Update dependencies (#1628)

vendor/github.com/google/gops/agent/sockopt_reuseport.go

@@ -0,0 +1,37 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !js && !plan9 && !solaris && !windows
+// +build !js,!plan9,!solaris,!windows
+
+package agent
+
+import (
+	"syscall"
+
+	"golang.org/x/sys/unix"
+)
+
+// setReuseAddrAndPortSockopts sets the SO_REUSEADDR and SO_REUSEPORT socket
+// options on c's underlying socket in order to increase the chance to re-bind()
+// to the same address and port upon agent restart.
+func setReuseAddrAndPortSockopts(network, address string, c syscall.RawConn) error {
+	var soerr error
+	if err := c.Control(func(su uintptr) {
+		sock := int(su)
+		// Allow reuse of recently-used addresses. This socket option is
+		// set by default on listeners in Go's net package, see
+		// net.setDefaultSockopts.
+		soerr = unix.SetsockoptInt(sock, unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)
+		if soerr != nil {
+			return
+		}
+		// Allow reuse of recently-used ports. This gives the agent a
+		// better chance to re-bind upon restarts.
+		soerr = unix.SetsockoptInt(sock, unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)
+	}); err != nil {
+		return err
+	}
+	return soerr
+}