package torrent
import (
- "github.com/anacrolix/dht"
+ "context"
+ "net"
+ "net/http"
+ "net/url"
+ "time"
+
+ "github.com/anacrolix/dht/v2"
+ "github.com/anacrolix/dht/v2/krpc"
+ "github.com/anacrolix/log"
+ "github.com/anacrolix/missinggo/v2"
"golang.org/x/time/rate"
"github.com/anacrolix/torrent/iplist"
+ "github.com/anacrolix/torrent/mse"
"github.com/anacrolix/torrent/storage"
+ "github.com/anacrolix/torrent/version"
)
-// Override Client defaults.
-type Config struct {
- // Store torrent file data in this directory unless TorrentDataOpener is
- // specified.
- DataDir string `long:"data-dir" description:"directory to store downloaded torrent data"`
- // The address to listen for new uTP and TCP bittorrent protocol
- // connections. DHT shares a UDP socket with uTP unless configured
- // otherwise.
- ListenAddr string `long:"listen-addr" value-name:"HOST:PORT"`
+// Contains config elements that are exclusive to tracker handling. There may be other fields in
+// ClientConfig that are also relevant.
+type ClientTrackerConfig struct {
// Don't announce to trackers. This only leaves DHT to discover peers.
DisableTrackers bool `long:"disable-trackers"`
- DisablePEX bool `long:"disable-pex"`
+ // Defines DialContext func to use for HTTP tracker announcements
+ TrackerDialContext func(ctx context.Context, network, addr string) (net.Conn, error)
+ // Defines ListenPacket func to use for UDP tracker announcements
+ TrackerListenPacket func(network, addr string) (net.PacketConn, error)
+ // Takes a tracker's hostname and requests DNS A and AAAA records.
+ // Used in case DNS lookups require a special setup (i.e., dns-over-https)
+ LookupTrackerIp func(*url.URL) ([]net.IP, error)
+}
+
+type ClientDhtConfig struct {
// Don't create a DHT.
- NoDHT bool `long:"disable-dht"`
- // Overrides the default DHT configuration.
- DHTConfig dht.ServerConfig
+ NoDHT bool `long:"disable-dht"`
+ DhtStartingNodes func(network string) dht.StartingNodesGetter
+ // Called for each anacrolix/dht Server created for the Client.
+ ConfigureAnacrolixDhtServer func(*dht.ServerConfig)
+ PeriodicallyAnnounceTorrentsToDht bool
+ // OnQuery hook func
+ DHTOnQuery func(query *krpc.Msg, source net.Addr) (propagate bool)
+}
+
+// Probably not safe to modify this after it's given to a Client.
+type ClientConfig struct {
+ ClientTrackerConfig
+ ClientDhtConfig
+
+ // Store torrent file data in this directory unless .DefaultStorage is
+ // specified.
+ DataDir string `long:"data-dir" description:"directory to store downloaded torrent data"`
+ // The address to listen for new uTP and TCP BitTorrent protocol connections. DHT shares a UDP
+ // socket with uTP unless configured otherwise.
+ ListenHost func(network string) string
+ ListenPort int
+ NoDefaultPortForwarding bool
+ UpnpID string
+ DisablePEX bool `long:"disable-pex"`
// Never send chunks to peers.
NoUpload bool `long:"no-upload"`
// Disable uploading even when it isn't fair.
DisableAggressiveUpload bool `long:"disable-aggressive-upload"`
// Upload even after there's nothing in it for us. By default uploading is
- // not altruistic, we'll upload slightly more than we download from each
- // peer.
+ // not altruistic, we'll only upload to encourage the peer to reciprocate.
Seed bool `long:"seed"`
- // Events are data bytes sent in pieces. The burst must be large enough to
- // fit a whole chunk, which is usually 16 KiB.
+ // Only applies to chunks uploaded to peers, to maintain responsiveness
+ // communicating local Client state to peers. Each limiter token
+ // represents one byte. The Limiter's burst must be large enough to fit a
+ // whole chunk, which is usually 16 KiB (see TorrentSpec.ChunkSize).
UploadRateLimiter *rate.Limiter
- // The events are bytes read from connections. The burst must be bigger
- // than the largest Read performed on a Conn minus one. This is likely to
- // be the larger of the main read loop buffer (~4096), and the requested
- // chunk size (~16KiB).
+ // Rate limits all reads from connections to peers. Each limiter token
+ // represents one byte. The Limiter's burst must be bigger than the
+ // largest Read performed on a the underlying rate-limiting io.Reader
+ // minus one. This is likely to be the larger of the main read loop buffer
+ // (~4096), and the requested chunk size (~16KiB, see
+ // TorrentSpec.ChunkSize).
DownloadRateLimiter *rate.Limiter
+ // Maximum unverified bytes across all torrents. Not used if zero.
+ MaxUnverifiedBytes int64
// User-provided Client peer ID. If not present, one is generated automatically.
PeerID string
DisableTCP bool `long:"disable-tcp"`
// Called to instantiate storage for each added torrent. Builtin backends
// are in the storage package. If not set, the "file" implementation is
- // used.
+ // used (and Closed when the Client is Closed).
DefaultStorage storage.ClientImpl
- EncryptionPolicy
+ HeaderObfuscationPolicy HeaderObfuscationPolicy
+ // The crypto methods to offer when initiating connections with header obfuscation.
+ CryptoProvides mse.CryptoMethod
+ // Chooses the crypto method to use when receiving connections with header obfuscation.
+ CryptoSelector mse.CryptoSelector
- IPBlocklist iplist.Ranger
- DisableIPv6 bool `long:"disable-ipv6"`
+ IPBlocklist iplist.Ranger
+ DisableIPv6 bool `long:"disable-ipv6"`
+ DisableIPv4 bool
+ DisableIPv4Peers bool
// Perform logging and any other behaviour that will help debug.
- Debug bool `help:"enable debugging"`
+ Debug bool `help:"enable debugging"`
+ Logger log.Logger
+
+ // Used for torrent sources and webseeding if set.
+ WebTransport http.RoundTripper
+ // Defines proxy for HTTP requests, such as for trackers. It's commonly set from the result of
+ // "net/http".ProxyURL(HTTPProxy).
+ HTTPProxy func(*http.Request) (*url.URL, error)
+ // Defines DialContext func to use for HTTP requests, such as for fetching metainfo and webtorrent seeds
+ HTTPDialContext func(ctx context.Context, network, addr string) (net.Conn, error)
+ // HTTPUserAgent changes default UserAgent for HTTP requests
+ HTTPUserAgent string
+ // HttpRequestDirector modifies the request before it's sent.
+ // Useful for adding authentication headers, for example
+ HttpRequestDirector func(*http.Request) error
+ // WebsocketTrackerHttpHeader returns a custom header to be used when dialing a websocket connection
+ // to the tracker. Useful for adding authentication headers
+ WebsocketTrackerHttpHeader func() http.Header
+ // Updated occasionally to when there's been some changes to client
+ // behaviour in case other clients are assuming anything of us. See also
+ // `bep20`.
+ ExtendedHandshakeClientVersion string
+ // Peer ID client identifier prefix. We'll update this occasionally to
+ // reflect changes to client behaviour that other clients may depend on.
+ // Also see `extendedHandshakeClientVersion`.
+ Bep20 string
+
+ // Peer dial timeout to use when there are limited peers.
+ NominalDialTimeout time.Duration
+ // Minimum peer dial timeout to use (even if we have lots of peers).
+ MinDialTimeout time.Duration
+ EstablishedConnsPerTorrent int
+ HalfOpenConnsPerTorrent int
+ TotalHalfOpenConns int
+ // Maximum number of peer addresses in reserve.
+ TorrentPeersHighWater int
+ // Minumum number of peers before effort is made to obtain more peers.
+ TorrentPeersLowWater int
+
+ // Limit how long handshake can take. This is to reduce the lingering
+ // impact of a few bad apples. 4s loses 1% of successful handshakes that
+ // are obtained with 60s timeout, and 5% of unsuccessful handshakes.
+ HandshakesTimeout time.Duration
+ // How long between writes before sending a keep alive message on a peer connection that we want
+ // to maintain.
+ KeepAliveTimeout time.Duration
+ // Maximum bytes to buffer per peer connection for peer request data before it is sent.
+ MaxAllocPeerRequestDataPerConn int64
+
+ // The IP addresses as our peers should see them. May differ from the
+ // local interfaces due to NAT or other network configurations.
+ PublicIp4 net.IP
+ PublicIp6 net.IP
+
+ // Accept rate limiting affects excessive connection attempts from IPs that fail during
+ // handshakes or request torrents that we don't have.
+ DisableAcceptRateLimiting bool
+ // Don't add connections that have the same peer ID as an existing
+ // connection for a given Torrent.
+ DropDuplicatePeerIds bool
+ // Drop peers that are complete if we are also complete and have no use for the peer. This is a
+ // bit of a special case, since a peer could also be useless if they're just not interested, or
+ // we don't intend to obtain all of a torrent's data.
+ DropMutuallyCompletePeers bool
+ // Whether to accept peer connections at all.
+ AcceptPeerConnections bool
+ // Whether a Client should want conns without delegating to any attached Torrents. This is
+ // useful when torrents might be added dynamically in callbacks for example.
+ AlwaysWantConns bool
+
+ Extensions PeerExtensionBits
+ // Bits that peers must have set to proceed past handshakes.
+ MinPeerExtensions PeerExtensionBits
+
+ DisableWebtorrent bool
+ DisableWebseeds bool
+
+ Callbacks Callbacks
+
+ // ICEServers defines a slice describing servers available to be used by
+ // ICE, such as STUN and TURN servers.
+ ICEServers []string
+
+ DialRateLimiter *rate.Limiter
+
+ PieceHashersPerTorrent int // default: 2
+}
+
+func (cfg *ClientConfig) SetListenAddr(addr string) *ClientConfig {
+ host, port, err := missinggo.ParseHostPort(addr)
+ if err != nil {
+ panic(err)
+ }
+ cfg.ListenHost = func(string) string { return host }
+ cfg.ListenPort = port
+ return cfg
+}
+
+func NewDefaultClientConfig() *ClientConfig {
+ cc := &ClientConfig{
+ HTTPUserAgent: version.DefaultHttpUserAgent,
+ ExtendedHandshakeClientVersion: version.DefaultExtendedHandshakeClientVersion,
+ Bep20: version.DefaultBep20Prefix,
+ UpnpID: version.DefaultUpnpId,
+ NominalDialTimeout: 20 * time.Second,
+ MinDialTimeout: 3 * time.Second,
+ EstablishedConnsPerTorrent: 50,
+ HalfOpenConnsPerTorrent: 25,
+ TotalHalfOpenConns: 100,
+ TorrentPeersHighWater: 500,
+ TorrentPeersLowWater: 50,
+ HandshakesTimeout: 4 * time.Second,
+ KeepAliveTimeout: time.Minute,
+ MaxAllocPeerRequestDataPerConn: 1 << 20,
+ ListenHost: func(string) string { return "" },
+ UploadRateLimiter: unlimited,
+ DownloadRateLimiter: unlimited,
+ DisableAcceptRateLimiting: true,
+ DropMutuallyCompletePeers: true,
+ HeaderObfuscationPolicy: HeaderObfuscationPolicy{
+ Preferred: true,
+ RequirePreferred: false,
+ },
+ CryptoSelector: mse.DefaultCryptoSelector,
+ CryptoProvides: mse.AllSupportedCrypto,
+ ListenPort: 42069,
+ Extensions: defaultPeerExtensionBytes(),
+ AcceptPeerConnections: true,
+ MaxUnverifiedBytes: 64 << 20,
+ DialRateLimiter: rate.NewLimiter(10, 10),
+ PieceHashersPerTorrent: 2,
+ }
+ cc.DhtStartingNodes = func(network string) dht.StartingNodesGetter {
+ return func() ([]dht.Addr, error) { return dht.GlobalBootstrapAddrs(network) }
+ }
+ cc.PeriodicallyAnnounceTorrentsToDht = true
+ return cc
}
-type EncryptionPolicy struct {
- DisableEncryption bool
- ForceEncryption bool // Don't allow unobfuscated connections.
- PreferNoEncryption bool
+type HeaderObfuscationPolicy struct {
+ RequirePreferred bool // Whether the value of Preferred is a strict requirement.
+ Preferred bool // Whether header obfuscation is preferred.
}