Field nmf = NetClientHandler.class.getField("netManager");
Field rsaf = NetworkManager.class.getField("remoteSocketAddress");
Field.setAccessible(new Field[]{nmf, rsaf}, true);
InetSocketAddress isa = (InetSocketAddress) rsaf.get(nmf.get(((EntityClientPlayerMP) mc.thePlayer).sendQueue));
String hostname = isa.getHostString();
int ip = isa.getPort();