Re-initialize hostapd/wpa_supplicant git repository based on 0.6.3 release

src/drivers/scan_helpers.c

@@ -0,0 +1,148 @@
+/*
+ * WPA Supplicant - Helper functions for scan result processing
+ * Copyright (c) 2007, 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 "drivers/driver.h"
+#include "ieee802_11_defs.h"
+
+
+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;
+}
+
+
+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] > rate)
+			rate = ie[i + 2];
+	}
+
+	ie = wpa_scan_get_ie(res, WLAN_EID_EXT_SUPP_RATES);
+	for (i = 0; ie && i < ie[1]; i++) {
+		if (ie[i + 2] > rate)
+			rate = ie[i + 2];
+	}
+
+	return rate;
+}
+
+
+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);
+}
+
+
+/* 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 */
+	maxrate_a = wpa_scan_get_max_rate(wa);
+	maxrate_b = wpa_scan_get_max_rate(wb);
+	if (maxrate_a != maxrate_b && abs(wb->level - wa->level) < 5)
+		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;
+}
+
+
+void wpa_scan_sort_results(struct wpa_scan_results *res)
+{
+	qsort(res->res, res->num, sizeof(struct wpa_scan_res *),
+	      wpa_scan_result_compar);
+}