Proxy


1   package socks;
2   import java.net.*;
3   import java.io.*;
4   import java.util.Hashtable  ;
5   import java.util.Enumeration  ;
6   
7   /**
8     Abstract class Proxy, base for classes Socks4Proxy and Socks5Proxy.
9     Defines methods for specifying default proxy, to be
10    used by all classes of this package.
11  */
12  
13  public abstract class Proxy{
14  
15  //Data members
16     protected InetRange directHosts = new InetRange();
17  
18     protected InetAddress proxyIP = null;
19     protected String   proxyHost = null;
20     protected int proxyPort;
21     protected Socket proxySocket = null;
22  
23     protected InputStream in;
24     protected OutputStream out;
25  
26     protected int version;
27  
28     protected Proxy chainProxy = null;
29  
30  
31  //Protected static/class variables
32     protected static Proxy defaultProxy = null;
33  
34  //Constructors
35  //====================
36     Proxy(Proxy chainProxy,
37           String   proxyHost,int proxyPort)throws UnknownHostException{ 
38        this.chainProxy = chainProxy;
39        this.proxyHost = proxyHost;
40  
41        if(chainProxy == null)
42           this.proxyIP   = InetAddress.getByName(proxyHost);
43        
44        this.proxyPort = proxyPort;
45     }
46  
47    
48     Proxy(String   proxyHost,int proxyPort)throws UnknownHostException{ 
49        this(null,proxyHost,proxyPort);
50     }
51  
52     Proxy(Proxy chainProxy,InetAddress proxyIP,int proxyPort){
53        this.chainProxy = chainProxy;
54        this.proxyIP = proxyIP;
55        this.proxyPort = proxyPort;
56     }
57  
58     Proxy(InetAddress proxyIP,int proxyPort){
59        this(null,proxyIP,proxyPort);
60     }
61  
62     Proxy(Proxy p){
63        this.proxyIP = p.proxyIP;
64        this.proxyPort = p.proxyPort;
65        this.version = p.version;
66        this.directHosts = p.directHosts;
67     }
68  
69  //Public instance methods
70  //========================
71  
72     /**
73        Get the port on which proxy server is running.
74      * @return Proxy port.
75      */
76     public int getPort(){
77       return proxyPort;
78     }
79     /**
80        Get the ip address of the proxy server host.
81      * @return Proxy InetAddress.
82      */
83     public InetAddress getInetAddress(){
84       return proxyIP;
85     }
86     /**
87      * Adds given ip to the list of direct addresses.
88      * This machine will be accessed without using proxy.
89      */
90     public void addDirect(InetAddress ip){
91        directHosts.add(ip);
92     }
93     /**
94      * Adds host to the list of direct addresses.
95      * This machine will be accessed without using proxy.
96      */
97     public boolean addDirect(String   host){
98        return directHosts.add(host);
99     }
100    /**
101     * Adds given range of addresses to the lsit of direct addresses,
102     * machines within this range will be accessed without using proxy.
103     */
104    public void addDirect(InetAddress from,InetAddress to){
105       directHosts.add(from,to);
106    }
107    /**
108     * Sets given InetRange as the list of direct address, previous
109     * list will be discarded, any changes done previously with
110     * addDirect(Inetaddress) will be lost.
111     * The machines in this range will be accessed without using proxy.
112     * @param ir InetRange which should be used to look up direct addresses.
113     * @see InetRange
114     */
115    public void setDirect(InetRange ir){
116      directHosts = ir;
117    }
118 
119    /**
120       Get the list of direct hosts.
121     * @return Current range of direct address as InetRange object.
122     * @see InetRange
123     */
124    public InetRange getDirect(){
125      return directHosts;
126    }
127    /**
128       Check wether the given host is on the list of direct address.
129       @param host Host name to check.
130     * @return true if the given host is specified as the direct addresses.
131     */
132     public boolean isDirect(String   host){
133         return directHosts.contains(host);
134     }
135    /**
136       Check wether the given host is on the list of direct addresses.
137       @param host Host address to check.
138     * @return true if the given host is specified as the direct address.
139     */
140     public boolean isDirect(InetAddress host){
141         return directHosts.contains(host);
142     }
143     /**
144       Set the proxy which should be used to connect to given proxy.
145       @param chainProxy Proxy to use to connect to this proxy.
146     */
147     public void setChainProxy(Proxy chainProxy){
148         this.chainProxy = chainProxy;
149     }
150     
151     /**
152       Get proxy which is used to connect to this proxy.
153       @return Proxy which is used to connect to this proxy, or null
154               if proxy is to be contacted directly.
155     */
156     public Proxy getChainProxy(){
157        return chainProxy;
158     }
159 
160     /**
161        Get string representation of this proxy.
162      * @returns string in the form:proxyHost:proxyPort \t Version versionNumber
163      */
164     public String   toString(){
165        return (""+proxyIP.getHostName()+":"+proxyPort+"\tVersion "+version);
166     }
167 
168 
169 //Public Static(Class) Methods
170 //==============================
171 
172    /**
173     * Sets SOCKS4 proxy as default.
174       @param hostName Host name on which SOCKS4 server is running.
175       @param port Port on which SOCKS4 server is running.
176       @param user Username to use for communications with proxy.
177     */
178    public static void setDefaultProxy(String   hostName,int port,String   user)
179                              throws UnknownHostException{
180       defaultProxy = new Socks4Proxy(hostName,port,user);
181    }
182 
183    /**
184     * Sets SOCKS4 proxy as default.
185       @param ipAddress Host address on which SOCKS4 server is running.
186       @param port Port on which SOCKS4 server is running.
187       @param user Username to use for communications with proxy.
188     */
189    public static void setDefaultProxy(InetAddress ipAddress,int port,
190                                       String   user){
191       defaultProxy = new Socks4Proxy(ipAddress,port,user);
192    }
193    /**
194     * Sets SOCKS5 proxy as default.
195     * Default proxy only supports no-authentication.
196       @param hostName Host name on which SOCKS5 server is running.
197       @param port Port on which SOCKS5 server is running.
198     */
199    public static void setDefaultProxy(String   hostName,int port)
200                              throws UnknownHostException{
201       defaultProxy = new Socks5Proxy(hostName,port);
202    }
203    /**
204     * Sets SOCKS5 proxy as default.
205     * Default proxy only supports no-authentication.
206       @param ipAddress Host address on which SOCKS5 server is running.
207       @param port Port on which SOCKS5 server is running.
208     */
209    public static void setDefaultProxy(InetAddress ipAddress,int port){
210       defaultProxy = new Socks5Proxy(ipAddress,port);
211    }
212    /**
213     * Sets default proxy.
214       @param p Proxy to use as default proxy.
215     */
216    public static void setDefaultProxy(Proxy p){
217      defaultProxy = p;
218    }
219 
220    /**
221       Get current default proxy.
222     * @return Current default proxy, or null if none is set.
223     */
224    public static Proxy getDefaultProxy(){
225      return defaultProxy;
226    }
227 
228    /**
229      Parses strings in the form: host[:port:user:password], and creates
230      proxy from information obtained from parsing.
231      <p>
232      Defaults: port = 1080.<br>
233      If user specified but not password, creates Socks4Proxy, if user
234      not specified creates Socks5Proxy, if both user and password are
235      speciefied creates Socks5Proxy with user/password authentication.
236      @param proxy_entry String in the form host[:port:user:password]
237      @return Proxy created from the string, null if entry was somehow
238              invalid(host unknown for example, or empty string)
239    */
240    public static Proxy parseProxy(String   proxy_entry){
241 
242       String   proxy_host;
243       int proxy_port = 1080;
244       String   proxy_user = null;
245       String   proxy_password = null;
246       Proxy proxy;
247 
248       java.util.StringTokenizer   st = new java.util.StringTokenizer  (
249                                          proxy_entry,":");
250       if(st.countTokens() < 1) return null;
251 
252       proxy_host = st.nextToken();
253       if(st.hasMoreTokens())
254          try{
255            proxy_port = Integer.parseInt(st.nextToken().trim());
256          }catch(NumberFormatException   nfe){}
257 
258       if(st.hasMoreTokens())
259          proxy_user = st.nextToken();
260 
261       if(st.hasMoreTokens())
262          proxy_password = st.nextToken();
263 
264       try{
265          if(proxy_user == null)
266            proxy = new Socks5Proxy(proxy_host,proxy_port);
267          else if(proxy_password == null)
268            proxy = new Socks4Proxy(proxy_host,proxy_port,proxy_user);
269          else{
270            proxy = new Socks5Proxy(proxy_host,proxy_port);
271            UserPasswordAuthentication upa = new UserPasswordAuthentication(
272                                             proxy_user, proxy_password);
273 
274            ((Socks5Proxy)proxy).setAuthenticationMethod(upa.METHOD_ID,upa);
275          }
276       }catch(UnknownHostException uhe){
277          return null;
278       }
279 
280       return proxy;
281    }
282 
283 
284 //Protected Methods
285 //=================
286 
287    protected void startSession()throws SocksException{
288        try{
289          if(chainProxy == null)
290             proxySocket = new Socket(proxyIP,proxyPort);
291          else if(proxyIP != null)
292             proxySocket = new SocksSocket(chainProxy,proxyIP,proxyPort);
293          else
294             proxySocket = new SocksSocket(chainProxy,proxyHost,proxyPort);
295 
296          in = proxySocket.getInputStream();
297          out = proxySocket.getOutputStream();
298        }catch(SocksException se){
299          throw se;
300        }catch(IOException io_ex){
301          throw new SocksException(SOCKS_PROXY_IO_ERROR,""+io_ex);
302        }
303    }
304 
305    protected abstract Proxy copy();
306    protected abstract ProxyMessage formMessage(int cmd,InetAddress ip,int port);
307    protected abstract ProxyMessage formMessage(int cmd,String   host,int port)
308              throws UnknownHostException;
309    protected abstract ProxyMessage formMessage(InputStream in)
310              throws SocksException,
311                     IOException;
312    
313 
314    protected ProxyMessage connect(InetAddress ip,int port)
315              throws SocksException{
316       try{
317          startSession();
318          ProxyMessage request  = formMessage(SOCKS_CMD_CONNECT,
319                                  ip,port);
320          return exchange(request);
321       }catch(SocksException se){
322          endSession();
323          throw se;
324       }
325    }
326    protected ProxyMessage connect(String   host,int port)
327              throws UnknownHostException,SocksException{
328       try{
329          startSession();
330          ProxyMessage request  = formMessage(SOCKS_CMD_CONNECT,
331                                  host,port);
332          return exchange(request);
333       }catch(SocksException se){
334          endSession();
335          throw se;
336       }
337    }
338 
339    protected ProxyMessage bind(InetAddress ip,int port)
340              throws SocksException{
341       try{
342          startSession();
343          ProxyMessage request  = formMessage(SOCKS_CMD_BIND,
344                              ip,port);
345          return exchange(request);
346       }catch(SocksException se){
347          endSession();
348          throw se;
349       }
350    }
351    protected ProxyMessage bind(String   host,int port)
352              throws UnknownHostException,SocksException{
353       try{
354          startSession();
355          ProxyMessage request  = formMessage(SOCKS_CMD_BIND,
356                              host,port);
357          return exchange(request);
358       }catch(SocksException se){
359          endSession();
360          throw se;
361       }
362    }
363 
364    protected ProxyMessage accept()
365              throws IOException,SocksException{
366       ProxyMessage msg;
367       try{
368          msg = formMessage(in);
369       }catch(InterruptedIOException iioe){
370          throw iioe;
371       }catch(IOException io_ex){
372          endSession();
373          throw new SocksException(SOCKS_PROXY_IO_ERROR,"While Trying accept:"
374          +io_ex);
375       }
376       return msg;
377    }
378 
379    protected ProxyMessage udpAssociate(InetAddress ip,int port)
380              throws SocksException{
381       try{
382          startSession();
383          ProxyMessage request  = formMessage(SOCKS_CMD_UDP_ASSOCIATE,
384                              ip,port);
385          if(request != null)
386            return exchange(request);
387       }catch(SocksException se){
388          endSession();
389          throw se;
390       }
391       //Only get here if request was null
392       endSession();
393       throw new SocksException(SOCKS_METHOD_NOTSUPPORTED,
394       "This version of proxy does not support UDP associate, use version 5");
395    }
396    protected ProxyMessage udpAssociate(String   host,int port)
397              throws UnknownHostException,SocksException{
398       try{
399          startSession();
400          ProxyMessage request  = formMessage(SOCKS_CMD_UDP_ASSOCIATE,
401                              host,port);
402          if(request != null) return exchange(request);
403       }catch(SocksException se){
404          endSession();
405          throw se;
406       }
407       //Only get here if request was null
408       endSession();
409       throw new SocksException(SOCKS_METHOD_NOTSUPPORTED,
410       "This version of proxy does not support UDP associate, use version 5");
411    }
412 
413 
414    protected void endSession(){
415       try{
416          if(proxySocket!=null) proxySocket.close();
417          proxySocket = null;
418       }catch(IOException io_ex){
419       }
420    }
421 
422    /**
423     *Sends the request to SOCKS server
424     */
425    protected void sendMsg(ProxyMessage msg)throws SocksException,
426                                                   IOException{
427       msg.write(out);
428    }
429 
430    /** 
431     * Reads the reply from the SOCKS server
432     */
433    protected ProxyMessage readMsg()throws SocksException,
434                                           IOException{
435       return formMessage(in);
436    }
437    /**
438     *Sends the request reads reply and returns it
439     *throws exception if something wrong with IO
440     *or the reply code is not zero
441     */
442    protected ProxyMessage exchange(ProxyMessage request)
443                            throws SocksException{
444       ProxyMessage reply;
445       try{
446          request.write(out);
447          reply = formMessage(in);
448       }catch(SocksException s_ex){
449          throw s_ex;
450       }catch(IOException ioe){
451          throw(new SocksException(SOCKS_PROXY_IO_ERROR,""+ioe));
452       }
453       return reply;
454    }
455 
456 
457 //Private methods
458 //===============
459 
460 
461 //Constants
462 
463    public static final int SOCKS_SUCCESS        =0;
464    public static final int SOCKS_FAILURE        =1;
465    public static final int SOCKS_BADCONNECT     =2;
466    public static final int SOCKS_BADNETWORK     =3;
467    public static final int SOCKS_HOST_UNREACHABLE   =4;
468    public static final int SOCKS_CONNECTION_REFUSED =5;
469    public static final int SOCKS_TTL_EXPIRE     =6;
470    public static final int SOCKS_CMD_NOT_SUPPORTED  =7;
471    public static final int SOCKS_ADDR_NOT_SUPPORTED =8;
472 
473    public static final int SOCKS_NO_PROXY       =1<<16;
474    public static final int SOCKS_PROXY_NO_CONNECT   =2<<16;
475    public static final int SOCKS_PROXY_IO_ERROR     =3<<16;
476    public static final int SOCKS_AUTH_NOT_SUPPORTED =4<<16;
477    public static final int SOCKS_AUTH_FAILURE       =5<<16;
478    public static final int SOCKS_JUST_ERROR     =6<<16;
479 
480    public static final int SOCKS_DIRECT_FAILED      =7<<16;
481    public static final int SOCKS_METHOD_NOTSUPPORTED    =8<<16;
482 
483 
484    static final int SOCKS_CMD_CONNECT       =0x1;
485    static final int SOCKS_CMD_BIND      =0x2;
486    static final int SOCKS_CMD_UDP_ASSOCIATE =0x3;
487 
488 }
489
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