From 1978008c8f2bb46c33f48f0a895becaf1830656a Mon Sep 17 00:00:00 2001
From: Antonio Ojea <aojea@google.com>
Date: Tue, 17 Jan 2023 11:19:23 +0000
Subject: [PATCH] add custom dialer optimized for probes

probe util dial set linger to 1s
---
 pkg/probe/dialer_others.go  | 42 +++++++++++++++++++++++++++++++++++++
 pkg/probe/dialer_windows.go | 42 +++++++++++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+)
 create mode 100644 pkg/probe/dialer_others.go
 create mode 100644 pkg/probe/dialer_windows.go

diff --git a/pkg/probe/dialer_others.go b/pkg/probe/dialer_others.go
new file mode 100644
index 00000000000..7b02daff340
--- /dev/null
+++ b/pkg/probe/dialer_others.go
@@ -0,0 +1,42 @@
+//go:build !windows
+// +build !windows
+
+/*
+Copyright 2023 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package probe
+
+import (
+	"net"
+	"syscall"
+)
+
+// ProbeDialer returns a dialer optimized for probes to avoid lingering sockets on TIME-WAIT state.
+// The dialer reduces the TIME-WAIT period to 1 seconds instead of the OS default of 60 seconds.
+// Using 1 second instead of 0 because SO_LINGER socket option to 0 causes pending data to be
+// discarded and the connection to be aborted with an RST rather than for the pending data to be
+// transmitted and the connection closed cleanly with a FIN.
+// Ref: https://issues.k8s.io/89898
+func ProbeDialer() *net.Dialer {
+	dialer := &net.Dialer{
+		Control: func(network, address string, c syscall.RawConn) error {
+			return c.Control(func(fd uintptr) {
+				syscall.SetsockoptLinger(int(fd), syscall.SOL_SOCKET, syscall.SO_LINGER, &syscall.Linger{Onoff: 1, Linger: 1})
+			})
+		},
+	}
+	return dialer
+}
diff --git a/pkg/probe/dialer_windows.go b/pkg/probe/dialer_windows.go
new file mode 100644
index 00000000000..ab0d020478c
--- /dev/null
+++ b/pkg/probe/dialer_windows.go
@@ -0,0 +1,42 @@
+//go:build windows
+// +build windows
+
+/*
+Copyright 2023 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package probe
+
+import (
+	"net"
+	"syscall"
+)
+
+// ProbeDialer returns a dialer optimized for probes to avoid lingering sockets on TIME-WAIT state.
+// The dialer reduces the TIME-WAIT period to 1 seconds instead of the OS default of 60 seconds.
+// Using 1 second instead of 0 because SO_LINGER socket option to 0 causes pending data to be
+// discarded and the connection to be aborted with an RST rather than for the pending data to be
+// transmitted and the connection closed cleanly with a FIN.
+// Ref: https://issues.k8s.io/89898
+func ProbeDialer() *net.Dialer {
+	dialer := &net.Dialer{
+		Control: func(network, address string, c syscall.RawConn) error {
+			return c.Control(func(fd uintptr) {
+				syscall.SetsockoptLinger(syscall.Handle(fd), syscall.SOL_SOCKET, syscall.SO_LINGER, &syscall.Linger{Onoff: 1, Linger: 1})
+			})
+		},
+	}
+	return dialer
+}