A library with some convenient ip address functions missing from the go standard library.

Right now, it contains only three functions. There is a much more complete IP address library available here, so I recommend you use that unless you need these specific functions.

Converts a given net.IP into a uint32. Assumes that the IP is an ipv4, and returns an error if it's not.

Given a uint32, converts it into a net.IP assuming that it's an ipv4 address.

Given an IPNet, return the last address within that IP range. Works for both ipv6 and ipv4.

(For an ipv4 address, this will be the broadcast address of the net range)

#Example

package main

import (
    "fmt"
    "net"
    "github.com/llimllib/ipaddress"
)

func main() {
	ip := net.ParseIP("1.2.3.4")

	ipn, err := ipaddress.IpToUint32(ip)
	if err != nil {
		fmt.Printf("Error")
	}

	fmt.Printf("ip %s is %d as an integer\n", ip, ipn)

	ips := ipaddress.Uint32ToIP(ipn).String()

	fmt.Printf("And we used Uint32ToIP to return it to %s\n", ips)

	_, netw, _ := net.ParseCIDR("1.2.3.4/24")
	last := ipaddress.LastAddress(netw)

	fmt.Printf("The last address in the net range is %s\n", last.String())

	//LastAddress works for ipv6 too
	_, net6, _ := net.ParseCIDR("2001:658:22a:cafe::/64")
	last = ipaddress.LastAddress(net6)

	fmt.Printf("The last address in the ipv6 network range is %s\n", last.String())
}

• Convert to/from integers for ipv6. How to do this when Go doesn't have a uint128?
• Count IPs in an IPMask

This code is licensed in the public domain under the WTFPL. Use it in any way you see fit, for any commercial or other use, with or without credit.