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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <fstab.h>
  20 #include <mntent.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <bits/libc-lock.h>
  25
  26 #define BUFFER_SIZE 0x1fc0
  27
  28 struct fstab_state
  29 {
  30   FILE *fs_fp;
  31   char *fs_buffer;
  32   struct mntent fs_mntres;
  33   struct fstab fs_ret;
  34 };
  35
  36 static struct fstab_state *fstab_init (int opt_rewind);
  37 static struct mntent *fstab_fetch (struct fstab_state *state);
  38 static struct fstab *fstab_convert (struct fstab_state *state);
  39
  40 static struct fstab_state fstab_state;
  41
  42
  43 int
  44 setfsent (void)
  45 {
  46   return fstab_init (1) != NULL;
  47 }
  48
  49
  50 struct fstab *
  51 getfsent (void)
  52 {
  53   struct fstab_state *state;
  54
  55   state = fstab_init (0);
  56   if (state == NULL)
  57     return NULL;
  58   if (fstab_fetch (state) == NULL)
  59     return NULL;
  60   return fstab_convert (state);
  61 }
  62
  63
  64 struct fstab *
  65 getfsspec (name)
  66      const char *name;
  67 {
  68   struct fstab_state *state;
  69   struct mntent *m;
  70
  71   state = fstab_init (1);
  72   if (state == NULL)
  73     return NULL;
  74   while ((m = fstab_fetch (state)) != NULL)
  75     if (strcmp (m->mnt_fsname, name) == 0)
  76       return fstab_convert (state);
  77   return NULL;
  78 }
  79
  80
  81 struct fstab *
  82 getfsfile (name)
  83      const char *name;
  84 {
  85   struct fstab_state *state;
  86   struct mntent *m;
  87
  88   state = fstab_init (1);
  89   if (state == NULL)
  90     return NULL;
  91   while ((m = fstab_fetch (state)) != NULL)
  92     if (strcmp (m->mnt_dir, name) == 0)
  93       return fstab_convert (state);
  94   return NULL;
  95 }
  96
  97
  98 void
  99 endfsent ()
 100 {
 101   struct fstab_state *state;
 102
 103   state = &fstab_state;
 104   if (state->fs_fp != NULL)
 105     {
 106       (void) __endmntent (state->fs_fp);
 107       state->fs_fp = NULL;
 108     }
 109 }
 110
 111
 112 static struct fstab_state *
 113 fstab_init (int opt_rewind)
 114 {
 115   struct fstab_state *state;
 116   char *buffer;
 117   FILE *fp;
 118
 119   state = &fstab_state;
 120
 121   buffer = state->fs_buffer;
 122   if (buffer == NULL)
 123     {
 124       buffer = (char *) malloc (BUFFER_SIZE);
 125       if (buffer == NULL)
 126         return NULL;
 127       state->fs_buffer = buffer;
 128     }
 129
 130   fp = state->fs_fp;
 131   if (fp != NULL)
 132     {
 133       if (opt_rewind)
 134         rewind (fp);
 135     }
 136   else
 137     {
 138       fp = __setmntent (_PATH_FSTAB, "r");
 139       if (fp == NULL)
 140         return NULL;
 141       state->fs_fp = fp;
 142     }
 143
 144   return state;
 145 }
 146
 147
 148 static struct mntent *
 149 fstab_fetch (struct fstab_state *state)
 150 {
 151   return __getmntent_r (state->fs_fp, &state->fs_mntres,
 152                         state->fs_buffer, BUFFER_SIZE);
 153 }
 154
 155
 156 static struct fstab *
 157 fstab_convert (struct fstab_state *state)
 158 {
 159   struct mntent *m;
 160   struct fstab *f;
 161
 162   m = &state->fs_mntres;
 163   f = &state->fs_ret;
 164
 165   f->fs_spec = m->mnt_fsname;
 166   f->fs_file = m->mnt_dir;
 167   f->fs_vfstype = m->mnt_type;
 168   f->fs_mntops = m->mnt_opts;
 169   f->fs_type = (__hasmntopt (m, FSTAB_RW) ? FSTAB_RW :
 170                 __hasmntopt (m, FSTAB_RQ) ? FSTAB_RQ :
 171                 __hasmntopt (m, FSTAB_RO) ? FSTAB_RO :
 172                 __hasmntopt (m, FSTAB_SW) ? FSTAB_SW :
 173                 __hasmntopt (m, FSTAB_XX) ? FSTAB_XX :
 174                 "??");
 175   f->fs_freq = m->mnt_freq;
 176   f->fs_passno = m->mnt_passno;
 177   return f;
 178 }
 179
 180
 181 /* Make sure the memory is freed if the programs ends while in
 182    memory-debugging mode and something actually was allocated.  */
 183 libc_freeres_fn (fstab_free)
 184 {
 185   char *buffer;
 186
 187   buffer = fstab_state.fs_buffer;
 188   free ((void *) buffer);
 189 }