diff --git a/application/models/Pureftp.php b/application/models/Pureftp.php
new file mode 100644
index 00000000..538ec8c6
--- /dev/null
+++ b/application/models/Pureftp.php
@@ -0,0 +1,90 @@
+<?php
+class Pureftp
+{
+	public $db;
+	public $pwd;
+	public $time;
+	public $data_path='/home/wlx/qhhdata';
+	
+	function __construct()
+	{
+	}
+	
+	// deal with online & offline user
+	// online user, the $user->path is a string, which is a path omit the $data_path (e.g., /test/data means the physical path is $data_path/test/data)
+	// offline user, the $user->path is an array of string
+	function createuser($user)
+	{
+		$this->insert_user($user);
+		// add system link directory
+		if (is_array($user->path))
+		{
+			foreach ($user->path as $path)
+				symlink($path,'/home/ftp/'.$user->username.'/'.str_replace('/','-',substr($path,strlen($this->data_path)+1)));
+		} else {
+			//online path, only one path
+			symlink($this->data_path.$user->path,'/home/ftp/'.$user->username.'/'.str_replace('/','-',substr($user->path,1)));
+		}
+		return $this->update_pwd($user);
+	}
+	
+	/*
+	 * insert user into pureftp table
+	 * param $user: username,
+	 * return null
+	 */
+	private function insert_user($user)
+	{
+		//插入到pureftp表中
+		$sql=$this->db->quoteInto("select * from pureftp where userid=?",$user->username);
+		$u=$this->db->fetchRow($sql);
+		if (empty($u))
+		{
+			$sql="insert into pureftp (userid,passwd,homedir) values('".$user->username."','".$user->password."','".'/home/ftp/'.$user->username."')";
+			$this->db->query($sql);
+			//create user home dir
+			mkdir('/home/ftp/'.$user->username);
+		}
+	}
+		
+	/* 
+	 * update password in the table used by pureftp
+	 * param $user: password,id,time,username
+	 * return: bool
+	 */
+	private function update_pwd($user)
+	{
+		$this->pwd=$user->password;//初始化
+		$this->time=$user->time;
+		//判断用户密码是否失效，或用户一次下载数据已经达到上限
+		$sql=$this->db->quoteInto("select * from ftpuser where userid=?",$user->id);
+		$u=$this->db->fetchRow($sql);
+		if (empty($u)) {
+			//插入ftpuser信息
+			$sql="insert into ftpuser (userid,pwd,ts_created,ts_invalid,datacount) values(?,?,now(),?,1)";
+			$this->db->query($sql,array($user->id,$user->password,$user->time));
+			return true;
+		} elseif (strtotime($u['ts_invalid'])<=time() or $u['datacount']<1) {
+			//更新用户密码和数据计数
+			$sql="update pureftp set passwd='".$user->password."' where userid='".$user->username."'";
+			//$this->db->query($sql,array($user->password,$user->username));
+			$this->db->query($sql); 
+			$sql="update ftpuser set pwd=?,ts_created=now(),ts_invalid=?,datacount=1 where userid=?";
+			$this->db->query($sql,array($user->password,$user->time,$user->id));
+			return true;			
+		} elseif (strtotime($u['ts_invalid'])>time()/* && $u['datacount']<$user->maxdata*/) {
+			//更新数据计数
+			//同步ftpuser和pureftp用户密码
+			$sql="update ftpuser set ts_invalid=?,datacount=datacount+?,pwd=pureftp.passwd 
+				from pureftp where ftpuser.userid=? and pureftp.userid=?";
+			$this->db->query($sql,array($user->time,$user->datacount,$user->id,$user->username));
+			$sql="select pwd,ts_invalid from ftpuser where userid=?";
+			$u=$this->db->fetchRow($sql,array($user->id));
+			$this->pwd=$u['pwd'];
+			$this->time=$u['ts_invalid'];			
+			return true;		
+		} else //同时下载数据数超过限制
+			return false;	
+	}	
+}
+?>
\ No newline at end of file