Add TCP keep alive support in MacOS, FreeBSD

transport/internet/sockopt_darwin.go

@@ -25,6 +25,15 @@ func applyOutboundSocketOptions(network string, address string, fd uintptr, conf
 				return 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)
+			}
+		}
 	}
 
 	return nil
@@ -42,6 +51,14 @@ func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig)
 				return 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)
+			}
+		}
 	}
 
 	return nil

transport/internet/sockopt_freebsd.go

@@ -141,6 +141,14 @@ func applyOutboundSocketOptions(network string, address string, fd uintptr, conf
 				return newError("failed to set TCP_FASTOPEN_CONNECT=0").Base(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 +183,14 @@ func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig)
 				return newError("failed to set TCP_FASTOPEN=0").Base(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() {