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, 413 insertions, 0 deletions

diff --git a/tools/testing/selftests/tc-testing/tdc.py b/tools/testing/selftests/tc-testing/tdc.py
new file mode 100755
index 000000000000..cd61b7844c0d
--- /dev/null
+++ b/tools/testing/selftests/tc-testing/tdc.py
@@ -0,0 +1,413 @@
+#!/usr/bin/env python3
+
+"""
+tdc.py - Linux tc (Traffic Control) unit test driver
+
+Copyright (C) 2017 Lucas Bates <lucasb@mojatatu.com>
+"""
+
+import re
+import os
+import sys
+import argparse
+import json
+import subprocess
+from collections import OrderedDict
+from string import Template
+
+from tdc_config import *
+from tdc_helper import *
+
+
+USE_NS = True
+
+
+def replace_keywords(cmd):
+    """
+    For a given executable command, substitute any known
+    variables contained within NAMES with the correct values
+    """
+    tcmd = Template(cmd)
+    subcmd = tcmd.safe_substitute(NAMES)
+    return subcmd
+
+
+def exec_cmd(command, nsonly=True):
+    """
+    Perform any required modifications on an executable command, then run
+    it in a subprocess and return the results.
+    """
+    if (USE_NS and nsonly):
+        command = 'ip netns exec $NS ' + command
+
+    if '$' in command:
+        command = replace_keywords(command)
+
+    proc = subprocess.Popen(command,
+        shell=True,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE)
+    (rawout, serr) = proc.communicate()
+
+    if proc.returncode != 0:
+        foutput = serr.decode("utf-8")
+    else:
+        foutput = rawout.decode("utf-8")
+
+    proc.stdout.close()
+    proc.stderr.close()
+    return proc, foutput
+
+
+def prepare_env(cmdlist):
+    """
+    Execute the setup/teardown commands for a test case. Optionally
+    terminate test execution if the command fails.
+    """
+    for cmdinfo in cmdlist:
+        if (type(cmdinfo) == list):
+            exit_codes = cmdinfo[1:]
+            cmd = cmdinfo[0]
+        else:
+            exit_codes = [0]
+            cmd = cmdinfo
+
+        if (len(cmd) == 0):
+            continue
+
+        (proc, foutput) = exec_cmd(cmd)
+
+        if proc.returncode not in exit_codes:
+            print
+            print("Could not execute:")
+            print(cmd)
+            print("\nError message:")
+            print(foutput)
+            print("\nAborting test run.")
+            ns_destroy()
+            exit(1)
+
+
+def test_runner(filtered_tests):
+    """
+    Driver function for the unit tests.
+
+    Prints information about the tests being run, executes the setup and
+    teardown commands and the command under test itself. Also determines
+    success/failure based on the information in the test case and generates
+    TAP output accordingly.
+    """
+    testlist = filtered_tests
+    tcount = len(testlist)
+    index = 1
+    tap = str(index) + ".." + str(tcount) + "\n"
+
+    for tidx in testlist:
+        result = True
+        tresult = ""
+        print("Test " + tidx["id"] + ": " + tidx["name"])
+        prepare_env(tidx["setup"])
+        (p, procout) = exec_cmd(tidx["cmdUnderTest"])
+        exit_code = p.returncode
+
+        if (exit_code != int(tidx["expExitCode"])):
+            result = False
+            print("exit:", exit_code, int(tidx["expExitCode"]))
+            print(procout)
+        else:
+            match_pattern = re.compile(str(tidx["matchPattern"]), re.DOTALL)
+            (p, procout) = exec_cmd(tidx["verifyCmd"])
+            match_index = re.findall(match_pattern, procout)
+            if len(match_index) != int(tidx["matchCount"]):
+                result = False
+
+        if result == True:
+            tresult += "ok "
+        else:
+            tresult += "not ok "
+        tap += tresult + str(index) + " " + tidx["id"] + " " + tidx["name"] + "\n"
+
+        if result == False:
+            tap += procout
+
+        prepare_env(tidx["teardown"])
+        index += 1
+
+    return tap
+
+
+def ns_create():
+    """
+    Create the network namespace in which the tests will be run and set up
+    the required network devices for it.
+    """
+    if (USE_NS):
+        cmd = 'ip netns add $NS'
+        exec_cmd(cmd, False)
+        cmd = 'ip link add $DEV0 type veth peer name $DEV1'
+        exec_cmd(cmd, False)
+        cmd = 'ip link set $DEV1 netns $NS'
+        exec_cmd(cmd, False)
+        cmd = 'ip link set $DEV0 up'
+        exec_cmd(cmd, False)
+        cmd = 'ip -s $NS link set $DEV1 up'
+        exec_cmd(cmd, False)
+
+
+def ns_destroy():
+    """
+    Destroy the network namespace for testing (and any associated network
+    devices as well)
+    """
+    if (USE_NS):
+        cmd = 'ip netns delete $NS'
+        exec_cmd(cmd, False)
+
+
+def has_blank_ids(idlist):
+    """
+    Search the list for empty ID fields and return true/false accordingly.
+    """
+    return not(all(k for k in idlist))
+
+
+def load_from_file(filename):
+    """
+    Open the JSON file containing the test cases and return them as an
+    ordered dictionary object.
+    """
+    with open(filename) as test_data:
+        testlist = json.load(test_data, object_pairs_hook=OrderedDict)
+    idlist = get_id_list(testlist)
+    if (has_blank_ids(idlist)):
+        for k in testlist:
+            k['filename'] = filename
+    return testlist
+
+
+def args_parse():
+    """
+    Create the argument parser.
+    """
+    parser = argparse.ArgumentParser(description='Linux TC unit tests')
+    return parser
+
+
+def set_args(parser):
+    """
+    Set the command line arguments for tdc.
+    """
+    parser.add_argument('-p', '--path', type=str,
+                        help='The full path to the tc executable to use')
+    parser.add_argument('-c', '--category', type=str, nargs='?', const='+c',
+                        help='Run tests only from the specified category, or if no category is specified, list known categories.')
+    parser.add_argument('-f', '--file', type=str,
+                        help='Run tests from the specified file')
+    parser.add_argument('-l', '--list', type=str, nargs='?', const="", metavar='CATEGORY',
+                        help='List all test cases, or those only within the specified category')
+    parser.add_argument('-s', '--show', type=str, nargs=1, metavar='ID', dest='showID',
+                        help='Display the test case with specified id')
+    parser.add_argument('-e', '--execute', type=str, nargs=1, metavar='ID',
+                        help='Execute the single test case with specified ID')
+    parser.add_argument('-i', '--id', action='store_true', dest='gen_id',
+                        help='Generate ID numbers for new test cases')
+    return parser
+    return parser
+
+
+def check_default_settings(args):
+    """
+    Process any arguments overriding the default settings, and ensure the
+    settings are correct.
+    """
+    # Allow for overriding specific settings
+    global NAMES
+
+    if args.path != None:
+         NAMES['TC'] = args.path
+    if not os.path.isfile(NAMES['TC']):
+        print("The specified tc path " + NAMES['TC'] + " does not exist.")
+        exit(1)
+
+
+def get_id_list(alltests):
+    """
+    Generate a list of all IDs in the test cases.
+    """
+    return [x["id"] for x in alltests]
+
+
+def check_case_id(alltests):
+    """
+    Check for duplicate test case IDs.
+    """
+    idl = get_id_list(alltests)
+    return [x for x in idl if idl.count(x) > 1]
+
+
+def does_id_exist(alltests, newid):
+    """
+    Check if a given ID already exists in the list of test cases.
+    """
+    idl = get_id_list(alltests)
+    return (any(newid == x for x in idl))
+
+
+def generate_case_ids(alltests):
+    """
+    If a test case has a blank ID field, generate a random hex ID for it
+    and then write the test cases back to disk.
+    """
+    import random
+    for c in alltests:
+        if (c["id"] == ""):
+            while True:
+                newid = str('%04x' % random.randrange(16**4))
+                if (does_id_exist(alltests, newid)):
+                    continue
+                else:
+                    c['id'] = newid
+                    break
+
+    ufilename = []
+    for c in alltests:
+        if ('filename' in c):
+            ufilename.append(c['filename'])
+    ufilename = get_unique_item(ufilename)
+    for f in ufilename:
+        testlist = []
+        for t in alltests:
+            if 'filename' in t:
+                if t['filename'] == f:
+                    del t['filename']
+                    testlist.append(t)
+        outfile = open(f, "w")
+        json.dump(testlist, outfile, indent=4)
+        outfile.close()
+
+
+def get_test_cases(args):
+    """
+    If a test case file is specified, retrieve tests from that file.
+    Otherwise, glob for all json files in subdirectories and load from
+    each one.
+    """
+    import fnmatch
+    if args.file != None:
+        if not os.path.isfile(args.file):
+            print("The specified test case file " + args.file + " does not exist.")
+            exit(1)
+        flist = [args.file]
+    else:
+        flist = []
+        for root, dirnames, filenames in os.walk('tc-tests'):
+            for filename in fnmatch.filter(filenames, '*.json'):
+                flist.append(os.path.join(root, filename))
+    alltests = list()
+    for casefile in flist:
+        alltests = alltests + (load_from_file(casefile))
+    return alltests
+
+
+def set_operation_mode(args):
+    """
+    Load the test case data and process remaining arguments to determine
+    what the script should do for this run, and call the appropriate
+    function.
+    """
+    alltests = get_test_cases(args)
+
+    if args.gen_id:
+        idlist = get_id_list(alltests)
+        if (has_blank_ids(idlist)):
+            alltests = generate_case_ids(alltests)
+        else:
+            print("No empty ID fields found in test files.")
+        exit(0)
+
+    duplicate_ids = check_case_id(alltests)
+    if (len(duplicate_ids) > 0):
+        print("The following test case IDs are not unique:")
+        print(str(set(duplicate_ids)))
+        print("Please correct them before continuing.")
+        exit(1)
+
+    ucat = get_test_categories(alltests)
+
+    if args.showID:
+        show_test_case_by_id(alltests, args.showID[0])
+        exit(0)
+
+    if args.execute:
+        target_id = args.execute[0]
+    else:
+        target_id = ""
+
+    if args.category:
+        if (args.category == '+c'):
+            print("Available categories:")
+            print_sll(ucat)
+            exit(0)
+        else:
+            target_category = args.category
+    else:
+        target_category = ""
+
+
+    testcases = get_categorized_testlist(alltests, ucat)
+
+    if args.list:
+        if (len(args.list) == 0):
+            list_test_cases(alltests)
+            exit(0)
+        elif(len(args.list > 0)):
+            if (args.list not in ucat):
+                print("Unknown category " + args.list)
+                print("Available categories:")
+                print_sll(ucat)
+                exit(1)
+            list_test_cases(testcases[args.list])
+            exit(0)
+
+    if (os.geteuid() != 0):
+        print("This script must be run with root privileges.\n")
+        exit(1)
+
+    ns_create()
+
+    if (len(target_category) == 0):
+        if (len(target_id) > 0):
+            alltests = list(filter(lambda x: target_id in x['id'], alltests))
+            if (len(alltests) == 0):
+                print("Cannot find a test case with ID matching " + target_id)
+                exit(1)
+        catresults = test_runner(alltests)
+        print("All test results: " + "\n\n" + catresults)
+    elif (len(target_category) > 0):
+        if (target_category not in ucat):
+            print("Specified category is not present in this file.")
+            exit(1)
+        else:
+            catresults = test_runner(testcases[target_category])
+            print("Category " + target_category + "\n\n" + catresults)
+
+    ns_destroy()
+
+
+def main():
+    """
+    Start of execution; set up argument parser and get the arguments,
+    and start operations.
+    """
+    parser = args_parse()
+    parser = set_args(parser)
+    (args, remaining) = parser.parse_known_args()
+    check_default_settings(args)
+
+    set_operation_mode(args)
+
+    exit(0)
+
+
+if __name__ == "__main__":
+    main()