mirror of
https://github.com/prometheus-community/windows_exporter.git
synced 2026-10-17 18:19:04 +02:00
hyperv: add virtual_hard_disk sub-collector (#2693)
Signed-off-by: EisenbergD <dominik.eisenberg@beiersdorf.com> Co-authored-by: EisenbergD <dominik.eisenberg@beiersdorf.com> Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
This commit is contained in:
Dominik Eisenberg
co-authored by
EisenbergD
Claude Opus 5.5
EisenbergD
Claude Opus 5.5
parent
89c5df9d8b
commit
ec7dcdc259
@@ -0,0 +1,260 @@
|
||||
// SPDX-License-Identifier: Apache-2.0
|
||||
//
|
||||
// Copyright The Prometheus 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.
|
||||
|
||||
//go:build windows
|
||||
|
||||
// Package virtdisk reads the size and type of virtual hard disks (VHD, VHDX,
|
||||
// VHD Set) through virtdisk.dll, the API behind Get-VHD.
|
||||
// https://learn.microsoft.com/en-us/windows/win32/api/virtdisk/
|
||||
package virtdisk
|
||||
|
||||
import (
|
||||
"encoding/binary"
|
||||
"fmt"
|
||||
"unsafe"
|
||||
|
||||
"golang.org/x/sys/windows"
|
||||
)
|
||||
|
||||
//nolint:gochecknoglobals
|
||||
var (
|
||||
modVirtdisk = windows.NewLazySystemDLL("virtdisk.dll")
|
||||
procOpenVirtualDisk = modVirtdisk.NewProc("OpenVirtualDisk")
|
||||
procGetVirtualDiskInformation = modVirtdisk.NewProc("GetVirtualDiskInformation")
|
||||
)
|
||||
|
||||
// Provider subtypes of GET_VIRTUAL_DISK_INFO_PROVIDER_SUBTYPE.
|
||||
const (
|
||||
ProviderSubtypeFixed uint32 = 2
|
||||
ProviderSubtypeDynamic uint32 = 3
|
||||
ProviderSubtypeDifferencing uint32 = 4
|
||||
)
|
||||
|
||||
const (
|
||||
virtualDiskAccessNone = 0x00000000 // VIRTUAL_DISK_ACCESS_NONE, required with version 2 parameters
|
||||
openVirtualDiskFlagNoParents = 0x00000001 // OPEN_VIRTUAL_DISK_FLAG_NO_PARENTS
|
||||
openVirtualDiskVersion2 = 2 // OPEN_VIRTUAL_DISK_VERSION_2
|
||||
|
||||
getVirtualDiskInfoSize = 1 // GET_VIRTUAL_DISK_INFO_SIZE
|
||||
getVirtualDiskInfoParentLocation = 3 // GET_VIRTUAL_DISK_INFO_PARENT_LOCATION
|
||||
getVirtualDiskInfoProviderSubtype = 7 // GET_VIRTUAL_DISK_INFO_PROVIDER_SUBTYPE
|
||||
)
|
||||
|
||||
// virtualStorageType is VIRTUAL_STORAGE_TYPE. The zero value is
|
||||
// VIRTUAL_STORAGE_TYPE_DEVICE_UNKNOWN with VIRTUAL_STORAGE_TYPE_VENDOR_UNKNOWN,
|
||||
// which lets OpenVirtualDisk detect VHD, VHDX and VHD Set files.
|
||||
type virtualStorageType struct {
|
||||
DeviceID uint32
|
||||
VendorID windows.GUID
|
||||
}
|
||||
|
||||
// openVirtualDiskParametersV2 is OPEN_VIRTUAL_DISK_PARAMETERS with
|
||||
// OPEN_VIRTUAL_DISK_VERSION_2. The union is 4-byte aligned.
|
||||
type openVirtualDiskParametersV2 struct {
|
||||
Version uint32
|
||||
GetInfoOnly int32 // BOOL
|
||||
ReadOnly int32 // BOOL
|
||||
ResiliencyGUID windows.GUID
|
||||
}
|
||||
|
||||
// getVirtualDiskInfo is GET_VIRTUAL_DISK_INFO. The union is 8-byte aligned
|
||||
// and its largest member is the 24-byte Size struct.
|
||||
type getVirtualDiskInfo struct {
|
||||
Version uint32
|
||||
_ uint32
|
||||
Union [24]byte
|
||||
}
|
||||
|
||||
// Info is the size and type of a virtual hard disk.
|
||||
type Info struct {
|
||||
// VirtualSize is the maximum size the virtual machine sees, in bytes.
|
||||
VirtualSize uint64
|
||||
// PhysicalSize is the size of the file on storage, in bytes.
|
||||
PhysicalSize uint64
|
||||
// ProviderSubtype is ProviderSubtypeFixed, ProviderSubtypeDynamic or ProviderSubtypeDifferencing.
|
||||
ProviderSubtype uint32
|
||||
}
|
||||
|
||||
// Available reports whether virtdisk.dll and the functions used by GetInfo
|
||||
// can be loaded. LazyProc.Call panics if they can't, so check this first.
|
||||
func Available() error {
|
||||
if err := procOpenVirtualDisk.Find(); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
return procGetVirtualDiskInformation.Find()
|
||||
}
|
||||
|
||||
// GetInfo opens the virtual hard disk at path read-only, without its parents,
|
||||
// and returns its size and provider subtype. It works on disks attached to
|
||||
// running virtual machines.
|
||||
func GetInfo(path string) (Info, error) {
|
||||
handle, err := open(path)
|
||||
if err != nil {
|
||||
return Info{}, err
|
||||
}
|
||||
|
||||
defer func() { _ = windows.CloseHandle(handle) }()
|
||||
|
||||
size, err := getInformation(handle, getVirtualDiskInfoSize)
|
||||
if err != nil {
|
||||
return Info{}, fmt.Errorf("GetVirtualDiskInformation size %s: %w", path, err)
|
||||
}
|
||||
|
||||
subtype, err := getInformation(handle, getVirtualDiskInfoProviderSubtype)
|
||||
if err != nil {
|
||||
return Info{}, fmt.Errorf("GetVirtualDiskInformation provider subtype %s: %w", path, err)
|
||||
}
|
||||
|
||||
return Info{
|
||||
VirtualSize: binary.LittleEndian.Uint64(size.Union[0:8]),
|
||||
PhysicalSize: binary.LittleEndian.Uint64(size.Union[8:16]),
|
||||
ProviderSubtype: binary.LittleEndian.Uint32(subtype.Union[0:4]),
|
||||
}, nil
|
||||
}
|
||||
|
||||
// ParentLocations returns the paths at which the parent of the differencing
|
||||
// disk at path is stored, as recorded in the disk. Disks without a parent
|
||||
// return none.
|
||||
func ParentLocations(path string) ([]string, error) {
|
||||
handle, err := open(path)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
defer func() { _ = windows.CloseHandle(handle) }()
|
||||
|
||||
subtype, err := getInformation(handle, getVirtualDiskInfoProviderSubtype)
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("GetVirtualDiskInformation provider subtype %s: %w", path, err)
|
||||
}
|
||||
|
||||
if binary.LittleEndian.Uint32(subtype.Union[0:4]) != ProviderSubtypeDifferencing {
|
||||
return nil, nil
|
||||
}
|
||||
|
||||
// GET_VIRTUAL_DISK_INFO with ParentLocation: the 8-byte aligned union starts
|
||||
// at offset 8 with the BOOL ParentResolved, followed by the MULTI_SZ
|
||||
// ParentLocationBuffer. A uint64 buffer keeps the alignment.
|
||||
buffer := make([]uint64, 512)
|
||||
|
||||
for range 4 {
|
||||
bytes := unsafe.Slice((*byte)(unsafe.Pointer(&buffer[0])), len(buffer)*8)
|
||||
binary.LittleEndian.PutUint32(bytes, getVirtualDiskInfoParentLocation)
|
||||
|
||||
infoSize := uint32(len(bytes))
|
||||
|
||||
ret, _, _ := procGetVirtualDiskInformation.Call(
|
||||
uintptr(handle),
|
||||
uintptr(unsafe.Pointer(&infoSize)),
|
||||
uintptr(unsafe.Pointer(&buffer[0])),
|
||||
0, // SizeUsed is optional
|
||||
)
|
||||
|
||||
switch windows.Errno(ret) {
|
||||
case 0:
|
||||
if infoSize < 12 || int(infoSize) > len(bytes) {
|
||||
return nil, fmt.Errorf("GetVirtualDiskInformation parent location %s: invalid size %d", path, infoSize)
|
||||
}
|
||||
|
||||
chars := unsafe.Slice((*uint16)(unsafe.Pointer(&bytes[12])), (int(infoSize)-12)/2)
|
||||
|
||||
return decodeMultiString(chars), nil
|
||||
case windows.ERROR_INSUFFICIENT_BUFFER, windows.ERROR_MORE_DATA:
|
||||
if int(infoSize) <= len(bytes) {
|
||||
return nil, fmt.Errorf("GetVirtualDiskInformation parent location %s: %w", path, windows.Errno(ret))
|
||||
}
|
||||
|
||||
buffer = make([]uint64, (int(infoSize)+7)/8)
|
||||
default:
|
||||
return nil, fmt.Errorf("GetVirtualDiskInformation parent location %s: %w", path, windows.Errno(ret))
|
||||
}
|
||||
}
|
||||
|
||||
return nil, fmt.Errorf("GetVirtualDiskInformation parent location %s: buffer did not stabilize", path)
|
||||
}
|
||||
|
||||
// decodeMultiString splits a MULTI_SZ into its strings.
|
||||
func decodeMultiString(chars []uint16) []string {
|
||||
var out []string
|
||||
|
||||
for len(chars) > 0 {
|
||||
end := 0
|
||||
for end < len(chars) && chars[end] != 0 {
|
||||
end++
|
||||
}
|
||||
|
||||
if end == 0 {
|
||||
break
|
||||
}
|
||||
|
||||
out = append(out, windows.UTF16ToString(chars[:end]))
|
||||
|
||||
if end == len(chars) {
|
||||
break
|
||||
}
|
||||
|
||||
chars = chars[end+1:]
|
||||
}
|
||||
|
||||
return out
|
||||
}
|
||||
|
||||
// open opens the virtual hard disk at path for reading its information only.
|
||||
// GetInfoOnly also opens a disk that is in use by a running virtual machine.
|
||||
func open(path string) (windows.Handle, error) {
|
||||
pathPtr, err := windows.UTF16PtrFromString(path)
|
||||
if err != nil {
|
||||
return 0, fmt.Errorf("virtual disk %s: %w", path, err)
|
||||
}
|
||||
|
||||
var (
|
||||
storageType virtualStorageType
|
||||
handle windows.Handle
|
||||
)
|
||||
|
||||
params := openVirtualDiskParametersV2{Version: openVirtualDiskVersion2, GetInfoOnly: 1}
|
||||
|
||||
ret, _, _ := procOpenVirtualDisk.Call(
|
||||
uintptr(unsafe.Pointer(&storageType)),
|
||||
uintptr(unsafe.Pointer(pathPtr)),
|
||||
virtualDiskAccessNone,
|
||||
openVirtualDiskFlagNoParents,
|
||||
uintptr(unsafe.Pointer(¶ms)),
|
||||
uintptr(unsafe.Pointer(&handle)),
|
||||
)
|
||||
if ret != 0 {
|
||||
return 0, fmt.Errorf("OpenVirtualDisk %s: %w", path, windows.Errno(ret))
|
||||
}
|
||||
|
||||
return handle, nil
|
||||
}
|
||||
|
||||
func getInformation(handle windows.Handle, version uint32) (getVirtualDiskInfo, error) {
|
||||
info := getVirtualDiskInfo{Version: version}
|
||||
infoSize := uint32(unsafe.Sizeof(info))
|
||||
|
||||
ret, _, _ := procGetVirtualDiskInformation.Call(
|
||||
uintptr(handle),
|
||||
uintptr(unsafe.Pointer(&infoSize)),
|
||||
uintptr(unsafe.Pointer(&info)),
|
||||
0, // SizeUsed is optional
|
||||
)
|
||||
if ret != 0 {
|
||||
return getVirtualDiskInfo{}, windows.Errno(ret)
|
||||
}
|
||||
|
||||
return info, nil
|
||||
}
|
||||
Reference in New Issue
Block a user