ForwardedPortRemote
Provides functionality for remote port forwarding.
using Microsoft.Extensions.Logging;
using Renci.SshNet.Abstractions;
using Renci.SshNet.Channels;
using Renci.SshNet.Common;
using Renci.SshNet.Messages.Connection;
using System;
using System.Globalization;
using System.Net;
using System.Threading;
namespace Renci.SshNet
{
public class ForwardedPortRemote : ForwardedPort
{
private ForwardedPortStatus _status;
private bool _requestStatus;
private EventWaitHandle _globalRequestResponse = new AutoResetEvent(false);
private CountdownEvent _pendingChannelCountdown;
private bool _isDisposed;
public override bool IsStarted => _status == ForwardedPortStatus.Started;
public IPAddress BoundHostAddress { get; set; }
public string BoundHost => BoundHostAddress.ToString();
public uint BoundPort { get; set; }
public IPAddress HostAddress { get; set; }
public string Host => HostAddress.ToString();
public uint Port { get; set; }
public ForwardedPortRemote(IPAddress boundHostAddress, uint boundPort, IPAddress hostAddress, uint port)
{
ThrowHelper.ThrowIfNull(boundHostAddress, "boundHostAddress");
ThrowHelper.ThrowIfNull(hostAddress, "hostAddress");
boundPort.ValidatePort("boundPort");
port.ValidatePort("port");
BoundHostAddress = boundHostAddress;
BoundPort = boundPort;
HostAddress = hostAddress;
Port = port;
_status = ForwardedPortStatus.Stopped;
}
public ForwardedPortRemote(uint boundPort, string host, uint port)
: this(string.Empty, boundPort, host, port)
{
}
public ForwardedPortRemote(string boundHost, uint boundPort, string host, uint port)
: this(Dns.GetHostAddresses(boundHost)[0], boundPort, Dns.GetHostAddresses(host)[0], port)
{
}
protected override void StartPort()
{
if (ForwardedPortStatus.ToStarting(ref _status)) {
InitializePendingChannelCountdown();
try {
base.Session.RegisterMessage("SSH_MSG_REQUEST_FAILURE");
base.Session.RegisterMessage("SSH_MSG_REQUEST_SUCCESS");
base.Session.RegisterMessage("SSH_MSG_CHANNEL_OPEN");
base.Session.RequestSuccessReceived += Session_RequestSuccess;
base.Session.RequestFailureReceived += Session_RequestFailure;
base.Session.ChannelOpenReceived += Session_ChannelOpening;
base.Session.SendMessage(new TcpIpForwardGlobalRequestMessage(BoundHost, BoundPort));
base.Session.WaitOnHandle(_globalRequestResponse);
if (!_requestStatus)
throw new SshException(string.Format(CultureInfo.CurrentCulture, "Port forwarding for '{0}' port '{1}' failed to start.", Host, Port));
} catch (Exception) {
_status = ForwardedPortStatus.Stopped;
base.Session.RequestSuccessReceived -= Session_RequestSuccess;
base.Session.RequestFailureReceived -= Session_RequestFailure;
base.Session.ChannelOpenReceived -= Session_ChannelOpening;
throw;
}
_status = ForwardedPortStatus.Started;
}
}
protected override void StopPort(TimeSpan timeout)
{
timeout.EnsureValidTimeout("timeout");
if (ForwardedPortStatus.ToStopping(ref _status)) {
base.StopPort(timeout);
base.Session.SendMessage(new CancelTcpIpForwardGlobalRequestMessage(BoundHost, BoundPort));
WaitHandle.WaitAny(new WaitHandle[2] {
_globalRequestResponse,
base.Session.MessageListenerCompleted
}, timeout);
base.Session.RequestSuccessReceived -= Session_RequestSuccess;
base.Session.RequestFailureReceived -= Session_RequestFailure;
base.Session.ChannelOpenReceived -= Session_ChannelOpening;
_pendingChannelCountdown.Signal();
if (!_pendingChannelCountdown.Wait(timeout)) {
ISession session = base.Session;
if (session != null)
session.SessionLoggerFactory.CreateLogger<ForwardedPortRemote>().LogInformation("Timeout waiting for pending channels in remote forwarded port to close.", Array.Empty<object>());
}
_status = ForwardedPortStatus.Stopped;
}
}
protected override void CheckDisposed()
{
ThrowHelper.ThrowObjectDisposedIf(_isDisposed, this);
}
private void Session_ChannelOpening(object sender, MessageEventArgs<ChannelOpenMessage> e)
{
ChannelOpenMessage channelOpenMessage = e.Message;
ChannelOpenInfo info2 = channelOpenMessage.Info;
ForwardedTcpipChannelInfo info = info2 as ForwardedTcpipChannelInfo;
if (info != null && info.ConnectedAddress == BoundHost && info.ConnectedPort == BoundPort) {
if (!IsStarted)
base.Session.SendMessage(new ChannelOpenFailureMessage(channelOpenMessage.LocalChannelNumber, string.Empty, 1));
else
ThreadAbstraction.ExecuteThread(delegate {
CountdownEvent pendingChannelCountdown = _pendingChannelCountdown;
pendingChannelCountdown.AddCount();
try {
RaiseRequestReceived(info.OriginatorAddress, info.OriginatorPort);
using (IChannelForwardedTcpip channelForwardedTcpip = base.Session.CreateChannelForwardedTcpip(channelOpenMessage.LocalChannelNumber, channelOpenMessage.InitialWindowSize, channelOpenMessage.MaximumPacketSize)) {
channelForwardedTcpip.Exception += Channel_Exception;
channelForwardedTcpip.Bind(new IPEndPoint(HostAddress, (int)Port), this);
}
} catch (Exception exception) {
RaiseExceptionEvent(exception);
} finally {
try {
pendingChannelCountdown.Signal();
} catch (ObjectDisposedException) {
}
}
});
}
}
private void InitializePendingChannelCountdown()
{
Interlocked.Exchange(ref _pendingChannelCountdown, new CountdownEvent(1))?.Dispose();
}
private void Channel_Exception(object sender, ExceptionEventArgs exceptionEventArgs)
{
RaiseExceptionEvent(exceptionEventArgs.Exception);
}
private void Session_RequestFailure(object sender, EventArgs e)
{
_requestStatus = false;
_globalRequestResponse.Set();
}
private void Session_RequestSuccess(object sender, MessageEventArgs<RequestSuccessMessage> e)
{
_requestStatus = true;
if (BoundPort == 0)
BoundPort = (e.Message.BoundPort.HasValue ? e.Message.BoundPort.Value : 0);
_globalRequestResponse.Set();
}
protected override void Dispose(bool disposing)
{
if (!_isDisposed) {
base.Dispose(disposing);
if (disposing) {
ISession session = base.Session;
if (session != null) {
base.Session = null;
session.RequestSuccessReceived -= Session_RequestSuccess;
session.RequestFailureReceived -= Session_RequestFailure;
session.ChannelOpenReceived -= Session_ChannelOpening;
}
EventWaitHandle globalRequestResponse = _globalRequestResponse;
if (globalRequestResponse != null) {
_globalRequestResponse = null;
globalRequestResponse.Dispose();
}
CountdownEvent pendingChannelCountdown = _pendingChannelCountdown;
if (pendingChannelCountdown != null) {
_pendingChannelCountdown = null;
pendingChannelCountdown.Dispose();
}
}
_isDisposed = true;
}
}
}
}