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/*
Copyright (C) 2001-2025 Free Software Foundation, Inc.
This file is part of GNU Inetutils.
GNU Inetutils is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.
GNU Inetutils 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see `http://www.gnu.org/licenses/'. */
#include <config.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
/*#include <netinet/ip_icmp.h> -- deliberately not including this */
#include <arpa/inet.h>
#include <icmp.h>
int
icmp_generic_encode (unsigned char *buffer, size_t bufsize, int type,
int ident, int seqno)
{
icmphdr_t *icmp;
if (bufsize < ICMP_MINLEN)
return -1;
icmp = (icmphdr_t *) buffer;
icmp->icmp_type = type;
icmp->icmp_code = 0;
icmp->icmp_cksum = 0;
icmp->icmp_seq = htons (seqno);
icmp->icmp_id = htons (ident);
icmp->icmp_cksum = icmp_cksum (buffer, bufsize);
return 0;
}
int
icmp_generic_decode (unsigned char *buffer, size_t bufsize,
struct ip **ipp, icmphdr_t **icmpp)
{
size_t hlen;
unsigned short cksum;
struct ip *ip;
icmphdr_t *icmp;
/* IP header */
ip = (struct ip *) buffer;
hlen = ip->ip_hl << 2;
if (bufsize < hlen + ICMP_MINLEN)
return -1;
/* ICMP header */
icmp = (icmphdr_t *) (buffer + hlen);
/* Prepare return values */
*ipp = ip;
*icmpp = icmp;
/* Recompute checksum */
cksum = icmp->icmp_cksum;
icmp->icmp_cksum = 0;
icmp->icmp_cksum = icmp_cksum ((unsigned char *) icmp, bufsize - hlen);
if (icmp->icmp_cksum != cksum)
return 1;
return 0;
}
int
icmp_echo_encode (unsigned char *buffer, size_t bufsize, int ident, int seqno)
{
return icmp_generic_encode (buffer, bufsize, ICMP_ECHO, ident, seqno);
}
int
icmp_echo_decode (unsigned char *buffer, size_t bufsize,
struct ip **ipp, icmphdr_t **icmpp)
{
return icmp_generic_decode (buffer, bufsize, ipp, icmpp);
}
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