OpenFlow Testing Framework
March, 2010

Copyright (c) 2010 The Board of Trustees of The Leland Stanford 
Junior University

Warning
+++++++

This is still experimental and it requires root privilege to
control the dataplane ports.  As a consequence, there may be
risks to the machine on which this is running.  Use caution.

Please see Helpful Notes below.

License
+++++++

The software included with this distribution is subject to the
OpenFlow Switching License as given in the included file LICENSE.
Details are also available at:

    http://www.openflow.org/wp/legal

Other software referenced in this distribution is subject to its
respective license.

Introduction
++++++++++++

    This test framework is meant to exercise a candidate OpenFlow
    switch (the device/switch under test, DUT or SUT).  It provides a
    connection like a controller to which the switch connects and it 
    controls data plane ports, sending and receiving packets, which 
    should be connected to the switch.

    There are two parts to running the test framework:

    * Building the python libraries that support the OF protocol
    * Running oft, the main entry point of the test framework

    Normally log output from oft is sent to the file oft.log, but
    can be redirected to the console by specifying --log-file="".
 
Quick Start
+++++++++++

    You need to have Python setup tools and Scapy installed on your
    system.  See 'Pre-requisites' below.

    Make sure your switch is running and trying to connect to a
    controller on the machine where you're running oft (normally port
    6633).  See below regarding run_switch.py for a script that starts 
    up a software switch on the test host.

    Currently, switches must be running version 1.0 of OpenFlow. 

      # git clone yuba:/usr/local/git/openflow-projects/oftest
      # cd oftest/tools/munger
      # make install
      # cd ../../tests
         Make sure the switch you want to test is running --
         see (4) below for the reference switch example.
      # ./oft --list
      # sudo ./oft
      # sudo ./oft --verbose --log-file=""    
      # sudo ./oft --test-spec=<mod> --platform=remote --host=...

Longer Start
++++++++++++

    1.  Pre-requisites:
        * An OF switch instance to test (see 4 below)
        * Root privilege on host running oft
        * Switch running OpenFlow 1.0 and attempting to connect 
          to a controller on the machine running oft.
        * Python 2.5.  You can run platforms using eth interfaces
          with Python 2.4.
        * Python setup tools (e.g.: sudo apt-get install python-setuptools)
        * oftest checked out (called <oftest> here)
        * scapy installed:  http://www.secdev.org/projects/scapy/
          'sudo apt-get install scapy' should work on Debian.
        * tcpdump installed (optional, but scapy will complain if it's
          not there)
        * Doxygen and doxypy for document generation (optional)
        * lint for source checking (optional)

    2.  Build the OpenFlow Python message classes

        Important:  The OF version used by the controller is based on 
        the file in <oftest>/tools/pylibopenflow/include/openflow.h
        This is currently the 1.0 release file.

        cd <oftest>/tools/munger
        make install

        This places files in <oftest>/src/python/oftest/src and then
        calls setuptools to install on the local host

    3.  Edit configuration if necessary
        Local platforms work with veth interface pairs and default to
        four ports.  You can adjust this a bit with the command line
        parameters port_count, base_of_port and base_if_index.
 
        Starting from remote.py as a simple example, you can add your
        own <platform>.py file and then have it imported with
        --platform=<platform> on the command line.  This is meant to 
        allow you to test remote switches attempting to connect to a
        controller on a network accessible to the test host.

    4.  Start the switch to test
        The switch must be running and actively attempting to 
        connect to a controller on the test host at the port number
        used by oft (6633 by default, or specified as --port=<n> as
        an argument to oft).

        If you're new to the test environment and want to check its 
        sanity, you can do the following.  This requires that
        your host kernel supports virtual ethernet interfaces.  This
        is best done in a window separate from where you will run oft.
 
        4A. Check out openflow (preferably at the same level as oftest):
            git clone git://openflowswitch.org/openflow.git
        4B. cd openflow; ./boot.sh; ./configure; make
        4C. cd ../oftest/tests
        4D. Run the switch startup script:
            sudo ./run_switch.py; Now you can run oft (see below).
        4F. Use --help to see command line switches.  If you use a port
            number other than the default, make sure you use the same
            one for the switch as for oft.
        4E. Use control-C to terminate the switch daemons.
        4F. To clean up the virtual ethernet interfaces, use
            sudo rmmod veth

    5.  Run oft
        See Warning above; requires sudo to control the dataplane
        cd <oftest>/tests
        sudo ./oft --help

Helpful Note: Rebuilding
++++++++++++++++++++++++

If you ever make a change to the code in src/oftest/python...
you must rebuild and reinstall the source code.  See Step (2)
in the Longer Start above.

If you see

    WARNING:..:Could not import file ...

There is likely a Python error in the file.  Try invoking the
Python cli directly and importing the file to get more information.

Helpful Note: Recovering From Crash
+++++++++++++++++++++++++++++++++++

If the test script, oft, becomes unresponsive, you may find that ^C 
does not break out of the script.  In this case you have two options:  

* Use ^Z to interrupt the script and return to the shell prompt.
* Start another terminal window to the same machine.

In either case, you then need to kill the process that is hung.  Use 
the following commands:

    me@host> ps aux | grep oft
    root         4  0.0      S<   Jul07   0:00 [ksoftirqd/0]
    ...
    root     14066  3.2      Tl   09:27   0:00 python ./oft ...
    me       14074  0.0      R+   09:28   0:00 grep oft
    
    me@host> sudo kill -9 14066

where 14066 is the process ID of the hung process.  (Replace it with 
the PID for your process.)

This is still preliminary work and there are bugs in the 
framework that need to be ironed out.  Please report any issues
to dtalayco@stanford.edu.


OFT Command Line Options
++++++++++++++++++++++++

    Here is a summary of the oft command line options.  Use --help to see
    the long and short command option names.

    platform          : String identifying the target platform
    controller_host   : Host on which test controller is running (for sockets)
    controller_port   : Port on which test controller listens for switch cxn
    port_count        : Number of ports in dataplane
    base_of_port      : Base OpenFlow port number in dataplane
    base_if_index     : Base OS network interface for dataplane
    test_dir          : Directory to search for test files (default .)
    test_spec         : Specification of test(s) to run
    log_file          : Filename for test logging
    list              : Boolean:  List all tests and exit
    debug             : String giving debug level (info, warning, error...)
    verbose           : Same as debug=verbose

Overview
++++++++

    The directory structure is currently:

     <oftest>
         `
         |-- doc
         |-- src
         |   `-- python
         |       `-- oftest
         |-- tests
         |   `-- oft and files with test cases
         `-- tools
             |-- munger
             `-- pylibopenflow

    The tools directory is what processes the OpenFlow header
    files to produce Python classes representing OpenFlow messages.
    The results are placed in src/python/oftest and currently
    include:

        message.py:      The main API providing OF message classes
        error.py:        Subclasses for error messages
        action.py:       Subclasses for action specification
        cstruct.py:      Direct representation of C structures in Python
        class_maps.py:   Addition info about C structures

    In addition, the following Python files are present in 
    src/python/oftest:

        controller.py:   The controller representation
        dataplane.py:    The dataplane representation
        action_list.py:  Action list class
        netutils.py:     e.g., set promisc on sockets
        ofutils.py:      Utilities related to OpenFlow messages
        oft_assert.py:   Test framework level assertion

    Tests are run from the tests directory.  The file oft is the
    top level entry point for tests.  Try ./oft --help for some more.

Important Notes
+++++++++++++++

    1.  If you edit any of the files in src/python/oftest or any of the
    scripts in tools/munger/scripts, you MUST re-run make install.  This
    is easy to forget.

    2.  If your running into issues with transactions, and it appears that
    OpenFlow messages aren't quite right, start by looking at any length
    fields in the packets.  With the local platform, you can use wireshark
    on the loopback interface as well as the dataplane veth interfaces.

Adding Your Own Test Cases
++++++++++++++++++++++++++

    You can:

        * Add cases to an existing file
        * Add a new file

    If you add cases to an existing file, each case should be its own
    class.  It must inherit from unittest.TestCase or one of its 
    derivatives and define runTest (that's how test cases are discovered).

    If you add a new file, it must implement a top level function called
    test_set_init which takes a configuration dictionary.  See basic.py
    for an example.  The main point of this is to pass the port map 
    object to the test cases.  But you can access any configuration
    parameters this way.  Each test case in the new file must derive
    from unittest.TestCase.

    CONVENTIONS:

    The first line of the doc string for a file and for a test class is 
    displayed in the list command.  Please keep it clear and under 50
    characters.


Using CentOS/RHEL
+++++++++++++++++

    CentOS/RHEL have two challenges:  they are very tied to Python 2.4
    (and Scapy requires Python 2.5 for its latest version) and they
    require a kernel upgrade to use veth pairs for local platform
    testing.  

    If you only need to control eth interfaces for a remote platform,
    you can use CentOS/RHEL without major disruption.  The key is to 
    download scapy-1.2 from the following link:

    wget http://hg.secdev.org/scapy/raw-file/v1.2.0.2/scapy.py

    See: http://www.dirk-loss.de/scapy-doc/installation.html#installing-scapy-v1-2
    for more info.

    Copy scapy.py to /usr/lib/python2.4/site-packages

    If you hit an error related to importing scapy.all, you just need
    to change the import to refer to scapy (not scapy.all).  See
    examples in parse.py for example.


Other Info
++++++++++

    * Build doc with
      + cd <oftest>/tools/munger
      + make doc
    Places the results in <oftest>/doc/html

    * Run lint on sources
      + cd <oftest>/tools/munger
      + make lint
    Places results in <oftest>/lint/*.log
    The file controller.log currently has some errors indicated


To Do
+++++

    * Need to have an overview of the components of the test, how they
      connect and how they are managed by the test framework.
    * See the Regression Test component on trac:
      http://www.openflowswitch.org/bugs/openflow
      http://www.openflowswitch.org/bugs/openflow/query?component=Regression+test+suite

    * Make the framework work with OF versions other than 1.0?