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
22    def post_suite(self, index):
23        '''run commands after test_runner goes into a test loop'''
24        super().post_suite(index)
25        if self.args.verbose:
26            print('{}.post_suite'.format(self.sub_class))
27
28        if self.args.namespace:
29            self._ns_destroy()
30
31    def add_args(self, parser):
32        super().add_args(parser)
33        self.argparser_group = self.argparser.add_argument_group(
34            'netns',
35            'options for nsPlugin(run commands in net namespace)')
36        self.argparser_group.add_argument(
37            '-n', '--namespace', action='store_true',
38            help='Run commands in namespace')
39        return self.argparser
40
41    def adjust_command(self, stage, command):
42        super().adjust_command(stage, command)
43        cmdform = 'list'
44        cmdlist = list()
45
46        if not self.args.namespace:
47            return command
48
49        if self.args.verbose:
50            print('{}.adjust_command'.format(self.sub_class))
51
52        if not isinstance(command, list):
53            cmdform = 'str'
54            cmdlist = command.split()
55        else:
56            cmdlist = command
57        if stage == 'setup' or stage == 'execute' or stage == 'verify' or stage == 'teardown':
58            if self.args.verbose:
59                print('adjust_command:  stage is {}; inserting netns stuff in command [{}] list [{}]'.format(stage, command, cmdlist))
60            cmdlist.insert(0, self.args.NAMES['NS'])
61            cmdlist.insert(0, 'exec')
62            cmdlist.insert(0, 'netns')
63            cmdlist.insert(0, 'ip')
64        else:
65            pass
66
67        if cmdform == 'str':
68            command = ' '.join(cmdlist)
69        else:
70            command = cmdlist
71
72        if self.args.verbose:
73            print('adjust_command:  return command [{}]'.format(command))
74        return command
75
76    def _ns_create(self):
77        '''
78        Create the network namespace in which the tests will be run and set up
79        the required network devices for it.
80        '''
81        if self.args.namespace:
82            cmd = 'ip netns add {}'.format(self.args.NAMES['NS'])
83            self._exec_cmd('pre', cmd)
84            cmd = 'ip link add $DEV0 type veth peer name $DEV1'
85            self._exec_cmd('pre', cmd)
86            cmd = 'ip link set $DEV1 netns {}'.format(self.args.NAMES['NS'])
87            self._exec_cmd('pre', cmd)
88            cmd = 'ip link set $DEV0 up'
89            self._exec_cmd('pre', cmd)
90            cmd = 'ip -n {} link set $DEV1 up'.format(self.args.NAMES['NS'])
91            self._exec_cmd('pre', cmd)
92            if self.args.device:
93                cmd = 'ip link set $DEV2 netns {}'.format(self.args.NAMES['NS'])
94                self._exec_cmd('pre', cmd)
95                cmd = 'ip -n {} link set $DEV2 up'.format(self.args.NAMES['NS'])
96                self._exec_cmd('pre', cmd)
97
98    def _ns_destroy(self):
99        '''
100        Destroy the network namespace for testing (and any associated network
101        devices as well)
102        '''
103        if self.args.namespace:
104            cmd = 'ip netns delete {}'.format(self.args.NAMES['NS'])
105            self._exec_cmd('post', cmd)
106
107    def _exec_cmd(self, stage, command):
108        '''
109        Perform any required modifications on an executable command, then run
110        it in a subprocess and return the results.
111        '''
112        if '$' in command:
113            command = self._replace_keywords(command)
114
115        self.adjust_command(stage, command)
116        if self.args.verbose:
117            print('_exec_cmd:  command "{}"'.format(command))
118        proc = subprocess.Popen(command,
119            shell=True,
120            stdout=subprocess.PIPE,
121            stderr=subprocess.PIPE,
122            env=ENVIR)
123        (rawout, serr) = proc.communicate()
124
125        if proc.returncode != 0 and len(serr) > 0:
126            foutput = serr.decode("utf-8")
127        else:
128            foutput = rawout.decode("utf-8")
129
130        proc.stdout.close()
131        proc.stderr.close()
132        return proc, foutput
133
134    def _replace_keywords(self, cmd):
135        """
136        For a given executable command, substitute any known
137        variables contained within NAMES with the correct values
138        """
139        tcmd = Template(cmd)
140        subcmd = tcmd.safe_substitute(self.args.NAMES)
141        return subcmd
142