release/src/router/busybox/util-linux/losetup.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini losetup implementation for busybox
   4  *
   5  * Copyright (C) 2002  Matt Kraai.
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   8  */
   9
  10 #include "libbb.h"
  11
  12 int losetup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  13 int losetup_main(int argc, char **argv)
  14 {
  15         char dev[] = LOOP_NAME"0";
  16         unsigned opt;
  17         char *opt_o;
  18         char *s;
  19         unsigned long long offset = 0;
  20
  21         /* max 2 args, all opts are mutually exclusive */
  22         opt_complementary = "?2:d--of:o--df:f-do";
  23         opt = getopt32(argv, "do:f", &opt_o);
  24         argc -= optind;
  25         argv += optind;
  26
  27         if (opt == 0x2) // -o
  28                 offset = xatoull(opt_o);
  29
  30         if (opt == 0x4 && argc) // -f does not take any argument
  31                 bb_show_usage();
  32
  33         if (opt == 0x1) { // -d
  34                 /* detach takes exactly one argument */
  35                 if (argc != 1)
  36                         bb_show_usage();
  37                 if (del_loop(argv[0]))
  38                         bb_simple_perror_msg_and_die(argv[0]);
  39                 return EXIT_SUCCESS;
  40         }
  41
  42         if (argc == 2) {
  43                 /* -o or no option */
  44                 if (set_loop(&argv[0], argv[1], offset) < 0)
  45                         bb_simple_perror_msg_and_die(argv[0]);
  46                 return EXIT_SUCCESS;
  47         }
  48
  49         if (argc == 1) {
  50                 /* -o or no option */
  51                 s = query_loop(argv[0]);
  52                 if (!s)
  53                         bb_simple_perror_msg_and_die(argv[0]);
  54                 printf("%s: %s\n", argv[0], s);
  55                 if (ENABLE_FEATURE_CLEAN_UP)
  56                         free(s);
  57                 return EXIT_SUCCESS;
  58         }
  59
  60         /* -o, -f or no option */
  61         while (1) {
  62                 s = query_loop(dev);
  63                 if (!s) {
  64                         if (opt == 0x4) {
  65                                 puts(dev);
  66                                 return EXIT_SUCCESS;
  67                         }
  68                 } else {
  69                         if (opt != 0x4)
  70                                 printf("%s: %s\n", dev, s);
  71                         if (ENABLE_FEATURE_CLEAN_UP)
  72                                 free(s);
  73                 }
  74
  75                 if (++dev[sizeof(dev) - 2] > '9')
  76                         break;
  77         }
  78         return EXIT_SUCCESS;
  79 }