#!/usr/bin/env python
# -*- coding: utf-8 -*-
from __future__ import (
absolute_import,
division,
print_function,
)
# --------------------------------------------
import logging
class NullHandler(logging.Handler):
def emit(self, record):
pass
logger = logging.getLogger('agentx.pdu')
logger.addHandler(NullHandler())
# --------------------------------------------
import struct
import pprint
import agentx
class PDU(object):
def __init__(self, type=0):
self.type = type
self.session_id = 0
self.transaction_id = 0
self.packet_id = 0
self.error = agentx.ERROR_NOAGENTXERROR
self.error_index = 0
self.decode_buf = ''
self.state = {}
self.values = []
def dump(self):
name = agentx.PDU_TYPE_NAME[self.type]
logger.debug('PDU DUMP: New PDU')
logger.debug(
'PDU DUMP: Meta : [%s: %d %d %d]' %
(name, self.session_id, self.transaction_id, self.packet_id))
if 'payload_length' in self.state:
logger.debug('PDU DUMP: Length : %s' %
self.state['payload_length'])
if hasattr(self, 'response'):
logger.debug('PDU DUMP: Response : %s' % self.response)
if hasattr(self, 'values'):
logger.debug('PDU DUMP: Values : %s' %
pprint.pformat(self.values))
if hasattr(self, 'range_list'):
logger.debug('PDU DUMP: Range list: %s' %
pprint.pformat(self.range_list))
# ====================================================
# encode functions
def encode_oid(self, oid, include=0):
oid = oid.strip()
oid = oid.split('.')
oid = [int(i) for i in oid]
if len(oid) > 5 and oid[:4] == [1, 3, 6, 1]:
# prefix
prefix = oid[4]
oid = oid[5:]
else:
# no prefix
prefix = 0
buf = struct.pack('BBBB', len(oid), prefix, include, 0)
for i in range(len(oid)):
buf += struct.pack('!L', oid[i])
return buf
def encode_octet(self, octet):
octet = octet.encode("utf-8")
buf = struct.pack('!L', len(octet))
buf += octet
padding = (4 - (len(octet) % 4)) % 4
buf += chr(0).encode() * padding
return buf
def encode_value(self, type, name, value):
buf = struct.pack('!HH', type, 0)
buf += self.encode_oid(name)
if type in [agentx.TYPE_INTEGER]:
buf += struct.pack('!l', value)
elif type in [
agentx.TYPE_COUNTER32, agentx.TYPE_GAUGE32,
agentx.TYPE_TIMETICKS
]:
buf += struct.pack('!L', value)
elif type in [agentx.TYPE_COUNTER64]:
buf += struct.pack('!Q', value)
elif type in [agentx.TYPE_OBJECTIDENTIFIER]:
buf += self.encode_oid(value)
elif type in [
agentx.TYPE_IPADDRESS, agentx.TYPE_OPAQUE,
agentx.TYPE_OCTETSTRING
]:
buf += self.encode_octet(value)
elif type in [
agentx.TYPE_NULL, agentx.TYPE_NOSUCHOBJECT,
agentx.TYPE_NOSUCHINSTANCE, agentx.TYPE_ENDOFMIBVIEW
]:
# No data
pass
else:
logger.error('Unknown Type:' % type)
return buf
def encode_header(self, pdu_type, payload_length=0, flags=0):
flags = flags | 0x10 # Bit 5 = all ints in NETWORK_BYTE_ORDER
buf = struct.pack('BBBB', 1, pdu_type, flags, 0)
buf += struct.pack('!L', self.session_id) # sessionID
buf += struct.pack('!L', self.transaction_id) # transactionID
buf += struct.pack('!L', self.packet_id) # packetID
buf += struct.pack('!L', payload_length)
return buf
def encode(self):
buf = b''
if self.type == agentx.AGENTX_OPEN_PDU:
# timeout
buf += struct.pack('!BBBB', 5, 0, 0, 0)
# agent OID
buf += struct.pack('!L', 0)
# Agent Desc
buf += self.encode_octet('MyAgent')
elif self.type == agentx.AGENTX_PING_PDU:
# No extra data
pass
elif self.type == agentx.AGENTX_REGISTER_PDU:
range_subid = 0
timeout = 5
priority = 127
buf += struct.pack('BBBB', timeout, priority, range_subid, 0)
# Sub Tree
buf += self.encode_oid(self.oid)
elif self.type == agentx.AGENTX_RESPONSE_PDU:
buf += struct.pack('!LHH', 0, self.error, self.error_index)
for value in self.values:
buf += self.encode_value(value['type'], value['name'],
value['value'])
else:
# Unsupported PDU type
pass
return self.encode_header(self.type, len(buf)) + buf
# ====================================================
# decode functions
def set_decode_buf(self, buf):
self.decode_buf = buf
def decode_oid(self):
try:
t = struct.unpack('!BBBB', self.decode_buf[:4])
self.decode_buf = self.decode_buf[4:]
ret = {
'n_subid': t[0],
'prefix': t[1],
'include': t[2],
'reserved': t[3],
}
sub_ids = []
if ret['prefix']:
sub_ids = [1, 3, 6, 1]
sub_ids.append(ret['prefix'])
for i in range(ret['n_subid']):
t = struct.unpack('!L', self.decode_buf[:4])
self.decode_buf = self.decode_buf[4:]
sub_ids.append(t[0])
oid = '.'.join(str(i) for i in sub_ids)
return oid, ret['include']
except Exception as e:
logger.exception('Invalid packing OID header')
logger.debug('%s' % pprint.pformat(self.decode_buf))
def decode_search_range(self):
start_oid, include = self.decode_oid()
if start_oid == []:
return [], [], 0
end_oid, _ = self.decode_oid()
return start_oid, end_oid, include
def decode_search_range_list(self):
range_list = []
while len(self.decode_buf):
range_list.append(self.decode_search_range())
return range_list
def decode_octet(self):
try:
t = struct.unpack('!L', self.decode_buf[:4])
l = t[0]
self.decode_buf = self.decode_buf[4:]
padding = 4 - (l % 4)
buf = self.decode_buf[:l]
self.decode_buf = self.decode_buf[l + padding:]
return buf
except Exception as e:
logger.exception('Invalid packing octet header')
def decode_value(self):
try:
vtype, _ = struct.unpack('!HH', self.decode_buf[:4])
self.decode_buf = self.decode_buf[4:]
except Exception as e:
logger.exception('Invalid packing value header')
oid, _ = self.decode_oid()
if vtype in [
agentx.TYPE_INTEGER, agentx.TYPE_COUNTER32,
agentx.TYPE_GAUGE32, agentx.TYPE_TIMETICKS
]:
data = struct.unpack('!L', self.decode_buf[:4])
data = data[0]
self.decode_buf = self.decode_buf[4:]
elif vtype in [agentx.TYPE_COUNTER64]:
data = struct.unpack('!Q', self.decode_buf[:8])
data = data[0]
self.decode_buf = self.decode_buf[8:]
elif vtype in [agentx.TYPE_OBJECTIDENTIFIER]:
data, _ = self.decode_oid()
elif vtype in [
agentx.TYPE_IPADDRESS, agentx.TYPE_OPAQUE,
agentx.TYPE_OCTETSTRING
]:
data = self.decode_octet()
elif vtype in [
agentx.TYPE_NULL, agentx.TYPE_NOSUCHOBJECT,
agentx.TYPE_NOSUCHINSTANCE, agentx.TYPE_ENDOFMIBVIEW
]:
# No data
data = None
else:
logger.error('Unknown Type: %s' % vtype)
return {'type': vtype, 'name': oid, 'data': data}
def decode_header(self):
try:
t = struct.unpack('!BBBBLLLL', self.decode_buf[:20])
self.decode_buf = self.decode_buf[20:]
ret = {
'version': t[0],
'pdu_type': t[1],
'pdu_type_name': agentx.PDU_TYPE_NAME[t[1]],
'flags': t[2],
'reserved': t[3],
'session_id': t[4],
'transaction_id': t[5],
'packet_id': t[6],
'payload_length': t[7],
}
self.state = ret
self.type = ret['pdu_type']
self.session_id = ret['session_id']
self.packet_id = ret['packet_id']
self.transaction_id = ret['transaction_id']
self.decode_buf = self.decode_buf[:ret['payload_length']]
if ret['flags'] & 0x08: # content present
context = self.decode_octet()
logger.debug('Context: %s' % context)
return ret
except Exception as e:
logger.exception('Invalid packing: %d' % len(self.decode_buf))
logger.debug('%s' % pprint.pformat(self.decode_buf))
def decode(self, buf):
self.set_decode_buf(buf)
ret = self.decode_header()
if ret['pdu_type'] == agentx.AGENTX_RESPONSE_PDU:
# Decode Response Header
t = struct.unpack('!LHH', self.decode_buf[:8])
self.decode_buf = self.decode_buf[8:]
self.response = {
'sysUpTime': t[0],
'error': t[1],
'error_name': agentx.ERROR_NAMES[t[1]],
'index': t[2],
}
# Decode VarBindList
self.values = []
while len(self.decode_buf):
self.values.append(self.decode_value())
elif ret['pdu_type'] == agentx.AGENTX_GET_PDU:
self.range_list = self.decode_search_range_list()
elif ret['pdu_type'] == agentx.AGENTX_GETNEXT_PDU:
self.range_list = self.decode_search_range_list()
elif ret['pdu_type'] == agentx.AGENTX_TESTSET_PDU:
# Decode VarBindList
self.values = []
while len(self.decode_buf):
self.values.append(self.decode_value())
elif ret['pdu_type'] in [
agentx.AGENTX_COMMITSET_PDU, agentx.AGENTX_UNDOSET_PDU,
agentx.AGENTX_CLEANUPSET_PDU
]:
pass
else:
pdu_type_str = agentx.PDU_TYPE_NAME.get(
ret['pdu_type'], 'Unknown:' + str(ret['pdu_type']))
logger.error('Unsupported PDU type:' + pdu_type_str)