loopback: T1601: rewrite using XML/Python definitions

2 files changed, 148 insertions, 0 deletions

diff --git a/interface-definitions/interfaces-loopback.xml b/interface-definitions/interfaces-loopback.xml
new file mode 100644
index 000000000..267731b1c
--- /dev/null
+++ b/interface-definitions/interfaces-loopback.xml
@@ -0,0 +1,46 @@
+<?xml version="1.0"?>
+<interfaceDefinition>
+  <node name="interfaces">
+    <children>
+      <tagNode name="loopback" owner="${vyos_conf_scripts_dir}/interface-loopback.py">
+        <properties>
+          <help>Loopback interface</help>
+          <priority>300</priority>
+          <constraint>
+            <regex>lo$</regex>
+          </constraint>
+          <constraintErrorMessage>Loopback interface must be named lo</constraintErrorMessage>
+          <valueHelp>
+            <format>lo</format>
+            <description>Loopback interface</description>
+          </valueHelp>
+        </properties>
+        <children>
+          <leafNode name="address">
+            <properties>
+              <help>IP address</help>
+              <valueHelp>
+                <format>ipv4net</format>
+                <description>IPv4 address and prefix length</description>
+              </valueHelp>
+              <valueHelp>
+                <format>ipv6net</format>
+                <description>IPv6 address and prefix length</description>
+              </valueHelp>
+              <multi/>
+            </properties>
+          </leafNode>
+          <leafNode name="description">
+            <properties>
+              <help>Interface description</help>
+              <constraint>
+                <regex>^.{1,256}$</regex>
+              </constraint>
+              <constraintErrorMessage>Interface description too long (limit 256 characters)</constraintErrorMessage>
+            </properties>
+          </leafNode>
+        </children>
+      </tagNode>
+    </children>
+  </node>
+</interfaceDefinition>
diff --git a/src/conf_mode/interface-loopback.py b/src/conf_mode/interface-loopback.py
new file mode 100755
index 000000000..445a9af64
--- /dev/null
+++ b/src/conf_mode/interface-loopback.py
@@ -0,0 +1,102 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2019 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
+import sys
+import copy
+
+import vyos.configinterface as VyIfconfig
+
+from vyos.config import Config
+from vyos import ConfigError
+
+default_config_data = {
+    'address': [],
+    'address_remove': [],
+    'deleted': False,
+    'description': '',
+}
+
+def diff(first, second):
+    second = set(second)
+    return [item for item in first if item not in second]
+
+def get_config():
+    loopback = copy.deepcopy(default_config_data)
+    conf = Config()
+
+    # determine tagNode instance
+    try:
+        loopback['intf'] = os.environ['VYOS_TAGNODE_VALUE']
+    except KeyError as E:
+        print("Interface not specified")
+
+    # Check if interface has been removed
+    if not conf.exists('interfaces loopback ' + loopback['intf']):
+        loopback['deleted'] = True
+
+    # set new configuration level
+    conf.set_level('interfaces loopback ' + loopback['intf'])
+
+    # retrieve configured interface addresses
+    if conf.exists('address'):
+        loopback['address'] = conf.return_values('address')
+
+    # retrieve interface description
+    if conf.exists('description'):
+        loopback['description'] = conf.return_value('description')
+
+    # Determine interface addresses (currently effective) - to determine which
+    # address is no longer valid and needs to be removed from the interface
+    eff_addr = conf.return_effective_values('address')
+    act_addr = conf.return_values('address')
+    loopback['address_remove'] = diff(eff_addr, act_addr)
+
+    return loopback
+
+def verify(loopback):
+    return None
+
+def generate(loopback):
+    return None
+
+def apply(loopback):
+    # Remove loopback interface
+    if not loopback['deleted']:
+        # update interface description used e.g. within SNMP
+        VyIfconfig.set_description(loopback['intf'], loopback['description'])
+
+        # Configure interface address(es)
+        for addr in loopback['address']:
+            VyIfconfig.add_interface_address(loopback['intf'], addr)
+
+    # Remove interface address(es)
+    for addr in loopback['address_remove']:
+        VyIfconfig.remove_interface_address(loopback['intf'], addr)
+
+    return None
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        sys.exit(1)