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Update IOUtools. Ref #1627

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pull/1800/head
grossmj 4 years ago
parent 05ed9836e4
commit e4978004d0
2 changed files with 172 additions and 189 deletions
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221
gns3server/compute/iou/utils/iou_export.py
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@ -37,19 +37,19 @@ optional arguments:
-h, --help show this help message and exit
"""
import argparse
import sys
import struct
# Uncompress data in .Z file format.
# Ported from dynamips' fs_nvram.c to python
# Adapted from 7zip's ZDecoder.cpp, which is licensed under LGPL 2.1.
# Uncompress data in LZC format, .Z file format
# LZC uses the LZW compression algorithm with a variable dictionary size
# For LZW see https://en.wikipedia.org/wiki/Lempel–Ziv–Welch
# Performance: about 1 MByte/sec, 15-50 times slower than C implementation
def uncompress_LZC(data):
LZC_NUM_BITS_MIN = 9
LZC_NUM_BITS_MAX = 16
in_data = bytearray(data)
in_len = len(in_data)
in_data = bytearray(data)
in_len = len(in_data)
out_data = bytearray()
if in_len == 0:
@ -59,143 +59,144 @@ def uncompress_LZC(data):
if in_data[0] != 0x1F or in_data[1] != 0x9D:
raise ValueError('invalid header')
maxbits = in_data[2] & 0x1F
numItems = 1 << maxbits
blockMode = (in_data[2] & 0x80) != 0
if maxbits < LZC_NUM_BITS_MIN or maxbits > LZC_NUM_BITS_MAX:
max_bits = in_data[2] & 0x1F
if max_bits < LZC_NUM_BITS_MIN or max_bits > LZC_NUM_BITS_MAX:
raise ValueError('not supported')
parents = [0] * numItems
suffixes = [0] * numItems
in_pos = 3
numBits = LZC_NUM_BITS_MIN
head = 256
if blockMode:
num_items = 1 << max_bits
blockmode = (in_data[2] & 0x80) != 0
in_pos = 3
start_pos = in_pos
num_bits = LZC_NUM_BITS_MIN
dict_size = 1 << num_bits
head = 256
if blockmode:
head += 1
first_sym = True
# initialize dictionary
comp_dict = [None] * num_items
for i in range(0, 256):
comp_dict[i] = bytes(bytearray([i]))
needPrev = 0
bitPos = 0
numBufBits = 0
parents[256] = 0
suffixes[256] = 0
buf_extend = bytearray([0] * 3)
while True:
# fill buffer, when empty
if numBufBits == bitPos:
buf_len = min(in_len - in_pos, numBits)
buf = in_data[in_pos:in_pos + buf_len] + buf_extend
numBufBits = buf_len << 3
bitPos = 0
in_pos += buf_len
# extract next symbol
bytePos = bitPos >> 3
symbol = buf[bytePos] | buf[bytePos + 1] << 8 | buf[bytePos + 2] << 16
symbol >>= bitPos & 7
symbol &= (1 << numBits) - 1
bitPos += numBits
# check for special conditions: end, bad data, re-initialize dictionary
if bitPos > numBufBits:
break
if symbol >= head:
buf = buf_bits = 0
while in_pos < in_len:
# get next symbol
try:
while buf_bits < num_bits:
buf |= in_data[in_pos] << buf_bits
buf_bits += 8
in_pos += 1
buf, symbol = divmod(buf, dict_size)
buf_bits -= num_bits
except IndexError:
raise ValueError('invalid data')
if blockMode and symbol == 256:
numBufBits = bitPos = 0
numBits = LZC_NUM_BITS_MIN
# re-initialize dictionary
if blockmode and symbol == 256:
# skip to next buffer boundary
buf = buf_bits = 0
in_pos += (start_pos - in_pos) % num_bits
# reset to LZC_NUM_BITS_MIN
head = 257
needPrev = 0
num_bits = LZC_NUM_BITS_MIN
dict_size = 1 << num_bits
start_pos = in_pos
first_sym = True
continue
# convert symbol to string
stack = []
cur = symbol
while cur >= 256:
stack.append(suffixes[cur])
cur = parents[cur]
stack.append(cur)
if needPrev:
suffixes[head - 1] = cur
if symbol == head - 1:
stack[0] = cur
stack.reverse()
out_data.extend(stack)
# update parents, check for numBits change
if head < numItems:
needPrev = 1
parents[head] = symbol
head += 1
if head > (1 << numBits):
if numBits < maxbits:
numBufBits = bitPos = 0
numBits += 1
else:
needPrev = 0
# first symbol
if first_sym:
first_sym = False
if symbol >= 256:
raise ValueError('invalid data')
prev = symbol
out_data.extend(comp_dict[symbol])
continue
return out_data
# dictionary full
if head >= num_items:
out_data.extend(comp_dict[symbol])
continue
# update compression dictionary
if symbol < head:
comp_dict[head] = comp_dict[prev] + comp_dict[symbol][0:1]
elif symbol == head:
comp_dict[head] = comp_dict[prev] + comp_dict[prev][0:1]
else:
raise ValueError('invalid data')
prev = symbol
# extract 16 bit unsigned int from data
def get_uint16(data, off):
return data[off] << 8 | data[off + 1]
# output symbol
out_data.extend(comp_dict[symbol])
# update head, check for num_bits change
head += 1
if head >= dict_size and num_bits < max_bits:
num_bits += 1
dict_size = 1 << num_bits
start_pos = in_pos
# extract 32 bit unsigned int from data
def get_uint32(data, off):
return data[off] << 24 | data[off + 1] << 16 | data[off + 2] << 8 | data[off + 3]
return out_data
# export IOU NVRAM
# NVRAM format: https://github.com/ehlers/IOUtools/blob/master/NVRAM.md
def nvram_export(nvram):
nvram = bytearray(nvram)
# extract startup config
offset = 0
if len(nvram) < offset + 36:
raise ValueError('invalid length')
if get_uint16(nvram, offset + 0) != 0xABCD:
raise ValueError('no startup config')
format = get_uint16(nvram, offset + 2)
length = get_uint32(nvram, offset + 16)
offset += 36
if len(nvram) < offset + length:
# extract startup config
try:
(magic, data_format, _, _, _, _, length, _, _, _, _, _) = \
struct.unpack_from('>HHHHIIIIIHHI', nvram, offset=offset)
offset += 36
if magic != 0xABCD:
raise ValueError('no startup config')
if len(nvram) < offset+length:
raise ValueError('invalid length')
startup = nvram[offset:offset+length]
except struct.error:
raise ValueError('invalid length')
startup = nvram[offset:offset + length]
# compressed startup config
if format == 2:
# uncompress startup config
if data_format == 2:
try:
startup = uncompress_LZC(startup)
except ValueError as err:
raise ValueError('uncompress startup: ' + str(err))
offset += length
# alignment to multiple of 4
offset = (offset + 3) & ~3
# check for additonal offset of 4
if len(nvram) >= offset + 8 and \
get_uint16(nvram, offset + 4) == 0xFEDC and \
get_uint16(nvram, offset + 6) == 1:
offset += 4
# extract private config
private = None
if len(nvram) >= offset + 16 and get_uint16(nvram, offset + 0) == 0xFEDC:
length = get_uint32(nvram, offset + 12)
try:
# calculate offset of private header
length += (4 - length % 4) % 4 # alignment to multiple of 4
offset += length
# check for additonal offset of 4
(magic, data_format) = struct.unpack_from('>HH', nvram, offset=offset+4)
if magic == 0xFEDC and data_format == 1:
offset += 4
# extract private config
(magic, data_format, _, _, length) = \
struct.unpack_from('>HHIII', nvram, offset=offset)
offset += 16
if len(nvram) >= offset + length:
private = nvram[offset:offset + length]
if magic == 0xFEDC and data_format == 1:
if len(nvram) < offset+length:
raise ValueError('invalid length')
private = nvram[offset:offset+length]
# missing private header is not an error
except struct.error:
pass
return (startup, private)
if __name__ == '__main__':
# Main program
import argparse
import sys
parser = argparse.ArgumentParser(description='%(prog)s exports startup/private configuration from IOU NVRAM file.')
parser.add_argument('nvram', metavar='NVRAM',

140
gns3server/compute/iou/utils/iou_import.py
Unescape View File

@ -35,100 +35,82 @@ optional arguments:
create NVRAM file, size in kByte
"""
import argparse
import sys
# extract 16 bit unsigned int from data
def get_uint16(data, off):
return data[off] << 8 | data[off + 1]
# extract 32 bit unsigned int from data
def get_uint32(data, off):
return data[off] << 24 | data[off + 1] << 16 | data[off + 2] << 8 | data[off + 3]
# insert 16 bit unsigned int into data
def put_uint16(data, off, value):
data[off] = (value >> 8) & 0xff
data[off + 1] = value & 0xff
# insert 32 bit unsigned int into data
def put_uint32(data, off, value):
data[off] = (value >> 24) & 0xff
data[off + 1] = (value >> 16) & 0xff
data[off + 2] = (value >> 8) & 0xff
data[off + 3] = value & 0xff
import struct
# calculate padding
def padding(off, ios, nvram_len):
pad = (4 - off % 4) % 4 # padding to alignment of 4
# add 4 if IOS <= 15.0 or NVRAM area >= 64KB
if (ios <= 0x0F00 or nvram_len >= 64 * 1024) and pad != 0:
def padding(length, start_address):
pad = -length % 4 # padding to alignment of 4
# extra padding if pad != 0 and big start_address
if pad != 0 and (start_address & 0x80000000) != 0:
pad += 4
return pad
# update checksum
def checksum(data, start, end):
put_uint16(data, start + 4, 0) # set checksum to 0
chk = 0
idx = start
while idx < end - 1:
chk += get_uint16(data, idx)
idx += 2
if idx < end:
chk += data[idx] << 8
# calculate checksum of first two words
for word in struct.unpack_from('>2H', data, start):
chk += word
# add remaining words, ignoring old checksum at offset 4
struct_format = '>{:d}H'.format((end - start - 6) // 2)
for word in struct.unpack_from(struct_format, data, start+6):
chk += word
# handle 16 bit overflow
while chk >> 16:
chk = (chk & 0xffff) + (chk >> 16)
chk = chk ^ 0xffff
put_uint16(data, start + 4, chk) # set checksum
# save checksum
struct.pack_into('>H', data, start+4, chk)
# import IOU NVRAM
# NVRAM format: https://github.com/ehlers/IOUtools/blob/master/NVRAM.md
def nvram_import(nvram, startup, private, size):
BASE_ADDRESS = 0x10000000
DEFAULT_IOS = 0x0F04 # IOS 15.4
DEFAULT_IOS = 0x0F04 # IOS 15.4
base_address = 0x10000000
# check size parameter
if size is not None and (size < 8 or size > 1024):
raise ValueError('invalid size')
# create new nvram if nvram is empty or has wrong size
if nvram is None or (size is not None and len(nvram) != size * 1024):
nvram = bytearray([0] * (size * 1024))
if nvram is None or (size is not None and len(nvram) != size*1024):
nvram = bytearray([0] * (size*1024))
else:
nvram = bytearray(nvram)
# check nvram size
nvram_len = len(nvram)
if nvram_len < 8 * 1024 or nvram_len > 1024 * 1024 or nvram_len % 1024 != 0:
if nvram_len < 8*1024 or nvram_len > 1024*1024 or nvram_len % 1024 != 0:
raise ValueError('invalid NVRAM length')
nvram_len = nvram_len // 2
# get size of current config
config_len = 0
ios = None
try:
if get_uint16(nvram, 0) == 0xABCD:
ios = get_uint16(nvram, 6)
config_len = 36 + get_uint32(nvram, 16)
config_len += padding(config_len, ios, nvram_len)
if get_uint16(nvram, config_len) == 0xFEDC:
config_len += 16 + get_uint32(nvram, config_len + 12)
except IndexError:
(magic, _, _, ios, start_addr, _, length, _, _, _, _, _) = \
struct.unpack_from('>HHHHIIIIIHHI', nvram, offset=0)
if magic == 0xABCD:
base_address = start_addr - 36
config_len = 36 + length + padding(length, base_address)
(magic, _, _, _, length) = \
struct.unpack_from('>HHIII', nvram, offset=config_len)
if magic == 0xFEDC:
config_len += 16 + length
else:
ios = None
except struct.error:
raise ValueError('unknown nvram format')
if config_len > nvram_len:
raise ValueError('unknown nvram format')
# calculate max. config size
max_config = nvram_len - 2 * 1024 # reserve 2k for files
max_config = nvram_len - 2*1024 # reserve 2k for files
idx = max_config
empty_sector = bytearray([0] * 1024)
while True:
@ -136,45 +118,43 @@ def nvram_import(nvram, startup, private, size):
if idx < config_len:
break
# if valid file header:
if get_uint16(nvram, idx + 0) == 0xDCBA and \
get_uint16(nvram, idx + 4) < 8 and \
get_uint16(nvram, idx + 6) <= 992:
(magic, _, flags, length, _) = \
struct.unpack_from('>HHHH24s', nvram, offset=idx)
if magic == 0xDCBA and flags < 8 and length <= 992:
max_config = idx
elif nvram[idx:idx + 1024] != empty_sector:
elif nvram[idx:idx+1024] != empty_sector:
break
# import startup config
startup = bytearray(startup)
new_nvram = bytearray()
if ios is None:
# Target IOS version is unknown. As some IOU don't work nicely with
# the padding of a different version, the startup config is padded
# with '\n' to the alignment of 4.
ios = DEFAULT_IOS
startup.extend([ord('\n')] * ((4 - len(startup) % 4) % 4))
new_nvram = bytearray([0] * 36) # startup hdr
put_uint16(new_nvram, 0, 0xABCD) # magic
put_uint16(new_nvram, 2, 1) # raw data
put_uint16(new_nvram, 6, ios) # IOS version
put_uint32(new_nvram, 8, BASE_ADDRESS + 36) # start address
put_uint32(new_nvram, 12, BASE_ADDRESS + 36 + len(startup)) # end address
put_uint32(new_nvram, 16, len(startup)) # length
startup += b'\n' * (-len(startup) % 4)
new_nvram.extend(struct.pack('>HHHHIIIIIHHI',
0xABCD, # magic
1, # raw data
0, # checksum, not yet calculated
ios, # IOS version
base_address + 36, # start address
base_address + 36 + len(startup), # end address
len(startup), # length
0, 0, 0, 0, 0))
new_nvram.extend(startup)
new_nvram.extend([0] * padding(len(new_nvram), ios, nvram_len))
new_nvram.extend([0] * padding(len(new_nvram), base_address))
# import private config
if private is None:
private = bytearray()
else:
private = bytearray(private)
private = b''
offset = len(new_nvram)
new_nvram.extend([0] * 16) # private hdr
put_uint16(new_nvram, 0 + offset, 0xFEDC) # magic
put_uint16(new_nvram, 2 + offset, 1) # raw data
put_uint32(new_nvram, 4 + offset,
BASE_ADDRESS + offset + 16) # start address
put_uint32(new_nvram, 8 + offset,
BASE_ADDRESS + offset + 16 + len(private)) # end address
put_uint32(new_nvram, 12 + offset, len(private)) # length
new_nvram.extend(struct.pack('>HHIII',
0xFEDC, # magic
1, # raw data
base_address + offset + 16, # start address
base_address + offset + 16 + len(private), # end address
len(private) )) # length
new_nvram.extend(private)
# add rest
@ -190,6 +170,8 @@ def nvram_import(nvram, startup, private, size):
if __name__ == '__main__':
# Main program
import argparse
import sys
def check_size(string):
try:

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