Yeah, well, sometimes when you learn enough you understand that while some things CAN be done, they're not usually worth the hassle. So pardon me for not having more patience with the newbies. 30+ years of all this tends to leave you a bit jaded when encountering naive 'enthusiasm'.
I get it, you're an angry old man. The only thing I don't understand about your original post is: why? I can understand you thinking it's not worth the hassle, than why post?
Configuring the network routing is the hassle. Getting and keeping it properly configured and dealing with how the packets for all the necessary protocols are handled is tedious, at best. Versus just plugging in a wifi dongle that will 'just work' and stay that way.
One of the reasons for my post was to see if somebody already dealt with the network routing hassles (i.e. asking if an "easter egg" was there). Notice I didn't ask about iptables rules and other lower-level configuration of the network interfaces. I knew it wasn't worth that effort, especially since I have a couple old WRT routers in the part piles or could purchase a wireless card for the PC for very little money.
I too have used a WRT54 with DD-WRT as a client bridge for extending wifi to a local network... on my boat. The idea being to pickup an on-shore signal and route that to an on-boat network. Besides network addressing and protocol hassles, there was the performance hit. It was a lot slower than just making a direct connection. But what won out was just using a cellular data modem and a router instead.
What network addressing protocol hassles? This configuration "just works" for me, especially since bridges work on layer 2 of the OSI model. I have never had to worry about things like multicast/UDP/etc. not working because it was a wireless segment. It's a bridge that works great.
Now I can't argue how well it worked on that hole in the water you throw your money into, nor the performance hit.
So, in keeping with the curmudgeonly tack.. 'you kids, get off my lawn!'
My dad taught me not to walk on people's lawns, but I don't care if somebody is on mine. Just those darn cats...
Linux Guy - Occasional Chumby Hacker