Re: Need help.

[Vic Lee <llyzs@xxxxxxx>]

By the way, you might think it's difficult to write your own sockets,
but in my own opinion this is an advantage over openssh. For example, in
my project I can tunnel the ssh_channel with a local unix domain socket
to improve performance; I can tunnel only one accepted connection and
free the bound port immediately, so that I can re-used the same local
port in multiple threads/processes. These are impossible when using
openssh.

Vic

On Sun, 2009-09-13 at 17:39 +0800, Vic Lee wrote:
> Hi,
> 
> I think you will have to program with sockets yourself, that means, you
> need to:
> 
> 1. call socket(),bind(),listen(),etc
> 2. once connection comes in then call channel_open_forward to get a
> ssh_channel
> 3. running a separated thread (or use select/ssh_select) to transfer
> data from the socket to the channel back and fourth.
> 
> I have both experience with libssh and libssh2 and basically libssh2
> works in exactly the same way.
> 
> I don't think a library can do so much things for you, it's your duty to
> do the actual tunnelling :)
> 
> Vic
> 
> On Sun, 2009-09-13 at 13:27 +0400, Taras Halturin wrote:
> > thanx for the answer!
> > 
> > 
> > It is a pity :(. so,if i can't develop second half of the port
> > forwarding routines, i'll try to use libssh2. maybe there will be easy
> > to develop this feature for me.
> > 
> > 
> > WBR
> > 
> > 
> > Taras Halturin.
> > 
> > On Sun, Sep 13, 2009 at 1:14 PM, Aris Adamantiadis <aris@xxxxxxxxxxxx>
> > wrote:
> >         Hello Taras,
> >         
> >         I am sorry the documentation let you think it would be so
> >         easy... In fact channel_open_forward only does half the work,
> >         this is connecting to a remote host:port from the ssh server
> >         and stream it into a channel. However the port binding and the
> >         select loop (to verify if data is arriving and dispatching it)
> >         is unfortunately up to you.
> >         
> >         Looking at the select_loop in sample.c would be a good
> >         start-up for you, even if we should consider writing a working
> >         example in the examples directory. The functionnality you
> >         expected may be available in the 0.5 release.
> >         
> >         Andreas, Maybe we should make clear into the documentation
> >         about what I just stated above. I also only see online
> >         documentation for the 0.4.0 branch when the stable branch is
> >         still 0.3.x. Could you have a look ?
> >         Regards,
> >         
> >         Aris
> >         
> >         Taras Halturin a écrit :
> >         
> >         
> >                 Hi all!
> >                 
> >                 i'm trying to use libssh for the port forwarding and
> >                 it doesnt work for me :(. I need to forward remote
> >                 port to the local host like this:
> >                 ssh -L 22222:localhost:8222 fantom@xxxxxxxxxxxxx
> >                 
> >                 here is the code:
> >                 
> >                    static gboolean
> >                    do_open_channel (gchar *username, gchar *password,
> >                 gchar *remote,
> >                                     guint remote_port, guint
> >                 local_port)
> >                    {
> >                     SSH_SESSION *ssh = ssh_new();
> >                     SSH_OPTIONS *opts = ssh_options_new();
> >                     CHANNEL *ch = NULL;
> >                 
> >                     ssh_options_set_port (opts, 22);
> >                     ssh_options_set_host (opts, remote);
> >                    ssh_set_options (ssh, opts);
> >                 
> >                    if (ssh_connect(ssh) != SSH_OK)
> >                    {
> >                    g_warning ("Error at connection :%s
> >                 \n",ssh_get_error (ssh));
> >                    return FALSE;
> >                    }
> >                 
> >                    ssh_is_server_known(ssh);
> >                 
> >                    if (ssh_userauth_autopubkey(ssh) !=
> >                 SSH_AUTH_SUCCESS)
> >                    {
> >                    g_warning ("Authenticating with pubkey: %s
> >                 \n",ssh_get_error(ssh));
> >                    if (ssh_userauth_password (ssh, username,
> >                 password) != SSH_AUTH_SUCCESS)
> >                    {
> >                    g_warning ("Authentication with password failed: %s
> >                 \n",ssh_get_error
> >                    (ssh));
> >                    return FALSE;
> >                    }
> >                    }
> >                 
> >                    ch = channel_new (ssh);
> >                 
> >                    if (channel_open_forward (ch, remote, remote_port,
> >                 "127.0.0.1",
> >                    local_port) != SSH_OK)
> >                    {
> >                    g_warning ("Error when opening forward:%s\n",
> >                 ssh_get_error (ssh));
> >                    return FALSE;
> >                    }
> >                 
> >                    g_debug ("Chanel is forwarded");
> >                 
> >                    return TRUE;
> >                    //channel_close(channel);
> >                    //channel_free(channel);
> >                    //ssh_disconnect(ssh);
> >                    }
> >                 
> >                 
> >                 i'm calling this func with args:
> >                 
> >                 do_open_channel ("fantom","megapass", "myremote.host",
> >                 8222, 22222);
> >                 
> >                 No errors happend, "Chanel is forwarded" has printed,
> >                 but i can't see the listener on the 22222 port. What
> >                 is wrong? Could somebody help me?
> >                 
> >                 WBR
> >                 
> >                 Taras Halturin.
> >         
> >         
> > 
> > 
> 
> 
>