pw-reserve: require valid name + check rd_reserve_new errors

Empty name in rd_device_new triggers assert inside DBus, so bail out
before that.

src/tools/pw-reserve.c

@@ -142,8 +142,8 @@ int main(int argc, char *argv[])
 			return -1;
 		}
 	}
-	if (opt_name == NULL) {
-		fprintf(stderr, "name must be given\n");
+	if (opt_name == NULL || !rd_device_valid_device_name(opt_name)) {
+		fprintf(stderr, "valid name must be given\n");
 		return -1;
 	}
 
@@ -190,6 +190,11 @@ int main(int argc, char *argv[])
 			opt_appname,
 			opt_priority,
 			&reserve_callbacks, &impl);
+	if (!impl.device) {
+		res = -errno;
+		fprintf(stderr, "dbus connection failed: %m\n");
+		goto exit;
+	}
 
 	if (!opt_monitor) {
 		res = rd_device_acquire(impl.device);

src/tools/reserve.c

@@ -307,6 +307,34 @@ invalid:
 	return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 }
 
+bool rd_device_valid_device_name(const char *name)
+{
+	const char *p = name;
+
+	if (!p || !*p)
+		return false;
+
+	/* cf. dbus-marshal-validate.c:_dbus_validate_bus_name_full */
+	while (*p) {
+		switch (*p) {
+		case 'A' ... 'Z':
+		case 'a' ... 'z':
+		case '-':
+		case '_':
+			break;
+		case '0' ... '9':
+			if (p == name)
+				return false;
+			break;
+		default:
+			return false;
+		}
+		++p;
+	}
+
+	return true;
+}
+
 struct rd_device *
 rd_device_new(DBusConnection *connection, const char *device_name, const char *application_name,
 		int32_t priority, const struct rd_device_callbacks *callbacks, void *data)
@@ -314,6 +342,11 @@ rd_device_new(DBusConnection *connection, const char *device_name, const char *a
 	struct rd_device *d;
 	int res;
 
+	if (!rd_device_valid_device_name(device_name)) {
+		errno = EINVAL;
+		return NULL;
+	}
+
 	d = calloc(1, sizeof(struct rd_device));
 	if (d == NULL)
 		return NULL;

src/tools/reserve.h

@@ -7,6 +7,7 @@
 
 #include <dbus/dbus.h>
 #include <inttypes.h>
+#include <stdbool.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -51,6 +52,9 @@ void rd_device_release(struct rd_device *d);
 /** destroy a device */
 void rd_device_destroy(struct rd_device *d);
 
+/** check if device name is a valid name */
+bool rd_device_valid_device_name(const char *name);
+
 /* Set the application device name for an rd_device object. Returns 0
  * on success, a negative errno style return value on error. */
 int rd_device_set_application_device_name(struct rd_device *d, const char *name);