an empty file after sending it to tcp server in python - python

I am new to python and i am trying to make a multithreded tcp server and client to be able to send files between them. I did write some simple codes for these two programs but every time I get empty file on server's site. The file does create in the folder but when I open it it is blank inside. I also tried to send .png files but windows photoviewer doesn't open them saying they are empty. I didn't find anyone encourting such problem so that's why i am asking
Client.py
import socket # Import socket module
HOST = "localhost" # Host address / name
PORT = 2137 # Reserves port for the service
client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client.connect((HOST, PORT))
fileToSend = open('test.txt', 'rb')
print "File ready to be sent"
l = fileToSend.read(1024)
while l:
print "Sending the file"
client.send(l)
l = fileToSend.read(1024)
fileToSend.close() print "done"
client.close()
Server.py
import socket
from threading import Thread
from SocketServer import ThreadingMixIn
import sys
TCPHOST = "localhost"
TCPPORT = 2137
BUFFER_SIZE = 20
class ClientThread(Thread):
def __init__(self, HOST, PORT):
Thread.__init__(self)
self.HOST = HOST
self.PORT = PORT
print "New thread started for " + HOST + " on port " + str(PORT)
def run(self):
f = open('received.py', 'wb')
while True:
try:
data = conn.recv(1024)
except socket.error, e:
print "Error receiving data: %s" % e
sys.exit(1)
while data:
print "Receiving"
f.write(data)
data = conn.recv(1024)
f.close()
try:
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server.bind((TCPHOST, TCPPORT))
print "Socket created"
except socket.error, err:
print "Failed to create socket" % err
threads = []
while True:
server.listen(4)
print "Waiting for connections"
(conn, (HOST, PORT)) = server.accept()
thread = ClientThread(HOST, PORT)
thread.start()
threads.append(thread)
for t in threads:
t.join()

I am not sure what you actually want to do, because I see that you import SocketServer however you are not using it all.
If you are trying to run a simple socket server then the class ClientThread and all the other stuff about threads in that file are not necessary.
The following code in server.py will do the job
import socket
import sys
TCPHOST = "localhost"
TCPPORT = 2137
BUFFER_SIZE = 20
try:
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server.bind((TCPHOST, TCPPORT))
server.listen(4)
print "Socket created"
except socket.error, err:
print "Failed to create socket" % err
while True:
print "Waiting for connections"
(conn, (TCPHOST, TCPPORT)) = server.accept()
try:
while True:
data = conn.recv(1024)
f = open('received.py', 'wb')
if data:
print "Receiving " + data
f.write(data)
else:
f.close()
break;
except socket.error, e:
#pass
print "Error receiving data: %s" % e
#sys.exit(1)
finally:
conn.close()
However if you are trying to implement a threaded TCPServer using the ThreadingMixIn then you need to create a class that subclasses SocketServer and override its handle() function
Python documentation is quite helpful on this
https://docs.python.org/3.5/library/socketserver.html
(ThreadingMixin is at the bottom of the page)

Related

TimeoutError: WinError 10060 on different networks

I'm trying to send a file using in different networks.(Server is on my modem, client is my celluar data). Although i opened a port on my modem, it didn't work.(while on the same network, i can succesfully do the tranfer) I'm getting this error:
TimeoutError: [WinError 10060] A connection attempt failed because the connected party did not properly respond after a period of time, or established connectio n failed because connected host has failed to respond
Like here: Trying to connect socket to server in different networks raises WinError 10060 i've tried to make TCP_IP 0.0.0.0 but it didn't worked.
server.py:
import socket
from threading import Thread
TCP_IP = '192.168.1.29'#i've tried '0.0.0.0'
TCP_PORT = 9001
BUFFER_SIZE = 21000
class ClientThread(Thread):
def __init__(self,ip,port,sock):
Thread.__init__(self)
self.ip = ip
self.port = port
self.sock = sock
# print " New thread started for "+ip+":"+str(port)
def run(self):
filename='mytext.txt'
f = open(filename,'rb')
while True:
l = f.read(BUFFER_SIZE)
while (l):
self.sock.send(l)
l = f.read(BUFFER_SIZE)
if not l:
f.close()
self.sock.close()
break
tcpsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
tcpsock.bind((TCP_IP, TCP_PORT))
#i've tried this too: tcpsock.settimeout(600)
threads = []
while True:
tcpsock.listen(5)
print ("Waiting for incoming connections...")
(conn, (ip,port)) = tcpsock.accept()
print ('Got connection from ', (ip,port))
newthread = ClientThread(ip,port,conn)
newthread.start()
threads.append(newthread)
for t in threads:
t.join()
client.py:
import socket
TCP_IP = '172.2x.xx.x'#my static ip adress
TCP_PORT = 9001
BUFFER_SIZE = 21000
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((TCP_IP, TCP_PORT))
with open('received_file.jpg', 'wb') as f:
print ('file opened')
while True:
#print('receiving data...')
data = s.recv(BUFFER_SIZE)
print('data=%s', (data))
if not data:
f.close()
print ('file close()')
break
# write data to a file
f.write(data)
print('Successfully get the file')
s.close()
print('connection closed')

Python 2.7 UDP Port Scanner

Can you help me with the program now the problem is that when I enter localhost my program cannot find the open port or the closed one, if you really want to help me and you know how to solve it or fix it, please just compile my code separately just for me right now the program for some reason can’t get to receive a message from the host, I searched the entire Internet and can’t find anywhere the scanner has multiple UDP ports
import socket
import sys
# Ask for input
remoteServer = raw_input('Enter a remote host to scan: ')
remoteServerIP = socket.gethostbyname(remoteServer)
print( "-" * 60)
print ('Please wait, scanning remote host', remoteServerIP)
print( "-" * 60)
for port in range(1,1025):
try:
sock=socket.socket(family=socket.AF_INET, type=socket.SOCK_DGRAM)
sock.sendto('hello',(remoteServerIP,port))
#sock.settimeout(1)
data, address = sock.recvfrom(1024)
if data != None:
print ('Port {}: Open'.format(port))
else:
print ('Port {}: Closed'.format(port))
sock.close()
except socket.error as sock_err:
if(sock_err.errno == socket.errno.ECONNREFUSED):
print sock_err('Connection refused')
except socket.gaierror:
print 'Hostname could not be resolved. Exiting'
except socket.error:
print "Couldn't connect to server"
except KeyboardInterrupt:
print 'You pressed Ctrl+C'
Need to use ICMP packet.For the program to work, you need to enter python
I publish my code because the answer to this question is practically nonexistent and the task is actually difficult.
import socket
import sys
import subprocess
def getServiceName(port, proto):
try:
name = socket.getservbyport(int(port), proto)
except:
return None
return name
UDP_IP = sys.argv[1]
for RPORT in range(int(sys.argv[2]), int(sys.argv[3])):
MESSAGE = "ping"
client = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP)
if client == -1:
print("udp socket creation failed")
sock1 = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP)
if sock1 == -1:
print("icmp socket creation failed")
try:
client.sendto(MESSAGE.encode('utf_8'), (UDP_IP, RPORT))
sock1.settimeout(1)
data, addr = sock1.recvfrom(1024)
except socket.timeout:
serv = getServiceName(RPORT, 'udp')
if not serv:
pass
else:
print('Port {}: Open'.format(RPORT))
except socket.error as sock_err:
if (sock_err.errno == socket.errno.ECONNREFUSED):
print(sock_err('Connection refused'))
client.close()
sock1.close()

Python socket: Bad File Descriptor for simple client connection script

My script is very simple.
1.) Server listens for an HTTP connection
2.) Client establishes connection
3.) Server prints our the client's HTTP request data
When a client connects to the server and makes a browser request it triggers the Socket error "Bad File Descriptor".
I'm not sure why it does this. Can anyone help me out?
import socket
host = ''
port = 1000
def proxy(connection,client):
request = connection.recv(MAX_DATA_RECV)
print request
connection.close()
def main():
try:
# create a socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
# associate the socket to host and port
s.bind((host, port))
# listenning
s.listen(BACKLOG)
print("Listening for connections")
except socket.error, (value, message):
if s:
s.close()
print "Could not open socket:", message
# get the connection from client
while 1:
try:
conn, client_addr = s.accept()
print("Received connection from " + str(client_addr))
proxy(conn,client_addr)
#thread.start_new_thread(proxy, (conn,client_addr))
if s:
s.close()
except socket.error, (value,message):
print value
print message
sys.exit(1)
main()
You are closing the server socket after first client. Don't do this.
while True:
try:
conn, client_addr = s.accept()
print("Received connection from " + str(client_addr))
proxy(conn,client_addr)
except socket.error, (value,message):
print value
print message

How to close a connection of a client when multiple clients are connected?

I am having a multi-client server which listens to multiple clients. Now if to one server 5 clients are connected and I want to close the connection between the server and just one client then how am I going to do that.
My server code is:
import socket
import sys
from thread import *
try:
s = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
except socket.error,msg:
print "Socket Creation Error"
sys.exit();
print 'Socket Created'
host = ''
port = 65532
try:
s.bind((host, port))
except socket.error,msg:
print "Bind Failed";
sys.exit()
print "Socket bind complete"
s.listen(10)
print "Socket now listening"
def clientthread(conn):
i=0
while True:
data = conn.recv(1024)
reply = 'OK...' + data
conn.send(reply)
print data
while True:
conn, addr = s.accept()
start_new_thread(clientthread,(conn,))
conn.close()
s.close()

How to keep a socket open until client closes it?

I have simple python server and client.
Server:
import SocketServer
import threading
class MyTCPHandler(SocketServer.BaseRequestHandler):
def handle(self):
self.data = self.request.recv(1024).strip()
print str(self.client_address[0]) + " wrote: "
print self.data
self.request.send(self.data.upper())
if __name__ == "__main__":
HOST, PORT = "localhost", 3288
server = SocketServer.TCPServer((HOST, PORT), MyTCPHandler)
server.serve_forever()
Client:
import socket
import sys
from time import sleep
HOST, PORT = "localhost", 3288
data = "hello"
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
sock.connect((HOST, PORT))
sock.send(data + "\n")
received = sock.recv(1024)
sleep(10)
sock.send(data + "\n")
received = sock.recv(1024)
sleep(10)
sock.send(data + "\n")
received = sock.recv(1024)
finally:
sock.close()
Here is the output I get:
Server:
>python server.py
127.0.0.1 wrote:
hello
Client:
>python client.py
Traceback (most recent call last):
File "client.py", line 18, in <module>
received = sock.recv(1024)
socket.error: [Errno 10053] An established connection was aborted by the software in your host machine
I tried it on a linux machine as well. The server only receives one message and then I get an error on the recv statement of second message. I have just started learning networking on python but I think the server is closing the socket for some reason. How do I correct this?
A MyTcpHandler object is created for each connection, and handle is called to deal with the client. The connection is closed when handle returns, so you have to handle the complete communication from the client within the handle method:
class MyTCPHandler(SocketServer.BaseRequestHandler):
def handle(self):
while 1:
self.data = self.request.recv(1024)
if not self.data:
break
self.data = self.data.strip()
print str(self.client_address[0]) + " wrote: "
print self.data
self.request.send(self.data.upper())
NOTE: recv returns '' when the client closes the connection, so I moved .strip() after the recv so there is no false alarm due to the client sending only white space.
I'll first admit that it's been years since I last used SocketServer, so there might be more idiomatic approaches to solve your problem.
Note that your client opens a single connection and sends three sets of data and receives three sets of data. (Hopefully the TCP stack will send buffered data once you call receive() on the socket.)
Your server is expecting to handle a client connection completely, from start to finish, when it is called from the SocketServer callback mechanism. Your current class does a little bit of IO and then quits. You just need to extend your server callback to do more:
class MyTCPHandler(SocketServer.BaseRequestHandler):
def handle(self):
self.data = self.request.recv(1024).strip()
print str(self.client_address[0]) + " wrote: "
print self.data
self.request.send(self.data.upper())
foo = self.request.recv(1024).strip()
self.request.send(foo.lower())
bar = self.request.recv(1024).strip()
self.request.send("goodbye " + bar)
TO a similar problem here error: [Errno 10053]
I also tried the same thing and got the same error.
If there is a simple code like this to demonstrate this error:
import socket
host = 'localhost'
port = 5001
size = 102400
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host,port))
for msg in ['Hello, world','Test','anything goes here']:
s.send(msg)
data = s.recv(size)
print 'Received:', data
s.close()
If you create a socket object and the amt it can send and echo back from server to see how much it receivers, if you vary that, say 1024 to 102400(in this code);
Which means the socket should not get closed but again in my Windows OS, the server side keeps listening and printing any data that client sends but on the Client side you get this error;
However if it is that the client can connect only once and send and receive only once, then that is how it was designed. Trying this works without any errors:
for msg in ['Hello, world','Test','anything goes here']:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host,port))
s.send(msg)
data = s.recv(size)
s.close()
print 'Received:', data
I am not sure if one socket object works only once to send and recieve data.
UPDATE
I think the issue was the capacity per client socket to receive data as per the buffersize fixed;
That's why the second code snippet above works thus creating new client connection sockets on the server. But that way lots of sockets are going to get used up.
Instead the following code fixed that problem by checking the amt of size being used up. If it exceeds the given amount, it creates a new socket at clients' but makes sure the message is sent; Actually the problem was with the server code but fixed it.
size = 10
This is a quick baby attempt at the code. I am sure you would understand and optimize it for the better!
client code:
messag = ['Hello, world', 'Test', 'anything goes here']
def client_to_server(messag,host,port,size):
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))
countmsg = 0
restmsg = ''
for msg in messag:
strl = tmsg = msg
if len(restmsg):
tmsg = restmsg + ' ' + msg
countmsg = len(tmsg)
if countmsg <= size:
pass
else:
restmsg = tmsg[size:]
tmsg = tmsg[:size]
#s.close()
countmsg = len(tmsg)
#s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
#s.connect((host, port))
print 'Sending to server msg {}'.format(tmsg)
s.send(tmsg)
# s.settimeout(1)
try:
data = s.recv(size)
print 'Received:', data
if strl == data:
print strl,data
countmsg = 0
restmsg = ''
except (socket.error), e:
print e.args,e.message
s.close()
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))
s.close()
if restmsg:
client_to_server([restmsg],host,port,size)
return
client_to_server(messag,host,port,size)
Server Code:
size = 1024 #This has to be bigger than client buf size!
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host, port))
s.listen(backlog)
while True:
#this is what accepts and creates a P2P dedicated client socket per socket
client, address = s.accept()
try:
data = client.recv(size)
while data or 0:
print "Client sent {} | Server sending data to client address {}".format(data, address)
client.send(data)
data = client.recv(size)
else: client.close()
except (socket.error), e:
client.close()
print e.args, e.message
Try it out. This uses the same socket.

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