Add default uint field value support

Signed-off-by: Chris Koch <[email protected]>

dmidecode/struct_parser.go

@@ -104,8 +104,47 @@ func parseStruct(t *smbios.Table, off int, complete bool, sp interface{}) (int,
 			return off, fmt.Errorf("failed to parse %s.%s: %s", svtn, f.Name, verr)
 		}
 	}
+
 	if complete && i < sv.NumField() {
 		return off, fmt.Errorf("%s incomplete, got %d of %d fields", svtn, i, sv.NumField())
 	}
+
+	// Fill in defaults
+	for ; i < sv.NumField(); i++ {
+		f := sv.Type().Field(i)
+		fv := sv.Field(i)
+		ft := fv.Type()
+		tags := f.Tag.Get(fieldTagKey)
+		// fmt.Printf("XX %02Xh f %s t %s k %s %s\n", off, f.Name, f.Type.Name(), fv.Kind(), tags)
+		// Check tags first
+		ignore := false
+		var defValue uint64
+		for _, tag := range strings.Split(tags, ",") {
+			tp := strings.Split(tag, "=")
+			switch tp[0] {
+			case "-":
+				ignore = true
+			case "skip":
+				numBytes, _ := strconv.Atoi(tp[1])
+				off += numBytes
+			case "default":
+				defValue, _ = strconv.ParseUint(tp[1], 0, 64)
+			}
+		}
+		if ignore {
+			continue
+		}
+		switch fv.Kind() {
+		case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+			fv.SetUint(defValue)
+			off += int(ft.Size())
+		case reflect.Struct:
+			off, err := parseStruct(t, off, true /* complete */, fv)
+			if err != nil {
+				return off, err
+			}
+		}
+	}
+
 	return off, nil
 }

dmidecode/struct_parser_test.go

@@ -52,17 +52,21 @@ func TestParseStructUnsupported(t *testing.T) {
 	}
 }
 
+type supportedTypes struct {
+	smbios.Table
+	SupportedField uint64
+}
+
 func TestParseStructSupported(t *testing.T) {
 	buffer := []byte{
 		0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11,
 	}
 	table := smbios.Table{
 		Data: buffer,
 	}
-	unknownType := &UnknownTypes{
+	unknownType := &supportedTypes{
 		Table: table,
 	}
-
 	off, err := parseStruct(&table, 0, false, unknownType)
 	if err != nil {
 		t.Errorf("TestParseStructUnsupported : parseStruct() = %d, '%v' want: 'nil'", off, err)

dmidecode/type0_bios_information.go

@@ -36,7 +36,7 @@ func ParseBIOSInfo(t *smbios.Table) (*BIOSInfo, error) {
 		return nil, fmt.Errorf("%w: %d", ErrUnexpectedTableType, t.Type)
 	}
 	if t.Length < 0x12 {
-		return nil, io.ErrUnexpectedEOF
+		return nil, fmt.Errorf("%w: BIOS info table must be at least %d bytes", io.ErrUnexpectedEOF, 0x12)
 	}
 	bi := &BIOSInfo{
 		Header: t.Header,

dmidecode/type0_bios_information_test.go

@@ -287,6 +287,44 @@ func TestParseBIOSInfo(t *testing.T) {
 			},
 			err: ErrUnexpectedTableType,
 		},
+		{
+			name: "BIOS short",
+			table: &smbios.Table{
+				Header: smbios.Header{
+					Length: 18,
+					Type:   smbios.TableTypeBIOSInfo,
+				},
+				Data: []byte{
+					0x00, // vendor string
+					0x01, // version string
+					0x02, 0x03,
+					0x02,                                           // release date string
+					0x00,                                           // rom size
+					0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // bios chars
+					0x00,
+					0x00,
+				},
+				Strings: []string{
+					"version!",
+					"release date!",
+				},
+			},
+			want: &BIOSInfo{
+				Header: smbios.Header{
+					Length: 18,
+					Type:   smbios.TableTypeBIOSInfo,
+				},
+				Version:                "version!",
+				StartingAddressSegment: 0x302,
+				ReleaseDate:            "release date!",
+				Characteristics:        0x1,
+				BIOSMajor:              0xff,
+				BIOSMinor:              0xff,
+				ECMajor:                0xff,
+				ECMinor:                0xff,
+				ExtendedROMSize:        0,
+			},
+		},
 	} {
 		t.Run(tt.name, func(t *testing.T) {
 			got, err := ParseBIOSInfo(tt.table)