Finish the HW5

chatserver/client.py

@@ -1,3 +1,4 @@
+import os
 import socket
 import sys
 import select
@@ -15,13 +16,29 @@ def main():
         SERVER_HOST = sys.argv[1]
         SERVER_PORT = int(sys.argv[2])
 
+    # Prompt user for a local directory path for file operations
+    while True:
+        local_path = input("Enter a local directory path for sending/receiving files: ").strip()
+        if os.path.isdir(local_path):
+            print(f"Using directory: {local_path}")
+            break
+        else:
+            print("Invalid directory. Please enter a valid path.")
+
     # create a socket object
     client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     try:
         # connect to the server
         client_socket.connect((SERVER_HOST, SERVER_PORT))
         print(f"Connected to chat server at {SERVER_HOST}:{SERVER_PORT}")
-        
+
+        # Prompt user for a username and send it to the server
+        username = input("Enter your username: ").strip()
+        client_socket.send(username.encode('utf-8'))
+
+        # Send the local path to the server
+        client_socket.send(f"SET_PATH {local_path}".encode('utf-8'))
+
         while True:
             # use select to wait for either server messages or user input
             read_sockets, _, _ = select.select([client_socket, sys.stdin], [], [])
@@ -33,16 +50,43 @@ def main():
                     if not server_message:
                         print("Disconnected from server")
                         return
-                    print(f"\n{server_message}")
+                    if server_message.startswith("FILE_REQUEST"):
-                    print("> ", end="", flush=True)
+                        # Handle file request
+                        _, sending_username, filename = server_message.split()
+                        file_path = os.path.join(local_path, filename)
+                        if os.path.isfile(file_path):
+                            file_size = os.path.getsize(file_path)
+                            with open(file_path, "rb") as f:
+                                file_bytes = f.read()
+                            filetype = "File"
+                            client_socket.send(
+                                f"@{sending_username}@CLIENT -f {filename} {filetype} {file_size} {file_bytes.decode('latin1')} ENDFILE".encode('utf-8')
+                            )
+                        else:
+                            client_socket.send(
+                                f"@{sending_username}@CLIENT -f {filename} NOTFOUND".encode('utf-8')
+                            )
+                    elif server_message.startswith("FILE_TRANSFER"):
+                        # Handle file transfer
+                        _, sending_username, filename, filetype, filelength = server_message.split()
+                        file_bytes = client_socket.recv(int(filelength))
+                        end_marker = client_socket.recv(BUFFER_SIZE).decode('utf-8')
+                        if end_marker == "ENDFILE":
+                            file_path = os.path.join(local_path, filename)
+                            with open(file_path, "wb") as f:
+                                f.write(file_bytes)
+                            print(f"Received file '{filename}' from {sending_username}.")
+                    else:
+                        print(f"\n{server_message}")
+                        print("> ", end="", flush=True)
                 else:
-                    # prompt for user input
+                    # Prompt for user input
-                    client_message = input()
+                    client_message = input("> ").strip()
-                    if client_message.strip() == "%!":
+                    if client_message == "%!":
                         print("Exiting chat...")
                         return
-                    
+
-                    # send message to server
+                    # Send message to server
                     client_socket.send(client_message.encode('utf-8'))
     
     except Exception as e:

chatserver/server.py

@@ -1,139 +1,168 @@
+import os
 import socket
 import select
+import threading
 
 CHATPORT = 8181
 BUFFER_SIZE = 1024
 MAX_CONNECT_QUEUE = 10
 
-def main():
+def format_file_info(file_path):
-    # set the flag variable to true for infinite loop
+    """Helper function to format file information."""
-    quitFlag = True
+    file_size = os.path.getsize(file_path)
-    # create a socket object
+    if file_size < 1000:
-    server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        size_str = f"{file_size} B"
-    # set the socket options, SO_REUSEADDR allows to reuse the same port
+    elif file_size < 1000000:
-    # SO_KEEPALIVE enables the socket to send keepalive messages
+        size_str = f"{file_size / 1000:.2f} KB"
-    server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    else:
-    server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
+        size_str = f"{file_size / 1000000:.2f} MB"
-    # bind the socket to the address and port
+    file_type = "Directory" if os.path.isdir(file_path) else "File"
-    server_socket.bind(('', CHATPORT))
+    return f"{os.path.basename(file_path)} - {file_type} - {size_str}"
-    # listen for incoming connections
-    server_socket.listen(MAX_CONNECT_QUEUE)
-    # set the server socket to non-blocking
-    server_socket.setblocking(False)
 
-    # create a list to store the sockets, server and client
+def handle_client(sock, client_address, socket_list, usernames, chat_rooms, client_states, user_paths):
-    socket_list = [server_socket]
+    """Handle communication with a single client."""
-    # since a socket is associated with a username and a chatroom, 
+    try:
-    # and each one can only be associated one way at once, use dictionaries to
+        while True:
-    # associate with each other.
+            message = sock.recv(BUFFER_SIZE).decode('utf-8')
-    usernames = {}
+            if not message:
-    chat_rooms = {}
+                break
-    # keep track of the states of each client connected, and if they are 
+
-    # technically in an 'unsafe' state like in change username or chatroom mode.
+            state = client_states.get(sock, "NORMAL")
-    client_states = {}
+            if state == "WAITING_FOR_USERNAME":
-    # let the user know the server is listening on port CHATPORT.
+                # Handle username setup
+                usernames[sock] = message.strip()
+                chat_rooms[sock] = "default"
+                sock.send(b"\nUsername accepted. You are now in the 'default' chatroom.")
+                client_states[sock] = "NORMAL"
+                user_paths[sock] = None  # Initialize path for the user
+            elif state == "NORMAL":
+                if message.startswith("SET_PATH"):
+                    # Handle setting the user's directory path
+                    _, path = message.split(" ", 1)
+                    if os.path.isdir(path):
+                        user_paths[sock] = path
+                        sock.send(b"Directory path set successfully.")
+                    else:
+                        sock.send(b"Error: Invalid directory path.")
+                elif message.startswith("@") and "-ls" in message:
+                    # Handle directory listing request
+                    parts = message.split()
+                    if len(parts) == 2 and parts[1] == "-ls":
+                        target_username = parts[0][1:]  # Extract the username after '@'
+                        target_sock = next((s for s, u in usernames.items() if u == target_username), None)
+                        if target_sock:
+                            user_path = user_paths.get(target_sock)
+                            if user_path and os.path.isdir(user_path):
+                                files = os.listdir(user_path)
+                                if files:
+                                    file_list = "\n".join(
+                                        [format_file_info(os.path.join(user_path, f)) for f in files]
+                                    )
+                                    sock.send(f"Files in {target_username}'s directory:\n{file_list}".encode('utf-8'))
+                                else:
+                                    sock.send(f"No files in {target_username}'s directory.".encode('utf-8'))
+                            else:
+                                sock.send(f"Error: {target_username} has no valid directory set.".encode('utf-8'))
+                        else:
+                            sock.send(b"Error: Target user not found.")
+                    else:
+                        sock.send(b"Error: Invalid message format.")
+                elif message.startswith("@") and "-f" in message:
+                    # Handle file request or transfer
+                    parts = message.split()
+                    if len(parts) >= 3 and "-f" in parts[1]:
+                        usernames_part = parts[0]
+                        if usernames_part.count("@") == 2:
+                            receiving_username, sending_username = usernames_part[1:].split("@")
+                            receiving_sock = next((s for s, u in usernames.items() if u == receiving_username), None)
+                            if receiving_sock:
+                                if len(parts) == 3:
+                                    # File request
+                                    filename = parts[2]
+                                    receiving_sock.send(f"FILE_REQUEST {sending_username} {filename}".encode('utf-8'))
+                                elif len(parts) > 5 and parts[-1] == "ENDFILE":
+                                    # File transfer
+                                    filename = parts[2]
+                                    filetype = parts[3]
+                                    filelength = int(parts[4])
+                                    filebytes = " ".join(parts[5:-1]).encode('utf-8')
+                                    receiving_sock.send(
+                                        f"FILE_TRANSFER {sending_username} {filename} {filetype} {filelength}".encode('utf-8')
+                                    )
+                                    receiving_sock.send(filebytes)
+                                    receiving_sock.send(b"ENDFILE")
+                            else:
+                                sock.send(b"Error: Receiving user not found.")
+                        else:
+                            sock.send(b"Error: Invalid message format.")
+                elif message.strip() == "%!":
+                    # Handle client exit
+                    break
+                else:
+                    # Broadcast message to other clients in the same chat room
+                    username = usernames.get(sock, "Unknown")
+                    chat_room = chat_rooms.get(sock, "default")
+                    send_message = f"{username} >> {message}".encode('utf-8')
+                    for client_sock in socket_list:
+                        if chat_rooms.get(client_sock) == chat_room:
+                            try:
+                                client_sock.send(send_message)
+                            except Exception as e:
+                                print(f"Error sending message to {client_sock}: {e}")
+                                client_sock.close()
+                                socket_list.remove(client_sock)
+    except Exception as e:
+        print(f"Error with client {client_address}: {e}")
+    finally:
+        # Clean up on client disconnect
+        sock.close()
+        socket_list.remove(sock)
+        if sock in usernames:
+            del usernames[sock]
+        if sock in chat_rooms:
+            del chat_rooms[sock]
+        if sock in client_states:
+            del client_states[sock]
+        if sock in user_paths:
+            del user_paths[sock]
+        print(f"Client {client_address} disconnected.")
+
+def main():
+    # Initialize server
+    server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    server_socket.bind(('', CHATPORT))
+    server_socket.listen(MAX_CONNECT_QUEUE)
     print(f"Chatserver listening on port: {CHATPORT}")
 
-    # infinite loop for the program
+    # Shared data structures
-    while quitFlag:
+    socket_list = []
-        # use the select function to monitor the sockets
+    usernames = {}
-        read_sockets, _, _ = select.select(socket_list, [], [])
+    chat_rooms = {}
-        # loop through the sockets
+    client_states = {}
-        for sock in read_sockets:
+    user_paths = {}
-            # if the socket is the server socket, accept the connection
-            if sock == server_socket:
-                client_socket, client_address = server_socket.accept()
-                client_socket.setblocking(False)
-                socket_list.append(client_socket)
-                print("\nAccepted connection from new client.")
-                client_socket.send(b"\nWelcome to the chat server!\n")
-                client_socket.send(b"\nUse '%!' to exit, or '%?' for help.\n")
-                client_socket.send(b"\nType in a username: ")
-                client_states[client_socket] = "WAITING_FOR_USERNAME"
-            # otherwise the socket is a client socket.
-            else:
-                # try to receive the message from the client
-                try:
-                    message = sock.recv(BUFFER_SIZE).decode('utf-8')
-                    if message:
-                        state = client_states.get(sock, "NORMAL")
-                        if state == "WAITING_FOR_USERNAME":
-                            usernames[sock] = message.strip()
-                            chat_rooms[sock] = "default"
-                            sock.send(b"\nUsername accepted. You are now in the 'default' chatroom.")
-                            client_states[sock] = "NORMAL"
-                        elif state == "WAITING_FOR_NEW_USERNAME":
-                            usernames[sock] = message.strip()
-                            sock.send(b"\nUsername changed successfully.")
-                            print(f"\nClient switched username to {usernames[sock]}.")
-                            client_states[sock] = "NORMAL"
-                        elif state == "WAITING_FOR_NEW_CHATROOM":
-                            old_chatroom = chat_rooms[sock]
-                            chat_rooms[sock] = message.strip()
-                            sock.send(f"\nSwitched to chatroom '{chat_rooms[sock]}.'".encode('utf-8'))
-                            print(f"\nClient switched to chatroom '{chat_rooms[sock]}.'")
-                            if old_chatroom != "default" and old_chatroom not in chat_rooms.values():
-                                print(f"\nChatroom '{old_chatroom}' is empty and removed.")
-                            client_states[sock] = "NORMAL"
-                        else:
-                            if message.strip() == "%!":
-                                sock.close()
-                                socket_list.remove(sock)
-                                del usernames[sock]
-                                del chat_rooms[sock]
-                                del client_states[sock]
-                                print("\nClient has closed connection.")
-                            elif message.strip() == "%?":
-                                print("\nClient requested help.")
-                                sock.send(b"Help: (%?)\n")
-                                sock.send(b"Send messages like normal. Use enter to send a message.\n")
-                                sock.send(b"Available Commands:\n")
-                                sock.send(b"\t%? : Show this help prompt.\n")
-                                sock.send(b"\t%! : Exit from the Chat Server.\n")
-                                sock.send(b"\t%* : Switch to another chatroom.\n")
-                                sock.send(b"\t%$ : Change Username.\n")
-                            elif message.strip() == "%*":
-                                sock.send(b"\nEnter chatroom name: ")
-                                client_states[sock] = "WAITING_FOR_NEW_CHATROOM"
-                            elif message.strip() == "%$":
-                                sock.send(b"\nEnter new username: ")
-                                client_states[sock] = "WAITING_FOR_NEW_USERNAME"
-                            else:
-                                username = usernames[sock]
-                                chat_room = chat_rooms[sock]
-                                send_message = f"{username} >> {message}".encode('utf-8')
-                                for client_sock in socket_list:
-                                    if client_sock != server_socket and chat_rooms.get(client_sock) == chat_room:
-                                        client_sock.send(send_message)
-                    else:
-                        sock.close()
-                        socket_list.remove(sock)
-                        if sock in usernames:
-                            del usernames[sock]
-                        if sock in chat_rooms:
-                            old_chatroom = chat_rooms[sock]
-                            del chat_rooms[sock]
-                            if old_chatroom != "default" and old_chatroom not in chat_rooms.values():
-                                print(f"\nChatroom '{old_chatroom}' is empty and has been removed.")
-                        if sock in client_states:
-                            del client_states[sock]
-                        print("\nClient has closed connection.")
-                except Exception as err:
-                    print(f"Error: {err}")
-                    sock.close()
-                    socket_list.remove(sock)
-                    if sock in usernames:
-                        del usernames[sock]
-                    if sock in chat_rooms:
-                        old_chatroom = chat_rooms[sock]
-                        del chat_rooms[sock]
-                        if old_chatroom != "default" and old_chatroom not in chat_rooms.values():
-                            print(f"\nChatroom '{old_chatroom}' is empty and has been removed.")
-                    if sock in client_states:
-                        del client_states[sock]
-                    print("\nClient has closed connection.")
 
-    server_socket.close()
+    try:
+        while True:
+            client_socket, client_address = server_socket.accept()
+            print(f"Accepted connection from {client_address}")
+            socket_list.append(client_socket)
+
+            # Initialize client state
+            client_states[client_socket] = "WAITING_FOR_USERNAME"
+            user_paths[client_socket] = None
+
+            # Start a new thread for the client
+            client_thread = threading.Thread(
+                target=handle_client,
+                args=(client_socket, client_address, socket_list, usernames, chat_rooms, client_states, user_paths),
+                daemon=True
+            )
+            client_thread.start()
+    except KeyboardInterrupt:
+        print("\nShutting down server...")
+    finally:
+        server_socket.close()
 
 if __name__ == "__main__":
     main()

echoserver/Makefile

@@ -1,20 +0,0 @@
-CC = gcc -Wall -std=c11 -pedantic
-SOURCES = echoserver.c 
-OBJECTS = echoserver.o 
-
-all: echoserver
-
-echoserver: $(OBJECTS)
-	$(CC) $(OBJECTS) -o echoserver
-
-echoserver.o: echoserver.c
-	$(CC) -c echoserver.c -o echoserver.o
-
-clean:
-	rm -f $(OBJECTS) echoserver echoserver.out
-
-clean_objects:
-	rm -f $(OBJECTS)
-
-run:
-	./echoserver

echoserver/README.md

@@ -1,10 +0,0 @@
-# Running the echoserver
-Use `make` to compile the echoserver.
-Use `make run` to run the echoserver. This will run on an infinite loop.
-Use `Ctrl+C` to stop the echoserver.
-
-## echoserver communication
-Communicating with the server can happen using telnet in TCP mode.
-
-## echoserver information
-The echoserver runs on TCP port 8888.

echoserver/echoserver.c

@@ -1,150 +0,0 @@
-// header files
-#include "echoserver.h"
-
-// constants
-// echoserver port is 8888
-#define ECHOPORT 8888
-#define BUFFER_SIZE 1024
-#define MAX_CONNECT_QUEUE 10
-
-// prototypes
-
-// main function
-int main(int argc, char **argv)
-{
-    // initialize program (variables and structs)
-    bool quitFlag = true;
-    int socketEchoFD;
-    int clientEchoFD;
-    int reuseAddrOpt = 1;
-    int keepAliveOpt = 1;
-    char message[BUFFER_SIZE];
-    int messageBytes;
-    struct sockaddr_in serverAddr;
-    struct sockaddr_storage clientAddr;
-    socklen_t clientSize;
-    memset(&serverAddr, 0, sizeof(serverAddr));
-    memset(&clientAddr, 0, sizeof(clientAddr));
-    // define a TCP socket
-    socketEchoFD = socket(AF_INET, SOCK_STREAM, 0);
-    if(socketEchoFD < 0)
-    {
-        printf("Unable to create the socket.\n");
-        return -1;
-    }
-    // use the setsockopt function to make the socket accept different configurations
-    // allow for the reuse of the address/bind.
-    setsockopt(socketEchoFD, SOL_SOCKET, SO_REUSEADDR, &reuseAddrOpt, sizeof(reuseAddrOpt));
-    // also need to set the socket to keepalive using setsockopt
-    setsockopt(socketEchoFD, SOL_SOCKET, SO_KEEPALIVE, &keepAliveOpt, sizeof(keepAliveOpt));
-    // bind the TCP socket to port 8888 / ECHOPORT
-    serverAddr.sin_family = AF_INET;
-    serverAddr.sin_addr.s_addr = INADDR_ANY;
-    serverAddr.sin_port = htons(ECHOPORT);
-    int bindCheck = bind(socketEchoFD, &serverAddr, sizeof(serverAddr));
-    if(bindCheck < 0)
-    {
-        printf("Unable to bind the socket to the port or address.\n Is either in use?");
-        return -1;
-    }
-    // use fnctl to set the non-blocking flag for the socket
-    fcntl(socketEchoFD, F_SETFL, O_NONBLOCK);
-    // the server will now accept client connections by listening.
-    listen(socketEchoFD, MAX_CONNECT_QUEUE);
-    // create a file descriptor set, to keep track of the sockets in use using fd_set and FD_ZERO?
-    fd_set socketList;
-    FD_ZERO(&socketList);
-    // add the socketEchoFD to the file descriptor set using fd_set
-    FD_SET(socketEchoFD, &socketList);
-    // max file descriptor, this will be used to 'find' the socket currently connected
-    int maxFD = socketEchoFD;
-    // while loop that will continue to listen for messages from clients.
-    printf("Echoserver listening on port: %d\n", ECHOPORT);
-    while (quitFlag)
-    {
-        // set of active connections
-        fd_set activeSet = socketList;
-        // use the select() function here to check the set of sockets
-        int selectedFD = select(maxFD+1, &activeSet, NULL, NULL, NULL);
-        // check to make sure select() didn't error out.
-        if(selectedFD == -1)
-        {
-            //
-            printf("\nUnable to select socket to listen to.\n");
-            return -1;
-        }
-        // for loop that loops up to the max file descriptor.
-        for(int fileIter = 0; fileIter <= maxFD; fileIter++)
-        {
-            // check to see if the file descriptor is in the set of sockets using FD_ISSET()
-            if(FD_ISSET(fileIter, &activeSet))
-            {
-                // if the server socket is being written to/read from,
-                if(fileIter == socketEchoFD)
-                {
-                    // create a client socket using accept
-                    clientSize = sizeof(clientAddr);
-                    clientEchoFD = accept(socketEchoFD, &clientAddr, &clientSize);
-                    // check to see if the client socket is connected (-1)
-                    if(clientEchoFD == -1)
-                    {
-                        printf("\nCould not connect the client to a socket.\n");
-                        return -1;
-                    }
-                    else
-                    {
-                        // set the non blocking flag using fnctl
-                        fcntl(clientEchoFD, F_SETFL, O_NONBLOCK);
-                        // add the client socket to the set of file descriptor sockets
-                        FD_SET(clientEchoFD, &socketList);
-                        // check to see if the new socket FD is greater than the current max (clientSocket > maxFD)
-                        if(clientEchoFD > maxFD)
-                        {
-                            // if it is, set the new max.
-                            maxFD = clientEchoFD;
-                        }
-                        printf("\nConnected client to socket.\n");
-                    }
-                    printf("\nAccepted connection from new client.\n");
-                }
-                // if the client socket(s) are being written to/read from,
-                else
-                {
-                    // grab the data from the client, save to message.
-                    messageBytes = recv(fileIter, message, BUFFER_SIZE, 0);
-                    // make sure that the connection is still open before attempting to send.
-                    if(messageBytes <= 0) // old: messageBytes <= 0
-                    {
-                        // if it is not open, close the socket and remove the socket from the socket list using FD_CLR()
-                        close(fileIter);
-                        FD_CLR(fileIter, &socketList);
-                        printf("\nClient has closed connection.\n");
-                    }
-                    else
-                    {
-                        // if it is open, send the message back to the client over the client socket
-                        send(fileIter, message, messageBytes, 0);
-                        printf("\nMessage has been sent back to client.\n");
-                    }
-                }
-            }
-        }
-    }
-    // close the socket
-    close(socketEchoFD);
-    // profit???
-    return 0;
-}
-
-// function definitions
-
-/*
-Name: ???
-Process: ???
-Function Input/Parameters: ???
-Function Output/Parameters: ???
-Function Output/Returned: ???
-Device Input/Device: ???
-Device Output/Device: ???
-Dependencies: ???
-*/

echoserver/echoserver.h

@@ -1,25 +0,0 @@
-#ifndef ECHOSERVER
-#define ECHOSERVER
-
-// included libraries
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <math.h>
-#include <stdbool.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <sys/select.h>
-#include <netdb.h>
-#include <time.h>
-#include <unistd.h>
-#include <errno.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <fcntl.h>
-
-// data structures
-
-// function prototypes
-
-#endif // ECHOSERVER

networksim/README.md

@@ -1,7 +0,0 @@
-# Adapted tcp-variants-comparison file
-The `tcp-variants-comparison.cc` file has been adapted to allow for multiple TCP variants to be run in one simulation.
-In order to change the variants ran, find line 510-524. This is where the magic of which variants to run is.
-The code relies on multiple flows to also be ran, which can be found using the number of cases - 1. If you want to test the file, you'll want to replace the file with this modified version, which must then be rebuilt. You should be able to use `./ns3 build tcp-variants-comparison` (or `./ns3 build examples/tcp-variants-comparison` might work better) although this hasn't been tested, and the best method is to use ccache to cache the build before making the modification.
-
-## How to find the cwnd of multiple TCP variants (how to run)
-The command `./ns3 run tcp-variants-comparison --command-template="%s --tracing=1 --prefix_name=CS460Homework4_TCPCmp --num_flows=3 --access_delay=50ms"` can be used to find the comparisons between TCP variants. You'll want the number of flows to equal the amount of cases in the switch statement.

networksim/tcp-variants-comparison.cc

@@ -1,624 +0,0 @@
-/*
- * Copyright (c) 2013 ResiliNets, ITTC, University of Kansas
- *
- * SPDX-License-Identifier: GPL-2.0-only
- *
- * Authors: Justin P. Rohrer, Truc Anh N. Nguyen <annguyen@ittc.ku.edu>, Siddharth Gangadhar
- * <siddharth@ittc.ku.edu>
- *
- * James P.G. Sterbenz <jpgs@ittc.ku.edu>, director
- * ResiliNets Research Group  https://resilinets.org/
- * Information and Telecommunication Technology Center (ITTC)
- * and Department of Electrical Engineering and Computer Science
- * The University of Kansas Lawrence, KS USA.
- *
- * Work supported in part by NSF FIND (Future Internet Design) Program
- * under grant CNS-0626918 (Postmodern Internet Architecture),
- * NSF grant CNS-1050226 (Multilayer Network Resilience Analysis and Experimentation on GENI),
- * US Department of Defense (DoD), and ITTC at The University of Kansas.
- *
- * "TCP Westwood(+) Protocol Implementation in ns-3"
- * Siddharth Gangadhar, Trúc Anh Ngọc Nguyễn , Greeshma Umapathi, and James P.G. Sterbenz,
- * ICST SIMUTools Workshop on ns-3 (WNS3), Cannes, France, March 2013
- */
-
-#include "ns3/applications-module.h"
-#include "ns3/core-module.h"
-#include "ns3/enum.h"
-#include "ns3/error-model.h"
-#include "ns3/event-id.h"
-#include "ns3/flow-monitor-helper.h"
-#include "ns3/internet-module.h"
-#include "ns3/ipv4-global-routing-helper.h"
-#include "ns3/network-module.h"
-#include "ns3/point-to-point-module.h"
-#include "ns3/tcp-header.h"
-#include "ns3/traffic-control-module.h"
-#include "ns3/udp-header.h"
-
-#include <fstream>
-#include <iostream>
-#include <string>
-
-using namespace ns3;
-
-NS_LOG_COMPONENT_DEFINE("TcpVariantsComparison");
-
-static std::map<uint32_t, bool> firstCwnd;                      //!< First congestion window.
-static std::map<uint32_t, bool> firstSshThr;                    //!< First SlowStart threshold.
-static std::map<uint32_t, bool> firstRtt;                       //!< First RTT.
-static std::map<uint32_t, bool> firstRto;                       //!< First RTO.
-static std::map<uint32_t, Ptr<OutputStreamWrapper>> cWndStream; //!< Congstion window output stream.
-static std::map<uint32_t, Ptr<OutputStreamWrapper>>
-    ssThreshStream; //!< SlowStart threshold output stream.
-static std::map<uint32_t, Ptr<OutputStreamWrapper>> rttStream;      //!< RTT output stream.
-static std::map<uint32_t, Ptr<OutputStreamWrapper>> rtoStream;      //!< RTO output stream.
-static std::map<uint32_t, Ptr<OutputStreamWrapper>> nextTxStream;   //!< Next TX output stream.
-static std::map<uint32_t, Ptr<OutputStreamWrapper>> nextRxStream;   //!< Next RX output stream.
-static std::map<uint32_t, Ptr<OutputStreamWrapper>> inFlightStream; //!< In flight output stream.
-static std::map<uint32_t, uint32_t> cWndValue;                      //!< congestion window value.
-static std::map<uint32_t, uint32_t> ssThreshValue;                  //!< SlowStart threshold value.
-
-/**
- * Get the Node Id From Context.
- *
- * @param context The context.
- * @return the node ID.
- */
-static uint32_t
-GetNodeIdFromContext(std::string context)
-{
-    const std::size_t n1 = context.find_first_of('/', 1);
-    const std::size_t n2 = context.find_first_of('/', n1 + 1);
-    return std::stoul(context.substr(n1 + 1, n2 - n1 - 1));
-}
-
-/**
- * Congestion window tracer.
- *
- * @param context The context.
- * @param oldval Old value.
- * @param newval New value.
- */
-static void
-CwndTracer(std::string context, uint32_t oldval, uint32_t newval)
-{
-    uint32_t nodeId = GetNodeIdFromContext(context);
-
-    if (firstCwnd[nodeId])
-    {
-        *cWndStream[nodeId]->GetStream() << "0.0 " << oldval << std::endl;
-        firstCwnd[nodeId] = false;
-    }
-    *cWndStream[nodeId]->GetStream() << Simulator::Now().GetSeconds() << " " << newval << std::endl;
-    cWndValue[nodeId] = newval;
-
-    if (!firstSshThr[nodeId])
-    {
-        *ssThreshStream[nodeId]->GetStream()
-            << Simulator::Now().GetSeconds() << " " << ssThreshValue[nodeId] << std::endl;
-    }
-}
-
-/**
- * Slow start threshold tracer.
- *
- * @param context The context.
- * @param oldval Old value.
- * @param newval New value.
- */
-static void
-SsThreshTracer(std::string context, uint32_t oldval, uint32_t newval)
-{
-    uint32_t nodeId = GetNodeIdFromContext(context);
-
-    if (firstSshThr[nodeId])
-    {
-        *ssThreshStream[nodeId]->GetStream() << "0.0 " << oldval << std::endl;
-        firstSshThr[nodeId] = false;
-    }
-    *ssThreshStream[nodeId]->GetStream()
-        << Simulator::Now().GetSeconds() << " " << newval << std::endl;
-    ssThreshValue[nodeId] = newval;
-
-    if (!firstCwnd[nodeId])
-    {
-        *cWndStream[nodeId]->GetStream()
-            << Simulator::Now().GetSeconds() << " " << cWndValue[nodeId] << std::endl;
-    }
-}
-
-/**
- * RTT tracer.
- *
- * @param context The context.
- * @param oldval Old value.
- * @param newval New value.
- */
-static void
-RttTracer(std::string context, Time oldval, Time newval)
-{
-    uint32_t nodeId = GetNodeIdFromContext(context);
-
-    if (firstRtt[nodeId])
-    {
-        *rttStream[nodeId]->GetStream() << "0.0 " << oldval.GetSeconds() << std::endl;
-        firstRtt[nodeId] = false;
-    }
-    *rttStream[nodeId]->GetStream()
-        << Simulator::Now().GetSeconds() << " " << newval.GetSeconds() << std::endl;
-}
-
-/**
- * RTO tracer.
- *
- * @param context The context.
- * @param oldval Old value.
- * @param newval New value.
- */
-static void
-RtoTracer(std::string context, Time oldval, Time newval)
-{
-    uint32_t nodeId = GetNodeIdFromContext(context);
-
-    if (firstRto[nodeId])
-    {
-        *rtoStream[nodeId]->GetStream() << "0.0 " << oldval.GetSeconds() << std::endl;
-        firstRto[nodeId] = false;
-    }
-    *rtoStream[nodeId]->GetStream()
-        << Simulator::Now().GetSeconds() << " " << newval.GetSeconds() << std::endl;
-}
-
-/**
- * Next TX tracer.
- *
- * @param context The context.
- * @param old Old sequence number.
- * @param nextTx Next sequence number.
- */
-static void
-NextTxTracer(std::string context, SequenceNumber32 old [[maybe_unused]], SequenceNumber32 nextTx)
-{
-    uint32_t nodeId = GetNodeIdFromContext(context);
-
-    *nextTxStream[nodeId]->GetStream()
-        << Simulator::Now().GetSeconds() << " " << nextTx << std::endl;
-}
-
-/**
- * In-flight tracer.
- *
- * @param context The context.
- * @param old Old value.
- * @param inFlight In flight value.
- */
-static void
-InFlightTracer(std::string context, uint32_t old [[maybe_unused]], uint32_t inFlight)
-{
-    uint32_t nodeId = GetNodeIdFromContext(context);
-
-    *inFlightStream[nodeId]->GetStream()
-        << Simulator::Now().GetSeconds() << " " << inFlight << std::endl;
-}
-
-/**
- * Next RX tracer.
- *
- * @param context The context.
- * @param old Old sequence number.
- * @param nextRx Next sequence number.
- */
-static void
-NextRxTracer(std::string context, SequenceNumber32 old [[maybe_unused]], SequenceNumber32 nextRx)
-{
-    uint32_t nodeId = GetNodeIdFromContext(context);
-
-    *nextRxStream[nodeId]->GetStream()
-        << Simulator::Now().GetSeconds() << " " << nextRx << std::endl;
-}
-
-/**
- * Congestion window trace connection.
- *
- * @param cwnd_tr_file_name Congestion window trace file name.
- * @param nodeId Node ID.
- */
-static void
-TraceCwnd(std::string cwnd_tr_file_name, uint32_t nodeId)
-{
-    AsciiTraceHelper ascii;
-    cWndStream[nodeId] = ascii.CreateFileStream(cwnd_tr_file_name);
-    Config::Connect("/NodeList/" + std::to_string(nodeId) +
-                        "/$ns3::TcpL4Protocol/SocketList/0/CongestionWindow",
-                    MakeCallback(&CwndTracer));
-}
-
-/**
- * Slow start threshold trace connection.
- *
- * @param ssthresh_tr_file_name Slow start threshold trace file name.
- * @param nodeId Node ID.
- */
-static void
-TraceSsThresh(std::string ssthresh_tr_file_name, uint32_t nodeId)
-{
-    AsciiTraceHelper ascii;
-    ssThreshStream[nodeId] = ascii.CreateFileStream(ssthresh_tr_file_name);
-    Config::Connect("/NodeList/" + std::to_string(nodeId) +
-                        "/$ns3::TcpL4Protocol/SocketList/0/SlowStartThreshold",
-                    MakeCallback(&SsThreshTracer));
-}
-
-/**
- * RTT trace connection.
- *
- * @param rtt_tr_file_name RTT trace file name.
- * @param nodeId Node ID.
- */
-static void
-TraceRtt(std::string rtt_tr_file_name, uint32_t nodeId)
-{
-    AsciiTraceHelper ascii;
-    rttStream[nodeId] = ascii.CreateFileStream(rtt_tr_file_name);
-    Config::Connect("/NodeList/" + std::to_string(nodeId) + "/$ns3::TcpL4Protocol/SocketList/0/RTT",
-                    MakeCallback(&RttTracer));
-}
-
-/**
- * RTO trace connection.
- *
- * @param rto_tr_file_name RTO trace file name.
- * @param nodeId Node ID.
- */
-static void
-TraceRto(std::string rto_tr_file_name, uint32_t nodeId)
-{
-    AsciiTraceHelper ascii;
-    rtoStream[nodeId] = ascii.CreateFileStream(rto_tr_file_name);
-    Config::Connect("/NodeList/" + std::to_string(nodeId) + "/$ns3::TcpL4Protocol/SocketList/0/RTO",
-                    MakeCallback(&RtoTracer));
-}
-
-/**
- * Next TX trace connection.
- *
- * @param next_tx_seq_file_name Next TX trace file name.
- * @param nodeId Node ID.
- */
-static void
-TraceNextTx(std::string& next_tx_seq_file_name, uint32_t nodeId)
-{
-    AsciiTraceHelper ascii;
-    nextTxStream[nodeId] = ascii.CreateFileStream(next_tx_seq_file_name);
-    Config::Connect("/NodeList/" + std::to_string(nodeId) +
-                        "/$ns3::TcpL4Protocol/SocketList/0/NextTxSequence",
-                    MakeCallback(&NextTxTracer));
-}
-
-/**
- * In flight trace connection.
- *
- * @param in_flight_file_name In flight trace file name.
- * @param nodeId Node ID.
- */
-static void
-TraceInFlight(std::string& in_flight_file_name, uint32_t nodeId)
-{
-    AsciiTraceHelper ascii;
-    inFlightStream[nodeId] = ascii.CreateFileStream(in_flight_file_name);
-    Config::Connect("/NodeList/" + std::to_string(nodeId) +
-                        "/$ns3::TcpL4Protocol/SocketList/0/BytesInFlight",
-                    MakeCallback(&InFlightTracer));
-}
-
-/**
- * Next RX trace connection.
- *
- * @param next_rx_seq_file_name Next RX trace file name.
- * @param nodeId Node ID.
- */
-static void
-TraceNextRx(std::string& next_rx_seq_file_name, uint32_t nodeId)
-{
-    AsciiTraceHelper ascii;
-    nextRxStream[nodeId] = ascii.CreateFileStream(next_rx_seq_file_name);
-    Config::Connect("/NodeList/" + std::to_string(nodeId) +
-                        "/$ns3::TcpL4Protocol/SocketList/1/RxBuffer/NextRxSequence",
-                    MakeCallback(&NextRxTracer));
-}
-
-int
-main(int argc, char* argv[])
-{
-    std::string transport_prot = "TcpWestwoodPlus";
-    double error_p = 0.0;
-    std::string bandwidth = "2Mbps";
-    std::string delay = "0.01ms";
-    std::string access_bandwidth = "10Mbps";
-    std::string access_delay = "45ms";
-    bool tracing = false;
-    std::string prefix_file_name = "TcpVariantsComparison";
-    uint64_t data_mbytes = 0;
-    uint32_t mtu_bytes = 400;
-    uint16_t num_flows = 1;
-    double duration = 100.0;
-    uint32_t run = 0;
-    bool flow_monitor = false;
-    bool pcap = false;
-    bool sack = true;
-    std::string queue_disc_type = "ns3::PfifoFastQueueDisc";
-    std::string recovery = "ns3::TcpClassicRecovery";
-
-    CommandLine cmd(__FILE__);
-    cmd.AddValue("transport_prot",
-                 "Transport protocol to use: TcpNewReno, TcpLinuxReno, "
-                 "TcpHybla, TcpHighSpeed, TcpHtcp, TcpVegas, TcpScalable, TcpVeno, "
-                 "TcpBic, TcpYeah, TcpIllinois, TcpWestwoodPlus, TcpLedbat, "
-                 "TcpLp, TcpDctcp, TcpCubic, TcpBbr",
-                 transport_prot);
-    cmd.AddValue("error_p", "Packet error rate", error_p);
-    cmd.AddValue("bandwidth", "Bottleneck bandwidth", bandwidth);
-    cmd.AddValue("delay", "Bottleneck delay", delay);
-    cmd.AddValue("access_bandwidth", "Access link bandwidth", access_bandwidth);
-    cmd.AddValue("access_delay", "Access link delay", access_delay);
-    cmd.AddValue("tracing", "Flag to enable/disable tracing", tracing);
-    cmd.AddValue("prefix_name", "Prefix of output trace file", prefix_file_name);
-    cmd.AddValue("data", "Number of Megabytes of data to transmit", data_mbytes);
-    cmd.AddValue("mtu", "Size of IP packets to send in bytes", mtu_bytes);
-    cmd.AddValue("num_flows", "Number of flows", num_flows);
-    cmd.AddValue("duration", "Time to allow flows to run in seconds", duration);
-    cmd.AddValue("run", "Run index (for setting repeatable seeds)", run);
-    cmd.AddValue("flow_monitor", "Enable flow monitor", flow_monitor);
-    cmd.AddValue("pcap_tracing", "Enable or disable PCAP tracing", pcap);
-    cmd.AddValue("queue_disc_type",
-                 "Queue disc type for gateway (e.g. ns3::CoDelQueueDisc)",
-                 queue_disc_type);
-    cmd.AddValue("sack", "Enable or disable SACK option", sack);
-    cmd.AddValue("recovery", "Recovery algorithm type to use (e.g., ns3::TcpPrrRecovery", recovery);
-    cmd.Parse(argc, argv);
-
-    transport_prot = std::string("ns3::") + transport_prot;
-
-    SeedManager::SetSeed(1);
-    SeedManager::SetRun(run);
-
-    // User may find it convenient to enable logging
-    // LogComponentEnable("TcpVariantsComparison", LOG_LEVEL_ALL);
-    // LogComponentEnable("BulkSendApplication", LOG_LEVEL_INFO);
-    // LogComponentEnable("PfifoFastQueueDisc", LOG_LEVEL_ALL);
-
-    // Calculate the ADU size
-    Header* temp_header = new Ipv4Header();
-    uint32_t ip_header = temp_header->GetSerializedSize();
-    NS_LOG_LOGIC("IP Header size is: " << ip_header);
-    delete temp_header;
-    temp_header = new TcpHeader();
-    uint32_t tcp_header = temp_header->GetSerializedSize();
-    NS_LOG_LOGIC("TCP Header size is: " << tcp_header);
-    delete temp_header;
-    uint32_t tcp_adu_size = mtu_bytes - 20 - (ip_header + tcp_header);
-    NS_LOG_LOGIC("TCP ADU size is: " << tcp_adu_size);
-
-    // Set the simulation start and stop time
-    double start_time = 0.1;
-    double stop_time = start_time + duration;
-
-    // 2 MB of TCP buffer
-    Config::SetDefault("ns3::TcpSocket::RcvBufSize", UintegerValue(1 << 21));
-    Config::SetDefault("ns3::TcpSocket::SndBufSize", UintegerValue(1 << 21));
-    Config::SetDefault("ns3::TcpSocketBase::Sack", BooleanValue(sack));
-
-    Config::SetDefault("ns3::TcpL4Protocol::RecoveryType",
-                       TypeIdValue(TypeId::LookupByName(recovery)));
-    // Select TCP variant
-    TypeId tcpTid;
-    NS_ABORT_MSG_UNLESS(TypeId::LookupByNameFailSafe(transport_prot, &tcpTid),
-                        "TypeId " << transport_prot << " not found");
-    Config::SetDefault("ns3::TcpL4Protocol::SocketType",
-                       TypeIdValue(TypeId::LookupByName(transport_prot)));
-
-    // Create gateways, sources, and sinks
-    NodeContainer gateways;
-    gateways.Create(1);
-    NodeContainer sources;
-    sources.Create(num_flows);
-    NodeContainer sinks;
-    sinks.Create(num_flows);
-
-    // Configure the error model
-    // Here we use RateErrorModel with packet error rate
-    Ptr<UniformRandomVariable> uv = CreateObject<UniformRandomVariable>();
-    uv->SetStream(50);
-    RateErrorModel error_model;
-    error_model.SetRandomVariable(uv);
-    error_model.SetUnit(RateErrorModel::ERROR_UNIT_PACKET);
-    error_model.SetRate(error_p);
-
-    PointToPointHelper UnReLink;
-    UnReLink.SetDeviceAttribute("DataRate", StringValue(bandwidth));
-    UnReLink.SetChannelAttribute("Delay", StringValue(delay));
-    UnReLink.SetDeviceAttribute("ReceiveErrorModel", PointerValue(&error_model));
-
-    InternetStackHelper stack;
-    stack.InstallAll();
-
-    TrafficControlHelper tchPfifo;
-    tchPfifo.SetRootQueueDisc("ns3::PfifoFastQueueDisc");
-
-    TrafficControlHelper tchCoDel;
-    tchCoDel.SetRootQueueDisc("ns3::CoDelQueueDisc");
-
-    Ipv4AddressHelper address;
-    address.SetBase("10.0.0.0", "255.255.255.0");
-
-    // Configure the sources and sinks net devices
-    // and the channels between the sources/sinks and the gateways
-    PointToPointHelper LocalLink;
-    LocalLink.SetDeviceAttribute("DataRate", StringValue(access_bandwidth));
-    LocalLink.SetChannelAttribute("Delay", StringValue(access_delay));
-
-    Ipv4InterfaceContainer sink_interfaces;
-
-    DataRate access_b(access_bandwidth);
-    DataRate bottle_b(bandwidth);
-    Time access_d(access_delay);
-    Time bottle_d(delay);
-
-    uint32_t size = static_cast<uint32_t>((std::min(access_b, bottle_b).GetBitRate() / 8) *
-                                          ((access_d + bottle_d) * 2).GetSeconds());
-
-    Config::SetDefault("ns3::PfifoFastQueueDisc::MaxSize",
-                       QueueSizeValue(QueueSize(QueueSizeUnit::PACKETS, size / mtu_bytes)));
-    Config::SetDefault("ns3::CoDelQueueDisc::MaxSize",
-                       QueueSizeValue(QueueSize(QueueSizeUnit::BYTES, size)));
-
-    for (uint32_t i = 0; i < num_flows; i++)
-    {
-        NetDeviceContainer devices;
-        devices = LocalLink.Install(sources.Get(i), gateways.Get(0));
-        tchPfifo.Install(devices);
-        address.NewNetwork();
-        Ipv4InterfaceContainer interfaces = address.Assign(devices);
-
-        devices = UnReLink.Install(gateways.Get(0), sinks.Get(i));
-        if (queue_disc_type == "ns3::PfifoFastQueueDisc")
-        {
-            tchPfifo.Install(devices);
-        }
-        else if (queue_disc_type == "ns3::CoDelQueueDisc")
-        {
-            tchCoDel.Install(devices);
-        }
-        else
-        {
-            NS_FATAL_ERROR("Queue not recognized. Allowed values are ns3::CoDelQueueDisc or "
-                           "ns3::PfifoFastQueueDisc");
-        }
-        address.NewNetwork();
-        interfaces = address.Assign(devices);
-        sink_interfaces.Add(interfaces.Get(1));
-    }
-
-    NS_LOG_INFO("Initialize Global Routing.");
-    Ipv4GlobalRoutingHelper::PopulateRoutingTables();
-
-    uint16_t port = 50000;
-    Address sinkLocalAddress(InetSocketAddress(Ipv4Address::GetAny(), port));
-    PacketSinkHelper sinkHelper("ns3::TcpSocketFactory", sinkLocalAddress);
-
-    for (uint32_t i = 0; i < sources.GetN(); i++)
-    {
-        // Assign a different TCP variant to each flow
-        std::string tcpVariant;
-        switch (i % 2) // Example: Rotate between two TCP variants
-        {
-        case 0:
-            tcpVariant = "ns3::TcpNewReno";
-            break;
-        case 1:
-            tcpVariant = "ns3::TcpCubic";
-            break;
-        default:
-            tcpVariant = "ns3::TcpNewReno";
-        }
-
-        // Set the TCP variant for this flow
-        Config::Set("/NodeList/" + std::to_string(sources.Get(i)->GetId()) +
-                        "/$ns3::TcpL4Protocol/SocketType",
-                    StringValue(tcpVariant));
-
-        // Configure the BulkSend application
-        Address remoteAddress(InetSocketAddress(sink_interfaces.GetAddress(i, 0), port));
-        BulkSendHelper ftp("ns3::TcpSocketFactory", remoteAddress);
-        ftp.SetAttribute("SendSize", UintegerValue(tcp_adu_size));
-        ftp.SetAttribute("MaxBytes", UintegerValue(data_mbytes * 1000000));
-
-        ApplicationContainer sourceApp = ftp.Install(sources.Get(i));
-        sourceApp.Start(Seconds(start_time * i));
-        sourceApp.Stop(Seconds(stop_time - 3));
-
-        // Configure the PacketSink application
-        sinkHelper.SetAttribute("Protocol", TypeIdValue(TcpSocketFactory::GetTypeId()));
-        ApplicationContainer sinkApp = sinkHelper.Install(sinks.Get(i));
-        sinkApp.Start(Seconds(start_time * i));
-        sinkApp.Stop(Seconds(stop_time));
-    }
-
-    // Set up tracing if enabled
-    if (tracing)
-    {
-        std::ofstream ascii;
-        Ptr<OutputStreamWrapper> ascii_wrap;
-        ascii.open(prefix_file_name + "-ascii");
-        ascii_wrap = new OutputStreamWrapper(prefix_file_name + "-ascii", std::ios::out);
-        stack.EnableAsciiIpv4All(ascii_wrap);
-
-        for (uint16_t index = 0; index < num_flows; index++)
-        {
-            std::string flowString;
-            if (num_flows > 1)
-            {
-                flowString = "-flow" + std::to_string(index);
-            }
-
-            firstCwnd[index + 1] = true;
-            firstSshThr[index + 1] = true;
-            firstRtt[index + 1] = true;
-            firstRto[index + 1] = true;
-
-            Simulator::Schedule(Seconds(start_time * index + 0.00001),
-                                &TraceCwnd,
-                                prefix_file_name + flowString + "-cwnd.data",
-                                index + 1);
-            Simulator::Schedule(Seconds(start_time * index + 0.00001),
-                                &TraceSsThresh,
-                                prefix_file_name + flowString + "-ssth.data",
-                                index + 1);
-            Simulator::Schedule(Seconds(start_time * index + 0.00001),
-                                &TraceRtt,
-                                prefix_file_name + flowString + "-rtt.data",
-                                index + 1);
-            Simulator::Schedule(Seconds(start_time * index + 0.00001),
-                                &TraceRto,
-                                prefix_file_name + flowString + "-rto.data",
-                                index + 1);
-            Simulator::Schedule(Seconds(start_time * index + 0.00001),
-                                &TraceNextTx,
-                                prefix_file_name + flowString + "-next-tx.data",
-                                index + 1);
-            Simulator::Schedule(Seconds(start_time * index + 0.00001),
-                                &TraceInFlight,
-                                prefix_file_name + flowString + "-inflight.data",
-                                index + 1);
-            Simulator::Schedule(Seconds(start_time * index + 0.1),
-                                &TraceNextRx,
-                                prefix_file_name + flowString + "-next-rx.data",
-                                num_flows + index + 1);
-        }
-    }
-
-    if (pcap)
-    {
-        UnReLink.EnablePcapAll(prefix_file_name, true);
-        LocalLink.EnablePcapAll(prefix_file_name, true);
-    }
-
-    // Flow monitor
-    FlowMonitorHelper flowHelper;
-    if (flow_monitor)
-    {
-        flowHelper.InstallAll();
-    }
-
-    Simulator::Stop(Seconds(stop_time));
-    Simulator::Run();
-
-    if (flow_monitor)
-    {
-        flowHelper.SerializeToXmlFile(prefix_file_name + ".flowmonitor", true, true);
-    }
-
-    Simulator::Destroy();
-    return 0;
-}

timeserver/Makefile

@@ -1,20 +0,0 @@
-CC = gcc -Wall -std=c11 -pedantic
-SOURCES = timeserver.c 
-OBJECTS = timeserver.o 
-
-all: timeserver
-
-timeserver: $(OBJECTS)
-	$(CC) $(OBJECTS) -o timeserver
-
-timeserver.o: timeserver.c
-	$(CC) -c timeserver.c -o timeserver.o
-
-clean:
-	rm -f $(OBJECTS) timeserver timeserver.out
-
-clean_objects:
-	rm -f $(OBJECTS)
-
-run:
-	./timeserver

timeserver/README.md

@@ -1,16 +0,0 @@
-# Running the timeserver
-Use `make` to compile the timeserver.
-Use `make run` to run the timeserver. This will run on an infinite loop.
-Use `Ctrl+C` to stop the timeserver.
-
-## timeserver communication
-Communicating with the server can happen using netcat in UDP mode (-u flag).
-
-## timeserver information
-The timeserver runs on UDP port 8888.
-The timeserver will wait for `time\r\n` to be sent on this port, and if received,
-will send back a response of the time (in ms) since January 1st, 1970 (UNIX Epoch).
-
-## pcap information
-A demonstration of the timeserver has been captured with Wireshark in the 
-included `demo.pcap` file.

timeserver/timeserver.c

@@ -1,83 +0,0 @@
-// header files
-#include "timeserver.h"
-
-// constants
-// timeserver port is 8888
-#define TIMEPORT 8888
-#define BUFFER_SIZE 1024
-
-// prototypes
-
-// main function
-int main(int argc, char **argv)
-{
-    // initialize program (variables and structs)
-    bool quitFlag = true;
-    int socketTimeFD;
-    char message[BUFFER_SIZE];
-    struct sockaddr_in serverAddr, clientAddr;
-    memset(&serverAddr, 0, sizeof(serverAddr));
-    memset(&clientAddr, 0, sizeof(clientAddr));
-    // define a UDP socket
-    socketTimeFD = socket(AF_INET, SOCK_DGRAM, 0);
-    if(socketTimeFD < 0)
-    {
-        printf("Unable to create the socket.");
-        return -1;
-    }
-    // bind the UDP socket to port 8888 / TIMEPORT
-    serverAddr.sin_family = AF_INET;
-    serverAddr.sin_addr.s_addr = INADDR_ANY;
-    serverAddr.sin_port = htons(TIMEPORT);
-    int bindCheck = bind(socketTimeFD, &serverAddr, sizeof(serverAddr));
-    if(bindCheck < 0)
-    {
-        printf("Unable to bind the socket to the port or address.\n Is either in use?");
-        return -1;
-    }
-    // while loop to see if the "time\r\n" has been received (recv call?)
-    printf("Timeserver listening on port: %d\n", TIMEPORT);
-    while(quitFlag)
-    {
-        int clientAddrLen;
-        int receivedDataLen;
-        // grab the data from the client
-        receivedDataLen = recvfrom(socketTimeFD, message, BUFFER_SIZE, MSG_WAITALL, &clientAddr, &clientAddrLen);
-        message[receivedDataLen] = '\0';
-        // if "time\r\n" is received, then send() back the linux epoch.
-        if(strcmp(message, "time\n") == 0 || strcmp(message, "time\r\n") == 0)
-        {
-            // setup the reply message
-            char reply[BUFFER_SIZE];
-            // add the current time to the reply
-            sprintf(reply, "%d", time(NULL));
-            // send the reply to the requestee
-            sendto(socketTimeFD, (const char *)reply, strlen(reply), 0, (const struct sockaddr *) &clientAddr, clientAddrLen);
-            // log the time command recv'd
-            printf("\nServer received time. Replied with: %d\n", time(NULL));
-        }
-        else if (strcmp(message, "close\n") == 0 || strcmp(message, "quit\n") == 0 || strcmp(message, "q\n") == 0)
-        {
-            // if the server recv'd the close command, then close the server.
-            printf("\nServer received close.\n");
-            quitFlag = false;
-        }
-    }
-    // close the socket
-    close(socketTimeFD);
-    // profit???
-    return 0;
-}
-
-// function definitions
-
-/*
-Name: ???
-Process: ???
-Function Input/Parameters: ???
-Function Output/Parameters: ???
-Function Output/Returned: ???
-Device Input/Device: ???
-Device Output/Device: ???
-Dependencies: ???
-*/

timeserver/timeserver.h

@@ -1,23 +0,0 @@
-#ifndef TIMESERVER
-#define TIMESERVER
-
-// included libraries
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <math.h>
-#include <stdbool.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netdb.h>
-#include <time.h>
-#include <unistd.h>
-#include <errno.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-
-// data structures
-
-// function prototypes
-
-#endif // TIMESERVER