feat: Add support for reading CPU (dev.cpu.*.temperature) and ACPI thermal zone (hw.acpi.thermal.tz*) temperature sensors on FreeBSD systems. (#2227)

Co-authored-by: roib <roib@elsec.us>

agent/sensors_default.go

@@ -1,4 +1,4 @@
-//go:build !windows
+//go:build !windows && !freebsd
 
 package agent
 

agent/sensors_freebsd.go

@@ -0,0 +1,14 @@
+//go:build freebsd
+
+package agent
+
+import (
+	"context"
+
+	"github.com/shirou/gopsutil/v4/sensors"
+	"golang.org/x/sys/unix"
+)
+
+var getSensorTemps = func(ctx context.Context) ([]sensors.TemperatureStat, error) {
+	return getFreeBSDSensorTemps(ctx, unix.SysctlUint32)
+}

agent/sensors_freebsd_common.go

@@ -0,0 +1,81 @@
+//go:build freebsd || testing
+
+package agent
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/shirou/gopsutil/v4/sensors"
+)
+
+const (
+	freebsdZeroCelsiusDeciKelvin = 2731
+	freebsdAcpiThermalZoneCount  = 16
+)
+
+type freebsdSysctlUintReader func(name string) (uint32, error)
+
+func getFreeBSDSensorTemps(ctx context.Context, readSysctl freebsdSysctlUintReader) ([]sensors.TemperatureStat, error) {
+	cpuCount, err := readSysctl("hw.ncpu")
+	if err != nil {
+		return nil, err
+	}
+	temps := make([]sensors.TemperatureStat, 0, int(cpuCount)+freebsdAcpiThermalZoneCount)
+	for cpu := uint32(0); cpu < cpuCount; cpu++ {
+		select {
+		case <-ctx.Done():
+			return temps, ctx.Err()
+		default:
+		}
+
+		sensorName := fmt.Sprintf("dev.cpu.%d.temperature", cpu)
+		value, err := readSysctl(sensorName)
+		if err != nil {
+			continue
+		}
+		temp, ok := freebsdDeciKelvinToCelsius(value)
+		if !ok {
+			continue
+		}
+		temps = append(temps, sensors.TemperatureStat{
+			SensorKey:   sensorName,
+			Temperature: temp,
+		})
+	}
+
+	for zone := 0; zone < freebsdAcpiThermalZoneCount; zone++ {
+		select {
+		case <-ctx.Done():
+			return temps, ctx.Err()
+		default:
+		}
+
+		sensorName := fmt.Sprintf("hw.acpi.thermal.tz%d.temperature", zone)
+		value, err := readSysctl(sensorName)
+		if err != nil {
+			continue
+		}
+		temp, ok := freebsdDeciKelvinToCelsius(value)
+		if !ok {
+			continue
+		}
+		temps = append(temps, sensors.TemperatureStat{
+			SensorKey:   sensorName,
+			Temperature: temp,
+		})
+	}
+
+	return temps, nil
+}
+
+func freebsdDeciKelvinToCelsius(value uint32) (float64, bool) {
+	if value <= freebsdZeroCelsiusDeciKelvin {
+		return 0, false
+	}
+	temp := float64(int64(value)-freebsdZeroCelsiusDeciKelvin) / 10
+	if temp <= 0 || temp >= 200 {
+		return 0, false
+	}
+	return temp, true
+}

agent/sensors_freebsd_common_test.go

@@ -0,0 +1,167 @@
+//go:build testing
+
+package agent
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+var errFakeFreeBSDSysctlNotFound = errors.New("sysctl not found")
+
+type fakeFreeBSDSysctls struct {
+	values map[string]uint32
+	errs   map[string]error
+}
+
+func (f fakeFreeBSDSysctls) read(name string) (uint32, error) {
+	if err, ok := f.errs[name]; ok {
+		return 0, err
+	}
+	if value, ok := f.values[name]; ok {
+		return value, nil
+	}
+	return 0, errFakeFreeBSDSysctlNotFound
+}
+
+func TestFreeBSDDeciKelvinToCelsius(t *testing.T) {
+	tests := []struct {
+		name     string
+		value    uint32
+		expected float64
+		ok       bool
+	}{
+		{
+			name:     "45 Celsius",
+			value:    3181,
+			expected: 45,
+			ok:       true,
+		},
+		{
+			name:     "fractional Celsius",
+			value:    3186,
+			expected: 45.5,
+			ok:       true,
+		},
+		{
+			name:  "zero deci-Kelvin",
+			value: 0,
+			ok:    false,
+		},
+		{
+			name:  "zero Celsius",
+			value: freebsdZeroCelsiusDeciKelvin,
+			ok:    false,
+		},
+		{
+			name:  "below zero Celsius",
+			value: freebsdZeroCelsiusDeciKelvin - 1,
+			ok:    false,
+		},
+		{
+			name:  "invalid signed integer",
+			value: 1<<32 - 1,
+			ok:    false,
+		},
+		{
+			name:  "unreasonably high Celsius",
+			value: freebsdZeroCelsiusDeciKelvin + 2000,
+			ok:    false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result, ok := freebsdDeciKelvinToCelsius(tt.value)
+			assert.Equal(t, tt.ok, ok)
+			assert.InDelta(t, tt.expected, result, 0.001)
+		})
+	}
+}
+
+func TestGetFreeBSDSensorTemps(t *testing.T) {
+	reader := fakeFreeBSDSysctls{
+		values: map[string]uint32{
+			"hw.ncpu":                         4,
+			"dev.cpu.0.temperature":           3231,
+			"dev.cpu.1.temperature":           3242,
+			"dev.cpu.3.temperature":           freebsdZeroCelsiusDeciKelvin,
+			"hw.acpi.thermal.tz0.temperature": 3101,
+			"hw.acpi.thermal.tz2.temperature": 3116,
+			"hw.acpi.thermal.tz3.temperature": freebsdZeroCelsiusDeciKelvin,
+			"unrelated.sensor.value":          9999,
+			"dev.cpu.99.temperature":          9999,
+			"dev.amdtemp.0.core0.foo":         9999,
+		},
+	}
+
+	temps, err := getFreeBSDSensorTemps(context.Background(), reader.read)
+
+	require.NoError(t, err)
+	require.Len(t, temps, 4)
+	assert.Equal(t, "dev.cpu.0.temperature", temps[0].SensorKey)
+	assert.InDelta(t, 50.0, temps[0].Temperature, 0.001)
+	assert.Equal(t, "dev.cpu.1.temperature", temps[1].SensorKey)
+	assert.InDelta(t, 51.1, temps[1].Temperature, 0.001)
+	assert.Equal(t, "hw.acpi.thermal.tz0.temperature", temps[2].SensorKey)
+	assert.InDelta(t, 37.0, temps[2].Temperature, 0.001)
+	assert.Equal(t, "hw.acpi.thermal.tz2.temperature", temps[3].SensorKey)
+	assert.InDelta(t, 38.5, temps[3].Temperature, 0.001)
+}
+
+func TestGetFreeBSDSensorTempsCpuCountError(t *testing.T) {
+	reader := fakeFreeBSDSysctls{
+		errs: map[string]error{
+			"hw.ncpu": errors.New("permission denied"),
+		},
+	}
+
+	temps, err := getFreeBSDSensorTemps(context.Background(), reader.read)
+
+	assert.Nil(t, temps)
+	assert.EqualError(t, err, "permission denied")
+}
+
+func TestGetFreeBSDSensorTempsNoTemperatureSysctls(t *testing.T) {
+	reader := fakeFreeBSDSysctls{
+		values: map[string]uint32{"hw.ncpu": 2},
+	}
+
+	temps, err := getFreeBSDSensorTemps(context.Background(), reader.read)
+
+	require.NoError(t, err)
+	assert.Empty(t, temps)
+}
+
+func TestGetFreeBSDSensorTempsAcpiOnly(t *testing.T) {
+	reader := fakeFreeBSDSysctls{
+		values: map[string]uint32{
+			"hw.ncpu":                         0,
+			"hw.acpi.thermal.tz0.temperature": 3081,
+		},
+	}
+
+	temps, err := getFreeBSDSensorTemps(context.Background(), reader.read)
+
+	require.NoError(t, err)
+	require.Len(t, temps, 1)
+	assert.Equal(t, "hw.acpi.thermal.tz0.temperature", temps[0].SensorKey)
+	assert.InDelta(t, 35.0, temps[0].Temperature, 0.001)
+}
+
+func TestGetFreeBSDSensorTempsContextCancelled(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+	reader := fakeFreeBSDSysctls{
+		values: map[string]uint32{"hw.ncpu": 2},
+	}
+
+	temps, err := getFreeBSDSensorTemps(ctx, reader.read)
+
+	assert.Empty(t, temps)
+	assert.ErrorIs(t, err, context.Canceled)
+}