From ca70102fcf782e7a61d3d1b7672d74eb8db32129 Mon Sep 17 00:00:00 2001
From: Nicolas Fort <nicolasfort1988@gmail.com>
Date: Tue, 18 Oct 2022 11:41:45 +0000
Subject: T2408: dhcp-relay: Add listen-interface and upstream-interface
 feature

---
 data/templates/dhcp-relay/dhcrelay.conf.j2       |  5 ++-
 interface-definitions/dhcp-relay.xml.in          | 49 +++++++++++++++++++++++-
 smoketest/scripts/cli/test_service_dhcp-relay.py | 37 ++++++++++++++++++
 src/conf_mode/dhcp_relay.py                      | 13 +++++++
 4 files changed, 102 insertions(+), 2 deletions(-)

diff --git a/data/templates/dhcp-relay/dhcrelay.conf.j2 b/data/templates/dhcp-relay/dhcrelay.conf.j2
index 11710bd8e..c26c263fd 100644
--- a/data/templates/dhcp-relay/dhcrelay.conf.j2
+++ b/data/templates/dhcp-relay/dhcrelay.conf.j2
@@ -2,5 +2,8 @@
 
 {% set max_size = '-A ' ~ relay_options.max_size if relay_options.max_size is vyos_defined %}
 {# hop_count and relay_agents_packets is a default option, thus it is always present #}
+{% if interface is vyos_defined %}
 OPTIONS="-c {{ relay_options.hop_count }} -a -m {{ relay_options.relay_agents_packets }} {{ max_size }} -i {{ interface | join(' -i ') }} {{ server | join(' ') }}"
-
+{% else %}
+OPTIONS="-c {{ relay_options.hop_count }} -a -m {{ relay_options.relay_agents_packets }} {{ max_size }} -id {{ listen_interface | join(' -id ') }} -iu {{ upstream_interface | join(' -iu ') }} {{ server | join(' ') }}"
+{% endif %}
\ No newline at end of file
diff --git a/interface-definitions/dhcp-relay.xml.in b/interface-definitions/dhcp-relay.xml.in
index 27d0a3e6c..746cc2fb4 100644
--- a/interface-definitions/dhcp-relay.xml.in
+++ b/interface-definitions/dhcp-relay.xml.in
@@ -9,7 +9,54 @@
           <priority>910</priority>
         </properties>
         <children>
-          #include <include/generic-interface-multi-broadcast.xml.i>
+          <leafNode name="interface">
+            <properties>
+              <help>Interface Name to use [To be deprecated]. Only for backward compatibility. Use listen-interface and upstream-interface instead of this option </help>
+              <completionHelp>
+                <script>${vyos_completion_dir}/list_interfaces.py --broadcast</script>
+              </completionHelp>
+              <valueHelp>
+                <format>txt</format>
+                <description>Interface name</description>
+              </valueHelp>
+              <constraint>
+                <validator name="interface-name"/>
+              </constraint>
+              <multi/>
+            </properties>
+          </leafNode>
+          <leafNode name="listen-interface">
+            <properties>
+              <help>Interface for DHCP Relay Agent to listen for requests</help>
+              <completionHelp>
+                <script>${vyos_completion_dir}/list_interfaces.py</script>
+              </completionHelp>
+              <valueHelp>
+                <format>txt</format>
+                <description>Interface name</description>
+              </valueHelp>
+              <constraint>
+                <validator name="interface-name"/>
+              </constraint>
+              <multi/>
+            </properties>
+          </leafNode>
+          <leafNode name="upstream-interface">
+            <properties>
+              <help>Interface for DHCP Relay Agent forward requests out</help>
+              <completionHelp>
+                <script>${vyos_completion_dir}/list_interfaces.py</script>
+              </completionHelp>
+              <valueHelp>
+                <format>txt</format>
+                <description>Interface name</description>
+              </valueHelp>
+              <constraint>
+                <validator name="interface-name"/>
+              </constraint>
+              <multi/>
+            </properties>
+          </leafNode>
           <node name="relay-options">
             <properties>
               <help>Relay options</help>
diff --git a/smoketest/scripts/cli/test_service_dhcp-relay.py b/smoketest/scripts/cli/test_service_dhcp-relay.py
index bbfd9e032..92f87c06c 100755
--- a/smoketest/scripts/cli/test_service_dhcp-relay.py
+++ b/smoketest/scripts/cli/test_service_dhcp-relay.py
@@ -82,6 +82,43 @@ class TestServiceDHCPRelay(VyOSUnitTestSHIM.TestCase):
         # Check for running process
         self.assertTrue(process_named_running(PROCESS_NAME))
 
+    def test_relay_interfaces(self):
+        max_size = '800'
+        hop_count = '20'
+        agents_packets = 'append'
+        servers = ['192.0.2.1', '192.0.2.2']
+        listen_iface = 'eth0'
+        up_iface = 'eth1'
+
+        self.cli_set(base_path + ['interface', up_iface])
+        self.cli_set(base_path + ['listen-interface', listen_iface])
+        # check validate() - backward interface plus listen_interface
+        with self.assertRaises(ConfigSessionError):
+            self.cli_commit()
+        self.cli_delete(base_path + ['interface'])
+
+        self.cli_set(base_path + ['upstream-interface', up_iface])
+
+        for server in servers:
+            self.cli_set(base_path + ['server', server])
+
+        # commit changes
+        self.cli_commit()
+
+        # Check configured port
+        config = read_file(RELAY_CONF)
+
+        # Test configured relay interfaces
+        self.assertIn(f'-id {listen_iface}', config)
+        self.assertIn(f'-iu {up_iface}', config)
+
+        # Test relay servers
+        for server in servers:
+            self.assertIn(f' {server}', config)
+
+        # Check for running process
+        self.assertTrue(process_named_running(PROCESS_NAME))
+
 if __name__ == '__main__':
     unittest.main(verbosity=2)
 
diff --git a/src/conf_mode/dhcp_relay.py b/src/conf_mode/dhcp_relay.py
index 4de2ca2f3..07ec1c7a3 100755
--- a/src/conf_mode/dhcp_relay.py
+++ b/src/conf_mode/dhcp_relay.py
@@ -21,6 +21,7 @@ from sys import exit
 from vyos.config import Config
 from vyos.configdict import dict_merge
 from vyos.template import render
+from vyos.base import Warning
 from vyos.util import call
 from vyos.util import dict_search
 from vyos.xml import defaults
@@ -59,6 +60,18 @@ def verify(relay):
         raise ConfigError('No DHCP relay server(s) configured.\n' \
                           'At least one DHCP relay server required.')
 
+    if 'interface' in relay:
+        if 'upstream_interface' in relay or 'listen_interface' in relay:
+            raise ConfigError('<interface> configuration is not compatible with upstream/listen interface')
+        else:
+            Warning('<interface> is going to be deprecated.\n'  \
+                    'Please use <listen-interface> and <upstream-interface>')
+
+    if 'upstream_interface' in relay and 'listen_interface' not in relay:
+        raise ConfigError('No listen-interface configured')
+    if 'listen_interface' in relay and 'upstream_interface' not in relay:
+        raise ConfigError('No upstream-interface configured')
+
     return None
 
 def generate(relay):
-- 
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