I need the UDP_server to take the request("message") multiple times (5-6 time will be ok) to calculate the arithmetic mean of the recorded response times (the time required from the moment you send the message to the time the response arrives from server). Probably I can do that with a "for", but I don't really know where to place it or to use it.
UDP_server code:
import socket
server_port = 21060
server_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
server_socket.bind(('127.0.0.1', server_port))
print ('[SERVER] Listening at: {}'.format(server_socket.getsockname()))
while True:
message, address = server_socket.recvfrom(65535)
modified_message = str(len(str(message).split(",")))
print ('[SERVER] The client at {}, originally sent: {}'.format(address, repr(message)))
server_socket.sendto(bytes('Server is sending back: "{}".'.format(modified_message), encoding='utf8'), address)
server_socket.close()
UDP_client code:
import socket
import string
import random
from time import time
def random_string(length, chars=string.ascii_letters + string.digits):
return ''.join(random.choice(chars) for x in range(length))
server_port = 21060
client_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
input_s = random_string(100)
sent_time = time()
client_socket.sendto(bytes(input_s, encoding='utf8'), ('127.0.0.1', server_port))
input_s_modified, address = client_socket.recvfrom(65535)
received_time = time()
print ('[CLIENT] Response from server {}, is: "{}"'.format(address, str(input_s_modified.decode('utf8'))))
client_socket.close()
print("Time response =", received_time - sent_time, 'seconds')
Related
OSError: [WinError 10057] A request to send or receive data was disallowed because the socket is not connected and (when sending on a datagram socket using a sendto call) no address was supplied.
I am getting the above error..My server and client can send and receive their first messages but I get this error if I try to send more than one message.
My Server Code is here
import socket
import threading
import time
from tkinter import *
#functions
def t_recv():
r = threading.Thread(target=recv)
r.start()
def recv():
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as listensocket:
port = 5354
maxconnections = 9
ip = socket.gethostbyname(socket.gethostname())
print(ip)
server = (ip, port)
FORMAT = 'utf-8'
listensocket.bind((server))
listensocket.listen(maxconnections)
(clientsocket, address) = listensocket.accept()
msg = f'\[ALERT\] {address} has joined the chat.'
lstbox.insert(0, msg)
while True:
sendermessage = clientsocket.recv(1024).decode(FORMAT)
if not sendermessage == "":
time.sleep(3)
lstbox.insert(0, 'Client: ' +sendermessage)
def t_sendmsg():
s = threading.Thread(target=sendmsg)
s.start()
at = 0
def sendmsg():
global at
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as g:
hostname = 'Lenovo-PC'
port = 5986
if at==0:
g.connect((hostname, port))
msg = messagebox.get()
lstbox.insert(0, 'You: ' +msg)
g.send(msg.encode())
at += 1
else:
msg = messagebox.get()
lstbox.insert(0, 'You: ' +msg)
g.send(msg.encode())
And my client code is same with minor difference
import socket
import time
import threading
from tkinter import *
#functions
def t_recv():
r = threading.Thread(target=recv)
r.start()
def recv():
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as listensocket:
port = 5986
maxconnections = 9
ip = socket.gethostname()
print(ip)
FORMAT = 'utf-8'
host = 'MY_IP' # My actual ip is there in the code
listensocket.bind((host, port))
listensocket.listen(maxconnections)
(clientsocket, address) = listensocket.accept()
while True:
sendermessage = clientsocket.recv(1024).decode(FORMAT)
if not sendermessage == "":
time.sleep(3)
lstbox.insert(0, 'Server: ' +sendermessage)
def t_sendmsg():
s = threading.Thread(target=sendmsg)
s.start()
at = 0
def sendmsg():
global at
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as g:
hostname = 'Lenovo-PC'
port = 5354
if at==0:
g.connect((hostname, port))
msg = messagebox.get()
lstbox.insert(0, 'You: ' +msg)
g.send(msg.encode())
at += 1
else:
msg = messagebox.get()
lstbox.insert(0, 'You: ' +msg)
g.send(msg.encode())
Please let me know what changes are required to be made in order to make it run for every message.
I tried to put
g.connect((hostname, port))
the above line in the loop so that it will connect every time loop iterates. But it did not help.
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as g:
...
if at==0:
g.connect((hostname, port))
...
g.send(msg.encode())
at += 1
else:
...
g.send(msg.encode())
In the if at==0 condition it connects to the server, in the else part not. But is still trying to send something on the not connected socket.
this is for server authentication for my application.
(im working on login function so dont mind about it)
what i wanna do is to make server receive heartbeat from client
and close client socket if its doesnt respond in a few min
also i want to detect number of connections per user.
for receiving heartbeat, i can make the client send heartbeat constantly but
how do you make the server decect it? i know time measurement is needed but
if i put time.perf_counter() right before 'client_socket.recv(1024)' the counter function wont be executed because its waiting on receiving. so how would i solve this?
and im also trying to make it detect number of connections per user. (5 maximum connections per user) for detection, i give username + 1 when a user is connected and give -1 when the user disconnects but im not sure if the method im doing is correct or a good way to do so.
i'd be appreciated if you could help me out
------------------------server----------------------------
import socket
from _thread import *
import sys
import time
username = ['test123', 'hongengi']
userconnect= 0
def threaded(client_socket, addr):
print('Connected by :', addr[0], ':', addr[1])
while True:
try:
data = client_socket.recv(1024)
print (data.decode())
print('Received from ' + addr[0],':',addr[1] , data.decode())
if data.decode() == ".": # heartbeat
heartbeat = time.perf_counter()
print ("heartbeat")
if data.decode() == "test123":
print ("login success")
userconnect == userconnect + 1
if not data:
print ("no data / disconnect ")
print('Disconnected by ' + addr[0],':',addr[1])
userconnect == userconnect - 1
break
client_socket.send(data)
except (ConnectionResetError, socket.error) as e:
print ("error occurs")
print('Disconnected by ' + addr[0],':',addr[1])
userconnect == userconnect - 1
break
client_socket.close()
HOST = '127.0.0.1'
PORT = 5000
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind((HOST, PORT))
server_socket.listen()
print('server start')
while True:
print('wait')
client_socket, addr = server_socket.accept()
start_new_thread(threaded, (client_socket, addr))
server_socket.close()
------------------------client----------------------------
import socket
SERVER_IP = 'localhost'
SERVER_PORT = 5000
SIZE = 100
SERVER_ADDR = (SERVER_IP, SERVER_PORT)
heartbeat = "."
client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client_socket.connect(SERVER_ADDR)
#username = "test123"
#userpass = "123123"
while True:
client_socket.send(heartbeat.encode())
msg = client_socket.recv(SIZE)
print (msg.decode())
One end of a socket is never "notified" when the other socket closes. There is no direct connection, so the only way to tell this is to time out. You can use socket.timeout to establish a timeout time. Your recv will then return with 0 bytes, and that's an indication that your timeout expired.
How to set timeout on python's socket recv method?
I am trying to create a function to send and receive information over a socket client & server. It appears that my code is somehow blocking. In the code the first command iteration in my for loop is carried out but then the process becomes blocked. Does anyone have any suggestions how to do this using threading or multithreading?
My code is below:
import socket
import json
import sys
import time
import select
import queue
Ni_Rio_IP= "172.22.11.2"
Ni_Base_IP= "172.22.11.1"
class AliceRio:
def __init__(self, ip_rio, ip_pc):
self.ip_rio = ip_rio
AliceRio.udp_port_rio = 60006
self.ip_pc = ip_pc
AliceRio.udp_port_pc = 50005
AliceRio.json= '{"Dest":"","Name":"","Time":"","Val":{"Str":[],"Pos":[[]],"Data":[[]]},"IP":0,"Port":0,"RT error":{"status":false,"code":0,"source":""}}'
AliceRio.dict= json.loads(self.json)
def PrintUDP(self):
print("RIO IP: %s" % self.ip_rio)
print("RIO UDP port: %s" % self.udp_port_rio)
print("PC IP: %s" % self.ip_pc)
print("PC UDP port: %s" % self.udp_port_pc)
def SendRec(self, send_str):
# Set up socket for sending
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # Internet, UDP
sock.sendto(bytes(send_str, 'utf-8'), (self.ip_rio, self.udp_port_rio))
sock.close()
print('got here')
# Set up socket for receiving
sock = socket.socket(socket.AF_INET,socket.SOCK_DGRAM) # Internet, UDP
sock.bind((self.ip_pc, self.udp_port_pc))
rec_str, addr = sock.recvfrom(1024) # buffer size is 1024 bytes
print('got here2')
sock.close()
return rec_str
def Receive(self, rec_str):
sock = socket.socket(socket.AF_INET,socket.SOCK_DGRAM) # Internet, UDP
sock.bind((self.ip_pc, self.udp_port_pc))
rec_str, addr = sock.recvfrom(1024) # buffer size is 1024 bytes
sock.close()
return rec_str
def Send(self, send_str):
# Set up socket for sending
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # Internet, UDP
sock.sendto(bytes(send_str, 'utf-8'), (self.ip_rio, self.udp_port_rio))
sock.close()
#return rec_str
def Aim(self, aim_perc):
if aim_perc < 0 or aim_perc > 100: return "aim_perc out of range"
send_dict=AliceRio.dict
send_dict["Dest"]='Rio'
send_dict["Name"]='Laser Control'
Laser_Mode=1
Simmer_A=0
Pulse_A= 0
Pulse_ms= 20
send_dict["Val"]["Str"]=[str(Laser_Mode), str(aim_perc), str(Simmer_A), str(Pulse_A), str(Pulse_ms)]
send_json=json.dumps(send_dict)
# send it out
self.SendRec(send_json)
rec_json= self.SendRec(send_json)
rec_dict=json.loads(rec_json)
return "Aim laser now at " + rec_dict["Val"]["Str"][1] +'%'
def PWM_Laser_Fan(self, fan_perc):
send_dict=AliceRio.dict
send_dict["Dest"]='Rio'
send_dict["Name"]='PWM Laser'
send_dict["Val"]["Str"][0]=str(fan_perc)
send_json=json.dumps(send_dict)
# send it out
rec_json= self.SendRec(send_json)
rec_dict=json.loads(rec_json)
return rec_dict["Val"]["Str"][0]
def Poll(self):
send_dict=AliceRio.dict
send_dict["Dest"]='Rio'
send_dict["Name"]='Poll'
send_json=json.dumps(send_dict)
# send it out
rec_json= self.SendRec(send_json)
rec_dict=json.loads(rec_json)
if rec_dict["Val"]["Data"][0][0]==0: pid_mode='off'
else: pid_mode='PID'
print('PID mode:', pid_mode)
print('Pos X:', rec_dict["Val"]["Data"][0][1])
print('Pos Y:', rec_dict["Val"]["Data"][0][2])
print('Home:', rec_dict["Val"]["Data"][0][3])
print('Enabled:', rec_dict["Val"]["Data"][0][4])
def PIDControl(self, pid_mode,pid_center):
if pid_mode=="off": mode= 0
elif pid_mode=="PID":mode =1
else: return "pid_mode not valid"
if pid_center[0] not in range(-2048,2048): return "center x-pos not in range"
if pid_center[1] not in range(-2048,2048): return "center y-pos not in range"
send_dict=AliceRio.dict
send_dict["Dest"]='Rio'
send_dict["Name"]='PID Control'
send_dict["Val"]["Str"]=[str(mode), str(pid_center[0]), str(pid_center[1])]
send_json=json.dumps(send_dict)
# send it out
rec_json= self.SendRec(send_json)
rec_dict=json.loads(rec_json)
return "PID mode now at " + rec_dict["Val"]["Str"][0]
Alice1 = AliceRio(Ni_Rio_IP, Ni_Base_IP)
Alice1.PrintUDP()
for i in range(10):
Alice1.Aim((i*10)+10)
time.sleep(0.2)
I would suggest learning to use Pdb and trace through the execution of your program to find where it is getting caught.
Also when learning/developing with sockets I've found that it helps to have separate programs for your client and server in the beginning so you can see how both sides are handling exchanges instead of going the threading route to start since the logging can get confusing, best of luck!
Module threading does help in this scenario.
We can create a thread to receiving incoming messages. And when new message received the thread trigger an event to notify the waiting method SendRec.
import sys
import socket
import json
import threading
import time
class AliceRio:
def __init__(self, .....):
# .........
self.s_in = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
self.s_in.bind((self.ip_pc, self.udp_port_pc))
self.evt = threading.Event()
self.last_msg = None
def _recv(self):
while True:
msg, _ = self.s_in.recvfrom(1024)
self.last_msg = msg
self.evt.set()
def SendRec(self, send_str):
if not hasattr(self, 'th_recv'):
th = threading.Thread(target=self._recv)
th.setDaemon(True)
th.start()
self.th_recv = th
self.evt.clear()
rio_endpoint = (self.ip_rio, self.udp_port_rio)
s_out = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s_out.sendto(bytes(send_str, 'utf-8'), rio_endpoint)
s_out.close()
if self.evt.wait(timeout=15.0) and self.last_msg:
return self.last_msg
raise Exception('timeout waiting for response.')
import socket
server=port = 2160
client_socket = socket.socket(AF_INET, socket.SOCK_DGRAM)
input_s = 'hello, server!' # the message
client_socket.sendto(bytes(inpus_s, encoding='utf8'),('127.0.0.1', server_port)) # sending message
input_s_modified, adress = client_socket.recvfrom(65535) # receiving from server
print ('[CLIENT] Response from server {}, is: "{}"'.format(adress, str(input_s_modified.decode('utf8'))))
client_socket.close() # closing socket
You can get the time difference by sending the current timestamp, then having the server send back the difference between the server time and the time that it received in its data.
On the client side, you can prepend the data like so:
# Import the time module
from time import time
...
# Add prefix with client timestamp
input_s = str(time()) + '|hello, server!' # the message
And in the backend / server side code, you can modify the data like so:
# Get the client time
client_time = data.split(b"|")[0]
# Get the time difference
tiime_dif = time() - float(client_time)
# Modify the send data to include the time difference
connection.sendall(str(time_dif).encode() + "|".encode() + data)
When you put all of this info together, you end up with something like this:
# CLIENT
import socket
# Import the time module
from time import time
server=port = 2160
client_socket = socket.socket(AF_INET, socket.SOCK_DGRAM)
# Add prefix with client timestamp
input_s = str(time()) + '|hello, server!' # the message
client_socket.sendto(bytes(inpus_s, encoding='utf8'),('127.0.0.1', server_port)) # sending message
input_s_modified, adress = client_socket.recvfrom(65535) # receiving from server
print ('[CLIENT] Response from server {}, is: "{}"'.format(adress, str(input_s_modified.decode('utf8'))))
client_socket.close() # closing socket
# SERVER
# Get the client time
client_time = data.split(b"|")[0]
# Get the time difference
tiime_dif = time() - float(client_time)
# Modify the send data to include the time difference
connection.sendall(str(time_dif).encode() + "|".encode() + data)
# import socket
# Import the time module
from time import time
server_port = 2160
client_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
# Add prefix with client timestamp
input_s = str(time()) + '|hello, server!' # the message
client_socket.sendto(bytes(input_s, encoding='utf8'),('127.0.0.1', server_port)) #
sending message
input_s_modified, adress = client_socket.recvfrom(65535) # receiving from server
print ('[CLIENT] Response from server {}, is: "{}"'.format(adress,
str(input_s_modified.decode('utf8'))))
client_socket.close() # closing socket
Here is my socket server and client:
import socket
import threading
import chardet
bind_ip = '0.0.0.0'
bind_port = 9999
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind((bind_ip, bind_port))
server.listen(1) # max backlog of connections
print (('Listening on {}:{}').format(bind_ip, bind_port))
def handle_client_connection(client_socket):
request = client_socket.recv(4096 )
result = chardet.detect(request)
print(result)
print (request.decode(result['encoding']))
client_socket.send('ACK!'.encode(result['encoding']))
client_socket.close()
while True:
client_sock, address = server.accept()
print (('Accepted connection from {}:{}').format(address[0], address[1]))
client_handler = threading.Thread(
target=handle_client_connection,
args=(client_sock,) # without comma you'd get a... TypeError: handle_client_connection() argument after * must be a sequence, not _socketobject
)
client_handler.start()
The client is this:
import socket
client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client.connect(('127.0.0.1', 9999))
client.send(str('test data').encode("utf-16"))
response = client.recv(4096)
print(response.decode("utf-16"))
How to make the socket server secured from DOS or DDos attacks?