allow to disable application layer heartbeat to reduce traffic cost (#2758)

fix #2754

client/control.go

@@ -311,16 +311,27 @@ func (ctl *Control) msgHandler() {
 	}()
 	defer ctl.msgHandlerShutdown.Done()
 
+	var hbSendCh <-chan time.Time
+	// TODO(fatedier): disable heartbeat if TCPMux is enabled.
+	// Just keep it here to keep compatible with old version frps.
+	if ctl.clientCfg.HeartbeatInterval > 0 {
 		hbSend := time.NewTicker(time.Duration(ctl.clientCfg.HeartbeatInterval) * time.Second)
 		defer hbSend.Stop()
+		hbSendCh = hbSend.C
+	}
+
+	var hbCheckCh <-chan time.Time
+	// Check heartbeat timeout only if TCPMux is not enabled and users don't disable heartbeat feature.
+	if ctl.clientCfg.HeartbeatInterval > 0 && ctl.clientCfg.HeartbeatTimeout > 0 && !ctl.clientCfg.TCPMux {
 		hbCheck := time.NewTicker(time.Second)
 		defer hbCheck.Stop()
+		hbCheckCh = hbCheck.C
+	}
 
 	ctl.lastPong = time.Now()
-
 	for {
 		select {
-		case <-hbSend.C:
+		case <-hbSendCh:
 			// send heartbeat to server
 			xl.Debug("send heartbeat to server")
 			pingMsg := &msg.Ping{}
@@ -329,7 +340,7 @@ func (ctl *Control) msgHandler() {
 				return
 			}
 			ctl.sendCh <- pingMsg
-		case <-hbCheck.C:
+		case <-hbCheckCh:
 			if time.Since(ctl.lastPong) > time.Duration(ctl.clientCfg.HeartbeatTimeout)*time.Second {
 				xl.Warn("heartbeat timeout")
 				// let reader() stop

client/service.go

@@ -249,7 +249,7 @@ func (svr *Service) login() (conn net.Conn, session *fmux.Session, err error) {
 
 	if svr.cfg.TCPMux {
 		fmuxCfg := fmux.DefaultConfig()
-		fmuxCfg.KeepAliveInterval = 20 * time.Second
+		fmuxCfg.KeepAliveInterval = time.Duration(svr.cfg.TCPMuxKeepaliveInterval) * time.Second
 		fmuxCfg.LogOutput = io.Discard
 		session, err = fmux.Client(conn, fmuxCfg)
 		if err != nil {

conf/frpc_full.ini

@@ -61,6 +61,9 @@ pool_count = 5
 
 # if tcp stream multiplexing is used, default is true, it must be same with frps
 tcp_mux = true
+# specify keep alive interval for tcp mux.
+# only valid if tcp_mux is true.
+# tcp_mux_keepalive_interval = 60
 
 # your proxy name will be changed to {user}.{proxy}
 user = your_name
@@ -89,7 +92,8 @@ tls_enable = true
 # start = ssh,dns
 
 # heartbeat configure, it's not recommended to modify the default value
-# the default value of heartbeat_interval is 10 and heartbeat_timeout is 90
+# The default value of heartbeat_interval is 10 and heartbeat_timeout is 90. Set negative value
+# to disable it.
 # heartbeat_interval = 30
 # heartbeat_timeout = 90
 

conf/frps_full.ini

@@ -92,7 +92,7 @@ oidc_skip_expiry_check = false
 oidc_skip_issuer_check = false
 
 # heartbeat configure, it's not recommended to modify the default value
-# the default value of heartbeat_timeout is 90
+# the default value of heartbeat_timeout is 90. Set negative value to disable it.
 # heartbeat_timeout = 90
 
 # user_conn_timeout configure, it's not recommended to modify the default value
@@ -121,6 +121,9 @@ subdomain_host = frps.com
 
 # if tcp stream multiplexing is used, default is true
 tcp_mux = true
+# specify keep alive interval for tcp mux.
+# only valid if tcp_mux is true.
+# tcp_mux_keepalive_interval = 60
 
 # custom 404 page for HTTP requests
 # custom_404_page = /path/to/404.html

pkg/config/client.go

@@ -86,6 +86,9 @@ type ClientCommonConf struct {
 	// the server must have TCP multiplexing enabled as well. By default, this
 	// value is true.
 	TCPMux bool `ini:"tcp_mux" json:"tcp_mux"`
+	// TCPMuxKeepaliveInterval specifies the keep alive interval for TCP stream multipler.
+	// If TCPMux is true, heartbeat of application layer is unnecessary because it can only rely on heartbeat in TCPMux.
+	TCPMuxKeepaliveInterval int64 `ini:"tcp_mux_keepalive_interval" json:"tcp_mux_keepalive_interval"`
 	// User specifies a prefix for proxy names to distinguish them from other
 	// clients. If this value is not "", proxy names will automatically be
 	// changed to "{user}.{proxy_name}". By default, this value is "".
@@ -129,11 +132,11 @@ type ClientCommonConf struct {
 	DisableCustomTLSFirstByte bool `ini:"disable_custom_tls_first_byte" json:"disable_custom_tls_first_byte"`
 	// HeartBeatInterval specifies at what interval heartbeats are sent to the
 	// server, in seconds. It is not recommended to change this value. By
-	// default, this value is 30.
+	// default, this value is 30. Set negative value to disable it.
 	HeartbeatInterval int64 `ini:"heartbeat_interval" json:"heartbeat_interval"`
 	// HeartBeatTimeout specifies the maximum allowed heartbeat response delay
 	// before the connection is terminated, in seconds. It is not recommended
-	// to change this value. By default, this value is 90.
+	// to change this value. By default, this value is 90. Set negative value to disable it.
 	HeartbeatTimeout int64 `ini:"heartbeat_timeout" json:"heartbeat_timeout"`
 	// Client meta info
 	Metas map[string]string `ini:"-" json:"metas"`
@@ -163,6 +166,7 @@ func GetDefaultClientConf() ClientCommonConf {
 		AssetsDir:               "",
 		PoolCount:               1,
 		TCPMux:                  true,
+		TCPMuxKeepaliveInterval: 60,
 		User:                    "",
 		DNSServer:               "",
 		LoginFailExit:           true,
@@ -189,13 +193,11 @@ func (cfg *ClientCommonConf) Complete() {
 }
 
 func (cfg *ClientCommonConf) Validate() error {
-	if cfg.HeartbeatInterval <= 0 {
+	if cfg.HeartbeatTimeout > 0 && cfg.HeartbeatInterval > 0 {
-		return fmt.Errorf("invalid heartbeat_interval")
-	}
-
 		if cfg.HeartbeatTimeout < cfg.HeartbeatInterval {
 			return fmt.Errorf("invalid heartbeat_timeout, heartbeat_timeout is less than heartbeat_interval")
 		}
+	}
 
 	if cfg.TLSEnable == false {
 		if cfg.TLSCertFile != "" {

pkg/config/client_test.go

@@ -274,6 +274,7 @@ func Test_LoadClientCommonConf(t *testing.T) {
 		AssetsDir:               "./static9",
 		PoolCount:               59,
 		TCPMux:                  true,
+		TCPMuxKeepaliveInterval: 60,
 		User:                    "your_name",
 		LoginFailExit:           true,
 		Protocol:                "tcp",

pkg/config/server.go

@@ -118,6 +118,9 @@ type ServerCommonConf struct {
 	// from a client to share a single TCP connection. By default, this value
 	// is true.
 	TCPMux bool `ini:"tcp_mux" json:"tcp_mux"`
+	// TCPMuxKeepaliveInterval specifies the keep alive interval for TCP stream multipler.
+	// If TCPMux is true, heartbeat of application layer is unnecessary because it can only rely on heartbeat in TCPMux.
+	TCPMuxKeepaliveInterval int64 `ini:"tcp_mux_keepalive_interval" json:"tcp_mux_keepalive_interval"`
 	// Custom404Page specifies a path to a custom 404 page to display. If this
 	// value is "", a default page will be displayed. By default, this value is
 	// "".
@@ -154,7 +157,7 @@ type ServerCommonConf struct {
 	TLSTrustedCaFile string `ini:"tls_trusted_ca_file" json:"tls_trusted_ca_file"`
 	// HeartBeatTimeout specifies the maximum time to wait for a heartbeat
 	// before terminating the connection. It is not recommended to change this
-	// value. By default, this value is 90.
+	// value. By default, this value is 90. Set negative value to disable it.
 	HeartbeatTimeout int64 `ini:"heartbeat_timeout" json:"heartbeat_timeout"`
 	// UserConnTimeout specifies the maximum time to wait for a work
 	// connection. By default, this value is 10.
@@ -194,6 +197,7 @@ func GetDefaultServerConf() ServerCommonConf {
 		DetailedErrorsToClient:  true,
 		SubDomainHost:           "",
 		TCPMux:                  true,
+		TCPMuxKeepaliveInterval: 60,
 		AllowPorts:              make(map[int]struct{}),
 		MaxPoolCount:            5,
 		MaxPortsPerClient:       0,

pkg/config/server_test.go

@@ -139,6 +139,7 @@ func Test_LoadServerCommonConf(t *testing.T) {
 				TLSTrustedCaFile:        "ca.crt",
 				SubDomainHost:           "frps.com",
 				TCPMux:                  true,
+				TCPMuxKeepaliveInterval: 60,
 				UDPPacketSize:           1509,
 
 				HTTPPlugins: map[string]plugin.HTTPPluginOptions{
@@ -189,6 +190,7 @@ func Test_LoadServerCommonConf(t *testing.T) {
 				LogMaxDays:              3,
 				DetailedErrorsToClient:  true,
 				TCPMux:                  true,
+				TCPMuxKeepaliveInterval: 60,
 				AllowPorts:              make(map[int]struct{}),
 				MaxPoolCount:            5,
 				HeartbeatTimeout:        90,

server/control.go

@@ -400,12 +400,19 @@ func (ctl *Control) manager() {
 	defer ctl.allShutdown.Start()
 	defer ctl.managerShutdown.Done()
 
+	var heartbeatCh <-chan time.Time
+	if ctl.serverCfg.TCPMux || ctl.serverCfg.HeartbeatTimeout <= 0 {
+		// Don't need application heartbeat here.
+		// yamux will do same thing.
+	} else {
 		heartbeat := time.NewTicker(time.Second)
 		defer heartbeat.Stop()
+		heartbeatCh = heartbeat.C
+	}
 
 	for {
 		select {
-		case <-heartbeat.C:
+		case <-heartbeatCh:
 			if time.Since(ctl.lastPing) > time.Duration(ctl.serverCfg.HeartbeatTimeout)*time.Second {
 				xl.Warn("heartbeat timeout")
 				return

server/service.go

@@ -406,7 +406,7 @@ func (svr *Service) HandleListener(l net.Listener) {
 		go func(ctx context.Context, frpConn net.Conn) {
 			if svr.cfg.TCPMux {
 				fmuxCfg := fmux.DefaultConfig()
-				fmuxCfg.KeepAliveInterval = 20 * time.Second
+				fmuxCfg.KeepAliveInterval = time.Duration(svr.cfg.TCPMuxKeepaliveInterval) * time.Second
 				fmuxCfg.LogOutput = io.Discard
 				session, err := fmux.Server(frpConn, fmuxCfg)
 				if err != nil {

test/e2e/features/heartbeat.go

@@ -0,0 +1,48 @@
+package features
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/fatedier/frp/test/e2e/framework"
+
+	. "github.com/onsi/ginkgo"
+)
+
+var _ = Describe("[Feature: Heartbeat]", func() {
+	f := framework.NewDefaultFramework()
+
+	It("disable application layer heartbeat", func() {
+		serverPort := f.AllocPort()
+		serverConf := fmt.Sprintf(`
+		[common]
+		bind_addr = 0.0.0.0
+		bind_port = %d
+		heartbeat_timeout = -1
+		tcp_mux_keepalive_interval = 2
+		`, serverPort)
+
+		remotePort := f.AllocPort()
+		clientConf := fmt.Sprintf(`
+		[common]
+		server_port = %d
+		log_level = trace
+		heartbeat_interval = -1
+		heartbeat_timeout = -1
+		tcp_mux_keepalive_interval = 2
+
+		[tcp]
+		type = tcp
+		local_port = %d
+		remote_port = %d
+		`, serverPort, f.PortByName(framework.TCPEchoServerPort), remotePort)
+
+		// run frps and frpc
+		f.RunProcesses([]string{serverConf}, []string{clientConf})
+
+		framework.NewRequestExpect(f).Protocol("tcp").Port(remotePort).Ensure()
+
+		time.Sleep(5 * time.Second)
+		framework.NewRequestExpect(f).Protocol("tcp").Port(remotePort).Ensure()
+	})
+})