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Java > Open Source Codes > socks > SocksServerSocket


1 package socks;
2
3 import java.net.*;
4 import java.io.*;
5
6 /**
7    SocksServerSocket allows to accept connections from one particular
8    host through the SOCKS4 or SOCKS5 proxy.
9 */
10 public class SocksServerSocket extends ServerSocket{
11    //Data members
12 protected Proxy proxy;
13    protected String JavaDoc localHost;
14    protected InetAddress localIP;
15    protected int localPort;
16
17    boolean doing_direct = false;
18    InetAddress remoteAddr;
19
20    /**
21     * Creates ServerSocket capable of accepting one connection
22     * through the firewall, uses default Proxy.
23     *@param host Host from which the connection should be recieved.
24     *@param port Port number of the primary connection.
25     */
26    public SocksServerSocket(String JavaDoc host,int port)
27       throws SocksException,UnknownHostException,IOException{
28       this(Proxy.defaultProxy,host,port);
29    }
30    /**
31     *Creates ServerSocket capable of accepting one connection
32     *through the firewall, uses given proxy.
33     *@param p Proxy object to use.
34     *@param host Host from which the connection should be recieved.
35     *@param port Port number of the primary connection.
36     */
37    public SocksServerSocket(Proxy p,String JavaDoc host,int port)
38       throws SocksException,UnknownHostException,IOException{
39
40
41       super(0);
42       if(p == null) throw new SocksException(Proxy.SOCKS_NO_PROXY);
43       //proxy=p;
44 proxy = p.copy();
45       if(proxy.isDirect(host)){
46          remoteAddr = InetAddress.getByName(host);
47          proxy = null;
48          doDirect();
49       }else{
50          processReply(proxy.bind(host,port));
51       }
52    }
53
54    /**
55     * Creates ServerSocket capable of accepting one connection
56     * through the firewall, uses default Proxy.
57     *@param ip Host from which the connection should be recieved.
58     *@param port Port number of the primary connection.
59     */
60    public SocksServerSocket(InetAddress ip, int port) throws SocksException,
61                                                              IOException{
62       this(Proxy.defaultProxy,ip,port);
63    }
64
65    /**
66     *Creates ServerSocket capable of accepting one connection
67     *through the firewall, uses given proxy.
68     *@param p Proxy object to use.
69     *@param ip Host from which the connection should be recieved.
70     *@param port Port number of the primary connection.
71     */
72    public SocksServerSocket(Proxy p,InetAddress ip, int port)
73           throws SocksException,IOException{
74       super(0);
75
76       if(p == null) throw new SocksException(Proxy.SOCKS_NO_PROXY);
77       this.proxy = p.copy();
78
79       if(proxy.isDirect(ip)){
80          remoteAddr = ip;
81          doDirect();
82       }else{
83          processReply(proxy.bind(ip,port));
84       }
85    }
86
87
88    /**
89     * Accepts the incoming connection.
90     */
91    public Socket accept() throws IOException{
92       Socket s;
93
94       if(!doing_direct){
95          if(proxy == null) return null;
96
97          ProxyMessage msg = proxy.accept();
98          s = msg.ip == null? new SocksSocket(msg.host,msg.port,proxy)
99                                   : new SocksSocket(msg.ip,msg.port,proxy);
100          //Set timeout back to 0
101 proxy.proxySocket.setSoTimeout(0);
102       }else{ //Direct Connection
103
104           //Mimic the proxy behaviour,
105 //only accept connections from the speciefed host.
106 while(true){
107             s = super.accept();
108             if(s.getInetAddress().equals(remoteAddr)){
109                //got the connection from the right host
110 //Close listenning socket.
111 break;
112             }else
113                s.close(); //Drop all connections from other hosts
114 }
115
116       }
117       proxy = null;
118       //Return accepted socket
119 return s;
120    }
121
122    /**
123     * Closes the connection to proxy if socket have not been accepted, if
124     * the direct connection is used, closes direct ServerSocket. If the
125     * client socket have been allready accepted, does nothing.
126     */
127    public void close() throws IOException{
128       super.close();
129       if(proxy != null) proxy.endSession();
130       proxy = null;
131    }
132
133    /**
134      Get the name of the host proxy is using to listen for incoming
135      connection.
136      <P>
137      Usefull when address is returned by proxy as the hostname.
138      @return the hostname of the address proxy is using to listen
139      for incoming connection.
140     */
141    public String JavaDoc getHost(){
142       return localHost;
143    }
144
145    /**
146     * Get address assigned by proxy to listen for incomming
147     * connections, or the local machine address if doing direct
148     * connection.
149     */
150    public InetAddress getInetAddress(){
151       if(localIP == null){
152      try{
153        localIP = InetAddress.getByName(localHost);
154      }catch(UnknownHostException e){
155        return null;
156      }
157       }
158       return localIP;
159    }
160
161    /**
162     * Get port assigned by proxy to listen for incoming connections, or
163        the port chosen by local system, if accepting directly.
164     */
165    public int getLocalPort(){
166       return localPort;
167    }
168
169    /**
170     Set Timeout.
171
172     @param timeout Amount of time in milliseconds, accept should wait for
173                    incoming connection before failing with exception.
174                    Zero timeout implies infinity.
175    */
176    public void setSoTimeout(int timeout) throws SocketException{
177       super.setSoTimeout(timeout);
178       if(!doing_direct) proxy.proxySocket.setSoTimeout(timeout);
179    }
180
181
182 //Private Methods
183 //////////////////
184
185    private void processReply(ProxyMessage reply)throws SocksException{
186       localPort = reply.port;
187       /*
188        * If the server have assigned same host as it was contacted on
189        * it might return an address of all zeros
190        */
191       if(reply.host.equals("0.0.0.0")){
192          localIP = proxy.proxyIP;
193          localHost = localIP.getHostName();
194       }else{
195          localHost = reply.host;
196          localIP = reply.ip;
197       }
198    }
199
200    private void doDirect(){
201       doing_direct = true;
202       localPort = super.getLocalPort();
203       localIP = super.getInetAddress();
204       localHost = localIP.getHostName();
205    }
206
207 }
208
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