| 1 | /*␊ |
| 2 | * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.␊ |
| 3 | *␊ |
| 4 | * @APPLE_LICENSE_HEADER_START@␊ |
| 5 | * ␊ |
| 6 | * Copyright (c) 1999-2004 Apple Computer, Inc. All Rights Reserved.␊ |
| 7 | * ␊ |
| 8 | * This file contains Original Code and/or Modifications of Original Code␊ |
| 9 | * as defined in and that are subject to the Apple Public Source License␊ |
| 10 | * Version 2.0 (the 'License'). You may not use this file except in␊ |
| 11 | * compliance with the License. Please obtain a copy of the License at␊ |
| 12 | * http://www.opensource.apple.com/apsl/ and read it before using this␊ |
| 13 | * file.␊ |
| 14 | * ␊ |
| 15 | * The Original Code and all software distributed under the License are␊ |
| 16 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER␊ |
| 17 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,␊ |
| 18 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,␊ |
| 19 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.␊ |
| 20 | * Please see the License for the specific language governing rights and␊ |
| 21 | * limitations under the License.␊ |
| 22 | * ␊ |
| 23 | * @APPLE_LICENSE_HEADER_END@␊ |
| 24 | */␊ |
| 25 | /*␊ |
| 26 | * dmazar, 14/7/2011␊ |
| 27 | * support for EXFAT volume label reading␊ |
| 28 | * EXFAT info from: http://www.ntfs.com/exfat-overview.htm␊ |
| 29 | *␊ |
| 30 | * EXFAT shares partition type with NTFS (0x7) and easiest way of␊ |
| 31 | * adding it was through ntfs.c module. All functions here are called␊ |
| 32 | * from similar ntfs.c funcs as fallback (if not NTFS, maybe it's EXFAT).␊ |
| 33 | */␊ |
| 34 | ␊ |
| 35 | #include "libsaio.h"␊ |
| 36 | #include "sl.h"␊ |
| 37 | ␊ |
| 38 | #ifndef DEBUG_EXFAT␊ |
| 39 | #define DEBUG_EXFAT 0␊ |
| 40 | #endif␊ |
| 41 | ␊ |
| 42 | #if DEBUG_EXFAT␊ |
| 43 | #define DBG(x...)␉␉printf(x)␊ |
| 44 | #define PAUSE()␉␉␉getchar()␊ |
| 45 | #else␊ |
| 46 | #define DBG(x...)␊ |
| 47 | #define PAUSE()␊ |
| 48 | #endif␊ |
| 49 | ␊ |
| 50 | #define␉EXFAT_BBID␉"EXFAT "␊ |
| 51 | #define␉EXFAT_BBIDLEN␉8␊ |
| 52 | ␊ |
| 53 | #define MAX_BLOCK_SIZE␉␉4096␊ |
| 54 | #define MAX_CLUSTER_SIZE␉32 * 1024 * 1024␊ |
| 55 | ␊ |
| 56 | #define ERROR -1␊ |
| 57 | ␊ |
| 58 | ␊ |
| 59 | /*␊ |
| 60 | * boot sector of the partition␊ |
| 61 | * http://www.ntfs.com/exfat-boot-sector.htm␊ |
| 62 | */␊ |
| 63 | struct exfatbootfile {␊ |
| 64 | ␉u_int8_t reserved1[3];␉/* JumpBoot: 0xEB7690 */␊ |
| 65 | ␉u_int8_t bf_sysid[8];␉/* FileSystemName: 'EXFAT ' */␊ |
| 66 | ␉u_int8_t reserved2[53];␉/* MustBeZero */␊ |
| 67 | ␉u_int64_t bf_prtoff;␉␉/* PartitionOffset: In sectors; if 0, shall be ignored */␊ |
| 68 | ␉u_int64_t bf_vollen;␉␉/* VolumeLength: Size of exFAT volume in sectors */␊ |
| 69 | ␉u_int32_t bf_fatoff;␉␉/* FatOffset: In sectors */␊ |
| 70 | ␉u_int32_t bf_fatlen;␉␉/* FatLength: In sectors. May exceed the required space in order to align the second FAT */␊ |
| 71 | ␉u_int32_t bf_cloff;␉␉/* ClusterHeapOffset: In sectors. */␊ |
| 72 | ␉u_int32_t bf_clcnt;␉␉/* ClusterCount: 2^32-11 is the maximum number of clusters could be described. */␊ |
| 73 | ␉u_int32_t bf_rdircl;␉␉/* RootDirectoryCluster. */␊ |
| 74 | ␉u_int32_t bf_volsn;␉␉/* VolumeSerialNumber. */␊ |
| 75 | ␉u_int16_t bf_fsrev;␉␉/* FileSystemRevision: as MAJOR.minor, major revision is high byte, minor is low byte; currently 01.00. */␊ |
| 76 | ␉u_int16_t bf_volflags;␉/* VolumeFlags. */␊ |
| 77 | ␉u_int8_t bf_bpss;␉␉/* BytesPerSectorShift: Power of 2. Minimum 9 (512 bytes per sector), maximum 12 (4096 bytes per sector) */␊ |
| 78 | |
| 79 | ␉u_int8_t bf_nfats;␉␉/* NumberOfFats: 2 is for TexFAT only */␊ |
| 80 | ␉u_int8_t bf_drvs;␉␉/* DriveSelect: Extended INT 13h drive number; typically 0x80 */␊ |
| 81 | |
| 82 | ␉u_int8_t reserved3[7];␉/* Reserved */␊ |
| 83 | ␉u_int8_t bootcode[390];␉/* BootCode */␊ |
| 84 | ␉u_int16_t bf_bsig;␉␉/* BootSignature: 0xAA55 */␊ |
| 85 | };␊ |
| 86 | ␊ |
| 87 | struct direntry_label {␊ |
| 88 | ␉u_int8_t type;␉␉␉/* EntryType: 0x83 (or 0x03 if label is empty) */␊ |
| 89 | ␉u_int8_t llen;␉␉␉/* CharacterCount: Length in Unicode characters (max 11) */␊ |
| 90 | ␉u_int16_t label[11];␉␉/* VolumeLabel: Unicode characters (max 11) */␊ |
| 91 | ␉u_int8_t reserved1[8];␉/* Reserved */␊ |
| 92 | };␊ |
| 93 | ␊ |
| 94 | ␊ |
| 95 | /**␊ |
| 96 | * Reads volume label into str.␊ |
| 97 | * Reads boot sector, performs dome checking, loads root dir␊ |
| 98 | * and parses volume label.␊ |
| 99 | */␊ |
| 100 | void␊ |
| 101 | EXFATGetDescription(CICell ih, char *str, long strMaxLen)␊ |
| 102 | {␊ |
| 103 | struct exfatbootfile *boot;␊ |
| 104 | u_int32_t bytesPerSector = 0;␊ |
| 105 | u_int32_t sectorsPerCluster = 0;␊ |
| 106 | long long rdirOffset = 0;␊ |
| 107 | char *buf = NULL;␊ |
| 108 | struct direntry_label *dire = NULL;␊ |
| 109 | int loopControl = 0;␊ |
| 110 | ␊ |
| 111 | DBG("EXFAT: start %x:%x\n", ih->biosdev, ih->part_no);␊ |
| 112 | ␉␊ |
| 113 | buf = (char *)malloc(MAX_BLOCK_SIZE);␊ |
| 114 | if (buf == 0)␊ |
| 115 | {␊ |
| 116 | goto error;␊ |
| 117 | }␊ |
| 118 | ␊ |
| 119 | /*␊ |
| 120 | * Read the boot sector, check signatures, and do some minimal␊ |
| 121 | * sanity checking. NOTE: the size of the read below is intended␊ |
| 122 | * to be a multiple of all supported block sizes, so we don't␊ |
| 123 | * have to determine or change the device's block size.␊ |
| 124 | */␊ |
| 125 | Seek(ih, 0);␊ |
| 126 | Read(ih, (long)buf, MAX_BLOCK_SIZE);␊ |
| 127 | ␊ |
| 128 | // take our boot structure␊ |
| 129 | boot = (struct exfatbootfile *) buf;␊ |
| 130 | ␊ |
| 131 | /*␊ |
| 132 | * The first three bytes are an Intel x86 jump instruction. I assume it␊ |
| 133 | * can be the same forms as DOS FAT:␊ |
| 134 | * 0xE9 0x?? 0x??␊ |
| 135 | * 0xEC 0x?? 0x90␊ |
| 136 | * where 0x?? means any byte value is OK.␊ |
| 137 | */␊ |
| 138 | if (boot->reserved1[0] != 0xE9␊ |
| 139 | && (boot->reserved1[0] != 0xEB || boot->reserved1[2] != 0x90))␊ |
| 140 | {␊ |
| 141 | goto error;␊ |
| 142 | }␊ |
| 143 | ␊ |
| 144 | // Check the "EXFAT " signature.␊ |
| 145 | if (memcmp((const char *)boot->bf_sysid, EXFAT_BBID, EXFAT_BBIDLEN) != 0)␊ |
| 146 | {␊ |
| 147 | goto error;␊ |
| 148 | }␊ |
| 149 | ␊ |
| 150 | /*␊ |
| 151 | * Make sure the bytes per sector and sectors per cluster are␊ |
| 152 | * powers of two, and within reasonable ranges.␊ |
| 153 | */␊ |
| 154 | bytesPerSector = 1 << boot->bf_bpss;␉/* Just one byte; no swapping needed */␊ |
| 155 | DBG("EXFAT: bpss=%d, bytesPerSector=%d\n", boot->bf_bpss, bytesPerSector);␊ |
| 156 | if (boot->bf_bpss < 9 || boot->bf_bpss > 12)␊ |
| 157 | {␊ |
| 158 | DBG("EXFAT: invalid bytes per sector shift(%d)\n", boot->bf_bpss);␊ |
| 159 | goto error;␊ |
| 160 | }␊ |
| 161 | ␊ |
| 162 | sectorsPerCluster = 1 << boot->bf_spcs;␉/* Just one byte; no swapping needed */␊ |
| 163 | DBG("EXFAT: spcs=%d, sectorsPerCluster=%d\n", boot->bf_spcs, sectorsPerCluster);␊ |
| 164 | if (boot->bf_spcs > (25 - boot->bf_bpss))␊ |
| 165 | {␊ |
| 166 | DBG("EXFAT: invalid sectors per cluster shift (%d)\n", boot->bf_spcs);␊ |
| 167 | goto error;␊ |
| 168 | }␊ |
| 169 | ␊ |
| 170 | // calculate root dir cluster offset␊ |
| 171 | rdirOffset = boot->bf_cloff + (boot->bf_rdircl - 2) * sectorsPerCluster;␊ |
| 172 | DBG("EXFAT: rdirOffset=%d\n", rdirOffset);␊ |
| 173 | ␊ |
| 174 | // load MAX_BLOCK_SIZE bytes of root dir␊ |
| 175 | Seek(ih, rdirOffset * bytesPerSector);␊ |
| 176 | Read(ih, (long)buf, MAX_BLOCK_SIZE);␊ |
| 177 | DBG("buf 0 1 2 = %x %x %x\n", 0x00ff & buf[0], 0x00ff & buf[1], 0x00ff & buf[2]);␊ |
| 178 | ␊ |
| 179 | str[0] = '\0';␊ |
| 180 | ␊ |
| 181 | /*␊ |
| 182 | * Search for volume label dir entry (type 0x83), convert from unicode and put to str.␊ |
| 183 | * Set loopControl var to avoid searching outside of buf.␊ |
| 184 | */␊ |
| 185 | loopControl = MAX_BLOCK_SIZE / sizeof(struct direntry_label);␊ |
| 186 | dire = (struct direntry_label *)buf;␊ |
| 187 | while (loopControl && dire->type && dire->type != 0x83)␊ |
| 188 | {␊ |
| 189 | dire++;␊ |
| 190 | loopControl--;␊ |
| 191 | }␊ |
| 192 | if (dire->type == 0x83 && dire->llen > 0 && dire->llen <= 11)␊ |
| 193 | {␊ |
| 194 | utf_encodestr( dire->label, (int)dire->llen, (u_int8_t *)str, strMaxLen, OSLittleEndian );␊ |
| 195 | }␊ |
| 196 | DBG("EXFAT: label=%s\n", str);␊ |
| 197 | ␊ |
| 198 | free(buf);␊ |
| 199 | PAUSE();␊ |
| 200 | return;␊ |
| 201 | ␊ |
| 202 | error:␊ |
| 203 | if (buf) free(buf);␊ |
| 204 | DBG("EXFAT: error\n");␊ |
| 205 | PAUSE();␊ |
| 206 | return;␊ |
| 207 | }␊ |
| 208 | ␊ |
| 209 | /**␊ |
| 210 | * Sets UUID to uuidStr.␊ |
| 211 | * Reads the boot sector, does some checking, generates UUID␊ |
| 212 | * (like the one you get on Windows???)␊ |
| 213 | */␊ |
| 214 | long EXFATGetUUID(CICell ih, char *uuidStr)␊ |
| 215 | {␊ |
| 216 | struct exfatbootfile *boot;␊ |
| 217 | void *buf = malloc(MAX_BLOCK_SIZE);␊ |
| 218 | if ( !buf )␊ |
| 219 | return -1;␊ |
| 220 | ␊ |
| 221 | /*␊ |
| 222 | * Read the boot sector, check signatures, and do some minimal␊ |
| 223 | * sanity checking.␉ NOTE: the size of the read below is intended␊ |
| 224 | * to be a multiple of all supported block sizes, so we don't␊ |
| 225 | * have to determine or change the device's block size.␊ |
| 226 | */␊ |
| 227 | Seek(ih, 0);␊ |
| 228 | Read(ih, (long)buf, MAX_BLOCK_SIZE);␊ |
| 229 | ␊ |
| 230 | boot = (struct exfatbootfile *) buf;␊ |
| 231 | ␊ |
| 232 | /*␊ |
| 233 | * Check the "EXFAT " signature.␊ |
| 234 | */␊ |
| 235 | if (memcmp((const char *)boot->bf_sysid, EXFAT_BBID, EXFAT_BBIDLEN) != 0)␊ |
| 236 | return -1;␊ |
| 237 | ␊ |
| 238 | // Check for non-null volume serial number␊ |
| 239 | if( !boot->bf_volsn )␊ |
| 240 | return -1;␊ |
| 241 | ␊ |
| 242 | // Use UUID like the one you get on Windows␊ |
| 243 | sprintf(uuidStr, "%04X-%04X", (unsigned short)(boot->bf_volsn >> 16) & 0xFFFF,␊ |
| 244 | (unsigned short)boot->bf_volsn & 0xFFFF);␊ |
| 245 | ␊ |
| 246 | DBG("EXFATGetUUID: %x:%x = %s\n", ih->biosdev, ih->part_no, uuidStr);␊ |
| 247 | return 0;␊ |
| 248 | } ␊ |
| 249 | ␊ |
| 250 | /**␊ |
| 251 | * Returns true if given buffer is the boot rec of the EXFAT volume.␊ |
| 252 | */␊ |
| 253 | bool EXFATProbe(const void * buffer)␊ |
| 254 | {␊ |
| 255 | bool result = false;␊ |
| 256 | ␊ |
| 257 | // boot sector structure␊ |
| 258 | const struct exfatbootfile␉* boot = buffer;␊ |
| 259 | ␊ |
| 260 | // Looking for EXFAT signature.␊ |
| 261 | if (memcmp((const char *)boot->bf_sysid, EXFAT_BBID, EXFAT_BBIDLEN) == 0)␊ |
| 262 | result = true;␊ |
| 263 | ␉␊ |
| 264 | DBG("EXFATProbe: %d\n", result ? 1 : 0);␊ |
| 265 | return result;␊ |
| 266 | }␊ |
| 267 | |
