/*      $NetBSD: stdhosts.c,v 1.20 2011/08/30 21:10:29 joerg Exp $       */

/*
 * Copyright (c) 1994 Mats O Jansson <moj@stacken.kth.se>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: stdhosts.c,v 1.20 2011/08/30 21:10:29 joerg Exp $");
#endif

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <err.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <netdb.h>

#include "protos.h"

__dead static void      usage(void);

int
main(int argc, char *argv[])
{
        struct in_addr host_addr;
        FILE    *data_file;
        size_t   line_no;
        size_t   len;
        char    *line, *k, *v, *addr_string;
        const char *fname;
        int      ch;
        int      af = 1 << 4;   /*IPv4*/
        struct addrinfo hints, *res;

        addr_string = NULL;             /* XXX gcc -Wuninitialized */

        while ((ch = getopt(argc, argv, "n")) != -1) {
                switch (ch) {
                case 'n':
                        af |= 1 << 6;   /*IPv6*/
                        break;
                default:
                        usage();
                        /* NOTREACHED */
                }
        }
        argc -= optind;
        argv += optind;

        if (argc > 1)
                usage();

        if (argc == 1) {
                fname = argv[0];
                data_file = fopen(fname, "r");
                if (data_file == NULL)
                        err(1, "%s", fname); 
        } else {
                fname = "<stdin>";
                data_file = stdin;
        }

        line_no = 0;
        for (;
            (line = fparseln(data_file, &len, &line_no, NULL,
                FPARSELN_UNESCALL));
            free(line)) {
                if (len == 0)
                        continue;

                v = line;
                for (k = v; *v && !isspace((unsigned char)*v); v++)
                        ;
                while (*v && isspace((unsigned char)*v))
                        *v++ = '\0';

                memset(&hints, 0, sizeof(hints));
                hints.ai_socktype = SOCK_DGRAM;         /*dummy*/
                hints.ai_flags = AI_NUMERICHOST;

                if ((af & (1 << 4)) != 0 && inet_aton(k, &host_addr) == 1 &&
                    (addr_string = inet_ntoa(host_addr)) != NULL) {
                        /* IPv4 */
                        printf("%s %s\n", addr_string, v);
                } else if ((af & (1 << 6)) != 0 &&
                           getaddrinfo(k, "0", &hints, &res) == 0) {
                        /* IPv6, with scope extension permitted */
                        freeaddrinfo(res);
                        printf("%s %s\n", k, v);
                } else
                        warnx("%s line %lu: syntax error", fname,
                            (unsigned long)line_no);
        }

        exit(0);
}

static void
usage(void)
{

        fprintf(stderr, "usage: %s [-n] [file]\n", getprogname());
        exit(1);
}