test: provide kernel version as a parameter

Signed-off-by: Andrea Terzolo <andrea.terzolo@suse.com>

Author: Andreagit97

internal/bpf/policy_values.go

@@ -88,22 +88,19 @@ func stringPaddedLen(s int) int {
 	if s <= stringMapSize6 {
 		return stringMapSize6
 	}
-	if kernels.CurrVersionIsGreaterOrEqualThan("5.11") {
-		if s <= stringMapSize7 {
-			return stringMapSize7
-		}
-		if s <= stringMapSize8 {
-			return stringMapSize8
-		}
-		if s <= stringMapSize9 {
-			return stringMapSize9
-		}
-		return stringMapSize10
+	if s <= stringMapSize7 {
+		return stringMapSize7
+	}
+	if s <= stringMapSize8 {
+		return stringMapSize8
+	}
+	if s <= stringMapSize9 {
+		return stringMapSize9
 	}
-	return stringMapSize7
+	return stringMapSize10
 }
 
-func argStringSelectorValue(v string, removeNul bool) ([MaxStringMapsSize]byte, int, error) {
+func argStringSelectorValue(v string, removeNul bool, currKernelVer int) ([MaxStringMapsSize]byte, int, error) {
 	if removeNul {
 		// Remove any trailing nul characters ("\0" or 0x00)
 		for v[len(v)-1] == 0 {
@@ -119,7 +116,7 @@ func argStringSelectorValue(v string, removeNul bool) ([MaxStringMapsSize]byte,
 	}
 
 	switch {
-	case kernels.CurrVersionIsLowerThan("5.11"):
+	case kernels.VersionIsLowerThan(currKernelVer, "5.11"):
 		// Until 5.11 we have max size of 512
 		if s > stringMapSize7 {
 			return ret, 0, errors.New("string is too long")
@@ -137,7 +134,7 @@ func argStringSelectorValue(v string, removeNul bool) ([MaxStringMapsSize]byte,
 }
 
 func putValueInMap(m SelectorStringMaps, v string) error {
-	value, size, err := argStringSelectorValue(v, false)
+	value, size, err := argStringSelectorValue(v, false, kernels.GetCurrKernelVersion())
 	if err != nil {
 		return fmt.Errorf("value %s invalid: %w", v, err)
 	}

internal/bpf/policy_values_test.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/neuvector/runtime-enforcer/internal/kernels"
 	"github.com/stretchr/testify/require"
 )
 
@@ -44,7 +45,7 @@ func TestStringPaddedLen(t *testing.T) {
 			expected: stringMapSize10,
 		},
 		{
-			// this method has no limits
+			// this method has no limits in input size
 			in:       stringMapSize10 * 10,
 			expected: stringMapSize10,
 		},
@@ -57,32 +58,46 @@ func TestStringPaddedLen(t *testing.T) {
 }
 
 func TestArgStringSelectorValue(t *testing.T) {
-	getExpectedValue := func(v string) [MaxStringMapsSize]byte {
-		ret := [MaxStringMapsSize]byte{}
-		copy(ret[:], []byte(v))
-		return ret
-	}
 
 	tests := []struct {
-		name string
-		in   string
+		kernelVer string
+		len       int
+		hasError  bool
 	}{
 		{
-			// example input taken from a kind cluster with cri-containerd
-			name: "less than 256 bytes",
-			in:   "/usr/bin/cri-containerd",
+			// this is ok
+			kernelVer: "5.9",
+			len:       stringMapSize7,
+			hasError:  false,
+		},
+		{
+			kernelVer: "5.9",
+			len:       stringMapSize7 + 1,
+			hasError:  true,
+		},
+		{
+			kernelVer: "5.11",
+			len:       MaxStringMapsSize,
+			hasError:  false,
 		},
 		{
-			// example input taken from a kind cluster with cri-containerd
-			name: "more than 256 bytes",
-			in:   strings.Repeat("AB", 500),
+			kernelVer: "5.11",
+			len:       MaxStringMapsSize + 1,
+			hasError:  true,
 		},
 	}
 	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			outBytes, _, err := argStringSelectorValue(tt.in, false)
-			require.NoError(t, err)
-			require.Equal(t, getExpectedValue(tt.in), outBytes)
+		t.Run(fmt.Sprintf("kernel_%s_len_%d", tt.kernelVer, tt.len), func(t *testing.T) {
+			_, _, err := argStringSelectorValue(
+				strings.Repeat("a", tt.len),
+				false,
+				int(kernels.KernelStringToNumeric(tt.kernelVer)),
+			)
+			if tt.hasError {
+				require.Error(t, err)
+			} else {
+				require.NoError(t, err)
+			}
 		})
 	}
 }

internal/kernels/kernels.go

@@ -37,6 +37,15 @@ func getKernelVersionFromSystem() (int, error) {
 	return int(KernelStringToNumeric(release)), nil
 }
 
+func GetCurrKernelVersion() int {
+	return currKernelVersion
+}
+
+func VersionIsLowerThan(curr int, kernel string) bool {
+	intVersion := int(KernelStringToNumeric(kernel))
+	return curr < intVersion
+}
+
 func CurrVersionIsLowerThan(kernel string) bool {
 	intVersion := int(KernelStringToNumeric(kernel))
 	return currKernelVersion < intVersion