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/*
* netsniff-ng - the packet sniffing beast
* Copyright 2009, 2010 Daniel Borkmann.
* Subject to the GPL, version 2.
*/
#include <stdio.h>
#include <stdint.h>
#include <netinet/in.h> /* for ntohs() */
#include "proto.h"
#include "protos.h"
#include "csum.h"
#include "pkt_buff.h"
#include "built_in.h"
struct icmphdr {
uint8_t type;
uint8_t code;
uint16_t checksum;
union {
struct {
uint16_t id;
uint16_t sequence;
} echo;
uint32_t gateway;
struct {
uint16_t ____unused;
uint16_t mtu;
} frag;
} un;
} __packed;
static void icmp(struct pkt_buff *pkt)
{
struct icmphdr *icmp = (struct icmphdr *) pkt_pull(pkt, sizeof(*icmp));
uint16_t csum;
if (icmp == NULL)
return;
csum = calc_csum(icmp, pkt_len(pkt) + sizeof(*icmp), 0);
tprintf(" [ ICMP ");
tprintf("Type (%u), ", icmp->type);
tprintf("Code (%u), ", icmp->code);
tprintf("CSum (0x%.4x) is %s", ntohs(icmp->checksum),
csum ? colorize_start_full(black, red) "bogus (!)"
colorize_end() : "ok");
tprintf(" ]\n");
}
static void icmp_less(struct pkt_buff *pkt)
{
struct icmphdr *icmp = (struct icmphdr *) pkt_pull(pkt, sizeof(*icmp));
if (icmp == NULL)
return;
tprintf(" Type %u Code %u", icmp->type, icmp->code);
}
struct protocol icmpv4_ops = {
.key = 0x01,
.print_full = icmp,
.print_less = icmp_less,
};
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