icmp.c

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/*
 * icmp.c
 *
 * Copyright (c) 2001 Dug Song <dugsong@monkey.org>
 *
 * $Id: icmp.c,v 1.6 2002/02/08 07:43:53 dugsong Exp $
 */

#include "config.h"

#include <sys/types.h>

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "dnet.h"
#include "aton.h"
#include "mod.h"

void
icmp_usage(void)
{
        fprintf(stderr, "Usage: dnet icmp [type|code <value>] ...\n");
        exit(1);
}

int
icmp_main(int argc, char *argv[])
{
        struct icmp_hdr *icmp;
        u_char *p, buf[IP_LEN_MAX];     /* XXX */
        char *name, *value;
        int c, len;

        icmp = (struct icmp_hdr *)buf;
        
        memset(icmp, 0, sizeof(*icmp));
        icmp->icmp_type = ICMP_ECHO;
        icmp->icmp_code = 0;
        
        for (c = 1; c + 1 < argc; c += 2) {
                name = argv[c];
                value = argv[c + 1];

                if (strcmp(name, "type") == 0) {
                        icmp->icmp_type = atoi(value);
                } else if (strcmp(name, "code") == 0) {
                        icmp->icmp_code = atoi(value);
                } else
                        icmp_usage();
        }
        argc -= c;
        argv += c;

        if (argc != 0)
                icmp_usage();

        p = buf + ICMP_HDR_LEN;
        
        if (!isatty(STDIN_FILENO)) {
                len = sizeof(buf) - (p - buf);
                while ((c = read(STDIN_FILENO, p, len)) > 0) {
                        p += c;
                        len -= c;
                }
        }
        len = p - buf;
        
        if (write(STDOUT_FILENO, buf, len) != len)
                err(1, "write");

        return (0);
}

struct mod mod_icmp = {
        "icmp",
        MOD_TYPE_ENCAP,
        icmp_main
};

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