Re: valid_referers dynamic hostname

Hello!

On Sat, May 18, 2013 at 01:31:50PM -0400, vlad031@binkmail.com wrote:

> Sorry for posting here - don't know for sure if it's the right place.
>
> I have an issue:
>
> 1) I use nginx as reverse proxy, but I don't always know the domain name for
> which I'm serving, so my setup looks like this:
>
> server_name _ $host 0.0.0.0;

The "$host" string here means exactly "$host". There is no
variable expansion for server_name (expect for a special name
"$hostname", which isn't actually a variable but a special name).

Most likely requests are handled in the sever{} block in question
as it's used as a default server.

> 2) I try to block invalid referers but when I try to add $host to
> valid_referers - it doesn't seem to work:
>
> valid_referers none blocked server_names $host ~\.google\. ~\.yahoo\.
> ~\.bing\. ~\.ask\. ~\.live\. ~\.googleusercontent.com\. ;

The valid_referers directive doesn't support variables.

> How can I make this work?
> Also please note that I don't know regexp.

What you are trying to do, i.e. allow referers which match Host
header in a request, currently can't be done using the referers
module only.

With a litle help from the rewrite module it's possible though.
Something like this should work:

valid_referers none blocked server_names ~\.google\. ...;

set $temp "$host:$http_referer";

if ($temp ~* "^(.*):https?://\1") {
set $invalid_referer "0";
}

if ($invalid_referer) {
return 403;
}


--
Maxim Dounin
http://nginx.org/en/donation.html

_______________________________________________
nginx mailing list
nginx@nginx.org
http://mailman.nginx.org/mailman/listinfo/nginx