Merge pull request #1258 from c-po/t4319-disable-ipv6

T4319: bugfixes for disabled IPv6 (current)

7 files changed, 101 insertions, 20 deletions

diff --git a/python/vyos/ifconfig/interface.py b/python/vyos/ifconfig/interface.py
index 4fda1c0a9..6b9a4d03e 100755
--- a/python/vyos/ifconfig/interface.py
+++ b/python/vyos/ifconfig/interface.py
@@ -39,7 +39,7 @@ from vyos.util import read_file
 from vyos.util import get_interface_config
 from vyos.util import get_interface_namespace
 from vyos.util import is_systemd_service_active
-from vyos.util import sysctl_read
+from vyos.util import is_ipv6_enabled
 from vyos.template import is_ipv4
 from vyos.template import is_ipv6
 from vyos.validate import is_intf_addr_assigned
@@ -1083,6 +1083,10 @@ class Interface(Control):
 
         addr_is_v4 = is_ipv4(addr)
 
+        # Failsave - do not add IPv6 address if IPv6 is disabled
+        if is_ipv6(addr) and not is_ipv6_enabled():
+            return False
+
         # add to interface
         if addr == 'dhcp':
             self.set_dhcp(True)
@@ -1498,7 +1502,7 @@ class Interface(Control):
         self.set_ipv4_source_validation(value)
 
         # Only change IPv6 parameters if IPv6 was not explicitly disabled
-        if sysctl_read('net.ipv6.conf.all.disable_ipv6') == '0':
+        if is_ipv6_enabled():
             # Configure MSS value for IPv6 TCP connections
             tmp = dict_search('ipv6.adjust_mss', config)
             value = tmp if (tmp != None) else '0'
diff --git a/python/vyos/ifconfig/loopback.py b/python/vyos/ifconfig/loopback.py
index de554ef44..30c890fdf 100644
--- a/python/vyos/ifconfig/loopback.py
+++ b/python/vyos/ifconfig/loopback.py
@@ -13,9 +13,8 @@
 # You should have received a copy of the GNU Lesser General Public
 # License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 
-import vyos.util
-
 from vyos.ifconfig.interface import Interface
+from vyos.util import is_ipv6_enabled
 
 @Interface.register
 class LoopbackIf(Interface):
@@ -34,8 +33,6 @@ class LoopbackIf(Interface):
         }
     }
 
-    name = 'loopback'
-
     def remove(self):
         """
         Loopback interface can not be deleted from operating system. We can
@@ -62,11 +59,11 @@ class LoopbackIf(Interface):
         on any interface. """
 
         addr = config.get('address', [])
-        # We must ensure that the loopback addresses are never deleted from the system
-        addr += ['127.0.0.1/8']
 
-        if (vyos.util.sysctl_read('net.ipv6.conf.all.disable_ipv6') == '0'):
-            addr += ['::1/128']
+        # We must ensure that the loopback addresses are never deleted from the system
+        addr.append('127.0.0.1/8')
+        if is_ipv6_enabled():
+            addr.append('::1/128')
 
         # Update IP address entry in our dictionary
         config.update({'address' : addr})
diff --git a/python/vyos/util.py b/python/vyos/util.py
index f46775490..f3f323c34 100644
--- a/python/vyos/util.py
+++ b/python/vyos/util.py
@@ -1019,3 +1019,7 @@ def sysctl_write(name, value):
         call(f'sysctl -wq {name}={value}')
         return True
     return False
+
+def is_ipv6_enabled() -> bool:
+    """ Check if IPv6 support on the system is enabled or not """
+    return (sysctl_read('net.ipv6.conf.all.disable_ipv6') == '0')
diff --git a/smoketest/scripts/cli/test_system_ipv6.py b/smoketest/scripts/cli/test_system_ipv6.py
index 3112d2e46..6fe58701b 100755
--- a/smoketest/scripts/cli/test_system_ipv6.py
+++ b/smoketest/scripts/cli/test_system_ipv6.py
@@ -17,7 +17,11 @@
 import unittest
 
 from base_vyostest_shim import VyOSUnitTestSHIM
+
+from vyos.template import is_ipv4
 from vyos.util import read_file
+from vyos.util import is_ipv6_enabled
+from vyos.validate import is_intf_addr_assigned
 
 base_path = ['system', 'ipv6']
 
@@ -42,6 +46,14 @@ class TestSystemIPv6(VyOSUnitTestSHIM.TestCase):
         self.assertEqual(read_file(file_forwarding), '0')
 
     def test_system_ipv6_disable(self):
+        # Verify previous "enable" state
+        self.assertEqual(read_file(file_disable), '0')
+        self.assertTrue(is_ipv6_enabled())
+
+        loopbacks = ['127.0.0.1', '::1']
+        for addr in loopbacks:
+            self.assertTrue(is_intf_addr_assigned('lo', addr))
+
         # Do not assign any IPv6 address on interfaces, this requires a reboot
         # which can not be tested, but we can read the config file :)
         self.cli_set(base_path + ['disable'])
@@ -49,6 +61,13 @@ class TestSystemIPv6(VyOSUnitTestSHIM.TestCase):
 
         # Verify configuration file
         self.assertEqual(read_file(file_disable), '1')
+        self.assertFalse(is_ipv6_enabled())
+
+        for addr in loopbacks:
+            if is_ipv4(addr):
+                self.assertTrue(is_intf_addr_assigned('lo', addr))
+            else:
+                self.assertFalse(is_intf_addr_assigned('lo', addr))
 
     def test_system_ipv6_strict_dad(self):
         # This defaults to 1
diff --git a/smoketest/scripts/cli/test_vrf.py b/smoketest/scripts/cli/test_vrf.py
index 5ffa9c086..5daea589c 100755
--- a/smoketest/scripts/cli/test_vrf.py
+++ b/smoketest/scripts/cli/test_vrf.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2020-2021 VyOS maintainers and contributors
+# Copyright (C) 2020-2022 VyOS maintainers and contributors
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 or later as
@@ -25,9 +25,10 @@ from base_vyostest_shim import VyOSUnitTestSHIM
 from vyos.configsession import ConfigSessionError
 from vyos.ifconfig import Interface
 from vyos.ifconfig import Section
-from vyos.template import is_ipv6
+from vyos.template import is_ipv4
 from vyos.util import cmd
 from vyos.util import read_file
+from vyos.util import get_interface_config
 from vyos.validate import is_intf_addr_assigned
 
 base_path = ['vrf']
@@ -105,10 +106,13 @@ class VRFTest(VyOSUnitTestSHIM.TestCase):
             frrconfig = self.getFRRconfig(f'vrf {vrf}')
             self.assertIn(f' vni {table}', frrconfig)
 
+            tmp = get_interface_config(vrf)
+            self.assertEqual(int(table), tmp['linkinfo']['info_data']['table'])
+
             # Increment table ID for the next run
             table = str(int(table) + 1)
 
-    def test_vrf_loopback_ips(self):
+    def test_vrf_loopbacks_ips(self):
         table = '2000'
         for vrf in vrfs:
             base = base_path + ['name', vrf]
@@ -119,10 +123,48 @@ class VRFTest(VyOSUnitTestSHIM.TestCase):
         self.cli_commit()
 
         # Verify VRF configuration
+        loopbacks = ['127.0.0.1', '::1']
         for vrf in vrfs:
-            self.assertTrue(vrf in interfaces())
-            self.assertTrue(is_intf_addr_assigned(vrf, '127.0.0.1'))
-            self.assertTrue(is_intf_addr_assigned(vrf, '::1'))
+            # Ensure VRF was created
+            self.assertIn(vrf, interfaces())
+            # Test for proper loopback IP assignment
+            for addr in loopbacks:
+                self.assertTrue(is_intf_addr_assigned(vrf, addr))
+
+    def test_vrf_loopbacks_no_ipv6(self):
+        table = '2002'
+        for vrf in vrfs:
+            base = base_path + ['name', vrf]
+            self.cli_set(base + ['table', str(table)])
+            table = str(int(table) + 1)
+
+        # Globally disable IPv6 - this will remove all IPv6 interface addresses
+        self.cli_set(['system', 'ipv6', 'disable'])
+
+        # commit changes
+        self.cli_commit()
+
+        # Verify VRF configuration
+        table = '2002'
+        loopbacks = ['127.0.0.1', '::1']
+        for vrf in vrfs:
+            # Ensure VRF was created
+            self.assertIn(vrf, interfaces())
+
+            # Verify VRF table ID
+            tmp = get_interface_config(vrf)
+            self.assertEqual(int(table), tmp['linkinfo']['info_data']['table'])
+
+            # Test for proper loopback IP assignment
+            for addr in loopbacks:
+                if is_ipv4(addr):
+                    self.assertTrue(is_intf_addr_assigned(vrf, addr))
+                else:
+                    self.assertFalse(is_intf_addr_assigned(vrf, addr))
+
+            table = str(int(table) + 1)
+
+        self.cli_delete(['system', 'ipv6'])
 
     def test_vrf_bind_all(self):
         table = '2000'
diff --git a/src/conf_mode/vrf.py b/src/conf_mode/vrf.py
index 6a521a0dd..c3e2d8efd 100755
--- a/src/conf_mode/vrf.py
+++ b/src/conf_mode/vrf.py
@@ -30,6 +30,7 @@ from vyos.util import get_interface_config
 from vyos.util import popen
 from vyos.util import run
 from vyos.util import sysctl_write
+from vyos.util import is_ipv6_enabled
 from vyos import ConfigError
 from vyos import frr
 from vyos import airbag
@@ -215,10 +216,11 @@ def apply(vrf):
 
             # set VRF description for e.g. SNMP monitoring
             vrf_if = Interface(name)
-            # We also should add proper loopback IP addresses to the newly
-            # created VRFs for services bound to the loopback address (SNMP, NTP)
+            # We also should add proper loopback IP addresses to the newly added
+            # VRF for services bound to the loopback address (SNMP, NTP)
             vrf_if.add_addr('127.0.0.1/8')
-            vrf_if.add_addr('::1/128')
+            if is_ipv6_enabled():
+                vrf_if.add_addr('::1/128')
             # add VRF description if available
             vrf_if.set_alias(config.get('description', ''))
 
diff --git a/src/tests/test_util.py b/src/tests/test_util.py
index 9bd27adc0..91890262c 100644
--- a/src/tests/test_util.py
+++ b/src/tests/test_util.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2020-2021 VyOS maintainers and contributors
+# Copyright (C) 2020-2022 VyOS maintainers and contributors
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 or later as
@@ -23,3 +23,16 @@ class TestVyOSUtil(TestCase):
         expected_data = {"foo_bar": {"baz_quux": None}}
         new_data = mangle_dict_keys(data, '-', '_')
         self.assertEqual(new_data, expected_data)
+
+    def test_sysctl_read(self):
+        self.assertEqual(sysctl_read('net.ipv4.conf.lo.forwarding'), '1')
+
+    def test_ipv6_enabled(self):
+        tmp = sysctl_read('net.ipv6.conf.all.disable_ipv6')
+        # We need to test for both variants as this depends on how the
+        # Docker container is started (with or without IPv6 support) - so we
+        # will simply check both cases to not make the users life miserable.
+        if tmp == '0':
+            self.assertTrue(is_ipv6_enabled())
+        else:
+            self.assertFalse(is_ipv6_enabled())