dvmmbr.cpp@ 96407

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1	/* $Id: dvmmbr.cpp 96407 2022-08-22 17:43:14Z vboxsync $ */
2	/** @file
3	* IPRT Disk Volume Management API (DVM) - MBR format backend.
4	*/
5
6	/*
7	* Copyright (C) 2011-2022 Oracle and/or its affiliates.
8	*
9	* This file is part of VirtualBox base platform packages, as
10	* available from https://www.virtualbox.org.
11	*
12	* This program is free software; you can redistribute it and/or
13	* modify it under the terms of the GNU General Public License
14	* as published by the Free Software Foundation, in version 3 of the
15	* License.
16	*
17	* This program is distributed in the hope that it will be useful, but
18	* WITHOUT ANY WARRANTY; without even the implied warranty of
19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20	* General Public License for more details.
21	*
22	* You should have received a copy of the GNU General Public License
23	* along with this program; if not, see <https://www.gnu.org/licenses>.
24	*
25	* The contents of this file may alternatively be used under the terms
26	* of the Common Development and Distribution License Version 1.0
27	* (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
28	* in the VirtualBox distribution, in which case the provisions of the
29	* CDDL are applicable instead of those of the GPL.
30	*
31	* You may elect to license modified versions of this file under the
32	* terms and conditions of either the GPL or the CDDL or both.
33	*
34	* SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
35	*/
36
37
38	/*********************************************************************************************************************************
39	* Header Files *
40	*********************************************************************************************************************************/
41	#define LOG_GROUP RTLOGGROUP_FS
42	#include <iprt/types.h>
43	#include <iprt/assert.h>
44	#include <iprt/mem.h>
45	#include <iprt/dvm.h>
46	#include <iprt/list.h>
47	#include <iprt/log.h>
48	#include <iprt/string.h>
49	#include <iprt/uuid.h>
50	#include "internal/dvm.h"
51
52
53	/*********************************************************************************************************************************
54	* Defined Constants And Macros *
55	*********************************************************************************************************************************/
56	/** Checks if the partition type is an extended partition container. */
57	#define RTDVMMBR_IS_EXTENDED(a_bType) ((a_bType) == 0x05 \|\| (a_bType) == 0x0f)
58
59
60	/*********************************************************************************************************************************
61	* Structures and Typedefs *
62	*********************************************************************************************************************************/
63	/** Pointer to a MBR sector. */
64	typedef struct RTDVMMBRSECTOR *PRTDVMMBRSECTOR;
65
66
67	/** The on-disk Cylinder/Head/Sector (CHS) info. */
68	typedef struct MBRCHSADDR
69	{
70	uint8_t uHead;
71	uint8_t uSector : 6;
72	uint8_t uCylinderH : 2;
73	uint8_t uCylinderL;
74	} MBRCHSADDR;
75	AssertCompileSize(MBRCHSADDR, 3);
76
77
78	/** A decoded cylinder/head/sector address. */
79	typedef struct RTDVMMBRCHSADDR
80	{
81	uint16_t uCylinder;
82	uint8_t uHead;
83	uint8_t uSector;
84	} RTDVMMBRCHSADDR;
85
86
87	/**
88	* MBR entry.
89	*/
90	typedef struct RTDVMMBRENTRY
91	{
92	/** Our entry in the in-use partition entry list (RTDVMMBRENTRY). */
93	RTLISTNODE ListEntry;
94	/** Pointer to the MBR sector containing this entry. */
95	PRTDVMMBRSECTOR pSector;
96	/** Pointer to the next sector in the extended partition table chain. */
97	PRTDVMMBRSECTOR pChain;
98	/** The byte offset of the start of the partition (relative to disk). */
99	uint64_t offPart;
100	/** Number of bytes for this partition. */
101	uint64_t cbPart;
102	/** The partition/filesystem type. */
103	uint8_t bType;
104	/** The partition flags. */
105	uint8_t fFlags;
106	/** Bad entry. */
107	bool fBad;
108	/** RTDVMVOLIDX_IN_TABLE - Zero-based index within the table in pSector.
109	* (Also the index into RTDVMMBRSECTOR::aEntries.) */
110	uint8_t idxTable;
111	/** RTDVMVOLIDX_ALL - One-based index. All primary entries are included,
112	* whether they are used or not. In the extended table chain, only USED
113	* entries are counted (but we include RTDVMMBR_IS_EXTENDED entries). */
114	uint8_t idxAll;
115	/** RTDVMVOLIDX_USER_VISIBLE - One-base index. Skips all unused entries
116	* and RTDVMMBR_IS_EXTENDED. */
117	uint8_t idxVisible;
118	/** RTDVMVOLIDX_LINUX - One-based index following the /dev/sdaX scheme. */
119	uint8_t idxLinux;
120	uint8_t bUnused;
121	/** The first CHS address of this partition */
122	RTDVMMBRCHSADDR FirstChs;
123	/** The last CHS address of this partition */
124	RTDVMMBRCHSADDR LastChs;
125	} RTDVMMBRENTRY;
126	/** Pointer to an MBR entry. */
127	typedef RTDVMMBRENTRY *PRTDVMMBRENTRY;
128
129	/**
130	* A MBR sector.
131	*/
132	typedef struct RTDVMMBRSECTOR
133	{
134	/** Internal representation of the entries. */
135	RTDVMMBRENTRY aEntries[4];
136	/** The byte offset of this MBR sector (relative to disk).
137	* We keep this for detecting cycles now, but it will be needed if we start
138	* updating the partition table at some point. */
139	uint64_t offOnDisk;
140	/** Pointer to the previous sector if this isn't a primary one. */
141	PRTDVMMBRENTRY pPrevSector;
142	/** Set if this is the primary MBR, cleared if an extended. */
143	bool fIsPrimary;
144	/** Number of used entries. */
145	uint8_t cUsed;
146	/** Number of extended entries. */
147	uint8_t cExtended;
148	/** The extended entry we're following (we only follow one, except when
149	* fIsPrimary is @c true). UINT8_MAX if none. */
150	uint8_t idxExtended;
151	#if ARCH_BITS == 64
152	uint32_t uAlignmentPadding;
153	#endif
154	/** The raw data. */
155	uint8_t abData[RT_FLEXIBLE_ARRAY_NESTED];
156	} RTDVMMBRSECTOR;
157
158	/**
159	* MBR volume manager data.
160	*/
161	typedef struct RTDVMFMTINTERNAL
162	{
163	/** Pointer to the underlying disk. */
164	PCRTDVMDISK pDisk;
165	/** Head of the list of in-use RTDVMMBRENTRY structures. This excludes
166	* extended partition table entries. */
167	RTLISTANCHOR PartitionHead;
168	/** The sector size to use when doing address calculation based on partition
169	* table sector addresses and counts. */
170	uint32_t cbSector;
171	/** The total number of partitions, not counting extended ones. */
172	uint32_t cPartitions;
173	/** The actual primary MBR sector. */
174	RTDVMMBRSECTOR Primary;
175	} RTDVMFMTINTERNAL;
176	/** Pointer to the MBR volume manager. */
177	typedef RTDVMFMTINTERNAL *PRTDVMFMTINTERNAL;
178
179	/**
180	* MBR volume data.
181	*/
182	typedef struct RTDVMVOLUMEFMTINTERNAL
183	{
184	/** Pointer to the volume manager. */
185	PRTDVMFMTINTERNAL pVolMgr;
186	/** The MBR entry. */
187	PRTDVMMBRENTRY pEntry;
188	} RTDVMVOLUMEFMTINTERNAL;
189	/** Pointer to an MBR volume. */
190	typedef RTDVMVOLUMEFMTINTERNAL *PRTDVMVOLUMEFMTINTERNAL;
191
192
193	/*********************************************************************************************************************************
194	* Global Variables *
195	*********************************************************************************************************************************/
196	/**
197	* Mapping of FS types to DVM volume types.
198	*
199	* @see https://en.wikipedia.org/wiki/Partition_type
200	* @see http://www.win.tue.nl/~aeb/partitions/partition_types-1.html
201	*/
202	static const struct RTDVMMBRFS2VOLTYPE
203	{
204	/** MBR FS Id. */
205	uint8_t bFsId;
206	/** DVM volume type. */
207	RTDVMVOLTYPE enmVolType;
208	} g_aFs2DvmVolTypes[] =
209	{
210	{ 0x01, RTDVMVOLTYPE_FAT12 },
211	{ 0x04, RTDVMVOLTYPE_FAT16 },
212	{ 0x06, RTDVMVOLTYPE_FAT16 }, /* big FAT16 */
213	{ 0x07, RTDVMVOLTYPE_NTFS }, /* Simplification: Used for HPFS, exFAT, ++, too but NTFS is the more common one. */
214	{ 0x0b, RTDVMVOLTYPE_FAT32 },
215	{ 0x0c, RTDVMVOLTYPE_FAT32 },
216	{ 0x0e, RTDVMVOLTYPE_FAT16 },
217
218	/* Hidden variants of the above: */
219	{ 0x11, RTDVMVOLTYPE_FAT12 },
220	{ 0x14, RTDVMVOLTYPE_FAT16 },
221	{ 0x16, RTDVMVOLTYPE_FAT16 },
222	{ 0x17, RTDVMVOLTYPE_NTFS },
223	{ 0x1b, RTDVMVOLTYPE_FAT32 },
224	{ 0x1c, RTDVMVOLTYPE_FAT32 },
225	{ 0x1e, RTDVMVOLTYPE_FAT16 },
226
227	{ 0x82, RTDVMVOLTYPE_LINUX_SWAP },
228	{ 0x83, RTDVMVOLTYPE_LINUX_NATIVE },
229	{ 0x8e, RTDVMVOLTYPE_LINUX_LVM },
230	{ 0xa5, RTDVMVOLTYPE_FREEBSD },
231	{ 0xa9, RTDVMVOLTYPE_NETBSD },
232	{ 0xa6, RTDVMVOLTYPE_OPENBSD },
233	{ 0xaf, RTDVMVOLTYPE_DARWIN_HFS },
234	{ 0xbf, RTDVMVOLTYPE_SOLARIS },
235	{ 0xfd, RTDVMVOLTYPE_LINUX_SOFTRAID }
236	};
237
238
239	static DECLCALLBACK(int) rtDvmFmtMbrProbe(PCRTDVMDISK pDisk, uint32_t *puScore)
240	{
241	int rc = VINF_SUCCESS;
242	*puScore = RTDVM_MATCH_SCORE_UNSUPPORTED;
243	if (pDisk->cbDisk > RT_MAX(512, pDisk->cbSector))
244	{
245	/* Read from the disk and check for the 0x55aa signature at the end. */
246	size_t cbAlignedSize = RT_MAX(512, pDisk->cbSector);
247	uint8_t pbMbr = (uint8_t )RTMemTmpAllocZ(cbAlignedSize);
248	if (pbMbr)
249	{
250	rc = rtDvmDiskRead(pDisk, 0, pbMbr, cbAlignedSize);
251	if ( RT_SUCCESS(rc)
252	&& pbMbr[510] == 0x55
253	&& pbMbr[511] == 0xaa)
254	puScore = RTDVM_MATCH_SCORE_SUPPORTED; / Not perfect because GPTs have a protective MBR. */
255	/** @todo this could easily confuser a DOS, OS/2 or NT boot sector with a MBR... */
256	RTMemTmpFree(pbMbr);
257	}
258	else
259	rc = VERR_NO_TMP_MEMORY;
260	}
261
262	return rc;
263	}
264
265
266	static void rtDvmFmtMbrDestroy(PRTDVMFMTINTERNAL pThis)
267	{
268	/*
269	* Delete chains of extended partitions.
270	*/
271	for (unsigned i = 0; i < 4; i++)
272	{
273	PRTDVMMBRSECTOR pCur = pThis->Primary.aEntries[i].pChain;
274	while (pCur)
275	{
276	PRTDVMMBRSECTOR pNext = pCur->idxExtended != UINT8_MAX ? pCur->aEntries[pCur->idxExtended].pChain : NULL;
277
278	RT_ZERO(pCur->aEntries);
279	pCur->pPrevSector = NULL;
280	RTMemFree(pCur);
281
282	pCur = pNext;
283	}
284	}
285
286	/*
287	* Now kill this.
288	*/
289	pThis->pDisk = NULL;
290	RT_ZERO(pThis->Primary.aEntries);
291	RTMemFree(pThis);
292	}
293
294
295	/**
296	* Decodes the on-disk cylinder/head/sector info and stores it the
297	* destination structure.
298	*/
299	DECLINLINE(void) rtDvmFmtMbrDecodeChs(RTDVMMBRCHSADDR pDst, uint8_t pbRaw)
300	{
301	MBRCHSADDR pRawChs = (MBRCHSADDR )pbRaw;
302	pDst->uCylinder = RT_MAKE_U16(pRawChs->uCylinderL, pRawChs->uCylinderH);
303	pDst->uSector = pRawChs->uSector;
304	pDst->uHead = pRawChs->uHead;
305	}
306
307
308	static int rtDvmFmtMbrReadExtended(PRTDVMFMTINTERNAL pThis, PRTDVMMBRENTRY pPrimaryEntry,
309	uint8_t pidxAll, uint8_t pidxVisible, uint8_t *pidxLinux)
310	{
311	uint64_t const cbExt = pPrimaryEntry->cbPart;
312	uint64_t const offExtBegin = pPrimaryEntry->offPart;
313
314	uint64_t offCurBegin = offExtBegin;
315	PRTDVMMBRENTRY pCurEntry = pPrimaryEntry;
316	for (unsigned cTables = 1; ; cTables++)
317	{
318	/*
319	* Do some sanity checking.
320	*/
321	/* Check the address of the partition table. */
322	if (offCurBegin - offExtBegin >= cbExt)
323	{
324	LogRel(("rtDvmFmtMbrReadExtended: offCurBegin=%#RX64 is outside the extended partition: %#RX64..%#RX64 (LB %#RX64)\n",
325	offCurBegin, offExtBegin, offExtBegin + cbExt - 1, cbExt));
326	pCurEntry->fBad = true;
327	return -VERR_OUT_OF_RANGE;
328	}
329
330	/* Limit the chain length. */
331	if (cTables > 64)
332	{
333	LogRel(("rtDvmFmtMbrReadExtended: offCurBegin=%#RX64 is the %uth table, we stop here.\n", offCurBegin, cTables));
334	pCurEntry->fBad = true;
335	return -VERR_TOO_MANY_SYMLINKS;
336	}
337
338	/* Check for obvious cycles. */
339	for (PRTDVMMBRENTRY pPrev = pCurEntry->pSector->pPrevSector; pPrev != NULL; pPrev = pPrev->pSector->pPrevSector)
340	if (pPrev->offPart == offCurBegin)
341	{
342	LogRel(("rtDvmFmtMbrReadExtended: Cycle! We've seen offCurBegin=%#RX64 before\n", offCurBegin));
343	pCurEntry->fBad = true;
344	return -VERR_TOO_MANY_SYMLINKS;
345	}
346
347	/*
348	* Allocate a new sector entry and read the sector with the table.
349	*/
350	size_t const cbMbr = RT_MAX(512, pThis->pDisk->cbSector);
351	PRTDVMMBRSECTOR pNext = (PRTDVMMBRSECTOR)RTMemAllocZVar(RT_UOFFSETOF_DYN(RTDVMMBRSECTOR, abData[cbMbr]));
352	if (!pNext)
353	return VERR_NO_MEMORY;
354	pNext->offOnDisk = offCurBegin;
355	pNext->pPrevSector = pCurEntry;
356	//pNext->fIsPrimary = false;
357	//pNext->cUsed = 0;
358	//pNext->cExtended = 0;
359	pNext->idxExtended = UINT8_MAX;
360
361	uint8_t *pabData = &pNext->abData[0];
362	int rc = rtDvmDiskReadUnaligned(pThis->pDisk, pNext->offOnDisk, pabData, cbMbr);
363	if ( RT_FAILURE(rc)
364	\|\| pabData[510] != 0x55
365	\|\| pabData[511] != 0xaa)
366	{
367	if (RT_FAILURE(rc))
368	LogRel(("rtDvmFmtMbrReadExtended: Error reading extended partition table at sector %#RX64: %Rrc\n", offCurBegin, rc));
369	else
370	LogRel(("rtDvmFmtMbrReadExtended: Extended partition table at sector %#RX64 does not have a valid DOS signature: %#x %#x\n",
371	offCurBegin, pabData[510], pabData[511]));
372	RTMemFree(pNext);
373	pCurEntry->fBad = true;
374	return rc;
375	}
376	pCurEntry->pChain = pNext;
377
378	/*
379	* Process the table, taking down the first forward entry.
380	*
381	* As noted in the caller of this function, we only deal with one extended
382	* partition entry at this level since noone really ever put more than one
383	* here anyway.
384	*/
385	PRTDVMMBRENTRY pEntry = &pNext->aEntries[0];
386	uint8_t *pbMbrEntry = &pabData[446];
387	for (unsigned i = 0; i < 4; i++, pEntry++, pbMbrEntry += 16)
388	{
389	pEntry->pSector = pNext;
390	pEntry->idxTable = (uint8_t)i;
391	RTListInit(&pEntry->ListEntry);
392
393	uint8_t const bType = pbMbrEntry[4];
394	if (bType != 0)
395	{
396	pEntry->bType = bType;
397	pEntry->fFlags = pbMbrEntry[0];
398	pEntry->idxAll = *pidxAll;
399	*pidxAll += 1;
400
401	rtDvmFmtMbrDecodeChs(&pEntry->FirstChs, &pbMbrEntry[1]);
402	rtDvmFmtMbrDecodeChs(&pEntry->LastChs, &pbMbrEntry[5]);
403
404	pEntry->offPart = RT_MAKE_U32_FROM_U8(pbMbrEntry[0x08 + 0],
405	pbMbrEntry[0x08 + 1],
406	pbMbrEntry[0x08 + 2],
407	pbMbrEntry[0x08 + 3]);
408	pEntry->offPart *= pThis->cbSector;
409	pEntry->cbPart = RT_MAKE_U32_FROM_U8(pbMbrEntry[0x0c + 0],
410	pbMbrEntry[0x0c + 1],
411	pbMbrEntry[0x0c + 2],
412	pbMbrEntry[0x0c + 3]);
413	pEntry->cbPart *= pThis->cbSector;
414	if (!RTDVMMBR_IS_EXTENDED(bType))
415	{
416	pEntry->offPart += offCurBegin;
417	pEntry->idxVisible = *pidxVisible;
418	*pidxVisible += 1;
419	pEntry->idxLinux = *pidxLinux;
420	*pidxLinux += 1;
421
422	pThis->cPartitions++;
423	RTListAppend(&pThis->PartitionHead, &pEntry->ListEntry);
424	Log2(("rtDvmFmtMbrReadExtended: %#012RX64::%u: vol%u bType=%#04x fFlags=%#04x offPart=%#012RX64 cbPart=%#012RX64\n",
425	offCurBegin, i, pThis->cPartitions - 1, pEntry->bType, pEntry->fFlags, pEntry->offPart, pEntry->cbPart));
426	}
427	else
428	{
429	pEntry->offPart += offExtBegin;
430	pNext->cExtended++;
431	if (pNext->idxExtended == UINT8_MAX)
432	pNext->idxExtended = (uint8_t)i;
433	else
434	{
435	pEntry->fBad = true;
436	LogRel(("rtDvmFmtMbrReadExtended: Warning! Both #%u and #%u are extended partition table entries! Only following the former\n",
437	i, pNext->idxExtended));
438	}
439	Log2(("rtDvmFmtMbrReadExtended: %#012RX64::%u: ext%u bType=%#04x fFlags=%#04x offPart=%#012RX64 cbPart=%#012RX64\n",
440	offCurBegin, i, pNext->cExtended - 1, pEntry->bType, pEntry->fFlags, pEntry->offPart, pEntry->cbPart));
441	}
442	pNext->cUsed++;
443
444	}
445	/* else: unused */
446	}
447
448	/*
449	* We're done if we didn't find any extended partition table entry.
450	* Otherwise, advance to the next one.
451	*/
452	if (!pNext->cExtended)
453	return VINF_SUCCESS;
454	pCurEntry = &pNext->aEntries[pNext->idxExtended];
455	offCurBegin = pCurEntry->offPart;
456	}
457	}
458
459
460	static DECLCALLBACK(int) rtDvmFmtMbrOpen(PCRTDVMDISK pDisk, PRTDVMFMT phVolMgrFmt)
461	{
462	int rc;
463	size_t const cbMbr = RT_MAX(512, pDisk->cbSector);
464	PRTDVMFMTINTERNAL pThis = (PRTDVMFMTINTERNAL)RTMemAllocZVar(RT_UOFFSETOF_DYN(RTDVMFMTINTERNAL, Primary.abData[cbMbr]));
465	if (pThis)
466	{
467	pThis->pDisk = pDisk;
468	//pThis->cPartitions = 0;
469	RTListInit(&pThis->PartitionHead);
470	//pThis->Primary.offOnDisk = 0;
471	//pThis->Primary.pPrevSector = NULL;
472	pThis->Primary.fIsPrimary = true;
473	//pThis->Primary.cUsed = 0;
474	//pThis->Primary.cExtended = 0;
475	pThis->Primary.idxExtended = UINT8_MAX;
476
477	/* We'll use the sector size reported by the disk.
478
479	Though, giiven that the MBR was hardwired to 512 byte sectors, we probably
480	should do some probing when the sector size differs from 512, but that can
481	wait till there is a real need for it and we've got some semi reliable
482	heuristics for doing that. */
483	pThis->cbSector = (uint32_t)pDisk->cbSector;
484	AssertLogRelMsgStmt( pThis->cbSector >= 512
485	&& pThis->cbSector <= _64K,
486	("cbSector=%#x\n", pThis->cbSector),
487	pThis->cbSector = 512);
488
489	/*
490	* Read the primary MBR.
491	*/
492	uint8_t *pabData = &pThis->Primary.abData[0];
493	rc = rtDvmDiskRead(pDisk, 0, pabData, cbMbr);
494	if (RT_SUCCESS(rc))
495	{
496	Assert(pabData[510] == 0x55 && pabData[511] == 0xaa);
497
498	/*
499	* Setup basic data for the 4 entries.
500	*/
501	PRTDVMMBRENTRY pEntry = &pThis->Primary.aEntries[0];
502	uint8_t *pbMbrEntry = &pabData[446];
503	uint8_t idxVisible = 1;
504	for (unsigned i = 0; i < 4; i++, pEntry++, pbMbrEntry += 16)
505	{
506	pEntry->pSector = &pThis->Primary;
507	pEntry->idxTable = (uint8_t)i;
508	RTListInit(&pEntry->ListEntry);
509
510	uint8_t const bType = pbMbrEntry[4];
511	if (bType != 0)
512	{
513	pEntry->bType = bType;
514	pEntry->fFlags = pbMbrEntry[0];
515	pEntry->idxAll = (uint8_t)(i + 1);
516
517	rtDvmFmtMbrDecodeChs(&pEntry->FirstChs, &pbMbrEntry[1]);
518	rtDvmFmtMbrDecodeChs(&pEntry->LastChs, &pbMbrEntry[5]);
519
520	pEntry->offPart = RT_MAKE_U32_FROM_U8(pbMbrEntry[0x08 + 0],
521	pbMbrEntry[0x08 + 1],
522	pbMbrEntry[0x08 + 2],
523	pbMbrEntry[0x08 + 3]);
524	pEntry->offPart *= pThis->cbSector;
525	pEntry->cbPart = RT_MAKE_U32_FROM_U8(pbMbrEntry[0x0c + 0],
526	pbMbrEntry[0x0c + 1],
527	pbMbrEntry[0x0c + 2],
528	pbMbrEntry[0x0c + 3]);
529	pEntry->cbPart *= pThis->cbSector;
530	if (!RTDVMMBR_IS_EXTENDED(bType))
531	{
532	pEntry->idxVisible = idxVisible++;
533	pEntry->idxLinux = (uint8_t)(i + 1);
534	pThis->cPartitions++;
535	RTListAppend(&pThis->PartitionHead, &pEntry->ListEntry);
536	Log2(("rtDvmFmtMbrOpen: %u: vol%u bType=%#04x fFlags=%#04x offPart=%#012RX64 cbPart=%#012RX64\n",
537	i, pThis->cPartitions - 1, pEntry->bType, pEntry->fFlags, pEntry->offPart, pEntry->cbPart));
538	}
539	else
540	{
541	pThis->Primary.cExtended++;
542	Log2(("rtDvmFmtMbrOpen: %u: ext%u bType=%#04x fFlags=%#04x offPart=%#012RX64 cbPart=%#012RX64\n",
543	i, pThis->Primary.cExtended - 1, pEntry->bType, pEntry->fFlags, pEntry->offPart, pEntry->cbPart));
544	}
545	pThis->Primary.cUsed++;
546	}
547	/* else: unused */
548	}
549
550	/*
551	* Now read any extended partitions. Since it's no big deal for us, we allow
552	* the primary partition table to have more than one extended partition. However
553	* in the extended tables we only allow a single forward link to avoid having to
554	* deal with recursion.
555	*/
556	if (pThis->Primary.cExtended > 0)
557	{
558	uint8_t idxAll = 5;
559	uint8_t idxLinux = 5;
560	for (unsigned i = 0; i < 4; i++)
561	if (RTDVMMBR_IS_EXTENDED(pThis->Primary.aEntries[i].bType))
562	{
563	if (pThis->Primary.idxExtended == UINT8_MAX)
564	pThis->Primary.idxExtended = (uint8_t)i;
565	rc = rtDvmFmtMbrReadExtended(pThis, &pThis->Primary.aEntries[i], &idxAll, &idxVisible, &idxLinux);
566	if (RT_FAILURE(rc))
567	break;
568	}
569	}
570	if (RT_SUCCESS(rc))
571	{
572	*phVolMgrFmt = pThis;
573	return rc;
574	}
575	}
576	rtDvmFmtMbrDestroy(pThis);
577	}
578	else
579	rc = VERR_NO_MEMORY;
580
581	return rc;
582	}
583
584	static DECLCALLBACK(int) rtDvmFmtMbrInitialize(PCRTDVMDISK pDisk, PRTDVMFMT phVolMgrFmt)
585	{
586	int rc;
587	size_t const cbMbr = RT_MAX(512, pDisk->cbSector);
588	PRTDVMFMTINTERNAL pThis = (PRTDVMFMTINTERNAL)RTMemAllocZVar(RT_UOFFSETOF_DYN(RTDVMFMTINTERNAL, Primary.abData[cbMbr]));
589	if (pThis)
590	{
591	pThis->pDisk = pDisk;
592	//pThis->cPartitions = 0;
593	RTListInit(&pThis->PartitionHead);
594	//pThis->Primary.offOnDisk = 0
595	//pThis->Primary.pPrevSector = NULL;
596	pThis->Primary.fIsPrimary = true;
597	//pThis->Primary.cUsed = 0;
598	//pThis->Primary.cExtended = 0;
599	pThis->Primary.idxExtended = UINT8_MAX;
600
601	/* Setup a new MBR and write it to the disk. */
602	uint8_t *pabData = &pThis->Primary.abData[0];
603	RT_BZERO(pabData, 512);
604	pabData[510] = 0x55;
605	pabData[511] = 0xaa;
606	rc = rtDvmDiskWrite(pDisk, 0, pabData, cbMbr);
607	if (RT_SUCCESS(rc))
608	{
609	pThis->pDisk = pDisk;
610	*phVolMgrFmt = pThis;
611	}
612	else
613	RTMemFree(pThis);
614	}
615	else
616	rc = VERR_NO_MEMORY;
617
618	return rc;
619	}
620
621	static DECLCALLBACK(void) rtDvmFmtMbrClose(RTDVMFMT hVolMgrFmt)
622	{
623	rtDvmFmtMbrDestroy(hVolMgrFmt);
624	}
625
626	static DECLCALLBACK(int) rtDvmFmtMbrQueryRangeUse(RTDVMFMT hVolMgrFmt, uint64_t off, uint64_t cbRange, bool *pfUsed)
627	{
628	PRTDVMFMTINTERNAL pThis = hVolMgrFmt;
629
630	/*
631	* The MBR definitely uses the first 512 bytes, but we consider anything up
632	* to 1MB of alignment padding / cylinder gap to be considered in use too.
633	*
634	* The cylinder gap has been used by several boot managers and boot loaders
635	* to store code and data.
636	*/
637	if (off < (uint64_t)_1M)
638	{
639	*pfUsed = true;
640	return VINF_SUCCESS;
641	}
642
643	/* Ditto for any extended partition tables. */
644	for (uint32_t iPrimary = 0; iPrimary < 4; iPrimary++)
645	{
646	PRTDVMMBRSECTOR pCur = pThis->Primary.aEntries[iPrimary].pChain;
647	while (pCur)
648	{
649	if ( off < pCur->offOnDisk + _1M
650	&& off + cbRange > pCur->offOnDisk)
651	{
652	*pfUsed = true;
653	return VINF_SUCCESS;
654	}
655
656
657	if (pCur->idxExtended == UINT8_MAX)
658	break;
659	pCur = pCur->aEntries[pCur->idxExtended].pChain;
660	}
661
662	}
663
664	/* Not in use. */
665	*pfUsed = false;
666	return VINF_SUCCESS;
667	}
668
669	/** @copydoc RTDVMFMTOPS::pfnQueryDiskUuid */
670	static DECLCALLBACK(int) rtDvmFmtMbrQueryDiskUuid(RTDVMFMT hVolMgrFmt, PRTUUID pUuid)
671	{
672	PRTDVMFMTINTERNAL pThis = hVolMgrFmt;
673	uint32_t idDisk = RT_MAKE_U32_FROM_U8(pThis->Primary.abData[440],
674	pThis->Primary.abData[441],
675	pThis->Primary.abData[442],
676	pThis->Primary.abData[443]);
677	if (idDisk != 0)
678	{
679	RTUuidClear(pUuid);
680	pUuid->Gen.u32TimeLow = idDisk;
681	return VINF_NOT_SUPPORTED;
682	}
683	return VERR_NOT_SUPPORTED;
684	}
685
686	static DECLCALLBACK(uint32_t) rtDvmFmtMbrGetValidVolumes(RTDVMFMT hVolMgrFmt)
687	{
688	PRTDVMFMTINTERNAL pThis = hVolMgrFmt;
689
690	return pThis->cPartitions;
691	}
692
693	static DECLCALLBACK(uint32_t) rtDvmFmtMbrGetMaxVolumes(RTDVMFMT hVolMgrFmt)
694	{
695	NOREF(hVolMgrFmt);
696	return 4; /** @todo Add support for EBR? */
697	}
698
699	/**
700	* Creates a new volume.
701	*
702	* @returns IPRT status code.
703	* @param pThis The MBR volume manager data.
704	* @param pEntry The MBR entry to create a volume handle for.
705	* @param phVolFmt Where to store the volume data on success.
706	*/
707	static int rtDvmFmtMbrVolumeCreate(PRTDVMFMTINTERNAL pThis, PRTDVMMBRENTRY pEntry, PRTDVMVOLUMEFMT phVolFmt)
708	{
709	PRTDVMVOLUMEFMTINTERNAL pVol = (PRTDVMVOLUMEFMTINTERNAL)RTMemAllocZ(sizeof(RTDVMVOLUMEFMTINTERNAL));
710	if (pVol)
711	{
712	pVol->pVolMgr = pThis;
713	pVol->pEntry = pEntry;
714	*phVolFmt = pVol;
715	return VINF_SUCCESS;
716	}
717	return VERR_NO_MEMORY;
718	}
719
720	static DECLCALLBACK(int) rtDvmFmtMbrQueryFirstVolume(RTDVMFMT hVolMgrFmt, PRTDVMVOLUMEFMT phVolFmt)
721	{
722	PRTDVMFMTINTERNAL pThis = hVolMgrFmt;
723	if (pThis->cPartitions != 0)
724	return rtDvmFmtMbrVolumeCreate(pThis, RTListGetFirst(&pThis->PartitionHead, RTDVMMBRENTRY, ListEntry), phVolFmt);
725	return VERR_DVM_MAP_EMPTY;
726	}
727
728	static DECLCALLBACK(int) rtDvmFmtMbrQueryNextVolume(RTDVMFMT hVolMgrFmt, RTDVMVOLUMEFMT hVolFmt, PRTDVMVOLUMEFMT phVolFmtNext)
729	{
730	PRTDVMFMTINTERNAL pThis = hVolMgrFmt;
731	PRTDVMVOLUMEFMTINTERNAL pCurVol = hVolFmt;
732	if (pCurVol)
733	{
734	PRTDVMMBRENTRY pNextEntry = RTListGetNext(&pThis->PartitionHead, pCurVol->pEntry, RTDVMMBRENTRY, ListEntry);
735	if (pNextEntry)
736	return rtDvmFmtMbrVolumeCreate(pThis, pNextEntry, phVolFmtNext);
737	return VERR_DVM_MAP_NO_VOLUME;
738	}
739	if (pThis->cPartitions != 0)
740	return rtDvmFmtMbrVolumeCreate(pThis, RTListGetFirst(&pThis->PartitionHead, RTDVMMBRENTRY, ListEntry), phVolFmtNext);
741	return VERR_DVM_MAP_EMPTY;
742	}
743
744	/**
745	* Helper for rtDvmFmtMbrQueryTableLocations that calculates the padding and/or
746	* free space at @a off.
747	*
748	* Because nothing need to be sorted by start offset, we have to traverse all
749	* partition tables to determine this.
750	*/
751	static uint64_t rtDvmFmtMbrCalcTablePadding(PRTDVMFMTINTERNAL pThis, uint64_t off)
752	{
753	uint64_t offNext = pThis->pDisk->cbDisk;
754	for (unsigned i = 0; i < 4; i++)
755	{
756	/* Check this primary entry */
757	uint64_t offCur = pThis->Primary.aEntries[i].offPart;
758	if (offCur >= off && offCur < offNext && pThis->Primary.aEntries[i].bType != 0)
759	offNext = offCur;
760
761	/* If it's an extended partition, check the chained ones too. */
762	for (PRTDVMMBRSECTOR pCur = pThis->Primary.aEntries[i].pChain;
763	pCur != NULL;
764	pCur = pCur->idxExtended != UINT8_MAX ? pCur->aEntries[pCur->idxExtended].pChain : NULL)
765	{
766	for (unsigned j = 0; j < 4; j++)
767	{
768	offCur = pCur->aEntries[j].offPart;
769	if (offCur >= off && offCur < offNext && pCur->aEntries[j].bType != 0)
770	offNext = offCur;
771	}
772	}
773	}
774	Assert(offNext >= off);
775	return offNext - off;
776	}
777
778	/** @copydoc RTDVMFMTOPS::pfnQueryTableLocations */
779	static DECLCALLBACK(int) rtDvmFmtMbrQueryTableLocations(RTDVMFMT hVolMgrFmt, uint32_t fFlags, PRTDVMTABLELOCATION paLocations,
780	size_t cLocations, size_t *pcActual)
781	{
782	PRTDVMFMTINTERNAL pThis = hVolMgrFmt;
783	RT_NOREF(fFlags);
784
785	/*
786	* The MBR.
787	*/
788	int rc = VINF_SUCCESS;
789	size_t iLoc = 0;
790	if (cLocations > 0)
791	{
792	paLocations[iLoc].off = pThis->Primary.offOnDisk;
793	paLocations[iLoc].cb = pThis->cbSector;
794	paLocations[iLoc].cbPadding = rtDvmFmtMbrCalcTablePadding(pThis, 0 + pThis->cbSector);
795	}
796	else
797	rc = VERR_BUFFER_OVERFLOW;
798	iLoc++;
799
800	/*
801	* Now do the extended partitions.
802	*
803	* Remember, we only support multiple in the primary MBR, only the first
804	* one is honored in the chained ones.
805	*/
806	for (unsigned i = 0; i < 4; i++)
807	{
808	for (PRTDVMMBRSECTOR pCur = pThis->Primary.aEntries[i].pChain;
809	pCur != NULL;
810	pCur = pCur->idxExtended != UINT8_MAX ? pCur->aEntries[pCur->idxExtended].pChain : NULL)
811	{
812	if (cLocations > iLoc)
813	{
814	paLocations[iLoc].off = pCur->offOnDisk;
815	paLocations[iLoc].cb = pThis->cbSector;
816	paLocations[iLoc].cbPadding = rtDvmFmtMbrCalcTablePadding(pThis, pCur->offOnDisk + pThis->cbSector);
817	}
818	else
819	rc = VERR_BUFFER_OVERFLOW;
820	iLoc++;
821	}
822	}
823
824	/*
825	* Return values.
826	*/
827	if (pcActual)
828	*pcActual = iLoc;
829	else if (cLocations != iLoc && RT_SUCCESS(rc))
830	{
831	RT_BZERO(&paLocations[iLoc], (cLocations - iLoc) * sizeof(paLocations[0]));
832	rc = VERR_BUFFER_UNDERFLOW;
833	}
834	return rc;
835	}
836
837	static DECLCALLBACK(void) rtDvmFmtMbrVolumeClose(RTDVMVOLUMEFMT hVolFmt)
838	{
839	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
840
841	pVol->pVolMgr = NULL;
842	pVol->pEntry = NULL;
843
844	RTMemFree(pVol);
845	}
846
847	static DECLCALLBACK(uint64_t) rtDvmFmtMbrVolumeGetSize(RTDVMVOLUMEFMT hVolFmt)
848	{
849	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
850
851	return pVol->pEntry->cbPart;
852	}
853
854	static DECLCALLBACK(int) rtDvmFmtMbrVolumeQueryName(RTDVMVOLUMEFMT hVolFmt, char **ppszVolName)
855	{
856	NOREF(hVolFmt); NOREF(ppszVolName);
857	return VERR_NOT_SUPPORTED;
858	}
859
860	static DECLCALLBACK(RTDVMVOLTYPE) rtDvmFmtMbrVolumeGetType(RTDVMVOLUMEFMT hVolFmt)
861	{
862	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
863
864	uint8_t const bType = pVol->pEntry->bType;
865	for (unsigned i = 0; i < RT_ELEMENTS(g_aFs2DvmVolTypes); i++)
866	if (g_aFs2DvmVolTypes[i].bFsId == bType)
867	return g_aFs2DvmVolTypes[i].enmVolType;
868
869	return RTDVMVOLTYPE_UNKNOWN;
870	}
871
872	static DECLCALLBACK(uint64_t) rtDvmFmtMbrVolumeGetFlags(RTDVMVOLUMEFMT hVolFmt)
873	{
874	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
875
876	uint64_t fFlags = DVMVOLUME_F_CONTIGUOUS;
877	if (pVol->pEntry->fFlags & 0x80)
878	fFlags \|= DVMVOLUME_FLAGS_BOOTABLE \| DVMVOLUME_FLAGS_ACTIVE;
879
880	return fFlags;
881	}
882
883	static DECLCALLBACK(int) rtDvmFmtMbrVolumeQueryRange(RTDVMVOLUMEFMT hVolFmt, uint64_t poffStart, uint64_t poffLast)
884	{
885	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
886	*poffStart = pVol->pEntry->offPart;
887	*poffLast = pVol->pEntry->offPart + pVol->pEntry->cbPart - 1;
888	return VINF_SUCCESS;
889	}
890
891	static DECLCALLBACK(bool) rtDvmFmtMbrVolumeIsRangeIntersecting(RTDVMVOLUMEFMT hVolFmt, uint64_t offStart, size_t cbRange,
892	uint64_t poffVol, uint64_t pcbIntersect)
893	{
894	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
895
896	if (RTDVM_RANGE_IS_INTERSECTING(pVol->pEntry->offPart, pVol->pEntry->cbPart, offStart))
897	{
898	*poffVol = offStart - pVol->pEntry->offPart;
899	*pcbIntersect = RT_MIN(cbRange, pVol->pEntry->offPart + pVol->pEntry->cbPart - offStart);
900	return true;
901	}
902	return false;
903	}
904
905	/** @copydoc RTDVMFMTOPS::pfnVolumeQueryTableLocation */
906	static DECLCALLBACK(int) rtDvmFmtMbrVolumeQueryTableLocation(RTDVMVOLUMEFMT hVolFmt, uint64_t poffTable, uint64_t pcbTable)
907	{
908	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
909	*poffTable = pVol->pEntry->pSector->offOnDisk;
910	*pcbTable = RT_MAX(512, pVol->pVolMgr->pDisk->cbSector);
911	return VINF_SUCCESS;
912	}
913
914	/** @copydoc RTDVMFMTOPS::pfnVolumeGetIndex */
915	static DECLCALLBACK(uint32_t) rtDvmFmtMbrVolumeGetIndex(RTDVMVOLUMEFMT hVolFmt, RTDVMVOLIDX enmIndex)
916	{
917	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
918	switch (enmIndex)
919	{
920	case RTDVMVOLIDX_USER_VISIBLE:
921	return pVol->pEntry->idxVisible;
922	case RTDVMVOLIDX_ALL:
923	return pVol->pEntry->idxAll;
924	case RTDVMVOLIDX_IN_TABLE:
925	return pVol->pEntry->idxTable;
926	case RTDVMVOLIDX_LINUX:
927	return pVol->pEntry->idxLinux;
928
929	case RTDVMVOLIDX_INVALID:
930	case RTDVMVOLIDX_HOST:
931	case RTDVMVOLIDX_END:
932	case RTDVMVOLIDX_32BIT_HACK:
933	break;
934	/* no default! */
935	}
936	return UINT32_MAX;
937	}
938
939	/** @copydoc RTDVMFMTOPS::pfnVolumeQueryProp */
940	static DECLCALLBACK(int) rtDvmFmtMbrVolumeQueryProp(RTDVMVOLUMEFMT hVolFmt, RTDVMVOLPROP enmProperty,
941	void pvBuf, size_t cbBuf, size_t pcbBuf)
942	{
943	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
944	switch (enmProperty)
945	{
946	case RTDVMVOLPROP_MBR_FIRST_CYLINDER:
947	*pcbBuf = sizeof(uint16_t);
948	Assert(cbBuf >= *pcbBuf);
949	(uint16_t )pvBuf = pVol->pEntry->FirstChs.uCylinder;
950	return VINF_SUCCESS;
951	case RTDVMVOLPROP_MBR_LAST_CYLINDER:
952	*pcbBuf = sizeof(uint16_t);
953	Assert(cbBuf >= *pcbBuf);
954	(uint16_t )pvBuf = pVol->pEntry->LastChs.uCylinder;
955	return VINF_SUCCESS;
956
957	case RTDVMVOLPROP_MBR_FIRST_HEAD:
958	*pcbBuf = sizeof(uint8_t);
959	Assert(cbBuf >= *pcbBuf);
960	(uint8_t )pvBuf = pVol->pEntry->FirstChs.uHead;
961	return VINF_SUCCESS;
962	case RTDVMVOLPROP_MBR_LAST_HEAD:
963	*pcbBuf = sizeof(uint8_t);
964	Assert(cbBuf >= *pcbBuf);
965	(uint8_t )pvBuf = pVol->pEntry->LastChs.uHead;
966	return VINF_SUCCESS;
967
968	case RTDVMVOLPROP_MBR_FIRST_SECTOR:
969	*pcbBuf = sizeof(uint8_t);
970	Assert(cbBuf >= *pcbBuf);
971	(uint8_t )pvBuf = pVol->pEntry->FirstChs.uSector;
972	return VINF_SUCCESS;
973	case RTDVMVOLPROP_MBR_LAST_SECTOR:
974	*pcbBuf = sizeof(uint8_t);
975	Assert(cbBuf >= *pcbBuf);
976	(uint8_t )pvBuf = pVol->pEntry->LastChs.uSector;
977	return VINF_SUCCESS;
978
979	case RTDVMVOLPROP_MBR_TYPE:
980	*pcbBuf = sizeof(uint8_t);
981	Assert(cbBuf >= *pcbBuf);
982	(uint8_t )pvBuf = pVol->pEntry->bType;
983	return VINF_SUCCESS;
984
985	case RTDVMVOLPROP_GPT_TYPE:
986	case RTDVMVOLPROP_GPT_UUID:
987	return VERR_NOT_SUPPORTED;
988
989	case RTDVMVOLPROP_INVALID:
990	case RTDVMVOLPROP_END:
991	case RTDVMVOLPROP_32BIT_HACK:
992	break;
993	/* not default! */
994	}
995	RT_NOREF(cbBuf);
996	AssertFailed();
997	return VERR_NOT_SUPPORTED;
998	}
999
1000	static DECLCALLBACK(int) rtDvmFmtMbrVolumeRead(RTDVMVOLUMEFMT hVolFmt, uint64_t off, void *pvBuf, size_t cbRead)
1001	{
1002	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
1003	AssertReturn(off + cbRead <= pVol->pEntry->cbPart, VERR_INVALID_PARAMETER);
1004
1005	return rtDvmDiskRead(pVol->pVolMgr->pDisk, pVol->pEntry->offPart + off, pvBuf, cbRead);
1006	}
1007
1008	static DECLCALLBACK(int) rtDvmFmtMbrVolumeWrite(RTDVMVOLUMEFMT hVolFmt, uint64_t off, const void *pvBuf, size_t cbWrite)
1009	{
1010	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
1011	AssertReturn(off + cbWrite <= pVol->pEntry->cbPart, VERR_INVALID_PARAMETER);
1012
1013	return rtDvmDiskWrite(pVol->pVolMgr->pDisk, pVol->pEntry->offPart + off, pvBuf, cbWrite);
1014	}
1015
1016	DECL_HIDDEN_CONST(const RTDVMFMTOPS) g_rtDvmFmtMbr =
1017	{
1018	/* pszFmt */
1019	"MBR",
1020	/* enmFormat */
1021	RTDVMFORMATTYPE_MBR,
1022	/* pfnProbe */
1023	rtDvmFmtMbrProbe,
1024	/* pfnOpen */
1025	rtDvmFmtMbrOpen,
1026	/* pfnInitialize */
1027	rtDvmFmtMbrInitialize,
1028	/* pfnClose */
1029	rtDvmFmtMbrClose,
1030	/* pfnQueryRangeUse */
1031	rtDvmFmtMbrQueryRangeUse,
1032	/* pfnQueryDiskUuid */
1033	rtDvmFmtMbrQueryDiskUuid,
1034	/* pfnGetValidVolumes */
1035	rtDvmFmtMbrGetValidVolumes,
1036	/* pfnGetMaxVolumes */
1037	rtDvmFmtMbrGetMaxVolumes,
1038	/* pfnQueryFirstVolume */
1039	rtDvmFmtMbrQueryFirstVolume,
1040	/* pfnQueryNextVolume */
1041	rtDvmFmtMbrQueryNextVolume,
1042	/* pfnQueryTableLocations */
1043	rtDvmFmtMbrQueryTableLocations,
1044	/* pfnVolumeClose */
1045	rtDvmFmtMbrVolumeClose,
1046	/* pfnVolumeGetSize */
1047	rtDvmFmtMbrVolumeGetSize,
1048	/* pfnVolumeQueryName */
1049	rtDvmFmtMbrVolumeQueryName,
1050	/* pfnVolumeGetType */
1051	rtDvmFmtMbrVolumeGetType,
1052	/* pfnVolumeGetFlags */
1053	rtDvmFmtMbrVolumeGetFlags,
1054	/* pfnVolumeQueryRange */
1055	rtDvmFmtMbrVolumeQueryRange,
1056	/* pfnVOlumeIsRangeIntersecting */
1057	rtDvmFmtMbrVolumeIsRangeIntersecting,
1058	/* pfnVolumeQueryTableLocation */
1059	rtDvmFmtMbrVolumeQueryTableLocation,
1060	/* pfnVolumeGetIndex */
1061	rtDvmFmtMbrVolumeGetIndex,
1062	/* pfnVolumeQueryProp */
1063	rtDvmFmtMbrVolumeQueryProp,
1064	/* pfnVolumeRead */
1065	rtDvmFmtMbrVolumeRead,
1066	/* pfnVolumeWrite */
1067	rtDvmFmtMbrVolumeWrite
1068	};
1069

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source: vbox/trunk/src/VBox/Runtime/common/dvm/dvmmbr.cpp@ 96407

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