1 | package nu.fw.jeti.plugins.filetransfer.socks5.jsocks; |
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2 | import java.net.*; |
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3 | import java.io.*; |
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4 | |
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5 | /** |
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6 | Datagram socket to interract through the firewall.<BR> |
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7 | Can be used same way as the normal DatagramSocket. One should |
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8 | be carefull though with the datagram sizes used, as additional data |
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9 | is present in both incomming and outgoing datagrams. |
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10 | <p> |
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11 | SOCKS5 protocol allows to send host address as either: |
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12 | <ul> |
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13 | <li> IPV4, normal 4 byte address. (10 bytes header size) |
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14 | <li> IPV6, version 6 ip address (not supported by Java as for now). |
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15 | 22 bytes header size. |
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16 | <li> Host name,(7+length of the host name bytes header size). |
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17 | </ul> |
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18 | As with other Socks equivalents, direct addresses are handled |
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19 | transparently, that is data will be send directly when required |
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20 | by the proxy settings. |
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21 | <p> |
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22 | <b>NOTE:</b><br> |
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23 | Unlike other SOCKS Sockets, it <b>does not</b> support proxy chaining, |
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24 | and will throw an exception if proxy has a chain proxy attached. The |
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25 | reason for that is not my laziness, but rather the restrictions of |
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26 | the SOCKSv5 protocol. Basicaly SOCKSv5 proxy server, needs to know from |
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27 | which host:port datagrams will be send for association, and returns address |
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28 | to which datagrams should be send by the client, but it does not |
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29 | inform client from which host:port it is going to send datagrams, in fact |
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30 | there is even no guarantee they will be send at all and from the same address |
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31 | each time. |
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32 | |
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33 | */ |
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34 | public class Socks5DatagramSocket extends DatagramSocket{ |
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35 | |
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36 | InetAddress relayIP; |
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37 | int relayPort; |
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38 | Socks5Proxy proxy; |
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39 | private boolean server_mode = false; |
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40 | UDPEncapsulation encapsulation; |
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41 | |
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42 | |
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43 | /** |
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44 | Construct Datagram socket for communication over SOCKS5 proxy |
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45 | server. This constructor uses default proxy, the one set with |
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46 | Proxy.setDefaultProxy() method. If default proxy is not set or |
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47 | it is set to version4 proxy, which does not support datagram |
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48 | forwarding, throws SocksException. |
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49 | |
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50 | */ |
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51 | public Socks5DatagramSocket() throws SocksException, |
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52 | IOException{ |
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53 | this(Proxy.defaultProxy,0,null); |
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54 | } |
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55 | /** |
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56 | Construct Datagram socket for communication over SOCKS5 proxy |
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57 | server. And binds it to the specified local port. |
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58 | This constructor uses default proxy, the one set with |
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59 | Proxy.setDefaultProxy() method. If default proxy is not set or |
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60 | it is set to version4 proxy, which does not support datagram |
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61 | forwarding, throws SocksException. |
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62 | */ |
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63 | public Socks5DatagramSocket(int port) throws SocksException, |
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64 | IOException{ |
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65 | this(Proxy.defaultProxy,port,null); |
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66 | } |
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67 | /** |
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68 | Construct Datagram socket for communication over SOCKS5 proxy |
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69 | server. And binds it to the specified local port and address. |
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70 | This constructor uses default proxy, the one set with |
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71 | Proxy.setDefaultProxy() method. If default proxy is not set or |
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72 | it is set to version4 proxy, which does not support datagram |
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73 | forwarding, throws SocksException. |
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74 | */ |
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75 | public Socks5DatagramSocket(int port,InetAddress ip) throws SocksException, |
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76 | IOException{ |
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77 | this(Proxy.defaultProxy,port,ip); |
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78 | } |
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79 | |
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80 | /** |
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81 | Constructs datagram socket for communication over specified proxy. |
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82 | And binds it to the given local address and port. Address of null |
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83 | and port of 0, signify any availabale port/address. |
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84 | Might throw SocksException, if: |
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85 | <ol> |
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86 | <li> Given version of proxy does not support UDP_ASSOCIATE. |
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87 | <li> Proxy can't be reached. |
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88 | <li> Authorization fails. |
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89 | <li> Proxy does not want to perform udp forwarding, for any reason. |
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90 | </ol> |
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91 | Might throw IOException if binding dtagram socket to given address/port |
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92 | fails. |
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93 | See java.net.DatagramSocket for more details. |
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94 | */ |
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95 | public Socks5DatagramSocket(Proxy p,int port,InetAddress ip) |
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96 | throws SocksException, |
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97 | IOException{ |
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98 | super(port,ip); |
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99 | if(p == null) throw new SocksException(Proxy.SOCKS_NO_PROXY); |
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100 | if(!(p instanceof Socks5Proxy)) |
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101 | throw new SocksException(-1,"Datagram Socket needs Proxy version 5"); |
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102 | |
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103 | if(p.chainProxy != null) |
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104 | throw new SocksException(Proxy.SOCKS_JUST_ERROR, |
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105 | "Datagram Sockets do not support proxy chaining."); |
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106 | |
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107 | proxy =(Socks5Proxy) p.copy(); |
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108 | |
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109 | ProxyMessage msg = proxy.udpAssociate(super.getLocalAddress(), |
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110 | super.getLocalPort()); |
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111 | relayIP = msg.ip; |
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112 | if(relayIP.getHostAddress().equals("0.0.0.0")) relayIP = proxy.proxyIP; |
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113 | relayPort = msg.port; |
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114 | |
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115 | encapsulation = proxy.udp_encapsulation; |
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116 | |
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117 | //debug("Datagram Socket:"+getLocalAddress()+":"+getLocalPort()+"\n"); |
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118 | //debug("Socks5Datagram: "+relayIP+":"+relayPort+"\n"); |
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119 | } |
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120 | |
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121 | /** |
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122 | Used by UDPRelayServer. |
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123 | */ |
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124 | Socks5DatagramSocket(boolean server_mode,UDPEncapsulation encapsulation, |
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125 | InetAddress relayIP,int relayPort) |
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126 | throws IOException{ |
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127 | super(); |
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128 | this.server_mode = server_mode; |
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129 | this.relayIP = relayIP; |
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130 | this.relayPort = relayPort; |
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131 | this.encapsulation = encapsulation; |
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132 | this.proxy = null; |
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133 | } |
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134 | |
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135 | /** |
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136 | Sends the Datagram either through the proxy or directly depending |
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137 | on current proxy settings and destination address. <BR> |
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138 | |
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139 | <B> NOTE: </B> DatagramPacket size should be at least 10 bytes less |
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140 | than the systems limit. |
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141 | |
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142 | <P> |
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143 | See documentation on java.net.DatagramSocket |
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144 | for full details on how to use this method. |
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145 | @param dp Datagram to send. |
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146 | @throws IOException If error happens with I/O. |
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147 | */ |
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148 | public void send(DatagramPacket dp) throws IOException{ |
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149 | //If the host should be accessed directly, send it as is. |
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150 | if(!server_mode && proxy.isDirect(dp.getAddress())){ |
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151 | super.send(dp); |
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152 | //debug("Sending directly:"); |
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153 | return; |
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154 | } |
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155 | |
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156 | byte[] head = formHeader(dp.getAddress(),dp.getPort()); |
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157 | byte[] buf = new byte[head.length + dp.getLength()]; |
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158 | byte[] data = dp.getData(); |
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159 | //Merge head and data |
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160 | System.arraycopy(head,0,buf,0,head.length); |
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161 | //System.arraycopy(data,dp.getOffset(),buf,head.length,dp.getLength()); |
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162 | System.arraycopy(data,0,buf,head.length,dp.getLength()); |
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163 | |
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164 | if(encapsulation != null) |
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165 | buf = encapsulation.udpEncapsulate(buf,true); |
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166 | |
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167 | super.send(new DatagramPacket(buf,buf.length,relayIP,relayPort)); |
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168 | } |
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169 | /** |
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170 | This method allows to send datagram packets with address type DOMAINNAME. |
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171 | SOCKS5 allows to specify host as names rather than ip addresses.Using |
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172 | this method one can send udp datagrams through the proxy, without having |
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173 | to know the ip address of the destination host. |
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174 | <p> |
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175 | If proxy specified for that socket has an option resolveAddrLocally set |
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176 | to true host will be resolved, and the datagram will be send with address |
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177 | type IPV4, if resolve fails, UnknownHostException is thrown. |
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178 | @param dp Datagram to send, it should contain valid port and data |
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179 | @param host Host name to which datagram should be send. |
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180 | @throws IOException If error happens with I/O, or the host can't be |
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181 | resolved when proxy settings say that hosts should be resolved locally. |
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182 | @see Socks5Proxy#resolveAddrLocally(boolean) |
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183 | */ |
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184 | public void send(DatagramPacket dp, String host) throws IOException{ |
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185 | if(proxy.isDirect(host)){ |
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186 | dp.setAddress(InetAddress.getByName(host)); |
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187 | super.send(dp); |
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188 | return; |
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189 | } |
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190 | |
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191 | if(((Socks5Proxy)proxy).resolveAddrLocally){ |
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192 | dp.setAddress(InetAddress.getByName(host)); |
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193 | } |
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194 | |
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195 | byte[] head = formHeader(host,dp.getPort()); |
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196 | byte[] buf = new byte[head.length + dp.getLength()]; |
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197 | byte[] data = dp.getData(); |
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198 | //Merge head and data |
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199 | System.arraycopy(head,0,buf,0,head.length); |
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200 | //System.arraycopy(data,dp.getOffset(),buf,head.length,dp.getLength()); |
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201 | System.arraycopy(data,0,buf,head.length,dp.getLength()); |
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202 | |
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203 | if(encapsulation != null) |
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204 | buf = encapsulation.udpEncapsulate(buf,true); |
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205 | |
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206 | super.send(new DatagramPacket(buf,buf.length,relayIP,relayPort)); |
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207 | } |
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208 | |
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209 | /** |
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210 | * Receives udp packet. If packet have arrived from the proxy relay server, |
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211 | * it is processed and address and port of the packet are set to the |
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212 | * address and port of sending host.<BR> |
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213 | * If the packet arrived from anywhere else it is not changed.<br> |
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214 | * <B> NOTE: </B> DatagramPacket size should be at least 10 bytes bigger |
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215 | * than the largest packet you expect (this is for IPV4 addresses). |
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216 | * For hostnames and IPV6 it is even more. |
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217 | @param dp Datagram in which all relevent information will be copied. |
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218 | */ |
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219 | public void receive(DatagramPacket dp) throws IOException{ |
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220 | super.receive(dp); |
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221 | |
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222 | if(server_mode){ |
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223 | //Drop all datagrams not from relayIP/relayPort |
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224 | int init_length = dp.getLength(); |
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225 | int initTimeout = getSoTimeout(); |
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226 | long startTime = System.currentTimeMillis(); |
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227 | |
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228 | while(!relayIP.equals(dp.getAddress()) || |
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229 | relayPort != dp.getPort()){ |
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230 | |
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231 | //Restore datagram size |
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232 | dp.setLength(init_length); |
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233 | |
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234 | //If there is a non-infinit timeout on this socket |
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235 | //Make sure that it happens no matter how often unexpected |
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236 | //packets arrive. |
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237 | if(initTimeout != 0){ |
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238 | int newTimeout = initTimeout - (int)(System.currentTimeMillis() - |
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239 | startTime); |
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240 | if(newTimeout <= 0) throw new InterruptedIOException( |
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241 | "In Socks5DatagramSocket->receive()"); |
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242 | setSoTimeout(newTimeout); |
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243 | } |
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244 | |
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245 | super.receive(dp); |
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246 | } |
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247 | |
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248 | //Restore timeout settings |
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249 | if(initTimeout != 0) setSoTimeout(initTimeout); |
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250 | |
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251 | }else if(!relayIP.equals(dp.getAddress()) || |
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252 | relayPort != dp.getPort()) |
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253 | return; // Recieved direct packet |
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254 | //If the datagram is not from the relay server, return it it as is. |
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255 | |
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256 | byte[] data; |
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257 | data = dp.getData(); |
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258 | |
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259 | if(encapsulation != null) |
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260 | data = encapsulation.udpEncapsulate(data,false); |
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261 | |
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262 | int offset = 0; //Java 1.1 |
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263 | //int offset = dp.getOffset(); //Java 1.2 |
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264 | |
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265 | ByteArrayInputStream bIn = new ByteArrayInputStream(data,offset, |
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266 | dp.getLength()); |
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267 | |
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268 | |
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269 | ProxyMessage msg = new Socks5Message(bIn); |
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270 | dp.setPort(msg.port); |
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271 | dp.setAddress(msg.getInetAddress()); |
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272 | |
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273 | //what wasn't read by the Message is the data |
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274 | int data_length = bIn.available(); |
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275 | //Shift data to the left |
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276 | System.arraycopy(data,offset+dp.getLength()-data_length, |
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277 | data,offset,data_length); |
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278 | |
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279 | |
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280 | dp.setLength(data_length); |
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281 | } |
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282 | |
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283 | /** |
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284 | * Returns port assigned by the proxy, to which datagrams are relayed. |
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285 | * It is not the same port to which other party should send datagrams. |
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286 | @return Port assigned by socks server to which datagrams are send |
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287 | for association. |
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288 | */ |
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289 | public int getLocalPort(){ |
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290 | if(server_mode) return super.getLocalPort(); |
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291 | return relayPort; |
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292 | } |
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293 | /** |
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294 | * Address assigned by the proxy, to which datagrams are send for relay. |
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295 | * It is not necesseraly the same address, to which other party should send |
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296 | * datagrams. |
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297 | @return Address to which datagrams are send for association. |
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298 | */ |
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299 | public InetAddress getLocalAddress(){ |
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300 | if(server_mode) return super.getLocalAddress(); |
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301 | return relayIP; |
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302 | } |
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303 | |
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304 | /** |
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305 | * Closes datagram socket, and proxy connection. |
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306 | */ |
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307 | public void close(){ |
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308 | if(!server_mode) proxy.endSession(); |
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309 | super.close(); |
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310 | } |
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311 | |
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312 | /** |
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313 | This method checks wether proxy still runs udp forwarding service |
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314 | for this socket. |
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315 | <p> |
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316 | This methods checks wether the primary connection to proxy server |
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317 | is active. If it is, chances are that proxy continues to forward |
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318 | datagrams being send from this socket. If it was closed, most likely |
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319 | datagrams are no longer being forwarded by the server. |
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320 | <p> |
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321 | Proxy might decide to stop forwarding datagrams, in which case it |
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322 | should close primary connection. This method allows to check, wether |
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323 | this have been done. |
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324 | <p> |
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325 | You can specify timeout for which we should be checking EOF condition |
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326 | on the primary connection. Timeout is in milliseconds. Specifying 0 as |
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327 | timeout implies infinity, in which case method will block, until |
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328 | connection to proxy is closed or an error happens, and then return false. |
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329 | <p> |
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330 | One possible scenario is to call isProxyactive(0) in separate thread, |
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331 | and once it returned notify other threads about this event. |
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332 | |
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333 | @param timeout For how long this method should block, before returning. |
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334 | @return true if connection to proxy is active, false if eof or error |
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335 | condition have been encountered on the connection. |
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336 | */ |
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337 | public boolean isProxyAlive(int timeout){ |
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338 | if(server_mode) return false; |
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339 | if(proxy != null){ |
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340 | try{ |
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341 | proxy.proxySocket.setSoTimeout(timeout); |
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342 | |
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343 | int eof = proxy.in.read(); |
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344 | if(eof < 0) return false; // EOF encountered. |
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345 | else return true; // This really should not happen |
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346 | |
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347 | }catch(InterruptedIOException iioe){ |
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348 | return true; // read timed out. |
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349 | }catch(IOException ioe){ |
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350 | return false; |
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351 | } |
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352 | } |
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353 | return false; |
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354 | } |
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355 | |
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356 | //PRIVATE METHODS |
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357 | ////////////////// |
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358 | |
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359 | |
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360 | private byte[] formHeader(InetAddress ip, int port){ |
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361 | Socks5Message request = new Socks5Message(0,ip,port); |
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362 | request.data[0] = 0; |
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363 | return request.data; |
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364 | } |
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365 | |
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366 | |
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367 | private byte[] formHeader(String host,int port){ |
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368 | Socks5Message request = new Socks5Message(0,host,port); |
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369 | request.data[0] = 0; |
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370 | return request.data; |
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371 | } |
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372 | |
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373 | |
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374 | /*====================================================================== |
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375 | |
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376 | //Mainly Test functions |
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377 | ////////////////////// |
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378 | |
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379 | private String bytes2String(byte[] b){ |
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380 | String s=""; |
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381 | char[] hex_digit = { '0','1','2','3','4','5','6','7','8','9', |
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382 | 'A','B','C','D','E','F'}; |
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383 | for(int i=0;i<b.length;++i){ |
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384 | int i1 = (b[i] & 0xF0) >> 4; |
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385 | int i2 = b[i] & 0xF; |
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386 | s+=hex_digit[i1]; |
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387 | s+=hex_digit[i2]; |
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388 | s+=" "; |
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389 | } |
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390 | return s; |
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391 | } |
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392 | private static final void debug(String s){ |
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393 | if(DEBUG) |
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394 | System.out.print(s); |
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395 | } |
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396 | |
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397 | private static final boolean DEBUG = true; |
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398 | |
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399 | |
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400 | public static void usage(){ |
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401 | System.err.print( |
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402 | "Usage: java Socks.SocksDatagramSocket host port [socksHost socksPort]\n"); |
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403 | } |
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404 | |
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405 | static final int defaultProxyPort = 1080; //Default Port |
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406 | static final String defaultProxyHost = "www-proxy"; //Default proxy |
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407 | |
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408 | public static void main(String args[]){ |
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409 | int port; |
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410 | String host; |
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411 | int proxyPort; |
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412 | String proxyHost; |
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413 | InetAddress ip; |
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414 | |
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415 | if(args.length > 1 && args.length < 5){ |
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416 | try{ |
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417 | |
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418 | host = args[0]; |
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419 | port = Integer.parseInt(args[1]); |
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420 | |
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421 | proxyPort =(args.length > 3)? Integer.parseInt(args[3]) |
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422 | : defaultProxyPort; |
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423 | |
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424 | host = args[0]; |
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425 | ip = InetAddress.getByName(host); |
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426 | |
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427 | proxyHost =(args.length > 2)? args[2] |
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428 | : defaultProxyHost; |
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429 | |
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430 | Proxy.setDefaultProxy(proxyHost,proxyPort); |
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431 | Proxy p = Proxy.getDefaultProxy(); |
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432 | p.addDirect("lux"); |
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433 | |
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434 | |
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435 | DatagramSocket ds = new Socks5DatagramSocket(); |
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436 | |
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437 | |
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438 | BufferedReader in = new BufferedReader( |
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439 | new InputStreamReader(System.in)); |
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440 | String s; |
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441 | |
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442 | System.out.print("Enter line:"); |
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443 | s = in.readLine(); |
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444 | |
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445 | while(s != null){ |
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446 | byte[] data = (s+"\r\n").getBytes(); |
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447 | DatagramPacket dp = new DatagramPacket(data,0,data.length, |
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448 | ip,port); |
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449 | System.out.println("Sending to: "+ip+":"+port); |
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450 | ds.send(dp); |
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451 | dp = new DatagramPacket(new byte[1024],1024); |
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452 | |
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453 | System.out.println("Trying to recieve on port:"+ |
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454 | ds.getLocalPort()); |
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455 | ds.receive(dp); |
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456 | System.out.print("Recieved:\n"+ |
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457 | "From:"+dp.getAddress()+":"+dp.getPort()+ |
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458 | "\n\n"+ |
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459 | new String(dp.getData(),dp.getOffset(),dp.getLength())+"\n" |
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460 | ); |
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461 | System.out.print("Enter line:"); |
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462 | s = in.readLine(); |
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463 | |
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464 | } |
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465 | ds.close(); |
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466 | System.exit(1); |
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467 | |
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468 | }catch(SocksException s_ex){ |
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469 | System.err.println("SocksException:"+s_ex); |
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470 | s_ex.printStackTrace(); |
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471 | System.exit(1); |
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472 | }catch(IOException io_ex){ |
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473 | io_ex.printStackTrace(); |
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474 | System.exit(1); |
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475 | }catch(NumberFormatException num_ex){ |
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476 | usage(); |
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477 | num_ex.printStackTrace(); |
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478 | System.exit(1); |
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479 | } |
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480 | |
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481 | }else{ |
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482 | usage(); |
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483 | } |
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484 | } |
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485 | */ |
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486 | |
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487 | } |
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