source: libpacketdump/eth_0.c

/*
 *
 * Copyright (c) 2007-2016 The University of Waikato, Hamilton, New Zealand.
 * All rights reserved.
 *
 * This file is part of libtrace.
 *
 * This code has been developed by the University of Waikato WAND
 * research group. For further information please see http://www.wand.net.nz/
 *
 * libtrace 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 3 of the License, or
 * (at your option) any later version.
 *
 * libtrace 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 program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <ctype.h>
#include "libpacketdump.h"

#define WIDTH 16

/* This is an example of a decoder for a protocol that we know exists, but is undocumented.
 * We dump the protocol as hex, and then skip onto the next header which we do know exists.
 */

DLLEXPORT void decode(int link_type UNUSED,const char *packet,unsigned len)
{
        unsigned int i=0;
        printf(" Ubiquity:");
        for(i=0;i<132; /* Nothing */ ) {
                unsigned int j;
                printf("\n ");
                for(j=0;j<WIDTH;j++) {
                        if (i+j<len)
                                printf(" %02x",(unsigned char)packet[i+j]);
                        else
                                printf("   ");
                }
                printf("    ");
                for(j=0;j<WIDTH;j++) {
                        if (i+j<len)
                                if (isprint((unsigned char)packet[i+j]))
                                        printf("%c",(unsigned char)packet[i+j]);
                                else
                                        printf(".");
                        else
                                printf("   ");
                }
                if (i+WIDTH>len)
                        break;
                else
                        i+=WIDTH;
        }
        printf("\n");
        if (len>132)
                decode_next(packet+132,len-132,"link",4);
        return;
}