/*      $NetBSD: sethostent.c,v 1.21 2023/12/07 22:33:49 kre Exp $      */

/*
* Copyright (c) 1985, 1993
*      The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)sethostent.c        8.1 (Berkeley) 6/4/93";
static char rcsid[] = "Id: sethostent.c,v 8.5 1996/09/28 06:51:07 vixie Exp ";
#else
__RCSID("$NetBSD: sethostent.c,v 1.21 2023/12/07 22:33:49 kre Exp $");
#endif
#endif /* LIBC_SCCS and not lint */

#include "namespace.h"
#include <sys/param.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>
#include <assert.h>
#include <string.h>
#include <nsswitch.h>
#include <netdb.h>
#include <resolv.h>
#include <errno.h>
#include <stdlib.h>

#include "hostent.h"

#ifdef __weak_alias
__weak_alias(sethostent,_sethostent)
__weak_alias(endhostent,_endhostent)
#endif

#ifndef _REENTRANT
void    res_close(void);
#endif

static struct hostent *_hf_gethtbyname2(const char *, int, struct getnamaddr *);

void
/*ARGSUSED*/
sethostent(int stayopen)
{
#ifndef _REENTRANT
       if ((_res.options & RES_INIT) == 0 && res_init() == -1)
               return;
       if (stayopen)
               _res.options |= RES_STAYOPEN | RES_USEVC;
#endif
       sethostent_r(&_h_file);
}

void
endhostent(void)
{
#ifndef _REENTRANT
       _res.options &= ~(RES_STAYOPEN | RES_USEVC);
       res_close();
#endif
       endhostent_r(&_h_file);
}
static const char *_h_hosts = _PATH_HOSTS;

void
_hf_sethostsfile(const char *f) {
       _h_hosts = f;
}

void
sethostent_r(FILE **hf)
{
       if (!*hf)
               *hf = fopen(_h_hosts, "re");
       else
               rewind(*hf);
}

void
endhostent_r(FILE **hf)
{
       if (*hf) {
               (void)fclose(*hf);
               *hf = NULL;
       }
}

/*ARGSUSED*/
int
_hf_gethtbyname(void *rv, void *cb_data, va_list ap)
{
       struct hostent *hp;
       const char *name;
       int af;
       struct getnamaddr *info = rv;

       _DIAGASSERT(rv != NULL);

       name = va_arg(ap, char *);
       /* NOSTRICT skip string len */(void)va_arg(ap, int);
       af = va_arg(ap, int);

#if 0
       {
               res_state res = __res_get_state();
               if (res == NULL)
                       return NS_NOTFOUND;
               if (res->options & RES_USE_INET6)
                       hp = _hf_gethtbyname2(name, AF_INET6, info);
               else
                       hp = NULL;
               if (hp == NULL)
                       hp = _hf_gethtbyname2(name, AF_INET, info);
               __res_put_state(res);
       }
#else
       hp = _hf_gethtbyname2(name, af, info);
#endif
       if (hp == NULL) {
               *info->he = HOST_NOT_FOUND;
               return NS_NOTFOUND;
       }
       return NS_SUCCESS;
}

struct hostent *
_hf_gethtbyname2(const char *name, int af, struct getnamaddr *info)
{
       struct hostent *hp, hent;
       char *buf, *ptr;
       size_t len, anum, num, i;
       FILE *hf;
       char *aliases[MAXALIASES];
       char *addr_ptrs[MAXADDRS];

       _DIAGASSERT(name != NULL);

       hf = NULL;
       sethostent_r(&hf);
       if (hf == NULL) {
               errno = EINVAL;
               *info->he = NETDB_INTERNAL;
               return NULL;
       }

       if ((ptr = buf = malloc(len = info->buflen)) == NULL) {
               endhostent_r(&hf);
               *info->he = NETDB_INTERNAL;
               return NULL;
       }

       anum = 0;               /* XXX: gcc */
       hent.h_name = NULL;     /* XXX: gcc */
       hent.h_addrtype = 0;    /* XXX: gcc */
       hent.h_length = 0;      /* XXX: gcc */

       for (num = 0; num < MAXADDRS;) {
               info->hp->h_addrtype = af;
               info->hp->h_length = 0;

               hp = gethostent_r(hf, info->hp, info->buf, info->buflen,
                   info->he);
               if (hp == NULL)
                       break;

               if (strcasecmp(hp->h_name, name) != 0) {
                       char **cp;
                       for (cp = hp->h_aliases; *cp != NULL; cp++)
                               if (strcasecmp(*cp, name) == 0)
                                       break;
                       if (*cp == NULL) continue;
               }

               if (num == 0) {
                       hent.h_addrtype = af = hp->h_addrtype;
                       hent.h_length = hp->h_length;

                       HENT_SCOPY(hent.h_name, hp->h_name, ptr, len);
                       for (anum = 0; hp->h_aliases[anum]; anum++) {
                               if (anum >= __arraycount(aliases))
                                       goto nospc;
                               HENT_SCOPY(aliases[anum], hp->h_aliases[anum],
                                   ptr, len);
                       }
                       ptr = (void *)ALIGN(ptr);
                       if ((size_t)(ptr - buf) >= info->buflen)
                               goto nospc;
               }

               if (num >= __arraycount(addr_ptrs))
                       goto nospc;
               HENT_COPY(addr_ptrs[num], hp->h_addr_list[0], hp->h_length, ptr,
                   len);
               num++;
       }
       endhostent_r(&hf);

       if (num == 0) {
               *info->he = HOST_NOT_FOUND;
               free(buf);
               return NULL;
       }

       hp = info->hp;
       ptr = info->buf;
       len = info->buflen;

       hp->h_addrtype = hent.h_addrtype;
       hp->h_length = hent.h_length;

       HENT_ARRAY(hp->h_aliases, anum, ptr, len);
       HENT_ARRAY(hp->h_addr_list, num, ptr, len);

       for (i = 0; i < num; i++)
               HENT_COPY(hp->h_addr_list[i], addr_ptrs[i], hp->h_length, ptr,
                   len);
       hp->h_addr_list[num] = NULL;

       HENT_SCOPY(hp->h_name, hent.h_name, ptr, len);

       for (i = 0; i < anum; i++)
               HENT_SCOPY(hp->h_aliases[i], aliases[i], ptr, len);
       hp->h_aliases[anum] = NULL;

       free(buf);
       return hp;
nospc:
       endhostent_r(&hf);
       *info->he = NETDB_INTERNAL;
       free(buf);
       errno = ENOSPC;
       return NULL;
}

/*ARGSUSED*/
int
_hf_gethtbyaddr(void *rv, void *cb_data, va_list ap)
{
       struct hostent *hp;
       const unsigned char *addr;
       struct getnamaddr *info = rv;
       FILE *hf;

       _DIAGASSERT(rv != NULL);

       addr = va_arg(ap, unsigned char *);
       info->hp->h_length = va_arg(ap, int);
       info->hp->h_addrtype = va_arg(ap, int);

       hf = NULL;
       sethostent_r(&hf);
       if (hf == NULL) {
               *info->he = NETDB_INTERNAL;
               return NS_UNAVAIL;
       }
       while ((hp = gethostent_r(hf, info->hp, info->buf, info->buflen,
           info->he)) != NULL)
               if (!memcmp(hp->h_addr_list[0], addr, (size_t)hp->h_length))
                       break;
       endhostent_r(&hf);

       if (hp == NULL) {
               *info->he = HOST_NOT_FOUND;
               return NS_NOTFOUND;
       }
       return NS_SUCCESS;
}

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