diff options
Diffstat (limited to 'cloudinit')
-rw-r--r-- | cloudinit/net/__init__.py | 34 | ||||
-rw-r--r-- | cloudinit/net/dhcp.py | 90 | ||||
-rw-r--r-- | cloudinit/net/tests/test_dhcp.py | 120 | ||||
-rw-r--r-- | cloudinit/net/tests/test_init.py | 39 |
4 files changed, 280 insertions, 3 deletions
diff --git a/cloudinit/net/__init__.py b/cloudinit/net/__init__.py index e758006f..624c9b42 100644 --- a/cloudinit/net/__init__.py +++ b/cloudinit/net/__init__.py @@ -679,7 +679,7 @@ class EphemeralIPv4Network(object): """ def __init__(self, interface, ip, prefix_or_mask, broadcast, router=None, - connectivity_url=None): + connectivity_url=None, static_routes=None): """Setup context manager and validate call signature. @param interface: Name of the network interface to bring up. @@ -690,6 +690,7 @@ class EphemeralIPv4Network(object): @param router: Optionally the default gateway IP. @param connectivity_url: Optionally, a URL to verify if a usable connection already exists. + @param static_routes: Optionally a list of static routes from DHCP """ if not all([interface, ip, prefix_or_mask, broadcast]): raise ValueError( @@ -706,6 +707,7 @@ class EphemeralIPv4Network(object): self.ip = ip self.broadcast = broadcast self.router = router + self.static_routes = static_routes self.cleanup_cmds = [] # List of commands to run to cleanup state. def __enter__(self): @@ -718,7 +720,21 @@ class EphemeralIPv4Network(object): return self._bringup_device() - if self.router: + + # rfc3442 requires us to ignore the router config *if* classless static + # routes are provided. + # + # https://tools.ietf.org/html/rfc3442 + # + # If the DHCP server returns both a Classless Static Routes option and + # a Router option, the DHCP client MUST ignore the Router option. + # + # Similarly, if the DHCP server returns both a Classless Static Routes + # option and a Static Routes option, the DHCP client MUST ignore the + # Static Routes option. + if self.static_routes: + self._bringup_static_routes() + elif self.router: self._bringup_router() def __exit__(self, excp_type, excp_value, excp_traceback): @@ -762,6 +778,20 @@ class EphemeralIPv4Network(object): ['ip', '-family', 'inet', 'addr', 'del', cidr, 'dev', self.interface]) + def _bringup_static_routes(self): + # static_routes = [("169.254.169.254/32", "130.56.248.255"), + # ("0.0.0.0/0", "130.56.240.1")] + for net_address, gateway in self.static_routes: + via_arg = [] + if gateway != "0.0.0.0/0": + via_arg = ['via', gateway] + util.subp( + ['ip', '-4', 'route', 'add', net_address] + via_arg + + ['dev', self.interface], capture=True) + self.cleanup_cmds.insert( + 0, ['ip', '-4', 'route', 'del', net_address] + via_arg + + ['dev', self.interface]) + def _bringup_router(self): """Perform the ip commands to fully setup the router if needed.""" # Check if a default route exists and exit if it does diff --git a/cloudinit/net/dhcp.py b/cloudinit/net/dhcp.py index c98a97cd..17379918 100644 --- a/cloudinit/net/dhcp.py +++ b/cloudinit/net/dhcp.py @@ -92,10 +92,14 @@ class EphemeralDHCPv4(object): nmap = {'interface': 'interface', 'ip': 'fixed-address', 'prefix_or_mask': 'subnet-mask', 'broadcast': 'broadcast-address', + 'static_routes': 'rfc3442-classless-static-routes', 'router': 'routers'} kwargs = dict([(k, self.lease.get(v)) for k, v in nmap.items()]) if not kwargs['broadcast']: kwargs['broadcast'] = bcip(kwargs['prefix_or_mask'], kwargs['ip']) + if kwargs['static_routes']: + kwargs['static_routes'] = ( + parse_static_routes(kwargs['static_routes'])) if self.connectivity_url: kwargs['connectivity_url'] = self.connectivity_url ephipv4 = EphemeralIPv4Network(**kwargs) @@ -272,4 +276,90 @@ def networkd_get_option_from_leases(keyname, leases_d=None): return data[keyname] return None + +def parse_static_routes(rfc3442): + """ parse rfc3442 format and return a list containing tuple of strings. + + The tuple is composed of the network_address (including net length) and + gateway for a parsed static route. + + @param rfc3442: string in rfc3442 format + @returns: list of tuple(str, str) for all valid parsed routes until the + first parsing error. + + E.g. + sr = parse_state_routes("32,169,254,169,254,130,56,248,255,0,130,56,240,1") + sr = [ + ("169.254.169.254/32", "130.56.248.255"), ("0.0.0.0/0", "130.56.240.1") + ] + + Python version of isc-dhclient's hooks: + /etc/dhcp/dhclient-exit-hooks.d/rfc3442-classless-routes + """ + # raw strings from dhcp lease may end in semi-colon + rfc3442 = rfc3442.rstrip(";") + tokens = rfc3442.split(',') + static_routes = [] + + def _trunc_error(cidr, required, remain): + msg = ("RFC3442 string malformed. Current route has CIDR of %s " + "and requires %s significant octets, but only %s remain. " + "Verify DHCP rfc3442-classless-static-routes value: %s" + % (cidr, required, remain, rfc3442)) + LOG.error(msg) + + current_idx = 0 + for idx, tok in enumerate(tokens): + if idx < current_idx: + continue + net_length = int(tok) + if net_length in range(25, 33): + req_toks = 9 + if len(tokens[idx:]) < req_toks: + _trunc_error(net_length, req_toks, len(tokens[idx:])) + return static_routes + net_address = ".".join(tokens[idx+1:idx+5]) + gateway = ".".join(tokens[idx+5:idx+req_toks]) + current_idx = idx + req_toks + elif net_length in range(17, 25): + req_toks = 8 + if len(tokens[idx:]) < req_toks: + _trunc_error(net_length, req_toks, len(tokens[idx:])) + return static_routes + net_address = ".".join(tokens[idx+1:idx+4] + ["0"]) + gateway = ".".join(tokens[idx+4:idx+req_toks]) + current_idx = idx + req_toks + elif net_length in range(9, 17): + req_toks = 7 + if len(tokens[idx:]) < req_toks: + _trunc_error(net_length, req_toks, len(tokens[idx:])) + return static_routes + net_address = ".".join(tokens[idx+1:idx+3] + ["0", "0"]) + gateway = ".".join(tokens[idx+3:idx+req_toks]) + current_idx = idx + req_toks + elif net_length in range(1, 9): + req_toks = 6 + if len(tokens[idx:]) < req_toks: + _trunc_error(net_length, req_toks, len(tokens[idx:])) + return static_routes + net_address = ".".join(tokens[idx+1:idx+2] + ["0", "0", "0"]) + gateway = ".".join(tokens[idx+2:idx+req_toks]) + current_idx = idx + req_toks + elif net_length == 0: + req_toks = 5 + if len(tokens[idx:]) < req_toks: + _trunc_error(net_length, req_toks, len(tokens[idx:])) + return static_routes + net_address = "0.0.0.0" + gateway = ".".join(tokens[idx+1:idx+req_toks]) + current_idx = idx + req_toks + else: + LOG.error('Parsed invalid net length "%s". Verify DHCP ' + 'rfc3442-classless-static-routes value.', net_length) + return static_routes + + static_routes.append(("%s/%s" % (net_address, net_length), gateway)) + + return static_routes + # vi: ts=4 expandtab diff --git a/cloudinit/net/tests/test_dhcp.py b/cloudinit/net/tests/test_dhcp.py index 51390249..91f503c9 100644 --- a/cloudinit/net/tests/test_dhcp.py +++ b/cloudinit/net/tests/test_dhcp.py @@ -8,7 +8,8 @@ from textwrap import dedent import cloudinit.net as net from cloudinit.net.dhcp import ( InvalidDHCPLeaseFileError, maybe_perform_dhcp_discovery, - parse_dhcp_lease_file, dhcp_discovery, networkd_load_leases) + parse_dhcp_lease_file, dhcp_discovery, networkd_load_leases, + parse_static_routes) from cloudinit.util import ensure_file, write_file from cloudinit.tests.helpers import ( CiTestCase, HttprettyTestCase, mock, populate_dir, wrap_and_call) @@ -64,6 +65,123 @@ class TestParseDHCPLeasesFile(CiTestCase): self.assertItemsEqual(expected, parse_dhcp_lease_file(lease_file)) +class TestDHCPRFC3442(CiTestCase): + + def test_parse_lease_finds_rfc3442_classless_static_routes(self): + """parse_dhcp_lease_file returns rfc3442-classless-static-routes.""" + lease_file = self.tmp_path('leases') + content = dedent(""" + lease { + interface "wlp3s0"; + fixed-address 192.168.2.74; + option subnet-mask 255.255.255.0; + option routers 192.168.2.1; + option rfc3442-classless-static-routes 0,130,56,240,1; + renew 4 2017/07/27 18:02:30; + expire 5 2017/07/28 07:08:15; + } + """) + expected = [ + {'interface': 'wlp3s0', 'fixed-address': '192.168.2.74', + 'subnet-mask': '255.255.255.0', 'routers': '192.168.2.1', + 'rfc3442-classless-static-routes': '0,130,56,240,1', + 'renew': '4 2017/07/27 18:02:30', + 'expire': '5 2017/07/28 07:08:15'}] + write_file(lease_file, content) + self.assertItemsEqual(expected, parse_dhcp_lease_file(lease_file)) + + @mock.patch('cloudinit.net.dhcp.EphemeralIPv4Network') + @mock.patch('cloudinit.net.dhcp.maybe_perform_dhcp_discovery') + def test_obtain_lease_parses_static_routes(self, m_maybe, m_ipv4): + """EphemeralDHPCv4 parses rfc3442 routes for EphemeralIPv4Network""" + lease = [ + {'interface': 'wlp3s0', 'fixed-address': '192.168.2.74', + 'subnet-mask': '255.255.255.0', 'routers': '192.168.2.1', + 'rfc3442-classless-static-routes': '0,130,56,240,1', + 'renew': '4 2017/07/27 18:02:30', + 'expire': '5 2017/07/28 07:08:15'}] + m_maybe.return_value = lease + eph = net.dhcp.EphemeralDHCPv4() + eph.obtain_lease() + expected_kwargs = { + 'interface': 'wlp3s0', + 'ip': '192.168.2.74', + 'prefix_or_mask': '255.255.255.0', + 'broadcast': '192.168.2.255', + 'static_routes': [('0.0.0.0/0', '130.56.240.1')], + 'router': '192.168.2.1'} + m_ipv4.assert_called_with(**expected_kwargs) + + +class TestDHCPParseStaticRoutes(CiTestCase): + + with_logs = True + + def parse_static_routes_empty_string(self): + self.assertEqual([], parse_static_routes("")) + + def test_parse_static_routes_invalid_input_returns_empty_list(self): + rfc3442 = "32,169,254,169,254,130,56,248" + self.assertEqual([], parse_static_routes(rfc3442)) + + def test_parse_static_routes_bogus_width_returns_empty_list(self): + rfc3442 = "33,169,254,169,254,130,56,248" + self.assertEqual([], parse_static_routes(rfc3442)) + + def test_parse_static_routes_single_ip(self): + rfc3442 = "32,169,254,169,254,130,56,248,255" + self.assertEqual([('169.254.169.254/32', '130.56.248.255')], + parse_static_routes(rfc3442)) + + def test_parse_static_routes_single_ip_handles_trailing_semicolon(self): + rfc3442 = "32,169,254,169,254,130,56,248,255;" + self.assertEqual([('169.254.169.254/32', '130.56.248.255')], + parse_static_routes(rfc3442)) + + def test_parse_static_routes_default_route(self): + rfc3442 = "0,130,56,240,1" + self.assertEqual([('0.0.0.0/0', '130.56.240.1')], + parse_static_routes(rfc3442)) + + def test_parse_static_routes_class_c_b_a(self): + class_c = "24,192,168,74,192,168,0,4" + class_b = "16,172,16,172,16,0,4" + class_a = "8,10,10,0,0,4" + rfc3442 = ",".join([class_c, class_b, class_a]) + self.assertEqual(sorted([ + ("192.168.74.0/24", "192.168.0.4"), + ("172.16.0.0/16", "172.16.0.4"), + ("10.0.0.0/8", "10.0.0.4") + ]), sorted(parse_static_routes(rfc3442))) + + def test_parse_static_routes_logs_error_truncated(self): + bad_rfc3442 = { + "class_c": "24,169,254,169,10", + "class_b": "16,172,16,10", + "class_a": "8,10,10", + "gateway": "0,0", + "netlen": "33,0", + } + for rfc3442 in bad_rfc3442.values(): + self.assertEqual([], parse_static_routes(rfc3442)) + + logs = self.logs.getvalue() + self.assertEqual(len(bad_rfc3442.keys()), len(logs.splitlines())) + + def test_parse_static_routes_returns_valid_routes_until_parse_err(self): + class_c = "24,192,168,74,192,168,0,4" + class_b = "16,172,16,172,16,0,4" + class_a_error = "8,10,10,0,0" + rfc3442 = ",".join([class_c, class_b, class_a_error]) + self.assertEqual(sorted([ + ("192.168.74.0/24", "192.168.0.4"), + ("172.16.0.0/16", "172.16.0.4"), + ]), sorted(parse_static_routes(rfc3442))) + + logs = self.logs.getvalue() + self.assertIn(rfc3442, logs.splitlines()[0]) + + class TestDHCPDiscoveryClean(CiTestCase): with_logs = True diff --git a/cloudinit/net/tests/test_init.py b/cloudinit/net/tests/test_init.py index 6d2affe7..d393e6ad 100644 --- a/cloudinit/net/tests/test_init.py +++ b/cloudinit/net/tests/test_init.py @@ -549,6 +549,45 @@ class TestEphemeralIPV4Network(CiTestCase): self.assertEqual(expected_setup_calls, m_subp.call_args_list) m_subp.assert_has_calls(expected_teardown_calls) + def test_ephemeral_ipv4_network_with_rfc3442_static_routes(self, m_subp): + params = { + 'interface': 'eth0', 'ip': '192.168.2.2', + 'prefix_or_mask': '255.255.255.0', 'broadcast': '192.168.2.255', + 'static_routes': [('169.254.169.254/32', '192.168.2.1'), + ('0.0.0.0/0', '192.168.2.1')], + 'router': '192.168.2.1'} + expected_setup_calls = [ + mock.call( + ['ip', '-family', 'inet', 'addr', 'add', '192.168.2.2/24', + 'broadcast', '192.168.2.255', 'dev', 'eth0'], + capture=True, update_env={'LANG': 'C'}), + mock.call( + ['ip', '-family', 'inet', 'link', 'set', 'dev', 'eth0', 'up'], + capture=True), + mock.call( + ['ip', '-4', 'route', 'add', '169.254.169.254/32', + 'via', '192.168.2.1', 'dev', 'eth0'], capture=True), + mock.call( + ['ip', '-4', 'route', 'add', '0.0.0.0/0', + 'via', '192.168.2.1', 'dev', 'eth0'], capture=True)] + expected_teardown_calls = [ + mock.call( + ['ip', '-4', 'route', 'del', '0.0.0.0/0', + 'via', '192.168.2.1', 'dev', 'eth0'], capture=True), + mock.call( + ['ip', '-4', 'route', 'del', '169.254.169.254/32', + 'via', '192.168.2.1', 'dev', 'eth0'], capture=True), + mock.call( + ['ip', '-family', 'inet', 'link', 'set', 'dev', + 'eth0', 'down'], capture=True), + mock.call( + ['ip', '-family', 'inet', 'addr', 'del', + '192.168.2.2/24', 'dev', 'eth0'], capture=True) + ] + with net.EphemeralIPv4Network(**params): + self.assertEqual(expected_setup_calls, m_subp.call_args_list) + m_subp.assert_has_calls(expected_setup_calls + expected_teardown_calls) + class TestApplyNetworkCfgNames(CiTestCase): V1_CONFIG = textwrap.dedent("""\ |