dragonfly/pkg/util/net/iputils/ip_utils.go

146 lines
2.9 KiB
Go

/*
* Copyright 2020 The Dragonfly Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package iputils
import (
"net"
"os"
"sort"
"github.com/pkg/errors"
)
var IPv4 string
func init() {
ip, err := externalIPv4()
if err != nil {
panic(err)
}
IPv4 = ip
}
// IsIPv4 returns whether the ip is a valid IPv4 Address.
func IsIPv4(ip string) bool {
addr := net.ParseIP(ip)
if addr != nil {
return addr.To4() != nil
}
return false
}
// externalIPv4 returns the first IPv4 available.
func externalIPv4() (string, error) {
ips, err := ipAddrs()
if err != nil {
return "", err
}
if len(ips) == 0 {
return "", errors.Errorf("not found any ip")
}
var values []string
for _, ip := range ips {
ip = ip.To4()
if ip == nil {
continue // not an ipv4 address
}
values = append(values, ip.String())
}
if len(values) > 0 {
return values[0], nil
}
return "", errors.Errorf("not found any ipv4")
}
// ipAddrs returns all the valid IPs available.
// refer to https://github.com/dragonflyoss/Dragonfly2/pull/652
func ipAddrs() ([]net.IP, error) {
// use prefer ip possible
var prefers []net.IP
host, err := os.Hostname()
if err == nil {
addrs, _ := net.LookupIP(host)
for _, addr := range addrs {
if addr == nil || addr.IsLoopback() || addr.IsLinkLocalUnicast() {
continue
}
prefers = append(prefers, addr)
}
}
ifaces, err := net.Interfaces()
if err != nil {
return nil, err
}
var preferAddrs []net.IP
var normalAddrs []net.IP
for _, iface := range ifaces {
if iface.Flags&net.FlagUp == 0 {
continue // interface down
}
if iface.Flags&net.FlagLoopback != 0 {
continue // loopback interface
}
addrs, err := iface.Addrs()
if err != nil {
return nil, err
}
for _, addr := range addrs {
var ip net.IP
switch v := addr.(type) {
case *net.IPNet:
ip = v.IP
case *net.IPAddr:
ip = v.IP
}
if ip == nil || ip.IsLoopback() || ip.IsLinkLocalUnicast() {
continue
}
var isPrefer bool
for _, preferAddr := range prefers {
if preferAddr.Equal(ip) {
isPrefer = true
}
}
if isPrefer {
preferAddrs = append(preferAddrs, ip)
} else {
normalAddrs = append(normalAddrs, ip)
}
}
}
sortIP(preferAddrs)
sortIP(normalAddrs)
return append(preferAddrs, normalAddrs...), nil
}
func sortIP(addrs []net.IP) {
sort.Slice(addrs, func(i, j int) bool {
return addrs[i].String() < addrs[j].String()
})
}