login/getutent_r.c

   1 /* Copyright (C) 1996, 1997 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 Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    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    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <assert.h>
  22 #include <libc-lock.h>
  23 #include <stdio.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26 #include <utmp.h>
  27
  28 #include "utmp-private.h"
  29
  30
  31 /* The various backends we have.  */
  32 static int setutent_unknown (int reset);
  33 static int getutent_r_unknown (struct utmp *buffer, 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 struct utfuncs __libc_utmp_unknown_functions =
  39 {
  40   setutent_unknown,
  41   getutent_r_unknown,
  42   NULL,
  43   NULL,
  44   pututline_unknown,
  45   endutent_unknown,
  46   NULL
  47 };
  48
  49 /* Currently selected backend.  */
  50 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)
  54
  55
  56 void
  57 __setutent (void)
  58 {
  59   __libc_lock_lock (__libc_utmp_lock);
  60
  61   (void) (*__libc_utmp_jump_table->setutent) (1);
  62
  63   __libc_lock_unlock (__libc_utmp_lock);
  64 }
  65 weak_alias (__setutent, setutent)
  66
  67
  68 static int
  69 setutent_unknown (int reset)
  70 {
  71   /* We have to test whether it is still not decided which backend to use.  */
  72   assert (__libc_utmp_jump_table == &__libc_utmp_unknown_functions);
  73
  74   /* See whether utmpd is running.  */
  75   if ((*__libc_utmp_daemon_functions.setutent) (reset))
  76     __libc_utmp_jump_table = &__libc_utmp_daemon_functions;
  77   else
  78     {
  79       /* Use the normal file, but if the current file is _PATH_UTMP or
  80          _PATH_WTMP and the corresponding extended file (with an extra
  81          'x' added to the pathname) exists, we use the extended file,
  82          because the original file is in a different format.  */
  83       if (strcmp (__libc_utmp_file_name, _PATH_UTMP) == 0
  84           && __access (_PATH_UTMP "x", F_OK) == 0)
  85         __utmpname (_PATH_UTMP "x");
  86       else if (strcmp (__libc_utmp_file_name, _PATH_WTMP) == 0
  87                && __access (_PATH_WTMP "x", F_OK) == 0)
  88         __utmpname (_PATH_WTMP "x");
  89
  90       (*__libc_utmp_file_functions.setutent) (reset);
  91       __libc_utmp_jump_table = &__libc_utmp_file_functions;
  92     }
  93
  94   return 0;
  95 }
  96
  97
  98 void
  99 __endutent (void)
 100 {
 101   __libc_lock_lock (__libc_utmp_lock);
 102
 103   (*__libc_utmp_jump_table->endutent) ();
 104
 105   __libc_lock_unlock (__libc_utmp_lock);
 106 }
 107 weak_alias (__endutent, endutent)
 108
 109
 110 static void
 111 endutent_unknown (void)
 112 {
 113   /* Huh, how do we came here?  Nothing to do.  */
 114 }
 115
 116
 117 int
 118 __getutent_r (struct utmp *buffer, struct utmp **result)
 119 {
 120   int retval;
 121
 122   __libc_lock_lock (__libc_utmp_lock);
 123
 124   retval = (*__libc_utmp_jump_table->getutent_r) (buffer, result);
 125
 126   __libc_lock_unlock (__libc_utmp_lock);
 127
 128   return retval;
 129 }
 130 weak_alias (__getutent_r, getutent_r)
 131
 132
 133 static int
 134 getutent_r_unknown (struct utmp *buffer, struct utmp **result)
 135 {
 136   /* It is not yet initialized.  */
 137   setutent_unknown (0);
 138
 139   return (*__libc_utmp_jump_table->getutent_r) (buffer, result);
 140 }
 141
 142
 143 struct utmp *
 144 __pututline (const struct utmp *data)
 145 {
 146   struct utmp *buffer;
 147
 148   __libc_lock_lock (__libc_utmp_lock);
 149
 150   buffer = (*__libc_utmp_jump_table->pututline) (data);
 151
 152   __libc_lock_unlock (__libc_utmp_lock);
 153
 154   return buffer;
 155 }
 156 weak_alias (__pututline, pututline)
 157
 158
 159 static struct utmp *
 160 pututline_unknown (const struct utmp *data)
 161 {
 162   /* It is not yet initialized.  */
 163   setutent_unknown (0);
 164
 165   return (*__libc_utmp_jump_table->pututline) (data);
 166 }