mirror of https://github.com/fatedier/frp.git
136 lines
3.0 KiB
Go
136 lines
3.0 KiB
Go
// Copyright 2017 fatedier, fatedier@gmail.com
|
|
//
|
|
// 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 udp
|
|
|
|
import (
|
|
"encoding/base64"
|
|
"net"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/fatedier/frp/models/msg"
|
|
"github.com/fatedier/frp/utils/errors"
|
|
"github.com/fatedier/frp/utils/pool"
|
|
)
|
|
|
|
func NewUdpPacket(buf []byte, laddr, raddr *net.UDPAddr) *msg.UdpPacket {
|
|
return &msg.UdpPacket{
|
|
Content: base64.StdEncoding.EncodeToString(buf),
|
|
LocalAddr: laddr,
|
|
RemoteAddr: raddr,
|
|
}
|
|
}
|
|
|
|
func GetContent(m *msg.UdpPacket) (buf []byte, err error) {
|
|
buf, err = base64.StdEncoding.DecodeString(m.Content)
|
|
return
|
|
}
|
|
|
|
func ForwardUserConn(udpConn *net.UDPConn, readCh <-chan *msg.UdpPacket, sendCh chan<- *msg.UdpPacket) {
|
|
// read
|
|
go func() {
|
|
for udpMsg := range readCh {
|
|
buf, err := GetContent(udpMsg)
|
|
if err != nil {
|
|
continue
|
|
}
|
|
udpConn.WriteToUDP(buf, udpMsg.RemoteAddr)
|
|
}
|
|
}()
|
|
|
|
// write
|
|
buf := pool.GetBuf(1500)
|
|
defer pool.PutBuf(buf)
|
|
for {
|
|
n, remoteAddr, err := udpConn.ReadFromUDP(buf)
|
|
if err != nil {
|
|
udpConn.Close()
|
|
return
|
|
}
|
|
// buf[:n] will be encoded to string, so the bytes can be reused
|
|
udpMsg := NewUdpPacket(buf[:n], nil, remoteAddr)
|
|
select {
|
|
case sendCh <- udpMsg:
|
|
default:
|
|
}
|
|
}
|
|
return
|
|
}
|
|
|
|
func Forwarder(dstAddr *net.UDPAddr, readCh <-chan *msg.UdpPacket, sendCh chan<- msg.Message) {
|
|
var (
|
|
mu sync.RWMutex
|
|
)
|
|
udpConnMap := make(map[string]*net.UDPConn)
|
|
|
|
// read from dstAddr and write to sendCh
|
|
writerFn := func(raddr *net.UDPAddr, udpConn *net.UDPConn) {
|
|
addr := raddr.String()
|
|
defer func() {
|
|
mu.Lock()
|
|
delete(udpConnMap, addr)
|
|
mu.Unlock()
|
|
}()
|
|
|
|
buf := pool.GetBuf(1500)
|
|
for {
|
|
udpConn.SetReadDeadline(time.Now().Add(30 * time.Second))
|
|
n, _, err := udpConn.ReadFromUDP(buf)
|
|
if err != nil {
|
|
return
|
|
}
|
|
|
|
udpMsg := NewUdpPacket(buf[:n], nil, raddr)
|
|
if err = errors.PanicToError(func() {
|
|
select {
|
|
case sendCh <- udpMsg:
|
|
default:
|
|
}
|
|
}); err != nil {
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
// read from readCh
|
|
go func() {
|
|
for udpMsg := range readCh {
|
|
buf, err := GetContent(udpMsg)
|
|
if err != nil {
|
|
continue
|
|
}
|
|
mu.Lock()
|
|
udpConn, ok := udpConnMap[udpMsg.RemoteAddr.String()]
|
|
if !ok {
|
|
udpConn, err = net.DialUDP("udp", nil, dstAddr)
|
|
if err != nil {
|
|
continue
|
|
}
|
|
udpConnMap[udpMsg.RemoteAddr.String()] = udpConn
|
|
}
|
|
mu.Unlock()
|
|
|
|
_, err = udpConn.Write(buf)
|
|
if err != nil {
|
|
udpConn.Close()
|
|
}
|
|
|
|
if !ok {
|
|
go writerFn(udpMsg.RemoteAddr, udpConn)
|
|
}
|
|
}
|
|
}()
|
|
}
|