archive/tar: remove file type bits from mode field

When writing tar files by using the FileInfoHeader the type bits was set in the mode field of the header This is not correct according to the standard (GNU/Posix) and other implementations. Fixed #20150 Change-Id: I3be7d946a1923ad5827cf45c696546a5e287ebba Reviewed-on: https://go-review.googlesource.com/42093 Reviewed-by: Joe Tsai <[email protected]> Run-TryBot: Joe Tsai <[email protected]> TryBot-Result: Gobot Gobot <[email protected]>
golang · May 13, 2017 · 66b5a2f · 66b5a2f
1 parent 8f06e21
commit 66b5a2f
Show file tree

Hide file tree

Showing 2 changed files with 22 additions and 24 deletions.
diff --git a/src/archive/tar/common.go b/src/archive/tar/common.go
@@ -158,11 +158,15 @@ func (fi headerFileInfo) Mode() (mode os.FileMode) {
 // sysStat, if non-nil, populates h from system-dependent fields of fi.
 var sysStat func(fi os.FileInfo, h *Header) error
 
-// Mode constants from the tar spec.
 const (
-	c_ISUID  = 04000   // Set uid
-	c_ISGID  = 02000   // Set gid
-	c_ISVTX  = 01000   // Save text (sticky bit)
+	// Mode constants from the USTAR spec:
+	// See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13_06
+	c_ISUID = 04000 // Set uid
+	c_ISGID = 02000 // Set gid
+	c_ISVTX = 01000 // Save text (sticky bit)
+
+	// Common Unix mode constants; these are not defined in any common tar standard.
+	// Header.FileInfo understands these, but FileInfoHeader will never produce these.
 	c_ISDIR  = 040000  // Directory
 	c_ISFIFO = 010000  // FIFO
 	c_ISREG  = 0100000 // Regular file
@@ -208,30 +212,24 @@ func FileInfoHeader(fi os.FileInfo, link string) (*Header, error) {
 	}
 	switch {
 	case fm.IsRegular():
-		h.Mode |= c_ISREG
 		h.Typeflag = TypeReg
 		h.Size = fi.Size()
 	case fi.IsDir():
 		h.Typeflag = TypeDir
-		h.Mode |= c_ISDIR
 		h.Name += "/"
 	case fm&os.ModeSymlink != 0:
 		h.Typeflag = TypeSymlink
-		h.Mode |= c_ISLNK
 		h.Linkname = link
 	case fm&os.ModeDevice != 0:
 		if fm&os.ModeCharDevice != 0 {
-			h.Mode |= c_ISCHR
 			h.Typeflag = TypeChar
 		} else {
-			h.Mode |= c_ISBLK
 			h.Typeflag = TypeBlock
 		}
 	case fm&os.ModeNamedPipe != 0:
 		h.Typeflag = TypeFifo
-		h.Mode |= c_ISFIFO
 	case fm&os.ModeSocket != 0:
-		h.Mode |= c_ISSOCK
+		return nil, fmt.Errorf("archive/tar: sockets not supported")
 	default:
 		return nil, fmt.Errorf("archive/tar: unknown file mode %v", fm)
 	}

diff --git a/src/archive/tar/tar_test.go b/src/archive/tar/tar_test.go
@@ -29,7 +29,7 @@ func TestFileInfoHeader(t *testing.T) {
 	if g, e := h.Name, "small.txt"; g != e {
 		t.Errorf("Name = %q; want %q", g, e)
 	}
-	if g, e := h.Mode, int64(fi.Mode().Perm())|c_ISREG; g != e {
+	if g, e := h.Mode, int64(fi.Mode().Perm()); g != e {
 		t.Errorf("Mode = %#o; want %#o", g, e)
 	}
 	if g, e := h.Size, int64(5); g != e {
@@ -57,7 +57,7 @@ func TestFileInfoHeaderDir(t *testing.T) {
 		t.Errorf("Name = %q; want %q", g, e)
 	}
 	// Ignoring c_ISGID for golang.org/issue/4867
-	if g, e := h.Mode&^c_ISGID, int64(fi.Mode().Perm())|c_ISDIR; g != e {
+	if g, e := h.Mode&^c_ISGID, int64(fi.Mode().Perm()); g != e {
 		t.Errorf("Mode = %#o; want %#o", g, e)
 	}
 	if g, e := h.Size, int64(0); g != e {
@@ -157,7 +157,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 		// regular file.
 		h: &Header{
 			Name:     "test.txt",
-			Mode:     0644 | c_ISREG,
+			Mode:     0644,
 			Size:     12,
 			ModTime:  time.Unix(1360600916, 0),
 			Typeflag: TypeReg,
@@ -167,7 +167,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 		// symbolic link.
 		h: &Header{
 			Name:     "link.txt",
-			Mode:     0777 | c_ISLNK,
+			Mode:     0777,
 			Size:     0,
 			ModTime:  time.Unix(1360600852, 0),
 			Typeflag: TypeSymlink,
@@ -177,7 +177,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 		// character device node.
 		h: &Header{
 			Name:     "dev/null",
-			Mode:     0666 | c_ISCHR,
+			Mode:     0666,
 			Size:     0,
 			ModTime:  time.Unix(1360578951, 0),
 			Typeflag: TypeChar,
@@ -187,7 +187,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 		// block device node.
 		h: &Header{
 			Name:     "dev/sda",
-			Mode:     0660 | c_ISBLK,
+			Mode:     0660,
 			Size:     0,
 			ModTime:  time.Unix(1360578954, 0),
 			Typeflag: TypeBlock,
@@ -197,7 +197,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 		// directory.
 		h: &Header{
 			Name:     "dir/",
-			Mode:     0755 | c_ISDIR,
+			Mode:     0755,
 			Size:     0,
 			ModTime:  time.Unix(1360601116, 0),
 			Typeflag: TypeDir,
@@ -207,7 +207,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 		// fifo node.
 		h: &Header{
 			Name:     "dev/initctl",
-			Mode:     0600 | c_ISFIFO,
+			Mode:     0600,
 			Size:     0,
 			ModTime:  time.Unix(1360578949, 0),
 			Typeflag: TypeFifo,
@@ -217,7 +217,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 		// setuid.
 		h: &Header{
 			Name:     "bin/su",
-			Mode:     0755 | c_ISREG | c_ISUID,
+			Mode:     0755 | c_ISUID,
 			Size:     23232,
 			ModTime:  time.Unix(1355405093, 0),
 			Typeflag: TypeReg,
@@ -227,7 +227,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 		// setguid.
 		h: &Header{
 			Name:     "group.txt",
-			Mode:     0750 | c_ISREG | c_ISGID,
+			Mode:     0750 | c_ISGID,
 			Size:     0,
 			ModTime:  time.Unix(1360602346, 0),
 			Typeflag: TypeReg,
@@ -237,7 +237,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 		// sticky.
 		h: &Header{
 			Name:     "sticky.txt",
-			Mode:     0600 | c_ISREG | c_ISVTX,
+			Mode:     0600 | c_ISVTX,
 			Size:     7,
 			ModTime:  time.Unix(1360602540, 0),
 			Typeflag: TypeReg,
@@ -247,7 +247,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 		// hard link.
 		h: &Header{
 			Name:     "hard.txt",
-			Mode:     0644 | c_ISREG,
+			Mode:     0644,
 			Size:     0,
 			Linkname: "file.txt",
 			ModTime:  time.Unix(1360600916, 0),
@@ -258,7 +258,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 		// More information.
 		h: &Header{
 			Name:     "info.txt",
-			Mode:     0600 | c_ISREG,
+			Mode:     0600,
 			Size:     0,
 			Uid:      1000,
 			Gid:      1000,