Error trying to pass (large) image over socket in python ..

Question

I am trying to pass an image over python socket for smaller images it works fine but for larger images it gives error as

socket.error: [Errno 10040] A message sent on a datagram socket was larger than the internal message buffer or some other network limit, or the buffer used to receive a datagram into was smaller than the datagram itself

I am using

socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

Thanks for any clue .

I tried using SOCK_STREAM, it does not work .. It just says me starting ... and hangs out . with no output .. Its not coming out of send function

import thread
import socket
import ImageGrab

class p2p:
    def __init__(self):
     socket.setdefaulttimeout(50)
     #send port
     self.send_port = 3000
     #receive port
     self.recv_port=2000

     #OUR IP HERE
     self.peerid = '127.0.0.1:'
     #DESTINATION 
     self.recv_peers = '127.0.0.1'

     #declaring sender socket
     self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM )
     self.socket.bind(('127.0.0.1', self.send_port))
     self.socket.settimeout(50)

     #receiver socket
     self.serverSocket=socket.socket(socket.AF_INET, socket.SOCK_STREAM )
     self.serverSocket.bind(('127.0.0.1', self.recv_port))
     self.serverSocket.settimeout(50)

     #starting thread for reception
     thread.start_new_thread(self.receiveData, ())

     #grabbing screenshot
     image = ImageGrab.grab()
     image.save("c:\\test.jpg")
     f = open("c:\\ test.jpg", "rb")
     data = f.read()
     #sending
     self.sendData(data)
     print 'sent...'
     f.close()

     while 1: pass

    def receiveData(self):
     f = open("c:\\received.png","wb")
     while 1:
      data,address = self.serverSocket.recvfrom(1024)
      if not data: break
      f.write(data)
     try:
      f.close()
     except:
      print 'could not save'
     print "received"
    def sendData(self,data):
     self.socket.sendto(data, (self.recv_peers,self.recv_port))
if __name__=='__main__':
    print 'Started......'  
    p2p()

Answer 1

The message you are sending is being truncated.

Since you haven't shown the actual code that sends, I'm guessing you are trying to write the entire image to the socket. You'll have to break the image into several, smaller chunks.

Answer 2

Your image is too big to be sent in one UDP packet. You need to split the image data into several packets that are sent individually.

If you don't have a special reason to use UDP you could also use TCP by specifying socket.SOCK_STREAM instead of socket.SOCK_DGRAM. There you don't have to worry about packet sizes and ordering.