resolv/res_hostalias.c

   1 /* HOSTALIASES-based name resolution.  Public legacy functions.
   2    Copyright (C) 2017-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <netdb.h>
  20 #include <resolv-internal.h>
  21 #include <resolv_context.h>
  22
  23 /* Common part of res_hostalias and hostalias.  */
  24 static const char *
  25 context_hostalias_common (struct resolv_context *ctx,
  26                           const char *name, char *dst, size_t siz)
  27 {
  28   if (ctx == NULL)
  29     {
  30       RES_SET_H_ERRNO (&_res, NETDB_INTERNAL);
  31       return NULL;
  32     }
  33   const char *result = __res_context_hostalias (ctx, name, dst, siz);
  34   __resolv_context_put (ctx);
  35   return result;
  36 }
  37
  38 const char *
  39 res_hostalias (res_state statp, const char *name, char *dst, size_t siz)
  40 {
  41   return context_hostalias_common
  42     (__resolv_context_get_override (statp), name, dst, siz);
  43 }
  44
  45 const char *
  46 hostalias (const char *name)
  47 {
  48   static char abuf[MAXDNAME];
  49   return context_hostalias_common
  50     (__resolv_context_get (), name, abuf, sizeof (abuf));
  51 }