libdmg-hfsplus/hfs/rawfile.c

500 строки
12 KiB
C

#include <stdlib.h>
#include <string.h>
#include <hfs/hfsplus.h>
int writeExtents(RawFile* rawFile);
int isBlockUsed(Volume* volume, uint32_t block)
{
unsigned char byte;
READ(volume->allocationFile, block / 8, 1, &byte);
return (byte & (1 << (7 - (block % 8)))) != 0;
}
int setBlockUsed(Volume* volume, uint32_t block, int used) {
unsigned char byte;
READ(volume->allocationFile, block / 8, 1, &byte);
if(used) {
byte |= (1 << (7 - (block % 8)));
} else {
byte &= ~(1 << (7 - (block % 8)));
}
ASSERT(WRITE(volume->allocationFile, block / 8, 1, &byte), "WRITE");
return TRUE;
}
int allocate(RawFile* rawFile, off_t size) {
unsigned char* zeros;
Volume* volume;
HFSPlusForkData* forkData;
uint32_t blocksNeeded;
uint32_t blocksToAllocate;
Extent* extent;
Extent* lastExtent;
uint32_t curBlock;
volume = rawFile->volume;
forkData = rawFile->forkData;
extent = rawFile->extents;
blocksNeeded = ((uint64_t)size / (uint64_t)volume->volumeHeader->blockSize) + (((size % volume->volumeHeader->blockSize) == 0) ? 0 : 1);
if(blocksNeeded > forkData->totalBlocks) {
zeros = (unsigned char*) malloc(volume->volumeHeader->blockSize);
memset(zeros, 0, volume->volumeHeader->blockSize);
blocksToAllocate = blocksNeeded - forkData->totalBlocks;
if(blocksToAllocate > volume->volumeHeader->freeBlocks) {
return FALSE;
}
lastExtent = NULL;
while(extent != NULL) {
lastExtent = extent;
extent = extent->next;
}
if(lastExtent == NULL) {
rawFile->extents = (Extent*) malloc(sizeof(Extent));
lastExtent = rawFile->extents;
lastExtent->blockCount = 0;
lastExtent->next = NULL;
curBlock = volume->volumeHeader->nextAllocation;
} else {
curBlock = lastExtent->startBlock + lastExtent->blockCount;
}
while(blocksToAllocate > 0) {
if(isBlockUsed(volume, curBlock)) {
if(lastExtent->blockCount > 0) {
lastExtent->next = (Extent*) malloc(sizeof(Extent));
lastExtent = lastExtent->next;
lastExtent->blockCount = 0;
lastExtent->next = NULL;
}
curBlock = volume->volumeHeader->nextAllocation;
volume->volumeHeader->nextAllocation++;
if(volume->volumeHeader->nextAllocation >= volume->volumeHeader->totalBlocks) {
volume->volumeHeader->nextAllocation = 0;
}
} else {
if(lastExtent->blockCount == 0) {
lastExtent->startBlock = curBlock;
}
/* zero out allocated block */
ASSERT(WRITE(volume->image, curBlock * volume->volumeHeader->blockSize, volume->volumeHeader->blockSize, zeros), "WRITE");
setBlockUsed(volume, curBlock, TRUE);
volume->volumeHeader->freeBlocks--;
blocksToAllocate--;
curBlock++;
lastExtent->blockCount++;
if(curBlock >= volume->volumeHeader->totalBlocks) {
curBlock = volume->volumeHeader->nextAllocation;
}
}
}
free(zeros);
} else if(blocksNeeded < forkData->totalBlocks) {
blocksToAllocate = blocksNeeded;
lastExtent = NULL;
while(blocksToAllocate > 0) {
if(blocksToAllocate > extent->blockCount) {
blocksToAllocate -= extent->blockCount;
lastExtent = extent;
extent = extent->next;
} else {
break;
}
}
if(blocksToAllocate == 0 && lastExtent != NULL) {
// snip the extent list here, since we don't need the rest
lastExtent->next = NULL;
} else if(blocksNeeded == 0) {
rawFile->extents = NULL;
}
do {
for(curBlock = (extent->startBlock + blocksToAllocate); curBlock < (extent->startBlock + extent->blockCount); curBlock++) {
setBlockUsed(volume, curBlock, FALSE);
volume->volumeHeader->freeBlocks++;
}
lastExtent = extent;
extent = extent->next;
if(blocksToAllocate == 0)
{
free(lastExtent);
} else {
lastExtent->next = NULL;
lastExtent->blockCount = blocksToAllocate;
}
blocksToAllocate = 0;
} while(extent != NULL);
}
writeExtents(rawFile);
forkData->logicalSize = size;
forkData->totalBlocks = blocksNeeded;
updateVolume(rawFile->volume);
if(rawFile->catalogRecord != NULL) {
updateCatalog(rawFile->volume, rawFile->catalogRecord);
}
return TRUE;
}
static int rawFileRead(io_func* io,off_t location, size_t size, void *buffer) {
RawFile* rawFile;
Volume* volume;
Extent* extent;
size_t blockSize;
off_t fileLoc;
off_t locationInBlock;
size_t possible;
rawFile = (RawFile*) io->data;
volume = rawFile->volume;
blockSize = volume->volumeHeader->blockSize;
extent = rawFile->extents;
fileLoc = 0;
locationInBlock = location;
while(TRUE) {
fileLoc += extent->blockCount * blockSize;
if(fileLoc <= location) {
locationInBlock -= extent->blockCount * blockSize;
extent = extent->next;
if(extent == NULL)
break;
} else {
break;
}
}
while(size > 0) {
if(extent == NULL)
return FALSE;
possible = extent->blockCount * blockSize - locationInBlock;
if(size > possible) {
ASSERT(READ(volume->image, extent->startBlock * blockSize + locationInBlock, possible, buffer), "READ");
size -= possible;
buffer = (void*)(((size_t)buffer) + possible);
extent = extent->next;
} else {
ASSERT(READ(volume->image, extent->startBlock * blockSize + locationInBlock, size, buffer), "READ");
break;
}
locationInBlock = 0;
}
return TRUE;
}
static int rawFileWrite(io_func* io,off_t location, size_t size, void *buffer) {
RawFile* rawFile;
Volume* volume;
Extent* extent;
size_t blockSize;
off_t fileLoc;
off_t locationInBlock;
size_t possible;
rawFile = (RawFile*) io->data;
volume = rawFile->volume;
blockSize = volume->volumeHeader->blockSize;
if(rawFile->forkData->logicalSize < (location + size)) {
ASSERT(allocate(rawFile, location + size), "allocate");
}
extent = rawFile->extents;
fileLoc = 0;
locationInBlock = location;
while(TRUE) {
fileLoc += extent->blockCount * blockSize;
if(fileLoc <= location) {
locationInBlock -= extent->blockCount * blockSize;
extent = extent->next;
if(extent == NULL)
break;
} else {
break;
}
}
while(size > 0) {
if(extent == NULL)
return FALSE;
possible = extent->blockCount * blockSize - locationInBlock;
if(size > possible) {
ASSERT(WRITE(volume->image, extent->startBlock * blockSize + locationInBlock, possible, buffer), "WRITE");
size -= possible;
buffer = (void*)(((size_t)buffer) + possible);
extent = extent->next;
} else {
ASSERT(WRITE(volume->image, extent->startBlock * blockSize + locationInBlock, size, buffer), "WRITE");
break;
}
locationInBlock = 0;
}
return TRUE;
}
static void closeRawFile(io_func* io) {
RawFile* rawFile;
Extent* extent;
Extent* toRemove;
rawFile = (RawFile*) io->data;
extent = rawFile->extents;
while(extent != NULL) {
toRemove = extent;
extent = extent->next;
free(toRemove);
}
free(rawFile);
free(io);
}
int removeExtents(RawFile* rawFile) {
uint32_t blocksLeft;
HFSPlusForkData* forkData;
uint32_t currentBlock;
uint32_t startBlock;
uint32_t blockCount;
HFSPlusExtentDescriptor* descriptor;
int currentExtent;
HFSPlusExtentKey extentKey;
int exact;
extentKey.keyLength = sizeof(HFSPlusExtentKey) - sizeof(extentKey.keyLength);
extentKey.forkType = 0;
extentKey.fileID = rawFile->id;
forkData = rawFile->forkData;
blocksLeft = forkData->totalBlocks;
currentExtent = 0;
currentBlock = 0;
descriptor = (HFSPlusExtentDescriptor*) forkData->extents;
while(blocksLeft > 0) {
if(currentExtent == 8) {
if(rawFile->volume->extentsTree == NULL) {
hfs_panic("no extents overflow file loaded yet!");
return FALSE;
}
if(descriptor != ((HFSPlusExtentDescriptor*) forkData->extents)) {
free(descriptor);
}
extentKey.startBlock = currentBlock;
descriptor = (HFSPlusExtentDescriptor*) search(rawFile->volume->extentsTree, (BTKey*)(&extentKey), &exact, NULL, NULL);
if(descriptor == NULL || exact == FALSE) {
hfs_panic("inconsistent extents information!");
return FALSE;
} else {
removeFromBTree(rawFile->volume->extentsTree, (BTKey*)(&extentKey));
currentExtent = 0;
continue;
}
}
startBlock = descriptor[currentExtent].startBlock;
blockCount = descriptor[currentExtent].blockCount;
currentBlock += blockCount;
blocksLeft -= blockCount;
currentExtent++;
}
if(descriptor != ((HFSPlusExtentDescriptor*) forkData->extents)) {
free(descriptor);
}
return TRUE;
}
int writeExtents(RawFile* rawFile) {
Extent* extent;
int currentExtent;
HFSPlusExtentKey extentKey;
HFSPlusExtentDescriptor descriptor[8];
HFSPlusForkData* forkData;
removeExtents(rawFile);
forkData = rawFile->forkData;
currentExtent = 0;
extent = rawFile->extents;
memset(forkData->extents, 0, sizeof(HFSPlusExtentRecord));
while(extent != NULL && currentExtent < 8) {
((HFSPlusExtentDescriptor*)forkData->extents)[currentExtent].startBlock = extent->startBlock;
((HFSPlusExtentDescriptor*)forkData->extents)[currentExtent].blockCount = extent->blockCount;
extent = extent->next;
currentExtent++;
}
if(extent != NULL) {
extentKey.keyLength = sizeof(HFSPlusExtentKey) - sizeof(extentKey.keyLength);
extentKey.forkType = 0;
extentKey.fileID = rawFile->id;
currentExtent = 0;
while(extent != NULL) {
if(currentExtent == 0) {
memset(descriptor, 0, sizeof(HFSPlusExtentRecord));
}
if(currentExtent == 8) {
extentKey.startBlock = descriptor[0].startBlock;
addToBTree(rawFile->volume->extentsTree, (BTKey*)(&extentKey), sizeof(HFSPlusExtentRecord), (unsigned char *)(&(descriptor[0])));
currentExtent = 0;
}
descriptor[currentExtent].startBlock = extent->startBlock;
descriptor[currentExtent].blockCount = extent->blockCount;
currentExtent++;
extent = extent->next;
}
extentKey.startBlock = descriptor[0].startBlock;
addToBTree(rawFile->volume->extentsTree, (BTKey*)(&extentKey), sizeof(HFSPlusExtentRecord), (unsigned char *)(&(descriptor[0])));
}
return TRUE;
}
int readExtents(RawFile* rawFile) {
uint32_t blocksLeft;
HFSPlusForkData* forkData;
uint32_t currentBlock;
Extent* extent;
Extent* lastExtent;
HFSPlusExtentDescriptor* descriptor;
int currentExtent;
HFSPlusExtentKey extentKey;
int exact;
extentKey.keyLength = sizeof(HFSPlusExtentKey) - sizeof(extentKey.keyLength);
extentKey.forkType = 0;
extentKey.fileID = rawFile->id;
forkData = rawFile->forkData;
blocksLeft = forkData->totalBlocks;
currentExtent = 0;
currentBlock = 0;
descriptor = (HFSPlusExtentDescriptor*) forkData->extents;
lastExtent = NULL;
while(blocksLeft > 0) {
extent = (Extent*) malloc(sizeof(Extent));
if(currentExtent == 8) {
if(rawFile->volume->extentsTree == NULL) {
hfs_panic("no extents overflow file loaded yet!");
return FALSE;
}
if(descriptor != ((HFSPlusExtentDescriptor*) forkData->extents)) {
free(descriptor);
}
extentKey.startBlock = currentBlock;
descriptor = (HFSPlusExtentDescriptor*) search(rawFile->volume->extentsTree, (BTKey*)(&extentKey), &exact, NULL, NULL);
if(descriptor == NULL || exact == FALSE) {
hfs_panic("inconsistent extents information!");
return FALSE;
} else {
currentExtent = 0;
continue;
}
}
extent->startBlock = descriptor[currentExtent].startBlock;
extent->blockCount = descriptor[currentExtent].blockCount;
extent->next = NULL;
currentBlock += extent->blockCount;
blocksLeft -= extent->blockCount;
currentExtent++;
if(lastExtent == NULL) {
rawFile->extents = extent;
} else {
lastExtent->next = extent;
}
lastExtent = extent;
}
if(descriptor != ((HFSPlusExtentDescriptor*) forkData->extents)) {
free(descriptor);
}
return TRUE;
}
io_func* openRawFile(HFSCatalogNodeID id, HFSPlusForkData* forkData, HFSPlusCatalogRecord* catalogRecord, Volume* volume) {
io_func* io;
RawFile* rawFile;
io = (io_func*) malloc(sizeof(io_func));
rawFile = (RawFile*) malloc(sizeof(RawFile));
rawFile->id = id;
rawFile->volume = volume;
rawFile->forkData = forkData;
rawFile->catalogRecord = catalogRecord;
rawFile->extents = NULL;
io->data = rawFile;
io->read = &rawFileRead;
io->write = &rawFileWrite;
io->close = &closeRawFile;
if(!readExtents(rawFile)) {
return NULL;
}
return io;
}