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, "<1", TOYFLAG_BIN))
8USE_FSTYPE(NEWTOY(fstype, "<1", TOYFLAG_BIN))
9
10config BLKID
11  bool "blkid"
12  default y
13  help
14    usage: blkid DEV...
15
16    Prints type, label and UUID of filesystem on a block device or image.
17
18config FSTYPE
19  bool "fstype"
20  default y
21  help
22    usage: fstype DEV...
23
24    Prints type of filesystem on a block device or image.
25*/
26
27#define FOR_blkid
28#include "toys.h"
29
30struct fstype {
31  char *name;
32  uint64_t magic;
33  int magic_len, magic_offset, uuid_off, label_len, label_off;
34};
35
36static const struct fstype fstypes[] = {
37  {"ext2", 0xEF53, 2, 1080, 1128, 16, 1144}, // keep this first for ext3/4 check
38  // NTFS label actually 8/16 0x4d80 but horrible: 16 bit wide characters via
39  // codepage, something called a uuid that's only 8 bytes long...
40  {"ntfs", 0x5346544e, 4, 3, 0x48+(8<<24), 0, 0},
41
42  {"adfs", 0xadf5, 2, 0xc00, 0,0,0},
43  {"bfs", 0x1badface, 4, 0, 0,0,0},
44  {"btrfs", 0x4D5F53665248425FULL, 8, 65600, 65803, 256, 65819},
45  {"cramfs", 0x28cd3d45, 4, 0, 0, 16, 48},
46  {"f2fs", 0xF2F52010, 4, 1024, 1132, 16, 1110},
47  {"jfs", 0x3153464a, 4, 32768, 32920, 16, 32904},
48  {"nilfs", 0x3434, 2, 1030, 1176, 80, 1192},
49  {"reiserfs", 0x724573496552ULL, 6, 8244, 8276, 16, 8292},
50  {"reiserfs", 0x724573496552ULL, 6, 65588, 65620, 16, 65536},
51  {"romfs", 0x2d6d6f72, 4, 0, 0,0,0},
52  {"squashfs", 0x73717368, 4, 0, 0,0,0},
53  {"xiafs", 0x012fd16d, 4, 572, 0,0,0},
54  {"xfs", 0x42534658, 4, 0, 32, 12, 108},
55  {"vfat", 0x3233544146ULL, 5, 82, 67+(4<<24), 11, 71},  // fat32
56  {"vfat", 0x31544146, 4, 54, 39+(4<<24), 11, 43}     // fat1
57};
58
59/* TODO if no args use proc/partitions */
60void do_blkid(int fd, char *name)
61{
62  int off, i, j;
63  char *type;
64
65  off = i = 0;
66
67  for (;;) {
68    int pass = 0, len;
69
70    // Read next block of data
71    len = readall(fd, toybuf, sizeof(toybuf));
72    if (len != sizeof(toybuf)) return;
73
74    // Iterate through types in range
75    for (i=0; i < sizeof(fstypes)/sizeof(struct fstype); i++) {
76      uint64_t test;
77
78      // Skip tests not in this 4k block
79      if (fstypes[i].magic_offset > off+sizeof(toybuf)) {
80        pass++;
81        continue;
82      }
83      if (fstypes[i].magic_offset < off) continue;
84
85      // Populate 64 bit little endian magic value
86      test = 0;
87      for (j = 0; j < fstypes[i].magic_len; j++)
88        test += ((uint64_t)toybuf[j+fstypes[i].magic_offset-off])<<(8*j);
89      if (test == fstypes[i].magic) break;
90    }
91
92    if (i == sizeof(fstypes)/sizeof(struct fstype)) {
93      off += len;
94      if (pass) continue;
95      return;
96    }
97    break;
98  }
99
100  // distinguish ext2/3/4
101  type = fstypes[i].name;
102  if (!i) {
103    if (toybuf[1116]&4) type = "ext3";
104    if (toybuf[1120]&64) type = "ext4";
105  }
106
107  // Could special case NTFS here...
108
109  // Output for fstype
110  if (*toys.which->name == 'f') {
111    puts(type);
112    return;
113  }
114
115  // output for blkid
116  printf("%s:",name);
117
118  if (fstypes[i].label_len)
119    printf(" LABEL=\"%.*s\"", fstypes[i].label_len,
120           toybuf+fstypes[i].label_off-off);
121
122  if (fstypes[i].uuid_off) {
123    int bits = 0x550, size = fstypes[i].uuid_off >> 24,
124        uoff = (fstypes[i].uuid_off & ((1<<24)-1))-off;
125
126    if (size) bits = 4*(size == 4);
127    else size = 16;
128
129    printf(" UUID=\"");
130    for (j = 0; j < size; j++) printf("-%02x"+!(bits & (1<<j)), toybuf[uoff+j]);
131    printf("\"");
132  }
133
134  printf(" TYPE=\"%s\"\n", type);
135}
136
137void blkid_main(void)
138{
139  loopfiles(toys.optargs, do_blkid);
140}
141
142void fstype_main(void)
143{
144  blkid_main();
145}
146