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Full readonly filesystem access
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@ecpre
ecpre committed Feb 21, 2023
1 parent e5daf73 commit d65c905
Showing 1 changed file with 82 additions and 56 deletions.
138 changes: 82 additions & 56 deletions FuseRedSea.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,8 @@
#define _FILE_OFFSET_BITS 64
#define BLOCK_SIZE 512 // RedSea Block Size
#define ISO_9660_SECTOR_SIZE 2048
#define UNIX_CDATE_SECONDS 62167132800 // seconds to subtract from CDate seconds for unix time
// 719527*84000
#include <fuse.h>
#include <stdlib.h>
#include <unistd.h>
Expand All @@ -11,7 +13,7 @@

/* RedSea FUSE driver
* for the TempleOS RedSea filesystem
*
* as of right now read only
*/

struct redsea_file {
Expand Down Expand Up @@ -42,13 +44,39 @@ struct redsea_directory** directory_structs;
struct redsea_file** file_structs;
int directory_count = 1;
int file_count = 0;
FILE* image; // image is going to be global. makes it easier

bool is_directory(const char *path) {
//Converts templeOS CDate (Christ date?) format to unix time.
long long int cdate_to_unix(unsigned long long int cdate) {
unsigned int lower = cdate & 0xFFFFFFFF;
unsigned int upper = (cdate>>32) & 0xFFFFFFFF;
unsigned long long int cdate_upper_seconds = upper*86400LL;
long int cdate_lower_seconds = lower/49710;
unsigned long long int unix_seconds = cdate_upper_seconds+cdate_lower_seconds-UNIX_CDATE_SECONDS;
return unix_seconds;
}

bool is_directory(const char* path) {
for (int i = 0; i < directory_count; i++) {
if (strcmp (path, directory_paths[i]) == 0) return true;
}
return false;
}

unsigned long long int directory_position(const char* path) {
for (unsigned long long int i=0; i<directory_count; i++) {
if (strcmp (path, directory_paths[i]) == 0) return i;
}
return -1;
}

unsigned long long int file_position(const char* path) {
for (unsigned long long int i = 0; i < file_count; i++) {
if (strcmp (path, file_paths[i]) == 0) return i;
}
return -1;
}

// double directory array
void expand_directories() {
max_directory_count *= 2;
Expand Down Expand Up @@ -93,22 +121,17 @@ bool redsea_identity_check(unsigned int boot_catalog, FILE* image) {
fseek(image, (boot_catalog*ISO_9660_SECTOR_SIZE+4), SEEK_SET);
fread(&buf, 4, 1, image);
unsigned int tos_string = 0x706d6554; // check for TempleOS fs signature. not the actual signature location
// but will always be there. I should probably make this look for the
// actual RedSea signature
// but will this will always be there. I should probably make this
// look for the actual RedSea signature. :/
if (buf != tos_string) return false;
return true;
}

/*
* Reads all the files and child directories of a given redsea directory
* Called in main as redsea_read_files(rdb, image, ".");
* *directory is the name of the directory being searched.
* block is the directory's starting block
* image is the image file being read.
* size is the size of the directory
* First called in main.
*/
//void redsea_read_files(unsigned long long int block, unsigned long long int size, FILE* image, unsigned char *directory, unsigned char *path_so_far) {
void redsea_read_files(struct redsea_directory* directory, FILE* image, unsigned char *path_so_far) {
void redsea_read_files(struct redsea_directory* directory, unsigned char *path_so_far) {

unsigned long long int block = directory->block;
unsigned long long int size = directory->size;
Expand All @@ -122,21 +145,14 @@ void redsea_read_files(struct redsea_directory* directory, FILE* image, unsigned
unsigned long long int file_block;
unsigned long long int file_size;
unsigned long long int timestamp;
int seek_count = 0;
int subdirec = -1;
struct redsea_directory* subdirectories[size/64]; // directory size / 64 is max entries in a directory
unsigned char subdirectory_paths[size/64][512];
//unsigned long long int subdirectory_blocks[size/64];
//unsigned long long int subdirectory_sizes[size/64];
unsigned char path[strlen(path_so_far)+40];
fseek(image, (block*BLOCK_SIZE), SEEK_SET);
for ( ;; ) {
fread(&filetype, 2, 1, image);
seek_count+=2;
if (filetype == 0) {
//printf("%d\n", seek_count);
//printf("%x\n", filetype);
//printf("directory end\n");
break; // end of directory
}
printf("0x%04x ", filetype);
Expand All @@ -153,27 +169,18 @@ void redsea_read_files(struct redsea_directory* directory, FILE* image, unsigned
}
name[i] = '\0'; // terminate file name
fseek(image, 37-i, SEEK_CUR);
seek_count+= (37-i);
break;
}
name[i] = current;
}
fread(&file_block, 8, 1, image);
seek_count+=8;
//printf("%x\n", file_block);
//printf("%s\n", name);

fread(&file_size, 8, 1, image);
seek_count+=8;
strcpy(path, path_so_far);
strcat(path, "/");
strcat(path, name);
fread(&timestamp, 8, 1, image); // TODO: This is the date timestamp. Follows format of 0xFFFFFFFF 0xFFFFFFFF
// with upper 32 bits being days since Christ's birth on January 2nd 1BC
// and lower 32 bits being the time of day divided by 4 billion

printf("%s BLOCK %x SIZE %x TIMESTAMP %x \n", path, file_block, file_size, timestamp);
seek_count+=8;
fread(&timestamp, 8, 1, image);
printf("%s BLOCK %#lx SIZE %#lx TIMESTAMP %#016lx \n", path, file_block, file_size, timestamp);
if (filetype == 0x0810) {
if (strcmp(directory_name, name) != 0 && strcmp("..", name) != 0) {
subdirec++;
Expand Down Expand Up @@ -205,7 +212,6 @@ void redsea_read_files(struct redsea_directory* directory, FILE* image, unsigned
}
file_paths[file_count] = malloc(strlen(path)+1);
strcpy(file_paths[file_count], path);
printf("%s\n", file_paths[file_count]);
// create file entry struct after inserting path
struct redsea_file* file_entry = malloc(sizeof(struct redsea_file));
strcpy(file_entry->name, name);
Expand All @@ -227,28 +233,39 @@ void redsea_read_files(struct redsea_directory* directory, FILE* image, unsigned

struct redsea_directory* subdir = subdirectories[i];
unsigned char* sub_path = subdirectory_paths[i];
redsea_read_files(subdir, image, sub_path);
printf("EOD\n");
redsea_read_files(subdir, sub_path);
}

}

/* Gets the contents of a given file
*
*/

unsigned char* redsea_file_content(struct redsea_file* rs_file, size_t size, off_t offset) {
rewind(image);
unsigned char* content = malloc(size);
printf("%d\n", size);
fseek(image, (rs_file->block)*BLOCK_SIZE+offset, SEEK_SET);
fread(content, 1, size, image);
return content;
}

static int fuse_rs_file_attributes(const char *path, struct stat *st) {
if (strcmp(path, "/") == 0 || is_directory(path)) {
for (int i = 0; i < directory_count; i++) {
if (strcmp(path, directory_paths[i]) == 0) {
st->st_size = directory_structs[i]->size;
}
}
unsigned long long int did = directory_position(path); // did is Directory ID
if (did == -1) return -1;
st->st_size = directory_structs[did]->size;
st->st_mtime = cdate_to_unix(directory_structs[did]->mod_date);
st->st_mode = S_IFDIR | 0755;
st->st_nlink = 2;

}
else {
for (int i = 0; i<file_count; i++) {
if (strcmp(path, file_paths[i]) == 0) {
st->st_size = file_structs[i]->size;
}
}
unsigned long long int fid = file_position(path); // fid is File ID
if (fid == -1) return -1;
st->st_size = file_structs[fid]->size;
st->st_mtime = cdate_to_unix(file_structs[fid]->mod_date);
st-> st_mode = S_IFREG | 0644;
st-> st_nlink = 2;
}
Expand All @@ -261,20 +278,30 @@ static int fuse_rs_file_attributes(const char *path, struct stat *st) {
static int fuse_rs_read_directory(const char *path, void *buffer, fuse_fill_dir_t filler, off_t offset, struct fuse_file_info *fi) {
filler(buffer, ".", NULL, 0);
filler(buffer, "..", NULL, 0);
for (int i = 0; i < directory_count; i++) {
if (strcmp(path, directory_paths[i]) == 0) {
unsigned long long int num_children = directory_structs[i]->num_children;
for (int j = 0; j<num_children; j++) {
filler(buffer, directory_structs[i]->children[j], NULL, 0);
}
}
unsigned long long int did = directory_position(path); // did is Directory ID
unsigned long long int num_children = directory_structs[did]->num_children;
if (did==-1) return -1;
for (int j = 0; j<num_children; j++) {
filler(buffer, directory_structs[did]->children[j], NULL, 0);
}
return 0;
}

static int fuse_rs_read_file(const char *path, char *buffer, size_t size, off_t offset, struct fuse_file_info *fi) {
unsigned long long int fid = file_position(path);
if (fid == -1) return -1;
unsigned char* file_contents;

file_contents = redsea_file_content(file_structs[fid], size, offset);
memcpy(buffer, file_contents, size);

return size;
}

static struct fuse_operations redsea_ops = {
.getattr = fuse_rs_file_attributes,
.readdir = fuse_rs_read_directory
.readdir = fuse_rs_read_directory,
.read = fuse_rs_read_file // all I have implemented now. write access soon. maybe
};

char *devfile = NULL;
Expand All @@ -293,17 +320,16 @@ int main(int argc, char **argv) {
argc--;
}

FILE* image = fopen(devfile, "rb"); // open disk image
image = fopen(devfile, "rb"); // open disk image
unsigned int bcp = boot_catalog_pointer(image);
if (redsea_identity_check(bcp, image)) printf("good\n");
else printf("bad\n");
printf("0x%x\n", bcp);
printf("0x%x\n", 0x8800);
else printf("bad. not redsea?\n");
printf("%#x\n", bcp);
unsigned int rdb = root_directory_block(0x58, image); // first param should always be 0x58, but maybe I don't know the specification well enough
fseek(image, (rdb*BLOCK_SIZE)+48, SEEK_SET);
unsigned long long int size;
fread(&size, 8, 1, image); // get root directory size before reading. probably inefficient
printf("size: %x\n", size);
printf("size: %#lx\n", size);
struct redsea_directory* root_directory = malloc(sizeof(struct redsea_directory));
strcpy(root_directory->name, ".");
root_directory->size = size;
Expand All @@ -315,7 +341,7 @@ int main(int argc, char **argv) {
directory_structs[0] = root_directory;

//redsea_read_files(rdb, size, image, ".", "");
redsea_read_files(root_directory, image, "");
redsea_read_files(root_directory, "");

return fuse_main(argc, argv, &redsea_ops, NULL);

Expand Down

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