/*      $NetBSD: ypalias_init.c,v 1.3 2024/06/02 11:44:29 andvar Exp $  */

/*
* Copyright (c) 2009 The NetBSD Foundation
* 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.
* 3. The name of the author may not be used to endorse or promote
*    products derived from this software without specific prior written
*    permission.
*
* 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.
*/

/* Code contributed by Greywolf <[email protected]>
* 28 August 2003.  All rights released to The NetBSD Foundation.
*/

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: ypalias_init.c,v 1.3 2024/06/02 11:44:29 andvar Exp $");
#endif

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

#include "ypalias_init.h"

#ifndef _PATH_YPNICKNAMES
#define _PATH_YPNICKNAMES   "/var/yp/nicknames"
#endif

const struct ypalias def_ypaliases[] = {
       { "passwd", "passwd.byname" },
       { "group", "group.byname" },
       { "networks", "networks.byaddr" },
       { "hosts", "hosts.byaddr" },
       { "protocols", "protocols.bynumber" },
       { "services", "services.byname" },
       { "aliases", "mail.aliases" },
       { "ethers", "ethers.byname" },
       { NULL, NULL },
};

const struct ypalias *
ypalias_init(void)
{
       FILE *fp;
       char *cp, *line;
       struct ypalias *ypa;
       size_t nypalias = 50;
       size_t i = 0, len, lineno;

       if ((fp = fopen(_PATH_YPNICKNAMES, "r")) == NULL)
               return &def_ypaliases[0];

       if ((ypa = calloc(sizeof(*ypa), nypalias)) == NULL)
               goto out;

       lineno = 1;
       for (; (line = fparseln(fp, &len, &lineno, NULL,
           FPARSELN_UNESCALL));) {
               cp = line;
               /* Ignore malformed lines */
               if ((ypa[i].alias = strsep(&line, " \t\n")) == NULL ||
                   (ypa[i].name = strsep(&line, " \t\n")) == NULL ||
                   ypa[i].alias != cp) {
                       warnx("%s, %zu: syntax error, ignored",
                           _PATH_YPNICKNAMES, lineno);
                       free(cp);
               } else
                       i++;
               if (i == nypalias) {
                       nypalias <<= 1;
                       if (reallocarr(&ypa, nypalias, sizeof(*ypa)) != 0)
                               goto out;
               }
       }
       ypa[i].alias = ypa[i].name = NULL;
       i++;

       (void)fclose(fp);
       if (reallocarr(&ypa, i, sizeof(*ypa)) == 0)
               return ypa;
out:
       warn("Cannot allocate alias space, returning default list");
       if (ypa) {
               do
                       free(__UNCONST(ypa[--i].alias));
               while (i != 0);
               free(ypa);
       }
       (void)fclose(fp);
       return def_ypaliases;
}