miscutils/ubirename.c

   1 /* ubirename - port of the ubirename from the mtd-utils package
   2  *
   3  * A utility to rename one UBI volume.
   4  *
   5  * 2016-03-01 Sven Eisenberg <sven.eisenberg@novero.com>
   6  *
   7  * Licensed under GPLv2, see file LICENSE in this source tree.
   8  */
   9 //config:config UBIRENAME
  10 //config:       bool "ubirename (2.7 kb)"
  11 //config:       default y
  12 //config:       help
  13 //config:       Utility to rename UBI volumes
  14
  15 //applet:IF_UBIRENAME(APPLET(ubirename, BB_DIR_USR_SBIN, BB_SUID_DROP))
  16 /* not NOEXEC: if flash operation stalls, use less memory in "hung" process */
  17
  18 //kbuild:lib-$(CONFIG_UBIRENAME) += ubirename.o
  19
  20 //usage:#define ubirename_trivial_usage
  21 //usage:        "UBI_DEVICE OLD_VOLNAME NEW_VOLNAME [OLD2 NEW2]..."
  22 //usage:#define ubirename_full_usage "\n\n"
  23 //usage:        "Rename UBI volumes on UBI_DEVICE"
  24
  25 #include "libbb.h"
  26 #include <mtd/mtd-user.h>
  27
  28 #ifndef __packed
  29 # define __packed __attribute__((packed))
  30 #endif
  31
  32 // from ubi-media.h
  33 #define UBI_MAX_VOLUME_NAME 127
  34 #define UBI_MAX_VOLUMES     128
  35 // end ubi-media.h
  36
  37 // from ubi-user.h
  38 /* ioctl commands of UBI character devices */
  39 #define UBI_IOC_MAGIC 'o'
  40
  41 /* Re-name volumes */
  42 #define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_req)
  43
  44 /* Maximum amount of UBI volumes that can be re-named at one go */
  45 #define UBI_MAX_RNVOL 32
  46
  47 struct ubi_rnvol_req {
  48         int32_t count;
  49         int8_t  padding1[12];
  50         struct {
  51                 int32_t vol_id;
  52                 int16_t name_len;
  53                 int8_t  padding2[2];
  54                 char    name[UBI_MAX_VOLUME_NAME + 1];
  55         } ents[UBI_MAX_RNVOL];
  56 } __packed;
  57 // end ubi-user.h
  58
  59 int ubirename_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  60 int ubirename_main(int argc, char **argv)
  61 {
  62         struct ubi_rnvol_req *rnvol;
  63         const char *ubi_devname;
  64         unsigned ubi_devnum;
  65         unsigned n;
  66
  67         /* argc can be 4, 6, 8, ... */
  68         if ((argc & 1) || (argc >>= 1) < 2)
  69                 bb_show_usage();
  70
  71         rnvol = xzalloc(sizeof(*rnvol));
  72         rnvol->count = --argc;
  73         if (argc > ARRAY_SIZE(rnvol->ents))
  74                 bb_simple_error_msg_and_die("too many renames requested");
  75
  76         ubi_devname = argv[1];
  77         ubi_devnum = ubi_devnum_from_devname(ubi_devname);
  78
  79         n = 0;
  80         argv += 2;
  81         while (argv[0]) {
  82                 rnvol->ents[n].vol_id = ubi_get_volid_by_name(ubi_devnum, argv[0]);
  83
  84                 /* strnlen avoids overflow of 16-bit field (paranoia) */
  85                 rnvol->ents[n].name_len = strnlen(argv[1], sizeof(rnvol->ents[n].name));
  86                 if (rnvol->ents[n].name_len >= sizeof(rnvol->ents[n].name))
  87                         bb_error_msg_and_die("new name '%s' is too long", argv[1]);
  88
  89                 strcpy(rnvol->ents[n].name, argv[1]);
  90                 n++;
  91                 argv += 2;
  92         }
  93
  94         xioctl(xopen(ubi_devname, O_RDONLY), UBI_IOCRNVOL, rnvol);
  95
  96         return 0;
  97 }