// loop for reading messages from frpc after control connection is established
func msgReader(cli *client.ProxyClient, c *conn.Conn, msgSendChan chan interface{}) error {
// for heartbeat
var heartbeatTimeout bool = false
timer := time.AfterFunc(time.Duration(client.HeartBeatTimeout)*time.Second, func() {
heartbeatTimeout = true
c.Close()
log.Error("ProxyName [%s], heartbeatRes from frps timeout", cli.Name)
})
defer timer.Stop()
for {
buf, err := c.ReadLine()
if err == io.EOF || c == nil || c.IsClosed() {
c.Close()
log.Warn("ProxyName [%s], frps close this control conn!", cli.Name)
var delayTime time.Duration = 1
// loop until reconnect to frps
for {
log.Info("ProxyName [%s], try to reconnect to frps [%s:%d]...", cli.Name, client.ServerAddr, client.ServerPort)
c, err = loginToServer(cli)
if err == nil {
close(msgSendChan)
msgSendChan = make(chan interface{}, 1024)
go heartbeatSender(c, msgSendChan)
go msgSender(cli, c, msgSendChan)
break
}
if delayTime < 60 {
delayTime = delayTime * 2
}
time.Sleep(delayTime * time.Second)
}
continue
} else if err != nil {
log.Warn("ProxyName [%s], read from frps error: %v", cli.Name, err)
continue
}
ctlRes := &msg.ControlRes{}
if err := json.Unmarshal([]byte(buf), &ctlRes); err != nil {
log.Warn("ProxyName [%s], parse msg from frps error: %v : %s", cli.Name, err, buf)
continue
}
switch ctlRes.Type {
case consts.HeartbeatRes:
log.Debug("ProxyName [%s], receive heartbeat response", cli.Name)
timer.Reset(time.Duration(client.HeartBeatTimeout) * time.Second)
case consts.NoticeUserConn:
log.Debug("ProxyName [%s], new user connection", cli.Name)
// join local and remote connections, async
go cli.StartTunnel(client.ServerAddr, client.ServerPort)
default:
log.Warn("ProxyName [%s}, unsupport msgType [%d]", cli.Name, ctlRes.Type)
}
}
return nil
}
func echoWorker(c *conn.Conn) {
for {
buff, err := c.ReadLine()
if err == io.EOF {
break
}
if err != nil {
fmt.Printf("echo server read error: %v\n", err)
return
}
c.Write(buff)
}
}
// loop for sending messages from channel to frpc
func msgSender(s *server.ProxyServer, c *conn.Conn, msgSendChan chan interface{}) {
for {
msg, ok := <-msgSendChan
if !ok {
break
}
buf, _ := json.Marshal(msg)
err := c.Write(string(buf) + "\n")
if err != nil {
log.Warn("ProxyName [%s], write to client error, proxy exit", s.Name)
s.Close()
break
}
}
}
func heartbeatSender(c *conn.Conn, msgSendChan chan interface{}) {
heartbeatReq := &msg.ControlReq{
Type: consts.HeartbeatReq,
}
log.Info("Start to send heartbeat to frps")
for {
time.Sleep(time.Duration(client.HeartBeatInterval) * time.Second)
if c != nil && !c.IsClosed() {
log.Debug("Send heartbeat to server")
msgSendChan <- heartbeatReq
} else {
break
}
}
log.Debug("Heartbeat goroutine exit")
}
// loop for reading messages from frpc after control connection is established
func msgReader(s *server.ProxyServer, c *conn.Conn, msgSendChan chan interface{}) error {
// for heartbeat
var heartbeatTimeout bool = false
timer := time.AfterFunc(time.Duration(server.HeartBeatTimeout)*time.Second, func() {
heartbeatTimeout = true
s.Close()
log.Error("ProxyName [%s], client heartbeat timeout", s.Name)
})
defer timer.Stop()
for {
buf, err := c.ReadLine()
if err != nil {
if err == io.EOF {
log.Warn("ProxyName [%s], client is dead!", s.Name)
return err
} else if c == nil || c.IsClosed() {
log.Warn("ProxyName [%s], client connection is closed", s.Name)
return err
}
log.Warn("ProxyName [%s], read error: %v", s.Name, err)
continue
}
cliReq := &msg.ControlReq{}
if err := json.Unmarshal([]byte(buf), &cliReq); err != nil {
log.Warn("ProxyName [%s], parse msg from frpc error: %v : %s", s.Name, err, buf)
continue
}
switch cliReq.Type {
case consts.HeartbeatReq:
log.Debug("ProxyName [%s], get heartbeat", s.Name)
timer.Reset(time.Duration(server.HeartBeatTimeout) * time.Second)
heartbeatRes := &msg.ControlRes{
Type: consts.HeartbeatRes,
}
msgSendChan <- heartbeatRes
default:
log.Warn("ProxyName [%s}, unsupport msgType [%d]", s.Name, cliReq.Type)
}
}
return nil
}
func (v *VhostMuxer) handle(c *conn.Conn) {
if err := c.SetDeadline(time.Now().Add(v.timeout)); err != nil {
return
}
sConn, name, err := v.vhostFunc(c)
if err != nil {
return
}
name = strings.ToLower(name)
l, ok := v.getListener(name)
if !ok {
return
}
if err = sConn.SetDeadline(time.Time{}); err != nil {
return
}
c.TcpConn = sConn
l.accept <- c
}
// connection from every client and server
func controlWorker(c *conn.Conn) {
// if login message type is NewWorkConn, don't close this connection
var closeFlag bool = true
var s *server.ProxyServer
defer func() {
if closeFlag {
c.Close()
if s != nil {
s.Close()
}
}
}()
// get login message
buf, err := c.ReadLine()
if err != nil {
log.Warn("Read error, %v", err)
return
}
log.Debug("Get msg from frpc: %s", buf)
cliReq := &msg.ControlReq{}
if err := json.Unmarshal([]byte(buf), &cliReq); err != nil {
log.Warn("Parse msg from frpc error: %v : %s", err, buf)
return
}
// login when type is NewCtlConn or NewWorkConn
ret, info := doLogin(cliReq, c)
s, ok := server.ProxyServers[cliReq.ProxyName]
if !ok {
log.Warn("ProxyName [%s] is not exist", cliReq.ProxyName)
return
}
// if login type is NewWorkConn, nothing will be send to frpc
if cliReq.Type != consts.NewWorkConn {
cliRes := &msg.ControlRes{
Type: consts.NewCtlConnRes,
Code: ret,
Msg: info,
}
byteBuf, _ := json.Marshal(cliRes)
err = c.Write(string(byteBuf) + "\n")
if err != nil {
log.Warn("ProxyName [%s], write to client error, proxy exit", s.Name)
time.Sleep(1 * time.Second)
return
}
} else {
closeFlag = false
return
}
// if login failed, just return
if ret > 0 {
return
}
// create a channel for sending messages
msgSendChan := make(chan interface{}, 1024)
go msgSender(s, c, msgSendChan)
go noticeUserConn(s, msgSendChan)
// loop for reading control messages from frpc and deal with different types
msgReader(s, c, msgSendChan)
close(msgSendChan)
log.Info("ProxyName [%s], I'm dead!", s.Name)
return
}
// start listening for user conns
func (p *ProxyServer) Start(c *conn.Conn) (err error) {
p.CtlConn = c
p.Init()
if p.Type == "tcp" {
l, err := conn.Listen(p.BindAddr, p.ListenPort)
if err != nil {
return err
}
p.listeners = append(p.listeners, l)
} else if p.Type == "http" {
for _, domain := range p.CustomDomains {
l, err := VhostMuxer.Listen(domain)
if err != nil {
return err
}
p.listeners = append(p.listeners, l)
}
}
p.Lock()
p.Status = consts.Working
p.Unlock()
// start a goroutine for every listener to accept user connection
for _, listener := range p.listeners {
go func(l Listener) {
for {
// block
// if listener is closed, err returned
c, err := l.Accept()
if err != nil {
log.Info("ProxyName [%s], listener is closed", p.Name)
return
}
log.Debug("ProxyName [%s], get one new user conn [%s]", p.Name, c.GetRemoteAddr())
if p.Status != consts.Working {
log.Debug("ProxyName [%s] is not working, new user conn close", p.Name)
c.Close()
return
}
// start another goroutine for join two conns from frpc and user
go func() {
workConn, err := p.getWorkConn()
if err != nil {
return
}
userConn := c
// msg will transfer to another without modifying
// l means local, r means remote
log.Debug("Join two connections, (l[%s] r[%s]) (l[%s] r[%s])", workConn.GetLocalAddr(), workConn.GetRemoteAddr(),
userConn.GetLocalAddr(), userConn.GetRemoteAddr())
if p.UseEncryption {
go conn.JoinMore(userConn, workConn, p.AuthToken)
} else {
go conn.Join(userConn, workConn)
}
}()
}
}(listener)
}
return nil
}