def next_cluster(self, cluster):
last_position = self.partition.disk.image.tell()
self.partition.disk.image.seek(lba(self.first_sector) + cluster * 4)
next_cluster = int.from_bytes(self.partition.disk.image.read(4),
byteorder="little")
self.partition.disk.image.seek(last_position)
return next_cluster & MASK
def read_cluster(self, cluster):
last_position = self.disk.image.tell()
self.disk.image.seek(lba(self.get_sector(cluster)))
data = self.disk.image.read(self.bytes_per_sector *
self.sectors_per_cluster)
self.disk.image.seek(last_position)
return data
def print_chain(self, cluster):
last_position = self.partition.disk.image.tell()
self.partition.disk.image.seek(lba(self.first_sector) + cluster * 4)
current_cluster = int.from_bytes(self.partition.disk.image.read(4),
byteorder="little") & MASK
print(current_cluster, end='')
while current_cluster < 0x0FFFFFF8 or current_cluster == 0x00000000:
current_cluster = self.next_cluster(current_cluster) & MASK
print(" -> " + str(current_cluster), end='')
print()
self.partition.disk.image.seek(last_position)
def delete_entry(self, directory, name):
last_position = self.disk.image.tell()
entry = [e for e in directory.entries if e.name() == name][0]
self.disk.image.seek(
lba(self.get_sector(directory.first_cluster)) +
entry.first_line * 32)
for i in range(entry.length):
self.disk.image.write(b'\xE5')
self.disk.image.seek(31, 1)
self.delete_cluster_chain(entry.cluster)
directory.read_from_disk()
self.disk.image.seek(last_position)
def find_free_cluster(self, cluster=2):
last_position = self.partition.disk.image.tell()
self.partition.disk.image.seek(
lba(self.first_sector) + (cluster + 1) * 4)
current_cluster = int.from_bytes(self.partition.disk.image.read(4),
byteorder="little") & MASK
cluster_number = max(cluster + 1, 2)
while current_cluster != 0x00000000:
current_cluster = int.from_bytes(self.partition.disk.image.read(4),
byteorder="little") & MASK
cluster_number += 1
self.partition.disk.image.seek(last_position)
return cluster_number
def read_from_disk(self):
last_position = self.partition.disk.image.tell()
entry_block = list()
self.entries = list()
self.free_entries = list()
entries_per_cluster = self.partition.sectors_per_cluster * self.partition.bytes_per_sector // 32
first_free_entry_number = -1
first_entry_number = -1
current_cluster = self.first_cluster
while current_cluster < 0x0FFFFFF8:
self.partition.disk.image.seek(
lba(self.partition.get_sector(current_cluster)))
for entry_number in range(0, entries_per_cluster):
entry = self.partition.disk.image.read(32)
if entry[0] == 0x00:
if first_free_entry_number != -1:
self.free_entries.append(
(first_free_entry_number,
(entries_per_cluster - first_free_entry_number),
True))
else:
self.free_entries.append(
(entry_number, entries_per_cluster - entry_number,
True))
first_free_entry_number = -1
break
elif entry[0] == 0xE5:
if first_free_entry_number == -1:
first_free_entry_number = entry_number
continue
else:
if first_entry_number == -1:
first_entry_number = entry_number
if first_free_entry_number != -1:
self.free_entries.append(
(first_free_entry_number,
entry_number - first_free_entry_number, False))
first_free_entry_number = -1
entry_block.append(entry)
if entry[11] != 0x0F:
self.entries.append(
Entry.from_binary(entry_block, first_entry_number))
first_entry_number = -1
entry_block = list()
current_cluster = self.partition.next_cluster(current_cluster)
self.partition.disk.image.seek(last_position)
def write(self, entry):
last_position = self.partition.disk.image.tell()
entry = entry.encode()
free_entry = self.free_entries[0]
for e in self.free_entries:
if e[1] > len(entry) or e[2]:
free_entry = e
current_directory_cluster = self.first_cluster
while free_entry[
0] > self.partition.bytes_per_sector * self.partition.sectors_per_cluster / 32:
current_directory_cluster = self.partition.next_cluster(
current_directory_cluster)
free_entry[
0] -= self.partition.bytes_per_sector * self.partition.sectors_per_cluster / 32
self.partition.disk.image.seek(
lba(self.partition.get_sector(current_directory_cluster)) +
free_entry[0] * 32)
if free_entry[2]:
if len(entry) < free_entry[1]:
self.partition.disk.image.write(b''.join(entry))
else:
self.partition.disk.image.write(b''.join(
entry[:free_entry[1]]))
self.partition.write_to_fat(
current_directory_cluster,
self.partition.next_free_cluster(
current_directory_cluster))
if len(entry[free_entry[1]:]) != 0:
self.partition.disk.image.write(b''.join(
entry[free_entry[1]:]))
self.partition.disk.image.write(b'\xe5')
else:
self.partition.disk.image.write(b''.join(entry))
self.partition.disk.image.seek(last_position)
def write_cluster(self, cluster, data):
last_position = self.disk.image.tell()
self.disk.image.seek(lba(self.get_sector(cluster)))
self.disk.image.write(data)
self.disk.image.seek(last_position)
def __init__(self, disk, number):
self.number = number
self.disk = disk
last_position = self.disk.image.tell()
self.disk.image.seek(0x1BE + self.number * 16 * 8)
self.boot_flag = int.from_bytes(self.disk.image.read(1),
byteorder="little")
self.CHS_begin = int.from_bytes(self.disk.image.read(3),
byteorder="little")
self.partition_type = int.from_bytes(self.disk.image.read(1),
byteorder="little")
self.CHS_end = int.from_bytes(self.disk.image.read(3),
byteorder="little")
self.first_sector = int.from_bytes(self.disk.image.read(4),
byteorder="little")
self.sectors_number = int.from_bytes(self.disk.image.read(4),
byteorder="little")
self.fat32 = self.partition_type == 0x0B or self.partition_type == 0x0C
if self.fat32:
self.disk.image.seek(lba(self.first_sector) + 0x0B)
self.bytes_per_sector = int.from_bytes(self.disk.image.read(2),
byteorder="little")
self.sectors_per_cluster = int.from_bytes(self.disk.image.read(1),
byteorder="little")
self.reserved_sectors = int.from_bytes(self.disk.image.read(2),
byteorder="little")
self.number_of_FATs = int.from_bytes(self.disk.image.read(1),
byteorder="little")
self.disk.image.seek(lba(self.first_sector) + 0x24)
self.sectors_per_FAT = int.from_bytes(self.disk.image.read(4),
byteorder="little")
self.disk.image.seek(lba(self.first_sector) + 0x2C)
self.root_cluster = int.from_bytes(self.disk.image.read(4),
byteorder="little")
self.disk.image.seek(lba(self.first_sector) + 0x1FE)
print("Partition",
number,
"volume signature ................................. ",
end='')
if int.from_bytes(self.disk.image.read(2),
byteorder="big") == 0x55AA:
print(colors.OK + "OK" + colors.END)
else:
print(colors.FAIL + "FAIL" + colors.END)
self.fat = list()
for i in range(self.number_of_FATs):
self.fat.append(
FileAllocationTable(
self, self.first_sector + self.reserved_sectors +
i * self.sectors_per_FAT))
self.first_cluster = self.first_sector + self.reserved_sectors + self.number_of_FATs * self.sectors_per_FAT
self.current_directory = Directory(self, self.root_cluster)
self.current_path = Path()
self.disk.image.seek(last_position)
def write(self, cluster, next_cluster):
last_position = self.partition.disk.image.tell()
self.partition.disk.image.seek(lba(self.first_sector) + cluster * 4)
self.partition.disk.image.write(
next_cluster.to_bytes(4, byteorder="little"))
self.partition.disk.image.seek(last_position)
