SSH to tunnel through a firewall when local machine does not actually have ssh

Question

I am looking for a solution to the standard ssh middleman tunneling with a twist.

I have four machines ABCD.

A is a the local device (embedded and no ssh available) that is not on the fire walled network

B is a server that is accessible from 'A' and can SSH to 'C'

C is a server on the fire walled network

D is a computer on the fire walled network that is running a service on a tcp port 9090 that a needs access to.

Is it possible to issue an SSH command from 'B that allow 'A' to connect to 9090 on 'D'?

Answer 1

B and C need an SSH server to forward B:9090 to D:9090. Then A can connect to B:9090.

On B:

ssh -g -L 9090:D:9090 -N C

-g allows remote hosts like A to connect to local forwarded ports.