// The MIT License (MIT)
//
// Copyright (c) .NET Foundation and Contributors
//
// All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using MediaBrowser.Model.IO;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Http.Extensions;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Infrastructure;
using Microsoft.Extensions.Logging;
using Microsoft.Net.Http.Headers;
namespace Jellyfin.Server.Infrastructure
{
///
public class SymlinkFollowingPhysicalFileResultExecutor : PhysicalFileResultExecutor
{
///
/// Initializes a new instance of the class.
///
/// An instance of the interface.
public SymlinkFollowingPhysicalFileResultExecutor(ILoggerFactory loggerFactory) : base(loggerFactory)
{
}
///
protected override FileMetadata GetFileInfo(string path)
{
var fileInfo = new FileInfo(path);
var length = fileInfo.Length;
// This may or may not be fixed in .NET 6, but looks like it will not https://github.com/dotnet/aspnetcore/issues/34371
if ((fileInfo.Attributes & FileAttributes.ReparsePoint) == FileAttributes.ReparsePoint)
{
using var fileHandle = File.OpenHandle(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
length = RandomAccess.GetLength(fileHandle);
}
return new FileMetadata
{
Exists = fileInfo.Exists,
Length = length,
LastModified = fileInfo.LastWriteTimeUtc
};
}
///
protected override Task WriteFileAsync(ActionContext context, PhysicalFileResult result, RangeItemHeaderValue? range, long rangeLength)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (result == null)
{
throw new ArgumentNullException(nameof(result));
}
if (range != null && rangeLength == 0)
{
return Task.CompletedTask;
}
// It's a bit of wasted IO to perform this check again, but non-symlinks shouldn't use this code
if (!IsSymLink(result.FileName))
{
return base.WriteFileAsync(context, result, range, rangeLength);
}
var response = context.HttpContext.Response;
if (range != null)
{
return SendFileAsync(
result.FileName,
response,
offset: range.From ?? 0L,
count: rangeLength);
}
return SendFileAsync(
result.FileName,
response,
offset: 0,
count: null);
}
private async Task SendFileAsync(string filePath, HttpResponse response, long offset, long? count)
{
var fileInfo = GetFileInfo(filePath);
if (offset < 0 || offset > fileInfo.Length)
{
throw new ArgumentOutOfRangeException(nameof(offset), offset, string.Empty);
}
if (count.HasValue
&& (count.Value < 0 || count.Value > fileInfo.Length - offset))
{
throw new ArgumentOutOfRangeException(nameof(count), count, string.Empty);
}
// Copied from SendFileFallback.SendFileAsync
const int BufferSize = 1024 * 16;
await using var fileStream = new FileStream(
filePath,
FileMode.Open,
FileAccess.Read,
FileShare.ReadWrite,
bufferSize: BufferSize,
options: FileOptions.Asynchronous | FileOptions.SequentialScan);
fileStream.Seek(offset, SeekOrigin.Begin);
await StreamCopyOperation
.CopyToAsync(fileStream, response.Body, count, BufferSize, CancellationToken.None)
.ConfigureAwait(true);
}
private static bool IsSymLink(string path) => (File.GetAttributes(path) & FileAttributes.ReparsePoint) == FileAttributes.ReparsePoint;
}
}