pppoe: T3090: migrate to vyos.ifconfig library to use the full potential

Now that MSS clamping is done on the "per-interface" level the entire PPPoE
stuff would have needed to get a full copy in GNU BASH for this or, participate
in the common library.

Add a new PPP ip-up script named 99-vyos-pppoe-callback which will call the
vyos.ifconfig.PPPoEIf.update() function to configure everything as done with
all other interfaces. This removes duplicated code for VRF assignment and route
installation when a PPPoE interface is brought up or down.

1 files changed, 108 insertions, 2 deletions

diff --git a/python/vyos/ifconfig/pppoe.py b/python/vyos/ifconfig/pppoe.py
index 6acf7d1c7..9153863de 100644
--- a/python/vyos/ifconfig/pppoe.py
+++ b/python/vyos/ifconfig/pppoe.py
@@ -1,4 +1,4 @@
-# Copyright 2020 VyOS maintainers and contributors <maintainers@vyos.io>
+# Copyright 2020-2021 VyOS maintainers and contributors <maintainers@vyos.io>
 #
 # This library is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
@@ -14,6 +14,7 @@
 # License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 
 from vyos.ifconfig.interface import Interface
+from vyos.util import get_interface_config
 
 @Interface.register
 class PPPoEIf(Interface):
@@ -26,7 +27,31 @@ class PPPoEIf(Interface):
         },
     }
 
-    # stub this interface is created in the configure script
+    def _remove_routes(self, vrf=''):
+        # Always delete default routes when interface is removed
+        if vrf:
+            vrf = f'-c "vrf {vrf}"'
+        self._cmd(f'vtysh -c "conf t" {vrf} -c "no ip route 0.0.0.0/0 {self.ifname} tag 210"')
+        self._cmd(f'vtysh -c "conf t" {vrf} -c "no ipv6 route ::/0 {self.ifname} tag 210"')
+
+    def remove(self):
+        """
+        Remove interface from operating system. Removing the interface
+        deconfigures all assigned IP addresses and clear possible DHCP(v6)
+        client processes.
+        Example:
+        >>> from vyos.ifconfig import Interface
+        >>> i = Interface('pppoe0')
+        >>> i.remove()
+        """
+
+        tmp = get_interface_config(self.ifname)
+        vrf = ''
+        if 'master' in tmp:
+            self._remove_routes(tmp['master'])
+
+        # remove bond master which places members in disabled state
+        super().remove()
 
     def _create(self):
         # we can not create this interface as it is managed outside
@@ -35,3 +60,84 @@ class PPPoEIf(Interface):
     def _delete(self):
         # we can not create this interface as it is managed outside
         pass
+
+    def del_addr(self, addr):
+        # we can not create this interface as it is managed outside
+        pass
+
+    def get_mac(self):
+        """ Get a synthetic MAC address. """
+        return self.get_mac_synthetic()
+
+    def update(self, config):
+        """ General helper function which works on a dictionary retrived by
+        get_config_dict(). It's main intention is to consolidate the scattered
+        interface setup code and provide a single point of entry when workin
+        on any interface. """
+
+        # remove old routes from an e.g. old VRF assignment
+        vrf = ''
+        if 'vrf_old' in config:
+            vrf = config['vrf_old']
+        self._remove_routes(vrf)
+
+        # DHCPv6 PD handling is a bit different on PPPoE interfaces, as we do
+        # not require an 'address dhcpv6' CLI option as with other interfaces
+        if 'dhcpv6_options' in config and 'pd' in config['dhcpv6_options']:
+            self.set_dhcpv6(True)
+        else:
+            self.set_dhcpv6(False)
+
+        super().update(config)
+
+        if 'default_route' not in config or config['default_route'] == 'none':
+            return
+
+        #
+        # Set default routes pointing to pppoe interface
+        #
+        vrf = ''
+        sed_opt = '^ip route'
+
+        install_v4 = True
+        install_v6 = True
+
+        # generate proper configuration string when VRFs are in use
+        if 'vrf' in config:
+            tmp = config['vrf']
+            vrf = f'-c "vrf {tmp}"'
+            sed_opt = f'vrf {tmp}'
+
+        if config['default_route'] == 'auto':
+            # only add route if there is no default route present
+            tmp = self._cmd(f'vtysh -c "show running-config staticd no-header" | sed -n "/{sed_opt}/,/!/p"')
+            for line in tmp.splitlines():
+                line = line.lstrip()
+                if line.startswith('ip route 0.0.0.0/0'):
+                    install_v4 = False
+                    continue
+
+                if 'ipv6' in config and line.startswith('ipv6 route ::/0'):
+                    install_v6 = False
+                    continue
+
+        elif config['default_route'] == 'force':
+            # Force means that all static routes are replaced with the ones from this interface
+            tmp = self._cmd(f'vtysh -c "show running-config staticd no-header" | sed -n "/{sed_opt}/,/!/p"')
+            for line in tmp.splitlines():
+                if self.ifname in line:
+                    # It makes no sense to remove a route with our interface and the later re-add it.
+                    # This will only make traffic disappear - which is a no-no!
+                    continue
+
+                line = line.lstrip()
+                if line.startswith('ip route 0.0.0.0/0'):
+                    self._cmd(f'vtysh -c "conf t" {vrf} -c "no {line}"')
+
+                if 'ipv6' in config and line.startswith('ipv6 route ::/0'):
+                    self._cmd(f'vtysh -c "conf t" {vrf} -c "no {line}"')
+
+        if install_v4:
+            self._cmd(f'vtysh -c "conf t" {vrf} -c "ip route 0.0.0.0/0 {self.ifname} tag 210"')
+        if install_v6 and 'ipv6' in config:
+            self._cmd(f'vtysh -c "conf t" {vrf} -c "ipv6 route ::/0 {self.ifname} tag 210"')