nss/getXXent_r.c

   1 /* Copyright (C) 1996-2000,2002,2004,2007, 2009 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <bits/libc-lock.h>
  22
  23 #include "nsswitch.h"
  24
  25 /*******************************************************************\
  26 |* Here we assume several symbols to be defined:                   *|
  27 |*                                                                 *|
  28 |* LOOKUP_TYPE   - the return type of the function                 *|
  29 |*                                                                 *|
  30 |* SETFUNC_NAME  - name of the non-reentrant setXXXent function    *|
  31 |*                                                                 *|
  32 |* GETFUNC_NAME  - name of the non-reentrant getXXXent function    *|
  33 |*                                                                 *|
  34 |* ENDFUNC_NAME  - name of the non-reentrant endXXXent function    *|
  35 |*                                                                 *|
  36 |* DATABASE_NAME - name of the database the function accesses      *|
  37 |*                 (e.g., host, services, ...)                     *|
  38 |*                                                                 *|
  39 |* Optionally the following vars can be defined:                   *|
  40 |*                                                                 *|
  41 |* STAYOPEN      - variable declaration for setXXXent function     *|
  42 |*                                                                 *|
  43 |* STAYOPEN_VAR  - variable name for setXXXent function            *|
  44 |*                                                                 *|
  45 |* NEED_H_ERRNO  - an extra parameter will be passed to point to   *|
  46 |*                 the global `h_errno' variable.                  *|
  47 |*                                                                 *|
  48 \*******************************************************************/
  49
  50 /* To make the real sources a bit prettier.  */
  51 #define REENTRANT_GETNAME APPEND_R (GETFUNC_NAME)
  52 #define APPEND_R(Name) CONCAT2_2 (Name, _r)
  53 #define INTERNAL(Name) CONCAT2_2 (__, Name)
  54 #define CONCAT2_1(Pre, Post) CONCAT2_2 (Pre, Post)
  55 #define CONCAT2_2(Pre, Post) Pre##Post
  56 #define NEW(name) NEW1 (name)
  57 #define NEW1(name) __new_##name
  58
  59 #define SETFUNC_NAME_STRING STRINGIZE (SETFUNC_NAME)
  60 #define GETFUNC_NAME_STRING STRINGIZE (REENTRANT_GETNAME)
  61 #define ENDFUNC_NAME_STRING STRINGIZE (ENDFUNC_NAME)
  62 #define DATABASE_NAME_STRING STRINGIZE (DATABASE_NAME)
  63 #define STRINGIZE(Name) STRINGIZE1 (Name)
  64 #define STRINGIZE1(Name) #Name
  65
  66 #ifndef DB_LOOKUP_FCT
  67 # define DB_LOOKUP_FCT CONCAT3_1 (__nss_, DATABASE_NAME, _lookup2)
  68 # define CONCAT3_1(Pre, Name, Post) CONCAT3_2 (Pre, Name, Post)
  69 # define CONCAT3_2(Pre, Name, Post) Pre##Name##Post
  70 #endif
  71
  72 /* Sometimes we need to store error codes in the `h_errno' variable.  */
  73 #ifdef NEED_H_ERRNO
  74 # define H_ERRNO_PARM , int *h_errnop
  75 # define H_ERRNO_VAR , &h_errno
  76 # define H_ERRNO_VAR_P &h_errno
  77 #else
  78 # define H_ERRNO_PARM
  79 # define H_ERRNO_VAR
  80 # define H_ERRNO_VAR_P NULL
  81 #endif
  82
  83 /* Some databases take the `stayopen' flag.  */
  84 #ifdef STAYOPEN
  85 # define STAYOPEN_TMP CONCAT2_1 (STAYOPEN, _tmp)
  86 # define STAYOPEN_TMPVAR &CONCAT2_1 (STAYOPEN_VAR, _tmp)
  87 #else
  88 # define STAYOPEN void
  89 # define STAYOPEN_VAR 0
  90 # define STAYOPEN_TMPVAR NULL
  91 #endif
  92
  93 #ifndef NEED__RES
  94 # define NEED__RES 0
  95 #endif
  96
  97 /* This handle for the NSS data base is shared between all
  98    set/get/endXXXent functions.  */
  99 static service_user *nip;
 100 /* Remember the last service used since the last call to  `endXXent'.  */
 101 static service_user *last_nip;
 102 /* Remember the first service_entry, it's always the same.  */
 103 static service_user *startp;
 104
 105 #ifdef STAYOPEN_TMP
 106 /* We need to remember the last `stayopen' flag given by the user
 107    since the `setent' function is only called for the first available
 108    service.  */
 109 static STAYOPEN_TMP;
 110 #endif
 111
 112 /* Protect above variable against multiple uses at the same time.  */
 113 __libc_lock_define_initialized (static, lock)
 114
 115 /* The lookup function for the first entry of this service.  */
 116 extern int DB_LOOKUP_FCT (service_user **nip, const char *name,
 117                           const char *name2, void **fctp)
 118      internal_function;
 119 libc_hidden_proto (DB_LOOKUP_FCT)
 120 \f
 121 void
 122 SETFUNC_NAME (STAYOPEN)
 123 {
 124   int save;
 125
 126   __libc_lock_lock (lock);
 127   __nss_setent (SETFUNC_NAME_STRING, DB_LOOKUP_FCT, &nip, &startp,
 128                 &last_nip, STAYOPEN_VAR, STAYOPEN_TMPVAR, NEED__RES);
 129
 130   save = errno;
 131   __libc_lock_unlock (lock);
 132   __set_errno (save);
 133 }
 134
 135
 136 void
 137 ENDFUNC_NAME (void)
 138 {
 139   int save;
 140
 141   /* If the service has not been used before do not do anything.  */
 142   if (startp != NULL)
 143     {
 144       __libc_lock_lock (lock);
 145       __nss_endent (ENDFUNC_NAME_STRING, DB_LOOKUP_FCT, &nip, &startp,
 146                     &last_nip, NEED__RES);
 147       save = errno;
 148       __libc_lock_unlock (lock);
 149       __set_errno (save);
 150     }
 151 }
 152
 153
 154 int
 155 INTERNAL (REENTRANT_GETNAME) (LOOKUP_TYPE *resbuf, char *buffer, size_t buflen,
 156                               LOOKUP_TYPE **result H_ERRNO_PARM)
 157 {
 158   int status;
 159   int save;
 160
 161   __libc_lock_lock (lock);
 162   status = __nss_getent_r (GETFUNC_NAME_STRING, SETFUNC_NAME_STRING,
 163                            DB_LOOKUP_FCT, &nip, &startp, &last_nip,
 164                            STAYOPEN_TMPVAR, NEED__RES, resbuf, buffer,
 165                            buflen, (void **) result, H_ERRNO_VAR_P);
 166   save = errno;
 167   __libc_lock_unlock (lock);
 168   __set_errno (save);
 169   return status;
 170 }
 171
 172
 173 #ifdef NO_COMPAT_NEEDED
 174 strong_alias (INTERNAL (REENTRANT_GETNAME), REENTRANT_GETNAME);
 175 #else
 176 # include <shlib-compat.h>
 177 # if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1_2)
 178 #  define OLD(name) OLD1 (name)
 179 #  define OLD1(name) __old_##name
 180
 181 int
 182 attribute_compat_text_section
 183 OLD (REENTRANT_GETNAME) (LOOKUP_TYPE *resbuf, char *buffer, size_t buflen,
 184                          LOOKUP_TYPE **result H_ERRNO_PARM)
 185 {
 186   int ret = INTERNAL (REENTRANT_GETNAME) (resbuf, buffer, buflen,
 187                                           result H_ERRNO_VAR);
 188
 189   if (ret != 0)
 190     ret = -1;
 191
 192   return ret;
 193 }
 194
 195 #  define do_symbol_version(real, name, version) \
 196   compat_symbol (libc, real, name, version)
 197 do_symbol_version (OLD (REENTRANT_GETNAME), REENTRANT_GETNAME, GLIBC_2_0);
 198 # endif
 199
 200 /* As INTERNAL (REENTRANT_GETNAME) may be hidden, we need an alias
 201    in between so that the REENTRANT_GETNAME@@GLIBC_2.1.2 is not
 202    hidden too.  */
 203 strong_alias (INTERNAL (REENTRANT_GETNAME), NEW (REENTRANT_GETNAME));
 204
 205 # define do_default_symbol_version(real, name, version) \
 206   versioned_symbol (libc, real, name, version)
 207 do_default_symbol_version (NEW (REENTRANT_GETNAME),
 208                            REENTRANT_GETNAME, GLIBC_2_1_2);
 209 #endif
 210
 211 static_link_warning (SETFUNC_NAME)
 212 static_link_warning (ENDFUNC_NAME)
 213 static_link_warning (REENTRANT_GETNAME)