CODEWITHSUNDEEP
python
crypto
crypto

Reputation: 11

Python server-client relationship over network problems

I wrote a program for my networking class that measures upload and download speeds by sending a file over a socket and timing the transfer, and I used Python. The problem I'm having is that the server and client can talk just fine when running on the same machine, but as soon as I put the server program on another machine on my network, no file transfer happens. They talk to each other (Client says "connected to server" and server says "connection from xxx.xxx.xxx.xxx") but the file transfer size and speed are shown as 0 and 0.

Here's the server code:

import util
import socket
import os
import shutil
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = ""
port = 12345
f = open("receivedfromclient.txt", "r+")
print "Waiting for clients..."
s.bind((host, port))
s.listen(5)
c, addr = s.accept()
print "Client connected:", addr
start = time.clock()
msg = c.recv(257024)
stop = time.clock()
duration = stop-start
f.write(str(msg))
b = os.path.getsize("receivedfromclient.txt")
print "File size = ", b, "bits"
print "Time to transfer from client  = ", duration, " seconds"
bw = (b/duration)/1048576
print "The upload bit rate is ", bw, "Mpbs"
f.close()
shutil.copy("receivedfromclient.txt", "sendtoclient.txt")
f.open("sendtoclient.txt")
c.send(f.read())
f.close()
c.close()
s.close()

and the client code is similar:

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = raw_input("Please enter host address: ")#socket.gethostname()
port = 12345
sendfile = raw_input("Please enter name of file to transfer: ")
f = open(sendfile,"rb")
g = open("receivedfromserver.txt","w")
print "Connecting to ", host, port
s.connect((host, port))
s.send(f.read())

and so on. Can anybody tell me what I'm doing wrong here?

Upvotes: 1

Views: 383

Answers (1)

Andreas Florath
Andreas Florath

Reputation: 4612

Hmm - there are at least some problems:

The major one is, that IMHO it is not clear what you really want to do.

Here is your code with some remarks:

# import util <-- NOT NEEDED
import socket
import os
import shutil
import time # <-- Added
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = ""
port = 12345
f = open("receivedfromclient.txt", "r+")
print "Waiting for clients..."
s.bind((host, port))
s.listen(5)
c, addr = s.accept() # <-- FORGOTTEN ()
print "Client connected:", addr
start = time.clock()
msg = c.recv(257024) # <-- You need some loop here to get the whole file
stop = time.clock()
duration = stop-start
f.write(str(msg))
b = os.path.getsize("receivedfromclient.txt") # <-- = instead of .
print "File size = ", b, "bits"
print "Time to transfer from client  = ", duration, " seconds"
bw = (b/duration)/1048576
print "The upload bit rate is ", bw, "Mpbs"
f.close()
shutil.copy("receivedfromclient.txt", "sendtoclient.txt")
f.open("sendtoclient.txt")
c.send(f.read())
f.close()
c.close()
s.close()

One problem here is, that start is in mostly all cases equal to stop - so you get a Division By Zero error in (b/duration).

In the client part at least a import socket is missing; the g is not needed at all.

Please explain further, what you want to do.

If you want to transfer files, there are a lot of ways to do (sftp, rsync, nc, ...).

Upvotes: 0

Related Questions