greendns_test.py

# coding: utf-8
"""Tests for the eventlet.support.greendns module"""

import os
import socket
import tempfile
import time
from dns.resolver import NoAnswer, Answer, Resolver

from eventlet.support import greendns
from eventlet.support.greendns import dns
import tests
import tests.mock


def _make_host_resolver():
    """Returns a HostResolver instance

    The hosts file will be empty but accessible as a py.path.local
    instance using the ``hosts`` attribute.
    """
    hosts = tempfile.NamedTemporaryFile()
    hr = greendns.HostsResolver(fname=hosts.name)
    hr.hosts = hosts
    hr._last_stat = 0
    return hr


class TestHostsResolver(tests.LimitedTestCase):

    def test_default_fname(self):
        hr = greendns.HostsResolver()
        assert os.path.exists(hr.fname)

    def test_readlines_lines(self):
        hr = _make_host_resolver()
        hr.hosts.write(b'line0\n')
        hr.hosts.flush()
        assert list(hr._readlines()) == ['line0']
        hr._last_stat = 0
        hr.hosts.write(b'line1\n')
        hr.hosts.flush()
        assert list(hr._readlines()) == ['line0', 'line1']
        # Test reading of varied newline styles
        hr._last_stat = 0
        hr.hosts.seek(0)
        hr.hosts.truncate()
        hr.hosts.write(b'\naa\r\nbb\r  cc  \n\n\tdd ee')
        hr.hosts.flush()
        assert list(hr._readlines()) == ['aa', 'bb', 'cc', 'dd ee']
        # Test comments, including inline comments
        hr._last_stat = 0
        hr.hosts.seek(0)
        hr.hosts.truncate()
        hr.hosts.write(b'''\
# First couple lines
# are comments.
line1
#comment
line2 # inline comment
''')
        hr.hosts.flush()
        assert list(hr._readlines()) == ['line1', 'line2']

    def test_readlines_missing_file(self):
        hr = _make_host_resolver()
        hr.hosts.close()
        hr._last_stat = 0
        assert list(hr._readlines()) == []

    def test_load_no_contents(self):
        hr = _make_host_resolver()
        hr._load()
        assert not hr._v4
        assert not hr._v6
        assert not hr._aliases

    def test_load_v4_v6_cname_aliases(self):
        hr = _make_host_resolver()
        hr.hosts.write(b'1.2.3.4 v4.example.com v4\n'
                       b'dead:beef::1 v6.example.com v6\n')
        hr.hosts.flush()
        hr._load()
        assert hr._v4 == {'v4.example.com': '1.2.3.4', 'v4': '1.2.3.4'}
        assert hr._v6 == {'v6.example.com': 'dead:beef::1',
                          'v6': 'dead:beef::1'}
        assert hr._aliases == {'v4': 'v4.example.com',
                               'v6': 'v6.example.com'}

    def test_load_v6_link_local(self):
        hr = _make_host_resolver()
        hr.hosts.write(b'fe80:: foo\n'
                       b'fe80:dead:beef::1 bar\n')
        hr.hosts.flush()
        hr._load()
        assert not hr._v4
        assert not hr._v6

    def test_query_A(self):
        hr = _make_host_resolver()
        hr._v4 = {'v4.example.com': '1.2.3.4'}
        ans = hr.query('v4.example.com')
        assert ans[0].address == '1.2.3.4'

    def test_query_ans_types(self):
        # This assumes test_query_A above succeeds
        hr = _make_host_resolver()
        hr._v4 = {'v4.example.com': '1.2.3.4'}
        hr._last_stat = time.time()
        ans = hr.query('v4.example.com')
        assert isinstance(ans, greendns.dns.resolver.Answer)
        assert ans.response is None
        assert ans.qname == dns.name.from_text('v4.example.com')
        assert ans.rdtype == dns.rdatatype.A
        assert ans.rdclass == dns.rdataclass.IN
        assert ans.canonical_name == dns.name.from_text('v4.example.com')
        assert ans.expiration
        assert isinstance(ans.rrset, dns.rrset.RRset)
        assert ans.rrset.rdtype == dns.rdatatype.A
        assert ans.rrset.rdclass == dns.rdataclass.IN
        ttl = greendns.HOSTS_TTL
        assert ttl - 1 <= ans.rrset.ttl <= ttl + 1
        rr = ans.rrset[0]
        assert isinstance(rr, greendns.dns.rdtypes.IN.A.A)
        assert rr.rdtype == dns.rdatatype.A
        assert rr.rdclass == dns.rdataclass.IN
        assert rr.address == '1.2.3.4'

    def test_query_AAAA(self):
        hr = _make_host_resolver()
        hr._v6 = {'v6.example.com': 'dead:beef::1'}
        ans = hr.query('v6.example.com', dns.rdatatype.AAAA)
        assert ans[0].address == 'dead:beef::1'

    def test_query_unknown_raises(self):
        hr = _make_host_resolver()
        with tests.assert_raises(greendns.dns.resolver.NoAnswer):
            hr.query('example.com')

    def test_query_unknown_no_raise(self):
        hr = _make_host_resolver()
        ans = hr.query('example.com', raise_on_no_answer=False)
        assert isinstance(ans, greendns.dns.resolver.Answer)
        assert ans.response is None
        assert ans.qname == dns.name.from_text('example.com')
        assert ans.rdtype == dns.rdatatype.A
        assert ans.rdclass == dns.rdataclass.IN
        assert ans.canonical_name == dns.name.from_text('example.com')
        assert ans.expiration
        assert isinstance(ans.rrset, greendns.dns.rrset.RRset)
        assert ans.rrset.rdtype == dns.rdatatype.A
        assert ans.rrset.rdclass == dns.rdataclass.IN
        assert len(ans.rrset) == 0

    def test_query_CNAME(self):
        hr = _make_host_resolver()
        hr._aliases = {'host': 'host.example.com'}
        ans = hr.query('host', dns.rdatatype.CNAME)
        assert ans[0].target == dns.name.from_text('host.example.com')
        assert str(ans[0].target) == 'host.example.com.'

    def test_query_unknown_type(self):
        hr = _make_host_resolver()
        with tests.assert_raises(greendns.dns.resolver.NoAnswer):
            hr.query('example.com', dns.rdatatype.MX)

    def test_getaliases(self):
        hr = _make_host_resolver()
        hr._aliases = {'host': 'host.example.com',
                       'localhost': 'host.example.com'}
        res = set(hr.getaliases('host'))
        assert res == set(['host.example.com', 'localhost'])

    def test_getaliases_unknown(self):
        hr = _make_host_resolver()
        assert hr.getaliases('host.example.com') == []

    def test_getaliases_fqdn(self):
        hr = _make_host_resolver()
        hr._aliases = {'host': 'host.example.com'}
        res = set(hr.getaliases('host.example.com'))
        assert res == set(['host'])

    def test_hosts_case_insensitive(self):
        name = 'example.com'
        hr = _make_host_resolver()
        hr.hosts.write(b'1.2.3.4 ExAmPlE.CoM\n')
        hr.hosts.flush()
        hr._load()

        ans = hr.query(name)
        rr = ans.rrset[0]
        assert isinstance(rr, greendns.dns.rdtypes.IN.A.A)
        assert rr.rdtype == dns.rdatatype.A
        assert rr.rdclass == dns.rdataclass.IN
        assert rr.address == '1.2.3.4'


def _make_mock_base_resolver():
    """A mocked base resolver class"""
    class RR(object):
        pass

    class Resolver(object):
        aliases = ['cname.example.com']
        raises = None
        rr = RR()
        rr6 = RR()

        def query(self, *args, **kwargs):
            self.args = args
            self.kwargs = kwargs
            if self.raises:
                raise self.raises()
            if hasattr(self, 'rrset'):
                rrset = self.rrset
            else:
                if self.rr6 and self.args[1] == dns.rdatatype.AAAA:
                    rrset = [self.rr6]
                else:
                    rrset = [self.rr]
            return greendns.HostsAnswer('foo', 1, 1, rrset, False)

        def getaliases(self, *args, **kwargs):
            return self.aliases

    return Resolver


class TestUdp(tests.LimitedTestCase):

    def setUp(self):
        # Store this so we can reuse it for each test
        self.query = greendns.dns.message.Message()
        self.query.flags = greendns.dns.flags.QR
        self.query_wire = self.query.to_wire()
        super(TestUdp, self).setUp()

    def test_udp_ipv4(self):
        with tests.mock.patch('eventlet.support.greendns.socket.socket.recvfrom',
                              return_value=(self.query_wire,
                                            ('127.0.0.1', 53))):
            greendns.udp(self.query, '127.0.0.1')

    def test_udp_ipv4_timeout(self):
        with tests.mock.patch('eventlet.support.greendns.socket.socket.recvfrom',
                              side_effect=socket.timeout):
            with tests.assert_raises(dns.exception.Timeout):
                greendns.udp(self.query, '127.0.0.1', timeout=0.1)

    def test_udp_ipv4_wrong_addr_ignore(self):
        with tests.mock.patch('eventlet.support.greendns.socket.socket.recvfrom',
                              side_effect=socket.timeout):
            with tests.assert_raises(dns.exception.Timeout):
                greendns.udp(self.query, '127.0.0.1', timeout=0.1, ignore_unexpected=True)

    def test_udp_ipv4_wrong_addr(self):
        with tests.mock.patch('eventlet.support.greendns.socket.socket.recvfrom',
                              return_value=(self.query_wire,
                                            ('127.0.0.2', 53))):
            with tests.assert_raises(dns.query.UnexpectedSource):
                greendns.udp(self.query, '127.0.0.1')

    def test_udp_ipv6(self):
        with tests.mock.patch('eventlet.support.greendns.socket.socket.recvfrom',
                              return_value=(self.query_wire,
                                            ('::1', 53, 0, 0))):
            greendns.udp(self.query, '::1')

    def test_udp_ipv6_timeout(self):
        with tests.mock.patch('eventlet.support.greendns.socket.socket.recvfrom',
                              side_effect=socket.timeout):
            with tests.assert_raises(dns.exception.Timeout):
                greendns.udp(self.query, '::1', timeout=0.1)

    def test_udp_ipv6_addr_zeroes(self):
        with tests.mock.patch('eventlet.support.greendns.socket.socket.recvfrom',
                              return_value=(self.query_wire,
                                            ('0:00:0000::1', 53, 0, 0))):
            greendns.udp(self.query, '::1')

    def test_udp_ipv6_wrong_addr_ignore(self):
        with tests.mock.patch('eventlet.support.greendns.socket.socket.recvfrom',
                              side_effect=socket.timeout):
            with tests.assert_raises(dns.exception.Timeout):
                greendns.udp(self.query, '::1', timeout=0.1, ignore_unexpected=True)

    def test_udp_ipv6_wrong_addr(self):
        with tests.mock.patch('eventlet.support.greendns.socket.socket.recvfrom',
                              return_value=(self.query_wire,
                                            ('ffff:0000::1', 53, 0, 0))):
            with tests.assert_raises(dns.query.UnexpectedSource):
                greendns.udp(self.query, '::1')


class TestProxyResolver(tests.LimitedTestCase):

    def test_clear(self):
        rp = greendns.ResolverProxy()
        resolver = rp._resolver
        rp.clear()
        assert rp._resolver != resolver

    def _make_mock_hostsresolver(self):
        """A mocked HostsResolver"""
        base_resolver = _make_mock_base_resolver()
        base_resolver.rr.address = '1.2.3.4'
        return base_resolver()

    def _make_mock_resolver(self):
        """A mocked Resolver"""
        base_resolver = _make_mock_base_resolver()
        base_resolver.rr.address = '5.6.7.8'
        return base_resolver()

    def test_hosts(self):
        hostsres = self._make_mock_hostsresolver()
        rp = greendns.ResolverProxy(hostsres)
        ans = rp.query('host.example.com')
        assert ans[0].address == '1.2.3.4'

    def test_hosts_noanswer(self):
        hostsres = self._make_mock_hostsresolver()
        res = self._make_mock_resolver()
        rp = greendns.ResolverProxy(hostsres)
        rp._resolver = res
        hostsres.raises = greendns.dns.resolver.NoAnswer
        ans = rp.query('host.example.com')
        assert ans[0].address == '5.6.7.8'

    def test_resolver(self):
        res = self._make_mock_resolver()
        rp = greendns.ResolverProxy()
        rp._resolver = res
        ans = rp.query('host.example.com')
        assert ans[0].address == '5.6.7.8'

    def test_noanswer(self):
        res = self._make_mock_resolver()
        rp = greendns.ResolverProxy()
        rp._resolver = res
        res.raises = greendns.dns.resolver.NoAnswer
        with tests.assert_raises(greendns.dns.resolver.NoAnswer):
            rp.query('host.example.com')

    def test_nxdomain(self):
        res = self._make_mock_resolver()
        rp = greendns.ResolverProxy()
        rp._resolver = res
        res.raises = greendns.dns.resolver.NXDOMAIN
        with tests.assert_raises(greendns.dns.resolver.NXDOMAIN):
            rp.query('host.example.com')

    def test_noanswer_hosts(self):
        hostsres = self._make_mock_hostsresolver()
        res = self._make_mock_resolver()
        rp = greendns.ResolverProxy(hostsres)
        rp._resolver = res
        hostsres.raises = greendns.dns.resolver.NoAnswer
        res.raises = greendns.dns.resolver.NoAnswer
        with tests.assert_raises(greendns.dns.resolver.NoAnswer):
            rp.query('host.example.com')

    def _make_mock_resolver_aliases(self):

        class RR(object):
            target = 'host.example.com'

        class Resolver(object):
            call_count = 0
            exc_type = greendns.dns.resolver.NoAnswer

            def query(self, *args, **kwargs):
                self.args = args
                self.kwargs = kwargs
                self.call_count += 1
                if self.call_count < 2:
                    return greendns.HostsAnswer(args[0], 1, 5, [RR()], False)
                else:
                    raise self.exc_type()

        return Resolver()

    def test_getaliases(self):
        aliases_res = self._make_mock_resolver_aliases()
        rp = greendns.ResolverProxy()
        rp._resolver = aliases_res
        aliases = set(rp.getaliases('alias.example.com'))
        assert aliases == set(['host.example.com'])

    def test_getaliases_fqdn(self):
        aliases_res = self._make_mock_resolver_aliases()
        rp = greendns.ResolverProxy()
        rp._resolver = aliases_res
        rp._resolver.call_count = 1
        assert rp.getaliases('host.example.com') == []

    def test_getaliases_nxdomain(self):
        aliases_res = self._make_mock_resolver_aliases()
        rp = greendns.ResolverProxy()
        rp._resolver = aliases_res
        rp._resolver.call_count = 1
        rp._resolver.exc_type = greendns.dns.resolver.NXDOMAIN
        assert rp.getaliases('host.example.com') == []


class TestResolve(tests.LimitedTestCase):

    def setUp(self):
        base_resolver = _make_mock_base_resolver()
        base_resolver.rr.address = '1.2.3.4'
        self._old_resolver = greendns.resolver
        greendns.resolver = base_resolver()

    def tearDown(self):
        greendns.resolver = self._old_resolver

    def test_A(self):
        ans = greendns.resolve('host.example.com', socket.AF_INET)
        assert ans[0].address == '1.2.3.4'
        assert greendns.resolver.args == ('host.example.com', dns.rdatatype.A)

    def test_AAAA(self):
        greendns.resolver.rr6.address = 'dead:beef::1'
        ans = greendns.resolve('host.example.com', socket.AF_INET6)
        assert ans[0].address == 'dead:beef::1'
        assert greendns.resolver.args == ('host.example.com', dns.rdatatype.AAAA)

    def test_unknown_rdtype(self):
        with tests.assert_raises(socket.gaierror):
            greendns.resolve('host.example.com', socket.AF_INET6 + 1)

    def test_timeout(self):
        greendns.resolver.raises = greendns.dns.exception.Timeout
        with tests.assert_raises(socket.gaierror):
            greendns.resolve('host.example.com')

    def test_exc(self):
        greendns.resolver.raises = greendns.dns.exception.DNSException
        with tests.assert_raises(socket.gaierror):
            greendns.resolve('host.example.com')

    def test_noraise_noanswer(self):
        greendns.resolver.rrset = None
        ans = greendns.resolve('example.com', raises=False)
        assert not ans.rrset

    def test_noraise_nxdomain(self):
        greendns.resolver.raises = greendns.dns.resolver.NXDOMAIN
        ans = greendns.resolve('example.com', raises=False)
        assert not ans.rrset


class TestResolveCname(tests.LimitedTestCase):

    def setUp(self):
        base_resolver = _make_mock_base_resolver()
        base_resolver.rr.target = 'cname.example.com'
        self._old_resolver = greendns.resolver
        greendns.resolver = base_resolver()

    def tearDown(self):
        greendns.resolver = self._old_resolver

    def test_success(self):
        cname = greendns.resolve_cname('alias.example.com')
        assert cname == 'cname.example.com'

    def test_timeout(self):
        greendns.resolver.raises = greendns.dns.exception.Timeout
        with tests.assert_raises(socket.gaierror):
            greendns.resolve_cname('alias.example.com')

    def test_nodata(self):
        greendns.resolver.raises = greendns.dns.exception.DNSException
        with tests.assert_raises(socket.gaierror):
            greendns.resolve_cname('alias.example.com')

    def test_no_answer(self):
        greendns.resolver.raises = greendns.dns.resolver.NoAnswer
        assert greendns.resolve_cname('host.example.com') == 'host.example.com'


def _make_mock_resolve():
    """A stubbed out resolve function

    This monkeypatches the greendns.resolve() function with a mock.
    You must give it answers by calling .add().
    """

    class MockAnswer(list):
        pass

    class MockResolve(object):

        def __init__(self):
            self.answers = {}

        def __call__(self, name, family=socket.AF_INET, raises=True,
                     _proxy=None, use_network=True):
            qname = dns.name.from_text(name)
            try:
                rrset = self.answers[name][family]
            except KeyError:
                if raises:
                    raise greendns.dns.resolver.NoAnswer()
                rrset = dns.rrset.RRset(qname, 1, 1)
            ans = MockAnswer()
            ans.qname = qname
            ans.rrset = rrset
            ans.extend(rrset.items)
            return ans

        def add(self, name, addr):
            """Add an address to a name and family"""
            try:
                rdata = dns.rdtypes.IN.A.A(dns.rdataclass.IN,
                                           dns.rdatatype.A, addr)
                family = socket.AF_INET
            except (socket.error, dns.exception.SyntaxError):
                rdata = dns.rdtypes.IN.AAAA.AAAA(dns.rdataclass.IN,
                                                 dns.rdatatype.AAAA, addr)
                family = socket.AF_INET6
            family_dict = self.answers.setdefault(name, {})
            rrset = family_dict.get(family)
            if not rrset:
                family_dict[family] = rrset = dns.rrset.RRset(
                    dns.name.from_text(name), rdata.rdclass, rdata.rdtype)
            rrset.add(rdata)

    resolve = MockResolve()
    return resolve


class TestGetaddrinfo(tests.LimitedTestCase):

    def _make_mock_resolve_cname(self):
        """A stubbed out cname function"""

        class ResolveCname(object):
            qname = None
            cname = 'cname.example.com'

            def __call__(self, host):
                self.qname = host
                return self.cname

        resolve_cname = ResolveCname()
        return resolve_cname

    def setUp(self):
        self._old_resolve = greendns.resolve
        self._old_resolve_cname = greendns.resolve_cname
        self._old_orig_getaddrinfo = greendns.socket.getaddrinfo

    def tearDown(self):
        greendns.resolve = self._old_resolve
        greendns.resolve_cname = self._old_resolve_cname
        greendns.socket.getaddrinfo = self._old_orig_getaddrinfo

    def test_getaddrinfo(self):
        greendns.resolve = _make_mock_resolve()
        greendns.resolve.add('example.com', '127.0.0.2')
        greendns.resolve.add('example.com', '::1')
        res = greendns.getaddrinfo('example.com', 'domain')
        addr = ('127.0.0.2', 53)
        tcp = (socket.AF_INET, socket.SOCK_STREAM, socket.IPPROTO_TCP, addr)
        udp = (socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP, addr)
        addr = ('::1', 53, 0, 0)
        tcp6 = (socket.AF_INET6, socket.SOCK_STREAM, socket.IPPROTO_TCP, addr)
        udp6 = (socket.AF_INET6, socket.SOCK_DGRAM, socket.IPPROTO_UDP, addr)
        filt_res = [ai[:3] + (ai[4],) for ai in res]
        assert tcp in filt_res
        assert udp in filt_res
        assert tcp6 in filt_res
        assert udp6 in filt_res

    def test_getaddrinfo_idn(self):
        greendns.resolve = _make_mock_resolve()
        idn_name = u'евентлет.com'
        greendns.resolve.add(idn_name.encode('idna').decode('ascii'), '127.0.0.2')
        res = greendns.getaddrinfo(idn_name, 'domain')
        addr = ('127.0.0.2', 53)
        tcp = (socket.AF_INET, socket.SOCK_STREAM, socket.IPPROTO_TCP, addr)
        udp = (socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP, addr)
        filt_res = [ai[:3] + (ai[4],) for ai in res]
        assert tcp in filt_res
        assert udp in filt_res

    def test_getaddrinfo_inet(self):
        greendns.resolve = _make_mock_resolve()
        greendns.resolve.add('example.com', '127.0.0.2')
        res = greendns.getaddrinfo('example.com', 'domain', socket.AF_INET)
        addr = ('127.0.0.2', 53)
        tcp = (socket.AF_INET, socket.SOCK_STREAM, socket.IPPROTO_TCP, addr)
        udp = (socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP, addr)
        assert tcp in [ai[:3] + (ai[4],) for ai in res]
        assert udp in [ai[:3] + (ai[4],) for ai in res]

    def test_getaddrinfo_inet6(self):
        greendns.resolve = _make_mock_resolve()
        greendns.resolve.add('example.com', '::1')
        res = greendns.getaddrinfo('example.com', 'domain', socket.AF_INET6)
        addr = ('::1', 53, 0, 0)
        tcp = (socket.AF_INET6, socket.SOCK_STREAM, socket.IPPROTO_TCP, addr)
        udp = (socket.AF_INET6, socket.SOCK_DGRAM, socket.IPPROTO_UDP, addr)
        assert tcp in [ai[:3] + (ai[4],) for ai in res]
        assert udp in [ai[:3] + (ai[4],) for ai in res]

    def test_getaddrinfo_only_a_ans(self):
        greendns.resolve = _make_mock_resolve()
        greendns.resolve.add('example.com', '1.2.3.4')
        res = greendns.getaddrinfo('example.com', 0)
        addr = [('1.2.3.4', 0)] * len(res)
        assert addr == [ai[-1] for ai in res]

    def test_getaddrinfo_only_aaaa_ans(self):
        greendns.resolve = _make_mock_resolve()
        greendns.resolve.add('example.com', 'dead:beef::1')
        res = greendns.getaddrinfo('example.com', 0)
        addr = [('dead:beef::1', 0, 0, 0)] * len(res)
        assert addr == [ai[-1] for ai in res]

    def test_getaddrinfo_hosts_only_ans_with_timeout(self):
        def clear_raises(res_self):
            res_self.raises = None
            return greendns.dns.resolver.NoAnswer()

        hostsres = _make_mock_base_resolver()
        hostsres.raises = clear_raises
        hostsres.rr.address = '1.2.3.4'
        greendns.resolver = greendns.ResolverProxy(hostsres())
        res = _make_mock_base_resolver()
        res.raises = greendns.dns.exception.Timeout
        greendns.resolver._resolver = res()

        result = greendns.getaddrinfo('example.com', 0, 0)
        addr = [('1.2.3.4', 0)] * len(result)
        assert addr == [ai[-1] for ai in result]

    def test_getaddrinfo_hosts_only_ans_with_error(self):
        def clear_raises(res_self):
            res_self.raises = None
            return greendns.dns.resolver.NoAnswer()

        hostsres = _make_mock_base_resolver()
        hostsres.raises = clear_raises
        hostsres.rr.address = '1.2.3.4'
        greendns.resolver = greendns.ResolverProxy(hostsres())
        res = _make_mock_base_resolver()
        res.raises = greendns.dns.exception.DNSException
        greendns.resolver._resolver = res()

        result = greendns.getaddrinfo('example.com', 0, 0)
        addr = [('1.2.3.4', 0)] * len(result)
        assert addr == [ai[-1] for ai in result]

    def test_getaddrinfo_hosts_only_timeout(self):
        hostsres = _make_mock_base_resolver()
        hostsres.raises = greendns.dns.resolver.NoAnswer
        greendns.resolver = greendns.ResolverProxy(hostsres())
        res = _make_mock_base_resolver()
        res.raises = greendns.dns.exception.Timeout
        greendns.resolver._resolver = res()

        with tests.assert_raises(socket.gaierror):
            greendns.getaddrinfo('example.com', 0, 0)

    def test_getaddrinfo_hosts_only_dns_error(self):
        hostsres = _make_mock_base_resolver()
        hostsres.raises = greendns.dns.resolver.NoAnswer
        greendns.resolver = greendns.ResolverProxy(hostsres())
        res = _make_mock_base_resolver()
        res.raises = greendns.dns.exception.DNSException
        greendns.resolver._resolver = res()

        with tests.assert_raises(socket.gaierror):
            greendns.getaddrinfo('example.com', 0, 0)

    def test_canonname(self):
        greendns.resolve = _make_mock_resolve()
        greendns.resolve.add('host.example.com', '1.2.3.4')
        greendns.resolve_cname = self._make_mock_resolve_cname()
        res = greendns.getaddrinfo('host.example.com', 0,
                                   0, 0, 0, socket.AI_CANONNAME)
        assert res[0][3] == 'cname.example.com'

    def test_host_none(self):
        res = greendns.getaddrinfo(None, 80)
        for addr in set(ai[-1] for ai in res):
            assert addr in [('127.0.0.1', 80), ('::1', 80, 0, 0)]

    def test_host_none_passive(self):
        res = greendns.getaddrinfo(None, 80, 0, 0, 0, socket.AI_PASSIVE)
        for addr in set(ai[-1] for ai in res):
            assert addr in [('0.0.0.0', 80), ('::', 80, 0, 0)]

    def test_v4mapped(self):
        greendns.resolve = _make_mock_resolve()
        greendns.resolve.add('example.com', '1.2.3.4')
        res = greendns.getaddrinfo('example.com', 80,
                                   socket.AF_INET6, 0, 0, socket.AI_V4MAPPED)
        addrs = set(ai[-1] for ai in res)
        assert addrs == set([('::ffff:1.2.3.4', 80, 0, 0)])

    def test_v4mapped_all(self):
        greendns.resolve = _make_mock_resolve()
        greendns.resolve.add('example.com', '1.2.3.4')
        greendns.resolve.add('example.com', 'dead:beef::1')
        res = greendns.getaddrinfo('example.com', 80, socket.AF_INET6, 0, 0,
                                   socket.AI_V4MAPPED | socket.AI_ALL)
        addrs = set(ai[-1] for ai in res)
        for addr in addrs:
            assert addr in [('::ffff:1.2.3.4', 80, 0, 0),
                            ('dead:beef::1', 80, 0, 0)]

    def test_numericserv(self):
        greendns.resolve = _make_mock_resolve()
        greendns.resolve.add('example.com', '1.2.3.4')
        with tests.assert_raises(socket.gaierror):
            greendns.getaddrinfo('example.com', 'www', 0, 0, 0, socket.AI_NUMERICSERV)

    def test_numerichost(self):
        greendns.resolve = _make_mock_resolve()
        greendns.resolve.add('example.com', '1.2.3.4')
        with tests.assert_raises(socket.gaierror):
            greendns.getaddrinfo('example.com', 80, 0, 0, 0, socket.AI_NUMERICHOST)

    def test_noport(self):
        greendns.resolve = _make_mock_resolve()
        greendns.resolve.add('example.com', '1.2.3.4')
        ai = greendns.getaddrinfo('example.com', None)
        assert ai[0][-1][1] == 0

    def test_AI_ADDRCONFIG(self):
        # When the users sets AI_ADDRCONFIG but only has an IPv4
        # address configured we will iterate over the results, but the
        # call for the IPv6 address will fail rather then return an
        # empty list.  In that case we should catch the exception and
        # only return the ones which worked.
        def getaddrinfo(addr, port, family, socktype, proto, aiflags):
            if addr == '127.0.0.1':
                return [(socket.AF_INET, 1, 0, '', ('127.0.0.1', 0))]
            elif addr == '::1' and aiflags & socket.AI_ADDRCONFIG:
                raise socket.error(socket.EAI_ADDRFAMILY,
                                   'Address family for hostname not supported')
            elif addr == '::1' and not aiflags & socket.AI_ADDRCONFIG:
                return [(socket.AF_INET6, 1, 0, '', ('::1', 0, 0, 0))]
        greendns.socket.getaddrinfo = getaddrinfo
        greendns.resolve = _make_mock_resolve()
        greendns.resolve.add('localhost', '127.0.0.1')
        greendns.resolve.add('localhost', '::1')
        res = greendns.getaddrinfo('localhost', None,
                                   0, 0, 0, socket.AI_ADDRCONFIG)
        assert res == [(socket.AF_INET, 1, 0, '', ('127.0.0.1', 0))]

    def test_AI_ADDRCONFIG_noaddr(self):
        # If AI_ADDRCONFIG is used but there is no address we need to
        # get an exception, not an empty list.
        def getaddrinfo(addr, port, family, socktype, proto, aiflags):
            raise socket.error(socket.EAI_ADDRFAMILY,
                               'Address family for hostname not supported')
        greendns.socket.getaddrinfo = getaddrinfo
        greendns.resolve = _make_mock_resolve()
        try:
            greendns.getaddrinfo('::1', None, 0, 0, 0, socket.AI_ADDRCONFIG)
        except socket.error as e:
            assert e.errno == socket.EAI_ADDRFAMILY


class TestIsIpAddr(tests.LimitedTestCase):

    def test_isv4(self):
        assert greendns.is_ipv4_addr('1.2.3.4')

    def test_isv4_false(self):
        assert not greendns.is_ipv4_addr('260.0.0.0')

    def test_isv6(self):
        assert greendns.is_ipv6_addr('dead:beef::1')

    def test_isv6_invalid(self):
        assert not greendns.is_ipv6_addr('foobar::1')

    def test_v4(self):
        assert greendns.is_ip_addr('1.2.3.4')

    def test_v4_illegal(self):
        assert not greendns.is_ip_addr('300.0.0.1')

    def test_v6_addr(self):
        assert greendns.is_ip_addr('::1')

    def test_isv4_none(self):
        assert not greendns.is_ipv4_addr(None)

    def test_isv6_none(self):
        assert not greendns.is_ipv6_addr(None)

    def test_none(self):
        assert not greendns.is_ip_addr(None)


class TestGethostbyname(tests.LimitedTestCase):

    def setUp(self):
        self._old_resolve = greendns.resolve
        greendns.resolve = _make_mock_resolve()

    def tearDown(self):
        greendns.resolve = self._old_resolve

    def test_ipaddr(self):
        assert greendns.gethostbyname('1.2.3.4') == '1.2.3.4'

    def test_name(self):
        greendns.resolve.add('host.example.com', '1.2.3.4')
        assert greendns.gethostbyname('host.example.com') == '1.2.3.4'


class TestGetaliases(tests.LimitedTestCase):

    def _make_mock_resolver(self):
        base_resolver = _make_mock_base_resolver()
        resolver = base_resolver()
        resolver.aliases = ['cname.example.com']
        return resolver

    def setUp(self):
        self._old_resolver = greendns.resolver
        greendns.resolver = self._make_mock_resolver()

    def tearDown(self):
        greendns.resolver = self._old_resolver

    def test_getaliases(self):
        assert greendns.getaliases('host.example.com') == ['cname.example.com']


class TestGethostbyname_ex(tests.LimitedTestCase):

    def _make_mock_getaliases(self):

        class GetAliases(object):
            aliases = ['cname.example.com']

            def __call__(self, *args, **kwargs):
                return self.aliases

        getaliases = GetAliases()
        return getaliases

    def setUp(self):
        self._old_resolve = greendns.resolve
        greendns.resolve = _make_mock_resolve()
        self._old_getaliases = greendns.getaliases

    def tearDown(self):
        greendns.resolve = self._old_resolve
        greendns.getaliases = self._old_getaliases

    def test_ipaddr(self):
        res = greendns.gethostbyname_ex('1.2.3.4')
        assert res == ('1.2.3.4', [], ['1.2.3.4'])

    def test_name(self):
        greendns.resolve.add('host.example.com', '1.2.3.4')
        greendns.getaliases = self._make_mock_getaliases()
        greendns.getaliases.aliases = []
        res = greendns.gethostbyname_ex('host.example.com')
        assert res == ('host.example.com', [], ['1.2.3.4'])

    def test_multiple_addrs(self):
        greendns.resolve.add('host.example.com', '1.2.3.4')
        greendns.resolve.add('host.example.com', '1.2.3.5')
        greendns.getaliases = self._make_mock_getaliases()
        greendns.getaliases.aliases = []
        res = greendns.gethostbyname_ex('host.example.com')
        assert res == ('host.example.com', [], ['1.2.3.4', '1.2.3.5'])


class TinyDNSTests(tests.LimitedTestCase):

    def test_raise_dns_tcp(self):
        # https://github.com/eventlet/eventlet/issues/499
        # None means we don't want the server to find the IP
        with tests.dns_tcp_server(None) as dnsaddr:
            resolver = Resolver()
            resolver.nameservers = [dnsaddr[0]]
            resolver.nameserver_ports[dnsaddr[0]] = dnsaddr[1]

            with self.assertRaises(NoAnswer):
                resolver.query('host.example.com', 'a', tcp=True)

    def test_noraise_dns_tcp(self):
        # https://github.com/eventlet/eventlet/issues/499
        expected_ip = "192.168.1.1"
        with tests.dns_tcp_server(expected_ip) as dnsaddr:
            resolver = Resolver()
            resolver.nameservers = [dnsaddr[0]]
            resolver.nameserver_ports[dnsaddr[0]] = dnsaddr[1]
            response = resolver.query('host.example.com', 'a', tcp=True)
            self.assertIsInstance(response, Answer)
            self.assertEqual(list(response.rrset.items)[0].address, expected_ip)


def test_reverse_name():
    tests.run_isolated('greendns_from_address_203.py')


def test_proxy_resolve_unqualified():
    # https://github.com/eventlet/eventlet/issues/363
    rp = greendns.ResolverProxy(filename=None)
    rp._resolver.search.append(dns.name.from_text('example.com'))
    with tests.mock.patch('dns.resolver.Resolver.query', side_effect=dns.resolver.NoAnswer) as m:
        try:
            rp.query('machine')
            assert False, 'Expected NoAnswer exception'
        except dns.resolver.NoAnswer:
            pass
        assert any(call[0][0] == dns.name.from_text('machine') for call in m.call_args_list)
        assert any(call[0][0] == dns.name.from_text('machine.') for call in m.call_args_list)


def test_hosts_priority():
    name = 'example.com'
    addr_from_ns = '1.0.2.0'

    hr = _make_host_resolver()
    rp = greendns.ResolverProxy(hosts_resolver=hr, filename=None)
    base = _make_mock_base_resolver()
    base.rr.address = addr_from_ns
    rp._resolver = base()

    # Default behavior
    rrns = greendns.resolve(name, _proxy=rp).rrset[0]
    assert rrns.address == addr_from_ns

    # Hosts result must shadow that from nameservers
    hr.hosts.write(b'1.2.3.4 example.com\ndead:beef::1 example.com\n')
    hr.hosts.flush()
    hr._load()
    rrs4 = greendns.resolve(name, family=socket.AF_INET, _proxy=rp).rrset
    assert len(rrs4) == 1
    assert rrs4[0].address == '1.2.3.4', rrs4[0].address
    rrs6 = greendns.resolve(name, family=socket.AF_INET6, _proxy=rp).rrset
    assert len(rrs6) == 1
    assert rrs6[0].address == 'dead:beef::1', rrs6[0].address


def test_hosts_no_network():

    name = 'example.com'
    addr_from_ns = '1.0.2.0'
    addr6_from_ns = 'dead:beef::1'

    hr = _make_host_resolver()
    rp = greendns.ResolverProxy(hosts_resolver=hr, filename=None)
    base = _make_mock_base_resolver()
    base.rr.address = addr_from_ns
    base.rr6.address = addr6_from_ns
    rp._resolver = base()

    with tests.mock.patch.object(greendns, 'resolver',
                                 new_callable=tests.mock.PropertyMock(return_value=rp)):
        res = greendns.getaddrinfo('example.com', 'domain', socket.AF_UNSPEC)
        # Default behavior
        addr = (addr_from_ns, 53)
        tcp = (socket.AF_INET, socket.SOCK_STREAM, socket.IPPROTO_TCP, addr)
        udp = (socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP, addr)
        addr = (addr6_from_ns, 53, 0, 0)
        tcp6 = (socket.AF_INET6, socket.SOCK_STREAM, socket.IPPROTO_TCP, addr)
        udp6 = (socket.AF_INET6, socket.SOCK_DGRAM, socket.IPPROTO_UDP, addr)
        filt_res = [ai[:3] + (ai[4],) for ai in res]
        assert tcp in filt_res
        assert udp in filt_res
        assert tcp6 in filt_res
        assert udp6 in filt_res

        # Hosts result must shadow that from nameservers
        hr = _make_host_resolver()
        hr.hosts.write(b'1.2.3.4 example.com')
        hr.hosts.flush()
        hr._load()
        greendns.resolver._hosts = hr

        res = greendns.getaddrinfo('example.com', 'domain', socket.AF_UNSPEC)
        filt_res = [ai[:3] + (ai[4],) for ai in res]

        # Make sure that only IPv4 entry from hosts is present.
        assert tcp not in filt_res
        assert udp not in filt_res
        assert tcp6 not in filt_res
        assert udp6 not in filt_res

        addr = ('1.2.3.4', 53)
        tcp = (socket.AF_INET, socket.SOCK_STREAM, socket.IPPROTO_TCP, addr)
        udp = (socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP, addr)
        assert tcp in filt_res
        assert udp in filt_res


def test_import_rdtypes_then_eventlet():
    # https://github.com/eventlet/eventlet/issues/479
    tests.run_isolated('greendns_import_rdtypes_then_eventlet.py')