This got a little complicated.
My first few attempts at
binat made me lose all connection to the QNX thingy. Digging a little deep, it seems like I didn't set up the alias IP addresses correctly. However, thinking about it a bit longer, I abandon further attempts as it would complicate day-to-day operation (or you could chalk it up to my laziness
)
I got HTTP port redirection working and since the "FTP servers" are also web servers (and supports directory listing). I just threw my hands up and said this is good enough.
My attempt at "fancy" FTP access didn't seem as crucial anymore... so I left it at that. Maybe leave it for my future self to circle back around to it... maybe when I get "ftp-proxy" to compile on QNX.
Do much appreciate all the replies though. I learned quite a bit about PF during this exercise (though the emphasis on the "a bit").