Block a List of IP Addresses in PHP
Here's a simple PHP snippet that you can place at the top of a file to determine whether the IPv4 address of a request is blacklisted:
$blacklist = array(
'127.0.0.1',
'192.168.1.1',
// etc.
);
$ip = isset($_SERVER['REMOTE_ADDR']) ? trim($_SERVER['REMOTE_ADDR']) : '';
if (($key = array_search($ip, $blacklist)) !== false) {
echo 'You are forbidden from accessing this resource!';
exit();
}
// If the process has not exited, then the IP address is not blacklisted.
You could also pull a list of IP addresses from a file:
$blacklist = file('blacklist.txt', FILE_IGNORE_NEW_LINES);
In the above example, each line of blacklist.txt should contain a single and unique IP address.
Adding a 403 response code
If you haven't already, you might want to consider responding with a 403 error:
http_response_code(403);
echo trim('
<!DOCTYPE html><html><head><title>403</title></head><body>You are forbidden from accessing this resource!</body></html>
');
exit();
Conclusion
Anyway, this is just one of many simple ways to block a list of IP addresses from accessing a resource on your PHP server.
If you're running into issues, remember to add this snippet to the top of the files you want to add it to!