#!/usr/bin/python3

import os
import sys
import time
import unittest
import tempfile
import subprocess


class TestNetworkd(unittest.TestCase):
    @classmethod
    def setUp(self):
        self.iface = 'test_eth42'
        self.if_router = 'router_eth42'
        self.dnsmasq = None
        self.workdir_obj = tempfile.TemporaryDirectory()
        self.workdir = self.workdir_obj.name
        self.config = '/run/systemd/network/test_eth42.network'
        os.makedirs(os.path.dirname(self.config), exist_ok=True)

        # avoid "Failed to open /dev/tty" errors in containers
        os.environ['SYSTEMD_LOG_TARGET'] = 'journal'

    def tearDown(self):
        self.shutdown_iface()
        if os.path.exists(self.config):
            os.unlink(self.config)
        subprocess.call(['systemctl', 'stop', 'systemd-networkd'])

    def create_iface(self, ipv6=False):
        '''Create test interface with DHCP server behind it'''

        # add veth pair
        subprocess.check_call(['ip', 'link', 'add', 'name', self.iface, 'type',
                               'veth', 'peer', 'name', self.if_router])

        # give our router an IP
        subprocess.check_call(['ip', 'a', 'flush', 'dev', self.if_router])
        subprocess.check_call(['ip', 'a', 'add', '192.168.5.1/24', 'dev', self.if_router])
        if ipv6:
            subprocess.check_call(['ip', 'a', 'add', '2600::1/64', 'dev', self.if_router])
        subprocess.check_call(['ip', 'link', 'set', self.if_router, 'up'])

        # add DHCP server
        self.dnsmasq_log = os.path.join(self.workdir, 'dnsmasq.log')
        lease_file = os.path.join(self.workdir, 'dnsmasq.leases')
        if ipv6:
            extra_opts = ['--enable-ra', '--dhcp-range=2600::10,2600::20']
        else:
            extra_opts = []
        self.dnsmasq = subprocess.Popen(
            ['dnsmasq', '--keep-in-foreground', '--log-queries',
             '--log-facility=' + self.dnsmasq_log, '--conf-file=/dev/null',
             '--dhcp-leasefile=' + lease_file, '--bind-interfaces',
             '--interface=' + self.if_router, '--except-interface=lo',
             '--dhcp-range=192.168.5.10,192.168.5.200'] + extra_opts)

    def shutdown_iface(self):
        '''Remove test interface and stop DHCP server'''

        if self.if_router:
            subprocess.check_call(['ip', 'link', 'del', 'dev', self.if_router])
            self.if_router = None
        if self.dnsmasq:
            self.dnsmasq.kill()
            self.dnsmasq.wait()
            self.dnsmasq = None

    def do_test(self, coldplug=True, ipv6=False):
        with open(self.config, 'w') as f:
            f.write('''[Match]
Name=%s
[Network]
DHCP=yes''' % self.iface)

        if coldplug:
            # create interface first, then start networkd
            self.create_iface(ipv6=ipv6)
            subprocess.check_call(['systemctl', 'start', 'systemd-networkd'])
        else:
            # start networkd first, then create interface
            subprocess.check_call(['systemctl', 'start', 'systemd-networkd'])
            self.create_iface(ipv6=ipv6)

        subprocess.check_call(['/lib/systemd/systemd-networkd-wait-online',
                               '--interface', self.iface, '--timeout=10'])

        try:
            if ipv6:
                # check iface state and IP 6 address; FIXME: we need to wait a bit
                # longer, as the iface is "configure" already with IPv4
                timeout = 10
                while timeout > 0:
                    out = subprocess.check_output(['ip', '-6', 'a', 'show', 'dev', self.iface])
                    if b'state UP' in out and 'scope global' in out:
                        break
                    time.sleep(1)
                    timeout -= 1

                self.assertRegex(out, b'inet6 2600::.* scope global .*dynamic')
                self.assertRegex(out, b'inet6 fe80::.* scope link')
            else:
                # should have link-local address on IPv6 only
                out = subprocess.check_output(['ip', '-6', 'a', 'show', 'dev', self.iface])
                self.assertRegex(out, b'inet6 fe80::.* scope link')
                self.assertNotIn(b'scope global', out)

            # should have IPv4 address
            out = subprocess.check_output(['ip', '-4', 'a', 'show', 'dev', self.iface])
            self.assertIn(b'state UP', out)
            self.assertRegex(out, b'inet 192.168.5.\d+/.* scope global dynamic')

            # check networkctl state
            out = subprocess.check_output(['networkctl'], universal_newlines=True)
            self.assertRegex(out, '%s\s+ether\s+routable\s+unmanaged' % self.if_router)
            self.assertRegex(out, '%s\s+ether\s+routable\s+configured' % self.iface)

            out = subprocess.check_output(['networkctl', 'status', self.iface],
                                          universal_newlines=True)
            self.assertRegex(out, 'Type:\s+ether')
            self.assertRegex(out, 'State:\s+routable.*configured')
            self.assertRegex(out, 'Address:\s+192.168.5.\d+')
            if ipv6:
                self.assertRegex(out, '2600::')
            else:
                self.assertNotIn('2600::', out)
            self.assertRegex(out, 'fe80::')
            self.assertRegex(out, 'Gateway:\s+192.168.5.1')
            self.assertRegex(out, 'DNS:\s+192.168.5.1')
        except AssertionError:
            # show dnsmasq log on failure
            with open(self.dnsmasq_log) as f:
                sys.stderr.write('\n\n----- dnsmasq log ----\n%s\n------\n' % f.read())
            raise

        # verify resolv.conf if it gets dynamically managed
        if os.path.islink('/etc/resolv.conf'):
            for timeout in range(50):
                with open('/etc/resolv.conf') as f:
                    if 'nameserver 192.168.5.1\n' in f.read():
                        break
                time.sleep(0.1)
            else:
                self.fail('nameserver 192.168.5.1 not found in /etc/resolv.conf')

        if not coldplug:
            # check post-down.d hook
            self.shutdown_iface()

    def test_coldplug_dhcp_ip4(self):
        self.do_test(coldplug=True, ipv6=False)

    def test_coldplug_dhcp_ip6(self):
        self.do_test(coldplug=True, ipv6=True)

    def test_hotplug_dhcp_ip4(self):
        self.do_test(coldplug=False, ipv6=False)

    def test_hotplug_dhcp_ip6(self):
        self.do_test(coldplug=False, ipv6=True)

if __name__ == '__main__':
    unittest.main(testRunner=unittest.TextTestRunner(stream=sys.stdout,
                                                     verbosity=2))
