simple ftp server by python

ftpserver.py

#!/usr/bin/env python3
# coding: utf-8

import os,socket,threading,time
allow_delete = False
local_ip = socket.gethostbyname(socket.gethostname())
local_port = 21
currdir=os.path.abspath('.')

class FTPserverThread(threading.Thread):
    def __init__(self,conn,addr):
        self.conn=conn
        self.addr=addr
        self.basewd=currdir
        self.cwd=self.basewd
        self.rest=False
        self.pasv_mode=False
        threading.Thread.__init__(self)

    def run(self):
        self.conn.send('220 Welcome!\r\n')
        while True:
            cmd=self.conn.recv(256)
            if not cmd: break
            else:
                print ('Recieved:',cmd)
                try:
                    func=getattr(self,cmd[:4].strip().upper())
                    func(cmd)
                except Exception as e:
                    print ('ERROR:',e)
                    #traceback.print_exc()
                    self.conn.send('500 Sorry.\r\n')

    def SYST(self,cmd):
        self.conn.send('215 UNIX Type: L8\r\n')
    def OPTS(self,cmd):
        if cmd[5:-2].upper()=='UTF8 ON':
            self.conn.send('200 OK.\r\n')
        else:
            self.conn.send('451 Sorry.\r\n')
    def USER(self,cmd):
        self.conn.send('331 OK.\r\n')
    def PASS(self,cmd):
        self.conn.send('230 OK.\r\n')
        #self.conn.send('530 Incorrect.\r\n')
    def QUIT(self,cmd):
        self.conn.send('221 Goodbye.\r\n')
    def NOOP(self,cmd):
        self.conn.send('200 OK.\r\n')
    def TYPE(self,cmd):
        self.mode=cmd[5]
        self.conn.send('200 Binary mode.\r\n')

    def CDUP(self,cmd):
        if not os.path.samefile(self.cwd,self.basewd):
            #learn from stackoverflow
            self.cwd=os.path.abspath(os.path.join(self.cwd,'..'))
        self.conn.send('200 OK.\r\n')
    def PWD(self,cmd):
        cwd=os.path.relpath(self.cwd,self.basewd)
        if cwd=='.':
            cwd='/'
        else:
            cwd='/'+cwd
        self.conn.send('257 \"%s\"\r\n' % cwd)
    def CWD(self,cmd):
        chwd=cmd[4:-2]
        if chwd=='/':
            self.cwd=self.basewd
        elif chwd[0]=='/':
            self.cwd=os.path.join(self.basewd,chwd[1:])
        else:
            self.cwd=os.path.join(self.cwd,chwd)
        self.conn.send('250 OK.\r\n')

    def PORT(self,cmd):
        if self.pasv_mode:
            self.servsock.close()
            self.pasv_mode = False
        l=cmd[5:].split(',')
        self.dataAddr='.'.join(l[:4])
        self.dataPort=(int(l[4])<<8)+int(l[5])
        self.conn.send('200 Get port.\r\n')

    def PASV(self,cmd): # from http://goo.gl/3if2U
        self.pasv_mode = True
        self.servsock = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
        self.servsock.bind((local_ip,0))
        self.servsock.listen(1)
        ip, port = self.servsock.getsockname()
        print ('open', ip, port)
        self.conn.send('227 Entering Passive Mode (%s,%u,%u).\r\n' %
                (','.join(ip.split('.')), port>>8&0xFF, port&0xFF))

    def start_datasock(self):
        if self.pasv_mode:
            self.datasock, addr = self.servsock.accept()
            print ('connect:', addr)
        else:
            self.datasock=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
            self.datasock.connect((self.dataAddr,self.dataPort))

    def stop_datasock(self):
        self.datasock.close()
        if self.pasv_mode:
            self.servsock.close()


    def LIST(self,cmd):
        self.conn.send('150 Here comes the directory listing.\r\n')
        self.start_datasock()
        for t in os.listdir(self.cwd):
            k=self.toListItem(os.path.join(self.cwd,t))
            self.datasock.send(buff + buff + buff + '\r\n')
            print ("[+] Crafted packet sent . . . [+]"            )
            #self.datasock.send(buff + buff + '\r\n')
        self.stop_datasock()
        self.conn.send('226 Directory send OK.\r\n')

    def toListItem(self,fn):
        st=os.stat(fn)
        fullmode='rwxrwxrwx'
        mode=''
        for i in range(9):
            mode+=((st.st_mode>>(8-i))&1) and fullmode[i] or '-'
        d=(os.path.isdir(fn)) and 'd' or '-'
        ftime=time.strftime(' %b %d %H:%M ', time.gmtime(st.st_mtime))
        return d+mode+' 1 user group '+str(st.st_size)+ftime+os.path.basename(fn)

    def MKD(self,cmd):
        dn=os.path.join(self.cwd,cmd[4:-2])
        os.mkdir(dn)
        self.conn.send('257 Directory created.\r\n')

    def RMD(self,cmd):
        dn=os.path.join(self.cwd,cmd[4:-2])
        if allow_delete:
            os.rmdir(dn)
            self.conn.send('250 Directory deleted.\r\n')
        else:
            self.conn.send('450 Not allowed.\r\n')

    def DELE(self,cmd):
        fn=os.path.join(self.cwd,cmd[5:-2])
        if allow_delete:
            os.remove(fn)
            self.conn.send('250 File deleted.\r\n')
        else:
            self.conn.send('450 Not allowed.\r\n')

    def RNFR(self,cmd):
        self.rnfn=os.path.join(self.cwd,cmd[5:-2])
        self.conn.send('350 Ready.\r\n')

    def RNTO(self,cmd):
        fn=os.path.join(self.cwd,cmd[5:-2])
        os.rename(self.rnfn,fn)
        self.conn.send('250 File renamed.\r\n')

    def REST(self,cmd):
        self.pos=int(cmd[5:-2])
        self.rest=True
        self.conn.send('250 File position reseted.\r\n')

    def RETR(self,cmd):
        fn=os.path.join(self.cwd,cmd[5:-2])
        #fn=os.path.join(self.cwd,cmd[5:-2]).lstrip('/')
        print ('Downlowding:',fn)
        if self.mode=='I':
            fi=open(fn,'rb')
        else:
            fi=open(fn,'r')
        self.conn.send('150 Opening data connection.\r\n')
        if self.rest:
            fi.seek(self.pos)
            self.rest=False
        data= fi.read(1024)
        self.start_datasock()
        while data:
            self.datasock.send(data)
            data=fi.read(1024)
        fi.close()
        self.stop_datasock()
        self.conn.send('226 Transfer complete.\r\n')

    def STOR(self,cmd):
        fn=os.path.join(self.cwd,cmd[5:-2])
        print ('Uplaoding:',fn)
        if self.mode=='I':
            fo=open(fn,'wb')
        else:
            fo=open(fn,'w')
        self.conn.send('150 Opening data connection.\r\n')
        self.start_datasock()
        while True:
            data=self.datasock.recv(1024)
            if not data: break
            fo.write(data)
        fo.close()
        self.stop_datasock()
        self.conn.send('226 Transfer complete.\r\n')

class FTPserver(threading.Thread):
    def __init__(self):
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.sock.bind((local_ip,local_port))
        threading.Thread.__init__(self)

    def run(self):
        self.sock.listen(5)
        while True:
            th=FTPserverThread(self.sock.accept())
            th.daemon=True
            th.start()

    def stop(self):
        self.sock.close()

if __name__=='__main__':
    ftp=FTPserver()
    ftp.daemon=True
    ftp.start()
    print ('On', local_ip, ':', local_port)
    input('Enter to end...\n')
    ftp.stop()

Hello Zoe, I am currently working on your ftpserver.py script, I manage to have the port listening but do not allow me to log in anonymously. How do you go about logging in? and also can use this scirpt via the Filezilla client

Thank you for your help :)