tcptest/USING at master · bilouro/tcptest · GitHub

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== Using tcptest ==
=== Directories ===
 . doc any doc file (rfc, source documentation)

 . src any source file

 . src/others some test driven development milestones

 . src/pcs packet construction set from ports with some merges from current

 . src/scripts any tcptest script

 . src/scripts/fastners any script to call others in order to make it fast

 . src/scripts/tests any unittest script (conformance or regression test)

=== Script by script ===
 . tcpconnect.py This script make three way handshake(3wh), it's a raw one-method script. It was the first functional file, made to understand the tcp/ip 3wh and connection finalization. Serveral prints on screen for a better following of packet exchanged.

 . fasteners/tcpconnect.sh Calls tcpconnect with args.

 . tests/cthreewayhandshake_nooptions.py tcpconnect.py adapted to unittest. Code was refactured, removed duplicated code, several methods acting as utils created.

 . tests/c3waywithoutoptions.py first script using tcptest.py. Now code calls tcptest module, more readable and mature code.

 . tests/tcptest.py tcptest module. (detailed in the next section)

 . tests/csynbroadcast.py Sends a syn to ip broadcast addr, but to a specific MAC.

 . tests/cresetfromclosedstate.py Establish a conn, set DUT to make active close, wait 2MSL, and inject syn with the same finalized sequence number. rst and fin are also tested.

 . tests/cresetFromNonSyncState.py resetTcp created. tcptest.threewayhandshakenoopt created. (a)Make 3wh and then sends an out of window ack. (b)with connection established start active close and then sends an out of window ack

 . tests/cresetFromSyncState.py (a)Send an out of order acknowledgment, without any previous messages. (b)send an out of order acknowledgment at SYN_RECEIVE DUT's status.

=== tcptest module (main) ===

 . assertAcknowledgmentPresent assert that ack_number is different from None and greater then 0.

 . assertSequencePresent assert that sequence is different from None and greater then 0.

 . assertExpectedSequence assert receive segments carries the expected sequence number.

 . assertExpectedAcknowledgment assert receive segments carries the expected ack_number.

 . assertSequenceAcknowledgmentOK calls assertAcknowledgmentPresent, assertSequencePresent, assertExpectedSequence, assertExpectedAcknowledgment

 . assertSynPresent assert syn bit is set.

 . assertReset assert rst bit is set.

 . assertFin assert fin bit is set.

 . createip create ip packet. Using tcb this method set all basic ip attributes automatically.

 . createtcp create tcp segment (called by createip). Using tcb this method set all basic tcp attributes automatically.

 . createethernet create ethernet frame.

 . createwritepacket Calls (a)createethernet, set ip to ethernet packet and write bytes to network device.

 . receive Receive packet for specific tcb.

 . createsyn Calls create ip then set syn flag.

 . createfin Calls create ip then set fin flag.

 . createrstfromreceivedtcp Create and reset segment according rfc.

 . createfakerstfromtcb Resets a not received segment.

 . createoutofwindowack Create an ack out of current window.

 . threewayhandshakenoopt Calls createsyn, createwritepacket(syn sent), receive(ack+syn), createip(ack)

 . closeconnection Sends a fin, expect ack+fin(together or not) then send ack

 . passivecloseconnection Expect a fin, send ack+fin and expect an ack.

 . tcp_cksum  Calcs tcp check sum

 . ip_cksum Calcs ip check sum

=== DUT - The Device Under Test ===
 . I'm using a virtual machine to make my tests, for both DUT and Testing Station. To make the testes I turned inetd server on as following:
  1. uncomment following line, to start discard server. Its start a socket that discards every data received. port #9
   . discard stream  tcp     nowait  root    internal
  1. force inetd server start: /etc/rc.d/inetd forcestart

=== Testing Station ===
 . Machine where pcs and tcptest runs.  To make the tests we need set:
  1. sysctl net.inet.tcp.blackhole=2
  1. sysctl net.inet.tcp.log_debug=1 (useful to detect errors of packet creation, also ck_sum)

=== Legends ===
 . 3wh - Three way handshake
 . DUT - Device Under Test
 . Testing Station - where the tests are executed