mtab.c

   1 /* vi: set sw=4 ts=4: */
   2 #include "busybox.h"
   3 #include <stdlib.h>
   4 #include <unistd.h>
   5 #include <errno.h>
   6 #include <string.h>
   7 #include <stdio.h>
   8 #include <mntent.h>
   9 #include <fstab.h>
  10 #include <sys/mount.h>
  11
  12 extern const char mtab_file[];  /* Defined in utility.c */
  13
  14
  15 void erase_mtab(const char *name)
  16 {
  17         struct mntent entries[20];
  18         int count = 0;
  19         FILE *mountTable = setmntent(mtab_file, "r");
  20         struct mntent *m;
  21
  22         /* Check if reading the mtab file failed */
  23         if (mountTable == 0
  24 #if ! defined BB_FEATURE_USE_PROCFS
  25                 ) {
  26 #else
  27                 /* Bummer.  fall back on trying the /proc filesystem */
  28                 && (mountTable = setmntent("/proc/mounts", "r")) == 0) {
  29 #endif
  30                 perror(mtab_file);
  31                 return;
  32         }
  33
  34         while ((m = getmntent(mountTable)) != 0) {
  35                 entries[count].mnt_fsname = strdup(m->mnt_fsname);
  36                 entries[count].mnt_dir = strdup(m->mnt_dir);
  37                 entries[count].mnt_type = strdup(m->mnt_type);
  38                 entries[count].mnt_opts = strdup(m->mnt_opts);
  39                 entries[count].mnt_freq = m->mnt_freq;
  40                 entries[count].mnt_passno = m->mnt_passno;
  41                 count++;
  42         }
  43         endmntent(mountTable);
  44         if ((mountTable = setmntent(mtab_file, "w"))) {
  45                 int i;
  46
  47                 for (i = 0; i < count; i++) {
  48                         int result = (strcmp(entries[i].mnt_fsname, name) == 0
  49                                                   || strcmp(entries[i].mnt_dir, name) == 0);
  50
  51                         if (result)
  52                                 continue;
  53                         else
  54                                 addmntent(mountTable, &entries[i]);
  55                 }
  56                 endmntent(mountTable);
  57         } else if (errno != EROFS)
  58                 perror(mtab_file);
  59 }
  60
  61 void write_mtab(char *blockDevice, char *directory,
  62                                 char *filesystemType, long flags, char *string_flags)
  63 {
  64         FILE *mountTable = setmntent(mtab_file, "a+");
  65         struct mntent m;
  66
  67         if (mountTable == 0) {
  68                 perror(mtab_file);
  69                 return;
  70         }
  71         if (mountTable) {
  72                 int length = strlen(directory);
  73
  74                 if (length > 1 && directory[length - 1] == '/')
  75                         directory[length - 1] = '\0';
  76
  77 #ifdef BB_FEATURE_USE_PROCFS
  78                 if (filesystemType == 0) {
  79                         struct mntent *p = find_mount_point(blockDevice, "/proc/mounts");
  80
  81                         if (p && p->mnt_type)
  82                                 filesystemType = p->mnt_type;
  83                 }
  84 #endif
  85                 m.mnt_fsname = blockDevice;
  86                 m.mnt_dir = directory;
  87                 m.mnt_type = filesystemType ? filesystemType : "default";
  88
  89                 if (*string_flags) {
  90                         m.mnt_opts = string_flags;
  91                 } else {
  92                         if ((flags | MS_RDONLY) == flags)
  93                                 m.mnt_opts = "ro";
  94                         else
  95                                 m.mnt_opts = "rw";
  96                 }
  97
  98                 m.mnt_freq = 0;
  99                 m.mnt_passno = 0;
 100                 addmntent(mountTable, &m);
 101                 endmntent(mountTable);
 102         }
 103 }