aspnetcore/test/Kestrel.FunctionalTests/MaxRequestBufferSizeTests.cs

356 lines
16 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.IO;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Testing;
using Microsoft.Extensions.Logging;
using Xunit;
using Xunit.Abstractions;
namespace Microsoft.AspNetCore.Server.Kestrel.FunctionalTests
{
public class MaxRequestBufferSizeTests
{
private const int _dataLength = 20 * 1024 * 1024;
private static readonly string[] _requestLines = new[]
{
"POST / HTTP/1.0\r\n",
$"Content-Length: {_dataLength}\r\n",
"\r\n"
};
private readonly Action<ILoggingBuilder> _configureLoggingDelegate;
public MaxRequestBufferSizeTests(ITestOutputHelper output)
{
_configureLoggingDelegate = builder => builder.AddXunit(output);
}
public static IEnumerable<object[]> LargeUploadData
{
get
{
var maxRequestBufferSizeValues = new Tuple<long?, bool>[] {
// Smallest buffer that can hold a test request line without causing
// the server to hang waiting for the end of the request line or
// a header line.
Tuple.Create((long?)(_requestLines.Max(line => line.Length)), true),
// Small buffer, but large enough to hold all request headers.
Tuple.Create((long?)16 * 1024, true),
// Default buffer.
Tuple.Create((long?)1024 * 1024, true),
// Larger than default, but still significantly lower than data, so client should be paused.
// On Windows, the client is usually paused around (MaxRequestBufferSize + 700,000).
// On Linux, the client is usually paused around (MaxRequestBufferSize + 10,000,000).
Tuple.Create((long?)5 * 1024 * 1024, true),
// Even though maxRequestBufferSize < _dataLength, client should not be paused since the
// OS-level buffers in client and/or server will handle the overflow.
Tuple.Create((long?)_dataLength - 1, false),
// Buffer is exactly the same size as data. Exposed race condition where
// the connection was resumed after socket was disconnected.
Tuple.Create((long?)_dataLength, false),
// Largest possible buffer, should never trigger backpressure.
Tuple.Create((long?)long.MaxValue, false),
// Disables all code related to computing and limiting the size of the input buffer.
Tuple.Create((long?)null, false)
};
var sslValues = new[] { true, false };
return from maxRequestBufferSize in maxRequestBufferSizeValues
from ssl in sslValues
select new object[] {
maxRequestBufferSize.Item1,
ssl,
maxRequestBufferSize.Item2
};
}
}
[Theory]
[MemberData(nameof(LargeUploadData))]
public async Task LargeUpload(long? maxRequestBufferSize, bool connectionAdapter, bool expectPause)
{
// Parameters
var data = new byte[_dataLength];
var bytesWrittenTimeout = TimeSpan.FromMilliseconds(100);
var bytesWrittenPollingInterval = TimeSpan.FromMilliseconds(bytesWrittenTimeout.TotalMilliseconds / 10);
var maxSendSize = 4096;
// Initialize data with random bytes
(new Random()).NextBytes(data);
var startReadingRequestBody = new TaskCompletionSource<object>();
var clientFinishedSendingRequestBody = new TaskCompletionSource<object>();
var lastBytesWritten = DateTime.MaxValue;
using (var host = StartWebHost(maxRequestBufferSize, data, connectionAdapter, startReadingRequestBody, clientFinishedSendingRequestBody))
{
var port = host.GetPort();
using (var socket = CreateSocket(port))
using (var stream = new NetworkStream(socket))
{
await WritePostRequestHeaders(stream, data.Length);
var bytesWritten = 0;
Func<Task> sendFunc = async () =>
{
while (bytesWritten < data.Length)
{
var size = Math.Min(data.Length - bytesWritten, maxSendSize);
await stream.WriteAsync(data, bytesWritten, size).ConfigureAwait(false);
bytesWritten += size;
lastBytesWritten = DateTime.Now;
}
Assert.Equal(data.Length, bytesWritten);
clientFinishedSendingRequestBody.TrySetResult(null);
};
var sendTask = sendFunc();
if (expectPause)
{
// The minimum is (maxRequestBufferSize - maxSendSize + 1), since if bytesWritten is
// (maxRequestBufferSize - maxSendSize) or smaller, the client should be able to
// complete another send.
var minimumExpectedBytesWritten = maxRequestBufferSize.Value - maxSendSize + 1;
// The maximum is harder to determine, since there can be OS-level buffers in both the client
// and server, which allow the client to send more than maxRequestBufferSize before getting
// paused. We assume the combined buffers are smaller than the difference between
// data.Length and maxRequestBufferSize.
var maximumExpectedBytesWritten = data.Length - 1;
// Block until the send task has gone a while without writing bytes AND
// the bytes written exceeds the minimum expected. This indicates the server buffer
// is full.
//
// If the send task is paused before the expected number of bytes have been
// written, keep waiting since the pause may have been caused by something else
// like a slow machine.
while ((DateTime.Now - lastBytesWritten) < bytesWrittenTimeout ||
bytesWritten < minimumExpectedBytesWritten)
{
await Task.Delay(bytesWrittenPollingInterval);
}
// Verify the number of bytes written before the client was paused.
Assert.InRange(bytesWritten, minimumExpectedBytesWritten, maximumExpectedBytesWritten);
// Tell server to start reading request body
startReadingRequestBody.TrySetResult(null);
// Wait for sendTask to finish sending the remaining bytes
await sendTask;
}
else
{
// Ensure all bytes can be sent before the server starts reading
await sendTask;
// Tell server to start reading request body
startReadingRequestBody.TrySetResult(null);
}
using (var reader = new StreamReader(stream, Encoding.ASCII))
{
var response = reader.ReadToEnd();
Assert.Contains($"bytesRead: {data.Length}", response);
}
}
}
}
[Fact]
public async Task ServerShutsDownGracefullyWhenMaxRequestBufferSizeExceeded()
{
// Parameters
var data = new byte[_dataLength];
var bytesWrittenTimeout = TimeSpan.FromMilliseconds(100);
var bytesWrittenPollingInterval = TimeSpan.FromMilliseconds(bytesWrittenTimeout.TotalMilliseconds / 10);
var maxSendSize = 4096;
var startReadingRequestBody = new TaskCompletionSource<object>();
var clientFinishedSendingRequestBody = new TaskCompletionSource<object>();
var lastBytesWritten = DateTime.MaxValue;
using (var host = StartWebHost(16 * 1024, data, false, startReadingRequestBody, clientFinishedSendingRequestBody))
{
var port = host.GetPort();
using (var socket = CreateSocket(port))
using (var stream = new NetworkStream(socket))
{
await WritePostRequestHeaders(stream, data.Length);
var bytesWritten = 0;
Func<Task> sendFunc = async () =>
{
while (bytesWritten < data.Length)
{
var size = Math.Min(data.Length - bytesWritten, maxSendSize);
await stream.WriteAsync(data, bytesWritten, size).ConfigureAwait(false);
bytesWritten += size;
lastBytesWritten = DateTime.Now;
}
clientFinishedSendingRequestBody.TrySetResult(null);
};
var ignore = sendFunc();
// The minimum is (maxRequestBufferSize - maxSendSize + 1), since if bytesWritten is
// (maxRequestBufferSize - maxSendSize) or smaller, the client should be able to
// complete another send.
var minimumExpectedBytesWritten = (16 * 1024) - maxSendSize + 1;
// The maximum is harder to determine, since there can be OS-level buffers in both the client
// and server, which allow the client to send more than maxRequestBufferSize before getting
// paused. We assume the combined buffers are smaller than the difference between
// data.Length and maxRequestBufferSize.
var maximumExpectedBytesWritten = data.Length - 1;
// Block until the send task has gone a while without writing bytes AND
// the bytes written exceeds the minimum expected. This indicates the server buffer
// is full.
//
// If the send task is paused before the expected number of bytes have been
// written, keep waiting since the pause may have been caused by something else
// like a slow machine.
while ((DateTime.Now - lastBytesWritten) < bytesWrittenTimeout ||
bytesWritten < minimumExpectedBytesWritten)
{
await Task.Delay(bytesWrittenPollingInterval);
}
// Verify the number of bytes written before the client was paused.
Assert.InRange(bytesWritten, minimumExpectedBytesWritten, maximumExpectedBytesWritten);
// Dispose host prior to closing connection to verify the server doesn't throw during shutdown
// if a connection no longer has alloc and read callbacks configured.
host.Dispose();
}
}
}
private IWebHost StartWebHost(long? maxRequestBufferSize,
byte[] expectedBody,
bool useConnectionAdapter,
TaskCompletionSource<object> startReadingRequestBody,
TaskCompletionSource<object> clientFinishedSendingRequestBody)
{
var host = TransportSelector.GetWebHostBuilder()
.ConfigureLogging(_configureLoggingDelegate)
.UseKestrel(options =>
{
options.Listen(new IPEndPoint(IPAddress.Loopback, 0), listenOptions =>
{
if (useConnectionAdapter)
{
listenOptions.ConnectionAdapters.Add(new PassThroughConnectionAdapter());
}
});
options.Limits.MaxRequestBufferSize = maxRequestBufferSize;
if (maxRequestBufferSize.HasValue &&
maxRequestBufferSize.Value < options.Limits.MaxRequestLineSize)
{
options.Limits.MaxRequestLineSize = (int)maxRequestBufferSize;
}
if (maxRequestBufferSize.HasValue &&
maxRequestBufferSize.Value < options.Limits.MaxRequestHeadersTotalSize)
{
options.Limits.MaxRequestHeadersTotalSize = (int)maxRequestBufferSize;
}
options.Limits.MinRequestBodyDataRate = null;
})
.UseContentRoot(Directory.GetCurrentDirectory())
.Configure(app => app.Run(async context =>
{
await startReadingRequestBody.Task.TimeoutAfter(TimeSpan.FromSeconds(120));
var buffer = new byte[expectedBody.Length];
var bytesRead = 0;
while (bytesRead < buffer.Length)
{
bytesRead += await context.Request.Body.ReadAsync(buffer, bytesRead, buffer.Length - bytesRead);
}
await clientFinishedSendingRequestBody.Task.TimeoutAfter(TimeSpan.FromSeconds(120));
// Verify client didn't send extra bytes
if (await context.Request.Body.ReadAsync(new byte[1], 0, 1) != 0)
{
context.Response.StatusCode = StatusCodes.Status500InternalServerError;
await context.Response.WriteAsync("Client sent more bytes than expectedBody.Length");
return;
}
// Verify bytes received match expectedBody
for (int i = 0; i < expectedBody.Length; i++)
{
if (buffer[i] != expectedBody[i])
{
context.Response.StatusCode = StatusCodes.Status500InternalServerError;
await context.Response.WriteAsync($"Bytes received do not match expectedBody at position {i}");
return;
}
}
await context.Response.WriteAsync($"bytesRead: {bytesRead.ToString()}");
}))
.Build();
host.Start();
return host;
}
private static Socket CreateSocket(int port)
{
var socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
// Timeouts large enough to prevent false positives, but small enough to fail quickly.
socket.SendTimeout = 10 * 1000;
socket.ReceiveTimeout = 120 * 1000;
socket.Connect(IPAddress.Loopback, port);
return socket;
}
private static async Task WritePostRequestHeaders(Stream stream, int contentLength)
{
using (var writer = new StreamWriter(stream, Encoding.ASCII, bufferSize: 1024, leaveOpen: true))
{
foreach (var line in _requestLines)
{
await writer.WriteAsync(line).ConfigureAwait(false);
}
}
}
}
}