diff options
Diffstat (limited to 'src/VBox/Runtime/common/fs/fatvfs.cpp')
| -rw-r--r-- | src/VBox/Runtime/common/fs/fatvfs.cpp | 6374 |
1 files changed, 6374 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/fs/fatvfs.cpp b/src/VBox/Runtime/common/fs/fatvfs.cpp new file mode 100644 index 00000000..e7cb5b46 --- /dev/null +++ b/src/VBox/Runtime/common/fs/fatvfs.cpp @@ -0,0 +1,6374 @@ +/* $Id: fatvfs.cpp $ */ +/** @file + * IPRT - FAT Virtual Filesystem. + */ + +/* + * Copyright (C) 2017-2023 Oracle and/or its affiliates. + * + * This file is part of VirtualBox base platform packages, as + * available from https://www.virtualbox.org. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, in version 3 of the + * License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <https://www.gnu.org/licenses>. + * + * The contents of this file may alternatively be used under the terms + * of the Common Development and Distribution License Version 1.0 + * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included + * in the VirtualBox distribution, in which case the provisions of the + * CDDL are applicable instead of those of the GPL. + * + * You may elect to license modified versions of this file under the + * terms and conditions of either the GPL or the CDDL or both. + * + * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 + */ + + +/********************************************************************************************************************************* +* Header Files * +*********************************************************************************************************************************/ +#define LOG_GROUP RTLOGGROUP_FS +#include "internal/iprt.h" +#include <iprt/fsvfs.h> + +#include <iprt/asm.h> +#include <iprt/assert.h> +#include <iprt/ctype.h> +#include <iprt/file.h> +#include <iprt/err.h> +#include <iprt/log.h> +#include <iprt/mem.h> +#include <iprt/path.h> +#include <iprt/poll.h> +#include <iprt/rand.h> +#include <iprt/string.h> +#include <iprt/sg.h> +#include <iprt/thread.h> +#include <iprt/uni.h> +#include <iprt/utf16.h> +#include <iprt/vfs.h> +#include <iprt/vfslowlevel.h> +#include <iprt/zero.h> +#include <iprt/formats/fat.h> + +#include "internal/fs.h" + + +/********************************************************************************************************************************* +* Defined Constants And Macros * +*********************************************************************************************************************************/ +/** + * Gets the cluster from a directory entry. + * + * @param a_pDirEntry Pointer to the directory entry. + * @param a_pVol Pointer to the volume. + */ +#define RTFSFAT_GET_CLUSTER(a_pDirEntry, a_pVol) \ + ( (a_pVol)->enmFatType >= RTFSFATTYPE_FAT32 \ + ? RT_MAKE_U32((a_pDirEntry)->idxCluster, (a_pDirEntry)->u.idxClusterHigh) \ + : (a_pDirEntry)->idxCluster ) + +/** + * Rotates a unsigned 8-bit value one bit to the right. + * + * @returns Rotated 8-bit value. + * @param a_bValue The value to rotate. + */ +#define RTFSFAT_ROT_R1_U8(a_bValue) (((a_bValue) >> 1) | (uint8_t)((a_bValue) << 7)) + + +/** Maximum number of characters we will create in a long file name. */ +#define RTFSFAT_MAX_LFN_CHARS 255 + + +/********************************************************************************************************************************* +* Structures and Typedefs * +*********************************************************************************************************************************/ +/** Pointer to a FAT directory instance. */ +typedef struct RTFSFATDIRSHRD *PRTFSFATDIRSHRD; +/** Pointer to a FAT volume (VFS instance data). */ +typedef struct RTFSFATVOL *PRTFSFATVOL; + + +/** The number of entire in a chain part. */ +#define RTFSFATCHAINPART_ENTRIES (256U - 4U) + +/** + * A part of the cluster chain covering up to 252 clusters. + */ +typedef struct RTFSFATCHAINPART +{ + /** List entry. */ + RTLISTNODE ListEntry; + /** Chain entries. */ + uint32_t aEntries[RTFSFATCHAINPART_ENTRIES]; +} RTFSFATCHAINPART; +AssertCompile(sizeof(RTFSFATCHAINPART) <= _1K); +typedef RTFSFATCHAINPART *PRTFSFATCHAINPART; +typedef RTFSFATCHAINPART const *PCRTFSFATCHAINPART; + + +/** + * A FAT cluster chain. + */ +typedef struct RTFSFATCHAIN +{ + /** The chain size in bytes. */ + uint32_t cbChain; + /** The chain size in entries. */ + uint32_t cClusters; + /** The cluster size. */ + uint32_t cbCluster; + /** The shift count for converting between clusters and bytes. */ + uint8_t cClusterByteShift; + /** List of chain parts (RTFSFATCHAINPART). */ + RTLISTANCHOR ListParts; +} RTFSFATCHAIN; +/** Pointer to a FAT chain. */ +typedef RTFSFATCHAIN *PRTFSFATCHAIN; +/** Pointer to a const FAT chain. */ +typedef RTFSFATCHAIN const *PCRTFSFATCHAIN; + + +/** + * FAT file system object (common part to files and dirs (shared)). + */ +typedef struct RTFSFATOBJ +{ + /** The parent directory keeps a list of open objects (RTFSFATOBJ). */ + RTLISTNODE Entry; + /** Reference counter. */ + uint32_t volatile cRefs; + /** The parent directory (not released till all children are close). */ + PRTFSFATDIRSHRD pParentDir; + /** The byte offset of the directory entry in the parent dir. + * This is set to UINT32_MAX for the root directory. */ + uint32_t offEntryInDir; + /** Attributes. */ + RTFMODE fAttrib; + /** The object size. */ + uint32_t cbObject; + /** The access time. */ + RTTIMESPEC AccessTime; + /** The modificaton time. */ + RTTIMESPEC ModificationTime; + /** The birth time. */ + RTTIMESPEC BirthTime; + /** Cluster chain. */ + RTFSFATCHAIN Clusters; + /** Pointer to the volume. */ + struct RTFSFATVOL *pVol; + /** Set if we've maybe dirtied the FAT. */ + bool fMaybeDirtyFat; + /** Set if we've maybe dirtied the directory entry. */ + bool fMaybeDirtyDirEnt; +} RTFSFATOBJ; +/** Poitner to a FAT file system object. */ +typedef RTFSFATOBJ *PRTFSFATOBJ; + +/** + * Shared FAT file data. + */ +typedef struct RTFSFATFILESHRD +{ + /** Core FAT object info. */ + RTFSFATOBJ Core; +} RTFSFATFILESHRD; +/** Pointer to shared FAT file data. */ +typedef RTFSFATFILESHRD *PRTFSFATFILESHRD; + + +/** + * Per handle data for a FAT file. + */ +typedef struct RTFSFATFILE +{ + /** Pointer to the shared data. */ + PRTFSFATFILESHRD pShared; + /** The current file offset. */ + uint32_t offFile; +} RTFSFATFILE; +/** Pointer to the per handle data of a FAT file. */ +typedef RTFSFATFILE *PRTFSFATFILE; + + +/** + * FAT shared directory structure. + * + * We work directories in one of two buffering modes. If there are few entries + * or if it's the FAT12/16 root directory, we map the whole thing into memory. + * If it's too large, we use an inefficient sector buffer for now. + * + * Directory entry updates happens exclusively via the directory, so any open + * files or subdirs have a parent reference for doing that. The parent OTOH, + * keeps a list of open children. + */ +typedef struct RTFSFATDIRSHRD +{ + /** Core FAT object info. */ + RTFSFATOBJ Core; + /** Open child objects (RTFSFATOBJ). */ + RTLISTNODE OpenChildren; + + /** Number of directory entries. */ + uint32_t cEntries; + + /** If fully buffered. */ + bool fFullyBuffered; + /** Set if this is a linear root directory. */ + bool fIsLinearRootDir; + /** The size of the memory paEntries points at. */ + uint32_t cbAllocatedForEntries; + + /** Pointer to the directory buffer. + * In fully buffering mode, this is the whole of the directory. Otherwise it's + * just a sector worth of buffers. */ + PFATDIRENTRYUNION paEntries; + /** The disk offset corresponding to what paEntries points to. + * UINT64_MAX if notthing read into paEntries yet. */ + uint64_t offEntriesOnDisk; + union + { + /** Data for the full buffered mode. + * No need to messing around with clusters here, as we only uses this for + * directories with a contiguous mapping on the disk. + * So, if we grow a directory in a non-contiguous manner, we have to switch + * to sector buffering on the fly. */ + struct + { + /** Number of sectors mapped by paEntries and pbDirtySectors. */ + uint32_t cSectors; + /** Number of dirty sectors. */ + uint32_t cDirtySectors; + /** Dirty sector bitmap (one bit per sector). */ + uint8_t *pbDirtySectors; + } Full; + /** The simple sector buffering. + * This only works for clusters, so no FAT12/16 root directory fun. */ + struct + { + /** The directory offset, UINT32_MAX if invalid. */ + uint32_t offInDir; + /** Dirty flag. */ + bool fDirty; + } Simple; + } u; +} RTFSFATDIRSHRD; +/** Pointer to a shared FAT directory instance. */ +typedef RTFSFATDIRSHRD *PRTFSFATDIRSHRD; + + +/** + * The per handle FAT directory data. + */ +typedef struct RTFSFATDIR +{ + /** Core FAT object info. */ + PRTFSFATDIRSHRD pShared; + /** The current directory offset. */ + uint32_t offDir; +} RTFSFATDIR; +/** Pointer to a per handle FAT directory data. */ +typedef RTFSFATDIR *PRTFSFATDIR; + + +/** + * File allocation table cache entry. + */ +typedef struct RTFSFATCLUSTERMAPENTRY +{ + /** The byte offset into the fat, UINT32_MAX if invalid entry. */ + uint32_t offFat; + /** Pointer to the data. */ + uint8_t *pbData; + /** Dirty bitmap. Indexed by byte offset right shifted by + * RTFSFATCLUSTERMAPCACHE::cDirtyShift. */ + uint64_t bmDirty; +} RTFSFATCLUSTERMAPENTRY; +/** Pointer to a file allocation table cache entry. */ +typedef RTFSFATCLUSTERMAPENTRY *PRTFSFATCLUSTERMAPENTRY; + +/** + * File allocation table cache. + */ +typedef struct RTFSFATCLUSTERMAPCACHE +{ + /** Number of cache entries (power of two). */ + uint32_t cEntries; + /** This shift count to use in the first step of the index calculation. */ + uint32_t cEntryIndexShift; + /** The AND mask to use in the second step of the index calculation. */ + uint32_t fEntryIndexMask; + /** The max size of data in a cache entry (power of two). */ + uint32_t cbEntry; + /** The AND mask to use to get the entry offset. */ + uint32_t fEntryOffsetMask; + /** Dirty bitmap shift count. */ + uint32_t cDirtyShift; + /** The dirty cache line size (multiple of two). */ + uint32_t cbDirtyLine; + /** The FAT size. */ + uint32_t cbFat; + /** The Number of clusters in the FAT. */ + uint32_t cClusters; + /** Cluster allocation search hint. */ + uint32_t idxAllocHint; + /** Pointer to the volume (for disk access). */ + PRTFSFATVOL pVol; + /** The cache name. */ + const char *pszName; + /** Cache entries. */ + RT_FLEXIBLE_ARRAY_EXTENSION + RTFSFATCLUSTERMAPENTRY aEntries[RT_FLEXIBLE_ARRAY]; +} RTFSFATCLUSTERMAPCACHE; +/** Pointer to a FAT linear metadata cache. */ +typedef RTFSFATCLUSTERMAPCACHE *PRTFSFATCLUSTERMAPCACHE; + + +/** + * BPB version. + */ +typedef enum RTFSFATBPBVER +{ + RTFSFATBPBVER_INVALID = 0, + RTFSFATBPBVER_NO_BPB, + RTFSFATBPBVER_DOS_2_0, + //RTFSFATBPBVER_DOS_3_2, - we don't try identify this one. + RTFSFATBPBVER_DOS_3_31, + RTFSFATBPBVER_EXT_28, + RTFSFATBPBVER_EXT_29, + RTFSFATBPBVER_FAT32_28, + RTFSFATBPBVER_FAT32_29, + RTFSFATBPBVER_END +} RTFSFATBPBVER; + + +/** + * A FAT volume. + */ +typedef struct RTFSFATVOL +{ + /** Handle to itself. */ + RTVFS hVfsSelf; + /** The file, partition, or whatever backing the FAT volume. */ + RTVFSFILE hVfsBacking; + /** The size of the backing thingy. */ + uint64_t cbBacking; + /** Byte offset of the bootsector relative to the start of the file. */ + uint64_t offBootSector; + /** The UTC offset in nanoseconds to use for this file system (FAT traditionally + * stores timestamps in local time). + * @remarks This may need improving later. */ + int64_t offNanoUTC; + /** The UTC offset in minutes to use for this file system (FAT traditionally + * stores timestamps in local time). + * @remarks This may need improving later. */ + int32_t offMinUTC; + /** Set if read-only mode. */ + bool fReadOnly; + /** Media byte. */ + uint8_t bMedia; + /** Reserved sectors. */ + uint32_t cReservedSectors; + /** The BPB version. Gives us an idea of the FAT file system version. */ + RTFSFATBPBVER enmBpbVersion; + + /** Logical sector size. */ + uint32_t cbSector; + /** The shift count for converting between sectors and bytes. */ + uint8_t cSectorByteShift; + /** The shift count for converting between clusters and bytes. */ + uint8_t cClusterByteShift; + /** The cluster size in bytes. */ + uint32_t cbCluster; + /** The number of data clusters, including the two reserved ones. */ + uint32_t cClusters; + /** The offset of the first cluster. */ + uint64_t offFirstCluster; + /** The total size from the BPB, in bytes. */ + uint64_t cbTotalSize; + + /** The FAT type. */ + RTFSFATTYPE enmFatType; + + /** Number of FAT entries (clusters). */ + uint32_t cFatEntries; + /** The size of a FAT, in bytes. */ + uint32_t cbFat; + /** Number of FATs. */ + uint32_t cFats; + /** The end of chain marker used by the formatter (FAT entry \#2). */ + uint32_t idxEndOfChain; + /** The maximum last cluster supported by the FAT format. */ + uint32_t idxMaxLastCluster; + /** FAT byte offsets. */ + uint64_t aoffFats[8]; + /** Pointer to the FAT (cluster map) cache. */ + PRTFSFATCLUSTERMAPCACHE pFatCache; + + /** The root directory byte offset. */ + uint64_t offRootDir; + /** Root directory cluster, UINT32_MAX if not FAT32. */ + uint32_t idxRootDirCluster; + /** Number of root directory entries, if fixed. UINT32_MAX for FAT32. */ + uint32_t cRootDirEntries; + /** The size of the root directory, rounded up to the nearest sector size. */ + uint32_t cbRootDir; + /** The root directory data (shared). */ + PRTFSFATDIRSHRD pRootDir; + + /** Serial number. */ + uint32_t uSerialNo; + /** The stripped volume label, if included in EBPB. */ + char szLabel[12]; + /** The file system type from the EBPB (also stripped). */ + char szType[9]; + /** Number of FAT32 boot sector copies. */ + uint8_t cBootSectorCopies; + /** FAT32 flags. */ + uint16_t fFat32Flags; + /** Offset of the FAT32 boot sector copies, UINT64_MAX if none. */ + uint64_t offBootSectorCopies; + + /** The FAT32 info sector byte offset, UINT64_MAX if not present. */ + uint64_t offFat32InfoSector; + /** The FAT32 info sector if offFat32InfoSector isn't UINT64_MAX. */ + FAT32INFOSECTOR Fat32InfoSector; +} RTFSFATVOL; +/** Pointer to a const FAT volume (VFS instance data). */ +typedef RTFSFATVOL const *PCRTFSFATVOL; + + + +/********************************************************************************************************************************* +* Global Variables * +*********************************************************************************************************************************/ +/** + * Codepage 437 translation table with invalid 8.3 characters marked as 0xffff or 0xfffe. + * + * The 0xfffe notation is used for characters that are valid in long file names but not short. + * + * @remarks The valid first 128 entries are 1:1 with unicode. + * @remarks Lower case characters are all marked invalid. + */ +static RTUTF16 g_awchFatCp437ValidChars[] = +{ /* 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f */ + 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, + 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, + 0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0xffff, 0xfffe, 0xfffe, 0x002d, 0xfffe, 0xffff, + 0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, 0x0038, 0x0039, 0xffff, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xffff, + 0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f, + 0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 0x0058, 0x0059, 0x005a, 0xfffe, 0xffff, 0xfffe, 0x005e, 0x005f, + 0x0060, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, + 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xfffe, 0xffff, 0xffff, 0xffff, 0x007e, 0xffff, + 0x00c7, 0x00fc, 0x00e9, 0x00e2, 0x00e4, 0x00e0, 0x00e5, 0x00e7, 0x00ea, 0x00eb, 0x00e8, 0x00ef, 0x00ee, 0x00ec, 0x00c4, 0x00c5, + 0x00c9, 0x00e6, 0x00c6, 0x00f4, 0x00f6, 0x00f2, 0x00fb, 0x00f9, 0x00ff, 0x00d6, 0x00dc, 0x00a2, 0x00a3, 0x00a5, 0x20a7, 0x0192, + 0x00e1, 0x00ed, 0x00f3, 0x00fa, 0x00f1, 0x00d1, 0x00aa, 0x00ba, 0x00bf, 0x2310, 0x00ac, 0x00bd, 0x00bc, 0x00a1, 0x00ab, 0x00bb, + 0x2591, 0x2592, 0x2593, 0x2502, 0x2524, 0x2561, 0x2562, 0x2556, 0x2555, 0x2563, 0x2551, 0x2557, 0x255d, 0x255c, 0x255b, 0x2510, + 0x2514, 0x2534, 0x252c, 0x251c, 0x2500, 0x253c, 0x255e, 0x255f, 0x255a, 0x2554, 0x2569, 0x2566, 0x2560, 0x2550, 0x256c, 0x2567, + 0x2568, 0x2564, 0x2565, 0x2559, 0x2558, 0x2552, 0x2553, 0x256b, 0x256a, 0x2518, 0x250c, 0x2588, 0x2584, 0x258c, 0x2590, 0x2580, + 0x03b1, 0x00df, 0x0393, 0x03c0, 0x03a3, 0x03c3, 0x00b5, 0x03c4, 0x03a6, 0x0398, 0x03a9, 0x03b4, 0x221e, 0x03c6, 0x03b5, 0x2229, + 0x2261, 0x00b1, 0x2265, 0x2264, 0x2320, 0x2321, 0x00f7, 0x2248, 0x00b0, 0x2219, 0x00b7, 0x221a, 0x207f, 0x00b2, 0x25a0, 0x00a0 +}; +AssertCompileSize(g_awchFatCp437ValidChars, 256*2); + +/** + * Codepage 437 translation table without invalid 8.3. character markings. + */ +static RTUTF16 g_awchFatCp437Chars[] = +{ /* 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f */ + 0x0000, 0x263a, 0x263b, 0x2665, 0x2666, 0x2663, 0x2660, 0x2022, 0x25d8, 0x25cb, 0x25d9, 0x2642, 0x2640, 0x266a, 0x266b, 0x263c, + 0x25ba, 0x25c4, 0x2195, 0x203c, 0x00b6, 0x00a7, 0x25ac, 0x21a8, 0x2191, 0x2193, 0x2192, 0x2190, 0x221f, 0x2194, 0x25b2, 0x25bc, + 0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f, + 0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f, + 0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047, 0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f, + 0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f, + 0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f, + 0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007a, 0x007b, 0x007c, 0x007d, 0x007e, 0x2302, + 0x00c7, 0x00fc, 0x00e9, 0x00e2, 0x00e4, 0x00e0, 0x00e5, 0x00e7, 0x00ea, 0x00eb, 0x00e8, 0x00ef, 0x00ee, 0x00ec, 0x00c4, 0x00c5, + 0x00c9, 0x00e6, 0x00c6, 0x00f4, 0x00f6, 0x00f2, 0x00fb, 0x00f9, 0x00ff, 0x00d6, 0x00dc, 0x00a2, 0x00a3, 0x00a5, 0x20a7, 0x0192, + 0x00e1, 0x00ed, 0x00f3, 0x00fa, 0x00f1, 0x00d1, 0x00aa, 0x00ba, 0x00bf, 0x2310, 0x00ac, 0x00bd, 0x00bc, 0x00a1, 0x00ab, 0x00bb, + 0x2591, 0x2592, 0x2593, 0x2502, 0x2524, 0x2561, 0x2562, 0x2556, 0x2555, 0x2563, 0x2551, 0x2557, 0x255d, 0x255c, 0x255b, 0x2510, + 0x2514, 0x2534, 0x252c, 0x251c, 0x2500, 0x253c, 0x255e, 0x255f, 0x255a, 0x2554, 0x2569, 0x2566, 0x2560, 0x2550, 0x256c, 0x2567, + 0x2568, 0x2564, 0x2565, 0x2559, 0x2558, 0x2552, 0x2553, 0x256b, 0x256a, 0x2518, 0x250c, 0x2588, 0x2584, 0x258c, 0x2590, 0x2580, + 0x03b1, 0x00df, 0x0393, 0x03c0, 0x03a3, 0x03c3, 0x00b5, 0x03c4, 0x03a6, 0x0398, 0x03a9, 0x03b4, 0x221e, 0x03c6, 0x03b5, 0x2229, + 0x2261, 0x00b1, 0x2265, 0x2264, 0x2320, 0x2321, 0x00f7, 0x2248, 0x00b0, 0x2219, 0x00b7, 0x221a, 0x207f, 0x00b2, 0x25a0, 0x00a0 +}; +AssertCompileSize(g_awchFatCp437Chars, 256*2); + + +/********************************************************************************************************************************* +* Internal Functions * +*********************************************************************************************************************************/ +static PRTFSFATOBJ rtFsFatDirShrd_LookupShared(PRTFSFATDIRSHRD pThis, uint32_t offEntryInDir); +static void rtFsFatDirShrd_AddOpenChild(PRTFSFATDIRSHRD pDir, PRTFSFATOBJ pChild); +static void rtFsFatDirShrd_RemoveOpenChild(PRTFSFATDIRSHRD pDir, PRTFSFATOBJ pChild); +static int rtFsFatDirShrd_GetEntryForUpdate(PRTFSFATDIRSHRD pThis, uint32_t offEntryInDir, + PFATDIRENTRY *ppDirEntry, uint32_t *puWriteLock); +static int rtFsFatDirShrd_PutEntryAfterUpdate(PRTFSFATDIRSHRD pThis, PFATDIRENTRY pDirEntry, uint32_t uWriteLock); +static int rtFsFatDirShrd_Flush(PRTFSFATDIRSHRD pThis); +static int rtFsFatDir_NewWithShared(PRTFSFATVOL pThis, PRTFSFATDIRSHRD pShared, PRTVFSDIR phVfsDir); +static int rtFsFatDir_New(PRTFSFATVOL pThis, PRTFSFATDIRSHRD pParentDir, PCFATDIRENTRY pDirEntry, uint32_t offEntryInDir, + uint32_t idxCluster, uint64_t offDisk, uint32_t cbDir, PRTVFSDIR phVfsDir); + + +/** + * Convers a cluster to a disk offset. + * + * @returns Disk byte offset, UINT64_MAX on invalid cluster. + * @param pThis The FAT volume instance. + * @param idxCluster The cluster number. + */ +DECLINLINE(uint64_t) rtFsFatClusterToDiskOffset(PRTFSFATVOL pThis, uint32_t idxCluster) +{ + AssertReturn(idxCluster >= FAT_FIRST_DATA_CLUSTER, UINT64_MAX); + AssertReturn(idxCluster < pThis->cClusters, UINT64_MAX); + return (idxCluster - FAT_FIRST_DATA_CLUSTER) * (uint64_t)pThis->cbCluster + + pThis->offFirstCluster; +} + + +#ifdef RT_STRICT +/** + * Assert chain consistency. + */ +static bool rtFsFatChain_AssertValid(PCRTFSFATCHAIN pChain) +{ + bool fRc = true; + uint32_t cParts = 0; + PRTFSFATCHAINPART pPart; + RTListForEach(&pChain->ListParts, pPart, RTFSFATCHAINPART, ListEntry) + cParts++; + + uint32_t cExpected = (pChain->cClusters + RTFSFATCHAINPART_ENTRIES - 1) / RTFSFATCHAINPART_ENTRIES; + AssertMsgStmt(cExpected == cParts, ("cExpected=%#x cParts=%#x\n", cExpected, cParts), fRc = false); + AssertMsgStmt(pChain->cbChain == (pChain->cClusters << pChain->cClusterByteShift), + ("cExpected=%#x cParts=%#x\n", cExpected, cParts), fRc = false); + return fRc; +} +#endif /* RT_STRICT */ + + +/** + * Initializes an empty cluster chain. + * + * @param pChain The chain. + * @param pVol The volume. + */ +static void rtFsFatChain_InitEmpty(PRTFSFATCHAIN pChain, PRTFSFATVOL pVol) +{ + pChain->cbCluster = pVol->cbCluster; + pChain->cClusterByteShift = pVol->cClusterByteShift; + pChain->cbChain = 0; + pChain->cClusters = 0; + RTListInit(&pChain->ListParts); +} + + +/** + * Deletes a chain, freeing it's resources. + * + * @param pChain The chain. + */ +static void rtFsFatChain_Delete(PRTFSFATCHAIN pChain) +{ + Assert(RT_IS_POWER_OF_TWO(pChain->cbCluster)); + Assert(RT_BIT_32(pChain->cClusterByteShift) == pChain->cbCluster); + + PRTFSFATCHAINPART pPart = RTListRemoveLast(&pChain->ListParts, RTFSFATCHAINPART, ListEntry); + while (pPart) + { + RTMemFree(pPart); + pPart = RTListRemoveLast(&pChain->ListParts, RTFSFATCHAINPART, ListEntry); + } + + pChain->cbChain = 0; + pChain->cClusters = 0; +} + + +/** + * Appends a cluster to a cluster chain. + * + * @returns IPRT status code. + * @param pChain The chain. + * @param idxCluster The cluster to append. + */ +static int rtFsFatChain_Append(PRTFSFATCHAIN pChain, uint32_t idxCluster) +{ + PRTFSFATCHAINPART pPart; + uint32_t idxLast = pChain->cClusters % RTFSFATCHAINPART_ENTRIES; + if (idxLast != 0) + pPart = RTListGetLast(&pChain->ListParts, RTFSFATCHAINPART, ListEntry); + else + { + pPart = (PRTFSFATCHAINPART)RTMemAllocZ(sizeof(*pPart)); + if (!pPart) + return VERR_NO_MEMORY; + RTListAppend(&pChain->ListParts, &pPart->ListEntry); + } + pPart->aEntries[idxLast] = idxCluster; + pChain->cClusters++; + pChain->cbChain += pChain->cbCluster; + return VINF_SUCCESS; +} + + +/** + * Reduces the number of clusters in the chain to @a cClusters. + * + * @param pChain The chain. + * @param cClustersNew The new cluster count. Must be equal or smaller to + * the current number of clusters. + */ +static void rtFsFatChain_Shrink(PRTFSFATCHAIN pChain, uint32_t cClustersNew) +{ + uint32_t cOldParts = (pChain->cClusters + RTFSFATCHAINPART_ENTRIES - 1) / RTFSFATCHAINPART_ENTRIES; + uint32_t cNewParts = (cClustersNew + RTFSFATCHAINPART_ENTRIES - 1) / RTFSFATCHAINPART_ENTRIES; + Assert(cOldParts >= cNewParts); + while (cOldParts-- > cNewParts) + RTMemFree(RTListRemoveLast(&pChain->ListParts, RTFSFATCHAINPART, ListEntry)); + pChain->cClusters = cClustersNew; + pChain->cbChain = cClustersNew << pChain->cClusterByteShift; + Assert(rtFsFatChain_AssertValid(pChain)); +} + + + +/** + * Converts a file offset to a disk offset. + * + * The disk offset is only valid until the end of the cluster it is within. + * + * @returns Disk offset. UINT64_MAX if invalid file offset. + * @param pChain The chain. + * @param offFile The file offset. + * @param pVol The volume. + */ +static uint64_t rtFsFatChain_FileOffsetToDiskOff(PCRTFSFATCHAIN pChain, uint32_t offFile, PCRTFSFATVOL pVol) +{ + uint32_t idxCluster = offFile >> pChain->cClusterByteShift; + if (idxCluster < pChain->cClusters) + { + PRTFSFATCHAINPART pPart = RTListGetFirst(&pChain->ListParts, RTFSFATCHAINPART, ListEntry); + while (idxCluster >= RTFSFATCHAINPART_ENTRIES) + { + idxCluster -= RTFSFATCHAINPART_ENTRIES; + pPart = RTListGetNext(&pChain->ListParts, pPart, RTFSFATCHAINPART, ListEntry); + } + return pVol->offFirstCluster + + ((uint64_t)(pPart->aEntries[idxCluster] - FAT_FIRST_DATA_CLUSTER) << pChain->cClusterByteShift) + + (offFile & (pChain->cbCluster - 1)); + } + return UINT64_MAX; +} + + +/** + * Checks if the cluster chain is contiguous on the disk. + * + * @returns true / false. + * @param pChain The chain. + */ +static bool rtFsFatChain_IsContiguous(PCRTFSFATCHAIN pChain) +{ + if (pChain->cClusters <= 1) + return true; + + PRTFSFATCHAINPART pPart = RTListGetFirst(&pChain->ListParts, RTFSFATCHAINPART, ListEntry); + uint32_t idxNext = pPart->aEntries[0]; + uint32_t cLeft = pChain->cClusters; + for (;;) + { + uint32_t const cInPart = RT_MIN(cLeft, RTFSFATCHAINPART_ENTRIES); + for (uint32_t iPart = 0; iPart < cInPart; iPart++) + if (pPart->aEntries[iPart] == idxNext) + idxNext++; + else + return false; + cLeft -= cInPart; + if (!cLeft) + return true; + pPart = RTListGetNext(&pChain->ListParts, pPart, RTFSFATCHAINPART, ListEntry); + } +} + + +/** + * Gets a cluster array index. + * + * This works the chain thing as an indexed array. + * + * @returns The cluster number, UINT32_MAX if out of bounds. + * @param pChain The chain. + * @param idx The index. + */ +static uint32_t rtFsFatChain_GetClusterByIndex(PCRTFSFATCHAIN pChain, uint32_t idx) +{ + if (idx < pChain->cClusters) + { + /* + * In the first part? + */ + PRTFSFATCHAINPART pPart; + if (idx < RTFSFATCHAINPART_ENTRIES) + { + pPart = RTListGetFirst(&pChain->ListParts, RTFSFATCHAINPART, ListEntry); + return pPart->aEntries[idx]; + } + + /* + * In the last part? + */ + uint32_t cParts = (pChain->cClusters + RTFSFATCHAINPART_ENTRIES - 1) / RTFSFATCHAINPART_ENTRIES; + uint32_t idxPart = idx / RTFSFATCHAINPART_ENTRIES; + uint32_t idxInPart = idx % RTFSFATCHAINPART_ENTRIES; + if (idxPart + 1 == cParts) + pPart = RTListGetLast(&pChain->ListParts, RTFSFATCHAINPART, ListEntry); + else + { + /* + * No, do linear search from the start, skipping the first part. + */ + pPart = RTListGetFirst(&pChain->ListParts, RTFSFATCHAINPART, ListEntry); + while (idxPart-- > 0) + pPart = RTListGetNext(&pChain->ListParts, pPart, RTFSFATCHAINPART, ListEntry); + } + + return pPart->aEntries[idxInPart]; + } + return UINT32_MAX; +} + + +/** + * Gets the first cluster. + * + * @returns The cluster number, UINT32_MAX if empty + * @param pChain The chain. + */ +static uint32_t rtFsFatChain_GetFirstCluster(PCRTFSFATCHAIN pChain) +{ + if (pChain->cClusters > 0) + { + PRTFSFATCHAINPART pPart = RTListGetFirst(&pChain->ListParts, RTFSFATCHAINPART, ListEntry); + return pPart->aEntries[0]; + } + return UINT32_MAX; +} + + + +/** + * Gets the last cluster. + * + * @returns The cluster number, UINT32_MAX if empty + * @param pChain The chain. + */ +static uint32_t rtFsFatChain_GetLastCluster(PCRTFSFATCHAIN pChain) +{ + if (pChain->cClusters > 0) + { + PRTFSFATCHAINPART pPart = RTListGetLast(&pChain->ListParts, RTFSFATCHAINPART, ListEntry); + return pPart->aEntries[(pChain->cClusters - 1) % RTFSFATCHAINPART_ENTRIES]; + } + return UINT32_MAX; +} + + +/** + * Creates a cache for the file allocation table (cluster map). + * + * @returns Pointer to the cache. + * @param pThis The FAT volume instance. + * @param pbFirst512FatBytes The first 512 bytes of the first FAT. + */ +static int rtFsFatClusterMap_Create(PRTFSFATVOL pThis, uint8_t const *pbFirst512FatBytes, PRTERRINFO pErrInfo) +{ + Assert(RT_ALIGN_32(pThis->cbFat, pThis->cbSector) == pThis->cbFat); + Assert(pThis->cbFat != 0); + + /* + * Figure the cache size. Keeping it _very_ simple for now as we just need + * something that works, not anything the performs like crazy. + * + * Note! Lowering the max cache size below 128KB will break ASSUMPTIONS in the FAT16 + * and eventually FAT12 code. + */ + uint32_t cEntries; + uint32_t cEntryIndexShift; + uint32_t fEntryIndexMask; + uint32_t cbEntry = pThis->cbFat; + uint32_t fEntryOffsetMask; + if (cbEntry <= _512K) + { + cEntries = 1; + cEntryIndexShift = 0; + fEntryIndexMask = 0; + fEntryOffsetMask = UINT32_MAX; + } + else + { + Assert(pThis->cbSector < _512K / 8); + cEntries = 8; + cEntryIndexShift = 9; + fEntryIndexMask = cEntries - 1; + AssertReturn(RT_IS_POWER_OF_TWO(cEntries), VERR_INTERNAL_ERROR_4); + + cbEntry = pThis->cbSector; + fEntryOffsetMask = pThis->cbSector - 1; + AssertReturn(RT_IS_POWER_OF_TWO(cbEntry), VERR_INTERNAL_ERROR_5); + } + + /* + * Allocate and initialize it all. + */ + PRTFSFATCLUSTERMAPCACHE pFatCache; + pFatCache = (PRTFSFATCLUSTERMAPCACHE)RTMemAllocZ(RT_UOFFSETOF_DYN(RTFSFATCLUSTERMAPCACHE, aEntries[cEntries])); + pThis->pFatCache = pFatCache; + if (!pFatCache) + return RTErrInfoSet(pErrInfo, VERR_NO_MEMORY, "Failed to allocate FAT cache"); + pFatCache->cEntries = cEntries; + pFatCache->fEntryIndexMask = fEntryIndexMask; + pFatCache->cEntryIndexShift = cEntryIndexShift; + pFatCache->cbEntry = cbEntry; + pFatCache->fEntryOffsetMask = fEntryOffsetMask; + pFatCache->pVol = pThis; + pFatCache->cbFat = pThis->cbFat; + pFatCache->cClusters = pThis->cClusters; + + unsigned i = cEntries; + while (i-- > 0) + { + pFatCache->aEntries[i].pbData = (uint8_t *)RTMemAlloc(cbEntry); + if (pFatCache->aEntries[i].pbData == NULL) + { + for (i++; i < cEntries; i++) + RTMemFree(pFatCache->aEntries[i].pbData); + RTMemFree(pFatCache); + return RTErrInfoSetF(pErrInfo, VERR_NO_MEMORY, "Failed to allocate FAT cache entry (%#x bytes)", cbEntry); + } + + pFatCache->aEntries[i].offFat = UINT32_MAX; + pFatCache->aEntries[i].bmDirty = 0; + } + Log3(("rtFsFatClusterMap_Create: cbFat=%#RX32 cEntries=%RU32 cEntryIndexShift=%RU32 fEntryIndexMask=%#RX32\n", + pFatCache->cbFat, pFatCache->cEntries, pFatCache->cEntryIndexShift, pFatCache->fEntryIndexMask)); + Log3(("rtFsFatClusterMap_Create: cbEntries=%#RX32 fEntryOffsetMask=%#RX32\n", pFatCache->cbEntry, pFatCache->fEntryOffsetMask)); + + /* + * Calc the dirty shift factor. + */ + cbEntry /= 64; + if (cbEntry < pThis->cbSector) + cbEntry = pThis->cbSector; + + pFatCache->cDirtyShift = 1; + pFatCache->cbDirtyLine = 1; + while (pFatCache->cbDirtyLine < cbEntry) + { + pFatCache->cDirtyShift++; + pFatCache->cbDirtyLine <<= 1; + } + Assert(pFatCache->cEntries == 1 || pFatCache->cbDirtyLine == pThis->cbSector); + Log3(("rtFsFatClusterMap_Create: cbDirtyLine=%#RX32 cDirtyShift=%u\n", pFatCache->cbDirtyLine, pFatCache->cDirtyShift)); + + /* + * Fill the cache if single entry or entry size is 512. + */ + if (pFatCache->cEntries == 1 || pFatCache->cbEntry == 512) + { + memcpy(pFatCache->aEntries[0].pbData, pbFirst512FatBytes, RT_MIN(512, pFatCache->cbEntry)); + if (pFatCache->cbEntry > 512) + { + int rc = RTVfsFileReadAt(pThis->hVfsBacking, pThis->aoffFats[0] + 512, + &pFatCache->aEntries[0].pbData[512], pFatCache->cbEntry - 512, NULL); + if (RT_FAILURE(rc)) + return RTErrInfoSet(pErrInfo, rc, "Error reading FAT into memory"); + } + pFatCache->aEntries[0].offFat = 0; + pFatCache->aEntries[0].bmDirty = 0; + } + + return VINF_SUCCESS; +} + + +/** + * Worker for rtFsFatClusterMap_Flush and rtFsFatClusterMap_FlushEntry. + * + * @returns IPRT status code. On failure, we're currently kind of screwed. + * @param pThis The FAT volume instance. + * @param iFirstEntry Entry to start flushing at. + * @param iLastEntry Last entry to flush. + */ +static int rtFsFatClusterMap_FlushWorker(PRTFSFATVOL pThis, uint32_t const iFirstEntry, uint32_t const iLastEntry) +{ + PRTFSFATCLUSTERMAPCACHE pFatCache = pThis->pFatCache; + Log3(("rtFsFatClusterMap_FlushWorker: %p %#x %#x\n", pThis, iFirstEntry, iLastEntry)); + + /* + * Walk the cache entries, accumulating segments to flush. + */ + int rc = VINF_SUCCESS; + uint64_t off = UINT64_MAX; + uint64_t offEdge = UINT64_MAX; + RTSGSEG aSgSegs[8]; + RT_ZERO(aSgSegs); /* Initialization required for GCC >= 11. */ + RTSGBUF SgBuf; + RTSgBufInit(&SgBuf, aSgSegs, RT_ELEMENTS(aSgSegs)); + SgBuf.cSegs = 0; /** @todo RTSgBuf API is stupid, make it smarter. */ + + for (uint32_t iFatCopy = 0; iFatCopy < pThis->cFats; iFatCopy++) + { + for (uint32_t iEntry = iFirstEntry; iEntry <= iLastEntry; iEntry++) + { + uint64_t bmDirty = pFatCache->aEntries[iEntry].bmDirty; + if ( bmDirty != 0 + && pFatCache->aEntries[iEntry].offFat != UINT32_MAX) + { + uint32_t offEntry = 0; + uint64_t iDirtyLine = 1; + while (offEntry < pFatCache->cbEntry) + { + if (pFatCache->aEntries[iEntry].bmDirty & iDirtyLine) + { + /* + * Found dirty cache line. + */ + uint64_t offDirtyLine = pThis->aoffFats[iFatCopy] + pFatCache->aEntries[iEntry].offFat + offEntry; + + /* Can we simply extend the last segment? */ + if ( offDirtyLine == offEdge + && offEntry) + { + Assert(SgBuf.cSegs > 0); + Assert( (uintptr_t)aSgSegs[SgBuf.cSegs - 1].pvSeg + aSgSegs[SgBuf.cSegs - 1].cbSeg + == (uintptr_t)&pFatCache->aEntries[iEntry].pbData[offEntry]); + aSgSegs[SgBuf.cSegs - 1].cbSeg += pFatCache->cbDirtyLine; + offEdge += pFatCache->cbDirtyLine; + } + else + { + /* Starting new job? */ + if (off == UINT64_MAX) + { + off = offDirtyLine; + Assert(SgBuf.cSegs == 0); + } + /* flush if not adjacent or if we're out of segments. */ + else if ( offDirtyLine != offEdge + || SgBuf.cSegs >= RT_ELEMENTS(aSgSegs)) + { + int rc2 = RTVfsFileSgWrite(pThis->hVfsBacking, off, &SgBuf, true /*fBlocking*/, NULL); + if (RT_FAILURE(rc2) && RT_SUCCESS(rc)) + rc = rc2; + RTSgBufReset(&SgBuf); + SgBuf.cSegs = 0; + off = offDirtyLine; + } + + /* Append segment. */ + aSgSegs[SgBuf.cSegs].cbSeg = pFatCache->cbDirtyLine; + aSgSegs[SgBuf.cSegs].pvSeg = &pFatCache->aEntries[iEntry].pbData[offEntry]; + SgBuf.cSegs++; + offEdge = offDirtyLine + pFatCache->cbDirtyLine; + } + + bmDirty &= ~iDirtyLine; + if (!bmDirty) + break; + } + iDirtyLine <<= 1; + offEntry += pFatCache->cbDirtyLine; + } + Assert(!bmDirty); + } + } + } + + /* + * Final flush job. + */ + if (SgBuf.cSegs > 0) + { + int rc2 = RTVfsFileSgWrite(pThis->hVfsBacking, off, &SgBuf, true /*fBlocking*/, NULL); + if (RT_FAILURE(rc2) && RT_SUCCESS(rc)) + rc = rc2; + } + + /* + * Clear the dirty flags on success. + */ + if (RT_SUCCESS(rc)) + for (uint32_t iEntry = iFirstEntry; iEntry <= iLastEntry; iEntry++) + pFatCache->aEntries[iEntry].bmDirty = 0; + + return rc; +} + + +/** + * Flushes out all dirty lines in the entire file allocation table cache. + * + * @returns IPRT status code. On failure, we're currently kind of screwed. + * @param pThis The FAT volume instance. + */ +static int rtFsFatClusterMap_Flush(PRTFSFATVOL pThis) +{ + return rtFsFatClusterMap_FlushWorker(pThis, 0, pThis->pFatCache->cEntries - 1); +} + + +/** + * Flushes out all dirty lines in the file allocation table (cluster map) cache + * entry. + * + * This is typically called prior to reusing the cache entry. + * + * @returns IPRT status code. On failure, we're currently kind of screwed. + * @param pFatCache The FAT cache + * @param iEntry The cache entry to flush. + */ +static int rtFsFatClusterMap_FlushEntry(PRTFSFATCLUSTERMAPCACHE pFatCache, uint32_t iEntry) +{ + return rtFsFatClusterMap_FlushWorker(pFatCache->pVol, iEntry, iEntry); +} + + +/** + * Gets a pointer to a FAT entry. + * + * @returns IPRT status code. On failure, we're currently kind of screwed. + * @param pFatCache The FAT cache. + * @param offFat The FAT byte offset to get the entry off. + * @param ppbEntry Where to return the pointer to the entry. + */ +static int rtFsFatClusterMap_GetEntry(PRTFSFATCLUSTERMAPCACHE pFatCache, uint32_t offFat, uint8_t **ppbEntry) +{ + int rc; + if (offFat < pFatCache->cbFat) + { + uint32_t const iEntry = (offFat >> pFatCache->cEntryIndexShift) & pFatCache->fEntryIndexMask; + uint32_t const offInEntry = offFat & pFatCache->fEntryOffsetMask; + uint32_t const offFatEntry = offFat - offInEntry; + + *ppbEntry = pFatCache->aEntries[iEntry].pbData + offInEntry; + + /* If it's already ready, return immediately. */ + if (pFatCache->aEntries[iEntry].offFat == offFatEntry) + { + Log3(("rtFsFatClusterMap_GetEntry: Hit entry %u for offFat=%#RX32\n", iEntry, offFat)); + return VINF_SUCCESS; + } + + /* Do we need to flush it? */ + rc = VINF_SUCCESS; + if ( pFatCache->aEntries[iEntry].bmDirty != 0 + && pFatCache->aEntries[iEntry].offFat != UINT32_MAX) + { + Log3(("rtFsFatClusterMap_GetEntry: Flushing entry %u for offFat=%#RX32\n", iEntry, offFat)); + rc = rtFsFatClusterMap_FlushEntry(pFatCache, iEntry); + } + if (RT_SUCCESS(rc)) + { + pFatCache->aEntries[iEntry].bmDirty = 0; + + /* Read in the entry from disk */ + rc = RTVfsFileReadAt(pFatCache->pVol->hVfsBacking, pFatCache->pVol->aoffFats[0] + offFatEntry, + pFatCache->aEntries[iEntry].pbData, pFatCache->cbEntry, NULL); + if (RT_SUCCESS(rc)) + { + Log3(("rtFsFatClusterMap_GetEntry: Loaded entry %u for offFat=%#RX32\n", iEntry, offFat)); + pFatCache->aEntries[iEntry].offFat = offFatEntry; + return VINF_SUCCESS; + } + /** @todo We can try other FAT copies here... */ + LogRel(("rtFsFatClusterMap_GetEntry: Error loading entry %u for offFat=%#RX32 (%#64RX32 LB %#x): %Rrc\n", + iEntry, offFat, pFatCache->pVol->aoffFats[0] + offFatEntry, pFatCache->cbEntry, rc)); + pFatCache->aEntries[iEntry].offFat = UINT32_MAX; + } + } + else + rc = VERR_OUT_OF_RANGE; + *ppbEntry = NULL; + return rc; +} + + +/** + * Gets a pointer to a FAT entry, extended version. + * + * @returns IPRT status code. On failure, we're currently kind of screwed. + * @param pFatCache The FAT cache. + * @param offFat The FAT byte offset to get the entry off. + * @param ppbEntry Where to return the pointer to the entry. + * @param pidxEntry Where to return the entry index. + */ +static int rtFsFatClusterMap_GetEntryEx(PRTFSFATCLUSTERMAPCACHE pFatCache, uint32_t offFat, + uint8_t **ppbEntry, uint32_t *pidxEntry) +{ + int rc; + if (offFat < pFatCache->cbFat) + { + uint32_t const iEntry = (offFat >> pFatCache->cEntryIndexShift) & pFatCache->fEntryIndexMask; + uint32_t const offInEntry = offFat & pFatCache->fEntryOffsetMask; + uint32_t const offFatEntry = offFat - offInEntry; + + *ppbEntry = pFatCache->aEntries[iEntry].pbData + offInEntry; + *pidxEntry = iEntry; + + /* If it's already ready, return immediately. */ + if (pFatCache->aEntries[iEntry].offFat == offFatEntry) + { + Log3(("rtFsFatClusterMap_GetEntryEx: Hit entry %u for offFat=%#RX32\n", iEntry, offFat)); + return VINF_SUCCESS; + } + + /* Do we need to flush it? */ + rc = VINF_SUCCESS; + if ( pFatCache->aEntries[iEntry].bmDirty != 0 + && pFatCache->aEntries[iEntry].offFat != UINT32_MAX) + { + Log3(("rtFsFatClusterMap_GetEntryEx: Flushing entry %u for offFat=%#RX32\n", iEntry, offFat)); + rc = rtFsFatClusterMap_FlushEntry(pFatCache, iEntry); + } + if (RT_SUCCESS(rc)) + { + pFatCache->aEntries[iEntry].bmDirty = 0; + + /* Read in the entry from disk */ + rc = RTVfsFileReadAt(pFatCache->pVol->hVfsBacking, pFatCache->pVol->aoffFats[0] + offFatEntry, + pFatCache->aEntries[iEntry].pbData, pFatCache->cbEntry, NULL); + if (RT_SUCCESS(rc)) + { + Log3(("rtFsFatClusterMap_GetEntryEx: Loaded entry %u for offFat=%#RX32\n", iEntry, offFat)); + pFatCache->aEntries[iEntry].offFat = offFatEntry; + return VINF_SUCCESS; + } + /** @todo We can try other FAT copies here... */ + LogRel(("rtFsFatClusterMap_GetEntryEx: Error loading entry %u for offFat=%#RX32 (%#64RX32 LB %#x): %Rrc\n", + iEntry, offFat, pFatCache->pVol->aoffFats[0] + offFatEntry, pFatCache->cbEntry, rc)); + pFatCache->aEntries[iEntry].offFat = UINT32_MAX; + } + } + else + rc = VERR_OUT_OF_RANGE; + *ppbEntry = NULL; + *pidxEntry = UINT32_MAX; + return rc; +} + + +/** + * Destroys the file allcation table cache, first flushing any dirty lines. + * + * @returns IRPT status code from flush (we've destroyed it regardless of the + * status code). + * @param pThis The FAT volume instance which cluster map shall be + * destroyed. + */ +static int rtFsFatClusterMap_Destroy(PRTFSFATVOL pThis) +{ + int rc = VINF_SUCCESS; + PRTFSFATCLUSTERMAPCACHE pFatCache = pThis->pFatCache; + if (pFatCache) + { + /* flush stuff. */ + rc = rtFsFatClusterMap_Flush(pThis); + + /* free everything. */ + uint32_t i = pFatCache->cEntries; + while (i-- > 0) + { + RTMemFree(pFatCache->aEntries[i].pbData); + pFatCache->aEntries[i].pbData = NULL; + } + pFatCache->cEntries = 0; + RTMemFree(pFatCache); + + pThis->pFatCache = NULL; + } + + return rc; +} + + +/** + * Worker for rtFsFatClusterMap_ReadClusterChain handling FAT12. + */ +static int rtFsFatClusterMap_Fat12_ReadClusterChain(PRTFSFATCLUSTERMAPCACHE pFatCache, uint32_t idxCluster, PRTFSFATCHAIN pChain) +{ + /* ASSUME that for FAT12 we cache the whole FAT in a single entry. That + way we don't need to deal with entries in different sectors and whatnot. */ + AssertReturn(pFatCache->cEntries == 1, VERR_INTERNAL_ERROR_4); + AssertReturn(pFatCache->cbEntry == pFatCache->cbFat, VERR_INTERNAL_ERROR_4); + AssertReturn(pFatCache->aEntries[0].offFat == 0, VERR_INTERNAL_ERROR_4); + + /* Special case for empty files. */ + if (idxCluster == 0) + return VINF_SUCCESS; + + /* Work cluster by cluster. */ + uint8_t const *pbFat = pFatCache->aEntries[0].pbData; + for (;;) + { + /* Validate the cluster, checking for end of file. */ + if ((uint32_t)(idxCluster - FAT_FIRST_DATA_CLUSTER) >= pFatCache->cClusters) + { + if (idxCluster >= FAT_FIRST_FAT12_EOC) + return VINF_SUCCESS; + Log(("Fat/ReadChain12: bogus cluster %#x vs %#x total\n", idxCluster, pFatCache->cClusters)); + return VERR_VFS_BOGUS_OFFSET; + } + + /* Add cluster to chain. */ + int rc = rtFsFatChain_Append(pChain, idxCluster); + if (RT_FAILURE(rc)) + return rc; + + /* Next cluster. */ +#ifdef LOG_ENABLED + const uint32_t idxPrevCluster = idxCluster; +#endif + bool fOdd = idxCluster & 1; + uint32_t offFat = idxCluster * 3 / 2; + idxCluster = RT_MAKE_U16(pbFat[offFat], pbFat[offFat + 1]); + if (fOdd) + idxCluster >>= 4; + else + idxCluster &= 0x0fff; + Log4(("Fat/ReadChain12: [%#x] %#x (next: %#x)\n", pChain->cClusters - 1, idxPrevCluster, idxCluster)); + } +} + + +/** + * Worker for rtFsFatClusterMap_ReadClusterChain handling FAT16. + */ +static int rtFsFatClusterMap_Fat16_ReadClusterChain(PRTFSFATCLUSTERMAPCACHE pFatCache, uint32_t idxCluster, PRTFSFATCHAIN pChain) +{ + /* ASSUME that for FAT16 we cache the whole FAT in a single entry. That + way we don't need to deal with entries in different sectors and whatnot. */ + AssertReturn(pFatCache->cEntries == 1, VERR_INTERNAL_ERROR_4); + AssertReturn(pFatCache->cbEntry == pFatCache->cbFat, VERR_INTERNAL_ERROR_4); + AssertReturn(pFatCache->aEntries[0].offFat == 0, VERR_INTERNAL_ERROR_4); + + /* Special case for empty files. */ + if (idxCluster == 0) + return VINF_SUCCESS; + + /* Work cluster by cluster. */ + uint8_t const *pbFat = pFatCache->aEntries[0].pbData; + for (;;) + { + /* Validate the cluster, checking for end of file. */ + if ((uint32_t)(idxCluster - FAT_FIRST_DATA_CLUSTER) >= pFatCache->cClusters) + { + if (idxCluster >= FAT_FIRST_FAT16_EOC) + return VINF_SUCCESS; + Log(("Fat/ReadChain16: bogus cluster %#x vs %#x total\n", idxCluster, pFatCache->cClusters)); + return VERR_VFS_BOGUS_OFFSET; + } + + /* Add cluster to chain. */ + int rc = rtFsFatChain_Append(pChain, idxCluster); + if (RT_FAILURE(rc)) + return rc; + + /* Next cluster. */ + idxCluster = RT_MAKE_U16(pbFat[idxCluster * 2], pbFat[idxCluster * 2 + 1]); + } +} + + +/** + * Worker for rtFsFatClusterMap_ReadClusterChain handling FAT32. + */ +static int rtFsFatClusterMap_Fat32_ReadClusterChain(PRTFSFATCLUSTERMAPCACHE pFatCache, uint32_t idxCluster, PRTFSFATCHAIN pChain) +{ + /* Special case for empty files. */ + if (idxCluster == 0) + return VINF_SUCCESS; + + /* Work cluster by cluster. */ + for (;;) + { + /* Validate the cluster, checking for end of file. */ + if ((uint32_t)(idxCluster - FAT_FIRST_DATA_CLUSTER) >= pFatCache->cClusters) + { + if (idxCluster >= FAT_FIRST_FAT32_EOC) + return VINF_SUCCESS; + Log(("Fat/ReadChain32: bogus cluster %#x vs %#x total\n", idxCluster, pFatCache->cClusters)); + return VERR_VFS_BOGUS_OFFSET; + } + + /* Add cluster to chain. */ + int rc = rtFsFatChain_Append(pChain, idxCluster); + if (RT_FAILURE(rc)) + return rc; + + /* Get the next cluster. */ + uint8_t *pbEntry; + rc = rtFsFatClusterMap_GetEntry(pFatCache, idxCluster * 4, &pbEntry); + if (RT_SUCCESS(rc)) + idxCluster = RT_MAKE_U32_FROM_U8(pbEntry[0], pbEntry[1], pbEntry[2], pbEntry[3]); + else + return rc; + } +} + + +/** + * Reads a cluster chain into memory + * + * @returns IPRT status code. + * @param pThis The FAT volume instance. + * @param idxFirstCluster The first cluster. + * @param pChain The chain element to read into (and thereby + * initialize). + */ +static int rtFsFatClusterMap_ReadClusterChain(PRTFSFATVOL pThis, uint32_t idxFirstCluster, PRTFSFATCHAIN pChain) +{ + pChain->cbCluster = pThis->cbCluster; + pChain->cClusterByteShift = pThis->cClusterByteShift; + pChain->cClusters = 0; + pChain->cbChain = 0; + RTListInit(&pChain->ListParts); + switch (pThis->enmFatType) + { + case RTFSFATTYPE_FAT12: return rtFsFatClusterMap_Fat12_ReadClusterChain(pThis->pFatCache, idxFirstCluster, pChain); + case RTFSFATTYPE_FAT16: return rtFsFatClusterMap_Fat16_ReadClusterChain(pThis->pFatCache, idxFirstCluster, pChain); + case RTFSFATTYPE_FAT32: return rtFsFatClusterMap_Fat32_ReadClusterChain(pThis->pFatCache, idxFirstCluster, pChain); + default: + AssertFailedReturn(VERR_INTERNAL_ERROR_2); + } +} + + +/** + * Sets bmDirty for entry @a iEntry. + * + * @param pFatCache The FAT cache. + * @param iEntry The cache entry. + * @param offEntry The offset into the cache entry that was dirtied. + */ +DECLINLINE(void) rtFsFatClusterMap_SetDirtyByte(PRTFSFATCLUSTERMAPCACHE pFatCache, uint32_t iEntry, uint32_t offEntry) +{ + uint8_t iLine = offEntry / pFatCache->cbDirtyLine; + pFatCache->aEntries[iEntry].bmDirty |= RT_BIT_64(iLine); +} + +/** + * Sets bmDirty for entry @a iEntry. + * + * @param pFatCache The FAT cache. + * @param iEntry The cache entry. + * @param pbIntoEntry Pointer into the cache entry that was dirtied. + */ +DECLINLINE(void) rtFsFatClusterMap_SetDirtyByteByPtr(PRTFSFATCLUSTERMAPCACHE pFatCache, uint32_t iEntry, uint8_t *pbIntoEntry) +{ + uintptr_t offEntry = pbIntoEntry - pFatCache->aEntries[iEntry].pbData; + Assert(offEntry < pFatCache->cbEntry); + rtFsFatClusterMap_SetDirtyByte(pFatCache, iEntry, (uint32_t)offEntry); +} + + +/** Sets a FAT12 cluster value. */ +static int rtFsFatClusterMap_SetCluster12(PRTFSFATCLUSTERMAPCACHE pFatCache, uint32_t idxCluster, uint32_t uValue) +{ + /* ASSUME that for FAT12 we cache the whole FAT in a single entry. That + way we don't need to deal with entries in different sectors and whatnot. */ + AssertReturn(pFatCache->cEntries == 1, VERR_INTERNAL_ERROR_4); + AssertReturn(pFatCache->cbEntry == pFatCache->cbFat, VERR_INTERNAL_ERROR_4); + AssertReturn(pFatCache->aEntries[0].offFat == 0, VERR_INTERNAL_ERROR_4); + AssertReturn(uValue < 0x1000, VERR_INTERNAL_ERROR_2); + + /* Make the change. */ + uint8_t *pbFat = pFatCache->aEntries[0].pbData; + uint32_t offFat = idxCluster * 3 / 2; + if (idxCluster & 1) + { + Log3(("Fat/SetCluster12: [%#x]: %#x -> %#x\n", idxCluster, (((pbFat[offFat]) & 0xf0) >> 4) | ((unsigned)pbFat[offFat + 1] << 4), uValue)); + pbFat[offFat] = ((uint8_t)0x0f & pbFat[offFat]) | ((uint8_t)uValue << 4); + pbFat[offFat + 1] = (uint8_t)(uValue >> 4); + } + else + { + Log3(("Fat/SetCluster12: [%#x]: %#x -> %#x\n", idxCluster, pbFat[offFat] | ((pbFat[offFat + 1] & 0x0f) << 8), uValue)); + pbFat[offFat] = (uint8_t)uValue; + pbFat[offFat + 1] = ((uint8_t)0xf0 & pbFat[offFat + 1]) | (uint8_t)(uValue >> 8); + } + + /* Update the dirty bits. */ + rtFsFatClusterMap_SetDirtyByte(pFatCache, 0, offFat); + rtFsFatClusterMap_SetDirtyByte(pFatCache, 0, offFat + 1); + + return VINF_SUCCESS; +} + + +/** Sets a FAT16 cluster value. */ +static int rtFsFatClusterMap_SetCluster16(PRTFSFATCLUSTERMAPCACHE pFatCache, uint32_t idxCluster, uint32_t uValue) +{ + /* ASSUME that for FAT16 we cache the whole FAT in a single entry. */ + AssertReturn(pFatCache->cEntries == 1, VERR_INTERNAL_ERROR_4); + AssertReturn(pFatCache->cbEntry == pFatCache->cbFat, VERR_INTERNAL_ERROR_4); + AssertReturn(pFatCache->aEntries[0].offFat == 0, VERR_INTERNAL_ERROR_4); + AssertReturn(uValue < 0x10000, VERR_INTERNAL_ERROR_2); + + /* Make the change. */ + uint8_t *pbFat = pFatCache->aEntries[0].pbData; + uint32_t offFat = idxCluster * 2; + pbFat[offFat] = (uint8_t)idxCluster; + pbFat[offFat + 1] = (uint8_t)(idxCluster >> 8); + + /* Update the dirty bits. */ + rtFsFatClusterMap_SetDirtyByte(pFatCache, 0, offFat); + + return VINF_SUCCESS; +} + + +/** Sets a FAT32 cluster value. */ +static int rtFsFatClusterMap_SetCluster32(PRTFSFATCLUSTERMAPCACHE pFatCache, uint32_t idxCluster, uint32_t uValue) +{ + AssertReturn(uValue < 0x10000000, VERR_INTERNAL_ERROR_2); + + /* Get the fat cache entry. */ + uint8_t *pbEntry; + uint32_t idxEntry; + int rc = rtFsFatClusterMap_GetEntryEx(pFatCache, idxCluster * 4, &pbEntry, &idxEntry); + if (RT_SUCCESS(rc)) + { + /* Make the change. */ + pbEntry[0] = (uint8_t)idxCluster; + pbEntry[1] = (uint8_t)(idxCluster >> 8); + pbEntry[2] = (uint8_t)(idxCluster >> 16); + pbEntry[3] = (uint8_t)(idxCluster >> 24); + + /* Update the dirty bits. */ + rtFsFatClusterMap_SetDirtyByteByPtr(pFatCache, idxEntry, pbEntry); + } + + return rc; +} + + +/** + * Marks the cluster @a idxCluster as the end of the cluster chain. + * + * @returns IPRT status code + * @param pThis The FAT volume instance. + * @param idxCluster The cluster to end the chain with. + */ +static int rtFsFatClusterMap_SetEndOfChain(PRTFSFATVOL pThis, uint32_t idxCluster) +{ + AssertReturn(idxCluster >= FAT_FIRST_DATA_CLUSTER, VERR_VFS_BOGUS_OFFSET); + AssertMsgReturn(idxCluster < pThis->cClusters, ("idxCluster=%#x cClusters=%#x\n", idxCluster, pThis->cClusters), + VERR_VFS_BOGUS_OFFSET); + switch (pThis->enmFatType) + { + case RTFSFATTYPE_FAT12: return rtFsFatClusterMap_SetCluster12(pThis->pFatCache, idxCluster, FAT_FIRST_FAT12_EOC); + case RTFSFATTYPE_FAT16: return rtFsFatClusterMap_SetCluster16(pThis->pFatCache, idxCluster, FAT_FIRST_FAT16_EOC); + case RTFSFATTYPE_FAT32: return rtFsFatClusterMap_SetCluster32(pThis->pFatCache, idxCluster, FAT_FIRST_FAT32_EOC); + default: AssertFailedReturn(VERR_INTERNAL_ERROR_3); + } +} + + +/** + * Marks the cluster @a idxCluster as free. + * @returns IPRT status code + * @param pThis The FAT volume instance. + * @param idxCluster The cluster to free. + */ +static int rtFsFatClusterMap_FreeCluster(PRTFSFATVOL pThis, uint32_t idxCluster) +{ + AssertReturn(idxCluster >= FAT_FIRST_DATA_CLUSTER, VERR_VFS_BOGUS_OFFSET); + AssertReturn(idxCluster < pThis->cClusters, VERR_VFS_BOGUS_OFFSET); + switch (pThis->enmFatType) + { + case RTFSFATTYPE_FAT12: return rtFsFatClusterMap_SetCluster12(pThis->pFatCache, idxCluster, 0); + case RTFSFATTYPE_FAT16: return rtFsFatClusterMap_SetCluster16(pThis->pFatCache, idxCluster, 0); + case RTFSFATTYPE_FAT32: return rtFsFatClusterMap_SetCluster32(pThis->pFatCache, idxCluster, 0); + default: AssertFailedReturn(VERR_INTERNAL_ERROR_3); + } +} + + +/** + * Worker for rtFsFatClusterMap_AllocateCluster that handles FAT12. + */ +static int rtFsFatClusterMap_AllocateCluster12(PRTFSFATCLUSTERMAPCACHE pFatCache, uint32_t idxPrevCluster, uint32_t *pidxCluster) +{ + /* ASSUME that for FAT12 we cache the whole FAT in a single entry. That + way we don't need to deal with entries in different sectors and whatnot. */ + AssertReturn(pFatCache->cEntries == 1, VERR_INTERNAL_ERROR_4); + AssertReturn(pFatCache->cbEntry == pFatCache->cbFat, VERR_INTERNAL_ERROR_4); + AssertReturn(pFatCache->aEntries[0].offFat == 0, VERR_INTERNAL_ERROR_4); + + /* + * Check that the previous cluster is a valid chain end. + */ + uint8_t *pbFat = pFatCache->aEntries[0].pbData; + uint32_t offFatPrev; + if (idxPrevCluster != UINT32_MAX) + { + offFatPrev = idxPrevCluster * 3 / 2; + AssertReturn(offFatPrev + 1 < pFatCache->cbFat, VERR_INTERNAL_ERROR_3); + uint32_t idxPrevValue; + if (idxPrevCluster & 1) + idxPrevValue = (pbFat[offFatPrev] >> 4) | ((uint32_t)pbFat[offFatPrev + 1] << 4); + else + idxPrevValue = pbFat[offFatPrev] | ((uint32_t)(pbFat[offFatPrev + 1] & 0x0f) << 8); + AssertReturn(idxPrevValue >= FAT_FIRST_FAT12_EOC, VERR_VFS_BOGUS_OFFSET); + } + else + offFatPrev = UINT32_MAX; + + /* + * Search cluster by cluster from the start (it's small, so easy trumps + * complicated optimizations). + */ + uint32_t idxCluster = FAT_FIRST_DATA_CLUSTER; + uint32_t offFat = 3; + while (idxCluster < pFatCache->cClusters) + { + if (idxCluster & 1) + { + if ( (pbFat[offFat] & 0xf0) != 0 + || pbFat[offFat + 1] != 0) + { + offFat += 2; + idxCluster++; + continue; + } + + /* Set EOC. */ + pbFat[offFat] |= 0xf0; + pbFat[offFat + 1] = 0xff; + } + else + { + if ( pbFat[offFat] + || pbFat[offFat + 1] & 0x0f) + { + offFat += 1; + idxCluster++; + continue; + } + + /* Set EOC. */ + pbFat[offFat] = 0xff; + pbFat[offFat + 1] |= 0x0f; + } + + /* Update the dirty bits. */ + rtFsFatClusterMap_SetDirtyByte(pFatCache, 0, offFat); + rtFsFatClusterMap_SetDirtyByte(pFatCache, 0, offFat + 1); + + /* Chain it onto the previous cluster. */ + if (idxPrevCluster != UINT32_MAX) + { + if (idxPrevCluster & 1) + { + pbFat[offFatPrev] = (pbFat[offFatPrev] & (uint8_t)0x0f) | (uint8_t)(idxCluster << 4); + pbFat[offFatPrev + 1] = (uint8_t)(idxCluster >> 4); + } + else + { + pbFat[offFatPrev] = (uint8_t)idxCluster; + pbFat[offFatPrev + 1] = (pbFat[offFatPrev + 1] & (uint8_t)0xf0) | ((uint8_t)(idxCluster >> 8) & (uint8_t)0x0f); + } + rtFsFatClusterMap_SetDirtyByte(pFatCache, 0, offFatPrev); + rtFsFatClusterMap_SetDirtyByte(pFatCache, 0, offFatPrev + 1); + } + + *pidxCluster = idxCluster; + return VINF_SUCCESS; + } + + return VERR_DISK_FULL; +} + + +/** + * Worker for rtFsFatClusterMap_AllocateCluster that handles FAT16. + */ +static int rtFsFatClusterMap_AllocateCluster16(PRTFSFATCLUSTERMAPCACHE pFatCache, uint32_t idxPrevCluster, uint32_t *pidxCluster) +{ + /* ASSUME that for FAT16 we cache the whole FAT in a single entry. */ + AssertReturn(pFatCache->cEntries == 1, VERR_INTERNAL_ERROR_4); + AssertReturn(pFatCache->cbEntry == pFatCache->cbFat, VERR_INTERNAL_ERROR_4); + AssertReturn(pFatCache->aEntries[0].offFat == 0, VERR_INTERNAL_ERROR_4); + + /* + * Check that the previous cluster is a valid chain end. + */ + uint8_t *pbFat = pFatCache->aEntries[0].pbData; + uint32_t offFatPrev; + if (idxPrevCluster != UINT32_MAX) + { + offFatPrev = idxPrevCluster * 2; + AssertReturn(offFatPrev + 1 < pFatCache->cbFat, VERR_INTERNAL_ERROR_3); + uint32_t idxPrevValue = RT_MAKE_U16(pbFat[offFatPrev], pbFat[offFatPrev + 1]); + AssertReturn(idxPrevValue >= FAT_FIRST_FAT16_EOC, VERR_VFS_BOGUS_OFFSET); + } + else + offFatPrev = UINT32_MAX; + + /* + * We start searching at idxAllocHint and continues to the end. The next + * iteration starts searching from the start and up to idxAllocHint. + */ + uint32_t idxCluster = RT_MIN(pFatCache->idxAllocHint, FAT_FIRST_DATA_CLUSTER); + uint32_t offFat = idxCluster * 2; + uint32_t cClusters = pFatCache->cClusters; + for (uint32_t i = 0; i < 2; i++) + { + while (idxCluster < cClusters) + { + if ( pbFat[offFat + 0] != 0x00 + || pbFat[offFat + 1] != 0x00) + { + /* In use - advance to the next one. */ + offFat += 2; + idxCluster++; + } + else + { + /* + * Found one. Grab it. + */ + /* Set EOC. */ + pbFat[offFat + 0] = 0xff; + pbFat[offFat + 1] = 0xff; + rtFsFatClusterMap_SetDirtyByte(pFatCache, 0, offFat); + + /* Chain it onto the previous cluster (if any). */ + if (idxPrevCluster != UINT32_MAX) + { + pbFat[offFatPrev + 0] = (uint8_t)idxCluster; + pbFat[offFatPrev + 1] = (uint8_t)(idxCluster >> 8); + rtFsFatClusterMap_SetDirtyByte(pFatCache, 0, offFatPrev); + } + + /* Update the allocation hint. */ + pFatCache->idxAllocHint = idxCluster + 1; + + /* Done. */ + *pidxCluster = idxCluster; + return VINF_SUCCESS; + } + } + + /* Wrap around to the start of the map. */ + cClusters = RT_MIN(pFatCache->idxAllocHint, pFatCache->cClusters); + idxCluster = FAT_FIRST_DATA_CLUSTER; + offFat = 4; + } + + return VERR_DISK_FULL; +} + + +/** + * Worker for rtFsFatClusterMap_AllocateCluster that handles FAT32. + */ +static int rtFsFatClusterMap_AllocateCluster32(PRTFSFATCLUSTERMAPCACHE pFatCache, uint32_t idxPrevCluster, uint32_t *pidxCluster) +{ + /* + * Check that the previous cluster is a valid chain end. + */ + int rc; + uint8_t *pbEntry; + if (idxPrevCluster != UINT32_MAX) + { + rc = rtFsFatClusterMap_GetEntry(pFatCache, idxPrevCluster * 4, &pbEntry); + if (RT_SUCCESS(rc)) + { + uint32_t idxPrevValue = RT_MAKE_U32_FROM_U8(pbEntry[0], pbEntry[1], pbEntry[2], pbEntry[3]); + AssertReturn(idxPrevValue >= FAT_FIRST_FAT32_EOC, VERR_VFS_BOGUS_OFFSET); + } + else + return rc; + } + + /* + * We start searching at idxAllocHint and continues to the end. The next + * iteration starts searching from the start and up to idxAllocHint. + */ + uint32_t idxCluster = RT_MIN(pFatCache->idxAllocHint, FAT_FIRST_DATA_CLUSTER); + uint32_t offFat = idxCluster * 4; + uint32_t cClusters = pFatCache->cClusters; + for (uint32_t i = 0; i < 2; i++) + { + while (idxCluster < cClusters) + { + /* Note! This could be done in cache entry chunks. */ + uint32_t idxEntry; + rc = rtFsFatClusterMap_GetEntryEx(pFatCache, offFat, &pbEntry, &idxEntry); + if (RT_SUCCESS(rc)) + { + if ( pbEntry[0] != 0x00 + || pbEntry[1] != 0x00 + || pbEntry[2] != 0x00 + || pbEntry[3] != 0x00) + { + /* In use - advance to the next one. */ + offFat += 4; + idxCluster++; + } + else + { + /* + * Found one. Grab it. + */ + /* Set EOC. */ + pbEntry[0] = 0xff; + pbEntry[1] = 0xff; + pbEntry[2] = 0xff; + pbEntry[3] = 0x0f; + rtFsFatClusterMap_SetDirtyByteByPtr(pFatCache, idxEntry, pbEntry); + + /* Chain it on the previous cluster (if any). */ + if (idxPrevCluster != UINT32_MAX) + { + rc = rtFsFatClusterMap_GetEntryEx(pFatCache, idxPrevCluster * 4, &pbEntry, &idxEntry); + if (RT_SUCCESS(rc)) + { + pbEntry[0] = (uint8_t)idxCluster; + pbEntry[1] = (uint8_t)(idxCluster >> 8); + pbEntry[2] = (uint8_t)(idxCluster >> 16); + pbEntry[3] = (uint8_t)(idxCluster >> 24); + rtFsFatClusterMap_SetDirtyByteByPtr(pFatCache, idxEntry, pbEntry); + } + else + { + /* Try free the cluster. */ + int rc2 = rtFsFatClusterMap_GetEntryEx(pFatCache, offFat, &pbEntry, &idxEntry); + if (RT_SUCCESS(rc2)) + { + pbEntry[0] = 0; + pbEntry[1] = 0; + pbEntry[2] = 0; + pbEntry[3] = 0; + rtFsFatClusterMap_SetDirtyByteByPtr(pFatCache, idxEntry, pbEntry); + } + return rc; + } + } + + /* Update the allocation hint. */ + pFatCache->idxAllocHint = idxCluster + 1; + + /* Done. */ + *pidxCluster = idxCluster; + return VINF_SUCCESS; + } + } + } + + /* Wrap around to the start of the map. */ + cClusters = RT_MIN(pFatCache->idxAllocHint, pFatCache->cClusters); + idxCluster = FAT_FIRST_DATA_CLUSTER; + offFat = 4; + } + + return VERR_DISK_FULL; +} + + +/** + * Allocates a cluster an appends it to the chain given by @a idxPrevCluster. + * + * @returns IPRT status code. + * @retval VERR_DISK_FULL if no more available clusters. + * @param pThis The FAT volume instance. + * @param idxPrevCluster The previous cluster, UINT32_MAX if first. + * @param pidxCluster Where to return the cluster number on success. + */ +static int rtFsFatClusterMap_AllocateCluster(PRTFSFATVOL pThis, uint32_t idxPrevCluster, uint32_t *pidxCluster) +{ + AssertReturn(idxPrevCluster == UINT32_MAX || (idxPrevCluster >= FAT_FIRST_DATA_CLUSTER && idxPrevCluster < pThis->cClusters), + VERR_INTERNAL_ERROR_5); + *pidxCluster = UINT32_MAX; + switch (pThis->enmFatType) + { + case RTFSFATTYPE_FAT12: return rtFsFatClusterMap_AllocateCluster12(pThis->pFatCache, idxPrevCluster, pidxCluster); + case RTFSFATTYPE_FAT16: return rtFsFatClusterMap_AllocateCluster16(pThis->pFatCache, idxPrevCluster, pidxCluster); + case RTFSFATTYPE_FAT32: return rtFsFatClusterMap_AllocateCluster32(pThis->pFatCache, idxPrevCluster, pidxCluster); + default: AssertFailedReturn(VERR_INTERNAL_ERROR_3); + } +} + + +/** + * Allocates clusters. + * + * Will free the clusters if it fails to allocate all of them. + * + * @returns IPRT status code. + * @param pThis The FAT volume instance. + * @param pChain The chain. + * @param cClusters Number of clusters to add to the chain. + */ +static int rtFsFatClusterMap_AllocateMoreClusters(PRTFSFATVOL pThis, PRTFSFATCHAIN pChain, uint32_t cClusters) +{ + int rc = VINF_SUCCESS; + uint32_t const cOldClustersInChain = pChain->cClusters; + uint32_t const idxOldLastCluster = rtFsFatChain_GetLastCluster(pChain); + uint32_t idxPrevCluster = idxOldLastCluster; + uint32_t iCluster = 0; + while (iCluster < cClusters) + { + uint32_t idxCluster; + rc = rtFsFatClusterMap_AllocateCluster(pThis, idxPrevCluster, &idxCluster); + if (RT_SUCCESS(rc)) + { + rc = rtFsFatChain_Append(pChain, idxCluster); + if (RT_SUCCESS(rc)) + { + /* next */ + iCluster++; + continue; + } + + /* Bail out, freeing any clusters we've managed to allocate by now. */ + rtFsFatClusterMap_FreeCluster(pThis, idxCluster); + } + if (idxOldLastCluster != UINT32_MAX) + rtFsFatClusterMap_SetEndOfChain(pThis, idxOldLastCluster); + while (iCluster-- > 0) + rtFsFatClusterMap_FreeCluster(pThis, rtFsFatChain_GetClusterByIndex(pChain, cOldClustersInChain + iCluster)); + rtFsFatChain_Shrink(pChain, iCluster); + break; + } + return rc; +} + + + +/** + * Converts a FAT timestamp into an IPRT timesspec. + * + * @param pTimeSpec Where to return the IRPT time. + * @param uDate The date part of the FAT timestamp. + * @param uTime The time part of the FAT timestamp. + * @param cCentiseconds Centiseconds part if applicable (0 otherwise). + * @param pVol The volume. + */ +static void rtFsFatDateTime2TimeSpec(PRTTIMESPEC pTimeSpec, uint16_t uDate, uint16_t uTime, + uint8_t cCentiseconds, PCRTFSFATVOL pVol) +{ + RTTIME Time; + Time.fFlags = RTTIME_FLAGS_TYPE_UTC; + Time.offUTC = 0; + Time.i32Year = 1980 + (uDate >> 9); + Time.u8Month = RT_MAX((uDate >> 5) & 0xf, 1); + Time.u8MonthDay = RT_MAX(uDate & 0x1f, 1); + Time.u8WeekDay = UINT8_MAX; + Time.u16YearDay = 0; + Time.u8Hour = uTime >> 11; + Time.u8Minute = (uTime >> 5) & 0x3f; + Time.u8Second = (uTime & 0x1f) << 1; + Time.u32Nanosecond = 0; + if (cCentiseconds > 0 && cCentiseconds < 200) /* screw complicated stuff for now. */ + { + if (cCentiseconds >= 100) + { + cCentiseconds -= 100; + Time.u8Second++; + } + Time.u32Nanosecond = cCentiseconds * UINT64_C(100000000); + } + + RTTimeImplode(pTimeSpec, RTTimeNormalize(&Time)); + RTTimeSpecSubNano(pTimeSpec, pVol->offNanoUTC); +} + + +/** + * Converts an IPRT timespec to a FAT timestamp. + * + * @returns The centiseconds part. + * @param pVol The volume. + * @param pTimeSpec The IPRT timespec to convert (UTC). + * @param puDate Where to return the date part of the FAT timestamp. + * @param puTime Where to return the time part of the FAT timestamp. + */ +static uint8_t rtFsFatTimeSpec2FatDateTime(PCRTFSFATVOL pVol, PCRTTIMESPEC pTimeSpec, uint16_t *puDate, uint16_t *puTime) +{ + RTTIMESPEC TimeSpec = *pTimeSpec; + RTTIME Time; + RTTimeExplode(&Time, RTTimeSpecSubNano(&TimeSpec, pVol->offNanoUTC)); + + if (puDate) + *puDate = ((uint16_t)(RT_MAX(Time.i32Year, 1980) - 1980) << 9) + | (Time.u8Month << 5) + | Time.u8MonthDay; + if (puTime) + *puTime = ((uint16_t)Time.u8Hour << 11) + | (Time.u8Minute << 5) + | (Time.u8Second >> 1); + return (Time.u8Second & 1) * 100 + Time.u32Nanosecond / 10000000; + +} + + +/** + * Gets the current FAT timestamp. + * + * @returns The centiseconds part. + * @param pVol The volume. + * @param puDate Where to return the date part of the FAT timestamp. + * @param puTime Where to return the time part of the FAT timestamp. + */ +static uint8_t rtFsFatCurrentFatDateTime(PCRTFSFATVOL pVol, uint16_t *puDate, uint16_t *puTime) +{ + RTTIMESPEC TimeSpec; + return rtFsFatTimeSpec2FatDateTime(pVol, RTTimeNow(&TimeSpec), puDate, puTime); +} + + +/** + * Initialization of a RTFSFATOBJ structure from a FAT directory entry. + * + * @note The RTFSFATOBJ::pParentDir and RTFSFATOBJ::Clusters members are + * properly initialized elsewhere. + * + * @param pObj The structure to initialize. + * @param pDirEntry The directory entry. + * @param offEntryInDir The offset in the parent directory. + * @param pVol The volume. + */ +static void rtFsFatObj_InitFromDirEntry(PRTFSFATOBJ pObj, PCFATDIRENTRY pDirEntry, uint32_t offEntryInDir, PRTFSFATVOL pVol) +{ + RTListInit(&pObj->Entry); + pObj->cRefs = 1; + pObj->pParentDir = NULL; + pObj->pVol = pVol; + pObj->offEntryInDir = offEntryInDir; + pObj->fAttrib = ((RTFMODE)pDirEntry->fAttrib << RTFS_DOS_SHIFT) & RTFS_DOS_MASK_OS2; + pObj->fAttrib = rtFsModeFromDos(pObj->fAttrib, (char *)&pDirEntry->achName[0], sizeof(pDirEntry->achName), 0, 0); + pObj->cbObject = pDirEntry->cbFile; + pObj->fMaybeDirtyFat = false; + pObj->fMaybeDirtyDirEnt = false; + rtFsFatDateTime2TimeSpec(&pObj->ModificationTime, pDirEntry->uModifyDate, pDirEntry->uModifyTime, 0, pVol); + rtFsFatDateTime2TimeSpec(&pObj->BirthTime, pDirEntry->uBirthDate, pDirEntry->uBirthTime, pDirEntry->uBirthCentiseconds, pVol); + rtFsFatDateTime2TimeSpec(&pObj->AccessTime, pDirEntry->uAccessDate, 0, 0, pVol); +} + + +/** + * Dummy initialization of a RTFSFATOBJ structure. + * + * @note The RTFSFATOBJ::pParentDir and RTFSFATOBJ::Clusters members are + * properly initialized elsewhere. + * + * @param pObj The structure to initialize. + * @param cbObject The object size. + * @param fAttrib The attributes. + * @param pVol The volume. + */ +static void rtFsFatObj_InitDummy(PRTFSFATOBJ pObj, uint32_t cbObject, RTFMODE fAttrib, PRTFSFATVOL pVol) +{ + RTListInit(&pObj->Entry); + pObj->cRefs = 1; + pObj->pParentDir = NULL; + pObj->pVol = pVol; + pObj->offEntryInDir = UINT32_MAX; + pObj->fAttrib = fAttrib; + pObj->cbObject = cbObject; + pObj->fMaybeDirtyFat = false; + pObj->fMaybeDirtyDirEnt = false; + RTTimeSpecSetDosSeconds(&pObj->AccessTime, 0); + RTTimeSpecSetDosSeconds(&pObj->ModificationTime, 0); + RTTimeSpecSetDosSeconds(&pObj->BirthTime, 0); +} + + +/** + * Flushes FAT object meta data. + * + * @returns IPRT status code + * @param pObj The common object structure. + */ +static int rtFsFatObj_FlushMetaData(PRTFSFATOBJ pObj) +{ + int rc = VINF_SUCCESS; + if (pObj->fMaybeDirtyFat) + { + rc = rtFsFatClusterMap_Flush(pObj->pVol); + if (RT_SUCCESS(rc)) + pObj->fMaybeDirtyFat = false; + } + if (pObj->fMaybeDirtyDirEnt) + { + int rc2 = rtFsFatDirShrd_Flush(pObj->pParentDir); + if (RT_SUCCESS(rc2)) + pObj->fMaybeDirtyDirEnt = false; + else if (RT_SUCCESS(rc)) + rc = rc2; + } + return rc; +} + + +/** + * Worker for rtFsFatFile_Close and rtFsFatDir_Close that does common work. + * + * @returns IPRT status code. + * @param pObj The common object structure. + */ +static int rtFsFatObj_Close(PRTFSFATOBJ pObj) +{ + int rc = rtFsFatObj_FlushMetaData(pObj); + if (pObj->pParentDir) + rtFsFatDirShrd_RemoveOpenChild(pObj->pParentDir, pObj); + rtFsFatChain_Delete(&pObj->Clusters); + return rc; +} + + +/** + * Worker for rtFsFatFile_QueryInfo and rtFsFatDir_QueryInfo + */ +static int rtFsFatObj_QueryInfo(PRTFSFATOBJ pThis, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr) +{ + LogFlow(("rtFsFatObj_QueryInfo: %p fMode=%#x\n", pThis, pThis->fAttrib)); + + pObjInfo->cbObject = pThis->cbObject; + pObjInfo->cbAllocated = pThis->Clusters.cbChain; + pObjInfo->AccessTime = pThis->AccessTime; + pObjInfo->ModificationTime = pThis->ModificationTime; + pObjInfo->ChangeTime = pThis->ModificationTime; + pObjInfo->BirthTime = pThis->BirthTime; + pObjInfo->Attr.fMode = pThis->fAttrib; + pObjInfo->Attr.enmAdditional = enmAddAttr; + + switch (enmAddAttr) + { + case RTFSOBJATTRADD_NOTHING: RT_FALL_THRU(); + case RTFSOBJATTRADD_UNIX: + pObjInfo->Attr.u.Unix.uid = NIL_RTUID; + pObjInfo->Attr.u.Unix.gid = NIL_RTGID; + pObjInfo->Attr.u.Unix.cHardlinks = 1; + pObjInfo->Attr.u.Unix.INodeIdDevice = 0; + pObjInfo->Attr.u.Unix.INodeId = 0; /* Could probably use the directory entry offset. */ + pObjInfo->Attr.u.Unix.fFlags = 0; + pObjInfo->Attr.u.Unix.GenerationId = 0; + pObjInfo->Attr.u.Unix.Device = 0; + break; + case RTFSOBJATTRADD_UNIX_OWNER: + pObjInfo->Attr.u.UnixOwner.uid = 0; + pObjInfo->Attr.u.UnixOwner.szName[0] = '\0'; + break; + case RTFSOBJATTRADD_UNIX_GROUP: + pObjInfo->Attr.u.UnixGroup.gid = 0; + pObjInfo->Attr.u.UnixGroup.szName[0] = '\0'; + break; + case RTFSOBJATTRADD_EASIZE: + pObjInfo->Attr.u.EASize.cb = 0; + break; + default: + return VERR_INVALID_PARAMETER; + } + return VINF_SUCCESS; +} + + +/** + * Worker for rtFsFatFile_SetMode and rtFsFatDir_SetMode. + */ +static int rtFsFatObj_SetMode(PRTFSFATOBJ pThis, RTFMODE fMode, RTFMODE fMask) +{ +#if 0 + if (fMask != ~RTFS_TYPE_MASK) + { + fMode |= ~fMask & ObjInfo.Attr.fMode; + } +#else + RT_NOREF(pThis, fMode, fMask); + return VERR_NOT_IMPLEMENTED; +#endif +} + + +/** + * Worker for rtFsFatFile_SetTimes and rtFsFatDir_SetTimes. + */ +static int rtFsFatObj_SetTimes(PRTFSFATOBJ pThis, PCRTTIMESPEC pAccessTime, PCRTTIMESPEC pModificationTime, + PCRTTIMESPEC pChangeTime, PCRTTIMESPEC pBirthTime) +{ +#if 0 + PRTFSFATFILE pThis = (PRTFSFATFILE)pvThis; +#else + RT_NOREF(pThis, pAccessTime, pModificationTime, pChangeTime, pBirthTime); + return VERR_NOT_IMPLEMENTED; +#endif +} + + + + +/** + * @interface_method_impl{RTVFSOBJOPS,pfnClose} + */ +static DECLCALLBACK(int) rtFsFatFile_Close(void *pvThis) +{ + PRTFSFATFILE pThis = (PRTFSFATFILE)pvThis; + LogFlow(("rtFsFatFile_Close(%p/%p)\n", pThis, pThis->pShared)); + + PRTFSFATFILESHRD pShared = pThis->pShared; + pThis->pShared = NULL; + + int rc = VINF_SUCCESS; + if (pShared) + { + if (ASMAtomicDecU32(&pShared->Core.cRefs) == 0) + { + LogFlow(("rtFsFatFile_Close: Destroying shared structure %p\n", pShared)); + rc = rtFsFatObj_Close(&pShared->Core); + RTMemFree(pShared); + } + else + rc = rtFsFatObj_FlushMetaData(&pShared->Core); + } + return rc; +} + + +/** + * @interface_method_impl{RTVFSOBJOPS,pfnQueryInfo} + */ +static DECLCALLBACK(int) rtFsFatFile_QueryInfo(void *pvThis, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr) +{ + PRTFSFATFILE pThis = (PRTFSFATFILE)pvThis; + return rtFsFatObj_QueryInfo(&pThis->pShared->Core, pObjInfo, enmAddAttr); +} + + +/** + * @interface_method_impl{RTVFSIOSTREAMOPS,pfnRead} + */ +static DECLCALLBACK(int) rtFsFatFile_Read(void *pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t *pcbRead) +{ + PRTFSFATFILE pThis = (PRTFSFATFILE)pvThis; + PRTFSFATFILESHRD pShared = pThis->pShared; + AssertReturn(pSgBuf->cSegs != 0, VERR_INTERNAL_ERROR_3); + RT_NOREF(fBlocking); + + /* + * Check for EOF. + */ + if (off == -1) + off = pThis->offFile; + if ((uint64_t)off >= pShared->Core.cbObject) + { + if (pcbRead) + { + *pcbRead = 0; + return VINF_EOF; + } + return VERR_EOF; + } + + /* + * Do the reading cluster by cluster. + */ + int rc = VINF_SUCCESS; + uint32_t cbFileLeft = pShared->Core.cbObject - (uint32_t)off; + uint32_t cbRead = 0; + size_t cbLeft = pSgBuf->paSegs[0].cbSeg; + uint8_t *pbDst = (uint8_t *)pSgBuf->paSegs[0].pvSeg; + while (cbLeft > 0) + { + if (cbFileLeft > 0) + { + uint64_t offDisk = rtFsFatChain_FileOffsetToDiskOff(&pShared->Core.Clusters, (uint32_t)off, pShared->Core.pVol); + if (offDisk != UINT64_MAX) + { + uint32_t cbToRead = pShared->Core.Clusters.cbCluster - ((uint32_t)off & (pShared->Core.Clusters.cbCluster - 1)); + if (cbToRead > cbLeft) + cbToRead = (uint32_t)cbLeft; + if (cbToRead > cbFileLeft) + cbToRead = cbFileLeft; + rc = RTVfsFileReadAt(pShared->Core.pVol->hVfsBacking, offDisk, pbDst, cbToRead, NULL); + if (RT_SUCCESS(rc)) + { + off += cbToRead; + pbDst += cbToRead; + cbRead += cbToRead; + cbFileLeft -= cbToRead; + cbLeft -= cbToRead; + continue; + } + } + else + rc = VERR_VFS_BOGUS_OFFSET; + } + else + rc = pcbRead ? VINF_EOF : VERR_EOF; + break; + } + + /* Update the offset and return. */ + pThis->offFile = off; + if (pcbRead) + *pcbRead = cbRead; + return rc; +} + + +/** + * Changes the size of a file or directory FAT object. + * + * @returns IPRT status code + * @param pObj The common object. + * @param cbFile The new file size. + */ +static int rtFsFatObj_SetSize(PRTFSFATOBJ pObj, uint32_t cbFile) +{ + AssertReturn( ((pObj->cbObject + pObj->Clusters.cbCluster - 1) >> pObj->Clusters.cClusterByteShift) + == pObj->Clusters.cClusters, VERR_INTERNAL_ERROR_3); + + /* + * Do nothing if the size didn't change. + */ + if (pObj->cbObject == cbFile) + return VINF_SUCCESS; + + /* + * Do we need to allocate or free clusters? + */ + int rc = VINF_SUCCESS; + uint32_t const cClustersNew = (cbFile + pObj->Clusters.cbCluster - 1) >> pObj->Clusters.cClusterByteShift; + AssertReturn(pObj->pParentDir, VERR_INTERNAL_ERROR_2); + if (pObj->Clusters.cClusters == cClustersNew) + { /* likely when writing small bits at a time. */ } + else if (pObj->Clusters.cClusters < cClustersNew) + { + /* Allocate and append new clusters. */ + do + { + uint32_t idxCluster; + rc = rtFsFatClusterMap_AllocateCluster(pObj->pVol, rtFsFatChain_GetLastCluster(&pObj->Clusters), &idxCluster); + if (RT_SUCCESS(rc)) + rc = rtFsFatChain_Append(&pObj->Clusters, idxCluster); + } while (pObj->Clusters.cClusters < cClustersNew && RT_SUCCESS(rc)); + pObj->fMaybeDirtyFat = true; + } + else + { + /* Free clusters we don't need any more. */ + if (cClustersNew > 0) + rc = rtFsFatClusterMap_SetEndOfChain(pObj->pVol, rtFsFatChain_GetClusterByIndex(&pObj->Clusters, cClustersNew - 1)); + if (RT_SUCCESS(rc)) + { + uint32_t iClusterToFree = cClustersNew; + while (iClusterToFree < pObj->Clusters.cClusters && RT_SUCCESS(rc)) + { + rc = rtFsFatClusterMap_FreeCluster(pObj->pVol, rtFsFatChain_GetClusterByIndex(&pObj->Clusters, iClusterToFree)); + iClusterToFree++; + } + + rtFsFatChain_Shrink(&pObj->Clusters, cClustersNew); + } + pObj->fMaybeDirtyFat = true; + } + if (RT_SUCCESS(rc)) + { + /* + * Update the object size, since we've got the right number of clusters backing it now. + */ + pObj->cbObject = cbFile; + + /* + * Update the directory entry. + */ + uint32_t uWriteLock; + PFATDIRENTRY pDirEntry; + rc = rtFsFatDirShrd_GetEntryForUpdate(pObj->pParentDir, pObj->offEntryInDir, &pDirEntry, &uWriteLock); + if (RT_SUCCESS(rc)) + { + pDirEntry->cbFile = cbFile; + uint32_t idxFirstCluster; + if (cClustersNew == 0) + idxFirstCluster = 0; /** @todo figure out if setting the cluster to 0 is the right way to deal with empty files... */ + else + idxFirstCluster = rtFsFatChain_GetFirstCluster(&pObj->Clusters); + pDirEntry->idxCluster = (uint16_t)idxFirstCluster; + if (pObj->pVol->enmFatType >= RTFSFATTYPE_FAT32) + pDirEntry->u.idxClusterHigh = (uint16_t)(idxFirstCluster >> 16); + + rc = rtFsFatDirShrd_PutEntryAfterUpdate(pObj->pParentDir, pDirEntry, uWriteLock); + pObj->fMaybeDirtyDirEnt = true; + } + } + Log3(("rtFsFatObj_SetSize: Returns %Rrc\n", rc)); + return rc; +} + + +/** + * @interface_method_impl{RTVFSIOSTREAMOPS,pfnWrite} + */ +static DECLCALLBACK(int) rtFsFatFile_Write(void *pvThis, RTFOFF off, PCRTSGBUF pSgBuf, bool fBlocking, size_t *pcbWritten) +{ + PRTFSFATFILE pThis = (PRTFSFATFILE)pvThis; + PRTFSFATFILESHRD pShared = pThis->pShared; + PRTFSFATVOL pVol = pShared->Core.pVol; + AssertReturn(pSgBuf->cSegs != 0, VERR_INTERNAL_ERROR_3); + RT_NOREF(fBlocking); + + if (pVol->fReadOnly) + return VERR_WRITE_PROTECT; + + if (off == -1) + off = pThis->offFile; + + /* + * Do the reading cluster by cluster. + */ + int rc = VINF_SUCCESS; + uint32_t cbWritten = 0; + size_t cbLeft = pSgBuf->paSegs[0].cbSeg; + uint8_t const *pbSrc = (uint8_t const *)pSgBuf->paSegs[0].pvSeg; + while (cbLeft > 0) + { + /* Figure out how much we can write. Checking for max file size and such. */ + uint32_t cbToWrite = pShared->Core.Clusters.cbCluster - ((uint32_t)off & (pShared->Core.Clusters.cbCluster - 1)); + if (cbToWrite > cbLeft) + cbToWrite = (uint32_t)cbLeft; + uint64_t offNew = (uint64_t)off + cbToWrite; + if (offNew < _4G) + { /*likely*/ } + else if ((uint64_t)off < _4G - 1U) + cbToWrite = _4G - 1U - off; + else + { + rc = VERR_FILE_TOO_BIG; + break; + } + + /* Grow the file? */ + if ((uint32_t)offNew > pShared->Core.cbObject) + { + rc = rtFsFatObj_SetSize(&pShared->Core, (uint32_t)offNew); + if (RT_SUCCESS(rc)) + { /* likely */} + else + break; + } + + /* Figure the disk offset. */ + uint64_t offDisk = rtFsFatChain_FileOffsetToDiskOff(&pShared->Core.Clusters, (uint32_t)off, pVol); + if (offDisk != UINT64_MAX) + { + rc = RTVfsFileWriteAt(pVol->hVfsBacking, offDisk, pbSrc, cbToWrite, NULL); + if (RT_SUCCESS(rc)) + { + off += cbToWrite; + pbSrc += cbToWrite; + cbWritten += cbToWrite; + cbLeft -= cbToWrite; + } + else + break; + } + else + { + rc = VERR_VFS_BOGUS_OFFSET; + break; + } + } + + /* Update the offset and return. */ + pThis->offFile = off; + if (pcbWritten) + *pcbWritten = cbWritten; + return rc; +} + + +/** + * @interface_method_impl{RTVFSIOSTREAMOPS,pfnFlush} + */ +static DECLCALLBACK(int) rtFsFatFile_Flush(void *pvThis) +{ + PRTFSFATFILE pThis = (PRTFSFATFILE)pvThis; + PRTFSFATFILESHRD pShared = pThis->pShared; + int rc1 = rtFsFatObj_FlushMetaData(&pShared->Core); + int rc2 = RTVfsFileFlush(pShared->Core.pVol->hVfsBacking); + return RT_FAILURE(rc1) ? rc1 : rc2; +} + + +/** + * @interface_method_impl{RTVFSIOSTREAMOPS,pfnPollOne} + */ +static DECLCALLBACK(int) rtFsFatFile_PollOne(void *pvThis, uint32_t fEvents, RTMSINTERVAL cMillies, bool fIntr, + uint32_t *pfRetEvents) +{ + NOREF(pvThis); + int rc; + if (fEvents != RTPOLL_EVT_ERROR) + { + *pfRetEvents = fEvents & ~RTPOLL_EVT_ERROR; + rc = VINF_SUCCESS; + } + else if (fIntr) + rc = RTThreadSleep(cMillies); + else + { + uint64_t uMsStart = RTTimeMilliTS(); + do + rc = RTThreadSleep(cMillies); + while ( rc == VERR_INTERRUPTED + && !fIntr + && RTTimeMilliTS() - uMsStart < cMillies); + if (rc == VERR_INTERRUPTED) + rc = VERR_TIMEOUT; + } + return rc; +} + + +/** + * @interface_method_impl{RTVFSIOSTREAMOPS,pfnTell} + */ +static DECLCALLBACK(int) rtFsFatFile_Tell(void *pvThis, PRTFOFF poffActual) +{ + PRTFSFATFILE pThis = (PRTFSFATFILE)pvThis; + *poffActual = pThis->offFile; + return VINF_SUCCESS; +} + + +/** + * @interface_method_impl{RTVFSOBJSETOPS,pfnMode} + */ +static DECLCALLBACK(int) rtFsFatFile_SetMode(void *pvThis, RTFMODE fMode, RTFMODE fMask) +{ + PRTFSFATFILE pThis = (PRTFSFATFILE)pvThis; + return rtFsFatObj_SetMode(&pThis->pShared->Core, fMode, fMask); +} + + +/** + * @interface_method_impl{RTVFSOBJSETOPS,pfnSetTimes} + */ +static DECLCALLBACK(int) rtFsFatFile_SetTimes(void *pvThis, PCRTTIMESPEC pAccessTime, PCRTTIMESPEC pModificationTime, + PCRTTIMESPEC pChangeTime, PCRTTIMESPEC pBirthTime) +{ + PRTFSFATFILE pThis = (PRTFSFATFILE)pvThis; + return rtFsFatObj_SetTimes(&pThis->pShared->Core, pAccessTime, pModificationTime, pChangeTime, pBirthTime); +} + + +/** + * @interface_method_impl{RTVFSOBJSETOPS,pfnSetOwner} + */ +static DECLCALLBACK(int) rtFsFatFile_SetOwner(void *pvThis, RTUID uid, RTGID gid) +{ + RT_NOREF(pvThis, uid, gid); + return VERR_NOT_SUPPORTED; +} + + +/** + * @interface_method_impl{RTVFSFILEOPS,pfnSeek} + */ +static DECLCALLBACK(int) rtFsFatFile_Seek(void *pvThis, RTFOFF offSeek, unsigned uMethod, PRTFOFF poffActual) +{ + PRTFSFATFILE pThis = (PRTFSFATFILE)pvThis; + PRTFSFATFILESHRD pShared = pThis->pShared; + + RTFOFF offNew; + switch (uMethod) + { + case RTFILE_SEEK_BEGIN: + offNew = offSeek; + break; + case RTFILE_SEEK_END: + offNew = (RTFOFF)pShared->Core.cbObject + offSeek; + break; + case RTFILE_SEEK_CURRENT: + offNew = (RTFOFF)pThis->offFile + offSeek; + break; + default: + return VERR_INVALID_PARAMETER; + } + if (offNew >= 0) + { + if (offNew <= _4G) + { + pThis->offFile = offNew; + *poffActual = offNew; + return VINF_SUCCESS; + } + return VERR_OUT_OF_RANGE; + } + return VERR_NEGATIVE_SEEK; +} + + +/** + * @interface_method_impl{RTVFSFILEOPS,pfnQuerySize} + */ +static DECLCALLBACK(int) rtFsFatFile_QuerySize(void *pvThis, uint64_t *pcbFile) +{ + PRTFSFATFILE pThis = (PRTFSFATFILE)pvThis; + PRTFSFATFILESHRD pShared = pThis->pShared; + *pcbFile = pShared->Core.cbObject; + return VINF_SUCCESS; +} + + +/** + * @interface_method_impl{RTVFSFILEOPS,pfnSetSize} + */ +static DECLCALLBACK(int) rtFsFatFile_SetSize(void *pvThis, uint64_t cbFile, uint32_t fFlags) +{ + PRTFSFATFILE pThis = (PRTFSFATFILE)pvThis; + PRTFSFATFILESHRD pShared = pThis->pShared; + AssertReturn(!fFlags, VERR_NOT_SUPPORTED); + if (cbFile > UINT32_MAX) + return VERR_FILE_TOO_BIG; + return rtFsFatObj_SetSize(&pShared->Core, (uint32_t)cbFile); +} + + +/** + * @interface_method_impl{RTVFSFILEOPS,pfnQueryMaxSize} + */ +static DECLCALLBACK(int) rtFsFatFile_QueryMaxSize(void *pvThis, uint64_t *pcbMax) +{ + RT_NOREF(pvThis); + *pcbMax = UINT32_MAX; + return VINF_SUCCESS; +} + + +/** + * FAT file operations. + */ +DECL_HIDDEN_CONST(const RTVFSFILEOPS) g_rtFsFatFileOps = +{ + { /* Stream */ + { /* Obj */ + RTVFSOBJOPS_VERSION, + RTVFSOBJTYPE_FILE, + "FatFile", + rtFsFatFile_Close, + rtFsFatFile_QueryInfo, + NULL, + RTVFSOBJOPS_VERSION + }, + RTVFSIOSTREAMOPS_VERSION, + RTVFSIOSTREAMOPS_FEAT_NO_SG, + rtFsFatFile_Read, + rtFsFatFile_Write, + rtFsFatFile_Flush, + rtFsFatFile_PollOne, + rtFsFatFile_Tell, + NULL /*pfnSkip*/, + NULL /*pfnZeroFill*/, + RTVFSIOSTREAMOPS_VERSION, + }, + RTVFSFILEOPS_VERSION, + 0, + { /* ObjSet */ + RTVFSOBJSETOPS_VERSION, + RT_UOFFSETOF(RTVFSFILEOPS, ObjSet) - RT_UOFFSETOF(RTVFSFILEOPS, Stream.Obj), + rtFsFatFile_SetMode, + rtFsFatFile_SetTimes, + rtFsFatFile_SetOwner, + RTVFSOBJSETOPS_VERSION + }, + rtFsFatFile_Seek, + rtFsFatFile_QuerySize, + rtFsFatFile_SetSize, + rtFsFatFile_QueryMaxSize, + RTVFSFILEOPS_VERSION +}; + + +/** + * Instantiates a new file. + * + * @returns IPRT status code. + * @param pThis The FAT volume instance. + * @param pParentDir The parent directory. + * @param pDirEntry The parent directory entry. + * @param offEntryInDir The byte offset of the directory entry in the parent + * directory. + * @param fOpen RTFILE_O_XXX flags. + * @param phVfsFile Where to return the file handle. + */ +static int rtFsFatFile_New(PRTFSFATVOL pThis, PRTFSFATDIRSHRD pParentDir, PCFATDIRENTRY pDirEntry, uint32_t offEntryInDir, + uint64_t fOpen, PRTVFSFILE phVfsFile) +{ + AssertPtr(pParentDir); + Assert(!(offEntryInDir & (sizeof(FATDIRENTRY) - 1))); + + PRTFSFATFILE pNewFile; + int rc = RTVfsNewFile(&g_rtFsFatFileOps, sizeof(*pNewFile), fOpen, pThis->hVfsSelf, NIL_RTVFSLOCK /*use volume lock*/, + phVfsFile, (void **)&pNewFile); + if (RT_SUCCESS(rc)) + { + pNewFile->offFile = 0; + pNewFile->pShared = NULL; + + /* + * Look for existing shared object, create a new one if necessary. + */ + PRTFSFATFILESHRD pShared = (PRTFSFATFILESHRD)rtFsFatDirShrd_LookupShared(pParentDir, offEntryInDir); + if (pShared) + { + LogFlow(("rtFsFatFile_New: cbObject=%#RX32 \n", pShared->Core.cbObject)); + pNewFile->pShared = pShared; + return VINF_SUCCESS; + } + + pShared = (PRTFSFATFILESHRD)RTMemAllocZ(sizeof(*pShared)); + if (pShared) + { + rtFsFatObj_InitFromDirEntry(&pShared->Core, pDirEntry, offEntryInDir, pThis); + pNewFile->pShared = pShared; + + rc = rtFsFatClusterMap_ReadClusterChain(pThis, RTFSFAT_GET_CLUSTER(pDirEntry, pThis), &pShared->Core.Clusters); + if (RT_SUCCESS(rc)) + { + /* + * Link into parent directory so we can use it to update + * our directory entry. + */ + rtFsFatDirShrd_AddOpenChild(pParentDir, &pShared->Core); + + /* + * Should we truncate the file or anything of that sort? + */ + if ( (fOpen & RTFILE_O_TRUNCATE) + || (fOpen & RTFILE_O_ACTION_MASK) == RTFILE_O_CREATE_REPLACE) + { + Log3(("rtFsFatFile_New: calling rtFsFatObj_SetSize to zap the file size.\n")); + rc = rtFsFatObj_SetSize(&pShared->Core, 0); + } + if (RT_SUCCESS(rc)) + { + LogFlow(("rtFsFatFile_New: cbObject=%#RX32 pShared=%p\n", pShared->Core.cbObject, pShared)); + return VINF_SUCCESS; + } + } + } + else + rc = VERR_NO_MEMORY; + + /* Destroy the file object. */ + RTVfsFileRelease(*phVfsFile); + } + *phVfsFile = NIL_RTVFSFILE; + return rc; +} + + +/** + * Looks up the shared structure for a child. + * + * @returns Referenced pointer to the shared structure, NULL if not found. + * @param pThis The directory. + * @param offEntryInDir The directory record offset of the child. + */ +static PRTFSFATOBJ rtFsFatDirShrd_LookupShared(PRTFSFATDIRSHRD pThis, uint32_t offEntryInDir) +{ + PRTFSFATOBJ pCur; + RTListForEach(&pThis->OpenChildren, pCur, RTFSFATOBJ, Entry) + { + if (pCur->offEntryInDir == offEntryInDir) + { + uint32_t cRefs = ASMAtomicIncU32(&pCur->cRefs); + Assert(cRefs > 1); RT_NOREF(cRefs); + return pCur; + } + } + return NULL; +} + + +/** + * Flush directory changes when having a fully buffered directory. + * + * @returns IPRT status code + * @param pThis The directory. + */ +static int rtFsFatDirShrd_FlushFullyBuffered(PRTFSFATDIRSHRD pThis) +{ + Assert(pThis->fFullyBuffered); + uint32_t const cbSector = pThis->Core.pVol->cbSector; + RTVFSFILE const hVfsBacking = pThis->Core.pVol->hVfsBacking; + int rc = VINF_SUCCESS; + for (uint32_t i = 0; i < pThis->u.Full.cSectors; i++) + if (ASMBitTest(pThis->u.Full.pbDirtySectors, i)) + { + int rc2 = RTVfsFileWriteAt(hVfsBacking, pThis->offEntriesOnDisk + i * cbSector, + (uint8_t *)pThis->paEntries + i * cbSector, cbSector, NULL); + if (RT_SUCCESS(rc2)) + ASMBitClear(pThis->u.Full.pbDirtySectors, i); + else if (RT_SUCCESS(rc)) + rc = rc2; + } + return rc; +} + + +/** + * Flush directory changes when using simple buffering. + * + * @returns IPRT status code + * @param pThis The directory. + */ +static int rtFsFatDirShrd_FlushSimple(PRTFSFATDIRSHRD pThis) +{ + Assert(!pThis->fFullyBuffered); + int rc; + if ( !pThis->u.Simple.fDirty + || pThis->offEntriesOnDisk != UINT64_MAX) + rc = VINF_SUCCESS; + else + { + Assert(pThis->u.Simple.offInDir != UINT32_MAX); + rc = RTVfsFileWriteAt(pThis->Core.pVol->hVfsBacking, pThis->offEntriesOnDisk, + pThis->paEntries, pThis->Core.pVol->cbSector, NULL); + if (RT_SUCCESS(rc)) + pThis->u.Simple.fDirty = false; + } + return rc; +} + + +/** + * Flush directory changes. + * + * @returns IPRT status code + * @param pThis The directory. + */ +static int rtFsFatDirShrd_Flush(PRTFSFATDIRSHRD pThis) +{ + if (pThis->fFullyBuffered) + return rtFsFatDirShrd_FlushFullyBuffered(pThis); + return rtFsFatDirShrd_FlushSimple(pThis); +} + + +/** + * Gets one or more entires at @a offEntryInDir. + * + * Common worker for rtFsFatDirShrd_GetEntriesAt and rtFsFatDirShrd_GetEntryForUpdate + * + * @returns IPRT status code. + * @param pThis The directory. + * @param offEntryInDir The directory offset in bytes. + * @param fForUpdate Whether it's for updating. + * @param ppaEntries Where to return pointer to the entry at + * @a offEntryInDir. + * @param pcEntries Where to return the number of entries + * @a *ppaEntries points to. + * @param puBufferReadLock Where to return the buffer read lock handle. + * Call rtFsFatDirShrd_ReleaseBufferAfterReading when + * done. + */ +static int rtFsFatDirShrd_GetEntriesAtCommon(PRTFSFATDIRSHRD pThis, uint32_t offEntryInDir, bool fForUpdate, + PFATDIRENTRYUNION *ppaEntries, uint32_t *pcEntries, uint32_t *puLock) +{ + *puLock = UINT32_MAX; + + int rc; + Assert(RT_ALIGN_32(offEntryInDir, sizeof(FATDIRENTRY)) == offEntryInDir); + Assert(pThis->Core.cbObject / sizeof(FATDIRENTRY) == pThis->cEntries); + uint32_t const idxEntryInDir = offEntryInDir / sizeof(FATDIRENTRY); + if (idxEntryInDir < pThis->cEntries) + { + if (pThis->fFullyBuffered) + { + /* + * Fully buffered: Return pointer to all the entires starting at offEntryInDir. + */ + *ppaEntries = &pThis->paEntries[idxEntryInDir]; + *pcEntries = pThis->cEntries - idxEntryInDir; + *puLock = !fForUpdate ? 1 : UINT32_C(0x80000001); + rc = VINF_SUCCESS; + } + else + { + /* + * Simple buffering: If hit, return the number of entries. + */ + PRTFSFATVOL pVol = pThis->Core.pVol; + uint32_t off = offEntryInDir - pThis->u.Simple.offInDir; + if (off < pVol->cbSector) + { + *ppaEntries = &pThis->paEntries[off / sizeof(FATDIRENTRY)]; + *pcEntries = (pVol->cbSector - off) / sizeof(FATDIRENTRY); + *puLock = !fForUpdate ? 1 : UINT32_C(0x80000001); + rc = VINF_SUCCESS; + } + else + { + /* + * Simple buffering: Miss. + * Flush dirty. Read in new sector. Return entries in sector starting + * at offEntryInDir. + */ + if (!pThis->u.Simple.fDirty) + rc = VINF_SUCCESS; + else + rc = rtFsFatDirShrd_FlushSimple(pThis); + if (RT_SUCCESS(rc)) + { + off = offEntryInDir & (pVol->cbSector - 1); + pThis->u.Simple.offInDir = (offEntryInDir & ~(pVol->cbSector - 1)); + pThis->offEntriesOnDisk = rtFsFatChain_FileOffsetToDiskOff(&pThis->Core.Clusters, pThis->u.Simple.offInDir, + pThis->Core.pVol); + rc = RTVfsFileReadAt(pThis->Core.pVol->hVfsBacking, pThis->offEntriesOnDisk, + pThis->paEntries, pVol->cbSector, NULL); + if (RT_SUCCESS(rc)) + { + *ppaEntries = &pThis->paEntries[off / sizeof(FATDIRENTRY)]; + *pcEntries = (pVol->cbSector - off) / sizeof(FATDIRENTRY); + *puLock = !fForUpdate ? 1 : UINT32_C(0x80000001); + rc = VINF_SUCCESS; + } + else + { + pThis->u.Simple.offInDir = UINT32_MAX; + pThis->offEntriesOnDisk = UINT64_MAX; + } + } + } + } + } + else + rc = VERR_FILE_NOT_FOUND; + return rc; +} + + +/** + * Puts back a directory entry after updating it, releasing the write lock and + * marking it dirty. + * + * @returns IPRT status code + * @param pThis The directory. + * @param pDirEntry The directory entry. + * @param uWriteLock The write lock. + */ +static int rtFsFatDirShrd_PutEntryAfterUpdate(PRTFSFATDIRSHRD pThis, PFATDIRENTRY pDirEntry, uint32_t uWriteLock) +{ + Assert(uWriteLock == UINT32_C(0x80000001)); + RT_NOREF(uWriteLock); + if (pThis->fFullyBuffered) + { + uint32_t idxSector = ((uintptr_t)pDirEntry - (uintptr_t)pThis->paEntries) / pThis->Core.pVol->cbSector; + ASMBitSet(pThis->u.Full.pbDirtySectors, idxSector); + } + else + pThis->u.Simple.fDirty = true; + return VINF_SUCCESS; +} + + +/** + * Gets the pointer to the given directory entry for the purpose of updating it. + * + * Call rtFsFatDirShrd_PutEntryAfterUpdate afterwards. + * + * @returns IPRT status code. + * @param pThis The directory. + * @param offEntryInDir The byte offset of the directory entry, within the + * directory. + * @param ppDirEntry Where to return the pointer to the directory entry. + * @param puWriteLock Where to return the write lock. + */ +static int rtFsFatDirShrd_GetEntryForUpdate(PRTFSFATDIRSHRD pThis, uint32_t offEntryInDir, PFATDIRENTRY *ppDirEntry, + uint32_t *puWriteLock) +{ + uint32_t cEntriesIgn; + return rtFsFatDirShrd_GetEntriesAtCommon(pThis, offEntryInDir, true /*fForUpdate*/, (PFATDIRENTRYUNION *)ppDirEntry, + &cEntriesIgn, puWriteLock); +} + + +/** + * Release a directory buffer after done reading from it. + * + * This is currently just a placeholder. + * + * @param pThis The directory. + * @param uBufferReadLock The buffer lock. + */ +static void rtFsFatDirShrd_ReleaseBufferAfterReading(PRTFSFATDIRSHRD pThis, uint32_t uBufferReadLock) +{ + RT_NOREF(pThis, uBufferReadLock); + Assert(uBufferReadLock == 1); +} + + +/** + * Gets one or more entires at @a offEntryInDir. + * + * @returns IPRT status code. + * @param pThis The directory. + * @param offEntryInDir The directory offset in bytes. + * @param ppaEntries Where to return pointer to the entry at + * @a offEntryInDir. + * @param pcEntries Where to return the number of entries + * @a *ppaEntries points to. + * @param puBufferReadLock Where to return the buffer read lock handle. + * Call rtFsFatDirShrd_ReleaseBufferAfterReading when + * done. + */ +static int rtFsFatDirShrd_GetEntriesAt(PRTFSFATDIRSHRD pThis, uint32_t offEntryInDir, + PCFATDIRENTRYUNION *ppaEntries, uint32_t *pcEntries, uint32_t *puBufferReadLock) +{ + return rtFsFatDirShrd_GetEntriesAtCommon(pThis, offEntryInDir, false /*fForUpdate*/, (PFATDIRENTRYUNION *)ppaEntries, + pcEntries, puBufferReadLock); +} + + +/** + * Translates a unicode codepoint to an uppercased CP437 index. + * + * @returns CP437 index if valie, UINT16_MAX if not. + * @param uc The codepoint to convert. + */ +static uint16_t rtFsFatUnicodeCodepointToUpperCodepage(RTUNICP uc) +{ + /* + * The first 128 chars have 1:1 translation for valid FAT chars. + */ + if (uc < 128) + { + if (g_awchFatCp437ValidChars[uc] == uc) + return (uint16_t)uc; + if (RT_C_IS_LOWER(uc)) + return uc - 0x20; + return UINT16_MAX; + } + + /* + * Try for uppercased, settle for lower case if no upper case variant in the table. + * This is really expensive, btw. + */ + RTUNICP ucUpper = RTUniCpToUpper(uc); + for (unsigned i = 128; i < 256; i++) + if (g_awchFatCp437ValidChars[i] == ucUpper) + return i; + if (ucUpper != uc) + for (unsigned i = 128; i < 256; i++) + if (g_awchFatCp437ValidChars[i] == uc) + return i; + return UINT16_MAX; +} + + +/** + * Convert filename string to 8-dot-3 format, doing necessary ASCII uppercasing + * and such. + * + * @returns true if 8.3 formattable name, false if not. + * @param pszName8Dot3 Where to return the 8-dot-3 name when returning + * @c true. Filled with zero on false. 8+3+1 bytes. + * @param pszName The filename to convert. + */ +static bool rtFsFatDir_StringTo8Dot3(char *pszName8Dot3, const char *pszName) +{ + /* + * Don't try convert names with more than 12 unicode chars in them. + */ + size_t const cucName = RTStrUniLen(pszName); + if (cucName <= 12 && cucName > 0) + { + /* + * Recode the input string as CP437, uppercasing it, validating the + * name, formatting it as a FAT directory entry string. + */ + size_t offDst = 0; + bool fExt = false; + for (;;) + { + RTUNICP uc; + int rc = RTStrGetCpEx(&pszName, &uc); + if (RT_SUCCESS(rc)) + { + if (uc) + { + if (offDst < 8+3) + { + uint16_t idxCp = rtFsFatUnicodeCodepointToUpperCodepage(uc); + if (idxCp != UINT16_MAX) + { + pszName8Dot3[offDst++] = (char)idxCp; + Assert(uc != '.'); + continue; + } + + /* Maybe the dot? */ + if ( uc == '.' + && !fExt + && offDst <= 8) + { + fExt = true; + while (offDst < 8) + pszName8Dot3[offDst++] = ' '; + continue; + } + } + } + /* String terminator: Check length, pad and convert 0xe5. */ + else if (offDst <= (size_t)(fExt ? 8 + 3 : 8)) + { + while (offDst < 8 + 3) + pszName8Dot3[offDst++] = ' '; + Assert(offDst == 8 + 3); + pszName8Dot3[offDst] = '\0'; + + if ((uint8_t)pszName8Dot3[0] == FATDIRENTRY_CH0_DELETED) + pszName8Dot3[0] = FATDIRENTRY_CH0_ESC_E5; + return true; + } + } + /* invalid */ + break; + } + } + memset(&pszName8Dot3[0], 0, 8+3+1); + return false; +} + + +/** + * Calculates the checksum of a directory entry. + * @returns Checksum. + * @param pDirEntry The directory entry to checksum. + */ +static uint8_t rtFsFatDir_CalcChecksum(PCFATDIRENTRY pDirEntry) +{ + uint8_t bChecksum = pDirEntry->achName[0]; + for (uint8_t off = 1; off < RT_ELEMENTS(pDirEntry->achName); off++) + { + bChecksum = RTFSFAT_ROT_R1_U8(bChecksum); + bChecksum += pDirEntry->achName[off]; + } + return bChecksum; +} + + +/** + * Locates a directory entry in a directory. + * + * @returns IPRT status code. + * @retval VERR_FILE_NOT_FOUND if not found. + * @param pThis The directory to search. + * @param pszEntry The entry to look for. + * @param poffEntryInDir Where to return the offset of the directory + * entry. + * @param pfLong Where to return long name indicator. + * @param pDirEntry Where to return a copy of the directory entry. + */ +static int rtFsFatDirShrd_FindEntry(PRTFSFATDIRSHRD pThis, const char *pszEntry, uint32_t *poffEntryInDir, bool *pfLong, + PFATDIRENTRY pDirEntry) +{ + /* Set return values. */ + *pfLong = false; + *poffEntryInDir = UINT32_MAX; + + /* + * Turn pszEntry into a 8.3 filename, if possible. + */ + char szName8Dot3[8+3+1]; + bool fIs8Dot3Name = rtFsFatDir_StringTo8Dot3(szName8Dot3, pszEntry); + + /* + * Scan the directory buffer by buffer. + */ + RTUTF16 wszName[260+1]; + uint8_t bChecksum = UINT8_MAX; + uint8_t idNextSlot = UINT8_MAX; + size_t cwcName = 0; + uint32_t offEntryInDir = 0; + uint32_t const cbDir = pThis->Core.cbObject; + Assert(RT_ALIGN_32(cbDir, sizeof(*pDirEntry)) == cbDir); + AssertCompile(FATDIRNAMESLOT_MAX_SLOTS * FATDIRNAMESLOT_CHARS_PER_SLOT < RT_ELEMENTS(wszName)); + wszName[260] = '\0'; + + while (offEntryInDir < cbDir) + { + /* Get chunk of entries starting at offEntryInDir. */ + uint32_t uBufferLock = UINT32_MAX; + uint32_t cEntries = 0; + PCFATDIRENTRYUNION paEntries = NULL; + int rc = rtFsFatDirShrd_GetEntriesAt(pThis, offEntryInDir, &paEntries, &cEntries, &uBufferLock); + if (RT_FAILURE(rc)) + return rc; + + /* + * Now work thru each of the entries. + */ + for (uint32_t iEntry = 0; iEntry < cEntries; iEntry++, offEntryInDir += sizeof(FATDIRENTRY)) + { + switch ((uint8_t)paEntries[iEntry].Entry.achName[0]) + { + default: + break; + case FATDIRENTRY_CH0_DELETED: + cwcName = 0; + continue; + case FATDIRENTRY_CH0_END_OF_DIR: + if (pThis->Core.pVol->enmBpbVersion >= RTFSFATBPBVER_DOS_2_0) + { + rtFsFatDirShrd_ReleaseBufferAfterReading(pThis, uBufferLock); + return VERR_FILE_NOT_FOUND; + } + cwcName = 0; + break; /* Technically a valid entry before DOS 2.0, or so some claim. */ + } + + /* + * Check for long filename slot. + */ + if ( paEntries[iEntry].Slot.fAttrib == FAT_ATTR_NAME_SLOT + && paEntries[iEntry].Slot.idxZero == 0 + && paEntries[iEntry].Slot.fZero == 0 + && (paEntries[iEntry].Slot.idSlot & ~FATDIRNAMESLOT_FIRST_SLOT_FLAG) <= FATDIRNAMESLOT_HIGHEST_SLOT_ID + && (paEntries[iEntry].Slot.idSlot & ~FATDIRNAMESLOT_FIRST_SLOT_FLAG) != 0) + { + /* New slot? */ + if (paEntries[iEntry].Slot.idSlot & FATDIRNAMESLOT_FIRST_SLOT_FLAG) + { + idNextSlot = paEntries[iEntry].Slot.idSlot & ~FATDIRNAMESLOT_FIRST_SLOT_FLAG; + bChecksum = paEntries[iEntry].Slot.bChecksum; + cwcName = idNextSlot * FATDIRNAMESLOT_CHARS_PER_SLOT; + wszName[cwcName] = '\0'; + } + /* Is valid next entry? */ + else if ( paEntries[iEntry].Slot.idSlot == idNextSlot + && paEntries[iEntry].Slot.bChecksum == bChecksum) + { /* likely */ } + else + cwcName = 0; + if (cwcName) + { + idNextSlot--; + size_t offName = idNextSlot * FATDIRNAMESLOT_CHARS_PER_SLOT; + memcpy(&wszName[offName], paEntries[iEntry].Slot.awcName0, sizeof(paEntries[iEntry].Slot.awcName0)); + memcpy(&wszName[offName + 5], paEntries[iEntry].Slot.awcName1, sizeof(paEntries[iEntry].Slot.awcName1)); + memcpy(&wszName[offName + 5 + 6], paEntries[iEntry].Slot.awcName2, sizeof(paEntries[iEntry].Slot.awcName2)); + } + } + /* + * Regular directory entry. Do the matching, first 8.3 then long name. + */ + else if ( fIs8Dot3Name + && !(paEntries[iEntry].Entry.fAttrib & FAT_ATTR_VOLUME) + && memcmp(paEntries[iEntry].Entry.achName, szName8Dot3, sizeof(paEntries[iEntry].Entry.achName)) == 0) + { + *poffEntryInDir = offEntryInDir; + *pDirEntry = paEntries[iEntry].Entry; + *pfLong = false; + rtFsFatDirShrd_ReleaseBufferAfterReading(pThis, uBufferLock); + return VINF_SUCCESS; + } + else if ( cwcName != 0 + && idNextSlot == 0 + && !(paEntries[iEntry].Entry.fAttrib & FAT_ATTR_VOLUME) + && rtFsFatDir_CalcChecksum(&paEntries[iEntry].Entry) == bChecksum + && RTUtf16ICmpUtf8(wszName, pszEntry) == 0) + { + *poffEntryInDir = offEntryInDir; + *pDirEntry = paEntries[iEntry].Entry; + *pfLong = true; + rtFsFatDirShrd_ReleaseBufferAfterReading(pThis, uBufferLock); + return VINF_SUCCESS; + } + else + cwcName = 0; + } + + rtFsFatDirShrd_ReleaseBufferAfterReading(pThis, uBufferLock); + } + + return VERR_FILE_NOT_FOUND; +} + + +/** + * Watered down version of rtFsFatDirShrd_FindEntry that is used by the short name + * generator to check for duplicates. + * + * @returns IPRT status code. + * @retval VERR_FILE_NOT_FOUND if not found. + * @retval VINF_SUCCESS if found. + * @param pThis The directory to search. + * @param pszEntry The entry to look for. + */ +static int rtFsFatDirShrd_FindEntryShort(PRTFSFATDIRSHRD pThis, const char *pszName8Dot3) +{ + Assert(strlen(pszName8Dot3) == 8+3); + + /* + * Scan the directory buffer by buffer. + */ + uint32_t offEntryInDir = 0; + uint32_t const cbDir = pThis->Core.cbObject; + Assert(RT_ALIGN_32(cbDir, sizeof(FATDIRENTRY)) == cbDir); + + while (offEntryInDir < cbDir) + { + /* Get chunk of entries starting at offEntryInDir. */ + uint32_t uBufferLock = UINT32_MAX; + uint32_t cEntries = 0; + PCFATDIRENTRYUNION paEntries = NULL; + int rc = rtFsFatDirShrd_GetEntriesAt(pThis, offEntryInDir, &paEntries, &cEntries, &uBufferLock); + if (RT_FAILURE(rc)) + return rc; + + /* + * Now work thru each of the entries. + */ + for (uint32_t iEntry = 0; iEntry < cEntries; iEntry++, offEntryInDir += sizeof(FATDIRENTRY)) + { + switch ((uint8_t)paEntries[iEntry].Entry.achName[0]) + { + default: + break; + case FATDIRENTRY_CH0_DELETED: + continue; + case FATDIRENTRY_CH0_END_OF_DIR: + if (pThis->Core.pVol->enmBpbVersion >= RTFSFATBPBVER_DOS_2_0) + { + rtFsFatDirShrd_ReleaseBufferAfterReading(pThis, uBufferLock); + return VERR_FILE_NOT_FOUND; + } + break; /* Technically a valid entry before DOS 2.0, or so some claim. */ + } + + /* + * Skip long filename slots. + */ + if ( paEntries[iEntry].Slot.fAttrib == FAT_ATTR_NAME_SLOT + && paEntries[iEntry].Slot.idxZero == 0 + && paEntries[iEntry].Slot.fZero == 0 + && (paEntries[iEntry].Slot.idSlot & ~FATDIRNAMESLOT_FIRST_SLOT_FLAG) <= FATDIRNAMESLOT_HIGHEST_SLOT_ID + && (paEntries[iEntry].Slot.idSlot & ~FATDIRNAMESLOT_FIRST_SLOT_FLAG) != 0) + { /* skipped */ } + /* + * Regular directory entry. Do the matching, first 8.3 then long name. + */ + else if (memcmp(paEntries[iEntry].Entry.achName, pszName8Dot3, sizeof(paEntries[iEntry].Entry.achName)) == 0) + { + rtFsFatDirShrd_ReleaseBufferAfterReading(pThis, uBufferLock); + return VINF_SUCCESS; + } + } + + rtFsFatDirShrd_ReleaseBufferAfterReading(pThis, uBufferLock); + } + + return VERR_FILE_NOT_FOUND; +} + + +/** + * Calculates the FATDIRENTRY::fCase flags for the given name. + * + * ASSUMES that the name is a 8.3 name. + * + * @returns Case flag mask. + * @param pszName The name. + */ +static uint8_t rtFsFatDir_CalcCaseFlags(const char *pszName) +{ + uint8_t bRet = FATDIRENTRY_CASE_F_LOWER_BASE | FATDIRENTRY_CASE_F_LOWER_EXT; + uint8_t bCurrent = FATDIRENTRY_CASE_F_LOWER_BASE; + for (;;) + { + RTUNICP uc; + int rc = RTStrGetCpEx(&pszName, &uc); + if (RT_SUCCESS(rc)) + { + if (uc != 0) + { + if (uc != '.') + { + if (RTUniCpIsUpper(uc)) + { + bRet &= ~bCurrent; + if (!bRet) + return 0; + } + } + else + bCurrent = FATDIRENTRY_CASE_F_LOWER_EXT; + } + else if (bCurrent == FATDIRENTRY_CASE_F_LOWER_BASE) + return bRet & ~FATDIRENTRY_CASE_F_LOWER_EXT; + else + return bRet; + } + else + return 0; + } +} + + +/** + * Checks if we need to generate a long name for @a pszEntry. + * + * @returns true if we need to, false if we don't. + * @param pszEntry The UTF-8 directory entry entry name. + * @param fIs8Dot3Name Whether we've managed to create a 8-dot-3 name. + * @param pDirEntry The directory entry with the 8-dot-3 name when + * fIs8Dot3Name is set. + */ +static bool rtFsFatDir_NeedLongName(const char *pszEntry, bool fIs8Dot3Name, PCFATDIRENTRY pDirEntry) +{ + /* + * Check the easy ways out first. + */ + + /* If we couldn't make a straight 8-dot-3 name out of it, the we + must do the long name thing. No question. */ + if (!fIs8Dot3Name) + return true; + + /* If both lower case flags are set, then the whole name must be + lowercased, so we won't need a long entry. */ + if (pDirEntry->fCase == (FATDIRENTRY_CASE_F_LOWER_BASE | FATDIRENTRY_CASE_F_LOWER_EXT)) + return false; + + /* + * Okay, check out the whole string then, part by part. (This is code + * similar to rtFsFatDir_CalcCaseFlags.) + */ + uint8_t fCurrent = pDirEntry->fCase & FATDIRENTRY_CASE_F_LOWER_BASE; + for (;;) + { + RTUNICP uc; + int rc = RTStrGetCpEx(&pszEntry, &uc); + if (RT_SUCCESS(rc)) + { + if (uc != 0) + { + if (uc != '.') + { + if ( fCurrent + || !RTUniCpIsLower(uc)) + { /* okay */ } + else + return true; + } + else + fCurrent = pDirEntry->fCase & FATDIRENTRY_CASE_F_LOWER_EXT; + } + /* It checked out to the end, so we don't need a long name. */ + else + return false; + } + else + return true; + } +} + + +/** + * Checks if the given long name is valid for a long file name or not. + * + * Encoding, length and character set limitations are checked. + * + * @returns IRPT status code. + * @param pwszEntry The long filename. + * @param cwc The length of the filename in UTF-16 chars. + */ +static int rtFsFatDir_ValidateLongName(PCRTUTF16 pwszEntry, size_t cwc) +{ + /* Length limitation. */ + if (cwc <= RTFSFAT_MAX_LFN_CHARS) + { + /* Character set limitations. */ + for (size_t off = 0; off < cwc; off++) + { + RTUTF16 wc = pwszEntry[off]; + if (wc < 128) + { + if (g_awchFatCp437ValidChars[wc] <= UINT16_C(0xfffe)) + { /* likely */ } + else + return VERR_INVALID_NAME; + } + } + + /* Name limitations. */ + if ( cwc == 1 + && pwszEntry[0] == '.') + return VERR_INVALID_NAME; + if ( cwc == 2 + && pwszEntry[0] == '.' + && pwszEntry[1] == '.') + return VERR_INVALID_NAME; + + /** @todo Check for more invalid names, also in the 8.3 case! */ + return VINF_SUCCESS; + } + return VERR_FILENAME_TOO_LONG; +} + + +/** + * Worker for rtFsFatDirShrd_GenerateShortName. + */ +static void rtFsFatDir_CopyShortName(char *pszDst, uint32_t cchDst, const char *pszSrc, size_t cchSrc, char chPad) +{ + /* Copy from source. */ + if (cchSrc > 0) + { + const char *pszSrcEnd = &pszSrc[cchSrc]; + while (cchDst > 0 && pszSrc != pszSrcEnd) + { + RTUNICP uc; + int rc = RTStrGetCpEx(&pszSrc, &uc); + if (RT_SUCCESS(rc)) + { + if (uc < 128) + { + if (g_awchFatCp437ValidChars[uc] != uc) + { + if (uc) + { + uc = RTUniCpToUpper(uc); + if (g_awchFatCp437ValidChars[uc] != uc) + uc = '_'; + } + else + break; + } + } + else + uc = '_'; + } + else + uc = '_'; + + *pszDst++ = (char)uc; + cchDst--; + } + } + + /* Pad the remaining space. */ + while (cchDst-- > 0) + *pszDst++ = chPad; +} + + +/** + * Generates a short filename. + * + * @returns IPRT status code. + * @param pThis The directory. + * @param pszEntry The long name (UTF-8). + * @param pDirEntry Where to put the short name. + */ +static int rtFsFatDirShrd_GenerateShortName(PRTFSFATDIRSHRD pThis, const char *pszEntry, PFATDIRENTRY pDirEntry) +{ + /* Do some input parsing. */ + const char *pszExt = RTPathSuffix(pszEntry); + size_t const cchBasename = pszExt ? pszExt - pszEntry : strlen(pszEntry); + size_t const cchExt = pszExt ? strlen(++pszExt) : 0; + + /* Fill in the extension first. It stays the same. */ + char szShortName[8+3+1]; + rtFsFatDir_CopyShortName(&szShortName[8], 3, pszExt, cchExt, ' '); + szShortName[8+3] = '\0'; + + /* + * First try single digit 1..9. + */ + rtFsFatDir_CopyShortName(szShortName, 6, pszEntry, cchBasename, '_'); + szShortName[6] = '~'; + for (uint32_t iLastDigit = 1; iLastDigit < 10; iLastDigit++) + { + szShortName[7] = iLastDigit + '0'; + int rc = rtFsFatDirShrd_FindEntryShort(pThis, szShortName); + if (rc == VERR_FILE_NOT_FOUND) + { + memcpy(pDirEntry->achName, szShortName, sizeof(pDirEntry->achName)); + return VINF_SUCCESS; + } + if (RT_FAILURE(rc)) + return rc; + } + + /* + * First try two digits 10..99. + */ + szShortName[5] = '~'; + for (uint32_t iFirstDigit = 1; iFirstDigit < 10; iFirstDigit++) + for (uint32_t iLastDigit = 0; iLastDigit < 10; iLastDigit++) + { + szShortName[6] = iFirstDigit + '0'; + szShortName[7] = iLastDigit + '0'; + int rc = rtFsFatDirShrd_FindEntryShort(pThis, szShortName); + if (rc == VERR_FILE_NOT_FOUND) + { + memcpy(pDirEntry->achName, szShortName, sizeof(pDirEntry->achName)); + return VINF_SUCCESS; + } + if (RT_FAILURE(rc)) + return rc; + } + + /* + * Okay, do random numbers then. + */ + szShortName[2] = '~'; + for (uint32_t i = 0; i < 8192; i++) + { + char szHex[68]; + ssize_t cchHex = RTStrFormatU32(szHex, sizeof(szHex), RTRandU32(), 16, 5, 0, RTSTR_F_CAPITAL | RTSTR_F_WIDTH | RTSTR_F_ZEROPAD); + AssertReturn(cchHex >= 5, VERR_NET_NOT_UNIQUE_NAME); + szShortName[7] = szHex[cchHex - 1]; + szShortName[6] = szHex[cchHex - 2]; + szShortName[5] = szHex[cchHex - 3]; + szShortName[4] = szHex[cchHex - 4]; + szShortName[3] = szHex[cchHex - 5]; + int rc = rtFsFatDirShrd_FindEntryShort(pThis, szShortName); + if (rc == VERR_FILE_NOT_FOUND) + { + memcpy(pDirEntry->achName, szShortName, sizeof(pDirEntry->achName)); + return VINF_SUCCESS; + } + if (RT_FAILURE(rc)) + return rc; + } + + return VERR_NET_NOT_UNIQUE_NAME; +} + + +/** + * Considers whether we need to create a long name or not. + * + * If a long name is needed and the name wasn't 8-dot-3 compatible, a 8-dot-3 + * name will be generated and stored in *pDirEntry. + * + * @returns IPRT status code + * @param pThis The directory. + * @param pszEntry The name. + * @param fIs8Dot3Name Whether we have a 8-dot-3 name already. + * @param pDirEntry Where to return the generated 8-dot-3 name. + * @param paSlots Where to return the long name entries. The array + * can hold at least FATDIRNAMESLOT_MAX_SLOTS entries. + * @param pcSlots Where to return the actual number of slots used. + */ +static int rtFsFatDirShrd_MaybeCreateLongNameAndShortAlias(PRTFSFATDIRSHRD pThis, const char *pszEntry, bool fIs8Dot3Name, + PFATDIRENTRY pDirEntry, PFATDIRNAMESLOT paSlots, uint32_t *pcSlots) +{ + RT_NOREF(pThis, pDirEntry, paSlots, pszEntry); + + /* + * If we don't need to create a long name, return immediately. + */ + if (!rtFsFatDir_NeedLongName(pszEntry, fIs8Dot3Name, pDirEntry)) + { + *pcSlots = 0; + return VINF_SUCCESS; + } + + /* + * Convert the name to UTF-16 and figure it's length (this validates the + * input encoding). Then do long name validation (length, charset limitation). + */ + RTUTF16 wszEntry[FATDIRNAMESLOT_MAX_SLOTS * FATDIRNAMESLOT_CHARS_PER_SLOT + 4]; + PRTUTF16 pwszEntry = wszEntry; + size_t cwcEntry; + int rc = RTStrToUtf16Ex(pszEntry, RTSTR_MAX, &pwszEntry, RT_ELEMENTS(wszEntry), &cwcEntry); + if (RT_SUCCESS(rc)) + rc = rtFsFatDir_ValidateLongName(pwszEntry, cwcEntry); + if (RT_SUCCESS(rc)) + { + /* + * Generate a short name if we need to. + */ + if (!fIs8Dot3Name) + rc = rtFsFatDirShrd_GenerateShortName(pThis, pszEntry, pDirEntry); + if (RT_SUCCESS(rc)) + { + /* + * Fill in the long name slots. First we pad the wszEntry with 0xffff + * until it is a multiple of of the slot count. That way we can copy + * the name straight into the entry without constaints. + */ + memset(&wszEntry[cwcEntry + 1], 0xff, + RT_MIN(sizeof(wszEntry) - (cwcEntry + 1) * sizeof(RTUTF16), + FATDIRNAMESLOT_CHARS_PER_SLOT * sizeof(RTUTF16))); + + uint8_t const bChecksum = rtFsFatDir_CalcChecksum(pDirEntry); + size_t const cSlots = (cwcEntry + FATDIRNAMESLOT_CHARS_PER_SLOT - 1) / FATDIRNAMESLOT_CHARS_PER_SLOT; + size_t iSlot = cSlots; + PCRTUTF16 pwszSrc = wszEntry; + while (iSlot-- > 0) + { + memcpy(paSlots[iSlot].awcName0, pwszSrc, sizeof(paSlots[iSlot].awcName0)); + pwszSrc += RT_ELEMENTS(paSlots[iSlot].awcName0); + memcpy(paSlots[iSlot].awcName1, pwszSrc, sizeof(paSlots[iSlot].awcName1)); + pwszSrc += RT_ELEMENTS(paSlots[iSlot].awcName1); + memcpy(paSlots[iSlot].awcName2, pwszSrc, sizeof(paSlots[iSlot].awcName2)); + pwszSrc += RT_ELEMENTS(paSlots[iSlot].awcName2); + + paSlots[iSlot].idSlot = (uint8_t)(cSlots - iSlot); + paSlots[iSlot].fAttrib = FAT_ATTR_NAME_SLOT; + paSlots[iSlot].fZero = 0; + paSlots[iSlot].idxZero = 0; + paSlots[iSlot].bChecksum = bChecksum; + } + paSlots[0].idSlot |= FATDIRNAMESLOT_FIRST_SLOT_FLAG; + *pcSlots = (uint32_t)cSlots; + return VINF_SUCCESS; + } + } + *pcSlots = UINT32_MAX; + return rc; +} + + +/** + * Searches the directory for a given number of free directory entries. + * + * The free entries must be consecutive of course. + * + * @returns IPRT status code. + * @retval VERR_DISK_FULL if no space was found, *pcFreeTail set. + * @param pThis The directory to search. + * @param cEntriesNeeded How many entries we need. + * @param poffEntryInDir Where to return the offset of the first entry we + * found. + * @param pcFreeTail Where to return the number of free entries at the + * end of the directory when VERR_DISK_FULL is + * returned. + */ +static int rtFsFatChain_FindFreeEntries(PRTFSFATDIRSHRD pThis, uint32_t cEntriesNeeded, + uint32_t *poffEntryInDir, uint32_t *pcFreeTail) +{ + /* First try make gcc happy. */ + *pcFreeTail = 0; + *poffEntryInDir = UINT32_MAX; + + /* + * Scan the whole directory, buffer by buffer. + */ + uint32_t offStartFreeEntries = UINT32_MAX; + uint32_t cFreeEntries = 0; + uint32_t offEntryInDir = 0; + uint32_t const cbDir = pThis->Core.cbObject; + Assert(RT_ALIGN_32(cbDir, sizeof(FATDIRENTRY)) == cbDir); + while (offEntryInDir < cbDir) + { + /* Get chunk of entries starting at offEntryInDir. */ + uint32_t uBufferLock = UINT32_MAX; + uint32_t cEntries = 0; + PCFATDIRENTRYUNION paEntries = NULL; + int rc = rtFsFatDirShrd_GetEntriesAt(pThis, offEntryInDir, &paEntries, &cEntries, &uBufferLock); + if (RT_FAILURE(rc)) + return rc; + + /* + * Now work thru each of the entries. + */ + for (uint32_t iEntry = 0; iEntry < cEntries; iEntry++, offEntryInDir += sizeof(FATDIRENTRY)) + { + uint8_t const bFirst = paEntries[iEntry].Entry.achName[0]; + if ( bFirst == FATDIRENTRY_CH0_DELETED + || bFirst == FATDIRENTRY_CH0_END_OF_DIR) + { + if (offStartFreeEntries != UINT32_MAX) + cFreeEntries++; + else + { + offStartFreeEntries = offEntryInDir; + cFreeEntries = 1; + } + if (cFreeEntries >= cEntriesNeeded) + { + *pcFreeTail = cEntriesNeeded; + *poffEntryInDir = offStartFreeEntries; + rtFsFatDirShrd_ReleaseBufferAfterReading(pThis, uBufferLock); + return VINF_SUCCESS; + } + + if (bFirst == FATDIRENTRY_CH0_END_OF_DIR) + { + if (pThis->Core.pVol->enmBpbVersion >= RTFSFATBPBVER_DOS_2_0) + { + rtFsFatDirShrd_ReleaseBufferAfterReading(pThis, uBufferLock); + *pcFreeTail = cFreeEntries = (cbDir - offStartFreeEntries) / sizeof(FATDIRENTRY); + if (cFreeEntries >= cEntriesNeeded) + { + *poffEntryInDir = offStartFreeEntries; + rtFsFatDirShrd_ReleaseBufferAfterReading(pThis, uBufferLock); + return VINF_SUCCESS; + } + return VERR_DISK_FULL; + } + } + } + else if (offStartFreeEntries != UINT32_MAX) + { + offStartFreeEntries = UINT32_MAX; + cFreeEntries = 0; + } + } + rtFsFatDirShrd_ReleaseBufferAfterReading(pThis, uBufferLock); + } + *pcFreeTail = cFreeEntries; + return VERR_DISK_FULL; +} + + +/** + * Try grow the directory. + * + * This is not called on the root directory. + * + * @returns IPRT status code. + * @retval VERR_DISK_FULL if we failed to allocated new space. + * @param pThis The directory to grow. + * @param cMinNewEntries The minimum number of new entries to allocated. + */ +static int rtFsFatChain_GrowDirectory(PRTFSFATDIRSHRD pThis, uint32_t cMinNewEntries) +{ + RT_NOREF(pThis, cMinNewEntries); + return VERR_DISK_FULL; +} + + +/** + * Inserts a directory with zero of more long name slots preceeding it. + * + * @returns IPRT status code. + * @param pThis The directory. + * @param pDirEntry The directory entry. + * @param paSlots The long name slots. + * @param cSlots The number of long name slots. + * @param poffEntryInDir Where to return the directory offset. + */ +static int rtFsFatChain_InsertEntries(PRTFSFATDIRSHRD pThis, PCFATDIRENTRY pDirEntry, PFATDIRNAMESLOT paSlots, uint32_t cSlots, + uint32_t *poffEntryInDir) +{ + uint32_t const cTotalEntries = cSlots + 1; + + /* + * Find somewhere to put the entries. Try extend the directory if we're + * not successful at first. + */ + uint32_t cFreeTailEntries; + uint32_t offFirstInDir; + int rc = rtFsFatChain_FindFreeEntries(pThis, cTotalEntries, &offFirstInDir, &cFreeTailEntries); + if (rc == VERR_DISK_FULL) + { + Assert(cFreeTailEntries < cTotalEntries); + + /* Try grow it and use the newly allocated space. */ + if ( pThis->Core.pParentDir + && pThis->cEntries < _64K /* Don't grow beyond 64K entries */) + { + offFirstInDir = pThis->Core.cbObject - cFreeTailEntries * sizeof(FATDIRENTRY); + rc = rtFsFatChain_GrowDirectory(pThis, cTotalEntries - cFreeTailEntries); + } + + if (rc == VERR_DISK_FULL) + { + /** @todo Try compact the directory if we couldn't grow it. */ + } + } + if (RT_SUCCESS(rc)) + { + /* + * Update the directory. + */ + uint32_t offCurrent = offFirstInDir; + for (uint32_t iSrcSlot = 0; iSrcSlot < cTotalEntries; iSrcSlot++, offCurrent += sizeof(FATDIRENTRY)) + { + uint32_t uBufferLock; + PFATDIRENTRY pDstEntry; + rc = rtFsFatDirShrd_GetEntryForUpdate(pThis, offCurrent, &pDstEntry, &uBufferLock); + if (RT_SUCCESS(rc)) + { + if (iSrcSlot < cSlots) + memcpy(pDstEntry, &paSlots[iSrcSlot], sizeof(*pDstEntry)); + else + memcpy(pDstEntry, pDirEntry, sizeof(*pDstEntry)); + rc = rtFsFatDirShrd_PutEntryAfterUpdate(pThis, pDstEntry, uBufferLock); + if (RT_SUCCESS(rc)) + continue; + + /* + * Bail out: Try mark any edited entries as deleted. + */ + iSrcSlot++; + } + while (iSrcSlot-- > 0) + { + int rc2 = rtFsFatDirShrd_GetEntryForUpdate(pThis, offFirstInDir + iSrcSlot * sizeof(FATDIRENTRY), + &pDstEntry, &uBufferLock); + if (RT_SUCCESS(rc2)) + { + pDstEntry->achName[0] = FATDIRENTRY_CH0_DELETED; + rtFsFatDirShrd_PutEntryAfterUpdate(pThis, pDstEntry, uBufferLock); + } + } + *poffEntryInDir = UINT32_MAX; + return rc; + } + AssertRC(rc); + + /* + * Successfully inserted all. + */ + *poffEntryInDir = offFirstInDir + cSlots * sizeof(FATDIRENTRY); + return VINF_SUCCESS; + } + + *poffEntryInDir = UINT32_MAX; + return rc; +} + + + +/** + * Creates a new directory entry. + * + * @returns IPRT status code + * @param pThis The directory. + * @param pszEntry The name of the new entry. + * @param fAttrib The attributes. + * @param cbInitial The initialize size. + * @param poffEntryInDir Where to return the offset of the directory entry. + * @param pDirEntry Where to return a copy of the directory entry. + * + * @remarks ASSUMES caller has already called rtFsFatDirShrd_FindEntry to make sure + * the entry doesn't exist. + */ +static int rtFsFatDirShrd_CreateEntry(PRTFSFATDIRSHRD pThis, const char *pszEntry, uint8_t fAttrib, uint32_t cbInitial, + uint32_t *poffEntryInDir, PFATDIRENTRY pDirEntry) +{ + PRTFSFATVOL pVol = pThis->Core.pVol; + *poffEntryInDir = UINT32_MAX; + if (pVol->fReadOnly) + return VERR_WRITE_PROTECT; + + /* + * Create the directory entries on the stack. + */ + bool fIs8Dot3Name = rtFsFatDir_StringTo8Dot3((char *)pDirEntry->achName, pszEntry); + pDirEntry->fAttrib = fAttrib; + pDirEntry->fCase = fIs8Dot3Name ? rtFsFatDir_CalcCaseFlags(pszEntry) : 0; + pDirEntry->uBirthCentiseconds = rtFsFatCurrentFatDateTime(pVol, &pDirEntry->uBirthDate, &pDirEntry->uBirthTime); + pDirEntry->uAccessDate = pDirEntry->uBirthDate; + pDirEntry->uModifyDate = pDirEntry->uBirthDate; + pDirEntry->uModifyTime = pDirEntry->uBirthTime; + pDirEntry->idxCluster = 0; /* Will fill this in later if cbInitial is non-zero. */ + pDirEntry->u.idxClusterHigh = 0; + pDirEntry->cbFile = cbInitial; + + /* + * Create long filename slots if necessary. + */ + uint32_t cSlots = UINT32_MAX; + FATDIRNAMESLOT aSlots[FATDIRNAMESLOT_MAX_SLOTS]; + AssertCompile(RTFSFAT_MAX_LFN_CHARS < RT_ELEMENTS(aSlots) * FATDIRNAMESLOT_CHARS_PER_SLOT); + int rc = rtFsFatDirShrd_MaybeCreateLongNameAndShortAlias(pThis, pszEntry, fIs8Dot3Name, pDirEntry, aSlots, &cSlots); + if (RT_SUCCESS(rc)) + { + Assert(cSlots <= FATDIRNAMESLOT_MAX_SLOTS); + + /* + * Allocate initial clusters if requested. + */ + RTFSFATCHAIN Clusters; + rtFsFatChain_InitEmpty(&Clusters, pVol); + if (cbInitial > 0) + { + rc = rtFsFatClusterMap_AllocateMoreClusters(pVol, &Clusters, + (cbInitial + Clusters.cbCluster - 1) >> Clusters.cClusterByteShift); + if (RT_SUCCESS(rc)) + { + uint32_t idxFirstCluster = rtFsFatChain_GetFirstCluster(&Clusters); + pDirEntry->idxCluster = (uint16_t)idxFirstCluster; + if (pVol->enmFatType >= RTFSFATTYPE_FAT32) + pDirEntry->u.idxClusterHigh = (uint16_t)(idxFirstCluster >> 16); + } + } + if (RT_SUCCESS(rc)) + { + /* + * Insert the directory entry and name slots. + */ + rc = rtFsFatChain_InsertEntries(pThis, pDirEntry, aSlots, cSlots, poffEntryInDir); + if (RT_SUCCESS(rc)) + { + rtFsFatChain_Delete(&Clusters); + return VINF_SUCCESS; + } + + for (uint32_t iClusterToFree = 0; iClusterToFree < Clusters.cClusters; iClusterToFree++) + rtFsFatClusterMap_FreeCluster(pVol, rtFsFatChain_GetClusterByIndex(&Clusters, iClusterToFree)); + rtFsFatChain_Delete(&Clusters); + } + } + return rc; +} + + +/** + * Releases a reference to a shared directory structure. + * + * @param pShared The shared directory structure. + */ +static int rtFsFatDirShrd_Release(PRTFSFATDIRSHRD pShared) +{ + uint32_t cRefs = ASMAtomicDecU32(&pShared->Core.cRefs); + Assert(cRefs < UINT32_MAX / 2); + if (cRefs == 0) + { + LogFlow(("rtFsFatDirShrd_Release: Destroying shared structure %p\n", pShared)); + Assert(pShared->Core.cRefs == 0); + + int rc; + if (pShared->paEntries) + { + rc = rtFsFatDirShrd_Flush(pShared); + RTMemFree(pShared->paEntries); + pShared->paEntries = NULL; + } + else + rc = VINF_SUCCESS; + + if ( pShared->fFullyBuffered + && pShared->u.Full.pbDirtySectors) + { + RTMemFree(pShared->u.Full.pbDirtySectors); + pShared->u.Full.pbDirtySectors = NULL; + } + + int rc2 = rtFsFatObj_Close(&pShared->Core); + if (RT_SUCCESS(rc)) + rc = rc2; + + RTMemFree(pShared); + return rc; + } + return VINF_SUCCESS; +} + + +/** + * Retains a reference to a shared directory structure. + * + * @param pShared The shared directory structure. + */ +static void rtFsFatDirShrd_Retain(PRTFSFATDIRSHRD pShared) +{ + uint32_t cRefs = ASMAtomicIncU32(&pShared->Core.cRefs); + Assert(cRefs > 1); NOREF(cRefs); +} + + +/** + * @interface_method_impl{RTVFSOBJOPS,pfnClose} + */ +static DECLCALLBACK(int) rtFsFatDir_Close(void *pvThis) +{ + PRTFSFATDIR pThis = (PRTFSFATDIR)pvThis; + PRTFSFATDIRSHRD pShared = pThis->pShared; + pThis->pShared = NULL; + if (pShared) + return rtFsFatDirShrd_Release(pShared); + return VINF_SUCCESS; +} + + +/** + * @interface_method_impl{RTVFSOBJOPS,pfnQueryInfo} + */ +static DECLCALLBACK(int) rtFsFatDir_QueryInfo(void *pvThis, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr) +{ + PRTFSFATDIR pThis = (PRTFSFATDIR)pvThis; + return rtFsFatObj_QueryInfo(&pThis->pShared->Core, pObjInfo, enmAddAttr); +} + + +/** + * @interface_method_impl{RTVFSOBJSETOPS,pfnMode} + */ +static DECLCALLBACK(int) rtFsFatDir_SetMode(void *pvThis, RTFMODE fMode, RTFMODE fMask) +{ + PRTFSFATDIR pThis = (PRTFSFATDIR)pvThis; + return rtFsFatObj_SetMode(&pThis->pShared->Core, fMode, fMask); +} + + +/** + * @interface_method_impl{RTVFSOBJSETOPS,pfnSetTimes} + */ +static DECLCALLBACK(int) rtFsFatDir_SetTimes(void *pvThis, PCRTTIMESPEC pAccessTime, PCRTTIMESPEC pModificationTime, + PCRTTIMESPEC pChangeTime, PCRTTIMESPEC pBirthTime) +{ + PRTFSFATDIR pThis = (PRTFSFATDIR)pvThis; + return rtFsFatObj_SetTimes(&pThis->pShared->Core, pAccessTime, pModificationTime, pChangeTime, pBirthTime); +} + + +/** + * @interface_method_impl{RTVFSOBJSETOPS,pfnSetOwner} + */ +static DECLCALLBACK(int) rtFsFatDir_SetOwner(void *pvThis, RTUID uid, RTGID gid) +{ + RT_NOREF(pvThis, uid, gid); + return VERR_NOT_SUPPORTED; +} + + +/** + * @interface_method_impl{RTVFSDIROPS,pfnOpen} + */ +static DECLCALLBACK(int) rtFsFatDir_Open(void *pvThis, const char *pszEntry, uint64_t fOpen, + uint32_t fFlags, PRTVFSOBJ phVfsObj) +{ + PRTFSFATDIR pThis = (PRTFSFATDIR)pvThis; + PRTFSFATDIRSHRD pShared = pThis->pShared; + int rc; + + /* + * Special cases '.' and '.' + */ + if (pszEntry[0] == '.') + { + PRTFSFATDIRSHRD pSharedToOpen; + if (pszEntry[1] == '\0') + pSharedToOpen = pShared; + else if (pszEntry[1] == '.' && pszEntry[2] == '\0') + { + pSharedToOpen = pShared->Core.pParentDir; + if (!pSharedToOpen) + pSharedToOpen = pShared; + } + else + pSharedToOpen = NULL; + if (pSharedToOpen) + { + if (fFlags & RTVFSOBJ_F_OPEN_DIRECTORY) + { + if ( (fOpen & RTFILE_O_ACTION_MASK) == RTFILE_O_OPEN + || (fOpen & RTFILE_O_ACTION_MASK) == RTFILE_O_OPEN_CREATE) + { + rtFsFatDirShrd_Retain(pSharedToOpen); + RTVFSDIR hVfsDir; + rc = rtFsFatDir_NewWithShared(pShared->Core.pVol, pSharedToOpen, &hVfsDir); + if (RT_SUCCESS(rc)) + { + *phVfsObj = RTVfsObjFromDir(hVfsDir); + RTVfsDirRelease(hVfsDir); + AssertStmt(*phVfsObj != NIL_RTVFSOBJ, rc = VERR_INTERNAL_ERROR_3); + } + } + else + rc = VERR_ACCESS_DENIED; + } + else + rc = VERR_IS_A_DIRECTORY; + return rc; + } + } + + /* + * Try open existing file. + */ + uint32_t offEntryInDir; + bool fLong; + FATDIRENTRY DirEntry; + rc = rtFsFatDirShrd_FindEntry(pShared, pszEntry, &offEntryInDir, &fLong, &DirEntry); + if (RT_SUCCESS(rc)) + { + switch (DirEntry.fAttrib & (FAT_ATTR_DIRECTORY | FAT_ATTR_VOLUME)) + { + case 0: + if (fFlags & RTVFSOBJ_F_OPEN_FILE) + { + if ( !(DirEntry.fAttrib & FAT_ATTR_READONLY) + || !(fOpen & RTFILE_O_WRITE)) + { + if ( (fOpen & RTFILE_O_ACTION_MASK) == RTFILE_O_OPEN + || (fOpen & RTFILE_O_ACTION_MASK) == RTFILE_O_OPEN_CREATE + || (fOpen & RTFILE_O_ACTION_MASK) == RTFILE_O_CREATE_REPLACE) + { + RTVFSFILE hVfsFile; + rc = rtFsFatFile_New(pShared->Core.pVol, pShared, &DirEntry, offEntryInDir, fOpen, &hVfsFile); + if (RT_SUCCESS(rc)) + { + *phVfsObj = RTVfsObjFromFile(hVfsFile); + RTVfsFileRelease(hVfsFile); + AssertStmt(*phVfsObj != NIL_RTVFSOBJ, rc = VERR_INTERNAL_ERROR_3); + } + } + else + rc = VERR_ALREADY_EXISTS; + } + else + rc = VERR_ACCESS_DENIED; + } + else + rc = VERR_IS_A_FILE; + break; + + case FAT_ATTR_DIRECTORY: + if (fFlags & RTVFSOBJ_F_OPEN_DIRECTORY) + { + if ( !(DirEntry.fAttrib & FAT_ATTR_READONLY) + || !(fOpen & RTFILE_O_WRITE)) + { + if ( (fOpen & RTFILE_O_ACTION_MASK) == RTFILE_O_OPEN + || (fOpen & RTFILE_O_ACTION_MASK) == RTFILE_O_OPEN_CREATE) + { + RTVFSDIR hVfsDir; + rc = rtFsFatDir_New(pShared->Core.pVol, pShared, &DirEntry, offEntryInDir, + RTFSFAT_GET_CLUSTER(&DirEntry, pShared->Core.pVol), UINT64_MAX /*offDisk*/, + DirEntry.cbFile, &hVfsDir); + if (RT_SUCCESS(rc)) + { + *phVfsObj = RTVfsObjFromDir(hVfsDir); + RTVfsDirRelease(hVfsDir); + AssertStmt(*phVfsObj != NIL_RTVFSOBJ, rc = VERR_INTERNAL_ERROR_3); + } + } + else if ((fOpen & RTFILE_O_ACTION_MASK) == RTFILE_O_CREATE_REPLACE) + rc = VERR_INVALID_FUNCTION; + else + rc = VERR_ALREADY_EXISTS; + } + else + rc = VERR_ACCESS_DENIED; + } + else + rc = VERR_IS_A_DIRECTORY; + break; + + default: + rc = VERR_PATH_NOT_FOUND; + break; + } + } + /* + * Create a file or directory? + */ + else if (rc == VERR_FILE_NOT_FOUND) + { + if ( ( (fOpen & RTFILE_O_ACTION_MASK) == RTFILE_O_CREATE + || (fOpen & RTFILE_O_ACTION_MASK) == RTFILE_O_OPEN_CREATE + || (fOpen & RTFILE_O_ACTION_MASK) == RTFILE_O_CREATE_REPLACE) + && (fFlags & RTVFSOBJ_F_CREATE_MASK) != RTVFSOBJ_F_CREATE_NOTHING) + { + if ((fFlags & RTVFSOBJ_F_CREATE_MASK) == RTVFSOBJ_F_CREATE_FILE) + { + rc = rtFsFatDirShrd_CreateEntry(pShared, pszEntry, FAT_ATTR_ARCHIVE, 0 /*cbInitial*/, &offEntryInDir, &DirEntry); + if (RT_SUCCESS(rc)) + { + RTVFSFILE hVfsFile; + rc = rtFsFatFile_New(pShared->Core.pVol, pShared, &DirEntry, offEntryInDir, fOpen, &hVfsFile); + if (RT_SUCCESS(rc)) + { + *phVfsObj = RTVfsObjFromFile(hVfsFile); + RTVfsFileRelease(hVfsFile); + AssertStmt(*phVfsObj != NIL_RTVFSOBJ, rc = VERR_INTERNAL_ERROR_3); + } + } + } + else if ((fFlags & RTVFSOBJ_F_CREATE_MASK) == RTVFSOBJ_F_CREATE_DIRECTORY) + { + rc = rtFsFatDirShrd_CreateEntry(pShared, pszEntry, FAT_ATTR_ARCHIVE | FAT_ATTR_DIRECTORY, + pShared->Core.pVol->cbCluster, &offEntryInDir, &DirEntry); + if (RT_SUCCESS(rc)) + { + RTVFSDIR hVfsDir; + rc = rtFsFatDir_New(pShared->Core.pVol, pShared, &DirEntry, offEntryInDir, + RTFSFAT_GET_CLUSTER(&DirEntry, pShared->Core.pVol), UINT64_MAX /*offDisk*/, + DirEntry.cbFile, &hVfsDir); + if (RT_SUCCESS(rc)) + { + *phVfsObj = RTVfsObjFromDir(hVfsDir); + RTVfsDirRelease(hVfsDir); + AssertStmt(*phVfsObj != NIL_RTVFSOBJ, rc = VERR_INTERNAL_ERROR_3); + } + } + } + else + rc = VERR_VFS_UNSUPPORTED_CREATE_TYPE; + } + } + + return rc; +} + + +/** + * @interface_method_impl{RTVFSDIROPS,pfnOpenSymlink} + */ +static DECLCALLBACK(int) rtFsFatDir_OpenSymlink(void *pvThis, const char *pszSymlink, PRTVFSSYMLINK phVfsSymlink) +{ + RT_NOREF(pvThis, pszSymlink, phVfsSymlink); + return VERR_NOT_SUPPORTED; +} + + +/** + * @interface_method_impl{RTVFSDIROPS,pfnCreateSymlink} + */ +static DECLCALLBACK(int) rtFsFatDir_CreateSymlink(void *pvThis, const char *pszSymlink, const char *pszTarget, + RTSYMLINKTYPE enmType, PRTVFSSYMLINK phVfsSymlink) +{ + RT_NOREF(pvThis, pszSymlink, pszTarget, enmType, phVfsSymlink); + return VERR_NOT_SUPPORTED; +} + + +/** + * @interface_method_impl{RTVFSDIROPS,pfnUnlinkEntry} + */ +static DECLCALLBACK(int) rtFsFatDir_UnlinkEntry(void *pvThis, const char *pszEntry, RTFMODE fType) +{ + RT_NOREF(pvThis, pszEntry, fType); + return VERR_NOT_IMPLEMENTED; +} + + +/** + * @interface_method_impl{RTVFSDIROPS,pfnRenameEntry} + */ +static DECLCALLBACK(int) rtFsFatDir_RenameEntry(void *pvThis, const char *pszEntry, RTFMODE fType, const char *pszNewName) +{ + RT_NOREF(pvThis, pszEntry, fType, pszNewName); + return VERR_NOT_IMPLEMENTED; +} + + +/** + * @interface_method_impl{RTVFSDIROPS,pfnRewindDir} + */ +static DECLCALLBACK(int) rtFsFatDir_RewindDir(void *pvThis) +{ + PRTFSFATDIR pThis = (PRTFSFATDIR)pvThis; + pThis->offDir = 0; + return VINF_SUCCESS; +} + + +/** + * Calculates the UTF-8 length of the name in the given directory entry. + * + * @returns The length in characters (bytes), excluding terminator. + * @param pShared The shared directory structure (for codepage). + * @param pEntry The directory entry. + */ +static size_t rtFsFatDir_CalcUtf8LengthForDirEntry(PRTFSFATDIRSHRD pShared, PCFATDIRENTRY pEntry) +{ + RT_NOREF(pShared); + PCRTUTF16 g_pawcMap = &g_awchFatCp437Chars[0]; + + /* The base name (this won't work with DBCS, but that's not a concern at the moment). */ + size_t offSrc = 8; + while (offSrc > 1 && RTUniCpIsSpace(g_pawcMap[pEntry->achName[offSrc - 1]])) + offSrc--; + + size_t cchRet = 0; + while (offSrc-- > 0) + cchRet += RTStrCpSize(g_pawcMap[pEntry->achName[offSrc]]); + + /* Extension. */ + offSrc = 11; + while (offSrc > 8 && RTUniCpIsSpace(g_pawcMap[pEntry->achName[offSrc - 1]])) + offSrc--; + if (offSrc > 8) + { + cchRet += 1; /* '.' */ + while (offSrc-- > 8) + cchRet += RTStrCpSize(g_pawcMap[pEntry->achName[offSrc]]); + } + + return cchRet; +} + + +/** + * Copies the name from the directory entry into a UTF-16 buffer. + * + * @returns Number of UTF-16 items written (excluding terminator). + * @param pShared The shared directory structure (for codepage). + * @param pEntry The directory entry. + * @param pwszDst The destination buffer. + * @param cwcDst The destination buffer size. + */ +static uint16_t rtFsFatDir_CopyDirEntryToUtf16(PRTFSFATDIRSHRD pShared, PCFATDIRENTRY pEntry, PRTUTF16 pwszDst, size_t cwcDst) +{ + Assert(cwcDst > 0); + + RT_NOREF(pShared); + PCRTUTF16 g_pawcMap = &g_awchFatCp437Chars[0]; + + /* The base name (this won't work with DBCS, but that's not a concern at the moment). */ + size_t cchSrc = 8; + while (cchSrc > 1 && RTUniCpIsSpace(g_pawcMap[pEntry->achName[cchSrc - 1]])) + cchSrc--; + + size_t offDst = 0; + for (size_t offSrc = 0; offSrc < cchSrc; offSrc++) + { + AssertReturnStmt(offDst + 1 < cwcDst, pwszDst[cwcDst - 1] = '\0', (uint16_t)cwcDst); + pwszDst[offDst++] = g_pawcMap[pEntry->achName[offSrc]]; + } + + /* Extension. */ + cchSrc = 3; + while (cchSrc > 0 && RTUniCpIsSpace(g_pawcMap[pEntry->achName[8 + cchSrc - 1]])) + cchSrc--; + if (cchSrc > 0) + { + AssertReturnStmt(offDst + 1 < cwcDst, pwszDst[cwcDst - 1] = '\0', (uint16_t)cwcDst); + pwszDst[offDst++] = '.'; + + for (size_t offSrc = 0; offSrc < cchSrc; offSrc++) + { + AssertReturnStmt(offDst + 1 < cwcDst, pwszDst[cwcDst - 1] = '\0', (uint16_t)cwcDst); + pwszDst[offDst++] = g_pawcMap[pEntry->achName[8 + offSrc]]; + } + } + + pwszDst[offDst] = '\0'; + return (uint16_t)offDst; +} + + +/** + * Copies the name from the directory entry into a UTF-8 buffer. + * + * @returns Number of UTF-16 items written (excluding terminator). + * @param pShared The shared directory structure (for codepage). + * @param pEntry The directory entry. + * @param pszDst The destination buffer. + * @param cbDst The destination buffer size. + */ +static uint16_t rtFsFatDir_CopyDirEntryToUtf8(PRTFSFATDIRSHRD pShared, PCFATDIRENTRY pEntry, char *pszDst, size_t cbDst) +{ + Assert(cbDst > 0); + + RT_NOREF(pShared); + PCRTUTF16 g_pawcMap = &g_awchFatCp437Chars[0]; + + /* The base name (this won't work with DBCS, but that's not a concern at the moment). */ + size_t cchSrc = 8; + while (cchSrc > 1 && RTUniCpIsSpace(g_pawcMap[pEntry->achName[cchSrc - 1]])) + cchSrc--; + + char * const pszDstEnd = pszDst + cbDst; + char *pszCurDst = pszDst; + for (size_t offSrc = 0; offSrc < cchSrc; offSrc++) + { + RTUNICP const uc = g_pawcMap[pEntry->achName[offSrc]]; + size_t cbCp = RTStrCpSize(uc); + AssertReturnStmt(cbCp < (size_t)(pszDstEnd - pszCurDst), *pszCurDst = '\0', (uint16_t)(pszDstEnd - pszCurDst)); + pszCurDst = RTStrPutCp(pszCurDst, uc); + } + + /* Extension. */ + cchSrc = 3; + while (cchSrc > 0 && RTUniCpIsSpace(g_pawcMap[pEntry->achName[8 + cchSrc - 1]])) + cchSrc--; + if (cchSrc > 0) + { + AssertReturnStmt(1U < (size_t)(pszDstEnd - pszCurDst), *pszCurDst = '\0', (uint16_t)(pszDstEnd - pszCurDst)); + *pszCurDst++ = '.'; + + for (size_t offSrc = 0; offSrc < cchSrc; offSrc++) + { + RTUNICP const uc = g_pawcMap[pEntry->achName[8 + offSrc]]; + size_t cbCp = RTStrCpSize(uc); + AssertReturnStmt(cbCp < (size_t)(pszDstEnd - pszCurDst), *pszCurDst = '\0', (uint16_t)(pszDstEnd - pszCurDst)); + pszCurDst = RTStrPutCp(pszCurDst, uc); + } + } + + *pszCurDst = '\0'; + return (uint16_t)(pszDstEnd - pszCurDst); +} + + +/** + * @interface_method_impl{RTVFSDIROPS,pfnReadDir} + */ +static DECLCALLBACK(int) rtFsFatDir_ReadDir(void *pvThis, PRTDIRENTRYEX pDirEntry, size_t *pcbDirEntry, + RTFSOBJATTRADD enmAddAttr) +{ + PRTFSFATDIR pThis = (PRTFSFATDIR)pvThis; + PRTFSFATDIRSHRD pShared = pThis->pShared; + + /* + * Fake '.' and '..' entries (required for root, we do it everywhere). + */ + if (pThis->offDir < 2) + { + size_t cbNeeded = RT_UOFFSETOF_DYN(RTDIRENTRYEX, szName[pThis->offDir + 2]); + if (cbNeeded < *pcbDirEntry) + *pcbDirEntry = cbNeeded; + else + { + *pcbDirEntry = cbNeeded; + return VERR_BUFFER_OVERFLOW; + } + + int rc; + if ( pThis->offDir == 0 + || pShared->Core.pParentDir == NULL) + rc = rtFsFatObj_QueryInfo(&pShared->Core, &pDirEntry->Info, enmAddAttr); + else + rc = rtFsFatObj_QueryInfo(&pShared->Core.pParentDir->Core, &pDirEntry->Info, enmAddAttr); + + pDirEntry->cwcShortName = 0; + pDirEntry->wszShortName[0] = '\0'; + pDirEntry->szName[0] = '.'; + pDirEntry->szName[1] = '.'; + pDirEntry->szName[++pThis->offDir] = '\0'; + pDirEntry->cbName = pThis->offDir; + return rc; + } + if ( pThis->offDir == 2 + && pShared->cEntries >= 2) + { + /* Skip '.' and '..' entries if present. */ + uint32_t uBufferLock = UINT32_MAX; + uint32_t cEntries = 0; + PCFATDIRENTRYUNION paEntries = NULL; + int rc = rtFsFatDirShrd_GetEntriesAt(pShared, 0, &paEntries, &cEntries, &uBufferLock); + if (RT_FAILURE(rc)) + return rc; + if ( (paEntries[0].Entry.fAttrib & FAT_ATTR_DIRECTORY) + && memcmp(paEntries[0].Entry.achName, RT_STR_TUPLE(". ")) == 0) + { + if ( (paEntries[1].Entry.fAttrib & FAT_ATTR_DIRECTORY) + && memcmp(paEntries[1].Entry.achName, RT_STR_TUPLE(".. ")) == 0) + pThis->offDir += sizeof(paEntries[0]) * 2; + else + pThis->offDir += sizeof(paEntries[0]); + } + rtFsFatDirShrd_ReleaseBufferAfterReading(pShared, uBufferLock); + } + + /* + * Scan the directory buffer by buffer. + */ + RTUTF16 wszName[260+1]; + uint8_t bChecksum = UINT8_MAX; + uint8_t idNextSlot = UINT8_MAX; + size_t cwcName = 0; + uint32_t offEntryInDir = pThis->offDir - 2; + uint32_t const cbDir = pShared->Core.cbObject; + Assert(RT_ALIGN_32(cbDir, sizeof(*pDirEntry)) == cbDir); + AssertCompile(FATDIRNAMESLOT_MAX_SLOTS * FATDIRNAMESLOT_CHARS_PER_SLOT < RT_ELEMENTS(wszName)); + wszName[260] = '\0'; + + while (offEntryInDir < cbDir) + { + /* Get chunk of entries starting at offEntryInDir. */ + uint32_t uBufferLock = UINT32_MAX; + uint32_t cEntries = 0; + PCFATDIRENTRYUNION paEntries = NULL; + int rc = rtFsFatDirShrd_GetEntriesAt(pShared, offEntryInDir, &paEntries, &cEntries, &uBufferLock); + if (RT_FAILURE(rc)) + return rc; + + /* + * Now work thru each of the entries. + */ + for (uint32_t iEntry = 0; iEntry < cEntries; iEntry++, offEntryInDir += sizeof(FATDIRENTRY)) + { + switch ((uint8_t)paEntries[iEntry].Entry.achName[0]) + { + default: + break; + case FATDIRENTRY_CH0_DELETED: + cwcName = 0; + continue; + case FATDIRENTRY_CH0_END_OF_DIR: + if (pShared->Core.pVol->enmBpbVersion >= RTFSFATBPBVER_DOS_2_0) + { + pThis->offDir = cbDir + 2; + rtFsFatDirShrd_ReleaseBufferAfterReading(pShared, uBufferLock); + return VERR_NO_MORE_FILES; + } + cwcName = 0; + break; /* Technically a valid entry before DOS 2.0, or so some claim. */ + } + + /* + * Check for long filename slot. + */ + if ( paEntries[iEntry].Slot.fAttrib == FAT_ATTR_NAME_SLOT + && paEntries[iEntry].Slot.idxZero == 0 + && paEntries[iEntry].Slot.fZero == 0 + && (paEntries[iEntry].Slot.idSlot & ~FATDIRNAMESLOT_FIRST_SLOT_FLAG) <= FATDIRNAMESLOT_HIGHEST_SLOT_ID + && (paEntries[iEntry].Slot.idSlot & ~FATDIRNAMESLOT_FIRST_SLOT_FLAG) != 0) + { + /* New slot? */ + if (paEntries[iEntry].Slot.idSlot & FATDIRNAMESLOT_FIRST_SLOT_FLAG) + { + idNextSlot = paEntries[iEntry].Slot.idSlot & ~FATDIRNAMESLOT_FIRST_SLOT_FLAG; + bChecksum = paEntries[iEntry].Slot.bChecksum; + cwcName = idNextSlot * FATDIRNAMESLOT_CHARS_PER_SLOT; + wszName[cwcName] = '\0'; + } + /* Is valid next entry? */ + else if ( paEntries[iEntry].Slot.idSlot == idNextSlot + && paEntries[iEntry].Slot.bChecksum == bChecksum) + { /* likely */ } + else + cwcName = 0; + if (cwcName) + { + idNextSlot--; + size_t offName = idNextSlot * FATDIRNAMESLOT_CHARS_PER_SLOT; + memcpy(&wszName[offName], paEntries[iEntry].Slot.awcName0, sizeof(paEntries[iEntry].Slot.awcName0)); + memcpy(&wszName[offName + 5], paEntries[iEntry].Slot.awcName1, sizeof(paEntries[iEntry].Slot.awcName1)); + memcpy(&wszName[offName + 5 + 6], paEntries[iEntry].Slot.awcName2, sizeof(paEntries[iEntry].Slot.awcName2)); + } + } + /* + * Got a regular directory entry. Try return it to the caller if not volume label. + */ + else if (!(paEntries[iEntry].Entry.fAttrib & FAT_ATTR_VOLUME)) + { + /* Do the length calc and check for overflows. */ + bool fLongName = false; + size_t cchName = 0; + if ( cwcName != 0 + && idNextSlot == 0 + && rtFsFatDir_CalcChecksum(&paEntries[iEntry].Entry) == bChecksum) + { + rc = RTUtf16CalcUtf8LenEx(wszName, cwcName, &cchName); + if (RT_SUCCESS(rc)) + fLongName = true; + } + if (!fLongName) + cchName = rtFsFatDir_CalcUtf8LengthForDirEntry(pShared, &paEntries[iEntry].Entry); + size_t cbNeeded = RT_UOFFSETOF_DYN(RTDIRENTRYEX, szName[cchName + 1]); + if (cbNeeded <= *pcbDirEntry) + *pcbDirEntry = cbNeeded; + else + { + *pcbDirEntry = cbNeeded; + return VERR_BUFFER_OVERFLOW; + } + + /* To avoid duplicating code in rtFsFatObj_InitFromDirRec and + rtFsFatObj_QueryInfo, we create a dummy RTFSFATOBJ on the stack. */ + RTFSFATOBJ TmpObj; + RT_ZERO(TmpObj); + rtFsFatObj_InitFromDirEntry(&TmpObj, &paEntries[iEntry].Entry, offEntryInDir, pShared->Core.pVol); + + rtFsFatDirShrd_ReleaseBufferAfterReading(pShared, uBufferLock); + + rc = rtFsFatObj_QueryInfo(&TmpObj, &pDirEntry->Info, enmAddAttr); + + /* Copy out the names. */ + pDirEntry->cbName = (uint16_t)cchName; + if (fLongName) + { + char *pszDst = &pDirEntry->szName[0]; + int rc2 = RTUtf16ToUtf8Ex(wszName, cwcName, &pszDst, cchName + 1, NULL); + AssertRC(rc2); + + pDirEntry->cwcShortName = rtFsFatDir_CopyDirEntryToUtf16(pShared, &paEntries[iEntry].Entry, + pDirEntry->wszShortName, + RT_ELEMENTS(pDirEntry->wszShortName)); + } + else + { + rtFsFatDir_CopyDirEntryToUtf8(pShared, &paEntries[iEntry].Entry, &pDirEntry->szName[0], cchName + 1); + pDirEntry->wszShortName[0] = '\0'; + pDirEntry->cwcShortName = 0; + } + + if (RT_SUCCESS(rc)) + pThis->offDir = offEntryInDir + sizeof(paEntries[iEntry]) + 2; + Assert(RTStrValidateEncoding(pDirEntry->szName) == VINF_SUCCESS); + return rc; + } + else + cwcName = 0; + } + + rtFsFatDirShrd_ReleaseBufferAfterReading(pShared, uBufferLock); + } + + pThis->offDir = cbDir + 2; + return VERR_NO_MORE_FILES; +} + + +/** + * FAT directory operations. + */ +static const RTVFSDIROPS g_rtFsFatDirOps = +{ + { /* Obj */ + RTVFSOBJOPS_VERSION, + RTVFSOBJTYPE_DIR, + "FatDir", + rtFsFatDir_Close, + rtFsFatDir_QueryInfo, + NULL, + RTVFSOBJOPS_VERSION + }, + RTVFSDIROPS_VERSION, + 0, + { /* ObjSet */ + RTVFSOBJSETOPS_VERSION, + RT_UOFFSETOF(RTVFSDIROPS, ObjSet) - RT_UOFFSETOF(RTVFSDIROPS, Obj), + rtFsFatDir_SetMode, + rtFsFatDir_SetTimes, + rtFsFatDir_SetOwner, + RTVFSOBJSETOPS_VERSION + }, + rtFsFatDir_Open, + NULL /* pfnFollowAbsoluteSymlink */, + NULL /* pfnOpenFile*/, + NULL /* pfnOpenDir */, + NULL /* pfnCreateDir */, + rtFsFatDir_OpenSymlink, + rtFsFatDir_CreateSymlink, + NULL /* pfnQueryEntryInfo */, + rtFsFatDir_UnlinkEntry, + rtFsFatDir_RenameEntry, + rtFsFatDir_RewindDir, + rtFsFatDir_ReadDir, + RTVFSDIROPS_VERSION, +}; + + + + +/** + * Adds an open child to the parent directory. + * + * Maintains an additional reference to the parent dir to prevent it from going + * away. If @a pDir is the root directory, it also ensures the volume is + * referenced and sticks around until the last open object is gone. + * + * @param pDir The directory. + * @param pChild The child being opened. + * @sa rtFsFatDirShrd_RemoveOpenChild + */ +static void rtFsFatDirShrd_AddOpenChild(PRTFSFATDIRSHRD pDir, PRTFSFATOBJ pChild) +{ + rtFsFatDirShrd_Retain(pDir); + + RTListAppend(&pDir->OpenChildren, &pChild->Entry); + pChild->pParentDir = pDir; +} + + +/** + * Removes an open child to the parent directory. + * + * @param pDir The directory. + * @param pChild The child being removed. + * + * @remarks This is the very last thing you do as it may cause a few other + * objects to be released recursively (parent dir and the volume). + * + * @sa rtFsFatDirShrd_AddOpenChild + */ +static void rtFsFatDirShrd_RemoveOpenChild(PRTFSFATDIRSHRD pDir, PRTFSFATOBJ pChild) +{ + AssertReturnVoid(pChild->pParentDir == pDir); + RTListNodeRemove(&pChild->Entry); + pChild->pParentDir = NULL; + + rtFsFatDirShrd_Release(pDir); +} + + +/** + * Instantiates a new shared directory instance. + * + * @returns IPRT status code. + * @param pThis The FAT volume instance. + * @param pParentDir The parent directory. This is NULL for the root + * directory. + * @param pDirEntry The parent directory entry. This is NULL for the + * root directory. + * @param offEntryInDir The byte offset of the directory entry in the parent + * directory. UINT32_MAX if root directory. + * @param idxCluster The cluster where the directory content is to be + * found. This can be UINT32_MAX if a root FAT12/16 + * directory. + * @param offDisk The disk byte offset of the FAT12/16 root directory. + * This is UINT64_MAX if idxCluster is given. + * @param cbDir The size of the directory. + * @param ppSharedDir Where to return shared FAT directory instance. + */ +static int rtFsFatDirShrd_New(PRTFSFATVOL pThis, PRTFSFATDIRSHRD pParentDir, PCFATDIRENTRY pDirEntry, uint32_t offEntryInDir, + uint32_t idxCluster, uint64_t offDisk, uint32_t cbDir, PRTFSFATDIRSHRD *ppSharedDir) +{ + Assert((idxCluster == UINT32_MAX) != (offDisk == UINT64_MAX)); + Assert((pDirEntry == NULL) == (offEntryInDir == UINT32_MAX)); + *ppSharedDir = NULL; + + int rc = VERR_NO_MEMORY; + PRTFSFATDIRSHRD pShared = (PRTFSFATDIRSHRD)RTMemAllocZ(sizeof(*pShared)); + if (pShared) + { + /* + * Initialize it all so rtFsFatDir_Close doesn't trip up in anyway. + */ + RTListInit(&pShared->OpenChildren); + if (pDirEntry) + rtFsFatObj_InitFromDirEntry(&pShared->Core, pDirEntry, offEntryInDir, pThis); + else + rtFsFatObj_InitDummy(&pShared->Core, cbDir, RTFS_TYPE_DIRECTORY | RTFS_DOS_DIRECTORY | RTFS_UNIX_ALL_PERMS, pThis); + + pShared->cEntries = cbDir / sizeof(FATDIRENTRY); + pShared->fIsLinearRootDir = idxCluster == UINT32_MAX; + pShared->fFullyBuffered = pShared->fIsLinearRootDir; + pShared->paEntries = NULL; + pShared->offEntriesOnDisk = UINT64_MAX; + if (pShared->fFullyBuffered) + pShared->cbAllocatedForEntries = RT_ALIGN_32(cbDir, pThis->cbSector); + else + pShared->cbAllocatedForEntries = pThis->cbSector; + + /* + * If clustered backing, read the chain and see if we cannot still do the full buffering. + */ + if (idxCluster != UINT32_MAX) + { + rc = rtFsFatClusterMap_ReadClusterChain(pThis, idxCluster, &pShared->Core.Clusters); + if (RT_SUCCESS(rc)) + { + if ( pShared->Core.Clusters.cClusters >= 1 + && pShared->Core.Clusters.cbChain <= _64K + && rtFsFatChain_IsContiguous(&pShared->Core.Clusters)) + { + Assert(pShared->Core.Clusters.cbChain >= cbDir); + pShared->cbAllocatedForEntries = pShared->Core.Clusters.cbChain; + pShared->fFullyBuffered = true; + } + + /* DOS doesn't set a size on directores, so use the cluster length instead. */ + if ( cbDir == 0 + && pShared->Core.Clusters.cbChain > 0) + { + cbDir = pShared->Core.Clusters.cbChain; + pShared->Core.cbObject = cbDir; + pShared->cEntries = cbDir / sizeof(FATDIRENTRY); + if (pShared->fFullyBuffered) + pShared->cbAllocatedForEntries = RT_ALIGN_32(cbDir, pThis->cbSector); + } + } + } + else + { + rtFsFatChain_InitEmpty(&pShared->Core.Clusters, pThis); + rc = VINF_SUCCESS; + } + if (RT_SUCCESS(rc)) + { + /* + * Allocate and initialize the buffering. Fill the buffer. + */ + pShared->paEntries = (PFATDIRENTRYUNION)RTMemAlloc(pShared->cbAllocatedForEntries); + if (!pShared->paEntries) + { + if (pShared->fFullyBuffered && !pShared->fIsLinearRootDir) + { + pShared->fFullyBuffered = false; + pShared->cbAllocatedForEntries = pThis->cbSector; + pShared->paEntries = (PFATDIRENTRYUNION)RTMemAlloc(pShared->cbAllocatedForEntries); + } + if (!pShared->paEntries) + rc = VERR_NO_MEMORY; + } + + if (RT_SUCCESS(rc)) + { + if (pShared->fFullyBuffered) + { + pShared->u.Full.cDirtySectors = 0; + pShared->u.Full.cSectors = pShared->cbAllocatedForEntries / pThis->cbSector; + pShared->u.Full.pbDirtySectors = (uint8_t *)RTMemAllocZ((pShared->u.Full.cSectors + 63) / 8); + if (pShared->u.Full.pbDirtySectors) + pShared->offEntriesOnDisk = offDisk != UINT64_MAX ? offDisk + : rtFsFatClusterToDiskOffset(pThis, idxCluster); + else + rc = VERR_NO_MEMORY; + } + else + { + pShared->offEntriesOnDisk = rtFsFatClusterToDiskOffset(pThis, idxCluster); + pShared->u.Simple.offInDir = 0; + pShared->u.Simple.fDirty = false; + } + if (RT_SUCCESS(rc)) + rc = RTVfsFileReadAt(pThis->hVfsBacking, pShared->offEntriesOnDisk, + pShared->paEntries, pShared->cbAllocatedForEntries, NULL); + if (RT_SUCCESS(rc)) + { + /* + * Link into parent directory so we can use it to update + * our directory entry. + */ + if (pParentDir) + rtFsFatDirShrd_AddOpenChild(pParentDir, &pShared->Core); + *ppSharedDir = pShared; + return VINF_SUCCESS; + } + } + + /* Free the buffer on failure so rtFsFatDir_Close doesn't try do anything with it. */ + RTMemFree(pShared->paEntries); + pShared->paEntries = NULL; + } + + Assert(pShared->Core.cRefs == 1); + rtFsFatDirShrd_Release(pShared); + } + return rc; +} + + +/** + * Instantiates a new directory with a shared structure presupplied. + * + * @returns IPRT status code. + * @param pThis The FAT volume instance. + * @param pShared Referenced pointer to the shared structure. The + * reference is always CONSUMED. + * @param phVfsDir Where to return the directory handle. + */ +static int rtFsFatDir_NewWithShared(PRTFSFATVOL pThis, PRTFSFATDIRSHRD pShared, PRTVFSDIR phVfsDir) +{ + /* + * Create VFS object around the shared structure. + */ + PRTFSFATDIR pNewDir; + int rc = RTVfsNewDir(&g_rtFsFatDirOps, sizeof(*pNewDir), 0 /*fFlags*/, pThis->hVfsSelf, + NIL_RTVFSLOCK /*use volume lock*/, phVfsDir, (void **)&pNewDir); + if (RT_SUCCESS(rc)) + { + /* + * Look for existing shared object, create a new one if necessary. + * We CONSUME a reference to pShared here. + */ + pNewDir->offDir = 0; + pNewDir->pShared = pShared; + return VINF_SUCCESS; + } + + rtFsFatDirShrd_Release(pShared); + *phVfsDir = NIL_RTVFSDIR; + return rc; +} + + + +/** + * Instantiates a new directory VFS, creating the shared structure as necessary. + * + * @returns IPRT status code. + * @param pThis The FAT volume instance. + * @param pParentDir The parent directory. This is NULL for the root + * directory. + * @param pDirEntry The parent directory entry. This is NULL for the + * root directory. + * @param offEntryInDir The byte offset of the directory entry in the parent + * directory. UINT32_MAX if root directory. + * @param idxCluster The cluster where the directory content is to be + * found. This can be UINT32_MAX if a root FAT12/16 + * directory. + * @param offDisk The disk byte offset of the FAT12/16 root directory. + * This is UINT64_MAX if idxCluster is given. + * @param cbDir The size of the directory. + * @param phVfsDir Where to return the directory handle. + */ +static int rtFsFatDir_New(PRTFSFATVOL pThis, PRTFSFATDIRSHRD pParentDir, PCFATDIRENTRY pDirEntry, uint32_t offEntryInDir, + uint32_t idxCluster, uint64_t offDisk, uint32_t cbDir, PRTVFSDIR phVfsDir) +{ + /* + * Look for existing shared object, create a new one if necessary. + */ + PRTFSFATDIRSHRD pShared = (PRTFSFATDIRSHRD)rtFsFatDirShrd_LookupShared(pParentDir, offEntryInDir); + if (!pShared) + { + int rc = rtFsFatDirShrd_New(pThis, pParentDir, pDirEntry, offEntryInDir, idxCluster, offDisk, cbDir, &pShared); + if (RT_FAILURE(rc)) + { + *phVfsDir = NIL_RTVFSDIR; + return rc; + } + } + return rtFsFatDir_NewWithShared(pThis, pShared, phVfsDir); +} + + + + + +/** + * @interface_method_impl{RTVFSOBJOPS::Obj,pfnClose} + */ +static DECLCALLBACK(int) rtFsFatVol_Close(void *pvThis) +{ + PRTFSFATVOL pThis = (PRTFSFATVOL)pvThis; + LogFlow(("rtFsFatVol_Close(%p)\n", pThis)); + + int rc = VINF_SUCCESS; + if (pThis->pRootDir != NULL) + { + Assert(RTListIsEmpty(&pThis->pRootDir->OpenChildren)); + Assert(pThis->pRootDir->Core.cRefs == 1); + rc = rtFsFatDirShrd_Release(pThis->pRootDir); + pThis->pRootDir = NULL; + } + + int rc2 = rtFsFatClusterMap_Destroy(pThis); + if (RT_SUCCESS(rc)) + rc = rc2; + + RTVfsFileRelease(pThis->hVfsBacking); + pThis->hVfsBacking = NIL_RTVFSFILE; + + return rc; +} + + +/** + * @interface_method_impl{RTVFSOBJOPS::Obj,pfnQueryInfo} + */ +static DECLCALLBACK(int) rtFsFatVol_QueryInfo(void *pvThis, PRTFSOBJINFO pObjInfo, RTFSOBJATTRADD enmAddAttr) +{ + RT_NOREF(pvThis, pObjInfo, enmAddAttr); + return VERR_WRONG_TYPE; +} + + +/** + * @interface_method_impl{RTVFSOPS,pfnOpenRoot} + */ +static DECLCALLBACK(int) rtFsFatVol_OpenRoot(void *pvThis, PRTVFSDIR phVfsDir) +{ + PRTFSFATVOL pThis = (PRTFSFATVOL)pvThis; + + rtFsFatDirShrd_Retain(pThis->pRootDir); /* consumed by the next call */ + return rtFsFatDir_NewWithShared(pThis, pThis->pRootDir, phVfsDir); +} + + +/** + * @interface_method_impl{RTVFSOPS,pfnQueryRangeState} + */ +static DECLCALLBACK(int) rtFsFatVol_QueryRangeState(void *pvThis, uint64_t off, size_t cb, bool *pfUsed) +{ + + + RT_NOREF(pvThis, off, cb, pfUsed); + return VERR_NOT_IMPLEMENTED; +} + + +DECL_HIDDEN_CONST(const RTVFSOPS) g_rtFsFatVolOps = +{ + { /* Obj */ + RTVFSOBJOPS_VERSION, + RTVFSOBJTYPE_VFS, + "FatVol", + rtFsFatVol_Close, + rtFsFatVol_QueryInfo, + NULL, + RTVFSOBJOPS_VERSION + }, + RTVFSOPS_VERSION, + 0 /* fFeatures */, + rtFsFatVol_OpenRoot, + rtFsFatVol_QueryRangeState, + RTVFSOPS_VERSION +}; + + +/** + * Tries to detect a DOS 1.x formatted image and fills in the BPB fields. + * + * There is no BPB here, but fortunately, there isn't much variety. + * + * @returns IPRT status code. + * @param pThis The FAT volume instance, BPB derived fields are filled + * in on success. + * @param pBootSector The boot sector. + * @param pbFatSector Points to the FAT sector, or whatever is 512 bytes after + * the boot sector. + * @param pErrInfo Where to return additional error information. + */ +static int rtFsFatVolTryInitDos1x(PRTFSFATVOL pThis, PCFATBOOTSECTOR pBootSector, uint8_t const *pbFatSector, + PRTERRINFO pErrInfo) +{ + /* + * PC-DOS 1.0 does a 2fh byte short jump w/o any NOP following it. + * Instead the following are three words and a 9 byte build date + * string. The remaining space is zero filled. + * + * Note! No idea how this would look like for 8" floppies, only got 5"1/4'. + * + * ASSUME all non-BPB disks are using this format. + */ + if ( pBootSector->abJmp[0] != 0xeb /* jmp rel8 */ + || pBootSector->abJmp[1] < 0x2f + || pBootSector->abJmp[1] >= 0x80 + || pBootSector->abJmp[2] == 0x90 /* nop */) + return RTErrInfoSetF(pErrInfo, VERR_VFS_UNKNOWN_FORMAT, + "No DOS v1.0 bootsector either - invalid jmp: %.3Rhxs", pBootSector->abJmp); + uint32_t const offJump = 2 + pBootSector->abJmp[1]; + uint32_t const offFirstZero = 2 /*jmp */ + 3 * 2 /* words */ + 9 /* date string */; + Assert(offFirstZero >= RT_UOFFSETOF(FATBOOTSECTOR, Bpb)); + uint32_t const cbZeroPad = RT_MIN(offJump - offFirstZero, + sizeof(pBootSector->Bpb.Bpb20) - (offFirstZero - RT_UOFFSETOF(FATBOOTSECTOR, Bpb))); + + if (!ASMMemIsAllU8((uint8_t const *)pBootSector + offFirstZero, cbZeroPad, 0)) + return RTErrInfoSetF(pErrInfo, VERR_VFS_UNKNOWN_FORMAT, + "No DOS v1.0 bootsector either - expected zero padding %#x LB %#x: %.*Rhxs", + offFirstZero, cbZeroPad, cbZeroPad, (uint8_t const *)pBootSector + offFirstZero); + + /* + * Check the FAT ID so we can tell if this is double or single sided, + * as well as being a valid FAT12 start. + */ + if ( (pbFatSector[0] != 0xfe && pbFatSector[0] != 0xff) + || pbFatSector[1] != 0xff + || pbFatSector[2] != 0xff) + return RTErrInfoSetF(pErrInfo, VERR_VFS_UNKNOWN_FORMAT, + "No DOS v1.0 bootsector either - unexpected start of FAT: %.3Rhxs", pbFatSector); + + /* + * Fixed DOS 1.0 config. + */ + pThis->enmFatType = RTFSFATTYPE_FAT12; + pThis->enmBpbVersion = RTFSFATBPBVER_NO_BPB; + pThis->bMedia = pbFatSector[0]; + pThis->cReservedSectors = 1; + pThis->cbSector = 512; + pThis->cbCluster = pThis->bMedia == 0xfe ? 1024 : 512; + pThis->cFats = 2; + pThis->cbFat = 512; + pThis->aoffFats[0] = pThis->offBootSector + pThis->cReservedSectors * 512; + pThis->aoffFats[1] = pThis->aoffFats[0] + pThis->cbFat; + pThis->offRootDir = pThis->aoffFats[1] + pThis->cbFat; + pThis->cRootDirEntries = 512; + pThis->offFirstCluster = pThis->offRootDir + RT_ALIGN_32(pThis->cRootDirEntries * sizeof(FATDIRENTRY), + pThis->cbSector); + pThis->cbTotalSize = pThis->bMedia == 0xfe ? 8 * 1 * 40 * 512 : 8 * 2 * 40 * 512; + pThis->cClusters = (pThis->cbTotalSize - (pThis->offFirstCluster - pThis->offBootSector)) / pThis->cbCluster; + return VINF_SUCCESS; +} + + +/** + * Worker for rtFsFatVolTryInitDos2Plus that handles remaining BPB fields. + * + * @returns IPRT status code. + * @param pThis The FAT volume instance, BPB derived fields are filled + * in on success. + * @param pBootSector The boot sector. + * @param fMaybe331 Set if it could be a DOS v3.31 BPB. + * @param pErrInfo Where to return additional error information. + */ +static int rtFsFatVolTryInitDos2PlusBpb(PRTFSFATVOL pThis, PCFATBOOTSECTOR pBootSector, bool fMaybe331, PRTERRINFO pErrInfo) +{ + pThis->enmBpbVersion = RTFSFATBPBVER_DOS_2_0; + + /* + * Figure total sector count. Could both be zero, in which case we have to + * fall back on the size of the backing stuff. + */ + if (pBootSector->Bpb.Bpb20.cTotalSectors16 != 0) + pThis->cbTotalSize = pBootSector->Bpb.Bpb20.cTotalSectors16 * pThis->cbSector; + else if ( pBootSector->Bpb.Bpb331.cTotalSectors32 != 0 + && fMaybe331) + { + pThis->enmBpbVersion = RTFSFATBPBVER_DOS_3_31; + pThis->cbTotalSize = pBootSector->Bpb.Bpb331.cTotalSectors32 * (uint64_t)pThis->cbSector; + } + else + pThis->cbTotalSize = pThis->cbBacking - pThis->offBootSector; + if (pThis->cReservedSectors * pThis->cbSector >= pThis->cbTotalSize) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, + "Bogus FAT12/16 total or reserved sector count: %#x vs %#x", + pThis->cReservedSectors, pThis->cbTotalSize / pThis->cbSector); + + /* + * The fat size. Complete FAT offsets. + */ + if ( pBootSector->Bpb.Bpb20.cSectorsPerFat == 0 + || ((uint32_t)pBootSector->Bpb.Bpb20.cSectorsPerFat * pThis->cFats + 1) * pThis->cbSector > pThis->cbTotalSize) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, "Bogus FAT12/16 sectors per FAT: %#x (total sectors %#RX64)", + pBootSector->Bpb.Bpb20.cSectorsPerFat, pThis->cbTotalSize / pThis->cbSector); + pThis->cbFat = pBootSector->Bpb.Bpb20.cSectorsPerFat * pThis->cbSector; + + AssertReturn(pThis->cFats < RT_ELEMENTS(pThis->aoffFats), VERR_VFS_BOGUS_FORMAT); + for (unsigned iFat = 1; iFat <= pThis->cFats; iFat++) + pThis->aoffFats[iFat] = pThis->aoffFats[iFat - 1] + pThis->cbFat; + + /* + * Do root directory calculations. + */ + pThis->idxRootDirCluster = UINT32_MAX; + pThis->offRootDir = pThis->aoffFats[pThis->cFats]; + if (pThis->cRootDirEntries == 0) + return RTErrInfoSet(pErrInfo, VERR_VFS_BOGUS_FORMAT, "Zero FAT12/16 root directory size"); + pThis->cbRootDir = pThis->cRootDirEntries * sizeof(FATDIRENTRY); + pThis->cbRootDir = RT_ALIGN_32(pThis->cbRootDir, pThis->cbSector); + + /* + * First cluster and cluster count checks and calcs. Determin FAT type. + */ + pThis->offFirstCluster = pThis->offRootDir + pThis->cbRootDir; + uint64_t cbSystemStuff = pThis->offFirstCluster - pThis->offBootSector; + if (cbSystemStuff >= pThis->cbTotalSize) + return RTErrInfoSet(pErrInfo, VERR_VFS_BOGUS_FORMAT, "Bogus FAT12/16 total size, root dir, or fat size"); + pThis->cClusters = (pThis->cbTotalSize - cbSystemStuff) / pThis->cbCluster; + + if (pThis->cClusters >= FAT_MAX_FAT16_DATA_CLUSTERS) + { + pThis->cClusters = FAT_MAX_FAT16_DATA_CLUSTERS; + pThis->enmFatType = RTFSFATTYPE_FAT16; + } + else if (pThis->cClusters >= FAT_MIN_FAT16_DATA_CLUSTERS) + pThis->enmFatType = RTFSFATTYPE_FAT16; + else + pThis->enmFatType = RTFSFATTYPE_FAT12; /** @todo Not sure if this is entirely the right way to go about it... */ + + uint32_t cClustersPerFat; + if (pThis->enmFatType == RTFSFATTYPE_FAT16) + cClustersPerFat = pThis->cbFat / 2; + else + cClustersPerFat = pThis->cbFat * 2 / 3; + if (pThis->cClusters > cClustersPerFat) + pThis->cClusters = cClustersPerFat; + + return VINF_SUCCESS; +} + + +/** + * Worker for rtFsFatVolTryInitDos2Plus and rtFsFatVolTryInitDos2PlusFat32 that + * handles common extended BPBs fields. + * + * @returns IPRT status code. + * @param pThis The FAT volume instance. + * @param bExtSignature The extended BPB signature. + * @param uSerialNumber The serial number. + * @param pachLabel Pointer to the volume label field. + * @param pachType Pointer to the file system type field. + */ +static void rtFsFatVolInitCommonEbpbBits(PRTFSFATVOL pThis, uint8_t bExtSignature, uint32_t uSerialNumber, + char const *pachLabel, char const *pachType) +{ + pThis->uSerialNo = uSerialNumber; + if (bExtSignature == FATEBPB_SIGNATURE) + { + memcpy(pThis->szLabel, pachLabel, RT_SIZEOFMEMB(FATEBPB, achLabel)); + pThis->szLabel[RT_SIZEOFMEMB(FATEBPB, achLabel)] = '\0'; + RTStrStrip(pThis->szLabel); + + memcpy(pThis->szType, pachType, RT_SIZEOFMEMB(FATEBPB, achType)); + pThis->szType[RT_SIZEOFMEMB(FATEBPB, achType)] = '\0'; + RTStrStrip(pThis->szType); + } + else + { + pThis->szLabel[0] = '\0'; + pThis->szType[0] = '\0'; + } +} + + +/** + * Worker for rtFsFatVolTryInitDos2Plus that deals with FAT32. + * + * @returns IPRT status code. + * @param pThis The FAT volume instance, BPB derived fields are filled + * in on success. + * @param pBootSector The boot sector. + * @param pErrInfo Where to return additional error information. + */ +static int rtFsFatVolTryInitDos2PlusFat32(PRTFSFATVOL pThis, PCFATBOOTSECTOR pBootSector, PRTERRINFO pErrInfo) +{ + pThis->enmFatType = RTFSFATTYPE_FAT32; + pThis->enmBpbVersion = pBootSector->Bpb.Fat32Ebpb.bExtSignature == FATEBPB_SIGNATURE + ? RTFSFATBPBVER_FAT32_29 : RTFSFATBPBVER_FAT32_28; + pThis->fFat32Flags = pBootSector->Bpb.Fat32Ebpb.fFlags; + + if (pBootSector->Bpb.Fat32Ebpb.uVersion != FAT32EBPB_VERSION_0_0) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, "Unsupported FAT32 version: %d.%d (%#x)", + RT_HI_U8(pBootSector->Bpb.Fat32Ebpb.uVersion), RT_LO_U8(pBootSector->Bpb.Fat32Ebpb.uVersion), + pBootSector->Bpb.Fat32Ebpb.uVersion); + + /* + * Figure total sector count. We expected it to be filled in. + */ + bool fUsing64BitTotalSectorCount = false; + if (pBootSector->Bpb.Fat32Ebpb.Bpb.cTotalSectors16 != 0) + pThis->cbTotalSize = pBootSector->Bpb.Fat32Ebpb.Bpb.cTotalSectors16 * pThis->cbSector; + else if (pBootSector->Bpb.Fat32Ebpb.Bpb.cTotalSectors32 != 0) + pThis->cbTotalSize = pBootSector->Bpb.Fat32Ebpb.Bpb.cTotalSectors32 * (uint64_t)pThis->cbSector; + else if ( pBootSector->Bpb.Fat32Ebpb.u.cTotalSectors64 <= UINT64_MAX / 512 + && pBootSector->Bpb.Fat32Ebpb.u.cTotalSectors64 > 3 + && pBootSector->Bpb.Fat32Ebpb.bExtSignature != FATEBPB_SIGNATURE_OLD) + { + pThis->cbTotalSize = pBootSector->Bpb.Fat32Ebpb.u.cTotalSectors64 * pThis->cbSector; + fUsing64BitTotalSectorCount = true; + } + else + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, "FAT32 total sector count out of range: %#RX64", + pBootSector->Bpb.Fat32Ebpb.u.cTotalSectors64); + if (pThis->cReservedSectors * pThis->cbSector >= pThis->cbTotalSize) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, + "Bogus FAT32 total or reserved sector count: %#x vs %#x", + pThis->cReservedSectors, pThis->cbTotalSize / pThis->cbSector); + + /* + * Fat size. We check the 16-bit field even if it probably should be zero all the time. + */ + if (pBootSector->Bpb.Fat32Ebpb.Bpb.cSectorsPerFat != 0) + { + if ( pBootSector->Bpb.Fat32Ebpb.cSectorsPerFat32 != 0 + && pBootSector->Bpb.Fat32Ebpb.cSectorsPerFat32 != pBootSector->Bpb.Fat32Ebpb.Bpb.cSectorsPerFat) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, + "Both 16-bit and 32-bit FAT size fields are set: %#RX16 vs %#RX32", + pBootSector->Bpb.Fat32Ebpb.Bpb.cSectorsPerFat, pBootSector->Bpb.Fat32Ebpb.cSectorsPerFat32); + pThis->cbFat = pBootSector->Bpb.Fat32Ebpb.Bpb.cSectorsPerFat * pThis->cbSector; + } + else + { + uint64_t cbFat = pBootSector->Bpb.Fat32Ebpb.cSectorsPerFat32 * (uint64_t)pThis->cbSector; + if ( cbFat == 0 + || cbFat >= FAT_MAX_FAT32_TOTAL_CLUSTERS * 4 + pThis->cbSector * 16) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, + "Bogus 32-bit FAT size: %#RX32", pBootSector->Bpb.Fat32Ebpb.cSectorsPerFat32); + pThis->cbFat = (uint32_t)cbFat; + } + + /* + * Complete the FAT offsets and first cluster offset, then calculate number + * of data clusters. + */ + AssertReturn(pThis->cFats < RT_ELEMENTS(pThis->aoffFats), VERR_VFS_BOGUS_FORMAT); + for (unsigned iFat = 1; iFat <= pThis->cFats; iFat++) + pThis->aoffFats[iFat] = pThis->aoffFats[iFat - 1] + pThis->cbFat; + pThis->offFirstCluster = pThis->aoffFats[pThis->cFats]; + + if (pThis->offFirstCluster - pThis->offBootSector >= pThis->cbTotalSize) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, + "Bogus 32-bit FAT size or total sector count: cFats=%d cbFat=%#x cbTotalSize=%#x", + pThis->cFats, pThis->cbFat, pThis->cbTotalSize); + + uint64_t cClusters = (pThis->cbTotalSize - (pThis->offFirstCluster - pThis->offBootSector)) / pThis->cbCluster; + if (cClusters <= FAT_MAX_FAT32_DATA_CLUSTERS) + pThis->cClusters = (uint32_t)cClusters; + else + pThis->cClusters = FAT_MAX_FAT32_DATA_CLUSTERS; + if (pThis->cClusters > (pThis->cbFat / 4 - FAT_FIRST_DATA_CLUSTER)) + pThis->cClusters = (pThis->cbFat / 4 - FAT_FIRST_DATA_CLUSTER); + + /* + * Root dir cluster. + */ + if ( pBootSector->Bpb.Fat32Ebpb.uRootDirCluster < FAT_FIRST_DATA_CLUSTER + || pBootSector->Bpb.Fat32Ebpb.uRootDirCluster >= pThis->cClusters) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, + "Bogus FAT32 root directory cluster: %#x", pBootSector->Bpb.Fat32Ebpb.uRootDirCluster); + pThis->idxRootDirCluster = pBootSector->Bpb.Fat32Ebpb.uRootDirCluster; + pThis->offRootDir = pThis->offFirstCluster + + (pBootSector->Bpb.Fat32Ebpb.uRootDirCluster - FAT_FIRST_DATA_CLUSTER) * pThis->cbCluster; + + /* + * Info sector. + */ + if ( pBootSector->Bpb.Fat32Ebpb.uInfoSectorNo == 0 + || pBootSector->Bpb.Fat32Ebpb.uInfoSectorNo == UINT16_MAX) + pThis->offFat32InfoSector = UINT64_MAX; + else if (pBootSector->Bpb.Fat32Ebpb.uInfoSectorNo >= pThis->cReservedSectors) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, + "Bogus FAT32 info sector number: %#x (reserved sectors %#x)", + pBootSector->Bpb.Fat32Ebpb.uInfoSectorNo, pThis->cReservedSectors); + else + { + pThis->offFat32InfoSector = pThis->cbSector * pBootSector->Bpb.Fat32Ebpb.uInfoSectorNo + pThis->offBootSector; + int rc = RTVfsFileReadAt(pThis->hVfsBacking, pThis->offFat32InfoSector, + &pThis->Fat32InfoSector, sizeof(pThis->Fat32InfoSector), NULL); + if (RT_FAILURE(rc)) + return RTErrInfoSetF(pErrInfo, rc, "Failed to read FAT32 info sector at offset %#RX64", pThis->offFat32InfoSector); + if ( pThis->Fat32InfoSector.uSignature1 != FAT32INFOSECTOR_SIGNATURE_1 + || pThis->Fat32InfoSector.uSignature2 != FAT32INFOSECTOR_SIGNATURE_2 + || pThis->Fat32InfoSector.uSignature3 != FAT32INFOSECTOR_SIGNATURE_3) + return RTErrInfoSetF(pErrInfo, rc, "FAT32 info sector signature mismatch: %#x %#x %#x", + pThis->Fat32InfoSector.uSignature1, pThis->Fat32InfoSector.uSignature2, + pThis->Fat32InfoSector.uSignature3); + } + + /* + * Boot sector copy. + */ + if ( pBootSector->Bpb.Fat32Ebpb.uBootSectorCopySectorNo == 0 + || pBootSector->Bpb.Fat32Ebpb.uBootSectorCopySectorNo == UINT16_MAX) + { + pThis->cBootSectorCopies = 0; + pThis->offBootSectorCopies = UINT64_MAX; + } + else if (pBootSector->Bpb.Fat32Ebpb.uBootSectorCopySectorNo >= pThis->cReservedSectors) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, + "Bogus FAT32 info boot sector copy location: %#x (reserved sectors %#x)", + pBootSector->Bpb.Fat32Ebpb.uBootSectorCopySectorNo, pThis->cReservedSectors); + else + { + /** @todo not sure if cbSector is correct here. */ + pThis->cBootSectorCopies = 3; + if ( (uint32_t)pBootSector->Bpb.Fat32Ebpb.uBootSectorCopySectorNo + pThis->cBootSectorCopies + > pThis->cReservedSectors) + pThis->cBootSectorCopies = (uint8_t)(pThis->cReservedSectors - pBootSector->Bpb.Fat32Ebpb.uBootSectorCopySectorNo); + pThis->offBootSectorCopies = pBootSector->Bpb.Fat32Ebpb.uBootSectorCopySectorNo * pThis->cbSector + pThis->offBootSector; + if ( pThis->offFat32InfoSector != UINT64_MAX + && pThis->offFat32InfoSector - pThis->offBootSectorCopies < (uint64_t)(pThis->cBootSectorCopies * pThis->cbSector)) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, "FAT32 info sector and boot sector copies overlap: %#x vs %#x", + pBootSector->Bpb.Fat32Ebpb.uInfoSectorNo, pBootSector->Bpb.Fat32Ebpb.uBootSectorCopySectorNo); + } + + /* + * Serial number, label and type. + */ + rtFsFatVolInitCommonEbpbBits(pThis, pBootSector->Bpb.Fat32Ebpb.bExtSignature, pBootSector->Bpb.Fat32Ebpb.uSerialNumber, + pBootSector->Bpb.Fat32Ebpb.achLabel, + fUsing64BitTotalSectorCount ? pBootSector->achOemName : pBootSector->Bpb.Fat32Ebpb.achLabel); + if (pThis->szType[0] == '\0') + memcpy(pThis->szType, "FAT32", 6); + + return VINF_SUCCESS; +} + + +/** + * Tries to detect a DOS 2.0+ formatted image and fills in the BPB fields. + * + * We ASSUME BPB here, but need to figure out which version of the BPB it is, + * which is lots of fun. + * + * @returns IPRT status code. + * @param pThis The FAT volume instance, BPB derived fields are filled + * in on success. + * @param pBootSector The boot sector. + * @param pbFatSector Points to the FAT sector, or whatever is 512 bytes after + * the boot sector. On successful return it will contain + * the first FAT sector. + * @param pErrInfo Where to return additional error information. + */ +static int rtFsFatVolTryInitDos2Plus(PRTFSFATVOL pThis, PCFATBOOTSECTOR pBootSector, uint8_t *pbFatSector, PRTERRINFO pErrInfo) +{ + /* + * Check if we've got a known jump instruction first, because that will + * give us a max (E)BPB size hint. + */ + uint8_t offJmp = UINT8_MAX; + if ( pBootSector->abJmp[0] == 0xeb + && pBootSector->abJmp[1] <= 0x7f) + offJmp = pBootSector->abJmp[1] + 2; + else if ( pBootSector->abJmp[0] == 0x90 + && pBootSector->abJmp[1] == 0xeb + && pBootSector->abJmp[2] <= 0x7f) + offJmp = pBootSector->abJmp[2] + 3; + else if ( pBootSector->abJmp[0] == 0xe9 + && pBootSector->abJmp[2] <= 0x7f) + offJmp = RT_MIN(127, RT_MAKE_U16(pBootSector->abJmp[1], pBootSector->abJmp[2])); + uint8_t const cbMaxBpb = offJmp - RT_UOFFSETOF(FATBOOTSECTOR, Bpb); + + /* + * Do the basic DOS v2.0 BPB fields. + */ + if (cbMaxBpb < sizeof(FATBPB20)) + return RTErrInfoSetF(pErrInfo, VERR_VFS_UNKNOWN_FORMAT, + "DOS signature, but jmp too short for any BPB: %#x (max %#x BPB)", offJmp, cbMaxBpb); + + if (pBootSector->Bpb.Bpb20.cFats == 0) + return RTErrInfoSet(pErrInfo, VERR_VFS_UNKNOWN_FORMAT, "DOS signature, number of FATs is zero, so not FAT file system"); + if (pBootSector->Bpb.Bpb20.cFats > 4) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, "DOS signature, too many FATs: %#x", pBootSector->Bpb.Bpb20.cFats); + pThis->cFats = pBootSector->Bpb.Bpb20.cFats; + + if (!FATBPB_MEDIA_IS_VALID(pBootSector->Bpb.Bpb20.bMedia)) + return RTErrInfoSetF(pErrInfo, VERR_VFS_UNKNOWN_FORMAT, + "DOS signature, invalid media byte: %#x", pBootSector->Bpb.Bpb20.bMedia); + pThis->bMedia = pBootSector->Bpb.Bpb20.bMedia; + + if (!RT_IS_POWER_OF_TWO(pBootSector->Bpb.Bpb20.cbSector)) + return RTErrInfoSetF(pErrInfo, VERR_VFS_UNKNOWN_FORMAT, + "DOS signature, sector size not power of two: %#x", pBootSector->Bpb.Bpb20.cbSector); + if ( pBootSector->Bpb.Bpb20.cbSector != 512 + && pBootSector->Bpb.Bpb20.cbSector != 4096 + && pBootSector->Bpb.Bpb20.cbSector != 1024 + && pBootSector->Bpb.Bpb20.cbSector != 128) + return RTErrInfoSetF(pErrInfo, VERR_VFS_UNKNOWN_FORMAT, + "DOS signature, unsupported sector size: %#x", pBootSector->Bpb.Bpb20.cbSector); + pThis->cbSector = pBootSector->Bpb.Bpb20.cbSector; + + if ( !RT_IS_POWER_OF_TWO(pBootSector->Bpb.Bpb20.cSectorsPerCluster) + || !pBootSector->Bpb.Bpb20.cSectorsPerCluster) + return RTErrInfoSetF(pErrInfo, VERR_VFS_UNKNOWN_FORMAT, "DOS signature, cluster size not non-zero power of two: %#x", + pBootSector->Bpb.Bpb20.cSectorsPerCluster); + pThis->cbCluster = pBootSector->Bpb.Bpb20.cSectorsPerCluster * pThis->cbSector; + + uint64_t const cMaxRoot = (pThis->cbBacking - pThis->offBootSector - 512) / sizeof(FATDIRENTRY); /* we'll check again later. */ + if (pBootSector->Bpb.Bpb20.cMaxRootDirEntries >= cMaxRoot) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, "DOS signature, too many root entries: %#x (max %#RX64)", + pBootSector->Bpb.Bpb20.cSectorsPerCluster, cMaxRoot); + pThis->cRootDirEntries = pBootSector->Bpb.Bpb20.cMaxRootDirEntries; + + if ( pBootSector->Bpb.Bpb20.cReservedSectors == 0 + || pBootSector->Bpb.Bpb20.cReservedSectors >= _32K) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, + "DOS signature, bogus reserved sector count: %#x", pBootSector->Bpb.Bpb20.cReservedSectors); + pThis->cReservedSectors = pBootSector->Bpb.Bpb20.cReservedSectors; + pThis->aoffFats[0] = pThis->offBootSector + pThis->cReservedSectors * pThis->cbSector; + + /* + * Jump ahead and check for FAT32 EBPB. + * If found, we simply ASSUME it's a FAT32 file system. + */ + int rc; + if ( ( sizeof(FAT32EBPB) <= cbMaxBpb + && pBootSector->Bpb.Fat32Ebpb.bExtSignature == FATEBPB_SIGNATURE) + || ( RT_UOFFSETOF(FAT32EBPB, achLabel) <= cbMaxBpb + && pBootSector->Bpb.Fat32Ebpb.bExtSignature == FATEBPB_SIGNATURE_OLD) ) + { + rc = rtFsFatVolTryInitDos2PlusFat32(pThis, pBootSector, pErrInfo); + if (RT_FAILURE(rc)) + return rc; + } + else + { + /* + * Check for extended BPB, otherwise we'll have to make qualified guesses + * about what kind of BPB we're up against based on jmp offset and zero fields. + * ASSUMES either FAT16 or FAT12. + */ + if ( ( sizeof(FATEBPB) <= cbMaxBpb + && pBootSector->Bpb.Ebpb.bExtSignature == FATEBPB_SIGNATURE) + || ( RT_UOFFSETOF(FATEBPB, achLabel) <= cbMaxBpb + && pBootSector->Bpb.Ebpb.bExtSignature == FATEBPB_SIGNATURE_OLD) ) + { + rtFsFatVolInitCommonEbpbBits(pThis, pBootSector->Bpb.Ebpb.bExtSignature, pBootSector->Bpb.Ebpb.uSerialNumber, + pBootSector->Bpb.Ebpb.achLabel, pBootSector->Bpb.Ebpb.achType); + rc = rtFsFatVolTryInitDos2PlusBpb(pThis, pBootSector, true /*fMaybe331*/, pErrInfo); + pThis->enmBpbVersion = pBootSector->Bpb.Ebpb.bExtSignature == FATEBPB_SIGNATURE + ? RTFSFATBPBVER_EXT_29 : RTFSFATBPBVER_EXT_28; + } + else + rc = rtFsFatVolTryInitDos2PlusBpb(pThis, pBootSector, cbMaxBpb >= sizeof(FATBPB331), pErrInfo); + if (RT_FAILURE(rc)) + return rc; + if (pThis->szType[0] == '\0') + memcpy(pThis->szType, pThis->enmFatType == RTFSFATTYPE_FAT12 ? "FAT12" : "FAT16", 6); + } + + /* + * Check the FAT ID. May have to read a bit of the FAT into the buffer. + */ + if (pThis->aoffFats[0] != pThis->offBootSector + 512) + { + rc = RTVfsFileReadAt(pThis->hVfsBacking, pThis->aoffFats[0], pbFatSector, 512, NULL); + if (RT_FAILURE(rc)) + return RTErrInfoSet(pErrInfo, rc, "error reading first FAT sector"); + } + if (pbFatSector[0] != pThis->bMedia) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, + "Media byte and FAT ID mismatch: %#x vs %#x (%.7Rhxs)", pbFatSector[0], pThis->bMedia, pbFatSector); + uint32_t idxOurEndOfChain; + switch (pThis->enmFatType) + { + case RTFSFATTYPE_FAT12: + if ((pbFatSector[1] & 0xf) != 0xf) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, "Bogus FAT ID patting (FAT12): %.3Rhxs", pbFatSector); + pThis->idxMaxLastCluster = FAT_LAST_FAT12_DATA_CLUSTER; + pThis->idxEndOfChain = (pbFatSector[1] >> 4) | ((uint32_t)pbFatSector[2] << 4); + idxOurEndOfChain = FAT_FIRST_FAT12_EOC | 0xf; + break; + + case RTFSFATTYPE_FAT16: + if (pbFatSector[1] != 0xff) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, "Bogus FAT ID patting (FAT16): %.4Rhxs", pbFatSector); + pThis->idxMaxLastCluster = FAT_LAST_FAT16_DATA_CLUSTER; + pThis->idxEndOfChain = RT_MAKE_U16(pbFatSector[2], pbFatSector[3]); + idxOurEndOfChain = FAT_FIRST_FAT16_EOC | 0xf; + break; + + case RTFSFATTYPE_FAT32: + if ( pbFatSector[1] != 0xff + || pbFatSector[2] != 0xff + || (pbFatSector[3] & 0x0f) != 0x0f) + return RTErrInfoSetF(pErrInfo, VERR_VFS_BOGUS_FORMAT, "Bogus FAT ID patting (FAT32): %.8Rhxs", pbFatSector); + pThis->idxMaxLastCluster = FAT_LAST_FAT32_DATA_CLUSTER; + pThis->idxEndOfChain = RT_MAKE_U32_FROM_U8(pbFatSector[4], pbFatSector[5], pbFatSector[6], pbFatSector[7]); + idxOurEndOfChain = FAT_FIRST_FAT32_EOC | 0xf; + break; + + default: AssertFailedReturn(VERR_INTERNAL_ERROR_2); + } + + if (pThis->idxEndOfChain <= pThis->idxMaxLastCluster) + { + Log(("rtFsFatVolTryInitDos2Plus: Bogus idxEndOfChain=%#x, using %#x instead\n", pThis->idxEndOfChain, idxOurEndOfChain)); + pThis->idxEndOfChain = idxOurEndOfChain; + } + + RT_NOREF(pbFatSector); + return VINF_SUCCESS; +} + + +/** + * Given a power of two value @a cb return exponent value. + * + * @returns Shift count + * @param cb The value. + */ +static uint8_t rtFsFatVolCalcByteShiftCount(uint32_t cb) +{ + Assert(RT_IS_POWER_OF_TWO(cb)); + unsigned iBit = ASMBitFirstSetU32(cb); + Assert(iBit >= 1); + iBit--; + return iBit; +} + + +/** + * Worker for RTFsFatVolOpen. + * + * @returns IPRT status code. + * @param pThis The FAT VFS instance to initialize. + * @param hVfsSelf The FAT VFS handle (no reference consumed). + * @param hVfsBacking The file backing the alleged FAT file system. + * Reference is consumed (via rtFsFatVol_Destroy). + * @param fReadOnly Readonly or readwrite mount. + * @param offBootSector The boot sector offset in bytes. + * @param pErrInfo Where to return additional error info. Can be NULL. + */ +static int rtFsFatVolTryInit(PRTFSFATVOL pThis, RTVFS hVfsSelf, RTVFSFILE hVfsBacking, + bool fReadOnly, uint64_t offBootSector, PRTERRINFO pErrInfo) +{ + /* + * First initialize the state so that rtFsFatVol_Destroy won't trip up. + */ + pThis->hVfsSelf = hVfsSelf; + pThis->hVfsBacking = hVfsBacking; /* Caller referenced it for us, we consume it; rtFsFatVol_Destroy releases it. */ + pThis->cbBacking = 0; + pThis->offBootSector = offBootSector; + pThis->offNanoUTC = RTTimeLocalDeltaNano(); + pThis->offMinUTC = pThis->offNanoUTC / RT_NS_1MIN; + pThis->fReadOnly = fReadOnly; + pThis->cReservedSectors = 1; + + pThis->cbSector = 512; + pThis->cbCluster = 512; + pThis->cClusters = 0; + pThis->offFirstCluster = 0; + pThis->cbTotalSize = 0; + + pThis->enmFatType = RTFSFATTYPE_INVALID; + pThis->cFatEntries = 0; + pThis->cFats = 0; + pThis->cbFat = 0; + for (unsigned i = 0; i < RT_ELEMENTS(pThis->aoffFats); i++) + pThis->aoffFats[i] = UINT64_MAX; + pThis->pFatCache = NULL; + + pThis->offRootDir = UINT64_MAX; + pThis->idxRootDirCluster = UINT32_MAX; + pThis->cRootDirEntries = UINT32_MAX; + pThis->cbRootDir = 0; + pThis->pRootDir = NULL; + + pThis->uSerialNo = 0; + pThis->szLabel[0] = '\0'; + pThis->szType[0] = '\0'; + pThis->cBootSectorCopies = 0; + pThis->fFat32Flags = 0; + pThis->offBootSectorCopies = UINT64_MAX; + pThis->offFat32InfoSector = UINT64_MAX; + RT_ZERO(pThis->Fat32InfoSector); + + /* + * Get stuff that may fail. + */ + int rc = RTVfsFileQuerySize(hVfsBacking, &pThis->cbBacking); + if (RT_FAILURE(rc)) + return rc; + pThis->cbTotalSize = pThis->cbBacking - pThis->offBootSector; + + /* + * Read the boot sector and the following sector (start of the allocation + * table unless it a FAT32 FS). We'll then validate the boot sector and + * start of the FAT, expanding the BPB into the instance data. + */ + union + { + uint8_t ab[512*2]; + uint16_t au16[512*2 / 2]; + uint32_t au32[512*2 / 4]; + FATBOOTSECTOR BootSector; + FAT32INFOSECTOR InfoSector; + } Buf; + RT_ZERO(Buf); + + rc = RTVfsFileReadAt(hVfsBacking, offBootSector, &Buf.BootSector, 512 * 2, NULL); + if (RT_FAILURE(rc)) + return RTErrInfoSet(pErrInfo, rc, "Unable to read bootsect"); + + /* + * Extract info from the BPB and validate the two special FAT entries. + * + * Check the DOS signature first. The PC-DOS 1.0 boot floppy does not have + * a signature and we ASSUME this is the case for all floppies formated by it. + */ + if (Buf.BootSector.uSignature != FATBOOTSECTOR_SIGNATURE) + { + if (Buf.BootSector.uSignature != 0) + return RTErrInfoSetF(pErrInfo, VERR_VFS_UNKNOWN_FORMAT, "No DOS bootsector signature: %#06x", Buf.BootSector.uSignature); + rc = rtFsFatVolTryInitDos1x(pThis, &Buf.BootSector, &Buf.ab[512], pErrInfo); + } + else + rc = rtFsFatVolTryInitDos2Plus(pThis, &Buf.BootSector, &Buf.ab[512], pErrInfo); + if (RT_FAILURE(rc)) + return rc; + + /* + * Calc shift counts. + */ + pThis->cSectorByteShift = rtFsFatVolCalcByteShiftCount(pThis->cbSector); + pThis->cClusterByteShift = rtFsFatVolCalcByteShiftCount(pThis->cbCluster); + + /* + * Setup the FAT cache. + */ + rc = rtFsFatClusterMap_Create(pThis, &Buf.ab[512], pErrInfo); + if (RT_FAILURE(rc)) + return rc; + + /* + * Create the root directory fun. + */ + if (pThis->idxRootDirCluster == UINT32_MAX) + rc = rtFsFatDirShrd_New(pThis, NULL /*pParentDir*/, NULL /*pDirEntry*/, UINT32_MAX /*offEntryInDir*/, + UINT32_MAX, pThis->offRootDir, pThis->cbRootDir, &pThis->pRootDir); + else + rc = rtFsFatDirShrd_New(pThis, NULL /*pParentDir*/, NULL /*pDirEntry*/, UINT32_MAX /*offEntryInDir*/, + pThis->idxRootDirCluster, UINT64_MAX, pThis->cbRootDir, &pThis->pRootDir); + return rc; +} + + +/** + * Opens a FAT file system volume. + * + * @returns IPRT status code. + * @param hVfsFileIn The file or device backing the volume. + * @param fReadOnly Whether to mount it read-only. + * @param offBootSector The offset of the boot sector relative to the start + * of @a hVfsFileIn. Pass 0 for floppies. + * @param phVfs Where to return the virtual file system handle. + * @param pErrInfo Where to return additional error information. + */ +RTDECL(int) RTFsFatVolOpen(RTVFSFILE hVfsFileIn, bool fReadOnly, uint64_t offBootSector, PRTVFS phVfs, PRTERRINFO pErrInfo) +{ + /* + * Quick input validation. + */ + AssertPtrReturn(phVfs, VERR_INVALID_POINTER); + *phVfs = NIL_RTVFS; + + uint32_t cRefs = RTVfsFileRetain(hVfsFileIn); + AssertReturn(cRefs != UINT32_MAX, VERR_INVALID_HANDLE); + + /* + * Create a new FAT VFS instance and try initialize it using the given input file. + */ + RTVFS hVfs = NIL_RTVFS; + void *pvThis = NULL; + int rc = RTVfsNew(&g_rtFsFatVolOps, sizeof(RTFSFATVOL), NIL_RTVFS, RTVFSLOCK_CREATE_RW, &hVfs, &pvThis); + if (RT_SUCCESS(rc)) + { + rc = rtFsFatVolTryInit((PRTFSFATVOL)pvThis, hVfs, hVfsFileIn, fReadOnly, offBootSector, pErrInfo); + if (RT_SUCCESS(rc)) + *phVfs = hVfs; + else + RTVfsRelease(hVfs); + } + else + RTVfsFileRelease(hVfsFileIn); + return rc; +} + + + + +/** + * Fills a range in the file with zeros in the most efficient manner. + * + * @returns IPRT status code. + * @param hVfsFile The file to write to. + * @param off Where to start filling with zeros. + * @param cbZeros How many zero blocks to write. + */ +static int rtFsFatVolWriteZeros(RTVFSFILE hVfsFile, uint64_t off, uint32_t cbZeros) +{ + while (cbZeros > 0) + { + uint32_t cbToWrite = sizeof(g_abRTZero64K); + if (cbToWrite > cbZeros) + cbToWrite = cbZeros; + int rc = RTVfsFileWriteAt(hVfsFile, off, g_abRTZero64K, cbToWrite, NULL); + if (RT_FAILURE(rc)) + return rc; + off += cbToWrite; + cbZeros -= cbToWrite; + } + return VINF_SUCCESS; +} + + +/** + * Formats a FAT volume. + * + * @returns IRPT status code. + * @param hVfsFile The volume file. + * @param offVol The offset into @a hVfsFile of the file. + * Typically 0. + * @param cbVol The size of the volume. Pass 0 if the rest of + * hVfsFile should be used. + * @param fFlags See RTFSFATVOL_FMT_F_XXX. + * @param cbSector The logical sector size. Must be power of two. + * Optional, pass zero to use 512. + * @param cSectorsPerCluster Number of sectors per cluster. Power of two. + * Optional, pass zero to auto detect. + * @param enmFatType The FAT type (12, 16, 32) to use. + * Optional, pass RTFSFATTYPE_INVALID for default. + * @param cHeads The number of heads to report in the BPB. + * Optional, pass zero to auto detect. + * @param cSectorsPerTrack The number of sectors per track to put in the + * BPB. Optional, pass zero to auto detect. + * @param bMedia The media byte value and FAT ID to use. + * Optional, pass zero to auto detect. + * @param cRootDirEntries Number of root directory entries. + * Optional, pass zero to auto detect. + * @param cHiddenSectors Number of hidden sectors. Pass 0 for + * unpartitioned media. + * @param pErrInfo Additional error information, maybe. Optional. + */ +RTDECL(int) RTFsFatVolFormat(RTVFSFILE hVfsFile, uint64_t offVol, uint64_t cbVol, uint32_t fFlags, uint16_t cbSector, + uint16_t cSectorsPerCluster, RTFSFATTYPE enmFatType, uint32_t cHeads, uint32_t cSectorsPerTrack, + uint8_t bMedia, uint16_t cRootDirEntries, uint32_t cHiddenSectors, PRTERRINFO pErrInfo) +{ + int rc; + uint32_t cFats = 2; + + /* + * Validate input. + */ + if (!cbSector) + cbSector = 512; + else + AssertMsgReturn( cbSector == 128 + || cbSector == 512 + || cbSector == 1024 + || cbSector == 4096, + ("cbSector=%#x\n", cbSector), + VERR_INVALID_PARAMETER); + AssertMsgReturn(cSectorsPerCluster == 0 || (cSectorsPerCluster <= 128 && RT_IS_POWER_OF_TWO(cSectorsPerCluster)), + ("cSectorsPerCluster=%#x\n", cSectorsPerCluster), VERR_INVALID_PARAMETER); + if (bMedia != 0) + { + AssertMsgReturn(FAT_ID_IS_VALID(bMedia), ("bMedia=%#x\n", bMedia), VERR_INVALID_PARAMETER); + AssertMsgReturn(FATBPB_MEDIA_IS_VALID(bMedia), ("bMedia=%#x\n", bMedia), VERR_INVALID_PARAMETER); + } + AssertReturn(!(fFlags & ~RTFSFATVOL_FMT_F_VALID_MASK), VERR_INVALID_FLAGS); + AssertReturn(enmFatType >= RTFSFATTYPE_INVALID && enmFatType < RTFSFATTYPE_END, VERR_INVALID_PARAMETER); + + if (!cbVol) + { + uint64_t cbFile; + rc = RTVfsFileQuerySize(hVfsFile, &cbFile); + AssertRCReturn(rc, rc); + AssertMsgReturn(cbFile > offVol, ("cbFile=%#RX64 offVol=%#RX64\n", cbFile, offVol), VERR_INVALID_PARAMETER); + cbVol = cbFile - offVol; + } + uint64_t const cSectorsInVol = cbVol / cbSector; + + /* + * Guess defaults if necessary. + */ + if (!cSectorsPerCluster || !cHeads || !cSectorsPerTrack || !bMedia || !cRootDirEntries) + { + static struct + { + uint64_t cbVol; + uint8_t bMedia; + uint8_t cHeads; + uint8_t cSectorsPerTrack; + uint8_t cSectorsPerCluster; + uint16_t cRootDirEntries; + } s_aDefaults[] = + { + /* cbVol, bMedia, cHeads, cSectorsPTrk, cSectorsPClstr, cRootDirEntries */ + { 163840, 0xfe, /* cyl: 40,*/ 1, 8, 1, 64 }, + { 184320, 0xfc, /* cyl: 40,*/ 1, 9, 2, 64 }, + { 327680, 0xff, /* cyl: 40,*/ 2, 8, 2, 112 }, + { 368640, 0xfd, /* cyl: 40,*/ 2, 9, 2, 112 }, + { 737280, 0xf9, /* cyl: 80,*/ 2, 9, 2, 112 }, + { 1228800, 0xf9, /* cyl: 80,*/ 2, 15, 2, 112 }, + { 1474560, 0xf0, /* cyl: 80,*/ 2, 18, 1, 224 }, + { 2949120, 0xf0, /* cyl: 80,*/ 2, 36, 2, 224 }, + { 528482304, 0xf8, /* cyl: 1024,*/ 16, 63, 0, 512 }, // 504MB limit + { UINT64_C(7927234560), 0xf8, /* cyl: 1024,*/ 240, 63, 0, 512 }, // 7.3GB limit + { UINT64_C(8422686720), 0xf8, /* cyl: 1024,*/ 255, 63, 0, 512 }, // 7.84GB limit + + }; + uint32_t iDefault = 0; + while ( iDefault < RT_ELEMENTS(s_aDefaults) - 1U + && cbVol > s_aDefaults[iDefault].cbVol) + iDefault++; + if (!cHeads) + cHeads = s_aDefaults[iDefault].cHeads; + if (!cSectorsPerTrack) + cSectorsPerTrack = s_aDefaults[iDefault].cSectorsPerTrack; + if (!bMedia) + bMedia = s_aDefaults[iDefault].bMedia; + if (!cRootDirEntries) + cRootDirEntries = s_aDefaults[iDefault].cRootDirEntries; + if (!cSectorsPerCluster) + { + cSectorsPerCluster = s_aDefaults[iDefault].cSectorsPerCluster; + if (!cSectorsPerCluster) + { + uint32_t cbFat12Overhead = cbSector /* boot sector */ + + RT_ALIGN_32(FAT_MAX_FAT12_TOTAL_CLUSTERS * 3 / 2, cbSector) * cFats /* FATs */ + + RT_ALIGN_32(cRootDirEntries * sizeof(FATDIRENTRY), cbSector) /* root dir */; + uint32_t cbFat16Overhead = cbSector /* boot sector */ + + RT_ALIGN_32(FAT_MAX_FAT16_TOTAL_CLUSTERS * 2, cbSector) * cFats /* FATs */ + + RT_ALIGN_32(cRootDirEntries * sizeof(FATDIRENTRY), cbSector) /* root dir */; + + if ( enmFatType == RTFSFATTYPE_FAT12 + || cbVol <= cbFat12Overhead + FAT_MAX_FAT12_DATA_CLUSTERS * 4 * cbSector) + { + enmFatType = RTFSFATTYPE_FAT12; + cSectorsPerCluster = 1; + while ( cSectorsPerCluster < 128 + && cSectorsInVol + > cbFat12Overhead / cbSector + + (uint32_t)cSectorsPerCluster * FAT_MAX_FAT12_DATA_CLUSTERS + + cSectorsPerCluster - 1) + cSectorsPerCluster <<= 1; + } + else if ( enmFatType == RTFSFATTYPE_FAT16 + || cbVol <= cbFat16Overhead + FAT_MAX_FAT16_DATA_CLUSTERS * 128 * cbSector) + { + enmFatType = RTFSFATTYPE_FAT16; + cSectorsPerCluster = 1; + while ( cSectorsPerCluster < 128 + && cSectorsInVol + > cbFat12Overhead / cbSector + + (uint32_t)cSectorsPerCluster * FAT_MAX_FAT16_DATA_CLUSTERS + + cSectorsPerCluster - 1) + cSectorsPerCluster <<= 1; + } + else + { + /* The target here is keeping the FAT size below 8MB. Seems windows + likes a minimum 4KB cluster size as wells as a max of 32KB (googling). */ + enmFatType = RTFSFATTYPE_FAT32; + uint32_t cbFat32Overhead = cbSector * 32 /* boot sector, info sector, boot sector copies, reserved sectors */ + + _8M * cFats; + if (cbSector >= _4K) + cSectorsPerCluster = 1; + else + cSectorsPerCluster = _4K / cbSector; + while ( cSectorsPerCluster < 128 + && cSectorsPerCluster * cbSector < _32K + && cSectorsInVol > cbFat32Overhead / cbSector + (uint64_t)cSectorsPerCluster * _2M) + cSectorsPerCluster <<= 1; + } + } + } + } + Assert(cSectorsPerCluster); + Assert(cRootDirEntries); + uint32_t cbRootDir = RT_ALIGN_32(cRootDirEntries * sizeof(FATDIRENTRY), cbSector); + uint32_t const cbCluster = cSectorsPerCluster * cbSector; + + /* + * If we haven't figured out the FAT type yet, do so. + * The file system code determins the FAT based on cluster counts, + * so we must do so here too. + */ + if (enmFatType == RTFSFATTYPE_INVALID) + { + uint32_t cbFat12Overhead = cbSector /* boot sector */ + + RT_ALIGN_32(FAT_MAX_FAT12_TOTAL_CLUSTERS * 3 / 2, cbSector) * cFats /* FATs */ + + RT_ALIGN_32(cRootDirEntries * sizeof(FATDIRENTRY), cbSector) /* root dir */; + if ( cbVol <= cbFat12Overhead + cbCluster + || (cbVol - cbFat12Overhead) / cbCluster <= FAT_MAX_FAT12_DATA_CLUSTERS) + enmFatType = RTFSFATTYPE_FAT12; + else + { + uint32_t cbFat16Overhead = cbSector /* boot sector */ + + RT_ALIGN_32(FAT_MAX_FAT16_TOTAL_CLUSTERS * 2, cbSector) * cFats /* FATs */ + + cbRootDir; + if ( cbVol <= cbFat16Overhead + cbCluster + || (cbVol - cbFat16Overhead) / cbCluster <= FAT_MAX_FAT16_DATA_CLUSTERS) + enmFatType = RTFSFATTYPE_FAT16; + else + enmFatType = RTFSFATTYPE_FAT32; + } + } + if (enmFatType == RTFSFATTYPE_FAT32) + cbRootDir = cbCluster; + + /* + * Calculate the FAT size and number of data cluster. + * + * Since the FAT size depends on how many data clusters there are, we start + * with a minimum FAT size and maximum clust count, then recalucate it. The + * result isn't necessarily stable, so we will only retry stabalizing the + * result a few times. + */ + uint32_t cbReservedFixed = enmFatType == RTFSFATTYPE_FAT32 ? 32 * cbSector : cbSector + cbRootDir; + uint32_t cbFat = cbSector; + if (cbReservedFixed + cbFat * cFats >= cbVol) + return RTErrInfoSetF(pErrInfo, VERR_DISK_FULL, "volume is too small (cbVol=%#RX64 rsvd=%#x cbFat=%#x cFat=%#x)", + cbVol, cbReservedFixed, cbFat, cFats); + uint32_t cMaxClusters = enmFatType == RTFSFATTYPE_FAT12 ? FAT_MAX_FAT12_DATA_CLUSTERS + : enmFatType == RTFSFATTYPE_FAT16 ? FAT_MAX_FAT16_DATA_CLUSTERS + : FAT_MAX_FAT12_DATA_CLUSTERS; + uint32_t cClusters = (uint32_t)RT_MIN((cbVol - cbReservedFixed - cbFat * cFats) / cbCluster, cMaxClusters); + uint32_t cPrevClusters; + uint32_t cTries = 4; + do + { + cPrevClusters = cClusters; + switch (enmFatType) + { + case RTFSFATTYPE_FAT12: + cbFat = (uint32_t)RT_MIN(FAT_MAX_FAT12_TOTAL_CLUSTERS, cClusters) * 3 / 2; + break; + case RTFSFATTYPE_FAT16: + cbFat = (uint32_t)RT_MIN(FAT_MAX_FAT16_TOTAL_CLUSTERS, cClusters) * 2; + break; + case RTFSFATTYPE_FAT32: + cbFat = (uint32_t)RT_MIN(FAT_MAX_FAT32_TOTAL_CLUSTERS, cClusters) * 4; + cbFat = RT_ALIGN_32(cbFat, _4K); + break; + default: + AssertFailedReturn(VERR_INTERNAL_ERROR_2); + } + cbFat = RT_ALIGN_32(cbFat, cbSector); + if (cbReservedFixed + cbFat * cFats >= cbVol) + return RTErrInfoSetF(pErrInfo, VERR_DISK_FULL, "volume is too small (cbVol=%#RX64 rsvd=%#x cbFat=%#x cFat=%#x)", + cbVol, cbReservedFixed, cbFat, cFats); + cClusters = (uint32_t)RT_MIN((cbVol - cbReservedFixed - cbFat * cFats) / cbCluster, cMaxClusters); + } while ( cClusters != cPrevClusters + && cTries-- > 0); + uint64_t const cTotalSectors = cClusters * (uint64_t)cSectorsPerCluster + (cbReservedFixed + cbFat * cFats) / cbSector; + + /* + * Check that the file system type and cluster count matches up. If they + * don't the type will be misdetected. + * + * Note! These assertions could trigger if the above calculations are wrong. + */ + switch (enmFatType) + { + case RTFSFATTYPE_FAT12: + AssertMsgReturn(cClusters >= FAT_MIN_FAT12_DATA_CLUSTERS && cClusters <= FAT_MAX_FAT12_DATA_CLUSTERS, + ("cClusters=%#x\n", cClusters), VERR_OUT_OF_RANGE); + break; + case RTFSFATTYPE_FAT16: + AssertMsgReturn(cClusters >= FAT_MIN_FAT16_DATA_CLUSTERS && cClusters <= FAT_MAX_FAT16_DATA_CLUSTERS, + ("cClusters=%#x\n", cClusters), VERR_OUT_OF_RANGE); + break; + case RTFSFATTYPE_FAT32: + AssertMsgReturn(cClusters >= FAT_MIN_FAT32_DATA_CLUSTERS && cClusters <= FAT_MAX_FAT32_DATA_CLUSTERS, + ("cClusters=%#x\n", cClusters), VERR_OUT_OF_RANGE); + RT_FALL_THRU(); + default: + AssertFailedReturn(VERR_INTERNAL_ERROR_2); + } + + /* + * Okay, create the boot sector. + */ + size_t cbBuf = RT_MAX(RT_MAX(_64K, cbCluster), cbSector * 2U); + uint8_t *pbBuf = (uint8_t *)RTMemTmpAllocZ(cbBuf); + AssertReturn(pbBuf, VERR_NO_TMP_MEMORY); + + const char *pszLastOp = "boot sector"; + PFATBOOTSECTOR pBootSector = (PFATBOOTSECTOR)pbBuf; + pBootSector->abJmp[0] = 0xeb; + pBootSector->abJmp[1] = RT_UOFFSETOF(FATBOOTSECTOR, Bpb) + + (enmFatType == RTFSFATTYPE_FAT32 ? sizeof(FAT32EBPB) : sizeof(FATEBPB)) - 2; + pBootSector->abJmp[2] = 0x90; + memcpy(pBootSector->achOemName, enmFatType == RTFSFATTYPE_FAT32 ? "FAT32 " : "IPRT 6.2", sizeof(pBootSector->achOemName)); + pBootSector->Bpb.Bpb331.cbSector = (uint16_t)cbSector; + pBootSector->Bpb.Bpb331.cSectorsPerCluster = (uint8_t)cSectorsPerCluster; + pBootSector->Bpb.Bpb331.cReservedSectors = enmFatType == RTFSFATTYPE_FAT32 ? cbReservedFixed / cbSector : 1; + pBootSector->Bpb.Bpb331.cFats = (uint8_t)cFats; + pBootSector->Bpb.Bpb331.cMaxRootDirEntries = enmFatType == RTFSFATTYPE_FAT32 ? 0 : cRootDirEntries; + pBootSector->Bpb.Bpb331.cTotalSectors16 = cTotalSectors <= UINT16_MAX ? (uint16_t)cTotalSectors : 0; + pBootSector->Bpb.Bpb331.bMedia = bMedia; + pBootSector->Bpb.Bpb331.cSectorsPerFat = enmFatType == RTFSFATTYPE_FAT32 ? 0 : cbFat / cbSector; + pBootSector->Bpb.Bpb331.cSectorsPerTrack = cSectorsPerTrack; + pBootSector->Bpb.Bpb331.cTracksPerCylinder = cHeads; + pBootSector->Bpb.Bpb331.cHiddenSectors = cHiddenSectors; + /* XP barfs if both cTotalSectors32 and cTotalSectors16 are set */ + pBootSector->Bpb.Bpb331.cTotalSectors32 = cTotalSectors <= UINT32_MAX && pBootSector->Bpb.Bpb331.cTotalSectors16 == 0 + ? (uint32_t)cTotalSectors : 0; + if (enmFatType != RTFSFATTYPE_FAT32) + { + pBootSector->Bpb.Ebpb.bInt13Drive = 0; + pBootSector->Bpb.Ebpb.bReserved = 0; + pBootSector->Bpb.Ebpb.bExtSignature = FATEBPB_SIGNATURE; + pBootSector->Bpb.Ebpb.uSerialNumber = RTRandU32(); + memset(pBootSector->Bpb.Ebpb.achLabel, ' ', sizeof(pBootSector->Bpb.Ebpb.achLabel)); + memcpy(pBootSector->Bpb.Ebpb.achType, enmFatType == RTFSFATTYPE_FAT12 ? "FAT12 " : "FAT16 ", + sizeof(pBootSector->Bpb.Ebpb.achType)); + } + else + { + pBootSector->Bpb.Fat32Ebpb.cSectorsPerFat32 = cbFat / cbSector; + pBootSector->Bpb.Fat32Ebpb.fFlags = 0; + pBootSector->Bpb.Fat32Ebpb.uVersion = FAT32EBPB_VERSION_0_0; + pBootSector->Bpb.Fat32Ebpb.uRootDirCluster = FAT_FIRST_DATA_CLUSTER; + pBootSector->Bpb.Fat32Ebpb.uInfoSectorNo = 1; + pBootSector->Bpb.Fat32Ebpb.uBootSectorCopySectorNo = 6; + RT_ZERO(pBootSector->Bpb.Fat32Ebpb.abReserved); + + pBootSector->Bpb.Fat32Ebpb.bInt13Drive = 0; + pBootSector->Bpb.Fat32Ebpb.bReserved = 0; + pBootSector->Bpb.Fat32Ebpb.bExtSignature = FATEBPB_SIGNATURE; + pBootSector->Bpb.Fat32Ebpb.uSerialNumber = RTRandU32(); + memset(pBootSector->Bpb.Fat32Ebpb.achLabel, ' ', sizeof(pBootSector->Bpb.Fat32Ebpb.achLabel)); + if (cTotalSectors > UINT32_MAX) + pBootSector->Bpb.Fat32Ebpb.u.cTotalSectors64 = cTotalSectors; + else + memcpy(pBootSector->Bpb.Fat32Ebpb.u.achType, "FAT32 ", sizeof(pBootSector->Bpb.Fat32Ebpb.u.achType)); + } + pbBuf[pBootSector->abJmp[1] + 2 + 0] = 0xcd; /* int 18h */ /** @todo find/implement booting of next boot device. */ + pbBuf[pBootSector->abJmp[1] + 2 + 1] = 0x18; + pbBuf[pBootSector->abJmp[1] + 2 + 2] = 0xcc; /* int3 */ + pbBuf[pBootSector->abJmp[1] + 2 + 3] = 0xcc; + + pBootSector->uSignature = FATBOOTSECTOR_SIGNATURE; + if (cbSector != sizeof(*pBootSector)) + *(uint16_t *)&pbBuf[cbSector - 2] = FATBOOTSECTOR_SIGNATURE; /** @todo figure out how disks with non-512 byte sectors work! */ + + rc = RTVfsFileWriteAt(hVfsFile, offVol, pBootSector, cbSector, NULL); + uint32_t const offFirstFat = pBootSector->Bpb.Bpb331.cReservedSectors * cbSector; + + /* + * Write the FAT32 info sector, 3 boot sector copies, and zero fill + * the other reserved sectors. + */ + if (RT_SUCCESS(rc) && enmFatType == RTFSFATTYPE_FAT32) + { + pszLastOp = "fat32 info sector"; + PFAT32INFOSECTOR pInfoSector = (PFAT32INFOSECTOR)&pbBuf[cbSector]; /* preserve the boot sector. */ + RT_ZERO(*pInfoSector); + pInfoSector->uSignature1 = FAT32INFOSECTOR_SIGNATURE_1; + pInfoSector->uSignature2 = FAT32INFOSECTOR_SIGNATURE_2; + pInfoSector->uSignature3 = FAT32INFOSECTOR_SIGNATURE_3; + pInfoSector->cFreeClusters = cClusters - 1; /* ASSUMES 1 cluster for the root dir. */ + pInfoSector->cLastAllocatedCluster = FAT_FIRST_DATA_CLUSTER; + rc = RTVfsFileWriteAt(hVfsFile, offVol + cbSector, pInfoSector, cbSector, NULL); + + uint32_t iSector = 2; + if (RT_SUCCESS(rc)) + { + pszLastOp = "fat32 unused reserved sectors"; + rc = rtFsFatVolWriteZeros(hVfsFile, offVol + iSector * cbSector, + (pBootSector->Bpb.Fat32Ebpb.uBootSectorCopySectorNo - iSector) * cbSector); + iSector = pBootSector->Bpb.Fat32Ebpb.uBootSectorCopySectorNo; + } + + if (RT_SUCCESS(rc)) + { + pszLastOp = "boot sector copy"; + for (uint32_t i = 0; i < 3 && RT_SUCCESS(rc); i++, iSector++) + rc = RTVfsFileWriteAt(hVfsFile, offVol + iSector * cbSector, pBootSector, cbSector, NULL); + } + + if (RT_SUCCESS(rc)) + { + pszLastOp = "fat32 unused reserved sectors"; + rc = rtFsFatVolWriteZeros(hVfsFile, offVol + iSector * cbSector, + (pBootSector->Bpb.Bpb331.cReservedSectors - iSector) * cbSector); + } + } + + /* + * The FATs. + */ + if (RT_SUCCESS(rc)) + { + pszLastOp = "fat"; + pBootSector = NULL; /* invalid */ + RT_BZERO(pbBuf, cbSector); + switch (enmFatType) + { + case RTFSFATTYPE_FAT32: + pbBuf[11] = 0x0f; /* EOC for root dir*/ + pbBuf[10] = 0xff; + pbBuf[9] = 0xff; + pbBuf[8] = 0xff; + pbBuf[7] = 0x0f; /* Formatter's EOC, followed by signed extend FAT ID. */ + pbBuf[6] = 0xff; + pbBuf[5] = 0xff; + pbBuf[4] = 0xff; + RT_FALL_THRU(); + case RTFSFATTYPE_FAT16: + pbBuf[3] = 0xff; + RT_FALL_THRU(); + case RTFSFATTYPE_FAT12: + pbBuf[2] = 0xff; + pbBuf[1] = 0xff; + pbBuf[0] = bMedia; /* FAT ID */ + break; + default: AssertFailed(); + } + for (uint32_t iFatCopy = 0; iFatCopy < cFats && RT_SUCCESS(rc); iFatCopy++) + { + rc = RTVfsFileWriteAt(hVfsFile, offVol + offFirstFat + cbFat * iFatCopy, pbBuf, cbSector, NULL); + if (RT_SUCCESS(rc) && cbFat > cbSector) + rc = rtFsFatVolWriteZeros(hVfsFile, offVol + offFirstFat + cbFat * iFatCopy + cbSector, cbFat - cbSector); + } + } + + /* + * The root directory. + */ + if (RT_SUCCESS(rc)) + { + /** @todo any mandatory directory entries we need to fill in here? */ + pszLastOp = "root dir"; + rc = rtFsFatVolWriteZeros(hVfsFile, offVol + offFirstFat + cbFat * cFats, cbRootDir); + } + + /* + * If long format, fill the rest of the disk with 0xf6. + */ + AssertCompile(RTFSFATVOL_FMT_F_QUICK != 0); + if (RT_SUCCESS(rc) && !(fFlags & RTFSFATVOL_FMT_F_QUICK)) + { + pszLastOp = "formatting data clusters"; + uint64_t offCur = offFirstFat + cbFat * cFats + cbRootDir; + uint64_t cbLeft = cTotalSectors * cbSector; + if (cbVol - cbLeft <= _256K) /* HACK ALERT! Format to end of volume if it's a cluster rounding thing. */ + cbLeft = cbVol; + if (cbLeft > offCur) + { + cbLeft -= offCur; + offCur += offVol; + + memset(pbBuf, 0xf6, cbBuf); + while (cbLeft > 0) + { + size_t cbToWrite = cbLeft >= cbBuf ? cbBuf : (size_t)cbLeft; + rc = RTVfsFileWriteAt(hVfsFile, offCur, pbBuf, cbToWrite, NULL); + if (RT_SUCCESS(rc)) + { + offCur += cbToWrite; + cbLeft -= cbToWrite; + } + else + break; + } + } + } + + /* + * Done. + */ + RTMemTmpFree(pbBuf); + if (RT_SUCCESS(rc)) + return rc; + return RTErrInfoSet(pErrInfo, rc, pszLastOp); +} + + +/** + * Formats a 1.44MB floppy image. + * + * @returns IPRT status code. + * @param hVfsFile The image. + */ +RTDECL(int) RTFsFatVolFormat144(RTVFSFILE hVfsFile, bool fQuick) +{ + return RTFsFatVolFormat(hVfsFile, 0 /*offVol*/, 1474560, fQuick ? RTFSFATVOL_FMT_F_QUICK : RTFSFATVOL_FMT_F_FULL, + 512 /*cbSector*/, 1 /*cSectorsPerCluster*/, RTFSFATTYPE_FAT12, 2 /*cHeads*/, 18 /*cSectors*/, + 0xf0 /*bMedia*/, 224 /*cRootDirEntries*/, 0 /*cHiddenSectors*/, NULL /*pErrInfo*/); +} + + +/** + * Formats a 2.88MB floppy image. + * + * @returns IPRT status code. + * @param hVfsFile The image. + */ +RTDECL(int) RTFsFatVolFormat288(RTVFSFILE hVfsFile, bool fQuick) +{ + return RTFsFatVolFormat(hVfsFile, 0 /*offVol*/, 2949120, fQuick ? RTFSFATVOL_FMT_F_QUICK : RTFSFATVOL_FMT_F_FULL, + 512 /*cbSector*/, 2 /*cSectorsPerCluster*/, RTFSFATTYPE_FAT12, 2 /*cHeads*/, 36 /*cSectors*/, + 0xf0 /*bMedia*/, 224 /*cRootDirEntries*/, 0 /*cHiddenSectors*/, NULL /*pErrInfo*/); +} + + +/** + * @interface_method_impl{RTVFSCHAINELEMENTREG,pfnValidate} + */ +static DECLCALLBACK(int) rtVfsChainFatVol_Validate(PCRTVFSCHAINELEMENTREG pProviderReg, PRTVFSCHAINSPEC pSpec, + PRTVFSCHAINELEMSPEC pElement, uint32_t *poffError, PRTERRINFO pErrInfo) +{ + RT_NOREF(pProviderReg); + + /* + * Basic checks. + */ + if (pElement->enmTypeIn != RTVFSOBJTYPE_FILE) + return pElement->enmTypeIn == RTVFSOBJTYPE_INVALID ? VERR_VFS_CHAIN_CANNOT_BE_FIRST_ELEMENT : VERR_VFS_CHAIN_TAKES_FILE; + if ( pElement->enmType != RTVFSOBJTYPE_VFS + && pElement->enmType != RTVFSOBJTYPE_DIR) + return VERR_VFS_CHAIN_ONLY_DIR_OR_VFS; + if (pElement->cArgs > 1) + return VERR_VFS_CHAIN_AT_MOST_ONE_ARG; + + /* + * Parse the flag if present, save in pElement->uProvider. + */ + bool fReadOnly = (pSpec->fOpenFile & RTFILE_O_ACCESS_MASK) == RTFILE_O_READ; + if (pElement->cArgs > 0) + { + const char *psz = pElement->paArgs[0].psz; + if (*psz) + { + if (!strcmp(psz, "ro")) + fReadOnly = true; + else if (!strcmp(psz, "rw")) + fReadOnly = false; + else + { + *poffError = pElement->paArgs[0].offSpec; + return RTErrInfoSet(pErrInfo, VERR_VFS_CHAIN_INVALID_ARGUMENT, "Expected 'ro' or 'rw' as argument"); + } + } + } + + pElement->uProvider = fReadOnly; + return VINF_SUCCESS; +} + + +/** + * @interface_method_impl{RTVFSCHAINELEMENTREG,pfnInstantiate} + */ +static DECLCALLBACK(int) rtVfsChainFatVol_Instantiate(PCRTVFSCHAINELEMENTREG pProviderReg, PCRTVFSCHAINSPEC pSpec, + PCRTVFSCHAINELEMSPEC pElement, RTVFSOBJ hPrevVfsObj, + PRTVFSOBJ phVfsObj, uint32_t *poffError, PRTERRINFO pErrInfo) +{ + RT_NOREF(pProviderReg, pSpec, poffError); + + int rc; + RTVFSFILE hVfsFileIn = RTVfsObjToFile(hPrevVfsObj); + if (hVfsFileIn != NIL_RTVFSFILE) + { + RTVFS hVfs; + rc = RTFsFatVolOpen(hVfsFileIn, pElement->uProvider != false, 0, &hVfs, pErrInfo); + RTVfsFileRelease(hVfsFileIn); + if (RT_SUCCESS(rc)) + { + *phVfsObj = RTVfsObjFromVfs(hVfs); + RTVfsRelease(hVfs); + if (*phVfsObj != NIL_RTVFSOBJ) + return VINF_SUCCESS; + rc = VERR_VFS_CHAIN_CAST_FAILED; + } + } + else + rc = VERR_VFS_CHAIN_CAST_FAILED; + return rc; +} + + +/** + * @interface_method_impl{RTVFSCHAINELEMENTREG,pfnCanReuseElement} + */ +static DECLCALLBACK(bool) rtVfsChainFatVol_CanReuseElement(PCRTVFSCHAINELEMENTREG pProviderReg, + PCRTVFSCHAINSPEC pSpec, PCRTVFSCHAINELEMSPEC pElement, + PCRTVFSCHAINSPEC pReuseSpec, PCRTVFSCHAINELEMSPEC pReuseElement) +{ + RT_NOREF(pProviderReg, pSpec, pReuseSpec); + if ( pElement->paArgs[0].uProvider == pReuseElement->paArgs[0].uProvider + || !pReuseElement->paArgs[0].uProvider) + return true; + return false; +} + + +/** VFS chain element 'file'. */ +static RTVFSCHAINELEMENTREG g_rtVfsChainFatVolReg = +{ + /* uVersion = */ RTVFSCHAINELEMENTREG_VERSION, + /* fReserved = */ 0, + /* pszName = */ "fat", + /* ListEntry = */ { NULL, NULL }, + /* pszHelp = */ "Open a FAT file system, requires a file object on the left side.\n" + "First argument is an optional 'ro' (read-only) or 'rw' (read-write) flag.\n", + /* pfnValidate = */ rtVfsChainFatVol_Validate, + /* pfnInstantiate = */ rtVfsChainFatVol_Instantiate, + /* pfnCanReuseElement = */ rtVfsChainFatVol_CanReuseElement, + /* uEndMarker = */ RTVFSCHAINELEMENTREG_VERSION +}; + +RTVFSCHAIN_AUTO_REGISTER_ELEMENT_PROVIDER(&g_rtVfsChainFatVolReg, rtVfsChainFatVolReg); + |