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 <getopt.h>
  11
  12 #include "libbb.h"
  13
  14 int losetup_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  15 int losetup_main(int argc, char **argv)
  16 {
  17         char dev[] = LOOP_NAME"0";
  18         unsigned opt;
  19         char *opt_o;
  20         char *s;
  21         unsigned long long offset = 0;
  22
  23         /* max 2 args, all opts are mutially exclusive */
  24         opt_complementary = "?2:d--of:o--df:f-do";
  25         opt = getopt32(argv, "do:f", &opt_o);
  26         argc -= optind;
  27         argv += optind;
  28
  29         if (opt == 0x2) // -o
  30                 offset = xatoull(opt_o);
  31
  32         if (opt == 0x4 && argc) // -f does not take any argument
  33                 bb_show_usage();
  34
  35         if (opt == 0x1) { // -d
  36                 /* detach takes exactly one argument */
  37                 if (argc != 1)
  38                         bb_show_usage();
  39                 if (del_loop(argv[0]))
  40                         bb_perror_nomsg_and_die();
  41                 return EXIT_SUCCESS;
  42         }
  43
  44         if (argc == 2) {
  45                 /* -o or no option */
  46                 if (set_loop(&argv[0], argv[1], offset) < 0)
  47                         bb_perror_nomsg_and_die();
  48                 return EXIT_SUCCESS;
  49         }
  50
  51         if (argc == 1) {
  52                 /* -o or no option */
  53                 s = query_loop(argv[0]);
  54                 if (!s)
  55                         bb_perror_nomsg_and_die();
  56                 printf("%s: %s\n", argv[0], s);
  57                 if (ENABLE_FEATURE_CLEAN_UP)
  58                         free(s);
  59                 return EXIT_SUCCESS;
  60         }
  61
  62         /* -o, -f or no option */
  63         while (1) {
  64                 s = query_loop(dev);
  65                 if (!s) {
  66                         if (opt == 0x4) {
  67                                 puts(dev);
  68                                 return EXIT_SUCCESS;
  69                         }
  70                 } else {
  71                         if (opt != 0x4)
  72                                 printf("%s: %s\n", dev, s);
  73                         if (ENABLE_FEATURE_CLEAN_UP)
  74                                 free(s);
  75                 }
  76
  77                 if (++dev[sizeof(dev) - 2] > '9')
  78                         break;
  79         }
  80         return EXIT_SUCCESS;
  81 }