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 if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p) { 75 wpa_s->wps->dev.p2p = 1; 76 if (!wps) { 77 wps = 1; 78 *req_type = WPS_REQ_ENROLLEE_INFO; 79 } 80 } 81 #endif /* CONFIG_P2P */ 82 83 return wps; 84 } 85 #endif /* CONFIG_WPS */ 86 87 88 int wpa_supplicant_enabled_networks(struct wpa_config *conf) 89 { 90 struct wpa_ssid *ssid = conf->ssid; 91 int count = 0; 92 while (ssid) { 93 if (!ssid->disabled) 94 count++; 95 ssid = ssid->next; 96 } 97 return count; 98 } 99 100 101 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s, 102 struct wpa_ssid *ssid) 103 { 104 while (ssid) { 105 if (!ssid->disabled) 106 break; 107 ssid = ssid->next; 108 } 109 110 /* ap_scan=2 mode - try to associate with each SSID. */ 111 if (ssid == NULL) { 112 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached " 113 "end of scan list - go back to beginning"); 114 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN; 115 wpa_supplicant_req_scan(wpa_s, 0, 0); 116 return; 117 } 118 if (ssid->next) { 119 /* Continue from the next SSID on the next attempt. */ 120 wpa_s->prev_scan_ssid = ssid; 121 } else { 122 /* Start from the beginning of the SSID list. */ 123 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN; 124 } 125 wpa_supplicant_associate(wpa_s, NULL, ssid); 126 } 127 128 129 static int int_array_len(const int *a) 130 { 131 int i; 132 for (i = 0; a && a[i]; i++) 133 ; 134 return i; 135 } 136 137 138 static void int_array_concat(int **res, const int *a) 139 { 140 int reslen, alen, i; 141 int *n; 142 143 reslen = int_array_len(*res); 144 alen = int_array_len(a); 145 146 n = os_realloc(*res, (reslen + alen + 1) * sizeof(int)); 147 if (n == NULL) { 148 os_free(*res); 149 *res = NULL; 150 return; 151 } 152 for (i = 0; i <= alen; i++) 153 n[reslen + i] = a[i]; 154 *res = n; 155 } 156 157 158 static int freq_cmp(const void *a, const void *b) 159 { 160 int _a = *(int *) a; 161 int _b = *(int *) b; 162 163 if (_a == 0) 164 return 1; 165 if (_b == 0) 166 return -1; 167 return _a - _b; 168 } 169 170 171 static void int_array_sort_unique(int *a) 172 { 173 int alen; 174 int i, j; 175 176 if (a == NULL) 177 return; 178 179 alen = int_array_len(a); 180 qsort(a, alen, sizeof(int), freq_cmp); 181 182 i = 0; 183 j = 1; 184 while (a[i] && a[j]) { 185 if (a[i] == a[j]) { 186 j++; 187 continue; 188 } 189 a[++i] = a[j++]; 190 } 191 if (a[i]) 192 i++; 193 a[i] = 0; 194 } 195 196 197 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s, 198 struct wpa_driver_scan_params *params) 199 { 200 int ret; 201 202 wpa_supplicant_notify_scanning(wpa_s, 1); 203 204 ret = wpa_drv_scan(wpa_s, params); 205 if (ret) { 206 wpa_supplicant_notify_scanning(wpa_s, 0); 207 wpas_notify_scan_done(wpa_s, 0); 208 } else 209 wpa_s->scan_runs++; 210 211 return ret; 212 } 213 214 215 static void 216 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx) 217 { 218 struct wpa_supplicant *wpa_s = eloop_ctx; 219 220 wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan"); 221 222 if (wpa_supplicant_req_sched_scan(wpa_s)) 223 wpa_supplicant_req_scan(wpa_s, 0, 0); 224 } 225 226 227 static void 228 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx) 229 { 230 struct wpa_supplicant *wpa_s = eloop_ctx; 231 232 wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it"); 233 234 wpa_s->sched_scan_timed_out = 1; 235 wpa_supplicant_cancel_sched_scan(wpa_s); 236 } 237 238 239 static int 240 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s, 241 struct wpa_driver_scan_params *params, 242 int interval) 243 { 244 int ret; 245 246 wpa_supplicant_notify_scanning(wpa_s, 1); 247 ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000); 248 if (ret) 249 wpa_supplicant_notify_scanning(wpa_s, 0); 250 else 251 wpa_s->sched_scanning = 1; 252 253 return ret; 254 } 255 256 257 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s) 258 { 259 int ret; 260 261 ret = wpa_drv_stop_sched_scan(wpa_s); 262 if (ret) { 263 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!"); 264 /* TODO: what to do if stopping fails? */ 265 return -1; 266 } 267 268 return ret; 269 } 270 271 272 static struct wpa_driver_scan_filter * 273 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids) 274 { 275 struct wpa_driver_scan_filter *ssids; 276 struct wpa_ssid *ssid; 277 size_t count; 278 279 *num_ssids = 0; 280 if (!conf->filter_ssids) 281 return NULL; 282 283 for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) { 284 if (ssid->ssid && ssid->ssid_len) 285 count++; 286 } 287 if (count == 0) 288 return NULL; 289 ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter)); 290 if (ssids == NULL) 291 return NULL; 292 293 for (ssid = conf->ssid; ssid; ssid = ssid->next) { 294 if (!ssid->ssid || !ssid->ssid_len) 295 continue; 296 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len); 297 ssids[*num_ssids].ssid_len = ssid->ssid_len; 298 (*num_ssids)++; 299 } 300 301 return ssids; 302 } 303 304 305 static void wpa_supplicant_optimize_freqs( 306 struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params) 307 { 308 #ifdef CONFIG_P2P 309 if (params->freqs == NULL && wpa_s->p2p_in_provisioning && 310 wpa_s->go_params) { 311 /* Optimize provisioning state scan based on GO information */ 312 if (wpa_s->p2p_in_provisioning < 5 && 313 wpa_s->go_params->freq > 0) { 314 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO " 315 "preferred frequency %d MHz", 316 wpa_s->go_params->freq); 317 params->freqs = os_zalloc(2 * sizeof(int)); 318 if (params->freqs) 319 params->freqs[0] = wpa_s->go_params->freq; 320 } else if (wpa_s->p2p_in_provisioning < 8 && 321 wpa_s->go_params->freq_list[0]) { 322 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common " 323 "channels"); 324 int_array_concat(¶ms->freqs, 325 wpa_s->go_params->freq_list); 326 if (params->freqs) 327 int_array_sort_unique(params->freqs); 328 } 329 wpa_s->p2p_in_provisioning++; 330 } 331 #endif /* CONFIG_P2P */ 332 333 #ifdef CONFIG_WPS 334 if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) { 335 /* 336 * Optimize post-provisioning scan based on channel used 337 * during provisioning. 338 */ 339 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz " 340 "that was used during provisioning", wpa_s->wps_freq); 341 params->freqs = os_zalloc(2 * sizeof(int)); 342 if (params->freqs) 343 params->freqs[0] = wpa_s->wps_freq; 344 wpa_s->after_wps--; 345 } 346 347 #endif /* CONFIG_WPS */ 348 } 349 350 351 #ifdef CONFIG_INTERWORKING 352 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s, 353 struct wpabuf *buf) 354 { 355 if (wpa_s->conf->interworking == 0) 356 return; 357 358 wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB); 359 wpabuf_put_u8(buf, 4); 360 wpabuf_put_u8(buf, 0x00); 361 wpabuf_put_u8(buf, 0x00); 362 wpabuf_put_u8(buf, 0x00); 363 wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */ 364 365 wpabuf_put_u8(buf, WLAN_EID_INTERWORKING); 366 wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 : 367 1 + ETH_ALEN); 368 wpabuf_put_u8(buf, wpa_s->conf->access_network_type); 369 /* No Venue Info */ 370 if (!is_zero_ether_addr(wpa_s->conf->hessid)) 371 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN); 372 } 373 #endif /* CONFIG_INTERWORKING */ 374 375 376 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s) 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(¶ms, 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(¶ms.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, ¶ms); 584 extra_ie = wpa_supplicant_extra_ies(wpa_s); 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, ¶ms.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 #ifdef CONFIG_P2P 602 if (wpa_s->p2p_in_provisioning) { 603 /* 604 * The interface may not yet be in P2P mode, so we have to 605 * explicitly request P2P probe to disable CCK rates. 606 */ 607 params.p2p_probe = 1; 608 } 609 #endif /* CONFIG_P2P */ 610 611 ret = wpa_supplicant_trigger_scan(wpa_s, ¶ms); 612 613 wpabuf_free(extra_ie); 614 os_free(params.freqs); 615 os_free(params.filter_ssids); 616 617 if (ret) { 618 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan"); 619 if (prev_state != wpa_s->wpa_state) 620 wpa_supplicant_set_state(wpa_s, prev_state); 621 wpa_supplicant_req_scan(wpa_s, 1, 0); 622 } 623 } 624 625 626 /** 627 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points 628 * @wpa_s: Pointer to wpa_supplicant data 629 * @sec: Number of seconds after which to scan 630 * @usec: Number of microseconds after which to scan 631 * 632 * This function is used to schedule a scan for neighboring access points after 633 * the specified time. 634 */ 635 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec) 636 { 637 /* If there's at least one network that should be specifically scanned 638 * then don't cancel the scan and reschedule. Some drivers do 639 * background scanning which generates frequent scan results, and that 640 * causes the specific SSID scan to get continually pushed back and 641 * never happen, which causes hidden APs to never get probe-scanned. 642 */ 643 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) && 644 wpa_s->conf->ap_scan == 1) { 645 struct wpa_ssid *ssid = wpa_s->conf->ssid; 646 647 while (ssid) { 648 if (!ssid->disabled && ssid->scan_ssid) 649 break; 650 ssid = ssid->next; 651 } 652 if (ssid) { 653 wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to " 654 "ensure that specific SSID scans occur"); 655 return; 656 } 657 } 658 659 wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec", 660 sec, usec); 661 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL); 662 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL); 663 } 664 665 666 /** 667 * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan 668 * @wpa_s: Pointer to wpa_supplicant data 669 * @sec: Number of seconds after which to scan 670 * @usec: Number of microseconds after which to scan 671 * 672 * This function is used to schedule periodic scans for neighboring 673 * access points after the specified time. 674 */ 675 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s, 676 int sec, int usec) 677 { 678 if (!wpa_s->sched_scan_supported) 679 return -1; 680 681 eloop_register_timeout(sec, usec, 682 wpa_supplicant_delayed_sched_scan_timeout, 683 wpa_s, NULL); 684 685 return 0; 686 } 687 688 689 /** 690 * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan 691 * @wpa_s: Pointer to wpa_supplicant data 692 * 693 * This function is used to schedule periodic scans for neighboring 694 * access points repeating the scan continuously. 695 */ 696 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s) 697 { 698 struct wpa_driver_scan_params params; 699 enum wpa_states prev_state; 700 struct wpa_ssid *ssid = NULL; 701 struct wpabuf *extra_ie = NULL; 702 int ret; 703 unsigned int max_sched_scan_ssids; 704 705 if (!wpa_s->sched_scan_supported) 706 return -1; 707 708 if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS) 709 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS; 710 else 711 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids; 712 713 if (wpa_s->sched_scanning) 714 return 0; 715 716 os_memset(¶ms, 0, sizeof(params)); 717 718 /* If we can't allocate space for the filters, we just don't filter */ 719 params.filter_ssids = os_zalloc(wpa_s->max_match_sets * 720 sizeof(struct wpa_driver_scan_filter)); 721 722 prev_state = wpa_s->wpa_state; 723 if (wpa_s->wpa_state == WPA_DISCONNECTED || 724 wpa_s->wpa_state == WPA_INACTIVE) 725 wpa_supplicant_set_state(wpa_s, WPA_SCANNING); 726 727 /* Find the starting point from which to continue scanning */ 728 ssid = wpa_s->conf->ssid; 729 if (wpa_s->prev_sched_ssid) { 730 while (ssid) { 731 if (ssid == wpa_s->prev_sched_ssid) { 732 ssid = ssid->next; 733 break; 734 } 735 ssid = ssid->next; 736 } 737 } 738 739 if (!ssid || !wpa_s->prev_sched_ssid) { 740 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list"); 741 742 wpa_s->sched_scan_interval = 2; 743 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2; 744 wpa_s->first_sched_scan = 1; 745 ssid = wpa_s->conf->ssid; 746 wpa_s->prev_sched_ssid = ssid; 747 } 748 749 while (ssid) { 750 if (ssid->disabled) { 751 wpa_s->prev_sched_ssid = ssid; 752 ssid = ssid->next; 753 continue; 754 } 755 756 if (params.filter_ssids && ssid->ssid && ssid->ssid_len) { 757 os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid, 758 ssid->ssid, ssid->ssid_len); 759 params.filter_ssids[params.num_filter_ssids].ssid_len = 760 ssid->ssid_len; 761 params.num_filter_ssids++; 762 } 763 764 if (ssid->scan_ssid) { 765 params.ssids[params.num_ssids].ssid = 766 ssid->ssid; 767 params.ssids[params.num_ssids].ssid_len = 768 ssid->ssid_len; 769 params.num_ssids++; 770 if (params.num_ssids >= max_sched_scan_ssids) { 771 wpa_s->prev_sched_ssid = ssid; 772 break; 773 } 774 } 775 776 if (params.num_filter_ssids >= wpa_s->max_match_sets) 777 break; 778 wpa_s->prev_sched_ssid = ssid; 779 ssid = ssid->next; 780 } 781 782 if (!params.num_ssids) { 783 os_free(params.filter_ssids); 784 return 0; 785 } 786 787 extra_ie = wpa_supplicant_extra_ies(wpa_s); 788 if (extra_ie) { 789 params.extra_ies = wpabuf_head(extra_ie); 790 params.extra_ies_len = wpabuf_len(extra_ie); 791 } 792 793 wpa_dbg(wpa_s, MSG_DEBUG, 794 "Starting sched scan: interval %d timeout %d", 795 wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout); 796 797 ret = wpa_supplicant_start_sched_scan(wpa_s, ¶ms, 798 wpa_s->sched_scan_interval); 799 wpabuf_free(extra_ie); 800 os_free(params.filter_ssids); 801 if (ret) { 802 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan"); 803 if (prev_state != wpa_s->wpa_state) 804 wpa_supplicant_set_state(wpa_s, prev_state); 805 return ret; 806 } 807 808 /* If we have more SSIDs to scan, add a timeout so we scan them too */ 809 if (ssid || !wpa_s->first_sched_scan) { 810 wpa_s->sched_scan_timed_out = 0; 811 eloop_register_timeout(wpa_s->sched_scan_timeout, 0, 812 wpa_supplicant_sched_scan_timeout, 813 wpa_s, NULL); 814 wpa_s->first_sched_scan = 0; 815 wpa_s->sched_scan_timeout /= 2; 816 wpa_s->sched_scan_interval *= 2; 817 } 818 819 return 0; 820 } 821 822 823 /** 824 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request 825 * @wpa_s: Pointer to wpa_supplicant data 826 * 827 * This function is used to cancel a scan request scheduled with 828 * wpa_supplicant_req_scan(). 829 */ 830 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s) 831 { 832 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request"); 833 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL); 834 } 835 836 837 /** 838 * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans 839 * @wpa_s: Pointer to wpa_supplicant data 840 * 841 * This function is used to stop a periodic scheduled scan. 842 */ 843 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s) 844 { 845 if (!wpa_s->sched_scanning) 846 return; 847 848 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan"); 849 eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL); 850 wpa_supplicant_stop_sched_scan(wpa_s); 851 } 852 853 854 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s, 855 int scanning) 856 { 857 if (wpa_s->scanning != scanning) { 858 wpa_s->scanning = scanning; 859 wpas_notify_scanning(wpa_s); 860 } 861 } 862 863 864 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res) 865 { 866 int rate = 0; 867 const u8 *ie; 868 int i; 869 870 ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES); 871 for (i = 0; ie && i < ie[1]; i++) { 872 if ((ie[i + 2] & 0x7f) > rate) 873 rate = ie[i + 2] & 0x7f; 874 } 875 876 ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES); 877 for (i = 0; ie && i < ie[1]; i++) { 878 if ((ie[i + 2] & 0x7f) > rate) 879 rate = ie[i + 2] & 0x7f; 880 } 881 882 return rate; 883 } 884 885 886 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie) 887 { 888 const u8 *end, *pos; 889 890 pos = (const u8 *) (res + 1); 891 end = pos + res->ie_len; 892 893 while (pos + 1 < end) { 894 if (pos + 2 + pos[1] > end) 895 break; 896 if (pos[0] == ie) 897 return pos; 898 pos += 2 + pos[1]; 899 } 900 901 return NULL; 902 } 903 904 905 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res, 906 u32 vendor_type) 907 { 908 const u8 *end, *pos; 909 910 pos = (const u8 *) (res + 1); 911 end = pos + res->ie_len; 912 913 while (pos + 1 < end) { 914 if (pos + 2 + pos[1] > end) 915 break; 916 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 && 917 vendor_type == WPA_GET_BE32(&pos[2])) 918 return pos; 919 pos += 2 + pos[1]; 920 } 921 922 return NULL; 923 } 924 925 926 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res, 927 u32 vendor_type) 928 { 929 struct wpabuf *buf; 930 const u8 *end, *pos; 931 932 buf = wpabuf_alloc(res->ie_len); 933 if (buf == NULL) 934 return NULL; 935 936 pos = (const u8 *) (res + 1); 937 end = pos + res->ie_len; 938 939 while (pos + 1 < end) { 940 if (pos + 2 + pos[1] > end) 941 break; 942 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 && 943 vendor_type == WPA_GET_BE32(&pos[2])) 944 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4); 945 pos += 2 + pos[1]; 946 } 947 948 if (wpabuf_len(buf) == 0) { 949 wpabuf_free(buf); 950 buf = NULL; 951 } 952 953 return buf; 954 } 955 956 957 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon( 958 const struct wpa_scan_res *res, u32 vendor_type) 959 { 960 struct wpabuf *buf; 961 const u8 *end, *pos; 962 963 if (res->beacon_ie_len == 0) 964 return NULL; 965 buf = wpabuf_alloc(res->beacon_ie_len); 966 if (buf == NULL) 967 return NULL; 968 969 pos = (const u8 *) (res + 1); 970 pos += res->ie_len; 971 end = pos + res->beacon_ie_len; 972 973 while (pos + 1 < end) { 974 if (pos + 2 + pos[1] > end) 975 break; 976 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 && 977 vendor_type == WPA_GET_BE32(&pos[2])) 978 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4); 979 pos += 2 + pos[1]; 980 } 981 982 if (wpabuf_len(buf) == 0) { 983 wpabuf_free(buf); 984 buf = NULL; 985 } 986 987 return buf; 988 } 989 990 991 /* 992 * Channels with a great SNR can operate at full rate. What is a great SNR? 993 * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general 994 * rule of thumb is that any SNR above 20 is good." This one 995 * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23 996 * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a 997 * conservative value. 998 */ 999 #define GREAT_SNR 30 1000 1001 /* Compare function for sorting scan results. Return >0 if @b is considered 1002 * better. */ 1003 static int wpa_scan_result_compar(const void *a, const void *b) 1004 { 1005 #define IS_5GHZ(n) (n > 4000) 1006 #define MIN(a,b) a < b ? a : b 1007 struct wpa_scan_res **_wa = (void *) a; 1008 struct wpa_scan_res **_wb = (void *) b; 1009 struct wpa_scan_res *wa = *_wa; 1010 struct wpa_scan_res *wb = *_wb; 1011 int wpa_a, wpa_b, maxrate_a, maxrate_b; 1012 int snr_a, snr_b; 1013 1014 /* WPA/WPA2 support preferred */ 1015 wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL || 1016 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL; 1017 wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL || 1018 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL; 1019 1020 if (wpa_b && !wpa_a) 1021 return 1; 1022 if (!wpa_b && wpa_a) 1023 return -1; 1024 1025 /* privacy support preferred */ 1026 if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 && 1027 (wb->caps & IEEE80211_CAP_PRIVACY)) 1028 return 1; 1029 if ((wa->caps & IEEE80211_CAP_PRIVACY) && 1030 (wb->caps & IEEE80211_CAP_PRIVACY) == 0) 1031 return -1; 1032 1033 if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) && 1034 !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) { 1035 snr_a = MIN(wa->level - wa->noise, GREAT_SNR); 1036 snr_b = MIN(wb->level - wb->noise, GREAT_SNR); 1037 } else { 1038 /* Not suitable information to calculate SNR, so use level */ 1039 snr_a = wa->level; 1040 snr_b = wb->level; 1041 } 1042 1043 /* best/max rate preferred if SNR close enough */ 1044 if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) || 1045 (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) { 1046 maxrate_a = wpa_scan_get_max_rate(wa); 1047 maxrate_b = wpa_scan_get_max_rate(wb); 1048 if (maxrate_a != maxrate_b) 1049 return maxrate_b - maxrate_a; 1050 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq)) 1051 return IS_5GHZ(wa->freq) ? -1 : 1; 1052 } 1053 1054 /* use freq for channel preference */ 1055 1056 /* all things being equal, use SNR; if SNRs are 1057 * identical, use quality values since some drivers may only report 1058 * that value and leave the signal level zero */ 1059 if (snr_b == snr_a) 1060 return wb->qual - wa->qual; 1061 return snr_b - snr_a; 1062 #undef MIN 1063 #undef IS_5GHZ 1064 } 1065 1066 1067 #ifdef CONFIG_WPS 1068 /* Compare function for sorting scan results when searching a WPS AP for 1069 * provisioning. Return >0 if @b is considered better. */ 1070 static int wpa_scan_result_wps_compar(const void *a, const void *b) 1071 { 1072 struct wpa_scan_res **_wa = (void *) a; 1073 struct wpa_scan_res **_wb = (void *) b; 1074 struct wpa_scan_res *wa = *_wa; 1075 struct wpa_scan_res *wb = *_wb; 1076 int uses_wps_a, uses_wps_b; 1077 struct wpabuf *wps_a, *wps_b; 1078 int res; 1079 1080 /* Optimization - check WPS IE existence before allocated memory and 1081 * doing full reassembly. */ 1082 uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL; 1083 uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL; 1084 if (uses_wps_a && !uses_wps_b) 1085 return -1; 1086 if (!uses_wps_a && uses_wps_b) 1087 return 1; 1088 1089 if (uses_wps_a && uses_wps_b) { 1090 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE); 1091 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE); 1092 res = wps_ap_priority_compar(wps_a, wps_b); 1093 wpabuf_free(wps_a); 1094 wpabuf_free(wps_b); 1095 if (res) 1096 return res; 1097 } 1098 1099 /* 1100 * Do not use current AP security policy as a sorting criteria during 1101 * WPS provisioning step since the AP may get reconfigured at the 1102 * completion of provisioning. 1103 */ 1104 1105 /* all things being equal, use signal level; if signal levels are 1106 * identical, use quality values since some drivers may only report 1107 * that value and leave the signal level zero */ 1108 if (wb->level == wa->level) 1109 return wb->qual - wa->qual; 1110 return wb->level - wa->level; 1111 } 1112 #endif /* CONFIG_WPS */ 1113 1114 1115 static void dump_scan_res(struct wpa_scan_results *scan_res) 1116 { 1117 size_t i; 1118 1119 if (scan_res->res == NULL || scan_res->num == 0) 1120 return; 1121 1122 wpa_printf(MSG_EXCESSIVE, "Sorted scan results"); 1123 1124 for (i = 0; i < scan_res->num; i++) { 1125 struct wpa_scan_res *r = scan_res->res[i]; 1126 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID)) 1127 == WPA_SCAN_LEVEL_DBM) { 1128 int snr = r->level - r->noise; 1129 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d " 1130 "noise=%d level=%d snr=%d%s flags=0x%x", 1131 MAC2STR(r->bssid), r->freq, r->qual, 1132 r->noise, r->level, snr, 1133 snr >= GREAT_SNR ? "*" : "", r->flags); 1134 } else { 1135 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d " 1136 "noise=%d level=%d flags=0x%x", 1137 MAC2STR(r->bssid), r->freq, r->qual, 1138 r->noise, r->level, r->flags); 1139 } 1140 } 1141 } 1142 1143 1144 /** 1145 * wpa_supplicant_get_scan_results - Get scan results 1146 * @wpa_s: Pointer to wpa_supplicant data 1147 * @info: Information about what was scanned or %NULL if not available 1148 * @new_scan: Whether a new scan was performed 1149 * Returns: Scan results, %NULL on failure 1150 * 1151 * This function request the current scan results from the driver and updates 1152 * the local BSS list wpa_s->bss. The caller is responsible for freeing the 1153 * results with wpa_scan_results_free(). 1154 */ 1155 struct wpa_scan_results * 1156 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s, 1157 struct scan_info *info, int new_scan) 1158 { 1159 struct wpa_scan_results *scan_res; 1160 size_t i; 1161 int (*compar)(const void *, const void *) = wpa_scan_result_compar; 1162 1163 scan_res = wpa_drv_get_scan_results2(wpa_s); 1164 if (scan_res == NULL) { 1165 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results"); 1166 return NULL; 1167 } 1168 1169 #ifdef CONFIG_WPS 1170 if (wpas_wps_in_progress(wpa_s)) { 1171 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS " 1172 "provisioning rules"); 1173 compar = wpa_scan_result_wps_compar; 1174 } 1175 #endif /* CONFIG_WPS */ 1176 1177 qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *), 1178 compar); 1179 dump_scan_res(scan_res); 1180 1181 wpa_bss_update_start(wpa_s); 1182 for (i = 0; i < scan_res->num; i++) 1183 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]); 1184 wpa_bss_update_end(wpa_s, info, new_scan); 1185 1186 return scan_res; 1187 } 1188 1189 1190 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s) 1191 { 1192 struct wpa_scan_results *scan_res; 1193 scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0); 1194 if (scan_res == NULL) 1195 return -1; 1196 wpa_scan_results_free(scan_res); 1197 1198 return 0; 1199 } 1200