consul/ipaddr/detect.go

142 lines
3.4 KiB
Go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package ipaddr
import (
"fmt"
"net"
)
// GetPrivateIPv4 returns the list of private network IPv4 addresses on
// all active interfaces.
func GetPrivateIPv4() ([]*net.IPAddr, error) {
addresses, err := activeInterfaceAddresses()
if err != nil {
return nil, fmt.Errorf("Failed to get interface addresses: %v", err)
}
var addrs []*net.IPAddr
for _, rawAddr := range addresses {
var ip net.IP
switch addr := rawAddr.(type) {
case *net.IPAddr:
ip = addr.IP
case *net.IPNet:
ip = addr.IP
default:
continue
}
if ip.To4() == nil {
continue
}
if !isPrivate(ip) {
continue
}
addrs = append(addrs, &net.IPAddr{IP: ip})
}
return addrs, nil
}
// GetPublicIPv6 returns the list of all public IPv6 addresses
// on all active interfaces.
func GetPublicIPv6() ([]*net.IPAddr, error) {
addresses, err := net.InterfaceAddrs()
if err != nil {
return nil, fmt.Errorf("Failed to get interface addresses: %v", err)
}
var addrs []*net.IPAddr
for _, rawAddr := range addresses {
var ip net.IP
switch addr := rawAddr.(type) {
case *net.IPAddr:
ip = addr.IP
case *net.IPNet:
ip = addr.IP
default:
continue
}
if ip.To4() != nil {
continue
}
if isPrivate(ip) {
continue
}
addrs = append(addrs, &net.IPAddr{IP: ip})
}
return addrs, nil
}
// privateBlocks contains non-forwardable address blocks which are used
// for private networks. RFC 6890 provides an overview of special
// address blocks.
var privateBlocks = []*net.IPNet{
parseCIDR("10.0.0.0/8"), // RFC 1918 IPv4 private network address
parseCIDR("100.64.0.0/10"), // RFC 6598 IPv4 shared address space
parseCIDR("127.0.0.0/8"), // RFC 1122 IPv4 loopback address
parseCIDR("169.254.0.0/16"), // RFC 3927 IPv4 link local address
parseCIDR("172.16.0.0/12"), // RFC 1918 IPv4 private network address
parseCIDR("192.0.0.0/24"), // RFC 6890 IPv4 IANA address
parseCIDR("192.0.2.0/24"), // RFC 5737 IPv4 documentation address
parseCIDR("192.168.0.0/16"), // RFC 1918 IPv4 private network address
parseCIDR("::1/128"), // RFC 1884 IPv6 loopback address
parseCIDR("fe80::/10"), // RFC 4291 IPv6 link local addresses
parseCIDR("fc00::/7"), // RFC 4193 IPv6 unique local addresses
parseCIDR("fec0::/10"), // RFC 1884 IPv6 site-local addresses
parseCIDR("2001:db8::/32"), // RFC 3849 IPv6 documentation address
}
func parseCIDR(s string) *net.IPNet {
_, block, err := net.ParseCIDR(s)
if err != nil {
panic(fmt.Sprintf("Bad CIDR %s: %s", s, err))
}
return block
}
func isPrivate(ip net.IP) bool {
for _, priv := range privateBlocks {
if priv.Contains(ip) {
return true
}
}
return false
}
// Returns addresses from interfaces that is up
func activeInterfaceAddresses() ([]net.Addr, error) {
var upAddrs []net.Addr
var loAddrs []net.Addr
interfaces, err := net.Interfaces()
if err != nil {
return nil, fmt.Errorf("Failed to get interfaces: %v", err)
}
for _, iface := range interfaces {
// Require interface to be up
if iface.Flags&net.FlagUp == 0 {
continue
}
addresses, err := iface.Addrs()
if err != nil {
return nil, fmt.Errorf("Failed to get interface addresses: %v", err)
}
if iface.Flags&net.FlagLoopback != 0 {
loAddrs = append(loAddrs, addresses...)
continue
}
upAddrs = append(upAddrs, addresses...)
}
if len(upAddrs) == 0 {
return loAddrs, nil
}
return upAddrs, nil
}