tailscale/safesocket/pipe_windows.go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause

package safesocket

import (
	"fmt"
	"net"
	"syscall"

	"github.com/Microsoft/go-winio"
)

func connect(s *ConnectionStrategy) (net.Conn, error) {
	return winio.DialPipe(s.path, nil)
}

func setFlags(network, address string, c syscall.RawConn) error {
	return c.Control(func(fd uintptr) {
		syscall.SetsockoptInt(syscall.Handle(fd), syscall.SOL_SOCKET,
			syscall.SO_REUSEADDR, 1)
	})
}

// windowsSDDL is the Security Descriptor set on the namedpipe.
// It provides read/write access to all users and the local system.
// It is a var for testing, do not change this value.
var windowsSDDL = "O:BAG:BAD:PAI(A;OICI;GWGR;;;BU)(A;OICI;GWGR;;;SY)"

func listen(path string) (net.Listener, error) {
	lc, err := winio.ListenPipe(
		path,
		&winio.PipeConfig{
			SecurityDescriptor: windowsSDDL,
			InputBufferSize:    256 * 1024,
			OutputBufferSize:   256 * 1024,
		},
	)
	if err != nil {
		return nil, fmt.Errorf("namedpipe.Listen: %w", err)
	}
	return lc, nil
}