From: Thomas Markwalder <tmark@isc.org>
Date: Mon, 20 Oct 2025 17:46:02 +0000 (-0400)
Subject: [#4145] Reset MT test code
X-Git-Tag: Kea-3.1.3~41
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f90a09bc9f4bc58465ecf1a49082120eb852aa2e;p=thirdparty%2Fkea.git

[#4145] Reset MT test code

new file:   changelog_unreleased/4145-an-empty-config-test-command-can-affect-ha-connections
modified:   src/bin/dhcp4/json_config_parser.cc
modified:   src/bin/dhcp6/json_config_parser.cc
modified:   src/lib/util/multi_threading_mgr.h
modified:   src/lib/util/tests/multi_threading_mgr_unittest.cc
---

diff --git a/changelog_unreleased/4145-an-empty-config-test-command-can-affect-ha-connections b/changelog_unreleased/4145-an-empty-config-test-command-can-affect-ha-connections
new file mode 100644
index 0000000000..0e0a404ae4
--- /dev/null
+++ b/changelog_unreleased/4145-an-empty-config-test-command-can-affect-ha-connections
@@ -0,0 +1,6 @@
+[bug]		tmark
+	Corrected an issue that was causing an
+	HA peer to not restart its dedicated listener
+	after handling a config-test command.
+	Applies to both kea-dhcp4 and kea-dhcp6.
+	(Gitlab #4145)
diff --git a/src/bin/dhcp4/json_config_parser.cc b/src/bin/dhcp4/json_config_parser.cc
index c819e71aa8..29b068bb65 100644
--- a/src/bin/dhcp4/json_config_parser.cc
+++ b/src/bin/dhcp4/json_config_parser.cc
@@ -753,9 +753,7 @@ configureDhcp4Server(Dhcpv4Srv& server, isc::data::ConstElementPtr config_set,
     LOG_DEBUG(dhcp4_logger, DBG_DHCP4_COMMAND, DHCP4_CONFIG_START)
         .arg(server.redactConfig(config_set)->str());
 
-    if (check_only) {
-        MultiThreadingMgr::instance().setTestMode(true);
-    }
+    MtTestMode();
 
     auto answer = processDhcp4Config(config_set);
 
diff --git a/src/bin/dhcp6/json_config_parser.cc b/src/bin/dhcp6/json_config_parser.cc
index 72a055bf38..431f37719b 100644
--- a/src/bin/dhcp6/json_config_parser.cc
+++ b/src/bin/dhcp6/json_config_parser.cc
@@ -870,9 +870,7 @@ configureDhcp6Server(Dhcpv6Srv& server, isc::data::ConstElementPtr config_set,
     LOG_DEBUG(dhcp6_logger, DBG_DHCP6_COMMAND, DHCP6_CONFIG_START)
         .arg(server.redactConfig(config_set)->str());
 
-    if (check_only) {
-        MultiThreadingMgr::instance().setTestMode(true);
-    }
+    MtTestMode();
 
     auto answer = processDhcp6Config(config_set);
 
diff --git a/src/lib/util/multi_threading_mgr.h b/src/lib/util/multi_threading_mgr.h
index f761f02eff..a9fdc3a8f2 100644
--- a/src/lib/util/multi_threading_mgr.h
+++ b/src/lib/util/multi_threading_mgr.h
@@ -387,6 +387,20 @@ public:
     virtual ~MultiThreadingCriticalSection();
 };
 
+/// @brief RAII wrapper for MT test mode.
+///
+/// The constructor enables test mode, the destructor disables it.
+class MtTestMode : public boost::noncopyable {
+public:
+    MtTestMode() {
+        MultiThreadingMgr::instance().setTestMode(true);
+    }
+
+    ~MtTestMode() {
+        MultiThreadingMgr::instance().setTestMode(false);
+    }
+};
+
 }  // namespace util
 }  // namespace isc
 
diff --git a/src/lib/util/tests/multi_threading_mgr_unittest.cc b/src/lib/util/tests/multi_threading_mgr_unittest.cc
index 400a7e95c0..733c474f0f 100644
--- a/src/lib/util/tests/multi_threading_mgr_unittest.cc
+++ b/src/lib/util/tests/multi_threading_mgr_unittest.cc
@@ -515,3 +515,14 @@ TEST_F(CriticalSectionCallbackTest, invocationsWithExceptions) {
     // Retest CriticalSections.
     runCriticalSections({}, {});
 }
+
+/// @brief Verifies that the RAII wrapper for MT test mode works.
+TEST_F(CriticalSectionCallbackTest, mtTestMode) {
+    ASSERT_FALSE(MultiThreadingMgr::instance().isTestMode());
+    {
+        MtTestMode mt;
+        ASSERT_TRUE(MultiThreadingMgr::instance().isTestMode());
+    }
+
+    ASSERT_FALSE(MultiThreadingMgr::instance().isTestMode());
+}