talos/pkg/net/net.go

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

package net

import (
	"errors"
	"net"
)

// IPAddrs finds and returns a list of non-loopback IPv4 addresses of the
// current machine.
func IPAddrs() (ips []net.IP, err error) {
	ips = []net.IP{}

	addrs, err := net.InterfaceAddrs()
	if err != nil {
		return
	}

	for _, a := range addrs {
		if ipnet, ok := a.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
			if ipnet.IP.To4() != nil {
				ips = append(ips, ipnet.IP)
			}
		}
	}

	return ips, nil
}

// FormatAddress checks that the address has a consistent format.
func FormatAddress(addr string) string {
	if ip := net.ParseIP(addr); ip != nil {
		// If this is an IPv6 address, encapsulate it in brackets
		if ip.To4() == nil {
			return "[" + ip.String() + "]"
		}

		return ip.String()
	}

	return addr
}

// NthIPInNetwork takes an IPNet and returns the nth IP in it.
func NthIPInNetwork(network *net.IPNet, n int) (net.IP, error) {
	ip := network.IP
	dst := make([]byte, len(ip))
	copy(dst, ip)

	for i := 0; i < n; i++ {
		for j := len(dst) - 1; j >= 0; j-- {
			dst[j]++

			if dst[j] > 0 {
				break
			}
		}
	}

	if network.Contains(dst) {
		return dst, nil
	}

	return nil, errors.New("network does not contain enough IPs")
}