[PATCH v3 4/8] core: adapter: Add parameter parsing to SetDiscoveryFilter

[Jakub Pawlowski <jpawlowski@google.com>]

This patch adds parameter parsing, and basic internal logic checks to
SetDiscoveryFilter method.
---
 src/adapter.c | 179 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 179 insertions(+)

diff --git a/src/adapter.c b/src/adapter.c
index 17acb94..47333b8 100644
--- a/src/adapter.c
+++ b/src/adapter.c
@@ -90,6 +90,10 @@
 
 #define SCAN_TYPE_BREDR (1 << BDADDR_BREDR)
 #define SCAN_TYPE_LE ((1 << BDADDR_LE_PUBLIC) | (1 << BDADDR_LE_RANDOM))
+#define SCAN_TYPE_DUAL (SCAN_TYPE_BREDR | SCAN_TYPE_LE)
+
+#define	DISTANCE_VAL_INVALID	0x7FFF
+#define	PATHLOSS_MAX 137
 
 static DBusConnection *dbus_conn = NULL;
 
@@ -144,6 +148,13 @@ struct conn_param {
 	uint16_t timeout;
 };
 
+struct discovery_filter {
+	uint8_t type;
+	uint16_t pathloss;
+	int16_t rssi;
+	GSList *uuids;
+};
+
 struct watch_client {
 	struct btd_adapter *adapter;
 	char *owner;
@@ -1759,9 +1770,177 @@ static DBusMessage *start_discovery(DBusConnection *conn,
 	return dbus_message_new_method_return(msg);
 }
 
+static bool parse_discovery_filter_entry(char *key, DBusMessageIter *value,
+				      GSList **uuids, int16_t *rssi,
+				      uint16_t *pathloss, uint8_t *transport)
+{
+	uint8_t type;
+
+	if (!strcmp("UUIDs", key)) {
+		DBusMessageIter arriter;
+
+		if (dbus_message_iter_get_arg_type(value) != DBUS_TYPE_ARRAY)
+			return false;
+
+		dbus_message_iter_recurse(value, &arriter);
+		while ((type = dbus_message_iter_get_arg_type(&arriter)) !=
+							DBUS_TYPE_INVALID) {
+			char *uuid_str;
+			char *result_uuid;
+			uuid_t uuid_tmp;
+
+			if (dbus_message_iter_get_arg_type(&arriter) !=
+							DBUS_TYPE_STRING)
+				return false;
+
+			dbus_message_iter_get_basic(&arriter, &uuid_str);
+			if (bt_string2uuid(&uuid_tmp, uuid_str) < 0)
+				return false;
+
+			result_uuid = bt_uuid2string(&uuid_tmp);
+
+			*uuids = g_slist_prepend(*uuids, result_uuid);
+
+			dbus_message_iter_next(&arriter);
+		}
+	} else if (!strcmp("RSSI", key)) {
+		if (dbus_message_iter_get_arg_type(value) != DBUS_TYPE_INT16)
+			return false;
+
+		dbus_message_iter_get_basic(value, rssi);
+		/* -127 <= RSSI <= +20 (spec V4.2 [Vol 2, Part E] 7.7.65.2) */
+		if (*rssi > 20 || *rssi < -127)
+			return false;
+
+	} else if (!strcmp("Pathloss", key)) {
+		if (dbus_message_iter_get_arg_type(value) != DBUS_TYPE_UINT16)
+			return false;
+
+		dbus_message_iter_get_basic(value, pathloss);
+		/* pathloss filter must be smaller that PATHLOSS_MAX */
+		if (*pathloss > PATHLOSS_MAX)
+			return false;
+
+	} else if (!strcmp("Transport", key)) {
+		char *transport_str;
+
+		if (dbus_message_iter_get_arg_type(value) != DBUS_TYPE_STRING)
+			return false;
+
+		dbus_message_iter_get_basic(value, &transport_str);
+
+		if (!strcmp(transport_str, "bredr"))
+			*transport = SCAN_TYPE_BREDR;
+		else if (!strcmp(transport_str, "le"))
+			*transport = SCAN_TYPE_LE;
+		else if (!strcmp(transport_str, "auto"))
+			*transport = SCAN_TYPE_DUAL;
+		else
+			return false;
+
+	} else {
+		DBG("Unknown key parameter: %s!\n", key);
+		return false;
+	}
+
+	return true;
+}
+
+/* This method is responsible for parsing parameters to SetDiscoveryFilter. If
+ * filter in msg was empty, sets *filter to NULL. If whole parsing was
+ * successful, sets *filter to proper value.
+ * Returns false on any error, and true on success.
+ */
+static bool parse_discovery_filter_dict(struct discovery_filter **filter,
+					DBusMessage *msg)
+{
+	DBusMessageIter iter, subiter, dictiter, variantiter;
+	GSList *uuids = NULL;
+	uint16_t pathloss = DISTANCE_VAL_INVALID;
+	int16_t rssi = DISTANCE_VAL_INVALID;
+	uint8_t transport = SCAN_TYPE_DUAL;
+	bool is_empty = true;
+
+	dbus_message_iter_init(msg, &iter);
+	if (dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY ||
+	    dbus_message_iter_get_element_type(&iter) != DBUS_TYPE_DICT_ENTRY)
+		return false;
+
+	dbus_message_iter_recurse(&iter, &subiter);
+	do {
+		int type = dbus_message_iter_get_arg_type(&subiter);
+		char *key;
+
+		if (type == DBUS_TYPE_INVALID)
+			break;
+
+		is_empty = false;
+		dbus_message_iter_recurse(&subiter, &dictiter);
+
+		dbus_message_iter_get_basic(&dictiter, &key);
+		if (!dbus_message_iter_next(&dictiter))
+			goto invalid_args;
+
+		if (dbus_message_iter_get_arg_type(&dictiter) !=
+							     DBUS_TYPE_VARIANT)
+			goto invalid_args;
+
+		dbus_message_iter_recurse(&dictiter, &variantiter);
+
+		if (!parse_discovery_filter_entry(key, &variantiter, &uuids,
+						  &rssi, &pathloss, &transport))
+			goto invalid_args;
+
+		dbus_message_iter_next(&subiter);
+	} while (true);
+
+	if (is_empty) {
+		*filter = NULL;
+		return true;
+	}
+
+	/* only pathlos or rssi can be set, never both */
+	if (pathloss != DISTANCE_VAL_INVALID && rssi != DISTANCE_VAL_INVALID)
+		goto invalid_args;
+
+	DBG("filtered discovery params: transport: %d rssi: %d pathloss: %d",
+	    transport, rssi, pathloss);
+
+	*filter = g_try_malloc(sizeof(**filter));
+	if (!*filter) {
+		g_slist_free_full(uuids, g_free);
+		return false;
+	}
+
+	(*filter)->type = transport;
+	(*filter)->pathloss = pathloss;
+	(*filter)->rssi = rssi;
+	(*filter)->uuids = uuids;
+
+	return true;
+
+invalid_args:
+	g_slist_free_full(uuids, g_free);
+	return false;
+}
+
 static DBusMessage *set_discovery_filter(DBusConnection *conn,
 					 DBusMessage *msg, void *user_data)
 {
+	struct btd_adapter *adapter = user_data;
+	struct discovery_filter *discovery_filter;
+
+	const char *sender = dbus_message_get_sender(msg);
+
+	DBG("sender %s", sender);
+
+	if (!(adapter->current_settings & MGMT_SETTING_POWERED))
+		return btd_error_not_ready(msg);
+
+	/* parse parameters */
+	if (!parse_discovery_filter_dict(&discovery_filter, msg))
+		return btd_error_invalid_args(msg);
+
 	return btd_error_failed(msg, "Not implemented yet");
 }
 
-- 
2.2.0.rc0.207.ga3a616c