def dump_logfile(volume_path, path):
with open(volume_path, "rb") as volume:
bootsector = layout.NtfsBootSector.from_buffer_copy(
volume.read(ctypes.sizeof(layout.NtfsBootSector)))
cluster_size = bootsector.bpb.bytes_per_sector * bootsector.bpb.sectors_per_cluster
if bootsector.clusters_per_mft_record < 0:
file_record_size = 1 << -bootsector.clusters_per_mft_record
else:
file_record_size = (bootsector.clusters_per_mft_record) << \
(layout.ffs(cluster_size) - 1)
logfile_offset = bootsector.mft_lcn * cluster_size
logfile_offset += 2 * file_record_size
volume.seek(logfile_offset)
buffer = bytearray(file_record_size)
volume.readinto(buffer)
layout.dofixup(buffer, sector_size=bootsector.bpb.bytes_per_sector)
file_record = layout.FileRecordSegmentHeader.from_buffer_copy(buffer)
data_stream = find_data_stream(buffer[file_record.attr_offset:])
with open(path, "wb") as logfile_stream:
for vcn, lcn, length in data_stream.runlist:
volume.seek(lcn * cluster_size)
while length > 0:
num = max(length, 64)
logfile_stream.write(volume.read(num * cluster_size))
length -= num
def dump_logfile(volume_path, path):
with open(volume_path, "rb") as volume:
bootsector = layout.NtfsBootSector.from_buffer_copy(
volume.read(ctypes.sizeof(layout.NtfsBootSector)))
cluster_size = bootsector.bpb.bytes_per_sector * bootsector.bpb.sectors_per_cluster
if bootsector.clusters_per_mft_record < 0:
file_record_size = 1 << -bootsector.clusters_per_mft_record
else:
file_record_size = (bootsector.clusters_per_mft_record) << \
(layout.ffs(cluster_size) - 1)
logfile_offset = bootsector.mft_lcn * cluster_size
logfile_offset += 2 * file_record_size
volume.seek(logfile_offset)
buffer = bytearray(file_record_size)
volume.readinto(buffer)
layout.dofixup(buffer, sector_size=bootsector.bpb.bytes_per_sector)
file_record = layout.FileRecordSegmentHeader.from_buffer_copy(buffer)
data_stream = find_data_stream(buffer[file_record.attr_offset:])
with open(path, "wb") as logfile_stream:
for vcn, lcn, length in data_stream.runlist:
volume.seek(lcn * cluster_size)
while length > 0:
num = max(length, 64)
logfile_stream.write(volume.read(num * cluster_size))
length -= num
def get_lsn_restart_blocks(logfile):
'''Returns restart blocks.
Block with higher current LSN is considered to be
valid (more up-to date). Remaining block is used as
a backup.
Returns:
tuple - (valid block, backup block)
'''
logfile.seek(0)
# Inspect logfile a bit...
sector = logfile.read(SECTOR_SIZE)
restart_header = layout.RestartPageHeader.from_buffer_copy(sector)
logfile.seek(0)
if restart_header.system_page_size > (1024 * 64):
# Max cluster size is 64kB
# https://support.microsoft.com/en-us/kb/140365
raise ValueError("invalid system page size?")
# Read first two pages from the logfile
pages = [
bytearray(restart_header.system_page_size),
bytearray(restart_header.system_page_size)
]
for page in pages:
logfile.readinto(page)
layout.dofixup(page, sector_size=SECTOR_SIZE)
block_first = None
block_second = None
if pages[0]:
block_first = get_restart_context(pages[0])
if pages[1]:
block_second = get_restart_context(pages[1])
if block_first and block_second:
if block_first.area.current_lsn < block_second.area.current_lsn:
# First block has lower LSN, so swap block, since we
# are returning first block as the valid one.
block_first, block_second = block_second, block_first
if not block_first:
# Swap blocks when first block is invalid.
block_first, block_second = block_second, block_first
return block_first, block_second
def get_lsn_restart_blocks(logfile):
'''Returns restart blocks.
Block with higher current LSN is considered to be
valid (more up-to date). Remaining block is used as
a backup.
Returns:
tuple - (valid block, backup block)
'''
logfile.seek(0)
# Inspect logfile a bit...
sector = logfile.read(SECTOR_SIZE)
restart_header = layout.RestartPageHeader.from_buffer_copy(sector)
logfile.seek(0)
if restart_header.system_page_size > (1024 * 64):
# Max cluster size is 64kB
# https://support.microsoft.com/en-us/kb/140365
raise ValueError("invalid system page size?")
# Read first two pages from the logfile
pages = [bytearray(restart_header.system_page_size),
bytearray(restart_header.system_page_size)]
for page in pages:
logfile.readinto(page)
layout.dofixup(page, sector_size=SECTOR_SIZE)
block_first = None
block_second = None
if pages[0]:
block_first = get_restart_context(pages[0])
if pages[1]:
block_second = get_restart_context(pages[1])
if block_first and block_second:
if block_first.area.current_lsn < block_second.area.current_lsn:
# First block has lower LSN, so swap block, since we
# are returning first block as the valid one.
block_first, block_second = block_second, block_first
if not block_first:
# Swap blocks when first block is invalid.
block_first, block_second = block_second, block_first
return block_first, block_second
def get_log_page(self, page):
'''Returns page from log.
Does USN fixups.
'''
self.logfile_stream.seek(page)
page = bytearray(self.lcb.log_page_size)
self.logfile_stream.readinto(page)
return layout.dofixup(page)
def get_log_page(self, page):
'''Returns page from log.
Does USN fixups.
'''
self.logfile_stream.seek(page)
page = bytearray(self.lcb.log_page_size)
self.logfile_stream.readinto(page)
return layout.dofixup(page)
