Added function to check filepath prefixes

Author: Priya Wadhwa

pkg/util/cloud_prepper.go

@@ -59,7 +59,7 @@ func (p CloudPrepper) GetFileSystem() (string, error) {
 		return "", err
 	}
 
-	return path, GetFileSystemFromReference(ref, p.ImageSource, path, []string{})
+	return path, GetFileSystemFromReference(ref, p.ImageSource, path, nil)
 }
 
 func (p CloudPrepper) GetConfig() (ConfigSchema, error) {

pkg/util/daemon_prepper.go

@@ -64,7 +64,7 @@ func (p DaemonPrepper) GetFileSystem() (string, error) {
 	if err != nil {
 		return "", err
 	}
-	return path, GetFileSystemFromReference(ref, src, path, []string{})
+	return path, GetFileSystemFromReference(ref, src, path, nil)
 }
 
 func (p DaemonPrepper) GetConfig() (ConfigSchema, error) {

pkg/util/docker_utils.go

@@ -115,7 +115,7 @@ func unpackDockerSave(tarPath string, target string) error {
 	}
 
 	for _, layer := range layers {
-		if err = UnTar(bytes.NewReader(layerMap[layer]), target, []string{}); err != nil {
+		if err = UnTar(bytes.NewReader(layerMap[layer]), target, nil); err != nil {
 			return fmt.Errorf("Could not unpack layer %s: %s", layer, err)
 		}
 	}

pkg/util/fs_utils.go

@@ -160,3 +160,22 @@ func CheckSameFile(f1name, f2name string) (bool, error) {
 	}
 	return true, nil
 }
+
+// HasFilepathPrefix checks if the given file path begins with prefix
+func HasFilepathPrefix(path, prefix string) bool {
+	path = filepath.Clean(path)
+	prefix = filepath.Clean(prefix)
+	pathArray := strings.Split(path, "/")
+	prefixArray := strings.Split(prefix, "/")
+
+	if len(pathArray) < len(prefixArray) {
+		return false
+	}
+	for index := range prefixArray {
+		if prefixArray[index] == pathArray[index] {
+			continue
+		}
+		return false
+	}
+	return true
+}

pkg/util/tar_prepper.go

@@ -61,7 +61,7 @@ func (p TarPrepper) GetConfig() (ConfigSchema, error) {
 		return ConfigSchema{}, err
 	}
 	defer f.Close()
-	if err := UnTar(f, tempDir, []string{}); err != nil {
+	if err := UnTar(f, tempDir, nil); err != nil {
 		return ConfigSchema{}, err
 	}
 

pkg/util/tar_utils.go

@@ -18,12 +18,11 @@ package util
 
 import (
 	"archive/tar"
+	"github.com/sirupsen/logrus"
 	"io"
 	"os"
 	"path/filepath"
 	"strings"
-
-	"github.com/sirupsen/logrus"
 )
 
 func unpackTar(tr *tar.Reader, path string, whitelist []string) error {
@@ -137,7 +136,7 @@ func walkAndRemove(p string) error {
 
 func checkWhitelist(target string, whitelist []string) bool {
 	for _, w := range whitelist {
-		if strings.HasPrefix(target, w) {
+		if HasFilepathPrefix(target, w) {
 			return true
 		}
 	}

util/fs_utils_test.go

@@ -156,3 +156,26 @@ func TestCheckSameFile(t *testing.T) {
 		}
 	}
 }
+
+func TestHasFilepathPrefix(t *testing.T) {
+	type test struct {
+		prefix       string
+		path         string
+		expectedBool bool
+	}
+
+	var tests = []test{
+		{"/foo", "/foo/bar", true},
+		{"/foo/", "/foo/bar", true},
+		{"/foo/bar", "/foo", false},
+		{"/foo/bar", "/foo/", false},
+		{"/foo", "/foobar", false},
+	}
+
+	for _, test := range tests {
+		hasPrefix := pkgutil.HasFilepathPrefix(test.path, test.prefix)
+		if hasPrefix != test.expectedBool {
+			t.Errorf("Got unexpected response: %v for prefix: %s and path: %s", hasPrefix, test.prefix, test.path)
+		}
+	}
+}