archive/zip: make zip understand os.FileMode.

Fixes implicit dependency on underlying os file modes.

R=rsc, r, n13m3y3r, gustavo, adg
CC=golang-dev
https://golang.org/cl/5440130

src/pkg/archive/zip/reader_test.go

@@ -9,6 +9,7 @@ import (
 	"encoding/binary"
 	"io"
 	"io/ioutil"
+	"os"
 	"testing"
 	"time"
 )
@@ -25,7 +26,7 @@ type ZipTestFile struct {
 	Content []byte // if blank, will attempt to compare against File
 	File    string // name of file to compare to (relative to testdata/)
 	Mtime   string // modified time in format "mm-dd-yy hh:mm:ss"
-	Mode    uint32
+	Mode    os.FileMode
 }
 
 // Caution: The Mtime values found for the test files should correspond to
@@ -47,13 +48,13 @@ var tests = []ZipTest{
 				Name:    "test.txt",
 				Content: []byte("This is a test text file.\n"),
 				Mtime:   "09-05-10 12:12:02",
-				Mode:    0x81a4,
+				Mode:    0644,
 			},
 			{
 				Name:  "gophercolor16x16.png",
 				File:  "gophercolor16x16.png",
 				Mtime: "09-05-10 15:52:58",
-				Mode:  0x81a4,
+				Mode:  0644,
 			},
 		},
 	},
@@ -64,6 +65,7 @@ var tests = []ZipTest{
 				Name:  "r/r.zip",
 				File:  "r.zip",
 				Mtime: "03-04-10 00:24:16",
+				Mode:  0666,
 			},
 		},
 	},
@@ -76,9 +78,43 @@ var tests = []ZipTest{
 				Name:    "filename",
 				Content: []byte("This is a test textfile.\n"),
 				Mtime:   "02-02-11 13:06:20",
+				Mode:    0666,
 			},
 		},
 	},
+	{
+		// created in windows XP file manager.
+		Name: "winxp.zip",
+		File: crossPlatform,
+	},
+	{
+		// created by Zip 3.0 under Linux
+		Name: "unix.zip",
+		File: crossPlatform,
+	},
+}
+
+var crossPlatform = []ZipTestFile{
+	{
+		Name:    "hello",
+		Content: []byte("world \r\n"),
+		Mode:    0666,
+	},
+	{
+		Name:    "dir/bar",
+		Content: []byte("foo \r\n"),
+		Mode:    0666,
+	},
+	{
+		Name:    "dir/empty/",
+		Content: []byte{},
+		Mode:    os.ModeDir | 0777,
+	},
+	{
+		Name:    "readonly",
+		Content: []byte("important \r\n"),
+		Mode:    0444,
+	},
 }
 
 func TestReader(t *testing.T) {
@@ -159,13 +195,15 @@ func readTestFile(t *testing.T, ft ZipTestFile, f *File) {
 		t.Errorf("name=%q, want %q", f.Name, ft.Name)
 	}
 
-	mtime, err := time.Parse("01-02-06 15:04:05", ft.Mtime)
-	if err != nil {
-		t.Error(err)
-		return
-	}
-	if ft := f.ModTime(); !ft.Equal(mtime) {
-		t.Errorf("%s: mtime=%s, want %s", f.Name, ft, mtime)
+	if ft.Mtime != "" {
+		mtime, err := time.Parse("01-02-06 15:04:05", ft.Mtime)
+		if err != nil {
+			t.Error(err)
+			return
+		}
+		if ft := f.ModTime(); !ft.Equal(mtime) {
+			t.Errorf("%s: mtime=%s, want %s", f.Name, ft, mtime)
+		}
 	}
 
 	testFileMode(t, f, ft.Mode)
@@ -191,7 +229,7 @@ func readTestFile(t *testing.T, ft ZipTestFile, f *File) {
 	r.Close()
 
 	var c []byte
-	if len(ft.Content) != 0 {
+	if ft.Content != nil {
 		c = ft.Content
 	} else if c, err = ioutil.ReadFile("testdata/" + ft.File); err != nil {
 		t.Error(err)
@@ -211,7 +249,7 @@ func readTestFile(t *testing.T, ft ZipTestFile, f *File) {
 	}
 }
 
-func testFileMode(t *testing.T, f *File, want uint32) {
+func testFileMode(t *testing.T, f *File, want os.FileMode) {
 	mode, err := f.Mode()
 	if want == 0 {
 		if err == nil {
@@ -220,7 +258,7 @@ func testFileMode(t *testing.T, f *File, want uint32) {
 	} else if err != nil {
 		t.Errorf("%s mode: %s", f.Name, err)
 	} else if mode != want {
-		t.Errorf("%s mode: want 0x%x, got 0x%x", f.Name, want, mode)
+		t.Errorf("%s mode: want %v, got %v", f.Name, want, mode)
 	}
 }
 

src/pkg/archive/zip/struct.go

@@ -12,7 +12,7 @@ This package does not support ZIP64 or disk spanning.
 package zip
 
 import (
-	"errors"
+	"os"
 	"time"
 )
 
@@ -32,7 +32,11 @@ const (
 	dataDescriptorLen        = 12
 
 	// Constants for the first byte in CreatorVersion
-	creatorUnix = 3
+	creatorFAT    = 0
+	creatorUnix   = 3
+	creatorNTFS   = 11
+	creatorVFAT   = 14
+	creatorMacOSX = 19
 )
 
 type FileHeader struct {
@@ -98,17 +102,85 @@ func (h *FileHeader) ModTime() time.Time {
 	return msDosTimeToTime(h.ModifiedDate, h.ModifiedTime)
 }
 
+// traditional names for Unix constants
+const (
+	s_IFMT  = 0xf000
+	s_IFDIR = 0x4000
+	s_IFREG = 0x8000
+	s_ISUID = 0x800
+	s_ISGID = 0x400
+
+	msdosDir      = 0x10
+	msdosReadOnly = 0x01
+)
+
 // Mode returns the permission and mode bits for the FileHeader.
 // An error is returned in case the information is not available.
-func (h *FileHeader) Mode() (mode uint32, err error) {
-	if h.CreatorVersion>>8 == creatorUnix {
-		return h.ExternalAttrs >> 16, nil
+func (h *FileHeader) Mode() (mode os.FileMode, err error) {
+	switch h.CreatorVersion >> 8 {
+	case creatorUnix, creatorMacOSX:
+		mode = unixModeToFileMode(h.ExternalAttrs >> 16)
+	case creatorNTFS, creatorVFAT, creatorFAT:
+		mode = msdosModeToFileMode(h.ExternalAttrs)
 	}
-	return 0, errors.New("file mode not available")
+	if len(h.Name) > 0 && h.Name[len(h.Name)-1] == '/' {
+		mode |= os.ModeDir
+	}
+	return mode, nil
 }
 
 // SetMode changes the permission and mode bits for the FileHeader.
-func (h *FileHeader) SetMode(mode uint32) {
+func (h *FileHeader) SetMode(mode os.FileMode) {
 	h.CreatorVersion = h.CreatorVersion&0xff | creatorUnix<<8
-	h.ExternalAttrs = mode << 16
+	h.ExternalAttrs = fileModeToUnixMode(mode) << 16
+
+	// set MSDOS attributes too, as the original zip does.
+	if mode&os.ModeDir != 0 {
+		h.ExternalAttrs |= msdosDir
+	}
+	if mode&0200 == 0 {
+		h.ExternalAttrs |= msdosReadOnly
+	}
+}
+
+func msdosModeToFileMode(m uint32) (mode os.FileMode) {
+	if m&msdosDir != 0 {
+		mode = os.ModeDir | 0777
+	} else {
+		mode = 0666
+	}
+	if m&msdosReadOnly != 0 {
+		mode &^= 0222
+	}
+	return mode
+}
+
+func fileModeToUnixMode(mode os.FileMode) uint32 {
+	var m uint32
+	if mode&os.ModeDir != 0 {
+		m = s_IFDIR
+	} else {
+		m = s_IFREG
+	}
+	if mode&os.ModeSetuid != 0 {
+		m |= s_ISUID
+	}
+	if mode&os.ModeSetgid != 0 {
+		m |= s_ISGID
+	}
+	return m | uint32(mode&0777)
+}
+
+func unixModeToFileMode(m uint32) os.FileMode {
+	var mode os.FileMode
+	if m&s_IFMT == s_IFDIR {
+		mode |= os.ModeDir
+	}
+	if m&s_ISGID != 0 {
+		mode |= os.ModeSetgid
+	}
+	if m&s_ISUID != 0 {
+		mode |= os.ModeSetuid
+	}
+	return mode | os.FileMode(m&0777)
 }

src/pkg/archive/zip/writer_test.go

@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"io/ioutil"
 	"math/rand"
+	"os"
 	"testing"
 )
 
@@ -17,7 +18,7 @@ type WriteTest struct {
 	Name   string
 	Data   []byte
 	Method uint16
-	Mode   uint32
+	Mode   os.FileMode
 }
 
 var writeTests = []WriteTest{
@@ -25,12 +26,31 @@ var writeTests = []WriteTest{
 		Name:   "foo",
 		Data:   []byte("Rabbits, guinea pigs, gophers, marsupial rats, and quolls."),
 		Method: Store,
+		Mode:   0666,
 	},
 	{
 		Name:   "bar",
 		Data:   nil, // large data set in the test
 		Method: Deflate,
-		Mode:   0x81ed,
+		Mode:   0644,
+	},
+	{
+		Name:   "setuid",
+		Data:   []byte("setuid file"),
+		Method: Deflate,
+		Mode:   0755 | os.ModeSetuid,
+	},
+	{
+		Name:   "setgid",
+		Data:   []byte("setgid file"),
+		Method: Deflate,
+		Mode:   0755 | os.ModeSetgid,
+	},
+	{
+		Name:   "setgid",
+		Data:   []byte("setgid file"),
+		Method: Deflate,
+		Mode:   0755 | os.ModeSetgid,
 	},
 }