5.next: Feature - IP validation incl subnet/range

[dereuromark]

Description

For a maintenance mode whitelist I would need to set also a subnet IP

A normal IP, like 5.146.197.42, represents one single device or host.

5.146.197.0/24 represents a range of IP addresses — specifically, all IPs from:
=> 5.146.197.0 to 5.146.197.255

Existing Validation:ip() would fail here for that.

We can either

• add a new rule for subnet/mask alone
• adjust the existing rule to allow subnets with feature flag toggle

maybe?

$type could be used to be set to subnet, or an additional bool flag.

Something along the lines of

    // Check for plain IP first (IPv4 or IPv6)
    if (filter_var($input, FILTER_VALIDATE_IP)) {
        return true;
    }

    // Check for CIDR format
    if (str_contains($input, '/')) {
        [$ip, $mask] = explode('/', $input, 2);

        // Validate IP part
        if (!filter_var($ip, FILTER_VALIDATE_IP)) {
            return false;
        }

        // Validate mask part (IPv4: 0-32, IPv6: 0-128)
        if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) {
            return is_numeric($mask) && $mask >= 0 && $mask <= 32;
        } 
        if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6)) {
            return is_numeric($mask) && $mask >= 0 && $mask <= 128;
        }
    }

    return false;

CakePHP Version

5.2

[LordSimal]

I have used https://github.com/mlocati/ip-lib for quite some time for my deploying logic since it has quite a few QoL methods and proper IPv6 support.

Of course I can understand, that we don't want to add a dependency just for this kind of validation logic, so I'd rather see it as an addition to either the localized plugin or a nice addition to the docs on how to add a validator like that.

[dereuromark]

The internal one I only see as basic sanity check (no numbers or completely invalid chars etc).
If you want real business critical tests, I would argue one goes for such libraries always by default.

In my case and others for the cake core internal one would be such simple "does this look like one" check :)