OSError: [Errno 22] Invalid argument for udp connection - python-3.x

The udp server and client on my local pc.
cat server.py
import socket
MAX_BYTES =65535
def server():
sock = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
sock.bind(('127.0.0.1',10000))
print('Listening at {}'.format(sock.getsockname()))
while True:
data,address = sock.recvfrom(MAX_BYTES)
text = data.decode('ascii')
print('The client at {} says {!r} '.format(address,text))
if __name__ == "__main__":
server()
Bind port 10000 with localhost-127.0.0.1,and listening to the message send from client.
cat client.py
import socket
import time
from datetime import datetime
MAX_BYTES =65535
def client():
sock = socket.socket(socket.AF_INET,socket.SOCK_DGRAM)
sock.bind(('127.0.0.1',10001))
text = 'The time is {}'.format(datetime.now())
data = text.encode('ascii')
while True:
time.sleep(10)
sock.sendto(data,('127.0.0.1',10000))
print('The OS assinged me the address {}'.format(sock.getsockname()))
if __name__ == "__main__":
client()
Run the server.py and client.py on my local pc,server can receive message send from client.
Now i change 127.0.0.1 in the line in client.py with my remote vps_ip.
sock.sendto(data,('127.0.0.1',10000))
into
sock.sendto(data,('remote_ip',10000))
Push server.py into my vps.Start client.py on my local pc,server.py on remote vps,start them all.
In my client,an error info occurs:
File "client.py", line 13, in client
sock.sendto(data,('remote_ip',10000))
OSError: [Errno 22] Invalid argument
How to make remote ip receive message send from my local client pc?

Two things that could be happening:
You're not passing the remote IP correctly. Make sure that your not passing literally 'remote_ip' and replace it with a valid IPv4 IP address string (IE: '192.168.0.100') for the server. (FYI technically on the server you can just put '0.0.0.0' to listen on all IP addresses)
You could still be binding the client to the local address to (127.0.0.1), but setting the destination to a valid external address (192.168.0.100). Remove the socket.bind line of code in the client to test this, you shouldn't need it.
If these both don't work, then add the results of a ping command running on the client and targeting the server.

Related

I am getting the error WinError 10057 in python 3.10.1 as I use it for sockets

I am new to network programming in python and I am trying to create a payment gateway for a project. I have run into an error with sending and receiving data between servers.
Here is my code for both the server and the client:
Server Script:
import socket
banka_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
banka_socket.bind(("192.168.0.22", 8082))
banka_socket.listen()
print("Waiting for bank A socket...")
connection_socket, address = banka_socket.accept()
print("Bank A connected")
message = banka_socket.recv(1024).decode()
print(message)
Client Script:
import socket
gateway_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
gateway_socket.connect(("192.168.0.22", 8082))
print("Gateway connected")
client_data = "hello"
message = client_data.encode()
gateway_socket.send(message)
The data is being sent and received on the same computer. I ran the server script and then I ran the client script. That's when I received the following error:
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
The code with the error was:
message = banka_socket.recv(1024).decode()
Please let me know how I fix my code, I've been struggling with this for a while now.

Don't understand why server won't respond to client (even after turning of firewall | Python | Server

I set up my server on MacBook air and my client is connecting from a Windows 10 machine. I turned off all security and firewalls on both machines (because that's what you do when you've lost all hope) and tried to connect from my windows machine multiple times, but to no avail. I'm on the same network btw (not using a VM).
Error:
TimeoutError: [WinError 10060] A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond
Server:
import socket, threading
import multiprocessing
from time import sleep
# tells us the bytes of the message
HEADER = 64
PORT = 5430
# or you could do socket.gethostbyname(socket.gethostname())
SERVER = socket.gethostbyname(socket.gethostname())
ADDR = (SERVER, PORT)
FORMAT = 'utf-8'
DISCONNECT_MESSAGE = '!END'
# defines the type of connection
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind(ADDR)
def start():
server.listen()
print(f'[LISTENING] Server is listening on {SERVER}')
while True:
conn, addr = server.accept()
print('[ACTIVE CONNECTIONS] 1')
start()
Client:
from time import sleep
import socket, subprocess
HEADER = 64
PORT = 5430
FORMAT = 'utf-8'
DISCONNECT_MESSAGE = '!END'
SERVER = '192.32.322.3'
ADDR = (SERVER, PORT)
client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client.connect(ADDR)

Python throw error byte like object required not list

I am trying to connect the socket via the following code
try:
# create an INET, STREAMing socket
self.client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# now connect to the web server on port 80 - the normal http port
self.client.connect((host, port))
user = ['User.loginByToken', access_token]
self.client.sendall(user)
# self.client._locust_environment = self.environment
except Exception as e:
color_print("\n[!] Check Server Address or Port", color="red", underline=True)
it throws an error memoryview: a bytes-like object is required, not 'list'. what can I do to solve it?
You need to convert user var to bytes in order to send thru a socket:
You can try this:
import json
user = json.dumps({'User.loginByToken': access_token})
user = user.encode("utf-8")

How to initiate a socket connection from server to client?

I have setup a tcp socket between a client and a server, very basic. Client side:
#!/usr/bin/env python3
import socket
# create a socket object
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# get local machine name
host = "81.88.95.250"
port = 25000
# connection to hostname on the port.
s.connect((host, port))
# Receive no more than 1024 bytes
msg = s.recv(1024)
s.close()
print (msg.decode('ascii'))
server side:
#!/usr/bin/env python3
import socket
# create a socket object
serversocket = socket.socket(
socket.AF_INET, socket.SOCK_STREAM)
# get local machine name
host = socket.gethostname()
port = 25000
# bind to the port
serversocket.bind((host, port))
# queue up to 5 requests
serversocket.listen(5)
while True:
# establish a connection
clientsocket,addr = serversocket.accept()
print("Got a connection from %s" % str(addr))
msg = 'Thank you for connecting'+ "\r\n"
clientsocket.send(msg.encode('ascii'))
clientsocket.close()
My target is to send notification from client to server, and that's easy. The difficult part is that I also need in some circumstances to start the connection from the server and to send a command to the client and this must be executed as soon as it is received, so I cannot setup a periodic "poll". But I'm quite confused on this part, because the client is behind a NAT, not exposed with a public IP.

How can I create a TCP server using Python 3?

How can I create a TCP server in python3 which will return all the files in the current directory?
You can use the socketserver library, this will serve the current working directory.
Here is the Server code
import socketserver
class MyTCPHandler(socketserver.BaseRequestHandler):
"""
The request handler class for our server.
It is instantiated once per connection to the server, and must
override the handle() method to implement communication to the
client.
"""
def handle(self):
# self.request is the TCP socket connected to the client
self.data = self.request.recv(1024).strip()
print("{} wrote:".format(self.client_address[0]))
print(self.data)
# just send back the same data, but upper-cased
self.request.sendall(self.data.upper())
# here you can do self.request.sendall(use the os library and display the ls command)
if __name__ == "__main__":
HOST, PORT = "localhost", 9999
# Create the server, binding to localhost on port 9999
with socketserver.TCPServer((HOST, PORT), MyTCPHandler) as server:
# Activate the server; this will keep running until you
# interrupt the program with Ctrl-C
server.serve_forever()
And here is the client side
import socket
import sys
HOST, PORT = "localhost", 9999
data = " ".join(sys.argv[1:])
# Create a socket (SOCK_STREAM means a TCP socket)
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
# Connect to server and send data
sock.connect((HOST, PORT))
sock.sendall(bytes(data + "\n", "utf-8"))
# Receive data from the server and shut down
received = str(sock.recv(1024), "utf-8")
print("Sent: {}".format(data))
print("Received: {}".format(received))
You should then get an output like
Server:
127.0.0.1 wrote:
b'hello world with TCP'
127.0.0.1 wrote:
b'python is nice'
Client:
$ python TCPClient.py hello world with TCP
Sent: hello world with TCP
Received: HELLO WORLD WITH TCP
$ python TCPClient.py python is nice
Sent: python is nice
Received: PYTHON IS NICE
You can then just use this code to send the current directory list
You can use socketserver which will serve the current working directory.
import socketserver # import socketserver preinstalled module
import http.server
httpd = socketserver.TCPServer(("127.0.0.1", 9000), http.server.SimpleHTTPRequestHandler)
httpd.serve_forever()

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