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diff --git a/tools/testing/selftests/tc-testing/README b/tools/testing/selftests/tc-testing/README new file mode 100644 index 000000000..b0954c873 --- /dev/null +++ b/tools/testing/selftests/tc-testing/README @@ -0,0 +1,257 @@ +tdc - Linux Traffic Control (tc) unit testing suite + +Author: Lucas Bates - lucasb@mojatatu.com + +tdc is a Python script to load tc unit tests from a separate JSON file and +execute them inside a network namespace dedicated to the task. + + +REQUIREMENTS +------------ + +* Minimum Python version of 3.4. Earlier 3.X versions may work but are not + guaranteed. + +* The kernel must have network namespace support if using nsPlugin + +* The kernel must have veth support available, as a veth pair is created + prior to running the tests when using nsPlugin. + +* The kernel must have the appropriate infrastructure enabled to run all tdc + unit tests. See the config file in this directory for minimum required + features. As new tests will be added, config options list will be updated. + +* All tc-related features being tested must be built in or available as + modules. To check what is required in current setup run: + ./tdc.py -c + + Note: + In the current release, tdc run will abort due to a failure in setup or + teardown commands - which includes not being able to run a test simply + because the kernel did not support a specific feature. (This will be + handled in a future version - the current workaround is to run the tests + on specific test categories that your kernel supports) + + +BEFORE YOU RUN +-------------- + +The path to the tc executable that will be most commonly tested can be defined +in the tdc_config.py file. Find the 'TC' entry in the NAMES dictionary and +define the path. + +If you need to test a different tc executable on the fly, you can do so by +using the -p option when running tdc: + ./tdc.py -p /path/to/tc + + +RUNNING TDC +----------- + +To use tdc, root privileges are required. This is because the +commands being tested must be run as root. The code that enforces +execution by root uid has been moved into a plugin (see PLUGIN +ARCHITECTURE, below). + +Tests that use a network device should have nsPlugin.py listed as a +requirement for that test. nsPlugin executes all commands within a +network namespace and creates a veth pair which may be used in those test +cases. To disable execution within the namespace, pass the -N option +to tdc when starting a test run; the veth pair will still be created +by the plugin. + +Running tdc without any arguments will run all tests. Refer to the section +on command line arguments for more information, or run: + ./tdc.py -h + +tdc will list the test names as they are being run, and print a summary in +TAP (Test Anything Protocol) format when they are done. If tests fail, +output captured from the failing test will be printed immediately following +the failed test in the TAP output. + + +OVERVIEW OF TDC EXECUTION +------------------------- + +One run of tests is considered a "test suite" (this will be refined in the +future). A test suite has one or more test cases in it. + +A test case has four stages: + + - setup + - execute + - verify + - teardown + +The setup and teardown stages can run zero or more commands. The setup +stage does some setup if the test needs it. The teardown stage undoes +the setup and returns the system to a "neutral" state so any other test +can be run next. These two stages require any commands run to return +success, but do not otherwise verify the results. + +The execute and verify stages each run one command. The execute stage +tests the return code against one or more acceptable values. The +verify stage checks the return code for success, and also compares +the stdout with a regular expression. + +Each of the commands in any stage will run in a shell instance. + + +USER-DEFINED CONSTANTS +---------------------- + +The tdc_config.py file contains multiple values that can be altered to suit +your needs. Any value in the NAMES dictionary can be altered without affecting +the tests to be run. These values are used in the tc commands that will be +executed as part of the test. More will be added as test cases require. + +Example: + $TC qdisc add dev $DEV1 ingress + +The NAMES values are used to substitute into the commands in the test cases. + + +COMMAND LINE ARGUMENTS +---------------------- + +Run tdc.py -h to see the full list of available arguments. + +usage: tdc.py [-h] [-p PATH] [-D DIR [DIR ...]] [-f FILE [FILE ...]] + [-c [CATG [CATG ...]]] [-e ID [ID ...]] [-l] [-s] [-i] [-v] [-N] + [-d DEVICE] [-P] [-n] [-V] + +Linux TC unit tests + +optional arguments: + -h, --help show this help message and exit + -p PATH, --path PATH The full path to the tc executable to use + -v, --verbose Show the commands that are being run + -N, --notap Suppress tap results for command under test + -d DEVICE, --device DEVICE + Execute test cases that use a physical device, where + DEVICE is its name. (If not defined, tests that require + a physical device will be skipped) + -P, --pause Pause execution just before post-suite stage + +selection: + select which test cases: files plus directories; filtered by categories + plus testids + + -D DIR [DIR ...], --directory DIR [DIR ...] + Collect tests from the specified directory(ies) + (default [tc-tests]) + -f FILE [FILE ...], --file FILE [FILE ...] + Run tests from the specified file(s) + -c [CATG [CATG ...]], --category [CATG [CATG ...]] + Run tests only from the specified category/ies, or if + no category/ies is/are specified, list known + categories. + -e ID [ID ...], --execute ID [ID ...] + Execute the specified test cases with specified IDs + +action: + select action to perform on selected test cases + + -l, --list List all test cases, or those only within the + specified category + -s, --show Display the selected test cases + -i, --id Generate ID numbers for new test cases + +netns: + options for nsPlugin (run commands in net namespace) + + -N, --no-namespace + Do not run commands in a network namespace. + +valgrind: + options for valgrindPlugin (run command under test under Valgrind) + + -V, --valgrind Run commands under valgrind + + +PLUGIN ARCHITECTURE +------------------- + +There is now a plugin architecture, and some of the functionality that +was in the tdc.py script has been moved into the plugins. + +The plugins are in the directory plugin-lib. The are executed from +directory plugins. Put symbolic links from plugins to plugin-lib, +and name them according to the order you want them to run. This is not +necessary if a test case being run requires a specific plugin to work. + +Example: + +bjb@bee:~/work/tc-testing$ ls -l plugins +total 4 +lrwxrwxrwx 1 bjb bjb 27 Oct 4 16:12 10-rootPlugin.py -> ../plugin-lib/rootPlugin.py +lrwxrwxrwx 1 bjb bjb 25 Oct 12 17:55 20-nsPlugin.py -> ../plugin-lib/nsPlugin.py +-rwxr-xr-x 1 bjb bjb 0 Sep 29 15:56 __init__.py + +The plugins are a subclass of TdcPlugin, defined in TdcPlugin.py and +must be called "SubPlugin" so tdc can find them. They are +distinguished from each other in the python program by their module +name. + +This base class supplies "hooks" to run extra functions. These hooks are as follows: + +pre- and post-suite +pre- and post-case +pre- and post-execute stage +adjust-command (runs in all stages and receives the stage name) + +The pre-suite hook receives the number of tests and an array of test ids. +This allows you to dump out the list of skipped tests in the event of a +failure during setup or teardown stage. + +The pre-case hook receives the ordinal number and test id of the current test. + +The adjust-command hook receives the stage id (see list below) and the +full command to be executed. This allows for last-minute adjustment +of the command. + +The stages are identified by the following strings: + + - pre (pre-suite) + - setup + - command + - verify + - teardown + - post (post-suite) + + +To write a plugin, you need to inherit from TdcPlugin in +TdcPlugin.py. To use the plugin, you have to put the +implementation file in plugin-lib, and add a symbolic link to it from +plugins. It will be detected at run time and invoked at the +appropriate times. There are a few examples in the plugin-lib +directory: + + - rootPlugin.py: + implements the enforcement of running as root + - nsPlugin.py: + sets up a network namespace and runs all commands in that namespace, + while also setting up dummy devices to be used in testing. + - valgrindPlugin.py + runs each command in the execute stage under valgrind, + and checks for leaks. + This plugin will output an extra test for each test in the test file, + one is the existing output as to whether the test passed or failed, + and the other is a test whether the command leaked memory or not. + (This one is a preliminary version, it may not work quite right yet, + but the overall template is there and it should only need tweaks.) + - buildebpfPlugin.py: + builds all programs in $EBPFDIR. + + +ACKNOWLEDGEMENTS +---------------- + +Thanks to: + +Jamal Hadi Salim, for providing valuable test cases +Keara Leibovitz, who wrote the CLI test driver that I used as a base for the + first version of the tc testing suite. This work was presented at + Netdev 1.2 Tokyo in October 2016. +Samir Hussain, for providing help while I dove into Python for the first time + and being a second eye for this code. |