miscutils/flash_lock_unlock.c

   1 /* vi: set sw=4 ts=4: */
   2 /* Ported to busybox from mtd-utils.
   3  *
   4  * Licensed under GPLv2, see file LICENSE in this source tree.
   5  */
   6 //config:config FLASH_LOCK
   7 //config:       bool "flash_lock"
   8 //config:       default n  # doesn't build on Ubuntu 8.04
   9 //config:       help
  10 //config:         The flash_lock binary from mtd-utils as of git head 5ec0c10d0. This
  11 //config:         utility locks part or all of the flash device.
  12 //config:
  13 //config:config FLASH_UNLOCK
  14 //config:       bool "flash_unlock"
  15 //config:       default n  # doesn't build on Ubuntu 8.04
  16 //config:       help
  17 //config:         The flash_unlock binary from mtd-utils as of git head 5ec0c10d0. This
  18 //config:         utility unlocks part or all of the flash device.
  19
  20 //applet:IF_FLASH_LOCK(APPLET_ODDNAME(flash_lock, flash_lock_unlock, BB_DIR_USR_SBIN, BB_SUID_DROP, flash_lock))
  21 //applet:IF_FLASH_UNLOCK(APPLET_ODDNAME(flash_unlock, flash_lock_unlock, BB_DIR_USR_SBIN, BB_SUID_DROP, flash_unlock))
  22
  23 //kbuild:lib-$(CONFIG_FLASH_LOCK) += flash_lock_unlock.o
  24 //kbuild:lib-$(CONFIG_FLASH_UNLOCK) += flash_lock_unlock.o
  25
  26 //usage:#define flash_lock_trivial_usage
  27 //usage:       "MTD_DEVICE OFFSET SECTORS"
  28 //usage:#define flash_lock_full_usage "\n\n"
  29 //usage:       "Lock part or all of an MTD device. If SECTORS is -1, then all sectors\n"
  30 //usage:       "will be locked, regardless of the value of OFFSET"
  31 //usage:
  32 //usage:#define flash_unlock_trivial_usage
  33 //usage:       "MTD_DEVICE"
  34 //usage:#define flash_unlock_full_usage "\n\n"
  35 //usage:       "Unlock an MTD device"
  36
  37 #include "libbb.h"
  38 #include <mtd/mtd-user.h>
  39
  40 int flash_lock_unlock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  41 int flash_lock_unlock_main(int argc UNUSED_PARAM, char **argv)
  42 {
  43         /* note: fields in these structs are 32-bits.
  44          * apparently we can't win anything by using off_t
  45          * or long long's for offset and/or sectors vars. */
  46         struct mtd_info_user info;
  47         struct erase_info_user lock;
  48         unsigned long offset;
  49         long sectors;
  50         int fd;
  51
  52 #define do_lock (ENABLE_FLASH_LOCK && (!ENABLE_FLASH_UNLOCK || (applet_name[6] == 'l')))
  53
  54         if (!argv[1])
  55                 bb_show_usage();
  56
  57         /* parse offset and number of sectors to lock */
  58         offset = 0;
  59         sectors = -1;
  60         if (do_lock) {
  61                 if (!argv[2] || !argv[3])
  62                         bb_show_usage();
  63                 offset = xstrtoul(argv[2], 0);
  64                 sectors = xstrtol(argv[3], 0);
  65         }
  66
  67         fd = xopen(argv[1], O_RDWR);
  68
  69         xioctl(fd, MEMGETINFO, &info);
  70
  71         lock.start = 0;
  72         lock.length = info.size;
  73         if (do_lock) {
  74                 unsigned long size = info.size - info.erasesize;
  75                 if (offset > size) {
  76                         bb_error_msg_and_die("%lx is beyond device size %lx\n",
  77                                         offset, size);
  78                 }
  79
  80                 if (sectors == -1) {
  81                         sectors = info.size / info.erasesize;
  82                 } else {
  83 // isn't this useless?
  84                         unsigned long num = info.size / info.erasesize;
  85                         if (sectors > num) {
  86                                 bb_error_msg_and_die("%ld are too many "
  87                                                 "sectors, device only has "
  88                                                 "%ld\n", sectors, num);
  89                         }
  90                 }
  91
  92                 lock.start = offset;
  93                 lock.length = sectors * info.erasesize;
  94                 xioctl(fd, MEMLOCK, &lock);
  95         } else {
  96                 xioctl(fd, MEMUNLOCK, &lock);
  97         }
  98
  99         return EXIT_SUCCESS;
 100 }