Inital support for Wii TMD parsing

tmd.go

@@ -3,10 +3,17 @@ package wiiudownloader
 import (
 	"bytes"
 	"encoding/binary"
+	"fmt"
 	"io"
 )
 
+const (
+	TMD_VERSION_WII  = 0x00
+	TMD_VERSION_WIIU = 0x01
+)
+
 type TMD struct {
+	Version      byte
 	TitleVersion uint16
 	ContentCount uint16
 	Contents     []Content
@@ -16,7 +23,45 @@ func parseTMD(data []byte) (*TMD, error) {
 	tmd := &TMD{}
 	reader := bytes.NewReader(data)
 
-	reader.Seek(476, io.SeekStart)
+	reader.Seek(0x180, io.SeekStart)
+	if err := binary.Read(reader, binary.BigEndian, &tmd.Version); err != nil {
+		return nil, err
+	}
+
+	switch tmd.Version {
+	case TMD_VERSION_WII:
+		reader.Seek(0x1DC, io.SeekStart)
+
+		if err := binary.Read(reader, binary.BigEndian, &tmd.TitleVersion); err != nil {
+			return nil, err
+		}
+
+		if err := binary.Read(reader, binary.BigEndian, &tmd.ContentCount); err != nil {
+			return nil, err
+		}
+
+		tmd.Contents = make([]Content, tmd.ContentCount)
+
+		for i := 0; i < int(tmd.ContentCount); i++ {
+			offset := 0x1E4 + (0x24 * i)
+
+			reader.Seek(int64(offset), io.SeekStart)
+			if err := binary.Read(reader, binary.BigEndian, &tmd.Contents[i].ID); err != nil {
+				return nil, err
+			}
+
+			reader.Seek(2, io.SeekCurrent)
+
+			if err := binary.Read(reader, binary.BigEndian, &tmd.Contents[i].Type); err != nil {
+				return nil, err
+			}
+
+			if err := binary.Read(reader, binary.BigEndian, &tmd.Contents[i].Size); err != nil {
+				return nil, err
+			}
+		}
+	case TMD_VERSION_WIIU:
+		reader.Seek(0x1DC, io.SeekStart)
 
 		if err := binary.Read(reader, binary.BigEndian, &tmd.TitleVersion); err != nil {
 			return nil, err
@@ -46,5 +91,8 @@ func parseTMD(data []byte) (*TMD, error) {
 				return nil, err
 			}
 		}
+	default:
+		return nil, fmt.Errorf("unknown TMD version: %d", tmd.Version)
+	}
 	return tmd, nil
 }