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完善数据接收

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This commit is contained in:
陈国伟 2021-09-15 15:22:28 +08:00
parent c252b205b1
commit cdebe403b5
1 changed files with 60 additions and 43 deletions
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103
FastGithub.Dns/DnsInterceptor.cs
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@ -49,7 +49,7 @@ namespace FastGithub.Dns
/// DNS拦截
/// </summary>
/// <param name="cancellationToken"></param>
unsafe public void Intercept(CancellationToken cancellationToken)
public void Intercept(CancellationToken cancellationToken)
{
var handle = WinDivert.WinDivertOpen(DNS_FILTER, WinDivertLayer.Network, 0, WinDivertOpenFlags.None);
if (handle == IntPtr.Zero)
@ -63,58 +63,75 @@ namespace FastGithub.Dns
var packetBuffer = new byte[ushort.MaxValue];
using var winDivertBuffer = new WinDivertBuffer(packetBuffer);
var winDivertAddress = new WinDivertAddress();
using var ioEvent = new AutoResetEvent(false);
while (cancellationToken.IsCancellationRequested == false)
{
winDivertAddress.Reset();
var overlapped = new NativeOverlapped
if (this.WinDivertRecvEx(handle, winDivertBuffer, ref winDivertAddress, ref packetLength, cancellationToken))
{
EventHandle = ioEvent.SafeWaitHandle.DangerousGetHandle()
};
// false表示异步完成
if (WinDivert.WinDivertRecvEx(handle, winDivertBuffer, 0, ref winDivertAddress, ref packetLength, ref overlapped) == false)
{
var error = Marshal.GetLastWin32Error();
if (error != ERROR_IO_PENDING)
try
{
this.logger.LogWarning($"Unknown IO error ID {error} while awaiting overlapped result.");
continue;
this.ProcessDnsPacket(packetBuffer, ref packetLength);
}
catch (Exception ex)
{
this.logger.LogWarning(ex.Message);
}
while (ioEvent.WaitOne(TimeSpan.FromSeconds(1d)) == false)
{
cancellationToken.ThrowIfCancellationRequested();
}
var asyncPacketLength = 0U;
if (Kernel32.GetOverlappedResult(handle, ref overlapped, ref asyncPacketLength, false) == false)
{
this.logger.LogWarning("Failed to get overlapped result.");
continue;
}
packetLength = asyncPacketLength;
WinDivert.WinDivertHelperCalcChecksums(winDivertBuffer, packetLength, ref winDivertAddress, WinDivertChecksumHelperParam.All);
WinDivert.WinDivertSend(handle, winDivertBuffer, packetLength, ref winDivertAddress);
}
try
{
this.ProcessDnsPacket(packetBuffer, ref packetLength);
}
catch (Exception ex)
{
this.logger.LogWarning(ex.Message);
}
WinDivert.WinDivertHelperCalcChecksums(winDivertBuffer, packetLength, ref winDivertAddress, WinDivertChecksumHelperParam.All);
WinDivert.WinDivertSend(handle, winDivertBuffer, packetLength, ref winDivertAddress);
}
WinDivert.WinDivertClose(handle);
DnsFlushResolverCache();
}
/// <summary>
/// 接收数据
/// </summary>
/// <param name="handle"></param>
/// <param name="winDivertBuffer"></param>
/// <param name="winDivertAddress"></param>
/// <param name="packetLength"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
private bool WinDivertRecvEx(IntPtr handle, WinDivertBuffer winDivertBuffer, ref WinDivertAddress winDivertAddress, ref uint packetLength, CancellationToken cancellationToken)
{
using var waitHandle = new EventWaitHandle(false, EventResetMode.ManualReset, null);
var overlapped = new NativeOverlapped
{
EventHandle = waitHandle.SafeWaitHandle.DangerousGetHandle()
};
winDivertAddress.Reset();
if (WinDivert.WinDivertRecvEx(handle, winDivertBuffer, 0, ref winDivertAddress, ref packetLength, ref overlapped))
{
return true;
}
var error = Marshal.GetLastWin32Error();
if (error != ERROR_IO_PENDING)
{
this.logger.LogWarning($"Unknown IO error ID {error} while awaiting overlapped result.");
return false;
}
while (waitHandle.WaitOne(TimeSpan.FromSeconds(1d)) == false)
{
cancellationToken.ThrowIfCancellationRequested();
}
var asyncPacketLength = 0U;
if (Kernel32.GetOverlappedResult(handle, ref overlapped, ref asyncPacketLength, false) == false)
{
this.logger.LogWarning("Failed to get overlapped result.");
return false;
}
packetLength = asyncPacketLength;
return true;
}
/// <summary>
/// 处理DNS数据包
/// </summary>
@ -140,14 +157,14 @@ namespace FastGithub.Dns
}
// 反转ip
var sourAddress = ipPacket.SourceAddress;
var sourceAddress = ipPacket.SourceAddress;
ipPacket.SourceAddress = ipPacket.DestinationAddress;
ipPacket.DestinationAddress = sourAddress;
ipPacket.DestinationAddress = sourceAddress;
// 反转端口
var sourPort = udpPacket.SourcePort;
var sourcePort = udpPacket.SourcePort;
udpPacket.SourcePort = udpPacket.DestinationPort;
udpPacket.DestinationPort = sourPort;
udpPacket.DestinationPort = sourcePort;
// 设置dns响应
var response = Response.FromRequest(request);