Develop Reference

Unable to get Socket to receive packets

I'm trying to send a message from Client to Server using socket. For some reason, the message is not received. example: the client sends 'myname_0' the server needs to receive it and decode it and continue further.
Listener:
import socket
class SocketSender():
def __init__(self):
self.sock = socket.socket()
ip = socket.gethostname() # IP to server.
port = 7000
self.sock.bind((ip, port))
print("Binding successful.")
self.sock.listen(2)
print("Listening....")
self.listening = True
# self.sock.connect((ip, port))
# print("Connected.")
def sendpacket(self, packet):
self.sock.send(packet.encode())
def receivepacket(self):
while self.listening:
con, addr = self.sock.accept()
print("Receiving packet from " + str(addr))
packet = self.sock.recv(1024).decode("utf-8")
return str(packet)
Sender:
import socket
sock = socket.socket()
ip = socket.gethostname()
port = 7000
sock.connect((ip, port))
print("connection to " + ip)
message = "test_0"
sock.send(message.encode("utf-8"))
When run:
import GUI
import SocketSender
# Entry: 0, Exit: 1
gui = GUI.ASGui()
# gui.run()
socket = SocketSender.SocketSender()
id = input()
while 1 == 1:
packet = socket.receivepacket()
name, state = packet.split("_")
break
if state == 0:
print("Welcome back, " + name)
else:
if state == 1:
print("Goodbye, " + name)
I do get the outputs Listening and Binded. But I am unable to receive a message. Help would be appreciated. Thank you.

How to implement iperf module for Bandwidth monitoring in this python chatroom?

https://iperf.fr/iperf-doc.php
https://iperf.fr/
//server.py
import socket
import select
import sys
from thread import *
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
if len(sys.argv) != 3:
print "Correct usage: script, IP address, port number"
exit()
IP_address = str(sys.argv[1])
Port = int(sys.argv[2])
server.bind((IP_address, Port))
server.listen(100)
list_of_clients = []
def clientthread(conn, addr):
conn.send("Welcome to this chatroom!")
while True:
try:
message = conn.recv(2048)
if message:
print "<" + addr[0] + "> " + message
message_to_send = "<" + addr[0] + "> " + message
broadcast(message_to_send, conn)
else:
remove(conn)
except:
continue
def broadcast(message, connection):
for clients in list_of_clients:
if clients!=connection:
try:
clients.send(message)
except:
clients.close()
remove(clients)
def remove(connection):
if connection in list_of_clients:
list_of_clients.remove(connection)
while True:
conn, addr = server.accept()
list_of_clients.append(conn)
print addr[0] + " connected"
start_new_thread(clientthread,(conn,addr))
conn.close()
server.close()
The client side script will simply attempt to access the server socket created at the specified IP address and port. Once it connects, it will continuously check as to whether the input comes from the server or from the client, and accordingly redirects output. If the input is from the server, it displays the message on the terminal. If the input is from the user, it sends the message that the users enters to the server for it to be broadcasted to other users.
//client.py
import socket
import select
import sys
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
if len(sys.argv) != 3:
print "Correct usage: script, IP address, port number"
exit()
IP_address = str(sys.argv[1])
Port = int(sys.argv[2])
server.connect((IP_address, Port))
while True:
sockets_list = [sys.stdin, server]
read_sockets,write_socket, error_socket = select.select(sockets_list,[],[])
for socks in read_sockets:
if socks == server:
message = socks.recv(2048)
print message
else:
message = sys.stdin.readline()
server.send(message)
sys.stdout.write("<You>")
sys.stdout.write(message)
sys.stdout.flush()
server.close()

Python sockets connecting but no data transfer

Just started learning python socket programming. I'm trying to send and receive data from a Raspberry Pi 3 using python sockets. I'm running the server program on the Raspberry Pi and the client program on my laptop running Ubuntu. Both are on the same WiFi network. The program runs and the client connects to the server, but there is no data transfer. Both the client and server do nothing. The two programs run properly if I try to run them both on the same device. Here's my code :-
Client
import socket
HOST = '172.16.31.51'
PORT = 5000
BUFSIZ = 1024
if __name__ == '__main__':
client_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = input("Enter hostname [%s]: " %HOST) or HOST
port = input("Enter port [%s]: " %PORT) or PORT
sock_addr = (host, int(port))
client_sock.connect(sock_addr)
payload = 'GET TIME'
try:
while True:
client_sock.send(payload.encode('utf-8'))
data = client_sock.recv(BUFSIZ)
print(repr(data))
more = input("Want to send more data to server[y/n]:")
if more.lower() == 'y':
payload = input("Enter payload: ")
else:
break
except KeyboardInterrupt:
print("Exited by user")
client_sock.close()
Server
import socket
from time import ctime
PORT = 5000
BUFSIZ = 1024
ADDR = ('', PORT)
if __name__ == '__main__':
server_socket = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
server_socket.bind(ADDR)
server_socket.listen(5)
server_socket.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR, 1)
while True:
print('Server waiting for connection...')
client_sock, addr = server_socket.accept()
print('Client connected from: ', addr)
while True:
data = client_sock.recv(BUFSIZ)
if not data or data.decode('utf-8') == 'END':
break
print("Received from client: %s" % data.decode('utf-8'))
print("Sending the server time to client: %s" %ctime())
try:
client_sock.send(bytes(ctime(), 'utf-8'))
except KeyboardInterrupt:
print("Exited by user")
client_sock.close()
server_socket.close()
EDIT:
The screenshots - https://imgur.com/a/NgzsC
As soon as I hit Ctrl + C, on the client side, the server seems to send some data before it disconnects from the client. Here's a screenshot of that - https://imgur.com/a/hoLwN

Your sockets work OK, but you made some other programming mistakes. Did you ever run it?
This is the modified working code.
(Hint: you can start testing just the client when you use nc -l 5000 as a simple manual server.
Client
import socket
HOST = '127.0.0.1'
PORT = 5000
BUFSIZ = 1024
if __name__ == '__main__':
client_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = str(raw_input("Enter hostname [%s]: " %HOST)) or HOST
port = str(raw_input("Enter port [%s]: " %PORT)) or PORT
sock_addr = (host, int(port))
client_sock.connect(sock_addr)
payload = 'GET TIME'
try:
while True:
client_sock.send(payload.encode('utf-8'))
data = client_sock.recv(BUFSIZ)
print(repr(data))
more = raw_input("Want to send more data to server[y/n]:")
if more.lower() == 'y':
payload = str(raw_input("Enter payload: "))
else:
break
except KeyboardInterrupt:
print("Exited by user")
client_sock.close()
Server
import socket
from time import ctime
PORT = 5004
BUFSIZ = 1024
ADDR = ('', PORT)
if __name__ == '__main__':
server_socket = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
server_socket.bind(ADDR)
server_socket.listen(5)
server_socket.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR, 1)
while True:
print('Server waiting for connection...')
client_sock, addr = server_socket.accept()
print('Client connected from: ', addr)
while True:
data = client_sock.recv(BUFSIZ)
if not data or data.decode('utf-8') == 'END':
break
print("Received from client: %s" % data.decode('utf-8'))
print("Sending the server time to client: %s" %ctime())
try:
client_sock.send( ctime().encode('utf-8') )
except KeyboardInterrupt:
print("Exited by user")
break;
client_sock.close()
server_socket.close()

Bad data being received

I am writing a client and server app in Python and I have a problem with received data. In the first "loop" I received good data but in the next "loop" I received bad data. What do I have to do? Maybe you have a better idea to send and receive data.
This is Client:
import socket
import pickle
import sys
host = socket.gethostname()
port = 2004
BUFFER_SIZE = 100000
print("What you want to do:\r1. Select from base\r2.Insert into base")
MESSAGE, MESSAGE1 = input("tcpClientA: Enter message/ Enter exit:").split(",")
tcpClientA = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpClientA.connect((host, port))
while MESSAGE != 'exit':
tcpClientA.send(MESSAGE.encode())
tcpClientA.send(MESSAGE1.encode())
lista=pickle.loads(tcpClientA.recv(BUFFER_SIZE).strip())
print(lista)
print("Variables 1 and 2 are: ", MESSAGE, MESSAGE1)
MESSAGE, MESSAGE1 = input("tcpClientA: Enter message to continue/ Enter exit:").split(",")
tcpClientA.close()
This is Server:
import socket
from threading import Thread
import pyodbc
import pickle
# Multithreaded Python server : TCP Server Socket Thread Pool
class ClientThread(Thread):
def __init__(self,ip,port):
Thread.__init__(self)
self.ip = ip
self.port = port
print ("[+] New server socket thread started for " + ip + ":" + str(port) )
def run(self):
while True :
connsql = pyodbc.connect('DRIVER={SQL Server};SERVER=I7-KOMPUTER\SQLEXPRESS;DATABASE=test')
cursor = connsql.cursor()
data = conn.recv(2048)
#datasplitx, datasplity = data.decode().split(",", 1)
try:
xy = []
xy = data.decode().split(" ")
print("dat: ",data.decode())
print("After del:",xy)
x=str(xy[0])
#y=str(xy[1])
#x, y = [str(x) for x in data.decode().split()]
#y=str(datasplit[1])
#x = str(datasplit[0])
#y = str(datasplit[1])
except ValueError:
print("List does not contain value")
print ("Server received data:", xy)
if x == 'exit':
break
if x == '1':
#if data.decode() == '1':
cursor.execute("select rtrim(name) from client")
rows = cursor.fetchall()
zap=pickle.dumps(rows)
conn.send(zap)
print(pickle.loads(zap))
if x == '2':
#if data.decode() == '2':
cursor.execute("insert into dbo.klient values('"+y+"')")
connsql.commit()
zro=pickle.dumps("Done.")
conn.send(zro)
del xy[:]
print ("cleared list: xy",xy)
# Multithreaded Python server : TCP Server Socket Program Stub
TCP_IP = '0.0.0.0'
TCP_PORT = 2004
BUFFER_SIZE = 1024 # Usually 1024, but we need quick response
tcpServer = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpServer.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
tcpServer.bind((TCP_IP, TCP_PORT))
threads = []
while True:
tcpServer.listen(4)
print ("Multithreaded Python server : Waiting for connections from TCP clients...\r" )
(conn, (ip,port)) = tcpServer.accept()
newthread = ClientThread(ip,port)
newthread.start()
threads.append(newthread)
print("Client IP: " +str(ip))
for t in threads:
t.join()

Creating a simple Chat application in Python (Sockets)

I'm trying to create a simple chat application using sockets (python). Where a client can send a message to server and server simply broadcast the message to all other clients except the one who has sent it.
Client has two threads, which are running forever
send: Send simply sends the cleints message to server.
receive: Receive the message from the server.
Server also has two threads, which are running forever
accept_cleint: To accept the incoming connection from the client.
broadcast_usr: Accepts the message from the client and just broadcast it to all other clients.
But I'm getting erroneous output (Please refer the below image). All threads suppose to be active all the times but Some times client can send message sometimes it can not. Say for example Tracey sends 'hi' 4 times but its not broadcasted, When John says 'bye' 2 times then 1 time its message gets braodcasted. It seems like there is some thread synchronization problem at sever, I'm not sure. Please tell me what's wrong.
Below is the code.
chat_client.py
import socket, threading
def send():
while True:
msg = raw_input('\nMe > ')
cli_sock.send(msg)
def receive():
while True:
sen_name = cli_sock.recv(1024)
data = cli_sock.recv(1024)
print('\n' + str(sen_name) + ' > ' + str(data))
if __name__ == "__main__":
# socket
cli_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# connect
HOST = 'localhost'
PORT = 5023
cli_sock.connect((HOST, PORT))
print('Connected to remote host...')
uname = raw_input('Enter your name to enter the chat > ')
cli_sock.send(uname)
thread_send = threading.Thread(target = send)
thread_send.start()
thread_receive = threading.Thread(target = receive)
thread_receive.start()
chat_server.py
import socket, threading
def accept_client():
while True:
#accept
cli_sock, cli_add = ser_sock.accept()
uname = cli_sock.recv(1024)
CONNECTION_LIST.append((uname, cli_sock))
print('%s is now connected' %uname)
def broadcast_usr():
while True:
for i in range(len(CONNECTION_LIST)):
try:
data = CONNECTION_LIST[i][1].recv(1024)
if data:
b_usr(CONNECTION_LIST[i][1], CONNECTION_LIST[i][0], data)
except Exception as x:
print(x.message)
break
def b_usr(cs_sock, sen_name, msg):
for i in range(len(CONNECTION_LIST)):
if (CONNECTION_LIST[i][1] != cs_sock):
CONNECTION_LIST[i][1].send(sen_name)
CONNECTION_LIST[i][1].send(msg)
if __name__ == "__main__":
CONNECTION_LIST = []
# socket
ser_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# bind
HOST = 'localhost'
PORT = 5023
ser_sock.bind((HOST, PORT))
# listen
ser_sock.listen(1)
print('Chat server started on port : ' + str(PORT))
thread_ac = threading.Thread(target = accept_client)
thread_ac.start()
thread_bs = threading.Thread(target = broadcast_usr)
thread_bs.start()

Ok I lied in my comment earlier, sorry. The issue is actually in the broadcast_usr() function on the server. It is blocking in the recv() method and preventing all but the currently selected user from talking at a single time as it progresses through the for loop. To fix this, I changed the server.py program to spawn a new broadcast_usr thread for each client connection that it accepts. I hope this helps.
import socket, threading
def accept_client():
while True:
#accept
cli_sock, cli_add = ser_sock.accept()
uname = cli_sock.recv(1024)
CONNECTION_LIST.append((uname, cli_sock))
print('%s is now connected' %uname)
thread_client = threading.Thread(target = broadcast_usr, args=[uname, cli_sock])
thread_client.start()
def broadcast_usr(uname, cli_sock):
while True:
try:
data = cli_sock.recv(1024)
if data:
print "{0} spoke".format(uname)
b_usr(cli_sock, uname, data)
except Exception as x:
print(x.message)
break
def b_usr(cs_sock, sen_name, msg):
for client in CONNECTION_LIST:
if client[1] != cs_sock:
client[1].send(sen_name)
client[1].send(msg)
if __name__ == "__main__":
CONNECTION_LIST = []
# socket
ser_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# bind
HOST = 'localhost'
PORT = 5023
ser_sock.bind((HOST, PORT))
# listen
ser_sock.listen(1)
print('Chat server started on port : ' + str(PORT))
thread_ac = threading.Thread(target = accept_client)
thread_ac.start()
#thread_bs = threading.Thread(target = broadcast_usr)
#thread_bs.start()

I tried to get around the bug you said #Atinesh. The client will be asked a username once and this 'uname' will be included in the data to be sent. See what I did to the 'send' function.
For easier visualization, I added a '\t' to all received messages.
import socket, threading
def send(uname):
while True:
msg = raw_input('\nMe > ')
data = uname + '>' + msg
cli_sock.send(data)
def receive():
while True:
data = cli_sock.recv(1024)
print('\t'+ str(data))
if __name__ == "__main__":
# socket
cli_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# connect
HOST = 'localhost'
PORT = 5023
uname = raw_input('Enter your name to enter the chat > ')
cli_sock.connect((HOST, PORT))
print('Connected to remote host...')
thread_send = threading.Thread(target = send,args=[uname])
thread_send.start()
thread_receive = threading.Thread(target = receive)
thread_receive.start()
You also have to modify your server code accordingly.
server.py
import socket, threading
def accept_client():
while True:
#accept
cli_sock, cli_add = ser_sock.accept()
CONNECTION_LIST.append(cli_sock)
thread_client = threading.Thread(target = broadcast_usr, args=[cli_sock])
thread_client.start()
def broadcast_usr(cli_sock):
while True:
try:
data = cli_sock.recv(1024)
if data:
b_usr(cli_sock, data)
except Exception as x:
print(x.message)
break
def b_usr(cs_sock, msg):
for client in CONNECTION_LIST:
if client != cs_sock:
client.send(msg)
if __name__ == "__main__":
CONNECTION_LIST = []
# socket
ser_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# bind
HOST = 'localhost'
PORT = 5023
ser_sock.bind((HOST, PORT))
# listen
ser_sock.listen(1)
print('Chat server started on port : ' + str(PORT))
thread_ac = threading.Thread(target = accept_client)
thread_ac.start()
The things that changed in the server side are: the user who connected and the user who spoke is not seen anymore. I don't know if it would mean that much if your purpose is to connect clients. Maybe if you want to strictly monitor clients via the server, there could be another way.