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#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "include/fs.h"
typedef int (*dfunc)(int);
static unsigned short
get_le_short(void *from)
{
unsigned char *p = from;
return ((unsigned short)(p[1]) << 8) +
(unsigned short)p[0];
}
static unsigned int get_le_long(void *from)
{
unsigned char *p = from;
return ((unsigned int)(p[3]) << 24) +
((unsigned int)(p[2]) << 16) +
((unsigned int)(p[1]) << 8) +
(unsigned int)p[0];
}
static unsigned short get_be_short(void *from)
{
unsigned char *p = from;
return ((unsigned short)(p[0]) << 8) +
(unsigned short)p[1];
}
static unsigned int get_be_long(void *from)
{
unsigned char *p = from;
return ((unsigned int)(p[0]) << 24) +
((unsigned int)(p[1]) << 16) +
((unsigned int)(p[2]) << 8) +
(unsigned int)p[3];
}
static int get_buffer(int fd, unsigned char *b, int offset, int len)
{
if(lseek(fd, offset, SEEK_SET) != offset)
return -1;
if(read(fd, b, len) != len)
return -1;
return 0;
}
#define MBR_BUF_SIZE 512
static int detect_mbr(int fd)
{
int ret = NONE;
unsigned char *buffer = (unsigned char*)malloc(MBR_BUF_SIZE);
if(get_buffer(fd, buffer, 0, MBR_BUF_SIZE) != 0)
goto out;
if((buffer[510] == 0x55) && (buffer[511] == 0xAA))
ret = MBR;
out:
free(buffer);
return ret;
}
#define EFI_BUF_OFFSET 512
#define EFI_BUF_SIZE 512
static int detect_efi(int fd)
{
int ret = NONE;
unsigned char *buffer = (unsigned char*)malloc(EFI_BUF_SIZE);
if(get_buffer(fd, buffer, EFI_BUF_OFFSET, EFI_BUF_SIZE) != 0)
goto out;
if(!memcmp(buffer, "EFI PART", 8))
ret = EFI;
out:
free(buffer);
return ret;
}
#define EXT2_BUF_SIZE 1024
static int detect_ext23(int fd)
{
int ret = NONE;
unsigned char *buffer = (unsigned char*)malloc(EXT2_BUF_SIZE);
if(get_buffer(fd, buffer, 1024, EXT2_BUF_SIZE) != 0)
goto out;
if(get_le_short(buffer + 56) == 0xEF53)
{
if(get_le_long(buffer + 92) & 0x0004)
{
if ((get_le_long(buffer + 96) < 0x0000040)
&& (get_le_long(buffer + 100) < 0x0000008))
ret = EXT3;
else
ret = EXT4;
}
else
ret = EXT2;
}
out:
free(buffer);
return ret;
}
#define FAT_BUF_SIZE 512
static int detect_fat(int fd)
{
int ret = NONE;
unsigned char *buffer = (unsigned char*)malloc(FAT_BUF_SIZE);
if(get_buffer(fd, buffer, 0, FAT_BUF_SIZE) != 0)
goto out;
if (((((buffer[0] & 0xff) == 0xEB) && ((buffer[2] & 0xff) == 0x90)) || ((buffer[0] & 0xff) == 0xE9))
&& ((buffer[510] & 0xff) == 0x55) /*&& ((buffer[511] & 0xff == 0xAA))*/
&& (memcmp(buffer + 3, "NTFS ", 8)))
ret = FAT;
out:
free(buffer);
return ret;
}
static int detect_exfat(int fd)
{
int ret = NONE;
unsigned char *buffer = (unsigned char*)malloc(FAT_BUF_SIZE);
if(get_buffer(fd, buffer, 0, FAT_BUF_SIZE) != 0)
goto out;
if (!memcmp(buffer + 3, "EXFAT ", 7))
ret = EXFAT;
out:
free(buffer);
return ret;
}
#define HFSPLUS_VOL_JOURNALED (1 << 13)
#define HFSPLUS_BUF_SIZE 512
static int detect_hfsplus(int fd)
{
int ret = NONE;
unsigned short magic;
unsigned int journal;
unsigned char *buffer = (unsigned char*)malloc(HFSPLUS_BUF_SIZE);
if(get_buffer(fd, buffer, 1024, HFSPLUS_BUF_SIZE) != 0)
goto out;
magic = get_be_short(buffer);
journal = get_be_long(buffer + 4) & HFSPLUS_VOL_JOURNALED;
if(magic == 0x482B || magic == 0x4858)
{
if(!journal)
ret = HFSPLUS;
else
ret = HFSPLUSJOURNAL;
}
out:
free(buffer);
return ret;
}
#define NTFS_BUF_SIZE 512
static int detect_ntfs(int fd)
{
int ret = NONE;
unsigned char *buffer = (unsigned char*)malloc(NTFS_BUF_SIZE);
if(get_buffer(fd, buffer, 0, NTFS_BUF_SIZE) != 0)
goto out;
if(!memcmp(buffer + 3, "NTFS ", 8))
ret = NTFS;
out:
free(buffer);
return ret;
}
#define EXTENDED_BUF_SIZE 512
static int detect_extended(int fd)
{
int ret = NONE;
unsigned char *buffer = (unsigned char*)malloc(MBR_BUF_SIZE);
if(get_buffer(fd, buffer, 0, 512) != 0)
goto out;
if((((buffer[0] & 0xff) == 0xEB) && ((buffer[2] & 0xff) == 0x90)) || ((buffer[0] & 0xff) == 0xE9))
goto out;
if(((buffer[510] & 0xff) == 0x55) && ((buffer[511] & 0xff) == 0xAA))
ret = EXTENDED;
out:
free(buffer);
return ret;
}
static dfunc funcs[] = {
detect_ext23,
detect_exfat,
detect_fat,
detect_ntfs,
detect_hfsplus,
detect_extended,
detect_efi,
detect_mbr,
};
int detect_fs(char *device)
{
int i = 0;
int ret = NONE;
int fd;
fd = open(device, O_RDONLY);
if(!fd)
return NONE;
while((i < 6) && (ret == NONE))
ret = funcs[i++](fd);
close(fd);
return ret;
}
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