private bool DispatchRequest(Request request)
{
bool bRet = false;
switch (request.Command)
{
case ConnectCommand:
var bind = new AddrSpec();
int bindPort = rnd.Next(65000, 65536);
IPEndPoint localEndpoint = new IPEndPoint(localhostIPAddr, bindPort);
bind.FQDN = "";
bind.IP = localhostIPAddr;
bind.Port = bindPort;
Socket target;
try
{
if (request.DestAddr.IP.AddressFamily == AddressFamily.InterNetwork)
{
target = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
}
else
{
target = new Socket(AddressFamily.InterNetworkV6, SocketType.Stream, ProtocolType.Tcp);
}
}
catch (Exception ex)
{
throw new SocksException("Failed to create socket for address.", SocksError.ConnectionRefused);
}
//target.Bind(localEndpoint);
//TcpClient target = new TcpClient(localEndpoint);
try
{
target.Connect(request.DestAddr.IP.ToString(), request.DestAddr.Port);
}
catch (Exception ex)
{
throw new SocksException($"Failed on client connect to {request.DestAddr.IP.ToString()}", SocksError.HostUnreachable, ex);
}
bRet = true;
//DebugWriteLine($"Successfully connected to {request.DestAddr.IP.ToString()}");
ClientConnection = target;
Bind = bind;
//var msgToSend = CreateFormattedMessageWithLength(SocksError.SuccessReply, bind, conn);
//AddMythicMessageToQueue(msgToSend);
//new Thread(() => conn.StartRelay()).Start();
break;
default:
throw new SocksException($"Command not supported: {request.Command}", SocksError.CommandNotSupported);
}
return(bRet);
}
private Request ParseAddrSpec(byte[] data)
{
int dataIndex = 0;
int headerIndex = 0;
byte[] header = new byte[3];
byte[] address = null;
IPAddress targetIP = null;
int targetPort;
AddrSpec addrSpec = new AddrSpec()
{
FQDN = "", IP = null, Port = -1
};
SocksError errorResponse;
if (data.Length <= 1)
{
throw new SocksException("Datagram was an invalid length.", SocksError.InvalidDatagram);
}
if (data.Length < 3)
{
throw new SocksException("Datagram was an invalid length.", SocksError.InvalidDatagram);
}
Array.Copy(data, header, 3);
dataIndex += 3;
// gonna assume this means fail to read header
if (header[0] != socks5Version)
{
throw new SocksException($"Got header frame requesting invalid SOCKS version {header[0]}.", SocksError.CommandNotSupported);
}
AddressType ipType = (AddressType)data[dataIndex];
dataIndex += 1;
switch (ipType)
{
case AddressType.IPv4Address:
address = new byte[4];
Array.Copy(data, dataIndex, address, 0, 4);
targetIP = new IPAddress(address);
dataIndex += 4;
addrSpec = new AddrSpec()
{
FQDN = "",
IP = targetIP
};
break;
case AddressType.IPV6Address:
address = new byte[16];
Array.Copy(data, dataIndex, address, 0, 16);
targetIP = new IPAddress(address);
dataIndex += 16;
addrSpec = new AddrSpec()
{
FQDN = "",
IP = targetIP,
};
break;
case AddressType.FQDNAddress:
int addrLength = data[dataIndex];
dataIndex += 1;
byte[] fqdnBytes = new byte[addrLength];
Array.Copy(data, dataIndex, fqdnBytes, 0, addrLength);
dataIndex += addrLength;
string fqdn = Encoding.UTF8.GetString(fqdnBytes);
try
{
var ipEntry = Dns.GetHostEntry(fqdn);
if (ipEntry.AddressList.Length == 0)
{
break;
}
foreach (var ipaddr in ipEntry.AddressList)
{
if (ipaddr.ToString().Contains("."))
{
targetIP = ipaddr;
break;
}
}
if (targetIP == null)
{
targetIP = ipEntry.AddressList[0];
}
addrSpec = new AddrSpec()
{
FQDN = fqdn,
IP = targetIP
};
break;
}
catch (Exception ex)
{
//DebugWriteLine($"Error while resolving FQDN: {ex.Message}");
//if (ByteSequenceEquals(data, new byte[] { 5, 1, 0, 5}) || ByteSequenceEquals(data, new byte[] { 5,2,0,2}))
//{
// var msg = new SocksDatagram()
// {
// server_id = conn.ServerID,
// data = Convert.ToBase64String(new byte[] { 5, 0 })
// };
// AddMythicMessageToQueue(msg);
//}
//new Thread(() => RemoveProxyConnection(conn)).Start();
break;
}
default:
//DebugWriteLine("AddrType was not IPv4, IPv6, or FQDN!");
//if (ByteSequenceEquals(data, new byte[] { 5, 1, 0, 5 }) || ByteSequenceEquals(data, new byte[] { 5, 2, 0, 2 }))
//{
// var msg = new SocksDatagram()
// {
// server_id = conn.ServerID,
// data = Convert.ToBase64String(new byte[] { 5, 0 })
// };
// AddMythicMessageToQueue(msg);
//}
//new Thread(() => RemoveProxyConnection(conn)).Start();
break;
}
if (targetIP == null)
{
throw new SocksException(SocksError.AddrTypeNotSupported);
}
if (data.Length < (dataIndex + 2))
{
throw new SocksException(SocksError.ServerFailure);
}
byte[] portBytes = new byte[2];
Array.Copy(data, dataIndex, portBytes, 0, 2);
dataIndex += 2;
targetPort = ((int)portBytes[0] << 8) | (int)portBytes[1];
addrSpec.Port = targetPort;
Request request = new Request()
{
Version = socks5Version,
Command = header[1],
DestAddr = addrSpec,
//BufCon = conn
};
int clientPort = rnd.Next(60000, 65536);
AddrSpec clientAddr = new AddrSpec()
{
FQDN = "",
IP = System.Net.IPAddress.Parse("127.0.0.1"),
Port = clientPort
};
request.RemoteAddr = clientAddr;
IPAddress destIPAddr;
if (request.DestAddr.FQDN != "")
{
if (request.DestAddr.IP == null)
{
//DebugWriteLine("About to resolve FQDN");
var dnsEntry = Dns.GetHostEntry(request.DestAddr.FQDN);
if (dnsEntry.AddressList.Length == 0)
{
throw new SocksException(SocksError.HostUnreachable);
}
request.DestAddr.IP = dnsEntry.AddressList[0];
}
}
return(request);
}