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(*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
*
384 wpa_supplicant_extra_ies(struct wpa_supplicant
*wpa_s
,
385 struct wpa_driver_scan_params
*params
)
387 struct wpabuf
*extra_ie
= NULL
;
390 enum wps_request_type req_type
= WPS_REQ_ENROLLEE_INFO
;
391 #endif /* CONFIG_WPS */
393 #ifdef CONFIG_INTERWORKING
394 if (wpa_s
->conf
->interworking
&&
395 wpabuf_resize(&extra_ie
, 100) == 0)
396 wpas_add_interworking_elements(wpa_s
, extra_ie
);
397 #endif /* CONFIG_INTERWORKING */
400 wps
= wpas_wps_in_use(wpa_s
, &req_type
);
403 struct wpabuf
*wps_ie
;
404 wps_ie
= wps_build_probe_req_ie(wps
== 2 ? DEV_PW_PUSHBUTTON
:
407 wpa_s
->wps
->uuid
, req_type
,
410 if (wpabuf_resize(&extra_ie
, wpabuf_len(wps_ie
)) == 0)
411 wpabuf_put_buf(extra_ie
, wps_ie
);
418 size_t ielen
= p2p_scan_ie_buf_len(wpa_s
->global
->p2p
);
419 if (wpabuf_resize(&extra_ie
, ielen
) == 0)
420 wpas_p2p_scan_ie(wpa_s
, extra_ie
);
422 #endif /* CONFIG_P2P */
424 #endif /* CONFIG_WPS */
430 static void wpa_supplicant_scan(void *eloop_ctx
, void *timeout_ctx
)
432 struct wpa_supplicant
*wpa_s
= eloop_ctx
;
433 struct wpa_ssid
*ssid
;
434 int scan_req
= 0, ret
;
435 struct wpabuf
*extra_ie
;
436 struct wpa_driver_scan_params params
;
438 enum wpa_states prev_state
;
440 if (wpa_s
->wpa_state
== WPA_INTERFACE_DISABLED
) {
441 wpa_dbg(wpa_s
, MSG_DEBUG
, "Skip scan - interface disabled");
445 if (wpa_s
->disconnected
&& !wpa_s
->scan_req
) {
446 wpa_supplicant_set_state(wpa_s
, WPA_DISCONNECTED
);
450 if (!wpa_supplicant_enabled_networks(wpa_s
) &&
452 wpa_dbg(wpa_s
, MSG_DEBUG
, "No enabled networks - do not scan");
453 wpa_supplicant_set_state(wpa_s
, WPA_INACTIVE
);
457 if (wpa_s
->conf
->ap_scan
!= 0 &&
458 (wpa_s
->drv_flags
& WPA_DRIVER_FLAGS_WIRED
)) {
459 wpa_dbg(wpa_s
, MSG_DEBUG
, "Using wired authentication - "
460 "overriding ap_scan configuration");
461 wpa_s
->conf
->ap_scan
= 0;
462 wpas_notify_ap_scan_changed(wpa_s
);
465 if (wpa_s
->conf
->ap_scan
== 0) {
466 wpa_supplicant_gen_assoc_event(wpa_s
);
471 if (wpas_p2p_in_progress(wpa_s
)) {
472 if (wpa_s
->wpa_state
== WPA_SCANNING
) {
473 wpa_dbg(wpa_s
, MSG_DEBUG
, "Delay station mode scan "
474 "while P2P operation is in progress");
475 wpa_supplicant_req_scan(wpa_s
, 5, 0);
477 wpa_dbg(wpa_s
, MSG_DEBUG
, "Do not request scan while "
478 "P2P operation is in progress");
482 #endif /* CONFIG_P2P */
484 if (wpa_s
->conf
->ap_scan
== 2)
487 max_ssids
= wpa_s
->max_scan_ssids
;
488 if (max_ssids
> WPAS_MAX_SCAN_SSIDS
)
489 max_ssids
= WPAS_MAX_SCAN_SSIDS
;
492 scan_req
= wpa_s
->scan_req
;
495 os_memset(¶ms
, 0, sizeof(params
));
497 prev_state
= wpa_s
->wpa_state
;
498 if (wpa_s
->wpa_state
== WPA_DISCONNECTED
||
499 wpa_s
->wpa_state
== WPA_INACTIVE
)
500 wpa_supplicant_set_state(wpa_s
, WPA_SCANNING
);
502 if (scan_req
!= 2 && wpa_s
->connect_without_scan
) {
503 for (ssid
= wpa_s
->conf
->ssid
; ssid
; ssid
= ssid
->next
) {
504 if (ssid
== wpa_s
->connect_without_scan
)
507 wpa_s
->connect_without_scan
= NULL
;
509 wpa_printf(MSG_DEBUG
, "Start a pre-selected network "
510 "without scan step");
511 wpa_supplicant_associate(wpa_s
, NULL
, ssid
);
517 if ((wpa_s
->p2p_in_provisioning
|| wpa_s
->show_group_started
) &&
519 wpa_printf(MSG_DEBUG
, "P2P: Use specific SSID for scan during "
520 "P2P group formation");
521 params
.ssids
[0].ssid
= wpa_s
->go_params
->ssid
;
522 params
.ssids
[0].ssid_len
= wpa_s
->go_params
->ssid_len
;
523 params
.num_ssids
= 1;
526 #endif /* CONFIG_P2P */
528 /* Find the starting point from which to continue scanning */
529 ssid
= wpa_s
->conf
->ssid
;
530 if (wpa_s
->prev_scan_ssid
!= WILDCARD_SSID_SCAN
) {
532 if (ssid
== wpa_s
->prev_scan_ssid
) {
540 if (scan_req
!= 2 && wpa_s
->conf
->ap_scan
== 2) {
541 wpa_s
->connect_without_scan
= NULL
;
542 wpa_s
->prev_scan_wildcard
= 0;
543 wpa_supplicant_assoc_try(wpa_s
, ssid
);
545 } else if (wpa_s
->conf
->ap_scan
== 2) {
547 * User-initiated scan request in ap_scan == 2; scan with
552 struct wpa_ssid
*start
= ssid
, *tssid
;
554 if (ssid
== NULL
&& max_ssids
> 1)
555 ssid
= wpa_s
->conf
->ssid
;
557 if (!wpas_network_disabled(wpa_s
, ssid
) &&
559 wpa_hexdump_ascii(MSG_DEBUG
, "Scan SSID",
560 ssid
->ssid
, ssid
->ssid_len
);
561 params
.ssids
[params
.num_ssids
].ssid
=
563 params
.ssids
[params
.num_ssids
].ssid_len
=
566 if (params
.num_ssids
+ 1 >= max_ssids
)
572 if (ssid
== NULL
&& max_ssids
> 1 &&
573 start
!= wpa_s
->conf
->ssid
)
574 ssid
= wpa_s
->conf
->ssid
;
577 for (tssid
= wpa_s
->conf
->ssid
; tssid
; tssid
= tssid
->next
) {
578 if (wpas_network_disabled(wpa_s
, tssid
))
580 if ((params
.freqs
|| !freqs_set
) && tssid
->scan_freq
) {
581 int_array_concat(¶ms
.freqs
,
584 os_free(params
.freqs
);
589 int_array_sort_unique(params
.freqs
);
592 if (ssid
&& max_ssids
== 1) {
594 * If the driver is limited to 1 SSID at a time interleave
595 * wildcard SSID scans with specific SSID scans to avoid
596 * waiting a long time for a wildcard scan.
598 if (!wpa_s
->prev_scan_wildcard
) {
599 params
.ssids
[0].ssid
= NULL
;
600 params
.ssids
[0].ssid_len
= 0;
601 wpa_s
->prev_scan_wildcard
= 1;
602 wpa_dbg(wpa_s
, MSG_DEBUG
, "Starting AP scan for "
603 "wildcard SSID (Interleave with specific)");
605 wpa_s
->prev_scan_ssid
= ssid
;
606 wpa_s
->prev_scan_wildcard
= 0;
607 wpa_dbg(wpa_s
, MSG_DEBUG
,
608 "Starting AP scan for specific SSID: %s",
609 wpa_ssid_txt(ssid
->ssid
, ssid
->ssid_len
));
614 wpa_s
->prev_scan_ssid
= ssid
;
615 wpa_dbg(wpa_s
, MSG_DEBUG
, "Include wildcard SSID in "
619 wpa_s
->prev_scan_ssid
= WILDCARD_SSID_SCAN
;
621 wpa_dbg(wpa_s
, MSG_DEBUG
, "Starting AP scan for wildcard "
626 #endif /* CONFIG_P2P */
628 wpa_supplicant_optimize_freqs(wpa_s
, ¶ms
);
629 extra_ie
= wpa_supplicant_extra_ies(wpa_s
, ¶ms
);
632 if (wpa_s
->conf
->hs20
&& wpabuf_resize(&extra_ie
, 6) == 0)
633 wpas_hs20_add_indication(extra_ie
);
634 #endif /* CONFIG_HS20 */
636 if (params
.freqs
== NULL
&& wpa_s
->next_scan_freqs
) {
637 wpa_dbg(wpa_s
, MSG_DEBUG
, "Optimize scan based on previously "
638 "generated frequency list");
639 params
.freqs
= wpa_s
->next_scan_freqs
;
641 os_free(wpa_s
->next_scan_freqs
);
642 wpa_s
->next_scan_freqs
= NULL
;
644 params
.filter_ssids
= wpa_supplicant_build_filter_ssids(
645 wpa_s
->conf
, ¶ms
.num_filter_ssids
);
647 params
.extra_ies
= wpabuf_head(extra_ie
);
648 params
.extra_ies_len
= wpabuf_len(extra_ie
);
652 if (wpa_s
->p2p_in_provisioning
||
653 (wpa_s
->show_group_started
&& wpa_s
->go_params
)) {
655 * The interface may not yet be in P2P mode, so we have to
656 * explicitly request P2P probe to disable CCK rates.
658 params
.p2p_probe
= 1;
660 #endif /* CONFIG_P2P */
662 ret
= wpa_supplicant_trigger_scan(wpa_s
, ¶ms
);
664 wpabuf_free(extra_ie
);
665 os_free(params
.freqs
);
666 os_free(params
.filter_ssids
);
669 wpa_msg(wpa_s
, MSG_WARNING
, "Failed to initiate AP scan");
670 if (prev_state
!= wpa_s
->wpa_state
)
671 wpa_supplicant_set_state(wpa_s
, prev_state
);
672 wpa_supplicant_req_scan(wpa_s
, 1, 0);
678 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
679 * @wpa_s: Pointer to wpa_supplicant data
680 * @sec: Number of seconds after which to scan
681 * @usec: Number of microseconds after which to scan
683 * This function is used to schedule a scan for neighboring access points after
684 * the specified time.
686 void wpa_supplicant_req_scan(struct wpa_supplicant
*wpa_s
, int sec
, int usec
)
688 /* If there's at least one network that should be specifically scanned
689 * then don't cancel the scan and reschedule. Some drivers do
690 * background scanning which generates frequent scan results, and that
691 * causes the specific SSID scan to get continually pushed back and
692 * never happen, which causes hidden APs to never get probe-scanned.
694 if (eloop_is_timeout_registered(wpa_supplicant_scan
, wpa_s
, NULL
) &&
695 wpa_s
->conf
->ap_scan
== 1) {
696 struct wpa_ssid
*ssid
= wpa_s
->conf
->ssid
;
699 if (!wpas_network_disabled(wpa_s
, ssid
) &&
705 wpa_dbg(wpa_s
, MSG_DEBUG
, "Not rescheduling scan to "
706 "ensure that specific SSID scans occur");
711 wpa_dbg(wpa_s
, MSG_DEBUG
, "Setting scan request: %d sec %d usec",
713 eloop_cancel_timeout(wpa_supplicant_scan
, wpa_s
, NULL
);
714 eloop_register_timeout(sec
, usec
, wpa_supplicant_scan
, wpa_s
, NULL
);
719 * wpa_supplicant_delayed_sched_scan - Request a delayed scheduled scan
720 * @wpa_s: Pointer to wpa_supplicant data
721 * @sec: Number of seconds after which to scan
722 * @usec: Number of microseconds after which to scan
724 * This function is used to schedule periodic scans for neighboring
725 * access points after the specified time.
727 int wpa_supplicant_delayed_sched_scan(struct wpa_supplicant
*wpa_s
,
730 if (!wpa_s
->sched_scan_supported
)
733 eloop_register_timeout(sec
, usec
,
734 wpa_supplicant_delayed_sched_scan_timeout
,
742 * wpa_supplicant_req_sched_scan - Start a periodic scheduled scan
743 * @wpa_s: Pointer to wpa_supplicant data
745 * This function is used to schedule periodic scans for neighboring
746 * access points repeating the scan continuously.
748 int wpa_supplicant_req_sched_scan(struct wpa_supplicant
*wpa_s
)
750 struct wpa_driver_scan_params params
;
751 enum wpa_states prev_state
;
752 struct wpa_ssid
*ssid
;
753 struct wpabuf
*wps_ie
= NULL
;
755 unsigned int max_sched_scan_ssids
;
759 if (!wpa_s
->sched_scan_supported
)
762 if (wpa_s
->max_sched_scan_ssids
> WPAS_MAX_SCAN_SSIDS
)
763 max_sched_scan_ssids
= WPAS_MAX_SCAN_SSIDS
;
765 max_sched_scan_ssids
= wpa_s
->max_sched_scan_ssids
;
766 if (max_sched_scan_ssids
< 1 || wpa_s
->conf
->disable_scan_offload
)
769 if (wpa_s
->sched_scanning
) {
770 wpa_dbg(wpa_s
, MSG_DEBUG
, "Already sched scanning");
775 for (ssid
= wpa_s
->conf
->ssid
; ssid
; ssid
= ssid
->next
) {
776 if (!wpas_network_disabled(wpa_s
, ssid
) && !ssid
->scan_ssid
) {
777 /* Use wildcard SSID to find this network */
779 } else if (!wpas_network_disabled(wpa_s
, ssid
) &&
784 if (!wpas_network_disabled(wpa_s
, ssid
) &&
785 ssid
->key_mgmt
== WPA_KEY_MGMT_WPS
) {
787 * Normal scan is more reliable and faster for WPS
788 * operations and since these are for short periods of
789 * time, the benefit of trying to use sched_scan would
792 wpa_dbg(wpa_s
, MSG_DEBUG
, "Use normal scan instead of "
793 "sched_scan for WPS");
796 #endif /* CONFIG_WPS */
801 if (wpa_s
->normal_scans
< 3 &&
802 (need_ssids
<= wpa_s
->max_scan_ssids
||
803 wpa_s
->max_scan_ssids
>= (int) max_sched_scan_ssids
)) {
805 * When normal scan can speed up operations, use that for the
806 * first operations before starting the sched_scan to allow
807 * user space sleep more. We do this only if the normal scan
808 * has functionality that is suitable for this or if the
809 * sched_scan does not have better support for multiple SSIDs.
811 wpa_dbg(wpa_s
, MSG_DEBUG
, "Use normal scan instead of "
812 "sched_scan for initial scans (normal_scans=%d)",
813 wpa_s
->normal_scans
);
817 os_memset(¶ms
, 0, sizeof(params
));
819 /* If we can't allocate space for the filters, we just don't filter */
820 params
.filter_ssids
= os_zalloc(wpa_s
->max_match_sets
*
821 sizeof(struct wpa_driver_scan_filter
));
823 prev_state
= wpa_s
->wpa_state
;
824 if (wpa_s
->wpa_state
== WPA_DISCONNECTED
||
825 wpa_s
->wpa_state
== WPA_INACTIVE
)
826 wpa_supplicant_set_state(wpa_s
, WPA_SCANNING
);
828 /* Find the starting point from which to continue scanning */
829 ssid
= wpa_s
->conf
->ssid
;
830 if (wpa_s
->prev_sched_ssid
) {
832 if (ssid
== wpa_s
->prev_sched_ssid
) {
840 if (!ssid
|| !wpa_s
->prev_sched_ssid
) {
841 wpa_dbg(wpa_s
, MSG_DEBUG
, "Beginning of SSID list");
843 wpa_s
->sched_scan_interval
= 10;
844 wpa_s
->sched_scan_timeout
= max_sched_scan_ssids
* 2;
845 wpa_s
->first_sched_scan
= 1;
846 ssid
= wpa_s
->conf
->ssid
;
847 wpa_s
->prev_sched_ssid
= ssid
;
851 wpa_dbg(wpa_s
, MSG_DEBUG
, "Add wildcard SSID to sched_scan");
856 if (wpas_network_disabled(wpa_s
, ssid
))
859 if (params
.num_filter_ssids
< wpa_s
->max_match_sets
&&
860 params
.filter_ssids
&& ssid
->ssid
&& ssid
->ssid_len
) {
861 wpa_dbg(wpa_s
, MSG_DEBUG
, "add to filter ssid: %s",
862 wpa_ssid_txt(ssid
->ssid
, ssid
->ssid_len
));
863 os_memcpy(params
.filter_ssids
[params
.num_filter_ssids
].ssid
,
864 ssid
->ssid
, ssid
->ssid_len
);
865 params
.filter_ssids
[params
.num_filter_ssids
].ssid_len
=
867 params
.num_filter_ssids
++;
868 } else if (params
.filter_ssids
&& ssid
->ssid
&& ssid
->ssid_len
)
870 wpa_dbg(wpa_s
, MSG_DEBUG
, "Not enough room for SSID "
871 "filter for sched_scan - drop filter");
872 os_free(params
.filter_ssids
);
873 params
.filter_ssids
= NULL
;
874 params
.num_filter_ssids
= 0;
877 if (ssid
->scan_ssid
&& ssid
->ssid
&& ssid
->ssid_len
) {
878 if (params
.num_ssids
== max_sched_scan_ssids
)
879 break; /* only room for broadcast SSID */
880 wpa_dbg(wpa_s
, MSG_DEBUG
,
881 "add to active scan ssid: %s",
882 wpa_ssid_txt(ssid
->ssid
, ssid
->ssid_len
));
883 params
.ssids
[params
.num_ssids
].ssid
=
885 params
.ssids
[params
.num_ssids
].ssid_len
=
888 if (params
.num_ssids
>= max_sched_scan_ssids
) {
889 wpa_s
->prev_sched_ssid
= ssid
;
893 (wpas_network_disabled(wpa_s
, ssid
) ||
900 wpa_s
->prev_sched_ssid
= ssid
;
904 if (params
.num_filter_ssids
== 0) {
905 os_free(params
.filter_ssids
);
906 params
.filter_ssids
= NULL
;
910 wps_ie
= wpa_supplicant_extra_ies(wpa_s
, ¶ms
);
912 if (ssid
|| !wpa_s
->first_sched_scan
) {
913 wpa_dbg(wpa_s
, MSG_DEBUG
,
914 "Starting sched scan: interval %d timeout %d",
915 wpa_s
->sched_scan_interval
, wpa_s
->sched_scan_timeout
);
917 wpa_dbg(wpa_s
, MSG_DEBUG
,
918 "Starting sched scan: interval %d (no timeout)",
919 wpa_s
->sched_scan_interval
);
922 ret
= wpa_supplicant_start_sched_scan(wpa_s
, ¶ms
,
923 wpa_s
->sched_scan_interval
);
925 os_free(params
.filter_ssids
);
927 wpa_msg(wpa_s
, MSG_WARNING
, "Failed to initiate sched scan");
928 if (prev_state
!= wpa_s
->wpa_state
)
929 wpa_supplicant_set_state(wpa_s
, prev_state
);
933 /* If we have more SSIDs to scan, add a timeout so we scan them too */
934 if (ssid
|| !wpa_s
->first_sched_scan
) {
935 wpa_s
->sched_scan_timed_out
= 0;
936 eloop_register_timeout(wpa_s
->sched_scan_timeout
, 0,
937 wpa_supplicant_sched_scan_timeout
,
939 wpa_s
->first_sched_scan
= 0;
940 wpa_s
->sched_scan_timeout
/= 2;
941 wpa_s
->sched_scan_interval
*= 2;
949 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
950 * @wpa_s: Pointer to wpa_supplicant data
952 * This function is used to cancel a scan request scheduled with
953 * wpa_supplicant_req_scan().
955 void wpa_supplicant_cancel_scan(struct wpa_supplicant
*wpa_s
)
957 wpa_dbg(wpa_s
, MSG_DEBUG
, "Cancelling scan request");
958 eloop_cancel_timeout(wpa_supplicant_scan
, wpa_s
, NULL
);
963 * wpa_supplicant_cancel_sched_scan - Stop running scheduled scans
964 * @wpa_s: Pointer to wpa_supplicant data
966 * This function is used to stop a periodic scheduled scan.
968 void wpa_supplicant_cancel_sched_scan(struct wpa_supplicant
*wpa_s
)
970 if (!wpa_s
->sched_scanning
)
973 wpa_dbg(wpa_s
, MSG_DEBUG
, "Cancelling sched scan");
974 eloop_cancel_timeout(wpa_supplicant_sched_scan_timeout
, wpa_s
, NULL
);
975 wpa_supplicant_stop_sched_scan(wpa_s
);
979 void wpa_supplicant_notify_scanning(struct wpa_supplicant
*wpa_s
,
982 if (wpa_s
->scanning
!= scanning
) {
983 wpa_s
->scanning
= scanning
;
984 wpas_notify_scanning(wpa_s
);
989 static int wpa_scan_get_max_rate(const struct wpa_scan_res
*res
)
995 ie
= wpa_scan_get_ie(res
, WLAN_EID_SUPP_RATES
);
996 for (i
= 0; ie
&& i
< ie
[1]; i
++) {
997 if ((ie
[i
+ 2] & 0x7f) > rate
)
998 rate
= ie
[i
+ 2] & 0x7f;
1001 ie
= wpa_scan_get_ie(res
, WLAN_EID_EXT_SUPP_RATES
);
1002 for (i
= 0; ie
&& i
< ie
[1]; i
++) {
1003 if ((ie
[i
+ 2] & 0x7f) > rate
)
1004 rate
= ie
[i
+ 2] & 0x7f;
1011 const u8
* wpa_scan_get_ie(const struct wpa_scan_res
*res
, u8 ie
)
1013 const u8
*end
, *pos
;
1015 pos
= (const u8
*) (res
+ 1);
1016 end
= pos
+ res
->ie_len
;
1018 while (pos
+ 1 < end
) {
1019 if (pos
+ 2 + pos
[1] > end
)
1030 const u8
* wpa_scan_get_vendor_ie(const struct wpa_scan_res
*res
,
1033 const u8
*end
, *pos
;
1035 pos
= (const u8
*) (res
+ 1);
1036 end
= pos
+ res
->ie_len
;
1038 while (pos
+ 1 < end
) {
1039 if (pos
+ 2 + pos
[1] > end
)
1041 if (pos
[0] == WLAN_EID_VENDOR_SPECIFIC
&& pos
[1] >= 4 &&
1042 vendor_type
== WPA_GET_BE32(&pos
[2]))
1051 struct wpabuf
* wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res
*res
,
1055 const u8
*end
, *pos
;
1057 buf
= wpabuf_alloc(res
->ie_len
);
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]))
1069 wpabuf_put_data(buf
, pos
+ 2 + 4, pos
[1] - 4);
1073 if (wpabuf_len(buf
) == 0) {
1082 struct wpabuf
* wpa_scan_get_vendor_ie_multi_beacon(
1083 const struct wpa_scan_res
*res
, u32 vendor_type
)
1086 const u8
*end
, *pos
;
1088 if (res
->beacon_ie_len
== 0)
1090 buf
= wpabuf_alloc(res
->beacon_ie_len
);
1094 pos
= (const u8
*) (res
+ 1);
1096 end
= pos
+ res
->beacon_ie_len
;
1098 while (pos
+ 1 < end
) {
1099 if (pos
+ 2 + pos
[1] > end
)
1101 if (pos
[0] == WLAN_EID_VENDOR_SPECIFIC
&& pos
[1] >= 4 &&
1102 vendor_type
== WPA_GET_BE32(&pos
[2]))
1103 wpabuf_put_data(buf
, pos
+ 2 + 4, pos
[1] - 4);
1107 if (wpabuf_len(buf
) == 0) {
1117 * Channels with a great SNR can operate at full rate. What is a great SNR?
1118 * This doc https://supportforums.cisco.com/docs/DOC-12954 says, "the general
1119 * rule of thumb is that any SNR above 20 is good." This one
1120 * http://www.cisco.com/en/US/tech/tk722/tk809/technologies_q_and_a_item09186a00805e9a96.shtml#qa23
1121 * recommends 25 as a minimum SNR for 54 Mbps data rate. 30 is chosen here as a
1122 * conservative value.
1124 #define GREAT_SNR 30
1126 /* Compare function for sorting scan results. Return >0 if @b is considered
1128 static int wpa_scan_result_compar(const void *a
, const void *b
)
1130 #define IS_5GHZ(n) (n > 4000)
1131 #define MIN(a,b) a < b ? a : b
1132 struct wpa_scan_res
**_wa
= (void *) a
;
1133 struct wpa_scan_res
**_wb
= (void *) b
;
1134 struct wpa_scan_res
*wa
= *_wa
;
1135 struct wpa_scan_res
*wb
= *_wb
;
1136 int wpa_a
, wpa_b
, maxrate_a
, maxrate_b
;
1139 /* WPA/WPA2 support preferred */
1140 wpa_a
= wpa_scan_get_vendor_ie(wa
, WPA_IE_VENDOR_TYPE
) != NULL
||
1141 wpa_scan_get_ie(wa
, WLAN_EID_RSN
) != NULL
;
1142 wpa_b
= wpa_scan_get_vendor_ie(wb
, WPA_IE_VENDOR_TYPE
) != NULL
||
1143 wpa_scan_get_ie(wb
, WLAN_EID_RSN
) != NULL
;
1145 if (wpa_b
&& !wpa_a
)
1147 if (!wpa_b
&& wpa_a
)
1150 /* privacy support preferred */
1151 if ((wa
->caps
& IEEE80211_CAP_PRIVACY
) == 0 &&
1152 (wb
->caps
& IEEE80211_CAP_PRIVACY
))
1154 if ((wa
->caps
& IEEE80211_CAP_PRIVACY
) &&
1155 (wb
->caps
& IEEE80211_CAP_PRIVACY
) == 0)
1158 if ((wa
->flags
& wb
->flags
& WPA_SCAN_LEVEL_DBM
) &&
1159 !((wa
->flags
| wb
->flags
) & WPA_SCAN_NOISE_INVALID
)) {
1160 snr_a
= MIN(wa
->level
- wa
->noise
, GREAT_SNR
);
1161 snr_b
= MIN(wb
->level
- wb
->noise
, GREAT_SNR
);
1163 /* Not suitable information to calculate SNR, so use level */
1168 /* best/max rate preferred if SNR close enough */
1169 if ((snr_a
&& snr_b
&& abs(snr_b
- snr_a
) < 5) ||
1170 (wa
->qual
&& wb
->qual
&& abs(wb
->qual
- wa
->qual
) < 10)) {
1171 maxrate_a
= wpa_scan_get_max_rate(wa
);
1172 maxrate_b
= wpa_scan_get_max_rate(wb
);
1173 if (maxrate_a
!= maxrate_b
)
1174 return maxrate_b
- maxrate_a
;
1175 if (IS_5GHZ(wa
->freq
) ^ IS_5GHZ(wb
->freq
))
1176 return IS_5GHZ(wa
->freq
) ? -1 : 1;
1179 /* use freq for channel preference */
1181 /* all things being equal, use SNR; if SNRs are
1182 * identical, use quality values since some drivers may only report
1183 * that value and leave the signal level zero */
1185 return wb
->qual
- wa
->qual
;
1186 return snr_b
- snr_a
;
1193 /* Compare function for sorting scan results when searching a WPS AP for
1194 * provisioning. Return >0 if @b is considered better. */
1195 static int wpa_scan_result_wps_compar(const void *a
, const void *b
)
1197 struct wpa_scan_res
**_wa
= (void *) a
;
1198 struct wpa_scan_res
**_wb
= (void *) b
;
1199 struct wpa_scan_res
*wa
= *_wa
;
1200 struct wpa_scan_res
*wb
= *_wb
;
1201 int uses_wps_a
, uses_wps_b
;
1202 struct wpabuf
*wps_a
, *wps_b
;
1205 /* Optimization - check WPS IE existence before allocated memory and
1206 * doing full reassembly. */
1207 uses_wps_a
= wpa_scan_get_vendor_ie(wa
, WPS_IE_VENDOR_TYPE
) != NULL
;
1208 uses_wps_b
= wpa_scan_get_vendor_ie(wb
, WPS_IE_VENDOR_TYPE
) != NULL
;
1209 if (uses_wps_a
&& !uses_wps_b
)
1211 if (!uses_wps_a
&& uses_wps_b
)
1214 if (uses_wps_a
&& uses_wps_b
) {
1215 wps_a
= wpa_scan_get_vendor_ie_multi(wa
, WPS_IE_VENDOR_TYPE
);
1216 wps_b
= wpa_scan_get_vendor_ie_multi(wb
, WPS_IE_VENDOR_TYPE
);
1217 res
= wps_ap_priority_compar(wps_a
, wps_b
);
1225 * Do not use current AP security policy as a sorting criteria during
1226 * WPS provisioning step since the AP may get reconfigured at the
1227 * completion of provisioning.
1230 /* all things being equal, use signal level; if signal levels are
1231 * identical, use quality values since some drivers may only report
1232 * that value and leave the signal level zero */
1233 if (wb
->level
== wa
->level
)
1234 return wb
->qual
- wa
->qual
;
1235 return wb
->level
- wa
->level
;
1237 #endif /* CONFIG_WPS */
1240 static void dump_scan_res(struct wpa_scan_results
*scan_res
)
1242 #ifndef CONFIG_NO_STDOUT_DEBUG
1245 if (scan_res
->res
== NULL
|| scan_res
->num
== 0)
1248 wpa_printf(MSG_EXCESSIVE
, "Sorted scan results");
1250 for (i
= 0; i
< scan_res
->num
; i
++) {
1251 struct wpa_scan_res
*r
= scan_res
->res
[i
];
1252 if ((r
->flags
& (WPA_SCAN_LEVEL_DBM
| WPA_SCAN_NOISE_INVALID
))
1253 == WPA_SCAN_LEVEL_DBM
) {
1254 int snr
= r
->level
- r
->noise
;
1255 wpa_printf(MSG_EXCESSIVE
, MACSTR
" freq=%d qual=%d "
1256 "noise=%d level=%d snr=%d%s flags=0x%x",
1257 MAC2STR(r
->bssid
), r
->freq
, r
->qual
,
1258 r
->noise
, r
->level
, snr
,
1259 snr
>= GREAT_SNR
? "*" : "", r
->flags
);
1261 wpa_printf(MSG_EXCESSIVE
, MACSTR
" freq=%d qual=%d "
1262 "noise=%d level=%d flags=0x%x",
1263 MAC2STR(r
->bssid
), r
->freq
, r
->qual
,
1264 r
->noise
, r
->level
, r
->flags
);
1267 #endif /* CONFIG_NO_STDOUT_DEBUG */
1271 int wpa_supplicant_filter_bssid_match(struct wpa_supplicant
*wpa_s
,
1276 if (wpa_s
->bssid_filter
== NULL
)
1279 for (i
= 0; i
< wpa_s
->bssid_filter_count
; i
++) {
1280 if (os_memcmp(wpa_s
->bssid_filter
+ i
* ETH_ALEN
, bssid
,
1289 static void filter_scan_res(struct wpa_supplicant
*wpa_s
,
1290 struct wpa_scan_results
*res
)
1294 if (wpa_s
->bssid_filter
== NULL
)
1297 for (i
= 0, j
= 0; i
< res
->num
; i
++) {
1298 if (wpa_supplicant_filter_bssid_match(wpa_s
,
1299 res
->res
[i
]->bssid
)) {
1300 res
->res
[j
++] = res
->res
[i
];
1302 os_free(res
->res
[i
]);
1307 if (res
->num
!= j
) {
1308 wpa_printf(MSG_DEBUG
, "Filtered out %d scan results",
1309 (int) (res
->num
- j
));
1316 * wpa_supplicant_get_scan_results - Get scan results
1317 * @wpa_s: Pointer to wpa_supplicant data
1318 * @info: Information about what was scanned or %NULL if not available
1319 * @new_scan: Whether a new scan was performed
1320 * Returns: Scan results, %NULL on failure
1322 * This function request the current scan results from the driver and updates
1323 * the local BSS list wpa_s->bss. The caller is responsible for freeing the
1324 * results with wpa_scan_results_free().
1326 struct wpa_scan_results
*
1327 wpa_supplicant_get_scan_results(struct wpa_supplicant
*wpa_s
,
1328 struct scan_info
*info
, int new_scan
)
1330 struct wpa_scan_results
*scan_res
;
1332 int (*compar
)(const void *, const void *) = wpa_scan_result_compar
;
1334 scan_res
= wpa_drv_get_scan_results2(wpa_s
);
1335 if (scan_res
== NULL
) {
1336 wpa_dbg(wpa_s
, MSG_DEBUG
, "Failed to get scan results");
1339 filter_scan_res(wpa_s
, scan_res
);
1342 if (wpas_wps_in_progress(wpa_s
)) {
1343 wpa_dbg(wpa_s
, MSG_DEBUG
, "WPS: Order scan results with WPS "
1344 "provisioning rules");
1345 compar
= wpa_scan_result_wps_compar
;
1347 #endif /* CONFIG_WPS */
1349 qsort(scan_res
->res
, scan_res
->num
, sizeof(struct wpa_scan_res
*),
1351 dump_scan_res(scan_res
);
1353 wpa_bss_update_start(wpa_s
);
1354 for (i
= 0; i
< scan_res
->num
; i
++)
1355 wpa_bss_update_scan_res(wpa_s
, scan_res
->res
[i
]);
1356 wpa_bss_update_end(wpa_s
, info
, new_scan
);
1362 int wpa_supplicant_update_scan_results(struct wpa_supplicant
*wpa_s
)
1364 struct wpa_scan_results
*scan_res
;
1365 scan_res
= wpa_supplicant_get_scan_results(wpa_s
, NULL
, 0);
1366 if (scan_res
== NULL
)
1368 wpa_scan_results_free(scan_res
);