diff --git a/client.py b/client.py
index a609e05aa36949c224addcf55602bb7131db93e6..494c50822ffb3413f0caa7156f6bdcf51ab27525 100644
--- a/client.py
+++ b/client.py
@@ -1,30 +1,88 @@
import socket
import threading
+from datetime import datetime
-def receive_messages():
- while True:
- try:
- # Empfange Nachricht vom Server
- data = client_socket.recv(1024)
- print(data.decode('utf-8'))
- except:
- break
-
-# Client-Konfiguration
-host = '127.0.0.1'
-port = 5555
-
-# Verbinde zum Server
-client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-client_socket.connect((host, port))
-print(f'Du bist jetzt im Chat')
-
-
-# Starte einen Thread, um Nachrichten vom Server zu empfangen
-receive_thread = threading.Thread(target=receive_messages)
-receive_thread.start()
-
-# Haupt-Thread zum Senden von Nachrichten
-while True:
- message = input()
- client_socket.send(message.encode('utf-8'))
+MULTICAST_GROUP_IP = '224.1.1.1'
+
+# Broadcast address and port
+
+CLIENT_MULTICAST_PORT = 5973
+
+# Local host information
+MY_HOST = socket.gethostname()
+MY_IP = socket.gethostbyname(MY_HOST)
+
+
+class Client():
+ def __init__(self):
+ self.currentLeader = ''
+ self.server_socket = None
+
+ # print the current date and time
+ def printwt(self, msg):
+ current_date_time = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
+ print(f'[{current_date_time}] {msg}')
+
+ # dynamic discoverey: client sends request to server group and gets the IP of server as reply
+ def MulticastSendAndReceive(self):
+ # Create a UDP socket
+ multicast_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+
+ # Set the time-to-live for messages to 1 so they do not go past the local network segment
+ multicast_socket.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, 1)
+
+ # Send message on multicast address
+ message = 'New client wants to connect: ' + MY_IP
+ multicast_socket.sendto(str.encode(message), (MULTICAST_GROUP_IP, CLIENT_MULTICAST_PORT))
+
+ self.printwt("Sent my IP to server group")
+
+ while True:
+ try:
+ # receive reply data (server IP) from the other participants
+ reply, addr = multicast_socket.recvfrom(1024)
+
+ if reply:
+ # decode received data
+ reply_addr = reply.decode()
+ self.currentLeader = reply_addr
+ self.printwt(f'Got Leader address: {self.currentLeader}')
+
+ # Connect to the server using TCP
+ self.server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+ self.server_socket.connect((self.currentLeader, 5555))
+ print("You have entered the chat room")
+
+ # Starte einen Thread, um Nachrichten zu empfangen
+ receive_thread = threading.Thread(target=self.receive_messages)
+ receive_thread.start()
+
+ # Haupt-Thread zum Senden von Nachrichten
+ while True:
+ message = input()
+ timestamped_message = f'[{datetime.now().strftime("%Y-%m-%d %H:%M:%S")}] {message}'
+ self.server_socket.send(timestamped_message.encode('utf-8'))
+
+ except socket.timeout:
+ pass
+
+ def receive_messages(self):
+ while True:
+ try:
+ data = self.server_socket.recv(1024)
+ if not data:
+ break
+ print(data.decode('utf-8'))
+ except:
+ break
+
+
+
+
+# starting all simultaneously working procedures
+if __name__ == "__main__":
+ client = Client()
+
+ thread1 = threading.Thread(target = client.MulticastSendAndReceive)
+ thread1.start()
+ thread1.join()
\ No newline at end of file
diff --git a/server.py b/server.py
index 0183a099b94b3e22dfb00c2075d5861b763de6f1..e5635903724c93c467e57370598fa7d5294fd086 100644
--- a/server.py
+++ b/server.py
@@ -1,59 +1,219 @@
import socket
import threading
+from datetime import datetime
+import time
+import struct
-def handle_client(client_socket, client_address):
- while True:
- try:
- # Empfange Nachricht vom Client
- data = client_socket.recv(1024)
- if not data:
+MULTICAST_GROUP_IP = '224.1.1.1'
+
+# Listening port Server Discovery
+SERVER_MULTICAST_PORT = 5974
+
+# Listening port Client Discovery
+CLIENT_MULTICAST_PORT = 5973
+
+# Local host information
+MY_HOST = socket.gethostname()
+MY_IP = socket.gethostbyname(MY_HOST)
+
+
+class Server():
+ def __init__(self):
+ self.leader_IP = '' # fix the leader IP
+ self.serverList = [] # list if servers and their addresses
+ self.clients = []
+ self.informServer = False
+ self.isLeader = False # New variable to track if the server is the leader
+
+
+ def printwt(self, msg):
+ current_date_time = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
+ print(f'[{current_date_time}] {msg}')
+
+
+ def print_group_view(self):
+ print("Group view is:", self.serverList)
+
+
+ #This function enables the server to listen to the server multicast port and reply the ip address
+ def MulticastListenAndReply(self):
+
+ # if my IP is not in the server list add it
+ if MY_IP not in self.serverList:
+ self.serverList.append(MY_IP)
+
+ # create socket bind to server address
+ multicast_listen_sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+ multicast_listen_sock.bind(('', SERVER_MULTICAST_PORT))
+
+ # tell the os to add the socket to the multicast group
+ multicast_group = socket.inet_aton(MULTICAST_GROUP_IP)
+ mreg = struct.pack('4sL', multicast_group, socket.INADDR_ANY)
+ multicast_listen_sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreg)
+
+
+ while True:
+
+ data, address = multicast_listen_sock.recvfrom(1024)
+
+ if data:
+ newServer_address = data.decode()
+ self.printwt(f'New participant wants to connect: {newServer_address}')
+ self.isLeader = False
+
+ # if the decoded address is not in the server list add it and print the list
+
+ if newServer_address not in self.serverList:
+ self.serverList.append(newServer_address)
+
+ reply_message = MY_IP
+ multicast_listen_sock.sendto(str.encode(reply_message), address)
+
+ self.printwt('Replied my IP to new participant')
+
+
+
+ time.sleep(1)
+ self.print_group_view()
+ self.printwt(f'The current leader IP is: {self.leader_IP}')
+
+
+ #this function enables the server to send a multicast to the server group and receive the answers of existing members
+ def MulticastSendAndReceive(self):
+
+ # create socket
+ multicast_group = (MULTICAST_GROUP_IP, SERVER_MULTICAST_PORT)
+ multicast_send_sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+ # Set a timeout so the socket does not block indefinitely when trying to receive data.
+ multicast_send_sock.settimeout(2)
+
+ # Set the time-to-live for messages to 1 so they do not go past the local network segment.
+ multicast_send_sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, 1)
+
+ message = MY_IP
+ multicast_send_sock.sendto(message.encode(), multicast_group)
+ self.printwt("Sent my IP to server group")
+
+ # if my IP is not in the server list add it
+ if MY_IP not in self.serverList:
+ self.serverList.append(MY_IP)
+
+ # listen for IPs from existing servers
+ maxLoop = 5
+ currentLoop = 0
+
+ # Anzahl der eingehenden Antworten initialisieren
+ num_responses = 0
+
+ while currentLoop < maxLoop:
+ print("Waiting for responses...") # Debug-Ausgabe
+ while True:
+ currentLoop += 1
+
+ try:
+ # receive reply data from the other participants
+ reply, address = multicast_send_sock.recvfrom(1024)
+
+ if reply:
+ reply_address = reply.decode()
+
+ # Debug-Ausgabe
+ print(f"Received response from: {reply_address}")
+
+ # if reply address is not in the server list, add it
+ if reply_address not in self.serverList:
+ self.serverList.append(reply_address)
+
+ # Erhöhe die Anzahl der eingehenden Antworten
+ num_responses += 1
+ print(f"Current server list: {self.serverList}") # Debug-Ausgabe
+
+ except socket.timeout:
+ break
+
+ if num_responses == 1:
+ multicast_send_sock.close()
+ self.isLeader = True
+ self.leader_IP = MY_IP # Hier wird die IP-Adresse des Leaders zugewiesen
+ self.printwt(f'I am the only server in the system, so the leader IP is: {self.leader_IP}')
+ time.sleep(1)
+
+
+ self.print_group_view()
+
+
+ # Listen to client multicast (request) and reply with Server IP
+ def ListenForClientAndReply(self):
+ # Create a UDP socket
+ listen_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+ # Enable reusing addresses
+ listen_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+ # Bind socket to address and port
+ listen_socket.bind((MY_IP, CLIENT_MULTICAST_PORT))
+
+ # tell the os to add the socket to the multicast group
+ multicast_group = socket.inet_aton(MULTICAST_GROUP_IP)
+ mreg = struct.pack('4sL', multicast_group, socket.INADDR_ANY)
+ listen_socket.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreg)
+
+ # print("Listening to multicast messages")
+
+ # Receiving multicast massage
+ while True:
+ data, addr = listen_socket.recvfrom(1024)
+
+ if data:
+ self.printwt(data.decode())
+
+ # if Iam the leader, answer the client including my IP
+ if MY_IP == self.leader_IP:
+ reply_message = MY_IP
+ listen_socket.sendto(str.encode(reply_message), addr)
+ self.printwt('Replied my IP to new client')
+
+ def handle_client(self, client_socket, client_address):
+ self.clients.append(client_socket)
+
+ while True:
+ try:
+ data = client_socket.recv(1024)
+ if not data:
+ break
+ self.multicast(data, client_socket)
+
+ except:
+ self.clients.remove(client_socket)
break
- # Sende die empfangene Nachricht an alle anderen Clients
- broadcast(data, client_socket, client_address)
- except:
- break
-
- # Client-Socket schließen
- client_socket.close()
-
-def broadcast(message, sender_socket, sender_address):
- for client in clients:
- try:
- # Sende die Nachricht an alle Clients, außer an den Absender
- if client != sender_socket:
- client.send(f"{sender_address}: {message}".encode('utf-8'))
- except:
- # Entferne defekte Verbindungen
- clients.remove(client)
-
-# Server-Konfiguration
-host = '192.168.2.42'
-port = 5555
-
-# Socket erstellen und binden
-server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-server_socket.bind((host, port))
-server_socket.listen(5)
-
-print(f'Server lauscht auf {host}:{port}')
-
-# Liste für die verbundenen Clients
-clients = []
-servers = [server_socket]
-
-while True:
- # Warten auf eine Verbindung
- connection_socket, client_address = server_socket.accept()
-
- # Wenn eine Verbindung von einem anderen Server kommt, füge ihn zur Serverliste hinzu
- if connection_socket != server_socket:
- servers.append(connection_socket)
- else:
- # Neuen Thread für jeden verbundenen Client erstellen
- client_thread = threading.Thread(target=handle_client, args=(connection_socket, client_address))
- client_thread.start()
-
- # Client-Socket zur Liste hinzufügen
- clients.append(connection_socket)
+ def multicast(self, message, sender_socket):
+ for client in self.clients:
+ try:
+ if client != sender_socket:
+ client.send(message)
+ except:
+ self.clients.remove(client)
+
+
+# starting all simultaneously working procedures
+if __name__== '__main__':
+ server = Server()
+
+ thread2 = threading.Thread(target = server.MulticastListenAndReply)
+ thread2.start()
+
+ thread3 = threading.Thread(target = server.MulticastSendAndReceive)
+ thread3.start()
+
+ thread1 = threading.Thread(target = server.ListenForClientAndReply)
+ thread1.start()
+
+ # Socket erstellen und binden
+ server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+ server_socket.bind((MY_IP, 5555))
+ server_socket.listen(5)
+
+ while True:
+ client_socket, client_address = server_socket.accept()
+ client_thread = threading.Thread(target=server.handle_client, args=(client_socket, client_address))
+ client_thread.start()
\ No newline at end of file