Twisted support implemented

18 files changed, 820 insertions, 0 deletions

diff --git a/THANKS b/THANKS
index b1b4d91..df55fb7 100644
--- a/THANKS
+++ b/THANKS
@@ -22,6 +22,7 @@ Ivan Zderadicka
 Randy Couey
 Brian Kyckelhahn
 Mark M Evans
+Filippo Giunchedi at Truelite Srl
 
 Thanks to Python Software Foundation for granting financial support 
 for the project.
diff --git a/examples/v3arch/twisted/agent/ntforg.py b/examples/v3arch/twisted/agent/ntforg.py
new file mode 100644
index 0000000..77df949
--- /dev/null
+++ b/examples/v3arch/twisted/agent/ntforg.py
@@ -0,0 +1,88 @@
+# Notification originator
+from twisted.internet import reactor
+from pysnmp.entity import engine, config
+from pysnmp.carrier.twisted import dispatch
+from pysnmp.carrier.twisted.dgram import udp
+from pysnmp.entity.rfc3413 import context
+from pysnmp.entity.rfc3413.twisted import ntforg
+from pysnmp.proto.api import v2c
+
+# Send either Teap or Inform request
+doInform = 1
+
+snmpEngine = engine.SnmpEngine()
+
+# Set Twisted dispatcher
+snmpEngine.registerTransportDispatcher(dispatch.TwistedDispatcher())
+
+# v1/2 setup
+config.addV1System(snmpEngine, 'test-agent', 'public')
+
+# v3 setup
+config.addV3User(
+    snmpEngine, 'test-user',
+    config.usmHMACMD5AuthProtocol, 'authkey1',
+    config.usmDESPrivProtocol, 'privkey1'
+    )
+
+# Transport params
+config.addTargetParams(snmpEngine, 'myParams', 'test-user', 'authPriv')
+#config.addTargetParams(snmpEngine, 'myParams', 'test-agent', 'noAuthNoPriv', 1)
+
+# Transport addresses
+config.addTargetAddr(
+    snmpEngine, 'myNMS', config.snmpUDPDomain,
+    ('127.0.0.1', 162), 'myParams', tagList='myManagementStations'
+    )
+
+# Notification targets
+if doInform:
+    config.addNotificationTarget(
+        snmpEngine, 'myNotifyName', 'myParams','myManagementStations','inform'
+    )
+else:
+    config.addNotificationTarget(    
+        snmpEngine, 'myNotifyName', 'myParams', 'myManagementStations', 'trap'
+        )
+
+# Transport
+config.addSocketTransport(
+    snmpEngine,
+    udp.domainName,
+    udp.UdpTwistedTransport().openClientMode()
+    )
+
+# Agent-side VACM setup
+config.addContext(snmpEngine, '')
+config.addVacmUser(snmpEngine, 1, 'test-agent', 'noAuthNoPriv',
+                                      (), (), (1,3,6)) # v1
+config.addVacmUser(snmpEngine, 2, 'test-agent', 'noAuthNoPriv',
+                                      (), (), (1,3,6)) # v2c
+config.addVacmUser(snmpEngine, 3, 'test-user', 'authPriv',
+                                      (), (), (1,3,6)) # v3
+
+# SNMP context
+snmpContext = context.SnmpContext(snmpEngine)
+
+# Twisted API follows
+
+def receiveResponse((sendRequestHandle, errorIndication)):
+    if errorIndication:
+        print 'Error: ', errorIndication
+    reactor.stop()
+    
+ntfOrg = ntforg.NotificationOriginator(snmpContext)
+
+df = ntfOrg.sendNotification(
+    snmpEngine,
+    # Notification targets
+    'myNotifyName',
+    # Trap OID (SNMPv2-MIB::coldStart)
+    (1,3,6,1,6,3,1,1,5,1),
+    # ((oid, value), ... )
+    (((1,3,6,1,2,1,1,5), v2c.OctetString('Example Notificator')),)
+    )
+
+if doInform:
+    df.addCallback(receiveResponse)
+    reactor.run()
diff --git a/examples/v3arch/twisted/manager/bulkgen.py b/examples/v3arch/twisted/manager/bulkgen.py
new file mode 100644
index 0000000..96201ac
--- /dev/null
+++ b/examples/v3arch/twisted/manager/bulkgen.py
@@ -0,0 +1,73 @@
+# BULK Command Generator
+from twisted.internet import reactor, defer
+from pysnmp.entity import engine, config
+from pysnmp.carrier.twisted import dispatch
+from pysnmp.carrier.twisted.dgram import udp
+from pysnmp.entity.rfc3413.twisted import cmdgen
+
+snmpEngine = engine.SnmpEngine()
+
+# Set Twisted dispatcher
+snmpEngine.registerTransportDispatcher(dispatch.TwistedDispatcher())
+
+# v1/2 setup
+config.addV1System(snmpEngine, 'test-agent', 'public')
+
+# v3 setup
+config.addV3User(
+    snmpEngine, 'test-user',
+    config.usmHMACMD5AuthProtocol, 'authkey1',
+    config.usmDESPrivProtocol, 'privkey1'
+    )
+
+# Transport params
+config.addTargetParams(snmpEngine, 'myParams', 'test-user', 'authPriv')
+#config.addTargetParams(snmpEngine, 'myParams', 'test-agent', 'noAuthNoPriv', 1)
+
+# Transport addresses
+config.addTargetAddr(
+    snmpEngine, 'myRouter', config.snmpUDPDomain,
+    ('127.0.0.1', 161), 'myParams'
+    )
+
+# Transport
+config.addSocketTransport(
+    snmpEngine,
+    udp.domainName,
+    udp.UdpTwistedTransport().openClientMode()
+    )
+
+# Twisted API follows
+
+def receiveResponse(
+    (errorIndication, errorStatus, errorIndex, varBindTable),
+    bulkCmdGen, snmpEngine):
+    if errorIndication or errorStatus:
+        print 'Error: ', errorIndication, errorStatus.prettyPrint(), errorIndex
+        reactor.stop()
+        return
+    for varBindRow in varBindTable:
+        for oid, val in varBindRow:
+            if val is None:
+                print oid.prettyPrint()
+            else:
+                print '%s = %s' % (oid.prettyPrint(), val.prettyPrint())
+    for oid, val in varBindTable[-1]:
+        if val is not None:
+            df = bulkCmdGen.sendReq(
+                snmpEngine, 'myRouter', 0, 25, varBindTable[-1]
+                )
+            df.addCallback(receiveResponse, bulkCmdGen, snmpEngine)
+            return
+    else:
+        reactor.stop()
+
+bulkCmdGen = cmdgen.BulkCommandGenerator()
+
+df = bulkCmdGen.sendReq(
+    snmpEngine, 'myRouter', 0, 25, (((1,3,6,1,2), None),)
+    )
+
+df.addCallback(receiveResponse, bulkCmdGen, snmpEngine)
+
+reactor.run()
diff --git a/examples/v3arch/twisted/manager/getgen.py b/examples/v3arch/twisted/manager/getgen.py
new file mode 100644
index 0000000..a2cb9a4
--- /dev/null
+++ b/examples/v3arch/twisted/manager/getgen.py
@@ -0,0 +1,62 @@
+# GET Command Generator
+from twisted.internet import reactor, defer
+from pysnmp.entity import engine, config
+from pysnmp.carrier.twisted import dispatch
+from pysnmp.carrier.twisted.dgram import udp
+from pysnmp.entity.rfc3413.twisted import cmdgen
+
+snmpEngine = engine.SnmpEngine()
+
+# Set Twisted dispatcher
+snmpEngine.registerTransportDispatcher(dispatch.TwistedDispatcher())
+
+# v1/2 setup
+config.addV1System(snmpEngine, 'test-agent', 'public')
+
+# v3 setup
+config.addV3User(
+    snmpEngine, 'test-user',
+    config.usmHMACMD5AuthProtocol, 'authkey1',
+    config.usmDESPrivProtocol, 'privkey1'
+    )
+
+# Transport params
+config.addTargetParams(snmpEngine, 'myParams', 'test-user', 'authPriv')
+#config.addTargetParams(snmpEngine, 'myParams', 'test-agent', 'noAuthNoPriv', 1)
+
+# Transport addresses
+config.addTargetAddr(
+    snmpEngine, 'myRouter', config.snmpUDPDomain,
+    ('127.0.0.1', 161), 'myParams'
+    )
+
+# Transport
+config.addSocketTransport(
+    snmpEngine,
+    udp.domainName,
+    udp.UdpTwistedTransport().openClientMode()
+    )
+
+# Twisted API follows
+
+def receiveResponse((errorIndication, errorStatus, errorIndex, varBinds)):
+    if errorIndication or errorStatus:
+        print 'Error: ', errorIndication, errorStatus.prettyPrint(), errorIndex
+        reactor.stop()
+        return
+    for oid, val in varBinds:
+        if val is None:
+            print oid.prettyPrint()
+        else:
+            print '%s = %s' % (oid.prettyPrint(), val.prettyPrint())
+    reactor.stop()
+
+getCmdGen = cmdgen.GetCommandGenerator()
+
+df = getCmdGen.sendReq(
+    snmpEngine, 'myRouter', (((1,3,6,1,2,1,1,1,0), None),)
+    )
+
+df.addCallback(receiveResponse)
+
+reactor.run()
diff --git a/examples/v3arch/twisted/manager/nextgen.py b/examples/v3arch/twisted/manager/nextgen.py
new file mode 100644
index 0000000..8fdc3a8
--- /dev/null
+++ b/examples/v3arch/twisted/manager/nextgen.py
@@ -0,0 +1,73 @@
+# GETNEXT Command Generator
+from twisted.internet import reactor, defer
+from pysnmp.entity import engine, config
+from pysnmp.carrier.twisted import dispatch
+from pysnmp.carrier.twisted.dgram import udp
+from pysnmp.entity.rfc3413.twisted import cmdgen
+
+snmpEngine = engine.SnmpEngine()
+
+# Set Twisted dispatcher
+snmpEngine.registerTransportDispatcher(dispatch.TwistedDispatcher())
+
+# v1/2 setup
+config.addV1System(snmpEngine, 'test-agent', 'public')
+
+# v3 setup
+config.addV3User(
+    snmpEngine, 'test-user',
+    config.usmHMACMD5AuthProtocol, 'authkey1',
+    config.usmDESPrivProtocol, 'privkey1'
+    )
+
+# Transport params
+config.addTargetParams(snmpEngine, 'myParams', 'test-user', 'authPriv')
+#config.addTargetParams(snmpEngine, 'myParams', 'test-agent', 'noAuthNoPriv', 1)
+
+# Transport addresses
+config.addTargetAddr(
+    snmpEngine, 'myRouter', config.snmpUDPDomain,
+    ('127.0.0.1', 161), 'myParams'
+    )
+
+# Transport
+config.addSocketTransport(
+    snmpEngine,
+    udp.domainName,
+    udp.UdpTwistedTransport().openClientMode()
+    )
+
+# Twisted API follows
+
+def receiveResponse(
+    (errorIndication, errorStatus, errorIndex, varBindTable),
+    nextCmdGen, snmpEngine):
+    if errorIndication or errorStatus:
+        print 'Error: ', errorIndication, errorStatus.prettyPrint(), errorIndex
+        reactor.stop()
+        return
+    for varBindRow in varBindTable:
+        for oid, val in varBindRow:
+            if val is None:
+                print oid.prettyPrint()
+            else:
+                print '%s = %s' % (oid.prettyPrint(), val.prettyPrint())
+    for oid, val in varBindTable[-1]:
+        if val is not None:
+            df = nextCmdGen.sendReq(
+                snmpEngine, 'myRouter', varBindTable[-1]
+                )
+            df.addCallback(receiveResponse, nextCmdGen, snmpEngine)
+            return
+    else:
+        reactor.stop()
+
+nextCmdGen = cmdgen.NextCommandGenerator()
+
+df = nextCmdGen.sendReq(
+    snmpEngine, 'myRouter', (((1,3,6,1,2,1,1), None),)
+    )
+
+df.addCallback(receiveResponse, nextCmdGen, snmpEngine)
+
+reactor.run()
diff --git a/examples/v3arch/twisted/manager/ntfrcv.py b/examples/v3arch/twisted/manager/ntfrcv.py
new file mode 100644
index 0000000..61bb5ca
--- /dev/null
+++ b/examples/v3arch/twisted/manager/ntfrcv.py
@@ -0,0 +1,48 @@
+# Notification Receiver (TRAP/INFORM)
+from twisted.internet import reactor
+from pysnmp.entity import engine, config
+from pysnmp.carrier.twisted import dispatch
+from pysnmp.carrier.twisted.dgram import udp
+from pysnmp.entity.rfc3413 import ntfrcv
+
+# Create SNMP engine with autogenernated engineID and pre-bound
+# to socket transport dispatcher
+snmpEngine = engine.SnmpEngine()
+
+# Set Twisted dispatcher
+snmpEngine.registerTransportDispatcher(dispatch.TwistedDispatcher())
+
+# v1/2 setup
+config.addV1System(snmpEngine, 'test-agent', 'public')
+
+# v3 setup
+config.addV3User(
+    snmpEngine, 'test-user',
+    config.usmHMACMD5AuthProtocol, 'authkey1',
+    config.usmDESPrivProtocol, 'privkey1'
+    )
+
+# Transport
+config.addSocketTransport(
+    snmpEngine,
+    udp.domainName,
+    udp.UdpTwistedTransport().openServerMode(('127.0.0.1', 1162))
+    )
+
+# Callback function for receiving notifications
+def cbFun(snmpEngine,
+          stateReference,
+          contextEngineId, contextName,
+          varBinds,
+          cbCtx):
+    transportDomain, transportAddress = snmpEngine.msgAndPduDsp.getTransportInfo(stateReference)
+    print 'Notification from %s, SNMP Engine \"%s\", Context \"%s\"' % (
+        transportAddress, contextEngineId, contextName
+        )
+    for name, val in varBinds:
+        print '%s = %s' % (name.prettyPrint(), val.prettyPrint())
+        
+# Apps registration
+ntfrcv.NotificationReceiver(snmpEngine, cbFun)
+
+reactor.run()
diff --git a/examples/v3arch/twisted/manager/setgen.py b/examples/v3arch/twisted/manager/setgen.py
new file mode 100644
index 0000000..4bdac57
--- /dev/null
+++ b/examples/v3arch/twisted/manager/setgen.py
@@ -0,0 +1,64 @@
+# SET Command Generator
+from twisted.internet import reactor, defer
+from pysnmp.entity import engine, config
+from pysnmp.carrier.twisted import dispatch
+from pysnmp.carrier.twisted.dgram import udp
+from pysnmp.entity.rfc3413.twisted import cmdgen
+from pysnmp.proto import rfc1902
+
+snmpEngine = engine.SnmpEngine()
+
+# Set Twisted dispatcher
+snmpEngine.registerTransportDispatcher(dispatch.TwistedDispatcher())
+
+# v1/2 setup
+config.addV1System(snmpEngine, 'test-agent', 'public')
+
+# v3 setup
+config.addV3User(
+    snmpEngine, 'test-user',
+    config.usmHMACMD5AuthProtocol, 'authkey1',
+    config.usmDESPrivProtocol, 'privkey1'
+    )
+
+# Transport params
+config.addTargetParams(snmpEngine, 'myParams', 'test-user', 'authPriv')
+#config.addTargetParams(snmpEngine, 'myParams', 'test-agent', 'noAuthNoPriv', 1)
+
+# Transport addresses
+config.addTargetAddr(
+    snmpEngine, 'myRouter', config.snmpUDPDomain,
+    ('127.0.0.1', 161), 'myParams'
+    )
+
+# Transport
+config.addSocketTransport(
+    snmpEngine,
+    udp.domainName,
+    udp.UdpTwistedTransport().openClientMode()
+    )
+
+# Twisted API follows
+
+def receiveResponse((errorIndication, errorStatus, errorIndex, varBinds)):
+    if errorIndication or errorStatus:
+        print 'Error: ', errorIndication, errorStatus.prettyPrint(), errorIndex
+        reactor.stop()
+        return
+    for oid, val in varBinds:
+        if val is None:
+            print oid.prettyPrint()
+        else:
+            print '%s = %s' % (oid.prettyPrint(), val.prettyPrint())
+    reactor.stop()
+
+getCmdGen = cmdgen.SetCommandGenerator()
+
+df = getCmdGen.sendReq(
+    snmpEngine, 'myRouter',
+    (((1,3,6,1,2,1,1,1,0), rfc1902.OctetString('Grinch')),)
+    )
+
+df.addCallback(receiveResponse)
+
+reactor.run()
diff --git a/pysnmp/carrier/twisted/__init__.py b/pysnmp/carrier/twisted/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/pysnmp/carrier/twisted/__init__.py
diff --git a/pysnmp/carrier/twisted/base.py b/pysnmp/carrier/twisted/base.py
new file mode 100644
index 0000000..ecceaca
--- /dev/null
+++ b/pysnmp/carrier/twisted/base.py
@@ -0,0 +1,26 @@
+#
+#  Copyright (C) 2008 Truelite Srl <info@truelite.it>
+#  Author: Filippo Giunchedi <filippo@truelite.it>
+#
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License Version 2
+#  as published by the Free Software Foundation
+#
+#  Description: twisted DatagramProtocol UDP transport
+#
+
+class AbstractTwistedTransport:
+    """Base Twisted Transport, to be used with TwistedDispatcher"""
+    def __init__(self):
+        self._writeQ = []
+
+    # AbstractTwistedTransport API
+    
+    def registerCbFun(self, cbFun):
+        self._cbFun = cbFun
+
+    def unregisterCbFun(self):
+        self._cbFun = None
+
+    def closeTransport(self):
+        self.unregisterCbFun()
diff --git a/pysnmp/carrier/twisted/dgram/__init__.py b/pysnmp/carrier/twisted/dgram/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/pysnmp/carrier/twisted/dgram/__init__.py
diff --git a/pysnmp/carrier/twisted/dgram/base.py b/pysnmp/carrier/twisted/dgram/base.py
new file mode 100644
index 0000000..75dd455
--- /dev/null
+++ b/pysnmp/carrier/twisted/dgram/base.py
@@ -0,0 +1,44 @@
+"""Implements twisted-based generic DGRAM transport"""
+from time import time
+from twisted.internet.protocol import DatagramProtocol
+from twisted.internet import reactor
+from pysnmp.carrier.twisted.base import AbstractTwistedTransport
+from pysnmp.carrier import error
+from pysnmp import debug
+
+class DgramTwistedTransport(DatagramProtocol, AbstractTwistedTransport):
+    """Base Twisted datagram Transport, to be used with TwistedDispatcher"""
+
+    # Twisted Datagram API
+    
+    def datagramReceived(self, datagram, address):
+        if self._cbFun is None:
+            raise error.CarrierError('Unable to call cbFun')
+        else:
+            # Callback fun is called through callLater() in attempt
+            # to make Twisted timed calls work under high load.
+            reactor.callLater(0, self._cbFun, self, address, datagram)
+
+    def startProtocol(self):
+        debug.logger & debug.flagIO and debug.logger('startProtocol: invoked')
+        while self._writeQ:
+            outgoingMessage, transportAddress = self._writeQ.pop(0)
+            debug.logger & debug.flagIO and debug.logger('startProtocol: transportAddress %s outgoingMessage %s' % (transportAddress, repr(outgoingMessage)))
+            try:
+                self.transport.write(outgoingMessage, transportAddress)
+            except Exception, why:
+                raise error.CarrierError('Twisted exception: %s' % (why,))
+
+    def stopProtocol(self):
+        debug.logger & debug.flagIO and debug.logger('stopProtocol: invoked')
+        self.closeTransport()
+
+    def sendMessage(self, outgoingMessage, transportAddress):
+        debug.logger & debug.flagIO and debug.logger('startProtocol: %s transportAddress %s outgoingMessage %s' % ((self.transport is None and "queuing" or "sending"), transportAddress, repr(outgoingMessage)))        
+        if self.transport is None:
+            self._writeQ.append((outgoingMessage, transportAddress))
+        else:
+            try:
+                self.transport.write(outgoingMessage, transportAddress)
+            except Exception, why:
+                raise error.CarrierError('Twisted exception: %s' % (why,))
diff --git a/pysnmp/carrier/twisted/dgram/udp.py b/pysnmp/carrier/twisted/dgram/udp.py
new file mode 100644
index 0000000..850ff1b
--- /dev/null
+++ b/pysnmp/carrier/twisted/dgram/udp.py
@@ -0,0 +1,25 @@
+"""Implements twisted-based UDP transport"""
+from twisted.internet import reactor
+from pysnmp.carrier.twisted.dgram.base import DgramTwistedTransport
+from pysnmp.carrier import error
+
+domainName = snmpUDPDomain = (1, 3, 6, 1, 6, 1, 1)
+
+class UdpTwistedTransport(DgramTwistedTransport):
+    # AbstractTwistedTransport API
+    
+    def openClientMode(self, iface=''):
+        try:
+            self._lport = reactor.listenUDP(0, self, iface)
+        except Exception, why:
+            raise error.CarrierError(why)
+        return self
+
+    def openServerMode(self, iface=None):
+        try:
+            self._lport = reactor.listenUDP(iface[1], self, iface[0])
+        except Exception, why:
+            raise error.CarrierError(why)
+        return self
+
+UdpTransport = UdpTwistedTransport
\ No newline at end of file
diff --git a/pysnmp/carrier/twisted/dgram/unix.py b/pysnmp/carrier/twisted/dgram/unix.py
new file mode 100644
index 0000000..75bfe17
--- /dev/null
+++ b/pysnmp/carrier/twisted/dgram/unix.py
@@ -0,0 +1,26 @@
+"""Implements twisted-based UNIX domain socket transport"""
+from twisted.internet import reactor
+from pysnmp.carrier.twisted.dgram.base import DgramTwistedTransport
+from pysnmp.carrier import error
+
+domainName = snmpLocalDomain = (1, 3, 6, 1, 2, 1, 100, 1, 13)
+
+class UnixTwistedTransport(DgramTwistedTransport):
+    # AbstractTwistedTransport API
+    
+    def openClientMode(self, iface=''):
+        try:
+            self._lport = reactor.connectUNIXDatagram(iface, self)
+        except Exception, why:
+            raise error.CarrierError(why)
+        return self
+
+    def openServerMode(self, iface=None):
+        try:
+            self._lport = reactor.listenUNIXDatagram(iface, self)
+        except Exception, why:
+            raise error.CarrierError(why)
+        
+        return self
+
+UnixTransport = UnixTwistedTransport
\ No newline at end of file
diff --git a/pysnmp/carrier/twisted/dispatch.py b/pysnmp/carrier/twisted/dispatch.py
new file mode 100644
index 0000000..36b4ccc
--- /dev/null
+++ b/pysnmp/carrier/twisted/dispatch.py
@@ -0,0 +1,53 @@
+#
+#  Copyright (C) 2008 Truelite Srl <info@truelite.it>
+#  Author: Filippo Giunchedi <filippo@truelite.it>
+#
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License Version 2
+#  as published by the Free Software Foundation
+#
+# Description: Transport dispatcher based on twisted.internet.reactor
+#
+from time import time
+from twisted.internet import reactor, task
+from pysnmp.carrier.base import AbstractTransportDispatcher
+from pysnmp.carrier import error
+
+class TwistedDispatcher(AbstractTransportDispatcher):
+    """TransportDispatcher based on twisted.internet.reactor"""
+    def __init__(self, *args, **kwargs):
+        AbstractTransportDispatcher.__init__(self)
+        self.__transportCount = 0
+        self.timeout = kwargs.get('timeout', 1.0)
+        self.loopingcall = task.LoopingCall(self.handleTimeout)
+
+    def handleTimeout(self):
+        self.handleTimerTick(time())
+
+    def runDispatcher(self, timeout=0.0):
+        if not reactor.running:
+            try:
+                reactor.run()
+            except Exception, why:
+                raise error.CarrierError(why)
+
+    # jobstarted/jobfinished might be okay as-is
+
+    def registerTransport(self, tDomain, transport):
+        if not self.loopingcall.running and self.timeout > 0:
+            self.loopingcall.start(self.timeout, now = False)
+        AbstractTransportDispatcher.registerTransport(
+            self, tDomain, transport
+            )
+        self.__transportCount = self.__transportCount + 1
+
+    def unregisterTransport(self, tDomain):
+        t = AbstractTransportDispatcher.getTransport(self, tDomain)
+        if t is not None:
+            AbstractTransportDispatcher.unregisterTransport(self, tDomain)
+            t.closeTransport()
+            self.__transportCount = self.__transportCount - 1
+
+        # The last transport has been removed, stop the timeout
+        if self.__transportCount > 0 and self.loopingcall.running:
+            self.loopingcall.stop()
diff --git a/pysnmp/entity/rfc3413/twisted/__init__.py b/pysnmp/entity/rfc3413/twisted/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/pysnmp/entity/rfc3413/twisted/__init__.py
diff --git a/pysnmp/entity/rfc3413/twisted/cmdgen.py b/pysnmp/entity/rfc3413/twisted/cmdgen.py
new file mode 100644
index 0000000..297c49d
--- /dev/null
+++ b/pysnmp/entity/rfc3413/twisted/cmdgen.py
@@ -0,0 +1,202 @@
+from twisted.internet import reactor, defer
+from pysnmp.entity.rfc3413 import cmdgen
+
+class GetCommandGenerator(cmdgen.GetCommandGenerator):
+    def sendReq(
+        self,
+        snmpEngine,
+        addrName,
+        varBinds,
+        contextEngineId=None,
+        contextName=''
+        ):
+        df = defer.Deferred()
+        cmdgen.GetCommandGenerator.sendReq(
+            self,
+            snmpEngine,
+            addrName,
+            varBinds,
+            None,
+            df,
+            contextEngineId,
+            contextName
+            )
+        return df
+
+    def _handleResponse(
+        self,
+        snmpEngine,
+        transportDomain,
+        transportAddress,
+        messageProcessingModel,
+        securityModel,
+        securityName,
+        securityLevel,
+        contextEngineId,
+        contextName,
+        pduVersion,
+        PDU,
+        timeout,
+        retryCount,
+        pMod,
+        rspPDU,
+        sendRequestHandle,
+        (cbFun, cbCtx)
+        ):        
+        cbCtx.callback(
+            (None,
+             pMod.apiPDU.getErrorStatus(rspPDU),
+             pMod.apiPDU.getErrorIndex(rspPDU),
+             pMod.apiPDU.getVarBinds(rspPDU))
+            )
+
+class SetCommandGenerator(cmdgen.SetCommandGenerator):
+    def sendReq(
+        self,
+        snmpEngine,
+        addrName,
+        varBinds,
+        contextEngineId=None,
+        contextName=''
+        ):
+        df = defer.Deferred()
+        cmdgen.SetCommandGenerator.sendReq(
+            self,
+            snmpEngine,
+            addrName,
+            varBinds,
+            None,
+            df,
+            contextEngineId,
+            contextName
+            )
+        return df
+
+    def _handleResponse(
+        self,
+        snmpEngine,
+        transportDomain,
+        transportAddress,
+        messageProcessingModel,
+        securityModel,
+        securityName,
+        securityLevel,
+        contextEngineId,
+        contextName,
+        pduVersion,
+        PDU,
+        timeout,
+        retryCount,
+        pMod,
+        rspPDU,
+        sendRequestHandle,
+        (cbFun, cbCtx)
+        ):        
+        cbCtx.callback(
+            (None,
+             pMod.apiPDU.getErrorStatus(rspPDU),
+             pMod.apiPDU.getErrorIndex(rspPDU),
+             pMod.apiPDU.getVarBinds(rspPDU))
+            )
+
+class NextCommandGenerator(cmdgen.NextCommandGenerator):
+    def sendReq(
+        self,
+        snmpEngine,
+        addrName,
+        varBinds,
+        contextEngineId=None,
+        contextName=''
+        ):
+        df = defer.Deferred()
+        cmdgen.NextCommandGenerator.sendReq(
+            self,
+            snmpEngine,
+            addrName,
+            varBinds,
+            None,
+            df,
+            contextEngineId,
+            contextName
+            )
+        return df
+
+    def _handleResponse(
+        self,
+        snmpEngine,
+        transportDomain,
+        transportAddress,
+        messageProcessingModel,
+        securityModel,
+        securityName,
+        securityLevel,
+        contextEngineId,
+        contextName,
+        pduVersion,
+        PDU,
+        timeout,
+        retryCount,
+        pMod,
+        rspPDU,
+        sendRequestHandle,
+        (cbFun, cbCtx)
+        ):        
+        cbCtx.callback(
+            (None,
+             pMod.apiPDU.getErrorStatus(rspPDU),
+             pMod.apiPDU.getErrorIndex(rspPDU),
+             pMod.apiPDU.getVarBindTable(PDU, rspPDU))
+            )
+
+class BulkCommandGenerator(cmdgen.BulkCommandGenerator):
+    def sendReq(
+        self,
+        snmpEngine,
+        addrName,
+        nonRepeaters,
+        maxRepetitions,
+        varBinds,
+        contextEngineId=None,
+        contextName=''
+        ):
+        df = defer.Deferred()
+        cmdgen.BulkCommandGenerator.sendReq(
+            self,
+            snmpEngine,
+            addrName,
+            nonRepeaters,
+            maxRepetitions,
+            varBinds,
+            None,
+            df,
+            contextEngineId=None,
+            contextName=''
+            )
+        return df
+
+    def _handleResponse(
+        self,
+        snmpEngine,
+        transportDomain,
+        transportAddress,
+        messageProcessingModel,
+        securityModel,
+        securityName,
+        securityLevel,
+        contextEngineId,
+        contextName,
+        pduVersion,
+        PDU,
+        timeout,
+        retryCount,
+        pMod,
+        rspPDU,
+        sendRequestHandle,
+        (cbFun, cbCtx)
+        ):        
+        cbCtx.callback(
+            (None,
+             pMod.apiBulkPDU.getErrorStatus(rspPDU),
+             pMod.apiBulkPDU.getErrorIndex(rspPDU),
+             pMod.apiBulkPDU.getVarBindTable(PDU, rspPDU))
+            )
diff --git a/pysnmp/entity/rfc3413/twisted/ntforg.py b/pysnmp/entity/rfc3413/twisted/ntforg.py
new file mode 100644
index 0000000..e02f2ab
--- /dev/null
+++ b/pysnmp/entity/rfc3413/twisted/ntforg.py
@@ -0,0 +1,32 @@
+from twisted.internet import reactor, defer
+from pysnmp.entity.rfc3413 import ntforg
+
+class NotificationOriginator(ntforg.NotificationOriginator):
+    def sendNotification(
+        self,
+        snmpEngine,
+        notificationTarget,
+        notificationName,
+        additionalVarBinds=None,
+        contextName=''
+        ):
+        df = defer.Deferred()
+        ntforg.NotificationOriginator.sendNotification(
+            self,
+            snmpEngine,
+            notificationTarget,
+            notificationName,
+            additionalVarBinds,
+            None,
+            df,
+            contextName=''
+            )
+        return df
+
+    def _handleResponse(
+        self,
+        sendRequestHandle,
+        errorIndication,
+        cbFun,
+        cbCtx):
+        cbCtx.callback((sendRequestHandle, errorIndication))
diff --git a/setup.py b/setup.py
index c4a0187..08d379f 100644
--- a/setup.py
+++ b/setup.py
@@ -15,9 +15,12 @@ setup(name="pysnmp",
                    'pysnmp.v4.carrier',
                    'pysnmp.v4.carrier.asynsock',
                    'pysnmp.v4.carrier.asynsock.dgram',
+                   'pysnmp.v4.carrier.twisted',
+                   'pysnmp.v4.carrier.twisted.dgram',                   
                    'pysnmp.v4.entity',
                    'pysnmp.v4.entity.rfc3413',
                    'pysnmp.v4.entity.rfc3413.oneliner',
+                   'pysnmp.v4.entity.rfc3413.twisted',
                    'pysnmp.v4.proto',
                    'pysnmp.v4.proto.mpmod',
                    'pysnmp.v4.proto.secmod',