ft_irc

Internet Relay Chat - 42
Version: 7.1

Summary

This project involves creating your own IRC server.
You will use an actual IRC client to connect to your server and test it.
Understanding solid standard protocols like those used in the Internet is a valuable skill for connected systems and networking.

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Introduction

Internet Relay Chat or IRC is a text-based communication protocol on the Internet.
It offers real-time messaging that can be either public or private.
Users can exchange direct messages and join group channels.
IRC clients connect to IRC servers in order to join channels.
IRC servers are connected together to form a network.

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General Rules

• Your program must not crash under any circumstances (even when memory is exhausted).
  Crashing or quitting unexpectedly results in a failing grade (0).
• You must provide a Makefile to compile your source files.
  The Makefile must not perform unnecessary relinking.
• The Makefile must include at least the following rules:
  • all, clean, fclean, re, and $(NAME).
• Code must be compiled with c++ using the following flags:
  • -Wall -Wextra -Werror
• Code must adhere to the C++98 standard and must still compile when adding -std=c++98.
• Prefer C++ features over their C equivalents (e.g., <cstring> instead of <string.h>).
• External libraries and Boost libraries are forbidden.

You are allowed to use C functions, but always prefer their C++ versions if possible.

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Mandatory Part

Program Name:

ircserv

Turn-In Files:

• Makefile, *.{h, hpp, cpp, tpp, ipp}
• Optional: configuration file.

Makefile:

• NAME, all, clean, fclean, re

Arguments:

• port: The listening port for incoming IRC connections.
• password: The connection password required by any IRC client to connect.

External Functions Allowed:

• socket, close, setsockopt, getsockname, getprotobyname, gethostbyname,
  getaddrinfo, freeaddrinfo, bind, connect, listen, accept,
  htons, htonl, ntohs, ntohl, inet_addr, inet_ntoa,
  send, recv, signal, sigaction, lseek, fstat, fcntl, poll (or equivalents).

Description:

Develop an IRC server in C++98.

You mustn’t develop a client. You mustn’t handle server-to-server communication.

Your executable will be run as follows:

./ircserv <port> <password>

• port: The port number on which your IRC server will be listening to for incoming IRC connections.
• password: The connection password. It will be needed by any IRC client that tries to connect to your server.

Note

Even if poll() is mentionned in the subject and the evaluation scale,
you can use any equivalent such as select(), kqueue(), or epoll().

Requirements:

• The server must handle multiple clients simultaneously and must not hang.
• Forking is not allowed.
• All I/O operations must be non-blocking.
• Use only one poll() (or equivalent) to handle all operations (read, write, listen, etc.).

Warning

Because you have to use non-blocking file descriptors,
it is possible to use read/recv or write/send functions with no poll() (or equivalent),
and your server wouldn’t be blocking.
But it would consume more system resources.
Thus, if you try to read/recv or write/send in any file descriptor
without using poll() (or equivalent), your grade will be 0.

• Several IRC clients exist. You have to choose one of them as a reference.
  Your reference client will be used during the evaluation process.
• Your reference client must be able to connect to your server without encountering any error.
• Communication between client and server has to be done via TCP/IP (v4 or v6).
• Using your reference client with your server must be similar to using it with any official IRC server.
  However, you only have to implement the following features:
  • Authentication.
  • Set a nickname and username.
  • Join channels.
  • Send and receive private messages using your reference client.
  • Forward messages sent from one client to a channel to all channel members.
  • Distinguish between operators and regular users.
  • Implement channel operator commands:
    • KICK: Remove a client from a channel.
    • INVITE: Invite a client to a channel.
    • TOPIC: View or modify the channel topic.
    • MODE: Modify channel modes:
      • i: Set/remove Invite-only channel.
      • t: Set/remove the restriction of the TOPIC command to channel operators.
      • k: Set/remove the channel key (password).
      • o: Give/take channel operator privileges.
      • l: Set/remove the user limit to channel.

For macOS only

Note

Since macOS doesn’t implement write() the same way as other Unix operating systems,
you are allowed to use fcntl().
You must use file descriptors in non-blocking mode
in order to get a behavior similar to the one of other Unix operating systems.

Warning

However, you are allowed to use fcntl() only as follows: fcntl(fd, F_SETFL, O_NONBLOCK); Any other flag is forbidden

Test Example

Verify absolutely every possible error and issue
(receiving partial data, low bandwidth, and so forth).

To ensure that your server correctly processes everything that you send to it,
the following simple test using nc can be done:

$> nc 127.0.0.1 6667
com^Dman^Dd

Use Ctrl+D to send the command in several parts: 'com', then 'man', then 'd\n'.

In order to process a command, you have to first aggregate the received packets in order to rebuild it.

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Bonus Part

Extra features you can add to your IRC server so it looks even more like and actual IRC server:

• Handle file transfer.
• A bot.

Warning

The bonus part will only be assessed if the mandatory part is perfectly implemented.
A perfect implementation means all mandatory requirements are met without any malfunctions.
If you have not passed ALL the mandatory requirements,
your bonus part will not be evaluated at all.

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Submission and Peer-Evaluation

• Submit the project via your Git repository as usual.
• Only the files in your repository will be evaluated.
• Double-check file names and paths before submission.

Testing:

You are encouraged to create test programs for your project,
even though they won't be submitted and won't be graded.
These tests could be especially useful to test your server during the defense
or for evaluating a peer’s project if you have to evaluate another ft_irc implementation one day.
Indeed, you are free to use whatever tests you need during the evaluation process.

Note

Your reference client will be used during the evaluation process.