login/getutent_r.c

   1 /* Copyright (C) 1996-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>
   4    and Paul Janzen <pcj@primenet.com>, 1996.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <libc-lock.h>
  21 #include <stdlib.h>
  22 #include <utmp.h>
  23
  24 #include "utmp-private.h"
  25
  26
  27 /* Functions defined here.  */
  28 static int setutent_unknown (void);
  29 static int getutent_r_unknown (struct utmp *buffer, struct utmp **result);
  30 static int getutid_r_unknown (const struct utmp *line, struct utmp *buffer,
  31                               struct utmp **result);
  32 static int getutline_r_unknown (const struct utmp *id, struct utmp *buffer,
  33                                 struct utmp **result);
  34 static struct utmp *pututline_unknown (const struct utmp *data);
  35 static void endutent_unknown (void);
  36
  37 /* Initial Jump table.  */
  38 const struct utfuncs __libc_utmp_unknown_functions =
  39 {
  40   setutent_unknown,
  41   getutent_r_unknown,
  42   getutid_r_unknown,
  43   getutline_r_unknown,
  44   pututline_unknown,
  45   endutent_unknown,
  46   NULL
  47 };
  48
  49 /* Currently selected backend.  */
  50 const struct utfuncs *__libc_utmp_jump_table = &__libc_utmp_unknown_functions;
  51
  52 /* We need to protect the opening of the file.  */
  53 __libc_lock_define_initialized (, __libc_utmp_lock attribute_hidden)
  54
  55
  56 static int
  57 setutent_unknown (void)
  58 {
  59   int result;
  60
  61   result = (*__libc_utmp_file_functions.setutent) ();
  62   if (result)
  63     __libc_utmp_jump_table = &__libc_utmp_file_functions;
  64
  65   return result;
  66 }
  67
  68
  69 static int
  70 getutent_r_unknown (struct utmp *buffer, struct utmp **result)
  71 {
  72   /* The backend was not yet initialized.  */
  73   if (setutent_unknown ())
  74     return (*__libc_utmp_jump_table->getutent_r) (buffer, result);
  75
  76   /* Not available.  */
  77   *result = NULL;
  78   return -1;
  79 }
  80
  81
  82 static int
  83 getutid_r_unknown (const struct utmp *id, struct utmp *buffer,
  84                    struct utmp **result)
  85 {
  86   /* The backend was not yet initialized.  */
  87   if (setutent_unknown ())
  88     return (*__libc_utmp_jump_table->getutid_r) (id, buffer, result);
  89
  90   /* Not available.  */
  91   *result = NULL;
  92   return -1;
  93 }
  94
  95
  96 static int
  97 getutline_r_unknown (const struct utmp *line, struct utmp *buffer,
  98                      struct utmp **result)
  99 {
 100   /* The backend was not yet initialized.  */
 101   if (setutent_unknown ())
 102     return (*__libc_utmp_jump_table->getutline_r) (line, buffer, result);
 103
 104   /* Not available.  */
 105   *result = NULL;
 106   return -1;
 107 }
 108
 109
 110 static struct utmp *
 111 pututline_unknown (const struct utmp *data)
 112 {
 113   /* The backend was not yet initialized.  */
 114   if (setutent_unknown ())
 115     return (*__libc_utmp_jump_table->pututline) (data);
 116
 117   /* Not available.  */
 118   return NULL;
 119 }
 120
 121
 122 static void
 123 endutent_unknown (void)
 124 {
 125   /* Nothing to do.  */
 126 }
 127
 128
 129 void
 130 __setutent (void)
 131 {
 132   __libc_lock_lock (__libc_utmp_lock);
 133
 134   (*__libc_utmp_jump_table->setutent) ();
 135
 136   __libc_lock_unlock (__libc_utmp_lock);
 137 }
 138 weak_alias (__setutent, setutent)
 139
 140
 141 int
 142 __getutent_r (struct utmp *buffer, struct utmp **result)
 143 {
 144   int retval;
 145
 146   __libc_lock_lock (__libc_utmp_lock);
 147
 148   retval = (*__libc_utmp_jump_table->getutent_r) (buffer, result);
 149
 150   __libc_lock_unlock (__libc_utmp_lock);
 151
 152   return retval;
 153 }
 154 weak_alias (__getutent_r, getutent_r)
 155
 156
 157 struct utmp *
 158 __pututline (const struct utmp *data)
 159 {
 160   struct utmp *buffer;
 161
 162   __libc_lock_lock (__libc_utmp_lock);
 163
 164   buffer = (*__libc_utmp_jump_table->pututline) (data);
 165
 166   __libc_lock_unlock (__libc_utmp_lock);
 167
 168   return buffer;
 169 }
 170 weak_alias (__pututline, pututline)
 171
 172
 173 void
 174 __endutent (void)
 175 {
 176   __libc_lock_lock (__libc_utmp_lock);
 177
 178   (*__libc_utmp_jump_table->endutent) ();
 179   __libc_utmp_jump_table = &__libc_utmp_unknown_functions;
 180
 181   __libc_lock_unlock (__libc_utmp_lock);
 182 }
 183 weak_alias (__endutent, endutent)