openvpn: T4974: move CLI node "enable-dco" -> "offload dco" to match other inetfaces

Keep a common CLI structure by re-using the already established offload
node from ethernet.

3 files changed, 35 insertions, 15 deletions

diff --git a/data/templates/openvpn/server.conf.j2 b/data/templates/openvpn/server.conf.j2
index 525605240..d144529f3 100644
--- a/data/templates/openvpn/server.conf.j2
+++ b/data/templates/openvpn/server.conf.j2
@@ -48,11 +48,10 @@ push "redirect-gateway def1"
 {% if use_lzo_compression is vyos_defined %}
 compress lzo
 {% endif %}
-{% if enable_dco is not vyos_defined %}
+{% if offload.dco is not vyos_defined %}
 disable-dco
 {% endif %}
 
-
 {% if mode is vyos_defined('client') %}
 #
 # OpenVPN Client mode
diff --git a/interface-definitions/interfaces-openvpn.xml.in b/interface-definitions/interfaces-openvpn.xml.in
index ca6d80f8b..127a8179b 100644
--- a/interface-definitions/interfaces-openvpn.xml.in
+++ b/interface-definitions/interfaces-openvpn.xml.in
@@ -285,6 +285,19 @@
               </constraint>
             </properties>
           </leafNode>
+          <node name="offload">
+            <properties>
+              <help>Configurable offload options</help>
+            </properties>
+            <children>
+              <leafNode name="dco">
+                <properties>
+                  <help>Enable data channel offload on this interface</help>
+                  <valueless/>
+                </properties>
+              </leafNode>
+            </children>
+          </node>
           <leafNode name="openvpn-option">
             <properties>
               <help>Additional OpenVPN options. You must use the syntax of openvpn.conf in this text-field. Using this without proper knowledge may result in a crashed OpenVPN server. Check system log to look for errors.</help>
@@ -793,12 +806,6 @@
               <valueless/>
             </properties>
           </leafNode>
-          <leafNode name="enable-dco">
-            <properties>
-              <help>Use to enable OpenVPN data channel offload on this TUN interface</help>
-              <valueless/>
-            </properties>
-          </leafNode>
           #include <include/interface/redirect.xml.i>
           #include <include/interface/vrf.xml.i>
         </children>
diff --git a/src/conf_mode/interfaces-openvpn.py b/src/conf_mode/interfaces-openvpn.py
index 653474ed0..3bef9b8f6 100755
--- a/src/conf_mode/interfaces-openvpn.py
+++ b/src/conf_mode/interfaces-openvpn.py
@@ -115,6 +115,18 @@ def get_config(config=None):
     if dict_search('server.mfa.totp', tmp) == None:
         del openvpn['server']['mfa']
 
+    # OpenVPN Data-Channel-Offload (DCO) is a Kernel module. If loaded it applies to all
+    # OpenVPN interfaces. Check if DCO is used by any other interface instance.
+    tmp = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True)
+    for interface, interface_config in tmp.items():
+        # If one interface has DCO configured, enable it. No need to further check
+        # all other OpenVPN interfaces. We must use a dedicated key to indicate
+        # the Kernel module must be loaded or not. The per interface "offload.dco"
+        # key is required per OpenVPN interface instance.
+        if dict_search('offload.dco', interface_config) != None:
+            openvpn['module_load_dco'] = {}
+            break
+
     return openvpn
 
 def is_ec_private_key(pki, cert_name):
@@ -675,6 +687,15 @@ def apply(openvpn):
         if interface in interfaces():
             VTunIf(interface).remove()
 
+    # dynamically load/unload DCO Kernel extension if requested
+    dco_module = 'ovpn_dco_v2'
+    if 'module_load_dco' in openvpn:
+        check_kmod(dco_module)
+    else:
+        unload_kmod(dco_module)
+
+    # Now bail out early if interface is disabled or got deleted
+    if 'deleted' in openvpn or 'disable' in openvpn:
         return None
 
     # verify specified IP address is present on any interface on this system
@@ -684,13 +705,6 @@ def apply(openvpn):
         if not is_addr_assigned(openvpn['local_host']):
             cmd('sysctl -w net.ipv4.ip_nonlocal_bind=1')
 
-    # dynamically load/unload DCO Kernel extension if requested
-    dco_module = 'ovpn_dco_v2'
-    if 'enable_dco' in openvpn:
-        check_kmod(dco_module)
-    else:
-        unload_kmod(dco_module)
-
     # No matching OpenVPN process running - maybe it got killed or none
     # existed - nevertheless, spawn new OpenVPN process
     action = 'reload-or-restart'