bridge: T6043: do not call vxlan dependency if interface does not exist (yet)

In order to keep the proper priority list during system startup and on initial
setup/commit for this feature the dependent VXLAN code should not be called,
if the interface in question does not exist (yet).

(cherry picked from commit dbe8c613bb80bc8b714398825054ade5942ea75b)

2 files changed, 57 insertions, 8 deletions

diff --git a/smoketest/scripts/cli/test_interfaces_bridge.py b/smoketest/scripts/cli/test_interfaces_bridge.py
index cdff49f4b..6cd2cf760 100755
--- a/smoketest/scripts/cli/test_interfaces_bridge.py
+++ b/smoketest/scripts/cli/test_interfaces_bridge.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2020-2023 VyOS maintainers and contributors
+# Copyright (C) 2020-2024 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
@@ -21,13 +21,12 @@ import unittest
 from base_interfaces_test import BasicInterfaceTest
 from copy import deepcopy
 from glob import glob
-from netifaces import interfaces
 
 from vyos.ifconfig import Section
 from vyos.utils.process import cmd
 from vyos.utils.file import read_file
 from vyos.utils.network import get_interface_config
-from vyos.utils.network import is_intf_addr_assigned
+from vyos.utils.network import interface_exists
 
 class BridgeInterfaceTest(BasicInterfaceTest.TestCase):
     @classmethod
@@ -388,5 +387,53 @@ class BridgeInterfaceTest(BasicInterfaceTest.TestCase):
                     for vif_c in vifc:
                         self.cli_delete(['interfaces', 'bridge', interface, 'member', 'interface', f'{member}.{vif_s}.{vif_c}'])
 
+    def test_bridge_tunnel_vxlan_multicast(self):
+        # Testcase for T6043 running VXLAN over gretap
+        br_if = 'br0'
+        tunnel_if = 'tun0'
+        eth_if = 'eth1'
+        vxlan_if = 'vxlan0'
+        multicast_group = '239.0.0.241'
+        vni = '123'
+
+        self.cli_set(['interfaces', 'bridge', br_if, 'member', 'interface', eth_if])
+        self.cli_set(['interfaces', 'bridge', br_if, 'member', 'interface', vxlan_if])
+
+        self.cli_set(['interfaces', 'ethernet', 'eth0', 'address', '192.0.2.2/30'])
+
+        self.cli_set(['interfaces', 'tunnel', tunnel_if, 'address', '10.0.0.2/24'])
+        self.cli_set(['interfaces', 'tunnel', tunnel_if, 'enable-multicast'])
+        self.cli_set(['interfaces', 'tunnel', tunnel_if, 'encapsulation', 'gretap'])
+        self.cli_set(['interfaces', 'tunnel', tunnel_if, 'mtu', '1500'])
+        self.cli_set(['interfaces', 'tunnel', tunnel_if, 'parameters', 'ip', 'ignore-df'])
+        self.cli_set(['interfaces', 'tunnel', tunnel_if, 'parameters', 'ip', 'key', '1'])
+        self.cli_set(['interfaces', 'tunnel', tunnel_if, 'parameters', 'ip', 'no-pmtu-discovery'])
+        self.cli_set(['interfaces', 'tunnel', tunnel_if, 'parameters', 'ip', 'ttl', '0'])
+        self.cli_set(['interfaces', 'tunnel', tunnel_if, 'remote', '203.0.113.2'])
+        self.cli_set(['interfaces', 'tunnel', tunnel_if, 'source-address', '192.0.2.2'])
+
+        self.cli_set(['interfaces', 'vxlan', vxlan_if, 'group', multicast_group])
+        self.cli_set(['interfaces', 'vxlan', vxlan_if, 'mtu', '1426'])
+        self.cli_set(['interfaces', 'vxlan', vxlan_if, 'source-interface', tunnel_if])
+        self.cli_set(['interfaces', 'vxlan', vxlan_if, 'vni', vni])
+
+        self.cli_commit()
+
+        self.assertTrue(interface_exists(eth_if))
+        self.assertTrue(interface_exists(vxlan_if))
+        self.assertTrue(interface_exists(tunnel_if))
+
+        tmp = get_interface_config(vxlan_if)
+        self.assertEqual(tmp['ifname'], vxlan_if)
+        self.assertEqual(tmp['linkinfo']['info_data']['link'], tunnel_if)
+        self.assertEqual(tmp['linkinfo']['info_data']['group'], multicast_group)
+        self.assertEqual(tmp['linkinfo']['info_data']['id'], int(vni))
+
+        bridge_members = []
+        for tmp in glob(f'/sys/class/net/{br_if}/lower_*'):
+            bridge_members.append(os.path.basename(tmp).replace('lower_', ''))
+        self.assertIn(eth_if, bridge_members)
+        self.assertIn(vxlan_if, bridge_members)
+
 if __name__ == '__main__':
     unittest.main(verbosity=2)
diff --git a/src/conf_mode/interfaces_bridge.py b/src/conf_mode/interfaces_bridge.py
index 29991e2da..9789f7bd3 100755
--- a/src/conf_mode/interfaces_bridge.py
+++ b/src/conf_mode/interfaces_bridge.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2019-2023 VyOS maintainers and contributors
+# Copyright (C) 2019-2024 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
@@ -31,6 +31,7 @@ from vyos.configdict import has_vrf_configured
 from vyos.configdep import set_dependents
 from vyos.configdep import call_dependents
 from vyos.utils.dict import dict_search
+from vyos.utils.network import interface_exists
 from vyos import ConfigError
 
 from vyos import airbag
@@ -85,9 +86,10 @@ def get_config(config=None):
                 bridge['member']['interface'][interface].update({'has_vlan' : ''})
 
             # When using VXLAN member interfaces that are configured for Single
-            # VXLAN Device (SVD) we need to call the VXLAN conf-mode script to re-create
-            # VLAN to VNI mappings if required
-            if interface.startswith('vxlan'):
+            # VXLAN Device (SVD) we need to call the VXLAN conf-mode script to
+            # re-create VLAN to VNI mappings if required, but only if the interface
+            # is already live on the system - this must not be done on first commit
+            if interface.startswith('vxlan') and interface_exists(interface):
                 set_dependents('vxlan', conf, interface)
 
     # delete empty dictionary keys - no need to run code paths if nothing is there to do
@@ -167,7 +169,7 @@ def apply(bridge):
         br.update(bridge)
 
     for interface in dict_search('member.interface', bridge) or []:
-        if interface.startswith('vxlan'):
+        if interface.startswith('vxlan') and interface_exists(interface):
             try:
                 call_dependents()
             except ConfigError: