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/****************************************************************************
** File: arp.c
**
** Author: Mike Borella
**
** Comments: Dump ICMP header information
**
*****************************************************************************/
#include <stdio.h>
#include <unistd.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include "config.h"
#include "arp.h"
extern u_char *packet_end;
void dump_arp(u_char *bp, int length, int caplen)
{
EtherARP *ap;
u_short pro, hrd, op;
struct in_addr spa, tpa;
char *etheraddr_string(u_char *ep);
/*
* ARP header announcement
*/
printf("----------------------------------------------------------\n");
printf(" ARP Header\n");
printf("----------------------------------------------------------\n");
/*
* Check for truncated packet
*/
ap = (EtherARP *) bp;
if (length < sizeof(EtherARP))
{
printf("Truncated packet\n");
return;
}
/*
* Dump ARP header fields
*/
hrd = ntohs(ap->ea_hdr.ar_hrd);
pro = ntohs(ap->ea_hdr.ar_pro);
op = ntohs(ap->ea_hdr.ar_op);
printf("Hardware type: %d\n", hrd);
printf("Protocol: %d\n", pro);
printf("Operation: %d ", op);
/*
* Figure out type of ARP
*/
switch (op)
{
case ARPOP_REQUEST:
printf("(ARP request)\n");
break;
case ARPOP_REPLY:
printf("(ARP reply)\n");
break;
case ARPOP_RREQUEST:
printf("(RARP request)\n");
break;
case ARPOP_RREPLY:
printf("(RARP reply)\n");
break;
default:
printf("(unknown)\n");
return;
}
/*
* Dump hardware and IP addresses
*/
memcpy((void *) &spa, (void *) &ap->arp_spa, sizeof (struct in_addr));
memcpy((void *) &tpa, (void *) &ap->arp_tpa, sizeof (struct in_addr));
printf("Sender hardware: %s\n", etheraddr_string(ap->arp_sha));
printf("Sender IP: %s\n", inet_ntoa(spa));
printf("Target hardware: %s\n", etheraddr_string(ap->arp_tha));
printf("Target IP: %s\n", inet_ntoa(tpa));
}
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