add dot and dot dot directories to sftp/ftp file listing

docs/full-configuration.md

@@ -106,7 +106,7 @@ The configuration file contains the following sections:
   - `enabled_ssh_commands`, list of enabled SSH commands. `*` enables all supported commands. More information can be found [here](./ssh-commands.md).
   - `keyboard_interactive_auth_hook`, string. Absolute path to an external program or an HTTP URL to invoke for keyboard interactive authentication. See [Keyboard Interactive Authentication](./keyboard-interactive.md) for more details.
   - `password_authentication`, boolean. Set to false to disable password authentication. This setting will disable multi-step authentication method using public key + password too. It is useful for public key only configurations if you need to manage old clients that will not attempt to authenticate with public keys if the password login method is advertised. Default: true.
-  - `folder_prefix`, string. Virtual root folder prefix to include in all file operations (ex: `/files`). The virtual paths used for per-directory permissions, file patterns etc. must not include the folder prefix. The prefix is only applied to SFTP requests, SCP and other SSH commands will be automatically disabled if you configure a prefix. This setting can help some specific migrations from SFTP servers based on OpenSSH and it is not recommended for general usage. Default: empty.
+  - `folder_prefix`, string. Virtual root folder prefix to include in all file operations (ex: `/files`). The virtual paths used for per-directory permissions, file patterns etc. must not include the folder prefix. The prefix is only applied to SFTP requests (in SFTP server mode), SCP and other SSH commands will be automatically disabled if you configure a prefix.  The prefix is ignored while running as OpenSSH's SFTP subsystem. This setting can help some specific migrations from SFTP servers based on OpenSSH and it is not recommended for general usage. Default: empty.
 - **"ftpd"**, the configuration for the FTP server
   - `bindings`, list of structs. Each struct has the following fields:
     - `port`, integer. The port used for serving FTP requests. 0 means disabled. Default: 0.

ftpd/cryptfs_test.go

@@ -57,8 +57,9 @@ func TestBasicFTPHandlingCryptFs(t *testing.T) {
 		}
 		list, err := client.List(".")
 		if assert.NoError(t, err) {
-			assert.Len(t, list, 1)
-			assert.Equal(t, testFileSize, int64(list[0].Size))
+			assert.Len(t, list, 2)
+			assert.Equal(t, ".", list[0].Name)
+			assert.Equal(t, testFileSize, int64(list[1].Size))
 		}
 		user, _, err = httpdtest.GetUserByUsername(user.Username, http.StatusOK)
 		assert.NoError(t, err)

ftpd/ftpd_test.go

@@ -536,6 +536,18 @@ func TestBasicFTPHandling(t *testing.T) {
 			if assert.NoError(t, err) {
 				assert.Equal(t, path.Join("/", testDir), curDir)
 			}
+			res, err := client.List(path.Join("/", testDir))
+			assert.NoError(t, err)
+			if assert.Len(t, res, 2) {
+				assert.Equal(t, ".", res[0].Name)
+				assert.Equal(t, "..", res[1].Name)
+			}
+			res, err = client.List(path.Join("/"))
+			assert.NoError(t, err)
+			if assert.Len(t, res, 2) {
+				assert.Equal(t, ".", res[0].Name)
+				assert.Equal(t, testDir, res[1].Name)
+			}
 			err = ftpUploadFile(testFilePath, testFileName, testFileSize, client, 0)
 			assert.NoError(t, err)
 			size, err := client.FileSize(path.Join("/", testDir, testFileName))

ftpd/handler.go

@@ -14,6 +14,7 @@ import (
 	"github.com/drakkan/sftpgo/v2/common"
 	"github.com/drakkan/sftpgo/v2/dataprovider"
 	"github.com/drakkan/sftpgo/v2/logger"
+	"github.com/drakkan/sftpgo/v2/util"
 	"github.com/drakkan/sftpgo/v2/vfs"
 )
 
@@ -271,7 +272,15 @@ func (c *Connection) Symlink(oldname, newname string) error {
 func (c *Connection) ReadDir(name string) ([]os.FileInfo, error) {
 	c.UpdateLastActivity()
 
-	return c.ListDir(name)
+	files, err := c.ListDir(name)
+	if err != nil {
+		return files, err
+	}
+	if name != "/" {
+		files = util.PrependFileInfo(files, vfs.NewFileInfo("..", true, 0, time.Now(), false))
+	}
+	files = util.PrependFileInfo(files, vfs.NewFileInfo(".", true, 0, time.Now(), false))
+	return files, nil
 }
 
 // GetHandle implements ClientDriverExtentionFileTransfer

sftpd/handler.go

@@ -12,6 +12,7 @@ import (
 	"github.com/drakkan/sftpgo/v2/common"
 	"github.com/drakkan/sftpgo/v2/dataprovider"
 	"github.com/drakkan/sftpgo/v2/logger"
+	"github.com/drakkan/sftpgo/v2/util"
 	"github.com/drakkan/sftpgo/v2/vfs"
 )
 
@@ -21,10 +22,11 @@ type Connection struct {
 	// client's version string
 	ClientVersion string
 	// Remote address for this connection
-	RemoteAddr net.Addr
-	LocalAddr  net.Addr
-	channel    io.ReadWriteCloser
-	command    string
+	RemoteAddr   net.Addr
+	LocalAddr    net.Addr
+	channel      io.ReadWriteCloser
+	command      string
+	folderPrefix string
 }
 
 // GetClientVersion returns the connected client's version
@@ -201,6 +203,11 @@ func (c *Connection) Filelist(request *sftp.Request) (sftp.ListerAt, error) {
 		if err != nil {
 			return nil, err
 		}
+		now := time.Now()
+		if request.Filepath != "/" || c.folderPrefix != "" {
+			files = util.PrependFileInfo(files, vfs.NewFileInfo("..", true, 0, now, false))
+		}
+		files = util.PrependFileInfo(files, vfs.NewFileInfo(".", true, 0, now, false))
 		return listerAt(files), nil
 	case "Stat":
 		if !c.User.HasPerm(dataprovider.PermListItems, path.Dir(request.Filepath)) {

sftpd/middleware.go

@@ -78,10 +78,15 @@ func (p *prefixMiddleware) Filelist(request *sftp.Request) (sftp.ListerAt, error
 	case pathIsPrefixParent:
 		switch request.Method {
 		case methodList:
+			now := time.Now()
 			fileName := p.nextListFolder(request.Filepath)
-			return listerAt([]os.FileInfo{
-				vfs.NewFileInfo(fileName, true, 0, time.Now(), false),
-			}), nil
+			files := make([]os.FileInfo, 0, 3)
+			files = append(files, vfs.NewFileInfo(".", true, 0, now, false))
+			if request.Filepath != "/" {
+				files = append(files, vfs.NewFileInfo("..", true, 0, now, false))
+			}
+			files = append(files, vfs.NewFileInfo(fileName, true, 0, now, false))
+			return listerAt(files), nil
 		case methodStat:
 			return listerAt([]os.FileInfo{
 				vfs.NewFileInfo(request.Filepath, true, 0, time.Now(), false),

sftpd/middleware_test.go

@@ -165,14 +165,15 @@ func (Suite *PrefixMiddlewareSuite) TestFileListForwarding() {
 
 func (Suite *PrefixMiddlewareSuite) TestFileList() {
 	var tests = []struct {
-		Method       string
-		FilePath     string
-		ExpectedErr  error
-		ExpectedPath string
+		Method        string
+		FilePath      string
+		ExpectedErr   error
+		ExpectedPath  string
+		ExpectedItems int
 	}{
-		{Method: `List`, FilePath: `/random`, ExpectedErr: sftp.ErrSSHFxPermissionDenied},
-		{Method: `List`, FilePath: `/`, ExpectedPath: `files`},
-		{Method: `Stat`, FilePath: `/`, ExpectedPath: `/`},
+		{Method: `List`, FilePath: `/random`, ExpectedErr: sftp.ErrSSHFxPermissionDenied, ExpectedItems: 0},
+		{Method: `List`, FilePath: `/`, ExpectedPath: `files`, ExpectedItems: 2},
+		{Method: `Stat`, FilePath: `/`, ExpectedPath: `/`, ExpectedItems: 1},
 		{Method: `NotAnOp`, ExpectedErr: sftp.ErrSSHFxOpUnsupported},
 	}
 
@@ -189,10 +190,13 @@ func (Suite *PrefixMiddlewareSuite) TestFileList() {
 			Suite.Nil(err)
 			Suite.IsType(listerAt{}, ListerAt)
 			if directList, ok := ListerAt.(listerAt); ok {
-				Suite.Len(directList, 1)
-				Suite.Equal(test.ExpectedPath, directList[0].Name())
-				Suite.InDelta(time.Now().Unix(), directList[0].ModTime().Unix(), 1)
-				Suite.True(directList[0].IsDir())
+				Suite.Len(directList, test.ExpectedItems)
+				if test.ExpectedItems > 1 {
+					Suite.Equal(".", directList[0].Name())
+				}
+				Suite.Equal(test.ExpectedPath, directList[test.ExpectedItems-1].Name())
+				Suite.InDelta(time.Now().Unix(), directList[test.ExpectedItems-1].ModTime().Unix(), 1)
+				Suite.True(directList[test.ExpectedItems-1].IsDir())
 			}
 		}
 	}

sftpd/server.go

@@ -451,6 +451,7 @@ func (c *Configuration) AcceptInboundConnection(conn net.Conn, config *ssh.Serve
 							RemoteAddr:    conn.RemoteAddr(),
 							LocalAddr:     conn.LocalAddr(),
 							channel:       channel,
+							folderPrefix:  c.FolderPrefix,
 						}
 						go c.handleSftpConnection(channel, &connection)
 					}
@@ -463,6 +464,7 @@ func (c *Configuration) AcceptInboundConnection(conn net.Conn, config *ssh.Serve
 						RemoteAddr:    conn.RemoteAddr(),
 						LocalAddr:     conn.LocalAddr(),
 						channel:       channel,
+						folderPrefix:  c.FolderPrefix,
 					}
 					ok = processSSHCommand(req.Payload, &connection, c.EnabledSSHCommands)
 				}

util/util.go

@@ -608,3 +608,12 @@ func GetRedactedURL(rawurl string) string {
 	}
 	return u.Redacted()
 }
+
+// PrependFileInfo prepends a file info to a slice in an efficient way.
+// We, optimistically, assume that the slice has enough capacity
+func PrependFileInfo(files []os.FileInfo, info os.FileInfo) []os.FileInfo {
+	files = append(files, nil)
+	copy(files[1:], files)
+	files[0] = info
+	return files
+}