source: libpacketdump/ospf2_1.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 <arpa/inet.h>
#include "libpacketdump.h"


DLLEXPORT void decode(int link_type UNUSED,const char *packet,unsigned len) {

        libtrace_ospf_hello_v2_t *hello = (libtrace_ospf_hello_v2_t *)packet;
        struct in_addr *neigh;

        if (len < 4) 
                return;
        printf(" OSPF Hello: Network Mask %s\n", inet_ntoa(hello->mask));
        if (len < 6)
                return;

        printf(" OSPF Hello: Interval %u ", ntohs(hello->interval));

        if (len < 7) {
                printf("\n");
                return;
        }

        printf("Options ");

        if (hello->hello_options.e_bit)
                printf("E ");
        if (hello->hello_options.mc_bit)
                printf("MC ");
        if (hello->hello_options.np_bit)
                printf("N/P ");
        if (hello->hello_options.ea_bit)
                printf("EA ");
        if (hello->hello_options.dc_bit)
                printf("DC ");
        printf("\n");

        if (len < 8) 
                return;

        printf(" OSPF Hello: Priority %u ", hello->priority);
        
        if (len < 12) {
                printf("\n");
                return;
        }

        printf("Dead Interval %u\n", ntohl(hello->deadint));
        
        if (len < 16) 
                return;

        printf(" OSPF Hello: Designated Router %s\n", inet_ntoa(hello->designated));

        if (len < 20)
                return;

        printf(" OSPF Hello: Backup Designated Router %s\n", inet_ntoa(hello->backup));

        neigh = (struct in_addr *)(packet + sizeof(libtrace_ospf_hello_v2_t));
        len -= sizeof(libtrace_ospf_hello_v2_t);
        while (len >= 4) {
                printf(" OSPF Hello: Neighbour %s\n", inet_ntoa(*neigh));
                neigh++;
                len -= sizeof(struct in_addr);
        }



        return;
}