[Feature request] Reverse tunnel support

[jpillora]

[Feature request] Reverse tunnel support

[jpillora]

I plan on merging this fork https://github.com/mcbernie/chisel at some point (supports using clients as proxy endpoints) and then with the chisel server also acting as a client (server can also provide remotes), then it would result in this functionality.

[sunshineco]

Pull request #72 implements reverse port forwarding.

[abraiante]

I second this. Initially I thought this was what Chisel did, but when setting it up I noticed it was the other way around.

My use case:

I have a local (like in the client) HTTP service, that I want to expose to the internet. Chisel is running on the server and I would to set-up a reverse tunnel, so issuing for instance, in the server a

wget http://localhost:8080

would open a connection to a port in the client where the HTTP service is offered.

The reverse tunnel would be set-up when Chisel clients connects to the server, and as @penguinpowernz mentioned it could be described in the command-line with something like the thing SSH client uses:

-L [bind_address:]port:host:hostport
             Specifies that the given port on the local (client) host is to be forwarded to the given host and port on the remote side.  This works by allocating a socket
             to listen to port on the local side, optionally bound to the specified bind_address.  Whenever a connection is made to this port, the connection is forwarded
             over the secure channel, and a connection is made to host port hostport from the remote machine.

 -R [bind_address:]port:host:hostport
             Specifies that the given port on the remote (server) host is to be forwarded to the given host and port on the local side.  This works by allocating a socket
             to listen to port on the remote side, and whenever a connection is made to this port, the connection is forwarded over the secure channel, and a connection is
             made to host port hostport from the local machine.

This would make chisel one of the most versatile hole-punching firewall tools I know.

[smerschjohann]

How is the status about this plan? Can I help with something?

[penguinpowernz]

How to extend the remote spec to signal remote port forward? Prefix with an R? Make the centre colon an equals sign?

[jpillora]

So this would make the server listen/accept connections and the client terminate them? I have another plan to allow clients to make connections #9 though since it's quite a large change I decided not to include it in the 1.2 release

[penguinpowernz]

Oh I'm thinking SSH protocol... perhaps I misunderstood the SSH related lines in your code.

Internally do you use SSH to do the local port forwards? If so we could simply use that to enact remote port forwards.

[jpillora]

No, internally, I use the SSH protocol. The SSH program implements it, so chisel would also need to implement it.

[vizv]

Initially I thought this was what Chisel did, but when setting it up I noticed it was the other way around.

That's exactly what I thought... After I setup the server, I found it's impossible to do the reverse tunneling.

Adding reverse tunnel support will be nice.

[hanscees]

Same here. This means the project page could use soms user scenario samples.

Me too. Did this get merged ?

[steom]

we who love the holes are all eagerly waiting

[zurp]

hey, is there any update on when/if this will land in chisel?

[segator]

very robust and stable, but we need reverse tunneling.

There is one around by the Rightscale / Goa design developer check It out to see if you like it. https://github.com/rightscale/wstunnel

…

On Sat, 4 Aug 2018, 15:24 Isaac Aymerich, ***@***.***> wrote: very robust and stable, but we need reverse tunneling. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#29 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ATuCwuAEIfaSBp1GoAjv6HU-v1AXEhGxks5uNaCggaJpZM4M6P5f> .

[jpillora]

#72 has been merged. @mcbernie's implementation (https://github.com/mcbernie/chisel) looks good though I haven't tested it. It could still be merged one day still though for now, I chose @sunshineco's implementation for its simplicity. chisel now implements remote forwarding like SSH. Search "reverse" in the README for more info, in short:

    When the chisel server has --reverse enabled, remotes can
    be prefixed with R to denote that they are reversed. That
    is, the server will listen and accept connections, and they
    will be proxied through the client which specified the remote.