10 "github.com/anacrolix/dht/v2"
11 "github.com/anacrolix/dht/v2/krpc"
12 "github.com/anacrolix/log"
13 "github.com/anacrolix/missinggo/v2"
14 "golang.org/x/time/rate"
16 "github.com/anacrolix/torrent/iplist"
17 "github.com/anacrolix/torrent/mse"
18 "github.com/anacrolix/torrent/storage"
19 "github.com/anacrolix/torrent/version"
22 // Probably not safe to modify this after it's given to a Client.
23 type ClientConfig struct {
24 // Store torrent file data in this directory unless .DefaultStorage is
26 DataDir string `long:"data-dir" description:"directory to store downloaded torrent data"`
27 // The address to listen for new uTP and TCP BitTorrent protocol connections. DHT shares a UDP
28 // socket with uTP unless configured otherwise.
29 ListenHost func(network string) string
31 NoDefaultPortForwarding bool
33 // Don't announce to trackers. This only leaves DHT to discover peers.
34 DisableTrackers bool `long:"disable-trackers"`
35 DisablePEX bool `long:"disable-pex"`
37 // Don't create a DHT.
38 NoDHT bool `long:"disable-dht"`
39 DhtStartingNodes func(network string) dht.StartingNodesGetter
40 // Called for each anacrolix/dht Server created for the Client.
41 ConfigureAnacrolixDhtServer func(*dht.ServerConfig)
42 PeriodicallyAnnounceTorrentsToDht bool
44 // Never send chunks to peers.
45 NoUpload bool `long:"no-upload"`
46 // Disable uploading even when it isn't fair.
47 DisableAggressiveUpload bool `long:"disable-aggressive-upload"`
48 // Upload even after there's nothing in it for us. By default uploading is
49 // not altruistic, we'll only upload to encourage the peer to reciprocate.
50 Seed bool `long:"seed"`
51 // Only applies to chunks uploaded to peers, to maintain responsiveness
52 // communicating local Client state to peers. Each limiter token
53 // represents one byte. The Limiter's burst must be large enough to fit a
54 // whole chunk, which is usually 16 KiB (see TorrentSpec.ChunkSize).
55 UploadRateLimiter *rate.Limiter
56 // Rate limits all reads from connections to peers. Each limiter token
57 // represents one byte. The Limiter's burst must be bigger than the
58 // largest Read performed on a the underlying rate-limiting io.Reader
59 // minus one. This is likely to be the larger of the main read loop buffer
60 // (~4096), and the requested chunk size (~16KiB, see
61 // TorrentSpec.ChunkSize).
62 DownloadRateLimiter *rate.Limiter
63 // Maximum unverified bytes across all torrents. Not used if zero.
64 MaxUnverifiedBytes int64
66 // User-provided Client peer ID. If not present, one is generated automatically.
68 // For the bittorrent protocol.
70 // For the bittorrent protocol.
71 DisableTCP bool `long:"disable-tcp"`
72 // Called to instantiate storage for each added torrent. Builtin backends
73 // are in the storage package. If not set, the "file" implementation is
74 // used (and Closed when the Client is Closed).
75 DefaultStorage storage.ClientImpl
77 HeaderObfuscationPolicy HeaderObfuscationPolicy
78 // The crypto methods to offer when initiating connections with header obfuscation.
79 CryptoProvides mse.CryptoMethod
80 // Chooses the crypto method to use when receiving connections with header obfuscation.
81 CryptoSelector mse.CryptoSelector
83 IPBlocklist iplist.Ranger
84 DisableIPv6 bool `long:"disable-ipv6"`
87 // Perform logging and any other behaviour that will help debug.
88 Debug bool `help:"enable debugging"`
91 // Defines proxy for HTTP requests, such as for trackers. It's commonly set from the result of
92 // "net/http".ProxyURL(HTTPProxy).
93 HTTPProxy func(*http.Request) (*url.URL, error)
94 // Defines DialContext func to use for HTTP requests, such as for fetching metainfo and webtorrent seeds
95 HTTPDialContext func(ctx context.Context, network, addr string) (net.Conn, error)
96 // Defines DialContext func to use for HTTP tracker announcements
97 TrackerDialContext func(ctx context.Context, network, addr string) (net.Conn, error)
98 // Defines ListenPacket func to use for UDP tracker announcements
99 TrackerListenPacket func(network, addr string) (net.PacketConn, error)
100 // Takes a tracker's hostname and requests DNS A and AAAA records.
101 // Used in case DNS lookups require a special setup (i.e., dns-over-https)
102 LookupTrackerIp func(*url.URL) ([]net.IP, error)
103 // HTTPUserAgent changes default UserAgent for HTTP requests
105 // Updated occasionally to when there's been some changes to client
106 // behaviour in case other clients are assuming anything of us. See also
108 ExtendedHandshakeClientVersion string
109 // Peer ID client identifier prefix. We'll update this occasionally to
110 // reflect changes to client behaviour that other clients may depend on.
111 // Also see `extendedHandshakeClientVersion`.
114 // Peer dial timeout to use when there are limited peers.
115 NominalDialTimeout time.Duration
116 // Minimum peer dial timeout to use (even if we have lots of peers).
117 MinDialTimeout time.Duration
118 EstablishedConnsPerTorrent int
119 HalfOpenConnsPerTorrent int
120 TotalHalfOpenConns int
121 // Maximum number of peer addresses in reserve.
122 TorrentPeersHighWater int
123 // Minumum number of peers before effort is made to obtain more peers.
124 TorrentPeersLowWater int
126 // Limit how long handshake can take. This is to reduce the lingering
127 // impact of a few bad apples. 4s loses 1% of successful handshakes that
128 // are obtained with 60s timeout, and 5% of unsuccessful handshakes.
129 HandshakesTimeout time.Duration
130 // How long between writes before sending a keep alive message on a peer connection that we want
132 KeepAliveTimeout time.Duration
134 // The IP addresses as our peers should see them. May differ from the
135 // local interfaces due to NAT or other network configurations.
139 // Accept rate limiting affects excessive connection attempts from IPs that fail during
140 // handshakes or request torrents that we don't have.
141 DisableAcceptRateLimiting bool
142 // Don't add connections that have the same peer ID as an existing
143 // connection for a given Torrent.
144 DropDuplicatePeerIds bool
145 // Drop peers that are complete if we are also complete and have no use for the peer. This is a
146 // bit of a special case, since a peer could also be useless if they're just not interested, or
147 // we don't intend to obtain all of a torrent's data.
148 DropMutuallyCompletePeers bool
149 // Whether to accept peer connections at all.
150 AcceptPeerConnections bool
151 // Whether a Client should want conns without delegating to any attached Torrents. This is
152 // useful when torrents might be added dynmically in callbacks for example.
156 DHTOnQuery func(query *krpc.Msg, source net.Addr) (propagate bool)
158 Extensions PeerExtensionBits
159 // Bits that peers must have set to proceed past handshakes.
160 MinPeerExtensions PeerExtensionBits
162 DisableWebtorrent bool
168 func (cfg *ClientConfig) SetListenAddr(addr string) *ClientConfig {
169 host, port, err := missinggo.ParseHostPort(addr)
173 cfg.ListenHost = func(string) string { return host }
174 cfg.ListenPort = port
178 func NewDefaultClientConfig() *ClientConfig {
180 HTTPUserAgent: version.DefaultHttpUserAgent,
181 ExtendedHandshakeClientVersion: version.DefaultExtendedHandshakeClientVersion,
182 Bep20: version.DefaultBep20Prefix,
183 UpnpID: version.DefaultUpnpId,
184 NominalDialTimeout: 20 * time.Second,
185 MinDialTimeout: 3 * time.Second,
186 EstablishedConnsPerTorrent: 50,
187 HalfOpenConnsPerTorrent: 25,
188 TotalHalfOpenConns: 100,
189 TorrentPeersHighWater: 500,
190 TorrentPeersLowWater: 50,
191 HandshakesTimeout: 4 * time.Second,
192 KeepAliveTimeout: time.Minute,
193 DhtStartingNodes: func(network string) dht.StartingNodesGetter {
194 return func() ([]dht.Addr, error) { return dht.GlobalBootstrapAddrs(network) }
196 PeriodicallyAnnounceTorrentsToDht: true,
197 ListenHost: func(string) string { return "" },
198 UploadRateLimiter: unlimited,
199 DownloadRateLimiter: unlimited,
200 DisableAcceptRateLimiting: true,
201 DropMutuallyCompletePeers: true,
202 HeaderObfuscationPolicy: HeaderObfuscationPolicy{
204 RequirePreferred: false,
206 CryptoSelector: mse.DefaultCryptoSelector,
207 CryptoProvides: mse.AllSupportedCrypto,
209 Extensions: defaultPeerExtensionBytes(),
210 AcceptPeerConnections: true,
211 MaxUnverifiedBytes: 64 << 20,
216 type HeaderObfuscationPolicy struct {
217 RequirePreferred bool // Whether the value of Preferred is a strict requirement.
218 Preferred bool // Whether header obfuscation is preferred.