sftpd: make file/dir removal and creation more standard

- remove a non empty directory. Before: the directory contents were
removed recursively. Now: removing a non empty directory fails.

- make a directory in a non existent path: Before: any necessary parents
were created. Now: it fails.

- remove a file. Before: files, directories and symlinks were removed.
Now: only files and symlink are removed, removing a directory using "Remove"
instead of "Rmdir" fails.

Upload a file in a non existent directory. Before: any necessary parents
were created. Now: it fails.

Now SFTPGo behaves as OpenSSH.

sftpd/handler.go

@@ -279,21 +279,23 @@ func (c Connection) handleSFTPRmdir(path string) error {
 		return sftp.ErrSSHFxPermissionDenied
 	}
 
-	numFiles, size, fileList, err := utils.ScanDirContents(path)
+	var fi os.FileInfo
-	if err != nil {
+	var err error
-		c.Log(logger.LevelError, logSender, "failed to remove directory %#v, scanning error: %v", path, err)
+	if fi, err = os.Lstat(path); err != nil {
+		c.Log(logger.LevelError, logSender, "failed to remove a dir %#v: stat error: %v", path, err)
 		return sftp.ErrSSHFxFailure
 	}
-	if err := os.RemoveAll(path); err != nil {
+	if !fi.IsDir() || fi.Mode()&os.ModeSymlink == os.ModeSymlink {
+		c.Log(logger.LevelDebug, logSender, "cannot remove %#v is not a directory", path)
+		return sftp.ErrSSHFxFailure
+	}
+
+	if err = os.Remove(path); err != nil {
 		c.Log(logger.LevelError, logSender, "failed to remove directory %#v: %v", path, err)
 		return sftp.ErrSSHFxFailure
 	}
 
 	logger.CommandLog(rmdirLogSender, path, "", c.User.Username, c.ID, c.protocol)
-	dataprovider.UpdateUserQuota(dataProvider, c.User, -numFiles, -size, false)
-	for _, p := range fileList {
-		executeAction(operationDelete, c.User.Username, p, "")
-	}
 	return sftp.ErrSSHFxOk
 }
 
@@ -314,11 +316,12 @@ func (c Connection) handleSFTPMkdir(path string) error {
 	if !c.User.HasPerm(dataprovider.PermCreateDirs) {
 		return sftp.ErrSSHFxPermissionDenied
 	}
-
+	if err := os.Mkdir(path, 0777); err != nil {
-	if err := c.createMissingDirs(filepath.Join(path, "testfile")); err != nil {
+		c.Log(logger.LevelError, logSender, "error creating missing dir: %#v error: %v", path, err)
-		c.Log(logger.LevelError, logSender, "error making missing dir for path %#v: %v", path, err)
 		return sftp.ErrSSHFxFailure
 	}
+	utils.SetPathPermissions(path, c.User.GetUID(), c.User.GetGID())
+
 	logger.CommandLog(mkdirLogSender, path, "", c.User.Username, c.ID, c.protocol)
 	return nil
 }
@@ -335,6 +338,10 @@ func (c Connection) handleSFTPRemove(path string) error {
 		c.Log(logger.LevelError, logSender, "failed to remove a file %#v: stat error: %v", path, err)
 		return sftp.ErrSSHFxFailure
 	}
+	if fi.IsDir() && fi.Mode()&os.ModeSymlink != os.ModeSymlink {
+		c.Log(logger.LevelDebug, logSender, "cannot remove %#v is not a file/symlink", path)
+		return sftp.ErrSSHFxFailure
+	}
 	size = fi.Size()
 	if err := os.Remove(path); err != nil {
 		c.Log(logger.LevelError, logSender, "failed to remove a file/symlink %#v: %v", path, err)
@@ -356,18 +363,6 @@ func (c Connection) handleSFTPUploadToNewFile(requestPath, filePath string) (io.
 		return nil, sftp.ErrSSHFxFailure
 	}
 
-	if _, err := os.Stat(filepath.Dir(requestPath)); os.IsNotExist(err) {
-		if !c.User.HasPerm(dataprovider.PermCreateDirs) {
-			return nil, sftp.ErrSSHFxPermissionDenied
-		}
-	}
-
-	err := c.createMissingDirs(requestPath)
-	if err != nil {
-		c.Log(logger.LevelError, logSender, "error making missing dir for path %#v: %v", requestPath, err)
-		return nil, sftp.ErrSSHFxFailure
-	}
-
 	file, err := os.Create(filePath)
 	if err != nil {
 		c.Log(logger.LevelError, logSender, "error creating file %#v: %v", requestPath, err)
@@ -569,23 +564,6 @@ func (c Connection) isSubDir(sub string) error {
 	return nil
 }
 
-func (c Connection) createMissingDirs(filePath string) error {
-	dirsToCreate, err := c.findNonexistentDirs(filePath)
-	if err != nil {
-		return err
-	}
-	last := len(dirsToCreate) - 1
-	for i := range dirsToCreate {
-		d := dirsToCreate[last-i]
-		if err := os.Mkdir(d, 0777); err != nil {
-			c.Log(logger.LevelError, logSender, "error creating missing dir: %#v", d)
-			return err
-		}
-		utils.SetPathPermissions(d, c.User.GetUID(), c.User.GetGID())
-	}
-	return nil
-}
-
 func (c Connection) close() error {
 	if c.channel != nil {
 		err := c.channel.Close()

sftpd/sftpd_test.go

@@ -201,8 +201,9 @@ func TestBasicSFTPHandling(t *testing.T) {
 		expectedQuotaSize := user.UsedQuotaSize + testFileSize
 		expectedQuotaFiles := user.UsedQuotaFiles + 1
 		err = createTestFile(testFilePath, testFileSize)
-		if err != nil {
+		err = sftpUploadFile(testFilePath, path.Join("/missing_dir", testFileName), testFileSize, client)
-			t.Errorf("unable to create test file: %v", err)
+		if err == nil {
+			t.Errorf("upload a file to a missing dir must fail")
 		}
 		err = sftpUploadFile(testFilePath, testFileName, testFileSize, client)
 		if err != nil {
@@ -317,10 +318,7 @@ func TestDirCommands(t *testing.T) {
 		t.Errorf("unable to add user: %v", err)
 	}
 	// remove the home dir to test auto creation
-	_, err = os.Stat(user.HomeDir)
+	os.RemoveAll(user.HomeDir)
-	if err == nil {
-		os.RemoveAll(user.HomeDir)
-	}
 	client, err := getSftpClient(user, usePubKey)
 	if err != nil {
 		t.Errorf("unable to create sftp client: %v", err)
@@ -339,13 +337,61 @@ func TestDirCommands(t *testing.T) {
 			t.Errorf("error rmdir: %v", err)
 		}
 		err = client.Mkdir("/test/test1")
+		if err == nil {
+			t.Errorf("recursive mkdir must fail")
+		}
+		client.Mkdir("/test")
+		err = client.Mkdir("/test/test1")
 		if err != nil {
-			t.Errorf("error mkdir all: %v", err)
+			t.Errorf("mkdir dir error: %v", err)
 		}
 		_, err = client.ReadDir("/this/dir/does/not/exist")
 		if err == nil {
 			t.Errorf("reading a missing dir must fail")
 		}
+		err = client.RemoveDirectory("/test/test1")
+		if err != nil {
+			t.Errorf("remove dir error: %v", err)
+		}
+		err = client.RemoveDirectory("/test")
+		if err != nil {
+			t.Errorf("remove dir error: %v", err)
+		}
+		_, err = client.Lstat("/test")
+		if err == nil {
+			t.Errorf("stat for deleted dir must not succeed")
+		}
+		err = client.RemoveDirectory("/test")
+		if err == nil {
+			t.Errorf("remove missing path must fail")
+		}
+	}
+	_, err = httpd.RemoveUser(user, http.StatusOK)
+	if err != nil {
+		t.Errorf("unable to remove user: %v", err)
+	}
+	os.RemoveAll(user.GetHomeDir())
+}
+
+func TestRemove(t *testing.T) {
+	usePubKey := true
+	user, _, err := httpd.AddUser(getTestUser(usePubKey), http.StatusOK)
+	if err != nil {
+		t.Errorf("unable to add user: %v", err)
+	}
+	client, err := getSftpClient(user, usePubKey)
+	if err != nil {
+		t.Errorf("unable to create sftp client: %v", err)
+	} else {
+		defer client.Close()
+		err = client.Mkdir("test")
+		if err != nil {
+			t.Errorf("error mkdir: %v", err)
+		}
+		err = client.Mkdir("/test/test1")
+		if err != nil {
+			t.Errorf("error mkdir subdir: %v", err)
+		}
 		testFileName := "/test_file.dat"
 		testFilePath := filepath.Join(homeBasePath, testFileName)
 		testFileSize := int64(65535)
@@ -357,20 +403,29 @@ func TestDirCommands(t *testing.T) {
 		if err != nil {
 			t.Errorf("file upload error: %v", err)
 		}
-		// internally client.Remove will call RemoveDirectory on failure
+		err = client.Remove("/test")
-		// the first remove will fail since test directory is not empty
+		if err == nil {
-		// the RemoveDirectory called internally by client.Remove will succeed
+			t.Errorf("remove non empty dir must fail")
+		}
+		err = client.RemoveDirectory(filepath.Join("/test", testFileName))
+		if err == nil {
+			t.Errorf("remove directory as file must fail")
+		}
+		err = client.Remove(filepath.Join("/test", testFileName))
+		if err != nil {
+			t.Errorf("remove file error: %v", err)
+		}
+		err = client.Remove(filepath.Join("/test", testFileName))
+		if err == nil {
+			t.Errorf("remove missing file must fail")
+		}
+		err = client.Remove("/test/test1")
+		if err != nil {
+			t.Errorf("remove dir error: %v", err)
+		}
 		err = client.Remove("/test")
 		if err != nil {
-			t.Errorf("error rmdir all: %v", err)
+			t.Errorf("remove dir error: %v", err)
-		}
-		_, err = client.Lstat("/test")
-		if err == nil {
-			t.Errorf("stat for deleted dir must not succeed")
-		}
-		err = client.Remove("/test")
-		if err == nil {
-			t.Errorf("remove missing path must fail")
 		}
 	}
 	_, err = httpd.RemoveUser(user, http.StatusOK)
@@ -1523,17 +1578,6 @@ func TestPermCreateDirs(t *testing.T) {
 		if err == nil {
 			t.Errorf("mkdir without permission should not succeed")
 		}
-		testFileName := "test_file.dat"
-		testFilePath := filepath.Join(homeBasePath, testFileName)
-		testFileSize := int64(65535)
-		err = createTestFile(testFilePath, testFileSize)
-		if err != nil {
-			t.Errorf("unable to create test file: %v", err)
-		}
-		err = sftpUploadFile(testFilePath, "/dir/subdir/test_file.dat", testFileSize, client)
-		if err == nil {
-			t.Errorf("mkdir without permission should not succeed")
-		}
 	}
 	_, err = httpd.RemoveUser(user, http.StatusOK)
 	if err != nil {