chown operations support for FTP server

3 files changed, 1079 insertions, 1041 deletions

diff --git a/FtpServer/IFileSystemHandler.cs b/FtpServer/IFileSystemHandler.cs
index c84e8426..e54adb56 100644
--- a/FtpServer/IFileSystemHandler.cs
+++ b/FtpServer/IFileSystemHandler.cs
@@ -13,6 +13,7 @@ namespace mooftpserv
         public bool IsDirectory;

         public long Size;

         public DateTime LastModifiedTimeUtc;

+        public string Mode;

     }

 

     /// <summary>

@@ -197,6 +198,8 @@ namespace mooftpserv
         /// A relative or absolute path.

         /// </param>

         ResultOrError<DateTime> GetLastModifiedTimeUtc(string path);

+

+        ResultOrError<bool> ChmodFile(string mode, string path);

     }

 }

 

diff --git a/FtpServer/NesMiniFileSystemHandler.cs b/FtpServer/NesMiniFileSystemHandler.cs
index 3d89c02e..f8a768b7 100644
--- a/FtpServer/NesMiniFileSystemHandler.cs
+++ b/FtpServer/NesMiniFileSystemHandler.cs
@@ -185,6 +185,7 @@ namespace mooftpserv
                 {

                     if (line.StartsWith("total")) continue;

                     FileSystemEntry entry = new FileSystemEntry();

+                    entry.Mode = line.Substring(1, 12).Trim();

                     entry.Name = line.Substring(69).Trim();

                     entry.IsDirectory = entry.Name.EndsWith("/");

                     if (entry.IsDirectory) entry.Name = entry.Name.Substring(0, entry.Name.Length - 1);

@@ -310,5 +311,18 @@ namespace mooftpserv
         {

             return ResultOrError<T>.MakeError(error);

         }

+

+        public ResultOrError<bool> ChmodFile(string mode, string path)

+        {

+            try

+            {

+                clovershell.ExecuteSimple(string.Format("chmod {0} {1}", mode, path), 1000, true);

+                return ResultOrError<bool>.MakeResult(true);

+            }

+            catch (Exception ex)

+            {

+                return MakeError<bool>(ex.Message);

+            }

+        }

     }

 }

diff --git a/FtpServer/Session.cs b/FtpServer/Session.cs
index 068156d5..c8516621 100644
--- a/FtpServer/Session.cs
+++ b/FtpServer/Session.cs
@@ -1,1045 +1,1066 @@
-using System;
-using System.IO;
-using System.Net;
-using System.Net.Sockets;
-using System.Text;
-using System.Threading;
-
-namespace mooftpserv
-{
-    /// <summary>
-    /// FTP session/connection. Does all the heavy lifting of the FTP protocol.
-    /// Reads commands, sends replies, manages data connections, and so on.
-    /// Each session creates its own thread.
-    /// </summary>
-    class Session
-    {
-        // transfer data type, ascii or binary
-        enum DataType { ASCII, IMAGE };
-
-        // buffer size to use for reading commands from the control connection
-        private static int CMD_BUFFER_SIZE = 4096;
-        // version from AssemblyInfo
-        private static string LIB_VERSION = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version.ToString(2);
-        // monthnames for LIST command, since DateTime returns localized names
-        private static string[] MONTHS = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
-        // response text for initial response. preceeded by application name and version number.
-        private static string[] HELLO_TEXT = { "What can I do for you?", "Good day, sir or madam.", "Hey ho let's go!", "The poor man's FTP server." };
-        // response text for general ok messages
-        private static string[] OK_TEXT = { "Sounds good.", "Success!", "Alright, I'll do it...", "Consider it done." };
-        // Result for FEAT command
-        private static string[] FEATURES = { "MDTM", "PASV", "SIZE", "TVFS", "UTF8" };
-
-        // local EOL flavor
-        private static byte[] localEolBytes = Encoding.ASCII.GetBytes(Environment.NewLine);
-        // FTP-mandated EOL flavor (= CRLF)
-        private static byte[] remoteEolBytes = Encoding.ASCII.GetBytes("\r\n");
-        // on Windows, no ASCII conversion is necessary (CRLF == CRLF)
-        private static bool noAsciiConv = (localEolBytes == remoteEolBytes);
-
-        // socket for the control connection
-        private Socket controlSocket;
-        // buffer size to use for sending/receiving with data connections
-        private int dataBufferSize;
-        // auth handler, checks user credentials
-        private IAuthHandler authHandler;
-        // file system handler, implements file system access for the FTP commands
-        private IFileSystemHandler fsHandler;
-        // log handler, used for diagnostic logging output. can be null.
-        private ILogHandler logHandler;
-        // Session thread, the control and data connections are processed in this thread
-        private Thread thread;
-
-        // .NET CF does not have Thread.IsAlive, so this flag replaces it
-        private bool threadAlive = false;
-        // Random Number Generator for OK and HELLO texts
-        private Random randomTextIndex;
-        // flag for whether the user has successfully logged in
-        private bool loggedIn = false;
-        // name of the logged in user, also used to remember the username when waiting for the PASS command
-        private string loggedInUser = null;
-        // argument of pending RNFR command, when waiting for an RNTO command
-        private string renameFromPath = null;
-
-        // remote data port. null when PASV is used.
-        private IPEndPoint dataPort = null;
-        // socket for data connections
-        private Socket dataSocket = null;
-        // .NET CF does not have Socket.Bound, so this flag replaces it
-        private bool dataSocketBound = false;
-        // buffer for reading from the control connection
-        private byte[] cmdRcvBuffer;
-        // number of bytes in the cmdRcvBuffer
-        private int cmdRcvBytes;
-        // buffer for sending/receiving with data connections
-        private byte[] dataBuffer;
-        // data type of the session, can be changed by the client
-        private DataType transferDataType = DataType.ASCII;
-
-        /// <summary>
-        /// Creates a new session, which can afterwards be started with Start().
-        /// </summary>
-        public Session(Socket socket, int bufferSize, IAuthHandler authHandler, IFileSystemHandler fileSystemHandler, ILogHandler logHandler)
-        {
-            this.controlSocket = socket;
-            this.dataBufferSize = bufferSize;
-            this.authHandler = authHandler;
-            this.fsHandler = fileSystemHandler;
-            this.logHandler = logHandler;
-
-            this.cmdRcvBuffer = new byte[CMD_BUFFER_SIZE];
-            this.cmdRcvBytes = 0;
-            this.dataBuffer = new byte[dataBufferSize + 1]; // +1 for partial EOL
-            this.randomTextIndex = new Random();
-
-            this.thread = new Thread(new ThreadStart(this.Work));
-        }
-
-        /// <summary>
-        /// Indicates whether the session is still open
-        /// </summary>
-        public bool IsOpen
-        {
-            get { return threadAlive; }
-        }
-
-        /// <summary>
-        /// Start the session in a new thread
-        /// </summary>
-        public void Start()
-        {
-            if (!threadAlive) {
-                this.thread.Start();
-                threadAlive = true;
-            }
-        }
-
-        /// <summary>
-        /// Stop the session
-        /// </summary>
-        public void Stop()
-        {
-            if (threadAlive) {
-                threadAlive = false;
-                thread.Abort();
-            }
-
-            if (controlSocket.Connected)
-                controlSocket.Close();
-
-            if (dataSocket != null && dataSocket.Connected)
-                dataSocket.Close();
-        }
-
-        /// <summary>
-        /// Main method of the session thread.
-        /// Reads commands and executes them.
-        /// </summary>
-        private void Work()
-        {
-            if (logHandler != null)
-                logHandler.NewControlConnection();
-
-            try {
-                if (!authHandler.AllowControlConnection()) {
-                    Respond(421, "Control connection refused.");
-                    // first flush, then close
-                    controlSocket.Shutdown(SocketShutdown.Both);
-                    controlSocket.Close();
-                    return;
-                }
-
-                Respond(220, String.Format("This is mooftpserv v{0}. {1}", LIB_VERSION, GetRandomText(HELLO_TEXT)));
-
-                // allow anonymous login?
-                if (authHandler.AllowLogin(null, null)) {
-                    loggedIn = true;
-                }
-
-                while (controlSocket.Connected) {
-                    string verb;
-                    string args;
-                    if (!ReadCommand(out verb, out args)) {
-                        if (controlSocket.Connected) {
-                            // assume clean disconnect if there are no buffered bytes
-                            if (cmdRcvBytes != 0)
-                                Respond(500, "Failed to read command, closing connection.");
-                            controlSocket.Close();
-                        }
-                        break;
-                    } else if (verb.Trim() == "") {
-                        // ignore empty lines
-                        continue;
-                    }
-
-                    try {
-                        if (loggedIn)
-                            ProcessCommand(verb, args);
-                        else if (verb == "QUIT") { // QUIT should always be allowed
-                            Respond(221, "Bye.");
-                            // first flush, then close
-                            controlSocket.Shutdown(SocketShutdown.Both);
-                            controlSocket.Close();
-                        } else {
-                            HandleAuth(verb, args);
-                        }
-                    } catch (Exception ex) {
-                        Respond(500, ex);
-                    }
-                }
-            } catch (Exception) {
-                // catch any uncaught stuff, the server should not throw anything
-            } finally {
-                if (controlSocket.Connected)
-                    controlSocket.Close();
-
-                if (logHandler != null)
-                    logHandler.ClosedControlConnection();
-
-                threadAlive = false;
-            }
-        }
-
-        /// <summary>
-        /// Process an FTP command.
-        /// </summary>
-        private void ProcessCommand(string verb, string arguments)
-        {
-            switch (verb) {
-                case "SYST":
-                {
-                    Respond(215, "UNIX emulated by mooftpserv");
-                    break;
-                }
-                case "QUIT":
-                {
-                    Respond(221, "Bye.");
-                    // first flush, then close
-                    controlSocket.Shutdown(SocketShutdown.Both);
-                    controlSocket.Close();
-                    break;
-                }
-                case "USER":
-                {
-                    Respond(230, "You are already logged in.");
-                    break;
-                }
-                case "PASS":
-                {
-                    Respond(230, "You are already logged in.");
-                    break;
-                }
-                case "FEAT":
-                {
-                    Respond(211, "Features:\r\n " + String.Join("\r\n ", FEATURES), true);
-                    Respond(211, "Features done.");
-                    break;
-                }
-                case "OPTS":
-                {
-                    // Windows Explorer uses lowercase args
-                    if (arguments != null && arguments.ToUpper() == "UTF8 ON")
-                        Respond(200, "Always in UTF8 mode.");
-                    else
-                        Respond(504, "Unknown option.");
-                    break;
-                }
-                case "TYPE":
-                {
-                    if (arguments == "A" || arguments == "A N") {
-                        transferDataType = DataType.ASCII;
-                        Respond(200, "Switching to ASCII mode.");
-                    } else if (arguments == "I") {
-                        transferDataType = DataType.IMAGE;
-                        Respond(200, "Switching to BINARY mode.");
-                    } else {
-                        Respond(500, "Unknown TYPE arguments.");
-                    }
-                    break;
-                }
-                case "PORT":
-                {
-                    IPEndPoint port = ParseAddress(arguments);
-                    if (port == null) {
-                        Respond(500, "Invalid host-port format.");
-                        break;
-                    }
-
-                    if (!authHandler.AllowActiveDataConnection(port)) {
-                        Respond(500, "PORT arguments refused.");
-                        break;
-                    }
-
-                    dataPort = port;
-                    CreateDataSocket(false);
-                    Respond(200, GetRandomText(OK_TEXT));
-                    break;
-                }
-                case "PASV":
-                {
-                    dataPort = null;
-
-                    try {
-                        CreateDataSocket(true);
-                    } catch (Exception ex) {
-                        Respond(500, ex);
-                        break;
-                    }
-
-                    string port = FormatAddress((IPEndPoint) dataSocket.LocalEndPoint);
-                    Respond(227, String.Format("Switched to passive mode ({0})", port));
-                    break;
-                }
-                case "XPWD":
-                case "PWD":
-                {
-                    ResultOrError<string> ret = fsHandler.GetCurrentDirectory();
-                    if (ret.HasError)
-                        Respond(500, ret.Error);
-                    else
-                        Respond(257, EscapePath(ret.Result));
-                    break;
-                }
-                case "XCWD":
-                case "CWD":
-                {
-                    ResultOrError<string> ret = fsHandler.ChangeDirectory(arguments);
-                    if (ret.HasError)
-                        Respond(550, ret.Error);
-                    else
-                        Respond(200, GetRandomText(OK_TEXT));
-                    break;
-                }
-                case "XCUP":
-                case "CDUP":
-                {
-                    ResultOrError<string> ret = fsHandler.ChangeDirectory("..");
-                    if (ret.HasError)
-                        Respond(550, ret.Error);
-                    else
-                        Respond(200, GetRandomText(OK_TEXT));
-                    break;
-                }
-                case "XMKD":
-                case "MKD":
-                {
-                    ResultOrError<string> ret = fsHandler.CreateDirectory(arguments);
-                    if (ret.HasError)
-                        Respond(550, ret.Error);
-                    else
-                        Respond(257, EscapePath(ret.Result));
-                    break;
-                }
-                case "XRMD":
-                case "RMD":
-                {
-                    ResultOrError<bool> ret = fsHandler.RemoveDirectory(arguments);
-                    if (ret.HasError)
-                        Respond(550, ret.Error);
-                    else
-                        Respond(250, GetRandomText(OK_TEXT));
-                    break;
-                }
-                case "RETR":
-                {
-                    ResultOrError<Stream> ret = fsHandler.ReadFile(arguments);
-                    if (ret.HasError) {
-                        Respond(550, ret.Error);
-                        break;
-                    }
-
-                    SendData(ret.Result);
-                    break;
-                }
-                case "STOR":
-                {
-                    ResultOrError<Stream> ret = fsHandler.WriteFile(arguments);
-                    if (ret.HasError) {
-                        Respond(550, ret.Error);
-                        break;
-                    }
+using System;

+using System.IO;

+using System.Net;

+using System.Net.Sockets;

+using System.Text;

+using System.Threading;

+

+namespace mooftpserv

+{

+    /// <summary>

+    /// FTP session/connection. Does all the heavy lifting of the FTP protocol.

+    /// Reads commands, sends replies, manages data connections, and so on.

+    /// Each session creates its own thread.

+    /// </summary>

+    class Session

+    {

+        // transfer data type, ascii or binary

+        enum DataType { ASCII, IMAGE };

+

+        // buffer size to use for reading commands from the control connection

+        private static int CMD_BUFFER_SIZE = 4096;

+        // version from AssemblyInfo

+        private static string LIB_VERSION = System.Reflection.Assembly.GetExecutingAssembly().GetName().Version.ToString(2);

+        // monthnames for LIST command, since DateTime returns localized names

+        private static string[] MONTHS = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };

+        // response text for initial response. preceeded by application name and version number.

+        private static string[] HELLO_TEXT = { "What can I do for you?", "Good day, sir or madam.", "Hey ho let's go!", "The poor man's FTP server." };

+        // response text for general ok messages

+        private static string[] OK_TEXT = { "Sounds good.", "Success!", "Alright, I'll do it...", "Consider it done." };

+        // Result for FEAT command

+        private static string[] FEATURES = { "MDTM", "PASV", "SIZE", "TVFS", "UTF8" };

+

+        // local EOL flavor

+        private static byte[] localEolBytes = Encoding.ASCII.GetBytes(Environment.NewLine);

+        // FTP-mandated EOL flavor (= CRLF)

+        private static byte[] remoteEolBytes = Encoding.ASCII.GetBytes("\r\n");

+        // on Windows, no ASCII conversion is necessary (CRLF == CRLF)

+        private static bool noAsciiConv = (localEolBytes == remoteEolBytes);

+

+        // socket for the control connection

+        private Socket controlSocket;

+        // buffer size to use for sending/receiving with data connections

+        private int dataBufferSize;

+        // auth handler, checks user credentials

+        private IAuthHandler authHandler;

+        // file system handler, implements file system access for the FTP commands

+        private IFileSystemHandler fsHandler;

+        // log handler, used for diagnostic logging output. can be null.

+        private ILogHandler logHandler;

+        // Session thread, the control and data connections are processed in this thread

+        private Thread thread;

+

+        // .NET CF does not have Thread.IsAlive, so this flag replaces it

+        private bool threadAlive = false;

+        // Random Number Generator for OK and HELLO texts

+        private Random randomTextIndex;

+        // flag for whether the user has successfully logged in

+        private bool loggedIn = false;

+        // name of the logged in user, also used to remember the username when waiting for the PASS command

+        private string loggedInUser = null;

+        // argument of pending RNFR command, when waiting for an RNTO command

+        private string renameFromPath = null;

+

+        // remote data port. null when PASV is used.

+        private IPEndPoint dataPort = null;

+        // socket for data connections

+        private Socket dataSocket = null;

+        // .NET CF does not have Socket.Bound, so this flag replaces it

+        private bool dataSocketBound = false;

+        // buffer for reading from the control connection

+        private byte[] cmdRcvBuffer;

+        // number of bytes in the cmdRcvBuffer

+        private int cmdRcvBytes;

+        // buffer for sending/receiving with data connections

+        private byte[] dataBuffer;

+        // data type of the session, can be changed by the client

+        private DataType transferDataType = DataType.ASCII;

+

+        /// <summary>

+        /// Creates a new session, which can afterwards be started with Start().

+        /// </summary>

+        public Session(Socket socket, int bufferSize, IAuthHandler authHandler, IFileSystemHandler fileSystemHandler, ILogHandler logHandler)

+        {

+            this.controlSocket = socket;

+            this.dataBufferSize = bufferSize;

+            this.authHandler = authHandler;

+            this.fsHandler = fileSystemHandler;

+            this.logHandler = logHandler;

+

+            this.cmdRcvBuffer = new byte[CMD_BUFFER_SIZE];

+            this.cmdRcvBytes = 0;

+            this.dataBuffer = new byte[dataBufferSize + 1]; // +1 for partial EOL

+            this.randomTextIndex = new Random();

+

+            this.thread = new Thread(new ThreadStart(this.Work));

+        }

+

+        /// <summary>

+        /// Indicates whether the session is still open

+        /// </summary>

+        public bool IsOpen

+        {

+            get { return threadAlive; }

+        }

+

+        /// <summary>

+        /// Start the session in a new thread

+        /// </summary>

+        public void Start()

+        {

+            if (!threadAlive) {

+                this.thread.Start();

+                threadAlive = true;

+            }

+        }

+

+        /// <summary>

+        /// Stop the session

+        /// </summary>

+        public void Stop()

+        {

+            if (threadAlive) {

+                threadAlive = false;

+                thread.Abort();

+            }

+

+            if (controlSocket.Connected)

+                controlSocket.Close();

+

+            if (dataSocket != null && dataSocket.Connected)

+                dataSocket.Close();

+        }

+

+        /// <summary>

+        /// Main method of the session thread.

+        /// Reads commands and executes them.

+        /// </summary>

+        private void Work()

+        {

+            if (logHandler != null)

+                logHandler.NewControlConnection();

+

+            try {

+                if (!authHandler.AllowControlConnection()) {

+                    Respond(421, "Control connection refused.");

+                    // first flush, then close

+                    controlSocket.Shutdown(SocketShutdown.Both);

+                    controlSocket.Close();

+                    return;

+                }

+

+                Respond(220, String.Format("This is mooftpserv v{0}. {1}", LIB_VERSION, GetRandomText(HELLO_TEXT)));

+

+                // allow anonymous login?

+                if (authHandler.AllowLogin(null, null)) {

+                    loggedIn = true;

+                }

+

+                while (controlSocket.Connected) {

+                    string verb;

+                    string args;

+                    if (!ReadCommand(out verb, out args)) {

+                        if (controlSocket.Connected) {

+                            // assume clean disconnect if there are no buffered bytes

+                            if (cmdRcvBytes != 0)

+                                Respond(500, "Failed to read command, closing connection.");

+                            controlSocket.Close();

+                        }

+                        break;

+                    } else if (verb.Trim() == "") {

+                        // ignore empty lines

+                        continue;

+                    }

+

+                    try {

+                        if (loggedIn)

+                            ProcessCommand(verb, args);

+                        else if (verb == "QUIT") { // QUIT should always be allowed

+                            Respond(221, "Bye.");

+                            // first flush, then close

+                            controlSocket.Shutdown(SocketShutdown.Both);

+                            controlSocket.Close();

+                        } else {

+                            HandleAuth(verb, args);

+                        }

+                    } catch (Exception ex) {

+                        Respond(500, ex);

+                    }

+                }

+            } catch (Exception) {

+                // catch any uncaught stuff, the server should not throw anything

+            } finally {

+                if (controlSocket.Connected)

+                    controlSocket.Close();

+

+                if (logHandler != null)

+                    logHandler.ClosedControlConnection();

+

+                threadAlive = false;

+            }

+        }

+

+        /// <summary>

+        /// Process an FTP command.

+        /// </summary>

+        private void ProcessCommand(string verb, string arguments)

+        {

+            switch (verb) {

+                case "SYST":

+                {

+                    Respond(215, "UNIX emulated by mooftpserv");

+                    break;

+                }

+                case "QUIT":

+                {

+                    Respond(221, "Bye.");

+                    // first flush, then close

+                    controlSocket.Shutdown(SocketShutdown.Both);

+                    controlSocket.Close();

+                    break;

+                }

+                case "USER":

+                {

+                    Respond(230, "You are already logged in.");

+                    break;

+                }

+                case "PASS":

+                {

+                    Respond(230, "You are already logged in.");

+                    break;

+                }

+                case "FEAT":

+                {

+                    Respond(211, "Features:\r\n " + String.Join("\r\n ", FEATURES), true);

+                    Respond(211, "Features done.");

+                    break;

+                }

+                case "OPTS":

+                {

+                    // Windows Explorer uses lowercase args

+                    if (arguments != null && arguments.ToUpper() == "UTF8 ON")

+                        Respond(200, "Always in UTF8 mode.");

+                    else

+                        Respond(504, "Unknown option.");

+                    break;

+                }

+                case "TYPE":

+                {

+                    if (arguments == "A" || arguments == "A N") {

+                        transferDataType = DataType.ASCII;

+                        Respond(200, "Switching to ASCII mode.");

+                    } else if (arguments == "I") {

+                        transferDataType = DataType.IMAGE;

+                        Respond(200, "Switching to BINARY mode.");

+                    } else {

+                        Respond(500, "Unknown TYPE arguments.");

+                    }

+                    break;

+                }

+                case "PORT":

+                {

+                    IPEndPoint port = ParseAddress(arguments);

+                    if (port == null) {

+                        Respond(500, "Invalid host-port format.");

+                        break;

+                    }

+

+                    if (!authHandler.AllowActiveDataConnection(port)) {

+                        Respond(500, "PORT arguments refused.");

+                        break;

+                    }

+

+                    dataPort = port;

+                    CreateDataSocket(false);

+                    Respond(200, GetRandomText(OK_TEXT));

+                    break;

+                }

+                case "PASV":

+                {

+                    dataPort = null;

+

+                    try {

+                        CreateDataSocket(true);

+                    } catch (Exception ex) {

+                        Respond(500, ex);

+                        break;

+                    }

+

+                    string port = FormatAddress((IPEndPoint) dataSocket.LocalEndPoint);

+                    Respond(227, String.Format("Switched to passive mode ({0})", port));

+                    break;

+                }

+                case "XPWD":

+                case "PWD":

+                {

+                    ResultOrError<string> ret = fsHandler.GetCurrentDirectory();

+                    if (ret.HasError)

+                        Respond(500, ret.Error);

+                    else

+                        Respond(257, EscapePath(ret.Result));

+                    break;

+                }

+                case "XCWD":

+                case "CWD":

+                {

+                    ResultOrError<string> ret = fsHandler.ChangeDirectory(arguments);

+                    if (ret.HasError)

+                        Respond(550, ret.Error);

+                    else

+                        Respond(200, GetRandomText(OK_TEXT));

+                    break;

+                }

+                case "XCUP":

+                case "CDUP":

+                {

+                    ResultOrError<string> ret = fsHandler.ChangeDirectory("..");

+                    if (ret.HasError)

+                        Respond(550, ret.Error);

+                    else

+                        Respond(200, GetRandomText(OK_TEXT));

+                    break;

+                }

+                case "XMKD":

+                case "MKD":

+                {

+                    ResultOrError<string> ret = fsHandler.CreateDirectory(arguments);

+                    if (ret.HasError)

+                        Respond(550, ret.Error);

+                    else

+                        Respond(257, EscapePath(ret.Result));

+                    break;

+                }

+                case "XRMD":

+                case "RMD":

+                {

+                    ResultOrError<bool> ret = fsHandler.RemoveDirectory(arguments);

+                    if (ret.HasError)

+                        Respond(550, ret.Error);

+                    else

+                        Respond(250, GetRandomText(OK_TEXT));

+                    break;

+                }

+                case "RETR":

+                {

+                    ResultOrError<Stream> ret = fsHandler.ReadFile(arguments);

+                    if (ret.HasError) {

+                        Respond(550, ret.Error);

+                        break;

+                    }

+

+                    SendData(ret.Result);

+                    break;

+                }

+                case "STOR":

+                {

+                    ResultOrError<Stream> ret = fsHandler.WriteFile(arguments);

+                    if (ret.HasError) {

+                        Respond(550, ret.Error);

+                        break;

+                    }

                     ReceiveData(ret.Result);

-                    var ret2 = fsHandler.WriteFileFinalize(arguments, ret.Result);
+                    var ret2 = fsHandler.WriteFileFinalize(arguments, ret.Result);

                     if (ret2.HasError)

                     {

                         Respond(550, ret.Error);

-                        break;
-                    }
-                    break;
-                }
-                case "DELE":
-                {
-                    ResultOrError<bool> ret = fsHandler.RemoveFile(arguments);
-                    if (ret.HasError)
-                        Respond(550, ret.Error);
-                    else
-                        Respond(250, GetRandomText(OK_TEXT));
-                    break;
-                }
-                case "RNFR":
-                {
-                    if (arguments == null || arguments.Trim() == "") {
-                        Respond(500, "Empty path is invalid.");
-                        break;
-                    }
-
-                    renameFromPath = arguments;
-                    Respond(350, "Waiting for target path.");
-                    break;
-                }
-                case "RNTO":
-                {
-                    if (renameFromPath == null) {
-                        Respond(503, "Use RNFR before RNTO.");
-                        break;
-                    }
-
-                    ResultOrError<bool> ret = fsHandler.RenameFile(renameFromPath, arguments);
-                    renameFromPath = null;
-                    if (ret.HasError)
-                        Respond(550, ret.Error);
-                    else
-                        Respond(250, GetRandomText(OK_TEXT));
-                    break;
-                }
-                case "MDTM":
-                {
-                    ResultOrError<DateTime> ret = fsHandler.GetLastModifiedTimeUtc(arguments);
-                    if (ret.HasError)
-                        Respond(550, ret.Error);
-                    else
-                        Respond(213, FormatTime(EnsureUnixTime(ret.Result)));
-                    break;
-                }
-                case "SIZE":
-                {
-                    ResultOrError<long> ret = fsHandler.GetFileSize(arguments);
-                    if (ret.HasError)
-                        Respond(550, ret.Error);
-                    else
-                        Respond(213, ret.Result.ToString());
-                    break;
-                }
-                case "LIST":
-                {
-                    // apparently browsers like to pass arguments to LIST
-                    // assuming they are passed through to the UNIX ls command
-                    arguments = RemoveLsArgs(arguments);
-
-                    ResultOrError<FileSystemEntry[]> ret = fsHandler.ListEntries(arguments);
-                    if (ret.HasError) {
-                        Respond(500, ret.Error);
-                        break;
-                    }
-
-                    SendData(MakeStream(FormatDirList(ret.Result)));
-                    break;
-                }
-                case "STAT":
-                {
-                    if (arguments == null || arguments.Trim() == "") {
-                        Respond(504, "Not implemented for these arguments.");
-                        break;
-                    }
-
-                    arguments = RemoveLsArgs(arguments);
-
-                    ResultOrError<FileSystemEntry[]> ret = fsHandler.ListEntries(arguments);
-                    if (ret.HasError) {
-                        Respond(500, ret.Error);
-                        break;
-                    }
-
-                    Respond(213, "Status:\r\n" + FormatDirList(ret.Result), true);
-                    Respond(213, "Status done.");
-                    break;
-                }
-                case "NLST":
-                {
-                    // remove common arguments, we do not support any of them
-                    arguments = RemoveLsArgs(arguments);
-
-                    ResultOrError<FileSystemEntry[]> ret = fsHandler.ListEntries(arguments);
-                    if (ret.HasError)
-                    {
-                        Respond(500, ret.Error);
-                        break;
-                    }
-
-                    SendData(MakeStream(FormatNLST(ret.Result)));
-                    break;
-                }
-                case "NOOP":
-                {
-                    Respond(200, GetRandomText(OK_TEXT));
-                    break;
-                }
-                default:
-                {
-                    Respond(500, "Unknown command.");
-                    break;
-                }
-            }
-        }
-
-        /// <summary>
-        /// Read a command from the control connection.
-        /// </summary>
-        /// <returns>
-        /// True if a command was read.
-        /// </returns>
-        /// <param name='verb'>
-        /// Will receive the verb of the command.
-        /// </param>
-        /// <param name='args'>
-        /// Will receive the arguments of the command, or null.
-        /// </param>
-        private bool ReadCommand(out string verb, out string args)
-        {
-            verb = null;
-            args = null;
-
-            int endPos = -1;
-            // can there already be a command in the buffer?
-            if (cmdRcvBytes > 0)
-                Array.IndexOf(cmdRcvBuffer, (byte)'\n', 0, cmdRcvBytes);
-
-            try {
-                // read data until a newline is found
-                do {
-                    int freeBytes = cmdRcvBuffer.Length - cmdRcvBytes;
-                    int bytes = controlSocket.Receive(cmdRcvBuffer, cmdRcvBytes, freeBytes, SocketFlags.None);
-                    if (bytes <= 0)
-                        break;
-
-                    cmdRcvBytes += bytes;
-
-                    // search \r\n
-                    endPos = Array.IndexOf(cmdRcvBuffer, (byte)'\r', 0, cmdRcvBytes);
-                    if (endPos != -1 && (cmdRcvBytes <= endPos + 1 || cmdRcvBuffer[endPos + 1] != (byte)'\n'))
-                        endPos = -1;
-                } while (endPos == -1 && cmdRcvBytes < cmdRcvBuffer.Length);
-            } catch (SocketException) {
-                // in case the socket is closed or has some other error while reading
-                return false;
-            }
-
-            if (endPos == -1)
-                return false;
-
-            string command = DecodeString(cmdRcvBuffer, endPos);
-
-            // remove the command from the buffer
-            cmdRcvBytes -= (endPos + 2);
-            Array.Copy(cmdRcvBuffer, endPos + 2, cmdRcvBuffer, 0, cmdRcvBytes);
-
-            // CF is missing a limited String.Split
-            string[] tokens = command.Split(' ');
-            verb = tokens[0].ToUpper(); // commands are case insensitive
-            args = (tokens.Length > 1 ? String.Join(" ", tokens, 1, tokens.Length - 1) : null);
-
-            if (logHandler != null)
-                logHandler.ReceivedCommand(verb, args);
-
-            return true;
-        }
-
-        /// <summary>
-        /// Send a response on the control connection
-        /// </summary>
-        private void Respond(uint code, string desc, bool moreFollows)
-        {
-            string response = code.ToString();
-            if (desc != null)
-                response += (moreFollows ? '-' : ' ') + desc;
-
-            if (!response.EndsWith("\r\n"))
-                response += "\r\n";
-
-            byte[] sendBuffer = EncodeString(response);
-            controlSocket.Send(sendBuffer);
-
-            if (logHandler != null)
-                logHandler.SentResponse(code, desc);
-        }
-
-        /// <summary>
-        /// Send a response on the control connection
-        /// </summary>
-        private void Respond(uint code, string desc)
-        {
-            Respond(code, desc, false);
-        }
-
-        /// <summary>
-        /// Send a response on the control connection, with an exception as text
-        /// </summary>
-        private void Respond(uint code, Exception ex)
-        {
-            Respond(code, ex.Message.Replace(Environment.NewLine, " "));
-        }
-
-        /// <summary>
-        /// Process FTP commands when the user is not yet logged in.
-        /// Mostly handles the login commands USER and PASS.
-        /// </summary>
-        private void HandleAuth(string verb, string args)
-        {
-            if (verb == "USER" && args != null) {
-                if (authHandler.AllowLogin(args, null)) {
-                    Respond(230, "Login successful.");
-                    loggedIn = true;
-                } else {
-                    loggedInUser = args;
-                    Respond(331, "Password please.");
-                }
-            } else if (verb == "PASS") {
-                if (loggedInUser != null) {
-                    if (authHandler.AllowLogin(loggedInUser, args)) {
-                        Respond(230, "Login successful.");
-                        loggedIn = true;
-                    } else {
-                        loggedInUser = null;
-                        Respond(530, "Login failed, please try again.");
-                    }
-                } else {
-                    Respond(530, "No USER specified.");
-                }
-            } else {
-                Respond(530, "Please login first.");
-            }
-        }
-
-        /// <summary>
-        /// Read from the given stream and send the data over a data connection
-        /// </summary>
-        private void SendData(Stream stream)
-        {
-            try {
-                bool passive = (dataPort == null);
-                using (Socket socket = OpenDataConnection()) {
-                    if (socket == null)
-                        return;
-
-                    IPEndPoint remote = (IPEndPoint) socket.RemoteEndPoint;
-                    IPEndPoint local = (IPEndPoint) socket.LocalEndPoint;
-
-                    if (logHandler != null)
-                        logHandler.NewDataConnection(remote, local, passive);
-
-                    try {
-                        while (true) {
-                            int bytes = stream.Read(dataBuffer, 0, dataBufferSize);
-                            if (bytes <= 0) {
-                                break;
-                            }
-
-                            if (transferDataType == DataType.IMAGE || noAsciiConv) {
-                                // TYPE I -> just pass through
-                                socket.Send(dataBuffer, bytes, SocketFlags.None);
-                            } else {
-                                // TYPE A -> convert local EOL style to CRLF
-
-                                // if the buffer ends with a potential partial EOL,
-                                // try to read the rest of the EOL
-                                // (i assume that the EOL has max. two bytes)
-                                if (localEolBytes.Length == 2 &&
-                                    dataBuffer[bytes - 1] == localEolBytes[0]) {
-                                    if (stream.Read(dataBuffer, bytes, 1) == 1)
-                                        ++bytes;
-                                }
-
-                                byte[] convBuffer = null;
-                                int convBytes = ConvertAsciiBytes(dataBuffer, bytes, true, out convBuffer);
-                                socket.Send(convBuffer, convBytes, SocketFlags.None);
-                            }
-                        }
-
-                        // flush socket before closing (done by using-statement)
-                        socket.Shutdown(SocketShutdown.Send);
-                        Respond(226, "Transfer complete.");
-                    } catch (Exception ex) {
-                        Respond(500, ex);
-                        return;
-                    } finally {
-                        if (logHandler != null)
-                            logHandler.ClosedDataConnection(remote, local, passive);
-                    }
-                }
-            } finally {
-                stream.Close();
-            }
-        }
-
-        /// <summary>
-        /// Read from a data connection and write to the given stream
-        /// </summary>
-        private void ReceiveData(Stream stream)
-        {
-            try {
-                bool passive = (dataPort == null);
-                using (Socket socket = OpenDataConnection()) {
-                    if (socket == null)
-                        return;
-
-                    IPEndPoint remote = (IPEndPoint) socket.RemoteEndPoint;
-                    IPEndPoint local = (IPEndPoint) socket.LocalEndPoint;
-
-                    if (logHandler != null)
-                        logHandler.NewDataConnection(remote, local, passive);
-
-                    try {
-                        while (true) {
-                            // fill up the in-memory buffer before writing to disk
-                            int totalBytes = 0;
-                            while (totalBytes < dataBufferSize) {
-                                int freeBytes = dataBufferSize - totalBytes;
-                                int newBytes = socket.Receive(dataBuffer, totalBytes, freeBytes, SocketFlags.None);
-
-                                if (newBytes > 0) {
-                                    totalBytes += newBytes;
-                                } else if (newBytes < 0) {
-                                    Respond(500, String.Format("Transfer failed: Receive() returned {0}", newBytes));
-                                    return;
-                                } else {
-                                    // end of data
-                                    break;
-                                }
-                            }
-
-                            // end of data
-                            if (totalBytes == 0)
-                                break;
-
-                            if (transferDataType == DataType.IMAGE || noAsciiConv) {
-                                // TYPE I -> just pass through
-                                stream.Write(dataBuffer, 0, totalBytes);
-                            } else {
-                                // TYPE A -> convert CRLF to local EOL style
-
-                                // if the buffer ends with a potential partial CRLF,
-                                // try to read the LF
-                                if (dataBuffer[totalBytes - 1] == remoteEolBytes[0]) {
-                                    if (socket.Receive(dataBuffer, totalBytes, 1, SocketFlags.None) == 1)
-                                        ++totalBytes;
-                                }
-
-                                byte[] convBuffer = null;
-                                int convBytes = ConvertAsciiBytes(dataBuffer, totalBytes, false, out convBuffer);
-                                stream.Write(convBuffer, 0, convBytes);
-                            }
-                        }
-
-                        socket.Shutdown(SocketShutdown.Receive);
-                        Respond(226, "Transfer complete.");
-                    } catch (Exception ex) {
-                        Respond(500, ex);
-                        return;
-                    } finally {
-                        if (logHandler != null)
-                            logHandler.ClosedDataConnection(remote, local, passive);
-                    }
-                }
-            } finally {
-                //stream.Close();
-            }
-        }
-
-        /// <summary>
-        /// Create a socket for a data connection.
-        /// </summary>
-        /// <param name='listen'>
-        /// If true, the socket will be bound to a local port for the PASV command.
-        /// Otherwise the socket can be used for connecting to the address given in a PORT command.
-        /// </param>
-        private void CreateDataSocket(bool listen)
-        {
-            if (dataSocket != null)
-                dataSocket.Close();
-
-            dataSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
-
-            if (listen) {
-                IPAddress serverIP = ((IPEndPoint) controlSocket.LocalEndPoint).Address;
-                dataSocket.Bind(new IPEndPoint(serverIP, 0));
-                dataSocketBound = true; // CF is missing Socket.IsBound
-                dataSocket.Listen(1);
-            }
-        }
-
-        /// <summary>
-        /// Opens an active or passive data connection and returns the socket
-        /// or null if there was no preceding PORT or PASV command or in case or error.
-        /// </summary>
-        private Socket OpenDataConnection()
-        {
-            if (dataPort == null && !dataSocketBound) {
-                Respond(425, "No data port configured, use PORT or PASV.");
-                return null;
-            }
-
-            Respond(150, "Opening data connection.");
-
-            try {
-                if (dataPort != null) {
-                    // active mode
-                    dataSocket.Connect(dataPort);
-                    dataPort = null;
-                    return dataSocket;
-                } else {
-                    // passive mode
-                    Socket socket = dataSocket.Accept();
-                    dataSocket.Close();
-                    dataSocketBound = false;
-                    return socket;
-                }
-            } catch (Exception ex) {
-                Respond(500, String.Format("Failed to open data connection: {0}", ex.Message.Replace(Environment.NewLine, " ")));
-                return null;
-            }
-        }
-
-        /// <summary>
-        /// Convert between different EOL flavors.
-        /// </summary>
-        /// <returns>
-        /// The number of bytes in the resultBuffer.
-        /// </returns>
-        /// <param name='buffer'>
-        /// The input buffer whose data will be converted.
-        /// </param>
-        /// <param name='len'>
-        /// The number of bytes in the input buffer.
-        /// </param>
-        /// <param name='localToRemote'>
-        /// If true, the conversion will be made from local to FTP flavor,
-        /// otherwise from FTP to local flavor.
-        /// </param>
-        /// <param name='resultBuffer'>
-        /// The resulting buffer with the converted text.
-        /// Can be the same reference as the input buffer if there is nothing to convert.
-        /// </param>
-        private int ConvertAsciiBytes(byte[] buffer, int len, bool localToRemote, out byte[] resultBuffer)
-        {
-            byte[] fromBytes = (localToRemote ? localEolBytes : remoteEolBytes);
-            byte[] toBytes = (localToRemote ? remoteEolBytes : localEolBytes);
-            resultBuffer = null;
-
-            int startIndex = 0;
-            int resultLen = 0;
-            int searchLen;
-            while ((searchLen = len - startIndex) > 0) {
-                // search for the first byte of the EOL sequence
-                int eolIndex = Array.IndexOf(buffer, fromBytes[0], startIndex, searchLen);
-
-                // shortcut if there is no EOL in the whole buffer
-                if (eolIndex == -1 && startIndex == 0) {
-                    resultBuffer = buffer;
-                    return len;
-                }
-
-                // allocate to worst-case size
-                if (resultBuffer == null)
-                    resultBuffer = new byte[len * 2];
-
-                if (eolIndex == -1) {
-                    Array.Copy(buffer, startIndex, resultBuffer, resultLen, searchLen);
-                    resultLen += searchLen;
-                    break;
-                } else {
-                    // compare the rest of the EOL
-                    int matchBytes = 1;
-                    for (int i = 1; i < fromBytes.Length && eolIndex + i < len; ++i) {
-                        if (buffer[eolIndex + i] == fromBytes[i])
-                            ++matchBytes;
-                    }
-
-                    if (matchBytes == fromBytes.Length) {
-                        // found an EOL to convert
-                        int copyLen = eolIndex - startIndex;
-                        if (copyLen > 0) {
-                            Array.Copy(buffer, startIndex, resultBuffer, resultLen, copyLen);
-                            resultLen += copyLen;
-                        }
-                        Array.Copy(toBytes, 0, resultBuffer, resultLen, toBytes.Length);
-                        resultLen += toBytes.Length;
-                        startIndex += copyLen + fromBytes.Length;
-                    } else {
-                        int copyLen = (eolIndex - startIndex) + 1;
-                        Array.Copy(buffer, startIndex, resultBuffer, resultLen, copyLen);
-                        resultLen += copyLen;
-                        startIndex += copyLen;
-                    }
-                }
-            }
-
-            return resultLen;
-        }
-
-        /// <summary>
-        /// Parse the argument of a PORT command into an IPEndPoint
-        /// </summary>
-        private IPEndPoint ParseAddress(string address)
-        {
-            string[] tokens = address.Split(',');
-            byte[] bytes = new byte[tokens.Length];
-            for (int i = 0; i < tokens.Length; ++i) {
-                try {
-                    // CF is missing TryParse
-                    bytes[i] = byte.Parse(tokens[i]);
-                } catch (Exception) {
-                    return null;
-                }
-            }
-
-            long ip = bytes[0] | bytes[1] << 8 | bytes[2] << 16 | bytes[3] << 24;
-            int port = bytes[4] << 8 | bytes[5];
-            return new IPEndPoint(ip, port);
-        }
-
-        /// <summary>
-        /// Format an IPEndPoint so that it can be used in a response for a PASV command
-        /// </summary>
-        private string FormatAddress(IPEndPoint address)
-        {
-            byte[] ip = address.Address.GetAddressBytes();
-            int port = address.Port;
-
-            return String.Format("{0},{1},{2},{3},{4},{5}",
-                                 ip[0], ip[1], ip[2], ip[3],
-                                 (port & 0xFF00) >> 8, port & 0x00FF);
-        }
-
-        /// <summary>
-        /// Formats a list of file system entries for a response to a LIST or STAT command
-        /// </summary>
-        private string FormatDirList(FileSystemEntry[] list)
-        {
-            int maxSizeChars = 0;
-            foreach (FileSystemEntry entry in list) {
-                maxSizeChars = Math.Max(maxSizeChars, entry.Size.ToString().Length);
-            }
-
-            DateTime sixMonthsAgo = EnsureUnixTime(DateTime.Now.ToUniversalTime().AddMonths(-6));
-
-            StringBuilder result = new StringBuilder();
-            foreach (FileSystemEntry entry in list) {
-                char dirflag = (entry.IsDirectory ? 'd' : '-');
-                string size = entry.Size.ToString().PadLeft(maxSizeChars);
-                DateTime time = EnsureUnixTime(entry.LastModifiedTimeUtc);
-                string timestr = MONTHS[time.Month - 1];
-                if (time < sixMonthsAgo)
-                    timestr += time.ToString(" dd  yyyy");
-                else
-                    timestr += time.ToString(" dd hh:mm");
-
-                result.AppendFormat("{0}rwxr--r-- 1 owner group {1} {2} {3}\r\n",
-                                    dirflag, size, timestr, entry.Name);
-            }
-
-            return result.ToString();
-        }
-
-        /// <summary>
-        /// Formats a list of file system entries for a response to an NLST command
-        /// </summary>
-        private string FormatNLST(FileSystemEntry[] list)
-        {
-            StringBuilder sb = new StringBuilder();
-            foreach (FileSystemEntry entry in list) {
-                sb.Append(entry.Name);
-                sb.Append("\r\n");
-            }
-            return sb.ToString();
-        }
-
-        /// <summary>
-        /// Format a timestamp for a reponse to a MDTM command
-        /// </summary>
-        private string FormatTime(DateTime time)
-        {
-            return time.ToString("yyyyMMddHHmmss");
-        }
-
-        /// <summary>
-        /// Restrict the year in a timestamp to >= 1970
-        /// </summary>
-        private DateTime EnsureUnixTime(DateTime time)
-        {
-            // the server claims to be UNIX, so there should be
-            // no timestamps before 1970.
-            // e.g. FileZilla does not handle them correctly.
-
-            int yearDiff = time.Year - 1970;
-            if (yearDiff < 0)
-              return time.AddYears(-yearDiff);
-            else
-              return time;
-        }
-
-        /// <summary>
-        /// Escape a path for a response to a PWD command
-        /// </summary>
-        private string EscapePath(string path)
-        {
-            // double-quotes in paths are escaped by doubling them
-            return '"' + path.Replace("\"", "\"\"") + '"';
-        }
-
-        /// <summary>
-        /// Remove "-a" or "-l" from the arguments for a LIST or STAT command
-        /// </summary>
-        private string RemoveLsArgs(string args)
-        {
-            if (args != null && (args.StartsWith("-a") || args.StartsWith("-l"))) {
-                if (args.Length == 2)
-                    return null;
-                else if (args.Length > 3 && args[2] == ' ')
-                    return args.Substring(3);
-            }
-
-            return args;
-        }
-
-        /// <summary>
-        /// Convert a string to a list of UTF8 bytes
-        /// </summary>
-        private byte[] EncodeString(string data)
-        {
-            return Encoding.UTF8.GetBytes(data);
-        }
-
-        /// <summary>
-        /// Convert a list of UTF8 bytes to a string
-        /// </summary>
-        private string DecodeString(byte[] data, int len)
-        {
-            return Encoding.UTF8.GetString(data, 0, len);
-        }
-
-        /// <summary>
-        /// Convert a list of UTF8 bytes to a string
-        /// </summary>
-        private string DecodeString(byte[] data)
-        {
-            return DecodeString(data, data.Length);
-        }
-
-        /// <summary>
-        /// Fill a stream with the given string as UTF8 bytes
-        /// </summary>
-        private Stream MakeStream(string data)
-        {
-            return new MemoryStream(EncodeString(data));
-        }
-
-        /// <summary>
-        /// Return a randomly selected text from the given list
-        /// </summary>
-        private string GetRandomText(string[] texts)
-        {
-            int index = randomTextIndex.Next(0, texts.Length);
-            return texts[index];
-        }
-    }
-}
+                        break;

+                    }

+                    break;

+                }

+                case "DELE":

+                {

+                    ResultOrError<bool> ret = fsHandler.RemoveFile(arguments);

+                    if (ret.HasError)

+                        Respond(550, ret.Error);

+                    else

+                        Respond(250, GetRandomText(OK_TEXT));

+                    break;

+                }

+                case "RNFR":

+                {

+                    if (arguments == null || arguments.Trim() == "") {

+                        Respond(500, "Empty path is invalid.");

+                        break;

+                    }

+

+                    renameFromPath = arguments;

+                    Respond(350, "Waiting for target path.");

+                    break;

+                }

+                case "RNTO":

+                {

+                    if (renameFromPath == null) {

+                        Respond(503, "Use RNFR before RNTO.");

+                        break;

+                    }

+

+                    ResultOrError<bool> ret = fsHandler.RenameFile(renameFromPath, arguments);

+                    renameFromPath = null;

+                    if (ret.HasError)

+                        Respond(550, ret.Error);

+                    else

+                        Respond(250, GetRandomText(OK_TEXT));

+                    break;

+                }

+                case "MDTM":

+                {

+                    ResultOrError<DateTime> ret = fsHandler.GetLastModifiedTimeUtc(arguments);

+                    if (ret.HasError)

+                        Respond(550, ret.Error);

+                    else

+                        Respond(213, FormatTime(EnsureUnixTime(ret.Result)));

+                    break;

+                }

+                case "SIZE":

+                {

+                    ResultOrError<long> ret = fsHandler.GetFileSize(arguments);

+                    if (ret.HasError)

+                        Respond(550, ret.Error);

+                    else

+                        Respond(213, ret.Result.ToString());

+                    break;

+                }

+                case "LIST":

+                {

+                    // apparently browsers like to pass arguments to LIST

+                    // assuming they are passed through to the UNIX ls command

+                    arguments = RemoveLsArgs(arguments);

+

+                    ResultOrError<FileSystemEntry[]> ret = fsHandler.ListEntries(arguments);

+                    if (ret.HasError) {

+                        Respond(500, ret.Error);

+                        break;

+                    }

+

+                    SendData(MakeStream(FormatDirList(ret.Result)));

+                    break;

+                }

+                case "STAT":

+                {

+                    if (arguments == null || arguments.Trim() == "") {

+                        Respond(504, "Not implemented for these arguments.");

+                        break;

+                    }

+

+                    arguments = RemoveLsArgs(arguments);

+

+                    ResultOrError<FileSystemEntry[]> ret = fsHandler.ListEntries(arguments);

+                    if (ret.HasError) {

+                        Respond(500, ret.Error);

+                        break;

+                    }

+

+                    Respond(213, "Status:\r\n" + FormatDirList(ret.Result), true);

+                    Respond(213, "Status done.");

+                    break;

+                }

+                case "NLST":

+                {

+                    // remove common arguments, we do not support any of them

+                    arguments = RemoveLsArgs(arguments);

+

+                    ResultOrError<FileSystemEntry[]> ret = fsHandler.ListEntries(arguments);

+                    if (ret.HasError)

+                    {

+                        Respond(500, ret.Error);

+                        break;

+                    }

+

+                    SendData(MakeStream(FormatNLST(ret.Result)));

+                    break;

+                }

+                case "NOOP":

+                {

+                    Respond(200, GetRandomText(OK_TEXT));

+                    break;

+                }

+                case "SITE":

+                {

+                    string[] tokens = arguments.Split(' ');

+                    var newverb = tokens[0].ToUpper(); // commands are case insensitive

+                    var newargs = (tokens.Length > 1 ? String.Join(" ", tokens, 1, tokens.Length - 1) : null);

+                    ProcessCommand(newverb, newargs);

+                    break;

+                }

+                case "CHMOD":

+                {

+                    string[] tokens = arguments.Split(' ');

+                    var mode = tokens[0].ToUpper(); // commands are case insensitive

+                    var file = (tokens.Length > 1 ? String.Join(" ", tokens, 1, tokens.Length - 1) : "");

+                    ResultOrError<bool> ret = fsHandler.ChmodFile(mode, file);

+                    if (ret.HasError)

+                        Respond(550, ret.Error);

+                    else

+                        Respond(250, GetRandomText(OK_TEXT));

+                    break;

+                }

+                default:

+                {

+                    Respond(500, "Unknown command.");

+                    break;

+                }

+            }

+        }

+

+        /// <summary>

+        /// Read a command from the control connection.

+        /// </summary>

+        /// <returns>

+        /// True if a command was read.

+        /// </returns>

+        /// <param name='verb'>

+        /// Will receive the verb of the command.

+        /// </param>

+        /// <param name='args'>

+        /// Will receive the arguments of the command, or null.

+        /// </param>

+        private bool ReadCommand(out string verb, out string args)

+        {

+            verb = null;

+            args = null;

+

+            int endPos = -1;

+            // can there already be a command in the buffer?

+            if (cmdRcvBytes > 0)

+                Array.IndexOf(cmdRcvBuffer, (byte)'\n', 0, cmdRcvBytes);

+

+            try {

+                // read data until a newline is found

+                do {

+                    int freeBytes = cmdRcvBuffer.Length - cmdRcvBytes;

+                    int bytes = controlSocket.Receive(cmdRcvBuffer, cmdRcvBytes, freeBytes, SocketFlags.None);

+                    if (bytes <= 0)

+                        break;

+

+                    cmdRcvBytes += bytes;

+

+                    // search \r\n

+                    endPos = Array.IndexOf(cmdRcvBuffer, (byte)'\r', 0, cmdRcvBytes);

+                    if (endPos != -1 && (cmdRcvBytes <= endPos + 1 || cmdRcvBuffer[endPos + 1] != (byte)'\n'))

+                        endPos = -1;

+                } while (endPos == -1 && cmdRcvBytes < cmdRcvBuffer.Length);

+            } catch (SocketException) {

+                // in case the socket is closed or has some other error while reading

+                return false;

+            }

+

+            if (endPos == -1)

+                return false;

+

+            string command = DecodeString(cmdRcvBuffer, endPos);

+

+            // remove the command from the buffer

+            cmdRcvBytes -= (endPos + 2);

+            Array.Copy(cmdRcvBuffer, endPos + 2, cmdRcvBuffer, 0, cmdRcvBytes);

+

+            // CF is missing a limited String.Split

+            string[] tokens = command.Split(' ');

+            verb = tokens[0].ToUpper(); // commands are case insensitive

+            args = (tokens.Length > 1 ? String.Join(" ", tokens, 1, tokens.Length - 1) : null);

+

+            if (logHandler != null)

+                logHandler.ReceivedCommand(verb, args);

+

+            return true;

+        }

+

+        /// <summary>

+        /// Send a response on the control connection

+        /// </summary>

+        private void Respond(uint code, string desc, bool moreFollows)

+        {

+            string response = code.ToString();

+            if (desc != null)

+                response += (moreFollows ? '-' : ' ') + desc;

+

+            if (!response.EndsWith("\r\n"))

+                response += "\r\n";

+

+            byte[] sendBuffer = EncodeString(response);

+            controlSocket.Send(sendBuffer);

+

+            if (logHandler != null)

+                logHandler.SentResponse(code, desc);

+        }

+

+        /// <summary>

+        /// Send a response on the control connection

+        /// </summary>

+        private void Respond(uint code, string desc)

+        {

+            Respond(code, desc, false);

+        }

+

+        /// <summary>

+        /// Send a response on the control connection, with an exception as text

+        /// </summary>

+        private void Respond(uint code, Exception ex)

+        {

+            Respond(code, ex.Message.Replace(Environment.NewLine, " "));

+        }

+

+        /// <summary>

+        /// Process FTP commands when the user is not yet logged in.

+        /// Mostly handles the login commands USER and PASS.

+        /// </summary>

+        private void HandleAuth(string verb, string args)

+        {

+            if (verb == "USER" && args != null) {

+                if (authHandler.AllowLogin(args, null)) {

+                    Respond(230, "Login successful.");

+                    loggedIn = true;

+                } else {

+                    loggedInUser = args;

+                    Respond(331, "Password please.");

+                }

+            } else if (verb == "PASS") {

+                if (loggedInUser != null) {

+                    if (authHandler.AllowLogin(loggedInUser, args)) {

+                        Respond(230, "Login successful.");

+                        loggedIn = true;

+                    } else {

+                        loggedInUser = null;

+                        Respond(530, "Login failed, please try again.");

+                    }

+                } else {

+                    Respond(530, "No USER specified.");

+                }

+            } else {

+                Respond(530, "Please login first.");

+            }

+        }

+

+        /// <summary>

+        /// Read from the given stream and send the data over a data connection

+        /// </summary>

+        private void SendData(Stream stream)

+        {

+            try {

+                bool passive = (dataPort == null);

+                using (Socket socket = OpenDataConnection()) {

+                    if (socket == null)

+                        return;

+

+                    IPEndPoint remote = (IPEndPoint) socket.RemoteEndPoint;

+                    IPEndPoint local = (IPEndPoint) socket.LocalEndPoint;

+

+                    if (logHandler != null)

+                        logHandler.NewDataConnection(remote, local, passive);

+

+                    try {

+                        while (true) {

+                            int bytes = stream.Read(dataBuffer, 0, dataBufferSize);

+                            if (bytes <= 0) {

+                                break;

+                            }

+

+                            if (transferDataType == DataType.IMAGE || noAsciiConv) {

+                                // TYPE I -> just pass through

+                                socket.Send(dataBuffer, bytes, SocketFlags.None);

+                            } else {

+                                // TYPE A -> convert local EOL style to CRLF

+

+                                // if the buffer ends with a potential partial EOL,

+                                // try to read the rest of the EOL

+                                // (i assume that the EOL has max. two bytes)

+                                if (localEolBytes.Length == 2 &&

+                                    dataBuffer[bytes - 1] == localEolBytes[0]) {

+                                    if (stream.Read(dataBuffer, bytes, 1) == 1)

+                                        ++bytes;

+                                }

+

+                                byte[] convBuffer = null;

+                                int convBytes = ConvertAsciiBytes(dataBuffer, bytes, true, out convBuffer);

+                                socket.Send(convBuffer, convBytes, SocketFlags.None);

+                            }

+                        }

+

+                        // flush socket before closing (done by using-statement)

+                        socket.Shutdown(SocketShutdown.Send);

+                        Respond(226, "Transfer complete.");

+                    } catch (Exception ex) {

+                        Respond(500, ex);

+                        return;

+                    } finally {

+                        if (logHandler != null)

+                            logHandler.ClosedDataConnection(remote, local, passive);

+                    }

+                }

+            } finally {

+                stream.Close();

+            }

+        }

+

+        /// <summary>

+        /// Read from a data connection and write to the given stream

+        /// </summary>

+        private void ReceiveData(Stream stream)

+        {

+            try {

+                bool passive = (dataPort == null);

+                using (Socket socket = OpenDataConnection()) {

+                    if (socket == null)

+                        return;

+

+                    IPEndPoint remote = (IPEndPoint) socket.RemoteEndPoint;

+                    IPEndPoint local = (IPEndPoint) socket.LocalEndPoint;

+

+                    if (logHandler != null)

+                        logHandler.NewDataConnection(remote, local, passive);

+

+                    try {

+                        while (true) {

+                            // fill up the in-memory buffer before writing to disk

+                            int totalBytes = 0;

+                            while (totalBytes < dataBufferSize) {

+                                int freeBytes = dataBufferSize - totalBytes;

+                                int newBytes = socket.Receive(dataBuffer, totalBytes, freeBytes, SocketFlags.None);

+

+                                if (newBytes > 0) {

+                                    totalBytes += newBytes;

+                                } else if (newBytes < 0) {

+                                    Respond(500, String.Format("Transfer failed: Receive() returned {0}", newBytes));

+                                    return;

+                                } else {

+                                    // end of data

+                                    break;

+                                }

+                            }

+

+                            // end of data

+                            if (totalBytes == 0)

+                                break;

+

+                            if (transferDataType == DataType.IMAGE || noAsciiConv) {

+                                // TYPE I -> just pass through

+                                stream.Write(dataBuffer, 0, totalBytes);

+                            } else {

+                                // TYPE A -> convert CRLF to local EOL style

+

+                                // if the buffer ends with a potential partial CRLF,

+                                // try to read the LF

+                                if (dataBuffer[totalBytes - 1] == remoteEolBytes[0]) {

+                                    if (socket.Receive(dataBuffer, totalBytes, 1, SocketFlags.None) == 1)

+                                        ++totalBytes;

+                                }

+

+                                byte[] convBuffer = null;

+                                int convBytes = ConvertAsciiBytes(dataBuffer, totalBytes, false, out convBuffer);

+                                stream.Write(convBuffer, 0, convBytes);

+                            }

+                        }

+

+                        socket.Shutdown(SocketShutdown.Receive);

+                        Respond(226, "Transfer complete.");

+                    } catch (Exception ex) {

+                        Respond(500, ex);

+                        return;

+                    } finally {

+                        if (logHandler != null)

+                            logHandler.ClosedDataConnection(remote, local, passive);

+                    }

+                }

+            } finally {

+                //stream.Close();

+            }

+        }

+

+        /// <summary>

+        /// Create a socket for a data connection.

+        /// </summary>

+        /// <param name='listen'>

+        /// If true, the socket will be bound to a local port for the PASV command.

+        /// Otherwise the socket can be used for connecting to the address given in a PORT command.

+        /// </param>

+        private void CreateDataSocket(bool listen)

+        {

+            if (dataSocket != null)

+                dataSocket.Close();

+

+            dataSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);

+

+            if (listen) {

+                IPAddress serverIP = ((IPEndPoint) controlSocket.LocalEndPoint).Address;

+                dataSocket.Bind(new IPEndPoint(serverIP, 0));

+                dataSocketBound = true; // CF is missing Socket.IsBound

+                dataSocket.Listen(1);

+            }

+        }

+

+        /// <summary>

+        /// Opens an active or passive data connection and returns the socket

+        /// or null if there was no preceding PORT or PASV command or in case or error.

+        /// </summary>

+        private Socket OpenDataConnection()

+        {

+            if (dataPort == null && !dataSocketBound) {

+                Respond(425, "No data port configured, use PORT or PASV.");

+                return null;

+            }

+

+            Respond(150, "Opening data connection.");

+

+            try {

+                if (dataPort != null) {

+                    // active mode

+                    dataSocket.Connect(dataPort);

+                    dataPort = null;

+                    return dataSocket;

+                } else {

+                    // passive mode

+                    Socket socket = dataSocket.Accept();

+                    dataSocket.Close();

+                    dataSocketBound = false;

+                    return socket;

+                }

+            } catch (Exception ex) {

+                Respond(500, String.Format("Failed to open data connection: {0}", ex.Message.Replace(Environment.NewLine, " ")));

+                return null;

+            }

+        }

+

+        /// <summary>

+        /// Convert between different EOL flavors.

+        /// </summary>

+        /// <returns>

+        /// The number of bytes in the resultBuffer.

+        /// </returns>

+        /// <param name='buffer'>

+        /// The input buffer whose data will be converted.

+        /// </param>

+        /// <param name='len'>

+        /// The number of bytes in the input buffer.

+        /// </param>

+        /// <param name='localToRemote'>

+        /// If true, the conversion will be made from local to FTP flavor,

+        /// otherwise from FTP to local flavor.

+        /// </param>

+        /// <param name='resultBuffer'>

+        /// The resulting buffer with the converted text.

+        /// Can be the same reference as the input buffer if there is nothing to convert.

+        /// </param>

+        private int ConvertAsciiBytes(byte[] buffer, int len, bool localToRemote, out byte[] resultBuffer)

+        {

+            byte[] fromBytes = (localToRemote ? localEolBytes : remoteEolBytes);

+            byte[] toBytes = (localToRemote ? remoteEolBytes : localEolBytes);

+            resultBuffer = null;

+

+            int startIndex = 0;

+            int resultLen = 0;

+            int searchLen;

+            while ((searchLen = len - startIndex) > 0) {

+                // search for the first byte of the EOL sequence

+                int eolIndex = Array.IndexOf(buffer, fromBytes[0], startIndex, searchLen);

+

+                // shortcut if there is no EOL in the whole buffer

+                if (eolIndex == -1 && startIndex == 0) {

+                    resultBuffer = buffer;

+                    return len;

+                }

+

+                // allocate to worst-case size

+                if (resultBuffer == null)

+                    resultBuffer = new byte[len * 2];

+

+                if (eolIndex == -1) {

+                    Array.Copy(buffer, startIndex, resultBuffer, resultLen, searchLen);

+                    resultLen += searchLen;

+                    break;

+                } else {

+                    // compare the rest of the EOL

+                    int matchBytes = 1;

+                    for (int i = 1; i < fromBytes.Length && eolIndex + i < len; ++i) {

+                        if (buffer[eolIndex + i] == fromBytes[i])

+                            ++matchBytes;

+                    }

+

+                    if (matchBytes == fromBytes.Length) {

+                        // found an EOL to convert

+                        int copyLen = eolIndex - startIndex;

+                        if (copyLen > 0) {

+                            Array.Copy(buffer, startIndex, resultBuffer, resultLen, copyLen);

+                            resultLen += copyLen;

+                        }

+                        Array.Copy(toBytes, 0, resultBuffer, resultLen, toBytes.Length);

+                        resultLen += toBytes.Length;

+                        startIndex += copyLen + fromBytes.Length;

+                    } else {

+                        int copyLen = (eolIndex - startIndex) + 1;

+                        Array.Copy(buffer, startIndex, resultBuffer, resultLen, copyLen);

+                        resultLen += copyLen;

+                        startIndex += copyLen;

+                    }

+                }

+            }

+

+            return resultLen;

+        }

+

+        /// <summary>

+        /// Parse the argument of a PORT command into an IPEndPoint

+        /// </summary>

+        private IPEndPoint ParseAddress(string address)

+        {

+            string[] tokens = address.Split(',');

+            byte[] bytes = new byte[tokens.Length];

+            for (int i = 0; i < tokens.Length; ++i) {

+                try {

+                    // CF is missing TryParse

+                    bytes[i] = byte.Parse(tokens[i]);

+                } catch (Exception) {

+                    return null;

+                }

+            }

+

+            long ip = bytes[0] | bytes[1] << 8 | bytes[2] << 16 | bytes[3] << 24;

+            int port = bytes[4] << 8 | bytes[5];

+            return new IPEndPoint(ip, port);

+        }

+

+        /// <summary>

+        /// Format an IPEndPoint so that it can be used in a response for a PASV command

+        /// </summary>

+        private string FormatAddress(IPEndPoint address)

+        {

+            byte[] ip = address.Address.GetAddressBytes();

+            int port = address.Port;

+

+            return String.Format("{0},{1},{2},{3},{4},{5}",

+                                 ip[0], ip[1], ip[2], ip[3],

+                                 (port & 0xFF00) >> 8, port & 0x00FF);

+        }

+

+        /// <summary>

+        /// Formats a list of file system entries for a response to a LIST or STAT command

+        /// </summary>

+        private string FormatDirList(FileSystemEntry[] list)

+        {

+            int maxSizeChars = 0;

+            foreach (FileSystemEntry entry in list) {

+                maxSizeChars = Math.Max(maxSizeChars, entry.Size.ToString().Length);

+            }

+

+            DateTime sixMonthsAgo = EnsureUnixTime(DateTime.Now.ToUniversalTime().AddMonths(-6));

+

+            StringBuilder result = new StringBuilder();

+            foreach (FileSystemEntry entry in list) {

+                char dirflag = (entry.IsDirectory ? 'd' : '-');

+                string size = entry.Size.ToString().PadLeft(maxSizeChars);

+                DateTime time = EnsureUnixTime(entry.LastModifiedTimeUtc);

+                string timestr = MONTHS[time.Month - 1];

+                if (time < sixMonthsAgo)

+                    timestr += time.ToString(" dd  yyyy");

+                else

+                    timestr += time.ToString(" dd hh:mm");

+                string mode = entry.Mode;

+

+                result.AppendFormat("{0}{4} 1 owner group {1} {2} {3}\r\n",

+                                    dirflag, size, timestr, entry.Name, mode ?? "rwxr--r--");

+            }

+

+            return result.ToString();

+        }

+

+        /// <summary>

+        /// Formats a list of file system entries for a response to an NLST command

+        /// </summary>

+        private string FormatNLST(FileSystemEntry[] list)

+        {

+            StringBuilder sb = new StringBuilder();

+            foreach (FileSystemEntry entry in list) {

+                sb.Append(entry.Name);

+                sb.Append("\r\n");

+            }

+            return sb.ToString();

+        }

+

+        /// <summary>

+        /// Format a timestamp for a reponse to a MDTM command

+        /// </summary>

+        private string FormatTime(DateTime time)

+        {

+            return time.ToString("yyyyMMddHHmmss");

+        }

+

+        /// <summary>

+        /// Restrict the year in a timestamp to >= 1970

+        /// </summary>

+        private DateTime EnsureUnixTime(DateTime time)

+        {

+            // the server claims to be UNIX, so there should be

+            // no timestamps before 1970.

+            // e.g. FileZilla does not handle them correctly.

+

+            int yearDiff = time.Year - 1970;

+            if (yearDiff < 0)

+              return time.AddYears(-yearDiff);

+            else

+              return time;

+        }

+

+        /// <summary>

+        /// Escape a path for a response to a PWD command

+        /// </summary>

+        private string EscapePath(string path)

+        {

+            // double-quotes in paths are escaped by doubling them

+            return '"' + path.Replace("\"", "\"\"") + '"';

+        }

+

+        /// <summary>

+        /// Remove "-a" or "-l" from the arguments for a LIST or STAT command

+        /// </summary>

+        private string RemoveLsArgs(string args)

+        {

+            if (args != null && (args.StartsWith("-a") || args.StartsWith("-l"))) {

+                if (args.Length == 2)

+                    return null;

+                else if (args.Length > 3 && args[2] == ' ')

+                    return args.Substring(3);

+            }

+

+            return args;

+        }

+

+        /// <summary>

+        /// Convert a string to a list of UTF8 bytes

+        /// </summary>

+        private byte[] EncodeString(string data)

+        {

+            return Encoding.UTF8.GetBytes(data);

+        }

+

+        /// <summary>

+        /// Convert a list of UTF8 bytes to a string

+        /// </summary>

+        private string DecodeString(byte[] data, int len)

+        {

+            return Encoding.UTF8.GetString(data, 0, len);

+        }

+

+        /// <summary>

+        /// Convert a list of UTF8 bytes to a string

+        /// </summary>

+        private string DecodeString(byte[] data)

+        {

+            return DecodeString(data, data.Length);

+        }

+

+        /// <summary>

+        /// Fill a stream with the given string as UTF8 bytes

+        /// </summary>

+        private Stream MakeStream(string data)

+        {

+            return new MemoryStream(EncodeString(data));

+        }

+

+        /// <summary>

+        /// Return a randomly selected text from the given list

+        /// </summary>

+        private string GetRandomText(string[] texts)

+        {

+            int index = randomTextIndex.Next(0, texts.Length);

+            return texts[index];

+        }

+    }

+}