Merge pull request #1 from dirtbags/py3

Python 3
This commit is contained in:
Neale Pickett 2018-10-11 08:27:28 -06:00 committed by GitHub
commit ad8d412f73
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10 changed files with 467 additions and 443 deletions

16
README.md Normal file
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@ -0,0 +1,16 @@
Dirtbags Netarch Library
========================
This is a library for advanced
[network archaeology](https://sites.google.com/view/cyberfire/foundry/classes/network-archaeology).
It provides a heavily field-tested framework for
exploring unknown TCP-based protocols,
and room to grow these explorations into full-blown decoders.
Get going
=========
Documentation sucks, sorry.
The way we go about things is to copy `dumbdecode.py` to a new file,
and start hacking onto it.

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TODO.md Normal file
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Things We Need To Do
====================
* documentation
* remove lingering py2-isms
* more logical way to chain together dispatcher, tcp resequencer
* some way to parallelize work

13
dumbdecode.py Executable file
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@ -0,0 +1,13 @@
#! /usr/bin/python3
import sys
from netarch import ip
from netarch import *
s = None
reseq = ip.Dispatch(*sys.argv[1:])
for h, d in reseq:
srv, first, chunk = d
if not s:
s = ip.Session(first)
s.handle(srv, first, chunk, reseq.last)

246
gapstr.py
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@ -1,246 +0,0 @@
#! /usr/bin/python
## 2008 Massive Blowout
"""Functions to treat a list as a byte array with gaps.
Lists should have only byte and numeric items.
"""
import __init__
import sys
class GapString:
def __init__(self, init=None, drop='?'):
self.contents = []
self.length = 0
self.drop = drop
if init:
self.append(init)
def __len__(self):
return int(self.length)
def loss(self):
ret = 0
for i in self.contents:
try:
ret += i
except TypeError:
pass
return ret
def __repr__(self):
return '<GapString of length %d>' % self.length
def append(self, i):
try:
self.length += len(i)
self.contents.append(i)
except TypeError:
self.length += i
self.contents.append(i)
def pop(self, idx=-1):
item = self.contents.pop(idx)
try:
self.length -= item
except TypeError:
self.length -= len(item)
return GapString(item)
def __str__(self):
ret = []
for i in self.contents:
try:
ret.append(self.drop * i)
except TypeError:
ret.append(i)
return ''.join(ret)
def __iter__(self):
for i in self.contents:
try:
for c in i:
yield c
except TypeError:
for j in range(i):
yield self.drop
def __nonzero__(self):
return self.length > 0
def hasgaps(self):
for i in self.contents:
try:
len(i)
except TypeError:
return True
return False
def hexdump(self, fd=sys.stdout):
offset = 0
d = __init__.HexDumper(fd)
for i in self.contents:
try:
for j in xrange(i):
d.dump_drop()
except TypeError:
for c in i:
d.dump_chr(c)
d.finish()
def extend(self, other):
self.contents += other.contents
self.length += other.length
def __getslice__(self, start, end):
end = min(self.length, end)
start = min(self.length, start)
new = self.__class__(drop=self.drop)
new.length = max(end - start, 0)
if new.length == 0:
new.contents = []
return new
new.contents = self.contents[:]
l = self.length - new.length - start
# Trim off the beginning
while start >= 0:
i = new.contents.pop(0)
try:
start -= i
if start < 0:
new.contents.insert(0, -start)
except TypeError:
start -= len(i)
if start < 0:
new.contents.insert(0, i[start:])
# Trim off the end
while l >= 0:
i = new.contents.pop()
try:
l -= i
if l < 0:
new.contents.append(-l)
except TypeError:
l -= len(i)
if l < 0:
new.contents.append(i[:-l])
return new
def __getitem__(self, idx):
if False:
c = self[idx:idx+1]
if c.hasgaps():
return self.drop[0]
else:
return c.contents[0][0]
else:
l = 0
for i in self.contents:
try:
l += len(i)
except TypeError:
l += i
if l > idx:
offs = idx - l
try:
return i[offs]
except:
return self.drop[0]
raise IndexError('Out of bounds')
def __add__(self, other):
if isinstance(other, str):
self.append(other)
else:
new = self.__class__(drop=self.drop)
new.extend(self)
new.extend(other)
return new
def __xor__(self, mask):
try:
mask = [ord(c) for c in mask]
except TypeError:
pass
try:
masklen = len(mask)
except TypeError:
masklen = 1
mask = [mask]
new = self.__class__(drop=self.drop)
for i in self.contents:
try:
r = []
offset = len(new) % masklen
for c in i:
o = ord(c)
r.append(chr(o ^ mask[offset]))
offset = (offset + 1) % masklen
new.append(''.join(r))
except TypeError:
new.append(i)
return new
def index(self, needle):
pos = 0
for i in self.contents:
try:
return pos + i.index(needle)
except AttributeError:
pos += i
except ValueError:
pos += len(i)
raise ValueError('substring not found')
def split(self, pivot=' ', times=None):
ret = []
cur = self
while (not times) or (len(ret) < times):
try:
pos = cur.index(pivot)
except ValueError:
break
ret.append(cur[:pos])
cur = cur[pos+len(pivot):]
ret.append(cur)
return ret
def startswith(self, what):
return (what == str(self[:len(what)]))
def endswith(self, what):
return (what == str(self[-len(what):]))
if __name__ == '__main__':
gs = GapString()
gs.append('hi')
assert str(gs) == 'hi'
assert str(gs[:40]) == 'hi'
gs.append(3)
assert str(gs) == 'hi???'
assert str(gs[:40]) == 'hi???'
assert str(gs[:3]) == 'hi?'
assert str(gs[-4:]) == 'i???'
assert str(gs + gs) == 'hi???hi???'
assert str(gs ^ 1) == 'ih???'
gs = GapString()
gs.append('123456789A')
assert str(gs[:4]) == '1234'
assert len(gs[:4]) == 4
assert len(gs[6:]) == 4
assert str(gs[:0]) == ''

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@ -1,156 +1,156 @@
#! /usr/bin/python
# -*- coding: utf-8 -*-
## 2008 Massive Blowout
#! /usr/bin/python3
import binascii
import sys
import struct
stdch = (u'␀·········␊··␍··'
u'················'
u' !"#$%&\'()*+,-./'
u'0123456789:;<=>?'
u'@ABCDEFGHIJKLMNO'
u'PQRSTUVWXYZ[\]^_'
u'`abcdefghijklmno'
u'pqrstuvwxyz{|}~·'
u'················'
u'················'
u'················'
u'················'
u'················'
u'················'
u'················'
u'················')
stdch = (
'␀·········␊··␍··'
'················'
' !"#$%&\'()*+,-./'
'0123456789:;<=>?'
'@ABCDEFGHIJKLMNO'
'PQRSTUVWXYZ[\]^_'
'`abcdefghijklmno'
'pqrstuvwxyz{|}~·'
'················'
'················'
'················'
'················'
'················'
'················'
'················'
'················'
)
decch = (u'␀␁␂␃␄␅␆␇␈␉␊␋␌␍␎␏'
u'␐␑␒␓␔␕␖␗␘␙␚·····'
u'␠!"#$%&\'()*+,-./'
u'0123456789:;<=>?'
u'@ABCDEFGHIJKLMNO'
u'PQRSTUVWXYZ[\]^_'
u'`abcdefghijklmno'
u'pqrstuvwxyz{|}~␡'
u'················'
u'················'
u'················'
u'················'
u'················'
u'················'
u'················'
u'················')
decch = (
'␀␁␂␃␄␅␆␇␈␉␊␋␌␍␎␏'
'␐␑␒␓␔␕␖␗␘␙␚·····'
'␠!"#$%&\'()*+,-./'
'0123456789:;<=>?'
'@ABCDEFGHIJKLMNO'
'PQRSTUVWXYZ[\]^_'
'`abcdefghijklmno'
'pqrstuvwxyz{|}~␡'
'················'
'················'
'················'
'················'
'················'
'················'
'················'
'················'
)
cgach = (u'·☺☻♥♦♣♠•◘○◙♂♀♪♫☼'
u'►◄↕‼¶§▬↨↑↓→←∟↔▲▼'
u' !"#$%&\'()*+,-./'
u'0123456789:;<=>?'
u'@ABCDEFGHIJKLMNO'
u'PQRSTUVWXYZ[\]^_'
u'`abcdefghijklmno'
u'pqrstuvwxyz{|}~⌂'
u'ÇüéâäàåçêëèïîìÄÅ'
u'ÉæÆôöòûùÿÖÜ¢£¥₧ƒ'
u'áíóúñѪº¿⌐¬½¼¡«»'
u'░▒▓│┤╡╢╖╕╣║╗╝╜╛┐'
u'└┴┬├─┼╞╟╚╔╩╦╠═╬╧'
u'╨╤╥╙╘╒╓╫╪┘┌█▄▌▐▀'
u'αßΓπΣσµτΦΘΩδ∞φε∩'
u'≡±≥≤⌠⌡÷≈°∙·√ⁿ²■¤')
shpch = (u'␀☺☻♥♦♣♠•◘○◙♂♀♪♫☼'
u'►◄↕‼¶§▬↨↑↓→←∟↔▲▼'
u'␣!"#$%&\'()*+,-./'
u'0123456789:;<=>?'
u'@ABCDEFGHIJKLMNO'
u'PQRSTUVWXYZ[\]^_'
u'`abcdefghijklmno'
u'pqrstuvwxyz{|}~⌂'
u'ÇüéâäàåçêëèïîìÄÅ'
u'ÉæÆôöòûùÿÖÜ¢£¥₧ƒ'
u'áíóúñѪº¿⌐¬½¼¡«»'
u'░▒▓│┤╡╢╖╕╣║╗╝╜╛┐'
u'└┴┬├─┼╞╟╚╔╩╦╠═╬╧'
u'╨╤╥╙╘╒╓╫╪┘┌█▄▌▐▀'
u'αßΓπΣσµτΦΘΩδ∞φε∩'
u'≡±≥≤⌠⌡÷≈°∙·√ⁿ²■¤')
cgach = (
'□☺☻♥♦♣♠•◘○◙♂♀♪♫☼'
'►◄↕‼¶§▬↨↑↓→←∟↔▲▼'
' !"#$%&\'()*+,-./'
'0123456789:;<=>?'
'@ABCDEFGHIJKLMNO'
'PQRSTUVWXYZ[\]^_'
'`abcdefghijklmno'
'pqrstuvwxyz{|}~⌂'
'ÇüéâäàåçêëèïîìÄÅ'
'ÉæÆôöòûùÿÖÜ¢£¥₧ƒ'
'áíóúñѪº¿⌐¬½¼¡«»'
'░▒▓│┤╡╢╖╕╣║╗╝╜╛┐'
'└┴┬├─┼╞╟╚╔╩╦╠═╬╧'
'╨╤╥╙╘╒╓╫╪┘┌█▄▌▐▀'
'αßΓπΣσµτΦΘΩδ∞φε∩'
'≡±≥≤⌠⌡÷≈°∙·√ⁿ²■¤'
)
fluffych = (
'·☺☻♥♦♣♠•◘○◙♂♀♪♫☼'
'►◄↕‼¶§▬↨↑↓→←∟↔▲▼'
' !"#$%&\'()*+,-./'
'0123456789:;<=>?'
'@ABCDEFGHIJKLMNO'
'PQRSTUVWXYZ[\]^_'
'`abcdefghijklmno'
'pqrstuvwxyz{|}~⌂'
'ÇüéâäàåçêëèïîìÄÅ'
'ÉæÆôöòûùÿÖÜ¢£¥₧ƒ'
'áíóúñѪº¿⌐¬½¼¡«»'
'░▒▓│┤╡╢╖╕╣║╗╝╜╛┐'
'└┴┬├─┼╞╟╚╔╩╦╠═╬╧'
'╨╤╥╙╘╒╓╫╪┘┌█▄▌▐▀'
'αßΓπΣσµτΦΘΩδ∞φε∩'
'≡±≥≤⌠⌡÷≈°∀∃√ⁿ²■¤'
)
def unpack(fmt, buf):
"""Unpack buf based on fmt, return the rest as a string."""
"""Unpack buf based on fmt, return the remainder."""
size = struct.calcsize(fmt)
vals = struct.unpack(fmt, str(buf[:size]))
vals = struct.unpack(fmt, bytes(buf[:size]))
return vals + (buf[size:],)
class HexDumper:
def __init__(self, fd=sys.stdout):
self.fd = fd
def __init__(self, output, charset=fluffych):
self.offset = 0
self.buf = []
self.last = None
self.elided = False
self.hexes = []
self.chars = []
self.charset = charset
self.output = output
def _to_printable(self, c):
if not c:
return u''
else:
return cgach[ord(c)]
def write(self, what):
self.fd.write(what.encode('utf-8'))
def _flush(self):
if not self.buf:
def _spit(self):
if self.chars == self.last:
if not self.elided:
self.output.write('*\n')
self.elided = True
self.hexes = []
self.chars = []
return
self.last = self.chars[:]
self.elided = False
o = []
for c in self.buf:
if c:
o.append(u'%02x' % ord(c))
pad = 16 - len(self.chars)
self.hexes += [' '] * pad
self.output.write('{:08x} '.format(self.offset - len(self.chars)))
self.output.write(' '.join(self.hexes[:8]))
self.output.write(' ')
self.output.write(' '.join(self.hexes[8:]))
self.output.write(' ')
self.output.write(''.join(self.chars))
self.output.write('\n')
self.hexes = []
self.chars = []
def add(self, b):
if self.offset and self.offset % 16 == 0:
self._spit()
if b is None:
h = ''
c = '<EFBFBD>'
else:
o.append(u'--')
o += ([u' '] * (16 - len(self.buf)))
p = [self._to_printable(c) for c in self.buf]
h = '{:02x}'.format(b)
c = self.charset[b]
self.chars.append(c)
self.hexes.append(h)
self.write(u'%08x ' % self.offset)
self.offset += 1
self.write(u' '.join(o[:8]))
self.write(u' ')
self.write(u' '.join(o[8:]))
self.write(u'')
self.write(u''.join(p))
self.write(u'\n')
self.offset += len(self.buf)
self.buf = []
def dump_chr(self, c):
self.buf.append(c)
if len(self.buf) == 16:
self._flush()
def dump_drop(self):
self.buf.append(None)
if len(self.buf) == 16:
self._flush()
def finish(self):
self._flush()
self.write('%08x\n' % self.offset)
def done(self):
self._spit()
self.output.write('{:08x}\n'.format(self.offset))
def hexdump(buf, f=sys.stdout):
def hexdump(buf, f=sys.stdout, charset=fluffych):
"Print a hex dump of buf"
d = HexDumper()
for c in buf:
d.dump_chr(c)
d.finish()
h = HexDumper(output=f, charset=charset)
for b in buf:
h.add(b)
h.done()
def cstring(buf):
@ -266,7 +266,7 @@ def bin(i, bits=None):
def unhex(s):
"""Decode a string as hex, stripping whitespace first"""
return [ord(i) for i in s.replace(' ', '').decode('hex')]
return binascii.unhexlify(s.replace(' ', ''))
def pp(value, bits=16):

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@ -1,29 +1,28 @@
#! /usr/bin/python
#! /usr/bin/python3
## IP resequencing + protocol reversing skeleton
## 2008 Massive Blowout
## 2008, 2018 Neale Pickett
import StringIO
import struct
import socket
import warnings
import heapq
import gapstr
import time
import io
try:
import pcap
except ImportError:
import py_pcap as pcap
warnings.warn("Using slow pure-python pcap library")
import netarch.py_pcap as pcap
import os
import cgi
import urllib
import UserDict
from __init__ import *
import urllib.parse
from netarch import unpack, hexdump
from netarch.trilobytes import TriloBytes
def unpack_nybbles(byte):
return (byte >> 4, byte & 0x0F)
transfers = os.environ.get('TRANSFERS', 'transfers')
IP = 0x0800
@ -43,6 +42,7 @@ class Frame:
def __init__(self, pkt):
((self.time, self.time_usec, _), frame) = pkt
# Ethernet
(self.eth_dhost,
self.eth_shost,
@ -132,15 +132,17 @@ class Frame:
def get_src_addr(self):
if not hasattr(self, "_src_addr"):
saddr = struct.pack('!i', self.saddr)
self.src_addr = socket.inet_ntoa(saddr)
return self.src_addr
self._src_addr = socket.inet_ntoa(saddr)
return self._src_addr
src_addr = property(get_src_addr)
def get_dst_addr(self):
if not hasattr(self, "_dst_addr"):
daddr = struct.pack('!i', self.daddr)
self.dst_addr = socket.inet_ntoa(daddr)
return self.dst_addr
self._dst_addr = socket.inet_ntoa(daddr)
return self._dst_addr
dst_addr = property(get_dst_addr)
def __repr__(self):
@ -231,7 +233,7 @@ class TCP_Recreate:
return ethhdr + iphdr + tcphdr + str(payload)
return ethhdr + iphdr + tcphdr + bytes(payload)
def write_pkt(self, timestamp, cli, payload, flags=0):
p = self.packet(cli, payload, flags)
@ -309,16 +311,14 @@ class TCP_Resequence:
pending = self.pending[xdi]
# Get a sorted list of sequence numbers
keys = pending.keys()
keys.sort()
keys = sorted(pending)
# Build up return value
gs = gapstr.GapString()
gs = TriloBytes()
if keys:
f = pending[keys[0]]
ret = (xdi, f, gs)
first = pending[keys[0]]
else:
ret = (xdi, None, gs)
first = None
# Fill in gs with our frames
for key in keys:
@ -328,13 +328,14 @@ class TCP_Resequence:
frame = pending[key]
if key > seq:
# Dropped frame(s)
if key - seq > 6000:
print "Gosh, bob, %d dropped octets sure is a lot!" % (key - seq)
gs.append(key - seq)
dropped = key - seq
if dropped > 6000:
print("Gosh, %d dropped octets sure is a lot!" % (dropped))
gs += [None] * dropped
seq = key
if key == seq:
# Default
gs.append(frame.payload)
gs += frame.payload
seq += len(frame.payload)
del pending[key]
elif key < seq:
@ -349,13 +350,14 @@ class TCP_Resequence:
self.handle = self.handle_drop
if seq != pkt.ack:
# Drop at the end
if pkt.ack - seq > 6000:
print 'Large drop at end of session!'
print ' %s' % ((pkt, pkt.time),)
print ' %x %x' % (pkt.ack, seq)
gs.append(pkt.ack - seq)
dropped = pkt.ack - seq
if dropped > 6000:
print('Large drop at end of session!')
print(' %s' % ((pkt, pkt.time),))
print(' %x %x' % (pkt.ack, seq))
gs += [None] * dropped
return ret
return (xdi, first, gs)
def handle(self, pkt):
@ -447,14 +449,14 @@ class Dispatch:
if not literal:
parts = filename.split(':::')
fn = parts[0]
fd = file(fn)
fd = open(fn, "rb")
pc = pcap.open(fd)
if len(parts) > 1:
pos = int(parts[1])
fd.seek(pos)
self._read(pc, fn, fd)
else:
fd = file(filename)
fd = open(filename, "rb")
pc = pcap.open(fd)
self._read(pc, filename, fd)
@ -490,7 +492,7 @@ class Dispatch:
class NeedMoreData(Exception):
pass
class Packet(UserDict.DictMixin):
class Packet:
"""Base class for a packet from a binary protocol.
This is a base class for making protocol reverse-engineering easier.
@ -549,43 +551,46 @@ class Packet(UserDict.DictMixin):
assert a in b, ('%r not in %r' % (a, b))
def show(self):
print '%s %3s: %s' % (self.__class__.__name__,
print('%s %3s: %s' % (self.__class__.__name__,
self.opcode,
self.opcode_desc)
self.opcode_desc))
if self.firstframe:
print ' %s:%d -> %s:%d (%s.%06dZ)' % (self.firstframe.src_addr,
print(' %s:%d -> %s:%d (%s.%06dZ)' % (self.firstframe.src_addr,
self.firstframe.sport,
self.firstframe.dst_addr,
self.firstframe.dport,
time.strftime('%Y-%m-%dT%T', time.gmtime(self.firstframe.time)),
self.firstframe.time_usec)
self.firstframe.time_usec))
if self.parts:
dl = len(self.parts[-1])
p = []
xp = []
for x in self.parts[:-1]:
if x == dl:
p.append('%3d!' % x)
xp.append('%3x!' % x)
else:
p.append('%3d' % x)
print ' parts: (%s) +%d bytes' % (','.join(p), dl)
xp.append('%3x' % x)
print(' parts: (%s) +%d octets' % (','.join(p), dl))
print(' 0xparts: (%s) +%x octets' % (','.join(xp), dl))
keys = self.params.keys()
keys.sort()
keys = sorted(self.params)
for k in keys:
print ' %12s: %s' % (k, self.params[k])
print(' %12s: %s' % (k, self.params[k]))
if self.subpackets:
for p in self.subpackets:
p.show()
elif self.payload:
try:
self.payload.hexdump()
hexdump(self.payload)
except AttributeError:
print ' payload: %r' % self.payload
print(' payload: %r' % self.payload)
def parse(self, data):
"""Parse a chunk of data (possibly a GapString).
"""Parse a chunk of data (possibly a TriloBytes).
Anything returned is not part of this packet and will be passed
in to a subsequent packet.
@ -600,7 +605,7 @@ class Packet(UserDict.DictMixin):
"""Handle data from a Session class."""
data = self.parse(data)
if self.opcode <> None:
if self.opcode != None:
try:
f = getattr(self, 'opcode_%s' % self.opcode)
except AttributeError:
@ -642,12 +647,12 @@ class Session:
pass
def handle(self, is_srv, frame, gs, lastpos):
def handle(self, is_srv, frame, data, lastpos):
"""Handle a data burst.
@param is_srv Is this from the server?
@param frame A frame associated with this packet, or None if it's all drops
@param gs A gapstring of the data
@param data A TriloBytes of the data
@param lastpos Last position in the source file, for debugging
"""
@ -659,21 +664,21 @@ class Session:
try:
saddr = frame.saddr
try:
(f, data) = self.pending.pop(saddr)
(f, buf) = self.pending.pop(saddr)
except KeyError:
f = frame
data = gapstr.GapString()
data.extend(gs)
buf = TriloBytes()
buf += data
try:
while data:
while buf:
p = self.Packet(self, f)
data = p.handle(data)
buf = p.handle(buf)
self.process(p)
except NeedMoreData:
self.pending[saddr] = (f, data)
self.pending[saddr] = (f, buf)
self.count += 1
except:
print ('Lastpos: %r' % (lastpos,))
print('Lastpos: %r' % (lastpos,))
raise
def process(self, packet):
@ -698,11 +703,11 @@ class Session:
fn = '%d-%s~%d-%s~%d---%s' % (frame.time,
frame.src_addr, frame.sport,
frame.dst_addr, frame.dport,
urllib.quote(fn, ''))
urllib.parse.quote(fn, ''))
fullfn = os.path.join(self.basename, fn)
fullfn2 = os.path.join(self.basename2, fn)
print ' writing %s' % (fn,)
fd = file(fullfn, 'w')
print(' writing %s' % (fn,))
fd = open(fullfn, 'wb')
try:
os.unlink(fullfn2)
except OSError:
@ -721,7 +726,9 @@ class Session:
class HtmlSession(Session):
def __init__(self, frame):
Session.__init__(self, frame)
self.sessfd = self.open_out('session.html')
fd = self.open_out('session.html')
fbuf = io.BufferedWriter(fd, 1024)
self.sessfd = io.TextIOWrapper(fbuf, encoding="utf-8")
self.sessfd.write('''<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"

View File

@ -1,13 +1,16 @@
#! /usr/bin/python
#! /usr/bin/python3
import struct
import builtins
_MAGIC = 0xA1B2C3D4
class pcap:
def __init__(self, stream, mode='rb', snaplen=65535, linktype=1):
class PcapFile:
def __init__(self, stream, mode='r', snaplen=65535, linktype=1):
if 'b' not in mode:
mode += 'b'
try:
self.stream = file(stream, mode)
self.stream = builtins.open(stream, mode)
except TypeError:
self.stream = stream
try:
@ -16,7 +19,7 @@ class pcap:
except IOError:
hdr = None
if hdr:
if 'r' in mode:
# We're in read mode
self._endian = None
for endian in '<>':
@ -71,17 +74,22 @@ class pcap:
break
yield r
open = pcap
open_offline = pcap
open = PcapFile
pcap = PcapFile
open_offline = PcapFile
if __name__ == '__main__':
p = open('test.pcap', 'w') # Create a new file
p.write(((0, 0, 3), 'foo')) # Add a packet
p.write(((0, 0, 3), 'bar'))
import io
f = io.BytesIO()
p = PcapFile(f, 'w')
p.write(((0, 0, 3), b'foo')) # Add a packet
p.write(((0, 0, 3), b'bar'))
del p
p = open(file('test.pcap')) # Also takes file objects
f.seek(0)
p = PcapFile(f)
assert ((p.version, p.thiszone, p.sigfigs, p.snaplen, p.linktype) ==
((2, 4), 0, 0, 65535, 1))
assert ([i for i in p] == [((0, 0, 3), 'foo'), ((0, 0, 3), 'bar')])
assert ([i for i in p] == [((0, 0, 3), b'foo'), ((0, 0, 3), b'bar')])

146
netarch/trilobytes.py Normal file
View File

@ -0,0 +1,146 @@
#! /usr/bin/python3
## 2008, 2018 Neale Pickett
import itertools
class TriloBytes:
"""Three-level byte array (0, 1, Missing).
This allows you to represent on-wire transactions with holes in the middle,
due to eg. dropped packets.
>>> tb = TriloBytes(b'hi')
>>> bytes(tb)
b'hi'
>>> bytes(tb[:40])
b'hi'
>>> tb = TriloBytes(b'hi') + [None] * 3
>>> bytes(tb)
b'hi???'
>>> bytes(tb[:40])
b'hi???'
>>> bytes(tb[:3])
b'hi?'
>>> bytes(tb[-4:])
b'i???'
>>> bytes(tb + tb)
b'hi???hi???'
>>> bytes(tb ^ 1)
b'ih???'
>>> bytes(tb ^ [32, 1])
b'Hh???'
>>> tb = TriloBytes(b'hi', drop=b'DROP')
>>> bytes(tb)
b'hi'
>>> tb += [None] * 7
>>> bytes(tb)
b'hiOPDROPD'
>>> tb = TriloBytes(b'00')^1
>>> tb[0]
1
>>> bytes(TriloBytes(b'00'))
b'\x00'
"""
def __init__(self, initializer=(), drop=b'?'):
self._drop = drop
self._contents = tuple(initializer)
@classmethod
def fromhex(cls, string):
"""
>>> bytes(TriloBytes.fromhex("616263"))
b'abc'
"""
return cls(bytes.fromhex(string))
def __len__(self):
"""
>>> len(TriloBytes(b'abc'))
3
"""
return len(self._contents)
def __nonzero__(self):
"""
>>> 10 if TriloBytes() else -10
-10
>>> 10 if TriloBytes(b'a') else -10
10
"""
return len(self) > 0
def __getitem__(self, key):
ret = self._contents[key]
try:
return TriloBytes(ret, self._drop)
except:
return ret
def __iter__(self):
for val in self._contents:
yield val
def __bytes__(self):
return bytes((d if v is None else v for v,d in zip(self,itertools.cycle(self._drop))))
def __add__(self, other):
try:
contents = self._contents + other._contents
except AttributeError:
contents = self._contents + tuple(other)
return TriloBytes(contents, self._drop)
def __eq__(self, other):
try:
return self._contents == other._contents
except:
return False
def __hash__(self):
return hash(self._contents)
def __xor__(self, mask):
try:
mask[0]
except TypeError:
mask = [mask]
return TriloBytes(((None if x is None or y is None else x^y) for x,y in zip(self._contents, itertools.cycle(mask))), drop=self._drop)
def __repr__(self):
"""
>>> TriloBytes(b'abc')
<TriloBytes missing 0 of 3>
>>> TriloBytes(b'abc') + [None]
<TriloBytes missing 1 of 4>
"""
return '<TriloBytes missing %d of %d>' % (self.missing(), len(self))
def decode(self, codec):
return bytes(self).decode(codec)
def missing(self):
"""
>>> TriloBytes(b'abc').missing()
0
>>> (TriloBytes(b'abc') + [None, None]).missing()
2
"""
return self._contents.count(None)
def map(self, func, *args):
return (v if v is not None else func(v, *args) for v in self)
if __name__ == '__main__':
import doctest
doctest.testmod()

73
netarch/unpack.py Normal file
View File

@ -0,0 +1,73 @@
#! /usr/bin/python3
ENDIAN_LITTLE = 1
ENDIAN_BIG = 2
ENDIAN_MIDDLE = 3
ENDIAN_NETWORK = ENDIAN_BIG
class Unpacker:
"""Class that lets you peel values off
>>> u = Unpacker(bytes((1, 0,2, 0,0,0,3, 0,0,0,0,0,0,0,4)))
>>> u.uint8()
1
>>> u.uint16()
2
>>> u.uint32()
3
>>> u.uint64()
4
>>> u = Unpacker(bytes((1,0, 104,105)), ENDIAN_LITTLE)
>>> u.uint16()
1
>>> u.buf
b'hi'
>>> u = Unpacker(bytes((1,0, 0,2)))
>>> u.uint16(ENDIAN_LITTLE)
1
>>> u.uint(16, ENDIAN_BIG)
2
>>> u = Unpacker(bytes((0,1,2,3)), ENDIAN_MIDDLE)
>>> '%08x' % u.uint32()
'01000302'
"""
def __init__(self, buf, endian=ENDIAN_NETWORK):
self.endian = endian
self.buf = buf
def uint(self, size, endian=None):
endian = endian or self.endian
if size not in (8, 16, 32, 64):
# XXX: I'm pretty sure this can be done, but I don't want to code it up right now.
raise ValueError("Can't do weird sizes")
noctets = size // 8
if endian == ENDIAN_BIG:
r = range(0, noctets)
elif endian == ENDIAN_LITTLE:
r = range(noctets-1, -1, -1)
elif endian == ENDIAN_MIDDLE:
r = (1, 0, 3, 2, 5, 4, 7, 6)[:noctets]
else:
raise ValueError("Unsupported byte order")
pull, self.buf = self.buf[:noctets], self.buf[noctets:]
acc = 0
for i in r:
acc = (acc << 8) | pull[i]
return acc
def uint8(self):
return self.uint(8)
def uint16(self, endian=None):
return self.uint(16, endian)
def uint32(self, endian=None):
return self.uint(32, endian)
def uint64(self, endian=None):
return self.uint(64, endian)
if __name__ == "__main__":
import doctest
doctest.testmod()