The easiest way to check if a user is coming from a given IP block and redirect?

Question

Here is the code I wrote in the application controller:

class ApplicationController < ActionController::Base protect_from_forgery before_filter :redirect_if_bolivia private def redirect_if_bolivia if (bolivia_ip_block).includes? request.remote_ip #redirect user to www.foo.com end end def bolivia_ip_block %w { 12.144.86.0 - 12.144.87.255 31.201.1.176 - 31.201.1.179 46.36.198.101 - 46.36.198.105 46.136.172.0 - 46.136.172.255 63.65.11.0 - 63.65.12.254 65.173.56.0 - 65.173.63.255 67.23.241.179 - 67.23.241.198 72.32.164.56 - 72.32.164.63 72.46.244.32 - 72.46.244.47 74.91.16.48 - 74.91.16.55 74.91.16.208 - 74.91.16.215 74.91.20.48 - 74.91.20.71 74.112.134.120 - 74.112.134.127 74.112.135.104 - 74.112.135.111 74.205.37.16 - 74.205.37.23 78.24.205.32 - 78.24.205.47 98.129.27.88 - 98.129.27.95 98.129.91.40 - 98.129.91.47 166.114.0.0 - 166.114.255.255 167.157.0.0 - 167.157.255.255 174.143.165.80 - 174.143.165.87 186.0.156.0 - 186.0.159.255 186.2.0.0 - 186.2.127.255 186.27.0.0 - 186.27.127.255 190.0.248.0 - 190.0.255.255 190.3.184.0 - 190.3.191.255 } end end 

So basically, what is the easiest way to check if request.remote_ip belongs to the IP block in Bolivia?

I don’t think that iterating through each block and spitting out the corresponding IP address, adding it to the array is effective. In fact, this would lead to the creation of an array of thousands of records for each individual query.

I am sure this is not a new problem, so I would like to find a proven solution.

Maybe I can check if the first three octets match, then it belongs to the block? How do I make this simple string comparison in Ruby?

Answer 1

You can convert subnets to CIDR since blocks are not arbitrary. Then you can use IPAddr # include

 require 'ipaddr' class ApplicationController < ActionController::Base protect_from_forgery before_filter :redirect_if_bolivia private def redirect_if_bolivia if bolivian_blocks.any? { |block| block.include?(request.remote_ip) } #redirect user to www.foo.com end end def bolivian_blocks %w{ 12.144.86.0/23 31.201.1.176/30 }.map { |subnet| IPAddr.new subnet } end end