kolibrios/programs/fs/unimg/fat12.c

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/* # KolibriOS Image Unpacker #
Extracts files from FAT12 KolibriOS image to specified folder.
Usage: unimg path/to/img [output/folder] [-e]
-e: Exit on success
If output folder is skipped, the image will be unpacked at /TMP0/1/[file-name]
Author: Magomed Kostoev (Boppan, mkostoevr): FAT12 file system, driver.
Contributor: Kiril Lipatov (Leency) */
#include <stdarg.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#define TCC 0
#define GCC 1
#include "compiller.h"
#ifdef GCC
#define con_init con_init
#endif
typedef struct {
size_t length;
size_t capacity;
char *data;
} String;
typedef struct {
char *image;
int imageSize;
const char *errorMessage;
int bytesPerSector;
int sectorsPerClaster;
int reservedSectorCount;
int numberOfFats;
int maxRootEntries;
int totalSectors;
int sectorsPerFat;
int firstFat;
int rootDirectory;
int dataRegion;
} Fat12;
typedef int (*ForEachCallback)(const char *, size_t, const uint8_t *, void *);
// system-dependent
static void mkdir(const char *name);
// misc
static void mkdir_p(const char *_name); // create folder creating its parents
static uint16_t get16(const void *_from, int index); // get uint16_t from array at offset
static uint32_t get32(const void *_from, int index); // get uint32_t from array at offset
// fat12
static int fat12__getItemNameSize(const void *_folderEntry);
static void fat12__getItemName(const void *_folderEntry, void *_name);
static int fat12__getNextClaster(const Fat12 *this, int currentClaster);
static int fat12__getFile(const Fat12 *this, void *_buffer, int size, int claster);
static int fat12__getOffsetByClaster(const Fat12 *this, int claster);
static int fat12__forEachFile_handleFolderEntry(const Fat12 *this, int folderEntryOffset, String *name,
ForEachCallback callback, void *callbackParam);
static int fat12__forEachFile_handleFolder(const Fat12 *this, int claster, String *name,
ForEachCallback callback, void *callbackParam);
static int fat12__forEachFile(const Fat12 *this, ForEachCallback callback, void *callbackParam);
static int fat12__open(Fat12 *this, const char *img);
static int fat12__error(Fat12 *this, const char *errorMessage);
static void mkdir(const char *name) {
#ifdef TCC
struct {
int fn;
int unused[4];
char b;
const char *path __attribute__((packed));
} info;
#else
struct {
int fn;
int unused[4];
char b;
const char *path;
} __attribute__((packed)) info;
#endif
memset(&info, 0, sizeof(info));
info.fn = 9;
info.b = 0;
info.path = name;
asm volatile ("int $0x40"::"a"(70), "b"(&info));
}
static void mkdir_p(const char *_name) {
char *name = calloc(strlen(_name) + 1, 1);
strcpy(name, _name);
char *ptr = name;
while (ptr) {
if (ptr != name) { *ptr = '/'; }
ptr = strchr(ptr + 1, '/');
if (ptr) { *ptr = 0; }
mkdir(name);
}
}
static uint32_t get32(const void *_from, int index) {
const uint8_t *from = _from;
return from[index] |
(from[index + 1] << 8) |
(from[index + 2] << 16) |
(from[index + 3] << 24);
}
static uint16_t get16(const void *_from, int index) {
const uint8_t *from = _from;
return from[index] | (from[index + 1] << 8);
}
static int fat12__getNextClaster(const Fat12 *this, int currentClaster) {
int nextClasterOffset = this->firstFat + currentClaster + (currentClaster >> 1);
if (currentClaster % 2 == 0) {
return get16(this->image, nextClasterOffset) & 0xfff;
} else {
return get16(this->image, nextClasterOffset) >> 4;
}
}
static int fat12__getFile(const Fat12 *this, void *_buffer, int size, int claster) {
int offset = 0;
char *buffer = _buffer;
while (claster < 0xff7) {
int toCopy = this->bytesPerSector * this->sectorsPerClaster;
void *clasterPtr = &this->image[fat12__getOffsetByClaster(this, claster)];
claster = fat12__getNextClaster(this, claster);
// if next claster is END OF FILE claster, copy only rest of file
if (claster >= 0xff7) { toCopy = size % toCopy; }
memcpy(&buffer[offset], clasterPtr, toCopy);
offset += toCopy;
}
return 1;
}
static int fat12__getOffsetByClaster(const Fat12 *this, int claster) {
return this->dataRegion + (claster - 2)
* this->bytesPerSector * this->sectorsPerClaster;
}
static int fat12__getItemNameSize(const void *_folderEntry) {
const uint8_t *folderEntry = _folderEntry;
// Long File Name entry, not a file itself
if ((folderEntry[11] & 0x0f) == 0x0f) { return 0; }
if ((folderEntry[11 - 32] & 0x0f) != 0x0f) {
// regular file "NAME8888" '.' "EXT" '\0'
int length = 13;
for (int i = 10; folderEntry[i] == ' ' && i != 7; i--) { length--; }
for (int i = 7; folderEntry[i] == ' ' && i != 0 - 1; i--) { length--; }
if (folderEntry[8] == ' ') { length--; } // no ext - no'.'
return length;
} else {
// file with long name
// format of Long File Name etries is described in fat12__getItemName
int length = 1;
for (int i = 1; i < 255 / 13; i++) {
//! TODO: Add UTF-16 support
length += 13;
if (folderEntry[i * -32] & 0x40) {
// if first char from back is 0xffff, this is stub after name
// otherwice is last character, so we can return calculated length
if (get16(folderEntry, i * -32 + 30) == 0xffff) { length--; } else { return length; }
if (get16(folderEntry, i * -32 + 28) == 0xffff) { length--; } else { return length; }
if (get16(folderEntry, i * -32 + 24) == 0xffff) { length--; } else { return length; }
if (get16(folderEntry, i * -32 + 22) == 0xffff) { length--; } else { return length; }
if (get16(folderEntry, i * -32 + 20) == 0xffff) { length--; } else { return length; }
if (get16(folderEntry, i * -32 + 18) == 0xffff) { length--; } else { return length; }
if (get16(folderEntry, i * -32 + 16) == 0xffff) { length--; } else { return length; }
if (get16(folderEntry, i * -32 + 14) == 0xffff) { length--; } else { return length; }
if (get16(folderEntry, i * -32 + 9) == 0xffff) { length--; } else { return length; }
if (get16(folderEntry, i * -32 + 7) == 0xffff) { length--; } else { return length; }
if (get16(folderEntry, i * -32 + 5) == 0xffff) { length--; } else { return length; }
if (get16(folderEntry, i * -32 + 3) == 0xffff) { length--; } else { return length; }
if (get16(folderEntry, i * -32 + 1) == 0xffff) { length--; } else { return length; }
return length;
}
}
}
return 0; // WAT?
}
static void fat12__getItemName(const void *_folderEntry, void *_name) {
const uint8_t *folderEntry = _folderEntry;
uint8_t *name = _name;
if ((folderEntry[11 - 32] & 0x0f) != 0x0f) {
int length = 8;
memset(name, 0, 13);
memcpy(name, folderEntry, 8);
while (name[length - 1] == ' ') { length--; }
if (folderEntry[9] != ' ') {
name[length++] = '.';
memcpy(&name[length], &folderEntry[8], 3);
length += 3;
}
while (name[length - 1] == ' ') { length--; }
name[length] = '\0';
} else {
// previous folder entries hold long name in format:
// 0 sequence nmber (in turn back to first Long File Name entry, from 1)
// 1 - 10 file name next characters in utf-16
// 11 file attributes (0x0f - LFN entry)
// 12 reserved
// 13 checksum
// 14 - 25 file name next characters
// 26 - 27 reserved
// 28 - 31 file name next characters
// in these entries name placed in sequential order
// but first characters are located in first previous entry
// next characters - in next previous etc.
// if current entry is orificated by 0x40 - the entry is last (cinains last characters)
// unneed places for characters in the last entry are filled by 0xff
int length = 0;
for (int i = 1; i < 255 / 13; i++) {
//! TODO: Add unicode support
name[length++] = folderEntry[i * -32 + 1];
name[length++] = folderEntry[i * -32 + 3];
name[length++] = folderEntry[i * -32 + 5];
name[length++] = folderEntry[i * -32 + 7];
name[length++] = folderEntry[i * -32 + 9];
name[length++] = folderEntry[i * -32 + 14];
name[length++] = folderEntry[i * -32 + 16];
name[length++] = folderEntry[i * -32 + 18];
name[length++] = folderEntry[i * -32 + 20];
name[length++] = folderEntry[i * -32 + 22];
name[length++] = folderEntry[i * -32 + 24];
name[length++] = folderEntry[i * -32 + 28];
name[length++] = folderEntry[i * -32 + 30];
if (folderEntry[i * -32] & 0x40) {
while (name[length - 1] == 0xff) { name[--length] = 0; }
name[length++] = 0;
return;
}
}
}
}
static int fat12__forEachFile_handleFolderEntry(const Fat12 *this, int folderEntryOffset, String *name,
ForEachCallback callback, void *callbackParam) {
int nameSize = 0;
if (this->image[folderEntryOffset] == 0) { return 1; } // zero-entry, not file nor folder
nameSize = fat12__getItemNameSize(&this->image[folderEntryOffset]); // includes sizeof '\0'
if (nameSize != 0) {
while (name->capacity < name->length + nameSize + 1) {
name->capacity += name->capacity / 2;
name->data = realloc(name->data, name->capacity);
}
name->data[name->length++] = '/';
fat12__getItemName(&this->image[folderEntryOffset], &name->data[name->length]);
name->length += nameSize - 1;
if ((this->image[folderEntryOffset + 11] & 0x10)) {
// the item is folder
// handle folder only if it isn't current folder or parent one
if (memcmp(&this->image[folderEntryOffset], ". ", 11) &&
memcmp(&this->image[folderEntryOffset], ".. ", 11)) {
if (!fat12__forEachFile_handleFolder(this, get16(this->image, folderEntryOffset + 26), name, callback, callbackParam)) {
return 0;
}
}
} else {
// the item is a regular file
void *buffer = NULL;
int size = get32(this->image, folderEntryOffset + 28);
int cluster = get16(this->image, folderEntryOffset + 26);
buffer = malloc(size);
if (!fat12__getFile(this, buffer, size, cluster)) {
free(buffer);
return 0;
}
callback(name->data, size, buffer, callbackParam);
free(buffer);
}
name->length -= nameSize - 1; // substract length of current item name
name->length--; // substract length of '/'
name->data[name->length] = '\0';
}
return 1;
}
static int fat12__forEachFile_handleFolder(const Fat12 *this, int claster, String *name,
ForEachCallback callback, void *callbackParam) {
for (; claster < 0xff7; claster = fat12__getNextClaster(this, claster)) {
int offset = fat12__getOffsetByClaster(this, claster);
for (int i = 0; i < (this->bytesPerSector * this->sectorsPerClaster / 32); i++) {
if (!fat12__forEachFile_handleFolderEntry(this, offset + 32 * i, name, callback, callbackParam)) {
return 0;
}
}
}
return 1;
}
static int fat12__forEachFile(const Fat12 *this, ForEachCallback callback, void *callbackParam) {
String name = { 0 };
name.capacity = 4096;
name.data = malloc(name.capacity);
name.length = 0;
name.data[0] = '\0';
for (int i = 0; i < this->maxRootEntries; i++) {
if (!fat12__forEachFile_handleFolderEntry(this, this->rootDirectory + 32 * i, &name, callback, callbackParam)) {
free(name.data);
return 0;
}
}
free(name.data);
return 1;
}
static int fat12__open(Fat12 *this, const char *img) {
FILE *fp = NULL;
if (!(fp = fopen(img, "rb"))) {
return fat12__error(this, "Can't open imput file");
}
fseek(fp, 0, SEEK_END);
this->imageSize = ftell(fp);
rewind(fp);
if (!(this->image = malloc(this->imageSize))) {
return fat12__error(this, "Can't allocate memory for image");
}
fread(this->image, 1, this->imageSize, fp);
fclose(fp);
this->bytesPerSector = *(uint16_t *)((uintptr_t)this->image + 11);
this->sectorsPerClaster = *(uint8_t *)((uintptr_t)this->image + 0x0d);
this->reservedSectorCount = *(uint16_t *)((uintptr_t)this->image + 0x0e);
this->numberOfFats = *(uint8_t *)((uintptr_t)this->image + 0x10);
this->maxRootEntries = *(uint16_t *)((uintptr_t)this->image + 0x11);
this->totalSectors = *(uint16_t *)((uintptr_t)this->image + 0x13);
if (!this->totalSectors) {
this->totalSectors = *(uint32_t *)((uintptr_t)this->image + 0x20);
}
this->sectorsPerFat = *(uint16_t *)((uintptr_t)this->image + 0x16);
this->firstFat = (0 + this->reservedSectorCount) * this->bytesPerSector;
this->rootDirectory = this->firstFat + this->numberOfFats
* this->sectorsPerFat * this->bytesPerSector;
this->dataRegion = this->rootDirectory + this->maxRootEntries * 32;
printf("\nBytes per sector: %d\n", this->bytesPerSector);
printf("Sectors per claster: %d\n", this->sectorsPerClaster);
printf("Reserver sector count: %d\n", this->reservedSectorCount);
printf("Number of FATs: %d\n", this->numberOfFats);
printf("Max root entries: %d\n", this->maxRootEntries);
printf("Total sectors: %d\n", this->totalSectors);
printf("Sectors per FAT: %d\n", this->sectorsPerFat);
printf("First FAT: %d\n", this->firstFat);
printf("Root directory: %d\n", this->rootDirectory);
printf("Data region: %d\n\n", this->dataRegion);
return 1;
}
static int fat12__error(Fat12 *this, const char *errorMessage) {
this->errorMessage = errorMessage;
return 0;
}
static int handleError(const Fat12 *fat12) {
printf("Error in Fat12: %s\n", fat12->errorMessage);
return -1;
}
void writeFile(const char *fileName, int size, const uint8_t *data) {
// FILE *fp = NULL;
// if (!(fp = fopen(fileName, "wb"))) { perror(NULL); }
// fwrite(data, 1, size, fp);
// fclose(fp);
struct Info {
int number;
int reserved0;
int reserved1;
int dataSize;
const void *data;
char zero;
const char *name;
} __attribute__((packed)) *info = calloc(sizeof(struct Info), 1);
info->number = 2; // create/overwrite file
info->dataSize = size;
info->data = data;
info->zero = 0;
info->name = fileName;
asm volatile ("int $0x40" :: "a"(70), "b"(info));
}
static int callback(const char *name, size_t size, const uint8_t *data, void *param) {
String *outputPath = param;
while (outputPath->capacity < outputPath->length + strlen(name) + 1 + 1) {
outputPath->capacity += outputPath->capacity / 2;
outputPath->data = realloc(outputPath->data, outputPath->capacity);
}
strcat(outputPath->data, name);
{ // don't let mkdir_p create folder where file should be located
char *fileNameDelim = NULL;
// no slash = no folders to create, outputPath->data contains only file name
// yes, I know, outputPath->data always contains '/', but who knows...
if ((fileNameDelim = strrchr(outputPath->data, '/'))) {
*fileNameDelim = '\0';
mkdir_p(outputPath->data);
*fileNameDelim = '/';
}
}
printf("Extracting %s\n", outputPath->data);
#ifdef TCC
FILE *fp = NULL;
if (!(fp = fopen(outputPath->data, "wb"))) { perror(NULL); }
fwrite(data, 1, size, fp);
fclose(fp);
#else
writeFile(outputPath->data, size, data);
#endif
outputPath->data[outputPath->length] = '\0';
return 0;
}
int main(int argc, char* argv[]) {
Fat12 fat12 = { 0 };
char *imageFile = NULL;
String outputFolder = { 0 };
int exit_code = 0;
char app_title[] = "UnImg - kolibri.img file unpacker";
con_init(-1, -1, -1, 350, app_title);
if (argc < 2) {
puts(" Usage:");
puts(" unimg \"/path/to/kolibri.img\" \"/optional/extract/path\"");
puts(" where optional key [-e] is exit on success");
exit(exit_code);
return -1;
} else {
imageFile = argv[1];
printf("File: %s\n", imageFile);
}
outputFolder.capacity = 4096;
outputFolder.data = malloc(outputFolder.capacity);
//! ACHTUNG: possible buffer overflow, is 4096 enough in KolibriOS?
if (argc >= 3 && argv[2][0] != '-') strcpy(outputFolder.data, argv[2]);
else {
strcpy(outputFolder.data, "/tmp0/1");
strcat(outputFolder.data, strrchr(imageFile, '/'));
}
outputFolder.length = strlen(outputFolder.data);
// handle -e parameter - exit on success
if (argc >= 3 && !strcmp(argv[argc - 1], "-e")) { exit_code = 1; }
if (!fat12__open(&fat12, imageFile)) {
return handleError(&fat12);
}
if (!fat12__forEachFile(&fat12, callback, &outputFolder)) {
return handleError(&fat12);
}
puts("\nDONE!");
exit(exit_code);
}