From 4a36cd77ee516a6ef4c98837012741616bed8c26 Mon Sep 17 00:00:00 2001
From: jaymode <jay@elastic.co>
Date: Wed, 26 Apr 2017 11:59:56 -0400
Subject: [PATCH] Test: bind regular socket instead of server socket so
 connection cannot be accepted

This commit creates a single server socket that will be connected to by local sockets. The local
sockets will use the port of the previously stopped ldap server as the local port. This will
prevent the ldap library from establishing a connection. The previous use of server sockets for
this did not work on all operating systems as the backlog parameter has platform specific meaning.

Original commit: elastic/x-pack-elasticsearch@03b6bf39d426ae7fa98de7615970da7ed832044a
---
 .../SessionFactoryLoadBalancingTests.java     | 23 ++++++++-----------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/plugin/src/test/java/org/elasticsearch/xpack/security/authc/ldap/support/SessionFactoryLoadBalancingTests.java b/plugin/src/test/java/org/elasticsearch/xpack/security/authc/ldap/support/SessionFactoryLoadBalancingTests.java
index adac30632df..5f10b79dcd4 100644
--- a/plugin/src/test/java/org/elasticsearch/xpack/security/authc/ldap/support/SessionFactoryLoadBalancingTests.java
+++ b/plugin/src/test/java/org/elasticsearch/xpack/security/authc/ldap/support/SessionFactoryLoadBalancingTests.java
@@ -73,7 +73,8 @@ public class SessionFactoryLoadBalancingTests extends LdapTestCase {
         // get a subset to kill
         final List<InMemoryDirectoryServer> ldapServersToKill = randomSubsetOf(numberToKill, ldapServers);
         final List<InMemoryDirectoryServer> ldapServersList = Arrays.asList(ldapServers);
-        final List<MockServerSocket> boundSockets = new ArrayList<>();
+        final InetAddress local = InetAddress.getByName("localhost");
+        final MockServerSocket mockServerSocket = new MockServerSocket(0, 0, local);
         final List<Thread> listenThreads = new ArrayList<>();
         final CountDownLatch latch = new CountDownLatch(ldapServersToKill.size());
         final CountDownLatch closeLatch = new CountDownLatch(1);
@@ -87,28 +88,24 @@ public class SessionFactoryLoadBalancingTests extends LdapTestCase {
                 ldapServers[index].shutDown(true);
 
                 // when running multiple test jvms, there is a chance that something else could
-                // start listening on this port so we try to avoid this by binding again to this
-                // port with a server socket. The server socket only has a backlog of size one and
-                // we start a thread that connects to this socket but the connection is never
-                // accepted so other connections will be rejected. The socket attempts a blocking
-                // read, which will hold up the thread until the server socket is closed at the end
-                // of the test.
+                // start listening on this port so we try to avoid this by creating a local socket
+                // that will be bound to the port the ldap server was running on and connecting to
+                // a mock server socket.
                 // NOTE: this is not perfect as there is a small amount of time between the shutdown
                 // of the ldap server and the opening of the socket
                 logger.debug("opening mock server socket listening on [{}]", port);
-                MockServerSocket mockServerSocket = new MockServerSocket(port, 1, InetAddress.getByName("localhost"));
                 Runnable runnable = () -> {
-                    try (Socket socket = new MockSocket(InetAddress.getByName("localhost"), port)) {
-                        logger.debug("opened socket [{}] and blocking other connections", socket);
+                    try (Socket socket = new MockSocket(InetAddress.getByName("localhost"), mockServerSocket.getLocalPort(), local, port)) {
+                        logger.debug("opened socket [{}]", socket);
                         latch.countDown();
                         closeLatch.await();
+                        logger.debug("closing socket [{}]", socket);
                     } catch (IOException | InterruptedException e) {
                         logger.debug("caught exception", e);
                     }
                 };
                 Thread thread = new Thread(runnable);
                 thread.start();
-                boundSockets.add(mockServerSocket);
                 listenThreads.add(thread);
 
                 assertThat(ldapServers[index].getListenPort(), is(-1));
@@ -128,9 +125,7 @@ public class SessionFactoryLoadBalancingTests extends LdapTestCase {
             }
         } finally {
             closeLatch.countDown();
-            for (MockServerSocket socket : boundSockets) {
-                socket.close();
-            }
+            mockServerSocket.close();
             for (Thread t : listenThreads) {
                 t.join();
             }