nss/getXXent_r.c

   1 /* Copyright (C) 1996-2022 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 #include <errno.h>
  19 #include <libc-lock.h>
  20
  21 #include "nsswitch.h"
  22
  23 /*******************************************************************\
  24 |* Here we assume several symbols to be defined:                   *|
  25 |*                                                                 *|
  26 |* LOOKUP_TYPE   - the return type of the function                 *|
  27 |*                                                                 *|
  28 |* SETFUNC_NAME  - name of the non-reentrant setXXXent function    *|
  29 |*                                                                 *|
  30 |* GETFUNC_NAME  - name of the non-reentrant getXXXent function    *|
  31 |*                                                                 *|
  32 |* ENDFUNC_NAME  - name of the non-reentrant endXXXent function    *|
  33 |*                                                                 *|
  34 |* DATABASE_NAME - name of the database the function accesses      *|
  35 |*                 (e.g., host, services, ...)                     *|
  36 |*                                                                 *|
  37 |* Optionally the following vars can be defined:                   *|
  38 |*                                                                 *|
  39 |* STAYOPEN      - variable declaration for setXXXent function     *|
  40 |*                                                                 *|
  41 |* STAYOPEN_VAR  - variable name for setXXXent function            *|
  42 |*                                                                 *|
  43 |* NEED_H_ERRNO  - an extra parameter will be passed to point to   *|
  44 |*                 the global `h_errno' variable.                  *|
  45 |*                                                                 *|
  46 \*******************************************************************/
  47
  48 /* To make the real sources a bit prettier.  */
  49 #define REENTRANT_GETNAME APPEND_R (GETFUNC_NAME)
  50 #define APPEND_R(Name) CONCAT2_2 (Name, _r)
  51 #define INTERNAL(Name) CONCAT2_2 (__, Name)
  52 #define CONCAT2_1(Pre, Post) CONCAT2_2 (Pre, Post)
  53 #define CONCAT2_2(Pre, Post) Pre##Post
  54 #define NEW(name) NEW1 (name)
  55 #define NEW1(name) __new_##name
  56
  57 #define SETFUNC_NAME_STRING STRINGIZE (SETFUNC_NAME)
  58 #define GETFUNC_NAME_STRING STRINGIZE (REENTRANT_GETNAME)
  59 #define ENDFUNC_NAME_STRING STRINGIZE (ENDFUNC_NAME)
  60 #define DATABASE_NAME_STRING STRINGIZE (DATABASE_NAME)
  61 #define STRINGIZE(Name) STRINGIZE1 (Name)
  62 #define STRINGIZE1(Name) #Name
  63
  64 #ifndef DB_LOOKUP_FCT
  65 # define DB_LOOKUP_FCT CONCAT3_1 (__nss_, DATABASE_NAME, _lookup2)
  66 # define CONCAT3_1(Pre, Name, Post) CONCAT3_2 (Pre, Name, Post)
  67 # define CONCAT3_2(Pre, Name, Post) Pre##Name##Post
  68 #endif
  69
  70 /* Sometimes we need to store error codes in the `h_errno' variable.  */
  71 #ifdef NEED_H_ERRNO
  72 # define H_ERRNO_PARM , int *h_errnop
  73 # define H_ERRNO_VAR , &h_errno
  74 # define H_ERRNO_VAR_P &h_errno
  75 #else
  76 # define H_ERRNO_PARM
  77 # define H_ERRNO_VAR
  78 # define H_ERRNO_VAR_P NULL
  79 #endif
  80
  81 /* Some databases take the `stayopen' flag.  */
  82 #ifdef STAYOPEN
  83 # define STAYOPEN_TMP CONCAT2_1 (STAYOPEN, _tmp)
  84 # define STAYOPEN_TMPVAR &CONCAT2_1 (STAYOPEN_VAR, _tmp)
  85 #else
  86 # define STAYOPEN void
  87 # define STAYOPEN_VAR 0
  88 # define STAYOPEN_TMPVAR NULL
  89 #endif
  90
  91 #ifndef NEED__RES
  92 # define NEED__RES 0
  93 #endif
  94
  95 /* This handle for the NSS data base is shared between all
  96    set/get/endXXXent functions.  */
  97 static nss_action_list nip;
  98 /* Remember the last service used since the last call to  `endXXent'.  */
  99 static nss_action_list last_nip;
 100 /* Remember the first service_entry across set/get/endent.  */
 101 static nss_action_list startp;
 102
 103 #ifdef STAYOPEN_TMP
 104 /* We need to remember the last `stayopen' flag given by the user
 105    since the `setent' function is only called for the first available
 106    service.  */
 107 static STAYOPEN_TMP;
 108 #endif
 109
 110 /* Protect above variable against multiple uses at the same time.  */
 111 __libc_lock_define_initialized (static, lock)
 112
 113 /* The lookup function for the first entry of this service.  */
 114 extern int DB_LOOKUP_FCT (nss_action_list *nip, const char *name,
 115                           const char *name2, void **fctp);
 116 libc_hidden_proto (DB_LOOKUP_FCT)
 117 \f
 118 void
 119 SETFUNC_NAME (STAYOPEN)
 120 {
 121   int save;
 122
 123   __libc_lock_lock (lock);
 124   __nss_setent (SETFUNC_NAME_STRING, DB_LOOKUP_FCT, &nip, &startp,
 125                 &last_nip, STAYOPEN_VAR, STAYOPEN_TMPVAR, NEED__RES);
 126
 127   save = errno;
 128   __libc_lock_unlock (lock);
 129   __set_errno (save);
 130 }
 131
 132
 133 void
 134 ENDFUNC_NAME (void)
 135 {
 136   int save;
 137
 138   /* If the service has not been used before do not do anything.  */
 139   if (startp != NULL)
 140     {
 141       __libc_lock_lock (lock);
 142       __nss_endent (ENDFUNC_NAME_STRING, DB_LOOKUP_FCT, &nip, &startp,
 143                     &last_nip, NEED__RES);
 144       save = errno;
 145       __libc_lock_unlock (lock);
 146       __set_errno (save);
 147     }
 148 }
 149
 150
 151 int
 152 INTERNAL (REENTRANT_GETNAME) (LOOKUP_TYPE *resbuf, char *buffer, size_t buflen,
 153                               LOOKUP_TYPE **result H_ERRNO_PARM)
 154 {
 155   int status;
 156   int save;
 157
 158   __libc_lock_lock (lock);
 159   status = __nss_getent_r (GETFUNC_NAME_STRING, SETFUNC_NAME_STRING,
 160                            DB_LOOKUP_FCT, &nip, &startp, &last_nip,
 161                            STAYOPEN_TMPVAR, NEED__RES, resbuf, buffer,
 162                            buflen, (void **) result, H_ERRNO_VAR_P);
 163   save = errno;
 164   __libc_lock_unlock (lock);
 165   __set_errno (save);
 166   return status;
 167 }
 168
 169
 170 #ifdef NO_COMPAT_NEEDED
 171 strong_alias (INTERNAL (REENTRANT_GETNAME), REENTRANT_GETNAME);
 172 #else
 173 # include <shlib-compat.h>
 174 # if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1_2)
 175 #  define OLD(name) OLD1 (name)
 176 #  define OLD1(name) __old_##name
 177
 178 int
 179 attribute_compat_text_section
 180 OLD (REENTRANT_GETNAME) (LOOKUP_TYPE *resbuf, char *buffer, size_t buflen,
 181                          LOOKUP_TYPE **result H_ERRNO_PARM)
 182 {
 183   int ret = INTERNAL (REENTRANT_GETNAME) (resbuf, buffer, buflen,
 184                                           result H_ERRNO_VAR);
 185
 186   if (ret != 0)
 187     ret = -1;
 188
 189   return ret;
 190 }
 191
 192 #  define do_symbol_version(real, name, version) \
 193   compat_symbol (libc, real, name, version)
 194 do_symbol_version (OLD (REENTRANT_GETNAME), REENTRANT_GETNAME, GLIBC_2_0);
 195 # endif
 196
 197 /* As INTERNAL (REENTRANT_GETNAME) may be hidden, we need an alias
 198    in between so that the REENTRANT_GETNAME@@GLIBC_2.1.2 is not
 199    hidden too.  */
 200 strong_alias (INTERNAL (REENTRANT_GETNAME), NEW (REENTRANT_GETNAME));
 201
 202 # define do_default_symbol_version(real, name, version) \
 203   versioned_symbol (libc, real, name, version)
 204 do_default_symbol_version (NEW (REENTRANT_GETNAME),
 205                            REENTRANT_GETNAME, GLIBC_2_1_2);
 206 #endif
 207
 208 nss_interface_function (SETFUNC_NAME)
 209 nss_interface_function (ENDFUNC_NAME)
 210 nss_interface_function (REENTRANT_GETNAME)