TCP Keep Alive Control for v4

infra/conf/transport_internet.go

@@ -391,6 +391,7 @@ type SocketConfig struct {
 	TProxy               string `json:"tproxy"`
 	AcceptProxyProtocol  bool   `json:"acceptProxyProtocol"`
 	TCPKeepAliveInterval int32  `json:"tcpKeepAliveInterval"`
+	TCPKeepAliveIdle     int32  `json:"tcpKeepAliveIdle"`
 }
 
 // Build implements Buildable.
@@ -426,6 +427,7 @@ func (c *SocketConfig) Build() (*internet.SocketConfig, error) {
 		Tproxy:               tproxy,
 		AcceptProxyProtocol:  c.AcceptProxyProtocol,
 		TcpKeepAliveInterval: c.TCPKeepAliveInterval,
+		TcpKeepAliveIdle:     c.TCPKeepAliveIdle,
 	}, nil
 }
 

transport/internet/config.proto

@@ -95,4 +95,6 @@ message SocketConfig {
   int32 tcp_keep_alive_interval = 8;
 
   uint32 tfo_queue_length = 9;
+
+  int32 tcp_keep_alive_idle = 10;
 }

transport/internet/sockopt_darwin.go

@@ -1,30 +1,46 @@
 package internet
 
 import (
-	"syscall"
+	"golang.org/x/sys/unix"
 )
 
 const (
-	// TCP_FASTOPEN is the socket option on darwin for TCP fast open.
-	TCP_FASTOPEN = 0x105 // nolint: golint,stylecheck
 	// TCP_FASTOPEN_SERVER is the value to enable TCP fast open on darwin for server connections.
 	TCP_FASTOPEN_SERVER = 0x01 // nolint: golint,stylecheck
 	// TCP_FASTOPEN_CLIENT is the value to enable TCP fast open on darwin for client connections.
-	TCP_FASTOPEN_CLIENT = 0x02 // nolint: golint,stylecheck
+	TCP_FASTOPEN_CLIENT = 0x02 // nolint: revive,stylecheck
+	// syscall.TCP_KEEPINTVL is missing on some darwin architectures.
+	sysTCP_KEEPINTVL = 0x101 // nolint: revive,stylecheck
 )
 
 func applyOutboundSocketOptions(network string, address string, fd uintptr, config *SocketConfig) error {
 	if isTCPSocket(network) {
 		switch config.Tfo {
 		case SocketConfig_Enable:
-			if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, TCP_FASTOPEN, TCP_FASTOPEN_CLIENT); err != nil {
+			if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, unix.TCP_FASTOPEN, TCP_FASTOPEN_CLIENT); err != nil {
 				return err
 			}
 		case SocketConfig_Disable:
-			if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, TCP_FASTOPEN, 0); err != nil {
+			if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, unix.TCP_FASTOPEN, 0); err != nil {
 				return err
 			}
 		}
+
+		if config.TcpKeepAliveIdle > 0 || config.TcpKeepAliveInterval > 0 {
+			if config.TcpKeepAliveIdle > 0 {
+				if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, unix.TCP_KEEPALIVE, int(config.TcpKeepAliveInterval)); err != nil {
+					return newError("failed to set TCP_KEEPINTVL", err)
+				}
+			}
+			if config.TcpKeepAliveInterval > 0 {
+				if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, sysTCP_KEEPINTVL, int(config.TcpKeepAliveIdle)); err != nil {
+					return newError("failed to set TCP_KEEPIDLE", err)
+				}
+			}
+			if err := unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1); err != nil {
+				return newError("failed to set SO_KEEPALIVE", err)
+			}
+		}
 	}
 
 	return nil
@@ -34,14 +50,29 @@ func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig)
 	if isTCPSocket(network) {
 		switch config.Tfo {
 		case SocketConfig_Enable:
-			if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, TCP_FASTOPEN, TCP_FASTOPEN_SERVER); err != nil {
+			if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, unix.TCP_FASTOPEN, TCP_FASTOPEN_SERVER); err != nil {
 				return err
 			}
 		case SocketConfig_Disable:
-			if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, TCP_FASTOPEN, 0); err != nil {
+			if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, unix.TCP_FASTOPEN, 0); err != nil {
 				return err
 			}
 		}
+		if config.TcpKeepAliveIdle > 0 || config.TcpKeepAliveInterval > 0 {
+			if config.TcpKeepAliveIdle > 0 {
+				if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, unix.TCP_KEEPALIVE, int(config.TcpKeepAliveInterval)); err != nil {
+					return newError("failed to set TCP_KEEPINTVL", err)
+				}
+			}
+			if config.TcpKeepAliveInterval > 0 {
+				if err := unix.SetsockoptInt(int(fd), unix.IPPROTO_TCP, sysTCP_KEEPINTVL, int(config.TcpKeepAliveIdle)); err != nil {
+					return newError("failed to set TCP_KEEPIDLE", err)
+				}
+			}
+			if err := unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_KEEPALIVE, 1); err != nil {
+				return newError("failed to set SO_KEEPALIVE", err)
+			}
+		}
 	}
 
 	return nil

transport/internet/sockopt_freebsd.go

@@ -141,6 +141,21 @@ func applyOutboundSocketOptions(network string, address string, fd uintptr, conf
 				return newError("failed to set TCP_FASTOPEN_CONNECT=0").Base(err)
 			}
 		}
+		if config.TcpKeepAliveIdle > 0 || config.TcpKeepAliveInterval > 0 {
+			if config.TcpKeepAliveIdle > 0 {
+				if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, syscall.TCP_KEEPIDLE, int(config.TcpKeepAliveIdle)); err != nil {
+					return newError("failed to set TCP_KEEPIDLE", err)
+				}
+			}
+			if config.TcpKeepAliveInterval > 0 {
+				if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, syscall.TCP_KEEPINTVL, int(config.TcpKeepAliveInterval)); err != nil {
+					return newError("failed to set TCP_KEEPINTVL", err)
+				}
+			}
+			if err := syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, syscall.SO_KEEPALIVE, 1); err != nil {
+				return newError("failed to set SO_KEEPALIVE", err)
+			}
+		}
 	}
 
 	if config.Tproxy.IsEnabled() {
@@ -175,6 +190,21 @@ func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig)
 				return newError("failed to set TCP_FASTOPEN=0").Base(err)
 			}
 		}
+		if config.TcpKeepAliveIdle > 0 || config.TcpKeepAliveInterval > 0 {
+			if config.TcpKeepAliveIdle > 0 {
+				if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, syscall.TCP_KEEPIDLE, int(config.TcpKeepAliveIdle)); err != nil {
+					return newError("failed to set TCP_KEEPIDLE", err)
+				}
+			}
+			if config.TcpKeepAliveInterval > 0 {
+				if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, syscall.TCP_KEEPINTVL, int(config.TcpKeepAliveInterval)); err != nil {
+					return newError("failed to set TCP_KEEPINTVL", err)
+				}
+			}
+			if err := syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, syscall.SO_KEEPALIVE, 1); err != nil {
+				return newError("failed to set SO_KEEPALIVE", err)
+			}
+		}
 	}
 
 	if config.Tproxy.IsEnabled() {

transport/internet/sockopt_linux.go

@@ -59,9 +59,19 @@ func applyOutboundSocketOptions(network string, address string, fd uintptr, conf
 			}
 		}
 
-		if config.TcpKeepAliveInterval != 0 {
-			if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, syscall.TCP_KEEPINTVL, int(config.TcpKeepAliveInterval)); err != nil {
-				return newError("failed to set TCP_KEEPINTVL", err)
+		if config.TcpKeepAliveInterval > 0 || config.TcpKeepAliveIdle > 0 {
+			if config.TcpKeepAliveInterval > 0 {
+				if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, syscall.TCP_KEEPINTVL, int(config.TcpKeepAliveInterval)); err != nil {
+					return newError("failed to set TCP_KEEPINTVL", err)
+				}
+			}
+			if config.TcpKeepAliveIdle > 0 {
+				if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, syscall.TCP_KEEPIDLE, int(config.TcpKeepAliveIdle)); err != nil {
+					return newError("failed to set TCP_KEEPIDLE", err)
+				}
+			}
+			if err := syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, syscall.SO_KEEPALIVE, 1); err != nil {
+				return newError("failed to set SO_KEEPALIVE", err)
 			}
 		}
 	}
@@ -93,9 +103,19 @@ func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig)
 			}
 		}
 
-		if config.TcpKeepAliveInterval != 0 {
-			if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, syscall.TCP_KEEPINTVL, int(config.TcpKeepAliveInterval)); err != nil {
-				return newError("failed to set TCP_KEEPINTVL", err)
+		if config.TcpKeepAliveInterval > 0 || config.TcpKeepAliveIdle > 0 {
+			if config.TcpKeepAliveInterval > 0 {
+				if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, syscall.TCP_KEEPINTVL, int(config.TcpKeepAliveInterval)); err != nil {
+					return newError("failed to set TCP_KEEPINTVL", err)
+				}
+			}
+			if config.TcpKeepAliveIdle > 0 {
+				if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, syscall.TCP_KEEPIDLE, int(config.TcpKeepAliveIdle)); err != nil {
+					return newError("failed to set TCP_KEEPIDLE", err)
+				}
+			}
+			if err := syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, syscall.SO_KEEPALIVE, 1); err != nil {
+				return newError("failed to set SO_KEEPALIVE", err)
 			}
 		}
 	}

transport/internet/sockopt_windows.go

@@ -25,6 +25,11 @@ func applyOutboundSocketOptions(network string, address string, fd uintptr, conf
 		if err := setTFO(syscall.Handle(fd), config.Tfo); err != nil {
 			return err
 		}
+		if config.TcpKeepAliveIdle > 0 {
+			if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.SOL_SOCKET, syscall.SO_KEEPALIVE, 1); err != nil {
+				return newError("failed to set SO_KEEPALIVE", err)
+			}
+		}
 	}
 
 	return nil
@@ -35,6 +40,11 @@ func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig)
 		if err := setTFO(syscall.Handle(fd), config.Tfo); err != nil {
 			return err
 		}
+		if config.TcpKeepAliveIdle > 0 {
+			if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.SOL_SOCKET, syscall.SO_KEEPALIVE, 1); err != nil {
+				return newError("failed to set SO_KEEPALIVE", err)
+			}
+		}
 	}
 
 	return nil

transport/internet/system_dialer.go

@@ -63,10 +63,14 @@ func (d *DefaultSystemDialer) Dial(ctx context.Context, src net.Address, dest ne
 			dest: destAddr,
 		}, nil
 	}
-
+	goStdKeepAlive := time.Duration(0)
+	if sockopt != nil && sockopt.TcpKeepAliveIdle != 0 {
+		goStdKeepAlive = time.Duration(-1)
+	}
 	dialer := &net.Dialer{
 		Timeout:   time.Second * 16,
 		LocalAddr: resolveSrcAddr(dest.Network, src),
+		KeepAlive: goStdKeepAlive,
 	}
 
 	if sockopt != nil || len(d.controllers) > 0 {

transport/internet/system_listener.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"runtime"
 	"syscall"
+	"time"
 
 	"github.com/pires/go-proxyproto"
 
@@ -49,6 +50,9 @@ func (dl *DefaultListener) Listen(ctx context.Context, addr net.Addr, sockopt *S
 		network = addr.Network()
 		address = addr.String()
 		lc.Control = getControlFunc(ctx, sockopt, dl.controllers)
+		if sockopt != nil && sockopt.TcpKeepAliveIdle != 0 {
+			lc.KeepAlive = time.Duration(-1)
+		}
 	case *net.UnixAddr:
 		lc.Control = nil
 		network = addr.Network()