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);
208 wpa_s
->normal_scans
++;
216 wpa_supplicant_delayed_sched_scan_timeout(void *eloop_ctx
, void *timeout_ctx
)
218 struct wpa_supplicant
*wpa_s
= eloop_ctx
;
220 wpa_dbg(wpa_s
, MSG_DEBUG
, "Starting delayed sched scan");
222 if (wpa_supplicant_req_sched_scan(wpa_s
))
223 wpa_supplicant_req_scan(wpa_s
, 0, 0);
228 wpa_supplicant_sched_scan_timeout(void *eloop_ctx
, void *timeout_ctx
)
230 struct wpa_supplicant
*wpa_s
= eloop_ctx
;
232 wpa_dbg(wpa_s
, MSG_DEBUG
, "Sched scan timeout - stopping it");
234 wpa_s
->sched_scan_timed_out
= 1;
235 wpa_supplicant_cancel_sched_scan(wpa_s
);
240 wpa_supplicant_start_sched_scan(struct wpa_supplicant
*wpa_s
,
241 struct wpa_driver_scan_params
*params
,
246 wpa_supplicant_notify_scanning(wpa_s
, 1);
247 ret
= wpa_drv_sched_scan(wpa_s
, params
, interval
* 1000);
249 wpa_supplicant_notify_scanning(wpa_s
, 0);
251 wpa_s
->sched_scanning
= 1;
257 static int wpa_supplicant_stop_sched_scan(struct wpa_supplicant
*wpa_s
)
261 ret
= wpa_drv_stop_sched_scan(wpa_s
);
263 wpa_dbg(wpa_s
, MSG_DEBUG
, "stopping sched_scan failed!");
264 /* TODO: what to do if stopping fails? */
272 static struct wpa_driver_scan_filter
*
273 wpa_supplicant_build_filter_ssids(struct wpa_config
*conf
, size_t *num_ssids
)
275 struct wpa_driver_scan_filter
*ssids
;
276 struct wpa_ssid
*ssid
;
280 if (!conf
->filter_ssids
)
283 for (count
= 0, ssid
= conf
->ssid
; ssid
; ssid
= ssid
->next
) {
284 if (ssid
->ssid
&& ssid
->ssid_len
)
289 ssids
= os_zalloc(count
* sizeof(struct wpa_driver_scan_filter
));
293 for (ssid
= conf
->ssid
; ssid
; ssid
= ssid
->next
) {
294 if (!ssid
->ssid
|| !ssid
->ssid_len
)
296 os_memcpy(ssids
[*num_ssids
].ssid
, ssid
->ssid
, ssid
->ssid_len
);
297 ssids
[*num_ssids
].ssid_len
= ssid
->ssid_len
;
305 static void wpa_supplicant_optimize_freqs(
306 struct wpa_supplicant
*wpa_s
, struct wpa_driver_scan_params
*params
)
309 if (params
->freqs
== NULL
&& wpa_s
->p2p_in_provisioning
&&
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));
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 "
324 int_array_concat(¶ms
->freqs
,
325 wpa_s
->go_params
->freq_list
);
327 int_array_sort_unique(params
->freqs
);
329 wpa_s
->p2p_in_provisioning
++;
331 #endif /* CONFIG_P2P */
334 if (params
->freqs
== NULL
&& wpa_s
->after_wps
&& wpa_s
->wps_freq
) {
336 * Optimize post-provisioning scan based on channel used
337 * during provisioning.
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));
343 params
->freqs
[0] = wpa_s
->wps_freq
;
347 if (params
->freqs
== NULL
&& wpa_s
->known_wps_freq
&& wpa_s
->wps_freq
)
349 /* Optimize provisioning scan based on already known channel */
350 wpa_dbg(wpa_s
, MSG_DEBUG
, "WPS: Scan only frequency %u MHz",
352 params
->freqs
= os_zalloc(2 * sizeof(int));
354 params
->freqs
[0] = wpa_s
->wps_freq
;
355 wpa_s
->known_wps_freq
= 0; /* only do this once */
357 #endif /* CONFIG_WPS */
361 #ifdef CONFIG_INTERWORKING
362 static void wpas_add_interworking_elements(struct wpa_supplicant
*wpa_s
,
365 if (wpa_s
->conf
->interworking
== 0)
368 wpabuf_put_u8(buf
, WLAN_EID_EXT_CAPAB
);
369 wpabuf_put_u8(buf
, 4);
370 wpabuf_put_u8(buf
, 0x00);
371 wpabuf_put_u8(buf
, 0x00);
372 wpabuf_put_u8(buf
, 0x00);
373 wpabuf_put_u8(buf
, 0x80); /* Bit 31 - Interworking */
375 wpabuf_put_u8(buf
, WLAN_EID_INTERWORKING
);
376 wpabuf_put_u8(buf
, is_zero_ether_addr(wpa_s
->conf
->hessid
) ? 1 :
378 wpabuf_put_u8(buf
, wpa_s
->conf
->access_network_type
);
380 if (!is_zero_ether_addr(wpa_s
->conf
->hessid
))
381 wpabuf_put_data(buf
, wpa_s
->conf
->hessid
, ETH_ALEN
);
383 #endif /* CONFIG_INTERWORKING */
386 static struct wpabuf
*
387 wpa_supplicant_extra_ies(struct wpa_supplicant
*wpa_s
,
388 struct wpa_driver_scan_params
*params
)
390 struct wpabuf
*extra_ie
= NULL
;
393 enum wps_request_type req_type
= WPS_REQ_ENROLLEE_INFO
;
394 #endif /* CONFIG_WPS */
396 #ifdef CONFIG_INTERWORKING
397 if (wpa_s
->conf
->interworking
&&
398 wpabuf_resize(&extra_ie
, 100) == 0)
399 wpas_add_interworking_elements(wpa_s
, extra_ie
);
400 #endif /* CONFIG_INTERWORKING */
403 wps
= wpas_wps_in_use(wpa_s
, &req_type
);
406 struct wpabuf
*wps_ie
;
407 wps_ie
= wps_build_probe_req_ie(wps
== 2, &wpa_s
->wps
->dev
,
408 wpa_s
->wps
->uuid
, req_type
,
411 if (wpabuf_resize(&extra_ie
, wpabuf_len(wps_ie
)) == 0)
412 wpabuf_put_buf(extra_ie
, wps_ie
);
419 size_t ielen
= p2p_scan_ie_buf_len(wpa_s
->global
->p2p
);
420 if (wpabuf_resize(&extra_ie
, ielen
) == 0)
421 wpas_p2p_scan_ie(wpa_s
, extra_ie
);
423 #endif /* CONFIG_P2P */
425 #endif /* CONFIG_WPS */
431 static void wpa_supplicant_scan(void *eloop_ctx
, void *timeout_ctx
)
433 struct wpa_supplicant
*wpa_s
= eloop_ctx
;
434 struct wpa_ssid
*ssid
;
435 int scan_req
= 0, ret
;
436 struct wpabuf
*extra_ie
;
437 struct wpa_driver_scan_params params
;
439 enum wpa_states prev_state
;
441 if (wpa_s
->wpa_state
== WPA_INTERFACE_DISABLED
) {
442 wpa_dbg(wpa_s
, MSG_DEBUG
, "Skip scan - interface disabled");
446 if (wpa_s
->disconnected
&& !wpa_s
->scan_req
) {
447 wpa_supplicant_set_state(wpa_s
, WPA_DISCONNECTED
);
451 if (!wpa_supplicant_enabled_networks(wpa_s
->conf
) &&
453 wpa_dbg(wpa_s
, MSG_DEBUG
, "No enabled networks - do not scan");
454 wpa_supplicant_set_state(wpa_s
, WPA_INACTIVE
);
458 if (wpa_s
->conf
->ap_scan
!= 0 &&
459 (wpa_s
->drv_flags
& WPA_DRIVER_FLAGS_WIRED
)) {
460 wpa_dbg(wpa_s
, MSG_DEBUG
, "Using wired authentication - "
461 "overriding ap_scan configuration");
462 wpa_s
->conf
->ap_scan
= 0;
463 wpas_notify_ap_scan_changed(wpa_s
);
466 if (wpa_s
->conf
->ap_scan
== 0) {
467 wpa_supplicant_gen_assoc_event(wpa_s
);
472 if (wpas_p2p_in_progress(wpa_s
)) {
473 if (wpa_s
->wpa_state
== WPA_SCANNING
) {
474 wpa_dbg(wpa_s
, MSG_DEBUG
, "Delay station mode scan "
475 "while P2P operation is in progress");
476 wpa_supplicant_req_scan(wpa_s
, 5, 0);
478 wpa_dbg(wpa_s
, MSG_DEBUG
, "Do not request scan while "
479 "P2P operation is in progress");
483 #endif /* CONFIG_P2P */
485 if (wpa_s
->conf
->ap_scan
== 2)
488 max_ssids
= wpa_s
->max_scan_ssids
;
489 if (max_ssids
> WPAS_MAX_SCAN_SSIDS
)
490 max_ssids
= WPAS_MAX_SCAN_SSIDS
;
493 scan_req
= wpa_s
->scan_req
;
496 os_memset(¶ms
, 0, sizeof(params
));
498 prev_state
= wpa_s
->wpa_state
;
499 if (wpa_s
->wpa_state
== WPA_DISCONNECTED
||
500 wpa_s
->wpa_state
== WPA_INACTIVE
)
501 wpa_supplicant_set_state(wpa_s
, WPA_SCANNING
);
503 if (scan_req
!= 2 && wpa_s
->connect_without_scan
) {
504 for (ssid
= wpa_s
->conf
->ssid
; ssid
; ssid
= ssid
->next
) {
505 if (ssid
== wpa_s
->connect_without_scan
)
508 wpa_s
->connect_without_scan
= NULL
;
510 wpa_printf(MSG_DEBUG
, "Start a pre-selected network "
511 "without scan step");
512 wpa_supplicant_associate(wpa_s
, NULL
, ssid
);
517 /* Find the starting point from which to continue scanning */
518 ssid
= wpa_s
->conf
->ssid
;
519 if (wpa_s
->prev_scan_ssid
!= WILDCARD_SSID_SCAN
) {
521 if (ssid
== wpa_s
->prev_scan_ssid
) {
529 if (scan_req
!= 2 && wpa_s
->conf
->ap_scan
== 2) {
530 wpa_s
->connect_without_scan
= NULL
;
531 wpa_supplicant_assoc_try(wpa_s
, ssid
);
533 } else if (wpa_s
->conf
->ap_scan
== 2) {
535 * User-initiated scan request in ap_scan == 2; scan with
540 struct wpa_ssid
*start
= ssid
, *tssid
;
542 if (ssid
== NULL
&& max_ssids
> 1)
543 ssid
= wpa_s
->conf
->ssid
;
545 if (!ssid
->disabled
&& ssid
->scan_ssid
) {
546 wpa_hexdump_ascii(MSG_DEBUG
, "Scan SSID",
547 ssid
->ssid
, ssid
->ssid_len
);
548 params
.ssids
[params
.num_ssids
].ssid
=
550 params
.ssids
[params
.num_ssids
].ssid_len
=
553 if (params
.num_ssids
+ 1 >= max_ssids
)
559 if (ssid
== NULL
&& max_ssids
> 1 &&
560 start
!= wpa_s
->conf
->ssid
)
561 ssid
= wpa_s
->conf
->ssid
;
564 for (tssid
= wpa_s
->conf
->ssid
; tssid
; tssid
= tssid
->next
) {
567 if ((params
.freqs
|| !freqs_set
) && tssid
->scan_freq
) {
568 int_array_concat(¶ms
.freqs
,
571 os_free(params
.freqs
);
576 int_array_sort_unique(params
.freqs
);
580 wpa_s
->prev_scan_ssid
= ssid
;
582 wpa_dbg(wpa_s
, MSG_DEBUG
, "Include wildcard SSID in "
586 wpa_dbg(wpa_s
, MSG_DEBUG
, "Starting AP scan for specific "
589 wpa_s
->prev_scan_ssid
= WILDCARD_SSID_SCAN
;
591 wpa_dbg(wpa_s
, MSG_DEBUG
, "Starting AP scan for wildcard "
595 wpa_supplicant_optimize_freqs(wpa_s
, ¶ms
);
596 extra_ie
= wpa_supplicant_extra_ies(wpa_s
, ¶ms
);
598 if (params
.freqs
== NULL
&& wpa_s
->next_scan_freqs
) {
599 wpa_dbg(wpa_s
, MSG_DEBUG
, "Optimize scan based on previously "
600 "generated frequency list");
601 params
.freqs
= wpa_s
->next_scan_freqs
;
603 os_free(wpa_s
->next_scan_freqs
);
604 wpa_s
->next_scan_freqs
= NULL
;
606 params
.filter_ssids
= wpa_supplicant_build_filter_ssids(
607 wpa_s
->conf
, ¶ms
.num_filter_ssids
);
609 params
.extra_ies
= wpabuf_head(extra_ie
);
610 params
.extra_ies_len
= wpabuf_len(extra_ie
);
614 if (wpa_s
->p2p_in_provisioning
) {
616 * The interface may not yet be in P2P mode, so we have to
617 * explicitly request P2P probe to disable CCK rates.
619 params
.p2p_probe
= 1;
621 #endif /* CONFIG_P2P */
623 ret
= wpa_supplicant_trigger_scan(wpa_s
, ¶ms
);
625 wpabuf_free(extra_ie
);
626 os_free(params
.freqs
);
627 os_free(params
.filter_ssids
);
630 wpa_msg(wpa_s
, MSG_WARNING
, "Failed to initiate AP scan");
631 if (prev_state
!= wpa_s
->wpa_state
)
632 wpa_supplicant_set_state(wpa_s
, prev_state
);
633 wpa_supplicant_req_scan(wpa_s
, 1, 0);
639 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
640 * @wpa_s: Pointer to wpa_supplicant data
641 * @sec: Number of seconds after which to scan
642 * @usec: Number of microseconds after which to scan
644 * This function is used to schedule a scan for neighboring access points after
645 * the specified time.
647 void wpa_supplicant_req_scan(struct wpa_supplicant
*wpa_s
, int sec
, int usec
)
649 /* If there's at least one network that should be specifically scanned
650 * then don't cancel the scan and reschedule. Some drivers do
651 * background scanning which generates frequent scan results, and that
652 * causes the specific SSID scan to get continually pushed back and
653 * never happen, which causes hidden APs to never get probe-scanned.
655 if (eloop_is_timeout_registered(wpa_supplicant_scan
, wpa_s
, NULL
) &&
656 wpa_s
->conf
->ap_scan
== 1) {
657 struct wpa_ssid
*ssid
= wpa_s
->conf
->ssid
;
660 if (!ssid
->disabled
&& ssid
->scan_ssid
)
665 wpa_dbg(wpa_s
, MSG_DEBUG
, "Not rescheduling scan to "
666 "ensure that specific SSID scans occur");
671 wpa_dbg(wpa_s
, MSG_DEBUG
, "Setting scan request: %d sec %d usec",
673 eloop_cancel_timeout(wpa_supplicant_scan
, wpa_s
, NULL
);
674 eloop_register_timeout(sec
, usec
, wpa_supplicant_scan
, wpa_s
, NULL
);
679 * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
680 * @wpa_s: Pointer to wpa_supplicant data
681 * @sec: Number of seconds after which to scan
682 * @usec: Number of microseconds after which to scan
684 * This function is used to schedule periodic scans for neighboring
685 * access points after the specified time.
687 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant
*wpa_s
,
690 if (!wpa_s
->sched_scan_supported
)
693 eloop_register_timeout(sec
, usec
,
694 wpa_supplicant_delayed_sched_scan_timeout
,
702 * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
703 * @wpa_s: Pointer to wpa_supplicant data
705 * This function is used to schedule periodic scans for neighboring
706 * access points repeating the scan continuously.
708 int wpa_supplicant_req_sched_scan(struct wpa_supplicant
*wpa_s
)
710 struct wpa_driver_scan_params params
;
711 enum wpa_states prev_state
;
712 struct wpa_ssid
*ssid
;
713 struct wpabuf
*wps_ie
= NULL
;
715 unsigned int max_sched_scan_ssids
;
719 if (!wpa_s
->sched_scan_supported
)
722 if (wpa_s
->max_sched_scan_ssids
> WPAS_MAX_SCAN_SSIDS
)
723 max_sched_scan_ssids
= WPAS_MAX_SCAN_SSIDS
;
725 max_sched_scan_ssids
= wpa_s
->max_sched_scan_ssids
;
726 if (max_sched_scan_ssids
< 1)
729 if (wpa_s
->sched_scanning
) {
730 wpa_dbg(wpa_s
, MSG_DEBUG
, "Already sched scanning");
735 for (ssid
= wpa_s
->conf
->ssid
; ssid
; ssid
= ssid
->next
) {
736 if (!ssid
->disabled
&& !ssid
->scan_ssid
) {
737 /* Use wildcard SSID to find this network */
739 } else if (!ssid
->disabled
&& ssid
->ssid_len
)
745 if (wpa_s
->normal_scans
< 3 &&
746 (need_ssids
<= wpa_s
->max_scan_ssids
||
747 wpa_s
->max_scan_ssids
>= (int) max_sched_scan_ssids
)) {
749 * When normal scan can speed up operations, use that for the
750 * first operations before starting the sched_scan to allow
751 * user space sleep more. We do this only if the normal scan
752 * has functionality that is suitable for this or if the
753 * sched_scan does not have better support for multiple SSIDs.
755 wpa_dbg(wpa_s
, MSG_DEBUG
, "Use normal scan instead of "
756 "sched_scan for initial scans (normal_scans=%d)",
757 wpa_s
->normal_scans
);
761 os_memset(¶ms
, 0, sizeof(params
));
763 /* If we can't allocate space for the filters, we just don't filter */
764 params
.filter_ssids
= os_zalloc(wpa_s
->max_match_sets
*
765 sizeof(struct wpa_driver_scan_filter
));
767 prev_state
= wpa_s
->wpa_state
;
768 if (wpa_s
->wpa_state
== WPA_DISCONNECTED
||
769 wpa_s
->wpa_state
== WPA_INACTIVE
)
770 wpa_supplicant_set_state(wpa_s
, WPA_SCANNING
);
772 /* Find the starting point from which to continue scanning */
773 ssid
= wpa_s
->conf
->ssid
;
774 if (wpa_s
->prev_sched_ssid
) {
776 if (ssid
== wpa_s
->prev_sched_ssid
) {
784 if (!ssid
|| !wpa_s
->prev_sched_ssid
) {
785 wpa_dbg(wpa_s
, MSG_DEBUG
, "Beginning of SSID list");
787 wpa_s
->sched_scan_interval
= 10;
788 wpa_s
->sched_scan_timeout
= max_sched_scan_ssids
* 2;
789 wpa_s
->first_sched_scan
= 1;
790 ssid
= wpa_s
->conf
->ssid
;
791 wpa_s
->prev_sched_ssid
= ssid
;
795 wpa_dbg(wpa_s
, MSG_DEBUG
, "Add wildcard SSID to sched_scan");
803 if (params
.num_filter_ssids
< wpa_s
->max_match_sets
&&
804 params
.filter_ssids
&& ssid
->ssid
&& ssid
->ssid_len
) {
805 wpa_dbg(wpa_s
, MSG_DEBUG
, "add to filter ssid: %s",
806 wpa_ssid_txt(ssid
->ssid
, ssid
->ssid_len
));
807 os_memcpy(params
.filter_ssids
[params
.num_filter_ssids
].ssid
,
808 ssid
->ssid
, ssid
->ssid_len
);
809 params
.filter_ssids
[params
.num_filter_ssids
].ssid_len
=
811 params
.num_filter_ssids
++;
812 } else if (params
.filter_ssids
&& ssid
->ssid
&& ssid
->ssid_len
)
814 wpa_dbg(wpa_s
, MSG_DEBUG
, "Not enough room for SSID "
815 "filter for sched_scan - drop filter");
816 os_free(params
.filter_ssids
);
817 params
.filter_ssids
= NULL
;
818 params
.num_filter_ssids
= 0;
821 if (ssid
->scan_ssid
&& ssid
->ssid
&& ssid
->ssid_len
) {
822 if (params
.num_ssids
== max_sched_scan_ssids
)
823 break; /* only room for broadcast SSID */
824 wpa_dbg(wpa_s
, MSG_DEBUG
,
825 "add to active scan ssid: %s",
826 wpa_ssid_txt(ssid
->ssid
, ssid
->ssid_len
));
827 params
.ssids
[params
.num_ssids
].ssid
=
829 params
.ssids
[params
.num_ssids
].ssid_len
=
832 if (params
.num_ssids
>= max_sched_scan_ssids
) {
833 wpa_s
->prev_sched_ssid
= ssid
;
839 wpa_s
->prev_sched_ssid
= ssid
;
843 if (params
.num_filter_ssids
== 0) {
844 os_free(params
.filter_ssids
);
845 params
.filter_ssids
= NULL
;
849 wps_ie
= wpa_supplicant_extra_ies(wpa_s
, ¶ms
);
851 if (ssid
|| !wpa_s
->first_sched_scan
) {
852 wpa_dbg(wpa_s
, MSG_DEBUG
,
853 "Starting sched scan: interval %d (no timeout)",
854 wpa_s
->sched_scan_interval
);
856 wpa_dbg(wpa_s
, MSG_DEBUG
,
857 "Starting sched scan: interval %d timeout %d",
858 wpa_s
->sched_scan_interval
, wpa_s
->sched_scan_timeout
);
861 ret
= wpa_supplicant_start_sched_scan(wpa_s
, ¶ms
,
862 wpa_s
->sched_scan_interval
);
864 os_free(params
.filter_ssids
);
866 wpa_msg(wpa_s
, MSG_WARNING
, "Failed to initiate sched scan");
867 if (prev_state
!= wpa_s
->wpa_state
)
868 wpa_supplicant_set_state(wpa_s
, prev_state
);
872 /* If we have more SSIDs to scan, add a timeout so we scan them too */
873 if (ssid
|| !wpa_s
->first_sched_scan
) {
874 wpa_s
->sched_scan_timed_out
= 0;
875 eloop_register_timeout(wpa_s
->sched_scan_timeout
, 0,
876 wpa_supplicant_sched_scan_timeout
,
878 wpa_s
->first_sched_scan
= 0;
879 wpa_s
->sched_scan_timeout
/= 2;
880 wpa_s
->sched_scan_interval
*= 2;
888 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
889 * @wpa_s: Pointer to wpa_supplicant data
891 * This function is used to cancel a scan request scheduled with
892 * wpa_supplicant_req_scan().
894 void wpa_supplicant_cancel_scan(struct wpa_supplicant
*wpa_s
)
896 wpa_dbg(wpa_s
, MSG_DEBUG
, "Cancelling scan request");
897 eloop_cancel_timeout(wpa_supplicant_scan
, wpa_s
, NULL
);
902 * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
903 * @wpa_s: Pointer to wpa_supplicant data
905 * This function is used to stop a periodic scheduled scan.
907 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant
*wpa_s
)
909 if (!wpa_s
->sched_scanning
)
912 wpa_dbg(wpa_s
, MSG_DEBUG
, "Cancelling sched scan");
913 eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout
, wpa_s
, NULL
);
914 wpa_supplicant_stop_sched_scan(wpa_s
);
918 void wpa_supplicant_notify_scanning(struct wpa_supplicant
*wpa_s
,
921 if (wpa_s
->scanning
!= scanning
) {
922 wpa_s
->scanning
= scanning
;
923 wpas_notify_scanning(wpa_s
);
928 static int wpa_scan_get_max_rate(const struct wpa_scan_res
*res
)
934 ie
= wpa_scan_get_ie(res
, WLAN_EID_SUPP_RATES
);
935 for (i
= 0; ie
&& i
< ie
[1]; i
++) {
936 if ((ie
[i
+ 2] & 0x7f) > rate
)
937 rate
= ie
[i
+ 2] & 0x7f;
940 ie
= wpa_scan_get_ie(res
, WLAN_EID_EXT_SUPP_RATES
);
941 for (i
= 0; ie
&& i
< ie
[1]; i
++) {
942 if ((ie
[i
+ 2] & 0x7f) > rate
)
943 rate
= ie
[i
+ 2] & 0x7f;
950 const u8
* wpa_scan_get_ie(const struct wpa_scan_res
*res
, u8 ie
)
954 pos
= (const u8
*) (res
+ 1);
955 end
= pos
+ res
->ie_len
;
957 while (pos
+ 1 < end
) {
958 if (pos
+ 2 + pos
[1] > end
)
969 const u8
* wpa_scan_get_vendor_ie(const struct wpa_scan_res
*res
,
974 pos
= (const u8
*) (res
+ 1);
975 end
= pos
+ res
->ie_len
;
977 while (pos
+ 1 < end
) {
978 if (pos
+ 2 + pos
[1] > end
)
980 if (pos
[0] == WLAN_EID_VENDOR_SPECIFIC
&& pos
[1] >= 4 &&
981 vendor_type
== WPA_GET_BE32(&pos
[2]))
990 struct wpabuf
* wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res
*res
,
996 buf
= wpabuf_alloc(res
->ie_len
);
1000 pos
= (const u8
*) (res
+ 1);
1001 end
= pos
+ res
->ie_len
;
1003 while (pos
+ 1 < end
) {
1004 if (pos
+ 2 + pos
[1] > end
)
1006 if (pos
[0] == WLAN_EID_VENDOR_SPECIFIC
&& pos
[1] >= 4 &&
1007 vendor_type
== WPA_GET_BE32(&pos
[2]))
1008 wpabuf_put_data(buf
, pos
+ 2 + 4, pos
[1] - 4);
1012 if (wpabuf_len(buf
) == 0) {
1021 struct wpabuf
* wpa_scan_get_vendor_ie_multi_beacon(
1022 const struct wpa_scan_res
*res
, u32 vendor_type
)
1025 const u8
*end
, *pos
;
1027 if (res
->beacon_ie_len
== 0)
1029 buf
= wpabuf_alloc(res
->beacon_ie_len
);
1033 pos
= (const u8
*) (res
+ 1);
1035 end
= pos
+ res
->beacon_ie_len
;
1037 while (pos
+ 1 < end
) {
1038 if (pos
+ 2 + pos
[1] > end
)
1040 if (pos
[0] == WLAN_EID_VENDOR_SPECIFIC
&& pos
[1] >= 4 &&
1041 vendor_type
== WPA_GET_BE32(&pos
[2]))
1042 wpabuf_put_data(buf
, pos
+ 2 + 4, pos
[1] - 4);
1046 if (wpabuf_len(buf
) == 0) {
1056 * Channels with a great SNR can operate at full rate. What is a great SNR?
1057 * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1058 * rule of thumb is that any SNR above 20 is good." This one
1059 * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1060 * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1061 * conservative value.
1063 #define GREAT_SNR 30
1065 /* Compare function for sorting scan results. Return >0 if @b is considered
1067 static int wpa_scan_result_compar(const void *a
, const void *b
)
1069 #define IS_5GHZ(n) (n > 4000)
1070 #define MIN(a,b) a < b ? a : 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 wpa_a
, wpa_b
, maxrate_a
, maxrate_b
;
1078 /* WPA/WPA2 support preferred */
1079 wpa_a
= wpa_scan_get_vendor_ie(wa
, WPA_IE_VENDOR_TYPE
) != NULL
||
1080 wpa_scan_get_ie(wa
, WLAN_EID_RSN
) != NULL
;
1081 wpa_b
= wpa_scan_get_vendor_ie(wb
, WPA_IE_VENDOR_TYPE
) != NULL
||
1082 wpa_scan_get_ie(wb
, WLAN_EID_RSN
) != NULL
;
1084 if (wpa_b
&& !wpa_a
)
1086 if (!wpa_b
&& wpa_a
)
1089 /* privacy support preferred */
1090 if ((wa
->caps
& IEEE80211_CAP_PRIVACY
) == 0 &&
1091 (wb
->caps
& IEEE80211_CAP_PRIVACY
))
1093 if ((wa
->caps
& IEEE80211_CAP_PRIVACY
) &&
1094 (wb
->caps
& IEEE80211_CAP_PRIVACY
) == 0)
1097 if ((wa
->flags
& wb
->flags
& WPA_SCAN_LEVEL_DBM
) &&
1098 !((wa
->flags
| wb
->flags
) & WPA_SCAN_NOISE_INVALID
)) {
1099 snr_a
= MIN(wa
->level
- wa
->noise
, GREAT_SNR
);
1100 snr_b
= MIN(wb
->level
- wb
->noise
, GREAT_SNR
);
1102 /* Not suitable information to calculate SNR, so use level */
1107 /* best/max rate preferred if SNR close enough */
1108 if ((snr_a
&& snr_b
&& abs(snr_b
- snr_a
) < 5) ||
1109 (wa
->qual
&& wb
->qual
&& abs(wb
->qual
- wa
->qual
) < 10)) {
1110 maxrate_a
= wpa_scan_get_max_rate(wa
);
1111 maxrate_b
= wpa_scan_get_max_rate(wb
);
1112 if (maxrate_a
!= maxrate_b
)
1113 return maxrate_b
- maxrate_a
;
1114 if (IS_5GHZ(wa
->freq
) ^ IS_5GHZ(wb
->freq
))
1115 return IS_5GHZ(wa
->freq
) ? -1 : 1;
1118 /* use freq for channel preference */
1120 /* all things being equal, use SNR; if SNRs are
1121 * identical, use quality values since some drivers may only report
1122 * that value and leave the signal level zero */
1124 return wb
->qual
- wa
->qual
;
1125 return snr_b
- snr_a
;
1132 /* Compare function for sorting scan results when searching a WPS AP for
1133 * provisioning. Return >0 if @b is considered better. */
1134 static int wpa_scan_result_wps_compar(const void *a
, const void *b
)
1136 struct wpa_scan_res
**_wa
= (void *) a
;
1137 struct wpa_scan_res
**_wb
= (void *) b
;
1138 struct wpa_scan_res
*wa
= *_wa
;
1139 struct wpa_scan_res
*wb
= *_wb
;
1140 int uses_wps_a
, uses_wps_b
;
1141 struct wpabuf
*wps_a
, *wps_b
;
1144 /* Optimization - check WPS IE existence before allocated memory and
1145 * doing full reassembly. */
1146 uses_wps_a
= wpa_scan_get_vendor_ie(wa
, WPS_IE_VENDOR_TYPE
) != NULL
;
1147 uses_wps_b
= wpa_scan_get_vendor_ie(wb
, WPS_IE_VENDOR_TYPE
) != NULL
;
1148 if (uses_wps_a
&& !uses_wps_b
)
1150 if (!uses_wps_a
&& uses_wps_b
)
1153 if (uses_wps_a
&& uses_wps_b
) {
1154 wps_a
= wpa_scan_get_vendor_ie_multi(wa
, WPS_IE_VENDOR_TYPE
);
1155 wps_b
= wpa_scan_get_vendor_ie_multi(wb
, WPS_IE_VENDOR_TYPE
);
1156 res
= wps_ap_priority_compar(wps_a
, wps_b
);
1164 * Do not use current AP security policy as a sorting criteria during
1165 * WPS provisioning step since the AP may get reconfigured at the
1166 * completion of provisioning.
1169 /* all things being equal, use signal level; if signal levels are
1170 * identical, use quality values since some drivers may only report
1171 * that value and leave the signal level zero */
1172 if (wb
->level
== wa
->level
)
1173 return wb
->qual
- wa
->qual
;
1174 return wb
->level
- wa
->level
;
1176 #endif /* CONFIG_WPS */
1179 static void dump_scan_res(struct wpa_scan_results
*scan_res
)
1181 #ifndef CONFIG_NO_STDOUT_DEBUG
1184 if (scan_res
->res
== NULL
|| scan_res
->num
== 0)
1187 wpa_printf(MSG_EXCESSIVE
, "Sorted scan results");
1189 for (i
= 0; i
< scan_res
->num
; i
++) {
1190 struct wpa_scan_res
*r
= scan_res
->res
[i
];
1191 if ((r
->flags
& (WPA_SCAN_LEVEL_DBM
| WPA_SCAN_NOISE_INVALID
))
1192 == WPA_SCAN_LEVEL_DBM
) {
1193 int snr
= r
->level
- r
->noise
;
1194 wpa_printf(MSG_EXCESSIVE
, MACSTR
" freq=%d qual=%d "
1195 "noise=%d level=%d snr=%d%s flags=0x%x",
1196 MAC2STR(r
->bssid
), r
->freq
, r
->qual
,
1197 r
->noise
, r
->level
, snr
,
1198 snr
>= GREAT_SNR
? "*" : "", r
->flags
);
1200 wpa_printf(MSG_EXCESSIVE
, MACSTR
" freq=%d qual=%d "
1201 "noise=%d level=%d flags=0x%x",
1202 MAC2STR(r
->bssid
), r
->freq
, r
->qual
,
1203 r
->noise
, r
->level
, r
->flags
);
1206 #endif /* CONFIG_NO_STDOUT_DEBUG */
1211 * wpa_supplicant_get_scan_results - Get scan results
1212 * @wpa_s: Pointer to wpa_supplicant data
1213 * @info: Information about what was scanned or %NULL if not available
1214 * @new_scan: Whether a new scan was performed
1215 * Returns: Scan results, %NULL on failure
1217 * This function request the current scan results from the driver and updates
1218 * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1219 * results with wpa_scan_results_free().
1221 struct wpa_scan_results
*
1222 wpa_supplicant_get_scan_results(struct wpa_supplicant
*wpa_s
,
1223 struct scan_info
*info
, int new_scan
)
1225 struct wpa_scan_results
*scan_res
;
1227 int (*compar
)(const void *, const void *) = wpa_scan_result_compar
;
1229 scan_res
= wpa_drv_get_scan_results2(wpa_s
);
1230 if (scan_res
== NULL
) {
1231 wpa_dbg(wpa_s
, MSG_DEBUG
, "Failed to get scan results");
1236 if (wpas_wps_in_progress(wpa_s
)) {
1237 wpa_dbg(wpa_s
, MSG_DEBUG
, "WPS: Order scan results with WPS "
1238 "provisioning rules");
1239 compar
= wpa_scan_result_wps_compar
;
1241 #endif /* CONFIG_WPS */
1243 qsort(scan_res
->res
, scan_res
->num
, sizeof(struct wpa_scan_res
*),
1245 dump_scan_res(scan_res
);
1247 wpa_bss_update_start(wpa_s
);
1248 for (i
= 0; i
< scan_res
->num
; i
++)
1249 wpa_bss_update_scan_res(wpa_s
, scan_res
->res
[i
]);
1250 wpa_bss_update_end(wpa_s
, info
, new_scan
);
1256 int wpa_supplicant_update_scan_results(struct wpa_supplicant
*wpa_s
)
1258 struct wpa_scan_results
*scan_res
;
1259 scan_res
= wpa_supplicant_get_scan_results(wpa_s
, NULL
, 0);
1260 if (scan_res
== NULL
)
1262 wpa_scan_results_free(scan_res
);