frp/pkg/nathole/utils.go

110 lines
2.4 KiB
Go

// Copyright 2023 The frp 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 nathole
import (
"bytes"
"fmt"
"net"
"strconv"
"github.com/fatedier/golib/crypto"
"github.com/pion/stun/v2"
"github.com/fatedier/frp/pkg/msg"
)
func EncodeMessage(m msg.Message, key []byte) ([]byte, error) {
buffer := bytes.NewBuffer(nil)
if err := msg.WriteMsg(buffer, m); err != nil {
return nil, err
}
buf, err := crypto.Encode(buffer.Bytes(), key)
if err != nil {
return nil, err
}
return buf, nil
}
func DecodeMessageInto(data, key []byte, m msg.Message) error {
buf, err := crypto.Decode(data, key)
if err != nil {
return err
}
return msg.ReadMsgInto(bytes.NewReader(buf), m)
}
type ChangedAddress struct {
IP net.IP
Port int
}
func (s *ChangedAddress) GetFrom(m *stun.Message) error {
a := (*stun.MappedAddress)(s)
return a.GetFromAs(m, stun.AttrChangedAddress)
}
func (s *ChangedAddress) String() string {
return net.JoinHostPort(s.IP.String(), strconv.Itoa(s.Port))
}
func ListAllLocalIPs() ([]net.IP, error) {
addrs, err := net.InterfaceAddrs()
if err != nil {
return nil, err
}
ips := make([]net.IP, 0, len(addrs))
for _, addr := range addrs {
ip, _, err := net.ParseCIDR(addr.String())
if err != nil {
continue
}
ips = append(ips, ip)
}
return ips, nil
}
func ListLocalIPsForNatHole(maxItems int) ([]string, error) {
if maxItems <= 0 {
return nil, fmt.Errorf("maxItems must be greater than 0")
}
ips, err := ListAllLocalIPs()
if err != nil {
return nil, err
}
filtered := make([]string, 0, maxItems)
for _, ip := range ips {
if len(filtered) >= maxItems {
break
}
// ignore ipv6 address
if ip.To4() == nil {
continue
}
// ignore localhost IP
if ip.IsLoopback() || ip.IsLinkLocalUnicast() || ip.IsLinkLocalMulticast() {
continue
}
filtered = append(filtered, ip.String())
}
return filtered, nil
}