Files
vpp-snmp-agent/agentx/network.py

222 lines
6.7 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from __future__ import (
absolute_import,
division,
print_function,
)
import socket
import time
import logging
import agentx
from agentx.pdu import PDU
class NullHandler(logging.Handler):
def emit(self, record):
pass
logger = logging.getLogger('agentx.network')
logger.addHandler(NullHandler())
class NetworkError(Exception):
pass
class Network():
def __init__(self, server_address = '/var/agentx/master'):
self.session_id = 0
self.transaction_id = 0
self.debug = 1
# Data Related Variables
self.data = {}
self.data_idx = []
self._connected = False
self._server_address = server_address
self._timeout = 0.1 # Seconds
def connect(self):
if self._connected:
return
try:
logger.info("Connecting to %s" % self._server_address)
if self._server_address.startswith('/'):
self.socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
self.socket.connect(self._server_address)
else:
self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host, port=self._server_address.split(':')
self.socket.connect((host, int(port)))
self.socket.settimeout(self._timeout)
self._connected = True
except socket.error:
logger.error("Failed to connect to %s" % self._server_address)
self._connected = False
def disconnect(self):
if not self._connected:
return
logger.info("Disconnecting from %s" % self._server_address)
self.socket.close()
self.socket = None
self._connected = False
return
def update(self, newdata):
if len(self.data) == 0:
logger.info("Setting initial serving dataset (%d OIDs)" % len(newdata))
else:
logger.info("Replacing serving dataset (%d OIDs)" % len(newdata))
del self.data
self.data = newdata.copy()
del self.data_idx
self.data_idx = sorted(self.data.keys(), key=lambda k: tuple(int(part) for part in k.split('.')))
def new_pdu(self, type):
pdu = PDU(type)
pdu.session_id = self.session_id
pdu.transaction_id = self.transaction_id
self.transaction_id += 1
return pdu
def response_pdu(self, org_pdu):
pdu = PDU(agentx.AGENTX_RESPONSE_PDU)
pdu.session_id = org_pdu.session_id
pdu.transaction_id = org_pdu.transaction_id
pdu.packet_id = org_pdu.packet_id
return pdu
def send_pdu(self, pdu):
if self.debug: pdu.dump()
self.socket.send(pdu.encode())
def recv_pdu(self):
buf = self.socket.recv(1024)
if not buf: return None
pdu = PDU()
pdu.decode(buf)
if self.debug: pdu.dump()
return pdu
# =========================================
def _get_next_oid(self, oid, endoid):
if oid in self.data:
# Exact match found
#logger.debug('get_next_oid, exact match of %s' % oid)
idx = self.data_idx.index(oid)
if idx == (len(self.data_idx) - 1):
# Last Item in MIB, No match!
return None
return self.data_idx[idx + 1]
else:
# No exact match, find prefix
#logger.debug('get_next_oid, no exact match of %s' % oid)
slist = oid.split('.')
elist = endoid.split('.')
for tmp_oid in self.data_idx:
tlist = tmp_oid.split('.')
for i in range(len(tlist)):
try:
sok = int(slist[i]) <= int(tlist[i])
eok = int(elist[i]) >= int(tlist[i])
if not (sok and eok):
break
except IndexError:
pass
if sok and eok:
return tmp_oid
return None # No match!
def start(self, oid_list):
self.connect()
if not self._connected:
return
logger.debug("==== Open PDU ====")
pdu = self.new_pdu(agentx.AGENTX_OPEN_PDU)
self.send_pdu(pdu)
pdu = self.recv_pdu()
self.session_id = pdu.session_id
logger.debug("==== Ping PDU ====")
pdu = self.new_pdu(agentx.AGENTX_PING_PDU)
self.send_pdu(pdu)
pdu = self.recv_pdu()
logger.debug("==== Register PDU ====")
for oid in oid_list:
logger.info("Registering: %s" % (oid))
pdu = self.new_pdu(agentx.AGENTX_REGISTER_PDU)
pdu.oid = oid
self.send_pdu(pdu)
pdu = self.recv_pdu()
return
def stop(self):
self.disconnect()
def is_connected(self):
return self._connected
def run(self, timeout = 0.1):
if not self._connected:
raise NetworkError('Not connected')
if timeout != self._timeout:
self.socket.settimeout(timeout)
self._timeout = timeout
try:
request = self.recv_pdu()
except socket.timeout:
return
if not request:
logger.error("Empty PDU, connection closed!")
self.disconnect()
raise NetworkError("Empty PDU, disconnecting")
response = self.response_pdu(request)
if request.type == agentx.AGENTX_GET_PDU:
logger.debug("Received GET PDU")
for rvalue in request.range_list:
oid = rvalue[0]
logger.debug("OID: %s" % (oid))
if oid in self.data:
logger.debug("OID Found")
response.values.append(self.data[oid])
else:
logger.debug("OID Not Found!")
response.values.append({
'type': agentx.TYPE_NOSUCHOBJECT,
'name': rvalue[0],
'value': 0
})
elif request.type == agentx.AGENTX_GETNEXT_PDU:
logger.debug("Received GET_NEXT PDU")
for rvalue in request.range_list:
oid = self._get_next_oid(rvalue[0], rvalue[1])
logger.debug("GET_NEXT: %s => %s" % (rvalue[0], oid))
if oid:
response.values.append(self.data[oid])
else:
response.values.append({
'type': agentx.TYPE_ENDOFMIBVIEW,
'name': rvalue[0],
'value': 0
})
else:
logger.warn("Received unsupported PDU %d" % request.type)
self.send_pdu(response)