add support for file nodes

base.go

@@ -30,7 +30,10 @@ const EndOfEntireDevicePath DeviceNodeSubType = 0xFF
 
 const ACPISubType DeviceNodeSubType = 1
 
-const HardDriveSubType DeviceNodeSubType = 1
+const (
+	HardDriveSubType DeviceNodeSubType = 1
+	FileSubType      DeviceNodeSubType = 4
+)
 
 type DevicePathNode interface {
 	Type() DeviceNodeType

file.go

@@ -0,0 +1,43 @@
+package devicepath
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+const (
+	filePrefix = "File"
+)
+
+type FileDevicePath struct {
+	path string
+}
+
+func (fp *FileDevicePath) Type() DeviceNodeType {
+	return MediaDevicePath
+}
+
+func (fp *FileDevicePath) SubType() DeviceNodeSubType {
+	return FileSubType
+}
+
+func (fp *FileDevicePath) Bytes() []byte {
+	return nil
+}
+
+func (fp *FileDevicePath) String() string {
+	return fmt.Sprintf("%s(%s)", filePrefix, fp.path)
+}
+
+func (fp *FileDevicePath) ParseString(raw string) error {
+	if !checkStringFormat(raw, filePrefix, -1) {
+		return ErrMalformedString
+	}
+	args := strings.Split(raw[len(filePrefix)+1:len(raw)-1], ",")
+	if len(args) != 1 {
+		return errors.New("unexpected number of arguments")
+	}
+	fp.path = args[0]
+	return nil
+}

file_test.go

@@ -0,0 +1,18 @@
+package devicepath_test
+
+import (
+	"testing"
+
+	"git.faercol.me/faercol/devicepath"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseFileString(t *testing.T) {
+	t.Run("ok", func(t *testing.T) {
+		var fileDev devicepath.FileDevicePath
+		expected := `File(\\EFI\\HTTPBOOT\\HTTP_BOOT_CLIENT.EFI)`
+		require.NoError(t, fileDev.ParseString(expected))
+		assert.Equal(t, expected, fileDev.String())
+	})
+}

parser.go

@@ -35,6 +35,7 @@ var prefixTypeAssociation = map[string]nodeGenerator{
 	pciPrefix:     func() DevicePathNode { return &PCIDevicePath{} },
 	pciRootPrefix: func() DevicePathNode { return &PCIRootDevicePath{} },
 	hdPrefix:      func() DevicePathNode { return &HardDriveDevicePath{} },
+	filePrefix:    func() DevicePathNode { return &FileDevicePath{} },
 }
 
 func Parsenode(raw string) (DevicePathNode, error) {

parser_test.go

@@ -18,8 +18,8 @@ func TestOK(t *testing.T) {
 }
 
 func TestParseDevicePathOK(t *testing.T) {
-	input := "PciRoot(0x0)/Pci(0x1,0x2)/Pci(0x0,0x1)/Sata(0,65535,0)"
+	input := "PciRoot(0x0)/Pci(0x1,0x2)/Pci(0x0,0x1)/Sata(0,65535,0)/HD(1,GPT,16f06d01-50da-6544-86bd-f3457f980086,0x1000,0x96000)/File(\\EFI\\HTTPBOOT\\HTTP_BOOT_CLIENT.EFI)"
 	res, err := devicepath.ParseDevicePath(input)
 	require.NoError(t, err)
-	assert.Equal(t, "PciRoot(0x0)/Pci(0x1,0x2)/Pci(0x0,0x1)/Sata(0,65535,0)", res.String())
+	assert.Equal(t, "PciRoot(0x0)/Pci(0x1,0x2)/Pci(0x0,0x1)/Sata(0,65535,0)/HD(1,GPT,16f06d01-50da-6544-86bd-f3457f980086,0x1000,0x96000)/File(\\EFI\\HTTPBOOT\\HTTP_BOOT_CLIENT.EFI)", res.String())
 }