PireToutPire

This project implements a simplified p2p network. It allows to send message from a peer to another in a decentralized manner. File sharing (like bittorrent) is also handled.

If user A sends a message M to user B and B is known by the service, the service will deliver M to user B. All messages sent by users will be transferred directly from one user to the other across the network, in peer-to-peer, and doesn't rely on a central server.

Implementation use the Kademlia DHT algorithm, and handle these 4 concepts:

• ping: check if a peer is alive
• find_node: find for the "closest" nodes, given a target
• store_value: store a value into the dht
• find_value: get a value store into the dht

On top of that, some concept have been taken from bittorent, such as:

• announce: tell which peers are able to share a file, even partially
• get_peers: retrieve all the peers who share a given file

Then:

• send_message: simply send a message to a user by its ID.

Documentation and explanation

There's a bunch of documentation available here: doc section.

Mainly, you'll find explanation about the concept, implementation choices, limitations and security flaws.

Running and playing with it

The simplest way you can launch a server is by doing that:

# Launch a new peer in seed mode (peer-id will be random)
cargo run -- seed

Simple use case: sending a message

In a first terminal:

# Start the first peer, this seed server will be joinable, via a bootstrap by other peers
cargo run -- --server-addr="127.0.0.1:4001" --peer-id=1 seed

In a second terminal:

# Join the seeder above:
cargo run -- --server-addr="127.0.0.1:4002" --peer-id=2 bootstrap 127.0.0.1:4001
# Pass in seed mode:
cargo run -- --server-addr="127.0.0.1:4002" --peer-id=2 seed

In a third one:

# Join the seeder above:
cargo run -- --server-addr="127.0.0.1:4003" --peer-id=3 bootstrap 127.0.0.1:4002
# List which peers we currently know:
cargo run -- --server-addr="127.0.0.1:4003" --peer-id=3 list
# Let's send a message to peer 1 (we only know through 2)!
cargo run -- --server-addr="127.0.0.1:4003" --peer-id=3 message 1 "Hello"

Help and more features

There is a CLI (using clap and colored) which can be called like that:

cargo run -- help

The help will show all the possibilities, as you can see here: Help.

Building

It's also possible to generate the binary using:

make build
./demo/pire2pire --help

Demo

A demo is provided to show all available features. This demo is a script which will simulate many situations, to show all handled features. Basically just run it, watch the presentation and press enter to pass to the next simulation.

make demo

A small glimpse of what it will looks like:

  _____  ______ __  __  ____
 |  __ \|  ____|  \/  |/ __ \
 | |  | | |__  | \  / | |  | |
 | |  | |  __| | |\/| | |  | |
 | |__| | |____| |  | | |__| |
 |_____/|______|_|  |_|\____/

CTRL + C will skip the current test, not the entire demo
Press CTRL + C twice to abort the demo
Press enter to start the demo

Tests

Everything is unit tested. You can launch all the tests with:

cargo test

Linting

You'll find some custom linters made with dylint. There are some very specific rules we were enforcing in my previous company. These are examples of what can be done.

Launch clippy:

cargo clippy

Launch personal linter:

# You might need to install dylint
cargo install cargo-dylint dylint-link

# Launch it!
cargo dylint --all -- --all-features --bins --examples --tests

VsCode integration

It's possible to change the default cargo command in VsCode to automatically launch clippy and dylint. Very handy to view at glance any warnings.

In settings.json, just override the default command like that:

    "rust-analyzer.checkOnSave.overrideCommand": [
        "cargo",
        "dylint",
        "--all",
        "--workspace",
        "--",
        "--all-targets",
        "--message-format=json"
    ]