We Keep Coding

Why does my Python P2P client works over LAN but not the Internet and how can I fix this

Why does my Python P2P client works over LAN but not the Internet and how can I fix this!
I would like to make a p2p messenger and I just don't know why the p2p functionality with UDP Hole Punching is not working. Please help!
Server:
This server holds peers ips and ports for the client.
The ping function pings the peers to check if they are still alive.
'''
import threading
import socket
import time
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.bind(("IP_ADDRESS", 8081))
addrs = []
print('Server started...')
def ping(addr):
try:
sock.sendto(b'ping', addr)
sock.settimeout(1)
data, addr = sock.recvfrom(1024)
sock.settimeout(None)
return True
except Exception as ex:
sock.settimeout(None)
return False
while True:
data, addr = sock.recvfrom(1024)
print(addr)
sock.sendto((addr[0]+' '+str(addr[1])).encode(), addr)
for a in addrs:
p = ping(a)
print(p, a)
if p:
sock.sendto((a[0]+' '+str(a[1])).encode(), addr)
addrs.append(addr)
sock.sendto(b'DONE', addr)
'''
Client:
import threading
import socket
import time
self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
self.addrs = []
self.chat_logs = ''
self.peers = ''
self.self_data = ('0.0.0.0', 0)
def recv_thread(self):
while True:
try:
data, addr = self.sock.recvfrom(1024)
if data == b'ping':
self.sock.sendto(b'pong', addr)
else:
data = data.decode()
new_user = True
for a in self.addrs:
if a == addr:
new_user = False
if new_user == False:
self.chat_logs += addr[0]+':'+str(addr[1])+' - '+data+'\n'
else:
self.chat_logs += addr[0]+':'+str(addr[1])+' joined the p2p network... \n'
self.addrs.append(addr)
except Exception as ex:
print(ex)
def send_msg(self):
message = self.messageBox.text()
if len(message) > 0:
self.chat_logs += 'You - '+message+'\n'
self.chatBox.setPlainText(self.chat_logs)
for a in self.addrs:
try:
self.sock.sendto(message.encode(), a)
except:
self.addrs.remove(a)
def get_peers(self, host):
host = host.split(':')
host = (host[0], int(host[1]))
self.sock.sendto(b'PEERS', host)
self.self_data, addr = self.sock.recvfrom(512)
self.self_data = self.self_data.decode().split()
self.self_data = (self.self_data[0], int(self.self_data[1]))
while True:
data, addr = self.sock.recvfrom(512)
if data == b'DONE':
break
else:
data = data.decode().split()
self.addrs.append((data[0], int(data[1])))
print(self.addrs)
for a in self.addrs:
try:
self.sock.sendto(b'join', a)
except:
self.addrs.remove(a)
t = threading.Thread(target=self.recv_thread)
t.start()
def connect_to_pears_network(self):
dlg = CustomDialog()
if dlg.exec():
text = dlg.message.text()
if len(text) > 6:
self.get_peers(text)
else:
pass
I hope I did this post right this is my first time making a post.

how can I send a message to all of my clients connect to my server (socket)

My code is below and I just can't seem to figure out how to send messages to my clients at once
Even when I try asking for help or anything like that they say Store each client and idk how to do that. also I did try it and look it up I did it but I want it to update instantly like discord
import socket
import threading
HEADER = 64
PORT = 5050
SERVER = socket.gethostbyname(socket.gethostname())
ADDR = (SERVER, PORT)
FORMAT = 'utf-8'
DISCONNECT_MESSAGE = "!stop"
NAME_MESSAGE = "!name"
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind(ADDR)
def handle_client(client, addr):
print(f'[INFO] {addr} connected.')
while True:
msg_length = client.recv(HEADER).decode(FORMAT)
if not msg_length:
msg_length = int(msg_length)
msg = client.recv(msg_length).decode(FORMAT)
if msg == DISCONNECT_MESSAGE:
print(f'[DISCONNECT] {addr} Disconnected')
break
elif msg == NAME_MESSAGE:
name_length = client.recv(HEADER).decode(FORMAT)
if name_length:
name_length = int(name_length)
name = client.recv(name_length).decode(FORMAT)
addr = name
else:
<Idk what to put here>
else:
break
def start():
server.listen()
print(f'[INFO] Server is listening on {SERVER}')
while True:
conn, addr = server.accept()
thread = threading.Thread(target=handle_client, args=(conn, addr))
thread.start()
print(f'\n[INFO] Active connections: {threading.activeCount() - 1}')
print('[INFO] Server is starting...')
start()

Echo server chat application having issues connecting

I'm a novice when it comes to networking, but for my distributed systems project I'm attempting to create a simple application that allows any computer on the same network with python to send messages to a server. I cannot get my computer and laptop to connect successfully, and I get a timeout error on the client side:
Here is my server code:
import socket
import select
HEADER_LENGTH = 10
IP = "127.0.0.1"
PORT = 1234
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind((IP, PORT))
server_socket.listen()
sockets_list = [server_socket]
clients = {}
def receive_message(client_socket):
try:
message_header = client_socket.recv(HEADER_LENGTH)
if not len(message_header):
return False
message_length = int(message_header.decode("utf-8").strip())
return {"header": message_header, "data" : client_socket.recv(message_length)}
except:
return False
while True:
read_sockets, _, exception_sockets = select.select(sockets_list, [], sockets_list)
for notified_socket in read_sockets:
if notified_socket == server_socket:
client_socket, client_address = server_socket.accept()
user = receive_message(client_socket)
if user is False:
continue
sockets_list.append(client_socket)
clients[client_socket] = user
print(f"Accepted new connection from {client_address[0]}:{client_address[1]} username:{user['data'].decode('utf-8')}")
else:
message = receive_message(notified_socket)
if message is False:
print(f"Closed connection from {clients[notified_socket]['data'].decode('utf-8')}")
sockets_list.remove(notified_socket)
del clients[notified_socket]
continue
user = clients[notified_socket]
print(f"Received message from {user['data'].decode('utf-8')}: {message['data'].decode('utf-8')}")
for client_socket in clients:
if client_socket != notified_socket:
client_socket.send(user['header'] + user['data'] + message['header'] + message['data'])
for notified_socket in exception_sockets:
sockets_list.remove(notified_socket)
del clients[notified_socket]
Here is my client code
import socket
import select
import errno
import sys
HEADER_LENGTH = 10
IP = "127.0.0.1"
PORT = 1234
my_username = input("Username: ")
client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client_socket.connect((IP, PORT))
client_socket.setblocking(False)
username = my_username.encode("utf-8")
username_header = f"{len(username):<{HEADER_LENGTH}}".encode("utf-8")
client_socket.send(username_header + username)
while True:
message = input(f"{my_username} > ")
if message:
message = message.encode("utf-8")
message_header = f"{len(message):<{HEADER_LENGTH}}".encode("utf-8")
client_socket.send(message_header + message)
try:
while True:
#receive things
username_header = client_socket.recv(HEADER_LENGTH)
if not len(username_header):
print("connection closed by the server")
sys.exit()
username_length = int(username_header.decode("utf-8").strip())
username = client_socket.recv(username_length).decode("utf-8")
message_header = client_socket.recv(HEADER_LENGTH)
message_length = int(message_header.decode("utf-8").strip())
message = client_socket.recv(message_length).decode("utf-8")
print(f"{username} > {message}")
except IOError as e:
if e.errno != errno.EAGAIN and e.errno != errno.EWOULDBLOCK:
print('Reading error', str(e))
sys.exit()
continue
except Exception as e:
print('General error', str(e))
sys.exit()
On the same machine, it works as expected since I'm using the hostname for both the server and client, but obviously, it will not work on separate devices.
How may I change this code so that I can get my laptop to act as a client, and my computer to act as a server? I only need to connect to devices on the same network. Thank you for any answers.

I found the solution myself, I just had to set the 'IP' in client to that of the server local IP, and lastly run both in IDLE so I would get the prompt to bypass the firewall, as I was running cmd previously and was not getting the option to bypass.

My python program freezes when I use 'recv()' with my client socket, how could I fix it?

I'm trying to make a mail app, using socket, tkinter, etc. When I launch the program, it freezes after the loading screen. It doesn't show any error, just freezes. I debugged it, and found out where the 'error' was. I've tried using setblocking() or settimeout(), etc, but nothing worked. Maybe tkinter is the problem? Here are the most important parts of my client script, and server script
CLIENT
client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
[...]
def after():
client_socket.connect((IP, PORT))
while True:
msg = client_socket.recv(HEADER) # It freezes here (I found out it was here by debugging)
try:
msg = msg.decode(FORMAT)
except Exception:
msg = pickle.loads(msg)
if msg:
pass
def load_win():
loading_bar.pack_forget()
loading_title.pack_forget()
loading_frame.pack_forget()
main_label.pack()
log_in_button.pack(pady=30)
sign_in_button.pack()
main_frame.pack(expand=YES)
win.geometry('720x480')
win.minsize(720, 480)
win.config(bg='#3D3D3D')
win.after(0, after)
def load_bar():
loading_bar['value'] += loading_bar['length'] // 100
def load():
total_nbr = 0
for x in range(100):
randint = random.randint(1000, 5000)
total_nbr += randint
loading_bar.after(randint, load_bar)
win.after(total_nbr//100, load_win)
[...]
win.after(0, load)
win.mainloop()
SERVER
[...]
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind((IP, PORT))
server_socket.listen()
[...]
while True:
client_socket, client_address = server_socket.accept()
[...]
while True:
msg = None
try:
msg = client_socket.recv(HEADER)
except Exception:
break
try:
msg = msg.decode(FORMAT)
except Exception:
msg = pickle.loads(msg)
if msg == 'get_clients':
client_socket.send(pickle.dumps(clients))

How can I receive multiple messages from one connection?

I have a server and I need it to receive multiple connections and messages.
The server receives new connections without problems but it doesn't get multiple messages from one connection.
import socket
import select
HEADER_LENGTH = 1024
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
try:
server_socket.bind((HOST, PORT))
except socket.error as e:
print(str(e))
print("Server is connected")
server_socket.listen(5)
sockets_list = [server_socket]
clients = {}
print("Server is listening")
def receive_message(conn):
try:
data = conn.recv(HEADER_LENGTH)
if not len(data):
return False
strdata = data.decode('utf-8')
print(strdata)
return strdata
except Exception as e:
print(e)
return False
def handle_client():
conn, addr = server_socket.accept()
print(f"Accepted new connection from {addr[0]}:{addr[1]}")
sockets_list.append(conn)
while True:
read_sockets, _, exception_sockets = select.select(sockets_list, [], [], 0)
for i in read_sockets:
if i == server_socket:
handle_client()
else:
print("received message")
message = receive_message(i)
if message is False:
sockets_list.remove(i)
try:
del clients[i]
except KeyError:
pass
continue
if message is not None:
clients[i] = message
if message is not None:
for client_socket in clients:
if client_socket != i:
client_socket.send(str.encode(message))
print("sent to all players")
What happens it that after receiving the first message, the server stops receiving messages from that connection.
And of course there is a lot more code but I showed you the relevant code.
I'll be very happy if someone helps me with that, I've surfed the web so much but haven't seen a solution for my problem.
updates:
I've tried to put socket.close() on my client side(written in Java) and then server gets maximum 2 messages and the problems with it are:
1. The server gets maximum 2 messages.
2. the connection changes(I need that the connection will stay static if possible)

try this code block
#-*- coding:utf-8 -*-
import socket
import sys
#get machine ip address
server_ip = socket.gethostbyname(socket.gethostname())
#create socket object
s = socket.socket()
#define port number
port = 6666
#bind ip and port to server
s.bind((server_ip,port))
#now waiting for clinet to connect
s.listen(5)
print("Enter this ip to connect your clinet")
print(server_ip)
clients = []
flag = True
recv_data = ""
if not clients:
c, addr = s.accept()
print("this is c ",c," this is Addr ",addr)
clients.append(c)
recv_data = c.recv(1024)
print(recv_data.decode("utf-8"))
if flag == True:
while recv_data.decode("utf-8") != "EX":
recv_data = c.recv(1024)
recv_data.decode("utf-8")
if recv_data.decode("utf-8") == "EX":
s.close()
print("check false")
break
s.close()