From eefbcd54660db5686b5469b3a0d21f82b97ab3de Mon Sep 17 00:00:00 2001
From: Tommi2Day <tommi2day@tommi2day.net>
Date: Tue, 16 Jan 2024 18:26:48 +0100
Subject: [PATCH 1/2] validate range return value in EvaluateThreshold

fixes #233
---
 nagios.go |  3 +++
 range.go  | 11 +++++++++++
 2 files changed, 14 insertions(+)

diff --git a/nagios.go b/nagios.go
index b4741af..dce167c 100644
--- a/nagios.go
+++ b/nagios.go
@@ -96,6 +96,9 @@ var (
 	// metric is not in a supported format.
 	ErrInvalidPerformanceDataFormat = errors.New("invalid performance data format")
 
+	// ErrInvalidRangeThreshold indicates that a given range threshold is not in a supported format.
+	ErrInvalidRangeThreshold = errors.New("invalid range threshold")
+
 	// TODO: Should we use field-specific errors or is the more general
 	// ErrInvalidPerformanceDataFormat "good enough" ? Wrapped versions of
 	// that error will likely already indicate which field is a problem, but
diff --git a/range.go b/range.go
index 845fb49..10f0710 100644
--- a/range.go
+++ b/range.go
@@ -9,6 +9,7 @@
 package nagios
 
 import (
+	"fmt"
 	"regexp"
 	"strconv"
 	"strings"
@@ -149,6 +150,11 @@ func (p *Plugin) EvaluateThreshold(perfData ...PerformanceData) error {
 		if perfData[i].Crit != "" {
 
 			CriticalThresholdObject := ParseRangeString(perfData[i].Crit)
+			if CriticalThresholdObject == nil {
+				err := fmt.Errorf("failed to parse critical range string %s: %w ", perfData[i].Crit, ErrInvalidRangeThreshold)
+				p.ExitStatusCode = StateUNKNOWNExitCode
+				return err
+			}
 
 			if CriticalThresholdObject.CheckRange(perfData[i].Value) {
 				p.ExitStatusCode = StateCRITICALExitCode
@@ -158,6 +164,11 @@ func (p *Plugin) EvaluateThreshold(perfData ...PerformanceData) error {
 
 		if perfData[i].Warn != "" {
 			warningThresholdObject := ParseRangeString(perfData[i].Warn)
+			if warningThresholdObject == nil {
+				err := fmt.Errorf("failed to parse warning range string %s: %w ", perfData[i].Warn, ErrInvalidRangeThreshold)
+				p.ExitStatusCode = StateUNKNOWNExitCode
+				return err
+			}
 
 			if warningThresholdObject.CheckRange(perfData[i].Value) {
 				p.ExitStatusCode = StateWARNINGExitCode

From b8a299bda2b604b73ec6d348ac55157d99e84cd0 Mon Sep 17 00:00:00 2001
From: Tommi2Day <tommi2day@tommi2day.net>
Date: Tue, 16 Jan 2024 18:44:08 +0100
Subject: [PATCH 2/2] add checks testing invalid critical and warning range

---
 range_test.go | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/range_test.go b/range_test.go
index a824bc3..ff9b0bd 100644
--- a/range_test.go
+++ b/range_test.go
@@ -188,6 +188,25 @@ func TestParseRange(t *testing.T) {
 		assert.Equal(t, StateCRITICALExitCode, plugin.ExitStatusCode)
 	})
 
+	t.Run("Plugin should return exit code Unknown when critical range is invalid", func(t *testing.T) {
+		var plugin = Plugin{
+			ExitStatusCode: StateOKExitCode,
+		}
+		plugin.ServiceOutput = pluginServiceOutput
+
+		perfdata := PerformanceData{
+			Label:             "perfdata label",
+			Value:             "41.0",
+			UnitOfMeasurement: "C",
+			Warn:              "5:30",
+			Crit:              "0:<=20", // invalid range as critical lower than warning
+		}
+		assert.NoError(t, plugin.AddPerfData(false, perfdata))
+		assert.Error(t, plugin.EvaluateThreshold(perfdata))
+
+		assert.Equal(t, StateUNKNOWNExitCode, plugin.ExitStatusCode)
+	})
+
 	t.Run("Plugin should return exit code CRITICAL when value is within warning range", func(t *testing.T) {
 		var plugin = Plugin{
 			ExitStatusCode: StateOKExitCode,
@@ -206,4 +225,23 @@ func TestParseRange(t *testing.T) {
 
 		assert.Equal(t, StateCRITICALExitCode, plugin.ExitStatusCode)
 	})
+
+	t.Run("Plugin should return exit code UNKNOWN and error when warning range is invalid", func(t *testing.T) {
+		var plugin = Plugin{
+			ExitStatusCode: StateOKExitCode,
+		}
+		plugin.ServiceOutput = pluginServiceOutput
+
+		perfdata := PerformanceData{
+			Label:             "perfdata label",
+			Value:             "-1.0",
+			UnitOfMeasurement: "C",
+			Warn:              "x20", // invalid range value
+			Crit:              "",
+		}
+		assert.NoError(t, plugin.AddPerfData(false, perfdata))
+		assert.Error(t, plugin.EvaluateThreshold(perfdata))
+
+		assert.Equal(t, StateUNKNOWNExitCode, plugin.ExitStatusCode)
+	})
 }