This function is used to cancel a scan request scheduled with
 824  * wpa_supplicant_req_scan().
 825  */
 826 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
 827 {
 828         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
 829         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 830 }
 831
 832
 833 /**
 834  * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
 835  * @wpa_s: Pointer to wpa_supplicant data
 836  *
 837  * This function is used to stop a periodic scheduled scan.
 838  */
 839 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
 840 {
 841         if (!wpa_s->sched_scanning)
 842                 return;
 843
 844         wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
 845         eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
 846         wpa_supplicant_stop_sched_scan(wpa_s);
 847 }
 848
 849
 850 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
 851                                     int scanning)
 852 {
 853         if (wpa_s->scanning != scanning) {
 854                 wpa_s->scanning = scanning;
 855                 wpas_notify_scanning(wpa_s);
 856         }
 857 }
 858
 859
 860 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
 861 {
 862         int rate = 0;
 863         const u8 *ie;
 864         int i;
 865
 866         ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
 867         for (i = 0; ie && i < ie[1]; i++) {
 868                 if ((ie[i + 2] & 0x7f) > rate)
 869                         rate = ie[i + 2] & 0x7f;
 870         }
 871
 872         ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
 873         for (i = 0; ie && i < ie[1]; i++) {
 874                 if ((ie[i + 2] & 0x7f) > rate)
 875                         rate = ie[i + 2] & 0x7f;
 876         }
 877
 878         return rate;
 879 }
 880
 881
 882 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
 883 {
 884         const u8 *end, *pos;
 885
 886         pos = (const u8 *) (res + 1);
 887         end = pos + res->ie_len;
 888
 889         while (pos + 1 < end) {
 890                 if (pos + 2 + pos[1] > end)
 891                         break;
 892                 if (pos[0] == ie)
 893                         return pos;
 894                 pos += 2 + pos[1];
 895         }
 896
 897         return NULL;
 898 }
 899
 900
 901 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
 902                                   u32 vendor_type)
 903 {
 904         const u8 *end, *pos;
 905
 906         pos = (const u8 *) (res + 1);
 907         end = pos + res->ie_len;
 908
 909         while (pos + 1 < end) {
 910                 if (pos + 2 + pos[1] > end)
 911                         break;
 912                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 913                     vendor_type == WPA_GET_BE32(&pos[2]))
 914                         return pos;
 915                 pos += 2 + pos[1];
 916         }
 917
 918         return NULL;
 919 }
 920
 921
 922 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
 923                                              u32 vendor_type)
 924 {
 925         struct wpabuf *buf;
 926         const u8 *end, *pos;
 927
 928         buf = wpabuf_alloc(res->ie_len);
 929         if (buf == NULL)
 930                 return NULL;
 931
 932         pos = (const u8 *) (res + 1);
 933         end = pos + res->ie_len;
 934
 935         while (pos + 1 < end) {
 936                 if (pos + 2 + pos[1] > end)
 937                         break;
 938                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 939                     vendor_type == WPA_GET_BE32(&pos[2]))
 940                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
 941                 pos += 2 + pos[1];
 942         }
 943
 944         if (wpabuf_len(buf) == 0) {
 945                 wpabuf_free(buf);
 946                 buf = NULL;
 947         }
 948
 949         return buf;
 950 }
 951
 952
 953 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
 954         const struct wpa_scan_res *res, u32 vendor_type)
 955 {
 956         struct wpabuf *buf;
 957         const u8 *end, *pos;
 958
 959         if (res->beacon_ie_len == 0)
 960                 return NULL;
 961         buf = wpabuf_alloc(res->beacon_ie_len);
 962         if (buf == NULL)
 963                 return NULL;
 964
 965         pos = (const u8 *) (res + 1);
 966         pos += res->ie_len;
 967         end = pos + res->beacon_ie_len;
 968
 969         while (pos + 1 < end) {
 970                 if (pos + 2 + pos[1] > end)
 971                         break;
 972                 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 973                     vendor_type == WPA_GET_BE32(&pos[2]))
 974                         wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
 975                 pos += 2 + pos[1];
 976         }
 977
 978         if (wpabuf_len(buf) == 0) {
 979                 wpabuf_free(buf);
 980                 buf = NULL;
 981         }
 982
 983         return buf;
 984 }
 985
 986
 987 /* Compare function for sorting scan results. Return >0 if @b is considered
 988  * better. */
 989 static int wpa_scan_result_compar(const void *a, const void *b)
 990 {
 991         struct wpa_scan_res **_wa = (void *) a;
 992         struct wpa_scan_res **_wb = (void *) b;
 993         struct wpa_scan_res *wa = *_wa;
 994         struct wpa_scan_res *wb = *_wb;
 995         int wpa_a, wpa_b, maxrate_a, maxrate_b;
 996
 997         /* WPA/WPA2 support preferred */
 998         wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
 999                 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1000         wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1001                 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1002
1003         if (wpa_b && !wpa_a)
1004                 return 1;
1005         if (!wpa_b && wpa_a)
1006                 return -1;
1007
1008         /* privacy support preferred */
1009         if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1010             (wb->caps & IEEE80211_CAP_PRIVACY))
1011                 return 1;
1012         if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1013             (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1014                 return -1;
1015
1016         /* best/max rate preferred if signal level close enough XXX */
1017         if ((wa->level && wb->level && abs(wb->level - wa->level) < 5) ||
1018             (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1019                 maxrate_a = wpa_scan_get_max_rate(wa);
1020                 maxrate_b = wpa_scan_get_max_rate(wb);
1021                 if (maxrate_a != maxrate_b)
1022                         return maxrate_b - maxrate_a;
1023         }
1024
1025         /* use freq for channel preference */
1026
1027         /* all things being equal, use signal level; if signal levels are
1028          * identical, use quality values since some drivers may only report
1029          * that value and leave the signal level zero */
1030         if (wb->level == wa->level)
1031                 return wb->qual - wa->qual;
1032         return wb->level - wa->level;
1033 }
1034
1035
1036 #ifdef CONFIG_WPS
1037 /* Compare function for sorting scan results when searching a WPS AP for
1038  * provisioning. Return >0 if @b is considered better. */
1039 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1040 {
1041         struct wpa_scan_res **_wa = (void *) a;
1042         struct wpa_scan_res **_wb = (void *) b;
1043         struct wpa_scan_res *wa = *_wa;
1044         struct wpa_scan_res *wb = *_wb;
1045         int uses_wps_a, uses_wps_b;
1046         struct wpabuf *wps_a, *wps_b;
1047         int res;
1048
1049         /* Optimization - check WPS IE existence before allocated memory and
1050          * doing full reassembly. */
1051         uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1052         uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1053         if (uses_wps_a && !uses_wps_b)
1054                 return -1;
1055         if (!uses_wps_a && uses_wps_b)
1056                 return 1;
1057
1058         if (uses_wps_a && uses_wps_b) {
1059                 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1060                 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1061                 res = wps_ap_priority_compar(wps_a, wps_b);
1062                 wpabuf_free(wps_a);
1063                 wpabuf_free(wps_b);
1064                 if (res)
1065                         return res;
1066         }
1067
1068         /*
1069          * Do not use current AP security policy as a sorting criteria during
1070          * WPS provisioning step since the AP may get reconfigured at the
1071          * completion of provisioning.
1072          */
1073
1074         /* all things being equal, use signal level; if signal levels are
1075          * identical, use quality values since some drivers may only report
1076          * that value and leave the signal level zero */
1077         if (wb->level == wa->level)
1078                 return wb->qual - wa->qual;
1079         return wb->level - wa->level;
1080 }
1081 #endif /* CONFIG_WPS */
1082
1083
1084 /**
1085  * wpa_supplicant_get_scan_results - Get scan results
1086  * @wpa_s: Pointer to wpa_supplicant data
1087  * @info: Information about what was scanned or %NULL if not available
1088  * @new_scan: Whether a new scan was performed
1089  * Returns: Scan results, %NULL on failure
1090  *
1091  * This function request the current scan results from the driver and updates
1092  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1093  * results with wpa_scan_results_free().
1094  */
1095 struct wpa_scan_results *
1096 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1097                                 struct scan_info *info, int new_scan)
1098 {
1099         struct wpa_scan_results *scan_res;
1100         size_t i;
1101         int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1102
1103         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
1104                 scan_res = ieee80211_sta_get_scan_results(wpa_s);
1105         else
1106                 scan_res = wpa_drv_get_scan_results2(wpa_s);
1107         if (scan_res == NULL) {
1108                 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1109                 return NULL;
1110         }
1111
1112 #ifdef CONFIG_WPS
1113         if (wpas_wps_in_progress(wpa_s)) {
1114                 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1115                         "provisioning rules");
1116                 compar = wpa_scan_result_wps_compar;
1117         }
1118 #endif /* CONFIG_WPS */
1119
1120         qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1121               compar);
1122
1123         wpa_bss_update_start(wpa_s);
1124         for (i = 0; i < scan_res->num; i++)
1125                 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1126         wpa_bss_update_end(wpa_s, info, new_scan);
1127
1128         return scan_res;
1129 }
1130
1131
1132 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1133 {
1134         struct wpa_scan_results *scan_res;
1135         scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1136         if (scan_res == NULL)
1137                 return -1;
1138         wpa_scan_results_free(scan_res);
1139
1140         return 0;
1141 }