/**
* Request a SOCKS connection to the application server given. If the request fails to complete
* successfully, an exception is thrown.
*/
private void socksRequestConnection(
InetAddress applicationServerAddress, int applicationServerPort) throws IOException {
socksSendRequest(
Socks4Message.COMMAND_CONNECT, applicationServerAddress, applicationServerPort);
Socks4Message reply = socksReadReply();
if (reply.getCommandOrResult() != Socks4Message.RETURN_SUCCESS) {
throw new IOException(reply.getErrorString(reply.getCommandOrResult()));
}
}
/** Read a SOCKS V4 reply. */
private Socks4Message socksReadReply() throws IOException {
Socks4Message reply = new Socks4Message();
int bytesRead = 0;
while (bytesRead < Socks4Message.REPLY_LENGTH) {
int count =
getInputStream()
.read(reply.getBytes(), bytesRead, Socks4Message.REPLY_LENGTH - bytesRead);
if (-1 == count) {
break;
}
bytesRead += count;
}
if (Socks4Message.REPLY_LENGTH != bytesRead) {
throw new SocketException(Msg.getString("KA011")); // $NON-NLS-1$
}
return reply;
}
/** Bind using a SOCKS server. */
private void socksBind() throws IOException {
try {
netImpl.connect(fd, trafficClass, socksGetServerAddress(), socksGetServerPort());
} catch (Exception e) {
throw new IOException(Msg.getString("K003f", e)); // $NON-NLS-1$
}
// There must be a connection to an application host for the bind to
// work.
if (lastConnectedAddress == null) {
throw new SocketException(Msg.getString("K0040")); // $NON-NLS-1$
}
// Use the last connected address and port in the bind request.
socksSendRequest(Socks4Message.COMMAND_BIND, lastConnectedAddress, lastConnectedPort);
Socks4Message reply = socksReadReply();
if (reply.getCommandOrResult() != Socks4Message.RETURN_SUCCESS) {
throw new IOException(reply.getErrorString(reply.getCommandOrResult()));
}
// A peculiarity of socks 4 - if the address returned is 0, use the
// original socks server address.
if (reply.getIP() == 0) {
address = socksGetServerAddress();
} else {
// IPv6 support not yet required as
// currently the Socks4Message.getIP() only returns int,
// so only works with IPv4 4byte addresses
byte[] replyBytes = new byte[4];
NetUtil.intToBytes(reply.getIP(), replyBytes, 0);
address = InetAddress.getByAddress(replyBytes);
}
localport = reply.getPort();
}
/** Send a SOCKS V4 request. */
private void socksSendRequest(int command, InetAddress address, int port) throws IOException {
Socks4Message request = new Socks4Message();
request.setCommandOrResult(command);
request.setPort(port);
request.setIP(address.getAddress());
request.setUserId("default"); // $NON-NLS-1$
getOutputStream().write(request.getBytes(), 0, request.getLength());
}
/** Perform an accept for a SOCKS bind. */
public void socksAccept() throws IOException {
Socks4Message reply = socksReadReply();
if (reply.getCommandOrResult() != Socks4Message.RETURN_SUCCESS) {
throw new IOException(reply.getErrorString(reply.getCommandOrResult()));
}
}