1 /*
2 * Copyright (c) 2017 Conrad Meyer <[email protected]>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include <stdint.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34
35 #include "fstyp.h"
36
37 struct exfat_vbr {
38 char ev_jmp[3];
39 char ev_fsname[8];
40 char ev_zeros[53];
41 uint64_t ev_part_offset;
42 uint64_t ev_vol_length;
43 uint32_t ev_fat_offset;
44 uint32_t ev_fat_length;
45 uint32_t ev_cluster_offset;
46 uint32_t ev_cluster_count;
47 uint32_t ev_rootdir_cluster;
48 uint32_t ev_vol_serial;
49 uint16_t ev_fs_revision;
50 uint16_t ev_vol_flags;
51 uint8_t ev_log_bytes_per_sect;
52 uint8_t ev_log_sect_per_clust;
53 uint8_t ev_num_fats;
54 uint8_t ev_drive_sel;
55 uint8_t ev_percent_used;
56 } __packed;
57
58 int
fstyp_exfat(FILE * fp,char * label,size_t size)59 fstyp_exfat(FILE *fp, char *label, size_t size)
60 {
61 struct exfat_vbr *ev;
62
63 ev = (struct exfat_vbr *)read_buf(fp, 0, 512);
64 if (ev == NULL || strncmp(ev->ev_fsname, "EXFAT ", 8) != 0)
65 goto fail;
66
67 /*
68 * Reading the volume label requires walking the root directory to look
69 * for a special label file. Left as an exercise for the reader.
70 */
71 free(ev);
72 return (0);
73
74 fail:
75 free(ev);
76 return (1);
77 }
78