Todo List

Timeout waiting for a particular response

For instance, to conform with tcp protocol, every segment sent must be acknowledged.
- So, to test that, we need to send some segment and wait for the acknowledgment.
- But, we need wait up to 2 MSL(Maximum Segment Lifetime) ONLY.
- Then, if timeout occurs the test will fail.
- Another usage, is about testing RESET generation.

Today we need set ether address like that: ethernet.ether_atob(“00:1c:42:9d:57:c9”)
It will be pretty good better like:
- ethernet(ip_pkt_already_configured) # constructor
- ethernet.configure(ip_pkt_already_configured) # or a utility method
.

As a introducing for this idea, we need to make a overview of the tcptest internals.
at the tcptest:
- to identify a pier we use constants:
  - * self.thisside = 0
  - * self.thatside = 1
    the constants are used to configure the socket. (eg)
  - tcb.ip = { self.thisside : pcs.inet_atol(“10.211.55.210”) , self.thatside : pcs.inet_atol(“10.211.55.220”)}
    and the same constants are used to access the interface
  - tcb.output = { self.thisside : pcs.PcapConnector(“ed0”) , self.thatside : pcs.PcapConnector(“ed0”) }
- .
  Through libpcap we can connect directly with the network interface or through dump files.

So, if we would access the remote interface or access the remote dump file, so we can have the total control of the test.(eg)
- tcb.output = { self.thisside : pcs.PcapConnector(“ed0”) , self.thatside : pcs.PcapConnector(“/mnt/sshfs/pcap.dump”) }
As a example we would check if the send packet is the same received.
- (ipsyn, tcpsyn) = createsyn(self, tcb, from_, to)
- createwritepacket(self, tcb, ipsyn, tcpsyn, from_, to)
- (ipsynreceived, tcpsynreceived) = receive(self, tcb, to, from_) # NOTICE TO AND FROM_ SWITCHED
- assertEqual(ipsyn, ipsynreceived, 'the fail warn')
- For the complete understanding see the receive method
- def receive(self, tcb, from_, to):
  - “”“receive packet for this socket
  - This method must handle timmers”“”
  - (ip, tcp) = (None, None)
  - while 1:
    - reply = tcb.output[ from_ ].read()
    - try:
      - packet = ethernet.ethernet(reply)
      - ip = packet.data
      - tcp = ip.data
      - if (tcb.ip[ from_ ]==ip.dst and \
      - tcb.ip[ to ]==ip.src and \
      - tcb.tcpport[ from_ ]==tcp.dport and \
      - tcb.tcpport[ to ]==tcp.sport):
        
        break
    - except:
      - print “packet ignored”
      - pass