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