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

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

     [ https://issues.apache.org/jira/browse/SSHD-1295?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Thomas Wolf resolved SSHD-1295.
-------------------------------
    Fix Version/s: 2.9.3
         Assignee: Thomas Wolf
       Resolution: Fixed

[Github PR 315|https://github.com/apache/mina-sshd/pull/315] has been merged.

> 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
>            Assignee: Thomas Wolf
>            Priority: Major
>             Fix For: 2.9.3
>
>
> 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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