John Davidson

Message:

I am trying to determine whether a website visitor came from an EU country, and if so show them a cookie consent banner per their law.

I downloaded a table listing IPv4 of all EU countries (ie: 1.178.224.0/19) and uploaded it to mySQL. There are 107,000 rows in the table. I can get the users IP using $_SERVER['REMOTE_ADDR']. I'm looking for the most simplified and quickest approach to check using PHP if the user's ip address falls in the range.

One idea was to create 2 columns in a table with the starting and ending long integers of each IPv4. The website would change the users IP address to a long integer using ip2long() and then see if it falls within the range of the 2 columns of any IPv4. Not sure if this is possible. If that's a good idea, how do I get the starting and ending long integer of an IPv4 address?

I found several solutions to see if an IP falls within the range (ie: 1.178.224.0/19) listed in my table, but with 107,000 rows this would probably take a while to process. I'm looking for a solution that runs quick so not to slow down every user who's not in an EU country.

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My Answer:
One approach you can take is to use bitwise operations to quickly determine if the user's IP falls within the range of the IPv4 addresses in your table. Here's a simplified example of how you can achieve this:

1. Convert the user's IP address to a long integer using ip2long():

php
$user_ip = ip2long($_SERVER['REMOTE_ADDR']);


2. Query your MySQL table to get the starting and ending long integers of each IPv4 range. Let's assume you have a table called `eu_countries` with columns `start_ip` and `end_ip`:

php
$query = "SELECT start_ip, end_ip FROM eu_countries";
$result = mysqli_query($connection, $query);


3. Loop through the results and check if the user's IP falls within any of the ranges:

php
while ($row = mysqli_fetch_assoc($result)) {
if ($user_ip >= $row['start_ip'] && $user_ip <= $row['end_ip']) {
// User is from an EU country, show cookie consent banner
break;
}
}


This approach should be relatively quick as it uses bitwise operations to compare the long integer representation of the user's IP address with the ranges in your table. Make sure to properly index your `start_ip` and `end_ip` columns in your MySQL table for optimal performance.