def __tcpEstablishConnection(self, serverIp):
"""Establishes a TCP connection by doing a handshake with
the server."""
clientPort = random.randint(1025, 65530)
# Sends a SYN message to establish connection
segment = TcpSegment("", clientPort, self.ircPort)
segment.setSYN()
datagram = IpDatagram(segment, self.ipAddr, serverIp)
datagram.setId(self.__nextPacketId())
self.link.putTargetQueue(datagram)
packet = self.netQueue.get()
# Receives packet containing server's SYN
segment = TcpSegment("", clientPort, self.ircPort)
segment.setAckNumber(packet.getSegment().getAckNumber())
segment.setACK()
segment.setSeqNumber(1)
segment.setSeqNumber(1)
datagram = IpDatagram(segment, self.ipAddr, packet.getOriginIp())
self.netQueue.task_done()
datagram.setId(self.__nextPacketId())
self.link.putTargetQueue(datagram)
# Defines the randomized client port number
self.application.setClientPort(clientPort)
def __tcpEstablishConnection(self, serverIp):
"""Establishes a TCP connection by doing a handshake with
the server."""
clientPort = random.randint(1025, 65530)
# Sends a SYN message to establish connection
segment = TcpSegment("", clientPort, self.ircPort)
segment.setSYN()
datagram = IpDatagram(segment, self.ipAddr, serverIp)
datagram.setId(self.__nextPacketId())
self.link.putTargetQueue(datagram)
packet = self.netQueue.get()
# Receives packet containing server's SYN
segment = TcpSegment("", clientPort, self.ircPort)
segment.setAckNumber(packet.getSegment().getAckNumber())
segment.setACK()
segment.setSeqNumber(1)
segment.setSeqNumber(1)
datagram = IpDatagram(segment, self.ipAddr, packet.getOriginIp())
self.netQueue.task_done()
datagram.setId(self.__nextPacketId())
self.link.putTargetQueue(datagram)
# Defines the randomized client port number
self.application.setClientPort(clientPort)
def __dnsConnect(self, name):
"""Connects to the DNS server to obtain the given name's
corresponding IP."""
segment = UdpSegment(name, 2000, self.dnsPort)
datagram = IpDatagram(segment, self.ipAddr, self.dnsAddr)
datagram.setId(self.__nextPacketId())
self.link.putTargetQueue(datagram)
packet = self.netQueue.get()
ip = packet.getSegment().getMessage().split(',')[1]
self.netQueue.task_done()
return ip
def __dnsConnect(self, name):
"""Connects to the DNS server to obtain the given name's
corresponding IP."""
segment = UdpSegment(name, 2000, self.dnsPort)
datagram = IpDatagram(segment, self.ipAddr, self.dnsAddr)
datagram.setId(self.__nextPacketId())
self.link.putTargetQueue(datagram)
packet = self.netQueue.get()
ip = packet.getSegment().getMessage().split(',')[1]
self.netQueue.task_done()
return ip
def __tcpCloseConnection(self, finalPacket):
"""Close TCP connection by doing a handshake with
the server."""
serverIp = finalPacket.getDestinationIp()
clientPort = finalPacket.getSegment().getOriginPort()
# Sends a FIN/ACK message to close connection
packet = self.netQueue.get()
# Receives packet containing server's SYN
segment = TcpSegment("", clientPort, self.ircPort)
segment.setAckNumber(packet.getSegment().getAckNumber())
segment.setACK()
segment.setSeqNumber(packet.getSegment().getAckNumber())
segment.setAckNumber(packet.getSegment().getSeqNumber() + 1)
datagram = IpDatagram(segment, self.ipAddr, packet.getOriginIp())
self.netQueue.task_done()
datagram.setId(self.__nextPacketId())
self.link.putTargetQueue(datagram)
def __tcpCloseConnection(self, finalPacket):
"""Close TCP connection by doing a handshake with
the server."""
serverIp = finalPacket.getDestinationIp()
clientPort = finalPacket.getSegment().getOriginPort()
# Sends a FIN/ACK message to close connection
packet = self.netQueue.get()
# Receives packet containing server's SYN
segment = TcpSegment("", clientPort, self.ircPort)
segment.setAckNumber(packet.getSegment().getAckNumber())
segment.setACK()
segment.setSeqNumber(packet.getSegment().getAckNumber())
segment.setAckNumber(packet.getSegment().getSeqNumber() + 1)
datagram = IpDatagram(segment, self.ipAddr, packet.getOriginIp())
self.netQueue.task_done()
datagram.setId(self.__nextPacketId())
self.link.putTargetQueue(datagram)
