wpa_supplicant/scan.c - LeafOS-Project/android_external_wpa_supplicant_8 - Gitiles

 /*
  * WPA Supplicant - Scanning
  * Copyright (c) 2003-2010, 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 "utils/includes.h"

 #include "utils/common.h"
 #include "utils/eloop.h"
 #include "common/ieee802_11_defs.h"
 #include "config.h"
 #include "wpa_supplicant_i.h"
 #include "driver_i.h"
 #include "mlme.h"
 #include "wps_supplicant.h"
 #include "p2p_supplicant.h"
 #include "p2p/p2p.h"
 #include "notify.h"
 #include "bss.h"
 #include "scan.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;
 		if (wpa_s->current_ssid != NULL)
 			wpas_notify_network_changed(wpa_s);
 	}
 	wpa_supplicant_initiate_eapol(wpa_s);
 	wpa_dbg(wpa_s, 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 */


 int wpa_supplicant_enabled_networks(struct wpa_config *conf)
 {
 	struct wpa_ssid *ssid = conf->ssid;
 	int count = 0;
 	while (ssid) {
 		if (!ssid->disabled)
 			count++;
 		ssid = ssid->next;
 	}
 	return count;
 }


 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
 				     struct wpa_ssid *ssid)
 {
 	while (ssid) {
 		if (!ssid->disabled)
 			break;
 		ssid = ssid->next;
 	}

 	/* ap_scan=2 mode - try to associate with each SSID. */
 	if (ssid == NULL) {
 		wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
 			"end of scan list - go back to beginning");
 		wpa_s->prev_scan_ssid = WILDCARD_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 = WILDCARD_SSID_SCAN;
 	}
 	wpa_supplicant_associate(wpa_s, NULL, ssid);
 }


 static int int_array_len(const int *a)
 {
 	int i;
 	for (i = 0; a && a[i]; i++)
 		;
 	return i;
 }


 static void int_array_concat(int **res, const int *a)
 {
 	int reslen, alen, i;
 	int *n;

 	reslen = int_array_len(*res);
 	alen = int_array_len(a);

 	n = os_realloc(*res, (reslen + alen + 1) * sizeof(int));
 	if (n == NULL) {
 		os_free(*res);
 		*res = NULL;
 		return;
 	}
 	for (i = 0; i <= alen; i++)
 		n[reslen + i] = a[i];
 	*res = n;
 }


 static int freq_cmp(const void *a, const void *b)
 {
 	int _a = *(int *) a;
 	int _b = *(int *) b;

 	if (_a == 0)
 		return 1;
 	if (_b == 0)
 		return -1;
 	return _a - _b;
 }


 static void int_array_sort_unique(int *a)
 {
 	int alen;
 	int i, j;

 	if (a == NULL)
 		return;

 	alen = int_array_len(a);
 	qsort(a, alen, sizeof(int), freq_cmp);

 	i = 0;
 	j = 1;
 	while (a[i] && a[j]) {
 		if (a[i] == a[j]) {
 			j++;
 			continue;
 		}
 		a[++i] = a[j++];
 	}
 	if (a[i])
 		i++;
 	a[i] = 0;
 }


 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
 				struct wpa_driver_scan_params *params)
 {
 	int ret;

 	wpa_supplicant_notify_scanning(wpa_s, 1);

 	if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
 		ret = ieee80211_sta_req_scan(wpa_s, params);
 	else
 		ret = wpa_drv_scan(wpa_s, params);

 	if (ret) {
 		wpa_supplicant_notify_scanning(wpa_s, 0);
 		wpas_notify_scan_done(wpa_s, 0);
 	} else
 		wpa_s->scan_runs++;

 	return ret;
 }


 static struct wpa_driver_scan_filter *
 wpa_supplicant_build_filter_ssids(struct wpa_config *conf, size_t *num_ssids)
 {
 	struct wpa_driver_scan_filter *ssids;
 	struct wpa_ssid *ssid;
 	size_t count;

 	*num_ssids = 0;
 	if (!conf->filter_ssids)
 		return NULL;

 	for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
 		if (ssid->ssid && ssid->ssid_len)
 			count++;
 	}
 	if (count == 0)
 		return NULL;
 	ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
 	if (ssids == NULL)
 		return NULL;

 	for (ssid = conf->ssid; ssid; ssid = ssid->next) {
 		if (!ssid->ssid || !ssid->ssid_len)
 			continue;
 		os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
 		ssids[*num_ssids].ssid_len = ssid->ssid_len;
 		(*num_ssids)++;
 	}

 	return ssids;
 }


 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 {
 	struct wpa_supplicant *wpa_s = eloop_ctx;
 	struct wpa_ssid *ssid;
 	int scan_req = 0, ret;
 	struct wpabuf *wps_ie = NULL;
 #ifdef CONFIG_WPS
 	int wps = 0;
 	enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 #endif /* CONFIG_WPS */
 	struct wpa_driver_scan_params params;
 	size_t max_ssids;
 	enum wpa_states prev_state;

 	if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 		wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
 		return;
 	}

 	if (wpa_s->disconnected && !wpa_s->scan_req) {
 		wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
 		return;
 	}

 	if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
 	    !wpa_s->scan_req) {
 		wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
 		wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 		return;
 	}

 	if (wpa_s->conf->ap_scan != 0 &&
 	    (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 		wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
 			"overriding ap_scan configuration");
 		wpa_s->conf->ap_scan = 0;
 		wpas_notify_ap_scan_changed(wpa_s);
 	}

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

 	if ((wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) ||
 	    wpa_s->conf->ap_scan == 2)
 		max_ssids = 1;
 	else {
 		max_ssids = wpa_s->max_scan_ssids;
 		if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 			max_ssids = WPAS_MAX_SCAN_SSIDS;
 	}

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

 	scan_req = wpa_s->scan_req;
 	wpa_s->scan_req = 0;

 	os_memset(&params, 0, sizeof(params));

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

 	/* Find the starting point from which to continue scanning */
 	ssid = wpa_s->conf->ssid;
 	if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 		while (ssid) {
 			if (ssid == wpa_s->prev_scan_ssid) {
 				ssid = ssid->next;
 				break;
 			}
 			ssid = ssid->next;
 		}
 	}

 	if (scan_req != 2 && (wpa_s->conf->ap_scan == 2 ||
 			      wpa_s->connect_without_scan)) {
 		wpa_s->connect_without_scan = 0;
 		wpa_supplicant_assoc_try(wpa_s, ssid);
 		return;
 	} else if (wpa_s->conf->ap_scan == 2) {
 		/*
 		 * User-initiated scan request in ap_scan == 2; scan with
 		 * wildcard SSID.
 		 */
 		ssid = NULL;
 	} else {
 		struct wpa_ssid *start = ssid, *tssid;
 		int freqs_set = 0;
 		if (ssid == NULL && max_ssids > 1)
 			ssid = wpa_s->conf->ssid;
 		while (ssid) {
 			if (!ssid->disabled && ssid->scan_ssid) {
 				wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 						  ssid->ssid, ssid->ssid_len);
 				params.ssids[params.num_ssids].ssid =
 					ssid->ssid;
 				params.ssids[params.num_ssids].ssid_len =
 					ssid->ssid_len;
 				params.num_ssids++;
 				if (params.num_ssids + 1 >= max_ssids)
 					break;
 			}
 			ssid = ssid->next;
 			if (ssid == start)
 				break;
 			if (ssid == NULL && max_ssids > 1 &&
 			    start != wpa_s->conf->ssid)
 				ssid = wpa_s->conf->ssid;
 		}

 		for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
 			if (tssid->disabled)
 				continue;
 			if ((params.freqs || !freqs_set) && tssid->scan_freq) {
 				int_array_concat(&params.freqs,
 						 tssid->scan_freq);
 			} else {
 				os_free(params.freqs);
 				params.freqs = NULL;
 			}
 			freqs_set = 1;
 		}
 		int_array_sort_unique(params.freqs);
 	}

 	if (ssid) {
 		wpa_s->prev_scan_ssid = ssid;
 		if (max_ssids > 1) {
 			wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
 				"the scan request");
 			params.num_ssids++;
 		}
 		wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for specific "
 			"SSID(s)");
 	} else {
 		wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 		params.num_ssids++;
 		wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 			"SSID");
 	}

 #ifdef CONFIG_P2P
 	wpa_s->wps->dev.p2p = 1;
 	if (!wps) {
 		wps = 1;
 		req_type = WPS_REQ_ENROLLEE_INFO;
 	}

 	if (params.freqs == NULL && wpa_s->p2p_in_provisioning &&
 	    wpa_s->go_params) {
 		/* Optimize provisioning state scan based on GO information */
 		if (wpa_s->p2p_in_provisioning < 5 &&
 		    wpa_s->go_params->freq > 0) {
 			wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
 				"preferred frequency %d MHz",
 				wpa_s->go_params->freq);
 			params.freqs = os_zalloc(2 * sizeof(int));
 			if (params.freqs)
 				params.freqs[0] = wpa_s->go_params->freq;
 		} else if (wpa_s->p2p_in_provisioning < 8 &&
 			   wpa_s->go_params->freq_list[0]) {
 			wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
 				"channels");
 			int_array_concat(&params.freqs,
 					 wpa_s->go_params->freq_list);
 			if (params.freqs)
 				int_array_sort_unique(params.freqs);
 		}
 		wpa_s->p2p_in_provisioning++;
 	}
 #endif /* CONFIG_P2P */

 #ifdef CONFIG_WPS
 	if (params.freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
 		/*
 		 * Optimize post-provisioning scan based on channel used
 		 * during provisioning.
 		 */
 		wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
 			"that was used during provisioning", wpa_s->wps_freq);
 		params.freqs = os_zalloc(2 * sizeof(int));
 		if (params.freqs)
 			params.freqs[0] = wpa_s->wps_freq;
 		wpa_s->after_wps--;
 	}

 	if (wps) {
 		wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
 						wpa_s->wps->uuid, req_type,
 						0, NULL);
 		if (wps_ie) {
 			params.extra_ies = wpabuf_head(wps_ie);
 			params.extra_ies_len = wpabuf_len(wps_ie);
 		}
 	}
 #endif /* CONFIG_WPS */

 #ifdef CONFIG_P2P
 	if (wps_ie) {
 		if (wpabuf_resize(&wps_ie, 100) == 0) {
 			wpas_p2p_scan_ie(wpa_s, wps_ie);
 			params.extra_ies = wpabuf_head(wps_ie);
 			params.extra_ies_len = wpabuf_len(wps_ie);
 		}
 	}
 #endif /* CONFIG_P2P */

 	if (params.freqs == NULL && wpa_s->next_scan_freqs) {
 		wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
 			"generated frequency list");
 		params.freqs = wpa_s->next_scan_freqs;
 	} else
 		os_free(wpa_s->next_scan_freqs);
 	wpa_s->next_scan_freqs = NULL;

 	params.filter_ssids = wpa_supplicant_build_filter_ssids(
 		wpa_s->conf, &params.num_filter_ssids);

 	ret = wpa_supplicant_trigger_scan(wpa_s, &params);

 	wpabuf_free(wps_ie);
 	os_free(params.freqs);
 	os_free(params.filter_ssids);

 	if (ret) {
 		wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
 		if (prev_state != wpa_s->wpa_state)
 			wpa_supplicant_set_state(wpa_s, prev_state);
 		wpa_supplicant_req_scan(wpa_s, 1, 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_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 			        "ensure that specific SSID scans occur");
 			return;
 		}
 	}

 	wpa_dbg(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_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
 	eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 }


 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
 				    int scanning)
 {
 	if (wpa_s->scanning != scanning) {
 		wpa_s->scanning = scanning;
 		wpas_notify_scanning(wpa_s);
 	}
 }


 static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
 {
 	int rate = 0;
 	const u8 *ie;
 	int i;

 	ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
 	for (i = 0; ie && i < ie[1]; i++) {
 		if ((ie[i + 2] & 0x7f) > rate)
 			rate = ie[i + 2] & 0x7f;
 	}

 	ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
 	for (i = 0; ie && i < ie[1]; i++) {
 		if ((ie[i + 2] & 0x7f) > rate)
 			rate = ie[i + 2] & 0x7f;
 	}

 	return rate;
 }


 const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
 {
 	const u8 *end, *pos;

 	pos = (const u8 *) (res + 1);
 	end = pos + res->ie_len;

 	while (pos + 1 < end) {
 		if (pos + 2 + pos[1] > end)
 			break;
 		if (pos[0] == ie)
 			return pos;
 		pos += 2 + pos[1];
 	}

 	return NULL;
 }


 const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
 				  u32 vendor_type)
 {
 	const u8 *end, *pos;

 	pos = (const u8 *) (res + 1);
 	end = pos + res->ie_len;

 	while (pos + 1 < end) {
 		if (pos + 2 + pos[1] > end)
 			break;
 		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 		    vendor_type == WPA_GET_BE32(&pos[2]))
 			return pos;
 		pos += 2 + pos[1];
 	}

 	return NULL;
 }


 struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
 					     u32 vendor_type)
 {
 	struct wpabuf *buf;
 	const u8 *end, *pos;

 	buf = wpabuf_alloc(res->ie_len);
 	if (buf == NULL)
 		return NULL;

 	pos = (const u8 *) (res + 1);
 	end = pos + res->ie_len;

 	while (pos + 1 < end) {
 		if (pos + 2 + pos[1] > end)
 			break;
 		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 		    vendor_type == WPA_GET_BE32(&pos[2]))
 			wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
 		pos += 2 + pos[1];
 	}

 	if (wpabuf_len(buf) == 0) {
 		wpabuf_free(buf);
 		buf = NULL;
 	}

 	return buf;
 }


 struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
 	const struct wpa_scan_res *res, u32 vendor_type)
 {
 	struct wpabuf *buf;
 	const u8 *end, *pos;

 	if (res->beacon_ie_len == 0)
 		return NULL;
 	buf = wpabuf_alloc(res->beacon_ie_len);
 	if (buf == NULL)
 		return NULL;

 	pos = (const u8 *) (res + 1);
 	pos += res->ie_len;
 	end = pos + res->beacon_ie_len;

 	while (pos + 1 < end) {
 		if (pos + 2 + pos[1] > end)
 			break;
 		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 		    vendor_type == WPA_GET_BE32(&pos[2]))
 			wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
 		pos += 2 + pos[1];
 	}

 	if (wpabuf_len(buf) == 0) {
 		wpabuf_free(buf);
 		buf = NULL;
 	}

 	return buf;
 }


 /* Compare function for sorting scan results. Return >0 if @b is considered
  * better. */
 static int wpa_scan_result_compar(const void *a, const void *b)
 {
 	struct wpa_scan_res **_wa = (void *) a;
 	struct wpa_scan_res **_wb = (void *) b;
 	struct wpa_scan_res *wa = *_wa;
 	struct wpa_scan_res *wb = *_wb;
 	int wpa_a, wpa_b, maxrate_a, maxrate_b;

 	/* WPA/WPA2 support preferred */
 	wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL ||
 		wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
 	wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL ||
 		wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;

 	if (wpa_b && !wpa_a)
 		return 1;
 	if (!wpa_b && wpa_a)
 		return -1;

 	/* privacy support preferred */
 	if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
 	    (wb->caps & IEEE80211_CAP_PRIVACY))
 		return 1;
 	if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
 	    (wb->caps & IEEE80211_CAP_PRIVACY) == 0)
 		return -1;

 	/* best/max rate preferred if signal level close enough XXX */
 	if ((wa->level && wb->level && abs(wb->level - wa->level) < 5) ||
 	    (wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
 		maxrate_a = wpa_scan_get_max_rate(wa);
 		maxrate_b = wpa_scan_get_max_rate(wb);
 		if (maxrate_a != maxrate_b)
 			return maxrate_b - maxrate_a;
 	}

 	/* use freq for channel preference */

 	/* all things being equal, use signal level; if signal levels are
 	 * identical, use quality values since some drivers may only report
 	 * that value and leave the signal level zero */
 	if (wb->level == wa->level)
 		return wb->qual - wa->qual;
 	return wb->level - wa->level;
 }


 #ifdef CONFIG_WPS
 /* Compare function for sorting scan results when searching a WPS AP for
  * provisioning. Return >0 if @b is considered better. */
 static int wpa_scan_result_wps_compar(const void *a, const void *b)
 {
 	struct wpa_scan_res **_wa = (void *) a;
 	struct wpa_scan_res **_wb = (void *) b;
 	struct wpa_scan_res *wa = *_wa;
 	struct wpa_scan_res *wb = *_wb;
 	int uses_wps_a, uses_wps_b;
 	struct wpabuf *wps_a, *wps_b;
 	int res;

 	/* Optimization - check WPS IE existence before allocated memory and
 	 * doing full reassembly. */
 	uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
 	uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
 	if (uses_wps_a && !uses_wps_b)
 		return -1;
 	if (!uses_wps_a && uses_wps_b)
 		return 1;

 	if (uses_wps_a && uses_wps_b) {
 		wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
 		wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
 		res = wps_ap_priority_compar(wps_a, wps_b);
 		wpabuf_free(wps_a);
 		wpabuf_free(wps_b);
 		if (res)
 			return res;
 	}

 	/*
 	 * Do not use current AP security policy as a sorting criteria during
 	 * WPS provisioning step since the AP may get reconfigured at the
 	 * completion of provisioning.
 	 */

 	/* all things being equal, use signal level; if signal levels are
 	 * identical, use quality values since some drivers may only report
 	 * that value and leave the signal level zero */
 	if (wb->level == wa->level)
 		return wb->qual - wa->qual;
 	return wb->level - wa->level;
 }
 #endif /* CONFIG_WPS */


 /**
  * wpa_supplicant_get_scan_results - Get scan results
  * @wpa_s: Pointer to wpa_supplicant data
  * @info: Information about what was scanned or %NULL if not available
  * @new_scan: Whether a new scan was performed
  * Returns: Scan results, %NULL on failure
  *
  * This function request the current scan results from the driver and updates
  * the local BSS list wpa_s->bss. The caller is responsible for freeing the
  * results with wpa_scan_results_free().
  */
 struct wpa_scan_results *
 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
 				struct scan_info *info, int new_scan)
 {
 	struct wpa_scan_results *scan_res;
 	size_t i;
 	int (*compar)(const void *, const void *) = wpa_scan_result_compar;

 	if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
 		scan_res = ieee80211_sta_get_scan_results(wpa_s);
 	else
 		scan_res = wpa_drv_get_scan_results2(wpa_s);
 	if (scan_res == NULL) {
 		wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
 		return NULL;
 	}

 #ifdef CONFIG_WPS
 	if (wpas_wps_in_progress(wpa_s)) {
 		wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
 			"provisioning rules");
 		compar = wpa_scan_result_wps_compar;
 	}
 #endif /* CONFIG_WPS */

 	qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
 	      compar);

 	wpa_bss_update_start(wpa_s);
 	for (i = 0; i < scan_res->num; i++)
 		wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
 	wpa_bss_update_end(wpa_s, info, new_scan);

 	return scan_res;
 }


 int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
 {
 	struct wpa_scan_results *scan_res;
 	scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
 	if (scan_res == NULL)
 		return -1;
 	wpa_scan_results_free(scan_res);

 	return 0;
 }


 void wpa_scan_results_free(struct wpa_scan_results *res)
 {
 	size_t i;

 	if (res == NULL)
 		return;

 	for (i = 0; i < res->num; i++)
 		os_free(res->res[i]);
 	os_free(res->res);
 	os_free(res);
 }
	/*
	* WPA Supplicant - Scanning
	* Copyright (c) 2003-2010, 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 "utils/includes.h"

	#include "utils/common.h"
	#include "utils/eloop.h"
	#include "common/ieee802_11_defs.h"
	#include "config.h"
	#include "wpa_supplicant_i.h"
	#include "driver_i.h"
	#include "mlme.h"
	#include "wps_supplicant.h"
	#include "p2p_supplicant.h"
	#include "p2p/p2p.h"
	#include "notify.h"
	#include "bss.h"
	#include "scan.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;
	if (wpa_s->current_ssid != NULL)
	wpas_notify_network_changed(wpa_s);
	}
	wpa_supplicant_initiate_eapol(wpa_s);
	wpa_dbg(wpa_s, 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 */


	int wpa_supplicant_enabled_networks(struct wpa_config *conf)
	{
	struct wpa_ssid *ssid = conf->ssid;
	int count = 0;
	while (ssid) {
	if (!ssid->disabled)
	count++;
	ssid = ssid->next;
	}
	return count;
	}


	static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
	struct wpa_ssid *ssid)
	{
	while (ssid) {
	if (!ssid->disabled)
	break;
	ssid = ssid->next;
	}

	/* ap_scan=2 mode - try to associate with each SSID. */
	if (ssid == NULL) {
	wpa_dbg(wpa_s, MSG_DEBUG, "wpa_supplicant_assoc_try: Reached "
	"end of scan list - go back to beginning");
	wpa_s->prev_scan_ssid = WILDCARD_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 = WILDCARD_SSID_SCAN;
	}
	wpa_supplicant_associate(wpa_s, NULL, ssid);
	}


	static int int_array_len(const int *a)
	{
	int i;
	for (i = 0; a && a[i]; i++)
	;
	return i;
	}


	static void int_array_concat(int *res, const int a)
	{
	int reslen, alen, i;
	int *n;

	reslen = int_array_len(*res);
	alen = int_array_len(a);

	n = os_realloc(res, (reslen + alen + 1) sizeof(int));
	if (n == NULL) {
	os_free(*res);
	*res = NULL;
	return;
	}
	for (i = 0; i <= alen; i++)
	n[reslen + i] = a[i];
	*res = n;
	}


	static int freq_cmp(const void a, const void b)
	{
	int _a = (int ) a;
	int _b = (int ) b;

	if (_a == 0)
	return 1;
	if (_b == 0)
	return -1;
	return _a - _b;
	}


	static void int_array_sort_unique(int *a)
	{
	int alen;
	int i, j;

	if (a == NULL)
	return;

	alen = int_array_len(a);
	qsort(a, alen, sizeof(int), freq_cmp);

	i = 0;
	j = 1;
	while (a[i] && a[j]) {
	if (a[i] == a[j]) {
	j++;
	continue;
	}
	a[++i] = a[j++];
	}
	if (a[i])
	i++;
	a[i] = 0;
	}


	int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
	struct wpa_driver_scan_params *params)
	{
	int ret;

	wpa_supplicant_notify_scanning(wpa_s, 1);

	if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
	ret = ieee80211_sta_req_scan(wpa_s, params);
	else
	ret = wpa_drv_scan(wpa_s, params);

	if (ret) {
	wpa_supplicant_notify_scanning(wpa_s, 0);
	wpas_notify_scan_done(wpa_s, 0);
	} else
	wpa_s->scan_runs++;

	return ret;
	}


	static struct wpa_driver_scan_filter *
	wpa_supplicant_build_filter_ssids(struct wpa_config conf, size_t num_ssids)
	{
	struct wpa_driver_scan_filter *ssids;
	struct wpa_ssid *ssid;
	size_t count;

	*num_ssids = 0;
	if (!conf->filter_ssids)
	return NULL;

	for (count = 0, ssid = conf->ssid; ssid; ssid = ssid->next) {
	if (ssid->ssid && ssid->ssid_len)
	count++;
	}
	if (count == 0)
	return NULL;
	ssids = os_zalloc(count * sizeof(struct wpa_driver_scan_filter));
	if (ssids == NULL)
	return NULL;

	for (ssid = conf->ssid; ssid; ssid = ssid->next) {
	if (!ssid->ssid \|\| !ssid->ssid_len)
	continue;
	os_memcpy(ssids[*num_ssids].ssid, ssid->ssid, ssid->ssid_len);
	ssids[*num_ssids].ssid_len = ssid->ssid_len;
	(*num_ssids)++;
	}

	return ssids;
	}


	static void wpa_supplicant_scan(void eloop_ctx, void timeout_ctx)
	{
	struct wpa_supplicant *wpa_s = eloop_ctx;
	struct wpa_ssid *ssid;
	int scan_req = 0, ret;
	struct wpabuf *wps_ie = NULL;
	#ifdef CONFIG_WPS
	int wps = 0;
	enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
	#endif /* CONFIG_WPS */
	struct wpa_driver_scan_params params;
	size_t max_ssids;
	enum wpa_states prev_state;

	if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
	wpa_dbg(wpa_s, MSG_DEBUG, "Skip scan - interface disabled");
	return;
	}

	if (wpa_s->disconnected && !wpa_s->scan_req) {
	wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
	return;
	}

	if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
	!wpa_s->scan_req) {
	wpa_dbg(wpa_s, MSG_DEBUG, "No enabled networks - do not scan");
	wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
	return;
	}

	if (wpa_s->conf->ap_scan != 0 &&
	(wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
	wpa_dbg(wpa_s, MSG_DEBUG, "Using wired authentication - "
	"overriding ap_scan configuration");
	wpa_s->conf->ap_scan = 0;
	wpas_notify_ap_scan_changed(wpa_s);
	}

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

	if ((wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) \|\|
	wpa_s->conf->ap_scan == 2)
	max_ssids = 1;
	else {
	max_ssids = wpa_s->max_scan_ssids;
	if (max_ssids > WPAS_MAX_SCAN_SSIDS)
	max_ssids = WPAS_MAX_SCAN_SSIDS;
	}

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

	scan_req = wpa_s->scan_req;
	wpa_s->scan_req = 0;

	os_memset(&params, 0, sizeof(params));

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

	/* Find the starting point from which to continue scanning */
	ssid = wpa_s->conf->ssid;
	if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
	while (ssid) {
	if (ssid == wpa_s->prev_scan_ssid) {
	ssid = ssid->next;
	break;
	}
	ssid = ssid->next;
	}
	}

	if (scan_req != 2 && (wpa_s->conf->ap_scan == 2 \|\|
	wpa_s->connect_without_scan)) {
	wpa_s->connect_without_scan = 0;
	wpa_supplicant_assoc_try(wpa_s, ssid);
	return;
	} else if (wpa_s->conf->ap_scan == 2) {
	/*
	* User-initiated scan request in ap_scan == 2; scan with
	* wildcard SSID.
	*/
	ssid = NULL;
	} else {
	struct wpa_ssid start = ssid, tssid;
	int freqs_set = 0;
	if (ssid == NULL && max_ssids > 1)
	ssid = wpa_s->conf->ssid;
	while (ssid) {
	if (!ssid->disabled && ssid->scan_ssid) {
	wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
	ssid->ssid, ssid->ssid_len);
	params.ssids[params.num_ssids].ssid =
	ssid->ssid;
	params.ssids[params.num_ssids].ssid_len =
	ssid->ssid_len;
	params.num_ssids++;
	if (params.num_ssids + 1 >= max_ssids)
	break;
	}
	ssid = ssid->next;
	if (ssid == start)
	break;
	if (ssid == NULL && max_ssids > 1 &&
	start != wpa_s->conf->ssid)
	ssid = wpa_s->conf->ssid;
	}

	for (tssid = wpa_s->conf->ssid; tssid; tssid = tssid->next) {
	if (tssid->disabled)
	continue;
	if ((params.freqs \|\| !freqs_set) && tssid->scan_freq) {
	int_array_concat(&params.freqs,
	tssid->scan_freq);
	} else {
	os_free(params.freqs);
	params.freqs = NULL;
	}
	freqs_set = 1;
	}
	int_array_sort_unique(params.freqs);
	}

	if (ssid) {
	wpa_s->prev_scan_ssid = ssid;
	if (max_ssids > 1) {
	wpa_dbg(wpa_s, MSG_DEBUG, "Include wildcard SSID in "
	"the scan request");
	params.num_ssids++;
	}
	wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for specific "
	"SSID(s)");
	} else {
	wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
	params.num_ssids++;
	wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
	"SSID");
	}

	#ifdef CONFIG_P2P
	wpa_s->wps->dev.p2p = 1;
	if (!wps) {
	wps = 1;
	req_type = WPS_REQ_ENROLLEE_INFO;
	}

	if (params.freqs == NULL && wpa_s->p2p_in_provisioning &&
	wpa_s->go_params) {
	/* Optimize provisioning state scan based on GO information */
	if (wpa_s->p2p_in_provisioning < 5 &&
	wpa_s->go_params->freq > 0) {
	wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only GO "
	"preferred frequency %d MHz",
	wpa_s->go_params->freq);
	params.freqs = os_zalloc(2 * sizeof(int));
	if (params.freqs)
	params.freqs[0] = wpa_s->go_params->freq;
	} else if (wpa_s->p2p_in_provisioning < 8 &&
	wpa_s->go_params->freq_list[0]) {
	wpa_dbg(wpa_s, MSG_DEBUG, "P2P: Scan only common "
	"channels");
	int_array_concat(&params.freqs,
	wpa_s->go_params->freq_list);
	if (params.freqs)
	int_array_sort_unique(params.freqs);
	}
	wpa_s->p2p_in_provisioning++;
	}
	#endif /* CONFIG_P2P */

	#ifdef CONFIG_WPS
	if (params.freqs == NULL && wpa_s->after_wps && wpa_s->wps_freq) {
	/*
	* Optimize post-provisioning scan based on channel used
	* during provisioning.
	*/
	wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Scan only frequency %u MHz "
	"that was used during provisioning", wpa_s->wps_freq);
	params.freqs = os_zalloc(2 * sizeof(int));
	if (params.freqs)
	params.freqs[0] = wpa_s->wps_freq;
	wpa_s->after_wps--;
	}

	if (wps) {
	wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
	wpa_s->wps->uuid, req_type,
	0, NULL);
	if (wps_ie) {
	params.extra_ies = wpabuf_head(wps_ie);
	params.extra_ies_len = wpabuf_len(wps_ie);
	}
	}
	#endif /* CONFIG_WPS */

	#ifdef CONFIG_P2P
	if (wps_ie) {
	if (wpabuf_resize(&wps_ie, 100) == 0) {
	wpas_p2p_scan_ie(wpa_s, wps_ie);
	params.extra_ies = wpabuf_head(wps_ie);
	params.extra_ies_len = wpabuf_len(wps_ie);
	}
	}
	#endif /* CONFIG_P2P */

	if (params.freqs == NULL && wpa_s->next_scan_freqs) {
	wpa_dbg(wpa_s, MSG_DEBUG, "Optimize scan based on previously "
	"generated frequency list");
	params.freqs = wpa_s->next_scan_freqs;
	} else
	os_free(wpa_s->next_scan_freqs);
	wpa_s->next_scan_freqs = NULL;

	params.filter_ssids = wpa_supplicant_build_filter_ssids(
	wpa_s->conf, &params.num_filter_ssids);

	ret = wpa_supplicant_trigger_scan(wpa_s, &params);

	wpabuf_free(wps_ie);
	os_free(params.freqs);
	os_free(params.filter_ssids);

	if (ret) {
	wpa_msg(wpa_s, MSG_WARNING, "Failed to initiate AP scan");
	if (prev_state != wpa_s->wpa_state)
	wpa_supplicant_set_state(wpa_s, prev_state);
	wpa_supplicant_req_scan(wpa_s, 1, 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_dbg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
	"ensure that specific SSID scans occur");
	return;
	}
	}

	wpa_dbg(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_dbg(wpa_s, MSG_DEBUG, "Cancelling scan request");
	eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
	}


	void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
	int scanning)
	{
	if (wpa_s->scanning != scanning) {
	wpa_s->scanning = scanning;
	wpas_notify_scanning(wpa_s);
	}
	}


	static int wpa_scan_get_max_rate(const struct wpa_scan_res *res)
	{
	int rate = 0;
	const u8 *ie;
	int i;

	ie = wpa_scan_get_ie(res, WLAN_EID_SUPP_RATES);
	for (i = 0; ie && i < ie[1]; i++) {
	if ((ie[i + 2] & 0x7f) > rate)
	rate = ie[i + 2] & 0x7f;
	}

	ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
	for (i = 0; ie && i < ie[1]; i++) {
	if ((ie[i + 2] & 0x7f) > rate)
	rate = ie[i + 2] & 0x7f;
	}

	return rate;
	}


	const u8 * wpa_scan_get_ie(const struct wpa_scan_res *res, u8 ie)
	{
	const u8 end, pos;

	pos = (const u8 *) (res + 1);
	end = pos + res->ie_len;

	while (pos + 1 < end) {
	if (pos + 2 + pos[1] > end)
	break;
	if (pos[0] == ie)
	return pos;
	pos += 2 + pos[1];
	}

	return NULL;
	}


	const u8 * wpa_scan_get_vendor_ie(const struct wpa_scan_res *res,
	u32 vendor_type)
	{
	const u8 end, pos;

	pos = (const u8 *) (res + 1);
	end = pos + res->ie_len;

	while (pos + 1 < end) {
	if (pos + 2 + pos[1] > end)
	break;
	if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
	vendor_type == WPA_GET_BE32(&pos[2]))
	return pos;
	pos += 2 + pos[1];
	}

	return NULL;
	}


	struct wpabuf * wpa_scan_get_vendor_ie_multi(const struct wpa_scan_res *res,
	u32 vendor_type)
	{
	struct wpabuf *buf;
	const u8 end, pos;

	buf = wpabuf_alloc(res->ie_len);
	if (buf == NULL)
	return NULL;

	pos = (const u8 *) (res + 1);
	end = pos + res->ie_len;

	while (pos + 1 < end) {
	if (pos + 2 + pos[1] > end)
	break;
	if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
	vendor_type == WPA_GET_BE32(&pos[2]))
	wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
	pos += 2 + pos[1];
	}

	if (wpabuf_len(buf) == 0) {
	wpabuf_free(buf);
	buf = NULL;
	}

	return buf;
	}


	struct wpabuf * wpa_scan_get_vendor_ie_multi_beacon(
	const struct wpa_scan_res *res, u32 vendor_type)
	{
	struct wpabuf *buf;
	const u8 end, pos;

	if (res->beacon_ie_len == 0)
	return NULL;
	buf = wpabuf_alloc(res->beacon_ie_len);
	if (buf == NULL)
	return NULL;

	pos = (const u8 *) (res + 1);
	pos += res->ie_len;
	end = pos + res->beacon_ie_len;

	while (pos + 1 < end) {
	if (pos + 2 + pos[1] > end)
	break;
	if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
	vendor_type == WPA_GET_BE32(&pos[2]))
	wpabuf_put_data(buf, pos + 2 + 4, pos[1] - 4);
	pos += 2 + pos[1];
	}

	if (wpabuf_len(buf) == 0) {
	wpabuf_free(buf);
	buf = NULL;
	}

	return buf;
	}


	/* Compare function for sorting scan results. Return >0 if @b is considered
	* better. */
	static int wpa_scan_result_compar(const void a, const void b)
	{
	struct wpa_scan_res *_wa = (void ) a;
	struct wpa_scan_res *_wb = (void ) b;
	struct wpa_scan_res wa = _wa;
	struct wpa_scan_res wb = _wb;
	int wpa_a, wpa_b, maxrate_a, maxrate_b;

	/* WPA/WPA2 support preferred */
	wpa_a = wpa_scan_get_vendor_ie(wa, WPA_IE_VENDOR_TYPE) != NULL \|\|
	wpa_scan_get_ie(wa, WLAN_EID_RSN) != NULL;
	wpa_b = wpa_scan_get_vendor_ie(wb, WPA_IE_VENDOR_TYPE) != NULL \|\|
	wpa_scan_get_ie(wb, WLAN_EID_RSN) != NULL;

	if (wpa_b && !wpa_a)
	return 1;
	if (!wpa_b && wpa_a)
	return -1;

	/* privacy support preferred */
	if ((wa->caps & IEEE80211_CAP_PRIVACY) == 0 &&
	(wb->caps & IEEE80211_CAP_PRIVACY))
	return 1;
	if ((wa->caps & IEEE80211_CAP_PRIVACY) &&
	(wb->caps & IEEE80211_CAP_PRIVACY) == 0)
	return -1;

	/* best/max rate preferred if signal level close enough XXX */
	if ((wa->level && wb->level && abs(wb->level - wa->level) < 5) \|\|
	(wa->qual && wb->qual && abs(wb->qual - wa->qual) < 10)) {
	maxrate_a = wpa_scan_get_max_rate(wa);
	maxrate_b = wpa_scan_get_max_rate(wb);
	if (maxrate_a != maxrate_b)
	return maxrate_b - maxrate_a;
	}

	/* use freq for channel preference */

	/* all things being equal, use signal level; if signal levels are
	* identical, use quality values since some drivers may only report
	* that value and leave the signal level zero */
	if (wb->level == wa->level)
	return wb->qual - wa->qual;
	return wb->level - wa->level;
	}


	#ifdef CONFIG_WPS
	/* Compare function for sorting scan results when searching a WPS AP for
	* provisioning. Return >0 if @b is considered better. */
	static int wpa_scan_result_wps_compar(const void a, const void b)
	{
	struct wpa_scan_res *_wa = (void ) a;
	struct wpa_scan_res *_wb = (void ) b;
	struct wpa_scan_res wa = _wa;
	struct wpa_scan_res wb = _wb;
	int uses_wps_a, uses_wps_b;
	struct wpabuf wps_a, wps_b;
	int res;

	/* Optimization - check WPS IE existence before allocated memory and
	* doing full reassembly. */
	uses_wps_a = wpa_scan_get_vendor_ie(wa, WPS_IE_VENDOR_TYPE) != NULL;
	uses_wps_b = wpa_scan_get_vendor_ie(wb, WPS_IE_VENDOR_TYPE) != NULL;
	if (uses_wps_a && !uses_wps_b)
	return -1;
	if (!uses_wps_a && uses_wps_b)
	return 1;

	if (uses_wps_a && uses_wps_b) {
	wps_a = wpa_scan_get_vendor_ie_multi(wa, WPS_IE_VENDOR_TYPE);
	wps_b = wpa_scan_get_vendor_ie_multi(wb, WPS_IE_VENDOR_TYPE);
	res = wps_ap_priority_compar(wps_a, wps_b);
	wpabuf_free(wps_a);
	wpabuf_free(wps_b);
	if (res)
	return res;
	}

	/*
	* Do not use current AP security policy as a sorting criteria during
	* WPS provisioning step since the AP may get reconfigured at the
	* completion of provisioning.
	*/

	/* all things being equal, use signal level; if signal levels are
	* identical, use quality values since some drivers may only report
	* that value and leave the signal level zero */
	if (wb->level == wa->level)
	return wb->qual - wa->qual;
	return wb->level - wa->level;
	}
	#endif /* CONFIG_WPS */


	/**
	* wpa_supplicant_get_scan_results - Get scan results
	* @wpa_s: Pointer to wpa_supplicant data
	* @info: Information about what was scanned or %NULL if not available
	* @new_scan: Whether a new scan was performed
	* Returns: Scan results, %NULL on failure
	*
	* This function request the current scan results from the driver and updates
	* the local BSS list wpa_s->bss. The caller is responsible for freeing the
	* results with wpa_scan_results_free().
	*/
	struct wpa_scan_results *
	wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
	struct scan_info *info, int new_scan)
	{
	struct wpa_scan_results *scan_res;
	size_t i;
	int (compar)(const void , const void *) = wpa_scan_result_compar;

	if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME)
	scan_res = ieee80211_sta_get_scan_results(wpa_s);
	else
	scan_res = wpa_drv_get_scan_results2(wpa_s);
	if (scan_res == NULL) {
	wpa_dbg(wpa_s, MSG_DEBUG, "Failed to get scan results");
	return NULL;
	}

	#ifdef CONFIG_WPS
	if (wpas_wps_in_progress(wpa_s)) {
	wpa_dbg(wpa_s, MSG_DEBUG, "WPS: Order scan results with WPS "
	"provisioning rules");
	compar = wpa_scan_result_wps_compar;
	}
	#endif /* CONFIG_WPS */

	qsort(scan_res->res, scan_res->num, sizeof(struct wpa_scan_res *),
	compar);

	wpa_bss_update_start(wpa_s);
	for (i = 0; i < scan_res->num; i++)
	wpa_bss_update_scan_res(wpa_s, scan_res->res[i]);
	wpa_bss_update_end(wpa_s, info, new_scan);

	return scan_res;
	}


	int wpa_supplicant_update_scan_results(struct wpa_supplicant *wpa_s)
	{
	struct wpa_scan_results *scan_res;
	scan_res = wpa_supplicant_get_scan_results(wpa_s, NULL, 0);
	if (scan_res == NULL)
	return -1;
	wpa_scan_results_free(scan_res);

	return 0;
	}


	void wpa_scan_results_free(struct wpa_scan_results *res)
	{
	size_t i;

	if (res == NULL)
	return;

	for (i = 0; i < res->num; i++)
	os_free(res->res[i]);
	os_free(res->res);
	os_free(res);
	}