mtab.c

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