T5474: establish common file name pattern for XML conf mode commands

We will use _ as CLI level divider. The XML definition filename and also
the Python helper should match the CLI node.

Example:
set interfaces ethernet -> interfaces_ethernet.xml.in
set interfaces bond -> interfaces_bond.xml.in
set service dhcp-server -> service_dhcp-server-xml.in

(cherry picked from commit 4ef110fd2c501b718344c72d495ad7e16d2bd465)

1 files changed, 236 insertions, 0 deletions

diff --git a/src/conf_mode/interfaces_vxlan.py b/src/conf_mode/interfaces_vxlan.py
new file mode 100755
index 000000000..4251e611b
--- /dev/null
+++ b/src/conf_mode/interfaces_vxlan.py
@@ -0,0 +1,236 @@
+#!/usr/bin/env python3
+#
+# 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
+# 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/>.
+
+import os
+
+from sys import exit
+from netifaces import interfaces
+
+from vyos.base import Warning
+from vyos.config import Config
+from vyos.configdict import get_interface_dict
+from vyos.configdict import leaf_node_changed
+from vyos.configdict import is_node_changed
+from vyos.configdict import node_changed
+from vyos.configverify import verify_address
+from vyos.configverify import verify_bridge_delete
+from vyos.configverify import verify_mtu_ipv6
+from vyos.configverify import verify_mirror_redirect
+from vyos.configverify import verify_source_interface
+from vyos.configverify import verify_bond_bridge_member
+from vyos.ifconfig import Interface
+from vyos.ifconfig import VXLANIf
+from vyos.template import is_ipv6
+from vyos.utils.dict import dict_search
+from vyos import ConfigError
+from vyos import airbag
+airbag.enable()
+
+def get_config(config=None):
+    """
+    Retrive CLI config as dictionary. Dictionary can never be empty, as at least
+    the interface name will be added or a deleted flag
+    """
+    if config:
+        conf = config
+    else:
+        conf = Config()
+    base = ['interfaces', 'vxlan']
+    ifname, vxlan = get_interface_dict(conf, base)
+
+    # VXLAN interfaces are picky and require recreation if certain parameters
+    # change. But a VXLAN interface should - of course - not be re-created if
+    # it's description or IP address is adjusted. Feels somehow logic doesn't it?
+    for cli_option in ['parameters', 'gpe', 'group', 'port', 'remote',
+                       'source-address', 'source-interface', 'vni']:
+        if is_node_changed(conf, base + [ifname, cli_option]):
+            vxlan.update({'rebuild_required': {}})
+            break
+
+    # When dealing with VNI filtering we need to know what VNI was actually removed,
+    # so build up a dict matching the vlan_to_vni structure but with removed values.
+    tmp = node_changed(conf, base + [ifname, 'vlan-to-vni'], recursive=True)
+    if tmp:
+        vxlan.update({'vlan_to_vni_removed': {}})
+        for vlan in tmp:
+            vni = leaf_node_changed(conf, base + [ifname, 'vlan-to-vni', vlan, 'vni'])
+            vxlan['vlan_to_vni_removed'].update({vlan : {'vni' : vni[0]}})
+
+    # We need to verify that no other VXLAN tunnel is configured when external
+    # mode is in use - Linux Kernel limitation
+    conf.set_level(base)
+    vxlan['other_tunnels'] = conf.get_config_dict([], key_mangling=('-', '_'),
+                                                  get_first_key=True,
+                                                  no_tag_node_value_mangle=True)
+
+    # This if-clause is just to be sure - it will always evaluate to true
+    ifname = vxlan['ifname']
+    if ifname in vxlan['other_tunnels']:
+        del vxlan['other_tunnels'][ifname]
+    if len(vxlan['other_tunnels']) == 0:
+        del vxlan['other_tunnels']
+
+    return vxlan
+
+def verify(vxlan):
+    if 'deleted' in vxlan:
+        verify_bridge_delete(vxlan)
+        return None
+
+    if int(vxlan['mtu']) < 1500:
+        Warning('RFC7348 recommends VXLAN tunnels preserve a 1500 byte MTU')
+
+    if 'group' in vxlan:
+        if 'source_interface' not in vxlan:
+            raise ConfigError('Multicast VXLAN requires an underlaying interface')
+        verify_source_interface(vxlan)
+
+    if not any(tmp in ['group', 'remote', 'source_address', 'source_interface'] for tmp in vxlan):
+        raise ConfigError('Group, remote, source-address or source-interface must be configured')
+
+    if 'vni' not in vxlan and dict_search('parameters.external', vxlan) == None:
+        raise ConfigError('Must either configure VXLAN "vni" or use "external" CLI option!')
+
+    if dict_search('parameters.external', vxlan) != None:
+        if 'vni' in vxlan:
+            raise ConfigError('Can not specify both "external" and "VNI"!')
+
+        if 'other_tunnels' in vxlan:
+            # When multiple VXLAN interfaces are defined and "external" is used,
+            # all VXLAN interfaces need to have vni-filter enabled!
+            # See Linux Kernel commit f9c4bb0b245cee35ef66f75bf409c9573d934cf9
+            other_vni_filter = False
+            for tunnel, tunnel_config in vxlan['other_tunnels'].items():
+                if dict_search('parameters.vni_filter', tunnel_config) != None:
+                    other_vni_filter = True
+                    break
+            # eqivalent of the C foo ? 'a' : 'b' statement
+            vni_filter = True and (dict_search('parameters.vni_filter', vxlan) != None) or False
+            # If either one is enabled, so must be the other. Both can be off and both can be on
+            if (vni_filter and not other_vni_filter) or (not vni_filter and other_vni_filter):
+                raise ConfigError(f'Using multiple VXLAN interfaces with "external" '\
+                    'requires all VXLAN interfaces to have "vni-filter" configured!')
+
+            if not vni_filter and not other_vni_filter:
+                other_tunnels = ', '.join(vxlan['other_tunnels'])
+                raise ConfigError(f'Only one VXLAN tunnel is supported when "external" '\
+                                f'CLI option is used and "vni-filter" is unset. '\
+                                f'Additional tunnels: {other_tunnels}')
+
+    if 'gpe' in vxlan and 'external' not in vxlan:
+        raise ConfigError(f'VXLAN-GPE is only supported when "external" '\
+                          f'CLI option is used.')
+
+    if 'source_interface' in vxlan:
+        # VXLAN adds at least an overhead of 50 byte - we need to check the
+        # underlaying device if our VXLAN package is not going to be fragmented!
+        vxlan_overhead = 50
+        if 'source_address' in vxlan and is_ipv6(vxlan['source_address']):
+            # IPv6 adds an extra 20 bytes overhead because the IPv6 header is 20
+            # bytes larger than the IPv4 header - assuming no extra options are
+            # in use.
+            vxlan_overhead += 20
+
+        # If source_address is not used - check IPv6 'remote' list
+        elif 'remote' in vxlan:
+            if any(is_ipv6(a) for a in vxlan['remote']):
+                vxlan_overhead += 20
+
+        lower_mtu = Interface(vxlan['source_interface']).get_mtu()
+        if lower_mtu < (int(vxlan['mtu']) + vxlan_overhead):
+            raise ConfigError(f'Underlaying device MTU is to small ({lower_mtu} '\
+                              f'bytes) for VXLAN overhead ({vxlan_overhead} bytes!)')
+
+    # Check for mixed IPv4 and IPv6 addresses
+    protocol = None
+    if 'source_address' in vxlan:
+        if is_ipv6(vxlan['source_address']):
+            protocol = 'ipv6'
+        else:
+            protocol = 'ipv4'
+
+    if 'remote' in vxlan:
+        error_msg = 'Can not mix both IPv4 and IPv6 for VXLAN underlay'
+        for remote in vxlan['remote']:
+            if is_ipv6(remote):
+                if protocol == 'ipv4':
+                    raise ConfigError(error_msg)
+                protocol = 'ipv6'
+            else:
+                if protocol == 'ipv6':
+                    raise ConfigError(error_msg)
+                protocol = 'ipv4'
+
+    if 'vlan_to_vni' in vxlan:
+        if 'is_bridge_member' not in vxlan:
+            raise ConfigError('VLAN to VNI mapping requires that VXLAN interface '\
+                              'is member of a bridge interface!')
+
+        vnis_used = []
+        for vif, vif_config in vxlan['vlan_to_vni'].items():
+            if 'vni' not in vif_config:
+                raise ConfigError(f'Must define VNI for VLAN "{vif}"!')
+            vni = vif_config['vni']
+            if vni in vnis_used:
+                raise ConfigError(f'VNI "{vni}" is already assigned to a different VLAN!')
+            vnis_used.append(vni)
+
+    if dict_search('parameters.neighbor_suppress', vxlan) != None:
+        if 'is_bridge_member' not in vxlan:
+            raise ConfigError('Neighbor suppression requires that VXLAN interface '\
+                              'is member of a bridge interface!')
+
+    verify_mtu_ipv6(vxlan)
+    verify_address(vxlan)
+    verify_bond_bridge_member(vxlan)
+    verify_mirror_redirect(vxlan)
+
+    # We use a defaultValue for port, thus it's always safe to use
+    if vxlan['port'] == '8472':
+        Warning('Starting from VyOS 1.4, the default port for VXLAN '\
+                'has been changed to 4789. This matches the IANA assigned '\
+                'standard port number!')
+
+    return None
+
+def generate(vxlan):
+    return None
+
+def apply(vxlan):
+    # Check if the VXLAN interface already exists
+    if 'rebuild_required' in vxlan or 'delete' in vxlan:
+        if vxlan['ifname'] in interfaces():
+            v = VXLANIf(vxlan['ifname'])
+            # VXLAN is super picky and the tunnel always needs to be recreated,
+            # thus we can simply always delete it first.
+            v.remove()
+
+    if 'deleted' not in vxlan:
+        # Finally create the new interface
+        v = VXLANIf(**vxlan)
+        v.update(vxlan)
+
+    return None
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        exit(1)