haruue / cidr4

A simple library to make calculations on a set of IP address.

CIDR4

A simple library to make calculations on a set of IP address.

Example

1. Install cidr4calc with go get

   go get haruue.moe/x/cidr4/cmd/cidr4calc
   

2. Create a script file cidr4set.txt

   # Empty lines and lines start with # will be omitted
   
   # CIDRs start with a PLUS(+) sign will make the CIDR plus into the CIDR set
   +0.0.0.0/1
   # The PLUS(+) sign can also be omitted
   128.0.0.0/1
   # CIDRs start with a MINUS(-) sign will make the CIDR minus from the CIDR set
   -192.0.2.0/24
   

3. Run cidr4calc with pipe

   $ cat cidr4set.txt | cidr4calc
   0.0.0.0/1
   128.0.0.0/2
   192.0.0.0/23
   192.0.3.0/24
   192.0.4.0/22
   192.0.8.0/21
   ...
   

Library Usage

see ExampleCIDRv4Set_Minus for an example to use this library.

Disclaimer

This library will always merge IP ranges when possible and split IP ranges whenever required. If you work on a BGP network, you'd better not use this library to "optimize" your route table. I won't take responsibility if you leak your route everywhere.