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#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Unix SMB/CIFS implementation.
# Copyright © Jelmer Vernooij <jelmer@samba.org> 2008
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
import sys
MAX_OPNUM = 1000
MAX_BASE_SIZE = 0x1000
MAX_IFACE_VERSION = 1000
DCERPC_FAULT_OP_RNG_ERROR = 0x1c010002
DCERPC_FAULT_NDR = 0x6f7
NT_STATUS_NET_WRITE_FAULT = -1073741614
sys.path.insert(0, "bin/python")
from samba.dcerpc import ClientConnection
def find_num_funcs(conn):
for i in xrange(MAX_OPNUM):
try:
conn.request(i, "")
except RuntimeError, (num, msg):
if num == DCERPC_FAULT_OP_RNG_ERROR:
return i
raise Exception("More than %d functions" % MAX_OPNUM)
class Function:
def __init__(self, conn, opnum):
self.conn = conn
self.opnum = opnum
def request(self, data):
assert isinstance(data, str)
self.conn.request(self.opnum, data)
def valid_ndr(self, data):
try:
self.request(data)
except RuntimeError, (num, msg):
if num == DCERPC_FAULT_NDR:
return False
return True
def find_base_request(self, start=""):
"""Find the smallest possible request that we can do that is
valid.
This generally means sending all zeroes so we get NULL pointers where
possible."""
# TODO: Don't try with just 0's as there may be switch_is() variables
# for which 0 is not a valid value or variables with range() set
# See how much input bytes we need
for i in range(MAX_BASE_SIZE):
data = start + chr(0) * i
if self.valid_ndr(data):
return data
return None
def check_decision_byte(self, base_request, i):
"""Check whether the specified byte is a possible "decision" byte,
e.g. a byte that is part of a pointer, array size variable or
discriminant.
Note that this function only checks if a byte is definitely a decision
byte. It may return False in some cases while the byte is actually
a decision byte."""
data = list(base_request)
data[i] = chr(1)
return not self.valid_ndr("".join(data))
def find_deferrant_data(self, base_request, idx):
data = list(base_request)
data[idx*4] = chr(1)
# Just check that this is a pointer to something non-empty:
assert not self.valid_ndr("".join(data))
newdata = self.find_base_request("".join(data))
if newdata is None:
return None
assert newdata.startswith(data)
return newdata[len(data):]
def find_idl(self):
base_request = self.find_base_request()
if base_request is None:
raise Exception("Unable to determine base size for opnum %d" % self.opnum)
print "\tBase request is %r" % base_request
decision_byte_map = map(lambda x: self.check_decision_byte(base_request, x), range(len(base_request)))
print decision_byte_map
# find pointers
possible_pointers = map(all,
[decision_byte_map[i*4:(i+1)*4] for i in range(int(len(base_request)/4))])
print possible_pointers
pointer_deferrant_bases = map(
lambda x: self.find_deferrant_data(base_request, x) if possible_pointers[x] else None, range(len(possible_pointers)))
print pointer_deferrant_bases
if len(sys.argv) < 3:
print "Usage: autoidl <binding> <UUID> [<version>]"
sys.exit(1)
(binding, uuid) = sys.argv[1:3]
if len(sys.argv) == 4:
version = sys.argv[3]
else:
version = None
if version is None:
for i in range(MAX_IFACE_VERSION):
try:
conn = ClientConnection(binding, (uuid, i))
except RuntimeError, (num, msg):
if num == NT_STATUS_NET_WRITE_FAULT:
continue
raise
else:
break
else:
conn = ClientConnection(binding, (uuid, version))
print "Figuring out number of connections...",
num_funcs = find_num_funcs(conn)
print "%d" % num_funcs
# Figure out the syntax for each one
for i in range(num_funcs):
print "Function %d" % i
data = Function(conn, i)
try:
data.find_idl()
except Exception, e:
print "Error: %r" % e
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