I was trying to follow the ktor documentation for Raw Sockets and in specific the part related to secured sockets (https://ktor.io/servers/raw-sockets.html):
runBlocking {
val socket = aSocket(ActorSelectorManager(ioCoroutineDispatcher)).tcp().connect(InetSocketAddress("google.com", 443)).tls()
val w = socket.openWriteChannel(autoFlush = false)
w.write("GET / HTTP/1.1\r\n")
w.write("Host: google.com\r\n")
w.write("\r\n")
w.flush()
val r = socket.openReadChannel()
println(r.readUTF8Line())
}
You can adjust a few optional parameters for the TLS connection:
suspend fun Socket.tls(
trustManager: X509TrustManager? = null,
randomAlgorithm: String = "NativePRNGNonBlocking",
serverName: String? = null,
coroutineContext: CoroutineContext = ioCoroutineDispatcher
): Socket
But the NativePRNGNonBlocking SecureRandom algorithm is not available on Windows, so my only option was to use SHA1PRNG (https://docs.oracle.com/javase/8/docs/technotes/guides/security/SunProviders.html#SecureRandomImp)
This is the code I'm running to connect to a listening socket :
socket = aSocket(ActorSelectorManager(Dispatchers.IO)).tcp().connect(InetSocketAddress(host, port))
.tls(Dispatchers.IO, randomAlgorithm = "SHA1PRNG")
Unfortunately, I always receive the same error: "Channel was closed"
If I remove tls, keeping only the raw socket:
socket = aSocket(ActorSelectorManager(Dispatchers.IO)).tcp().connect(InetSocketAddress(host, port))
Everything works as expected.
Does anyone has used Ktor Secure Sockets in Windows ? (Unfortunately, Ktor's documentation still has a long way to go).
Thanks,
J
Related
I use Raspberry Pi Pico with ESP8266 WiFi module, and I am trying to write a TCP client. Rasp Pi Pico is able to send AT commands and receive responses and send data through UART. Also the TCP client is able to send data to the TCP server, which runs in my laptop. However the problem is that the client is not able to connect to the server after some point.
Let me first show the server-side code. In server, I am trying to receive data basically. ConnectionResetError was a problem for me so I wrote the following except block. I am not sure it is buggy or not, since I'm kind of a noob in this area.
import socket
HOST = ""
PORT = 8080
mysocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
mysocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
mysocket.bind((HOST, PORT))
mysocket.listen(1)
while True:
print("Waiting...")
conn, addr = mysocket.accept()
print('[SERVER] - Connected from: %s' % str(addr))
while True:
try:
request = conn.recv(1024)
if not request:
break
conn.sendall(request.upper())
print('[SERVER] - Received Data: %s' % str(request))
except ConnectionResetError as cr_err:
break
conn.close()
print("[SERVER] - Disconnected")
Here is my client-side code. In client, I wrote two helper classes called ESP8266 and Sensor, in which I control the WiFi module and read analog value from a sensor. Pico first tries to start WiFi module, afterwards it tries to connect to TCP server and send data. After some point it does not connect to the TCP server, so it restart the WiFi module and reconnects.
class EndDevice:
def __init__(self, sensor_id):
self.__wifi_module = ESP8266(UART_PIN, BAUDRATE)
self.__sensor = Sensor(sensor_id, SENSOR_PIN)
def start(self):
self.__wifi_module.start()
self.__wifi_module.set_mode(STATION_MODE)
self.__wifi_module.join_access_point(AP_NAME, AP_PWD)
def reconnect(self):
self.__wifi_module.restart()
self.__wifi_module.set_mode(STATION_MODE)
self.__wifi_module.join_access_point(AP_NAME, AP_PWD)
def run(self):
retry_count = 0
while True:
if self.__wifi_module.start_connection("TCP", SERVER_HOST, SERVER_PORT):
self.__wifi_module.send_data(
str(self.__sensor.generate_package()))
self.__wifi_module.close_connection()
else:
retry_count += 1
if retry_count == MAX_RETRY:
break
if __name__ == "__main__":
pico = EndDevice("SM-0")
pico.start()
while True:
pico.run()
pico.reconnect()
Finally I will share some of the methods in classes ESP8266 and UARTHandler (which is used in ESP8266), so you can see if I do anything non-sense.
start_connection method in ESP8266 is as follows. In this method, I tried to send the corresponding AT command to connect to a TCP server. In the method self.__uart_handler.send_receive_cmd timeout duration is 2000ms, and other parameters are AT command, connection_type (TCP), server IP address and server port, in order.
def start_connection(self, conn_type, remote_ip, remote_port):
conn_type, remote_ip = "\"{}\"".format(conn_type), "\"{}\"".format(remote_ip)
response = self.__uart_handler.send_receive_cmd(2000, CONN_START, conn_type, remote_ip, str(remote_port))
if "OK" in response:
self.__log("Connected to {} at port {}.".format(remote_ip, remote_port))
return True
else:
self.__log("Failed to create a connection with {} at port {}.".format(remote_ip, remote_port))
return False
send_receive_cmd method in UARTHandler is as follows. In this method I use lots of helper methods as you can see, however they are just formatting and writing to UART or reading from UART. I also insert a timeout between UART-read and UART-write
def __generate_cmd(self, cmd, *args):
if len(args) != 0:
cmd += "="
for idx, each in enumerate(args):
cmd += str(each)
if idx != len(args)-1:
cmd += ","
cmd += "\r\n"
return cmd
def __send_cmd(self, cmd, *args):
sent_cmd = self.__generate_cmd(cmd, *args)
self.__uart.write(sent_cmd)
def __receive_response(self, cmd):
response = self.__uart.read()
try: return response.decode('utf-8')
except: return response
def send_receive_cmd(self, timeout, cmd, *args):
self.__send_cmd(cmd, *args)
utime.sleep_ms(timeout)
return self.__receive_response(self.__generate_cmd(cmd, *args))
Let me ask my question again. This codes are working properly in starting-restarting and sending data for (let me say) 3 connections. However, after some connect-disconnect later, TCP client is not able to make a connection with TCP server. Again after some failed connection attempt, WiFi module is restarted and TCP connection is made and working properly again.
I have set up a simple client-server communication code and it works well in my computer when my computer itself acts as a server and the client.
Now I am trying to run this same code on two different computers in different networks( different locations) where my computer will act as a server and my friend's computer as a client.
I have done port forwarding in my router as well as in my friend's router for the port which we are trying to communicate. We both have set up a static IP in our internal network behind the router. We both had shutdown the firewall while running the code.
I am running my code on Jupiter notebook and the same is my friend too.
here is my server code:
import socket
import threading
HEADER = 64
PORT = 5064
SERVER = '0.0.0.0'
ADDR = (SERVER, PORT)
FORMAT = 'utf-8'
DISCONNECT_MESSAGE = "quit"
Receive_from_client = "get info"
server = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
server.bind(ADDR)
def handle_client(conn, addr):
print("\n" + f"[NEW Connection] detected from IP: {addr[0]} & Port:{addr[1]} ")
conn.send(f"connected to server {ADDR}".encode(FORMAT))
connected =True
while connected:
msg_length = conn.recv(HEADER).decode(FORMAT) # decode the msg from byte to utf-8 format
if msg_length:
msg_length = int(msg_length)
msg = conn.recv(msg_length).decode(FORMAT)
if msg == DISCONNECT_MESSAGE:
connected = False
print(f" [Client][{addr}] {msg}")
print("Your session is disconnected")
break
if msg == Receive_from_client:
print("\n" + f"Send your msg to client with IP: {addr[0]}")
thread = threading.Thread(target = send2client, args = (conn, addr))
thread.start()
print(f" [Client][{addr}] {msg}")
conn.send(f"Msg received by server with IP:{addr[0]}".encode(FORMAT))
conn.close()
server.close()
def start():
server.listen()
print("\n"+ f"[LISTENING] Server is listening from IP: {SERVER} ")
while True:
conn, addr = server.accept()
thread = threading.Thread(target = handle_client, args = (conn, addr))
thread.start()
Here is the client code
import socket
import threading
HEADER = 64
PORT = 5064
FORMAT = 'utf-8'
DISCONNECT_MESSAGE = "quit"
SERVER = '103.192.207.250' # SERVERS public IP
ADDR = (SERVER, PORT)
client = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
client.connect(ADDR)
def send2server():
while True:
msg = input()
message = msg.encode(FORMAT)
msg_lenght = len(message)
send_length = str(msg_lenght).encode(FORMAT)
send_length += b' '*(HEADER - len(send_length))
client.send(send_length)
client.send(message)
print(client.recv(2048).decode(FORMAT))
if msg == DISCONNECT_MESSAGE:
print("session closed")
client.close()
def start():
print("\n"+ f"[LISTENING] client is listening from IP: {ADDR} ")
send2server()
I have opened the port by going on windows firewall defender and selecting new inbound and outbound rules to open 5064 TCP port.
but still, the code doesn't works..
my server keeps waiting for connection and the client-side after few seconds of running gives this error:
TCP error code 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
Even while my server is listening from port 5064 when I scan this port to check if the port is open or not it says closed.
How do I check if the port I have forwarded is for sure open and also how do I get this thing work?
I have tried all of this and if there is any other thing I am missing please tell. I am struggling to get this work for the past 3 days.
I am using micropython on my esp32. I want to send data from esp32 to AWS IoT MQTT Broker Endpoint.
But in micropython socket module, getaddrinfo(hostname, port) method return empty list every time. How can I solve it?
It is working when I use IP address instead of host name. But AWS MQTT broker endpoint has no static IP for its broker endpoint.
# My code:
sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)
sta_if.connect("wifiname", "password")
KEY_PATH = "/619e3d582c-private.pem.key"
CERT_PATH = "/619e3d582c-certificate.pem"
with open(KEY_PATH, 'r') as f:
PVT_KEY = f.read()
with open(CERT_PATH, 'r') as f:
CERT_KEY = f.read()
client = MQTTClient(client_id="esp32_micropython_shafik",
server="xxxxxxxxxxx.iot.eu-west-1.amazonaws.com",
port = 8883,
keepalive = 10000,
ssl = True,
ssl_params = {
"cert": CERT_KEY,
"key": PVT_KEY,
"server_side":False
} )
def checkwifi():
while not sta_if.isconnected():
time.sleep_ms(500)
print(".")
sta_if.connect()
def publish():
while True:
checkwifi()
msg = b'hello shafik'
client.publish(b"weather", msg)
time.sleep(1)
print("type", type(PVT_KEY))
client.connect()
publish()`
I am getting continuously this error:
umqtt/simple.py in 57 line,
IndexError: list index out of range.
How can I solve it?
I have solved this problem just changing my wifi network.
Actually this problem occurred for my ISP network issue, that's why socket module didn't work properly for fetching IP address properly.
I've been working on a client for this chat server but I am running into a bit of a challenge. The server uses Python's 3.4RC1 asyncio module.
Behavior:
My client connects. My second client connects. Either can send messages to the server BUT, the server is not broadcasting them as it should in a normal public chat room.
User1: Hello. Presses Enter.
User2 does not see it.
User2: Anyone there? Presses Enter.
User2 sees User1: Hello. and User2: Anyone there?
Just... strange. Not sure what I'm missing.
Here are the files. Give it a try.
Server:
from socket import socket, SO_REUSEADDR, SOL_SOCKET
from asyncio import Task, coroutine, get_event_loop
class Peer(object):
def __init__(self, server, sock, name):
self.loop = server.loop
self.name = name
self._sock = sock
self._server = server
Task(self._peer_handler())
def send(self, data):
return self.loop.sock_send(self._sock, data.encode('utf-8'))
#coroutine
def _peer_handler(self):
try:
yield from self._peer_loop()
except IOError:
pass
finally:
self._server.remove(self)
#coroutine
def _peer_loop(self):
while True:
buf = yield from self.loop.sock_recv(self._sock, 1024)
if buf == b'':
break
self._server.broadcast('%s: %s' % (self.name, buf.decode('utf-8')))
class Server(object):
def __init__(self, loop, port):
self.loop = loop
self._serv_sock = socket()
self._serv_sock.setblocking(0)
self._serv_sock.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
self._serv_sock.bind(('',port))
self._serv_sock.listen(5)
self._peers = []
Task(self._server())
def remove(self, peer):
self._peers.remove(peer)
self.broadcast('Peer %s quit!' % (peer.name,))
def broadcast(self, message):
for peer in self._peers:
peer.send(message)
#coroutine
def _server(self):
while True:
peer_sock, peer_name = yield from self.loop.sock_accept(self._serv_sock)
peer_sock.setblocking(0)
peer = Peer(self, peer_sock, peer_name)
self._peers.append(peer)
self.broadcast('Peer %s connected!' % (peer.name,))
def main():
loop = get_event_loop()
Server(loop, 1234)
loop.run_forever()
if __name__ == '__main__':
main()
Client:
# import socket
from socket import *
# form socket import socket, bind, listen, recv, send
HOST = 'localhost' #localhost / 192.168.1.1
# LAN - 192.168.1.1
PORT = 1234
s = socket(AF_INET, SOCK_STREAM)# 98% of all socket programming will use AF_INET and SOCK_STREAM
s.connect((HOST, PORT))
while True:
message = input("Your Message: ")
encoded_msg = message.encode('utf-8')
s.send(encoded_msg)
print('Awaiting Reply..')
reply = s.recv(1024)
decoded_reply = reply.decode('utf-8')
decoded_reply = repr(decoded_reply)
print('Received ', decoded_reply)
s.close()
Here's the non threaded server code I wrote. works great but ONLY between 2 people. How could this code be updated to broadcast every message received to all clients connected?
# import socket
from socket import *
# form socket import socket, bind, listen, recv, send
HOST = 'localhost' #localhost / 192.168.1.1
# LAN - 192.168.1.1
PORT = 1234
s = socket(AF_INET, SOCK_STREAM) # 98% of all socket programming will use AF_INET and SOCK_STREAM
s.bind((HOST, PORT))
s.listen(5) # how many connections it can receive at one time
conn, addr = s.accept() # accept the connection
print('Connected by', addr) # print the address of the person connected
while True:
data = conn.recv(1024)
decoded_data = data.decode('utf-8')
data = repr(decoded_data)
print('Received ', decoded_data)
reply = input("Reply: ")
encoded_reply = reply.encode('utf-8')
conn.sendall(encoded_reply)
print('Server Started')
conn.close()
Okay, let’s think about what your client does. You ask for a message to send, blocking for user input. Then you send that message and receive whatever there is at the server. Afterwards, you block again, waiting for another message.
So when client A sends a text, client B is likely blocking for user input. As such, B won’t actually check if the server sent anything. It will only display what’s there after you have sent something.
Obviously, in a chat, you don’t want to block on user input. You want to continue receiving new messages from the server even if the user isn’t sending messages. So you need to separate those, and run both asynchronously.
I haven’t really done much with asyncio yet, so I don’t really know if this can be nicely done with it, but you essentially just need to put the reading and sending into two separate concurrent tasks, e.g. using threads or concurrent.futures.
A quick example of what you could do, using threading:
from socket import *
from threading import Thread
HOST = 'localhost'
PORT = 1234
s = socket(AF_INET, SOCK_STREAM)
s.connect((HOST, PORT))
def keepReading ():
try:
while True:
reply = s.recv(1024).decode()
print('Received ', reply)
except ConnectionAbortedError:
pass
t = Thread(target=keepReading)
t.start()
try:
while True:
message = input('')
s.send(message.encode())
except EOFError:
pass
finally:
s.close()
So I am working on an iPhone app that requires a socket to handle multiple clients for online gaming. I have tried Twisted, and with much effort, I have failed to get a bunch of info to be sent at once, which is why I am now going to attempt socket.
My question is, using the code below, how would you be able to have multiple clients connected? I've tried lists, but I just can't figure out the format for that. How can this be accomplished where multiple clients are connected at once and I am able to send a message to a specific client?
Thank you!
#!/usr/bin/python # This is server.py file
import socket # Import socket module
s = socket.socket() # Create a socket object
host = socket.gethostname() # Get local machine name
port = 50000 # Reserve a port for your service.
print 'Server started!'
print 'Waiting for clients...'
s.bind((host, port)) # Bind to the port
s.listen(5) # Now wait for client connection.
c, addr = s.accept() # Establish connection with client.
print 'Got connection from', addr
while True:
msg = c.recv(1024)
print addr, ' >> ', msg
msg = raw_input('SERVER >> ')
c.send(msg);
#c.close() # Close the connection
Based on your question:
My question is, using the code below, how would you be able to have multiple clients connected? I've tried lists, but I just can't figure out the format for that. How can this be accomplished where multiple clients are connected at once and I am able to send a message to a specific client?
Using the code you gave, you can do this:
#!/usr/bin/python # This is server.py file
import socket # Import socket module
import thread
def on_new_client(clientsocket,addr):
while True:
msg = clientsocket.recv(1024)
#do some checks and if msg == someWeirdSignal: break:
print addr, ' >> ', msg
msg = raw_input('SERVER >> ')
#Maybe some code to compute the last digit of PI, play game or anything else can go here and when you are done.
clientsocket.send(msg)
clientsocket.close()
s = socket.socket() # Create a socket object
host = socket.gethostname() # Get local machine name
port = 50000 # Reserve a port for your service.
print 'Server started!'
print 'Waiting for clients...'
s.bind((host, port)) # Bind to the port
s.listen(5) # Now wait for client connection.
print 'Got connection from', addr
while True:
c, addr = s.accept() # Establish connection with client.
thread.start_new_thread(on_new_client,(c,addr))
#Note it's (addr,) not (addr) because second parameter is a tuple
#Edit: (c,addr)
#that's how you pass arguments to functions when creating new threads using thread module.
s.close()
As Eli Bendersky mentioned, you can use processes instead of threads, you can also check python threading module or other async sockets framework. Note: checks are left for you to implement how you want and this is just a basic framework.
accept can continuously provide new client connections. However, note that it, and other socket calls are usually blocking. Therefore you have a few options at this point:
Open new threads to handle clients, while the main thread goes back to accepting new clients
As above but with processes, instead of threads
Use asynchronous socket frameworks like Twisted, or a plethora of others
Here is the example from the SocketServer documentation which would make an excellent starting point
import SocketServer
class MyTCPHandler(SocketServer.BaseRequestHandler):
"""
The RequestHandler 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())
if __name__ == "__main__":
HOST, PORT = "localhost", 9999
# Create the server, binding to localhost on port 9999
server = SocketServer.TCPServer((HOST, PORT), MyTCPHandler)
# Activate the server; this will keep running until you
# interrupt the program with Ctrl-C
server.serve_forever()
Try it from a terminal like this
$ telnet localhost 9999
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Hello
HELLOConnection closed by foreign host.
$ telnet localhost 9999
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Sausage
SAUSAGEConnection closed by foreign host.
You'll probably need to use A Forking or Threading Mixin too
This program will open 26 sockets where you would be able to connect a lot of TCP clients to it.
#!usr/bin/python
from thread import *
import socket
import sys
def clientthread(conn):
buffer=""
while True:
data = conn.recv(8192)
buffer+=data
print buffer
#conn.sendall(reply)
conn.close()
def main():
try:
host = '192.168.1.3'
port = 6666
tot_socket = 26
list_sock = []
for i in range(tot_socket):
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
s.bind((host, port+i))
s.listen(10)
list_sock.append(s)
print "[*] Server listening on %s %d" %(host, (port+i))
while 1:
for j in range(len(list_sock)):
conn, addr = list_sock[j].accept()
print '[*] Connected with ' + addr[0] + ':' + str(addr[1])
start_new_thread(clientthread ,(conn,))
s.close()
except KeyboardInterrupt as msg:
sys.exit(0)
if __name__ == "__main__":
main()
def get_clients():
first_run = True
startMainMenu = False
while True:
if first_run:
global done
done = False
Thread(target=animate, args=("Waiting For Connection",)).start()
Client, address = objSocket.accept()
global menuIsOn
if menuIsOn:
menuIsOn = False # will stop main menu
startMainMenu = True
done = True
# Get Current Directory in Client Machine
current_client_directory = Client.recv(1024).decode("utf-8", errors="ignore")
# beep on connection
beep()
print(f"{bcolors.OKBLUE}\n***** Incoming Connection *****{bcolors.OKGREEN}")
print('* Connected to: ' + address[0] + ':' + str(address[1]))
try:
get_client_info(Client, first_run)
except Exception as e:
print("Error data received is not a json!")
print(e)
now = datetime.now()
current_time = now.strftime("%D %H:%M:%S")
print("* Current Time =", current_time)
print("* Current Folder in Client: " + current_client_directory + bcolors.WARNING)
connections.append(Client)
addresses.append(address)
if first_run:
Thread(target=threaded_main_menu, daemon=True).start()
first_run = False
else:
print(f"{bcolors.OKBLUE}* Hit Enter To Continue.{bcolors.WARNING}\n#>", end="")
if startMainMenu == True:
Thread(target=threaded_main_menu, daemon=True).start()
startMainMenu = False
#!/usr/bin/python
import sys
import os
import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
port = 50000
try:
s.bind((socket.gethostname() , port))
except socket.error as msg:
print(str(msg))
s.listen(10)
conn, addr = s.accept()
print 'Got connection from'+addr[0]+':'+str(addr[1]))
while 1:
msg = s.recv(1024)
print +addr[0]+, ' >> ', msg
msg = raw_input('SERVER >>'),host
s.send(msg)
s.close()