[thirdparty/hostap.git] / wpa_supplicant / scan.c

/*
 * WPA Supplicant - Scanning
 * Copyright (c) 2003-2008, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#include "common.h"
#include "eloop.h"
#include "config.h"
#include "wpa_supplicant_i.h"
#include "mlme.h"
#include "wps_supplicant.h"


static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
{
	struct wpa_ssid *ssid;
	union wpa_event_data data;

	ssid = wpa_supplicant_get_ssid(wpa_s);
	if (ssid == NULL)
		return;

	if (wpa_s->current_ssid == NULL)
		wpa_s->current_ssid = ssid;
	wpa_supplicant_initiate_eapol(wpa_s);
	wpa_printf(MSG_DEBUG, "Already associated with a configured network - "
		   "generating associated event");
	os_memset(&data, 0, sizeof(data));
	wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
}


#ifdef CONFIG_WPS
static int wpas_wps_in_use(struct wpa_config *conf,
			   enum wps_request_type *req_type)
{
	struct wpa_ssid *ssid;
	int wps = 0;

	for (ssid = conf->ssid; ssid; ssid = ssid->next) {
		if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
			continue;

		wps = 1;
		*req_type = wpas_wps_get_req_type(ssid);
		if (!ssid->eap.phase1)
			continue;

		if (os_strstr(ssid->eap.phase1, "pbc=1"))
			return 2;
	}

	return wps;
}
#endif /* CONFIG_WPS */

static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
{
	struct wpa_supplicant *wpa_s = eloop_ctx;
	struct wpa_ssid *ssid;
	int enabled, scan_req = 0, ret;
	struct wpabuf *wps_ie = NULL;
	const u8 *extra_ie = NULL;
	size_t extra_ie_len = 0;
	int wps = 0;
#ifdef CONFIG_WPS
	enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
#endif /* CONFIG_WPS */

	if (wpa_s->disconnected && !wpa_s->scan_req)
		return;

	enabled = 0;
	ssid = wpa_s->conf->ssid;
	while (ssid) {
		if (!ssid->disabled) {
			enabled++;
			break;
		}
		ssid = ssid->next;
	}
	if (!enabled && !wpa_s->scan_req) {
		wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
		wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
		return;
	}
	scan_req = wpa_s->scan_req;
	wpa_s->scan_req = 0;

	if (wpa_s->conf->ap_scan != 0 &&
	    wpa_s->driver && IS_WIRED(wpa_s->driver)) {
		wpa_printf(MSG_DEBUG, "Using wired authentication - "
			   "overriding ap_scan configuration");
		wpa_s->conf->ap_scan = 0;
	}

	if (wpa_s->conf->ap_scan == 0) {
		wpa_supplicant_gen_assoc_event(wpa_s);
		return;
	}

	if (wpa_s->wpa_state == WPA_DISCONNECTED ||
	    wpa_s->wpa_state == WPA_INACTIVE)
		wpa_supplicant_set_state(wpa_s, WPA_SCANNING);

	ssid = wpa_s->conf->ssid;
	if (wpa_s->prev_scan_ssid != BROADCAST_SSID_SCAN) {
		while (ssid) {
			if (ssid == wpa_s->prev_scan_ssid) {
				ssid = ssid->next;
				break;
			}
			ssid = ssid->next;
		}
	}
	while (ssid) {
		if (!ssid->disabled &&
		    (ssid->scan_ssid || wpa_s->conf->ap_scan == 2))
			break;
		ssid = ssid->next;
	}

	if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
		/*
		 * ap_scan=2 mode - try to associate with each SSID instead of
		 * scanning for each scan_ssid=1 network.
		 */
		if (ssid == NULL) {
			wpa_printf(MSG_DEBUG, "wpa_supplicant_scan: Reached "
				   "end of scan list - go back to beginning");
			wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;
			wpa_supplicant_req_scan(wpa_s, 0, 0);
			return;
		}
		if (ssid->next) {
			/* Continue from the next SSID on the next attempt. */
			wpa_s->prev_scan_ssid = ssid;
		} else {
			/* Start from the beginning of the SSID list. */
			wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;
		}
		wpa_supplicant_associate(wpa_s, NULL, ssid);
		return;
	}

	wpa_printf(MSG_DEBUG, "Starting AP scan (%s SSID)",
		   ssid ? "specific": "broadcast");
	if (ssid) {
		wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
				  ssid->ssid, ssid->ssid_len);
		wpa_s->prev_scan_ssid = ssid;
	} else
		wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;

#ifdef CONFIG_WPS
	wps = wpas_wps_in_use(wpa_s->conf, &req_type);
#endif /* CONFIG_WPS */

	if (wpa_s->scan_res_tried == 0 && wpa_s->conf->ap_scan == 1 &&
	    !wpa_s->use_client_mlme && wps != 2) {
		wpa_s->scan_res_tried++;
		wpa_s->scan_req = scan_req;
		wpa_printf(MSG_DEBUG, "Trying to get current scan results "
			   "first without requesting a new scan to speed up "
			   "initial association");
		wpa_supplicant_event(wpa_s, EVENT_SCAN_RESULTS, NULL);
		return;
	}

#ifdef CONFIG_WPS
	if (wps) {
		wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
						wpa_s->wps->uuid, req_type);
		if (wps_ie) {
			extra_ie = wpabuf_head(wps_ie);
			extra_ie_len = wpabuf_len(wps_ie);
		}
	}
#endif /* CONFIG_WPS */

	if (wpa_s->use_client_mlme) {
		ieee80211_sta_set_probe_req_ie(wpa_s, extra_ie, extra_ie_len);
		ret = ieee80211_sta_req_scan(wpa_s, ssid ? ssid->ssid : NULL,
					     ssid ? ssid->ssid_len : 0);
	} else {
		wpa_drv_set_probe_req_ie(wpa_s, extra_ie, extra_ie_len);
		ret = wpa_drv_scan(wpa_s, ssid ? ssid->ssid : NULL,
				   ssid ? ssid->ssid_len : 0);
	}

	wpabuf_free(wps_ie);

	if (ret) {
		wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
		wpa_supplicant_req_scan(wpa_s, 10, 0);
	}
}


/**
 * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 * @wpa_s: Pointer to wpa_supplicant data
 * @sec: Number of seconds after which to scan
 * @usec: Number of microseconds after which to scan
 *
 * This function is used to schedule a scan for neighboring access points after
 * the specified time.
 */
void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
{
	/* If there's at least one network that should be specifically scanned
	 * then don't cancel the scan and reschedule.  Some drivers do
	 * background scanning which generates frequent scan results, and that
	 * causes the specific SSID scan to get continually pushed back and
	 * never happen, which causes hidden APs to never get probe-scanned.
	 */
	if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
	    wpa_s->conf->ap_scan == 1) {
		struct wpa_ssid *ssid = wpa_s->conf->ssid;

		while (ssid) {
			if (!ssid->disabled && ssid->scan_ssid)
				break;
			ssid = ssid->next;
		}
		if (ssid) {
			wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
			        "ensure that specific SSID scans occur");
			return;
		}
	}

	wpa_msg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
		sec, usec);
	eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
	eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
}


/**
 * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 * @wpa_s: Pointer to wpa_supplicant data
 *
 * This function is used to cancel a scan request scheduled with
 * wpa_supplicant_req_scan().
 */
void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
{
	wpa_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
	eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
}
Commit	Line	Data
6fc6879b JM	1	/*
	2	* WPA Supplicant - Scanning
	3	* Copyright (c) 2003-2008, Jouni Malinen <j@w1.fi>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
	8	*
	9	* Alternatively, this software may be distributed under the terms of BSD
	10	* license.
	11	*
	12	* See README and COPYING for more details.
	13	*/
	14
	15	#include "includes.h"
	16
	17	#include "common.h"
	18	#include "eloop.h"
	19	#include "config.h"
	20	#include "wpa_supplicant_i.h"
	21	#include "mlme.h"
b01c18a8	22	#include "wps_supplicant.h"
6fc6879b JM	23
	24
	25	static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
	26	{
	27	struct wpa_ssid *ssid;
	28	union wpa_event_data data;
	29
	30	ssid = wpa_supplicant_get_ssid(wpa_s);
	31	if (ssid == NULL)
	32	return;
	33
	34	if (wpa_s->current_ssid == NULL)
	35	wpa_s->current_ssid = ssid;
	36	wpa_supplicant_initiate_eapol(wpa_s);
	37	wpa_printf(MSG_DEBUG, "Already associated with a configured network - "
	38	"generating associated event");
	39	os_memset(&data, 0, sizeof(data));
	40	wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
	41	}
	42
	43
ad08c363	44	#ifdef CONFIG_WPS
f90c86d4 JM	45	static int wpas_wps_in_use(struct wpa_config *conf,
f90c86d4 JM	46	enum wps_request_type *req_type)
ad08c363 JM	47	{
	48	struct wpa_ssid *ssid;
	49	int wps = 0;
ad08c363 JM	50
	51	for (ssid = conf->ssid; ssid; ssid = ssid->next) {
	52	if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
	53	continue;
	54
	55	wps = 1;
b01c18a8	56	*req_type = wpas_wps_get_req_type(ssid);
ad08c363 JM	57	if (!ssid->eap.phase1)
	58	continue;
	59
ad08c363 JM	60	if (os_strstr(ssid->eap.phase1, "pbc=1"))
	61	return 2;
	62	}
	63
	64	return wps;
	65	}
	66	#endif /* CONFIG_WPS */
	67
6fc6879b JM	68	static void wpa_supplicant_scan(void eloop_ctx, void timeout_ctx)
	69	{
	70	struct wpa_supplicant *wpa_s = eloop_ctx;
	71	struct wpa_ssid *ssid;
	72	int enabled, scan_req = 0, ret;
ad08c363	73	struct wpabuf *wps_ie = NULL;
6fc6879b JM	74	const u8 *extra_ie = NULL;
6fc6879b JM	75	size_t extra_ie_len = 0;
ad08c363	76	int wps = 0;
b01c18a8	77	#ifdef CONFIG_WPS
f90c86d4	78	enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
b01c18a8	79	#endif /* CONFIG_WPS */
6fc6879b JM	80
	81	if (wpa_s->disconnected && !wpa_s->scan_req)
	82	return;
	83
	84	enabled = 0;
	85	ssid = wpa_s->conf->ssid;
	86	while (ssid) {
	87	if (!ssid->disabled) {
	88	enabled++;
	89	break;
	90	}
	91	ssid = ssid->next;
	92	}
	93	if (!enabled && !wpa_s->scan_req) {
	94	wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
	95	wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
	96	return;
	97	}
	98	scan_req = wpa_s->scan_req;
	99	wpa_s->scan_req = 0;
	100
	101	if (wpa_s->conf->ap_scan != 0 &&
e519314e JW	102	wpa_s->driver && IS_WIRED(wpa_s->driver)) {
	103	wpa_printf(MSG_DEBUG, "Using wired authentication - "
	104	"overriding ap_scan configuration");
6fc6879b JM	105	wpa_s->conf->ap_scan = 0;
	106	}
	107
	108	if (wpa_s->conf->ap_scan == 0) {
	109	wpa_supplicant_gen_assoc_event(wpa_s);
	110	return;
	111	}
	112
	113	if (wpa_s->wpa_state == WPA_DISCONNECTED \|\|
	114	wpa_s->wpa_state == WPA_INACTIVE)
	115	wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
	116
	117	ssid = wpa_s->conf->ssid;
	118	if (wpa_s->prev_scan_ssid != BROADCAST_SSID_SCAN) {
	119	while (ssid) {
	120	if (ssid == wpa_s->prev_scan_ssid) {
	121	ssid = ssid->next;
	122	break;
	123	}
	124	ssid = ssid->next;
	125	}
	126	}
	127	while (ssid) {
	128	if (!ssid->disabled &&
	129	(ssid->scan_ssid \|\| wpa_s->conf->ap_scan == 2))
	130	break;
	131	ssid = ssid->next;
	132	}
	133
	134	if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
	135	/*
	136	* ap_scan=2 mode - try to associate with each SSID instead of
	137	* scanning for each scan_ssid=1 network.
	138	*/
	139	if (ssid == NULL) {
	140	wpa_printf(MSG_DEBUG, "wpa_supplicant_scan: Reached "
	141	"end of scan list - go back to beginning");
	142	wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;
	143	wpa_supplicant_req_scan(wpa_s, 0, 0);
	144	return;
	145	}
	146	if (ssid->next) {
	147	/* Continue from the next SSID on the next attempt. */
	148	wpa_s->prev_scan_ssid = ssid;
	149	} else {
	150	/* Start from the beginning of the SSID list. */
	151	wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;
	152	}
	153	wpa_supplicant_associate(wpa_s, NULL, ssid);
	154	return;
	155	}
	156
	157	wpa_printf(MSG_DEBUG, "Starting AP scan (%s SSID)",
	158	ssid ? "specific": "broadcast");
	159	if (ssid) {
	160	wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
	161	ssid->ssid, ssid->ssid_len);
	162	wpa_s->prev_scan_ssid = ssid;
	163	} else
	164	wpa_s->prev_scan_ssid = BROADCAST_SSID_SCAN;
	165
ad08c363	166	#ifdef CONFIG_WPS
b01c18a8	167	wps = wpas_wps_in_use(wpa_s->conf, &req_type);
ad08c363 JM	168	#endif /* CONFIG_WPS */
ad08c363 JM	169
6fc6879b	170	if (wpa_s->scan_res_tried == 0 && wpa_s->conf->ap_scan == 1 &&
ad08c363	171	!wpa_s->use_client_mlme && wps != 2) {
6fc6879b	172	wpa_s->scan_res_tried++;
2064c2f9	173	wpa_s->scan_req = scan_req;
6fc6879b JM	174	wpa_printf(MSG_DEBUG, "Trying to get current scan results "
	175	"first without requesting a new scan to speed up "
	176	"initial association");
	177	wpa_supplicant_event(wpa_s, EVENT_SCAN_RESULTS, NULL);
	178	return;
	179	}
	180
ad08c363 JM	181	#ifdef CONFIG_WPS
ad08c363 JM	182	if (wps) {
c0d041d9	183	wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
79da74a2	184	wpa_s->wps->uuid, req_type);
ad08c363 JM	185	if (wps_ie) {
	186	extra_ie = wpabuf_head(wps_ie);
	187	extra_ie_len = wpabuf_len(wps_ie);
	188	}
	189	}
	190	#endif /* CONFIG_WPS */
	191
6fc6879b JM	192	if (wpa_s->use_client_mlme) {
	193	ieee80211_sta_set_probe_req_ie(wpa_s, extra_ie, extra_ie_len);
	194	ret = ieee80211_sta_req_scan(wpa_s, ssid ? ssid->ssid : NULL,
	195	ssid ? ssid->ssid_len : 0);
	196	} else {
	197	wpa_drv_set_probe_req_ie(wpa_s, extra_ie, extra_ie_len);
	198	ret = wpa_drv_scan(wpa_s, ssid ? ssid->ssid : NULL,
	199	ssid ? ssid->ssid_len : 0);
	200	}
	201
ad08c363 JM	202	wpabuf_free(wps_ie);
ad08c363 JM	203
6fc6879b JM	204	if (ret) {
	205	wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
	206	wpa_supplicant_req_scan(wpa_s, 10, 0);
	207	}
	208	}
	209
	210
	211	/**
	212	* wpa_supplicant_req_scan - Schedule a scan for neighboring access points
	213	* @wpa_s: Pointer to wpa_supplicant data
	214	* @sec: Number of seconds after which to scan
	215	* @usec: Number of microseconds after which to scan
	216	*
	217	* This function is used to schedule a scan for neighboring access points after
	218	* the specified time.
	219	*/
	220	void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
	221	{
7e148849 DW	222	/* If there's at least one network that should be specifically scanned
	223	* then don't cancel the scan and reschedule. Some drivers do
	224	* background scanning which generates frequent scan results, and that
	225	* causes the specific SSID scan to get continually pushed back and
	226	* never happen, which causes hidden APs to never get probe-scanned.
	227	*/
	228	if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
	229	wpa_s->conf->ap_scan == 1) {
	230	struct wpa_ssid *ssid = wpa_s->conf->ssid;
	231
	232	while (ssid) {
	233	if (!ssid->disabled && ssid->scan_ssid)
	234	break;
	235	ssid = ssid->next;
	236	}
	237	if (ssid) {
	238	wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
	239	"ensure that specific SSID scans occur");
	240	return;
	241	}
	242	}
	243
6fc6879b JM	244	wpa_msg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
	245	sec, usec);
	246	eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
	247	eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
	248	}
	249
	250
	251	/**
	252	* wpa_supplicant_cancel_scan - Cancel a scheduled scan request
	253	* @wpa_s: Pointer to wpa_supplicant data
	254	*
	255	* This function is used to cancel a scan request scheduled with
	256	* wpa_supplicant_req_scan().
	257	*/
	258	void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
	259	{
	260	wpa_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
	261	eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
	262	}