providers/windows/os_windows.go

// Licensed to Elasticsearch B.V. under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Elasticsearch B.V. licenses this file to you 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 windows

import (
	"fmt"
	"strconv"
	"strings"

	"golang.org/x/sys/windows/registry"

	"github.com/elastic/go-sysinfo/types"
)

func OperatingSystem() (*types.OSInfo, error) {
	const key = registry.LOCAL_MACHINE
	const path = `SOFTWARE\Microsoft\Windows NT\CurrentVersion`
	const flags = registry.READ | registry.WOW64_64KEY

	k, err := registry.OpenKey(key, path, flags)
	if err != nil {
		return nil, fmt.Errorf(`failed to open HKLM\%v: %w`, path, err)
	}
	defer k.Close()

	osInfo := &types.OSInfo{
		Type:     "windows",
		Family:   "windows",
		Platform: "windows",
	}
	name := "ProductName"
	osInfo.Name, _, err = k.GetStringValue(name)
	if err != nil {
		return nil, fmt.Errorf(`failed to get value of HKLM\%v\%v: %w`, path, name, err)
	}

	// Newer versions (Win 10 and 2016) have CurrentMajor/CurrentMinor.
	major, _, majorErr := k.GetIntegerValue("CurrentMajorVersionNumber")
	minor, _, minorErr := k.GetIntegerValue("CurrentMinorVersionNumber")
	if majorErr == nil && minorErr == nil {
		osInfo.Major = int(major)
		osInfo.Minor = int(minor)
		osInfo.Version = fmt.Sprintf("%d.%d", major, minor)
	} else {
		name = "CurrentVersion"
		osInfo.Version, _, err = k.GetStringValue(name)
		if err != nil {
			return nil, fmt.Errorf(`failed to get value of HKLM\%v\%v: %w`, path, name, err)
		}
		parts := strings.SplitN(osInfo.Version, ".", 3)
		for i, p := range parts {
			switch i {
			case 0:
				osInfo.Major, _ = strconv.Atoi(p)
			case 1:
				osInfo.Minor, _ = strconv.Atoi(p)
			}
		}
	}

	name = "CurrentBuild"
	currentBuild, _, err := k.GetStringValue(name)
	if err != nil {
		return nil, fmt.Errorf(`failed to get value of HKLM\%v\%v: %w`, path, name, err)
	}
	osInfo.Build = currentBuild

	// Update Build Revision (optional)
	name = "UBR"
	updateBuildRevision, _, err := k.GetIntegerValue(name)
	if err != nil && err != registry.ErrNotExist {
		return nil, fmt.Errorf(`failed to get value of HKLM\%v\%v: %w`, path, name, err)
	} else {
		osInfo.Build = fmt.Sprintf("%v.%d", osInfo.Build, updateBuildRevision)
	}

	fixWindows11Naming(currentBuild, osInfo)

	return osInfo, nil
}

// fixWindows11Naming adjusts the OS name because the ProductName registry value
// was not changed in Windows 11 and still contains Windows 10. If the product
// name contains "Windows 10" and the version is greater than or equal to
// 10.0.22000 then "Windows 10" is replaced with "Windows 11" in the OS name.
//
// https://docs.microsoft.com/en-us/answers/questions/586619/windows-11-build-ver-is-still-10022000194.html
func fixWindows11Naming(currentBuild string, osInfo *types.OSInfo) {
	buildNumber, err := strconv.Atoi(currentBuild)
	if err != nil {
		return
	}

	// "Anything above [or equal] 10.0.22000.0 is Win 11. Anything below is Win 10."
	if osInfo.Major > 10 ||
		osInfo.Major == 10 && osInfo.Minor > 0 ||
		osInfo.Major == 10 && osInfo.Minor == 0 && buildNumber >= 22000 {
		osInfo.Name = strings.Replace(osInfo.Name, "Windows 10", "Windows 11", 1)
	}
}