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Tutorial on implementing FTP using socket

巴扎黑

Jul 18, 2017 pm 01:48 PM

socketserveraccomplish

 
    1、用户加密认证
    2、允许同时多用户登录
    3、每个用户有自己的家目录 ，且只能访问自己的家目录
    4、对用户进行磁盘配额，每个用户的可用空间不同
    5、允许用户在ftp server上随意切换目录
    6、允许用户查看当前目录下文件
    7、允许上传和下载文件，保证文件一致性
    8、文件传输过程中显示进度条
    附加功能：支持文件的断点续传

python 3.5


　　用socketserver实现FTP


　　
　　　　ConfigParser 是Python自带的模块， 用来读写配置文件，将用户信息以下边的格式存入account.py文件，读出后进行判断

[DEFAULT]

[alex]
Password = 123456Quotation = 100[jack]
Password = 123456Quotation = 100

    2、允许同时多用户登录
　　　　　　从scokerserver 继承 socketserver.ThreadingTCPServer即可实现

    3、每个用户有自己的家目录 ，且只能访问自己的家目录
　　　　　　将所有路径封装在home目录下

BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))

USER_HOME = '%s\home' % BASE_DIR
LOG_DIR = '%s\log' % BASE_DIR
LOG_LEVEL = 'DEBUG'

    4、允许用户在ftp server上随意切换目录
　　　　　　用os模块改变工作目录

os.chdir(func_val)

    5、允许用户查看当前目录下文件
　　　　　　用os模块的os.listdir,下为server端代码

    def _ls(self,*args,**kwargs):'''显示当前目录下的所有文件'''if os.getcwd() == '%s\\bin'% settings.BASE_DIR:
            user_home_dir = "%s\%s" % (settings.USER_HOME, self.user["Username"])
            self.request.send(json.dumps(os.listdir(user_home_dir)).encode())else:self.request.send(json.dumps(os.listdir()).encode())

    6、允许上传和下载文件，保证文件一致性
　　　　　　判断上传和下载的文件在传输前后的大小，用以判断文件是否保持一致

  1 #server端  2 #  3     def _put(self,*args,**kwargs):  4         '''上传文件命令'''  5         data = args[0]  6   7         response = self.get_response()  8         if response["status_code"] == 257:  # ready to receive  9             self.request.send(b'1')  # send confirmation to server 10             user_home_dir = "%s\%s" % (settings.USER_HOME, self.user["Username"]) 11             base_filename = "%s\%s" % (user_home_dir, data.get('filename')) 12             received_size = 0 13             file_obj = open(base_filename, 'wb') 14             if data.get('md5'): 15                 md5_obj = hashlib.md5() 16                 while received_size

get and put

    7、文件传输过程中显示进度条
　　　　　　根据已传文件大小和总文件大小比对判断，输出符号

 1     def show_progress(self,total): 2         '''显示进度条 3            total: 文件大小''' 4         received_size = 0 5         current_percent = 0 6         while received_size  current_percent: 8                 print(">",end='',flush=True) 9                 current_percent = int((received_size / total) * 100)10             new_size = yield11             received_size += new_size

进度条

    附加功能：支持文件的断点续传
　　　　　　将上次断点信息记录下来，也就是记录已传文件大小，再次启用时，将目标文件光标移到上次断点处，然后进行续传

 1     def _breakpoint(self,*args,**kwargs): 2         '''断点续传''' 3         data = args[0] 4         if data.get('filename') is None: 5             self.send_response(255) 6         user_home_dir = "%s\%s" % (settings.USER_HOME, self.user["Username"]) 7         file_abs_path = "%s\%s" % (user_home_dir, data.get('filename')) 8         print("file abs path", file_abs_path) 9         print(data.get('breakpoint'))10 11         if os.path.isfile(file_abs_path):12             file_obj = open(file_abs_path, 'rb')13             file_obj.seek(data.get('breakpoint'))14             file_size = os.path.getsize(file_abs_path)15             self.send_response(257, data={'file_size': file_size})16             self.request.recv(1)  # 等待客户端确认17 18             if data.get('md5'):19                 md5_obj = hashlib.md5()20                 for line in file_obj:21                     self.request.send(line)22                     md5_obj.update(line)23                 else:24                     file_obj.close()25                     md5_val = md5_obj.hexdigest()26                     self.send_response(258, {'md5': md5_val})27                     print("send file done...")28             else:29                 for line in file_obj:30                     self.request.send(line)31                 else:32                     file_obj.close()33                     print("send file done...")34         else:35             self.send_response(256)36         pass

breakpoint

　主要知识点：

    类的继承
    os模块的应用
    json模块的应用
    类方法的运用
    md5加密方法
    scoket链接
    scoketserver链接
    反射
    异常处理


小结：
          这个程序主要用socketserver实现了一台服务器链接多个客户端，并且进行信息交互，并且实现了几个简单的功能，如：get 文件下载、put 上传文件、cd 切换目录、ls 查看文件、breakpoint断点续传。

主要代码：

  1 #server端  2 #  3   4   5 import os,sys  6 import hashlib  7 import socket  8 import socketserver  9 import json 10 import configparser 11 from conf import settings 12  13  14 STATUS_CODE = { 15     250 : "Invalid cmd format,e.g:{'action':'get','filename':'test.py','size':344", 16     251 : "Invalid cmd", 17     252 : "Invalid auth data", 18     253 : "Wrong username or password..", 19     254 : "Passed authentication", 20     255 : "Filename doesn't provided", 21     256 : "File doesn't exist on server", 22     257 : "ready to send file", 23     258 : "md5 verification", 24     259 : "Directory has been switched" 25 } 26  27  28  29  30  31 class FTPHandler(socketserver.BaseRequestHandler): 32     '''定义request handler类，从BaseRequestHandler类继承''' 33     def handle(self): 34         ''' 35         获取服务器端的信息 36         如果传来cd命令，改变工作目录 37         ''' 38  39         while True: 40             self.data = self.request.recv(1024).strip() 41             if not self.data: 42                 print('Client closed..') 43                 break 44             data = json.loads(self.data.decode()) 45             if data.get('action') is not None: 46                 if hasattr(self,'_%s'%data.get('action')): 47                     func =getattr(self,'_%s'%data.get('action')) 48                     func_val = func(data) 49                     if data.get('action') == 'cd':     #cd 命令，改变工作目录 50                         os.chdir(func_val) 51                     else:pass 52                 else: 53                     print('Invalid cmd') 54                     self.send_response(251) 55             else: 56                 print('Invalid cmd format') 57                 self.send_response(250) 58  59  60     def send_response(self,status_code,data=None): 61         '''向客户端返回数据''' 62         response = {'status_code': status_code, 'status_msg':STATUS_CODE[status_code]} 63         if data: 64             response.update(data) 65         self.request.send(json.dumps(response).encode()) 66  67  68     def _auth(self,*args,**kwargs): 69         '''判断用户是否输入完整的用户名和密码 70            验证用户名和密码是否合法''' 71         data = args[0] 72         if data.get('username') is None or data.get('password') is None: 73             self.send_response(252) 74  75         user = self.authenticate(data.get('username'),data.get('password')) 76         if user is None: 77             self.send_response(253) 78         else: 79             print('passed authentication',user) 80             self.user = user 81             self.send_response(254) 82  83  84     def authenticate(self,username,password):       # 85         '''验证用户合法性，合法返回用户数据''' 86         config = configparser.ConfigParser() 87         config.read(settings.ACCOUNT_FILE) 88         if username in config.sections(): 89             _password = config[username]['Password'] 90             if _password == password: 91                 print('pass auth..',username) 92                 config[username]["Username"] = username 93                 return config[username] 94  95  96     def get_response(self): 97         '''接收客户端回复结果''' 98         data = self.request.recv(1024) 99         data = json.loads(data.decode())100         return data101 102 103     def show_progress(self,total):104         '''显示进度条105            total: 文件大小'''106         received_size = 0107         current_percent = 0108         while received_size  current_percent:110                 print(">",end='',flush=True)111                 current_percent = int((received_size / total) * 100)112             new_size = yield113             received_size += new_size114 115 116     def _put(self,*args,**kwargs):117         '''上传文件命令'''118         data = args[0]119 120         response = self.get_response()121         if response["status_code"] == 257:  # ready to receive122             self.request.send(b'1')  # send confirmation to server123             user_home_dir = "%s\%s" % (settings.USER_HOME, self.user["Username"])124             base_filename = "%s\%s" % (user_home_dir, data.get('filename'))125             received_size = 0126             file_obj = open(base_filename, 'wb')127             if data.get('md5'):128                 md5_obj = hashlib.md5()129                 while received_size

server端

  1 #client端  2 #  3   4 import socket  5 import hashlib  6 import os,json  7 import optparse  8 import socketserver  9  10  11 STATUS_CODE = { 12     250 : "Invalid cmd format,e.g:{'action':'get','filename':'test.py','size':344", 13     251 : "Invalid cmd", 14     252 : "Invalid auth data", 15     253 : "Wrong username or password..", 16     254 : "Passed authentication", 17     255 : "Filename doesn't provided", 18     256 : "File doesn't exist on server", 19     257 : "ready to send file", 20     258 : "md5 verification", 21     259 : "Directory has been switched" 22 } 23  24  25  26  27 class FTPClient(object): 28     '''客户端''' 29     def __init__(self): 30         '''用户信息输入格式化 31             变量定义''' 32         parser = optparse.OptionParser() 33         parser.add_option('-s', '--server', dest='server', help ='ftp server ip_addr') 34         parser.add_option('-p','--port', type='int', dest='port', help='ftp server port') 35         parser.add_option('-U', '--username', dest='username', help='username') 36         parser.add_option('-P', '--Password', dest='password', help='password') 37         self.options, self.args = parser.parse_args() 38         self.verify_args(self.options,self.args) 39         self.make_connection() 40  41  42     def make_connection(self): 43         '''连接服务器''' 44         self.sock = socket.socket() 45         self.sock.connect((self.options.server,self.options.port)) 46  47  48  49     def verify_args(self,options,args): 50         '''校验参数合法性''' 51         if options.username and options.password: 52             pass 53         elif options.username is None and options.password is None: 54             pass 55         else: 56             if options.username is None or options.password is None: 57                 print('Error:username and password must be provided together..') 58         if options.server and options.port: 59             if options.port > 0 and options.port  current_percent:108                 print(">",end='',flush=True)109                 current_percent = int((received_size / total) * 100)110             new_size = yield111             received_size += new_size112 113 114     def send_response(self,status_code,data=None):115         '''向服务器端返回数据'''116         response = {'status_code': status_code, 'status_msg':STATUS_CODE[status_code]}117         if data:118             response.update(data)119         self.sock.send(json.dumps(response).encode())120 121 122     def get_response(self):123         '''得到服务器端回复结果'''124         data = self.sock.recv(1024)125         data = json.loads(data.decode())126         return data127 128 129     def _get(self,cmd_list):130         '''下载文件'''131         print("get--",cmd_list)132         if len(cmd_list) == 1:133             print("no filename follows...")134             return135         data_header = {136             'action':'get',137             'filename':cmd_list[1]138         }139         if self.__md5_required(cmd_list):140             data_header['md5'] = True141 142         self.sock.send(json.dumps(data_header).encode())143         response = self.get_response()144         print(response)145         try:146             if response["status_code"] == 257:#ready to receive147                 self.sock.send(b'1') #send confirmation to server148                 base_filename = cmd_list[1].split('/')[-1]149                 received_size = 0150                 file_obj = open(base_filename,'wb')151                 if self.__md5_required(cmd_list):152                     md5_obj = hashlib.md5()153                     progress = self.show_progress(response['file_size']) #generator154                     progress.__next__()155                     while received_size " % cmd_list[1],end='')279 280 281     def _breakpoint(self,*args,**kwargs):282         '''断点续传'''283         with open('data\\breakpoint', 'rb') as br_po:284             data_header = json.loads(br_po.read().decode())285             br_po.close()286         if data_header:287             print(data_header)288             self.sock.send(json.dumps(data_header).encode())289             response = self.get_response()290             try:291                 if response["status_code"] == 257:  # ready to receive292                     self.sock.send(b'1')  # send confirmation to server293                     base_filename = data_header['filename'].split('/')[-1]294                     received_size = data_header['breakpoint']295                     file_obj = open(base_filename, 'ab')296                     file_obj.seek(data_header['breakpoint'])297                     if self.__md5_required(data_header):298                         md5_obj = hashlib.md5()299                         progress = self.show_progress(response['file_size'])  # generator300                         progress.__next__()301                         while received_size

client端

Create a TCP server
Idea: create a socket---bind the socket to a local address---monitor the connection---answer TCP client requests in an infinite loop (will return to the client after receiving end socket)---Accept TCP data---Send TCP data---Close sub-socket---Close server socket
from socket import *
from time import ctime

HOST = '' # Indicates that any valid address can be bound
PORT = 2157
BUFSIZ = 1024 # Keyword, size is 1k
ADR= (HOST, PORT)

tcpSerSock = socket(AF_INET, SOCK_STREAM) # Create a network-based, TCP server socket
tcpSerSock.bind(ADR)
tcpSerSock.listen(5) # Only allow 5 connections at the same time

while True: # Infinite loop answer
print 'waiting for connection....'
tcpCliSock, addr = tcpSerSock.accept() # Receive and save the client socket and client address
print '...connected from:', addr

while True:
data = tcpCliSock.recv(BUFSIZ) # Read buffer data
if not data:
break
tcpCliSock.send('{0} {1}' .format(ctime(), data)) #Send information to the client
tcpCliSock.close()
tcpSerSock.close()

Create TCP client
Idea: Create a client socket---connect---send data (exit if the send is empty)---receive data from the buffer (exit if the reception fails)-- -Close client socket
from socket import *

HOST = 'localhost'
PORT = 21567
BUFSIZ = 1024
ADDR = (HOST, PORT)

tcpCliSock = socket(AF_INET, SOCK_STREAM)
tcpCliSock.connect(ADDR)

while True:
data = raw_input('>')
if not data:
break
tcpCliSock.send(data)
data = tcpCliSock.recv(BUFSIZ)
if not data:
break
print data
tcpCliSock.close()

Create a UDP server
Idea: create a socket---bind the socket to a local address--receive data---send data
from socket import *
from time import ctime

HOST = '' # Indicates that any valid address can be bound
PORT = 2157
BUFSIZ = 1024 # Keyword, size is 1k
ADR= (HOST, PORT)

udpSerSock = socket(AF_INET, SOCK_DGRAM)
udpSerSock.bind(ADR)

while True:
print 'waiting for message...'
data, addr = udpSerSock. recvfrom(BUFSIZ)
udpSerSock.sendto('{0} {1}' .format(ctime(), data), addr)
print '...received from and returned to:', addr
udpSerSock.close()

Create a UDp client
Idea: Create a client socket---send data---receive data
from socket import *
from time import ctime

HOST = 'localhost' # Indicates that any valid address can be bound
PORT = 2157
BUFSIZ = 1024 # Keyword, size is 1k
ADDR= (HOST, PORT)

udpCliSock = socket(AF_INET, SOCK_DGRAM)

while True:
data = raw_input('>')
if not data:
break
udpCliSock .sendto(data, ADDR)
data, ADDR = udpCliSock.recvfrom(BUFSIZ)
if not data:
break
print data
udpCliSock.close()

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