Merge pull request #2536 from c-po/backport-pr-2527

pppoe: T5630: make MRU default to MTU if unspecified (backport #2527)

3 files changed, 51 insertions, 11 deletions

diff --git a/interface-definitions/interfaces-pppoe.xml.in b/interface-definitions/interfaces-pppoe.xml.in
index aa2965c65..cdecc6540 100644
--- a/interface-definitions/interfaces-pppoe.xml.in
+++ b/interface-definitions/interfaces-pppoe.xml.in
@@ -116,7 +116,7 @@
           </leafNode>
           <leafNode name="mru">
             <properties>
-              <help>Maximum Receive Unit (MRU)</help>
+              <help>Maximum Receive Unit (MRU) (default: MTU value)</help>
               <valueHelp>
                 <format>u32:128-16384</format>
                 <description>Maximum Receive Unit in byte</description>
@@ -126,7 +126,6 @@
               </constraint>
               <constraintErrorMessage>MRU must be between 128 and 16384</constraintErrorMessage>
             </properties>
-            <defaultValue>1492</defaultValue>
           </leafNode>
           <leafNode name="no-peer-dns">
             <properties>
diff --git a/smoketest/scripts/cli/test_interfaces_pppoe.py b/smoketest/scripts/cli/test_interfaces_pppoe.py
index 2aaccbb13..e46354aee 100755
--- a/smoketest/scripts/cli/test_interfaces_pppoe.py
+++ b/smoketest/scripts/cli/test_interfaces_pppoe.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2019-2020 VyOS maintainers and contributors
+# Copyright (C) 2019-2023 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
@@ -58,13 +58,11 @@ class PPPoEInterfaceTest(VyOSUnitTestSHIM.TestCase):
             user = 'VyOS-user-' + interface
             passwd = 'VyOS-passwd-' + interface
             mtu = '1400'
-            mru = '1300'
 
             self.cli_set(base_path + [interface, 'authentication', 'user', user])
             self.cli_set(base_path + [interface, 'authentication', 'password', passwd])
             self.cli_set(base_path + [interface, 'default-route', 'auto'])
             self.cli_set(base_path + [interface, 'mtu', mtu])
-            self.cli_set(base_path + [interface, 'mru', '9000'])
             self.cli_set(base_path + [interface, 'no-peer-dns'])
 
             # check validate() - a source-interface is required
@@ -72,11 +70,6 @@ class PPPoEInterfaceTest(VyOSUnitTestSHIM.TestCase):
                 self.cli_commit()
             self.cli_set(base_path + [interface, 'source-interface', self._source_interface])
 
-            # check validate() - MRU needs to be less or equal then MTU
-            with self.assertRaises(ConfigSessionError):
-                self.cli_commit()
-            self.cli_set(base_path + [interface, 'mru', mru])
-
         # commit changes
         self.cli_commit()
 
@@ -88,7 +81,7 @@ class PPPoEInterfaceTest(VyOSUnitTestSHIM.TestCase):
             tmp = get_config_value(interface, 'mtu')[1]
             self.assertEqual(tmp, mtu)
             tmp = get_config_value(interface, 'mru')[1]
-            self.assertEqual(tmp, mru)
+            self.assertEqual(tmp, mtu)
             tmp = get_config_value(interface, 'user')[1].replace('"', '')
             self.assertEqual(tmp, user)
             tmp = get_config_value(interface, 'password')[1].replace('"', '')
@@ -233,5 +226,47 @@ class PPPoEInterfaceTest(VyOSUnitTestSHIM.TestCase):
             tmp = get_config_value(interface, 'host-uniq')[1]
             self.assertEqual(tmp, f'"{host_uniq}"')
 
+    def test_pppoe_mtu_mru(self):
+        # Check if PPPoE dialer can be configured and runs
+        for interface in self._interfaces:
+            user = f'VyOS-user-{interface}'
+            passwd = f'VyOS-passwd-{interface}'
+            mtu = '1400'
+            mru = '1300'
+
+            self.cli_set(base_path + [interface, 'authentication', 'user', user])
+            self.cli_set(base_path + [interface, 'authentication', 'password', passwd])
+            self.cli_set(base_path + [interface, 'mtu', mtu])
+            self.cli_set(base_path + [interface, 'mru', '9000'])
+
+            # check validate() - a source-interface is required
+            with self.assertRaises(ConfigSessionError):
+                self.cli_commit()
+            self.cli_set(base_path + [interface, 'source-interface', self._source_interface])
+
+            # check validate() - MRU needs to be less or equal then MTU
+            with self.assertRaises(ConfigSessionError):
+                self.cli_commit()
+            self.cli_set(base_path + [interface, 'mru', mru])
+
+        # commit changes
+        self.cli_commit()
+
+        # verify configuration file(s)
+        for interface in self._interfaces:
+            user = f'VyOS-user-{interface}'
+            passwd = f'VyOS-passwd-{interface}'
+
+            tmp = get_config_value(interface, 'mtu')[1]
+            self.assertEqual(tmp, mtu)
+            tmp = get_config_value(interface, 'mru')[1]
+            self.assertEqual(tmp, mru)
+            tmp = get_config_value(interface, 'user')[1].replace('"', '')
+            self.assertEqual(tmp, user)
+            tmp = get_config_value(interface, 'password')[1].replace('"', '')
+            self.assertEqual(tmp, passwd)
+            tmp = get_config_value(interface, 'ifname')[1]
+            self.assertEqual(tmp, interface)
+
 if __name__ == '__main__':
     unittest.main(verbosity=2)
diff --git a/src/conf_mode/interfaces-pppoe.py b/src/conf_mode/interfaces-pppoe.py
index 49714c558..7434c5b3b 100755
--- a/src/conf_mode/interfaces-pppoe.py
+++ b/src/conf_mode/interfaces-pppoe.py
@@ -44,6 +44,12 @@ def get_config(config=None):
     base = ['interfaces', 'pppoe']
     pppoe = get_interface_dict(conf, base)
 
+    if 'deleted' not in pppoe:
+        # We always set the MRU value to the MTU size. This code path only re-creates
+        # the old behavior if MRU is not set on the CLI.
+        if 'mru' not in pppoe:
+            pppoe['mru'] = pppoe['mtu']
+
     return pppoe
 
 def verify(pppoe):