selftests: Introduce tc testsuite

Add the beginnings of a testsuite for tc functionality in the kernel.
These are a series of unit tests that use the tc executable and verify
the success of those commands by checking both the exit codes and the
output from tc's 'show' operation.

To run the tests:
  # cd tools/testing/selftests/tc-testing
  # sudo ./tdc.py

You can specify the tc executable to use with the -p argument on the command
line or editing the 'TC' variable in tdc_config.py. Refer to the README for
full details on how to run.

The initial complement of test cases are limited mostly to tc actions. Test
cases are most welcome; see the creating-testcases subdirectory for help
in creating them.

Signed-off-by: Lucas Bates <lucasb@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 69 insertions, 0 deletions

diff --git a/tools/testing/selftests/tc-testing/creating-testcases/AddingTestCases.txt b/tools/testing/selftests/tc-testing/creating-testcases/AddingTestCases.txt
new file mode 100644
index 000000000000..4e09257bc443
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+++ b/tools/testing/selftests/tc-testing/creating-testcases/AddingTestCases.txt
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+tdc - Adding test cases for tdc
+
+Author: Lucas Bates - lucasb@mojatatu.com
+
+ADDING TEST CASES
+-----------------
+
+User-defined tests should be added by defining a separate JSON file.  This
+will help prevent conflicts when updating the repository. Refer to
+template.json for the required JSON format for test cases.
+
+Include the 'id' field, but do not assign a value. Running tdc with the -i
+option will generate a unique ID for that test case.
+
+tdc will recursively search the 'tc' subdirectory for .json files.  Any
+test case files you create in these directories will automatically be included.
+If you wish to store your custom test cases elsewhere, be sure to run tdc
+with the -f argument and the path to your file.
+
+Be aware of required escape characters in the JSON data - particularly when
+defining the match pattern. Refer to the tctests.json file for examples when
+in doubt.
+
+
+TEST CASE STRUCTURE
+-------------------
+
+Each test case has required data:
+
+id:           A unique alphanumeric value to identify a particular test case
+name:         Descriptive name that explains the command under test
+category:     A list of single-word descriptions covering what the command
+              under test is testing. Example: filter, actions, u32, gact, etc.
+setup:        The list of commands required to ensure the command under test
+              succeeds. For example: if testing a filter, the command to create
+              the qdisc would appear here.
+cmdUnderTest: The tc command being tested itself.
+expExitCode:  The code returned by the command under test upon its termination.
+              tdc will compare this value against the actual returned value.
+verifyCmd:    The tc command to be run to verify successful execution.
+              For example: if the command under test creates a gact action,
+              verifyCmd should be "$TC actions show action gact"
+matchPattern: A regular expression to be applied against the output of the
+              verifyCmd to prove the command under test succeeded. This pattern
+              should be as specific as possible so that a false positive is not
+              matched.
+matchCount:   How many times the regex in matchPattern should match. A value
+              of 0 is acceptable.
+teardown:     The list of commands to clean up after the test is completed.
+              The environment should be returned to the same state as when
+              this test was started: qdiscs deleted, actions flushed, etc.
+
+
+SETUP/TEARDOWN ERRORS
+---------------------
+
+If an error is detected during the setup/teardown process, execution of the
+tests will immediately stop with an error message and the namespace in which
+the tests are run will be destroyed. This is to prevent inaccurate results
+in the test cases.
+
+Repeated failures of the setup/teardown may indicate a problem with the test
+case, or possibly even a bug in one of the commands that are not being tested.
+
+It's possible to include acceptable exit codes with the setup/teardown command
+so that it doesn't halt the script for an error that doesn't matter. Turn the
+individual command into a list, with the command being first, followed by all
+acceptable exit codes for the command.
+