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-rw-r--r--cloudinit/net/__init__.py34
-rw-r--r--cloudinit/net/dhcp.py90
-rw-r--r--cloudinit/net/tests/test_dhcp.py120
-rw-r--r--cloudinit/net/tests/test_init.py39
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("""\
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-20 07:44:07 +0000