private Type GetDataType(ExpressionNode node)
{
Type nodeType = node.GetType();
string typeName = null;
if (nodeType == typeof(NameNode))
{
typeName = ((NameNode)node)._name;
}
if (nodeType == typeof(ConstNode))
{
typeName = ((ConstNode)node)._val.ToString();
}
if (typeName == null)
{
throw ExprException.ArgumentType(s_funcs[_info]._name, 2, typeof(Type));
}
Type dataType = Type.GetType(typeName);
if (dataType == null)
{
throw ExprException.InvalidType(typeName);
}
// ReadXml might not be on the current call stack. So we'll use the TypeLimiter
// that was captured when this FunctionNode instance was created.
TypeLimiter.EnsureTypeIsAllowed(dataType, _capturedLimiter);
return(dataType);
}
internal FunctionNode(DataTable?table, string name) : base(table)
{
// Because FunctionNode instances are created eagerly but evaluated lazily,
// we need to capture the deserialization scope here. The scope could be
// null if no deserialization is in progress.
_capturedLimiter = TypeLimiter.Capture();
_name = name;
for (int i = 0; i < s_funcs.Length; i++)
{
if (string.Equals(s_funcs[i]._name, name, StringComparison.OrdinalIgnoreCase))
{
// we found the reserved word..
_info = i;
break;
}
}
if (_info < 0)
{
throw ExprException.UndefinedFunction(_name);
}
}
/// <summary>
/// Ensures the requested type is allowed by the rules of the active
/// deserialization scope. If a captured scope is provided, we'll use
/// that previously captured scope rather than the thread-static active
/// scope.
/// </summary>
/// <exception cref="InvalidOperationException">
/// If <paramref name="type"/> is not allowed.
/// </exception>
public static void EnsureTypeIsAllowed(Type type, TypeLimiter capturedLimiter = null)
{
if (type is null)
{
return; // nothing to check
}
Scope capturedScope = capturedLimiter?.m_instanceScope ?? s_activeScope;
if (capturedScope is null)
{
return; // we're not in a restricted scope
}
if (capturedScope.IsAllowedType(type))
{
return; // type was explicitly allowed
}
// We encountered a type that wasn't in the allow list.
// Throw an exception to fail the current operation.
throw ExceptionBuilder.TypeNotAllowed(type);
}