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Java > Open Source Codes > socks > Socks4Message


1 package socks;
2 import java.io.*;
3 import java.net.*;
4
5 /**
6   SOCKS4 Reply/Request message.
7 */
8
9 class Socks4Message extends ProxyMessage{
10
11    private byte[] msgBytes;
12    private int msgLength;
13
14    /**
15     * Server failed reply, cmd command for failed request
16     */
17    public Socks4Message(int cmd){
18       super(cmd,null,0);
19       this.user = null;
20
21       msgLength = 2;
22       msgBytes = new byte[2];
23
24       msgBytes[0] = (byte) 0;
25       msgBytes[1] = (byte) command;
26    }
27
28    /**
29     * Server successfull reply
30     */
31    public Socks4Message(int cmd,InetAddress ip,int port){
32       this(0,cmd,ip,port,null);
33    }
34
35    /**
36     * Client request
37     */
38    public Socks4Message(int cmd,InetAddress ip,int port,String JavaDoc user){
39       this(SOCKS_VERSION,cmd,ip,port,user);
40    }
41
42    /**
43     * Most general constructor
44     */
45    public Socks4Message(int version, int cmd,
46                         InetAddress ip,int port,String JavaDoc user){
47       super(cmd,ip,port);
48       this.user = user;
49       this.version = version;
50
51       msgLength = user == null?8:9+user.length();
52       msgBytes = new byte[msgLength];
53
54       msgBytes[0] = (byte) version;
55       msgBytes[1] = (byte) command;
56       msgBytes[2] = (byte) (port >> 8);
57       msgBytes[3] = (byte) port;
58
59       byte[] addr;
60
61       if(ip != null)
62         addr = ip.getAddress();
63       else{
64         addr = new byte[4];
65         addr[0]=addr[1]=addr[2]=addr[3]=0;
66       }
67       System.arraycopy(addr,0,msgBytes,4,4);
68
69       if(user != null){
70          byte[] buf = user.getBytes();
71          System.arraycopy(buf,0,msgBytes,8,buf.length);
72          msgBytes[msgBytes.length -1 ] = 0;
73       }
74    }
75
76    /**
77     *Initialise from the stream
78     *If clientMode is true attempts to read a server response
79     *otherwise reads a client request
80     *see read for more detail
81     */
82    public Socks4Message(InputStream in, boolean clientMode) throws IOException{
83       msgBytes = null;
84       read(in,clientMode);
85    }
86
87    public void read(InputStream in) throws IOException{
88         read(in,true);
89    }
90
91    public void read(InputStream in, boolean clientMode) throws IOException{
92        DataInputStream d_in = new DataInputStream(in);
93        version= d_in.readUnsignedByte();
94        command = d_in.readUnsignedByte();
95        if(clientMode && command != REPLY_OK){
96           String JavaDoc errMsg;
97           if(command >REPLY_OK && command < REPLY_BAD_IDENTD)
98              errMsg = replyMessage[command-REPLY_OK];
99           else
100              errMsg = "Unknown Reply Code";
101           throw new SocksException(command,errMsg);
102        }
103        port = d_in.readUnsignedShort();
104        byte[] addr = new byte[4];
105        d_in.readFully(addr);
106        ip=bytes2IP(addr);
107        host = ip.getHostName();
108        if(!clientMode){
109           int b = in.read();
110           //Hope there are no idiots with user name bigger than this
111 byte[] userBytes = new byte[256];
112           int i = 0;
113           for(i =0;i<userBytes.length && b>0;++i){
114              userBytes[i] = (byte) b;
115              b = in.read();
116           }
117           user = new String JavaDoc(userBytes,0,i);
118        }
119    }
120    public void write(OutputStream out) throws IOException{
121       if(msgBytes == null){
122          Socks4Message msg = new Socks4Message(version,command,ip,port,user);
123          msgBytes = msg.msgBytes;
124          msgLength = msg.msgLength;
125       }
126       out.write(msgBytes);
127    }
128
129    //Class methods
130 static InetAddress bytes2IP(byte[] addr){
131       String JavaDoc s = bytes2IPV4(addr,0);
132       try{
133          return InetAddress.getByName(s);
134       }catch(UnknownHostException uh_ex){
135         return null;
136       }
137    }
138
139    //Constants
140
141    static final String JavaDoc[] replyMessage ={
142           "Request Granted",
143           "Request Rejected or Failed",
144           "Failed request, can't connect to Identd",
145           "Failed request, bad user name"};
146
147    static final int SOCKS_VERSION = 4;
148
149    public final static int REQUEST_CONNECT = 1;
150    public final static int REQUEST_BIND = 2;
151
152    public final static int REPLY_OK = 90;
153    public final static int REPLY_REJECTED = 91;
154    public final static int REPLY_NO_CONNECT = 92;
155    public final static int REPLY_BAD_IDENTD = 93;
156
157 }
158
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