github.com/esmakov/bittorrent-client

A simple CLI bittorrent client

The mktorrent package is required to build test code.

Usage

go run main <add>|<info>|<parse> <path/to/file.torrent>

• The following commands are supported:
  • add: Add a new torrent and start downloading.
  • info: Display information about the torrent (total size, # of files, etc.)
  • parse: Display the torrent file structure.
• <path/to/file.torrent> is the required path to a .torrent file.

Features

• Parses Bencoded .torrent files and tracker responses
• Supports Bencoding structured data for serialization
• Parses and implements the peer message protocol
• Downloads single or multi-file torrents
• Checks existing data on disk and picks up from where you left off

Supported BEPs (BitTorrent Enhancement Proposals)

• 3: Basic BitTorrent protocol (in progress)
• 23: Tracker Returns Compact Peer Lists

TODOs

• Handle more than one torrent at a time

• Send keepalives

• Switch over to bytes.Buffer where appropriate

• Blacklist misbehaving peers

• Specify download directory

• More interesting bitmask visualization?

• Use already-written bencode package to generate .torrent files (instead of pobrn/mktorrent)

• Set log level (debug, info, errors)

Optimizations

• Better piece download strategies (rarest first)
• Better peer selection strategies (optimistic unchoking)

Protocol

• Support the dictionary model for tracker responses listing available peers

Extensions

• DHT
• Peer Exchange