Nginx, limiting traffic by referer?

Question

Nginx

Greetings.
From time to time, there is a problem with parasitic requests to a site of this kind: the owner of another, rather high-loaded site, hosts an iframe with a heavy request to ours, therefore, we have a flood of the form “some_IP request referrer_villain”. Yes, you can catch such attacks and block villains by referrers, but this is not enough: you need to minimize manual intervention.
Who is struggling with such a phenomenon? I see a scheme: set referrers not in the white list (the site itself) to limit requests per second (choose a really anomalous number). I just don't know how this can be done. Maybe someone has other ideas?
PS All of the above applies to Nginx.

Answer 1

blocking all referrers not from your site is of course not very good.
head-on solution:
1. create a full duplicate of your main location (where php is processed or whatever you have there), name it whatever you want.
2. add the only difference to this take - put limit_req there (you can set limit_req_zone to taste).
3. add an internal(!) redirect to the duplicated location in the server section if the referrer is not yours.
4.profit!

Answer 2

if ( $http_referer ~* (^google.com) ){
return 403;
}
Ban the google.com referrer (NOT google.com ).
This is for you just in case =) And then play around.

Answer 3

Request limit:
wiki.nginx.org/HttpLimitReqModule