Add /sys/class/watchdog statistics

sysfs/class_watchdog.go

@@ -0,0 +1,123 @@
+// Copyright 2023 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 linux
+// +build linux
+
+package sysfs
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/prometheus/procfs/internal/util"
+)
+
+const watchdogClassPath = "class/watchdog"
+
+// WatchdogStats contains info from files in /sys/class/watchdog for a single watchdog device.
+// https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-class-watchdog
+type WatchdogStats struct {
+	Name               string
+	Bootstatus         *int64  // /sys/class/watchdog/<Name>/bootstatus
+	Options            *string // /sys/class/watchdog/<Name>/options
+	FwVersion          *int64  // /sys/class/watchdog/<Name>/fw_version
+	Identity           *string // /sys/class/watchdog/<Name>/identity
+	Nowayout           *int64  // /sys/class/watchdog/<Name>/nowayout
+	State              *string // /sys/class/watchdog/<Name>/state
+	Status             *string // /sys/class/watchdog/<Name>/status
+	Timeleft           *int64  // /sys/class/watchdog/<Name>/timeleft
+	Timeout            *int64  // /sys/class/watchdog/<Name>/timeout
+	Pretimeout         *int64  // /sys/class/watchdog/<Name>/pretimeout
+	PretimeoutGovernor *string // /sys/class/watchdog/<Name>/pretimeout_governor
+	AccessCs0          *int64  // /sys/class/watchdog/<Name>/access_cs0
+}
+
+// WatchdogClass is a collection of statistics for every watchdog device in /sys/class/watchdog.
+//
+// The map keys are the names of the watchdog devices.
+type WatchdogClass map[string]WatchdogStats
+
+// WatchdogClass returns info for all watchdog devices read from /sys/class/watchdog.
+func (fs FS) WatchdogClass() (WatchdogClass, error) {
+	path := fs.sys.Path(watchdogClassPath)
+
+	dirs, err := os.ReadDir(path)
+	if err != nil {
+		return nil, fmt.Errorf("failed to list watchdog devices at %q: %w", path, err)
+	}
+
+	wds := make(WatchdogClass, len(dirs))
+	for _, d := range dirs {
+		stats, err := fs.parseWatchdog(d.Name())
+		if err != nil {
+			return nil, err
+		}
+
+		wds[stats.Name] = *stats
+	}
+
+	return wds, nil
+}
+
+func (fs FS) parseWatchdog(wdName string) (*WatchdogStats, error) {
+	path := fs.sys.Path(watchdogClassPath, wdName)
+	wd := WatchdogStats{Name: wdName}
+
+	for _, f := range [...]string{"bootstatus", "options", "fw_version", "identity", "nowayout", "state", "status", "timeleft", "timeout", "pretimeout", "pretimeout_governor", "access_cs0"} {
+		name := filepath.Join(path, f)
+		value, err := util.SysReadFile(name)
+		if err != nil {
+			if os.IsNotExist(err) {
+				continue
+			}
+			return nil, fmt.Errorf("failed to read file %q: %w", name, err)
+		}
+
+		vp := util.NewValueParser(value)
+
+		switch f {
+		case "bootstatus":
+			wd.Bootstatus = vp.PInt64()
+		case "options":
+			wd.Options = &value
+		case "fw_version":
+			wd.FwVersion = vp.PInt64()
+		case "identity":
+			wd.Identity = &value
+		case "nowayout":
+			wd.Nowayout = vp.PInt64()
+		case "state":
+			wd.State = &value
+		case "status":
+			wd.Status = &value
+		case "timeleft":
+			wd.Timeleft = vp.PInt64()
+		case "timeout":
+			wd.Timeout = vp.PInt64()
+		case "pretimeout":
+			wd.Pretimeout = vp.PInt64()
+		case "pretimeout_governor":
+			wd.PretimeoutGovernor = &value
+		case "access_cs0":
+			wd.AccessCs0 = vp.PInt64()
+		}
+
+		if err := vp.Err(); err != nil {
+			return nil, err
+		}
+	}
+
+	return &wd, nil
+}

sysfs/class_watchdog_test.go

@@ -0,0 +1,76 @@
+// Copyright 2023 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 linux
+// +build linux
+
+package sysfs
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func TestWatchdogClass(t *testing.T) {
+	fs, err := NewFS(sysTestFixtures)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := fs.WatchdogClass()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var (
+		bootstatus int64 = 1
+		fwVersion  int64 = 2
+		nowayout   int64
+		timeleft   int64 = 300
+		timeout    int64 = 60
+		pretimeout int64 = 120
+		accessCs0  int64
+
+		options            = "0x8380"
+		identity           = "Software Watchdog"
+		state              = "active"
+		status             = "0x8000"
+		pretimeoutGovernor = "noop"
+	)
+
+	want := WatchdogClass{
+		"watchdog0": {
+			Name:               "watchdog0",
+			Bootstatus:         &bootstatus,
+			Options:            &options,
+			FwVersion:          &fwVersion,
+			Identity:           &identity,
+			Nowayout:           &nowayout,
+			State:              &state,
+			Status:             &status,
+			Timeleft:           &timeleft,
+			Timeout:            &timeout,
+			Pretimeout:         &pretimeout,
+			PretimeoutGovernor: &pretimeoutGovernor,
+			AccessCs0:          &accessCs0,
+		},
+		"watchdog1": {
+			Name: "watchdog1",
+		},
+	}
+
+	if diff := cmp.Diff(want, got); diff != "" {
+		t.Fatalf("unexpected watchdog class (-want +got):\n%s", diff)
+	}
+}

testdata/fixtures.ttar

@@ -6269,6 +6269,75 @@ Lines: 1
 acpitz
 Mode: 664
 # ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Directory: fixtures/sys/class/watchdog
+Mode: 775
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Directory: fixtures/sys/class/watchdog/watchdog0
+Mode: 775
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/watchdog/watchdog0/access_cs0
+Lines: 1
+0EOF
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/watchdog/watchdog0/bootstatus
+Lines: 1
+1EOF
+Mode: 444
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/watchdog/watchdog0/fw_version
+Lines: 1
+2EOF
+Mode: 444
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/watchdog/watchdog0/identity
+Lines: 1
+Software WatchdogEOF
+Mode: 444
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/watchdog/watchdog0/nowayout
+Lines: 1
+0EOF
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/watchdog/watchdog0/options
+Lines: 1
+0x8380EOF
+Mode: 444
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/watchdog/watchdog0/pretimeout
+Lines: 1
+120EOF
+Mode: 444
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/watchdog/watchdog0/pretimeout_governor
+Lines: 1
+noopEOF
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/watchdog/watchdog0/state
+Lines: 1
+activeEOF
+Mode: 444
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/watchdog/watchdog0/status
+Lines: 1
+0x8000EOF
+Mode: 444
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/watchdog/watchdog0/timeleft
+Lines: 1
+300EOF
+Mode: 444
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/watchdog/watchdog0/timeout
+Lines: 1
+60EOF
+Mode: 444
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Directory: fixtures/sys/class/watchdog/watchdog1
+Mode: 775
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Directory: fixtures/sys/devices
 Mode: 755
 # ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -