dhcp-server: T1968: allow multiple static-routes to be configured

vyos@vyos# show service dhcp-server
 shared-network-name LAN {
     subnet 10.0.0.0/24 {
         default-router 10.0.0.1
         dns-server 194.145.150.1
         lease 88
         range 0 {
             start 10.0.0.100
             stop 10.0.0.200
         }
         static-route 192.168.10.0/24 {
             next-hop 10.0.0.2
         }
         static-route 192.168.20.0/24 {
             router 10.0.0.2
         }
     }
 }

(cherry picked from commit a4440bd589db645eb99f343a8163e188a700774c)

5 files changed, 85 insertions, 25 deletions

diff --git a/data/templates/dhcp-server/dhcpd.conf.tmpl b/data/templates/dhcp-server/dhcpd.conf.tmpl
index ff2e31998..58be7984d 100644
--- a/data/templates/dhcp-server/dhcpd.conf.tmpl
+++ b/data/templates/dhcp-server/dhcpd.conf.tmpl
@@ -114,9 +114,13 @@ shared-network {{ network | replace('_','-') }} {
 {%           if subnet_config.default_router and subnet_config.default_router is not none %}
 {%             set static_default_route = ', ' + '0.0.0.0/0' | isc_static_route(subnet_config.default_router) %}
 {%           endif %}
-{%           if subnet_config.static_route.router is defined and subnet_config.static_route.router is not none and subnet_config.static_route.destination_subnet is defined and subnet_config.static_route.destination_subnet is not none %}
-        option rfc3442-static-route {{ subnet_config.static_route.destination_subnet | isc_static_route(subnet_config.static_route.router) }}{{ static_default_route }};
-        option windows-static-route {{ subnet_config.static_route.destination_subnet | isc_static_route(subnet_config.static_route.router) }};
+{%           if subnet_config.static_route is defined and subnet_config.static_route is not none %}
+{%           set rfc3442_routes = [] %}
+{%           for route, route_options in subnet_config.static_route.items() %}
+{%             set rfc3442_routes = rfc3442_routes.append(route | isc_static_route(route_options.next_hop)) %}
+{%           endfor %}
+        option rfc3442-static-route {{ rfc3442_routes | join(', ') }}{{ static_default_route }};
+        option windows-static-route {{ rfc3442_routes | join(', ') }};
 {%           endif %}
 {%         endif %}
 {%         if subnet_config.ip_forwarding is defined %}
diff --git a/interface-definitions/dhcp-server.xml.in b/interface-definitions/dhcp-server.xml.in
index bafd6f6a2..c0f72dd86 100644
--- a/interface-definitions/dhcp-server.xml.in
+++ b/interface-definitions/dhcp-server.xml.in
@@ -357,26 +357,21 @@
                       </leafNode>
                     </children>
                   </tagNode>
-                  <node name="static-route">
+                  <tagNode name="static-route">
                     <properties>
-                      <help>Classless static route</help>
+                      <help>Classless static route destination subnet [REQUIRED]</help>
+                      <valueHelp>
+                        <format>ipv4net</format>
+                        <description>IPv4 address and prefix length</description>
+                      </valueHelp>
+                      <constraint>
+                        <validator name="ipv4-prefix"/>
+                      </constraint>
                     </properties>
                     <children>
-                      <leafNode name="destination-subnet">
-                        <properties>
-                          <help>Destination subnet [REQUIRED]</help>
-                          <valueHelp>
-                            <format>ipv4net</format>
-                            <description>IPv4 address and prefix length</description>
-                          </valueHelp>
-                          <constraint>
-                            <validator name="ipv4-prefix"/>
-                          </constraint>
-                        </properties>
-                      </leafNode>
-                      <leafNode name="router">
+                      <leafNode name="next-hop">
                         <properties>
-                          <help>IP address of router to be used to reach the destination subnet [REQUIRED]</help>
+                          <help>IP address of router to be used to reach the destination subnet</help>
                           <valueHelp>
                             <format>ipv4</format>
                             <description>IPv4 address of router</description>
@@ -387,7 +382,7 @@
                         </properties>
                       </leafNode>
                     </children>
-                  </node>
+                  </tagNode >
                   <leafNode name="subnet-parameters">
                     <properties>
                       <help>Additional subnet parameters for DHCP server. You must
diff --git a/smoketest/scripts/cli/test_service_dhcp-server.py b/smoketest/scripts/cli/test_service_dhcp-server.py
index 815bd333a..40977bb04 100755
--- a/smoketest/scripts/cli/test_service_dhcp-server.py
+++ b/smoketest/scripts/cli/test_service_dhcp-server.py
@@ -123,8 +123,7 @@ class TestServiceDHCPServer(VyOSUnitTestSHIM.TestCase):
         self.cli_set(pool + ['wpad-url', wpad])
         self.cli_set(pool + ['server-identifier', server_identifier])
 
-        self.cli_set(pool + ['static-route', 'destination-subnet', '10.0.0.0/24'])
-        self.cli_set(pool + ['static-route', 'router', '192.0.2.1'])
+        self.cli_set(pool + ['static-route', '10.0.0.0/24', 'next-hop', '192.0.2.1'])
 
         # check validate() - No DHCP address range or active static-mapping set
         with self.assertRaises(ConfigSessionError):
diff --git a/src/conf_mode/dhcp_server.py b/src/conf_mode/dhcp_server.py
index cdee72e09..8d6cef8b7 100755
--- a/src/conf_mode/dhcp_server.py
+++ b/src/conf_mode/dhcp_server.py
@@ -159,9 +159,10 @@ def verify(dhcp):
                               'lease subnet must be configured.')
 
         for subnet, subnet_config in network_config['subnet'].items():
-            if 'static_route' in subnet_config and len(subnet_config['static_route']) != 2:
-                raise ConfigError('Missing DHCP static-route parameter(s):\n' \
-                                  'destination-subnet | router must be defined!')
+            if 'static_route' in subnet_config:
+                for route, route_option in subnet_config['static_route'].items():
+                    if 'next_hop' not in route_option:
+                        raise ConfigError(f'DHCP static-route "{route}" requires router to be defined!')
 
             # Check if DHCP address range is inside configured subnet declaration
             if 'range' in subnet_config:
diff --git a/src/migration-scripts/dhcp-server/5-to-6 b/src/migration-scripts/dhcp-server/5-to-6
new file mode 100755
index 000000000..4cd2ec07a
--- /dev/null
+++ b/src/migration-scripts/dhcp-server/5-to-6
@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2021 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 sys
+from vyos.configtree import ConfigTree
+
+if (len(sys.argv) < 1):
+    print("Must specify file name!")
+    sys.exit(1)
+
+file_name = sys.argv[1]
+
+with open(file_name, 'r') as f:
+    config_file = f.read()
+
+base = ['service', 'dhcp-server', 'shared-network-name']
+config = ConfigTree(config_file)
+
+if not config.exists(base):
+    # Nothing to do
+    exit(0)
+
+# Run this for every instance if 'shared-network-name'
+for network in config.list_nodes(base):
+    base_network = base + [network]
+
+    if not config.exists(base_network + ['subnet']):
+        continue
+
+    # Run this for every specified 'subnet'
+    for subnet in config.list_nodes(base_network + ['subnet']):
+        base_subnet = base_network + ['subnet', subnet]
+
+        if config.exists(base_subnet + ['static-route']):
+            prefix = config.return_value(base_subnet + ['static-route', 'destination-subnet'])
+            router = config.return_value(base_subnet + ['static-route', 'router'])
+            config.delete(base_subnet + ['static-route'])
+
+            config.set(base_subnet + ['static-route', prefix, 'next-hop'], value=router)
+            config.set_tag(base_subnet + ['static-route'])
+
+try:
+    with open(file_name, 'w') as f:
+        f.write(config.to_string())
+except OSError as e:
+    print("Failed to save the modified config: {}".format(e))
+    exit(1)