// 想客户端返回响应码
private void RepleyCommandToUser(User user, string str)
{
try
{
user.commandSession.streamWriter.WriteLine(str);
AddInfo(string.Format("向客户端（{0}）发送[{1}]", user.commandSession.tcpClient.Client.RemoteEndPoint, str));
}
catch
{
AddInfo(string.Format("向客户端（{0}）发送信息失败", user.commandSession.tcpClient.Client.RemoteEndPoint));
}
}
// 使用数据连接发送字符串
private void SendByUserSession(User user, string sendString)
{
AddInfo("向用户发送(字符串信息)：[" + sendString + "]");
try
{
user.dataSession.streamWriter.WriteLine(sendString);
AddInfo("发送完毕");
}
finally
{
user.dataSession.Close();
}
}
// 监听端口，处理客户端连接
private void ListenClientConnect()
{
myTcpListener = new TcpListener(IPAddress.Parse(tbxFtpServerIp.Text), int.Parse(tbxFtpServerPort.Text));
// 开始监听传入的请求
myTcpListener.Start();
AddInfo("启动FTP服务成功！");
AddInfo("Ftp服务器运行中...[点击”停止“按钮停止FTP服务]");
while (true)
{
try
{
// 接收连接请求
TcpClient tcpClient = myTcpListener.AcceptTcpClient();
AddInfo(string.Format("客户端（{0}）与本机（{1}）建立Ftp连接", tcpClient.Client.RemoteEndPoint, myTcpListener.LocalEndpoint));
User user = new User();
user.commandSession = new UserSeesion(tcpClient);
user.workDir = tbxFtpRoot.Text;
Thread t = new Thread(UserProcessing);
t.IsBackground = true;
t.Start(user);
}
catch
{
break;
}
}
}
// 使用数据连接接收文件流(客户端发送上传文件功能)
private void ReadFileByUserSession(User user, FileStream fs)
{
AddInfo("接收用户上传数据（文件流）：[...");
try
{
if (user.isBinary)
{
byte[] bytes = new byte[1024];
BinaryWriter binaryWriter = new BinaryWriter(fs);
int count = user.dataSession.binaryReader.Read(bytes, 0, bytes.Length);
while (count > 0)
{
binaryWriter.Write(bytes, 0, count);
binaryWriter.Flush();
count = user.dataSession.binaryReader.Read(bytes, 0, bytes.Length);
}
}
else
{
StreamWriter streamWriter = new StreamWriter(fs);
while (user.dataSession.streamReader.Peek() > -1)
{
streamWriter.Write(user.dataSession.streamReader.ReadLine());
streamWriter.Flush();
}
}
AddInfo("...]接收完毕");
}
finally
{
user.dataSession.Close();
fs.Close();
}
}
// 处理USER命令，接收用户名但不进行验证
private void CommandUser(User user, string command, string param)
{
string sendString = string.Empty;
if (command == "USER")
{
sendString = "331 USER command OK, password required.";
user.userName = param;
// 设置loginOk=1为了确保后面紧接的要求输入密码
// 1表示已接收到用户名，等到接收密码
user.loginOK = 1;
}
else
{
sendString = "501 USER command syntax error.";
}
RepleyCommandToUser(user, sendString);
}
// 初始化数据连接
private void InitDataSession(User user)
{
TcpClient client = null;
if (user.isPassive)
{
AddInfo("采用被动模式返回LIST目录和文件列表");
client = user.dataListener.AcceptTcpClient();
}
else
{
AddInfo("采用主动模式向用户发送LIST目录和文件列表");
client = new TcpClient();
client.Connect(user.remoteEndPoint);
}
user.dataSession = new UserSeesion(client);
}
// 处理STOR命令，提供上传功能，接收客户端上传的文件
private void CommandSTOR(User user, string filename)
{
string sendString = "";
// 上传的文件全名
string path = user.currentDir + filename;
FileStream fs = new FileStream(path, FileMode.Create, FileAccess.Write);
// 发送150到用户，表示服务器状态良好
if (user.isBinary)
{
sendString = "150 Opening BINARY mode data connection for upload";
}
else
{
sendString = "150 Opeing ASCII mode data connection for upload";
}
RepleyCommandToUser(user, sendString);
InitDataSession(user);
ReadFileByUserSession(user, fs);
RepleyCommandToUser(user,"226 Transfer complete");
}
// 处理LIST/NLIST命令，想客户端发送当前或指定目录下的所有文件名和子目录名
private void CommandLIST(User user, string parameter)
{
string sendString = string.Empty;
DateTimeFormatInfo dateTimeFormat = new CultureInfo("en-US", true).DateTimeFormat;
// 得到目录列表
string[] dir = Directory.GetDirectories(user.currentDir);
if (string.IsNullOrEmpty(parameter) == false)
{
if (Directory.Exists(user.currentDir + parameter))
{
dir = Directory.GetDirectories(user.currentDir + parameter);
}
else
{
string s = user.currentDir.TrimEnd('/');
user.currentDir = s.Substring(0, s.LastIndexOf("/") + 1);
}
}
for (int i = 0; i < dir.Length; i++)
{
string folderName = Path.GetFileName(dir[i]);
DirectoryInfo d = new DirectoryInfo(dir[i]);
// 按下面的格式输出目录列表
sendString += @"dwr-\t" + Dns.GetHostName() + "\t" + dateTimeFormat.GetAbbreviatedMonthName(d.CreationTime.Month)
+ d.CreationTime.ToString(" dd yyyy") + "\t" + folderName + Environment.NewLine;
}
// 得到文件列表
string[] files = Directory.GetFiles(user.currentDir);
if (string.IsNullOrEmpty(parameter) == false)
{
if (Directory.Exists(user.currentDir + parameter + "/"))
{
files = Directory.GetFiles(user.currentDir + parameter + "/");
}
}
for (int i = 0; i < files.Length; i++)
{
FileInfo f = new FileInfo(files[i]);
string fileName = Path.GetFileName(files[i]);
// 按下面的格式输出文件列表
sendString += "-wr-\t" + Dns.GetHostName() + "\t" + f.Length + " "
+ dateTimeFormat.GetAbbreviatedMonthName(f.CreationTime.Month)
+ f.CreationTime.ToString(" dd yyyy") + "\t" + fileName + Environment.NewLine;
}
// List命令指示获得FTP服务器上的文件列表字符串信息
// 所以调用List命令过程，客户端接受的指示一些字符串
// 所以isBinary是false,代表传输的是ASCII数据
// 但是为了防止isBinary因为 设置user.isBinary = false而改变
// 所以事先保存user.IsBinary的引用（此时为true）,方便后面下载文件
bool isBinary = user.isBinary;
user.isBinary = false;
RepleyCommandToUser(user, "150 Opening ASCII data connection");
InitDataSession(user);
SendByUserSession(user, sendString);
RepleyCommandToUser(user, "226 Transfer complete");
user.isBinary = isBinary;
}
// 处理PWD命令，显示工作目录
private void CommandPWD(User user)
{
string sendString = string.Empty;
sendString = "257 '" + user.currentDir + "' is the current directory";
RepleyCommandToUser(user, sendString);
}
// 处理RETR命令，提供下载功能，将用户请求的文件发送给用户
private void CommandRETR(User user, string filename)
{
string sendString = "";
// 下载的文件全名
string path = user.currentDir + filename;
FileStream filestream = new FileStream(path, FileMode.Open, FileAccess.Read);
// 发送150到用户，表示服务器文件状态良好，将要打开数据连接传输文件
if (user.isBinary)
{
sendString = "150 Opening BINARY mode data connection for download";
}
else
{
sendString = "150 Opening ASCII mode data connection for download";
}
RepleyCommandToUser(user, sendString);
InitDataSession(user);
SendFileByUserSession(user, filestream);
RepleyCommandToUser(user, "226 Transfer complete");
}
// 处理PORT命令，使用主动模式进行传输
private void CommandPORT(User user, string portstring)
{
// 主动模式时，客户端必须告知服务器接收数据的端口号，PORT 命令格式为：PORT address
// address参数的格式为i1、i2、i3、i4、p1、p2,其中i1、i2、i3、i4表示IP地址
// 下面通过.字符串来组合这四个参数得到IP地址
// p1、p2表示端口号，下面通过int.Parse(temp[4]) << 8) | int.Parse(temp[5]
// 这个算法来获得一个大于1024的端口来发送给服务器
string sendString = string.Empty;
string[] temp = portstring.Split(',');
string ipString = "" + temp[0] + "." + temp[1] + "." + temp[2] + "." + temp[3];
// 客户端发出PORT命令把客户端的IP地址和随机的端口告诉服务器
int portNum = (int.Parse(temp[4]) << 8) | int.Parse(temp[5]);
user.remoteEndPoint = new IPEndPoint(IPAddress.Parse(ipString), portNum);
sendString = "200 PORT command successful.";
// 服务器以接受到的客户端IP地址和端口为目标发起主动连接请求
// 服务器根据客户端发送过来的IP地址和端口主动发起与客户端建立连接
RepleyCommandToUser(user, sendString);
}
// 处理PASV命令， 使用被动模式进行传输
private void CommandPASV(User user)
{
string sendString = string.Empty;
IPAddress localip = Dns.GetHostEntry("").AddressList[1];
// 被动模式，即服务器接收客户端的连接请求
// 被动模式下FTP服务器使用随机生成的端口进行传输数据
// 而主动模式下FTP服务器使用端口20进行数据传输
Random random = new Random();
int random1, random2;
int port;
while (true)
{
// 随机生成一个端口进行数据传输
random1 = random.Next(5, 200);
random2 = random.Next(0, 200);
// 生成的端口号控制>1024的随机端口
// 下面这个运算算法只是为了得到一个大于1024的端口值
port = random1 << 8 | random2;
try
{
user.dataListener = new TcpListener(localip, port);
AddInfo("TCP 数据连接已打开（被动模式）--" + localip.ToString() + "：" + port);
}
catch
{
continue;
}
user.isPassive = true;
string temp = localip.ToString().Replace('.', ',');
// 必须把端口号IP地址告诉客户端，客户端接收到响应命令后，
// 再通过新的端口连接服务器的端口P，然后进行文件数据传输
sendString = "227 Entering Passive Mode(" + temp + "," + random1 + "," + random2 + ")";
RepleyCommandToUser(user, sendString);
user.dataListener.Start();
break;
}
}
// 处理PASS命令，验证用户名和密码
private void CommandPassword(User user, string command, string param)
{
string sendString = string.Empty;
if (command == "PASS")
{
string password = null;
if (users.TryGetValue(user.userName, out password))
{
if (password == param)
{
sendString = "230 User logged in success";
// 2表示登录成功
user.loginOK = 2;
}
else
{
sendString = "530 Password incorrect.";
}
}
else
{
sendString = "530 User name or password incorrect.";
}
}
else
{
sendString = "501 PASS command Syntax error.";
}
RepleyCommandToUser(user, sendString);
// 用户当前工作目录
user.currentDir = user.workDir;
}
// 使用数据连接发送文件流（客户端发送下载文件命令）
private void SendFileByUserSession(User user, FileStream fs)
{
AddInfo("向用户发送(文件流)：[...");
try
{
if (user.isBinary)
{
byte[] bytes = new byte[1024];
BinaryReader binaryReader = new BinaryReader(fs);
int count = binaryReader.Read(bytes, 0, bytes.Length);
while (count > 0)
{
user.dataSession.binaryWriter.Write(bytes, 0, count);
user.dataSession.binaryWriter.Flush();
count = binaryReader.Read(bytes, 0, bytes.Length);
}
}
else
{
StreamReader streamReader = new StreamReader(fs);
while (streamReader.Peek() > -1)
{
user.dataSession.streamWriter.WriteLine(streamReader.ReadLine());
}
}
AddInfo("...]发送完毕！");
}
finally
{
user.dataSession.Close();
fs.Close();
}
}
// 处理TYPE命令,设置数据传输方式
private void CommandTYPE(User user, string param)
{
string sendstring = "";
if (param == "I")
{
// 二进制
user.isBinary = true;
sendstring = "220 Type set to I(Binary)";
}
else
{
// ASCII方式
user.isBinary = false;
sendstring = "330 Type set to A(ASCII)";
}
RepleyCommandToUser(user, sendstring);
}
// 处理CWD命令，改变工作目录
private void CommandCWD(User user, string temp)
{
string sendString = string.Empty;
try
{
string dir = user.workDir.TrimEnd('/') + temp;
// 是否为当前目录的子目录，且不包含父目录名称
if (Directory.Exists(dir))
{
user.currentDir = dir;
sendString = "250 Directory changed to '" + dir + "' successfully";
}
else
{
sendString = "550 Directory '" + dir + "' does not exist";
}
}
catch
{
sendString = "502 Directory changed unsuccessfully";
}
RepleyCommandToUser(user,sendString);
}
// 处理DELE命令，提供删除功能，删除服务器上的文件
private void CommandDELE(User user, string filename)
{
string sendString = "";
// 删除的文件全名
string path = user.currentDir + filename;
AddInfo("正在删除文件" + filename + "...");
File.Delete(path);
AddInfo("删除成功");
sendString = "250 File " + filename + " has been deleted.";
RepleyCommandToUser(user, sendString);
}