Proposal: X11 forwarding new API

[Vic Lee <llyzs@xxxxxxx>]

Hi,

Now I already have the proposal for the new X11 forwarding API based on
my requirement. I want to implement it in a listen/accept manner
(something like sockets). I believe this will be easier than using
callbacks for app developers (at least for me :) ).

1. int channel_x11_request(CHANNEL *channel, int single_connection, int
screen_number);
   Sends the "x11-req" channel request over an existing session channel

2. int channel_x11_accept(CHANNEL *channel);
   Accept an X11 forwarding channel (non-blocking). The argument should
be a newly created empty channel. Return SSH_AGAIN if no X11 forwarding
channel open request from the server.
   (Internally, this function can call ssh_handle_packets and find if
there's any x11 channel open request.)

Forward listening can be also implemented in a similar way
(channel_forward_listen, channel_forward_accept,
channel_forward_cancel), but right now I just need X11 forwarding so
lets focus on X11 forwarding first.

Please let me know what you think, and I will try to implement this
feature soon.

Thanks,

Vic