new file mode 100644

@@ -0,0 +1,72 @@

+package symlink

+

+import (

+	"fmt"

+	"os"

+	"path/filepath"

+	"strings"

+)

+

+// FollowSymlink will follow an existing link and scope it to the root

+// path provided.

+func FollowSymlinkInScope(link, root string) (string, error) {

+	prev := "/"

+

+	root, err := filepath.Abs(root)

+	if err != nil {

+		return "", err

+	}

+

+	link, err = filepath.Abs(link)

+	if err != nil {

+		return "", err

+	}

+

+	if !strings.HasPrefix(filepath.Dir(link), root) {

+		return "", fmt.Errorf("%s is not within %s", link, root)

+	}

+

+	for _, p := range strings.Split(link, "/") {

+		prev = filepath.Join(prev, p)

+		prev = filepath.Clean(prev)

+

+		for {

+			if !strings.HasPrefix(prev, root) {

+				// Don't resolve symlinks outside of root. For example,

+				// we don't have to check /home in the below.

+				//

+				//   /home -> usr/home

+				//   FollowSymlinkInScope("/home/bob/foo/bar", "/home/bob/foo")

+				break

+			}

+

+			stat, err := os.Lstat(prev)

+			if err != nil {

+				if os.IsNotExist(err) {

+					break

+				}

+				return "", err

+			}

+			if stat.Mode()&os.ModeSymlink == os.ModeSymlink {

+				dest, err := os.Readlink(prev)

+				if err != nil {

+					return "", err

+				}

+

+				switch dest[0] {

+				case '/':

+					prev = filepath.Join(root, dest)

+				case '.':

+					prev, _ = filepath.Abs(prev)

+

+					if prev = filepath.Clean(filepath.Join(filepath.Dir(prev), dest)); len(prev) < len(root) {

+						prev = filepath.Join(root, filepath.Base(dest))

+					}

+				}

+			} else {

+				break

+			}

+		}

+	}

+	return prev, nil

+}

new file mode 100644

@@ -0,0 +1,108 @@

+package symlink

+

+import (

+	"io/ioutil"

+	"os"

+	"path/filepath"

+	"testing"

+)

+

+func abs(t *testing.T, p string) string {

+	o, err := filepath.Abs(p)

+	if err != nil {

+		t.Fatal(err)

+	}

+	return o

+}

+

+func TestFollowSymLinkNormal(t *testing.T) {

+	link := "testdata/fs/a/d/c/data"

+

+	rewrite, err := FollowSymlinkInScope(link, "testdata")

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	if expected := abs(t, "testdata/b/c/data"); expected != rewrite {

+		t.Fatalf("Expected %s got %s", expected, rewrite)

+	}

+}

+

+func TestFollowSymLinkUnderLinkedDir(t *testing.T) {

+	dir, err := ioutil.TempDir("", "docker-fs-test")

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	os.Mkdir(filepath.Join(dir, "realdir"), 0700)

+	os.Symlink("realdir", filepath.Join(dir, "linkdir"))

+

+	linkDir := filepath.Join(dir, "linkdir", "foo")

+	dirUnderLinkDir := filepath.Join(dir, "linkdir", "foo", "bar")

+	os.MkdirAll(dirUnderLinkDir, 0700)

+

+	rewrite, err := FollowSymlinkInScope(dirUnderLinkDir, linkDir)

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	if rewrite != dirUnderLinkDir {

+		t.Fatalf("Expected %s got %s", dirUnderLinkDir, rewrite)

+	}

+}

+

+func TestFollowSymLinkRandomString(t *testing.T) {

+	if _, err := FollowSymlinkInScope("toto", "testdata"); err == nil {

+		t.Fatal("Random string should fail but didn't")

+	}

+}

+

+func TestFollowSymLinkLastLink(t *testing.T) {

+	link := "testdata/fs/a/d"

+

+	rewrite, err := FollowSymlinkInScope(link, "testdata")

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	if expected := abs(t, "testdata/b"); expected != rewrite {

+		t.Fatalf("Expected %s got %s", expected, rewrite)

+	}

+}

+

+func TestFollowSymLinkRelativeLink(t *testing.T) {

+	link := "testdata/fs/a/e/c/data"

+

+	rewrite, err := FollowSymlinkInScope(link, "testdata")

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	if expected := abs(t, "testdata/fs/b/c/data"); expected != rewrite {

+		t.Fatalf("Expected %s got %s", expected, rewrite)

+	}

+}

+

+func TestFollowSymLinkRelativeLinkScope(t *testing.T) {

+	link := "testdata/fs/a/f"

+

+	rewrite, err := FollowSymlinkInScope(link, "testdata")

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	if expected := abs(t, "testdata/test"); expected != rewrite {

+		t.Fatalf("Expected %s got %s", expected, rewrite)

+	}

+

+	link = "testdata/fs/b/h"

+

+	rewrite, err = FollowSymlinkInScope(link, "testdata")

+	if err != nil {

+		t.Fatal(err)

+	}

+

+	if expected := abs(t, "testdata/root"); expected != rewrite {

+		t.Fatalf("Expected %s got %s", expected, rewrite)

+	}

+}

new file mode 120000

@@ -0,0 +1 @@

+/b

\ No newline at end of file

new file mode 120000

@@ -0,0 +1 @@

+../b

\ No newline at end of file

new file mode 120000

@@ -0,0 +1 @@

+../../../../test

\ No newline at end of file

new file mode 120000

@@ -0,0 +1 @@

+../g

\ No newline at end of file

new file mode 120000

@@ -0,0 +1 @@

+../../../../../../../../../../../../root

\ No newline at end of file

deleted file mode 100644

@@ -1,103 +0,0 @@

-package utils

-

-import (

-	"fmt"

-	"os"

-	"path/filepath"

-	"strings"

-	"syscall"

-)

-

-// TreeSize walks a directory tree and returns its total size in bytes.

-func TreeSize(dir string) (size int64, err error) {

-	data := make(map[uint64]struct{})

-	err = filepath.Walk(dir, func(d string, fileInfo os.FileInfo, e error) error {

-		// Ignore directory sizes

-		if fileInfo == nil {

-			return nil

-		}

-

-		s := fileInfo.Size()

-		if fileInfo.IsDir() || s == 0 {

-			return nil

-		}

-

-		// Check inode to handle hard links correctly

-		inode := fileInfo.Sys().(*syscall.Stat_t).Ino

-		// inode is not a uint64 on all platforms. Cast it to avoid issues.

-		if _, exists := data[uint64(inode)]; exists {

-			return nil

-		}

-		// inode is not a uint64 on all platforms. Cast it to avoid issues.

-		data[uint64(inode)] = struct{}{}

-

-		size += s

-

-		return nil

-	})

-	return

-}

-

-// FollowSymlink will follow an existing link and scope it to the root

-// path provided.

-func FollowSymlinkInScope(link, root string) (string, error) {

-	prev := "/"

-

-	root, err := filepath.Abs(root)

-	if err != nil {

-		return "", err

-	}

-

-	link, err = filepath.Abs(link)

-	if err != nil {

-		return "", err

-	}

-

-	if !strings.HasPrefix(filepath.Dir(link), root) {

-		return "", fmt.Errorf("%s is not within %s", link, root)

-	}

-

-	for _, p := range strings.Split(link, "/") {

-		prev = filepath.Join(prev, p)

-		prev = filepath.Clean(prev)

-

-		for {

-			if !strings.HasPrefix(prev, root) {

-				// Don't resolve symlinks outside of root. For example,

-				// we don't have to check /home in the below.

-				//

-				//   /home -> usr/home

-				//   FollowSymlinkInScope("/home/bob/foo/bar", "/home/bob/foo")

-				break

-			}

-

-			stat, err := os.Lstat(prev)

-			if err != nil {

-				if os.IsNotExist(err) {

-					break

-				}

-				return "", err

-			}

-			if stat.Mode()&os.ModeSymlink == os.ModeSymlink {

-				dest, err := os.Readlink(prev)

-				if err != nil {

-					return "", err

-				}

-

-				switch dest[0] {

-				case '/':

-					prev = filepath.Join(root, dest)

-				case '.':

-					prev, _ = filepath.Abs(prev)

-

-					if prev = filepath.Clean(filepath.Join(filepath.Dir(prev), dest)); len(prev) < len(root) {

-						prev = filepath.Join(root, filepath.Base(dest))

-					}

-				}

-			} else {

-				break

-			}

-		}

-	}

-	return prev, nil

-}

deleted file mode 100644

@@ -1,108 +0,0 @@

-package utils

-

-import (

-	"io/ioutil"

-	"os"

-	"path/filepath"

-	"testing"

-)

-

-func abs(t *testing.T, p string) string {

-	o, err := filepath.Abs(p)

-	if err != nil {

-		t.Fatal(err)

-	}

-	return o

-}

-

-func TestFollowSymLinkNormal(t *testing.T) {

-	link := "testdata/fs/a/d/c/data"

-

-	rewrite, err := FollowSymlinkInScope(link, "testdata")

-	if err != nil {

-		t.Fatal(err)

-	}

-

-	if expected := abs(t, "testdata/b/c/data"); expected != rewrite {

-		t.Fatalf("Expected %s got %s", expected, rewrite)

-	}

-}

-

-func TestFollowSymLinkUnderLinkedDir(t *testing.T) {

-	dir, err := ioutil.TempDir("", "docker-fs-test")

-	if err != nil {

-		t.Fatal(err)

-	}

-

-	os.Mkdir(filepath.Join(dir, "realdir"), 0700)

-	os.Symlink("realdir", filepath.Join(dir, "linkdir"))

-

-	linkDir := filepath.Join(dir, "linkdir", "foo")

-	dirUnderLinkDir := filepath.Join(dir, "linkdir", "foo", "bar")

-	os.MkdirAll(dirUnderLinkDir, 0700)

-

-	rewrite, err := FollowSymlinkInScope(dirUnderLinkDir, linkDir)

-	if err != nil {

-		t.Fatal(err)

-	}

-

-	if rewrite != dirUnderLinkDir {

-		t.Fatalf("Expected %s got %s", dirUnderLinkDir, rewrite)

-	}

-}

-

-func TestFollowSymLinkRandomString(t *testing.T) {

-	if _, err := FollowSymlinkInScope("toto", "testdata"); err == nil {

-		t.Fatal("Random string should fail but didn't")

-	}

-}

-

-func TestFollowSymLinkLastLink(t *testing.T) {

-	link := "testdata/fs/a/d"

-

-	rewrite, err := FollowSymlinkInScope(link, "testdata")

-	if err != nil {

-		t.Fatal(err)

-	}

-

-	if expected := abs(t, "testdata/b"); expected != rewrite {

-		t.Fatalf("Expected %s got %s", expected, rewrite)

-	}

-}

-

-func TestFollowSymLinkRelativeLink(t *testing.T) {

-	link := "testdata/fs/a/e/c/data"

-

-	rewrite, err := FollowSymlinkInScope(link, "testdata")

-	if err != nil {

-		t.Fatal(err)

-	}

-

-	if expected := abs(t, "testdata/fs/b/c/data"); expected != rewrite {

-		t.Fatalf("Expected %s got %s", expected, rewrite)

-	}

-}

-

-func TestFollowSymLinkRelativeLinkScope(t *testing.T) {

-	link := "testdata/fs/a/f"

-

-	rewrite, err := FollowSymlinkInScope(link, "testdata")

-	if err != nil {

-		t.Fatal(err)

-	}

-

-	if expected := abs(t, "testdata/test"); expected != rewrite {

-		t.Fatalf("Expected %s got %s", expected, rewrite)

-	}

-

-	link = "testdata/fs/b/h"

-

-	rewrite, err = FollowSymlinkInScope(link, "testdata")

-	if err != nil {

-		t.Fatal(err)

-	}

-

-	if expected := abs(t, "testdata/root"); expected != rewrite {

-		t.Fatalf("Expected %s got %s", expected, rewrite)

-	}

-}

deleted file mode 120000

@@ -1 +0,0 @@

-/b

\ No newline at end of file

deleted file mode 120000

@@ -1 +0,0 @@

-../b

\ No newline at end of file

deleted file mode 120000

@@ -1 +0,0 @@

-../../../../test

\ No newline at end of file

deleted file mode 120000

@@ -1 +0,0 @@

-../g

\ No newline at end of file

deleted file mode 120000

@@ -1 +0,0 @@

-../../../../../../../../../../../../root

\ No newline at end of file

@@ -21,6 +21,7 @@ import (

 	"strconv"

 	"strings"

 	"sync"

+	"syscall"

 	"time"

 	"github.com/dotcloud/docker/dockerversion"

@@ -1091,3 +1092,33 @@ func ParseKeyValueOpt(opt string) (string, string, error) {

 	}

 	return strings.TrimSpace(parts[0]), strings.TrimSpace(parts[1]), nil

 }

+

+// TreeSize walks a directory tree and returns its total size in bytes.

+func TreeSize(dir string) (size int64, err error) {

+	data := make(map[uint64]struct{})

+	err = filepath.Walk(dir, func(d string, fileInfo os.FileInfo, e error) error {

+		// Ignore directory sizes

+		if fileInfo == nil {

+			return nil

+		}

+

+		s := fileInfo.Size()

+		if fileInfo.IsDir() || s == 0 {

+			return nil

+		}

+

+		// Check inode to handle hard links correctly

+		inode := fileInfo.Sys().(*syscall.Stat_t).Ino

+		// inode is not a uint64 on all platforms. Cast it to avoid issues.

+		if _, exists := data[uint64(inode)]; exists {

+			return nil

+		}

+		// inode is not a uint64 on all platforms. Cast it to avoid issues.

+		data[uint64(inode)] = struct{}{}

+

+		size += s

+

+		return nil

+	})

+	return

+}