1 /* 2 * Copyright (c) 2017 Conrad Meyer <cem@FreeBSD.org> 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 <stdint.h> 28 #include <stdio.h> 29 #include <stdlib.h> 30 #include <string.h> 31 32 #include "fstyp.h" 33 34 struct exfat_vbr { 35 char ev_jmp[3]; 36 char ev_fsname[8]; 37 char ev_zeros[53]; 38 uint64_t ev_part_offset; 39 uint64_t ev_vol_length; 40 uint32_t ev_fat_offset; 41 uint32_t ev_fat_length; 42 uint32_t ev_cluster_offset; 43 uint32_t ev_cluster_count; 44 uint32_t ev_rootdir_cluster; 45 uint32_t ev_vol_serial; 46 uint16_t ev_fs_revision; 47 uint16_t ev_vol_flags; 48 uint8_t ev_log_bytes_per_sect; 49 uint8_t ev_log_sect_per_clust; 50 uint8_t ev_num_fats; 51 uint8_t ev_drive_sel; 52 uint8_t ev_percent_used; 53 } __packed; 54 55 int 56 fstyp_exfat(FILE *fp, char *label, size_t size) 57 { 58 struct exfat_vbr *ev; 59 60 ev = (struct exfat_vbr *)read_buf(fp, 0, 512); 61 if (ev == NULL || strncmp(ev->ev_fsname, "EXFAT ", 8) != 0) 62 goto fail; 63 64 /* 65 * Reading the volume label requires walking the root directory to look 66 * for a special label file. Left as an exercise for the reader. 67 */ 68 free(ev); 69 return (0); 70 71 fail: 72 free(ev); 73 return (1); 74 } 75