From a05c003fbcbc17a8add7f6a4ad74af3933657883 Mon Sep 17 00:00:00 2001
From: user-1 <no@mail.yet>
Date: Sun, 12 Mar 2023 05:28:27 +0000
Subject: [PATCH] Project files added

---
 client.py | 151 ++++++++++++++++++++++++++++++++++++++
 server.py | 214 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 365 insertions(+)
 create mode 100644 client.py
 create mode 100644 server.py

diff --git a/client.py b/client.py
new file mode 100644
index 0000000..60c17ec
--- /dev/null
+++ b/client.py
@@ -0,0 +1,151 @@
+import socket
+import struct
+import logging
+import threading
+
+from pytun import TunTapDevice, IFF_TAP
+
+
+########################## Defining global variables
+
+
+ADDRESS = "127.0.0.1"; # Address to connect to
+PORT = 9999; # Port to connect to
+
+NIC_NAME = "client"; # Name for the TAP interface that gonna be created
+
+CONFIGURE_NIC = True; # If you prefer to set up the interface manualy set it to False
+
+NIC_IP = "10.0.0.2"; # IP to be set for the interface
+NIC_NETMASK = "255.255.255.0"; # Netmask to be used with the interface
+
+MTU = 1500; # MTU that gonna be set for the interface, please don't change it if you don't know what you are doing
+
+logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s %(message)s\n') # Sets logging level and format. Possible levels: DEBUG, INFO, WARNING, ERROR, CRITICAL     Read python logging module documentation for more detailes
+
+
+# Don't change if you don't know what are you doing
+connected = False # Stores the connection status
+
+########################## Defining global variables (END)
+
+
+
+
+
+########################## Defining functions
+
+
+def recive(socket, NIC): # A function that reads socket for new data and writes this data to the NIC
+
+    global MTU # Read what they are used for in "Defining global variables" section above
+    global connected
+
+    buffer_ = " " # Setting buffer to " " so it's not empty and the loop can start
+
+    while buffer_ != b'': # If buffer_ is b'' that meas the server closed the socket
+
+        buffer_ = socket.recv(MTU) # reciving data from the server
+        
+        if buffer_ != b'': # If buffer_ is still not empty, write it to the NIC
+
+            NIC.write(buffer_)
+
+            logging.debug(f'Recived: {buffer_}')
+
+    logging.info("Connection with the server lost. Reconnecting...")
+    connection = False
+
+
+
+
+def send(socket, NIC): # The function reads the NIC for new frames and send them to the server
+
+    global MTU  # Read what they are used for in "Defining global variables" section above
+    global connected
+
+    while connected == True:
+
+        buffer_ = NIC.read(MTU) # Reads outgoing frames
+        socket.send(buffer_) # Sends the frames
+
+        logging.debug(f'Sent: {buffer_}')
+
+
+
+
+def main():
+
+    global NIC_NAME # Read what they are used for in "Defining global variables" section above
+    global MTU
+    global CONFIGURE_NIC
+    global NIC_IP
+    global NIC_NETMASK
+    global ADDRESS
+    global PORT
+    global connected
+
+
+
+
+    # Setting up a TAP interface
+    NIC = TunTapDevice(flags=IFF_TAP, name=NIC_NAME)
+    NIC.mtu = MTU
+
+    if CONFIGURE_NIC:
+
+        NIC.addr = NIC_IP
+        NIC.netmask = NIC_NETMASK
+
+    NIC.up()
+
+
+
+
+    # Setting up a socket
+    client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+
+    
+    logging.info(f'Connecting to {ADDRESS}:{PORT}')
+
+    while True:    
+        
+        try:
+            
+            client_socket.connect((ADDRESS, PORT))
+            
+            connected = True
+
+            logging.info(f'Connected {ADDRESS}:{PORT}')
+            
+            sending_thread = threading.Thread(target=send, args=(client_socket, NIC))
+            sending_thread.start()
+
+            recive(client_socket, NIC)
+
+        except Exception: # If there is an error execute the code below
+
+            logging.debug("An error occurred during connection. Reconnecting")
+            client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # Recreating socket
+
+        except KeyboardInterrupt: # if there is a keyboard interrupt (CTRL + C) it gonna close the socket and the NIC and break the loop
+
+            NIC.close()
+            client_socket.close()
+            break
+
+
+
+
+
+
+
+########################## Defining functions (END)
+
+
+
+
+
+if __name__ == '__main__': # Starting the main function
+    main()
+
diff --git a/server.py b/server.py
new file mode 100644
index 0000000..e0e860c
--- /dev/null
+++ b/server.py
@@ -0,0 +1,214 @@
+import socket
+import struct
+import logging
+import threading
+
+from pytun import TunTapDevice, IFF_TAP
+
+
+
+
+
+########################## Setting global variables 
+
+
+ADDRESS = "127.0.0.1" # Address to listen on
+PORT = 9999 # Port to listen on
+
+NIC_NAME = "server" # Name for the TAP interface that gonna be created
+
+CONFIGURE_NIC = True # If you prefer to set up the interface manualy set it to False 
+
+NIC_IP = "10.0.0.1" # IP to be set for the interface
+NIC_NETMASK = "255.255.255.0" # Netmask to be used with the interface
+
+MTU = 1500 # MTU that gonna be set for the interface, please don't change it if you don't know what you are doing
+
+logging.basicConfig(level=logging.DEBUG, format='%(asctime)s - %(levelname)s %(message)s\n') # Sets logging level and format. Possible levels: DEBUG, INFO, WARNING, ERROR, CRITICAL     Read python logging module documentation for more detailes
+
+
+## Don't change this if you not sure what you are doing 
+client = {} # Dictionary of clients, Key is the MAC address of a client, Value is an object of class Client
+client_thread = {} # Client thread contains a Key that is MAC of a client, and object of type Thread, that runs "recive" function  
+
+
+########################## Setting global variables (END)
+
+
+
+
+
+########################## Defining functions 
+
+class Client: # Class Client contains a client info and some methods to work with the client
+
+    def __init__(self, socket, address, NIC, MAC): # Constructor for class Client 
+
+        self.socket = socket
+        self.address = address
+        self.NIC = NIC
+        self.MAC = MAC
+
+
+
+
+    def recive(self): # Function that listens the client socket for a frames and writes the frames into the NIC. It runs in a loop
+        
+        # Importing global variables
+        global MTU # Read what they are used for in "Defining global variables" section above
+        global client
+        global client_thread
+
+        buffer_ = " " # Setting buffer to " " so it's not empty and the loop can start
+
+        while buffer_ != b'': # If buffer_ is b'' that meas that client closed the socket, and needs to be deleted
+
+            buffer_ = self.socket.recv(MTU) # reciving data from the client
+            
+            if buffer_ != b'': # If buffer_ is still not empty, write it to the server's NIC
+                self.NIC.write(buffer_)
+                logging.debug(f'Recived: From {self.address}  {buffer_}')
+
+        logging.info(f'Connection closed: {self.address}') 
+
+        del client[self.MAC] # Deleting the client from the dictionary, and removing it's "recive" thread
+        del client_thread[self.MAC]
+
+
+
+
+    def send(self, frame): # Just sends the data to the client's socket
+
+        global MTU # Read what it used for in "Defining global variables" section above
+
+
+        self.socket.send(frame)
+
+        logging.debug(f'Sent: To {self.address}  {frame}')
+
+
+
+
+
+def send(client, NIC): # Not to be confused with "send" from the Client class, this one gets all outgoing frames and decides what client it needs to be sent to
+
+    global MTU # Read what it used for in "Defining global variables" section above
+
+
+    while True:
+
+        buffer_ = NIC.read(MTU) # Reads NIC for outgoing frames
+        dst = struct.unpack("! 4x 6s", buffer_[:10]) # Extracts destination MAC address from the frame 
+       
+        if (client.get(dst)): # If client with the destination MAC address exists, send the frame to the client
+
+            client[dst].send(buffer_)
+            logging.debug(f'Sending: To {dst}  {buffer_}')
+
+        else: # If client with the destination MAC address doesn't exist, then send the frame to all of the clients (Send to broadcast)
+            logging.warning(f'Client with MAC {dst} not found, sending to broadcast')
+        
+            for mac in client.keys(): # Going throught all of the clients, and send the frame to each of them
+                
+                 try: # The "try" needs to be here, in case a client closes connection, so instead of crashing the thread, it will print the error message
+
+                    logging.debug(f'Sending a broadcast message to  {mac}  {buffer_}')
+                    client[mac].send(buffer_)
+                    
+                 except:
+
+                    logging.error('Cannot send the frame to {mac}')
+
+
+
+
+
+
+def main():
+
+    # Importing global variables
+
+    global NIC_NAME # Read what they are used for in "Defining global variables" section above
+    global MTU
+    global CONFIGURE_NIC
+    global NIC_IP
+    global NIC_NETMASK
+    global ADDRESS
+    global PORT
+    global client
+    global client_thread
+
+
+
+    # Setting up a TAP interface
+    NIC = TunTapDevice(flags=IFF_TAP, name=NIC_NAME)
+    NIC.mtu = MTU
+
+    if CONFIGURE_NIC:
+
+        NIC.addr = NIC_IP
+        NIC.netmask = NIC_NETMASK
+
+    NIC.up()
+
+
+
+
+    # Setting up a socket
+    server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    server_socket.bind((ADDRESS, PORT))
+
+
+
+
+
+    # Creating a "routing" thread, it will read the outgoing frames, and decide to who it will be sent
+    routing = threading.Thread(target=send, args=(client, NIC));
+    FirstRun = False # Used to only start thread at the end of first cicle of the main loop, if you know more elegant way to do this, please let me know
+
+
+    # Main loop
+
+    try:
+
+        while True:
+
+            logging.info("Listening for a new client")
+
+            server_socket.listen(1) # Listening
+            new_client, new_client_address = server_socket.accept() # When there is a client accepting the connection request and creating socket for the new client (new_client), new_client_addrss contains... new client's address
+            buffer_ = new_client.recv(MTU) # Reciving a frame and putting it to the buffer
+            new_client_mac = struct.unpack("! 10x 6s", buffer_[:16]) # Extracting a source MAC address, to use it later as a Key for the new client
+            
+            logging.info(f'New client connected: {new_client_address}  MAC: {new_client_mac}')
+
+            client[new_client_mac] = Client(new_client, new_client_address, NIC, new_client_mac) # Creating an object of type Client with all the information for the new client, and putting it to "client" dictionary, using the client MAC address as a Key to access the client
+            new_client_thread = threading.Thread(target=client[new_client_mac].recive) # Creating a new thread that runs "recive" method, it will read client's socket for new data and write the data to the server's NIC. It runs in a loop
+            client_thread[new_client_mac] = new_client_thread # Putting the thread to "client_thread" and useing client's MAC as a Key, and the "new_client_thread" object as a value
+            client_thread[new_client_mac].start() # Starting the thread
+
+            logging.debug(f'Client list: {client.keys()}')
+
+            if FirstRun is False: # If loop runs the first time, start the routing function, it is required as the function will fail without a client's data (Might be fixed soon)
+                routing.start()
+                FirstRun = True
+
+
+
+
+    except KeyboardInterrupt: # When CTRL + C pressed run the code below
+
+        NIC.close() # Closing everything that needs to be closed
+        server_socket.close()
+
+    # Main loop (END)
+
+
+########################## Defining functions (END) 
+
+
+
+
+
+if __name__ == '__main__':  # Starting the Main function
+    main()