1import os
  2import signal
  3from string import Template
  4import subprocess
  5import time
  6from TdcPlugin import TdcPlugin
  7
  8from tdc_config import *
  9
 10class SubPlugin(TdcPlugin):
 11    def __init__(self):
 12        self.sub_class = 'ns/SubPlugin'
 13        super().__init__()
 14
 15    def pre_suite(self, testcount, testidlist):
 16        '''run commands before test_runner goes into a test loop'''
 17        super().pre_suite(testcount, testidlist)
 18
 19        if self.args.namespace:
 20            self._ns_create()
 21        else:
 22            self._ports_create()
 23
 24    def post_suite(self, index):
 25        '''run commands after test_runner goes into a test loop'''
 26        super().post_suite(index)
 27        if self.args.verbose:
 28            print('{}.post_suite'.format(self.sub_class))
 29
 30        if self.args.namespace:
 31            self._ns_destroy()
 32        else:
 33            self._ports_destroy()
 34
 35    def add_args(self, parser):
 36        super().add_args(parser)
 37        self.argparser_group = self.argparser.add_argument_group(
 38            'netns',
 39            'options for nsPlugin(run commands in net namespace)')
 40        self.argparser_group.add_argument(
 41            '-N', '--no-namespace', action='store_false', default=True,
 42            dest='namespace', help='Don\'t run commands in namespace')
 43        return self.argparser
 44
 45    def adjust_command(self, stage, command):
 46        super().adjust_command(stage, command)
 47        cmdform = 'list'
 48        cmdlist = list()
 49
 50        if not self.args.namespace:
 51            return command
 52
 53        if self.args.verbose:
 54            print('{}.adjust_command'.format(self.sub_class))
 55
 56        if not isinstance(command, list):
 57            cmdform = 'str'
 58            cmdlist = command.split()
 59        else:
 60            cmdlist = command
 61        if stage == 'setup' or stage == 'execute' or stage == 'verify' or stage == 'teardown':
 62            if self.args.verbose:
 63                print('adjust_command:  stage is {}; inserting netns stuff in command [{}] list [{}]'.format(stage, command, cmdlist))
 64            cmdlist.insert(0, self.args.NAMES['NS'])
 65            cmdlist.insert(0, 'exec')
 66            cmdlist.insert(0, 'netns')
 67            cmdlist.insert(0, self.args.NAMES['IP'])
 68        else:
 69            pass
 70
 71        if cmdform == 'str':
 72            command = ' '.join(cmdlist)
 73        else:
 74            command = cmdlist
 75
 76        if self.args.verbose:
 77            print('adjust_command:  return command [{}]'.format(command))
 78        return command
 79
 80    def _ports_create(self):
 81        cmd = '$IP link add $DEV0 type veth peer name $DEV1'
 82        self._exec_cmd('pre', cmd)
 83        cmd = '$IP link set $DEV0 up'
 84        self._exec_cmd('pre', cmd)
 85        if not self.args.namespace:
 86            cmd = '$IP link set $DEV1 up'
 87            self._exec_cmd('pre', cmd)
 88
 89    def _ports_destroy(self):
 90        cmd = '$IP link del $DEV0'
 91        self._exec_cmd('post', cmd)
 92
 93    def _ns_create(self):
 94        '''
 95        Create the network namespace in which the tests will be run and set up
 96        the required network devices for it.
 97        '''
 98        self._ports_create()
 99        if self.args.namespace:
100            cmd = '$IP netns add {}'.format(self.args.NAMES['NS'])
101            self._exec_cmd('pre', cmd)
102            cmd = '$IP link set $DEV1 netns {}'.format(self.args.NAMES['NS'])
103            self._exec_cmd('pre', cmd)
104            cmd = '$IP -n {} link set $DEV1 up'.format(self.args.NAMES['NS'])
105            self._exec_cmd('pre', cmd)
106            if self.args.device:
107                cmd = '$IP link set $DEV2 netns {}'.format(self.args.NAMES['NS'])
108                self._exec_cmd('pre', cmd)
109                cmd = '$IP -n {} link set $DEV2 up'.format(self.args.NAMES['NS'])
110                self._exec_cmd('pre', cmd)
111
112    def _ns_destroy(self):
113        '''
114        Destroy the network namespace for testing (and any associated network
115        devices as well)
116        '''
117        if self.args.namespace:
118            cmd = '$IP netns delete {}'.format(self.args.NAMES['NS'])
119            self._exec_cmd('post', cmd)
120
121    def _exec_cmd(self, stage, command):
122        '''
123        Perform any required modifications on an executable command, then run
124        it in a subprocess and return the results.
125        '''
126        if '$' in command:
127            command = self._replace_keywords(command)
128
129        self.adjust_command(stage, command)
130        if self.args.verbose:
131            print('_exec_cmd:  command "{}"'.format(command))
132        proc = subprocess.Popen(command,
133            shell=True,
134            stdout=subprocess.PIPE,
135            stderr=subprocess.PIPE,
136            env=ENVIR)
137        (rawout, serr) = proc.communicate()
138
139        if proc.returncode != 0 and len(serr) > 0:
140            foutput = serr.decode("utf-8")
141        else:
142            foutput = rawout.decode("utf-8")
143
144        proc.stdout.close()
145        proc.stderr.close()
146        return proc, foutput
147
148    def _replace_keywords(self, cmd):
149        """
150        For a given executable command, substitute any known
151        variables contained within NAMES with the correct values
152        """
153        tcmd = Template(cmd)
154        subcmd = tcmd.safe_substitute(self.args.NAMES)
155        return subcmd