[jira] [Created] (SSHD-1295) Connection attempt not canceled when a connection timeout occurs

["Thomas Wolf (Jira)" <ji...@apache.org>]

Thomas Wolf created SSHD-1295:
---------------------------------

             Summary: Connection attempt not canceled when a connection timeout occurs
                 Key: SSHD-1295
                 URL: https://issues.apache.org/jira/browse/SSHD-1295
             Project: MINA SSHD
          Issue Type: Bug
    Affects Versions: 2.9.2
            Reporter: Thomas Wolf


This is not a new bug; it's also present in earlier versions.

When {{client.connect().verify(timeout)}} times out, the underlying asynchronous connection attempt still continues _and may still succeed_. If that happens, there is a connection and session that the user cannot use or close. (Short of calling verify().getSession() again, but that is a pattern I have never seen, and it also makes using a timeout rather useless.)

This means that timeouts are inherently unreliable.

Here's a simple test case illustrating this problem (for {{org.apache.sshd.client.ClientTest}}):

{code:java}
@Test
public void testConnectTimeout() throws Exception {
    client.start();
    try {
        ConnectFuture future = client.connect(getCurrentTestName(), TEST_LOCALHOST, port);
        try {
            future.verify(1);
            fail("Timeout expected");
        } catch (InterruptedIOException | SshException e) {
            ClientSession session = null;
            try {
                session = future.verify(CONNECT_TIMEOUT).getSession();
            } catch (SshException e2) {
                assertTrue("Expected a timeout, got " + e2, e2.getMessage().contains("timeout"));
            }
            if (session != null) {
                assertTrue("Session should be closed", session.isClosed() || session.isClosing());
            }
        }
    } finally {
        client.stop();
    }
}
{code}

This test fails.

When the {{ConnectFuture}} times out (or is canceled, or waiting is interrupted), the underlying {{IoConnectFuture}} must be canceled. If we do get an {{IoSession}} all the same, but the {{ConnectFuture}} is already canceled or timed out, the {{IoSession}} must be closed immediately. Preferrably before a {{Session}} is created at all; otherwise, that SSH session must be closed, too. Creating a {{ClientSession}} already starts the application-level protocol (sending the SSH ident, or if a proxy is used, the proxy connect request).

The test also highlights another problem: there is no clear indication that the failure of {{verify()}} indicates a timeout. Probably there should be a dedicated exception for this, or at least the {{SshException}} should have a {{TimeoutException}} as cause.



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