Hi all, I am trying to write a port forward using POE.
Assume I want to forward connection from port 10086 to port 80, so telnet localhost 10086 can get the access to the web server.
I can use 'GET /' to get the index page of the web, and then the server will close my connection to 80, but I still connected to 10086. So my question is, how can I detect the server has closed my connection so that I can close the client?
my code for this forwarder can be found at here Update: Here is the code

#!/usr/bin/perl
use strict;
use warnings;
use Smart::Comments;
use POE
  qw/Wheel::SocketFactory Wheel::ReadWrite Filter::Stream Driver::SysR
+W/;

POE::Session->create(
    inline_states => {
        _start           => \&_create_socket,
        on_client_accept => \&client_accept,
        on_server_error  => \&server_error,
        on_client_error  => \&client_error,
    },
);

POE::Kernel->run;

sub _create_socket {
    my ($kernel, $heap) = @_[KERNEL, HEAP];
    $heap->{server} = POE::Wheel::SocketFactory->new(
        BindPort     => '10086',
        Reuse        => 1,
        SuccessEvent => 'on_client_accept',
        FailureEvent => 'on_server_error',
    );
}

sub client_accept {
    my ($client, $heap) = @_[ARG0, HEAP];

    #create new session handle remote host
    POE::Session->create(
        inline_states => {
            _start            => \&connect_to_remote,
            on_remote_connect => \&remote_connected,
            on_remote_fail    => \&remote_fail,
            forward_out       => \&forward_out,
            forward_in        => \&forward_in,
            remote_flush      => \&remote_flush,
        },
        args => [$client],
     );
}

sub connect_to_remote {
    my ($heap, $local_socket) = @_[HEAP, ARG0];

    #create socket connect to port we want to forward
    my $remote = POE::Wheel::SocketFactory->new(
        RemoteAddress => 'localhost',
        RemotePort    => '80',
        SuccessEvent  => 'on_remote_connect',
        FailureEvent  => 'on_remote_fail',
    );
    $heap->{remote} = $remote;

    # create wheel to read the local socket
    $heap->{local_wheel} = POE::Wheel::ReadWrite->new(
        Handle     => $local_socket,
        Filter     => POE::Filter::Stream->new(),
        InputEvent => 'forward_out',
    );
    $heap->{local_socket} = $local_socket;
}

sub remote_connected {
    my ($heap, $socket) = @_[HEAP, ARG0];
    my $wheel = POE::Wheel::ReadWrite->new(
        Handle       => $socket,
        Driver       => POE::Driver::SysRW->new(),
        Filter       => POE::Filter::Stream->new(),
        InputEvent   => 'forward_in',
#FlushedEvent => 'remote_flush',
    );
    $heap->{remote_wheel} = $wheel;
}

sub server_erorr {
    my ($operation, $errnum, $errstr) = @_[ARG0, ARG1, ARG2];
    warn "server opeartion: $operation failed with number: $errnum\n\t
         string: $errstr";
    delete $_[HEAP]{server};
}

sub client_error {
    my $id = $_[ARG3];
    delete $_[HEAP]{client}{$id}{x};
}

sub forward_out {
    my ($heap, $data, $wheel) = @_[HEAP, ARG0];
    $heap->{remote_wheel}->put($data);
}

sub forward_in {
    my ($heap, $data) = @_[HEAP, ARG0];
    $heap->{local_wheel}->put($data);
    $_[KERNEL]->yield('remote_flush')
}

sub port_fail {
    print "failed to connnect to port\n";
}

sub remote_fail {
    delete $_[HEAP]->{remote};
}

sub remote_flush {
    my $heap = $_[HEAP];
    print "remote flushed\n";
    print "remote have no remote\n" if !exists $heap->{remote};

    if (!$heap->{remote_wheel}->get_driver_out_octets) {
        $heap->{remote_wheel}->flush;
        delete $heap->{remote};
        $heap->{local_wheel}->put("remote server Disconnected\n");
#delete $heap->{local_wheel};
        $heap->{local_socket}->flush ;
        close $heap->{local_socket};

    }
}
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