package tracker import ( "context" "errors" "net/http" "net/url" "time" "github.com/anacrolix/dht/v2/krpc" ) // Marshalled as binary by the UDP client, so be careful making changes. type AnnounceRequest struct { InfoHash [20]byte PeerId [20]byte Downloaded int64 Left int64 // If less than 0, math.MaxInt64 will be used for HTTP trackers instead. Uploaded int64 // Apparently this is optional. None can be used for announces done at // regular intervals. Event AnnounceEvent IPAddress uint32 Key int32 NumWant int32 // How many peer addresses are desired. -1 for default. Port uint16 } // 82 bytes type AnnounceResponse struct { Interval int32 // Minimum seconds the local peer should wait before next announce. Leechers int32 Seeders int32 Peers []Peer } type AnnounceEvent int32 func (e AnnounceEvent) String() string { // See BEP 3, "event", and https://github.com/anacrolix/torrent/issues/416#issuecomment-751427001. return []string{"", "completed", "started", "stopped"}[e] } const ( None AnnounceEvent = iota Completed // The local peer just completed the torrent. Started // The local peer has just resumed this torrent. Stopped // The local peer is leaving the swarm. ) var ( ErrBadScheme = errors.New("unknown scheme") ) type Announce struct { TrackerUrl string Request AnnounceRequest HostHeader string HTTPProxy func(*http.Request) (*url.URL, error) ServerName string UserAgent string UdpNetwork string // If the port is zero, it's assumed to be the same as the Request.Port. ClientIp4 krpc.NodeAddr // If the port is zero, it's assumed to be the same as the Request.Port. ClientIp6 krpc.NodeAddr Context context.Context } // The code *is* the documentation. const DefaultTrackerAnnounceTimeout = 15 * time.Second func (me Announce) Do() (res AnnounceResponse, err error) { _url, err := url.Parse(me.TrackerUrl) if err != nil { return } if me.Context == nil { // This is just to maintain the old behaviour that should be a timeout of 15s. Users can // override it by providing their own Context. See comments elsewhere about longer timeouts // acting as rate limiting overloaded trackers. ctx, cancel := context.WithTimeout(context.Background(), DefaultTrackerAnnounceTimeout) defer cancel() me.Context = ctx } switch _url.Scheme { case "http", "https": return announceHTTP(me, _url) case "udp", "udp4", "udp6": return announceUDP(me, _url) default: err = ErrBadScheme return } }