vti: T5769: restore interface settings on down -> up event

On VTI interface link down the link-local IPv6 address is removed. As soon as
the IPSec tunnel is online again, vti-up-down helper is called which only places
the interface in up state using iproute2 command

    sudo ip link set vti0 up

This does not restore the IPv6 LL address. Instead use vyos.ifconfig to properly
re-initialize the VTI interface using the generic update() method.

1 files changed, 11 insertions, 10 deletions

diff --git a/src/etc/ipsec.d/vti-up-down b/src/etc/ipsec.d/vti-up-down
index 9eb6fac48..441b316c2 100755
--- a/src/etc/ipsec.d/vti-up-down
+++ b/src/etc/ipsec.d/vti-up-down
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2021 VyOS maintainers and contributors
+# Copyright (C) 2021-2023 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
@@ -13,8 +13,9 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
-## Script called up strongswan to bring the vti interface up/down based on the state of the IPSec tunnel.
-## Called as vti_up_down vti_intf_name
+
+# Script called up strongswan to bring the VTI interface up/down based on
+# the state of the IPSec tunnel. Called as vti_up_down vti_intf_name
 
 import os
 import sys
@@ -25,9 +26,10 @@ from syslog import LOG_PID
 from syslog import LOG_INFO
 
 from vyos.configquery import ConfigTreeQuery
+from vyos.configdict import get_interface_dict
+from vyos.ifconfig import VTIIf
 from vyos.utils.process import call
 from vyos.utils.network import get_interface_config
-from vyos.utils.network import get_interface_address
 
 if __name__ == '__main__':
     verb = os.getenv('PLUTO_VERB')
@@ -48,14 +50,13 @@ if __name__ == '__main__':
 
     vti_link_up = (vti_link['operstate'] != 'DOWN' if 'operstate' in vti_link else False)
 
-    config = ConfigTreeQuery()
-    vti_dict = config.get_config_dict(['interfaces', 'vti', interface],
-                                      get_first_key=True)
-
     if verb in ['up-client', 'up-host']:
         if not vti_link_up:
-            if 'disable' not in vti_dict:
-                call(f'sudo ip link set {interface} up')
+            conf = ConfigTreeQuery()
+            _, vti = get_interface_dict(conf.config, ['interfaces', 'vti'], interface)
+            if 'disable' not in vti:
+                tmp = VTIIf(interface)
+                tmp.update(vti)
             else:
                 syslog(f'Interface {interface} is admin down ...')
     elif verb in ['down-client', 'down-host']: