Support direct filesystem

disk.go

@@ -3,19 +3,30 @@ package disk
 import (
 	"io"
 
+	"github.com/masahiro331/go-disk/fs"
 	"github.com/masahiro331/go-disk/gpt"
 	"github.com/masahiro331/go-disk/mbr"
 	"github.com/masahiro331/go-disk/types"
 	"golang.org/x/xerrors"
 )
 
-type Driver interface {
-	Next() (types.Partition, error)
-}
-
-func NewDriver(sr *io.SectionReader) (Driver, error) {
+func NewDriver(
+	sr *io.SectionReader,
+	checkFsFuncs ...func(
+		r io.Reader,
+	) bool,
+) (types.Driver, error) {
 	m, err := mbr.NewMasterBootRecord(sr)
 	if err != nil {
+		if xerrors.Is(mbr.InvalidSignature, err) {
+			ok, err := fs.CheckFileSystem(sr, checkFsFuncs)
+			if err != nil {
+				return nil, xerrors.Errorf("failed to check filesystem: %w", err)
+			}
+			if ok {
+				return fs.NewDirectFileSystem(sr)
+			}
+		}
 		return nil, xerrors.Errorf("failed to new MBR: %w", err)
 	}
 
@@ -28,4 +39,4 @@ func NewDriver(sr *io.SectionReader) (Driver, error) {
 	}
 
 	return g, nil
-}
+}

fs/fs.go

@@ -0,0 +1,89 @@
+package fs
+
+import (
+	"io"
+
+	"github.com/masahiro331/go-disk/types"
+	"golang.org/x/xerrors"
+)
+
+var (
+	_ types.Driver    = &DirectFileSystem{}
+	_ types.Partition = &DirectFileSystemPartition{}
+)
+
+type DirectFileSystem struct {
+	Partition *DirectFileSystemPartition
+}
+
+func (d *DirectFileSystem) Next() (types.Partition, error) {
+	if d.Partition == nil {
+		return nil, io.EOF
+	}
+	partition := d.Partition
+	d.Partition = nil
+
+	return partition, nil
+}
+
+type DirectFileSystemPartition struct {
+	sectionReader *io.SectionReader
+}
+
+func (p DirectFileSystemPartition) Name() string {
+	return "0"
+}
+
+func (p DirectFileSystemPartition) GetType() []byte {
+	return []byte{}
+}
+
+func (p DirectFileSystemPartition) GetStartSector() uint64 {
+	return uint64(0)
+}
+
+func (p DirectFileSystemPartition) Bootable() bool {
+	return false
+}
+
+func (p DirectFileSystemPartition) GetSize() uint64 {
+	return uint64(p.sectionReader.Size())
+}
+
+func (p DirectFileSystemPartition) GetSectionReader() io.SectionReader {
+	return *p.sectionReader
+}
+
+func (p DirectFileSystemPartition) IsSupported() bool {
+	return true
+}
+
+func NewDirectFileSystem(sr *io.SectionReader) (*DirectFileSystem, error) {
+	_, err := sr.Seek(0, io.SeekStart)
+	if err != nil {
+		return nil, xerrors.Errorf("failed to DirectFileSystem seek offset error: %w", err)
+	}
+	return &DirectFileSystem{
+		Partition: &DirectFileSystemPartition{
+			sectionReader: sr,
+		},
+	}, nil
+}
+
+func CheckFileSystem(
+	r *io.SectionReader,
+	checkFsFuncs []func(
+		r io.Reader,
+	) bool,
+) (bool, error) {
+	for _, checkFsFunc := range checkFsFuncs {
+		_, err := r.Seek(0, io.SeekStart)
+		if err != nil {
+			return false, xerrors.Errorf("failed to seek offset error: %w", err)
+		}
+		if checkFsFunc(r) {
+			return true, nil
+		}
+	}
+	return false, nil
+}

types/types.go

@@ -2,6 +2,10 @@ package types
 
 import "io"
 
+type Driver interface {
+	Next() (Partition, error)
+}
+
 type Partition interface {
 	Bootable() bool
 	GetStartSector() uint64