dvmmbr.cpp@ 95841

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1	/* $Id: dvmmbr.cpp 93115 2022-01-01 11:31:46Z vboxsync $ */
2	/** @file
3	* IPRT Disk Volume Management API (DVM) - MBR format backend.
4	*/
5
6	/*
7	* Copyright (C) 2011-2022 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*
17	* The contents of this file may alternatively be used under the terms
18	* of the Common Development and Distribution License Version 1.0
19	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20	* VirtualBox OSE distribution, in which case the provisions of the
21	* CDDL are applicable instead of those of the GPL.
22	*
23	* You may elect to license modified versions of this file under the
24	* terms and conditions of either the GPL or the CDDL or both.
25	*/
26
27
28	/*********************************************************************************************************************************
29	* Header Files *
30	*********************************************************************************************************************************/
31	#define LOG_GROUP RTLOGGROUP_FS
32	#include <iprt/types.h>
33	#include <iprt/assert.h>
34	#include <iprt/mem.h>
35	#include <iprt/dvm.h>
36	#include <iprt/list.h>
37	#include <iprt/log.h>
38	#include <iprt/string.h>
39	#include <iprt/uuid.h>
40	#include "internal/dvm.h"
41
42
43	/*********************************************************************************************************************************
44	* Defined Constants And Macros *
45	*********************************************************************************************************************************/
46	/** Checks if the partition type is an extended partition container. */
47	#define RTDVMMBR_IS_EXTENDED(a_bType) ((a_bType) == 0x05 \|\| (a_bType) == 0x0f)
48
49
50	/*********************************************************************************************************************************
51	* Structures and Typedefs *
52	*********************************************************************************************************************************/
53	/** Pointer to a MBR sector. */
54	typedef struct RTDVMMBRSECTOR *PRTDVMMBRSECTOR;
55
56
57	/** The on-disk Cylinder/Head/Sector (CHS) info. */
58	typedef struct MBRCHSADDR
59	{
60	uint8_t uHead;
61	uint8_t uSector : 6;
62	uint8_t uCylinderH : 2;
63	uint8_t uCylinderL;
64	} MBRCHSADDR;
65	AssertCompileSize(MBRCHSADDR, 3);
66
67
68	/** A decoded cylinder/head/sector address. */
69	typedef struct RTDVMMBRCHSADDR
70	{
71	uint16_t uCylinder;
72	uint8_t uHead;
73	uint8_t uSector;
74	} RTDVMMBRCHSADDR;
75
76
77	/**
78	* MBR entry.
79	*/
80	typedef struct RTDVMMBRENTRY
81	{
82	/** Our entry in the in-use partition entry list (RTDVMMBRENTRY). */
83	RTLISTNODE ListEntry;
84	/** Pointer to the MBR sector containing this entry. */
85	PRTDVMMBRSECTOR pSector;
86	/** Pointer to the next sector in the extended partition table chain. */
87	PRTDVMMBRSECTOR pChain;
88	/** The byte offset of the start of the partition (relative to disk). */
89	uint64_t offPart;
90	/** Number of bytes for this partition. */
91	uint64_t cbPart;
92	/** The partition/filesystem type. */
93	uint8_t bType;
94	/** The partition flags. */
95	uint8_t fFlags;
96	/** Bad entry. */
97	bool fBad;
98	/** RTDVMVOLIDX_IN_TABLE - Zero-based index within the table in pSector.
99	* (Also the index into RTDVMMBRSECTOR::aEntries.) */
100	uint8_t idxTable;
101	/** RTDVMVOLIDX_ALL - One-based index. All primary entries are included,
102	* whether they are used or not. In the extended table chain, only USED
103	* entries are counted (but we include RTDVMMBR_IS_EXTENDED entries). */
104	uint8_t idxAll;
105	/** RTDVMVOLIDX_USER_VISIBLE - One-base index. Skips all unused entries
106	* and RTDVMMBR_IS_EXTENDED. */
107	uint8_t idxVisible;
108	/** RTDVMVOLIDX_LINUX - One-based index following the /dev/sdaX scheme. */
109	uint8_t idxLinux;
110	uint8_t bUnused;
111	/** The first CHS address of this partition */
112	RTDVMMBRCHSADDR FirstChs;
113	/** The last CHS address of this partition */
114	RTDVMMBRCHSADDR LastChs;
115	} RTDVMMBRENTRY;
116	/** Pointer to an MBR entry. */
117	typedef RTDVMMBRENTRY *PRTDVMMBRENTRY;
118
119	/**
120	* A MBR sector.
121	*/
122	typedef struct RTDVMMBRSECTOR
123	{
124	/** Internal representation of the entries. */
125	RTDVMMBRENTRY aEntries[4];
126	/** The byte offset of this MBR sector (relative to disk).
127	* We keep this for detecting cycles now, but it will be needed if we start
128	* updating the partition table at some point. */
129	uint64_t offOnDisk;
130	/** Pointer to the previous sector if this isn't a primary one. */
131	PRTDVMMBRENTRY pPrevSector;
132	/** Set if this is the primary MBR, cleared if an extended. */
133	bool fIsPrimary;
134	/** Number of used entries. */
135	uint8_t cUsed;
136	/** Number of extended entries. */
137	uint8_t cExtended;
138	/** The extended entry we're following (we only follow one, except when
139	* fIsPrimary is @c true). UINT8_MAX if none. */
140	uint8_t idxExtended;
141	#if ARCH_BITS == 64
142	uint32_t uAlignmentPadding;
143	#endif
144	/** The raw data. */
145	uint8_t abData[RT_FLEXIBLE_ARRAY_NESTED];
146	} RTDVMMBRSECTOR;
147
148	/**
149	* MBR volume manager data.
150	*/
151	typedef struct RTDVMFMTINTERNAL
152	{
153	/** Pointer to the underlying disk. */
154	PCRTDVMDISK pDisk;
155	/** Head of the list of in-use RTDVMMBRENTRY structures. This excludes
156	* extended partition table entries. */
157	RTLISTANCHOR PartitionHead;
158	/** The sector size to use when doing address calculation based on partition
159	* table sector addresses and counts. */
160	uint32_t cbSector;
161	/** The total number of partitions, not counting extended ones. */
162	uint32_t cPartitions;
163	/** The actual primary MBR sector. */
164	RTDVMMBRSECTOR Primary;
165	} RTDVMFMTINTERNAL;
166	/** Pointer to the MBR volume manager. */
167	typedef RTDVMFMTINTERNAL *PRTDVMFMTINTERNAL;
168
169	/**
170	* MBR volume data.
171	*/
172	typedef struct RTDVMVOLUMEFMTINTERNAL
173	{
174	/** Pointer to the volume manager. */
175	PRTDVMFMTINTERNAL pVolMgr;
176	/** The MBR entry. */
177	PRTDVMMBRENTRY pEntry;
178	} RTDVMVOLUMEFMTINTERNAL;
179	/** Pointer to an MBR volume. */
180	typedef RTDVMVOLUMEFMTINTERNAL *PRTDVMVOLUMEFMTINTERNAL;
181
182
183	/*********************************************************************************************************************************
184	* Global Variables *
185	*********************************************************************************************************************************/
186	/**
187	* Mapping of FS types to DVM volume types.
188	*
189	* @see https://en.wikipedia.org/wiki/Partition_type
190	* @see http://www.win.tue.nl/~aeb/partitions/partition_types-1.html
191	*/
192	static const struct RTDVMMBRFS2VOLTYPE
193	{
194	/** MBR FS Id. */
195	uint8_t bFsId;
196	/** DVM volume type. */
197	RTDVMVOLTYPE enmVolType;
198	} g_aFs2DvmVolTypes[] =
199	{
200	{ 0x01, RTDVMVOLTYPE_FAT12 },
201	{ 0x04, RTDVMVOLTYPE_FAT16 },
202	{ 0x06, RTDVMVOLTYPE_FAT16 }, /* big FAT16 */
203	{ 0x07, RTDVMVOLTYPE_NTFS }, /* Simplification: Used for HPFS, exFAT, ++, too but NTFS is the more common one. */
204	{ 0x0b, RTDVMVOLTYPE_FAT32 },
205	{ 0x0c, RTDVMVOLTYPE_FAT32 },
206	{ 0x0e, RTDVMVOLTYPE_FAT16 },
207
208	/* Hidden variants of the above: */
209	{ 0x11, RTDVMVOLTYPE_FAT12 },
210	{ 0x14, RTDVMVOLTYPE_FAT16 },
211	{ 0x16, RTDVMVOLTYPE_FAT16 },
212	{ 0x17, RTDVMVOLTYPE_NTFS },
213	{ 0x1b, RTDVMVOLTYPE_FAT32 },
214	{ 0x1c, RTDVMVOLTYPE_FAT32 },
215	{ 0x1e, RTDVMVOLTYPE_FAT16 },
216
217	{ 0x82, RTDVMVOLTYPE_LINUX_SWAP },
218	{ 0x83, RTDVMVOLTYPE_LINUX_NATIVE },
219	{ 0x8e, RTDVMVOLTYPE_LINUX_LVM },
220	{ 0xa5, RTDVMVOLTYPE_FREEBSD },
221	{ 0xa9, RTDVMVOLTYPE_NETBSD },
222	{ 0xa6, RTDVMVOLTYPE_OPENBSD },
223	{ 0xaf, RTDVMVOLTYPE_DARWIN_HFS },
224	{ 0xbf, RTDVMVOLTYPE_SOLARIS },
225	{ 0xfd, RTDVMVOLTYPE_LINUX_SOFTRAID }
226	};
227
228
229	static DECLCALLBACK(int) rtDvmFmtMbrProbe(PCRTDVMDISK pDisk, uint32_t *puScore)
230	{
231	int rc = VINF_SUCCESS;
232	*puScore = RTDVM_MATCH_SCORE_UNSUPPORTED;
233	if (pDisk->cbDisk > RT_MAX(512, pDisk->cbSector))
234	{
235	/* Read from the disk and check for the 0x55aa signature at the end. */
236	size_t cbAlignedSize = RT_MAX(512, pDisk->cbSector);
237	uint8_t pbMbr = (uint8_t )RTMemTmpAllocZ(cbAlignedSize);
238	if (pbMbr)
239	{
240	rc = rtDvmDiskRead(pDisk, 0, pbMbr, cbAlignedSize);
241	if ( RT_SUCCESS(rc)
242	&& pbMbr[510] == 0x55
243	&& pbMbr[511] == 0xaa)
244	puScore = RTDVM_MATCH_SCORE_SUPPORTED; / Not perfect because GPTs have a protective MBR. */
245	/** @todo this could easily confuser a DOS, OS/2 or NT boot sector with a MBR... */
246	RTMemTmpFree(pbMbr);
247	}
248	else
249	rc = VERR_NO_TMP_MEMORY;
250	}
251
252	return rc;
253	}
254
255
256	static void rtDvmFmtMbrDestroy(PRTDVMFMTINTERNAL pThis)
257	{
258	/*
259	* Delete chains of extended partitions.
260	*/
261	for (unsigned i = 0; i < 4; i++)
262	{
263	PRTDVMMBRSECTOR pCur = pThis->Primary.aEntries[i].pChain;
264	while (pCur)
265	{
266	PRTDVMMBRSECTOR pNext = pCur->idxExtended != UINT8_MAX ? pCur->aEntries[pCur->idxExtended].pChain : NULL;
267
268	RT_ZERO(pCur->aEntries);
269	pCur->pPrevSector = NULL;
270	RTMemFree(pCur);
271
272	pCur = pNext;
273	}
274	}
275
276	/*
277	* Now kill this.
278	*/
279	pThis->pDisk = NULL;
280	RT_ZERO(pThis->Primary.aEntries);
281	RTMemFree(pThis);
282	}
283
284
285	/**
286	* Decodes the on-disk cylinder/head/sector info and stores it the
287	* destination structure.
288	*/
289	DECLINLINE(void) rtDvmFmtMbrDecodeChs(RTDVMMBRCHSADDR pDst, uint8_t pbRaw)
290	{
291	MBRCHSADDR pRawChs = (MBRCHSADDR )pbRaw;
292	pDst->uCylinder = RT_MAKE_U16(pRawChs->uCylinderL, pRawChs->uCylinderH);
293	pDst->uSector = pRawChs->uSector;
294	pDst->uHead = pRawChs->uHead;
295	}
296
297
298	static int rtDvmFmtMbrReadExtended(PRTDVMFMTINTERNAL pThis, PRTDVMMBRENTRY pPrimaryEntry,
299	uint8_t pidxAll, uint8_t pidxVisible, uint8_t *pidxLinux)
300	{
301	uint64_t const cbExt = pPrimaryEntry->cbPart;
302	uint64_t const offExtBegin = pPrimaryEntry->offPart;
303
304	uint64_t offCurBegin = offExtBegin;
305	PRTDVMMBRENTRY pCurEntry = pPrimaryEntry;
306	for (unsigned cTables = 1; ; cTables++)
307	{
308	/*
309	* Do some sanity checking.
310	*/
311	/* Check the address of the partition table. */
312	if (offCurBegin - offExtBegin >= cbExt)
313	{
314	LogRel(("rtDvmFmtMbrReadExtended: offCurBegin=%#RX64 is outside the extended partition: %#RX64..%#RX64 (LB %#RX64)\n",
315	offCurBegin, offExtBegin, offExtBegin + cbExt - 1, cbExt));
316	pCurEntry->fBad = true;
317	return -VERR_OUT_OF_RANGE;
318	}
319
320	/* Limit the chain length. */
321	if (cTables > 64)
322	{
323	LogRel(("rtDvmFmtMbrReadExtended: offCurBegin=%#RX64 is the %uth table, we stop here.\n", offCurBegin, cTables));
324	pCurEntry->fBad = true;
325	return -VERR_TOO_MANY_SYMLINKS;
326	}
327
328	/* Check for obvious cycles. */
329	for (PRTDVMMBRENTRY pPrev = pCurEntry->pSector->pPrevSector; pPrev != NULL; pPrev = pPrev->pSector->pPrevSector)
330	if (pPrev->offPart == offCurBegin)
331	{
332	LogRel(("rtDvmFmtMbrReadExtended: Cycle! We've seen offCurBegin=%#RX64 before\n", offCurBegin));
333	pCurEntry->fBad = true;
334	return -VERR_TOO_MANY_SYMLINKS;
335	}
336
337	/*
338	* Allocate a new sector entry and read the sector with the table.
339	*/
340	size_t const cbMbr = RT_MAX(512, pThis->pDisk->cbSector);
341	PRTDVMMBRSECTOR pNext = (PRTDVMMBRSECTOR)RTMemAllocZVar(RT_UOFFSETOF_DYN(RTDVMMBRSECTOR, abData[cbMbr]));
342	if (!pNext)
343	return VERR_NO_MEMORY;
344	pNext->offOnDisk = offCurBegin;
345	pNext->pPrevSector = pCurEntry;
346	//pNext->fIsPrimary = false;
347	//pNext->cUsed = 0;
348	//pNext->cExtended = 0;
349	pNext->idxExtended = UINT8_MAX;
350
351	uint8_t *pabData = &pNext->abData[0];
352	int rc = rtDvmDiskReadUnaligned(pThis->pDisk, pNext->offOnDisk, pabData, cbMbr);
353	if ( RT_FAILURE(rc)
354	\|\| pabData[510] != 0x55
355	\|\| pabData[511] != 0xaa)
356	{
357	if (RT_FAILURE(rc))
358	LogRel(("rtDvmFmtMbrReadExtended: Error reading extended partition table at sector %#RX64: %Rrc\n", offCurBegin, rc));
359	else
360	LogRel(("rtDvmFmtMbrReadExtended: Extended partition table at sector %#RX64 does not have a valid DOS signature: %#x %#x\n",
361	offCurBegin, pabData[510], pabData[511]));
362	RTMemFree(pNext);
363	pCurEntry->fBad = true;
364	return rc;
365	}
366	pCurEntry->pChain = pNext;
367
368	/*
369	* Process the table, taking down the first forward entry.
370	*
371	* As noted in the caller of this function, we only deal with one extended
372	* partition entry at this level since noone really ever put more than one
373	* here anyway.
374	*/
375	PRTDVMMBRENTRY pEntry = &pNext->aEntries[0];
376	uint8_t *pbMbrEntry = &pabData[446];
377	for (unsigned i = 0; i < 4; i++, pEntry++, pbMbrEntry += 16)
378	{
379	pEntry->pSector = pNext;
380	pEntry->idxTable = (uint8_t)i;
381	RTListInit(&pEntry->ListEntry);
382
383	uint8_t const bType = pbMbrEntry[4];
384	if (bType != 0)
385	{
386	pEntry->bType = bType;
387	pEntry->fFlags = pbMbrEntry[0];
388	pEntry->idxAll = *pidxAll;
389	*pidxAll += 1;
390
391	rtDvmFmtMbrDecodeChs(&pEntry->FirstChs, &pbMbrEntry[1]);
392	rtDvmFmtMbrDecodeChs(&pEntry->LastChs, &pbMbrEntry[5]);
393
394	pEntry->offPart = RT_MAKE_U32_FROM_U8(pbMbrEntry[0x08 + 0],
395	pbMbrEntry[0x08 + 1],
396	pbMbrEntry[0x08 + 2],
397	pbMbrEntry[0x08 + 3]);
398	pEntry->offPart *= pThis->cbSector;
399	pEntry->cbPart = RT_MAKE_U32_FROM_U8(pbMbrEntry[0x0c + 0],
400	pbMbrEntry[0x0c + 1],
401	pbMbrEntry[0x0c + 2],
402	pbMbrEntry[0x0c + 3]);
403	pEntry->cbPart *= pThis->cbSector;
404	if (!RTDVMMBR_IS_EXTENDED(bType))
405	{
406	pEntry->offPart += offCurBegin;
407	pEntry->idxVisible = *pidxVisible;
408	*pidxVisible += 1;
409	pEntry->idxLinux = *pidxLinux;
410	*pidxLinux += 1;
411
412	pThis->cPartitions++;
413	RTListAppend(&pThis->PartitionHead, &pEntry->ListEntry);
414	Log2(("rtDvmFmtMbrReadExtended: %#012RX64::%u: vol%u bType=%#04x fFlags=%#04x offPart=%#012RX64 cbPart=%#012RX64\n",
415	offCurBegin, i, pThis->cPartitions - 1, pEntry->bType, pEntry->fFlags, pEntry->offPart, pEntry->cbPart));
416	}
417	else
418	{
419	pEntry->offPart += offExtBegin;
420	pNext->cExtended++;
421	if (pNext->idxExtended == UINT8_MAX)
422	pNext->idxExtended = (uint8_t)i;
423	else
424	{
425	pEntry->fBad = true;
426	LogRel(("rtDvmFmtMbrReadExtended: Warning! Both #%u and #%u are extended partition table entries! Only following the former\n",
427	i, pNext->idxExtended));
428	}
429	Log2(("rtDvmFmtMbrReadExtended: %#012RX64::%u: ext%u bType=%#04x fFlags=%#04x offPart=%#012RX64 cbPart=%#012RX64\n",
430	offCurBegin, i, pNext->cExtended - 1, pEntry->bType, pEntry->fFlags, pEntry->offPart, pEntry->cbPart));
431	}
432	pNext->cUsed++;
433
434	}
435	/* else: unused */
436	}
437
438	/*
439	* We're done if we didn't find any extended partition table entry.
440	* Otherwise, advance to the next one.
441	*/
442	if (!pNext->cExtended)
443	return VINF_SUCCESS;
444	pCurEntry = &pNext->aEntries[pNext->idxExtended];
445	offCurBegin = pCurEntry->offPart;
446	}
447	}
448
449
450	static DECLCALLBACK(int) rtDvmFmtMbrOpen(PCRTDVMDISK pDisk, PRTDVMFMT phVolMgrFmt)
451	{
452	int rc;
453	size_t const cbMbr = RT_MAX(512, pDisk->cbSector);
454	PRTDVMFMTINTERNAL pThis = (PRTDVMFMTINTERNAL)RTMemAllocZVar(RT_UOFFSETOF_DYN(RTDVMFMTINTERNAL, Primary.abData[cbMbr]));
455	if (pThis)
456	{
457	pThis->pDisk = pDisk;
458	//pThis->cPartitions = 0;
459	RTListInit(&pThis->PartitionHead);
460	//pThis->Primary.offOnDisk = 0;
461	//pThis->Primary.pPrevSector = NULL;
462	pThis->Primary.fIsPrimary = true;
463	//pThis->Primary.cUsed = 0;
464	//pThis->Primary.cExtended = 0;
465	pThis->Primary.idxExtended = UINT8_MAX;
466
467	/* We'll use the sector size reported by the disk.
468
469	Though, giiven that the MBR was hardwired to 512 byte sectors, we probably
470	should do some probing when the sector size differs from 512, but that can
471	wait till there is a real need for it and we've got some semi reliable
472	heuristics for doing that. */
473	pThis->cbSector = (uint32_t)pDisk->cbSector;
474	AssertLogRelMsgStmt( pThis->cbSector >= 512
475	&& pThis->cbSector <= _64K,
476	("cbSector=%#x\n", pThis->cbSector),
477	pThis->cbSector = 512);
478
479	/*
480	* Read the primary MBR.
481	*/
482	uint8_t *pabData = &pThis->Primary.abData[0];
483	rc = rtDvmDiskRead(pDisk, 0, pabData, cbMbr);
484	if (RT_SUCCESS(rc))
485	{
486	Assert(pabData[510] == 0x55 && pabData[511] == 0xaa);
487
488	/*
489	* Setup basic data for the 4 entries.
490	*/
491	PRTDVMMBRENTRY pEntry = &pThis->Primary.aEntries[0];
492	uint8_t *pbMbrEntry = &pabData[446];
493	uint8_t idxVisible = 1;
494	for (unsigned i = 0; i < 4; i++, pEntry++, pbMbrEntry += 16)
495	{
496	pEntry->pSector = &pThis->Primary;
497	pEntry->idxTable = (uint8_t)i;
498	RTListInit(&pEntry->ListEntry);
499
500	uint8_t const bType = pbMbrEntry[4];
501	if (bType != 0)
502	{
503	pEntry->bType = bType;
504	pEntry->fFlags = pbMbrEntry[0];
505	pEntry->idxAll = (uint8_t)(i + 1);
506
507	rtDvmFmtMbrDecodeChs(&pEntry->FirstChs, &pbMbrEntry[1]);
508	rtDvmFmtMbrDecodeChs(&pEntry->LastChs, &pbMbrEntry[5]);
509
510	pEntry->offPart = RT_MAKE_U32_FROM_U8(pbMbrEntry[0x08 + 0],
511	pbMbrEntry[0x08 + 1],
512	pbMbrEntry[0x08 + 2],
513	pbMbrEntry[0x08 + 3]);
514	pEntry->offPart *= pThis->cbSector;
515	pEntry->cbPart = RT_MAKE_U32_FROM_U8(pbMbrEntry[0x0c + 0],
516	pbMbrEntry[0x0c + 1],
517	pbMbrEntry[0x0c + 2],
518	pbMbrEntry[0x0c + 3]);
519	pEntry->cbPart *= pThis->cbSector;
520	if (!RTDVMMBR_IS_EXTENDED(bType))
521	{
522	pEntry->idxVisible = idxVisible++;
523	pEntry->idxLinux = (uint8_t)(i + 1);
524	pThis->cPartitions++;
525	RTListAppend(&pThis->PartitionHead, &pEntry->ListEntry);
526	Log2(("rtDvmFmtMbrOpen: %u: vol%u bType=%#04x fFlags=%#04x offPart=%#012RX64 cbPart=%#012RX64\n",
527	i, pThis->cPartitions - 1, pEntry->bType, pEntry->fFlags, pEntry->offPart, pEntry->cbPart));
528	}
529	else
530	{
531	pThis->Primary.cExtended++;
532	Log2(("rtDvmFmtMbrOpen: %u: ext%u bType=%#04x fFlags=%#04x offPart=%#012RX64 cbPart=%#012RX64\n",
533	i, pThis->Primary.cExtended - 1, pEntry->bType, pEntry->fFlags, pEntry->offPart, pEntry->cbPart));
534	}
535	pThis->Primary.cUsed++;
536	}
537	/* else: unused */
538	}
539
540	/*
541	* Now read any extended partitions. Since it's no big deal for us, we allow
542	* the primary partition table to have more than one extended partition. However
543	* in the extended tables we only allow a single forward link to avoid having to
544	* deal with recursion.
545	*/
546	if (pThis->Primary.cExtended > 0)
547	{
548	uint8_t idxAll = 5;
549	uint8_t idxLinux = 5;
550	for (unsigned i = 0; i < 4; i++)
551	if (RTDVMMBR_IS_EXTENDED(pThis->Primary.aEntries[i].bType))
552	{
553	if (pThis->Primary.idxExtended == UINT8_MAX)
554	pThis->Primary.idxExtended = (uint8_t)i;
555	rc = rtDvmFmtMbrReadExtended(pThis, &pThis->Primary.aEntries[i], &idxAll, &idxVisible, &idxLinux);
556	if (RT_FAILURE(rc))
557	break;
558	}
559	}
560	if (RT_SUCCESS(rc))
561	{
562	*phVolMgrFmt = pThis;
563	return rc;
564	}
565	}
566	rtDvmFmtMbrDestroy(pThis);
567	}
568	else
569	rc = VERR_NO_MEMORY;
570
571	return rc;
572	}
573
574	static DECLCALLBACK(int) rtDvmFmtMbrInitialize(PCRTDVMDISK pDisk, PRTDVMFMT phVolMgrFmt)
575	{
576	int rc;
577	size_t const cbMbr = RT_MAX(512, pDisk->cbSector);
578	PRTDVMFMTINTERNAL pThis = (PRTDVMFMTINTERNAL)RTMemAllocZVar(RT_UOFFSETOF_DYN(RTDVMFMTINTERNAL, Primary.abData[cbMbr]));
579	if (pThis)
580	{
581	pThis->pDisk = pDisk;
582	//pThis->cPartitions = 0;
583	RTListInit(&pThis->PartitionHead);
584	//pThis->Primary.offOnDisk = 0
585	//pThis->Primary.pPrevSector = NULL;
586	pThis->Primary.fIsPrimary = true;
587	//pThis->Primary.cUsed = 0;
588	//pThis->Primary.cExtended = 0;
589	pThis->Primary.idxExtended = UINT8_MAX;
590
591	/* Setup a new MBR and write it to the disk. */
592	uint8_t *pabData = &pThis->Primary.abData[0];
593	RT_BZERO(pabData, 512);
594	pabData[510] = 0x55;
595	pabData[511] = 0xaa;
596	rc = rtDvmDiskWrite(pDisk, 0, pabData, cbMbr);
597	if (RT_SUCCESS(rc))
598	{
599	pThis->pDisk = pDisk;
600	*phVolMgrFmt = pThis;
601	}
602	else
603	RTMemFree(pThis);
604	}
605	else
606	rc = VERR_NO_MEMORY;
607
608	return rc;
609	}
610
611	static DECLCALLBACK(void) rtDvmFmtMbrClose(RTDVMFMT hVolMgrFmt)
612	{
613	rtDvmFmtMbrDestroy(hVolMgrFmt);
614	}
615
616	static DECLCALLBACK(int) rtDvmFmtMbrQueryRangeUse(RTDVMFMT hVolMgrFmt, uint64_t off, uint64_t cbRange, bool *pfUsed)
617	{
618	PRTDVMFMTINTERNAL pThis = hVolMgrFmt;
619
620	/*
621	* The MBR definitely uses the first 512 bytes, but we consider anything up
622	* to 1MB of alignment padding / cylinder gap to be considered in use too.
623	*
624	* The cylinder gap has been used by several boot managers and boot loaders
625	* to store code and data.
626	*/
627	if (off < (uint64_t)_1M)
628	{
629	*pfUsed = true;
630	return VINF_SUCCESS;
631	}
632
633	/* Ditto for any extended partition tables. */
634	for (uint32_t iPrimary = 0; iPrimary < 4; iPrimary++)
635	{
636	PRTDVMMBRSECTOR pCur = pThis->Primary.aEntries[iPrimary].pChain;
637	while (pCur)
638	{
639	if ( off < pCur->offOnDisk + _1M
640	&& off + cbRange > pCur->offOnDisk)
641	{
642	*pfUsed = true;
643	return VINF_SUCCESS;
644	}
645
646
647	if (pCur->idxExtended == UINT8_MAX)
648	break;
649	pCur = pCur->aEntries[pCur->idxExtended].pChain;
650	}
651
652	}
653
654	/* Not in use. */
655	*pfUsed = false;
656	return VINF_SUCCESS;
657	}
658
659	/** @copydoc RTDVMFMTOPS::pfnQueryDiskUuid */
660	static DECLCALLBACK(int) rtDvmFmtMbrQueryDiskUuid(RTDVMFMT hVolMgrFmt, PRTUUID pUuid)
661	{
662	PRTDVMFMTINTERNAL pThis = hVolMgrFmt;
663	uint32_t idDisk = RT_MAKE_U32_FROM_U8(pThis->Primary.abData[440],
664	pThis->Primary.abData[441],
665	pThis->Primary.abData[442],
666	pThis->Primary.abData[443]);
667	if (idDisk != 0)
668	{
669	RTUuidClear(pUuid);
670	pUuid->Gen.u32TimeLow = idDisk;
671	return VINF_NOT_SUPPORTED;
672	}
673	return VERR_NOT_SUPPORTED;
674	}
675
676	static DECLCALLBACK(uint32_t) rtDvmFmtMbrGetValidVolumes(RTDVMFMT hVolMgrFmt)
677	{
678	PRTDVMFMTINTERNAL pThis = hVolMgrFmt;
679
680	return pThis->cPartitions;
681	}
682
683	static DECLCALLBACK(uint32_t) rtDvmFmtMbrGetMaxVolumes(RTDVMFMT hVolMgrFmt)
684	{
685	NOREF(hVolMgrFmt);
686	return 4; /** @todo Add support for EBR? */
687	}
688
689	/**
690	* Creates a new volume.
691	*
692	* @returns IPRT status code.
693	* @param pThis The MBR volume manager data.
694	* @param pEntry The MBR entry to create a volume handle for.
695	* @param phVolFmt Where to store the volume data on success.
696	*/
697	static int rtDvmFmtMbrVolumeCreate(PRTDVMFMTINTERNAL pThis, PRTDVMMBRENTRY pEntry, PRTDVMVOLUMEFMT phVolFmt)
698	{
699	PRTDVMVOLUMEFMTINTERNAL pVol = (PRTDVMVOLUMEFMTINTERNAL)RTMemAllocZ(sizeof(RTDVMVOLUMEFMTINTERNAL));
700	if (pVol)
701	{
702	pVol->pVolMgr = pThis;
703	pVol->pEntry = pEntry;
704	*phVolFmt = pVol;
705	return VINF_SUCCESS;
706	}
707	return VERR_NO_MEMORY;
708	}
709
710	static DECLCALLBACK(int) rtDvmFmtMbrQueryFirstVolume(RTDVMFMT hVolMgrFmt, PRTDVMVOLUMEFMT phVolFmt)
711	{
712	PRTDVMFMTINTERNAL pThis = hVolMgrFmt;
713	if (pThis->cPartitions != 0)
714	return rtDvmFmtMbrVolumeCreate(pThis, RTListGetFirst(&pThis->PartitionHead, RTDVMMBRENTRY, ListEntry), phVolFmt);
715	return VERR_DVM_MAP_EMPTY;
716	}
717
718	static DECLCALLBACK(int) rtDvmFmtMbrQueryNextVolume(RTDVMFMT hVolMgrFmt, RTDVMVOLUMEFMT hVolFmt, PRTDVMVOLUMEFMT phVolFmtNext)
719	{
720	PRTDVMFMTINTERNAL pThis = hVolMgrFmt;
721	PRTDVMVOLUMEFMTINTERNAL pCurVol = hVolFmt;
722	if (pCurVol)
723	{
724	PRTDVMMBRENTRY pNextEntry = RTListGetNext(&pThis->PartitionHead, pCurVol->pEntry, RTDVMMBRENTRY, ListEntry);
725	if (pNextEntry)
726	return rtDvmFmtMbrVolumeCreate(pThis, pNextEntry, phVolFmtNext);
727	return VERR_DVM_MAP_NO_VOLUME;
728	}
729	if (pThis->cPartitions != 0)
730	return rtDvmFmtMbrVolumeCreate(pThis, RTListGetFirst(&pThis->PartitionHead, RTDVMMBRENTRY, ListEntry), phVolFmtNext);
731	return VERR_DVM_MAP_EMPTY;
732	}
733
734	/**
735	* Helper for rtDvmFmtMbrQueryTableLocations that calculates the padding and/or
736	* free space at @a off.
737	*
738	* Because nothing need to be sorted by start offset, we have to traverse all
739	* partition tables to determine this.
740	*/
741	static uint64_t rtDvmFmtMbrCalcTablePadding(PRTDVMFMTINTERNAL pThis, uint64_t off)
742	{
743	uint64_t offNext = pThis->pDisk->cbDisk;
744	for (unsigned i = 0; i < 4; i++)
745	{
746	/* Check this primary entry */
747	uint64_t offCur = pThis->Primary.aEntries[i].offPart;
748	if (offCur >= off && offCur < offNext && pThis->Primary.aEntries[i].bType != 0)
749	offNext = offCur;
750
751	/* If it's an extended partition, check the chained ones too. */
752	for (PRTDVMMBRSECTOR pCur = pThis->Primary.aEntries[i].pChain;
753	pCur != NULL;
754	pCur = pCur->idxExtended != UINT8_MAX ? pCur->aEntries[pCur->idxExtended].pChain : NULL)
755	{
756	for (unsigned j = 0; j < 4; j++)
757	{
758	offCur = pCur->aEntries[j].offPart;
759	if (offCur >= off && offCur < offNext && pCur->aEntries[j].bType != 0)
760	offNext = offCur;
761	}
762	}
763	}
764	Assert(offNext >= off);
765	return offNext - off;
766	}
767
768	/** @copydoc RTDVMFMTOPS::pfnQueryTableLocations */
769	static DECLCALLBACK(int) rtDvmFmtMbrQueryTableLocations(RTDVMFMT hVolMgrFmt, uint32_t fFlags, PRTDVMTABLELOCATION paLocations,
770	size_t cLocations, size_t *pcActual)
771	{
772	PRTDVMFMTINTERNAL pThis = hVolMgrFmt;
773	RT_NOREF(fFlags);
774
775	/*
776	* The MBR.
777	*/
778	int rc = VINF_SUCCESS;
779	size_t iLoc = 0;
780	if (cLocations > 0)
781	{
782	paLocations[iLoc].off = pThis->Primary.offOnDisk;
783	paLocations[iLoc].cb = pThis->cbSector;
784	paLocations[iLoc].cbPadding = rtDvmFmtMbrCalcTablePadding(pThis, 0 + pThis->cbSector);
785	}
786	else
787	rc = VERR_BUFFER_OVERFLOW;
788	iLoc++;
789
790	/*
791	* Now do the extended partitions.
792	*
793	* Remember, we only support multiple in the primary MBR, only the first
794	* one is honored in the chained ones.
795	*/
796	for (unsigned i = 0; i < 4; i++)
797	{
798	for (PRTDVMMBRSECTOR pCur = pThis->Primary.aEntries[i].pChain;
799	pCur != NULL;
800	pCur = pCur->idxExtended != UINT8_MAX ? pCur->aEntries[pCur->idxExtended].pChain : NULL)
801	{
802	if (cLocations > iLoc)
803	{
804	paLocations[iLoc].off = pCur->offOnDisk;
805	paLocations[iLoc].cb = pThis->cbSector;
806	paLocations[iLoc].cbPadding = rtDvmFmtMbrCalcTablePadding(pThis, pCur->offOnDisk + pThis->cbSector);
807	}
808	else
809	rc = VERR_BUFFER_OVERFLOW;
810	iLoc++;
811	}
812	}
813
814	/*
815	* Return values.
816	*/
817	if (pcActual)
818	*pcActual = iLoc;
819	else if (cLocations != iLoc && RT_SUCCESS(rc))
820	{
821	RT_BZERO(&paLocations[iLoc], (cLocations - iLoc) * sizeof(paLocations[0]));
822	rc = VERR_BUFFER_UNDERFLOW;
823	}
824	return rc;
825	}
826
827	static DECLCALLBACK(void) rtDvmFmtMbrVolumeClose(RTDVMVOLUMEFMT hVolFmt)
828	{
829	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
830
831	pVol->pVolMgr = NULL;
832	pVol->pEntry = NULL;
833
834	RTMemFree(pVol);
835	}
836
837	static DECLCALLBACK(uint64_t) rtDvmFmtMbrVolumeGetSize(RTDVMVOLUMEFMT hVolFmt)
838	{
839	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
840
841	return pVol->pEntry->cbPart;
842	}
843
844	static DECLCALLBACK(int) rtDvmFmtMbrVolumeQueryName(RTDVMVOLUMEFMT hVolFmt, char **ppszVolName)
845	{
846	NOREF(hVolFmt); NOREF(ppszVolName);
847	return VERR_NOT_SUPPORTED;
848	}
849
850	static DECLCALLBACK(RTDVMVOLTYPE) rtDvmFmtMbrVolumeGetType(RTDVMVOLUMEFMT hVolFmt)
851	{
852	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
853
854	uint8_t const bType = pVol->pEntry->bType;
855	for (unsigned i = 0; i < RT_ELEMENTS(g_aFs2DvmVolTypes); i++)
856	if (g_aFs2DvmVolTypes[i].bFsId == bType)
857	return g_aFs2DvmVolTypes[i].enmVolType;
858
859	return RTDVMVOLTYPE_UNKNOWN;
860	}
861
862	static DECLCALLBACK(uint64_t) rtDvmFmtMbrVolumeGetFlags(RTDVMVOLUMEFMT hVolFmt)
863	{
864	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
865
866	uint64_t fFlags = DVMVOLUME_F_CONTIGUOUS;
867	if (pVol->pEntry->fFlags & 0x80)
868	fFlags \|= DVMVOLUME_FLAGS_BOOTABLE \| DVMVOLUME_FLAGS_ACTIVE;
869
870	return fFlags;
871	}
872
873	static DECLCALLBACK(int) rtDvmFmtMbrVolumeQueryRange(RTDVMVOLUMEFMT hVolFmt, uint64_t poffStart, uint64_t poffLast)
874	{
875	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
876	*poffStart = pVol->pEntry->offPart;
877	*poffLast = pVol->pEntry->offPart + pVol->pEntry->cbPart - 1;
878	return VINF_SUCCESS;
879	}
880
881	static DECLCALLBACK(bool) rtDvmFmtMbrVolumeIsRangeIntersecting(RTDVMVOLUMEFMT hVolFmt, uint64_t offStart, size_t cbRange,
882	uint64_t poffVol, uint64_t pcbIntersect)
883	{
884	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
885
886	if (RTDVM_RANGE_IS_INTERSECTING(pVol->pEntry->offPart, pVol->pEntry->cbPart, offStart))
887	{
888	*poffVol = offStart - pVol->pEntry->offPart;
889	*pcbIntersect = RT_MIN(cbRange, pVol->pEntry->offPart + pVol->pEntry->cbPart - offStart);
890	return true;
891	}
892	return false;
893	}
894
895	/** @copydoc RTDVMFMTOPS::pfnVolumeQueryTableLocation */
896	static DECLCALLBACK(int) rtDvmFmtMbrVolumeQueryTableLocation(RTDVMVOLUMEFMT hVolFmt, uint64_t poffTable, uint64_t pcbTable)
897	{
898	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
899	*poffTable = pVol->pEntry->pSector->offOnDisk;
900	*pcbTable = RT_MAX(512, pVol->pVolMgr->pDisk->cbSector);
901	return VINF_SUCCESS;
902	}
903
904	/** @copydoc RTDVMFMTOPS::pfnVolumeGetIndex */
905	static DECLCALLBACK(uint32_t) rtDvmFmtMbrVolumeGetIndex(RTDVMVOLUMEFMT hVolFmt, RTDVMVOLIDX enmIndex)
906	{
907	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
908	switch (enmIndex)
909	{
910	case RTDVMVOLIDX_USER_VISIBLE:
911	return pVol->pEntry->idxVisible;
912	case RTDVMVOLIDX_ALL:
913	return pVol->pEntry->idxAll;
914	case RTDVMVOLIDX_IN_TABLE:
915	return pVol->pEntry->idxTable;
916	case RTDVMVOLIDX_LINUX:
917	return pVol->pEntry->idxLinux;
918
919	case RTDVMVOLIDX_INVALID:
920	case RTDVMVOLIDX_HOST:
921	case RTDVMVOLIDX_END:
922	case RTDVMVOLIDX_32BIT_HACK:
923	break;
924	/* no default! */
925	}
926	return UINT32_MAX;
927	}
928
929	/** @copydoc RTDVMFMTOPS::pfnVolumeQueryProp */
930	static DECLCALLBACK(int) rtDvmFmtMbrVolumeQueryProp(RTDVMVOLUMEFMT hVolFmt, RTDVMVOLPROP enmProperty,
931	void pvBuf, size_t cbBuf, size_t pcbBuf)
932	{
933	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
934	switch (enmProperty)
935	{
936	case RTDVMVOLPROP_MBR_FIRST_CYLINDER:
937	*pcbBuf = sizeof(uint16_t);
938	Assert(cbBuf >= *pcbBuf);
939	(uint16_t )pvBuf = pVol->pEntry->FirstChs.uCylinder;
940	return VINF_SUCCESS;
941	case RTDVMVOLPROP_MBR_LAST_CYLINDER:
942	*pcbBuf = sizeof(uint16_t);
943	Assert(cbBuf >= *pcbBuf);
944	(uint16_t )pvBuf = pVol->pEntry->LastChs.uCylinder;
945	return VINF_SUCCESS;
946
947	case RTDVMVOLPROP_MBR_FIRST_HEAD:
948	*pcbBuf = sizeof(uint8_t);
949	Assert(cbBuf >= *pcbBuf);
950	(uint8_t )pvBuf = pVol->pEntry->FirstChs.uHead;
951	return VINF_SUCCESS;
952	case RTDVMVOLPROP_MBR_LAST_HEAD:
953	*pcbBuf = sizeof(uint8_t);
954	Assert(cbBuf >= *pcbBuf);
955	(uint8_t )pvBuf = pVol->pEntry->LastChs.uHead;
956	return VINF_SUCCESS;
957
958	case RTDVMVOLPROP_MBR_FIRST_SECTOR:
959	*pcbBuf = sizeof(uint8_t);
960	Assert(cbBuf >= *pcbBuf);
961	(uint8_t )pvBuf = pVol->pEntry->FirstChs.uSector;
962	return VINF_SUCCESS;
963	case RTDVMVOLPROP_MBR_LAST_SECTOR:
964	*pcbBuf = sizeof(uint8_t);
965	Assert(cbBuf >= *pcbBuf);
966	(uint8_t )pvBuf = pVol->pEntry->LastChs.uSector;
967	return VINF_SUCCESS;
968
969	case RTDVMVOLPROP_MBR_TYPE:
970	*pcbBuf = sizeof(uint8_t);
971	Assert(cbBuf >= *pcbBuf);
972	(uint8_t )pvBuf = pVol->pEntry->bType;
973	return VINF_SUCCESS;
974
975	case RTDVMVOLPROP_GPT_TYPE:
976	case RTDVMVOLPROP_GPT_UUID:
977	return VERR_NOT_SUPPORTED;
978
979	case RTDVMVOLPROP_INVALID:
980	case RTDVMVOLPROP_END:
981	case RTDVMVOLPROP_32BIT_HACK:
982	break;
983	/* not default! */
984	}
985	RT_NOREF(cbBuf);
986	AssertFailed();
987	return VERR_NOT_SUPPORTED;
988	}
989
990	static DECLCALLBACK(int) rtDvmFmtMbrVolumeRead(RTDVMVOLUMEFMT hVolFmt, uint64_t off, void *pvBuf, size_t cbRead)
991	{
992	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
993	AssertReturn(off + cbRead <= pVol->pEntry->cbPart, VERR_INVALID_PARAMETER);
994
995	return rtDvmDiskRead(pVol->pVolMgr->pDisk, pVol->pEntry->offPart + off, pvBuf, cbRead);
996	}
997
998	static DECLCALLBACK(int) rtDvmFmtMbrVolumeWrite(RTDVMVOLUMEFMT hVolFmt, uint64_t off, const void *pvBuf, size_t cbWrite)
999	{
1000	PRTDVMVOLUMEFMTINTERNAL pVol = hVolFmt;
1001	AssertReturn(off + cbWrite <= pVol->pEntry->cbPart, VERR_INVALID_PARAMETER);
1002
1003	return rtDvmDiskWrite(pVol->pVolMgr->pDisk, pVol->pEntry->offPart + off, pvBuf, cbWrite);
1004	}
1005
1006	DECL_HIDDEN_CONST(const RTDVMFMTOPS) g_rtDvmFmtMbr =
1007	{
1008	/* pszFmt */
1009	"MBR",
1010	/* enmFormat */
1011	RTDVMFORMATTYPE_MBR,
1012	/* pfnProbe */
1013	rtDvmFmtMbrProbe,
1014	/* pfnOpen */
1015	rtDvmFmtMbrOpen,
1016	/* pfnInitialize */
1017	rtDvmFmtMbrInitialize,
1018	/* pfnClose */
1019	rtDvmFmtMbrClose,
1020	/* pfnQueryRangeUse */
1021	rtDvmFmtMbrQueryRangeUse,
1022	/* pfnQueryDiskUuid */
1023	rtDvmFmtMbrQueryDiskUuid,
1024	/* pfnGetValidVolumes */
1025	rtDvmFmtMbrGetValidVolumes,
1026	/* pfnGetMaxVolumes */
1027	rtDvmFmtMbrGetMaxVolumes,
1028	/* pfnQueryFirstVolume */
1029	rtDvmFmtMbrQueryFirstVolume,
1030	/* pfnQueryNextVolume */
1031	rtDvmFmtMbrQueryNextVolume,
1032	/* pfnQueryTableLocations */
1033	rtDvmFmtMbrQueryTableLocations,
1034	/* pfnVolumeClose */
1035	rtDvmFmtMbrVolumeClose,
1036	/* pfnVolumeGetSize */
1037	rtDvmFmtMbrVolumeGetSize,
1038	/* pfnVolumeQueryName */
1039	rtDvmFmtMbrVolumeQueryName,
1040	/* pfnVolumeGetType */
1041	rtDvmFmtMbrVolumeGetType,
1042	/* pfnVolumeGetFlags */
1043	rtDvmFmtMbrVolumeGetFlags,
1044	/* pfnVolumeQueryRange */
1045	rtDvmFmtMbrVolumeQueryRange,
1046	/* pfnVOlumeIsRangeIntersecting */
1047	rtDvmFmtMbrVolumeIsRangeIntersecting,
1048	/* pfnVolumeQueryTableLocation */
1049	rtDvmFmtMbrVolumeQueryTableLocation,
1050	/* pfnVolumeGetIndex */
1051	rtDvmFmtMbrVolumeGetIndex,
1052	/* pfnVolumeQueryProp */
1053	rtDvmFmtMbrVolumeQueryProp,
1054	/* pfnVolumeRead */
1055	rtDvmFmtMbrVolumeRead,
1056	/* pfnVolumeWrite */
1057	rtDvmFmtMbrVolumeWrite
1058	};
1059

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source: vbox/trunk/src/VBox/Runtime/common/dvm/dvmmbr.cpp@ 95841

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