torrent-poc

A sans-io proof-of-concept implementation of the torrent protocol, implemented in Rust as a programming challenge for recruitment purposes.

Usage

$ cargo run -- --help
Usage: torrent-poc.exe <COMMAND>

Commands:
  leech  Connect to a known peer and start downloading a torrent
  seed   Listen for incoming connections and start seeding a torrent
  help   Print this message or the help of the given subcommand(s)

Options:
  -h, --help     Print help
  -V, --version  Print version

Demo

1. Start a torrent "seeder" by running cargo run -- seed --info-hash <info-hash> --port <port>.

   It will listen on all interfaces by default, but you can specify a specific IP address with --ip <ip>.

2. Start a torrent "leecher" by running cargo run -- leech --info-hash <info-hash> --port <port> --ip <ip>.

   The port and info hash must match the ones used by the seeder.

3. You should now see something similar to this:

   $ cargo run -- seed --info-hash 018e50b58106b84a42c223ccf0494334f8d55958 --port 12345
   2024-06-05T12:27:22.220504Z  INFO torrent_poc: My peer ID: -Rp1121-THMZfvNhcurL
   2024-06-05T12:27:22.220911Z  INFO torrent_poc: Listening on 0.0.0.0:12345
   2024-06-05T12:27:22.220982Z  INFO torrent_poc: Info hash: b6ae8e98e360a3d5d547dd43d42548ee786845ff
   2024-06-05T12:27:25.548916Z  INFO torrent_poc::torrent::connection_actor: Connection established with peer -Rp1121-8gJCKF636JRe
   2024-06-05T12:27:25.548922Z  INFO torrent_poc::torrent::torrent_actor: TorrentActor added connection to peer -Rp1121-8gJCKF636JRe
   # 10 seconds later
   2024-06-05T12:27:35.613601Z  WARN torrent_poc::connections::std_io_connection: error reading from the connection: Os { code: 10054, kind: ConnectionReset, message: "An existing connection was forcibly closed by the remote host." }
   2024-06-05T12:27:35.639136Z  INFO torrent_poc::torrent::torrent_actor: TorrentActor removed connection to peer -Rp1121-8gJCKF636JRe
   

   $ cargo run -- leech --info-hash 018e50b58106b84a42c223ccf0494334f8d55958 --port 12345 --ip 127.0.0.1
   2024-06-05T12:27:25.542483Z  INFO torrent_poc: My peer ID: -Rp1121-8gJCKF636JRe
   2024-06-05T12:27:25.543401Z  INFO torrent_poc: Connecting to peer at 127.0.0.1:12345
   2024-06-05T12:27:25.543532Z  INFO torrent_poc: Info hash: b6ae8e98e360a3d5d547dd43d42548ee786845ff
   2024-06-05T12:27:25.549016Z  INFO torrent_poc::torrent::connection_actor: Connection established with peer -Rp1121-THMZfvNhcurL
   2024-06-05T12:27:25.549031Z  INFO torrent_poc::torrent::torrent_actor: TorrentActor added connection to peer -Rp1121-THMZfvNhcurL
   # 10 seconds later
   2024-06-05T12:27:35.613681Z  WARN torrent_poc::connections::std_io_connection: error reading from the connection: Os { code: 10053, kind: ConnectionAborted, message: "An established connection was aborted by the software in your host machine." }