/**
* Encodes the proxy authorization request packet.
*
* @param request the socks proxy request data
* @return the encoded buffer
* @throws UnsupportedEncodingException if request's hostname charset can't be converted to ASCII.
*/
private IoBuffer encodeProxyRequestPacket(final SocksProxyRequest request)
throws UnsupportedEncodingException {
int len = 6;
InetSocketAddress adr = request.getEndpointAddress();
byte addressType = 0;
byte[] host = null;
if (adr != null && !adr.isUnresolved()) {
if (adr.getAddress() instanceof Inet6Address) {
len += 16;
addressType = SocksProxyConstants.IPV6_ADDRESS_TYPE;
} else if (adr.getAddress() instanceof Inet4Address) {
len += 4;
addressType = SocksProxyConstants.IPV4_ADDRESS_TYPE;
}
} else {
host = request.getHost() != null ? request.getHost().getBytes("ASCII") : null;
if (host != null) {
len += 1 + host.length;
addressType = SocksProxyConstants.DOMAIN_NAME_ADDRESS_TYPE;
} else {
throw new IllegalArgumentException(
"SocksProxyRequest object " + "has no suitable endpoint information");
}
}
IoBuffer buf = IoBuffer.allocate(len);
buf.put(request.getProtocolVersion());
buf.put(request.getCommandCode());
buf.put((byte) 0x00); // Reserved
buf.put(addressType);
if (host == null) {
buf.put(request.getIpAddress());
} else {
buf.put((byte) host.length);
buf.put(host);
}
buf.put(request.getPort());
return buf;
}
/**
* Encode a SOCKS4/SOCKS4a request and writes it to the next filter so it can be sent to the proxy
* server.
*
* @param nextFilter the next filter
* @param request the request to send.
*/
protected void writeRequest(final NextFilter nextFilter, final SocksProxyRequest request) {
try {
boolean isV4ARequest = Arrays.equals(request.getIpAddress(), SocksProxyConstants.FAKE_IP);
byte[] userID = request.getUserName().getBytes("ASCII");
byte[] host = isV4ARequest ? request.getHost().getBytes("ASCII") : null;
int len = 9 + userID.length;
if (isV4ARequest) {
len += host.length + 1;
}
IoBuffer buf = IoBuffer.allocate(len);
buf.put(request.getProtocolVersion());
buf.put(request.getCommandCode());
buf.put(request.getPort());
buf.put(request.getIpAddress());
buf.put(userID);
buf.put(SocksProxyConstants.TERMINATOR);
if (isV4ARequest) {
buf.put(host);
buf.put(SocksProxyConstants.TERMINATOR);
}
if (isV4ARequest) {
logger.debug(" sending SOCKS4a request");
} else {
logger.debug(" sending SOCKS4 request");
}
buf.flip();
writeData(nextFilter, buf);
} catch (Exception ex) {
closeSession("Unable to send Socks request: ", ex);
}
}