pppoe: T4384: replace default-route CLI option with common CLI nodes already present for DHCP

VyOS 1.4 still leverages PPPd internals on the CLI.

pppd supports three options for a default route, none, auto, force.
* none: No default route is installed on interface up
* auto: Default route is only installed if there is yet no default route
* force: overwrite any default route

There are several drawbacks in this design for VyOS and the users. If auto is
specified, this only counted for static default routes - but what about dynamic
ones? Same for force, only a static default route got replaced but dynamic ones
did not got taken into account.

The CLI is changed and we now re-use already existing nodes from the DHCP
interface configuration:
* no-default-route:
  On link up no default route is installed, same as the previous
  default-route none

* default-route-distance:
  We can now specify the distance of this route for the routing table on the
  system. This defaults to 210 as we have for DHCP interfaces. All this will be
  migrated using a CLI migration script.

4 files changed, 76 insertions, 30 deletions

diff --git a/src/conf_mode/interfaces-pppoe.py b/src/conf_mode/interfaces-pppoe.py
index bfb1fadd5..279369a32 100755
--- a/src/conf_mode/interfaces-pppoe.py
+++ b/src/conf_mode/interfaces-pppoe.py
@@ -22,7 +22,9 @@ from netifaces import interfaces
 
 from vyos.config import Config
 from vyos.configdict import get_interface_dict
+from vyos.configdict import is_node_changed
 from vyos.configdict import leaf_node_changed
+from vyos.configdict import get_pppoe_interfaces
 from vyos.configverify import verify_authentication
 from vyos.configverify import verify_source_interface
 from vyos.configverify import verify_interface_exists
@@ -52,28 +54,12 @@ def get_config(config=None):
     # We should only terminate the PPPoE session if critical parameters change.
     # All parameters that can be changed on-the-fly (like interface description)
     # should not lead to a reconnect!
-    tmp = leaf_node_changed(conf, ['access-concentrator'])
-    if tmp: pppoe.update({'shutdown_required': {}})
-
-    tmp = leaf_node_changed(conf, ['connect-on-demand'])
-    if tmp: pppoe.update({'shutdown_required': {}})
-
-    tmp = leaf_node_changed(conf, ['service-name'])
-    if tmp: pppoe.update({'shutdown_required': {}})
-
-    tmp = leaf_node_changed(conf, ['source-interface'])
-    if tmp: pppoe.update({'shutdown_required': {}})
-
-    tmp = leaf_node_changed(conf, ['vrf'])
-    # leaf_node_changed() returns a list, as VRF is a non-multi node, there
-    # will be only one list element
-    if tmp: pppoe.update({'vrf_old': tmp[0]})
-
-    tmp = leaf_node_changed(conf, ['authentication', 'user'])
-    if tmp: pppoe.update({'shutdown_required': {}})
-
-    tmp = leaf_node_changed(conf, ['authentication', 'password'])
-    if tmp: pppoe.update({'shutdown_required': {}})
+    for options in ['access-concentrator', 'connect-on-demand', 'service-name',
+                    'source-interface', 'vrf', 'no-default-route', 'authentication']:
+        if is_node_changed(conf, options):
+            pppoe.update({'shutdown_required': {}})
+            # bail out early - no need to further process other nodes
+            break
 
     return pppoe
 
@@ -120,7 +106,7 @@ def apply(pppoe):
         return None
 
     # reconnect should only be necessary when certain config options change,
-    # like ACS name, authentication, no-peer-dns, source-interface
+    # like ACS name, authentication ... (see get_config() for details)
     if ((not is_systemd_service_running(f'ppp@{ifname}.service')) or
         'shutdown_required' in pppoe):
 
@@ -130,6 +116,9 @@ def apply(pppoe):
             p.remove()
 
         call(f'systemctl restart ppp@{ifname}.service')
+        # When interface comes "live" a hook is called:
+        # /etc/ppp/ip-up.d/99-vyos-pppoe-callback
+        # which triggers PPPoEIf.update()
     else:
         if os.path.isdir(f'/sys/class/net/{ifname}'):
             p = PPPoEIf(ifname)
diff --git a/src/conf_mode/protocols_static.py b/src/conf_mode/protocols_static.py
index 87432bc1c..58e202928 100755
--- a/src/conf_mode/protocols_static.py
+++ b/src/conf_mode/protocols_static.py
@@ -22,6 +22,7 @@ from sys import argv
 from vyos.config import Config
 from vyos.configdict import dict_merge
 from vyos.configdict import get_dhcp_interfaces
+from vyos.configdict import get_pppoe_interfaces
 from vyos.configverify import verify_common_route_maps
 from vyos.configverify import verify_vrf
 from vyos.template import render_to_string
@@ -59,7 +60,9 @@ def get_config(config=None):
 
     # T3680 - get a list of all interfaces currently configured to use DHCP
     tmp = get_dhcp_interfaces(conf, vrf)
-    if tmp: static['dhcp'] = tmp
+    if tmp: static.update({'dhcp' : tmp})
+    tmp = get_pppoe_interfaces(conf, vrf)
+    if tmp: static.update({'pppoe' : tmp})
 
     return static
 
diff --git a/src/etc/ppp/ip-up.d/99-vyos-pppoe-callback b/src/etc/ppp/ip-up.d/99-vyos-pppoe-callback
index bb918a468..78ca09010 100755
--- a/src/etc/ppp/ip-up.d/99-vyos-pppoe-callback
+++ b/src/etc/ppp/ip-up.d/99-vyos-pppoe-callback
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 #
-# Copyright (C) 2021 VyOS maintainers and contributors
+# Copyright (C) 2021-2022 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
@@ -28,7 +28,8 @@ from syslog import openlog
 from syslog import LOG_PID
 from syslog import LOG_INFO
 
-from vyos.configquery import ConfigTreeQuery
+from vyos.configquery import Config
+from vyos.configdict import get_interface_dict
 from vyos.ifconfig import PPPoEIf
 from vyos.util import read_file
 
@@ -50,10 +51,9 @@ dialer_pid = read_file(f'/var/run/{interface}.pid')
 openlog(ident=f'pppd[{dialer_pid}]', facility=LOG_INFO)
 syslog('executing ' + argv[0])
 
-conf = ConfigTreeQuery()
-pppoe = conf.get_config_dict(['interfaces', 'pppoe', argv[6]],
-                             get_first_key=True, key_mangling=('-', '_'))
-pppoe['ifname'] = argv[6]
+conf = Config()
+pppoe = get_interface_dict(conf, ['interfaces', 'pppoe'], argv[6])
 
+# Update the config
 p = PPPoEIf(pppoe['ifname'])
 p.update(pppoe)
diff --git a/src/migration-scripts/interfaces/25-to-26 b/src/migration-scripts/interfaces/25-to-26
new file mode 100755
index 000000000..a8936235e
--- /dev/null
+++ b/src/migration-scripts/interfaces/25-to-26
@@ -0,0 +1,54 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2022 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/>.
+
+# T4384: pppoe: replace default-route CLI option with common CLI nodes already
+#        present for DHCP
+
+from sys import argv
+
+from vyos.ethtool import Ethtool
+from vyos.configtree import ConfigTree
+
+if (len(argv) < 1):
+    print("Must specify file name!")
+    exit(1)
+
+file_name = argv[1]
+with open(file_name, 'r') as f:
+    config_file = f.read()
+
+base = ['interfaces', 'pppoe']
+config = ConfigTree(config_file)
+
+if not config.exists(base):
+    exit(0)
+
+for ifname in config.list_nodes(base):
+    tmp_config = base + [ifname, 'default-route']
+    if config.exists(tmp_config):
+        # Retrieve current config value
+        value = config.return_value(tmp_config)
+        # Delete old Config node
+        config.delete(tmp_config)
+        if value == 'none':
+            config.set(base + [ifname, 'no-default-route'])
+
+try:
+    with open(file_name, 'w') as f:
+        f.write(config.to_string())
+except OSError as e:
+    print(f'Failed to save the modified config: {e}')
+    exit(1)