get full filename from Rock Ridge NM record

Author: kdomanski

image_reader.go

@@ -73,6 +73,10 @@ type File struct {
 
 var _ os.FileInfo = &File{}
 
+func (f *File) hasRockRidge() bool {
+	return f.susp != nil && f.susp.HasRockRidge
+}
+
 // IsDir returns true if the entry is a directory or false otherwise
 func (f *File) IsDir() bool {
 	return f.de.FileFlags&dirFlagDir != 0
@@ -94,6 +98,12 @@ func (f *File) Mode() os.FileMode {
 
 // Name returns the base name of the given entry
 func (f *File) Name() string {
+	if f.hasRockRidge() {
+		if name := f.de.SystemUseEntries.GetRockRidgeName(); name != "" {
+			return name
+		}
+	}
+
 	if f.IsDir() {
 		return f.de.Identifier
 	}

image_reader_test.go

@@ -144,15 +144,15 @@ func TestImageReaderSUSP(t *testing.T) {
 	assert.Len(t, children, 4)
 
 	dir1 := children[1]
-	assert.Equal(t, "DIR1", dir1.Name())
+	assert.Equal(t, "dir1", dir1.Name())
 
 	dir1Children, err := dir1.GetChildren()
 	assert.NoError(t, err)
 	assert.Len(t, dir1Children, 1)
 
 	// lorem ipsum
 	loremFile := dir1Children[0]
-	assert.Equal(t, "LOREM_IP.TXT", loremFile.Name())
+	assert.Equal(t, "lorem_ipsum.txt", loremFile.Name())
 	assert.Equal(t, int64(446), loremFile.Size())
 	assert.NotNil(t, loremFile.susp)
 	assert.True(t, loremFile.susp.HasRockRidge)
@@ -164,7 +164,6 @@ func TestImageReaderSUSP(t *testing.T) {
 
 	assert.Len(t, loremFile.de.SystemUseEntries, 4)
 	assert.Equal(t, "RR", loremFile.de.SystemUseEntries[0].Type())
-	assert.Equal(t, "NM", loremFile.de.SystemUseEntries[1].Type())
 	assert.Equal(t, "PX", loremFile.de.SystemUseEntries[2].Type())
 	assert.Equal(t, "TF", loremFile.de.SystemUseEntries[3].Type())
 }

rockridge.go

@@ -0,0 +1,61 @@
+package iso9660
+
+/* The following types of Rock Ridge records are being handled in some way:
+ * - [ ] PX (RR 4.1.1: POSIX file attributes)
+ * - [ ] PN (RR 4.1.2: POSIX device number)
+ * - [ ] SL (RR 4.1.3: symbolic link)
+ * - [ ] NM (RR 4.1.4: alternate name)
+ * - [ ] CL (RR 4.1.5.1: child link)
+ * - [ ] PL (RR 4.1.5.2: parent link)
+ * - [ ] RE (RR 4.1.5.3: relocated directory)
+ * - [ ] TF (RR 4.1.6: time stamp(s) for a file)
+ * - [ ] SF (RR 4.1.7: file data in sparse file format)
+ */
+
+const (
+	RockRidgeIdentifier = "RRIP_1991A"
+	RockRidgeVersion    = 1
+)
+
+type RockRidgeNameEntry struct {
+	Flags byte
+	Name  string
+}
+
+func suspHasRockRidge(se SystemUseEntrySlice) (bool, error) {
+	extensions, err := se.GetExtensionRecords()
+	if err != nil {
+		return false, err
+	}
+
+	for _, entry := range extensions {
+		if entry.Identifier == RockRidgeIdentifier && entry.Version == RockRidgeVersion {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
+func (s SystemUseEntrySlice) GetRockRidgeName() string {
+	var name string
+
+	for _, entry := range s {
+		if entry.Type() == "NM" {
+			nm := umarshalRockRidgeNameEntry(entry)
+			name += nm.Name
+		}
+	}
+
+	return name
+}
+
+func umarshalRockRidgeNameEntry(e SystemUseEntry) *RockRidgeNameEntry {
+	// There is a continuation flag in byte 0, but we determine continuation
+	// by simply reading all entries.
+
+	return &RockRidgeNameEntry{
+		Flags: e.Data()[0],
+		Name:  string(e.Data()[1:]),
+	}
+}