2 * WPA Supplicant - Scanning
3 * Copyright (c) 2003-2010, Jouni Malinen <j@w1.fi>
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.
9 * Alternatively, this software may be distributed under the terms of BSD
12 * See README and COPYING for more details.
15 #include "utils/includes.h"
17 #include "utils/common.h"
18 #include "utils/eloop.h"
19 #include "common/ieee802_11_defs.h"
21 #include "wpa_supplicant_i.h"
23 #include "wps_supplicant.h"
24 #include "p2p_supplicant.h"
31 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant
*wpa_s
)
33 struct wpa_ssid
*ssid
;
34 union wpa_event_data data
;
36 ssid
= wpa_supplicant_get_ssid(wpa_s
);
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
);
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
);
54 static int wpas_wps_in_use(struct wpa_supplicant
*wpa_s
,
55 enum wps_request_type
*req_type
)
57 struct wpa_ssid
*ssid
;
60 for (ssid
= wpa_s
->conf
->ssid
; ssid
; ssid
= ssid
->next
) {
61 if (!(ssid
->key_mgmt
& WPA_KEY_MGMT_WPS
))
65 *req_type
= wpas_wps_get_req_type(ssid
);
66 if (!ssid
->eap
.phase1
)
69 if (os_strstr(ssid
->eap
.phase1
, "pbc=1"))
74 wpa_s
->wps
->dev
.p2p
= 1;
77 *req_type
= WPS_REQ_ENROLLEE_INFO
;
79 #endif /* CONFIG_P2P */
83 #endif /* CONFIG_WPS */
86 int wpa_supplicant_enabled_networks(struct wpa_config
*conf
)
88 struct wpa_ssid
*ssid
= conf
->ssid
;
99 static void wpa_supplicant_assoc_try(struct wpa_supplicant
*wpa_s
,
100 struct wpa_ssid
*ssid
)
108 /* ap_scan=2 mode - try to associate with each SSID. */
110 wpa_dbg(wpa_s
, MSG_DEBUG
, "wpa_supplicant_assoc_try: Reached "
111 "end of scan list - go back to beginning");
112 wpa_s
->prev_scan_ssid
= WILDCARD_SSID_SCAN
;
113 wpa_supplicant_req_scan(wpa_s
, 0, 0);
117 /* Continue from the next SSID on the next attempt. */
118 wpa_s
->prev_scan_ssid
= ssid
;
120 /* Start from the beginning of the SSID list. */
121 wpa_s
->prev_scan_ssid
= WILDCARD_SSID_SCAN
;
123 wpa_supplicant_associate(wpa_s
, NULL
, ssid
);
127 static int int_array_len(const int *a
)
130 for (i
= 0; a
&& a
[i
]; i
++)
136 static void int_array_concat(int **res
, const int *a
)
141 reslen
= int_array_len(*res
);
142 alen
= int_array_len(a
);
144 n
= os_realloc(*res
, (reslen
+ alen
+ 1) * sizeof(int));
150 for (i
= 0; i
<= alen
; i
++)
151 n
[reslen
+ i
] = a
[i
];
156 static int freq_cmp(const void *a
, const void *b
)
169 static void int_array_sort_unique(int *a
)
177 alen
= int_array_len(a
);
178 qsort(a
, alen
, sizeof(int), freq_cmp
);
182 while (a
[i
] && a
[j
]) {
195 int wpa_supplicant_trigger_scan(struct wpa_supplicant
*wpa_s
,
196 struct wpa_driver_scan_params
*params
)
200 wpa_supplicant_notify_scanning(wpa_s
, 1);
202 ret
= wpa_drv_scan(wpa_s
, params
);
204 wpa_supplicant_notify_scanning(wpa_s
, 0);
205 wpas_notify_scan_done(wpa_s
, 0);
214 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx
, void *timeout_ctx
)
216 struct wpa_supplicant
*wpa_s
= eloop_ctx
;
218 wpa_dbg(wpa_s
, MSG_DEBUG
, "Starting delayed sched scan");
220 if (wpa_supplicant_req_sched_scan(wpa_s
))
221 wpa_supplicant_req_scan(wpa_s
, 0, 0);
226 wpa_supplicant_sched_scan_timeout(void *eloop_ctx
, void *timeout_ctx
)
228 struct wpa_supplicant
*wpa_s
= eloop_ctx
;
230 wpa_dbg(wpa_s
, MSG_DEBUG
, "Sched scan timeout - stopping it");
232 wpa_s
->sched_scan_timed_out
= 1;
233 wpa_supplicant_cancel_sched_scan(wpa_s
);
238 wpa_supplicant_start_sched_scan(struct wpa_supplicant
*wpa_s
,
239 struct wpa_driver_scan_params
*params
,
244 wpa_supplicant_notify_scanning(wpa_s
, 1);
245 ret
= wpa_drv_sched_scan(wpa_s
, params
, interval
* 1000);
247 wpa_supplicant_notify_scanning(wpa_s
, 0);
249 wpa_s
->sched_scanning
= 1;
255 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant
*wpa_s
)
259 ret
= wpa_drv_stop_sched_scan(wpa_s
);
261 wpa_dbg(wpa_s
, MSG_DEBUG
, "stopping sched_scan failed!");
262 /* TODO: what to do if stopping fails? */
270 static struct wpa_driver_scan_filter
*
271 wpa_supplicant_build_filter_ssids(struct wpa_config
*conf
, size_t *num_ssids
)
273 struct wpa_driver_scan_filter
*ssids
;
274 struct wpa_ssid
*ssid
;
278 if (!conf
->filter_ssids
)
281 for (count
= 0, ssid
= conf
->ssid
; ssid
; ssid
= ssid
->next
) {
282 if (ssid
->ssid
&& ssid
->ssid_len
)
287 ssids
= os_zalloc(count
* sizeof(struct wpa_driver_scan_filter
));
291 for (ssid
= conf
->ssid
; ssid
; ssid
= ssid
->next
) {
292 if (!ssid
->ssid
|| !ssid
->ssid_len
)
294 os_memcpy(ssids
[*num_ssids
].ssid
, ssid
->ssid
, ssid
->ssid_len
);
295 ssids
[*num_ssids
].ssid_len
= ssid
->ssid_len
;
303 static void wpa_supplicant_optimize_freqs(
304 struct wpa_supplicant
*wpa_s
, struct wpa_driver_scan_params
*params
)
307 if (params
->freqs
== NULL
&& wpa_s
->p2p_in_provisioning
&&
309 /* Optimize provisioning state scan based on GO information */
310 if (wpa_s
->p2p_in_provisioning
< 5 &&
311 wpa_s
->go_params
->freq
> 0) {
312 wpa_dbg(wpa_s
, MSG_DEBUG
, "P2P: Scan only GO "
313 "preferred frequency %d MHz",
314 wpa_s
->go_params
->freq
);
315 params
->freqs
= os_zalloc(2 * sizeof(int));
317 params
->freqs
[0] = wpa_s
->go_params
->freq
;
318 } else if (wpa_s
->p2p_in_provisioning
< 8 &&
319 wpa_s
->go_params
->freq_list
[0]) {
320 wpa_dbg(wpa_s
, MSG_DEBUG
, "P2P: Scan only common "
322 int_array_concat(¶ms
->freqs
,
323 wpa_s
->go_params
->freq_list
);
325 int_array_sort_unique(params
->freqs
);
327 wpa_s
->p2p_in_provisioning
++;
329 #endif /* CONFIG_P2P */
332 if (params
->freqs
== NULL
&& wpa_s
->after_wps
&& wpa_s
->wps_freq
) {
334 * Optimize post-provisioning scan based on channel used
335 * during provisioning.
337 wpa_dbg(wpa_s
, MSG_DEBUG
, "WPS: Scan only frequency %u MHz "
338 "that was used during provisioning", wpa_s
->wps_freq
);
339 params
->freqs
= os_zalloc(2 * sizeof(int));
341 params
->freqs
[0] = wpa_s
->wps_freq
;
345 #endif /* CONFIG_WPS */
349 #ifdef CONFIG_INTERWORKING
350 static void wpas_add_interworking_elements(struct wpa_supplicant
*wpa_s
,
353 if (wpa_s
->conf
->interworking
== 0)
356 wpabuf_put_u8(buf
, WLAN_EID_EXT_CAPAB
);
357 wpabuf_put_u8(buf
, 4);
358 wpabuf_put_u8(buf
, 0x00);
359 wpabuf_put_u8(buf
, 0x00);
360 wpabuf_put_u8(buf
, 0x00);
361 wpabuf_put_u8(buf
, 0x80); /* Bit 31 - Interworking */
363 wpabuf_put_u8(buf
, WLAN_EID_INTERWORKING
);
364 wpabuf_put_u8(buf
, is_zero_ether_addr(wpa_s
->conf
->hessid
) ? 1 :
366 wpabuf_put_u8(buf
, wpa_s
->conf
->access_network_type
);
368 if (!is_zero_ether_addr(wpa_s
->conf
->hessid
))
369 wpabuf_put_data(buf
, wpa_s
->conf
->hessid
, ETH_ALEN
);
371 #endif /* CONFIG_INTERWORKING */
374 static struct wpabuf
*
375 wpa_supplicant_extra_ies(struct wpa_supplicant
*wpa_s
,
376 struct wpa_driver_scan_params
*params
)
378 struct wpabuf
*extra_ie
= NULL
;
381 enum wps_request_type req_type
= WPS_REQ_ENROLLEE_INFO
;
382 #endif /* CONFIG_WPS */
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 */
391 wps
= wpas_wps_in_use(wpa_s
, &req_type
);
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
,
399 if (wpabuf_resize(&extra_ie
, wpabuf_len(wps_ie
)) == 0)
400 wpabuf_put_buf(extra_ie
, wps_ie
);
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
);
411 #endif /* CONFIG_P2P */
413 #endif /* CONFIG_WPS */
419 static void wpa_supplicant_scan(void *eloop_ctx
, void *timeout_ctx
)
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
;
427 enum wpa_states prev_state
;
429 if (wpa_s
->wpa_state
== WPA_INTERFACE_DISABLED
) {
430 wpa_dbg(wpa_s
, MSG_DEBUG
, "Skip scan - interface disabled");
434 if (wpa_s
->disconnected
&& !wpa_s
->scan_req
) {
435 wpa_supplicant_set_state(wpa_s
, WPA_DISCONNECTED
);
439 if (!wpa_supplicant_enabled_networks(wpa_s
->conf
) &&
441 wpa_dbg(wpa_s
, MSG_DEBUG
, "No enabled networks - do not scan");
442 wpa_supplicant_set_state(wpa_s
, WPA_INACTIVE
);
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
);
454 if (wpa_s
->conf
->ap_scan
== 0) {
455 wpa_supplicant_gen_assoc_event(wpa_s
);
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);
466 wpa_dbg(wpa_s
, MSG_DEBUG
, "Do not request scan while "
467 "P2P operation is in progress");
471 #endif /* CONFIG_P2P */
473 if (wpa_s
->conf
->ap_scan
== 2)
476 max_ssids
= wpa_s
->max_scan_ssids
;
477 if (max_ssids
> WPAS_MAX_SCAN_SSIDS
)
478 max_ssids
= WPAS_MAX_SCAN_SSIDS
;
481 scan_req
= wpa_s
->scan_req
;
484 os_memset(¶ms
, 0, sizeof(params
));
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
);
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
)
496 wpa_s
->connect_without_scan
= NULL
;
498 wpa_printf(MSG_DEBUG
, "Start a pre-selected network "
499 "without scan step");
500 wpa_supplicant_associate(wpa_s
, NULL
, ssid
);
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
) {
509 if (ssid
== wpa_s
->prev_scan_ssid
) {
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
);
521 } else if (wpa_s
->conf
->ap_scan
== 2) {
523 * User-initiated scan request in ap_scan == 2; scan with
528 struct wpa_ssid
*start
= ssid
, *tssid
;
530 if (ssid
== NULL
&& max_ssids
> 1)
531 ssid
= wpa_s
->conf
->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
=
538 params
.ssids
[params
.num_ssids
].ssid_len
=
541 if (params
.num_ssids
+ 1 >= max_ssids
)
547 if (ssid
== NULL
&& max_ssids
> 1 &&
548 start
!= wpa_s
->conf
->ssid
)
549 ssid
= wpa_s
->conf
->ssid
;
552 for (tssid
= wpa_s
->conf
->ssid
; tssid
; tssid
= tssid
->next
) {
555 if ((params
.freqs
|| !freqs_set
) && tssid
->scan_freq
) {
556 int_array_concat(¶ms
.freqs
,
559 os_free(params
.freqs
);
564 int_array_sort_unique(params
.freqs
);
568 wpa_s
->prev_scan_ssid
= ssid
;
570 wpa_dbg(wpa_s
, MSG_DEBUG
, "Include wildcard SSID in "
574 wpa_dbg(wpa_s
, MSG_DEBUG
, "Starting AP scan for specific "
577 wpa_s
->prev_scan_ssid
= WILDCARD_SSID_SCAN
;
579 wpa_dbg(wpa_s
, MSG_DEBUG
, "Starting AP scan for wildcard "
583 wpa_supplicant_optimize_freqs(wpa_s
, ¶ms
);
584 extra_ie
= wpa_supplicant_extra_ies(wpa_s
, ¶ms
);
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
;
591 os_free(wpa_s
->next_scan_freqs
);
592 wpa_s
->next_scan_freqs
= NULL
;
594 params
.filter_ssids
= wpa_supplicant_build_filter_ssids(
595 wpa_s
->conf
, ¶ms
.num_filter_ssids
);
597 params
.extra_ies
= wpabuf_head(extra_ie
);
598 params
.extra_ies_len
= wpabuf_len(extra_ie
);
602 if (wpa_s
->p2p_in_provisioning
) {
604 * The interface may not yet be in P2P mode, so we have to
605 * explicitly request P2P probe to disable CCK rates.
607 params
.p2p_probe
= 1;
609 #endif /* CONFIG_P2P */
611 ret
= wpa_supplicant_trigger_scan(wpa_s
, ¶ms
);
613 wpabuf_free(extra_ie
);
614 os_free(params
.freqs
);
615 os_free(params
.filter_ssids
);
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);
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
632 * This function is used to schedule a scan for neighboring access points after
633 * the specified time.
635 void wpa_supplicant_req_scan(struct wpa_supplicant
*wpa_s
, int sec
, int usec
)
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.
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
;
648 if (!ssid
->disabled
&& ssid
->scan_ssid
)
653 wpa_dbg(wpa_s
, MSG_DEBUG
, "Not rescheduling scan to "
654 "ensure that specific SSID scans occur");
659 wpa_dbg(wpa_s
, MSG_DEBUG
, "Setting scan request: %d sec %d usec",
661 eloop_cancel_timeout(wpa_supplicant_scan
, wpa_s
, NULL
);
662 eloop_register_timeout(sec
, usec
, wpa_supplicant_scan
, wpa_s
, NULL
);
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
672 * This function is used to schedule periodic scans for neighboring
673 * access points after the specified time.
675 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant
*wpa_s
,
678 if (!wpa_s
->sched_scan_supported
)
681 eloop_register_timeout(sec
, usec
,
682 wpa_supplicant_delayed_sched_scan_timeout
,
690 * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
691 * @wpa_s: Pointer to wpa_supplicant data
693 * This function is used to schedule periodic scans for neighboring
694 * access points repeating the scan continuously.
696 int wpa_supplicant_req_sched_scan(struct wpa_supplicant
*wpa_s
)
698 struct wpa_driver_scan_params params
;
699 enum wpa_states prev_state
;
700 struct wpa_ssid
*ssid
;
701 struct wpabuf
*wps_ie
= NULL
;
703 unsigned int max_sched_scan_ssids
;
705 if (!wpa_s
->sched_scan_supported
)
708 if (wpa_s
->max_sched_scan_ssids
> WPAS_MAX_SCAN_SSIDS
)
709 max_sched_scan_ssids
= WPAS_MAX_SCAN_SSIDS
;
711 max_sched_scan_ssids
= wpa_s
->max_sched_scan_ssids
;
713 if (wpa_s
->sched_scanning
) {
714 wpa_dbg(wpa_s
, MSG_DEBUG
, "Already sched scanning");
718 os_memset(¶ms
, 0, sizeof(params
));
720 /* If we can't allocate space for the filters, we just don't filter */
721 params
.filter_ssids
= os_zalloc(wpa_s
->max_match_sets
*
722 sizeof(struct wpa_driver_scan_filter
));
724 prev_state
= wpa_s
->wpa_state
;
725 if (wpa_s
->wpa_state
== WPA_DISCONNECTED
||
726 wpa_s
->wpa_state
== WPA_INACTIVE
)
727 wpa_supplicant_set_state(wpa_s
, WPA_SCANNING
);
729 /* Find the starting point from which to continue scanning */
730 ssid
= wpa_s
->conf
->ssid
;
731 if (wpa_s
->prev_sched_ssid
) {
733 if (ssid
== wpa_s
->prev_sched_ssid
) {
741 if (!ssid
|| !wpa_s
->prev_sched_ssid
) {
742 wpa_dbg(wpa_s
, MSG_DEBUG
, "Beginning of SSID list");
744 wpa_s
->sched_scan_interval
= 2;
745 wpa_s
->sched_scan_timeout
= max_sched_scan_ssids
* 2;
746 wpa_s
->first_sched_scan
= 1;
747 ssid
= wpa_s
->conf
->ssid
;
748 wpa_s
->prev_sched_ssid
= ssid
;
752 if (ssid
->disabled
) {
753 wpa_s
->prev_sched_ssid
= ssid
;
758 if (params
.filter_ssids
&& ssid
->ssid
&& ssid
->ssid_len
) {
759 wpa_dbg(wpa_s
, MSG_DEBUG
, "add to filter ssid: %s",
760 wpa_ssid_txt(ssid
->ssid
, ssid
->ssid_len
));
761 os_memcpy(params
.filter_ssids
[params
.num_filter_ssids
].ssid
,
762 ssid
->ssid
, ssid
->ssid_len
);
763 params
.filter_ssids
[params
.num_filter_ssids
].ssid_len
=
765 params
.num_filter_ssids
++;
768 if (ssid
->scan_ssid
&& ssid
->ssid
&& ssid
->ssid_len
) {
769 wpa_dbg(wpa_s
, MSG_DEBUG
,
770 "add to active scan ssid: %s",
771 wpa_ssid_txt(ssid
->ssid
, ssid
->ssid_len
));
772 params
.ssids
[params
.num_ssids
].ssid
=
774 params
.ssids
[params
.num_ssids
].ssid_len
=
777 if (params
.num_ssids
>= max_sched_scan_ssids
) {
778 wpa_s
->prev_sched_ssid
= ssid
;
783 if (params
.num_filter_ssids
>= wpa_s
->max_match_sets
)
785 wpa_s
->prev_sched_ssid
= ssid
;
790 wps_ie
= wpa_supplicant_extra_ies(wpa_s
, ¶ms
);
792 wpa_dbg(wpa_s
, MSG_DEBUG
,
793 "Starting sched scan: interval %d timeout %d",
794 wpa_s
->sched_scan_interval
, wpa_s
->sched_scan_timeout
);
796 ret
= wpa_supplicant_start_sched_scan(wpa_s
, ¶ms
,
797 wpa_s
->sched_scan_interval
);
799 os_free(params
.filter_ssids
);
801 wpa_msg(wpa_s
, MSG_WARNING
, "Failed to initiate sched scan");
802 if (prev_state
!= wpa_s
->wpa_state
)
803 wpa_supplicant_set_state(wpa_s
, prev_state
);
807 /* If we have more SSIDs to scan, add a timeout so we scan them too */
808 if (ssid
|| !wpa_s
->first_sched_scan
) {
809 wpa_s
->sched_scan_timed_out
= 0;
810 eloop_register_timeout(wpa_s
->sched_scan_timeout
, 0,
811 wpa_supplicant_sched_scan_timeout
,
813 wpa_s
->first_sched_scan
= 0;
814 wpa_s
->sched_scan_timeout
/= 2;
815 wpa_s
->sched_scan_interval
*= 2;
823 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
824 * @wpa_s: Pointer to wpa_supplicant data
826 * This function is used to cancel a scan request scheduled with
827 * wpa_supplicant_req_scan().
829 void wpa_supplicant_cancel_scan(struct wpa_supplicant
*wpa_s
)
831 wpa_dbg(wpa_s
, MSG_DEBUG
, "Cancelling scan request");
832 eloop_cancel_timeout(wpa_supplicant_scan
, wpa_s
, NULL
);
837 * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
838 * @wpa_s: Pointer to wpa_supplicant data
840 * This function is used to stop a periodic scheduled scan.
842 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant
*wpa_s
)
844 if (!wpa_s
->sched_scanning
)
847 wpa_dbg(wpa_s
, MSG_DEBUG
, "Cancelling sched scan");
848 eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout
, wpa_s
, NULL
);
849 wpa_supplicant_stop_sched_scan(wpa_s
);
853 void wpa_supplicant_notify_scanning(struct wpa_supplicant
*wpa_s
,
856 if (wpa_s
->scanning
!= scanning
) {
857 wpa_s
->scanning
= scanning
;
858 wpas_notify_scanning(wpa_s
);
863 static int wpa_scan_get_max_rate(const struct wpa_scan_res
*res
)
869 ie
= wpa_scan_get_ie(res
, WLAN_EID_SUPP_RATES
);
870 for (i
= 0; ie
&& i
< ie
[1]; i
++) {
871 if ((ie
[i
+ 2] & 0x7f) > rate
)
872 rate
= ie
[i
+ 2] & 0x7f;
875 ie
= wpa_scan_get_ie(res
, WLAN_EID_EXT_SUPP_RATES
);
876 for (i
= 0; ie
&& i
< ie
[1]; i
++) {
877 if ((ie
[i
+ 2] & 0x7f) > rate
)
878 rate
= ie
[i
+ 2] & 0x7f;
885 const u8
* wpa_scan_get_ie(const struct wpa_scan_res
*res
, u8 ie
)
889 pos
= (const u8
*) (res
+ 1);
890 end
= pos
+ res
->ie_len
;
892 while (pos
+ 1 < end
) {
893 if (pos
+ 2 + pos
[1] > end
)
904 const u8
* wpa_scan_get_vendor_ie(const struct wpa_scan_res
*res
,
909 pos
= (const u8
*) (res
+ 1);
910 end
= pos
+ res
->ie_len
;
912 while (pos
+ 1 < end
) {
913 if (pos
+ 2 + pos
[1] > end
)
915 if (pos
[0] == WLAN_EID_VENDOR_SPECIFIC
&& pos
[1] >= 4 &&
916 vendor_type
== WPA_GET_BE32(&pos
[2]))
925 struct wpabuf
* wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res
*res
,
931 buf
= wpabuf_alloc(res
->ie_len
);
935 pos
= (const u8
*) (res
+ 1);
936 end
= pos
+ res
->ie_len
;
938 while (pos
+ 1 < end
) {
939 if (pos
+ 2 + pos
[1] > end
)
941 if (pos
[0] == WLAN_EID_VENDOR_SPECIFIC
&& pos
[1] >= 4 &&
942 vendor_type
== WPA_GET_BE32(&pos
[2]))
943 wpabuf_put_data(buf
, pos
+ 2 + 4, pos
[1] - 4);
947 if (wpabuf_len(buf
) == 0) {
956 struct wpabuf
* wpa_scan_get_vendor_ie_multi_beacon(
957 const struct wpa_scan_res
*res
, u32 vendor_type
)
962 if (res
->beacon_ie_len
== 0)
964 buf
= wpabuf_alloc(res
->beacon_ie_len
);
968 pos
= (const u8
*) (res
+ 1);
970 end
= pos
+ res
->beacon_ie_len
;
972 while (pos
+ 1 < end
) {
973 if (pos
+ 2 + pos
[1] > end
)
975 if (pos
[0] == WLAN_EID_VENDOR_SPECIFIC
&& pos
[1] >= 4 &&
976 vendor_type
== WPA_GET_BE32(&pos
[2]))
977 wpabuf_put_data(buf
, pos
+ 2 + 4, pos
[1] - 4);
981 if (wpabuf_len(buf
) == 0) {
991 * Channels with a great SNR can operate at full rate. What is a great SNR?
992 * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
993 * rule of thumb is that any SNR above 20 is good." This one
994 * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
995 * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
996 * conservative value.
1000 /* Compare function for sorting scan results. Return >0 if @b is considered
1002 static int wpa_scan_result_compar(const void *a
, const void *b
)
1004 #define IS_5GHZ(n) (n > 4000)
1005 #define MIN(a,b) a < b ? a : b
1006 struct wpa_scan_res
**_wa
= (void *) a
;
1007 struct wpa_scan_res
**_wb
= (void *) b
;
1008 struct wpa_scan_res
*wa
= *_wa
;
1009 struct wpa_scan_res
*wb
= *_wb
;
1010 int wpa_a
, wpa_b
, maxrate_a
, maxrate_b
;
1013 /* WPA/WPA2 support preferred */
1014 wpa_a
= wpa_scan_get_vendor_ie(wa
, WPA_IE_VENDOR_TYPE
) != NULL
||
1015 wpa_scan_get_ie(wa
, WLAN_EID_RSN
) != NULL
;
1016 wpa_b
= wpa_scan_get_vendor_ie(wb
, WPA_IE_VENDOR_TYPE
) != NULL
||
1017 wpa_scan_get_ie(wb
, WLAN_EID_RSN
) != NULL
;
1019 if (wpa_b
&& !wpa_a
)
1021 if (!wpa_b
&& wpa_a
)
1024 /* privacy support preferred */
1025 if ((wa
->caps
& IEEE80211_CAP_PRIVACY
) == 0 &&
1026 (wb
->caps
& IEEE80211_CAP_PRIVACY
))
1028 if ((wa
->caps
& IEEE80211_CAP_PRIVACY
) &&
1029 (wb
->caps
& IEEE80211_CAP_PRIVACY
) == 0)
1032 if ((wa
->flags
& wb
->flags
& WPA_SCAN_LEVEL_DBM
) &&
1033 !((wa
->flags
| wb
->flags
) & WPA_SCAN_NOISE_INVALID
)) {
1034 snr_a
= MIN(wa
->level
- wa
->noise
, GREAT_SNR
);
1035 snr_b
= MIN(wb
->level
- wb
->noise
, GREAT_SNR
);
1037 /* Not suitable information to calculate SNR, so use level */
1042 /* best/max rate preferred if SNR close enough */
1043 if ((snr_a
&& snr_b
&& abs(snr_b
- snr_a
) < 5) ||
1044 (wa
->qual
&& wb
->qual
&& abs(wb
->qual
- wa
->qual
) < 10)) {
1045 maxrate_a
= wpa_scan_get_max_rate(wa
);
1046 maxrate_b
= wpa_scan_get_max_rate(wb
);
1047 if (maxrate_a
!= maxrate_b
)
1048 return maxrate_b
- maxrate_a
;
1049 if (IS_5GHZ(wa
->freq
) ^ IS_5GHZ(wb
->freq
))
1050 return IS_5GHZ(wa
->freq
) ? -1 : 1;
1053 /* use freq for channel preference */
1055 /* all things being equal, use SNR; if SNRs are
1056 * identical, use quality values since some drivers may only report
1057 * that value and leave the signal level zero */
1059 return wb
->qual
- wa
->qual
;
1060 return snr_b
- snr_a
;
1067 /* Compare function for sorting scan results when searching a WPS AP for
1068 * provisioning. Return >0 if @b is considered better. */
1069 static int wpa_scan_result_wps_compar(const void *a
, const void *b
)
1071 struct wpa_scan_res
**_wa
= (void *) a
;
1072 struct wpa_scan_res
**_wb
= (void *) b
;
1073 struct wpa_scan_res
*wa
= *_wa
;
1074 struct wpa_scan_res
*wb
= *_wb
;
1075 int uses_wps_a
, uses_wps_b
;
1076 struct wpabuf
*wps_a
, *wps_b
;
1079 /* Optimization - check WPS IE existence before allocated memory and
1080 * doing full reassembly. */
1081 uses_wps_a
= wpa_scan_get_vendor_ie(wa
, WPS_IE_VENDOR_TYPE
) != NULL
;
1082 uses_wps_b
= wpa_scan_get_vendor_ie(wb
, WPS_IE_VENDOR_TYPE
) != NULL
;
1083 if (uses_wps_a
&& !uses_wps_b
)
1085 if (!uses_wps_a
&& uses_wps_b
)
1088 if (uses_wps_a
&& uses_wps_b
) {
1089 wps_a
= wpa_scan_get_vendor_ie_multi(wa
, WPS_IE_VENDOR_TYPE
);
1090 wps_b
= wpa_scan_get_vendor_ie_multi(wb
, WPS_IE_VENDOR_TYPE
);
1091 res
= wps_ap_priority_compar(wps_a
, wps_b
);
1099 * Do not use current AP security policy as a sorting criteria during
1100 * WPS provisioning step since the AP may get reconfigured at the
1101 * completion of provisioning.
1104 /* all things being equal, use signal level; if signal levels are
1105 * identical, use quality values since some drivers may only report
1106 * that value and leave the signal level zero */
1107 if (wb
->level
== wa
->level
)
1108 return wb
->qual
- wa
->qual
;
1109 return wb
->level
- wa
->level
;
1111 #endif /* CONFIG_WPS */
1114 static void dump_scan_res(struct wpa_scan_results
*scan_res
)
1118 if (scan_res
->res
== NULL
|| scan_res
->num
== 0)
1121 wpa_printf(MSG_EXCESSIVE
, "Sorted scan results");
1123 for (i
= 0; i
< scan_res
->num
; i
++) {
1124 struct wpa_scan_res
*r
= scan_res
->res
[i
];
1125 if ((r
->flags
& (WPA_SCAN_LEVEL_DBM
| WPA_SCAN_NOISE_INVALID
))
1126 == WPA_SCAN_LEVEL_DBM
) {
1127 int snr
= r
->level
- r
->noise
;
1128 wpa_printf(MSG_EXCESSIVE
, MACSTR
" freq=%d qual=%d "
1129 "noise=%d level=%d snr=%d%s flags=0x%x",
1130 MAC2STR(r
->bssid
), r
->freq
, r
->qual
,
1131 r
->noise
, r
->level
, snr
,
1132 snr
>= GREAT_SNR
? "*" : "", r
->flags
);
1134 wpa_printf(MSG_EXCESSIVE
, MACSTR
" freq=%d qual=%d "
1135 "noise=%d level=%d flags=0x%x",
1136 MAC2STR(r
->bssid
), r
->freq
, r
->qual
,
1137 r
->noise
, r
->level
, r
->flags
);
1144 * wpa_supplicant_get_scan_results - Get scan results
1145 * @wpa_s: Pointer to wpa_supplicant data
1146 * @info: Information about what was scanned or %NULL if not available
1147 * @new_scan: Whether a new scan was performed
1148 * Returns: Scan results, %NULL on failure
1150 * This function request the current scan results from the driver and updates
1151 * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1152 * results with wpa_scan_results_free().
1154 struct wpa_scan_results
*
1155 wpa_supplicant_get_scan_results(struct wpa_supplicant
*wpa_s
,
1156 struct scan_info
*info
, int new_scan
)
1158 struct wpa_scan_results
*scan_res
;
1160 int (*compar
)(const void *, const void *) = wpa_scan_result_compar
;
1162 scan_res
= wpa_drv_get_scan_results2(wpa_s
);
1163 if (scan_res
== NULL
) {
1164 wpa_dbg(wpa_s
, MSG_DEBUG
, "Failed to get scan results");
1169 if (wpas_wps_in_progress(wpa_s
)) {
1170 wpa_dbg(wpa_s
, MSG_DEBUG
, "WPS: Order scan results with WPS "
1171 "provisioning rules");
1172 compar
= wpa_scan_result_wps_compar
;
1174 #endif /* CONFIG_WPS */
1176 qsort(scan_res
->res
, scan_res
->num
, sizeof(struct wpa_scan_res
*),
1178 dump_scan_res(scan_res
);
1180 wpa_bss_update_start(wpa_s
);
1181 for (i
= 0; i
< scan_res
->num
; i
++)
1182 wpa_bss_update_scan_res(wpa_s
, scan_res
->res
[i
]);
1183 wpa_bss_update_end(wpa_s
, info
, new_scan
);
1189 int wpa_supplicant_update_scan_results(struct wpa_supplicant
*wpa_s
)
1191 struct wpa_scan_results
*scan_res
;
1192 scan_res
= wpa_supplicant_get_scan_results(wpa_s
, NULL
, 0);
1193 if (scan_res
== NULL
)
1195 wpa_scan_results_free(scan_res
);