[jira] [Work logged] (SSHD-1055) Remote port forwarding mode does not handle EOF properly

["ASF GitHub Bot (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/SSHD-1055?focusedWorklogId=780633&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-780633 ]

ASF GitHub Bot logged work on SSHD-1055:
----------------------------------------

                Author: ASF GitHub Bot
            Created on: 12/Jun/22 16:26
            Start Date: 12/Jun/22 16:26
    Worklog Time Spent: 10m 
      Work Description: tomaswolf opened a new pull request, #227:
URL: https://github.com/apache/mina-sshd/pull/227

   Propagate an EOF on a tunnel for port forwarding to the socket by
   shutting down its output; otherwise the client connected to that
   socket may hang.
   
   Fix the MINA transport back-end to not close the IoSession on
   half-closure; it may still be needed to transport data the other way.
   
   Enable half-closure in the Netty transport back-end.
   
   Fix the Nio2 transport back-end to not re-try accepting connections
   when the channel is already closing.
   
   Half-closed sockets seem to be badly supported by any of the transport
   back-ends and may lead to (harmless) AsynchronousCloseExceptions or
   ClosedByInterruptExceptions being logged when the connection is finally
   closed completely.
   
   See also SSHD-964 and SSHD-902.




Issue Time Tracking
-------------------

            Worklog Id:     (was: 780633)
    Remaining Estimate: 0h
            Time Spent: 10m

> Remote port forwarding mode does not handle EOF properly
> --------------------------------------------------------
>
>                 Key: SSHD-1055
>                 URL: https://issues.apache.org/jira/browse/SSHD-1055
>             Project: MINA SSHD
>          Issue Type: Bug
>    Affects Versions: 2.5.1
>            Reporter: Feng Jiajie
>            Priority: Major
>          Time Spent: 10m
>  Remaining Estimate: 0h
>
> I want to call the remote server's gRPC service locally through an SSH tunnel. 
> MyApp -> MINA SSHD -> \{Internet} -> gRPC Server
> It works just fine with OpenSSH, but there is a small problem(no problems with core functions, only in unusual circumstances) with Mina SSHD.
> I think the problem is Mina SSHD's handling of EOF.
> Here is the example:
> Step 1. Start a gRPC server:
> Because we only need a gRPC server to reproduce the problem, so I write a simple version without any service: 
> {code:java}
> <dependency>
>     <groupId>io.grpc</groupId>
>     <artifactId>grpc-netty-shaded</artifactId>
>     <version>1.27.2</version>
> </dependency>
> <dependency>
>     <groupId>io.grpc</groupId>
>     <artifactId>grpc-protobuf</artifactId>
>     <version>1.27.2</version>
> </dependency>
> <dependency>
>     <groupId>io.grpc</groupId>
>     <artifactId>grpc-stub</artifactId>
>     <version>1.27.2</version>
> </dependency>
> {code}
> main: 
> {code:java}
> import io.grpc.Server;
> import io.grpc.ServerBuilder;
> public class EmptyGrpcServer {
>   public static void main(String[] args) throws Exception {
>     Server server = ServerBuilder.forPort(23645).build().start();
>     server.awaitTermination();
>   }
> }
> {code}
> Full example can be fond here: [https://github.com/grpc/grpc-java/blob/master/examples/src/main/java/io/grpc/examples/helloworld/HelloWorldServer.java] 
> Step 2. Start a MINA SSHD server: 
> {code:java}
> import org.apache.sshd.server.SshServer;
> import org.apache.sshd.server.forward.AcceptAllForwardingFilter;
> import org.apache.sshd.server.keyprovider.SimpleGeneratorHostKeyProvider;
> import java.nio.file.Paths;
> public class Example1 {
>   public static void main(String[] args) throws Exception {
>     SshServer sshd = SshServer.setUpDefaultServer();
>     sshd.setPort(12133);
>     sshd.setKeyPairProvider(new SimpleGeneratorHostKeyProvider(Paths.get("/tmp/a.ser")));
>     sshd.setPasswordAuthenticator((username, password, session) -> true);
>     sshd.setForwardingFilter(AcceptAllForwardingFilter.INSTANCE);
>     sshd.start();
>     Thread.sleep(10000000);
>   }
> }
> {code}
> Step 3. Create a channel using ssh client 
> {code:java}
> ssh -o 'ExitOnForwardFailure yes' -vvv -p 12133 -f -x -N -T -R 0.0.0.0:0:127.0.0.1:23645 test5@127.0.0.1
> {code}
> Step 4. Reproduce
> If I connect directly to the gRPC server using curl, cause gRPC using http/2, I would get error output like this: 
> {code:java}
> $ curl 127.0.0.1:23645
> ���+Unexpected HTTP/1.x request: GET /
> $
> {code}
> Then if I do step 3 with an OpenSSH server, I would get same error output:
> {code:java}
> $ ssh -o 'ExitOnForwardFailure yes' -f -x -N -T -R 0.0.0.0:0:127.0.0.1:23645 work@dev.kbyte.cn
> Allocated port 13525 for remote forward to 127.0.0.1:23645
> $
> $ curl dev.kbyte.cn:13525
> ���+Unexpected HTTP/1.x request: GET / 
> $
> {code}
> But when I do step 3 with MINA SSHD, curl would stuck without any output:
> {code:java}
> $ curl 127.0.0.1:55604
> {code}
> I found MINA SSHD had already got and wrote the package with the string "Unexpected.HTTP/1.x.request:.GET", and received SSH_MSG_CHANNEL_EOF.
> So I think handleEof should do more? like send SSH_MSG_CHANNEL_EOF to curl?
>  



--
This message was sent by Atlassian Jira
(v8.20.7#820007)

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@mina.apache.org
For additional commands, e-mail: dev-help@mina.apache.org