resolv/res_hconf.h

   1 /* Copyright (C) 1993-2023 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _RES_HCONF_H_
  19 #define _RES_HCONF_H_
  20
  21 #include <netdb.h>
  22
  23 #define TRIMDOMAINS_MAX 4
  24
  25 struct hconf
  26 {
  27   /* We keep the INITIALIZED member only for backwards compatibility.  New
  28      code should just call _res_hconf_init unconditionally.  For this field
  29      to be used safely, users must ensure that either (1) a call to
  30      _res_hconf_init happens-before any load from INITIALIZED, or (2) an
  31      assignment of zero to INITIALIZED happens-before any load from it, and
  32      these loads use acquire MO if the intent is to skip calling
  33      _res_hconf_init if the load returns a nonzero value.  Such acquire MO
  34      loads will then synchronize with the release MO store to INITIALIZED
  35      in do_init in res_hconf.c; see pthread_once for more detail.  */
  36   int initialized;
  37   int unused1;
  38   int unused2[4];
  39   int num_trimdomains;
  40   const char *trimdomain[TRIMDOMAINS_MAX];
  41   unsigned int flags;
  42 #  define HCONF_FLAG_INITED     (1 << 0) /* initialized? */
  43 #  define HCONF_FLAG_REORDER    (1 << 3) /* list best address first */
  44 #  define HCONF_FLAG_MULTI      (1 << 4) /* see comments for gethtbyname() */
  45 };
  46 extern struct hconf _res_hconf;
  47
  48 extern void _res_hconf_init (void) attribute_hidden;
  49 extern void _res_hconf_trim_domain (char *domain);
  50 extern void _res_hconf_trim_domains (struct hostent *hp);
  51 extern void _res_hconf_reorder_addrs (struct hostent *hp);
  52
  53 #endif /* _RES_HCONF_H_ */