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#!/usr/bin/env python2
import struct
import binascii
TYPES = {
(0x1ff, 0x001): 'reg',
(0x1ff, 0x002): 'dir',
(0x1ff, 0x011): 'superblock',
(0x1ff, 0x010): 'root',
(0x1ff, 0x030): 'delete',
(0x1f0, 0x080): 'globals',
(0x1ff, 0x0c0): 'tail soft',
(0x1ff, 0x0c1): 'tail hard',
(0x1ff, 0x0f0): 'crc',
(0x1ff, 0x040): 'struct dir',
(0x1ff, 0x041): 'struct inline',
(0x1ff, 0x042): 'struct ctz',
(0x100, 0x100): 'attr',
}
def typeof(type):
for prefix in range(9):
mask = 0x1ff & ~((1 << prefix)-1)
if (mask, type & mask) in TYPES:
return TYPES[mask, type & mask] + (
' [%0*x]' % (prefix/4, type & ((1 << prefix)-1))
if prefix else '')
else:
return '[%02x]' % type
def main(*blocks):
# find most recent block
file = None
rev = None
crc = None
versions = []
for block in blocks:
try:
nfile = open(block, 'rb')
ndata = nfile.read(4)
ncrc = binascii.crc32(ndata)
nrev, = struct.unpack('<I', ndata)
assert rev != nrev
if not file or ((rev - nrev) & 0x80000000):
file = nfile
rev = nrev
crc = ncrc
versions.append((nrev, '%s (rev %d)' % (block, nrev)))
except (IOError, struct.error):
pass
if not file:
print 'Bad metadata pair {%s}' % ', '.join(blocks)
return 1
print "--- %s ---" % ', '.join(v for _,v in sorted(versions, reverse=True))
# go through each tag, print useful information
print "%-4s %-8s %-14s %3s %3s %s" % (
'off', 'tag', 'type', 'id', 'len', 'dump')
tag = 0
off = 4
while True:
try:
data = file.read(4)
crc = binascii.crc32(data, crc)
ntag, = struct.unpack('<I', data)
except struct.error:
break
tag ^= ntag
off += 4
type = (tag & 0x7fc00000) >> 22
id = (tag & 0x003ff000) >> 12
size = (tag & 0x00000fff) >> 0
data = file.read(size)
if type == 0x0f0:
crc = binascii.crc32(data[:4], crc)
else:
crc = binascii.crc32(data, crc)
print '%04x: %08x %-14s %3s %3d %-23s %-8s' % (
off, tag,
typeof(type) + (' bad!' if type == 0x0f0 and ~crc else ''),
id if id != 0x3ff else '.', size,
' '.join('%02x' % ord(c) for c in data[:8]),
''.join(c if c >= ' ' and c <= '~' else '.' for c in data[:8]))
off += tag & 0xfff
if type == 0x0f0:
crc = 0
return 0
if __name__ == "__main__":
import sys
sys.exit(main(*sys.argv[1:]))
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