nss/getXXent_r.c

   1 /* Copyright (C) 1996-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   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 <errno.h>
  20 #include <libc-lock.h>
  21
  22 #include "nsswitch.h"
  23
  24 /*******************************************************************\
  25 |* Here we assume several symbols to be defined:                   *|
  26 |*                                                                 *|
  27 |* LOOKUP_TYPE   - the return type of the function                 *|
  28 |*                                                                 *|
  29 |* SETFUNC_NAME  - name of the non-reentrant setXXXent function    *|
  30 |*                                                                 *|
  31 |* GETFUNC_NAME  - name of the non-reentrant getXXXent function    *|
  32 |*                                                                 *|
  33 |* ENDFUNC_NAME  - name of the non-reentrant endXXXent function    *|
  34 |*                                                                 *|
  35 |* DATABASE_NAME - name of the database the function accesses      *|
  36 |*                 (e.g., host, services, ...)                     *|
  37 |*                                                                 *|
  38 |* Optionally the following vars can be defined:                   *|
  39 |*                                                                 *|
  40 |* STAYOPEN      - variable declaration for setXXXent function     *|
  41 |*                                                                 *|
  42 |* STAYOPEN_VAR  - variable name for setXXXent function            *|
  43 |*                                                                 *|
  44 |* NEED_H_ERRNO  - an extra parameter will be passed to point to   *|
  45 |*                 the global `h_errno' variable.                  *|
  46 |*                                                                 *|
  47 \*******************************************************************/
  48
  49 /* To make the real sources a bit prettier.  */
  50 #define REENTRANT_GETNAME APPEND_R (GETFUNC_NAME)
  51 #define APPEND_R(Name) CONCAT2_2 (Name, _r)
  52 #define INTERNAL(Name) CONCAT2_2 (__, Name)
  53 #define CONCAT2_1(Pre, Post) CONCAT2_2 (Pre, Post)
  54 #define CONCAT2_2(Pre, Post) Pre##Post
  55 #define NEW(name) NEW1 (name)
  56 #define NEW1(name) __new_##name
  57
  58 #define SETFUNC_NAME_STRING STRINGIZE (SETFUNC_NAME)
  59 #define GETFUNC_NAME_STRING STRINGIZE (REENTRANT_GETNAME)
  60 #define ENDFUNC_NAME_STRING STRINGIZE (ENDFUNC_NAME)
  61 #define DATABASE_NAME_STRING STRINGIZE (DATABASE_NAME)
  62 #define STRINGIZE(Name) STRINGIZE1 (Name)
  63 #define STRINGIZE1(Name) #Name
  64
  65 #ifndef DB_LOOKUP_FCT
  66 # define DB_LOOKUP_FCT CONCAT3_1 (__nss_, DATABASE_NAME, _lookup2)
  67 # define CONCAT3_1(Pre, Name, Post) CONCAT3_2 (Pre, Name, Post)
  68 # define CONCAT3_2(Pre, Name, Post) Pre##Name##Post
  69 #endif
  70
  71 /* Sometimes we need to store error codes in the `h_errno' variable.  */
  72 #ifdef NEED_H_ERRNO
  73 # define H_ERRNO_PARM , int *h_errnop
  74 # define H_ERRNO_VAR , &h_errno
  75 # define H_ERRNO_VAR_P &h_errno
  76 #else
  77 # define H_ERRNO_PARM
  78 # define H_ERRNO_VAR
  79 # define H_ERRNO_VAR_P NULL
  80 #endif
  81
  82 /* Some databases take the `stayopen' flag.  */
  83 #ifdef STAYOPEN
  84 # define STAYOPEN_TMP CONCAT2_1 (STAYOPEN, _tmp)
  85 # define STAYOPEN_TMPVAR &CONCAT2_1 (STAYOPEN_VAR, _tmp)
  86 #else
  87 # define STAYOPEN void
  88 # define STAYOPEN_VAR 0
  89 # define STAYOPEN_TMPVAR NULL
  90 #endif
  91
  92 #ifndef NEED__RES
  93 # define NEED__RES 0
  94 #endif
  95
  96 /* This handle for the NSS data base is shared between all
  97    set/get/endXXXent functions.  */
  98 static nss_action_list nip;
  99 /* Remember the last service used since the last call to  `endXXent'.  */
 100 static nss_action_list last_nip;
 101 /* Remember the first service_entry across set/get/endent.  */
 102 static nss_action_list startp;
 103
 104 #ifdef STAYOPEN_TMP
 105 /* We need to remember the last `stayopen' flag given by the user
 106    since the `setent' function is only called for the first available
 107    service.  */
 108 static STAYOPEN_TMP;
 109 #endif
 110
 111 /* Protect above variable against multiple uses at the same time.  */
 112 __libc_lock_define_initialized (static, lock)
 113
 114 /* The lookup function for the first entry of this service.  */
 115 extern int DB_LOOKUP_FCT (nss_action_list *nip, const char *name,
 116                           const char *name2, void **fctp);
 117 libc_hidden_proto (DB_LOOKUP_FCT)
 118 \f
 119 void
 120 SETFUNC_NAME (STAYOPEN)
 121 {
 122   int save;
 123
 124   __libc_lock_lock (lock);
 125   __nss_setent (SETFUNC_NAME_STRING, DB_LOOKUP_FCT, &nip, &startp,
 126                 &last_nip, STAYOPEN_VAR, STAYOPEN_TMPVAR, NEED__RES);
 127
 128   save = errno;
 129   __libc_lock_unlock (lock);
 130   __set_errno (save);
 131 }
 132
 133
 134 void
 135 ENDFUNC_NAME (void)
 136 {
 137   int save;
 138
 139   /* If the service has not been used before do not do anything.  */
 140   if (startp != NULL)
 141     {
 142       __libc_lock_lock (lock);
 143       __nss_endent (ENDFUNC_NAME_STRING, DB_LOOKUP_FCT, &nip, &startp,
 144                     &last_nip, NEED__RES);
 145       save = errno;
 146       __libc_lock_unlock (lock);
 147       __set_errno (save);
 148     }
 149 }
 150
 151
 152 int
 153 INTERNAL (REENTRANT_GETNAME) (LOOKUP_TYPE *resbuf, char *buffer, size_t buflen,
 154                               LOOKUP_TYPE **result H_ERRNO_PARM)
 155 {
 156   int status;
 157   int save;
 158
 159   __libc_lock_lock (lock);
 160   status = __nss_getent_r (GETFUNC_NAME_STRING, SETFUNC_NAME_STRING,
 161                            DB_LOOKUP_FCT, &nip, &startp, &last_nip,
 162                            STAYOPEN_TMPVAR, NEED__RES, resbuf, buffer,
 163                            buflen, (void **) result, H_ERRNO_VAR_P);
 164   save = errno;
 165   __libc_lock_unlock (lock);
 166   __set_errno (save);
 167   return status;
 168 }
 169
 170
 171 #ifdef NO_COMPAT_NEEDED
 172 strong_alias (INTERNAL (REENTRANT_GETNAME), REENTRANT_GETNAME);
 173 #else
 174 # include <shlib-compat.h>
 175 # if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1_2)
 176 #  define OLD(name) OLD1 (name)
 177 #  define OLD1(name) __old_##name
 178
 179 int
 180 attribute_compat_text_section
 181 OLD (REENTRANT_GETNAME) (LOOKUP_TYPE *resbuf, char *buffer, size_t buflen,
 182                          LOOKUP_TYPE **result H_ERRNO_PARM)
 183 {
 184   int ret = INTERNAL (REENTRANT_GETNAME) (resbuf, buffer, buflen,
 185                                           result H_ERRNO_VAR);
 186
 187   if (ret != 0)
 188     ret = -1;
 189
 190   return ret;
 191 }
 192
 193 #  define do_symbol_version(real, name, version) \
 194   compat_symbol (libc, real, name, version)
 195 do_symbol_version (OLD (REENTRANT_GETNAME), REENTRANT_GETNAME, GLIBC_2_0);
 196 # endif
 197
 198 /* As INTERNAL (REENTRANT_GETNAME) may be hidden, we need an alias
 199    in between so that the REENTRANT_GETNAME@@GLIBC_2.1.2 is not
 200    hidden too.  */
 201 strong_alias (INTERNAL (REENTRANT_GETNAME), NEW (REENTRANT_GETNAME));
 202
 203 # define do_default_symbol_version(real, name, version) \
 204   versioned_symbol (libc, real, name, version)
 205 do_default_symbol_version (NEW (REENTRANT_GETNAME),
 206                            REENTRANT_GETNAME, GLIBC_2_1_2);
 207 #endif
 208
 209 nss_interface_function (SETFUNC_NAME)
 210 nss_interface_function (ENDFUNC_NAME)
 211 nss_interface_function (REENTRANT_GETNAME)