node_exporter/collector/sysctl_bsd.go

123 lines
2.9 KiB
Go

// Copyright 2017 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.
// +build freebsd dragonfly
// +build !nomeminfo
package collector
import (
"fmt"
"github.com/prometheus/client_golang/prometheus"
"golang.org/x/sys/unix"
"unsafe"
)
// #include <sys/types.h>
import "C"
type bsdSysctlType uint8
// BSD-specific sysctl value types. There is an impedience mismatch between
// native C types, e.g. int vs long, and the golang unix.Sysctl variables
const (
// Default to uint32.
bsdSysctlTypeUint32 bsdSysctlType = iota
bsdSysctlTypeUint64
bsdSysctlTypeStructTimeval
)
// Contains all the info needed to map a single bsd-sysctl to a prometheus value.
type bsdSysctl struct {
// Prometheus name
name string
// Simple prometheus description
description string
// Prometheus type
valueType prometheus.ValueType
// Sysctl name
mib string
// Sysctl data-type
dataType bsdSysctlType
// Post-retrieval conversion hooks
conversion func(float64) float64
}
func (b bsdSysctl) Value() (float64, error) {
var tmp32 uint32
var tmp64 uint64
var tmpf64 float64
var err error
switch b.dataType {
case bsdSysctlTypeUint32:
tmp32, err = unix.SysctlUint32(b.mib)
tmpf64 = float64(tmp32)
case bsdSysctlTypeUint64:
tmp64, err = unix.SysctlUint64(b.mib)
tmpf64 = float64(tmp64)
case bsdSysctlTypeStructTimeval:
raw, err := unix.SysctlRaw(b.mib)
if err != nil {
return 0, err
}
/*
* From 10.3-RELEASE sources:
*
* /usr/include/sys/_timeval.h:47
* time_t tv_sec
* suseconds_t tv_usec
*
* /usr/include/sys/_types.h:60
* long __suseconds_t
*
* ... architecture dependent, via #ifdef:
* typedef __int64_t __time_t;
* typedef __int32_t __time_t;
*/
if len(raw) != (C.sizeof_time_t + C.sizeof_suseconds_t) {
// Shouldn't get here, unless the ABI changes...
return 0, fmt.Errorf(
"Length of bytes recieved from sysctl (%d) does not match expected bytes (%d).",
len(raw),
C.sizeof_time_t+C.sizeof_suseconds_t,
)
}
secondsUp := unsafe.Pointer(&raw[0])
susecondsUp := uintptr(secondsUp) + C.sizeof_time_t
unix := float64(*(*C.time_t)(secondsUp))
usec := float64(*(*C.suseconds_t)(unsafe.Pointer(susecondsUp)))
// This conversion maintains the usec precision. Using
// the time package did not.
tmpf64 = unix + (usec / float64(1000*1000))
}
if err != nil {
return 0, err
}
if b.conversion != nil {
return b.conversion(tmpf64), nil
}
return tmpf64, nil
}