This project implements a basic firewall application in C++. The firewall processes network traffic based on a set of rules provided in a specific format. It evaluates whether the traffic should be allowed or denied, logs the results, and displays them in a command-line interface (CLI). The processed results are also saved in a .DAT file for later review.

• Rule-Based Filtering: Evaluates network traffic against predefined firewall rules.
• Traffic Processing: Supports processing of traffic data from external files.
• Result Logging: Logs results in a .DAT file for further analysis.
• CLI Display: Displays processed results directly in the command-line interface.
• Customizable Rules: Rules can be easily modified by editing the input text file.

1. Rules File
   Contains the firewall rules in the following format:
   [RULE NO] [FIELD] [VALUE] [DECISION]

   • RULE NO: Unique identifier for each rule.
   • FIELD: The traffic field to match (e.g., SRC, DST, PRO).
   • VALUE: The value or range of values to match (e.g., IP address, protocol).
   • DECISION: Specifies whether the traffic should be ALLOW or DENY.

2. Traffic File
   Contains traffic data entries formatted as:
   [SRC:source_IP;DST:destination_IP;PRO:protocol;DATA_IN_HEX_FORMAT][...]

   • SRC: Source IP address.
   • DST: Destination IP address.
   • PRO: Protocol (e.g., TCP, UDP).
   • DATA_IN_HEX_FORMAT: Traffic data represented in hexadecimal format.

• Results File (results.dat)
  After processing the traffic against the firewall rules, the results are output in a .DAT file with the following structure:
  SRC: source_IP
DST: destination_IP
PRO: protocol
DECISION: ALLOW/DENY
RULE_NO: rule_number

1. Place the rules.txt and traffic.txt files in the same directory as the compiled program.
2. Run the firewall program with the following command:
   ./firewall rules.txt traffic.txt
   • rules.txt: The file containing firewall rules.
   • traffic.txt: The file containing network traffic data.

• After running the program, the processed traffic results will be written to results.dat.
• The results will also be displayed directly in the command-line interface for immediate review.

/firewall ├── main.cpp # Main logic of the firewall program ├── rules.txt # Input file with firewall rules ├── traffic.txt # Input file with traffic data ├── results.dat # Output file containing processed results ├── README.md # Project documentation (this file)

• C++11 or later (for the required language features)

To compile the program, use any C++ compiler. For example:
g++ -o firewall main.cpp

This project is open-source. Feel free to use and modify it according to your needs. Contributions and improvements are welcome!