pppoe-server: T6234: PPPoE-server pado-delay refactoring

(cherry picked from commit 107ee09)

data/templates/accel-ppp/pppoe.config.j2

@@ -67,7 +67,7 @@ service-name={{ service_name | join(',') }}
 {%     set delay_without_sessions = pado_delay.delays_without_sessions[0] | default('0') %}
 {%     set pado_delay_param = namespace(value=delay_without_sessions) %}
 {%     for delay, sessions in pado_delay.delays_with_sessions | sort(attribute='1') %}
-{%         if not loop.last %}
+{%         if not delay == 'disable' %}
 {%             set pado_delay_param.value = pado_delay_param.value + ',' + delay + ':' + sessions | string %}
 {%         else %}
 {%             set pado_delay_param.value = pado_delay_param.value + ',-1:' + sessions | string %}

interface-definitions/include/version/pppoe-server-version.xml.i

@@ -1,3 +1,3 @@
 <!-- include start from include/version/pppoe-server-version.xml.i -->
-<syntaxVersion component='pppoe-server' version='9'></syntaxVersion>
+<syntaxVersion component='pppoe-server' version='10'></syntaxVersion>
 <!-- include end -->

interface-definitions/service_pppoe-server.xml.in

@@ -73,12 +73,20 @@
           <tagNode name="pado-delay">
             <properties>
               <help>PADO delays</help>
+              <valueHelp>
+                <format>disable</format>
+                <description>Disable new connections</description>
+              </valueHelp>
+              <completionHelp>
+                <list>disable</list>
+              </completionHelp>
               <valueHelp>
                 <format>u32:1-999999</format>
                 <description>Number in ms</description>
               </valueHelp>
               <constraint>
                 <validator name="numeric" argument="--range 1-999999"/>
+                <regex>disable</regex>
               </constraint>
               <constraintErrorMessage>Invalid PADO delay</constraintErrorMessage>
             </properties>

smoketest/scripts/cli/test_service_pppoe-server.py

@@ -168,7 +168,14 @@ def test_pppoe_server_pado_delay(self):
         conf = ConfigParser(allow_no_value=True, delimiters='=')
         conf.read(self._config_file)
 
-        self.assertEqual(conf['pppoe']['pado-delay'], '10,20:200,-1:300')
+        self.assertEqual(conf['pppoe']['pado-delay'], '10,20:200,30:300')
+
+        self.set(['pado-delay', 'disable', 'sessions', '400'])
+        self.cli_commit()
+
+        conf = ConfigParser(allow_no_value=True, delimiters='=')
+        conf.read(self._config_file)
+        self.assertEqual(conf['pppoe']['pado-delay'], '10,20:200,30:300,-1:400')
 
 
 if __name__ == '__main__':

src/conf_mode/service_pppoe-server.py

@@ -84,12 +84,29 @@ def verify_pado_delay(pppoe):
         pado_delay = pppoe['pado_delay']
 
         delays_without_sessions = pado_delay['delays_without_sessions']
+        if 'disable' in delays_without_sessions:
+            raise ConfigError(
+                'Number of sessions must be specified for "pado-delay disable"'
+            )
+
         if len(delays_without_sessions) > 1:
             raise ConfigError(
                 f'Cannot add more then ONE pado-delay without sessions, '
                 f'but {len(delays_without_sessions)} were set'
             )
 
+        if 'disable' in [delay[0] for delay in pado_delay['delays_with_sessions']]:
+            # need to sort delays by sessions to verify if there is no delay
+            # for sessions after disabling
+            sorted_pado_delay = sorted(pado_delay['delays_with_sessions'], key=lambda k_v: k_v[1])
+            last_delay = sorted_pado_delay[-1]
+
+            if last_delay[0] != 'disable':
+                raise ConfigError(
+                    f'Cannot add pado-delay after disabled sessions, but '
+                    f'"pado-delay {last_delay[0]} sessions {last_delay[1]}" was set'
+                )
+
 def verify(pppoe):
     if not pppoe:
         return None

src/migration-scripts/pppoe-server/9-to-10

@@ -0,0 +1,56 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 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
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# Migration of pado-delay options
+
+from sys import argv
+from sys import exit
+from vyos.configtree import ConfigTree
+
+if len(argv) < 2:
+    print("Must specify file name!")
+    exit(1)
+
+file_name = argv[1]
+
+with open(file_name, 'r') as f:
+    config_file = f.read()
+
+config = ConfigTree(config_file)
+base = ['service', 'pppoe-server', 'pado-delay']
+if not config.exists(base):
+    exit(0)
+
+pado_delay = {}
+for delay in config.list_nodes(base):
+    sessions = config.return_value(base + [delay, 'sessions'])
+    pado_delay[delay] = sessions
+
+# need to define delay for latest sessions
+sorted_delays = dict(sorted(pado_delay.items(), key=lambda k_v: int(k_v[1])))
+last_delay = list(sorted_delays)[-1]
+
+# Rename last delay -> disable
+tmp = base + [last_delay]
+if config.exists(tmp):
+    config.rename(tmp, 'disable')
+
+try:
+    with open(file_name, 'w') as f:
+        f.write(config.to_string())
+except OSError as e:
+    print("Failed to save the modified config: {}".format(e))
+    exit(1)