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

1 files changed, 106 insertions, 0 deletions

diff --git a/src/conf_mode/service_dhcpv6-relay.py b/src/conf_mode/service_dhcpv6-relay.py
new file mode 100755
index 000000000..6537ca3c2
--- /dev/null
+++ b/src/conf_mode/service_dhcpv6-relay.py
@@ -0,0 +1,106 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2018-2020 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 vyos.config import Config
+from vyos.ifconfig import Interface
+from vyos.template import render
+from vyos.template import is_ipv6
+from vyos.utils.process import call
+from vyos.utils.network import is_ipv6_link_local
+from vyos import ConfigError
+from vyos import airbag
+airbag.enable()
+
+config_file = '/run/dhcp-relay/dhcrelay6.conf'
+
+def get_config(config=None):
+    if config:
+        conf = config
+    else:
+        conf = Config()
+    base = ['service', 'dhcpv6-relay']
+    if not conf.exists(base):
+        return None
+
+    relay = conf.get_config_dict(base, key_mangling=('-', '_'),
+                                 get_first_key=True,
+                                 with_recursive_defaults=True)
+
+    return relay
+
+def verify(relay):
+    # bail out early - looks like removal from running config
+    if not relay or 'disable' in relay:
+        return None
+
+    if 'upstream_interface' not in relay:
+        raise ConfigError('At least one upstream interface required!')
+    for interface, config in relay['upstream_interface'].items():
+        if 'address' not in config:
+            raise ConfigError('DHCPv6 server required for upstream ' \
+                              f'interface {interface}!')
+
+    if 'listen_interface' not in relay:
+        raise ConfigError('At least one listen interface required!')
+
+    # DHCPv6 relay requires at least one global unicat address assigned to the
+    # interface
+    for interface in relay['listen_interface']:
+        has_global = False
+        for addr in Interface(interface).get_addr():
+            if is_ipv6(addr) and not is_ipv6_link_local(addr):
+                has_global = True
+        if not has_global:
+            raise ConfigError(f'Interface {interface} does not have global '\
+                              'IPv6 address assigned!')
+
+    return None
+
+def generate(relay):
+    # bail out early - looks like removal from running config
+    if not relay or 'disable' in relay:
+        return None
+
+    render(config_file, 'dhcp-relay/dhcrelay6.conf.j2', relay)
+    return None
+
+def apply(relay):
+    # bail out early - looks like removal from running config
+    service_name = 'isc-dhcp-relay6.service'
+    if not relay or 'disable' in relay:
+        # DHCPv6 relay support is removed in the commit
+        call(f'systemctl stop {service_name}')
+        if os.path.exists(config_file):
+            os.unlink(config_file)
+        return None
+
+    call(f'systemctl restart {service_name}')
+
+    return None
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        exit(1)