Ejemplo n.º 1
0
    def __init__(self, socket):
        #print("initializing receiver")
        self.socket = socket
        self.connected = False
        self.observe = None
        self.observed = []

        self.inMsgs = {}
        self.outMsgs = {}

        self.puback = MQTTSN.Pubacks()
        self.pubrec = MQTTSN.Pubrecs()
        self.pubrel = MQTTSN.Pubrels()
        self.pubcomp = MQTTSN.Pubcomps()
Ejemplo n.º 2
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    def publish(self, topic, payload, qos=0, retained=False):
        publish = MQTTSN.Publishes()
        publish.Flags.QoS = qos
        publish.Flags.Retain = retained
        self.puback_flag = False  #reset flag
        if type(topic) == str and len(topic) > 2:
            print("invalid topic")
            return None
        if qos in [-1, 0]:  #qos 0 or -1
            publish.MsgId = 0
        else:
            publish.MsgId = self.__nextMsgid()
            print("MsgId=", publish.MsgId)
        if type(topic) == int:
            publish.Flags.TopicIdType = MQTTSN.TOPIC_NORMAL
            publish.TopicId = topic

        if type(topic) == str and len(topic) <= 2:
            publish.Flags.TopicIdType = MQTTSN.TOPIC_SHORTNAME
            publish.TopicId = topic
            #########

        publish.Data = payload
        a = publish.pack()
        self.sock.send(a.encode())
        self.__receiver.outMsgs[publish.MsgId] = publish
        #self.lookfor(MQTTSN.PUBACK)
        #return(self.waitfor(MQTTSN.PUBACK))
        return publish.MsgId
  def __init__(self, socket,client):
    #print("creating receiver object")
    self.socket = socket
    self.client=client
    self.connected = False
    self.running_loop = False
    self.observe = None
    self.observed = []

    self.inMsgs = {}
    self.outMsgs = {}

    self.puback = MQTTSN.Pubacks()
    self.pubrec = MQTTSN.Pubrecs()
    self.pubrel = MQTTSN.Pubrels()
    self.pubcomp = MQTTSN.Pubcomps()
Ejemplo n.º 4
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 def publish(self, topic, payload, qos=1, retained=False):
     if isinstance(payload, str) or isinstance(payload, bytes):
         pass
     else:
         raise TypeError('Payload must be str or bytes.')
     publish = MQTTSN.Publishes()
     publish.Flags.QoS = qos
     publish.Flags.Retain = retained
     if isinstance(topic, str):
         publish.Flags.TopicIdType = MQTTSN.TOPIC_SHORTNAME
         publish.TopicName = topic
     else:
         publish.Flags.TopicIdType = MQTTSN.TOPIC_NORMAL
         publish.TopicId = topic
         #print('Topico =', topic)
         #print('Id_de_topico =', msg.TopicId)
     if qos in [-1, 0]:
         publish.MsgId = 0
     else:
         publish.MsgId = self.__nextMsgid()
         #print("MsgId", publish.MsgId)
         self.__receiver.outMsgs[publish.MsgId] = publish
     publish.Data = payload
     self.sock.send(publish.pack())
     return publish.MsgId
Ejemplo n.º 5
0
  def connect(self, cleansession=True):
    self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    #self.sock.settimeout(5.0)

    self.sock.connect((self.host, self.port))

    connect = MQTTSN.Connects()
    connect.ClientId = self.clientid
    connect.CleanSession = cleansession
    connect.KeepAliveTimer = 0
    self.sock.send(connect.pack())

    response, address = MQTTSN.unpackPacket(MQTTSN.getPacket(self.sock))
    assert response.mh.MsgType == MQTTSN.CONNACK
    
    self.startReceiver()
Ejemplo n.º 6
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 def disconnect(self):
   disconnect = MQTTSN.Disconnects()
   if self.__receiver:
     self.__receiver.lookfor(MQTTSN.DISCONNECT)
   self.sock.send(disconnect.pack())
   msg = self.waitfor(MQTTSN.DISCONNECT)
   self.stopReceiver()
Ejemplo n.º 7
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def publish(topic, payload, retained=False, port=1883, host="localhost"):
  publish = MQTTSN.Publishes()
  publish.Flags.QoS = 3
  publish.Flags.Retain = retained
  if isinstance(payload, str):
    pass
  elif isinstance(payload, bytes):
    payload = payload.decode()
  if isinstance(topic, str):
    if len(topic) > 2:
      publish.Flags.TopicIdType = MQTTSN.TOPIC_NORMAL
      publish.TopicId = len(topic)
      payload = topic + payload
    else:
      publish.Flags.TopicIdType = MQTTSN.TOPIC_SHORTNAME
      publish.TopicName = topic
  else:
    publish.Flags.TopicIdType = MQTTSN.TOPIC_NORMAL
    publish.TopicId = topic
  publish.MsgId = 0
  #print("payload", payload)
  publish.Data = payload
  sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
  sock.sendto(publish.pack(), (host, port))
  sock.close()
  return
Ejemplo n.º 8
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 def subscribe(self, topic, qos=2):
     self.suback_flag = False
     self.sub_topicid = ""
     self.sub_msgid = ""
     self.sub_rc = ""
     subscribe = MQTTSN.Subscribes()
     subscribe.MsgId = self.__nextMsgid()
     if type(topic) is str:
         #print("topic is string  ",topic)
         subscribe.TopicName = topic
         if len(topic) > 2:
             subscribe.Flags.TopicIdType = MQTTSN.TOPIC_NORMAL
         else:
             subscribe.Flags.TopicIdType = MQTTSN.TOPIC_SHORTNAME
     else:
         subscribe.TopicId = topic  # should be int
         subscribe.Flags.TopicIdType = MQTTSN.TOPIC_PREDEFINED
     subscribe.Flags.QoS = qos
     self.sock.send(subscribe.pack().encode())
     self.lookfor(MQTTSN.SUBACK)
     msg = self.waitfor(MQTTSN.SUBACK, subscribe.MsgId)
     if msg != None:
         if subscribe.MsgId == msg.MsgId:
             print("received suback for msgid", msg.MsgId)
             print("topicid= ", msg.TopicId)
             return msg.ReturnCode, msg.TopicId
         else:
             raise SystemExit("Subscription failed quitting")
             return (None, None)
     else:
         return (None, None)
Ejemplo n.º 9
0
  def connect(self, cleansession=True):
    self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    self.sock.settimeout(5.0)

    self.sock.connect((self.host, self.port))

    connect = MQTTSN.Connects()
    connect.ClientId = self.clientid
    connect.CleanSession = cleansession
    connect.KeepAliveTimer = 0
    self.sock.send(connect.pack())

    response, address = MQTTSN.unpackPacket(MQTTSN.getPacket(self.sock))
    assert response.mh.MsgType == MQTTSN.CONNACK

    self.startReceiver()
Ejemplo n.º 10
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 def register(self, topicName):
   register = MQTTSN.Registers()
   register.TopicName = topicName
   if self.__receiver:
     self.__receiver.lookfor(MQTTSN.REGACK)
   self.sock.send(register.pack())
   msg = self.waitfor(MQTTSN.REGACK, register.MsgId)
   return msg.TopicId
Ejemplo n.º 11
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 def unsubscribe(self, topics):
   unsubscribe = MQTTSN.Unsubscribes()
   unsubscribe.MsgId = self.__nextMsgid()
   unsubscribe.data = topics
   if self.__receiver:
     self.__receiver.lookfor(MQTTSN.UNSUBACK)
   self.sock.send(unsubscribe.pack())
   msg = self.waitfor(MQTTSN.UNSUBACK, unsubscribe.MsgId)
Ejemplo n.º 12
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    def gwinfo(self, multicast_port, multicast_group):
        gwinfo = MQTTSN.GWInfos()
        if self.host != "":
            print("adding host ", type(gwinfo.GwAdd))
            gwinfo.GwAdd = self.host
        m = gwinfo.pack()
        m = m.encode()  #turn to bytes

        print(type(m))
        print("address type ", type(gwinfo.GwAdd))
        print("sending GW packet ", gwinfo)
        self.sock.sendto(m, (multicast_group, multicast_port))
Ejemplo n.º 13
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    def Search_GWs(self, multicast_port, multicast_group):
        if not self.multicast_flag:
            self.create_multicast_socket(multicast_port, multicast_group)

        searchgw = MQTTSN.SearchGWs()
        #print(type(searchgw))
        m = searchgw.pack()
        #print(type(m))
        m = m.encode()  #turn to bytes
        #print(type(m))
        print("sending GW packet ", searchgw)
        #sock2.sendto(m,(s_group, s_port))
        sock2.sendto(m, group)
Ejemplo n.º 14
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    def connect(self, host, port=1883, keepalive=60):
        self.host = host
        self.port = port
        self.bad_connect_flag = False
        self.connected_flag = False
        self.keepalive = keepalive

        self.sock.connect((self.host, self.port))

        connect = MQTTSN.Connects()
        connect.ClientId = self.clientid
        connect.CleanSession = self.cleansession
        connect.KeepAliveTimer = self.keepalive
        self.sock.send(connect.pack().encode())
Ejemplo n.º 15
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    def register(self, topicName):
        register = MQTTSN.Registers()
        register.TopicName = topicName

        if self.__receiver:  #this uses callbacks
            self.__receiver.lookfor(MQTTSN.REGACK)
            #print("\n\nsending register ",register.pack(),"\n\n")
        self.sock.send(register.pack().encode())
        self.lookfor(MQTTSN.REGACK)
        msg = self.waitfor(MQTTSN.REGACK, register.MsgId)
        if msg:
            return msg.TopicId
        else:
            return None
Ejemplo n.º 16
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 def subscribe(self, topic, qos=2):
   subscribe = MQTTSN.Subscribes()
   subscribe.MsgId = self.__nextMsgid()
   if type(topic) == types.StringType:
     subscribe.TopicName = topic
     if len(topic) > 2:
       subscribe.Flags.TopicIdType = MQTTSN.TOPIC_NORMAL
     else:
       subscribe.Flags.TopicIdType = MQTTSN.TOPIC_SHORTNAME
   else:
     subscribe.TopicId = topic # should be int
     subscribe.Flags.TopicIdType = MQTTSN.TOPIC_PREDEFINED
   subscribe.Flags.QoS = qos
   if self.__receiver:
     self.__receiver.lookfor(MQTTSN.SUBACK)
   self.sock.send(subscribe.pack())
   msg = self.waitfor(MQTTSN.SUBACK, subscribe.MsgId)
   return msg.ReturnCode, msg.TopicId
Ejemplo n.º 17
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 def publish(self, topic, payload, qos=0, retained=False):
   publish = MQTTSN.Publishes()
   publish.Flags.QoS = qos
   publish.Flags.Retain = retained
   if type(topic) == types.StringType:
     publish.Flags.TopicIdType = MQTTSN.TOPIC_SHORTNAME
     publish.TopicName = topic
   else:
     publish.Flags.TopicIdType = MQTTSN.TOPIC_NORMAL
     publish.TopicId = topic
   if qos in [-1, 0]:
     publish.MsgId = 0
   else:
     publish.MsgId = self.__nextMsgid()
     print "MsgId", publish.MsgId
     self.__receiver.outMsgs[publish.MsgId] = publish
   publish.Data = payload
   self.sock.send(publish.pack())
   return publish.MsgId
Ejemplo n.º 18
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 def subscribe(self, topic, qos=1):
     subscribe = MQTTSN.Subscribes()
     subscribe.MsgId = self.__nextMsgid()
     if isinstance(topic, str):
         subscribe.TopicName = topic
         if len(topic) > 2:
             subscribe.Flags.TopicIdType = MQTTSN.TOPIC_NORMAL
         else:
             subscribe.Flags.TopicIdType = MQTTSN.TOPIC_SHORTNAME
     else:
         subscribe.TopicId = topic  # should be int
         subscribe.Flags.TopicIdType = MQTTSN.TOPIC_PREDEFINED
     subscribe.Flags.QoS = qos
     if self.__receiver:
         self.__receiver.lookfor(MQTTSN.SUBACK)
     self.sock.send(subscribe.pack())
     msg = self.waitfor(MQTTSN.SUBACK, subscribe.MsgId)
     #print('Id_de_topico =',msg.TopicId)
     #print('Topico =',topic)
     self.topicmap.register(msg.TopicId, topic)
     return msg.ReturnCode, msg.TopicId
Ejemplo n.º 19
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def publish(topic, payload, retained=False, port=1884, host="192.168.137.150"):
    publish = MQTTSN.Publishes()
    publish.Flags.QoS = 3
    publish.Flags.Retain = retained
    if type(topic) == types.StringType:
        if len(topic) > 2:
            publish.Flags.TopicIdType = MQTTSN.TOPIC_NORMAL
            publish.TopicId = len(topic)
            payload = topic + payload
        else:
            publish.Flags.TopicIdType = MQTTSN.TOPIC_SHORTNAME
            publish.TopicName = topic
    else:
        publish.Flags.TopicIdType = MQTTSN.TOPIC_NORMAL
        publish.TopicId = topic
    publish.MsgId = 0
    print "payload", payload
    publish.Data = payload
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.sendto(publish.pack(), (host, port))
    sock.close()
    return
Ejemplo n.º 20
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def publish(topic, payload, retained=False, port=1883, host="localhost"):
    publish = MQTTSN.Publishes()
    publish.Flags.QoS = 3
    publish.Flags.Retain = retained
    if type(topic) == bytes:
        if len(topic) > 2:
            publish.Flags.TopicIdType = MQTTSN.TOPIC_NORMAL
            publish.TopicId = len(topic)
            payload = topic + payload
        else:
            publish.Flags.TopicIdType = MQTTSN.TOPIC_NORMAL
            publish.TopicName = topic
    if type(topic) == str and len(topic) <= 2:
        publish.Flags.TopicIdType = MQTTSN.TOPIC_SHORTNAME
        publish.TopicId = topic
    publish.MsgId = 0
    publish.Data = payload
    a = publish.pack()
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.sendto(a.encode(), (host, port))
    sock.close()
    return
Ejemplo n.º 21
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 def testFlags(self):
   flags = MQTTSN.Flags()
   outflags = MQTTSN.Flags()
   buf = flags.pack()
   outflags.unpack(buf[0])
   assert flags == outflags
Ejemplo n.º 22
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    def receive(self, topicmap, callback=None):
        packet = None
        try:
            packet, address = MQTTSN.unpackPacket(MQTTSN.getPacket(
                self.socket))
        except:
            if sys.exc_info()[0] != socket.timeout:
                #print("unexpected exception", sys.exc_info())
                raise sys.exc_info()
        if packet == None:
            time.sleep(0.1)
            return
        elif debug:
            print(packet)

        if self.observe == packet.mh.MsgType:
            #print("observed", packet)
            self.observed.append(packet)

        elif packet.mh.MsgType == MQTTSN.ADVERTISE:
            if hasattr(callback, "advertise"):
                callback.advertise(address, packet.GwId, packet.Duration)

        elif packet.mh.MsgType == MQTTSN.REGISTER:
            topicmap.register(packet.TopicId, packet.TopicName)

        elif packet.mh.MsgType == MQTTSN.PUBACK:
            "check if we are expecting a puback"
            if packet.MsgId in self.outMsgs and \
              self.outMsgs[packet.MsgId].Flags.QoS == 1:
                del self.outMsgs[packet.MsgId]
                if hasattr(callback, "published"):
                    callback.published(packet.MsgId)
            else:
                raise Exception("No QoS 1 message with message id " +
                                str(packet.MsgId) + " sent")

        elif packet.mh.MsgType == MQTTSN.PUBREC:
            if packet.MsgId in self.outMsgs:
                self.pubrel.MsgId = packet.MsgId
                self.socket.send(self.pubrel.pack())
            else:
                raise Exception("PUBREC received for unknown msg id "+ \
                            str(packet.MsgId))

        elif packet.mh.MsgType == MQTTSN.PUBREL:
            "release QOS 2 publication to client, & send PUBCOMP"
            msgid = packet.MsgId
            if packet.MsgId not in self.inMsgs:
                pass  # what should we do here?
            else:
                pub = self.inMsgs[packet.MsgId]
                topicname = topicmap.registered[pub.TopicId]
                if callback == None or \
                   callback.messageArrived(topicname, pub.Data, 2, pub.Flags.Retain, pub.MsgId):
                    del self.inMsgs[packet.MsgId]
                    self.pubcomp.MsgId = packet.MsgId
                    self.socket.send(self.pubcomp.pack())
                if callback == None:
                    return (topicname, pub.Data, 2, pub.Flags.Retain,
                            pub.MsgId)

        elif packet.mh.MsgType == MQTTSN.PUBCOMP:
            "finished with this message id"
            if packet.MsgId in self.outMsgs:
                del self.outMsgs[packet.MsgId]
                if hasattr(callback, "published"):
                    callback.published(packet.MsgId)
            else:
                raise Exception("PUBCOMP received for unknown msg id "+ \
                            str(packet.MsgId))

        elif packet.mh.MsgType == MQTTSN.PUBLISH:
            "finished with this message id"
            if packet.Flags.QoS in [0, 3]:
                qos = packet.Flags.QoS
                topicname = topicmap.registered[packet.TopicId]
                data = packet.Data
                if qos == 3:
                    qos = -1
                    if packet.Flags.TopicIdType == MQTTSN.TOPICID:
                        topicname = packet.Data[:packet.TopicId]
                        data = packet.Data[packet.TopicId:]
                if callback == None:
                    return (topicname, data, qos, packet.Flags.Retain,
                            packet.MsgId)
                else:
                    callback.messageArrived(topicname, data, qos,
                                            packet.Flags.Retain, packet.MsgId)
            elif packet.Flags.QoS == 1:
                topicname = topicmap.registered[packet.TopicId]
                if callback == None:
                    return (topicname, packet.Data, 1, packet.Flags.Retain,
                            packet.MsgId)
                else:
                    if callback.messageArrived(topicname, packet.Data, 1,
                                               packet.Flags.Retain,
                                               packet.MsgId):
                        self.puback.MsgId = packet.MsgId
                        self.socket.send(self.puback.pack())
            elif packet.Flags.QoS == 2:
                self.inMsgs[packet.MsgId] = packet
                self.pubrec.MsgId = packet.MsgId
                self.socket.send(self.pubrec.pack())

        else:
            raise Exception("Unexpected packet" + str(packet))
        return packet
Ejemplo n.º 23
0
 def disconnect(self):
     disconnect = MQTTSN.Disconnects()
     self.sock.send(disconnect.pack().encode())
     self.lookfor(MQTTSN.DISCONNECT)
     msg = self.waitfor(MQTTSN.DISCONNECT)
     return msg
  def receive(self, callback=None):

    packet = None
    try:
      packet, address = MQTTSN.unpackPacket(MQTTSN.getPacket(self.socket))
      #print("getting packet",packet,"\n")
    except Exception as e:
      if sys.exc_info()[0] != socket.timeout:
        print("getting packet unexpected exception", sys.exc_info())
        raise Exception("Packet receive error ",e)
    if packet == None:
      return
    elif debug:
      print("\nReceived packet data =",packet,"\n")
      return
    
    if self.observe == packet.mh.MsgType:
      #print("found what we were looking for",self.observe)
      self.observed.append(packet)
      return
    if packet.mh.MsgType == MQTTSN.CONNACK:
      if hasattr(callback, "on_connect"):
        print("found on connect")
        callback.on_connect(self.client,address,packet.ReturnCode)
    elif packet.mh.MsgType == MQTTSN.DISCONNECT:
      if hasattr(callback, "on_disconnect"):
        callback.on_disconnect(self.client,packet.Duration)
    elif packet.mh.MsgType == MQTTSN.SUBACK: ##added by me 
      if hasattr(callback, "on_subscribe"):
        callback.on_subscribe(self.client,packet.TopicId,packet.MsgId,packet.ReturnCode)
        
    elif packet.mh.MsgType == MQTTSN.ADVERTISE:
      if hasattr(callback, "advertise"):
        callback.advertise(self.client,address, packet.GwId, packet.Duration)

    elif packet.mh.MsgType == MQTTSN.REGISTER:
      if callback and hasattr(callback, "register"):
        callback.register(self.client,packet.TopicId, packet.TopicName)
    elif packet.mh.MsgType == MQTTSN.REGACK:
      if callback and hasattr(callback, "regack"):
        print("received regack")
        callback.regack(self.client,packet.TopicId)
    elif packet.mh.MsgType == MQTTSN.PUBACK:
      "check if we are expecting a puback"
      if packet.MsgId in self.outMsgs and \
        self.outMsgs[packet.MsgId].Flags.QoS == 1:
        del self.outMsgs[packet.MsgId]
        if hasattr(callback, "published"):
          callback.published(self.client,packet.MsgId)
      else:
        raise Exception("No QoS 1 message with message id "+str(packet.MsgId)+" sent")

    elif packet.mh.MsgType == MQTTSN.PUBREC:
      if packet.MsgId in self.outMsgs:
        self.pubrel.MsgId = packet.MsgId
        self.socket.send(self.pubrel.pack())
      else:
        raise Exception("PUBREC received for unknown msg id "+ \
                    str(packet.MsgId))

    elif packet.mh.MsgType == MQTTSN.PUBREL:
      "release QOS 2 publication to self.client, & send PUBCOMP"
      msgid = packet.MsgId
      if msgid not in self.inMsgs:
        pass # what should we do here?
      else:
        pub = self.inMsgs[packet.MsgId]
        if callback == None or \
           callback.messageArrived(self.client,pub.TopicId, pub.Data, 2, pub.Flags.Retain, pub.MsgId):
          del self.inMsgs[packet.MsgId]
          self.pubcomp.MsgId = packet.MsgId
          self.socket.send(self.pubcomp.pack())
        if callback == None:
          return (pub.pub.TopicId, pub.Data, 2, pub.Flags.Retain, pub.MsgId)

    elif packet.mh.MsgType == MQTTSN.PUBCOMP:
      #"finished with this message id"
      if packet.MsgId in self.outMsgs:
        del self.outMsgs[packet.MsgId]
        if hasattr(callback, "published"):
          callback.published(self.client,packet.MsgId)
      else:
        raise Exception("PUBCOMP received for unknown msg id "+ \
                    str(packet.MsgId))

    elif packet.mh.MsgType == MQTTSN.PUBLISH:
      #"finished with this message id ?"
      #print("here  ",packet)
      qos = packet.Flags.QoS
      topicname = packet.TopicName
      TopicId=packet.TopicId
      data = packet.Data
      #print("here  ",TopicId)
      if packet.Flags.QoS in [0, 3]:
        if qos == 3:
          qos = -1
          if packet.Flags.TopicIdType == MQTTSN.TOPICID:
            topicname = packet.Data[:packet.TopicId]
            data = packet.Data[packet.TopicId:]
        if callback == None:
          return (TopicId, data, qos, packet.Flags.Retain, packet.MsgId)
        else:
          callback.messageArrived(self.client,TopicId, data, qos, packet.Flags.Retain, packet.MsgId)
      elif packet.Flags.QoS == 1:
        if callback == None:
          return (packet.TopicId, packet.Data, 1,
                           packet.Flags.Retain, packet.MsgId)
        else:
          if callback.messageArrived(self.client,TopicId,data, 1,
                           packet.Flags.Retain, packet.MsgId):
            self.puback.MsgId = packet.MsgId
            self.socket.send(self.puback.pack().encode())
      elif packet.Flags.QoS == 2:
        self.inMsgs[packet.MsgId] = packet
        self.pubrec.MsgId = packet.MsgId
        self.socket.send(self.pubrec.pack())
    elif packet.mh.MsgType == MQTTSN.SEARCHGW: ##added by me 
        print(" Searching Gateway ")
        if hasattr(callback, "searchgw"):
          callback.searchgw(self.client,packet)
    elif packet.mh.MsgType == MQTTSN.ADVERTISE: ##added by me
        print(" Advertise info is ")
        if hasattr(callback, "advertise"):
          callback.advertise(self.client,packet)
    elif packet.mh.MsgType == MQTTSN.GWINFO: ##added by me
        print(" Search Gateway info is ")
        if hasattr(callback, "gwinfo"):
          print(" Search Gateway callback ")
          callback.gwinfo(self.client,packet)
    else:
      print("unexpected packet",packet)
      #raise Exception("Unexpected packet"+str(packet))
      return ""
    return packet
Ejemplo n.º 25
0
  def receive(self, callback=None):
    packet = None
    try:
      packet, address = MQTTSN.unpackPacket(MQTTSN.getPacket(self.socket))
    except:
      if sys.exc_info()[0] != socket.timeout:
        print "unexpected exception", sys.exc_info()
        raise sys.exc_info()
    if packet == None:
      time.sleep(0.1)
      return
    elif debug:
      print packet

    if self.observe == packet.mh.MsgType:
      print "observed", packet
      self.observed.append(packet)
        
    elif packet.mh.MsgType == MQTTSN.ADVERTISE:
      if hasattr(callback, "advertise"):
        callback.advertise(address, packet.GwId, packet.Duration)

    elif packet.mh.MsgType == MQTTSN.REGISTER:
      if callback and hasattr(callback, "register"):
        callback.register(packet.TopicId, packet.Topicname)

    elif packet.mh.MsgType == MQTTSN.PUBACK:
      "check if we are expecting a puback"
      if self.outMsgs.has_key(packet.MsgId) and \
        self.outMsgs[packet.MsgId].Flags.QoS == 1:
        del self.outMsgs[packet.MsgId]
        if hasattr(callback, "published"):
          callback.published(packet.MsgId)
      else:
        raise Exception("No QoS 1 message with message id "+str(packet.MsgId)+" sent")

    elif packet.mh.MsgType == MQTTSN.PUBREC:
      if self.outMsgs.has_key(packet.MsgId):
        self.pubrel.MsgId = packet.MsgId
        self.socket.send(self.pubrel.pack())
      else:
        raise Exception("PUBREC received for unknown msg id "+ \
                    str(packet.MsgId))

    elif packet.mh.MsgType == MQTTSN.PUBREL:
      "release QOS 2 publication to client, & send PUBCOMP"
      msgid = packet.MsgId
      if not self.inMsgs.has_key(msgid):
        pass # what should we do here?
      else:
        pub = self.inMsgs[packet.MsgId]
        if callback == None or \
           callback.messageArrived(pub.TopicName, pub.Data, 2, pub.Flags.Retain, pub.MsgId):
          del self.inMsgs[packet.MsgId]
          self.pubcomp.MsgId = packet.MsgId
          self.socket.send(self.pubcomp.pack())
        if callback == None:
          return (pub.TopicName, pub.Data, 2, pub.Flags.Retain, pub.MsgId)

    elif packet.mh.MsgType == MQTTSN.PUBCOMP:
      "finished with this message id"
      if self.outMsgs.has_key(packet.MsgId):
        del self.outMsgs[packet.MsgId]
        if hasattr(callback, "published"):
          callback.published(packet.MsgId)
      else:
        raise Exception("PUBCOMP received for unknown msg id "+ \
                    str(packet.MsgId))

    elif packet.mh.MsgType == MQTTSN.PUBLISH:
      "finished with this message id"
      if packet.Flags.QoS in [0, 3]:
        qos = packet.Flags.QoS
        topicname = packet.TopicName
        data = packet.Data
        if qos == 3:
          qos = -1
          if packet.Flags.TopicIdType == MQTTSN.TOPICID:
            topicname = packet.Data[:packet.TopicId]
            data = packet.Data[packet.TopicId:]
        if callback == None:
          return (topicname, data, qos, packet.Flags.Retain, packet.MsgId)
        else:
          callback.messageArrived(topicname, data, qos, packet.Flags.Retain, packet.MsgId)
      elif packet.Flags.QoS == 1:
        if callback == None:
          return (packet.topicName, packet.Data, 1,
                           packet.Flags.Retain, packet.MsgId)
        else:
          if callback.messageArrived(packet.TopicName, packet.Data, 1,
                           packet.Flags.Retain, packet.MsgId):
            self.puback.MsgId = packet.MsgId
            self.socket.send(self.puback.pack())
      elif packet.Flags.QoS == 2:
        self.inMsgs[packet.MsgId] = packet
        self.pubrec.MsgId = packet.MsgId
        self.socket.send(self.pubrec.pack())

    else:
      raise Exception("Unexpected packet"+str(packet))
    return packet