add iptables unit test infrastructure

This patch adds a python script to verify unit test cases.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/iptables-test.py b/iptables-test.py
new file mode 100755 (executable)
index 0000000..9e137f8
--- /dev/null
+++ b/iptables-test.py
@@ -0,0 +1,311 @@
+#!/usr/bin/python
+#
+# (C) 2012-2013 by Pablo Neira Ayuso <pablo@netfilter.org>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This software has been sponsored by Sophos Astaro <http://www.sophos.com>
+#
+
+import sys
+import os
+import subprocess
+import argparse
+
+IPTABLES = "iptables"
+IP6TABLES = "ip6tables"
+#IPTABLES = "xtables -4"
+#IP6TABLES = "xtables -6"
+
+IPTABLES_SAVE = "iptables-save"
+IP6TABLES_SAVE = "ip6tables-save"
+#IPTABLES_SAVE = ['xtables-save','-4']
+#IP6TABLES_SAVE = ['xtables-save','-6']
+
+EXTENSIONS_PATH = "extensions"
+LOGFILE="/tmp/iptables-test.log"
+log_file = None
+
+
+class Colors:
+    HEADER = '\033[95m'
+    BLUE = '\033[94m'
+    GREEN = '\033[92m'
+    YELLOW = '\033[93m'
+    RED = '\033[91m'
+    ENDC = '\033[0m'
+
+
+def print_error(reason, filename=None, lineno=None):
+    '''
+    Prints an error with nice colors, indicating file and line number.
+    '''
+    print (filename + ": " + Colors.RED + "ERROR" +
+        Colors.ENDC + ": line %d (%s)" % (lineno, reason))
+
+
+def delete_rule(iptables, rule, filename, lineno):
+    '''
+    Removes an iptables rule
+    '''
+    cmd = iptables + " -D " + rule
+    ret = execute_cmd(cmd, filename, lineno)
+    if ret == 1:
+        reason = "cannot delete: " + iptables + " -I " + rule
+        print_error(reason, filename, lineno)
+        return -1
+
+    return 0
+
+
+def run_test(iptables, rule, rule_save, res, filename, lineno):
+    '''
+    Executes an unit test. Returns the output of delete_rule().
+
+    Parameters:
+    :param  iptables: string with the iptables command to execute
+    :param rule: string with iptables arguments for the rule to test
+    :param rule_save: string to find the rule in the output of iptables -save
+    :param res: expected result of the rule. Valid values: "OK", "FAIL"
+    :param filename: name of the file tested (used for print_error purposes)
+    :param lineno: line number being tested (used for print_error purposes)
+    '''
+    ret = 0
+
+    cmd = iptables + " -A " + rule
+    ret = execute_cmd(cmd, filename, lineno)
+
+    #
+    # report failed test
+    #
+    if ret:
+        if res == "OK":
+            reason = "cannot load: " + cmd
+            print_error(reason, filename, lineno)
+            return -1
+        else:
+            # do not report this error
+            return 0
+    else:
+        if res == "FAIL":
+            reason = "should fail: " + cmd
+            print_error(reason, filename, lineno)
+            delete_rule(iptables, rule, filename, lineno)
+            return -1
+
+    matching = 0
+    splitted = iptables.split(" ")
+    if len(splitted) == 2:
+        if splitted[1] == '-4':
+            command = IPTABLES_SAVE
+        elif splitted[1] == '-6':
+            command = IP6TABLES_SAVE
+    elif len(splitted) == 1:
+        if splitted[0] == IPTABLES:
+            command = IPTABLES_SAVE
+        elif splitted[0] == IP6TABLES:
+            command = IP6TABLES_SAVE
+    args = splitted[1:]
+    proc = subprocess.Popen(command, stdin=subprocess.PIPE,
+                            stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    out, err = proc.communicate()
+
+    #
+    # check for segfaults
+    #
+    if proc.returncode == -11:
+        reason = "iptables-save segfaults: " + cmd
+        print_error(reason, filename, lineno)
+        delete_rule(iptables, rule, filename, lineno)
+        return -1
+
+    # find the rule
+    matching = out.find(rule_save)
+    if matching < 0:
+        reason = "cannot find: " + iptables + " -I " + rule
+        print_error(reason, filename, lineno)
+        delete_rule(iptables, rule, filename, lineno)
+        return -1
+
+    return delete_rule(iptables, rule, filename, lineno)
+
+
+def execute_cmd(cmd, filename, lineno):
+    '''
+    Executes a command, checking for segfaults and returning the command exit
+    code.
+
+    :param cmd: string with the command to be executed
+    :param filename: name of the file tested (used for print_error purposes)
+    :param lineno: line number being tested (used for print_error purposes)
+    '''
+    global log_file
+    print >> log_file, "command: %s" % cmd
+    ret = subprocess.call(cmd, shell=True, universal_newlines=True,
+        stderr=subprocess.STDOUT, stdout=log_file)
+    log_file.flush()
+
+    # generic check for segfaults
+    if ret  == -11:
+        reason = "command segfaults: " + cmd
+        print_error(reason, filename, lineno)
+    return ret
+
+
+def run_test_file(filename):
+    '''
+    Runs a test file
+
+    :param filename: name of the file with the test rules
+    '''
+    #
+    # if this is not a test file, skip.
+    #
+    if not filename.endswith(".t"):
+        return 0, 0
+
+    if "libipt_" in filename:
+        iptables = IPTABLES
+    elif "libip6t_" in filename:
+        iptables = IP6TABLES
+    elif "libxt_"  in filename:
+        iptables = IPTABLES
+    else:
+        # default to iptables if not known prefix
+        iptables = IPTABLES
+
+    f = open(filename)
+
+    tests = 0
+    passed = 0
+    table = ""
+    total_test_passed = True
+
+    for lineno, line in enumerate(f):
+        if line[0] == "#":
+            continue
+
+        if line[0] == ":":
+            chain_array = line.rstrip()[1:].split(",")
+            continue
+
+        # external non-iptables invocation, executed as is.
+        if line[0] == "@":
+            external_cmd = line.rstrip()[1:]
+            execute_cmd(external_cmd, filename, lineno)
+            continue
+
+        if line[0] == "*":
+            table = line.rstrip()[1:]
+            continue
+
+        if len(chain_array) == 0:
+            print "broken test, missing chain, leaving"
+            sys.exit()
+
+        test_passed = True
+        tests += 1
+
+        for chain in chain_array:
+            item = line.split(";")
+            if table == "":
+                rule = chain + " " + item[0]
+            else:
+                rule = chain + " -t " + table + " " + item[0]
+
+            if item[1] == "=":
+                rule_save = chain + " " + item[0]
+            else:
+                rule_save = chain + " " + item[1]
+
+            res = item[2].rstrip()
+
+            ret = run_test(iptables, rule, rule_save,
+                           res, filename, lineno + 1)
+            if ret < 0:
+                test_passed = False
+                total_test_passed = False
+                break
+
+        if test_passed:
+            passed += 1
+
+    if total_test_passed:
+        print filename + ": " + Colors.GREEN + "OK" + Colors.ENDC
+
+    f.close()
+    return tests, passed
+
+
+def show_missing():
+    '''
+    Show the list of missing test files
+    '''
+    file_list = os.listdir(EXTENSIONS_PATH)
+    testfiles = [i for i in file_list if i.endswith('.t')]
+    libfiles = [i for i in file_list
+                if i.startswith('lib') and i.endswith('.c')]
+
+    def test_name(x):
+        return x[0:-2] + '.t'
+    missing = [test_name(i) for i in libfiles
+               if not test_name(i) in testfiles]
+
+    print '\n'.join(missing)
+
+
+#
+# main
+#
+def main():
+    parser = argparse.ArgumentParser(description='Run iptables tests')
+    parser.add_argument('filename', nargs='?',
+                        metavar='path/to/file.t',
+                        help='Run only this test')
+    parser.add_argument('-m', '--missing', action='store_true',
+                        help='Check for missing tests')
+    args = parser.parse_args()
+
+    #
+    # show list of missing test files
+    #
+    if args.missing:
+        show_missing()
+        return
+
+    if os.getuid() != 0:
+        print "You need to be root to run this, sorry"
+        return
+
+    test_files = 0
+    tests = 0
+    passed = 0
+
+    # setup global var log file
+    global log_file
+    try:
+        log_file = open(LOGFILE, 'w')
+    except IOError:
+        print "Couldn't open log file %s" % LOGFILE
+        return
+
+    file_list = [os.path.join(EXTENSIONS_PATH, i)
+                 for i in os.listdir(EXTENSIONS_PATH)]
+    if args.filename:
+        file_list = [args.filename]
+    for filename in file_list:
+        file_tests, file_passed = run_test_file(filename)
+        if file_tests:
+            tests += file_tests
+            passed += file_passed
+            test_files += 1
+
+    print ("%d test files, %d unit tests, %d passed" %
+           (test_files, tests, passed))
+
+
+if __name__ == '__main__':
+    main()