aspnetcore/src/Microsoft.AspNetCore.Mvc.Core/Internal/HttpMethodActionConstraint.cs

89 lines
2.9 KiB
C#

// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using Microsoft.AspNetCore.Mvc.ActionConstraints;
using Microsoft.Extensions.Primitives;
namespace Microsoft.AspNetCore.Mvc.Internal
{
public class HttpMethodActionConstraint : IActionConstraint
{
public static readonly int HttpMethodConstraintOrder = 100;
private readonly IReadOnlyList<string> _httpMethods;
private readonly string OriginHeader = "Origin";
private readonly string AccessControlRequestMethod = "Access-Control-Request-Method";
private readonly string PreflightHttpMethod = "OPTIONS";
// Empty collection means any method will be accepted.
public HttpMethodActionConstraint(IEnumerable<string> httpMethods)
{
if (httpMethods == null)
{
throw new ArgumentNullException(nameof(httpMethods));
}
var methods = new List<string>();
foreach (var method in httpMethods)
{
if (string.IsNullOrEmpty(method))
{
throw new ArgumentException("httpMethod cannot be null or empty");
}
methods.Add(method);
}
_httpMethods = new ReadOnlyCollection<string>(methods);
}
public IEnumerable<string> HttpMethods => _httpMethods;
public int Order => HttpMethodConstraintOrder;
public bool Accept(ActionConstraintContext context)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (_httpMethods.Count == 0)
{
return true;
}
var request = context.RouteContext.HttpContext.Request;
var method = request.Method;
// Perf: Check http method before accessing the Headers collection.
if (string.Equals(method, PreflightHttpMethod, StringComparison.OrdinalIgnoreCase) &&
request.Headers.ContainsKey(OriginHeader))
{
// Update the http method if it is preflight request.
var accessControlRequestMethod = request.Headers[AccessControlRequestMethod];
if (!StringValues.IsNullOrEmpty(accessControlRequestMethod))
{
method = accessControlRequestMethod;
}
}
for (var i = 0; i < _httpMethods.Count; i++)
{
var supportedMethod = _httpMethods[i];
if (string.Equals(supportedMethod, method, StringComparison.OrdinalIgnoreCase))
{
return true;
}
}
return false;
}
}
}