ifconfig: backport ifconfig framework from 1.4 to support new tunnel options

It is easier to backport the entire vyos.ifconfig library from 1.4 instead of
backporting single pieces which are required to add new feature to the tunnel
interface section.

In addition that both libraries are now back in sync it will become much easier
to backport any other new feature introduced in VyOS 1.4!

1 files changed, 120 insertions, 149 deletions

diff --git a/python/vyos/ifconfig/tunnel.py b/python/vyos/ifconfig/tunnel.py
index 6f9d7abbf..e40756cc7 100644
--- a/python/vyos/ifconfig/tunnel.py
+++ b/python/vyos/ifconfig/tunnel.py
@@ -1,4 +1,4 @@
-# Copyright 2019-2020 VyOS maintainers and contributors <maintainers@vyos.io>
+# Copyright 2019-2021 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
@@ -16,13 +16,12 @@
 # https://developers.redhat.com/blog/2019/05/17/an-introduction-to-linux-virtual-interfaces-tunnels/
 # https://community.hetzner.com/tutorials/linux-setup-gre-tunnel
 
-from copy import deepcopy
-
 from netaddr import EUI
 from netaddr import mac_unix_expanded
 from random import getrandbits
 
 from vyos.ifconfig.interface import Interface
+from vyos.util import dict_search
 from vyos.validate import assert_list
 
 def enable_to_on(value):
@@ -32,11 +31,10 @@ def enable_to_on(value):
         return 'off'
     raise ValueError(f'expect enable or disable but got "{value}"')
 
-
 @Interface.register
-class _Tunnel(Interface):
+class TunnelIf(Interface):
     """
-    _Tunnel: private base class for tunnels
+    Tunnel: private base class for tunnels
     https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/ip/tunnel.c
     https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/ip/ip6tunnel.c
     """
@@ -49,54 +47,127 @@ class _Tunnel(Interface):
         },
     }
 
+    # This table represents a mapping from VyOS internal config dict to
+    # arguments used by iproute2. For more information please refer to:
+    # - https://man7.org/linux/man-pages/man8/ip-link.8.html
+    # - https://man7.org/linux/man-pages/man8/ip-tunnel.8.html
+    mapping = {
+        'source_address'                  : 'local',
+        'source_interface'                : 'dev',
+        'remote'                          : 'remote',
+        'parameters.ip.key'               : 'key',
+        'parameters.ip.tos'               : 'tos',
+        'parameters.ip.ttl'               : 'ttl',
+    }
+    mapping_ipv4 = {
+        'parameters.ip.key'               : 'key',
+        'parameters.ip.no_pmtu_discovery' : 'nopmtudisc',
+        'parameters.ip.ignore_df'         : 'ignore-df',
+        'parameters.ip.tos'               : 'tos',
+        'parameters.ip.ttl'               : 'ttl',
+        'parameters.erspan.direction'     : 'erspan_dir',
+        'parameters.erspan.hw_id'         : 'erspan_hwid',
+        'parameters.erspan.index'         : 'erspan',
+        'parameters.erspan.version'       : 'erspan_ver',
+    }
+    mapping_ipv6 = {
+        'parameters.ipv6.encaplimit'      : 'encaplimit',
+        'parameters.ipv6.flowlabel'       : 'flowlabel',
+        'parameters.ipv6.hoplimit'        : 'hoplimit',
+        'parameters.ipv6.tclass'          : 'tclass',
+    }
+
     # TODO: This is surely used for more than tunnels
     # TODO: could be refactored elsewhere
-    _command_set = {**Interface._command_set, **{
-        'multicast': {
-            'validate': lambda v: assert_list(v, ['enable', 'disable']),
-            'convert': enable_to_on,
-            'shellcmd': 'ip link set dev {ifname} multicast {value}',
-        },
-        'allmulticast': {
-            'validate': lambda v: assert_list(v, ['enable', 'disable']),
-            'convert': enable_to_on,
-            'shellcmd': 'ip link set dev {ifname} allmulticast {value}',
-        },
-    }}
-
-    _create_cmd = 'ip tunnel add {ifname} mode {type}'
+    _command_set = {
+        **Interface._command_set,
+        **{
+            'multicast': {
+                'validate': lambda v: assert_list(v, ['enable', 'disable']),
+                'convert': enable_to_on,
+                'shellcmd': 'ip link set dev {ifname} multicast {value}',
+            },
+            'allmulticast': {
+                'validate': lambda v: assert_list(v, ['enable', 'disable']),
+                'convert': enable_to_on,
+                'shellcmd': 'ip link set dev {ifname} allmulticast {value}',
+            },
+        }
+    }
 
-    def __init__(self, ifname, **config):
-        self.config = deepcopy(config) if config else {}
-        super().__init__(ifname, **config)
+    def __init__(self, ifname, **kargs):
+        # T3357: we do not have the 'encapsulation' in kargs when calling this
+        # class from op-mode like "show interfaces tunnel"
+        if 'encapsulation' in kargs:
+            self.iftype = kargs['encapsulation']
+            # The gretap interface has the possibility to act as L2 bridge
+            if self.iftype in ['gretap', 'ip6gretap']:
+                # no multicast, ttl or tos for gretap
+                self.definition = {
+                    **TunnelIf.definition,
+                    **{
+                        'bridgeable': True,
+                    },
+                }
+
+        super().__init__(ifname, **kargs)
 
     def _create(self):
-        # 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]])
-        self._cmd('{} {}'.format(self._create_cmd.format(**self.config), options))
-        self.set_admin_state('down')
+        if self.config['encapsulation'] in ['ipip6', 'ip6ip6', 'ip6gre']:
+            mapping = { **self.mapping, **self.mapping_ipv6 }
+        else:
+            mapping = { **self.mapping, **self.mapping_ipv4 }
+
+        cmd = 'ip tunnel add {ifname} mode {encapsulation}'
+        if self.iftype in ['gretap', 'ip6gretap', 'erspan', 'ip6erspan']:
+            cmd = 'ip link add name {ifname} type {encapsulation}'
+            # ERSPAN requires the serialisation of packets
+            if self.iftype in ['erspan', 'ip6erspan']:
+                cmd += ' seq'
+
+        for vyos_key, iproute2_key in mapping.items():
+            # dict_search will return an empty dict "{}" for valueless nodes like
+            # "parameters.nolearning" - thus we need to test the nodes existence
+            # by using isinstance()
+            tmp = dict_search(vyos_key, self.config)
+            if isinstance(tmp, dict):
+                cmd += f' {iproute2_key}'
+            elif tmp != None:
+                cmd += f' {iproute2_key} {tmp}'
+
+        self._cmd(cmd.format(**self.config))
 
-    def change_options(self):
-        change = 'ip tunnel change {ifname} mode {type}'
-
-        # 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]])
-        self._cmd('{} {}'.format(change.format(**self.config), options))
+        self.set_admin_state('down')
 
-    @classmethod
-    def get_config(cls):
-        return dict(zip(cls.options, ['']*len(cls.options)))
+    def _change_options(self):
+        # gretap interfaces do not support changing any parameter
+        if self.iftype in ['gretap', 'ip6gretap', 'erspan', 'ip6erspan']:
+            return
+
+        if self.config['encapsulation'] in ['ipip6', 'ip6ip6', 'ip6gre']:
+            mapping = { **self.mapping, **self.mapping_ipv6 }
+        else:
+            mapping = { **self.mapping, **self.mapping_ipv4 }
+
+        cmd = 'ip tunnel change {ifname} mode {encapsulation}'
+        for vyos_key, iproute2_key in mapping.items():
+            # dict_search will return an empty dict "{}" for valueless nodes like
+            # "parameters.nolearning" - thus we need to test the nodes existence
+            # by using isinstance()
+            tmp = dict_search(vyos_key, self.config)
+            if isinstance(tmp, dict):
+                cmd += f' {iproute2_key}'
+            elif tmp != None:
+                cmd += f' {iproute2_key} {tmp}'
+
+        self._cmd(cmd.format(**self.config))
 
     def get_mac(self):
         """
         Get current interface MAC (Media Access Contrl) address used.
-
         NOTE: Tunnel interfaces have no "MAC" address by default. The content
               of the 'address' file in /sys/class/net/device contains the
               local-ip thus we generate a random MAC address instead
-
         Example:
         >>> from vyos.ifconfig import Interface
         >>> Interface('eth0').get_mac()
@@ -113,113 +184,13 @@ class _Tunnel(Interface):
         mac.dialect = mac_unix_expanded
         return str(mac)
 
-class GREIf(_Tunnel):
-    """
-    GRE: Generic Routing Encapsulation
-
-    For more information please refer to:
-    RFC1701, RFC1702, RFC2784
-    https://tools.ietf.org/html/rfc2784
-    https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/ip/link_gre.c
-    """
-
-    default = {'type': 'gre'}
-    options = ['local', 'remote', 'dev', 'ttl', 'tos', 'key']
-
-# GreTap also called GRE Bridge
-class GRETapIf(_Tunnel):
-    """
-    GRETapIF: GreIF using TAP instead of TUN
-
-    https://en.wikipedia.org/wiki/TUN/TAP
-    """
-
-    # no multicast, ttl or tos for gretap
-    default = {'type': 'gretap'}
-    options = ['local', 'remote', 'ttl', 'tos', 'key']
-
-    _create_cmd = 'ip link add name {ifname} type {type}'
-
-    def change_options(self):
-        pass
-
-class IP6GREIf(_Tunnel):
-    """
-    IP6Gre: IPv6 Support for Generic Routing Encapsulation (GRE)
-
-    For more information please refer to:
-    https://tools.ietf.org/html/rfc7676
-    https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/ip/link_gre6.c
-    """
-
-    default = {'type': 'ip6gre'}
-    options = ['local', 'remote', 'dev', 'encaplimit',
-               'hoplimit', 'tclass', 'flowlabel']
-
-class IPIPIf(_Tunnel):
-    """
-    IPIP: IP Encapsulation within IP
-
-    For more information please refer to:
-    https://tools.ietf.org/html/rfc2003
-    """
-
-    # IPIP does not allow to pass multicast, unlike GRE
-    # but the interface itself can be set with multicast
-
-    default = {'type': 'ipip'}
-    options = ['local', 'remote', 'dev', 'ttl', 'tos', 'key']
-
-class IPIP6If(_Tunnel):
-    """
-    IPIP6: IPv4 over IPv6 tunnel
-
-    For more information please refer to:
-    https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/ip/link_ip6tnl.c
-    """
-
-    default = {'type': 'ipip6'}
-    options = ['local', 'remote', 'dev', 'encaplimit',
-               'hoplimit', 'tclass', 'flowlabel']
-
-class IP6IP6If(IPIP6If):
-    """
-    IP6IP6: IPv6 over IPv6 tunnel
-
-    For more information please refer to:
-    https://tools.ietf.org/html/rfc2473
-    """
-    default = {'type': 'ip6ip6'}
-
-
-class SitIf(_Tunnel):
-    """
-    Sit: Simple Internet Transition
-
-    For more information please refer to:
-    https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/ip/link_iptnl.c
-    """
-
-    default = {'type': 'sit'}
-    options = ['local', 'remote', 'dev', 'ttl', 'tos', 'key']
-
-class Sit6RDIf(SitIf):
-    """
-    Sit6RDIf: Simple Internet Transition with 6RD
-
-    https://en.wikipedia.org/wiki/IPv6_rapid_deployment
-    """
-    # TODO: check if key can really be used with 6RD
-    options = ['remote', 'ttl', 'tos', 'key', '6rd-prefix', '6rd-relay-prefix']
-
-    def _create(self):
-        # do not call _Tunnel.create, building fully here
-
-        create = 'ip tunnel add {ifname} mode {type} remote {remote}'
-        self._cmd(create.format(**self.config))
-        self.set_interface('state','down')
+    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. """
+        # Adjust iproute2 tunnel parameters if necessary
+        self._change_options()
 
-        set6rd = 'ip tunnel 6rd dev {ifname} 6rd-prefix {6rd-prefix}'
-        if '6rd-relay-prefix' in self.config:
-            set6rd += ' 6rd-relay-prefix {6rd-relay-prefix}'
-        self._cmd(set6rd.format(**self.config))
+        # call base class first
+        super().update(config)