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

/*
* Copyright (c) 1994 Mats O Jansson <[email protected]>
* 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);
}