apacheGH-298: Start service in AbstractServerSession

Services need to be started. In particular, the connection service
starts its heartbeat, if configured, when started. It was already
noticed in commit e74e204 that the server-side did not start services,
but at that time the effect was not recognized because tests were too
unstable back then. A test for server-side heartbeats was also missing.

sshd-core/src/main/java/org/apache/sshd/server/session/AbstractServerSession.java

@@ -287,7 +287,7 @@ public void startService(String name, Buffer buffer) throws Exception {
 
             throw new SshException(SshConstants.SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE, "Unknown service: " + name);
         }
-        currentService.set(service, factory.getName(), false);
+        currentService.set(service, factory.getName(), true);
     }
 
     @Override

sshd-core/src/test/java/org/apache/sshd/server/ServerTest.java

@@ -38,6 +38,7 @@
 import java.util.concurrent.Semaphore;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.atomic.AtomicReference;
 
 import org.apache.sshd.client.SshClient;
@@ -56,9 +57,11 @@
 import org.apache.sshd.common.channel.WindowClosedException;
 import org.apache.sshd.common.io.IoSession;
 import org.apache.sshd.common.kex.KexProposalOption;
+import org.apache.sshd.common.session.ReservedSessionMessagesHandler;
 import org.apache.sshd.common.session.Session;
 import org.apache.sshd.common.session.SessionContext;
 import org.apache.sshd.common.session.SessionDisconnectHandler;
+import org.apache.sshd.common.session.SessionHeartbeatController.HeartbeatType;
 import org.apache.sshd.common.session.SessionListener;
 import org.apache.sshd.common.session.helpers.AbstractConnectionService;
 import org.apache.sshd.common.session.helpers.AbstractSession;
@@ -68,6 +71,7 @@
 import org.apache.sshd.common.util.MapEntryUtils;
 import org.apache.sshd.common.util.MapEntryUtils.NavigableMapBuilder;
 import org.apache.sshd.common.util.OsUtils;
+import org.apache.sshd.common.util.buffer.Buffer;
 import org.apache.sshd.core.CoreModuleProperties;
 import org.apache.sshd.deprecated.ClientUserAuthServiceOld;
 import org.apache.sshd.server.auth.keyboard.InteractiveChallenge;
@@ -691,6 +695,26 @@ public void channelStateChanged(Channel channel, String hint) {
         }
     }
 
+    @Test
+    public void testServerHeartbeat() throws Exception {
+        sshd.setSessionHeartbeat(HeartbeatType.IGNORE, Duration.ofMillis(500));
+        sshd.start();
+        AtomicLong ignoreMessageCount = new AtomicLong(0);
+        client.setReservedSessionMessagesHandler(new ReservedSessionMessagesHandler() {
+
+            @Override
+            public void handleIgnoreMessage(Session session, Buffer buffer) throws Exception {
+                ignoreMessageCount.incrementAndGet();
+            }
+        });
+        client.start();
+        try (ClientSession s = createTestClientSession(sshd)) {
+            Thread.sleep(2000);
+        }
+        long ignoreMessages = ignoreMessageCount.get();
+        assertTrue("Epected some ignore messages (server-side heartbeat)", ignoreMessages > 0 && ignoreMessages <= 5);
+    }
+
     @Test
     public void testEnvironmentVariablesPropagationToServer() throws Exception {
         AtomicReference<Environment> envHolder = new AtomicReference<>(null);