diff options
Diffstat (limited to 'FtpServer/Session.cs')
-rw-r--r-- | FtpServer/Session.cs | 1266 |
1 files changed, 1266 insertions, 0 deletions
diff --git a/FtpServer/Session.cs b/FtpServer/Session.cs new file mode 100644 index 00000000..42075372 --- /dev/null +++ b/FtpServer/Session.cs @@ -0,0 +1,1266 @@ +using System;
+using System.Globalization;
+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 = { "hakchi2 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", "MLST modify*;perm*;size*;type*;unique*;UNIX.mode;", "PASV", "MFMT", "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);
+ if (ret2.HasError)
+ {
+ Respond(550, ret2.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)));
+ */
+ ResultOrError<string> ret = fsHandler.ListEntriesRaw(arguments);
+ if (ret.HasError)
+ {
+ Respond(500, ret.Error);
+ break;
+ }
+
+ SendData(MakeStream(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 "MLSD":
+ case "MLST":
+ {
+ ResultOrError<FileSystemEntry[]> ret = fsHandler.ListEntries(arguments);
+ if (ret.HasError)
+ {
+ Respond(500, ret.Error);
+ break;
+ }
+
+ SendData(MakeStream(FormatMLST(ret.Result)));
+ break;
+ }
+ case "MFMT":
+ {
+ string[] tokens = arguments.Split(' ');
+ var time = DateTime.ParseExact(tokens[0], "yyyyMMddHHmmss", CultureInfo.InvariantCulture);
+ var file = (tokens.Length > 1 ? String.Join(" ", tokens, 1, tokens.Length - 1) : null);
+ fsHandler.SetLastModifiedTimeUtc(file, time);
+ Respond(213, string.Format("213 Modify={0}; {1}", tokens[0], file));
+ 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;
+
+ if (string.IsNullOrEmpty(mode))
+ mode = dirflag + "rwxr--r--";
+
+ result.AppendFormat("{0} 1 owner group {1} {2} {3}\r\n",
+ mode, 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>
+ /// Formats a list of file system entries for a response to an MLST command
+ /// </summary>
+ private string FormatMLST(FileSystemEntry[] list)
+ {
+ StringBuilder sb = new StringBuilder();
+ var cd = fsHandler.GetCurrentDirectory();
+ foreach (FileSystemEntry entry in list)
+ {
+ int p = entry.Name.IndexOf(" -> ");
+ string l, f;
+ if (p >= 0)
+ {
+ l = entry.Name.Substring(0, p);
+ f = entry.Name.Substring(p + 4);
+ }
+ else
+ {
+ l = f = entry.Name;
+ }
+ sb.AppendFormat("modify={0:yyyyMMddHHmmss};perm={1};size={2};type={3};unique={4:X};unix.mode={5:D4}; {6}\r\n",
+ entry.LastModifiedTimeUtc,
+ "rw" + (entry.IsDirectory ? "l" : "") + (entry.Mode != null && entry.Mode.Contains("x") ? "x" : ""),
+ entry.Size,
+ (l != f) ? "symlink" : (entry.IsDirectory ? "dir" : "file"),
+ (cd.Result + f).GetHashCode(),
+ (string.IsNullOrEmpty(entry.Mode) || entry.Mode.Length < 10) ? 0 : (
+ ((entry.Mode[3] == 'S') ? 4000 : 0) +
+ ((entry.Mode[6] == 'S') ? 2000 : 0) +
+ ((entry.Mode[9] == 'T') ? 1000 : 0) +
+ ((entry.Mode[1] == 'r') ? 400 : 0) +
+ ((entry.Mode[2] == 'w') ? 200 : 0) +
+ ((entry.Mode[3] != '-') ? 100 : 0) +
+ ((entry.Mode[4] == 'r') ? 040 : 0) +
+ ((entry.Mode[5] == 'w') ? 020 : 0) +
+ ((entry.Mode[6] != '-') ? 010 : 0) +
+ ((entry.Mode[7] == 'r') ? 004 : 0) +
+ ((entry.Mode[8] == 'w') ? 002 : 0) +
+ ((entry.Mode[9] != '-') ? 001 : 0)
+ ),
+ l);
+ 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];
+ }
+ }
+}
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