2 * WPA Supplicant - Scanning
3 * Copyright (c) 2003-2010, Jouni Malinen <j@w1.fi>
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
9 #include "utils/includes.h"
11 #include "utils/common.h"
12 #include "utils/eloop.h"
13 #include "common/ieee802_11_defs.h"
15 #include "wpa_supplicant_i.h"
17 #include "wps_supplicant.h"
18 #include "p2p_supplicant.h"
20 #include "hs20_supplicant.h"
26 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
28 struct wpa_ssid *ssid;
29 union wpa_event_data data;
31 ssid = wpa_supplicant_get_ssid(wpa_s);
35 if (wpa_s->current_ssid == NULL) {
36 wpa_s->current_ssid = ssid;
37 if (wpa_s->current_ssid != NULL)
38 wpas_notify_network_changed(wpa_s);
40 wpa_supplicant_initiate_eapol(wpa_s);
41 wpa_dbg(wpa_s, MSG_DEBUG, "Already associated with a configured "
42 "network - generating associated event");
43 os_memset(&data, 0, sizeof(data));
44 wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
49 static int wpas_wps_in_use(struct wpa_supplicant *wpa_s,
50 enum wps_request_type *req_type)
52 struct wpa_ssid *ssid;
55 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
56 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
60 *req_type = wpas_wps_get_req_type(ssid);
61 if (!ssid->eap.phase1)
64 if (os_strstr(ssid->eap.phase1, "pbc=1"))
69 if (!wpa_s->global->p2p_disabled && wpa_s->global->p2p) {
70 wpa_s->wps->dev.p2p = 1;
73 *req_type = WPS_REQ_ENROLLEE_INFO;
76 #endif /* CONFIG_P2P */
80 #endif /* CONFIG_WPS */
83 int wpa_supplicant_enabled_networks(struct wpa_supplicant *wpa_s)
85 struct wpa_ssid *ssid = wpa_s->conf->ssid;
88 if (!wpas_network_disabled(wpa_s, ssid))
96 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
97 struct wpa_ssid *ssid)
100 if (!wpas_network_disabled(wpa_s, ssid))
105 /* ap_scan=2 mode - try to associate with each SSID. */
107 wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
108 "end of scan list - go back to beginning");
109 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
110 wpa_supplicant_req_scan(wpa_s, 0, 0);
114 /* Continue from the next SSID on the next attempt. */
115 wpa_s->prev_scan_ssid = ssid;
117 /* Start from the beginning of the SSID list. */
118 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
120 wpa_supplicant_associate(wpa_s, NULL, ssid);
124 static int int_array_len(const int *a)
127 for (i = 0; a && a[i]; i++)
133 static void int_array_concat(int **res, const int *a)
138 reslen = int_array_len(*res);
139 alen = int_array_len(a);
141 n = os_realloc_array(*res, reslen + alen + 1, sizeof(int));
147 for (i = 0; i <= alen; i++)
148 n[reslen + i] = a[i];
153 static int freq_cmp(const void *a, const void *b)
166 static void int_array_sort_unique(int *a)
174 alen = int_array_len(a);
175 qsort(a, alen, sizeof(int), freq_cmp);
179 while (a[i] && a[j]) {
192 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
193 struct wpa_driver_scan_params *params)
197 wpa_supplicant_notify_scanning(wpa_s, 1);
199 ret = wpa_drv_scan(wpa_s, params);
201 wpa_supplicant_notify_scanning(wpa_s, 0);
202 wpas_notify_scan_done(wpa_s, 0);
205 wpa_s->normal_scans++;
213 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
215 struct wpa_supplicant *wpa_s = eloop_ctx;
217 wpa_dbg(wpa_s, MSG_DEBUG, "Starting delayed sched scan");
219 if (wpa_supplicant_req_sched_scan(wpa_s))
220 wpa_supplicant_req_scan(wpa_s, 0, 0);
225 wpa_supplicant_sched_scan_timeout(void *eloop_ctx, void *timeout_ctx)
227 struct wpa_supplicant *wpa_s = eloop_ctx;
229 wpa_dbg(wpa_s, MSG_DEBUG, "Sched scan timeout - stopping it");
231 wpa_s->sched_scan_timed_out = 1;
232 wpa_supplicant_cancel_sched_scan(wpa_s);
237 wpa_supplicant_start_sched_scan(struct wpa_supplicant *wpa_s,
238 struct wpa_driver_scan_params *params,
243 wpa_supplicant_notify_scanning(wpa_s, 1);
244 ret = wpa_drv_sched_scan(wpa_s, params, interval * 1000);
246 wpa_supplicant_notify_scanning(wpa_s, 0);
248 wpa_s->sched_scanning = 1;
254 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant *wpa_s)
258 ret = wpa_drv_stop_sched_scan(wpa_s);
260 wpa_dbg(wpa_s, MSG_DEBUG, "stopping sched_scan failed!");
261 /* TODO: what to do if stopping fails? */
269 static struct wpa_driver_scan_filter *
270 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
272 struct wpa_driver_scan_filter *ssids;
273 struct wpa_ssid *ssid;
277 if (!conf->filter_ssids)
280 for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
281 if (ssid->ssid && ssid->ssid_len)
286 ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
290 for (ssid = conf->ssid; ssid; ssid = ssid->next) {
291 if (!ssid->ssid || !ssid->ssid_len)
293 os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
294 ssids[*num_ssids].ssid_len = ssid->ssid_len;
302 static void wpa_supplicant_optimize_freqs(
303 struct wpa_supplicant *wpa_s, struct wpa_driver_scan_params *params)
306 if (params->freqs == NULL && wpa_s->p2p_in_provisioning &&
308 /* Optimize provisioning state scan based on GO information */
309 if (wpa_s->p2p_in_provisioning < 5 &&
310 wpa_s->go_params->freq > 0) {
311 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
312 "preferred frequency %d MHz",
313 wpa_s->go_params->freq);
314 params->freqs = os_zalloc(2 * sizeof(int));
316 params->freqs[0] = wpa_s->go_params->freq;
317 } else if (wpa_s->p2p_in_provisioning < 8 &&
318 wpa_s->go_params->freq_list[0]) {
319 wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
321 int_array_concat(¶ms->freqs,
322 wpa_s->go_params->freq_list);
324 int_array_sort_unique(params->freqs);
326 wpa_s->p2p_in_provisioning++;
328 #endif /* CONFIG_P2P */
331 if (params->freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
333 * Optimize post-provisioning scan based on channel used
334 * during provisioning.
336 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
337 "that was used during provisioning", wpa_s->wps_freq);
338 params->freqs = os_zalloc(2 * sizeof(int));
340 params->freqs[0] = wpa_s->wps_freq;
344 if (params->freqs == NULL && wpa_s->known_wps_freq && wpa_s->wps_freq)
346 /* Optimize provisioning scan based on already known channel */
347 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz",
349 params->freqs = os_zalloc(2 * sizeof(int));
351 params->freqs[0] = wpa_s->wps_freq;
352 wpa_s->known_wps_freq = 0; /* only do this once */
354 #endif /* CONFIG_WPS */
358 #ifdef CONFIG_INTERWORKING
359 static void wpas_add_interworking_elements(struct wpa_supplicant *wpa_s,
362 if (wpa_s->conf->interworking == 0)
365 wpabuf_put_u8(buf, WLAN_EID_EXT_CAPAB);
366 wpabuf_put_u8(buf, 4);
367 wpabuf_put_u8(buf, 0x00);
368 wpabuf_put_u8(buf, 0x00);
369 wpabuf_put_u8(buf, 0x00);
370 wpabuf_put_u8(buf, 0x80); /* Bit 31 - Interworking */
372 wpabuf_put_u8(buf, WLAN_EID_INTERWORKING);
373 wpabuf_put_u8(buf, is_zero_ether_addr(wpa_s->conf->hessid) ? 1 :
375 wpabuf_put_u8(buf, wpa_s->conf->access_network_type);
377 if (!is_zero_ether_addr(wpa_s->conf->hessid))
378 wpabuf_put_data(buf, wpa_s->conf->hessid, ETH_ALEN);
380 #endif /* CONFIG_INTERWORKING */
383 static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
385 struct wpabuf *extra_ie = NULL;
388 enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
389 #endif /* CONFIG_WPS */
391 #ifdef CONFIG_INTERWORKING
392 if (wpa_s->conf->interworking &&
393 wpabuf_resize(&extra_ie, 100) == 0)
394 wpas_add_interworking_elements(wpa_s, extra_ie);
395 #endif /* CONFIG_INTERWORKING */
398 wps = wpas_wps_in_use(wpa_s, &req_type);
401 struct wpabuf *wps_ie;
402 wps_ie = wps_build_probe_req_ie(wps == 2 ? DEV_PW_PUSHBUTTON :
405 wpa_s->wps->uuid, req_type,
408 if (wpabuf_resize(&extra_ie, wpabuf_len(wps_ie)) == 0)
409 wpabuf_put_buf(extra_ie, wps_ie);
416 size_t ielen = p2p_scan_ie_buf_len(wpa_s->global->p2p);
417 if (wpabuf_resize(&extra_ie, ielen) == 0)
418 wpas_p2p_scan_ie(wpa_s, extra_ie);
420 #endif /* CONFIG_P2P */
422 #endif /* CONFIG_WPS */
428 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
430 struct wpa_supplicant *wpa_s = eloop_ctx;
431 struct wpa_ssid *ssid;
432 int scan_req = 0, ret;
433 struct wpabuf *extra_ie = NULL;
434 struct wpa_driver_scan_params params;
435 struct wpa_driver_scan_params *scan_params;
437 enum wpa_states prev_state;
439 if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
440 wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
444 if (wpa_s->disconnected && !wpa_s->scan_req) {
445 wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
449 if (!wpa_supplicant_enabled_networks(wpa_s) &&
451 wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
452 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
456 if (wpa_s->conf->ap_scan != 0 &&
457 (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
458 wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
459 "overriding ap_scan configuration");
460 wpa_s->conf->ap_scan = 0;
461 wpas_notify_ap_scan_changed(wpa_s);
464 if (wpa_s->conf->ap_scan == 0) {
465 wpa_supplicant_gen_assoc_event(wpa_s);
470 if (wpas_p2p_in_progress(wpa_s)) {
471 if (wpa_s->sta_scan_pending &&
472 wpas_p2p_in_progress(wpa_s) == 2 &&
473 wpa_s->p2p_cb_on_scan_complete) {
474 wpa_dbg(wpa_s, MSG_DEBUG, "Process pending station "
475 "mode scan during P2P search");
477 wpa_dbg(wpa_s, MSG_DEBUG, "Delay station mode scan "
478 "while P2P operation is in progress");
479 wpa_s->sta_scan_pending = 1;
480 wpa_supplicant_req_scan(wpa_s, 5, 0);
484 #endif /* CONFIG_P2P */
486 if (wpa_s->conf->ap_scan == 2)
489 max_ssids = wpa_s->max_scan_ssids;
490 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
491 max_ssids = WPAS_MAX_SCAN_SSIDS;
494 scan_req = wpa_s->scan_req;
497 os_memset(¶ms, 0, sizeof(params));
499 prev_state = wpa_s->wpa_state;
500 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
501 wpa_s->wpa_state == WPA_INACTIVE)
502 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
505 * If autoscan has set its own scanning parameters
507 if (wpa_s->autoscan_params != NULL) {
508 scan_params = wpa_s->autoscan_params;
512 if (scan_req != 2 && wpa_s->connect_without_scan) {
513 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
514 if (ssid == wpa_s->connect_without_scan)
517 wpa_s->connect_without_scan = NULL;
519 wpa_printf(MSG_DEBUG, "Start a pre-selected network "
520 "without scan step");
521 wpa_supplicant_associate(wpa_s, NULL, ssid);
527 if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
529 wpa_printf(MSG_DEBUG, "P2P: Use specific SSID for scan during "
530 "P2P group formation");
531 params.ssids[0].ssid = wpa_s->go_params->ssid;
532 params.ssids[0].ssid_len = wpa_s->go_params->ssid_len;
533 params.num_ssids = 1;
536 #endif /* CONFIG_P2P */
538 /* Find the starting point from which to continue scanning */
539 ssid = wpa_s->conf->ssid;
540 if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
542 if (ssid == wpa_s->prev_scan_ssid) {
550 if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
551 wpa_s->connect_without_scan = NULL;
552 wpa_s->prev_scan_wildcard = 0;
553 wpa_supplicant_assoc_try(wpa_s, ssid);
555 } else if (wpa_s->conf->ap_scan == 2) {
557 * User-initiated scan request in ap_scan == 2; scan with
562 struct wpa_ssid *start = ssid, *tssid;
564 if (ssid == NULL && max_ssids > 1)
565 ssid = wpa_s->conf->ssid;
567 if (!wpas_network_disabled(wpa_s, ssid) &&
569 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
570 ssid->ssid, ssid->ssid_len);
571 params.ssids[params.num_ssids].ssid =
573 params.ssids[params.num_ssids].ssid_len =
576 if (params.num_ssids + 1 >= max_ssids)
582 if (ssid == NULL && max_ssids > 1 &&
583 start != wpa_s->conf->ssid)
584 ssid = wpa_s->conf->ssid;
587 for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
588 if (wpas_network_disabled(wpa_s, tssid))
590 if ((params.freqs || !freqs_set) && tssid->scan_freq) {
591 int_array_concat(¶ms.freqs,
594 os_free(params.freqs);
599 int_array_sort_unique(params.freqs);
602 if (ssid && max_ssids == 1) {
604 * If the driver is limited to 1 SSID at a time interleave
605 * wildcard SSID scans with specific SSID scans to avoid
606 * waiting a long time for a wildcard scan.
608 if (!wpa_s->prev_scan_wildcard) {
609 params.ssids[0].ssid = NULL;
610 params.ssids[0].ssid_len = 0;
611 wpa_s->prev_scan_wildcard = 1;
612 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for "
613 "wildcard SSID (Interleave with specific)");
615 wpa_s->prev_scan_ssid = ssid;
616 wpa_s->prev_scan_wildcard = 0;
617 wpa_dbg(wpa_s, MSG_DEBUG,
618 "Starting AP scan for specific SSID: %s",
619 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
624 wpa_s->prev_scan_ssid = ssid;
625 wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
629 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
631 wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
636 #endif /* CONFIG_P2P */
638 wpa_supplicant_optimize_freqs(wpa_s, ¶ms);
639 extra_ie = wpa_supplicant_extra_ies(wpa_s);
642 if (wpa_s->conf->hs20 && wpabuf_resize(&extra_ie, 6) == 0)
643 wpas_hs20_add_indication(extra_ie);
644 #endif /* CONFIG_HS20 */
646 if (params.freqs == NULL && wpa_s->next_scan_freqs) {
647 wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
648 "generated frequency list");
649 params.freqs = wpa_s->next_scan_freqs;
651 os_free(wpa_s->next_scan_freqs);
652 wpa_s->next_scan_freqs = NULL;
654 params.filter_ssids = wpa_supplicant_build_filter_ssids(
655 wpa_s->conf, ¶ms.num_filter_ssids);
657 params.extra_ies = wpabuf_head(extra_ie);
658 params.extra_ies_len = wpabuf_len(extra_ie);
662 if (wpa_s->p2p_in_provisioning ||
663 (wpa_s->show_group_started && wpa_s->go_params)) {
665 * The interface may not yet be in P2P mode, so we have to
666 * explicitly request P2P probe to disable CCK rates.
668 params.p2p_probe = 1;
670 #endif /* CONFIG_P2P */
672 scan_params = ¶ms;
675 ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
677 wpabuf_free(extra_ie);
678 os_free(params.freqs);
679 os_free(params.filter_ssids);
682 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
683 if (prev_state != wpa_s->wpa_state)
684 wpa_supplicant_set_state(wpa_s, prev_state);
685 wpa_supplicant_req_scan(wpa_s, 1, 0);
691 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
692 * @wpa_s: Pointer to wpa_supplicant data
693 * @sec: Number of seconds after which to scan
694 * @usec: Number of microseconds after which to scan
696 * This function is used to schedule a scan for neighboring access points after
697 * the specified time.
699 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
701 /* If there's at least one network that should be specifically scanned
702 * then don't cancel the scan and reschedule. Some drivers do
703 * background scanning which generates frequent scan results, and that
704 * causes the specific SSID scan to get continually pushed back and
705 * never happen, which causes hidden APs to never get probe-scanned.
707 if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
708 wpa_s->conf->ap_scan == 1) {
709 struct wpa_ssid *ssid = wpa_s->conf->ssid;
712 if (!wpas_network_disabled(wpa_s, ssid) &&
718 wpa_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
719 "ensure that specific SSID scans occur");
724 wpa_dbg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
726 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
727 eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
732 * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
733 * @wpa_s: Pointer to wpa_supplicant data
734 * @sec: Number of seconds after which to scan
735 * @usec: Number of microseconds after which to scan
737 * This function is used to schedule periodic scans for neighboring
738 * access points after the specified time.
740 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant *wpa_s,
743 if (!wpa_s->sched_scan_supported)
746 eloop_register_timeout(sec, usec,
747 wpa_supplicant_delayed_sched_scan_timeout,
755 * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
756 * @wpa_s: Pointer to wpa_supplicant data
758 * This function is used to schedule periodic scans for neighboring
759 * access points repeating the scan continuously.
761 int wpa_supplicant_req_sched_scan(struct wpa_supplicant *wpa_s)
763 struct wpa_driver_scan_params params;
764 struct wpa_driver_scan_params *scan_params;
765 enum wpa_states prev_state;
766 struct wpa_ssid *ssid = NULL;
767 struct wpabuf *extra_ie = NULL;
769 unsigned int max_sched_scan_ssids;
773 if (!wpa_s->sched_scan_supported)
776 if (wpa_s->max_sched_scan_ssids > WPAS_MAX_SCAN_SSIDS)
777 max_sched_scan_ssids = WPAS_MAX_SCAN_SSIDS;
779 max_sched_scan_ssids = wpa_s->max_sched_scan_ssids;
780 if (max_sched_scan_ssids < 1 || wpa_s->conf->disable_scan_offload)
783 if (wpa_s->sched_scanning) {
784 wpa_dbg(wpa_s, MSG_DEBUG, "Already sched scanning");
789 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
790 if (!wpas_network_disabled(wpa_s, ssid) && !ssid->scan_ssid) {
791 /* Use wildcard SSID to find this network */
793 } else if (!wpas_network_disabled(wpa_s, ssid) &&
798 if (!wpas_network_disabled(wpa_s, ssid) &&
799 ssid->key_mgmt == WPA_KEY_MGMT_WPS) {
801 * Normal scan is more reliable and faster for WPS
802 * operations and since these are for short periods of
803 * time, the benefit of trying to use sched_scan would
806 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
807 "sched_scan for WPS");
810 #endif /* CONFIG_WPS */
815 if (wpa_s->normal_scans < 3 &&
816 (need_ssids <= wpa_s->max_scan_ssids ||
817 wpa_s->max_scan_ssids >= (int) max_sched_scan_ssids)) {
819 * When normal scan can speed up operations, use that for the
820 * first operations before starting the sched_scan to allow
821 * user space sleep more. We do this only if the normal scan
822 * has functionality that is suitable for this or if the
823 * sched_scan does not have better support for multiple SSIDs.
825 wpa_dbg(wpa_s, MSG_DEBUG, "Use normal scan instead of "
826 "sched_scan for initial scans (normal_scans=%d)",
827 wpa_s->normal_scans);
831 os_memset(¶ms, 0, sizeof(params));
833 /* If we can't allocate space for the filters, we just don't filter */
834 params.filter_ssids = os_zalloc(wpa_s->max_match_sets *
835 sizeof(struct wpa_driver_scan_filter));
837 prev_state = wpa_s->wpa_state;
838 if (wpa_s->wpa_state == WPA_DISCONNECTED ||
839 wpa_s->wpa_state == WPA_INACTIVE)
840 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
842 if (wpa_s->autoscan_params != NULL) {
843 scan_params = wpa_s->autoscan_params;
847 /* Find the starting point from which to continue scanning */
848 ssid = wpa_s->conf->ssid;
849 if (wpa_s->prev_sched_ssid) {
851 if (ssid == wpa_s->prev_sched_ssid) {
859 if (!ssid || !wpa_s->prev_sched_ssid) {
860 wpa_dbg(wpa_s, MSG_DEBUG, "Beginning of SSID list");
862 if (wpa_s->sched_scan_interval == 0)
863 wpa_s->sched_scan_interval = 10;
864 wpa_s->sched_scan_timeout = max_sched_scan_ssids * 2;
865 wpa_s->first_sched_scan = 1;
866 ssid = wpa_s->conf->ssid;
867 wpa_s->prev_sched_ssid = ssid;
871 wpa_dbg(wpa_s, MSG_DEBUG, "Add wildcard SSID to sched_scan");
876 if (wpas_network_disabled(wpa_s, ssid))
879 if (params.num_filter_ssids < wpa_s->max_match_sets &&
880 params.filter_ssids && ssid->ssid && ssid->ssid_len) {
881 wpa_dbg(wpa_s, MSG_DEBUG, "add to filter ssid: %s",
882 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
883 os_memcpy(params.filter_ssids[params.num_filter_ssids].ssid,
884 ssid->ssid, ssid->ssid_len);
885 params.filter_ssids[params.num_filter_ssids].ssid_len =
887 params.num_filter_ssids++;
888 } else if (params.filter_ssids && ssid->ssid && ssid->ssid_len)
890 wpa_dbg(wpa_s, MSG_DEBUG, "Not enough room for SSID "
891 "filter for sched_scan - drop filter");
892 os_free(params.filter_ssids);
893 params.filter_ssids = NULL;
894 params.num_filter_ssids = 0;
897 if (ssid->scan_ssid && ssid->ssid && ssid->ssid_len) {
898 if (params.num_ssids == max_sched_scan_ssids)
899 break; /* only room for broadcast SSID */
900 wpa_dbg(wpa_s, MSG_DEBUG,
901 "add to active scan ssid: %s",
902 wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
903 params.ssids[params.num_ssids].ssid =
905 params.ssids[params.num_ssids].ssid_len =
908 if (params.num_ssids >= max_sched_scan_ssids) {
909 wpa_s->prev_sched_ssid = ssid;
913 (wpas_network_disabled(wpa_s, ssid) ||
920 wpa_s->prev_sched_ssid = ssid;
924 if (params.num_filter_ssids == 0) {
925 os_free(params.filter_ssids);
926 params.filter_ssids = NULL;
929 extra_ie = wpa_supplicant_extra_ies(wpa_s);
931 params.extra_ies = wpabuf_head(extra_ie);
932 params.extra_ies_len = wpabuf_len(extra_ie);
935 scan_params = ¶ms;
938 if (ssid || !wpa_s->first_sched_scan) {
939 wpa_dbg(wpa_s, MSG_DEBUG,
940 "Starting sched scan: interval %d timeout %d",
941 wpa_s->sched_scan_interval, wpa_s->sched_scan_timeout);
943 wpa_dbg(wpa_s, MSG_DEBUG,
944 "Starting sched scan: interval %d (no timeout)",
945 wpa_s->sched_scan_interval);
948 ret = wpa_supplicant_start_sched_scan(wpa_s, scan_params,
949 wpa_s->sched_scan_interval);
950 wpabuf_free(extra_ie);
951 os_free(params.filter_ssids);
953 wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate sched scan");
954 if (prev_state != wpa_s->wpa_state)
955 wpa_supplicant_set_state(wpa_s, prev_state);
959 /* If we have more SSIDs to scan, add a timeout so we scan them too */
960 if (ssid || !wpa_s->first_sched_scan) {
961 wpa_s->sched_scan_timed_out = 0;
962 eloop_register_timeout(wpa_s->sched_scan_timeout, 0,
963 wpa_supplicant_sched_scan_timeout,
965 wpa_s->first_sched_scan = 0;
966 wpa_s->sched_scan_timeout /= 2;
967 wpa_s->sched_scan_interval *= 2;
975 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
976 * @wpa_s: Pointer to wpa_supplicant data
978 * This function is used to cancel a scan request scheduled with
979 * wpa_supplicant_req_scan().
981 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
983 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
984 eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
989 * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
990 * @wpa_s: Pointer to wpa_supplicant data
992 * This function is used to stop a periodic scheduled scan.
994 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant *wpa_s)
996 if (!wpa_s->sched_scanning)
999 wpa_dbg(wpa_s, MSG_DEBUG, "Cancelling sched scan");
1000 eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout, wpa_s, NULL);
1001 wpa_supplicant_stop_sched_scan(wpa_s);
1005 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
1008 if (wpa_s->scanning != scanning) {
1009 wpa_s->scanning = scanning;
1010 wpas_notify_scanning(wpa_s);
1015 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
1021 ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
1022 for (i = 0; ie && i < ie[1]; i++) {
1023 if ((ie[i + 2] & 0x7f) > rate)
1024 rate = ie[i + 2] & 0x7f;
1027 ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
1028 for (i = 0; ie && i < ie[1]; i++) {
1029 if ((ie[i + 2] & 0x7f) > rate)
1030 rate = ie[i + 2] & 0x7f;
1037 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
1039 const u8 *end, *pos;
1041 pos = (const u8 *) (res + 1);
1042 end = pos + res->ie_len;
1044 while (pos + 1 < end) {
1045 if (pos + 2 + pos[1] > end)
1056 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
1059 const u8 *end, *pos;
1061 pos = (const u8 *) (res + 1);
1062 end = pos + res->ie_len;
1064 while (pos + 1 < end) {
1065 if (pos + 2 + pos[1] > end)
1067 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1068 vendor_type == WPA_GET_BE32(&pos[2]))
1077 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
1081 const u8 *end, *pos;
1083 buf = wpabuf_alloc(res->ie_len);
1087 pos = (const u8 *) (res + 1);
1088 end = pos + res->ie_len;
1090 while (pos + 1 < end) {
1091 if (pos + 2 + pos[1] > end)
1093 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1094 vendor_type == WPA_GET_BE32(&pos[2]))
1095 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1099 if (wpabuf_len(buf) == 0) {
1108 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
1109 const struct wpa_scan_res *res, u32 vendor_type)
1112 const u8 *end, *pos;
1114 if (res->beacon_ie_len == 0)
1116 buf = wpabuf_alloc(res->beacon_ie_len);
1120 pos = (const u8 *) (res + 1);
1122 end = pos + res->beacon_ie_len;
1124 while (pos + 1 < end) {
1125 if (pos + 2 + pos[1] > end)
1127 if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
1128 vendor_type == WPA_GET_BE32(&pos[2]))
1129 wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
1133 if (wpabuf_len(buf) == 0) {
1143 * Channels with a great SNR can operate at full rate. What is a great SNR?
1144 * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1145 * rule of thumb is that any SNR above 20 is good." This one
1146 * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1147 * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1148 * conservative value.
1150 #define GREAT_SNR 30
1152 /* Compare function for sorting scan results. Return >0 if @b is considered
1154 static int wpa_scan_result_compar(const void *a, const void *b)
1156 #define IS_5GHZ(n) (n > 4000)
1157 #define MIN(a,b) a < b ? a : b
1158 struct wpa_scan_res **_wa = (void *) a;
1159 struct wpa_scan_res **_wb = (void *) b;
1160 struct wpa_scan_res *wa = *_wa;
1161 struct wpa_scan_res *wb = *_wb;
1162 int wpa_a, wpa_b, maxrate_a, maxrate_b;
1165 /* WPA/WPA2 support preferred */
1166 wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
1167 wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
1168 wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
1169 wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;
1171 if (wpa_b && !wpa_a)
1173 if (!wpa_b && wpa_a)
1176 /* privacy support preferred */
1177 if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
1178 (wb->caps & IEEE80211_CAP_PRIVACY))
1180 if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
1181 (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
1184 if ((wa->flags & wb->flags & WPA_SCAN_LEVEL_DBM) &&
1185 !((wa->flags | wb->flags) & WPA_SCAN_NOISE_INVALID)) {
1186 snr_a = MIN(wa->level - wa->noise, GREAT_SNR);
1187 snr_b = MIN(wb->level - wb->noise, GREAT_SNR);
1189 /* Not suitable information to calculate SNR, so use level */
1194 /* best/max rate preferred if SNR close enough */
1195 if ((snr_a && snr_b && abs(snr_b - snr_a) < 5) ||
1196 (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
1197 maxrate_a = wpa_scan_get_max_rate(wa);
1198 maxrate_b = wpa_scan_get_max_rate(wb);
1199 if (maxrate_a != maxrate_b)
1200 return maxrate_b - maxrate_a;
1201 if (IS_5GHZ(wa->freq) ^ IS_5GHZ(wb->freq))
1202 return IS_5GHZ(wa->freq) ? -1 : 1;
1205 /* use freq for channel preference */
1207 /* all things being equal, use SNR; if SNRs are
1208 * identical, use quality values since some drivers may only report
1209 * that value and leave the signal level zero */
1211 return wb->qual - wa->qual;
1212 return snr_b - snr_a;
1219 /* Compare function for sorting scan results when searching a WPS AP for
1220 * provisioning. Return >0 if @b is considered better. */
1221 static int wpa_scan_result_wps_compar(const void *a, const void *b)
1223 struct wpa_scan_res **_wa = (void *) a;
1224 struct wpa_scan_res **_wb = (void *) b;
1225 struct wpa_scan_res *wa = *_wa;
1226 struct wpa_scan_res *wb = *_wb;
1227 int uses_wps_a, uses_wps_b;
1228 struct wpabuf *wps_a, *wps_b;
1231 /* Optimization - check WPS IE existence before allocated memory and
1232 * doing full reassembly. */
1233 uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
1234 uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
1235 if (uses_wps_a && !uses_wps_b)
1237 if (!uses_wps_a && uses_wps_b)
1240 if (uses_wps_a && uses_wps_b) {
1241 wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
1242 wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
1243 res = wps_ap_priority_compar(wps_a, wps_b);
1251 * Do not use current AP security policy as a sorting criteria during
1252 * WPS provisioning step since the AP may get reconfigured at the
1253 * completion of provisioning.
1256 /* all things being equal, use signal level; if signal levels are
1257 * identical, use quality values since some drivers may only report
1258 * that value and leave the signal level zero */
1259 if (wb->level == wa->level)
1260 return wb->qual - wa->qual;
1261 return wb->level - wa->level;
1263 #endif /* CONFIG_WPS */
1266 static void dump_scan_res(struct wpa_scan_results *scan_res)
1268 #ifndef CONFIG_NO_STDOUT_DEBUG
1271 if (scan_res->res == NULL || scan_res->num == 0)
1274 wpa_printf(MSG_EXCESSIVE, "Sorted scan results");
1276 for (i = 0; i < scan_res->num; i++) {
1277 struct wpa_scan_res *r = scan_res->res[i];
1279 if ((r->flags & (WPA_SCAN_LEVEL_DBM | WPA_SCAN_NOISE_INVALID))
1280 == WPA_SCAN_LEVEL_DBM) {
1281 int snr = r->level - r->noise;
1282 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1283 "noise=%d level=%d snr=%d%s flags=0x%x",
1284 MAC2STR(r->bssid), r->freq, r->qual,
1285 r->noise, r->level, snr,
1286 snr >= GREAT_SNR ? "*" : "", r->flags);
1288 wpa_printf(MSG_EXCESSIVE, MACSTR " freq=%d qual=%d "
1289 "noise=%d level=%d flags=0x%x",
1290 MAC2STR(r->bssid), r->freq, r->qual,
1291 r->noise, r->level, r->flags);
1293 pos = (u8 *) (r + 1);
1295 wpa_hexdump(MSG_EXCESSIVE, "IEs", pos, r->ie_len);
1297 if (r->beacon_ie_len)
1298 wpa_hexdump(MSG_EXCESSIVE, "Beacon IEs",
1299 pos, r->beacon_ie_len);
1301 #endif /* CONFIG_NO_STDOUT_DEBUG */
1305 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant *wpa_s,
1310 if (wpa_s->bssid_filter == NULL)
1313 for (i = 0; i < wpa_s->bssid_filter_count; i++) {
1314 if (os_memcmp(wpa_s->bssid_filter + i * ETH_ALEN, bssid,
1323 static void filter_scan_res(struct wpa_supplicant *wpa_s,
1324 struct wpa_scan_results *res)
1328 if (wpa_s->bssid_filter == NULL)
1331 for (i = 0, j = 0; i < res->num; i++) {
1332 if (wpa_supplicant_filter_bssid_match(wpa_s,
1333 res->res[i]->bssid)) {
1334 res->res[j++] = res->res[i];
1336 os_free(res->res[i]);
1341 if (res->num != j) {
1342 wpa_printf(MSG_DEBUG, "Filtered out %d scan results",
1343 (int) (res->num - j));
1350 * wpa_supplicant_get_scan_results - Get scan results
1351 * @wpa_s: Pointer to wpa_supplicant data
1352 * @info: Information about what was scanned or %NULL if not available
1353 * @new_scan: Whether a new scan was performed
1354 * Returns: Scan results, %NULL on failure
1356 * This function request the current scan results from the driver and updates
1357 * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1358 * results with wpa_scan_results_free().
1360 struct wpa_scan_results *
1361 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
1362 struct scan_info *info, int new_scan)
1364 struct wpa_scan_results *scan_res;
1366 int (*compar)(const void *, const void *) = wpa_scan_result_compar;
1368 scan_res = wpa_drv_get_scan_results2(wpa_s);
1369 if (scan_res == NULL) {
1370 wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
1373 filter_scan_res(wpa_s, scan_res);
1376 if (wpas_wps_in_progress(wpa_s)) {
1377 wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
1378 "provisioning rules");
1379 compar = wpa_scan_result_wps_compar;
1381 #endif /* CONFIG_WPS */
1383 qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
1385 dump_scan_res(scan_res);
1387 wpa_bss_update_start(wpa_s);
1388 for (i = 0; i < scan_res->num; i++)
1389 wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
1390 wpa_bss_update_end(wpa_s, info, new_scan);
1396 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
1398 struct wpa_scan_results *scan_res;
1399 scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
1400 if (scan_res == NULL)
1402 wpa_scan_results_free(scan_res);