tunnel: T3173: Add nopmtudisc parameter for tunnels conf-mode

3 files changed, 35 insertions, 4 deletions

diff --git a/interface-definitions/interfaces-tunnel.xml.in b/interface-definitions/interfaces-tunnel.xml.in
index 3a4db6f09..273aa648e 100644
--- a/interface-definitions/interfaces-tunnel.xml.in
+++ b/interface-definitions/interfaces-tunnel.xml.in
@@ -177,6 +177,25 @@
                   <help>IPv4 specific tunnel parameters</help>
                 </properties>
                 <children>
+                  <leafNode name="pmtu-discovery">
+                    <properties>
+                      <help>Path MTU Discovery parameters</help>
+                      <completionHelp>
+                        <list>disable enable</list>
+                      </completionHelp>
+                      <valueHelp>
+                        <format>disable</format>
+                        <description>Disable Path MTU Discovery for tunnel</description>
+                      </valueHelp>
+                      <valueHelp>
+                        <format>enable</format>
+                        <description>Enable Path MTU Discovery for tunnel (by default)</description>
+                      </valueHelp>
+                      <constraint>
+                        <regex>^(disable|enable)$</regex>
+                      </constraint>
+                    </properties>
+                  </leafNode>
                   <leafNode name="ttl">
                     <properties>
                       <help>Time to live field</help>
diff --git a/python/vyos/ifconfig/tunnel.py b/python/vyos/ifconfig/tunnel.py
index 00dc36420..8ecb59755 100644
--- a/python/vyos/ifconfig/tunnel.py
+++ b/python/vyos/ifconfig/tunnel.py
@@ -72,16 +72,22 @@ class _Tunnel(Interface):
 
         # add " option-name option-name-value ..." for all options set
         options = " ".join(["{} {}".format(k, self.config[k])
-                            for k in self.options if k in self.config and self.config[k]])
+                            for k in self.options if k in self.config and self.config[k] and k is not 'pmtud'])
         self._cmd('{} {}'.format(create.format(**self.config), options))
         self.set_admin_state('down')
 
     def change_options(self):
-        change = 'ip tunnel cha {ifname} mode {type}'
+        change = 'ip tunnel cha {ifname} mode {type} pmtudisc'
 
         # add " option-name option-name-value ..." for all options set
+        # option 'pmtud' doesn't has any value like 'ttl' or 'key' (ip tunnel cha tunX [no]pmtudisc)
         options = " ".join(["{} {}".format(k, self.config[k])
-                            for k in self.options if k in self.config and self.config[k]])
+                            for k in self.options if k in self.config and self.config[k] and k is not 'pmtud'])
+
+        # set interfaces tunnel tunX parameters ip pmtu-discovery disable
+        if 'disable' in self.config['pmtud']:
+            change = 'ip tunnel cha {ifname} mode {type} nopmtudisc'
+
         self._cmd('{} {}'.format(change.format(**self.config), options))
 
     @classmethod
@@ -142,7 +148,7 @@ class GREIf(_Tunnel):
     """
 
     default = {'type': 'gre'}
-    options = ['local', 'remote', 'dev', 'ttl', 'tos', 'key']
+    options = ['local', 'remote', 'dev', 'ttl', 'tos', 'key', 'pmtud']
 
 # GreTap also called GRE Bridge
 class GRETapIf(_Tunnel):
diff --git a/src/conf_mode/interfaces-tunnel.py b/src/conf_mode/interfaces-tunnel.py
index ffeb57784..f79405388 100755
--- a/src/conf_mode/interfaces-tunnel.py
+++ b/src/conf_mode/interfaces-tunnel.py
@@ -126,6 +126,11 @@ def verify(tunnel):
     if 'source_interface' in tunnel:
         verify_interface_exists(tunnel['source_interface'])
 
+    # ttl != 0 and nopmtudisc are incompatible
+    if 'pmtu_discovery' in tunnel['parameters']['ip']:
+        if 'disable' in tunnel['parameters']['ip']['pmtu_discovery'] and "0" not in tunnel['parameters']['ip']['ttl']:
+            raise ConfigError('ip ttl should be set to "0" with option "pmtu-discovery disable"')
+
 def generate(tunnel):
     return None
 
@@ -164,6 +169,7 @@ def apply(tunnel):
         'local_ip'                   : 'local',
         'remote_ip'                  : 'remote',
         'source_interface'           : 'dev',
+        'parameters.ip.pmtu_discovery' : 'pmtud',
         'parameters.ip.ttl'          : 'ttl',
         'parameters.ip.tos'          : 'tos',
         'parameters.ip.key'          : 'key',