banning & ip range

[alexho]

hello again people with my mysql stuff behind me now i wish to make a good application for banning people a basis method i will use is like this : there will also be certain actions such as posting too much in a amoutn of time will result in ban, so its important i get it to work to keep things in order, and abusers out.

being done only by admin or mod
banning a user for X # of time..

<form method="post" action="....ya">
<input name="howlong"> lets say for infinte would be so they are banned forever value would be in hours 0 = forever.
<input name=usertoban> and a specifie ip to ban
<input type=submit>
</form>

sorry lazy i didnt put stuff in correct syntax..

Also how would i ban a range or ip addresses?
the biggest problem would be for temporary bans not 0 that are perm bans, so that if things expire it would then allow them to go to the site, this method im unsure about tackling i dont know how other people would temporary ban, any suggestions?

 

[enouwee]

Given an address, a network and a CIDR mask, returns whether the address is matched or not:

function isBanned($address, $net, $cidr)
{
        $mask = 0xffffffff << (32 - $cidr);
        return ((ip2long($net) & $mask) == (ip2long($address) & $mask));
}

Example:

isBanned('192.168.28.47', '192.168.0.0', 16) # = true
isBanned('192.168.28.47', '192.168.0.0', 20) # = false

As for rate-limited bans, you could use a token bucket to track the posts made during a given time slot.