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fix(inputs.win_perf_counter): Do not rely on returned buffer size (#1…
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…4241)
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@srebhan
srebhan authored Nov 7, 2023
1 parent 247a808 commit 0e2203d
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Showing 6 changed files with 187 additions and 107 deletions.
4 changes: 4 additions & 0 deletions plugins/inputs/win_perf_counters/README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -345,6 +345,10 @@ See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
## e.g. IgnoredErrors = ["PDH_NO_DATA"]
# IgnoredErrors = []

## Maximum size of the buffer for values returned by the API
## Increase this value if you experience "buffer limit reached" errors.
# MaxBufferSize = "4MiB"

## NOTE: Due to the way TOML is parsed, tables must be at the END of the
## plugin definition, otherwise additional config options are read as part of
## the table
Expand Down
145 changes: 95 additions & 50 deletions plugins/inputs/win_perf_counters/performance_query.go
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Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,11 @@ import (
"unsafe"
)

// Initial buffer size for return buffers
const initialBufferSize = uint32(1024) // 1kB

var errBufferLimitReached = errors.New("buffer limit reached")

// CounterValue is abstraction for PdhFmtCountervalueItemDouble
type CounterValue struct {
InstanceName string
Expand All @@ -36,7 +41,7 @@ type PerformanceQuery interface {
}

type PerformanceQueryCreator interface {
NewPerformanceQuery(string) PerformanceQuery
NewPerformanceQuery(string, uint32) PerformanceQuery
}

// PdhError represents error returned from Performance Counters API
Expand All @@ -58,14 +63,14 @@ func NewPdhError(code uint32) error {

// PerformanceQueryImpl is implementation of PerformanceQuery interface, which calls phd.dll functions
type PerformanceQueryImpl struct {
query pdhQueryHandle
maxBufferSize uint32
query pdhQueryHandle
}

type PerformanceQueryCreatorImpl struct {
}
type PerformanceQueryCreatorImpl struct{}

func (m PerformanceQueryCreatorImpl) NewPerformanceQuery(string) PerformanceQuery {
return &PerformanceQueryImpl{}
func (m PerformanceQueryCreatorImpl) NewPerformanceQuery(_ string, maxBufferSize uint32) PerformanceQuery {
return &PerformanceQueryImpl{maxBufferSize: maxBufferSize}
}

// Open creates a new counterPath that is used to manage the collection of performance data.
Expand Down Expand Up @@ -124,64 +129,82 @@ func (m *PerformanceQueryImpl) AddEnglishCounterToQuery(counterPath string) (pdh

// GetCounterPath return counter information for given handle
func (m *PerformanceQueryImpl) GetCounterPath(counterHandle pdhCounterHandle) (string, error) {
var bufSize uint32
var buff []byte
var ret uint32
if ret = PdhGetCounterInfo(counterHandle, 0, &bufSize, nil); ret == PdhMoreData {
buff = make([]byte, bufSize)
bufSize = uint32(len(buff))
if ret = PdhGetCounterInfo(counterHandle, 0, &bufSize, &buff[0]); ret == ErrorSuccess {
ci := (*PdhCounterInfo)(unsafe.Pointer(&buff[0])) //nolint:gosec // G103: Valid use of unsafe call to create PDH_COUNTER_INFO
for buflen := initialBufferSize; buflen <= m.maxBufferSize; buflen *= 2 {
buf := make([]byte, buflen)

// Get the info with the current buffer size
size := buflen
ret := PdhGetCounterInfo(counterHandle, 0, &size, &buf[0])
if ret == ErrorSuccess {
ci := (*PdhCounterInfo)(unsafe.Pointer(&buf[0])) //nolint:gosec // G103: Valid use of unsafe call to create PDH_COUNTER_INFO
return UTF16PtrToString(ci.SzFullPath), nil
}

// Use the size as a hint if it exceeds the current buffer size
if size > buflen {
buflen = size
}

// We got a non-recoverable error so exit here
if ret != PdhMoreData {
return "", NewPdhError(ret)
}
}
return "", NewPdhError(ret)

return "", errBufferLimitReached
}

// ExpandWildCardPath examines local computer and returns those counter paths that match the given counter path which contains wildcard characters.
func (m *PerformanceQueryImpl) ExpandWildCardPath(counterPath string) ([]string, error) {
var bufSize uint32
var buff []uint16
var ret uint32
for buflen := initialBufferSize; buflen <= m.maxBufferSize; buflen *= 2 {
buf := make([]uint16, buflen)

if ret = PdhExpandWildCardPath(counterPath, nil, &bufSize); ret == PdhMoreData {
buff = make([]uint16, bufSize)
bufSize = uint32(len(buff))
ret = PdhExpandWildCardPath(counterPath, &buff[0], &bufSize)
// Get the info with the current buffer size
size := buflen
ret := PdhExpandWildCardPath(counterPath, &buf[0], &size)
if ret == ErrorSuccess {
list := UTF16ToStringArray(buff)
return list, nil
return UTF16ToStringArray(buf), nil
}

// Use the size as a hint if it exceeds the current buffer size
if size > buflen {
buflen = size
}

// We got a non-recoverable error so exit here
if ret != PdhMoreData {
return nil, NewPdhError(ret)
}
}
return nil, NewPdhError(ret)

return nil, errBufferLimitReached
}

// GetFormattedCounterValueDouble computes a displayable value for the specified counter
func (m *PerformanceQueryImpl) GetFormattedCounterValueDouble(hCounter pdhCounterHandle) (float64, error) {
var counterType uint32
var value PdhFmtCountervalueDouble
var ret uint32

if ret = PdhGetFormattedCounterValueDouble(hCounter, &counterType, &value); ret == ErrorSuccess {
if value.CStatus == PdhCstatusValidData || value.CStatus == PdhCstatusNewData {
return value.DoubleValue, nil
}
return 0, NewPdhError(value.CStatus)
if ret := PdhGetFormattedCounterValueDouble(hCounter, &counterType, &value); ret != ErrorSuccess {
return 0, NewPdhError(ret)
}
return 0, NewPdhError(ret)
if value.CStatus == PdhCstatusValidData || value.CStatus == PdhCstatusNewData {
return value.DoubleValue, nil
}
return 0, NewPdhError(value.CStatus)
}

func (m *PerformanceQueryImpl) GetFormattedCounterArrayDouble(hCounter pdhCounterHandle) ([]CounterValue, error) {
var buffSize uint32
var itemCount uint32
var ret uint32
for buflen := initialBufferSize; buflen <= m.maxBufferSize; buflen *= 2 {
buf := make([]byte, buflen)

if ret = PdhGetFormattedCounterArrayDouble(hCounter, &buffSize, &itemCount, nil); ret == PdhMoreData {
buff := make([]byte, buffSize)

if ret = PdhGetFormattedCounterArrayDouble(hCounter, &buffSize, &itemCount, &buff[0]); ret == ErrorSuccess {
// Get the info with the current buffer size
var itemCount uint32
size := buflen
ret := PdhGetFormattedCounterArrayDouble(hCounter, &size, &itemCount, &buf[0])
if ret == ErrorSuccess {
//nolint:gosec // G103: Valid use of unsafe call to create PDH_FMT_COUNTERVALUE_ITEM_DOUBLE
items := (*[1 << 20]PdhFmtCountervalueItemDouble)(unsafe.Pointer(&buff[0]))[:itemCount]
items := (*[1 << 20]PdhFmtCountervalueItemDouble)(unsafe.Pointer(&buf[0]))[:itemCount]
values := make([]CounterValue, 0, itemCount)
for _, item := range items {
if item.FmtValue.CStatus == PdhCstatusValidData || item.FmtValue.CStatus == PdhCstatusNewData {
Expand All @@ -191,21 +214,32 @@ func (m *PerformanceQueryImpl) GetFormattedCounterArrayDouble(hCounter pdhCounte
}
return values, nil
}

// Use the size as a hint if it exceeds the current buffer size
if size > buflen {
buflen = size
}

// We got a non-recoverable error so exit here
if ret != PdhMoreData {
return nil, NewPdhError(ret)
}
}
return nil, NewPdhError(ret)

return nil, errBufferLimitReached
}

func (m *PerformanceQueryImpl) GetRawCounterArray(hCounter pdhCounterHandle) ([]CounterValue, error) {
var buffSize uint32
var itemCount uint32
var ret uint32
for buflen := initialBufferSize; buflen <= m.maxBufferSize; buflen *= 2 {
buf := make([]byte, buflen)

if ret = PdhGetRawCounterArray(hCounter, &buffSize, &itemCount, nil); ret == PdhMoreData {
buff := make([]byte, buffSize)

if ret = PdhGetRawCounterArray(hCounter, &buffSize, &itemCount, &buff[0]); ret == ErrorSuccess {
// Get the info with the current buffer size
var itemCount uint32
size := buflen
ret := PdhGetRawCounterArray(hCounter, &size, &itemCount, &buf[0])
if ret == ErrorSuccess {
//nolint:gosec // G103: Valid use of unsafe call to create PDH_RAW_COUNTER_ITEM
items := (*[1 << 20]PdhRawCounterItem)(unsafe.Pointer(&buff[0]))[:itemCount]
items := (*[1 << 20]PdhRawCounterItem)(unsafe.Pointer(&buf[0]))[:itemCount]
values := make([]CounterValue, 0, itemCount)
for _, item := range items {
if item.RawValue.CStatus == PdhCstatusValidData || item.RawValue.CStatus == PdhCstatusNewData {
Expand All @@ -215,8 +249,19 @@ func (m *PerformanceQueryImpl) GetRawCounterArray(hCounter pdhCounterHandle) ([]
}
return values, nil
}

// Use the size as a hint if it exceeds the current buffer size
if size > buflen {
buflen = size
}

// We got a non-recoverable error so exit here
if ret != PdhMoreData {
return nil, NewPdhError(ret)
}
}
return nil, NewPdhError(ret)

return nil, errBufferLimitReached
}

func (m *PerformanceQueryImpl) CollectData() error {
Expand Down
4 changes: 4 additions & 0 deletions plugins/inputs/win_perf_counters/sample.conf
View file
Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,10 @@
## e.g. IgnoredErrors = ["PDH_NO_DATA"]
# IgnoredErrors = []

## Maximum size of the buffer for values returned by the API
## Increase this value if you experience "buffer limit reached" errors.
# MaxBufferSize = "4MiB"

## NOTE: Due to the way TOML is parsed, tables must be at the END of the
## plugin definition, otherwise additional config options are read as part of
## the table
Expand Down
16 changes: 14 additions & 2 deletions plugins/inputs/win_perf_counters/win_perf_counters.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@ import (
_ "embed"
"errors"
"fmt"
"math"
"os"
"strings"
"sync"
Expand All @@ -20,6 +21,8 @@ import (
//go:embed sample.conf
var sampleConfig string

var defaultMaxBufferSize = config.Size(100 * 1024 * 1024)

type WinPerfCounters struct {
PrintValid bool `toml:"PrintValid"`
PreVistaSupport bool `toml:"PreVistaSupport" deprecated:"1.7.0;determined dynamically"`
Expand All @@ -29,6 +32,7 @@ type WinPerfCounters struct {
UseWildcardsExpansion bool
LocalizeWildcardsExpansion bool
IgnoredErrors []string `toml:"IgnoredErrors"`
MaxBufferSize config.Size
Sources []string

Log telegraf.Logger
Expand Down Expand Up @@ -207,7 +211,7 @@ func (m *WinPerfCounters) AddItem(counterPath, computer, objectName, instance, c
if !ok {
hostCounter = &hostCountersInfo{computer: computer, tag: sourceTag}
m.hostCounters[computer] = hostCounter
hostCounter.query = m.queryCreator.NewPerformanceQuery(computer)
hostCounter.query = m.queryCreator.NewPerformanceQuery(computer, uint32(m.MaxBufferSize))
if err := hostCounter.query.Open(); err != nil {
return err
}
Expand Down Expand Up @@ -579,9 +583,16 @@ func isKnownCounterDataError(err error) bool {
}

func (m *WinPerfCounters) Init() error {
// Check the buffer size
if m.MaxBufferSize < config.Size(initialBufferSize) {
return fmt.Errorf("maximum buffer size should at least be %d", 2*initialBufferSize)
}
if m.MaxBufferSize > math.MaxUint32 {
return fmt.Errorf("maximum buffer size should be smaller than %d", uint32(math.MaxUint32))
}

if m.UseWildcardsExpansion && !m.LocalizeWildcardsExpansion {
// Counters must not have wildcards with this option

found := false
wildcards := []string{"*", "?"}

Expand Down Expand Up @@ -614,6 +625,7 @@ func init() {
return &WinPerfCounters{
CountersRefreshInterval: config.Duration(time.Second * 60),
LocalizeWildcardsExpansion: true,
MaxBufferSize: defaultMaxBufferSize,
queryCreator: &PerformanceQueryCreatorImpl{},
}
})
Expand Down
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