[
https://issues.apache.org/jira/browse/SSHD-848?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16642913#comment-16642913
]
ASF GitHub Bot commented on SSHD-848:
-------------------------------------
GitHub user robertodeandrea opened a pull request:
https://github.com/apache/mina-sshd/pull/68
SSHD-848 Problem opening local port forwarding channel
This is our proposed code change to handle problem reported in SSHD-848.
I'll wait your comments.
Regards
Roberto
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/robertodeandrea/mina-sshd master
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/mina-sshd/pull/68.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #68
----
commit 9f2d49a97963d9f4330d96578142d67e06b44c07
Author: roberto.deandrea <roberto.deandrea@...>
Date: 2018-10-09T07:37:46Z
SSHD-848 Proposed change code
----
> Possible bug opening local port forwarding channel
> --------------------------------------------------
>
> Key: SSHD-848
> URL: https://issues.apache.org/jira/browse/SSHD-848
> Project: MINA SSHD
> Issue Type: Bug
> Affects Versions: 2.0.1
> Reporter: Roberto Deandrea
> Priority: Major
> Attachments: testlpf.ko, testlpf.ok
>
>
> Hi , We found a possible bug opening a local port forwarding channel.
> Scenario : The SSH client and server are based on Apache SSHD 2.0.1. There is
> a FTP client sending a file through a local port forwarding channel to a
> target server.
> The problem manifests when the SSH server is busy and returns the
> SSH_MSG_CHANNEL_OPEN_CONFIRMATION with a some delay and the client is very
> fast to send only a few bytes on a local port forwarding channel.
> The outcome is the FTP client is NOT able to send bytes through the channel
> to the target server.
> Into SSH client traces we see :
> org.apache.sshd.common.channel.WindowClosedException: Already closed:
> Window[client/remote](TcpipClientChannel[id=4,
> recipient=4]-ClientSessionImpl[roberto@/192.168.50.61:10022])
>
> According to us there is a chance that if we don't AWAIT the local port
> forward channel is TOTALLY opened, when the client is very fast to send
> bytes... it closes its connection, ao the channel that is already closing
> prevents bytes to flow through the channel to the target server.
>
> We guess there is a code bug in *DefaultForwardingFilter.sessionCreated()*
> method.
> We add the following line at the end of the method and the problem seems
> definitely fixed.
> *channel.getOpenFuture().await();*
>
> Please, can you troubleshoot this issue and comment about our potential code
> fix ?
> Thanks in advance.
>
> I attached the files:
> testslpf.ko SSH client traces with original code and a failed attempt
> testslpf.ok SSH client traces with our code changes and a successful attempt
>
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
