Make keepalive optional on client -> server and server -> proxy connections. Use KeepAlive value in config (seconds).

cmd/ck-client/ck-client.go

@@ -23,7 +23,7 @@ import (
 var version string
 
 func makeSession(sta *client.State, isAdmin bool) *mux.Session {
-	log.Info("Attemtping to start a new session")
+	log.Info("Attempting to start a new session")
 	if !isAdmin {
 		// sessionID is usergenerated. There shouldn't be a security concern because the scope of
 		// sessionID is limited to its UID.
@@ -32,7 +32,7 @@ func makeSession(sta *client.State, isAdmin bool) *mux.Session {
 		atomic.StoreUint32(&sta.SessionID, binary.BigEndian.Uint32(quad))
 	}
 
-	d := net.Dialer{Control: protector}
+	d := net.Dialer{Control: protector, KeepAlive: sta.KeepAlive}
 	connsCh := make(chan net.Conn, sta.NumConn)
 	var _sessionKey atomic.Value
 	var wg sync.WaitGroup

cmd/ck-server/ck-server.go

@@ -174,7 +174,8 @@ func dispatchConnection(conn net.Conn, sta *server.State) {
 			}
 		}
 		proxyAddr := sta.ProxyBook[ci.ProxyMethod]
-		localConn, err := net.Dial(proxyAddr.Network(), proxyAddr.String())
+		d := net.Dialer{KeepAlive: sta.KeepAlive}
+		localConn, err := d.Dial(proxyAddr.Network(), proxyAddr.String())
 		if err != nil {
 			log.Errorf("Failed to connect to %v: %v", ci.ProxyMethod, err)
 			user.CloseSession(ci.SessionId, "Failed to connect to proxy server")

internal/client/state.go

@@ -24,6 +24,7 @@ type rawConfig struct {
 	Transport        string
 	NumConn          int
 	StreamTimeout    int
+	KeepAlive        int
 	RemoteHost       string
 	RemotePort       int
 }
@@ -50,6 +51,7 @@ type State struct {
 	ServerName       string
 	NumConn          int
 	Timeout          time.Duration
+	KeepAlive        time.Duration
 }
 
 // semi-colon separated value. This is for Android plugin options
@@ -138,6 +140,11 @@ func (sta *State) ParseConfig(conf string) (err error) {
 	} else {
 		sta.Timeout = time.Duration(preParse.StreamTimeout) * time.Second
 	}
+	if preParse.KeepAlive <= 0 {
+		sta.KeepAlive = -1
+	} else {
+		sta.KeepAlive = time.Duration(preParse.KeepAlive) * time.Second
+	}
 	sta.UID = preParse.UID
 
 	pub, ok := ecdh.Unmarshal(preParse.PublicKey)

internal/server/state.go

@@ -24,6 +24,7 @@ type rawConfig struct {
 	AdminUID      []byte
 	DatabasePath  string
 	StreamTimeout int
+	KeepAlive     int
 	CncMode       bool
 }
 
@@ -35,6 +36,7 @@ type State struct {
 	Now       func() time.Time
 	AdminUID  []byte
 	Timeout   time.Duration
+	KeepAlive time.Duration
 
 	BypassUID map[[16]byte]struct{}
 	staticPv  crypto.PrivateKey
@@ -173,6 +175,12 @@ func (sta *State) ParseConfig(conf string) (err error) {
 		sta.Timeout = time.Duration(preParse.StreamTimeout) * time.Second
 	}
 
+	if preParse.KeepAlive <= 0 {
+		sta.KeepAlive = -1
+	} else {
+		sta.KeepAlive = time.Duration(preParse.KeepAlive) * time.Second
+	}
+
 	sta.RedirHost, sta.RedirPort, err = parseRedirAddr(preParse.RedirAddr)
 	if err != nil {
 		return fmt.Errorf("unable to parse RedirAddr: %v", err)