/MSNPSHARP_DEV/ProxyServer/FtpClient.cs
C# | 342 lines | 254 code | 4 blank | 84 comment | 29 complexity | 1f22caed738f54ad56fa8695538c6b4b MD5 | raw file
- /*
- Copyright ?2002, The KPD-Team
- All rights reserved.
- http://www.mentalis.org/
-
- Redistribution and use in source and binary forms, with or without
- modification, are permitted provided that the following conditions
- are met:
-
- - Redistributions of source code must retain the above copyright
- notice, this list of conditions and the following disclaimer.
-
- - Neither the name of the KPD-Team, nor the names of its contributors
- may be used to endorse or promote products derived from this
- software without specific prior written permission.
-
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
- THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
- INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
- SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
- OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
- using System;
- using System.Text;
- using System.Net;
- using System.Net.Sockets;
- using Org.Mentalis.Proxy;
-
- namespace Org.Mentalis.Proxy.Ftp {
-
- ///<summary>Relays FTP commands between a remote host and a local client.</summary>
- ///<remarks>This class supports the 'OPEN' command, 'USER user@host:port' and 'USER user@host port'.</remarks>
- public sealed class FtpClient : Client {
- ///<summary>Initializes a new instance of the FtpClient class.</summary>
- ///<param name="ClientSocket">The Socket connection between this proxy server and the local client.</param>
- ///<param name="Destroyer">The callback method to be called when this Client object disconnects from the local client and the remote server.</param>
- public FtpClient(Socket ClientSocket, DestroyDelegate Destroyer) : base(ClientSocket, Destroyer) {}
- ///<summary>Sends a welcome message to the client.</summary>
- public override void StartHandshake() {
- try {
- string ToSend = "220 Mentalis.org FTP proxy server ready.\r\n";
- ClientSocket.BeginSend(Encoding.ASCII.GetBytes(ToSend), 0, ToSend.Length, SocketFlags.None, new AsyncCallback(this.OnHelloSent), ClientSocket);
- } catch {
- Dispose();
- }
- }
- ///<summary>Called when the welcome message has been sent to the client.</summary>
- ///<param name="ar">The result of the asynchronous operation.</param>
- private void OnHelloSent(IAsyncResult ar) {
- try {
- if (ClientSocket.EndSend(ar) <= 0) {
- Dispose();
- return;
- }
- ClientSocket.BeginReceive(Buffer, 0, Buffer.Length, SocketFlags.None, new AsyncCallback(this.OnReceiveCommand), ClientSocket);
- } catch {
- Dispose();
- }
- }
- ///<summary>Called when we have received some bytes from the client.</summary>
- ///<param name="ar">The result of the asynchronous operation.</param>
- private void OnReceiveCommand(IAsyncResult ar) {
- try {
- int Ret = ClientSocket.EndReceive(ar);
- string Command;
- if (Ret <= 0) {
- Dispose();
- return;
- }
- FtpCommand += Encoding.ASCII.GetString(Buffer, 0, Ret);
- if (FtpClient.IsValidCommand(FtpCommand)) {
- Command = FtpCommand;
- if (ProcessCommand(Command))
- DestinationSocket.BeginSend(Encoding.ASCII.GetBytes(Command), 0, Command.Length, SocketFlags.None, new AsyncCallback(this.OnCommandSent), DestinationSocket);
- FtpCommand = "";
- } else {
- ClientSocket.BeginReceive(Buffer, 0, Buffer.Length, SocketFlags.None, new AsyncCallback(this.OnReceiveCommand), ClientSocket);
- }
- } catch {
- Dispose();
- }
- }
- ///<summary>Processes an FTP command, sent from the client.</summary>
- ///<param name="Command">The command to process.</param>
- ///<returns>True if the command may be sent to the server, false otherwise.</returns>
- private bool ProcessCommand(string Command) {
- try {
- int Ret = Command.IndexOf(' ');
- if (Ret < 0)
- Ret = Command.Length;
- switch (Command.Substring(0, Ret).ToUpper().Trim()) {
- case "OPEN":
- ConnectTo(ParseIPPort(Command.Substring(Ret + 1)));
- break;
- case "USER":
- Ret = Command.IndexOf('@');
- if (Ret < 0) {
- return true;
- } else {
- User = Command.Substring(0, Ret).Trim() + "\r\n";
- ConnectTo(ParseIPPort(Command.Substring(Ret + 1)));
- }
- break;
- case "PORT":
- ProcessPortCommand(Command.Substring(5).Trim());
- break;
- case "PASV":
- DataForward = new FtpDataConnection();
- DataForward.ProcessPasv(this);
- return true;
- default:
- return true;
- }
- return false;
- } catch {
- Dispose();
- return false;
- }
- }
- ///<summary>Processes a PORT command, sent from the client.</summary>
- ///<param name="Input">The parameters of the PORT command.</param>
- private void ProcessPortCommand(string Input) {
- try {
- string [] Parts = Input.Split(',');
- if (Parts.Length == 6) {
- DataForward = new FtpDataConnection();
- string Reply = DataForward.ProcessPort(new IPEndPoint(IPAddress.Parse(String.Join(".", Parts, 0, 4)), int.Parse(Parts[4]) * 256 + int.Parse(Parts[5])));
- DestinationSocket.BeginSend(Encoding.ASCII.GetBytes(Reply), 0, Reply.Length, SocketFlags.None, new AsyncCallback(this.OnCommandSent), DestinationSocket);
- }
- } catch {
- Dispose();
- }
- }
- ///<summary>Parses an IP address and port from a specified input string.</summary>
- ///<remarks>The input string is of the following form:<br> <c>HOST:PORT</c></br><br><em>or</em></br><br> <c>HOST PORT</c></br></remarks>
- ///<param name="Input">The string to parse.</param>
- ///<returns>An instance of the IPEndPoint class if successful, null otherwise.</returns>
- private IPEndPoint ParseIPPort(string Input) {
- Input = Input.Trim();
- int Ret = Input.IndexOf(':');
- if (Ret < 0)
- Ret = Input.IndexOf(' ');
- try {
- if (Ret > 0) {
- return new IPEndPoint(Dns.GetHostEntry(Input.Substring(0, Ret)).AddressList[0], int.Parse(Input.Substring(Ret + 1)));
- } else {
- return new IPEndPoint(Dns.GetHostEntry(Input).AddressList[0], 21);
- }
- } catch {
- return null;
- }
- }
- ///<summary>Connects to the specified endpoint.</summary>
- ///<param name="RemoteServer">The IPEndPoint to connect to.</param>
- ///<exception cref="SocketException">There was an error connecting to the specified endpoint</exception>
- private void ConnectTo(IPEndPoint RemoteServer) {
- if (DestinationSocket != null) {
- try {
- DestinationSocket.Shutdown(SocketShutdown.Both);
- } catch {
- } finally {
- DestinationSocket.Close();
- }
- }
- try {
- DestinationSocket = new Socket(RemoteServer.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
- DestinationSocket.BeginConnect(RemoteServer, new AsyncCallback(this.OnRemoteConnected), DestinationSocket);
- } catch {
- throw new SocketException();
- }
- }
- ///<summary>Called when we're connected to the remote FTP server.</summary>
- ///<param name="ar">The result of the asynchronous operation.</param>
- private void OnRemoteConnected(IAsyncResult ar) {
- try {
- DestinationSocket.EndConnect(ar);
- ClientSocket.BeginReceive(Buffer, 0, Buffer.Length, SocketFlags.None, new AsyncCallback(this.OnReceiveCommand), ClientSocket);
- if (User.Equals(""))
- DestinationSocket.BeginReceive(RemoteBuffer, 0, RemoteBuffer.Length, SocketFlags.None, new AsyncCallback(this.OnReplyReceived), DestinationSocket);
- else
- DestinationSocket.BeginReceive(RemoteBuffer, 0, RemoteBuffer.Length, SocketFlags.None, new AsyncCallback(this.OnIgnoreReply), DestinationSocket);
- } catch {
- Dispose();
- }
- }
- ///<summary>Called when we receive a reply from the FTP server that should be ignored.</summary>
- ///<param name="ar">The result of the asynchronous operation.</param>
- private void OnIgnoreReply(IAsyncResult ar) {
- try {
- int Ret = DestinationSocket.EndReceive(ar);
- if (Ret <= 0) {
- Dispose();
- return;
- }
- FtpReply += Encoding.ASCII.GetString(RemoteBuffer, 0, Ret);
- if (FtpClient.IsValidReply(FtpReply)) {
- DestinationSocket.BeginReceive(RemoteBuffer, 0, RemoteBuffer.Length, SocketFlags.None, new AsyncCallback(this.OnReplyReceived), DestinationSocket);
- DestinationSocket.BeginSend(Encoding.ASCII.GetBytes(User), 0, User.Length, SocketFlags.None, new AsyncCallback(this.OnCommandSent), DestinationSocket);
- } else {
- DestinationSocket.BeginReceive(RemoteBuffer, 0, RemoteBuffer.Length, SocketFlags.None, new AsyncCallback(this.OnIgnoreReply), DestinationSocket);
- }
- } catch {
- Dispose();
- }
- }
- ///<summary>Called when an FTP command has been successfully sent to the FTP server.</summary>
- ///<param name="ar">The result of the asynchronous operation.</param>
- private void OnCommandSent(IAsyncResult ar) {
- try {
- if (DestinationSocket.EndSend(ar) <= 0) {
- Dispose();
- return;
- }
- ClientSocket.BeginReceive(Buffer, 0, Buffer.Length, SocketFlags.None, new AsyncCallback(this.OnReceiveCommand), ClientSocket);
- } catch {
- Dispose();
- }
- }
- ///<summary>Called when we receive a reply from the FTP server.</summary>
- ///<param name="ar">The result of the asynchronous operation.</param>
- private void OnReplyReceived(IAsyncResult ar) {
- try {
- int Ret = DestinationSocket.EndReceive(ar);
- if (Ret <= 0) {
- Dispose();
- return;
- }
- if (DataForward != null && DataForward.ExpectsReply) {
- if (!DataForward.ProcessPasvReplyRecv(Encoding.ASCII.GetString(RemoteBuffer, 0, Ret)))
- DestinationSocket.BeginReceive(RemoteBuffer, 0, RemoteBuffer.Length, SocketFlags.None, new AsyncCallback(this.OnReplyReceived), DestinationSocket);
- } else {
- ClientSocket.BeginSend(RemoteBuffer, 0, Ret, SocketFlags.None, new AsyncCallback(this.OnReplySent), ClientSocket);
- }
- } catch {
- Dispose();
- }
- }
- ///<summary>Called when the reply from the FTP server has been sent to the local FTP client.</summary>
- ///<param name="ar">The result of the asynchronous operation.</param>
- private void OnReplySent(IAsyncResult ar) {
- try {
- int Ret = ClientSocket.EndSend(ar);
- if (Ret <= 0) {
- Dispose();
- return;
- }
- DestinationSocket.BeginReceive(RemoteBuffer, 0, RemoteBuffer.Length, SocketFlags.None, new AsyncCallback(this.OnReplyReceived), DestinationSocket);
- } catch {
- Dispose();
- }
- }
- ///<summary>Sends a string to the local FTP client.</summary>
- ///<param name="Command">The result of the asynchronous operation.</param>
- internal void SendCommand(string Command) {
- ClientSocket.BeginSend(Encoding.ASCII.GetBytes(Command), 0, Command.Length, SocketFlags.None, new AsyncCallback(this.OnReplySent), ClientSocket);
- }
- ///<summary>Checks whether a specified command is a complete FTP command or not.</summary>
- ///<param name="Command">A string containing the command to check.</param>
- ///<returns>True if the command is complete, false otherwise.</returns>
- internal static bool IsValidCommand(string Command) {
- return (Command.IndexOf("\r\n") >= 0);
- }
- ///<summary>Checks whether a specified reply is a complete FTP reply or not.</summary>
- ///<param name="Input">A string containing the reply to check.</param>
- ///<returns>True is the reply is complete, false otherwise.</returns>
- internal static bool IsValidReply(string Input) {
- string [] Lines = Input.Split('\n');
- try {
- if (Lines[Lines.Length - 2].Trim().Substring(3, 1).Equals(" "))
- return true;
- } catch {}
- return false;
- }
- ///<summary>Gets or sets a property that can be used to store the received FTP command.</summary>
- ///<value>A string that can be used to store the received FTP command.</value>
- private string FtpCommand {
- get {
- return m_FtpCommand;
- }
- set {
- m_FtpCommand = value;
- }
- }
- ///<summary>Gets or sets a property that can be used to store the received FTP reply.</summary>
- ///<value>A string that can be used to store the received FTP reply.</value>
- private string FtpReply {
- get {
- return m_FtpReply;
- }
- set {
- m_FtpReply = value;
- }
- }
- ///<summary>Gets or sets a string containing the logged on username.</summary>
- ///<value>A string containing the logged on username.</value>
- private string User {
- get {
- return m_User;
- }
- set {
- m_User = value;
- }
- }
- ///<summary>Gets or sets the dataconnection object used to transmit files and other data from and to the FTP server.</summary>
- ///<value>An FtpDataConnection object that's used to transmit files and other data from and to the FTP server.</value>
- internal FtpDataConnection DataForward {
- get {
- return m_DataForward;
- }
- set {
- m_DataForward = value;
- }
- }
- ///<summary>Returns text information about this FtpClient object.</summary>
- ///<returns>A string representing this FtpClient object.</returns>
- public override string ToString() {
- try {
- return "FTP connection from " + ((IPEndPoint)ClientSocket.RemoteEndPoint).Address.ToString() + " to " + ((IPEndPoint)DestinationSocket.RemoteEndPoint).Address.ToString();
- } catch {
- return "Incoming FTP connection";
- }
- }
- // private variables
- /// <summary>Holds the value of the User property.</summary>
- private string m_User = "";
- /// <summary>Holds the value of the FtpCommand property.</summary>
- private string m_FtpCommand = "";
- /// <summary>Holds the value of the FtpReply property.</summary>
- private string m_FtpReply = "";
- /// <summary>Holds the value of the DataForward property.</summary>
- private FtpDataConnection m_DataForward;
- }
-
- }