misc/fstab.c

   1 /* Copyright (C) 1995, 1996, 1997, 1998, 2000, 2008
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   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 <fstab.h>
  21 #include <mntent.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <bits/libc-lock.h>
  26
  27 #define BUFFER_SIZE 0x1fc0
  28
  29 struct fstab_state
  30 {
  31   FILE *fs_fp;
  32   char *fs_buffer;
  33   struct mntent fs_mntres;
  34   struct fstab fs_ret;
  35 };
  36
  37 static struct fstab_state *fstab_init (int opt_rewind);
  38 static struct mntent *fstab_fetch (struct fstab_state *state);
  39 static struct fstab *fstab_convert (struct fstab_state *state);
  40
  41 static struct fstab_state fstab_state;
  42
  43
  44 int
  45 setfsent (void)
  46 {
  47   return fstab_init (1) != NULL;
  48 }
  49
  50
  51 struct fstab *
  52 getfsent (void)
  53 {
  54   struct fstab_state *state;
  55
  56   state = fstab_init (0);
  57   if (state == NULL)
  58     return NULL;
  59   if (fstab_fetch (state) == NULL)
  60     return NULL;
  61   return fstab_convert (state);
  62 }
  63
  64
  65 struct fstab *
  66 getfsspec (name)
  67      const char *name;
  68 {
  69   struct fstab_state *state;
  70   struct mntent *m;
  71
  72   state = fstab_init (1);
  73   if (state == NULL)
  74     return NULL;
  75   while ((m = fstab_fetch (state)) != NULL)
  76     if (strcmp (m->mnt_fsname, name) == 0)
  77       return fstab_convert (state);
  78   return NULL;
  79 }
  80
  81
  82 struct fstab *
  83 getfsfile (name)
  84      const char *name;
  85 {
  86   struct fstab_state *state;
  87   struct mntent *m;
  88
  89   state = fstab_init (1);
  90   if (state == NULL)
  91     return NULL;
  92   while ((m = fstab_fetch (state)) != NULL)
  93     if (strcmp (m->mnt_dir, name) == 0)
  94       return fstab_convert (state);
  95   return NULL;
  96 }
  97
  98
  99 void
 100 endfsent ()
 101 {
 102   struct fstab_state *state;
 103
 104   state = &fstab_state;
 105   if (state->fs_fp != NULL)
 106     {
 107       (void) __endmntent (state->fs_fp);
 108       state->fs_fp = NULL;
 109     }
 110 }
 111
 112
 113 static struct fstab_state *
 114 fstab_init (int opt_rewind)
 115 {
 116   struct fstab_state *state;
 117   char *buffer;
 118   FILE *fp;
 119
 120   state = &fstab_state;
 121
 122   buffer = state->fs_buffer;
 123   if (buffer == NULL)
 124     {
 125       buffer = (char *) malloc (BUFFER_SIZE);
 126       if (buffer == NULL)
 127         return NULL;
 128       state->fs_buffer = buffer;
 129     }
 130
 131   fp = state->fs_fp;
 132   if (fp != NULL)
 133     {
 134       if (opt_rewind)
 135         rewind (fp);
 136     }
 137   else
 138     {
 139       fp = __setmntent (_PATH_FSTAB, "r");
 140       if (fp == NULL)
 141         return NULL;
 142       state->fs_fp = fp;
 143     }
 144
 145   return state;
 146 }
 147
 148
 149 static struct mntent *
 150 fstab_fetch (struct fstab_state *state)
 151 {
 152   return __getmntent_r (state->fs_fp, &state->fs_mntres,
 153                         state->fs_buffer, BUFFER_SIZE);
 154 }
 155
 156
 157 static struct fstab *
 158 fstab_convert (struct fstab_state *state)
 159 {
 160   struct mntent *m;
 161   struct fstab *f;
 162
 163   m = &state->fs_mntres;
 164   f = &state->fs_ret;
 165
 166   f->fs_spec = m->mnt_fsname;
 167   f->fs_file = m->mnt_dir;
 168   f->fs_vfstype = m->mnt_type;
 169   f->fs_mntops = m->mnt_opts;
 170   f->fs_type = (__hasmntopt (m, FSTAB_RW) ? FSTAB_RW :
 171                 __hasmntopt (m, FSTAB_RQ) ? FSTAB_RQ :
 172                 __hasmntopt (m, FSTAB_RO) ? FSTAB_RO :
 173                 __hasmntopt (m, FSTAB_SW) ? FSTAB_SW :
 174                 __hasmntopt (m, FSTAB_XX) ? FSTAB_XX :
 175                 "??");
 176   f->fs_freq = m->mnt_freq;
 177   f->fs_passno = m->mnt_passno;
 178   return f;
 179 }
 180
 181
 182 /* Make sure the memory is freed if the programs ends while in
 183    memory-debugging mode and something actually was allocated.  */
 184 libc_freeres_fn (fstab_free)
 185 {
 186   char *buffer;
 187
 188   buffer = fstab_state.fs_buffer;
 189   free ((void *) buffer);
 190 }