Situation:

A notebook with:
Cable network at eth0
Wireless network at wlan0, already set up fine

And you want the cable network to access the WLAN.

1. Give eth0 an IP in the same segment as you are, but the all-ones netmask:
ifconfig eth0 172.17.0.253 netmask 255.255.255.255 up
2. Start parprouted:
parprouted eth0 wlan0
3. Enable IP forwarding:
echo 1 > /proc/sys/net/ipv4/ip_forward

Done, your WLAN and your wired network are virtually one network segment now. Only thing that won't work are broadcasts (e.g. DHCP).

I am using this as interim solution as my ethernet/WLAN AP is broken.

BTW, real bridging would be done with the "brctl" program, but this is not working for WLAN adaptors other than Prism ones.

Oh, what? If you think that's bad, if you think you're down... then spy what I did:
I reenabled kernel module loading on my grsec-patched laptop.

Oh what?!

Yea, it negates alot of security features of pax. Yeah, if you get root you can inject whatever code you want into the kernel. But you know what?

That's how it's going to be on the laptop from now on.