22 "github.com/anacrolix/chansync"
23 "github.com/anacrolix/chansync/events"
24 "github.com/anacrolix/dht/v2"
25 "github.com/anacrolix/dht/v2/krpc"
26 . "github.com/anacrolix/generics"
27 g "github.com/anacrolix/generics"
28 "github.com/anacrolix/log"
29 "github.com/anacrolix/missinggo/perf"
30 "github.com/anacrolix/missinggo/v2"
31 "github.com/anacrolix/missinggo/v2/bitmap"
32 "github.com/anacrolix/missinggo/v2/pproffd"
33 "github.com/anacrolix/sync"
34 "github.com/davecgh/go-spew/spew"
35 "github.com/dustin/go-humanize"
36 gbtree "github.com/google/btree"
37 "github.com/pion/datachannel"
39 "github.com/anacrolix/torrent/bencode"
40 "github.com/anacrolix/torrent/internal/check"
41 "github.com/anacrolix/torrent/internal/limiter"
42 "github.com/anacrolix/torrent/iplist"
43 "github.com/anacrolix/torrent/metainfo"
44 "github.com/anacrolix/torrent/mse"
45 pp "github.com/anacrolix/torrent/peer_protocol"
46 utHolepunch "github.com/anacrolix/torrent/peer_protocol/ut-holepunch"
47 request_strategy "github.com/anacrolix/torrent/request-strategy"
48 "github.com/anacrolix/torrent/storage"
49 "github.com/anacrolix/torrent/tracker"
50 "github.com/anacrolix/torrent/types/infohash"
51 "github.com/anacrolix/torrent/webtorrent"
54 // Clients contain zero or more Torrents. A Client manages a blocklist, the
55 // TCP/UDP protocol ports, and DHT as desired.
57 // An aggregate of stats over all connections. First in struct to ensure 64-bit alignment of
63 closed chansync.SetOnce
69 defaultStorage *storage.Client
73 dhtServers []DhtServer
74 ipBlockList iplist.Ranger
76 // Set of addresses that have our client ID. This intentionally will
77 // include ourselves if we end up trying to connect to our own address
78 // through legitimate channels.
79 dopplegangerAddrs map[string]struct{}
80 badPeerIPs map[netip.Addr]struct{}
81 torrents map[InfoHash]*Torrent
82 pieceRequestOrder map[interface{}]*request_strategy.PieceRequestOrder
84 acceptLimiter map[ipStr]int
87 websocketTrackers websocketTrackers
89 activeAnnounceLimiter limiter.Instance
90 httpClient *http.Client
92 clientHolepunchAddrSets
97 func (cl *Client) BadPeerIPs() (ips []string) {
99 ips = cl.badPeerIPsLocked()
104 func (cl *Client) badPeerIPsLocked() (ips []string) {
105 ips = make([]string, len(cl.badPeerIPs))
107 for k := range cl.badPeerIPs {
114 func (cl *Client) PeerID() PeerID {
118 // Returns the port number for the first listener that has one. No longer assumes that all port
119 // numbers are the same, due to support for custom listeners. Returns zero if no port number is
121 func (cl *Client) LocalPort() (port int) {
122 for i := 0; i < len(cl.listeners); i += 1 {
123 if port = addrPortOrZero(cl.listeners[i].Addr()); port != 0 {
130 func writeDhtServerStatus(w io.Writer, s DhtServer) {
131 dhtStats := s.Stats()
132 fmt.Fprintf(w, " ID: %x\n", s.ID())
133 spew.Fdump(w, dhtStats)
136 // Writes out a human readable status of the client, such as for writing to a
138 func (cl *Client) WriteStatus(_w io.Writer) {
141 w := bufio.NewWriter(_w)
143 fmt.Fprintf(w, "Listen port: %d\n", cl.LocalPort())
144 fmt.Fprintf(w, "Peer ID: %+q\n", cl.PeerID())
145 fmt.Fprintf(w, "Extension bits: %v\n", cl.config.Extensions)
146 fmt.Fprintf(w, "Announce key: %x\n", cl.announceKey())
147 fmt.Fprintf(w, "Banned IPs: %d\n", len(cl.badPeerIPsLocked()))
148 cl.eachDhtServer(func(s DhtServer) {
149 fmt.Fprintf(w, "%s DHT server at %s:\n", s.Addr().Network(), s.Addr().String())
150 writeDhtServerStatus(w, s)
152 dumpStats(w, cl.statsLocked())
153 torrentsSlice := cl.torrentsAsSlice()
154 fmt.Fprintf(w, "# Torrents: %d\n", len(torrentsSlice))
156 sort.Slice(torrentsSlice, func(l, r int) bool {
157 return torrentsSlice[l].infoHash.AsString() < torrentsSlice[r].infoHash.AsString()
159 for _, t := range torrentsSlice {
161 fmt.Fprint(w, "<unknown name>")
163 fmt.Fprint(w, t.name())
169 "%f%% of %d bytes (%s)",
170 100*(1-float64(t.bytesMissingLocked())/float64(t.info.TotalLength())),
172 humanize.Bytes(uint64(t.length())))
174 w.WriteString("<missing metainfo>")
182 func (cl *Client) initLogger() {
183 logger := cl.config.Logger
188 logger = logger.FilterLevel(log.Debug)
190 cl.logger = logger.WithValues(cl)
193 func (cl *Client) announceKey() int32 {
194 return int32(binary.BigEndian.Uint32(cl.peerID[16:20]))
197 // Initializes a bare minimum Client. *Client and *ClientConfig must not be nil.
198 func (cl *Client) init(cfg *ClientConfig) {
200 g.MakeMap(&cl.dopplegangerAddrs)
201 cl.torrents = make(map[metainfo.Hash]*Torrent)
202 cl.activeAnnounceLimiter.SlotsPerKey = 2
203 cl.event.L = cl.locker()
204 cl.ipBlockList = cfg.IPBlocklist
205 cl.httpClient = &http.Client{
206 Transport: &http.Transport{
207 Proxy: cfg.HTTPProxy,
208 DialContext: cfg.HTTPDialContext,
209 // I think this value was observed from some webseeds. It seems reasonable to extend it
210 // to other uses of HTTP from the client.
216 func NewClient(cfg *ClientConfig) (cl *Client, err error) {
218 cfg = NewDefaultClientConfig()
224 go cl.acceptLimitClearer()
233 storageImpl := cfg.DefaultStorage
234 if storageImpl == nil {
235 // We'd use mmap by default but HFS+ doesn't support sparse files.
236 storageImplCloser := storage.NewFile(cfg.DataDir)
237 cl.onClose = append(cl.onClose, func() {
238 if err := storageImplCloser.Close(); err != nil {
239 cl.logger.Printf("error closing default storage: %s", err)
242 storageImpl = storageImplCloser
244 cl.defaultStorage = storage.NewClient(storageImpl)
246 if cfg.PeerID != "" {
247 missinggo.CopyExact(&cl.peerID, cfg.PeerID)
249 o := copy(cl.peerID[:], cfg.Bep20)
250 _, err = rand.Read(cl.peerID[o:])
252 panic("error generating peer id")
256 sockets, err := listenAll(cl.listenNetworks(), cl.config.ListenHost, cl.config.ListenPort, cl.firewallCallback, cl.logger)
264 for _, _s := range sockets {
265 s := _s // Go is fucking retarded.
266 cl.onClose = append(cl.onClose, func() { go s.Close() })
267 if peerNetworkEnabled(parseNetworkString(s.Addr().Network()), cl.config) {
268 cl.dialers = append(cl.dialers, s)
269 cl.listeners = append(cl.listeners, s)
270 if cl.config.AcceptPeerConnections {
271 go cl.acceptConnections(s)
278 for _, s := range sockets {
279 if pc, ok := s.(net.PacketConn); ok {
280 ds, err := cl.NewAnacrolixDhtServer(pc)
284 cl.dhtServers = append(cl.dhtServers, AnacrolixDhtServerWrapper{ds})
285 cl.onClose = append(cl.onClose, func() { ds.Close() })
290 cl.websocketTrackers = websocketTrackers{
293 GetAnnounceRequest: func(event tracker.AnnounceEvent, infoHash [20]byte) (tracker.AnnounceRequest, error) {
296 t, ok := cl.torrents[infoHash]
298 return tracker.AnnounceRequest{}, errors.New("torrent not tracked by client")
300 return t.announceRequest(event), nil
302 Proxy: cl.config.HTTPProxy,
303 WebsocketTrackerHttpHeader: cl.config.WebsocketTrackerHttpHeader,
304 ICEServers: cl.config.ICEServers,
305 DialContext: cl.config.TrackerDialContext,
306 OnConn: func(dc datachannel.ReadWriteCloser, dcc webtorrent.DataChannelContext) {
309 t, ok := cl.torrents[dcc.InfoHash]
311 cl.logger.WithDefaultLevel(log.Warning).Printf(
312 "got webrtc conn for unloaded torrent with infohash %x",
318 go t.onWebRtcConn(dc, dcc)
325 func (cl *Client) AddDhtServer(d DhtServer) {
326 cl.dhtServers = append(cl.dhtServers, d)
329 // Adds a Dialer for outgoing connections. All Dialers are used when attempting to connect to a
330 // given address for any Torrent.
331 func (cl *Client) AddDialer(d Dialer) {
334 cl.dialers = append(cl.dialers, d)
335 for _, t := range cl.torrents {
340 func (cl *Client) Listeners() []Listener {
344 // Registers a Listener, and starts Accepting on it. You must Close Listeners provided this way
346 func (cl *Client) AddListener(l Listener) {
347 cl.listeners = append(cl.listeners, l)
348 if cl.config.AcceptPeerConnections {
349 go cl.acceptConnections(l)
353 func (cl *Client) firewallCallback(net.Addr) bool {
355 block := !cl.wantConns() || !cl.config.AcceptPeerConnections
358 torrent.Add("connections firewalled", 1)
360 torrent.Add("connections not firewalled", 1)
365 func (cl *Client) listenOnNetwork(n network) bool {
366 if n.Ipv4 && cl.config.DisableIPv4 {
369 if n.Ipv6 && cl.config.DisableIPv6 {
372 if n.Tcp && cl.config.DisableTCP {
375 if n.Udp && cl.config.DisableUTP && cl.config.NoDHT {
381 func (cl *Client) listenNetworks() (ns []network) {
382 for _, n := range allPeerNetworks {
383 if cl.listenOnNetwork(n) {
390 // Creates an anacrolix/dht Server, as would be done internally in NewClient, for the given conn.
391 func (cl *Client) NewAnacrolixDhtServer(conn net.PacketConn) (s *dht.Server, err error) {
392 logger := cl.logger.WithNames("dht", conn.LocalAddr().String())
393 cfg := dht.ServerConfig{
394 IPBlocklist: cl.ipBlockList,
396 OnAnnouncePeer: cl.onDHTAnnouncePeer,
397 PublicIP: func() net.IP {
398 if connIsIpv6(conn) && cl.config.PublicIp6 != nil {
399 return cl.config.PublicIp6
401 return cl.config.PublicIp4
403 StartingNodes: cl.config.DhtStartingNodes(conn.LocalAddr().Network()),
404 OnQuery: cl.config.DHTOnQuery,
407 if f := cl.config.ConfigureAnacrolixDhtServer; f != nil {
410 s, err = dht.NewServer(&cfg)
412 go s.TableMaintainer()
417 func (cl *Client) Closed() events.Done {
418 return cl.closed.Done()
421 func (cl *Client) eachDhtServer(f func(DhtServer)) {
422 for _, ds := range cl.dhtServers {
427 // Stops the client. All connections to peers are closed and all activity will come to a halt.
428 func (cl *Client) Close() (errs []error) {
429 var closeGroup sync.WaitGroup // For concurrent cleanup to complete before returning
431 for _, t := range cl.torrents {
432 err := t.close(&closeGroup)
434 errs = append(errs, err)
437 for i := range cl.onClose {
438 cl.onClose[len(cl.onClose)-1-i]()
443 closeGroup.Wait() // defer is LIFO. We want to Wait() after cl.unlock()
447 func (cl *Client) ipBlockRange(ip net.IP) (r iplist.Range, blocked bool) {
448 if cl.ipBlockList == nil {
451 return cl.ipBlockList.Lookup(ip)
454 func (cl *Client) ipIsBlocked(ip net.IP) bool {
455 _, blocked := cl.ipBlockRange(ip)
459 func (cl *Client) wantConns() bool {
460 if cl.config.AlwaysWantConns {
463 for _, t := range cl.torrents {
464 if t.wantIncomingConns() {
471 // TODO: Apply filters for non-standard networks, particularly rate-limiting.
472 func (cl *Client) rejectAccepted(conn net.Conn) error {
474 return errors.New("don't want conns right now")
476 ra := conn.RemoteAddr()
477 if rip := addrIpOrNil(ra); rip != nil {
478 if cl.config.DisableIPv4Peers && rip.To4() != nil {
479 return errors.New("ipv4 peers disabled")
481 if cl.config.DisableIPv4 && len(rip) == net.IPv4len {
482 return errors.New("ipv4 disabled")
484 if cl.config.DisableIPv6 && len(rip) == net.IPv6len && rip.To4() == nil {
485 return errors.New("ipv6 disabled")
487 if cl.rateLimitAccept(rip) {
488 return errors.New("source IP accepted rate limited")
490 if cl.badPeerIPPort(rip, missinggo.AddrPort(ra)) {
491 return errors.New("bad source addr")
497 func (cl *Client) acceptConnections(l Listener) {
499 conn, err := l.Accept()
500 torrent.Add("client listener accepts", 1)
502 holepunchAddr, holepunchErr := addrPortFromPeerRemoteAddr(conn.RemoteAddr())
503 if holepunchErr == nil {
505 if g.MapContains(cl.undialableWithoutHolepunch, holepunchAddr) {
506 setAdd(&cl.accepted, holepunchAddr)
509 cl.undialableWithoutHolepunchDialedAfterHolepunchConnect,
512 setAdd(&cl.probablyOnlyConnectedDueToHolepunch, holepunchAddr)
517 conn = pproffd.WrapNetConn(conn)
519 closed := cl.closed.IsSet()
521 if !closed && conn != nil {
522 reject = cl.rejectAccepted(conn)
532 log.Fmsg("error accepting connection: %s", err).LogLevel(log.Debug, cl.logger)
537 torrent.Add("rejected accepted connections", 1)
538 cl.logger.LazyLog(log.Debug, func() log.Msg {
539 return log.Fmsg("rejecting accepted conn: %v", reject)
543 go cl.incomingConnection(conn)
545 cl.logger.LazyLog(log.Debug, func() log.Msg {
546 return log.Fmsg("accepted %q connection at %q from %q",
552 torrent.Add(fmt.Sprintf("accepted conn remote IP len=%d", len(addrIpOrNil(conn.RemoteAddr()))), 1)
553 torrent.Add(fmt.Sprintf("accepted conn network=%s", conn.RemoteAddr().Network()), 1)
554 torrent.Add(fmt.Sprintf("accepted on %s listener", l.Addr().Network()), 1)
559 // Creates the PeerConn.connString for a regular net.Conn PeerConn.
560 func regularNetConnPeerConnConnString(nc net.Conn) string {
561 return fmt.Sprintf("%s-%s", nc.LocalAddr(), nc.RemoteAddr())
564 func (cl *Client) incomingConnection(nc net.Conn) {
566 if tc, ok := nc.(*net.TCPConn); ok {
569 remoteAddr, _ := tryIpPortFromNetAddr(nc.RemoteAddr())
570 c := cl.newConnection(
574 remoteAddr: nc.RemoteAddr(),
575 localPublicAddr: cl.publicAddr(remoteAddr.IP),
576 network: nc.RemoteAddr().Network(),
577 connString: regularNetConnPeerConnConnString(nc),
584 c.Discovery = PeerSourceIncoming
585 cl.runReceivedConn(c)
588 // Returns a handle to the given torrent, if it's present in the client.
589 func (cl *Client) Torrent(ih metainfo.Hash) (t *Torrent, ok bool) {
592 t, ok = cl.torrents[ih]
596 func (cl *Client) torrent(ih metainfo.Hash) *Torrent {
597 return cl.torrents[ih]
600 type DialResult struct {
605 func countDialResult(err error) {
607 torrent.Add("successful dials", 1)
609 torrent.Add("unsuccessful dials", 1)
613 func reducedDialTimeout(minDialTimeout, max time.Duration, halfOpenLimit, pendingPeers int) (ret time.Duration) {
614 ret = max / time.Duration((pendingPeers+halfOpenLimit)/halfOpenLimit)
615 if ret < minDialTimeout {
621 // Returns whether an address is known to connect to a client with our own ID.
622 func (cl *Client) dopplegangerAddr(addr string) bool {
623 _, ok := cl.dopplegangerAddrs[addr]
627 // Returns a connection over UTP or TCP, whichever is first to connect.
628 func (cl *Client) dialFirst(ctx context.Context, addr string) (res DialResult) {
629 return DialFirst(ctx, addr, cl.dialers)
632 // Returns a connection over UTP or TCP, whichever is first to connect.
633 func DialFirst(ctx context.Context, addr string, dialers []Dialer) (res DialResult) {
637 defer pool.startDrainer()
638 for _, _s := range dialers {
641 return pool.getFirst()
644 func dialFromSocket(ctx context.Context, s Dialer, addr string) net.Conn {
645 c, err := s.Dial(ctx, addr)
647 log.Levelf(log.Debug, "error dialing %q: %v", addr, err)
649 // This is a bit optimistic, but it looks non-trivial to thread this through the proxy code. Set
650 // it now in case we close the connection forthwith. Note this is also done in the TCP dialer
651 // code to increase the chance it's done.
652 if tc, ok := c.(*net.TCPConn); ok {
659 func (cl *Client) noLongerHalfOpen(t *Torrent, addr string, attemptKey outgoingConnAttemptKey) {
660 path := t.getHalfOpenPath(addr, attemptKey)
662 panic("should exist")
666 if cl.numHalfOpen < 0 {
667 panic("should not be possible")
669 for _, t := range cl.torrents {
674 func (cl *Client) countHalfOpenFromTorrents() (count int) {
675 for _, t := range cl.torrents {
676 count += t.numHalfOpenAttempts()
681 // Performs initiator handshakes and returns a connection. Returns nil *PeerConn if no connection
682 // for valid reasons.
683 func (cl *Client) initiateProtocolHandshakes(
688 newConnOpts newConnectionOpts,
690 c *PeerConn, err error,
692 c = cl.newConnection(nc, newConnOpts)
693 c.headerEncrypted = encryptHeader
694 ctx, cancel := context.WithTimeout(ctx, cl.config.HandshakesTimeout)
696 dl, ok := ctx.Deadline()
700 err = nc.SetDeadline(dl)
704 err = cl.initiateHandshakes(c, t)
708 func doProtocolHandshakeOnDialResult(
710 obfuscatedHeader bool,
714 c *PeerConn, err error,
718 addrIpPort, _ := tryIpPortFromNetAddr(addr)
719 c, err = cl.initiateProtocolHandshakes(
720 context.Background(), nc, t, obfuscatedHeader,
724 // It would be possible to retrieve a public IP from the dialer used here?
725 localPublicAddr: cl.publicAddr(addrIpPort.IP),
726 network: dr.Dialer.DialerNetwork(),
727 connString: regularNetConnPeerConnConnString(nc),
735 // Returns nil connection and nil error if no connection could be established for valid reasons.
736 func (cl *Client) dialAndCompleteHandshake(opts outgoingConnOpts) (c *PeerConn, err error) {
737 // It would be better if dial rate limiting could be tested when considering to open connections
738 // instead. Doing it here means if the limit is low, and the half-open limit is high, we could
739 // end up with lots of outgoing connection attempts pending that were initiated on stale data.
741 dialReservation := cl.config.DialRateLimiter.Reserve()
742 if !opts.receivedHolepunchConnect {
743 if !dialReservation.OK() {
744 err = errors.New("can't make dial limit reservation")
747 time.Sleep(dialReservation.Delay())
750 torrent.Add("establish outgoing connection", 1)
751 addr := opts.peerInfo.Addr
752 dialPool := dialPool{
753 resCh: make(chan DialResult),
756 defer dialPool.startDrainer()
757 dialTimeout := opts.t.getDialTimeoutUnlocked()
759 ctx, cancel := context.WithTimeout(context.Background(), dialTimeout)
761 for _, d := range cl.dialers {
765 holepunchAddr, holepunchAddrErr := addrPortFromPeerRemoteAddr(addr)
766 headerObfuscationPolicy := opts.HeaderObfuscationPolicy
767 obfuscatedHeaderFirst := headerObfuscationPolicy.Preferred
768 firstDialResult := dialPool.getFirst()
769 if firstDialResult.Conn == nil {
770 // No dialers worked. Try to initiate a holepunching rendezvous.
771 if holepunchAddrErr == nil {
773 if !opts.receivedHolepunchConnect {
774 g.MakeMapIfNilAndSet(&cl.undialableWithoutHolepunch, holepunchAddr, struct{}{})
776 if !opts.skipHolepunchRendezvous {
777 opts.t.trySendHolepunchRendezvous(holepunchAddr)
781 err = fmt.Errorf("all initial dials failed")
784 if opts.receivedHolepunchConnect && holepunchAddrErr == nil {
786 if g.MapContains(cl.undialableWithoutHolepunch, holepunchAddr) {
787 g.MakeMapIfNilAndSet(&cl.dialableOnlyAfterHolepunch, holepunchAddr, struct{}{})
789 g.MakeMapIfNil(&cl.dialedSuccessfullyAfterHolepunchConnect)
790 g.MapInsert(cl.dialedSuccessfullyAfterHolepunchConnect, holepunchAddr, struct{}{})
793 c, err = doProtocolHandshakeOnDialResult(
795 obfuscatedHeaderFirst,
800 torrent.Add("initiated conn with preferred header obfuscation", 1)
805 "error doing protocol handshake with header obfuscation %v",
806 obfuscatedHeaderFirst,
808 firstDialResult.Conn.Close()
809 // We should have just tried with the preferred header obfuscation. If it was required, there's nothing else to try.
810 if headerObfuscationPolicy.RequirePreferred {
813 // Reuse the dialer that returned already but failed to handshake.
815 ctx, cancel := context.WithTimeout(context.Background(), dialTimeout)
817 dialPool.add(ctx, firstDialResult.Dialer)
819 secondDialResult := dialPool.getFirst()
820 if secondDialResult.Conn == nil {
823 c, err = doProtocolHandshakeOnDialResult(
825 !obfuscatedHeaderFirst,
830 torrent.Add("initiated conn with fallback header obfuscation", 1)
835 "error doing protocol handshake with header obfuscation %v",
836 !obfuscatedHeaderFirst,
838 secondDialResult.Conn.Close()
842 type outgoingConnOpts struct {
845 // Don't attempt to connect unless a connect message is received after initiating a rendezvous.
846 requireRendezvous bool
847 // Don't send rendezvous requests to eligible relays.
848 skipHolepunchRendezvous bool
849 // Outgoing connection attempt is in response to holepunch connect message.
850 receivedHolepunchConnect bool
851 HeaderObfuscationPolicy HeaderObfuscationPolicy
854 // Called to dial out and run a connection. The addr we're given is already
855 // considered half-open.
856 func (cl *Client) outgoingConnection(
857 opts outgoingConnOpts,
858 attemptKey outgoingConnAttemptKey,
860 c, err := cl.dialAndCompleteHandshake(opts)
862 c.conn.SetWriteDeadline(time.Time{})
866 // Don't release lock between here and addPeerConn, unless it's for failure.
867 cl.noLongerHalfOpen(opts.t, opts.peerInfo.Addr.String(), attemptKey)
872 "error establishing outgoing connection to %v: %v",
880 c.Discovery = opts.peerInfo.Source
881 c.trusted = opts.peerInfo.Trusted
882 opts.t.runHandshookConnLoggingErr(c)
885 // The port number for incoming peer connections. 0 if the client isn't listening.
886 func (cl *Client) incomingPeerPort() int {
887 return cl.LocalPort()
890 func (cl *Client) initiateHandshakes(c *PeerConn, t *Torrent) error {
891 if c.headerEncrypted {
894 rw, c.cryptoMethod, err = mse.InitiateHandshake(
901 cl.config.CryptoProvides,
905 return fmt.Errorf("header obfuscation handshake: %w", err)
908 ih, err := cl.connBtHandshake(c, &t.infoHash)
910 return fmt.Errorf("bittorrent protocol handshake: %w", err)
912 if ih != t.infoHash {
913 return errors.New("bittorrent protocol handshake: peer infohash didn't match")
918 // Calls f with any secret keys. Note that it takes the Client lock, and so must be used from code
919 // that won't also try to take the lock. This saves us copying all the infohashes everytime.
920 func (cl *Client) forSkeys(f func([]byte) bool) {
923 if false { // Emulate the bug from #114
925 for ih := range cl.torrents {
929 for range cl.torrents {
936 for ih := range cl.torrents {
943 func (cl *Client) handshakeReceiverSecretKeys() mse.SecretKeyIter {
944 if ret := cl.config.Callbacks.ReceiveEncryptedHandshakeSkeys; ret != nil {
950 // Do encryption and bittorrent handshakes as receiver.
951 func (cl *Client) receiveHandshakes(c *PeerConn) (t *Torrent, err error) {
952 defer perf.ScopeTimerErr(&err)()
954 rw, c.headerEncrypted, c.cryptoMethod, err = handleEncryption(c.rw(), cl.handshakeReceiverSecretKeys(), cl.config.HeaderObfuscationPolicy, cl.config.CryptoSelector)
956 if err == nil || err == mse.ErrNoSecretKeyMatch {
957 if c.headerEncrypted {
958 torrent.Add("handshakes received encrypted", 1)
960 torrent.Add("handshakes received unencrypted", 1)
963 torrent.Add("handshakes received with error while handling encryption", 1)
966 if err == mse.ErrNoSecretKeyMatch {
971 if cl.config.HeaderObfuscationPolicy.RequirePreferred && c.headerEncrypted != cl.config.HeaderObfuscationPolicy.Preferred {
972 err = errors.New("connection does not have required header obfuscation")
975 ih, err := cl.connBtHandshake(c, nil)
977 return nil, fmt.Errorf("during bt handshake: %w", err)
985 var successfulPeerWireProtocolHandshakePeerReservedBytes expvar.Map
989 "successful_peer_wire_protocol_handshake_peer_reserved_bytes",
990 &successfulPeerWireProtocolHandshakePeerReservedBytes)
993 func (cl *Client) connBtHandshake(c *PeerConn, ih *metainfo.Hash) (ret metainfo.Hash, err error) {
994 res, err := pp.Handshake(c.rw(), ih, cl.peerID, cl.config.Extensions)
998 successfulPeerWireProtocolHandshakePeerReservedBytes.Add(
999 hex.EncodeToString(res.PeerExtensionBits[:]), 1)
1001 c.PeerExtensionBytes = res.PeerExtensionBits
1002 c.PeerID = res.PeerID
1003 c.completedHandshake = time.Now()
1004 if cb := cl.config.Callbacks.CompletedHandshake; cb != nil {
1010 func (cl *Client) runReceivedConn(c *PeerConn) {
1011 err := c.conn.SetDeadline(time.Now().Add(cl.config.HandshakesTimeout))
1015 t, err := cl.receiveHandshakes(c)
1017 cl.logger.LazyLog(log.Debug, func() log.Msg {
1019 "error receiving handshakes on %v: %s", c, err,
1021 "network", c.Network,
1024 torrent.Add("error receiving handshake", 1)
1026 cl.onBadAccept(c.RemoteAddr)
1031 torrent.Add("received handshake for unloaded torrent", 1)
1032 cl.logger.LazyLog(log.Debug, func() log.Msg {
1033 return log.Fmsg("received handshake for unloaded torrent")
1036 cl.onBadAccept(c.RemoteAddr)
1040 torrent.Add("received handshake for loaded torrent", 1)
1041 c.conn.SetWriteDeadline(time.Time{})
1044 t.runHandshookConnLoggingErr(c)
1047 // Client lock must be held before entering this.
1048 func (cl *Client) runHandshookConn(c *PeerConn, t *Torrent) error {
1050 for i, b := range cl.config.MinPeerExtensions {
1051 if c.PeerExtensionBytes[i]&b != b {
1052 return fmt.Errorf("peer did not meet minimum peer extensions: %x", c.PeerExtensionBytes[:])
1055 if c.PeerID == cl.peerID {
1058 addr := c.RemoteAddr.String()
1059 cl.dopplegangerAddrs[addr] = struct{}{}
1061 // Because the remote address is not necessarily the same as its client's torrent listen
1062 // address, we won't record the remote address as a doppleganger. Instead, the initiator
1063 // can record *us* as the doppleganger.
1065 t.logger.Levelf(log.Debug, "local and remote peer ids are the same")
1068 c.r = deadlineReader{c.conn, c.r}
1069 completedHandshakeConnectionFlags.Add(c.connectionFlags(), 1)
1070 if connIsIpv6(c.conn) {
1071 torrent.Add("completed handshake over ipv6", 1)
1073 if err := t.addPeerConn(c); err != nil {
1074 return fmt.Errorf("adding connection: %w", err)
1076 defer t.dropConnection(c)
1077 c.startMessageWriter()
1078 cl.sendInitialMessages(c, t)
1079 c.initUpdateRequestsTimer()
1080 err := c.mainReadLoop()
1082 return fmt.Errorf("main read loop: %w", err)
1087 func (p *Peer) initUpdateRequestsTimer() {
1089 if p.updateRequestsTimer != nil {
1090 panic(p.updateRequestsTimer)
1093 if enableUpdateRequestsTimer {
1094 p.updateRequestsTimer = time.AfterFunc(math.MaxInt64, p.updateRequestsTimerFunc)
1098 const peerUpdateRequestsTimerReason = "updateRequestsTimer"
1100 func (c *Peer) updateRequestsTimerFunc() {
1102 defer c.locker().Unlock()
1103 if c.closed.IsSet() {
1106 if c.isLowOnRequests() {
1107 // If there are no outstanding requests, then a request update should have already run.
1110 if d := time.Since(c.lastRequestUpdate); d < updateRequestsTimerDuration {
1111 // These should be benign, Timer.Stop doesn't guarantee that its function won't run if it's
1112 // already been fired.
1113 torrent.Add("spurious timer requests updates", 1)
1116 c.updateRequests(peerUpdateRequestsTimerReason)
1119 // Maximum pending requests we allow peers to send us. If peer requests are buffered on read, this
1120 // instructs the amount of memory that might be used to cache pending writes. Assuming 512KiB
1121 // (1<<19) cached for sending, for 16KiB (1<<14) chunks.
1122 const localClientReqq = 1024
1124 // See the order given in Transmission's tr_peerMsgsNew.
1125 func (cl *Client) sendInitialMessages(conn *PeerConn, torrent *Torrent) {
1126 if conn.PeerExtensionBytes.SupportsExtended() && cl.config.Extensions.SupportsExtended() {
1127 conn.write(pp.Message{
1129 ExtendedID: pp.HandshakeExtendedID,
1130 ExtendedPayload: func() []byte {
1131 msg := pp.ExtendedHandshakeMessage{
1132 M: map[pp.ExtensionName]pp.ExtensionNumber{
1133 pp.ExtensionNameMetadata: metadataExtendedId,
1134 utHolepunch.ExtensionName: utHolepunchExtendedId,
1136 V: cl.config.ExtendedHandshakeClientVersion,
1137 Reqq: localClientReqq,
1138 YourIp: pp.CompactIp(conn.remoteIp()),
1139 Encryption: cl.config.HeaderObfuscationPolicy.Preferred || !cl.config.HeaderObfuscationPolicy.RequirePreferred,
1140 Port: cl.incomingPeerPort(),
1141 MetadataSize: torrent.metadataSize(),
1142 // TODO: We can figure these out specific to the socket used.
1143 Ipv4: pp.CompactIp(cl.config.PublicIp4.To4()),
1144 Ipv6: cl.config.PublicIp6.To16(),
1146 if !cl.config.DisablePEX {
1147 msg.M[pp.ExtensionNamePex] = pexExtendedId
1149 return bencode.MustMarshal(msg)
1154 if conn.fastEnabled() {
1155 if torrent.haveAllPieces() {
1156 conn.write(pp.Message{Type: pp.HaveAll})
1157 conn.sentHaves.AddRange(0, bitmap.BitRange(conn.t.NumPieces()))
1159 } else if !torrent.haveAnyPieces() {
1160 conn.write(pp.Message{Type: pp.HaveNone})
1161 conn.sentHaves.Clear()
1167 if conn.PeerExtensionBytes.SupportsDHT() && cl.config.Extensions.SupportsDHT() && cl.haveDhtServer() {
1168 conn.write(pp.Message{
1175 func (cl *Client) dhtPort() (ret uint16) {
1176 if len(cl.dhtServers) == 0 {
1179 return uint16(missinggo.AddrPort(cl.dhtServers[len(cl.dhtServers)-1].Addr()))
1182 func (cl *Client) haveDhtServer() bool {
1183 return len(cl.dhtServers) > 0
1186 // Process incoming ut_metadata message.
1187 func (cl *Client) gotMetadataExtensionMsg(payload []byte, t *Torrent, c *PeerConn) error {
1188 var d pp.ExtendedMetadataRequestMsg
1189 err := bencode.Unmarshal(payload, &d)
1190 if _, ok := err.(bencode.ErrUnusedTrailingBytes); ok {
1191 } else if err != nil {
1192 return fmt.Errorf("error unmarshalling bencode: %s", err)
1196 case pp.DataMetadataExtensionMsgType:
1197 c.allStats(add(1, func(cs *ConnStats) *Count { return &cs.MetadataChunksRead }))
1198 if !c.requestedMetadataPiece(piece) {
1199 return fmt.Errorf("got unexpected piece %d", piece)
1201 c.metadataRequests[piece] = false
1202 begin := len(payload) - d.PieceSize()
1203 if begin < 0 || begin >= len(payload) {
1204 return fmt.Errorf("data has bad offset in payload: %d", begin)
1206 t.saveMetadataPiece(piece, payload[begin:])
1207 c.lastUsefulChunkReceived = time.Now()
1208 err = t.maybeCompleteMetadata()
1210 // Log this at the Torrent-level, as we don't partition metadata by Peer yet, so we
1211 // don't know who to blame. TODO: Also errors can be returned here that aren't related
1212 // to verifying metadata, which should be fixed. This should be tagged with metadata, so
1213 // log consumers can filter for this message.
1214 t.logger.WithDefaultLevel(log.Warning).Printf("error completing metadata: %v", err)
1217 case pp.RequestMetadataExtensionMsgType:
1218 if !t.haveMetadataPiece(piece) {
1219 c.write(t.newMetadataExtensionMessage(c, pp.RejectMetadataExtensionMsgType, d.Piece, nil))
1222 start := (1 << 14) * piece
1223 c.logger.WithDefaultLevel(log.Debug).Printf("sending metadata piece %d", piece)
1224 c.write(t.newMetadataExtensionMessage(c, pp.DataMetadataExtensionMsgType, piece, t.metadataBytes[start:start+t.metadataPieceSize(piece)]))
1226 case pp.RejectMetadataExtensionMsgType:
1229 return errors.New("unknown msg_type value")
1233 func (cl *Client) badPeerAddr(addr PeerRemoteAddr) bool {
1234 if ipa, ok := tryIpPortFromNetAddr(addr); ok {
1235 return cl.badPeerIPPort(ipa.IP, ipa.Port)
1240 // Returns whether the IP address and port are considered "bad".
1241 func (cl *Client) badPeerIPPort(ip net.IP, port int) bool {
1242 if port == 0 || ip == nil {
1245 if cl.dopplegangerAddr(net.JoinHostPort(ip.String(), strconv.FormatInt(int64(port), 10))) {
1248 if _, ok := cl.ipBlockRange(ip); ok {
1251 ipAddr, ok := netip.AddrFromSlice(ip)
1255 if _, ok := cl.badPeerIPs[ipAddr]; ok {
1261 // Return a Torrent ready for insertion into a Client.
1262 func (cl *Client) newTorrent(ih metainfo.Hash, specStorage storage.ClientImpl) (t *Torrent) {
1263 return cl.newTorrentOpt(AddTorrentOpts{
1265 Storage: specStorage,
1269 // Return a Torrent ready for insertion into a Client.
1270 func (cl *Client) newTorrentOpt(opts AddTorrentOpts) (t *Torrent) {
1271 // use provided storage, if provided
1272 storageClient := cl.defaultStorage
1273 if opts.Storage != nil {
1274 storageClient = storage.NewClient(opts.Storage)
1279 infoHash: opts.InfoHash,
1280 peers: prioritizedPeers{
1282 getPrio: func(p PeerInfo) peerPriority {
1284 return bep40PriorityIgnoreError(cl.publicAddr(ipPort.IP), ipPort)
1287 conns: make(map[*PeerConn]struct{}, 2*cl.config.EstablishedConnsPerTorrent),
1289 storageOpener: storageClient,
1290 maxEstablishedConns: cl.config.EstablishedConnsPerTorrent,
1292 metadataChanged: sync.Cond{
1295 webSeeds: make(map[string]*Peer),
1296 gotMetainfoC: make(chan struct{}),
1298 t.smartBanCache.Hash = sha1.Sum
1299 t.smartBanCache.Init()
1300 t.networkingEnabled.Set()
1301 t.logger = cl.logger.WithDefaultLevel(log.Debug)
1302 t.sourcesLogger = t.logger.WithNames("sources")
1303 if opts.ChunkSize == 0 {
1304 opts.ChunkSize = defaultChunkSize
1306 t.setChunkSize(opts.ChunkSize)
1310 // A file-like handle to some torrent data resource.
1311 type Handle interface {
1318 func (cl *Client) AddTorrentInfoHash(infoHash metainfo.Hash) (t *Torrent, new bool) {
1319 return cl.AddTorrentInfoHashWithStorage(infoHash, nil)
1322 // Adds a torrent by InfoHash with a custom Storage implementation.
1323 // If the torrent already exists then this Storage is ignored and the
1324 // existing torrent returned with `new` set to `false`
1325 func (cl *Client) AddTorrentInfoHashWithStorage(infoHash metainfo.Hash, specStorage storage.ClientImpl) (t *Torrent, new bool) {
1328 t, ok := cl.torrents[infoHash]
1334 t = cl.newTorrent(infoHash, specStorage)
1335 cl.eachDhtServer(func(s DhtServer) {
1336 if cl.config.PeriodicallyAnnounceTorrentsToDht {
1337 go t.dhtAnnouncer(s)
1340 cl.torrents[infoHash] = t
1341 cl.clearAcceptLimits()
1342 t.updateWantPeersEvent()
1343 // Tickle Client.waitAccept, new torrent may want conns.
1344 cl.event.Broadcast()
1348 // Adds a torrent by InfoHash with a custom Storage implementation. If the torrent already exists
1349 // then this Storage is ignored and the existing torrent returned with `new` set to `false`.
1350 func (cl *Client) AddTorrentOpt(opts AddTorrentOpts) (t *Torrent, new bool) {
1351 infoHash := opts.InfoHash
1354 t, ok := cl.torrents[infoHash]
1360 t = cl.newTorrentOpt(opts)
1361 cl.eachDhtServer(func(s DhtServer) {
1362 if cl.config.PeriodicallyAnnounceTorrentsToDht {
1363 go t.dhtAnnouncer(s)
1366 cl.torrents[infoHash] = t
1367 t.setInfoBytesLocked(opts.InfoBytes)
1368 cl.clearAcceptLimits()
1369 t.updateWantPeersEvent()
1370 // Tickle Client.waitAccept, new torrent may want conns.
1371 cl.event.Broadcast()
1375 type AddTorrentOpts struct {
1377 Storage storage.ClientImpl
1378 ChunkSize pp.Integer
1382 // Add or merge a torrent spec. Returns new if the torrent wasn't already in the client. See also
1383 // Torrent.MergeSpec.
1384 func (cl *Client) AddTorrentSpec(spec *TorrentSpec) (t *Torrent, new bool, err error) {
1385 t, new = cl.AddTorrentOpt(AddTorrentOpts{
1386 InfoHash: spec.InfoHash,
1387 Storage: spec.Storage,
1388 ChunkSize: spec.ChunkSize,
1392 // ChunkSize was already applied by adding a new Torrent, and MergeSpec disallows changing
1394 modSpec.ChunkSize = 0
1396 err = t.MergeSpec(&modSpec)
1397 if err != nil && new {
1403 // The trackers will be merged with the existing ones. If the Info isn't yet known, it will be set.
1404 // spec.DisallowDataDownload/Upload will be read and applied
1405 // The display name is replaced if the new spec provides one. Note that any `Storage` is ignored.
1406 func (t *Torrent) MergeSpec(spec *TorrentSpec) error {
1407 if spec.DisplayName != "" {
1408 t.SetDisplayName(spec.DisplayName)
1410 if spec.InfoBytes != nil {
1411 err := t.SetInfoBytes(spec.InfoBytes)
1417 cl.AddDhtNodes(spec.DhtNodes)
1418 t.UseSources(spec.Sources)
1421 t.initialPieceCheckDisabled = spec.DisableInitialPieceCheck
1422 for _, url := range spec.Webseeds {
1425 for _, peerAddr := range spec.PeerAddrs {
1427 Addr: StringAddr(peerAddr),
1428 Source: PeerSourceDirect,
1432 if spec.ChunkSize != 0 {
1433 panic("chunk size cannot be changed for existing Torrent")
1435 t.addTrackers(spec.Trackers)
1437 t.dataDownloadDisallowed.SetBool(spec.DisallowDataDownload)
1438 t.dataUploadDisallowed = spec.DisallowDataUpload
1442 func (cl *Client) dropTorrent(infoHash metainfo.Hash, wg *sync.WaitGroup) (err error) {
1443 t, ok := cl.torrents[infoHash]
1445 err = fmt.Errorf("no such torrent")
1449 delete(cl.torrents, infoHash)
1453 func (cl *Client) allTorrentsCompleted() bool {
1454 for _, t := range cl.torrents {
1458 if !t.haveAllPieces() {
1465 // Returns true when all torrents are completely downloaded and false if the
1466 // client is stopped before that.
1467 func (cl *Client) WaitAll() bool {
1470 for !cl.allTorrentsCompleted() {
1471 if cl.closed.IsSet() {
1479 // Returns handles to all the torrents loaded in the Client.
1480 func (cl *Client) Torrents() []*Torrent {
1483 return cl.torrentsAsSlice()
1486 func (cl *Client) torrentsAsSlice() (ret []*Torrent) {
1487 for _, t := range cl.torrents {
1488 ret = append(ret, t)
1493 func (cl *Client) AddMagnet(uri string) (T *Torrent, err error) {
1494 spec, err := TorrentSpecFromMagnetUri(uri)
1498 T, _, err = cl.AddTorrentSpec(spec)
1502 func (cl *Client) AddTorrent(mi *metainfo.MetaInfo) (T *Torrent, err error) {
1503 ts, err := TorrentSpecFromMetaInfoErr(mi)
1507 T, _, err = cl.AddTorrentSpec(ts)
1511 func (cl *Client) AddTorrentFromFile(filename string) (T *Torrent, err error) {
1512 mi, err := metainfo.LoadFromFile(filename)
1516 return cl.AddTorrent(mi)
1519 func (cl *Client) DhtServers() []DhtServer {
1520 return cl.dhtServers
1523 func (cl *Client) AddDhtNodes(nodes []string) {
1524 for _, n := range nodes {
1525 hmp := missinggo.SplitHostMaybePort(n)
1526 ip := net.ParseIP(hmp.Host)
1528 cl.logger.Printf("won't add DHT node with bad IP: %q", hmp.Host)
1531 ni := krpc.NodeInfo{
1532 Addr: krpc.NodeAddr{
1537 cl.eachDhtServer(func(s DhtServer) {
1543 func (cl *Client) banPeerIP(ip net.IP) {
1544 // We can't take this from string, because it will lose netip's v4on6. net.ParseIP parses v4
1545 // addresses directly to v4on6, which doesn't compare equal with v4.
1546 ipAddr, ok := netip.AddrFromSlice(ip)
1550 g.MakeMapIfNilAndSet(&cl.badPeerIPs, ipAddr, struct{}{})
1551 for _, t := range cl.torrents {
1552 t.iterPeers(func(p *Peer) {
1553 if p.remoteIp().Equal(ip) {
1554 t.logger.Levelf(log.Warning, "dropping peer %v with banned ip %v", p, ip)
1555 // Should this be a close?
1562 type newConnectionOpts struct {
1564 remoteAddr PeerRemoteAddr
1565 localPublicAddr peerLocalPublicAddr
1570 func (cl *Client) newConnection(nc net.Conn, opts newConnectionOpts) (c *PeerConn) {
1571 if opts.network == "" {
1572 panic(opts.remoteAddr)
1576 outgoing: opts.outgoing,
1579 PeerMaxRequests: 250,
1581 RemoteAddr: opts.remoteAddr,
1582 localPublicAddr: opts.localPublicAddr,
1583 Network: opts.network,
1584 callbacks: &cl.config.Callbacks,
1586 connString: opts.connString,
1589 c.peerRequestDataAllocLimiter.Max = cl.config.MaxAllocPeerRequestDataPerConn
1590 c.initRequestState()
1591 // TODO: Need to be much more explicit about this, including allowing non-IP bannable addresses.
1592 if opts.remoteAddr != nil {
1593 netipAddrPort, err := netip.ParseAddrPort(opts.remoteAddr.String())
1595 c.bannableAddr = Some(netipAddrPort.Addr())
1599 c.logger = cl.logger.WithDefaultLevel(log.Warning)
1600 c.logger = c.logger.WithContextText(fmt.Sprintf("%T %p", c, c))
1601 c.setRW(connStatsReadWriter{nc, c})
1602 c.r = &rateLimitedReader{
1603 l: cl.config.DownloadRateLimiter,
1608 "inited with remoteAddr %v network %v outgoing %t",
1609 opts.remoteAddr, opts.network, opts.outgoing,
1611 for _, f := range cl.config.Callbacks.NewPeer {
1617 func (cl *Client) onDHTAnnouncePeer(ih metainfo.Hash, ip net.IP, port int, portOk bool) {
1624 t.addPeers([]PeerInfo{{
1625 Addr: ipPortAddr{ip, port},
1626 Source: PeerSourceDhtAnnouncePeer,
1630 func firstNotNil(ips ...net.IP) net.IP {
1631 for _, ip := range ips {
1639 func (cl *Client) eachListener(f func(Listener) bool) {
1640 for _, s := range cl.listeners {
1647 func (cl *Client) findListener(f func(Listener) bool) (ret Listener) {
1648 for i := 0; i < len(cl.listeners); i += 1 {
1649 if ret = cl.listeners[i]; f(ret) {
1656 func (cl *Client) publicIp(peer net.IP) net.IP {
1657 // TODO: Use BEP 10 to determine how peers are seeing us.
1658 if peer.To4() != nil {
1660 cl.config.PublicIp4,
1661 cl.findListenerIp(func(ip net.IP) bool { return ip.To4() != nil }),
1666 cl.config.PublicIp6,
1667 cl.findListenerIp(func(ip net.IP) bool { return ip.To4() == nil }),
1671 func (cl *Client) findListenerIp(f func(net.IP) bool) net.IP {
1672 l := cl.findListener(
1673 func(l Listener) bool {
1674 return f(addrIpOrNil(l.Addr()))
1680 return addrIpOrNil(l.Addr())
1683 // Our IP as a peer should see it.
1684 func (cl *Client) publicAddr(peer net.IP) IpPort {
1685 return IpPort{IP: cl.publicIp(peer), Port: uint16(cl.incomingPeerPort())}
1688 // ListenAddrs addresses currently being listened to.
1689 func (cl *Client) ListenAddrs() (ret []net.Addr) {
1691 ret = make([]net.Addr, len(cl.listeners))
1692 for i := 0; i < len(cl.listeners); i += 1 {
1693 ret[i] = cl.listeners[i].Addr()
1699 func (cl *Client) PublicIPs() (ips []net.IP) {
1700 if ip := cl.config.PublicIp4; ip != nil {
1701 ips = append(ips, ip)
1703 if ip := cl.config.PublicIp6; ip != nil {
1704 ips = append(ips, ip)
1709 func (cl *Client) onBadAccept(addr PeerRemoteAddr) {
1710 ipa, ok := tryIpPortFromNetAddr(addr)
1714 ip := maskIpForAcceptLimiting(ipa.IP)
1715 if cl.acceptLimiter == nil {
1716 cl.acceptLimiter = make(map[ipStr]int)
1718 cl.acceptLimiter[ipStr(ip.String())]++
1721 func maskIpForAcceptLimiting(ip net.IP) net.IP {
1722 if ip4 := ip.To4(); ip4 != nil {
1723 return ip4.Mask(net.CIDRMask(24, 32))
1728 func (cl *Client) clearAcceptLimits() {
1729 cl.acceptLimiter = nil
1732 func (cl *Client) acceptLimitClearer() {
1735 case <-cl.closed.Done():
1737 case <-time.After(15 * time.Minute):
1739 cl.clearAcceptLimits()
1745 func (cl *Client) rateLimitAccept(ip net.IP) bool {
1746 if cl.config.DisableAcceptRateLimiting {
1749 return cl.acceptLimiter[ipStr(maskIpForAcceptLimiting(ip).String())] > 0
1752 func (cl *Client) rLock() {
1756 func (cl *Client) rUnlock() {
1760 func (cl *Client) lock() {
1764 func (cl *Client) unlock() {
1768 func (cl *Client) locker() *lockWithDeferreds {
1772 func (cl *Client) String() string {
1773 return fmt.Sprintf("<%[1]T %[1]p>", cl)
1776 // Returns connection-level aggregate connStats at the Client level. See the comment on
1777 // TorrentStats.ConnStats.
1778 func (cl *Client) ConnStats() ConnStats {
1779 return cl.connStats.Copy()
1782 func (cl *Client) Stats() ClientStats {
1785 return cl.statsLocked()