Merge pull request #3106 from sarthurdev/T6102

dhcp: T6102: Fix clear DHCP lease op-mode

5 files changed, 70 insertions, 115 deletions

diff --git a/op-mode-definitions/clear-dhcp-server-lease.xml.in b/op-mode-definitions/clear-dhcp-server-lease.xml.in
deleted file mode 100644
index aef0eb22a..000000000
--- a/op-mode-definitions/clear-dhcp-server-lease.xml.in
+++ /dev/null
@@ -1,20 +0,0 @@
-<?xml version="1.0"?>
-<interfaceDefinition>
-  <node name="clear">
-    <children>
-      <node name="dhcp-server">
-        <properties>
-          <help>Clear DHCP server lease</help>
-        </properties>
-        <children>
-          <tagNode name="lease">
-            <properties>
-              <help>DHCP server lease</help>
-            </properties>
-            <command>sudo ${vyos_op_scripts_dir}/clear_dhcp_lease.py --ip $4</command>
-          </tagNode>
-        </children>
-      </node>
-    </children>
-  </node>
-</interfaceDefinition>
diff --git a/op-mode-definitions/dhcp.xml.in b/op-mode-definitions/dhcp.xml.in
index 0db7471e5..3c42c8e8f 100644
--- a/op-mode-definitions/dhcp.xml.in
+++ b/op-mode-definitions/dhcp.xml.in
@@ -1,5 +1,35 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <interfaceDefinition>
+  <node name="clear">
+    <children>
+      <node name="dhcp-server">
+        <properties>
+          <help>Clear DHCP server lease</help>
+        </properties>
+        <children>
+          <tagNode name="lease">
+            <properties>
+              <help>DHCP server lease</help>
+            </properties>
+            <command>${vyos_op_scripts_dir}/dhcp.py clear_dhcp_server_lease --family inet --address $4</command>
+          </tagNode>
+        </children>
+      </node>
+      <node name="dhcpv6-server">
+        <properties>
+          <help>Clear DHCPv6 server lease</help>
+        </properties>
+        <children>
+          <tagNode name="lease">
+            <properties>
+              <help>DHCPv6 server lease</help>
+            </properties>
+            <command>${vyos_op_scripts_dir}/dhcp.py clear_dhcp_server_lease --family inet6 --address $4</command>
+          </tagNode>
+        </children>
+      </node>
+    </children>
+  </node>
   <node name="show">
     <children>
       <node name="dhcp">
diff --git a/python/vyos/kea.py b/python/vyos/kea.py
index 2328d0b00..89ae7ca81 100644
--- a/python/vyos/kea.py
+++ b/python/vyos/kea.py
@@ -56,6 +56,8 @@ kea6_options = {
     'captive_portal': 'v6-captive-portal'
 }
 
+kea_ctrl_socket = '/run/kea/dhcp{inet}-ctrl-socket'
+
 def kea_parse_options(config):
     options = []
 
@@ -294,7 +296,9 @@ def kea6_parse_subnet(subnet, config):
 
     return out
 
-def _ctrl_socket_command(path, command, args=None):
+def _ctrl_socket_command(inet, command, args=None):
+    path = kea_ctrl_socket.format(inet=inet)
+
     if not os.path.exists(path):
         return None
 
@@ -319,19 +323,25 @@ def _ctrl_socket_command(path, command, args=None):
         return json.loads(result.decode('utf-8'))
 
 def kea_get_leases(inet):
-    ctrl_socket = f'/run/kea/dhcp{inet}-ctrl-socket'
-
-    leases = _ctrl_socket_command(ctrl_socket, f'lease{inet}-get-all')
+    leases = _ctrl_socket_command(inet, f'lease{inet}-get-all')
 
     if not leases or 'result' not in leases or leases['result'] != 0:
         return []
 
     return leases['arguments']['leases']
 
-def kea_get_active_config(inet):
-    ctrl_socket = f'/run/kea/dhcp{inet}-ctrl-socket'
+def kea_delete_lease(inet, ip_address):
+    args = {'ip-address': ip_address}
 
-    config = _ctrl_socket_command(ctrl_socket, 'config-get')
+    result = _ctrl_socket_command(inet, f'lease{inet}-del', args)
+
+    if result and 'result' in result:
+        return result['result'] == 0
+
+    return False
+
+def kea_get_active_config(inet):
+    config = _ctrl_socket_command(inet, 'config-get')
 
     if not config or 'result' not in config or config['result'] != 0:
         return None
diff --git a/src/op_mode/clear_dhcp_lease.py b/src/op_mode/clear_dhcp_lease.py
deleted file mode 100755
index 7d4b47104..000000000
--- a/src/op_mode/clear_dhcp_lease.py
+++ /dev/null
@@ -1,88 +0,0 @@
-#!/usr/bin/env python3
-#
-# Copyright 2023 VyOS maintainers and contributors <maintainers@vyos.io>
-#
-# This library is free software; you can redistribute it and/or
-# modify it under the terms of the GNU Lesser General Public
-# License as published by the Free Software Foundation; either
-# version 2.1 of the License, or (at your option) any later version.
-#
-# This library 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
-# Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public
-# License along with this library.  If not, see <http://www.gnu.org/licenses/>.
-
-import argparse
-import re
-
-from vyos.configquery import ConfigTreeQuery
-from vyos.kea import kea_parse_leases
-from vyos.utils.io import ask_yes_no
-from vyos.utils.process import call
-from vyos.utils.commit import commit_in_progress
-
-# TODO: Update to use Kea control socket command "lease4-del"
-
-config = ConfigTreeQuery()
-base = ['service', 'dhcp-server']
-lease_file = '/config/dhcp/dhcp4-leases.csv'
-
-
-def del_lease_ip(address):
-    """
-    Read lease_file and write data to this file
-    without specific section "lease ip"
-    Delete section "lease x.x.x.x { x;x;x; }"
-    """
-    with open(lease_file, encoding='utf-8') as f:
-        data = f.read().rstrip()
-        pattern = rf"^{address},[^\n]+\n"
-        # Delete lease for ip block
-        data = re.sub(pattern, '', data)
-
-    # Write new data to original lease_file
-    with open(lease_file, 'w', encoding='utf-8') as f:
-        f.write(data)
-
-def is_ip_in_leases(address):
-    """
-    Return True if address found in the lease file
-    """
-    leases = kea_parse_leases(lease_file)
-    for lease in leases:
-        if address == lease['address']:
-            return True
-    print(f'Address "{address}" not found in "{lease_file}"')
-    return False
-
-if not config.exists(base):
-    print('DHCP-server not configured!')
-    exit(0)
-
-if config.exists(base + ['failover']):
-    print('Lease cannot be reset in failover mode!')
-    exit(0)
-
-
-if __name__ == '__main__':
-    parser = argparse.ArgumentParser()
-    parser.add_argument('--ip', help='IPv4 address', action='store', required=True)
-
-    args = parser.parse_args()
-    address = args.ip
-
-    if not is_ip_in_leases(address):
-        exit(1)
-
-    if commit_in_progress():
-        print('Cannot clear DHCP lease while a commit is in progress')
-        exit(1)
-
-    if not ask_yes_no(f'This will restart DHCP server.\nContinue?'):
-        exit(1)
-    else:
-        del_lease_ip(address)
-        call('systemctl restart kea-dhcp4-server.service')
diff --git a/src/op_mode/dhcp.py b/src/op_mode/dhcp.py
index 1d9ad0e76..d27e1baf7 100755
--- a/src/op_mode/dhcp.py
+++ b/src/op_mode/dhcp.py
@@ -31,6 +31,7 @@ from vyos.configquery import ConfigTreeQuery
 from vyos.kea import kea_get_active_config
 from vyos.kea import kea_get_leases
 from vyos.kea import kea_get_pool_from_subnet_id
+from vyos.kea import kea_delete_lease
 from vyos.utils.process import is_systemd_service_running
 
 time_string = "%a %b %d %H:%M:%S %Z %Y"
@@ -360,6 +361,28 @@ def show_server_static_mappings(raw: bool, family: ArgFamily, pool: typing.Optio
     else:
         return _get_formatted_server_static_mappings(static_mappings, family=family)
 
+def _lease_valid(inet, address):
+    leases = kea_get_leases(inet)
+    for lease in leases:
+        if address == lease['ip-address']:
+            return True
+    return False
+
+@_verify
+def clear_dhcp_server_lease(family: ArgFamily, address: str):
+    v = 'v6' if family == 'inet6' else ''
+    inet = '6' if family == 'inet6' else '4'
+
+    if not _lease_valid(inet, address):
+        print(f'Lease not found on DHCP{v} server')
+        return None
+
+    if not kea_delete_lease(inet, address):
+        print(f'Failed to clear lease for "{address}"')
+        return None
+
+    print(f'Lease "{address}" has been cleared')
+
 def _get_raw_client_leases(family='inet', interface=None):
     from time import mktime
     from datetime import datetime