#***********************#
# Elias Sepuru #
# Boikanyo Radiokana #
# FTP Server #
# 07-May-2019 #
#***********************#
import socket
import os
import time
import threading
import math
class serverThread(threading.Thread):
def __init__(self, conn, addr,usersDB, currDir,IP, port):
threading.Thread.__init__(self)
self.conn = conn
self.addr = addr
self.serverIP = IP
self.serverPort = port
self.baseWD = currDir
self.cwd = self.baseWD
self.rest = False
self.PASVmode = False
self.isLoggedIn = False
self.users = usersDB
self.validUser = False
self.isConnected = True
self.islist = False
self.mode = 'I' #Default Mode
self.allowDelete = True
def run(self):
self.isConnected = True
# Welcome Message
resp = '220 Welcome!'
self.sendReply(resp)
# Await for connection from clients
while True:
cmd = self.conn.recv(256).decode()
if not cmd or not self.isConnected : break
else:
print('Recieved: ', cmd)
try:
func = getattr(self,cmd[:4].strip().upper())
func(cmd)
except Exception as err:
print('Error: ', err)
resp = '500 Syntax error, command unrecognized.'
self.sendReply(resp)
self.conn.close()
def sendReply(self,reply):
self.conn.send((reply + '\r\n').encode())
def notLoggedInMSG(self):
res = '530 Please login with USER and PASS.'
self.sendReply(res)
def paramError(self,cmd):
res = '501 \'' + cmd[:-2] + '\': parameter not understood.'
self.sendReply(res)
def resetState(self):
# RESET STATE of affairs
self.isLoggedIn = False
self.validUser = False
self.user = None
def SYST(self,cmd):
resp = '215 UNIX Type: L8.'
self.sendReply(resp)
def USER(self,cmd):
#RESET STATE, Incase someone logs in while the other is still logged in
self.resetState()
# Extract username in the command
self.user = cmd[5:-2]
# Read users file
users = open(self.users, 'r').read()
# Check if user exists on the database
for u in users.split('\n'):
if self.user == u.split(' ')[0] and len(u.split(' ')[0]) != 0:
self.validUser = True
resp = '331 User name okay, need password.'
self.sendReply(resp)
break
if not self.validUser:
resp = '530 Invalid User.'
self.sendReply(resp)
self.validUser = False
def PASS(self,cmd):
# Check if user name is entered
if self.validUser:
password = cmd[5:-2]
pws = open(self.users, 'r').read()
# Check if password matches user
for p in pws.split('\n'):
if len(p.split(' ')[0]) != 0:
if password == p.split(' ')[1] and self.user == p.split(' ')[0]:
self.isLoggedIn = True
resp = '230 User logged in, proceed.'
self.sendReply(resp)
break
if not self.isLoggedIn:
resp = '530 Invalid password for ' + self.user
self.sendReply(resp)
else:
self.notLoggedInMSG()
def QUIT(self,cmd):
# If the user is logged in, they are logged out
if self.isLoggedIn:
self.resetState()
resp = '221 Logged out'
self.sendReply(resp)
else:
resp = '221 Service closing control connection'
self.sendReply(resp)
self.isConnected = False
def STRU(self,cmd):
# Obsolete command
stru = cmd[5]
if stru == 'F':
resp = '200 F.'
else:
resp = '504 Command obsolete'
self.sendReply(resp)
def MODE(self,cmd):
# Obsolete command
mode = cmd[5]
if mode == 'S':
resp = '200 MODE set to stream.'
else:
resp = '504 Command obsolete'
self.sendReply(resp)
def NOOP(self,cmd):
# To check if the connection is alive
resp = '200 OK.'
self.sendReply(resp)
def TYPE(self,cmd):
# ASCII or Binary Mode
mode = cmd[5]
# Confirm I or A
if mode.upper() == 'I':
self.mode = mode
resp = '200 Binary mode.'
self.sendReply(resp)
elif mode.upper() == 'A':
self.mode = mode
resp = '200 ASCII mode.'
self.sendReply(resp)
else:
# Unknown parameter
self.paramError(cmd)
def PWD(self,cmd):
# Cant't print working directory if not looged in
if self.isLoggedIn:
# The path relative to the root
tempDir = '/' + self.cwd
cwd = os.path.relpath(tempDir,'/')
if cwd == '.':
cwd = '/'
else:
cwd = '/' + cwd
resp = '257' + ' "' + cwd + '" is the current dir.'
self.sendReply(resp)
else:
self.notLoggedInMSG()
def CWD(self,cmd):
if self.isLoggedIn:
# Get the directory
chwd = cmd[4:-2]
# Base directory?
if chwd == '.' or chwd == '/':
self.cwd = self.baseWD
resp = '250 OK.'
self.sendReply(resp)
else:
# Consider /dir or dir
if chwd[0] == '/':
chwd = chwd[1:]
tempCwd = os.path.join(self.cwd, chwd)
# Does the path exist?
if os.path.exists(tempCwd):
self.cwd = tempCwd
resp = '250 OK.'
self.sendReply(resp)
else:
resp = '550 The system cannot find the file specified.'
self.sendReply(resp)
else:
self.notLoggedInMSG()
def PASV(self,cmd):
# Cant't try to establish connection without logging in
if self.isLoggedIn:
self.PASVmode = True
self.serverSocket = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
self.serverSocket.bind((self.serverIP,0))
self.serverSocket.listen(1)
ip, port = self.serverSocket.getsockname()
# Condition IP with the RFC959 standard
ip = ip.split('.')
ip = ','.join(ip)
# Condition the port with the RFC959 standard
p1 = math.floor(port/256)
p2 = port%256
print('open...\nIP: ' + str(ip) +'\nPORT: '+ str(port))
# Prepare the connection settings for take-off
resp = '227 Entering Passive Mode (' + str(ip) + ',' + str(p1) + ',' +str(p2) + ').'
self.sendReply(resp)
else:
self.notLoggedInMSG()
def PORT(self,cmd):
# Cant't try to establish connection without logging in
if self.isLoggedIn:
# check if Passive Mode
if self.PASVmode:
self.serverSocket.close()
self.PASVmode = False
# Split the connection settings
conSettings = cmd[5:].split(',')
# Generate the IP address from the connection settings
self.DTPaddr = '.'.join(conSettings[:4])
# Generate the PORT from the connection settings
# This is with respect to RFC959
self.DTPport = ((int(conSettings[4])<<8)) + int(conSettings[5])
print('Connected to :', self.DTPaddr, self.DTPport)
# Acknowledge
resp = '200 Got it.'
self.sendReply(resp)
self.DTPsocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.DTPsocket.connect((self.DTPaddr,self.DTPport))
else:
self.notLoggedInMSG()
def startDTPsocket(self):
try:
if self.PASVmode:
self.DTPsocket, addr = self.serverSocket.accept()
print('connect: ', addr)
except socket.error:
resp = '425 Cannot open Data Connection'
self.sendReply(resp)
def stopDTPsocket(self):
self.DTPsocket.close()
if self.PASVmode:
self.serverSocket.close()
def sendData(self, data):
# Mode of sending?
if not self.islist and self.mode == 'I':
self.DTPsocket.send((data))
else:
self.DTPsocket.send((data+'\r\n').encode())
def LIST(self,cmd):
# Can't list if not logged in
if self.isLoggedIn:
resp = '150 File status okay; about to open data connection.'
self.sendReply(resp)
print('list: ', self.cwd)
# Ready the socket for data transfer
self.startDTPsocket()
# Get each file in the directory
for l in os.listdir(self.cwd):
ll = self.toList(os.path.join(self.cwd,l))
# Send as str/ASCII
self.islist = True
self.sendData(ll)
self.islist = False
# Done
self.stopDTPsocket()
resp = '200 Listing completed.'
self.sendReply(resp)
else:
self.notLoggedInMSG()
def toList(self,l):
st = os.stat(l)
fullmode ='rwxrwxrwx'
mode = ''
# Prep the directory listing with regards to RFC959
for i in range(9):
mode+=((st.st_mode>>(8-i))&1) and fullmode[i] or '-'
d = (os.path.isdir(l)) and 'd' or '-'
fhist = time.strftime(' %b %d %H:%M ',time.gmtime(st.st_mtime))
return d + mode+ '\t1 user'+'\t group \t\t' + str(st.st_size) + '\t' + fhist + '\t' + os.path.basename(l)
def MKD(self,cmd):
#Can't make new directory if not logged in
if self.isLoggedIn:
dirName = os.path.join(self.cwd,cmd[4:-2])
os.mkdir(dirName)
resp = '257 Directory created.'
self.sendReply(resp)
else:
self.notLoggedInMSG()
def RMD(self,cmd):
# Can't delete directory if not logged in
if self.isLoggedIn:
dirName = os.path.join(self.cwd,cmd[4:-2])
# Check if specified path exists
if os.path.exists(dirName):
# Allow deletion if only deletion is allowed
if self.allowDelete:
os.rmdir(dirName)
resp = '250 Directory deleted.'
self.sendReply(resp)
else:
resp = '450 Not allowed.'
self.sendReply(resp)
else:
resp = '550 The system cannot find the file specified.'
self.sendReply(resp)
else:
self.notLoggedInMSG()
def STOR(self,cmd):
# Cant store files if not logged in
if self.isLoggedIn:
# Create file path
fileName = os.path.join(self.cwd,cmd[5:-2])
print('Uploading: ', fileName)
# Upload mode?
if self.mode == 'I':
oFile = open(fileName,'wb')
else:
oFile = open(fileName, 'w')
resp = '150 Opening data connection.'
self.sendReply(resp)
# Ready the socket for upload
self.startDTPsocket()
# Get the file
while True:
data = self.DTPsocket.recv(8192)
#print(data)
if not data:
break
oFile.write(data)
# Done
self.stopDTPsocket()
resp = '226 Transfer complete.'
self.sendReply(resp)
print('Upload success')
oFile.close()
else:
self.notLoggedInMSG()
def RETR(self,cmd):
# Cant retrieve files if not logged in
if self.isLoggedIn:
fileName = os.path.join(self.cwd, cmd[5:-2])
# For Filezilla
if fileName[0] == '/':
fileName = fileName[1:]
# Check if file exist
if os.path.exists(fileName):
print('Downloading :', fileName)
# Mode?
if self.mode == 'I':
rFile = open(fileName, 'rb')
else:
rFile = open(fileName, 'r')
# Open data connection
resp = '150 Opening file data connection.'
self.sendReply(resp)
data = rFile.read(8192)
self.startDTPsocket()
# Send the file
while data:
self.sendData(data)
data = rFile.read(8192)
rFile.close()
self.stopDTPsocket()
resp = '226 Transfer complete.'
self.sendReply(resp)
else:
# File does not exist
resp = '550 The system cannot find the file specified.'
self.sendReply(resp)
else:
self.notLoggedInMSG()
class FTPserver(threading.Thread):
# The lookout class, waits for contact from client
def __init__(self,usersDB,homeDir,IP,Port):
self.sock = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
self.serverIP = IP
self.serverPort = Port
self.sock.bind((self.serverIP, self.serverPort))
self.usersDB = usersDB
self.homeDir = homeDir
threading.Thread.__init__(self)
def run(self):
self.sock.listen(5)
while True:
connectionSocket, addr = self.sock.accept()
thread = serverThread(connectionSocket, addr,self.usersDB, self.homeDir,self.serverIP,self.serverPort)
thread.daemon = True
thread.start()
def stop(self):
self.sock.close()
def Main():
serverPort = 21
#! For some reason this now gives localhost only
#! serverIP = socket.gethostbyname(socket.gethostname())
#* New method
server = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
server.connect(("8.8.8.8", 80))
serverIP = server.getsockname()[0]
# Database for users
users = './users.txt'
# Default directory
homeDir = '../'
# Make new thread for each new connection
cThread = FTPserver(users,homeDir,serverIP,serverPort)
cThread.daemon = True
cThread.start()
# Wait for contact
print('FTP-Application running on', serverIP, ':', serverPort)
input('Enter to end...\n')
cThread.stop()
Main()