CloudFlare PHP IP Rewriting

This module makes it easy for developers to add rewrite CloudFlare IP Addresses for actual end-user IP Addresses at the application layer. It is recommended to either install mod_cloudflare for Apache or use nginx rewrite rules (https://support.cloudflare.com/hc/en-us/articles/200170706-Does-CloudFlare-have-an-IP-module-for-Nginx-) if possible.

For those cases, where the IP can not be guaranteed to be rewritten by one of these alternate means, this module can be used to rewrite the IP address.

How it works

$is_cf = CloudFlare\IpRewrite::isCloudFlare();
$original_ip = CloudFlare\IpRewrite::getOriginalIP();
$rewritten_ip = CloudFlare\IpRewrite::getRewrittenIP();

The class exposes three methods for interaction. A call to any of these methods will trigger the rewriting, storing the rewritten values for any subsequent calls. If the IP is rewritten, $_SERVER["REMOTE_ADDR"] will also be updated to reflect the end-user's IP address.

CloudFlare\IpRewrite::isCloudFlare(); returns true if the CF_CONNECTING_IP header is present in the request. If the rewrite happened at the server level, this function will still return true, even though it did not rewrite the IP address.

CloudFlare\IpRewrite::getOriginalIP() returns the original ip address from $_SERVER["REMOTE_ADDR"], before this module alters it.

CloudFlare\IpRewrite::getRewrittenIP() returns the rewritten ip address, if a rewrite occurs, otherwise it will return false.

Best practice

The best course of action is to call CloudFlare\IpRewrite::isCloudFlare(); to guarantee that a rewrite has occured. From that point forward, $_SERVER["REMOTE_ADDR"] can be used to retrieve the end-users IP address (whether the call came through CloudFlare or not).

CloudFlare\IpRewrite::getOriginalIP() and CloudFlare\IpRewrite::getRewrittenIP() should be used if you need visibility into the rewrite that has occured.

Testing this module

This module comes with a set of tests that can be run using phpunit. To run the tests, run composer install on the package and then one of the following commands:

Basic Tests

phpunit -c phpunit.xml.dist

With code coverage report in coverage folder

phpunit -c phpunit.xml.dist --coverage-html coverage