/* * $Id$ * * Copyright (C) 2003-2015 JNode.org * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published * by the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public * License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this library; If not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ package org.jnode.test.net; import org.jnode.net.SocketBuffer; import org.jnode.net.ipv4.IPv4Utils; import org.jnode.util.NumberUtils; /** * @author epr */ public class ChecksumTest { public static void main(String[] args) { SocketBuffer skbuf = new SocketBuffer(); skbuf.insert(20); for (int i = 0; i < 20; i++) { skbuf.set(i, i); } skbuf.set16(10, 0); final int ccs = IPv4Utils.calcChecksum(skbuf, 0, 20); skbuf.set16(10, ccs); final int ccs2 = IPv4Utils.calcChecksum(skbuf, 0, 20); System.out.println("ccs=0x" + NumberUtils.hex(ccs) + ", ccs2=0x" + NumberUtils.hex(ccs2)); } }