/src/net/sourceforge/jsocks/Proxy.java

package net.sourceforge.jsocks;

import java.io.IOException;

import java.io.InputStream;

import java.io.InterruptedIOException;

import java.io.OutputStream;

import java.net.InetAddress;

import java.net.Socket;

import java.net.UnknownHostException;



/**

  Abstract class Proxy, base for classes Socks4Proxy and Socks5Proxy.

  Defines methods for specifying default proxy, to be

  used by all classes of this package.

*/



public abstract class Proxy{



//Data members

   //protected InetRange directHosts = new InetRange();



   protected InetAddress proxyIP = null;

   protected String proxyHost = null;

   protected int proxyPort;

   protected Socket proxySocket = null;



   protected InputStream in;

   protected OutputStream out;



   protected int version;



   protected Proxy chainProxy = null;





//Protected static/class variables

   protected static Proxy defaultProxy = null;



//Constructors

//====================

	Proxy(String proxyHost, int proxyPort) throws UnknownHostException {

		this.proxyHost = proxyHost;

		this.proxyIP = InetAddress.getByName(proxyHost);

		this.proxyPort = proxyPort;

	}



   Proxy(Proxy chainProxy,InetAddress proxyIP,int proxyPort){

      this.chainProxy = chainProxy;

      this.proxyIP = proxyIP;

      this.proxyPort = proxyPort;

   }



   Proxy(InetAddress proxyIP,int proxyPort){

      this.proxyIP = proxyIP;

      this.proxyPort = proxyPort;

   }



   Proxy(Proxy p){

      this.proxyIP = p.proxyIP;

      this.proxyPort = p.proxyPort;

      this.version = p.version;

   }



//Public instance methods

//========================



   /**

      Get the port on which proxy server is running.

    * @return Proxy port.

    */

   public int getPort(){

     return proxyPort;

   }

   /**

      Get the ip address of the proxy server host.

    * @return Proxy InetAddress.

    */

   public InetAddress getInetAddress(){

     return proxyIP;

   }



    /**

       Get string representation of this proxy.

     * @returns string in the form:proxyHost:proxyPort \t Version versionNumber

     */

    public String toString(){

       return (""+proxyIP.getHostName()+":"+proxyPort+"\tVersion "+version);

    }





//Public Static(Class) Methods

//==============================



   /**

    * Sets SOCKS4 proxy as default.

      @param hostName Host name on which SOCKS4 server is running.

      @param port Port on which SOCKS4 server is running.

      @param user Username to use for communications with proxy.

    */

   public static void setDefaultProxy(String hostName,int port,String user)

                             throws UnknownHostException{

      defaultProxy = new Socks4Proxy(hostName,port,user);

   }



   /**

    * Sets SOCKS4 proxy as default.

      @param ipAddress Host address on which SOCKS4 server is running.

      @param port Port on which SOCKS4 server is running.

      @param user Username to use for communications with proxy.

    */

   public static void setDefaultProxy(InetAddress ipAddress,int port,

                                      String user){

      defaultProxy = new Socks4Proxy(ipAddress,port,user);

   }

   /**

    * Sets SOCKS5 proxy as default.

    * Default proxy only supports no-authentication.

      @param hostName Host name on which SOCKS5 server is running.

      @param port Port on which SOCKS5 server is running.

    */

   public static void setDefaultProxy(String hostName,int port)

                             throws UnknownHostException{

      defaultProxy = new Socks5Proxy(hostName,port);

   }

   /**

    * Sets SOCKS5 proxy as default.

    * Default proxy only supports no-authentication.

      @param ipAddress Host address on which SOCKS5 server is running.

      @param port Port on which SOCKS5 server is running.

    */

   public static void setDefaultProxy(InetAddress ipAddress,int port){

      defaultProxy = new Socks5Proxy(ipAddress,port);

   }

   /**

    * Sets default proxy.

      @param p Proxy to use as default proxy.

    */

   public static void setDefaultProxy(Proxy p){

     defaultProxy = p;

   }



   /**

      Get current default proxy.

    * @return Current default proxy, or null if none is set.

    */

   public static Proxy getDefaultProxy(){

     return defaultProxy;

   }



   /**

     Parses strings in the form: host[:port:user:password], and creates

     proxy from information obtained from parsing.

     <p>

     Defaults: port = 1080.<br>

     If user specified but not password, creates Socks4Proxy, if user

     not specified creates Socks5Proxy, if both user and password are

     speciefied creates Socks5Proxy with user/password authentication.

     @param proxy_entry String in the form host[:port:user:password]

     @return Proxy created from the string, null if entry was somehow

             invalid(host unknown for example, or empty string)

   */

   public static Proxy parseProxy(String proxy_entry){



      String proxy_host;

      int proxy_port = 1080;

      String proxy_user = null;

      String proxy_password = null;

      Proxy proxy;



      java.util.StringTokenizer st = new java.util.StringTokenizer(

                                         proxy_entry,":");

      if(st.countTokens() < 1) return null;



      proxy_host = st.nextToken();

      if(st.hasMoreTokens())

         try{

           proxy_port = Integer.parseInt(st.nextToken().trim());

         }catch(NumberFormatException nfe){}



      if(st.hasMoreTokens())

         proxy_user = st.nextToken();



      if(st.hasMoreTokens())

         proxy_password = st.nextToken();



      try{

         if(proxy_user == null)

           proxy = new Socks5Proxy(proxy_host,proxy_port);

         else if(proxy_password == null)

           proxy = new Socks4Proxy(proxy_host,proxy_port,proxy_user);

         else{

           proxy = new Socks5Proxy(proxy_host,proxy_port);

           /*

           UserPasswordAuthentication upa = new UserPasswordAuthentication(

                                            proxy_user, proxy_password);



           ((Socks5Proxy)proxy).setAuthenticationMethod(upa.METHOD_ID,upa);

           */

         }

      }catch(UnknownHostException uhe){

         return null;

      }



      return proxy;

   }





//Protected Methods

//=================



   protected void startSession()throws SocksException{

       try{

         proxySocket = new Socket(proxyIP,proxyPort);

         in = proxySocket.getInputStream();

         out = proxySocket.getOutputStream();

       }catch(SocksException se){

         throw se;

       }catch(IOException io_ex){

         throw new SocksException(SOCKS_PROXY_IO_ERROR,""+io_ex);

       }

   }



   protected abstract Proxy copy();

   protected abstract ProxyMessage formMessage(int cmd,InetAddress ip,int port);

   protected abstract ProxyMessage formMessage(int cmd,String host,int port)

             throws UnknownHostException;

   protected abstract ProxyMessage formMessage(InputStream in)

             throws SocksException,

                    IOException;

   



   protected ProxyMessage connect(InetAddress ip,int port)

             throws SocksException{

      try{

         startSession();

         ProxyMessage request  = formMessage(SOCKS_CMD_CONNECT,

			                     ip,port);

         return exchange(request);

      }catch(SocksException se){

         endSession();

         throw se;

      }

   }

   protected ProxyMessage connect(String host,int port)

             throws UnknownHostException,SocksException{

      try{

         startSession();

         ProxyMessage request  = formMessage(SOCKS_CMD_CONNECT,

			                     host,port);

         return exchange(request);

      }catch(SocksException se){

         endSession();

         throw se;

      }

   }



   protected ProxyMessage bind(InetAddress ip,int port)

             throws SocksException{

      try{

         startSession();

         ProxyMessage request  = formMessage(SOCKS_CMD_BIND,

				             ip,port);

         return exchange(request);

      }catch(SocksException se){

         endSession();

         throw se;

      }

   }

   protected ProxyMessage bind(String host,int port)

             throws UnknownHostException,SocksException{

      try{

         startSession();

         ProxyMessage request  = formMessage(SOCKS_CMD_BIND,

				             host,port);

         return exchange(request);

      }catch(SocksException se){

         endSession();

         throw se;

      }

   }



   protected ProxyMessage accept()

             throws IOException,SocksException{

      ProxyMessage msg;

      try{

         msg = formMessage(in);

      }catch(InterruptedIOException iioe){

         throw iioe;

      }catch(IOException io_ex){

         endSession();

         throw new SocksException(SOCKS_PROXY_IO_ERROR,"While Trying accept:"

         +io_ex);

      }

      return msg;

   }



   protected ProxyMessage udpAssociate(InetAddress ip,int port)

             throws SocksException{

      try{

         startSession();

         ProxyMessage request  = formMessage(SOCKS_CMD_UDP_ASSOCIATE,

				             ip,port);

         if(request != null)

           return exchange(request);

      }catch(SocksException se){

         endSession();

         throw se;

      }

      //Only get here if request was null

      endSession();

      throw new SocksException(SOCKS_METHOD_NOTSUPPORTED,

      "This version of proxy does not support UDP associate, use version 5");

   }

   protected ProxyMessage udpAssociate(String host,int port)

             throws UnknownHostException,SocksException{

      try{

         startSession();

         ProxyMessage request  = formMessage(SOCKS_CMD_UDP_ASSOCIATE,

				             host,port);

         if(request != null) return exchange(request);

      }catch(SocksException se){

         endSession();

         throw se;

      }

      //Only get here if request was null

      endSession();

      throw new SocksException(SOCKS_METHOD_NOTSUPPORTED,

      "This version of proxy does not support UDP associate, use version 5");

   }





   protected void endSession(){

      try{

         if(proxySocket!=null) proxySocket.close();

         proxySocket = null;

      }catch(IOException io_ex){

      }

   }



   /**

    *Sends the request to SOCKS server

    */

   protected void sendMsg(ProxyMessage msg)throws SocksException,

                                                  IOException{

      msg.write(out);

   }



   /** 

    * Reads the reply from the SOCKS server

    */

   protected ProxyMessage readMsg()throws SocksException,

                                          IOException{

      return formMessage(in);

   }

   /**

    *Sends the request reads reply and returns it

    *throws exception if something wrong with IO

    *or the reply code is not zero

    */

   protected ProxyMessage exchange(ProxyMessage request)

                           throws SocksException{

      ProxyMessage reply;

      try{

         request.write(out);

         reply = formMessage(in);

      }catch(SocksException s_ex){

         throw s_ex;

      }catch(IOException ioe){

         throw(new SocksException(SOCKS_PROXY_IO_ERROR,""+ioe));

      }

      return reply;

   }





//Private methods

//===============





//Constants



   public static final int SOCKS_SUCCESS		=0;

   public static final int SOCKS_FAILURE		=1;

   public static final int SOCKS_BADCONNECT		=2;

   public static final int SOCKS_BADNETWORK		=3;

   public static final int SOCKS_HOST_UNREACHABLE	=4;

   public static final int SOCKS_CONNECTION_REFUSED	=5;

   public static final int SOCKS_TTL_EXPIRE		=6;

   public static final int SOCKS_CMD_NOT_SUPPORTED	=7;

   public static final int SOCKS_ADDR_NOT_SUPPORTED	=8;



   public static final int SOCKS_NO_PROXY		=1<<16;

   public static final int SOCKS_PROXY_NO_CONNECT	=2<<16;

   public static final int SOCKS_PROXY_IO_ERROR		=3<<16;

   public static final int SOCKS_AUTH_NOT_SUPPORTED	=4<<16;

   public static final int SOCKS_AUTH_FAILURE		=5<<16;

   public static final int SOCKS_JUST_ERROR		=6<<16;



   public static final int SOCKS_DIRECT_FAILED		=7<<16;

   public static final int SOCKS_METHOD_NOTSUPPORTED	=8<<16;





   public static final int SOCKS_CMD_CONNECT 		=0x1;

   static final int SOCKS_CMD_BIND		=0x2;

   static final int SOCKS_CMD_UDP_ASSOCIATE	=0x3;



}