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OFTestReadme
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OpenFlow Testing Framework July, 2010
Copyright (c) 2010 The Board of Trustees of The Leland Stanford Junior University
Contents |
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.
Getting OFTest
You can check out OFTest with git with the following command: git clone git://openflow.org/oftest Releases may also be available at http://openflow.org/oftest
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 git://openflow.org/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 python-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://gitosis.stanford.edu/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
Check the online tutorial:
http://openflow.org/wk/index.php/OFTestTutorial
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
If you have problems, check the install location doxypy.py and
that it is set correctly in <oftest>/doc/Doxyfile
* 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.openflow.org/bugs/openflow
http://www.openflow.org/bugs/openflow/query?component=Regression+test+suite
* Make the framework work with OF versions other than 1.0?
Quick Navigation
OpenFlow White Paper
Download the OpenFlow Whitepaper (PDF)
OpenFlow Specification
Download v1.1.0 Implemented (PDF)