So you want to set up an open AP that can access a locally hosted website only? Or do you want a proxy server that passes the requests onto the internet.
If you want the former, that's easy. Just set up Apache or some other web server on your Linux box, bind it to eth1, host a page and you are done. If you want to redirect requests from particular URLs, enter the domain names in the hosts file with the IP address of your web server.
If you want to direct
any domain request to your locally hosted page (e.g.
www.google.com,
www.stuff.co.nz, etc etc), skip the hosts file bit above, set up a DNS server on your Linux box and create a root zone (
.) with a wildcard (
*) host record pointing to the IP of the web server. Make sure the DHCP server hands out the IP address of your local DNS server.
To take this a step further and redirect any requested
page e.g. (
www.google.com/imghp), edit your httpd.conf file and add a line that says
ErrorDocument 404 /. This will redirect any request to your web server to the default page.
Now if you want to set up a proxy for internet access, I suggest you install Squid on the Linux box. There is plenty of documentation out there on the web on getting this going.