Assert liveliness with periodic heartbeats in secure participants (#6411)

* Refs #24372. Assert liveliness with periodic heartbeats in secure participants.

Signed-off-by: Juan Lopez Fernandez <juanlopez@eprosima.com>

* Refs #24372. Added regression test.

Signed-off-by: danipiza <dpizarrogallego@gmail.com>

* Refs #24372. Revert change in returned value.

Signed-off-by: Miguel Company <miguelcompany@eprosima.com>

* Refs #24372. Improve null pointer checks.

Signed-off-by: Miguel Company <miguelcompany@eprosima.com>

* Refs #24372. Uncrustify.

Signed-off-by: Miguel Company <miguelcompany@eprosima.com>

---------

Signed-off-by: Juan Lopez Fernandez <juanlopez@eprosima.com>
Signed-off-by: danipiza <dpizarrogallego@gmail.com>
Signed-off-by: Miguel Company <miguelcompany@eprosima.com>
Co-authored-by: Juan Lopez Fernandez <juanlopez@eprosima.com>
Co-authored-by: danipiza <dpizarrogallego@gmail.com>

Author: 3 people

src/cpp/rtps/builtin/discovery/participant/PDPSimple.cpp

@@ -291,7 +291,6 @@ void PDPSimple::announceParticipantState(
 
         auto endpoints = dynamic_cast<fastdds::rtps::SimplePDPEndpoints*>(builtin_endpoints_.get());
         assert(endpoints && endpoints->writer.history_);
-
         if (!endpoints || !endpoints->writer.history_)
         {
             FASTDDS_UNREACHABLE();       // “cannot happen” invariant
@@ -303,6 +302,22 @@ void PDPSimple::announceParticipantState(
         if (!(dispose || new_change))
         {
             endpoints->writer.writer_->send_periodic_announcement();
+
+#if HAVE_SECURITY
+            if (mp_RTPSParticipant->is_secure())
+            {
+                // PDP non-secure endpoints are unmatched after participant authentication succeeds (and secure PDP
+                // endpoints are matched), and since the secure ones are TRANSIENT_LOCAL, we send periodic heartbeats
+                // to assert liveliness on remote participants
+                auto secure = dynamic_cast<fastdds::rtps::SimplePDPEndpointsSecure*>(builtin_endpoints_.get());
+                assert(secure && secure->secure_writer.writer_);
+                if (!secure || !secure->secure_writer.writer_)
+                {
+                    FASTDDS_UNREACHABLE();   // “cannot happen” invariant
+                }
+                secure->secure_writer.writer_->send_periodic_heartbeat(true, true);
+            }
+#endif // HAVE_SECURITY
         }
     }
 }

test/blackbox/common/BlackboxTestsSecurity.cpp

@@ -1315,6 +1315,98 @@ TEST_P(Security, RemoveParticipantProxyDataonSecurityManagerLeaseExpired_validat
 
 }
 
+// Regression test for secure PDP liveliness maintenance without user traffic.
+TEST(Security, SecureParticipantsDoNotLoseDiscoveryWithoutUserTraffic)
+{
+    PubSubReader<HelloWorldPubSubType> reader("HelloWorldTopic_secure_participant_liveliness");
+    PubSubWriter<HelloWorldPubSubType> writer("HelloWorldTopic_secure_participant_liveliness");
+    const auto idle_timeout = std::chrono::seconds(6);
+    const auto data_timeout = std::chrono::seconds(10);
+    // Keep the lease short so loss of secure PDP liveliness shows up quickly
+    const auto lease_duration = eprosima::fastdds::dds::Duration_t(3, 0);
+    const auto announcement_period = eprosima::fastdds::dds::Duration_t(1, 0);
+    // Use UDP transport to later block the fallback participant DATA(P) traffic
+    auto reader_transport = std::make_shared<test_UDPv4TransportDescriptor>();
+    auto writer_transport = std::make_shared<test_UDPv4TransportDescriptor>();
+
+    const std::string governance_file("governance_helloworld_all_enable.smime");
+    const std::string permissions_file("permissions_helloworld.smime");
+
+    CommonPermissionsConfigure(reader, writer, governance_file, permissions_file);
+    // Force the test through UDP to avoid local shortcuts masking the secure discovery behavior
+    reader.disable_builtin_transport().add_user_transport_to_pparams(reader_transport);
+    writer.disable_builtin_transport().add_user_transport_to_pparams(writer_transport);
+
+    // Two secure participants that authenticate, discover each other, and exchange user data
+    reader.lease_duration(lease_duration, announcement_period)
+            .history_depth(10)
+            .reliability(eprosima::fastdds::dds::RELIABLE_RELIABILITY_QOS)
+            .init();
+    ASSERT_TRUE(reader.isInitialized());
+
+    writer.lease_duration(lease_duration, announcement_period)
+            .history_depth(10)
+            .reliability(eprosima::fastdds::dds::RELIABLE_RELIABILITY_QOS)
+            .init();
+    ASSERT_TRUE(writer.isInitialized());
+
+    reader.wait_authorized();
+    writer.wait_authorized();
+
+    // Wait until both endpoints are matched
+    reader.wait_discovery();
+    writer.wait_discovery();
+
+    // Verify discovery state stayed stable
+    auto assert_still_discovered = [&reader, &writer]()
+            {
+                ASSERT_TRUE(reader.is_matched());
+                ASSERT_TRUE(writer.is_matched());
+                ASSERT_EQ(reader.get_matched(), 1u);
+                ASSERT_EQ(writer.get_matched(), 1u);
+
+                const auto reader_status = reader.get_subscription_matched_status();
+                const auto writer_status = writer.get_publication_matched_status();
+                ASSERT_EQ(reader_status.total_count, 1);
+                ASSERT_EQ(writer_status.total_count, 1);
+            };
+
+    // Check the secure participants must not be undiscovered just because user traffic stops
+    auto assert_idle_period_keeps_discovery = [&reader, &writer, &idle_timeout, &assert_still_discovered]()
+            {
+                ASSERT_FALSE(reader.wait_participant_undiscovery(idle_timeout));
+                ASSERT_FALSE(writer.wait_participant_undiscovery(idle_timeout));
+
+                assert_still_discovered();
+            };
+
+    // Discovery is only useful if data can still flow after the idle window
+    auto assert_data_flow = [&reader, &writer, &data_timeout, &assert_still_discovered]()
+            {
+                auto data = default_helloworld_data_generator(2);
+
+                reader.startReception(data);
+                writer.send(data);
+
+                ASSERT_TRUE(data.empty());
+                ASSERT_EQ(reader.block_for_all(data_timeout), 2u);
+                assert_still_discovered();
+            };
+
+    ASSERT_NO_FATAL_FAILURE(assert_still_discovered());
+
+    // After the secure PDP endpoints are established, stop the unprotected participant DATA(P)
+    // traffic, to depend on the secure liveliness maintenance path
+    reader_transport->test_transport_options->always_drop_participant_builtin_topic_data = true;
+    writer_transport->test_transport_options->always_drop_participant_builtin_topic_data = true;
+
+    // Exercise the idle scenario twice to catch both immediate loss and unstable recovery/rematch behavior
+    ASSERT_NO_FATAL_FAILURE(assert_idle_period_keeps_discovery());
+    ASSERT_NO_FATAL_FAILURE(assert_data_flow());
+    ASSERT_NO_FATAL_FAILURE(assert_idle_period_keeps_discovery());
+    ASSERT_NO_FATAL_FAILURE(assert_data_flow());
+}
+
 TEST(Security, AllowUnauthenticatedParticipants_EntityCreationFailsIfRTPSProtectionIsNotNONE)
 {
     PubSubReader<HelloWorldPubSubType> reader("HelloWorldTopic");