wifi: Allow max number of scan entries

Do no limit the scan entries to 4 (G_SUPPLICANT_MAX_FAST_SCAN)
but use the limit given by the driver. The limit is given by wpa_s.
If the supplicant does not return the limit, then use 4 as a max
value.

3 files changed, 85 insertions, 24 deletions

diff --git a/gsupplicant/gsupplicant.h b/gsupplicant/gsupplicant.h
index 883de7f4..5dc53642 100644
--- a/gsupplicant/gsupplicant.h
+++ b/gsupplicant/gsupplicant.h
@@ -73,8 +73,6 @@ extern "C" {
 #define G_SUPPLICANT_PAIRWISE_TKIP	(1 << 1)
 #define G_SUPPLICANT_PAIRWISE_CCMP	(1 << 2)
 
-#define G_SUPPLICANT_MAX_FAST_SCAN	4
-
 #define G_SUPPLICANT_WPS_CONFIGURED     (1 << 0)
 #define G_SUPPLICANT_WPS_PBC            (1 << 1)
 #define G_SUPPLICANT_WPS_PIN            (1 << 2)
@@ -139,15 +137,26 @@ struct _GSupplicantSSID {
 
 typedef struct _GSupplicantSSID GSupplicantSSID;
 
+/*
+ * Max number of SSIDs that can be scanned.
+ * In wpa_s 0.7x the limit is 4.
+ * In wps_s 0.8 or later it is 16.
+ * The value is only used if wpa_supplicant does not return any max limit
+ * for number of scannable SSIDs.
+ */
+#define WPAS_MAX_SCAN_SSIDS 4
+
+struct scan_ssid {
+	unsigned char ssid[32];
+	uint8_t ssid_len;
+};
+
 struct _GSupplicantScanParams {
-	struct scan_ssid {
-		unsigned char ssid[32];
-		uint8_t ssid_len;
-	} ssids[G_SUPPLICANT_MAX_FAST_SCAN];
+	GSList *ssids;
 
 	uint8_t num_ssids;
 
-	uint16_t freqs[G_SUPPLICANT_MAX_FAST_SCAN];
+	uint16_t *freqs;
 };
 
 typedef struct _GSupplicantScanParams GSupplicantScanParams;
@@ -250,6 +259,14 @@ typedef struct _GSupplicantCallbacks GSupplicantCallbacks;
 int g_supplicant_register(const GSupplicantCallbacks *callbacks);
 void g_supplicant_unregister(const GSupplicantCallbacks *callbacks);
 
+static inline
+void g_supplicant_free_scan_params(GSupplicantScanParams *scan_params)
+{
+	g_slist_free_full(scan_params->ssids, g_free);
+	g_free(scan_params->freqs);
+	g_free(scan_params);
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/gsupplicant/supplicant.c b/gsupplicant/supplicant.c
index 58d40c13..867fa028 100644
--- a/gsupplicant/supplicant.c
+++ b/gsupplicant/supplicant.c
@@ -742,6 +742,9 @@ unsigned int g_supplicant_interface_get_max_scan_ssids(
 	if (interface == NULL)
 		return 0;
 
+	if (interface->max_scan_ssids == 0)
+		return WPAS_MAX_SCAN_SSIDS;
+
 	return interface->max_scan_ssids;
 }
 
@@ -2618,7 +2621,7 @@ static void interface_scan_result(const char *error,
 	}
 
 	if (data != NULL && data->scan_params != NULL)
-		g_free(data->scan_params);
+		g_supplicant_free_scan_params(data->scan_params);
 
 	dbus_free(data);
 }
@@ -2643,7 +2646,7 @@ static void add_scan_frequencies(DBusMessageIter *iter,
 	unsigned int freq;
 	int i;
 
-	for (i = 0; i < G_SUPPLICANT_MAX_FAST_SCAN; i++) {
+	for (i = 0; i < scan_data->num_ssids; i++) {
 		freq = scan_data->freqs[i];
 		if (!freq)
 			break;
@@ -2668,11 +2671,13 @@ static void append_ssid(DBusMessageIter *iter,
 static void append_ssids(DBusMessageIter *iter, void *user_data)
 {
 	GSupplicantScanParams *scan_data = user_data;
-	int i;
+	GSList *list;
 
-	for (i = 0; i < scan_data->num_ssids; i++)
-		append_ssid(iter, scan_data->ssids[i].ssid,
-					scan_data->ssids[i].ssid_len);
+	for (list = scan_data->ssids; list; list = list->next) {
+		struct scan_ssid *scan_ssid = list->data;
+
+		append_ssid(iter, scan_ssid->ssid, scan_ssid->ssid_len);
+	}
 }
 
 static void supplicant_add_scan_frequency(DBusMessageIter *dict,
@@ -2683,7 +2688,7 @@ static void supplicant_add_scan_frequency(DBusMessageIter *dict,
 	DBusMessageIter entry, value, array;
 	const char *key = "Channels";
 
-	if (scan_params->freqs[0] != 0) {
+	if (scan_params->freqs && scan_params->freqs[0] != 0) {
 		dbus_message_iter_open_container(dict, DBUS_TYPE_DICT_ENTRY,
 						NULL, &entry);
 
diff --git a/plugins/wifi.c b/plugins/wifi.c
index 6e6bbca7..2f1f7a66 100644
--- a/plugins/wifi.c
+++ b/plugins/wifi.c
@@ -495,6 +495,7 @@ static int add_scan_param(gchar *hex_ssid, int freq,
 			int driver_max_scan_ssids)
 {
 	unsigned int i;
+	struct scan_ssid *scan_ssid;
 
 	if (driver_max_scan_ssids > scan_data->num_ssids && hex_ssid != NULL) {
 		gchar *ssid;
@@ -510,15 +511,44 @@ static int add_scan_param(gchar *hex_ssid, int freq,
 			ssid[j++] = hex;
 		}
 
-		memcpy(scan_data->ssids[scan_data->num_ssids].ssid, ssid, j);
-		scan_data->ssids[scan_data->num_ssids].ssid_len = j;
+		scan_ssid = g_try_new(struct scan_ssid, 1);
+		if (scan_ssid == NULL) {
+			g_free(ssid);
+			return -ENOMEM;
+		}
+
+		memcpy(scan_ssid->ssid, ssid, j);
+		scan_ssid->ssid_len = j;
+		scan_data->ssids = g_slist_prepend(scan_data->ssids,
+								scan_ssid);
+
 		scan_data->num_ssids++;
 
 		g_free(ssid);
+	} else
+		return -EINVAL;
+
+	scan_data->ssids = g_slist_reverse(scan_data->ssids);
+
+	if (scan_data->freqs == NULL) {
+		scan_data->freqs = g_try_malloc0(sizeof(uint16_t) *
+						scan_data->num_ssids);
+		if (scan_data->freqs == NULL) {
+			g_slist_free_full(scan_data->ssids, g_free);
+			return -ENOMEM;
+		}
+	} else {
+		scan_data->freqs = g_try_realloc(scan_data->freqs,
+				sizeof(uint16_t) * scan_data->num_ssids);
+		if (scan_data->freqs == NULL) {
+			g_slist_free_full(scan_data->ssids, g_free);
+			return -ENOMEM;
+		}
+		scan_data->freqs[scan_data->num_ssids - 1] = 0;
 	}
 
 	/* Don't add duplicate entries */
-	for (i = 0; i < G_SUPPLICANT_MAX_FAST_SCAN; i++) {
+	for (i = 0; i < scan_data->num_ssids; i++) {
 		if (scan_data->freqs[i] == 0) {
 			scan_data->freqs[i] = freq;
 			break;
@@ -639,8 +669,7 @@ static int get_latest_connections(int max_ssids,
 
 	g_strfreev(services);
 
-	num_ssids = num_ssids > G_SUPPLICANT_MAX_FAST_SCAN ?
-		G_SUPPLICANT_MAX_FAST_SCAN : num_ssids;
+	num_ssids = num_ssids > max_ssids ? max_ssids : num_ssids;
 
 	iter = g_sequence_get_begin_iter(latest_list);
 
@@ -690,7 +719,7 @@ static int wifi_scan_fast(struct connman_device *device)
 
 	ret = get_latest_connections(driver_max_ssids, scan_params);
 	if (ret <= 0) {
-		g_free(scan_params);
+		g_supplicant_free_scan_params(scan_params);
 		return wifi_scan(device);
 	}
 
@@ -702,7 +731,7 @@ static int wifi_scan_fast(struct connman_device *device)
 	if (ret == 0)
 		connman_device_set_scanning(device, TRUE);
 	else {
-		g_free(scan_params);
+		g_supplicant_free_scan_params(scan_params);
 		connman_device_unref(device);
 	}
 
@@ -715,6 +744,7 @@ static int wifi_scan_hidden(struct connman_device *device,
 {
 	struct wifi_data *wifi = connman_device_get_data(device);
 	GSupplicantScanParams *scan_params = NULL;
+	struct scan_ssid *scan_ssid;
 	struct hidden_params *hidden;
 	int ret;
 
@@ -729,8 +759,17 @@ static int wifi_scan_hidden(struct connman_device *device,
 	scan_params = g_try_malloc0(sizeof(GSupplicantScanParams));
 	if (scan_params == NULL)
 		return -ENOMEM;
-	memcpy(scan_params->ssids[0].ssid, ssid, ssid_len);
-	scan_params->ssids[0].ssid_len = ssid_len;
+
+	scan_ssid = g_try_new(struct scan_ssid, 1);
+	if (scan_ssid == NULL) {
+		g_free(scan_params);
+		return -ENOMEM;
+	}
+
+	memcpy(scan_ssid->ssid, ssid, ssid_len);
+	scan_ssid->ssid_len = ssid_len;
+	scan_params->ssids = g_slist_prepend(scan_params->ssids, scan_ssid);
+
 	scan_params->num_ssids = 1;
 
 	hidden = g_try_new0(struct hidden_params, 1);
@@ -753,7 +792,7 @@ static int wifi_scan_hidden(struct connman_device *device,
 		connman_device_set_scanning(device, TRUE);
 	else {
 		connman_device_unref(device);
-		g_free(scan_params);
+		g_supplicant_free_scan_params(scan_params);
 		hidden_free(wifi->hidden);
 		wifi->hidden = NULL;
 	}