gistfile1.txt

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;

/*
    We want any connection client to be able to set it's proxy settings to 127.0.0.1:1337
    We then want to route any incoming connections iteratively through a list of IP:Port entries in a configuration file delimited by newline.
    If a connection fails, it will iterate to the next IP:Port on the next line.

    Far from complete.
*/

namespace ConsoleProxyBouncer
{

    /* OutConnection object creates a TCPListener and a TCPClient object and then manages them as a unified connection */
    class OutConnection
    {
        public OutConnection()
        {
            TcpListener ThisListener = new TcpListener(this.ListenAddress, this.ListenPort);
        }
        

        // for the client
        public string Protocol
        {
            get
            {
                return Protocol;
            }
            set
            {
                Protocol = value;
            }
        }
        public IPAddress DestinationAddress
        {
            get
            {
                return DestinationAddress;
            }
            set
            {
                DestinationAddress = value;
            }
        }

        public int DestinationPort
        {
            get
            {
                return DestinationPort;
            }
            set
            {
                DestinationPort = value;
            }
        }

        // below for the listener
        public int ListenPort
        {
            get
            {
                return ListenPort;
            }
            set
            {
                ListenPort = value;
            }
        }

        // 127.0.0.1, this will probably end up const
        public IPAddress ListenAddress
        {
            get 
            {
                return ListenAddress;
            }
            set
            {
                ListenAddress = value;
            }
        }

        // checks to see if all the properties that should be set are set
        public bool CanConnect
        {
            get
            {
                
            }
            set
            {
                // you can't set this
            }
        }


        // return true if both the tcplistener and the tcpclient are connected
        public bool IsConnected
        {
            get;
            set;
        }

        public void Listen()
        {

        }
    }

    class Program
    {

        private void Throw(int ExitCode, string msg, params object[] args)
        {
            Console.WriteLine(String.Format(msg, args));
            Environment.Exit(ExitCode);
        }


        // deal with the configuration
        private bool IsValidIp(string addr)
        {
            IPAddress ip;
            bool valid = !string.IsNullOrEmpty(addr) && IPAddress.TryParse(addr, out ip);
            return valid;
        }

        private bool IsDigitsOnly(string str)

        {
            foreach (char c in str)
            {
                if (char.IsDigit(c))
                    return false;
            }

            return true;
        }

        private OutConnection CreateConnectionHandleFromLine (string line)
        {
            /* expected line string format:  
            "TCP 123.123.123.123 9999" | 
            "TCP 9999 123.123.123.123" | 
            "123.123.123.123 9999 TCP" |
            "123.123.123.123 TCP 9999" |
            "9999 123.123.123.123 TCP" |
            "9999 TCP 123.123.123.123"

            Tabs, commas, or spaces allowed.

            */

            // normalize whitespace
            line = line.Replace(",", "\t");
            line = line.Replace(" ", "\t");
            line = line.Replace("\t\t", "\t");


            // then split into a string array by tab character
            string[] properties = line.Split('\t');

            OutConnection NewConn = new OutConnection();


            foreach (string property in properties)
            {

                if (IsValidIp(property))
                {
                    // It's an IP Address.
                    // what a stupid way to do this
                    IPAddress bsval = null;
                    IPAddress.TryParse(property, out bsval);
                    // then it's an outbound IP Address, treat ityeah  as such
                    NewConn.DestinationAddress = bsval;                        
                }
                else if (IsDigitsOnly(property))
                {
                    // It's a port designation
                    NewConn.DestinationPort = Convert.ToInt32(property);
                }
                else if (property.Equals("TCP"))
                {
                    // Use a TCP connection.
                    // Alternate UDP is not currently supported yet.
                    NewConn.Protocol = "TCP";
                }

                /* now that all the properties we're looking for from the config file are set let's see if anything went wrong
                and exit if it did, return the connection if not. */
                 
                if (NewConn.CanConnect)
                {
                    // these are instantiated but are not turned on
                    return NewConn;
                } else {
                    Throw(-1, "Failed to set all the needed properties to one of the OutConnection objects.");
                }
            }

            // This will never execute but the requirement for this line requires this line simply because it requires this line.
            // HandledErrorThrow("There's a logic error in CreateConnectionHandleFromLine()", -1);
            return NewConn;
        }

        private List<OutConnection> getProxyEntries(string filePath)
        {
            List<OutConnection> SocketPairs = new List<OutConnection>();

            // read teh config file into a string array
            string[] ConfigFile = File.ReadAllLines(@"filePath");

            // for each line create a new OutConnection object and append it to a list of connection objectsro      
            foreach (string line in ConfigFile)
            {
                SocketPairs.Add(CreateConnectionHandleFromLine(line));
            }
            return SocketPairs;
        }

        public int Main(string[] args)
        {
            List<OutConnection> ConnectionCollection = getProxyEntries(@"C:\proxies.txt");

            foreach (OutConnection Connection in ConnectionCollection)
            {
                if (Connection.CanConnect)
                {
                    // wait for the connection
                    Connection.Listen();

                    while (Connection.IsConnected)
                    {
                        // do nothing, just keep rechecking until it's no longer connected
                    }
                    // once that's done, it'll iterate to the next one.
                }
                else
                {
                    Throw(-1, "The connection to {0}:{1} cannot be made as the result of either a configuration or parsing issue.", Connection.DestinationAddress, Connection.DestinationPort);
                }

            }
            return 0;
        }
    }
}