dhcp: dhcpv6: T3316: Add `subnet-id` so leases remain mapped to entries in the lease file (#2796)

4 files changed, 83 insertions, 4 deletions

diff --git a/src/conf_mode/service_dhcp-server.py b/src/conf_mode/service_dhcp-server.py
index ceaba019e..2418c8faa 100755
--- a/src/conf_mode/service_dhcp-server.py
+++ b/src/conf_mode/service_dhcp-server.py
@@ -165,6 +165,7 @@ def verify(dhcp):
     shared_networks =  len(dhcp['shared_network_name'])
     disabled_shared_networks = 0
 
+    subnet_ids = []
 
     # A shared-network requires a subnet definition
     for network, network_config in dhcp['shared_network_name'].items():
@@ -176,6 +177,14 @@ def verify(dhcp):
                               'lease subnet must be configured.')
 
         for subnet, subnet_config in network_config['subnet'].items():
+            if 'subnet_id' not in subnet_config:
+                raise ConfigError(f'Unique subnet ID not specified for subnet "{subnet}"')
+
+            if subnet_config['subnet_id'] in subnet_ids:
+                raise ConfigError(f'Subnet ID for subnet "{subnet}" is not unique')
+
+            subnet_ids.append(subnet_config['subnet_id'])
+
             # All delivered static routes require a next-hop to be set
             if 'static_route' in subnet_config:
                 for route, route_option in subnet_config['static_route'].items():
diff --git a/src/conf_mode/service_dhcpv6-server.py b/src/conf_mode/service_dhcpv6-server.py
index 9cc57dbcf..7cd801cdd 100755
--- a/src/conf_mode/service_dhcpv6-server.py
+++ b/src/conf_mode/service_dhcpv6-server.py
@@ -63,6 +63,7 @@ def verify(dhcpv6):
 
     # Inspect shared-network/subnet
     subnets = []
+    subnet_ids = []
     listen_ok = False
     for network, network_config in dhcpv6['shared_network_name'].items():
         # A shared-network requires a subnet definition
@@ -72,6 +73,14 @@ def verify(dhcpv6):
                               'each shared network!')
 
         for subnet, subnet_config in network_config['subnet'].items():
+            if 'subnet_id' not in subnet_config:
+                raise ConfigError(f'Unique subnet ID not specified for subnet "{subnet}"')
+
+            if subnet_config['subnet_id'] in subnet_ids:
+                raise ConfigError(f'Subnet ID for subnet "{subnet}" is not unique')
+
+            subnet_ids.append(subnet_config['subnet_id'])
+
             if 'address_range' in subnet_config:
                 if 'start' in subnet_config['address_range']:
                     range6_start = []
diff --git a/src/migration-scripts/dhcp-server/8-to-9 b/src/migration-scripts/dhcp-server/8-to-9
index 908420c18..810e403a6 100755
--- a/src/migration-scripts/dhcp-server/8-to-9
+++ b/src/migration-scripts/dhcp-server/8-to-9
@@ -16,6 +16,7 @@
 
 # T3316:
 # - Migrate dhcp options under new option node
+# - Add subnet IDs to existing subnets
 
 import sys
 import re
@@ -44,6 +45,8 @@ option_nodes = ['bootfile-name', 'bootfile-server', 'bootfile-size', 'captive-po
                 'tftp-server-name', 'time-offset', 'time-server', 'time-zone',
                 'vendor-option', 'wins-server', 'wpad-url']
 
+subnet_id = 1
+
 for network in config.list_nodes(base):
     for option in option_nodes:
         if config.exists(base + [network, option]):
@@ -56,10 +59,13 @@ for network in config.list_nodes(base):
             base_subnet = base + [network, 'subnet', subnet]
             
             for option in option_nodes:
-                if config.exists(base + [network, 'subnet', subnet, option]):
-                    config.set(base + [network, 'subnet', subnet, 'option'])
-                    config.copy(base + [network, 'subnet', subnet, option], base + [network, 'subnet', subnet, 'option', option])
-                    config.delete(base + [network, 'subnet', subnet, option])
+                if config.exists(base_subnet + [option]):
+                    config.set(base_subnet + ['option'])
+                    config.copy(base_subnet + [option], base_subnet + ['option', option])
+                    config.delete(base_subnet + [option])
+
+            config.set(base_subnet + ['subnet-id'], value=subnet_id)
+            subnet_id += 1
 
 try:
     with open(file_name, 'w') as f:
diff --git a/src/migration-scripts/dhcpv6-server/3-to-4 b/src/migration-scripts/dhcpv6-server/3-to-4
new file mode 100755
index 000000000..c065e3d43
--- /dev/null
+++ b/src/migration-scripts/dhcpv6-server/3-to-4
@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2024 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/>.
+
+# T3316:
+# - Add subnet IDs to existing subnets
+
+import sys
+import re
+from vyos.configtree import ConfigTree
+
+if len(sys.argv) < 2:
+    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', 'dhcpv6-server', 'shared-network-name']
+config = ConfigTree(config_file)
+
+if not config.exists(base):
+    # Nothing to do
+    sys.exit(0)
+
+subnet_id = 1
+
+for network in config.list_nodes(base):
+    if config.exists(base + [network, 'subnet']):
+        for subnet in config.list_nodes(base + [network, 'subnet']):
+            base_subnet = base + [network, 'subnet', subnet]
+
+            config.set(base_subnet + ['subnet-id'], value=subnet_id)
+            subnet_id += 1
+
+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)