Как вытащить торрент-файл из DHT?

DHT не обслуживает торренты. Он просто предоставляет списки пиров для отдельных информационных хэшей. Торрент-файлы, а точнее неизменяемый информационный словарь, предоставляются самими роями битторрентов.

Вам придется частично реализовать BEP3, BEP10 и, наконец, BEP9 для обмена метаданными. Дополнительно реализованы BEP29 и BEP11 может обеспечить улучшенную связь, что может быть полезно при получении метаданных в небольших группах.

Во-вторых, потребление ресурсов DHT без предоставления каких-либо или многократной забивки узлов запросами — особенно узла начальной загрузки — считается невоспитанным. Если вы намереваетесь получить большое количество торрент-файлов, вам следует запустить узел DHT в качестве демона, например. через dht lib (C) или мой (java). Моя реализация также содержит службу поиска метаданных. libtorrent также должен предоставить все необходимые компоненты для достижения того же.

Вот файл .pcap в кодировке base64, который показывает полное взаимодействие на практике (обратите внимание на последний пакет данных). Его декодирование и открытие в Wireshark покажет вам весь процесс — в сочетании с BEP, перечисленными в ответе 8472, это может служить примером.

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