libbb/mtab.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Utility routines.
   4  *
   5  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   8  */
   9
  10 #include <stdlib.h>
  11 #include <unistd.h>
  12 #include <errno.h>
  13 #include <string.h>
  14 #include <stdio.h>
  15 #include <mntent.h>
  16 #include "libbb.h"
  17
  18 #define MTAB_MAX_ENTRIES 40
  19
  20 #ifdef CONFIG_FEATURE_MTAB_SUPPORT
  21 void erase_mtab(const char *name)
  22 {
  23         struct mntent entries[MTAB_MAX_ENTRIES];
  24         int count = 0;
  25         FILE *mountTable = setmntent(bb_path_mtab_file, "r");
  26         struct mntent *m;
  27
  28         /* Check if reading the mtab file failed */
  29         if (mountTable == 0
  30                         /* Bummer.  fall back on trying the /proc filesystem */
  31                         && (mountTable = setmntent("/proc/mounts", "r")) == 0) {
  32                 bb_perror_msg(bb_path_mtab_file);
  33                 return;
  34         }
  35
  36         while (((m = getmntent(mountTable)) != 0) && (count < MTAB_MAX_ENTRIES))
  37         {
  38                 entries[count].mnt_fsname = strdup(m->mnt_fsname);
  39                 entries[count].mnt_dir = strdup(m->mnt_dir);
  40                 entries[count].mnt_type = strdup(m->mnt_type);
  41                 entries[count].mnt_opts = strdup(m->mnt_opts);
  42                 entries[count].mnt_freq = m->mnt_freq;
  43                 entries[count].mnt_passno = m->mnt_passno;
  44                 count++;
  45         }
  46         endmntent(mountTable);
  47         if ((mountTable = setmntent(bb_path_mtab_file, "w"))) {
  48                 int i;
  49
  50                 for (i = 0; i < count; i++) {
  51                         int result = (strcmp(entries[i].mnt_fsname, name) == 0
  52                                                   || strcmp(entries[i].mnt_dir, name) == 0);
  53
  54                         if (result)
  55                                 continue;
  56                         else
  57                                 addmntent(mountTable, &entries[i]);
  58                 }
  59                 endmntent(mountTable);
  60         } else if (errno != EROFS)
  61                 bb_perror_msg(bb_path_mtab_file);
  62 }
  63 #endif