Wildcard IP Banning with MySQL

Question

I\'m trying to implement an IP banning system into my web app using MySQL, i know i can do it using .htaccess but that\'s not neat to me.

Basically my curre

Answer 1

This is trickier if you want to ban subnets

Notes:

• A "wildcard" mapping should use 0 (eg 42.21.58.0) which defines that subnet
• the .0 may not be the subnet because of CIDR (could .128, .192 etc)

So:

• Store IP as a 4 byte binary or unsigned int
• Store the subnet mask as a binary (or uint) 4 for subnet blacklisting
• Look at INET_NTOA and INET_ATON for translating IP addresses

Then the WHERE clause becomes

WHERE ip = @ip   --whole IP
      OR
      (ip & mask = @ip) --subnet

If you make the mask 0xffffffff for exact IP addresses then you can always do ip & mask = @ip, with ip & mask as a computed column

Also, you have IPv6 to think of too