LXR toybox/toys/other/blkid.c

   1/* blkid.c - Prints type, label and UUID of filesystem(s).
   2 *
   3 * Copyright 2013 Brad Conroy <bconroy@uis.edu>
   4 *
   5 * See ftp://ftp.kernel.org/pub/linux/utils/util-linux/v2.24/libblkid-docs/api-index-full.html
   6
   7USE_BLKID(NEWTOY(blkid, "UL[!LU]", TOYFLAG_BIN))
   8USE_FSTYPE(NEWTOY(fstype, "<1", TOYFLAG_BIN))
   9
  10config BLKID
  11  bool "blkid"
  12  default y
  13  help
  14    usage: blkid [-UL] DEV...
  15
  16    Print type, label and UUID of filesystem on a block device or image.
  17
  18    -U  Show UUID only (or device with that UUID)
  19    -L  Show LABEL only (or device with that LABEL)
  20
  21config FSTYPE
  22  bool "fstype"
  23  default y
  24  help
  25    usage: fstype DEV...
  26
  27    Print type of filesystem on a block device or image.
  28*/
  29
  30#define FOR_blkid
  31#include "toys.h"
  32
  33struct fstype {
  34  char *name;
  35  uint64_t magic;
  36  int magic_len, magic_offset, uuid_off, label_len, label_off;
  37} static const fstypes[] = {
  38  {"ext2", 0xEF53, 2, 1080, 1128, 16, 1144}, // keep this first for ext3/4 check
  39  {"swap", 0x4341505350415753LL, 8, 4086, 1036, 15, 1052},
  40  // NTFS label actually 8/16 0x4d80 but horrible: 16 bit wide characters via
  41  // codepage, something called a uuid that's only 8 bytes long...
  42  {"ntfs", 0x5346544e, 4, 3, 0x48+(8<<24), 0, 0},
  43
  44  {"adfs", 0xadf5, 2, 0xc00, 0,0,0},
  45  {"bfs", 0x1badface, 4, 0, 0,0,0},
  46  {"btrfs", 0x4D5F53665248425FULL, 8, 65600, 65803, 256, 65819},
  47  {"cramfs", 0x28cd3d45, 4, 0, 0, 16, 48},
  48  {"f2fs", 0xF2F52010, 4, 1024, 1132, 16, 1110},
  49  {"jfs", 0x3153464a, 4, 32768, 32920, 16, 32904},
  50  {"nilfs", 0x3434, 2, 1030, 1176, 80, 1192},
  51  {"reiserfs", 0x724573496552ULL, 6, 8244, 8276, 16, 8292},
  52  {"reiserfs", 0x724573496552ULL, 6, 65588, 65620, 16, 65636},
  53  {"romfs", 0x2d6d6f72, 4, 0, 0,0,0},
  54  {"squashfs", 0x73717368, 4, 0, 0,0,0},
  55  {"xiafs", 0x012fd16d, 4, 572, 0,0,0},
  56  {"xfs", 0x42534658, 4, 0, 32, 12, 108},
  57  {"vfat", 0x3233544146ULL, 5, 82, 67+(4<<24), 11, 71},  // fat32
  58  {"vfat", 0x31544146, 4, 54, 39+(4<<24), 11, 43}     // fat1
  59};
  60
  61static void flagshow(char *s, char *name)
  62{
  63  if (*toys.optargs && strcmp(s, *toys.optargs)) return;
  64  printf("%s\n", *toys.optargs ? name : s);
  65  if (*toys.optargs) xexit();
  66}
  67
  68static void do_blkid(int fd, char *name)
  69{
  70  int off, i, j, len;
  71  char buf[128], *type, *s;
  72
  73  off = i = 0;
  74
  75  for (;;) {
  76    int pass = 0;
  77
  78    // Read next block of data
  79    len = readall(fd, toybuf, sizeof(toybuf));
  80    if (len != sizeof(toybuf)) return;
  81
  82    // Iterate through types in range
  83    for (i=0; i<ARRAY_LEN(fstypes); i++) {
  84      uint64_t test;
  85
  86      // Skip tests not in this 4k block
  87      if (fstypes[i].magic_offset > off+sizeof(toybuf)) {
  88        pass++;
  89        continue;
  90      }
  91      if (fstypes[i].magic_offset < off) continue;
  92
  93      // Populate 64 bit little endian magic value
  94      test = 0;
  95      for (j = 0; j < fstypes[i].magic_len; j++)
  96        test += ((uint64_t)toybuf[j+fstypes[i].magic_offset-off])<<(8*j);
  97      if (test == fstypes[i].magic) break;
  98    }
  99
 100    if (i == ARRAY_LEN(fstypes)) {
 101      off += len;
 102      if (pass) continue;
 103      return;
 104    }
 105    break;
 106  }
 107
 108  // distinguish ext2/3/4
 109  type = fstypes[i].name;
 110  if (!i) {
 111    if (toybuf[1116]&4) type = "ext3";
 112    if (toybuf[1120]&64) type = "ext4";
 113  }
 114
 115  // Could special case NTFS here...
 116
 117  // Output for fstype
 118  if (*toys.which->name == 'f') {
 119    puts(type);
 120    return;
 121  }
 122
 123  // output for blkid
 124  if (!toys.optflags) printf("%s:",name);
 125
 126  len = fstypes[i].label_len;
 127  if (!FLAG(U) && len) {
 128    s = toybuf+fstypes[i].label_off-off;
 129    if (!strcmp(type, "vfat")) {
 130      while (len && s[len-1]==' ') len--;
 131      if (strstart(&s, "NO NAME")) len=0;
 132    }
 133    if (len && *s) {
 134      sprintf(buf, "%.*s", len, s);
 135      if (FLAG(L)) return flagshow(buf, name);
 136      printf(" LABEL=\"%s\"", buf);
 137    }
 138  }
 139
 140  len = fstypes[i].uuid_off;
 141  if (!FLAG(L) && len) {
 142    int bits = 0x550, size = len >> 24, uoff = (len&((1<<24)-1))-off;
 143
 144    // Assemble UUID with whatever size and set of dashes this filesystem uses
 145    if (size) bits = 4*(size == 4);
 146    else size = 16;
 147    for (j = 0, s = buf; j < size; j++)
 148      s += sprintf(s, "-%02x"+!(bits & (1<<j)), toybuf[uoff+j]);
 149
 150    if (FLAG(U)) return flagshow(buf, name);
 151    printf(" UUID=\"%s\"", buf);
 152  }
 153
 154  if (toys.optflags) return;
 155
 156  printf(" TYPE=\"%s\"\n", type);
 157}
 158
 159void blkid_main(void)
 160{
 161  if (*toys.optargs && !FLAG(L) && !FLAG(U)) loopfiles(toys.optargs, do_blkid);
 162  else {
 163    unsigned int ma, mi, sz, fd;
 164    char *name = toybuf, *buffer = toybuf+1024, device[32];
 165    FILE *fp = xfopen("/proc/partitions", "r");
 166
 167    while (fgets(buffer, 1024, fp)) {
 168      *name = 0;
 169      if (sscanf(buffer, " %u %u %u %[^\n ]", &ma, &mi, &sz, name) != 4)
 170        continue;
 171
 172      sprintf(device, "/dev/%.20s", name);
 173      if (-1 == (fd = open(device, O_RDONLY))) {
 174        if (errno != ENOMEDIUM) perror_msg_raw(device);
 175      } else {
 176        do_blkid(fd, device);
 177        close(fd);
 178      }
 179    }
 180    if (CFG_TOYBOX_FREE) fclose(fp);
 181  }
 182
 183  if (FLAG(L) || FLAG(U)) toys.exitval = 2;
 184}
 185
 186void fstype_main(void)
 187{
 188  loopfiles(toys.optargs, do_blkid);
 189}
 190