Tunneling of server traffic through SSH when port forwarding is not available on the network?

At the At homeI have a small Raspberry Pi 3 running services exposed to the internet. For example, an HTTP server is running. I will call this server raspberry, I am able raspberry Remote over SSH: I opened Port 22 on my router At home and therefore traffic will be routed to my public IP for this port raspberry, So far, so good.

raspberryThe architecture is arm64 and it works FreeBSD That makes it impossible (I seem to have hacked around, but no dice), so I run a game server (Urban Terror 4.3) on it.

I also have another machine, a ThinkPad (later: Thinkpad) To run OpenBSD and it has one amd64 Architecture, the does Let me run the desired server. From ThinkpadI can access raspberry with SSH.

I'm not at the moment At homebut actually in another network abroad, I have an irresistible urge to host my server now, but I could not make it raspberry, Like I said.

Is it somehow possible to run the server? Thinkpad and tunnel through all traffic raspberry (since I can expose that to the internet while here abroad, I have no administrator rights for the router)?

Essentially, I want to run the server Thinkpad as if I let it run raspberry in terms of networking. That is, the server appears in server browsers, and players could connect: traffic would arrive raspberry through port eg 27900 and it would be sent via the Internet via SSH Thinkpad,

PS I realize that this is likely to cause poor performance due to traffic passing through SSH, but I would like to try it anyway.

Thanks in advance and sorry for the long post!