Keeping your Nginx limit_* Anti-DDoS behind CloudFlare's servers

[c0nw0nk]

So I noticed some unusual stuff going on lately mostly to do with people
using proxies to spoof / fake that files from my sites are hosted of their
sites.

Sitting behind CloudFlare the only decent way I can come up with to prevent
these websites who use proxy_pass and proxy_set_header to pretend that files
they are really hotlinking of my site is on and hosted by theirs is using
Nginx's built in Anti-DDoS feature.

Now if I was to use "$binary_remote_addr" I would end up blocking CloudFlare
IP's from serving traffic but CloudFlare do provide us with the real IP
address of users that pass through their service.
It comes in the form of "HTTP_CF_CONNECTING_IP"

But when it comes to limiting files that are being hot linked to break their
servers from serving traffic they are stealing from mine I don't know if I
should be using "$http_cf_connecting_ip" or the equivalent with "$binary_"
?

limit_req_zone $http_cf_connecting_ip zone=one:10m rate=30r/m;
limit_conn_zone $http_cf_connecting_ip zone=addr:10m;

location ~ \.mp4$ {
limit_conn addr 10; #Limit open connections from same ip
limit_req zone=one; #Limit max number of requests from same ip

mp4;
limit_rate_after 1m; #Limit download rate
limit_rate 1m; #Limit download rate
root '//172.168.0.1/StorageServ1/server/networkflare/public_www';
expires max;
valid_referers none blocked networkflare.com *.networkflare.com;
if ($invalid_referer) {
return   403;
}
}

So the above is my config that should work I have not tested it yet but I
really wanted to know what the purpose of the "$binary_" on these would be
and if i should make them resemble this. (Not even sure if the below is
correct I am sure someone will correct me if "$binary_http_cf_connecting_ip"
won't work.)

limit_req_zone $binary_http_cf_connecting_ip zone=one:10m rate=30r/m;
limit_conn_zone $binary_http_cf_connecting_ip zone=addr:10m;

Thanks for reading :) looking forward to anyone's better idea's / solutions
and also recommended changes to preventing stealing of my bandwidth on these
kinds of static files that can be up to >=2GB in size.

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,269502,269502#msg-269502