From 3ca132fe22f732a7d4191e7e1c1d2b00d4206690 Mon Sep 17 00:00:00 2001
From: sarthurdev <965089+sarthurdev@users.noreply.github.com>
Date: Thu, 20 Nov 2025 15:20:44 +0100
Subject: [PATCH] kea: T7913: Fixes for ping-check handling

- Kea docs state multi-threaded mode is required for ping checking.
- Parent scope needs enabling if shared-network/subnet has ping-check enabled.
---
 data/templates/dhcp-server/kea-dhcp4.conf.j2 |  7 ++++++-
 python/vyos/kea.py                           |  2 +-
 python/vyos/template.py                      | 12 +++++++++---
 src/conf_mode/service_dhcp-server.py         |  4 ++++
 4 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/data/templates/dhcp-server/kea-dhcp4.conf.j2 b/data/templates/dhcp-server/kea-dhcp4.conf.j2
index 7302c2cade..8519689a9f 100644
--- a/data/templates/dhcp-server/kea-dhcp4.conf.j2
+++ b/data/templates/dhcp-server/kea-dhcp4.conf.j2
@@ -28,6 +28,9 @@
             "persist": true,
             "name": "{{ lease_file }}"
         },
+        "multi-threading": {
+            "enable-multi-threading": true
+        },
 {% if client_class is vyos_defined %}
         "client-classes": {{ client_class | kea_client_class_json }},
 {% endif %}
@@ -75,16 +78,18 @@
                 }
             },
 {% endif %}
+{% if any_ping_check is vyos_defined %}
             {
                 "library": "/usr/lib/{{ machine }}-linux-gnu/kea/hooks/libdhcp_ping_check.so",
                 "parameters": {
-                    "enable-ping-check" : false,
+                    "enable-ping-check" : true,
                     "min-ping-requests" : 1,
                     "reply-timeout" : 100,
                     "ping-cltt-secs" : 60,
                     "ping-channel-threads" : 0
                 }
             },
+{% endif %}
             {
                 "library": "/usr/lib/{{ machine }}-linux-gnu/kea/hooks/libdhcp_lease_cmds.so",
                 "parameters": {}
diff --git a/python/vyos/kea.py b/python/vyos/kea.py
index 323fded5d9..a8b38d9997 100644
--- a/python/vyos/kea.py
+++ b/python/vyos/kea.py
@@ -158,7 +158,7 @@ def kea_parse_options(config):
 
 
 def kea_parse_subnet(subnet, config):
-    out = {'subnet': subnet, 'id': int(config['subnet_id']), 'user-context': {}}
+    out = {'subnet': subnet, 'id': int(config['subnet_id']), 'user-context': {'enable-ping-check': False}}
 
     if 'option' in config:
         out['option-data'] = kea_parse_options(config['option'])
diff --git a/python/vyos/template.py b/python/vyos/template.py
index 44278e963e..128471f42f 100755
--- a/python/vyos/template.py
+++ b/python/vyos/template.py
@@ -1015,7 +1015,7 @@ def kea_shared_network_json(shared_networks):
             'name': name,
             'authoritative': ('authoritative' in config),
             'subnet4': [],
-            'user-context': {}
+            'user-context': {'enable-ping-check': False}
         }
 
         if 'dynamic_dns_update' in config:
@@ -1030,15 +1030,21 @@ def kea_shared_network_json(shared_networks):
             if 'bootfile_server' in config['option']:
                 network['next-server'] = config['option']['bootfile_server']
 
-        if 'ping_check' in config:
-            network['user-context']['enable-ping-check'] = True
+        subnet_ping_check = False
 
         if 'subnet' in config:
             for subnet, subnet_config in config['subnet'].items():
                 if 'disable' in subnet_config:
                     continue
+
+                if 'ping_check' in subnet_config:
+                    subnet_ping_check = True
+
                 network['subnet4'].append(kea_parse_subnet(subnet, subnet_config))
 
+        if 'ping_check' in config or subnet_ping_check:
+            network['user-context']['enable-ping-check'] = True
+
         out.append(network)
 
     return dumps(out, indent=4)
diff --git a/src/conf_mode/service_dhcp-server.py b/src/conf_mode/service_dhcp-server.py
index a1294d77e1..c022d0a969 100755
--- a/src/conf_mode/service_dhcp-server.py
+++ b/src/conf_mode/service_dhcp-server.py
@@ -32,6 +32,7 @@
 from vyos.template import render
 from vyos.utils.dict import dict_search
 from vyos.utils.dict import dict_search_args
+from vyos.utils.dict import dict_search_recursive
 from vyos.utils.file import chmod_775
 from vyos.utils.file import makedir
 from vyos.utils.file import write_file
@@ -226,6 +227,9 @@ def get_config(config=None):
                 no_tag_node_value_mangle=True,
             )
 
+    if bool(list(dict_search_recursive(dhcp, 'ping_check'))):
+        dhcp['any_ping_check'] = True
+
     return dhcp
 
 def verify_ddns_domain_servers(domain_type, domain):