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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#include "libsaio.h"
27#include "sl.h"
28
29/*
30 * dmazar, 14/7/2011 - support for EXFAT volume label reading
31 */
32#include "exfat.h"
33
34#define BYTE_ORDER_MARK0xFEFF
35
36#include "ntfs_private.h"
37
38#define FS_TYPE"ntfs"
39#define FS_NAME_FILE"NTFS"
40
41#define MAX_BLOCK_SIZE2048
42#define MAX_CLUSTER_SIZE32768
43
44#define LABEL_LENGTH1024
45#define UNKNOWN_LABEL"Untitled NTFS"
46
47#define FSUR_IO_FAIL-1
48#define FSUR_UNRECOGNIZED-1
49#define FSUR_RECOGNIZED0
50
51#define ERROR-1
52
53/*
54 * Process per-sector "fixups" that NTFS uses to detect corruption of
55 * multi-sector data structures, like MFT records.
56 */
57static int
58ntfs_fixup(
59 char *buf,
60 size_t len,
61 u_int32_t magic,
62 u_int32_t bytesPerSector)
63{
64struct fixuphdr *fhp = (struct fixuphdr *) buf;
65int i;
66u_int16_t fixup;
67u_int16_t *fxp;
68u_int16_t *cfxp;
69 u_int32_tfixup_magic;
70 u_int16_tfixup_count;
71 u_int16_tfixup_offset;
72
73 fixup_magic = OSReadLittleInt32(&fhp->fh_magic,0);
74if (fixup_magic != magic) {
75error("ntfs_fixup: magic doesn't match: %08x != %08x\n",
76 fixup_magic, magic);
77return (ERROR);
78}
79 fixup_count = OSReadLittleInt16(&fhp->fh_fnum,0);
80if ((fixup_count - 1) * bytesPerSector != len) {
81error("ntfs_fixup: " \
82 "bad fixups number: %d for %ld bytes block\n",
83 fixup_count, (long)len);/* XXX printf kludge */
84return (ERROR);
85}
86 fixup_offset = OSReadLittleInt16(&fhp->fh_foff,0);
87if (fixup_offset >= len) {
88error("ntfs_fixup: invalid offset: %x", fixup_offset);
89return (ERROR);
90}
91fxp = (u_int16_t *) (buf + fixup_offset);
92cfxp = (u_int16_t *) (buf + bytesPerSector - 2);
93fixup = *fxp++;
94for (i = 1; i < fixup_count; i++, fxp++) {
95if (*cfxp != fixup) {
96error("ntfs_fixup: fixup %d doesn't match\n", i);
97return (ERROR);
98}
99*cfxp = *fxp;
100 cfxp = (u_int16_t *)(((caddr_t)cfxp) + bytesPerSector);
101}
102return (0);
103}
104
105/*
106 * Find a resident attribute of a given type. Returns a pointer to the
107 * attribute data, and its size in bytes.
108 */
109static int ntfs_find_attr(
110 char *buf,
111 u_int32_t attrType,
112 void **attrData,
113 size_t *attrSize)
114{
115 struct filerec *filerec;
116 struct attr *attr;
117 u_int16_t offset;
118
119 filerec = (struct filerec *) buf;
120 offset = OSReadLittleInt16(&filerec->fr_attroff,0);
121 attr = (struct attr *) (buf + offset);
122
123
124 while (attr->a_hdr.a_type != 0xFFFFFFFF)/* same for big/little endian */
125 {
126 if (OSReadLittleInt32(&attr->a_hdr.a_type,0) == attrType)
127 {
128 if (attr->a_hdr.a_flag != 0)
129 {
130 //verbose("NTFS: attriubte 0x%X is non-resident\n", attrType);
131 return 1;
132 }
133
134 *attrSize = OSReadLittleInt16(&attr->a_r.a_datalen,0);
135 *attrData = buf + offset + OSReadLittleInt16(&attr->a_r.a_dataoff,0);
136 return 0;/* found it! */
137 }
138
139 /* Skip to the next attribute */
140 offset += OSReadLittleInt32(&attr->a_hdr.reclen,0);
141 attr = (struct attr *) (buf + offset);
142 }
143
144 return 1;/* No matching attrType found */
145}
146
147/*
148 * Examine a volume to see if we recognize it as a mountable.
149 */
150void NTFSGetDescription(CICell ih, char *str, long strMaxLen)
151{
152struct bootfile *boot;
153unsigned bytesPerSector;
154unsigned sectorsPerCluster;
155int mftRecordSize;
156u_int64_t totalClusters;
157u_int64_t cluster, mftCluster;
158size_t mftOffset;
159void *nameAttr;
160size_t nameSize;
161char *buf;
162
163buf = (char *)malloc(MAX_CLUSTER_SIZE);
164if (buf == 0)
165{
166goto error;
167}
168
169/*
170 * Read the boot sector, check signatures, and do some minimal
171 * sanity checking. NOTE: the size of the read below is intended
172 * to be a multiple of all supported block sizes, so we don't
173 * have to determine or change the device's block size.
174 */
175Seek(ih, 0);
176Read(ih, (long)buf, MAX_BLOCK_SIZE);
177
178boot = (struct bootfile *) buf;
179
180/*
181 * The first three bytes are an Intel x86 jump instruction. I assume it
182 * can be the same forms as DOS FAT:
183 * 0xE9 0x?? 0x??
184 * 0xEC 0x?? 0x90
185 * where 0x?? means any byte value is OK.
186 */
187if (boot->reserved1[0] != 0xE9 && (boot->reserved1[0] != 0xEB || boot->reserved1[2] != 0x90))
188{
189goto error;
190}
191
192/*
193 * Check the "NTFS " signature.
194 */
195if (memcmp((const char *)boot->bf_sysid, "NTFS ", 8) != 0)
196{
197/*
198 * Check for EXFAT. Finish by jumping to error to free buf,
199 * although if it is EXFAT then it's no an error.
200 */
201EXFATGetDescription(ih, str, strMaxLen);
202goto error;
203}
204
205/*
206 * Make sure the bytes per sector and sectors per cluster are
207 * powers of two, and within reasonable ranges.
208 */
209bytesPerSector = OSReadLittleInt16(&boot->bf_bps,0);
210if ((bytesPerSector & (bytesPerSector-1)) || bytesPerSector < 512 || bytesPerSector > 32768)
211{
212//verbose("NTFS: invalid bytes per sector (%d)\n", bytesPerSector);
213goto error;
214}
215
216sectorsPerCluster = boot->bf_spc;/* Just one byte; no swapping needed */
217if ((sectorsPerCluster & (sectorsPerCluster-1)) || sectorsPerCluster > 128)
218{
219//verbose("NTFS: invalid sectors per cluster (%d)\n", bytesPerSector);
220goto error;
221}
222
223 /*
224 * Calculate the number of clusters from the number of sectors.
225 * Then bounds check the $MFT and $MFTMirr clusters.
226 */
227 totalClusters = OSReadLittleInt64(&boot->bf_spv,0) / sectorsPerCluster;
228 mftCluster = OSReadLittleInt64(&boot->bf_mftcn,0);
229 if (mftCluster > totalClusters)
230 {
231 ////verbose("NTFS: invalid $MFT cluster (%lld)\n", mftCluster);
232 goto error;
233 }
234 cluster = OSReadLittleInt64(&boot->bf_mftmirrcn,0);
235 if (cluster > totalClusters)
236 {
237 //verbose("NTFS: invalid $MFTMirr cluster (%lld)\n", cluster);
238 goto error;
239 }
240
241 /*
242 * Determine the size of an MFT record.
243 */
244 mftRecordSize = (int8_t) boot->bf_mftrecsz;
245 if (mftRecordSize < 0)
246 mftRecordSize = 1 << -mftRecordSize;
247 else
248 mftRecordSize *= bytesPerSector * sectorsPerCluster;
249 //verbose("NTFS: MFT record size = %d\n", mftRecordSize);
250
251 /*
252 * Read the MFT record for $Volume. This assumes the first four
253 * file records in the MFT are contiguous; if they aren't, we
254 * would have to map the $MFT itself.
255 *
256 * This will fail if the device sector size is larger than the
257 * MFT record size, since the $Volume record won't be aligned
258 * on a sector boundary.
259 */
260 mftOffset = mftCluster * sectorsPerCluster * bytesPerSector;
261 mftOffset += mftRecordSize * NTFS_VOLUMEINO;
262
263 Seek(ih, mftOffset);
264 Read(ih, (long)buf, mftRecordSize);
265#if UNUSED
266 if (lseek(fd, mftOffset, SEEK_SET) == -1)
267 {
268 //verbose("NTFS: lseek to $Volume failed: %s\n", strerror(errno));
269 goto error;
270 }
271 if (read(fd, buf, mftRecordSize) != mftRecordSize) {
272 //verbose("NTFS: error reading MFT $Volume record: %s\n", strerror(errno));
273 goto error;
274 }
275#endif
276
277 if (ntfs_fixup(buf, mftRecordSize, NTFS_FILEMAGIC, bytesPerSector) != 0) {
278 //verbose("NTFS: block fixup failed\n");
279 goto error;
280 }
281
282 /*
283 * Loop over the attributes, looking for $VOLUME_NAME (0x60).
284 */
285if(ntfs_find_attr(buf, NTFS_A_VOLUMENAME, &nameAttr, &nameSize) != 0)
286{
287//verbose("NTFS: $VOLUME_NAME attribute not found\n");
288goto error;
289}
290
291str[0] = '\0';
292
293utf_encodestr( nameAttr, nameSize / 2, (u_int8_t *)str, strMaxLen, OSLittleEndian );
294
295free(buf);
296return;
297
298 error:
299if (buf)
300{
301free(buf);
302}
303return;
304}
305
306long NTFSGetUUID(CICell ih, char *uuidStr)
307{
308bool NTFSProbe(const void*);
309
310struct bootfile *boot;
311void *buf = malloc(MAX_BLOCK_SIZE);
312if ( !buf )
313{
314return -1;
315}
316bzero(buf,MAX_BLOCK_SIZE);
317
318/*
319 * Read the boot sector, check signatures, and do some minimal
320 * sanity checking. NOTE: the size of the read below is intended
321 * to be a multiple of all supported block sizes, so we don't
322 * have to determine or change the device's block size.
323 */
324Seek(ih, 0);
325Read(ih, (long)buf, MAX_BLOCK_SIZE);
326
327boot = (struct bootfile *) buf;
328
329// Check for NTFS signature
330if ( memcmp((void*)boot->bf_sysid, NTFS_BBID, NTFS_BBIDLEN) != 0 )
331{
332// If not NTFS, maybe it is EXFAT
333free(buf);
334return EXFATGetUUID(ih, uuidStr);
335}
336
337// Check for non-null volume serial number
338if( !boot->bf_volsn )
339{
340free(buf);
341return -1;
342}
343
344// Use UUID like the one you get on Windows
345sprintf(uuidStr, "%04X-%04X",(unsigned short)(boot->bf_volsn >> 16) & 0xFFFF, (unsigned short)boot->bf_volsn & 0xFFFF);
346
347return 0;
348}
349
350bool NTFSProbe(const void *buffer)
351{
352bool result = false;
353
354const struct bootfile *part_bootfile = buffer;// NTFS boot sector structure
355
356// Looking for NTFS signature.
357if (strncmp((const char *)part_bootfile->bf_sysid, NTFS_BBID, NTFS_BBIDLEN) == 0)
358{
359result = true;
360}
361
362// If not NTFS, maybe it is EXFAT
363if (!result)
364{
365result = EXFATProbe(buffer);
366}
367
368return result;
369}
370

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