decode NFS file handle for nfs4j

decode_nfs4j_fh.py

#!/usr/bin/env python3

import sys 
import struct
import binascii

fh = sys.argv[1].upper()

version = struct.unpack('b', bytes.fromhex(fh[0:2]) )[0]
magic = fh[2:8]
generation = struct.unpack('>i', bytes.fromhex(fh[8:16]))[0]
index = struct.unpack('>i', bytes.fromhex(fh[16:24]))[0]
t =   struct.unpack('b', bytes.fromhex(fh[24:26]))[0]
l = struct.unpack('b', bytes.fromhex(fh[26:28]) )[0]
handle = bytes.fromhex(fh[28:])

INODE_TYPES = { 
    0: "INODE",
    1: "TAG",
    2: "TAGS",
    3: "ID",
    4: "PATHOF",
    5: "PARENT",
    6: "NAMWOF",
    7: "PGET",
    8: "PSET",
    9: "CONST",
    15: "LABEL"
}

print ('version   : {}'.format(version))
print ('magic     : {}'.format(magic))
print ('generation: {}'.format(generation))
print ('index     : {}'.format(index))
print ('type      : {}'.format(t))
print ('opaque len: {}'.format(l))
print ('handle    : {}'.format(fh[28:]))
print ('fsid      : {}'.format(struct.unpack('b', bytes.fromhex(fh[28:30]) )[0]))

inodeType = struct.unpack('b', bytes.fromhex(fh[30:32]) )[0]
print ('inode type: {}'.format(INODE_TYPES[inodeType]))
idLen = struct.unpack('b', bytes.fromhex(fh[32:34]) )[0]
print ('id len    : {}'.format(idLen))
print ('inumber   : {}'.format(int(fh[34:34+idLen*2], base=16)))
argsLen = struct.unpack('b', bytes.fromhex(fh[34+idLen*2:36+idLen*2]) )[0]
print ('args      : {}'.format(binascii.a2b_hex(fh[36+idLen*2:])))