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
         }
     }
 }

2 files changed, 65 insertions, 3 deletions

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)