16 "github.com/RoaringBitmap/roaring"
17 "github.com/anacrolix/chansync"
18 . "github.com/anacrolix/generics"
19 "github.com/anacrolix/log"
20 "github.com/anacrolix/missinggo/iter"
21 "github.com/anacrolix/missinggo/v2/bitmap"
22 "github.com/anacrolix/multiless"
23 "github.com/anacrolix/torrent/bencode"
24 "github.com/anacrolix/torrent/metainfo"
25 "github.com/anacrolix/torrent/mse"
26 pp "github.com/anacrolix/torrent/peer_protocol"
27 request_strategy "github.com/anacrolix/torrent/request-strategy"
28 "github.com/anacrolix/torrent/typed-roaring"
31 type PeerSource string
34 PeerSourceTracker = "Tr"
35 PeerSourceIncoming = "I"
36 PeerSourceDhtGetPeers = "Hg" // Peers we found by searching a DHT.
37 PeerSourceDhtAnnouncePeer = "Ha" // Peers that were announced to us by a DHT.
39 // The peer was given directly, such as through a magnet link.
40 PeerSourceDirect = "M"
43 type peerRequestState struct {
47 type PeerRemoteAddr interface {
51 // Since we have to store all the requests in memory, we can't reasonably exceed what would be
52 // indexable with the memory space available.
55 requestState = request_strategy.PeerRequestState
59 // First to ensure 64-bit alignment for atomics. See #262.
69 RemoteAddr PeerRemoteAddr
70 bannableAddr Option[bannableAddr]
71 // True if the connection is operating over MSE obfuscation.
73 cryptoMethod mse.CryptoMethod
76 closed chansync.SetOnce
77 // Set true after we've added our ConnStats generated during handshake to
78 // other ConnStat instances as determined when the *Torrent became known.
79 reconciledHandshakeStats bool
81 lastMessageReceived time.Time
82 completedHandshake time.Time
83 lastUsefulChunkReceived time.Time
84 lastChunkSent time.Time
86 // Stuff controlled by the local peer.
87 needRequestUpdate string
88 requestState requestState
89 updateRequestsTimer *time.Timer
90 lastRequestUpdate time.Time
91 peakRequests maxRequests
92 lastBecameInterested time.Time
93 priorInterest time.Duration
95 lastStartedExpectingToReceiveChunks time.Time
96 cumulativeExpectedToReceiveChunks time.Duration
97 _chunksReceivedWhileExpecting int64
100 piecesReceivedSinceLastRequestUpdate maxRequests
101 maxPiecesReceivedBetweenRequestUpdates maxRequests
102 // Chunks that we might reasonably expect to receive from the peer. Due to latency, buffering,
103 // and implementation differences, we may receive chunks that are no longer in the set of
104 // requests actually want. This could use a roaring.BSI if the memory use becomes noticeable.
105 validReceiveChunks map[RequestIndex]int
106 // Indexed by metadata piece, set to true if posted and pending a
108 metadataRequests []bool
109 sentHaves bitmap.Bitmap
111 // Stuff controlled by the remote peer.
114 peerRequests map[Request]*peerRequestState
115 PeerPrefersEncryption bool // as indicated by 'e' field in extension handshake
117 // The highest possible number of pieces the torrent could have based on
118 // communication with the peer. Generally only useful until we have the
120 peerMinPieces pieceIndex
121 // Pieces we've accepted chunks for from the peer.
122 peerTouchedPieces map[pieceIndex]struct{}
123 peerAllowedFast typedRoaring.Bitmap[pieceIndex]
125 PeerMaxRequests maxRequests // Maximum pending requests the peer allows.
126 PeerExtensionIDs map[pp.ExtensionName]pp.ExtensionNumber
127 PeerClientName atomic.Value
132 type peerRequests = orderedBitmap[RequestIndex]
134 func (p *Peer) initRequestState() {
135 p.requestState.Requests = &peerRequests{}
138 // Maintains the state of a BitTorrent-protocol based connection with a peer.
139 type PeerConn struct {
142 // A string that should identify the PeerConn's net.Conn endpoints. The net.Conn could
143 // be wrapping WebRTC, uTP, or TCP etc. Used in writing the conn status for peers.
148 PeerExtensionBytes pp.PeerExtensionBits
150 // The actual Conn, used for closing, and setting socket options. Do not use methods on this
151 // while holding any mutexes.
153 // The Reader and Writer for this Conn, with hooks installed for stats,
154 // limiting, deadlines etc.
158 messageWriter peerConnMsgWriter
160 uploadTimer *time.Timer
163 // The pieces the peer has claimed to have.
164 _peerPieces roaring.Bitmap
165 // The peer has everything. This can occur due to a special message, when
166 // we may not even know the number of pieces in the torrent yet.
170 func (cn *PeerConn) connStatusString() string {
171 return fmt.Sprintf("%+-55q %s %s", cn.PeerID, cn.PeerExtensionBytes, cn.connString)
174 func (cn *Peer) updateExpectingChunks() {
175 if cn.expectingChunks() {
176 if cn.lastStartedExpectingToReceiveChunks.IsZero() {
177 cn.lastStartedExpectingToReceiveChunks = time.Now()
180 if !cn.lastStartedExpectingToReceiveChunks.IsZero() {
181 cn.cumulativeExpectedToReceiveChunks += time.Since(cn.lastStartedExpectingToReceiveChunks)
182 cn.lastStartedExpectingToReceiveChunks = time.Time{}
187 func (cn *Peer) expectingChunks() bool {
188 if cn.requestState.Requests.IsEmpty() {
191 if !cn.requestState.Interested {
197 haveAllowedFastRequests := false
198 cn.peerAllowedFast.Iterate(func(i pieceIndex) bool {
199 haveAllowedFastRequests = roaringBitmapRangeCardinality[RequestIndex](
200 cn.requestState.Requests,
201 cn.t.pieceRequestIndexOffset(i),
202 cn.t.pieceRequestIndexOffset(i+1),
204 return !haveAllowedFastRequests
206 return haveAllowedFastRequests
209 func (cn *Peer) remoteChokingPiece(piece pieceIndex) bool {
210 return cn.peerChoking && !cn.peerAllowedFast.Contains(piece)
213 // Returns true if the connection is over IPv6.
214 func (cn *PeerConn) ipv6() bool {
219 return len(ip) == net.IPv6len
222 // Returns true the if the dialer/initiator has the lower client peer ID. TODO: Find the
223 // specification for this.
224 func (cn *PeerConn) isPreferredDirection() bool {
225 return bytes.Compare(cn.t.cl.peerID[:], cn.PeerID[:]) < 0 == cn.outgoing
228 // Returns whether the left connection should be preferred over the right one,
229 // considering only their networking properties. If ok is false, we can't
231 func (l *PeerConn) hasPreferredNetworkOver(r *PeerConn) bool {
232 var ml multiless.Computation
233 ml = ml.Bool(r.isPreferredDirection(), l.isPreferredDirection())
234 ml = ml.Bool(l.utp(), r.utp())
235 ml = ml.Bool(r.ipv6(), l.ipv6())
239 func (cn *Peer) cumInterest() time.Duration {
240 ret := cn.priorInterest
241 if cn.requestState.Interested {
242 ret += time.Since(cn.lastBecameInterested)
247 func (cn *PeerConn) peerHasAllPieces() (all, known bool) {
248 if cn.peerSentHaveAll {
251 if !cn.t.haveInfo() {
254 return cn._peerPieces.GetCardinality() == uint64(cn.t.numPieces()), true
257 func (cn *Peer) locker() *lockWithDeferreds {
258 return cn.t.cl.locker()
261 func (cn *Peer) supportsExtension(ext pp.ExtensionName) bool {
262 _, ok := cn.PeerExtensionIDs[ext]
266 // The best guess at number of pieces in the torrent for this peer.
267 func (cn *Peer) bestPeerNumPieces() pieceIndex {
269 return cn.t.numPieces()
271 return cn.peerMinPieces
274 func (cn *Peer) completedString() string {
275 have := pieceIndex(cn.peerPieces().GetCardinality())
276 if all, _ := cn.peerHasAllPieces(); all {
277 have = cn.bestPeerNumPieces()
279 return fmt.Sprintf("%d/%d", have, cn.bestPeerNumPieces())
282 func (cn *PeerConn) onGotInfo(info *metainfo.Info) {
283 cn.setNumPieces(info.NumPieces())
286 // Correct the PeerPieces slice length. Return false if the existing slice is invalid, such as by
287 // receiving badly sized BITFIELD, or invalid HAVE messages.
288 func (cn *PeerConn) setNumPieces(num pieceIndex) {
289 cn._peerPieces.RemoveRange(bitmap.BitRange(num), bitmap.ToEnd)
290 cn.peerPiecesChanged()
293 func (cn *PeerConn) peerPieces() *roaring.Bitmap {
294 return &cn._peerPieces
297 func eventAgeString(t time.Time) string {
301 return fmt.Sprintf("%.2fs ago", time.Since(t).Seconds())
304 func (cn *PeerConn) connectionFlags() (ret string) {
306 ret += string([]byte{b})
308 if cn.cryptoMethod == mse.CryptoMethodRC4 {
310 } else if cn.headerEncrypted {
313 ret += string(cn.Discovery)
320 func (cn *PeerConn) utp() bool {
321 return parseNetworkString(cn.Network).Udp
324 // Inspired by https://github.com/transmission/transmission/wiki/Peer-Status-Text.
325 func (cn *Peer) statusFlags() (ret string) {
327 ret += string([]byte{b})
329 if cn.requestState.Interested {
336 ret += cn.connectionFlags()
338 if cn.peerInterested {
347 func (cn *Peer) downloadRate() float64 {
348 num := cn._stats.BytesReadUsefulData.Int64()
352 return float64(num) / cn.totalExpectingTime().Seconds()
355 func (cn *Peer) iterContiguousPieceRequests(f func(piece pieceIndex, count int)) {
356 var last Option[pieceIndex]
358 next := func(item Option[pieceIndex]) {
363 f(last.Value(), count)
369 cn.requestState.Requests.Iterate(func(requestIndex request_strategy.RequestIndex) bool {
370 next(Some(cn.t.pieceIndexOfRequestIndex(requestIndex)))
373 next(None[pieceIndex]())
376 func (cn *Peer) writeStatus(w io.Writer, t *Torrent) {
377 // \t isn't preserved in <pre> blocks?
378 if cn.closed.IsSet() {
379 fmt.Fprint(w, "CLOSED: ")
381 fmt.Fprintln(w, cn.connStatusString())
382 prio, err := cn.peerPriority()
383 prioStr := fmt.Sprintf("%08x", prio)
385 prioStr += ": " + err.Error()
387 fmt.Fprintf(w, " bep40-prio: %v\n", prioStr)
388 fmt.Fprintf(w, " last msg: %s, connected: %s, last helpful: %s, itime: %s, etime: %s\n",
389 eventAgeString(cn.lastMessageReceived),
390 eventAgeString(cn.completedHandshake),
391 eventAgeString(cn.lastHelpful()),
393 cn.totalExpectingTime(),
396 " %s completed, %d pieces touched, good chunks: %v/%v:%v reqq: %d+%v/(%d/%d):%d/%d, flags: %s, dr: %.1f KiB/s\n",
397 cn.completedString(),
398 len(cn.peerTouchedPieces),
399 &cn._stats.ChunksReadUseful,
400 &cn._stats.ChunksRead,
401 &cn._stats.ChunksWritten,
402 cn.requestState.Requests.GetCardinality(),
403 cn.requestState.Cancelled.GetCardinality(),
404 cn.nominalMaxRequests(),
406 len(cn.peerRequests),
409 cn.downloadRate()/(1<<10),
411 fmt.Fprintf(w, " requested pieces:")
412 cn.iterContiguousPieceRequests(func(piece pieceIndex, count int) {
413 fmt.Fprintf(w, " %v(%v)", piece, count)
418 func (p *Peer) close() {
422 if p.updateRequestsTimer != nil {
423 p.updateRequestsTimer.Stop()
427 p.t.decPeerPieceAvailability(p)
429 for _, f := range p.callbacks.PeerClosed {
434 func (cn *PeerConn) onClose() {
435 if cn.pex.IsEnabled() {
442 if cb := cn.callbacks.PeerConnClosed; cb != nil {
447 // Peer definitely has a piece, for purposes of requesting. So it's not sufficient that we think
448 // they do (known=true).
449 func (cn *Peer) peerHasPiece(piece pieceIndex) bool {
450 if all, known := cn.peerHasAllPieces(); all && known {
453 return cn.peerPieces().ContainsInt(piece)
456 // 64KiB, but temporarily less to work around an issue with WebRTC. TODO: Update when
457 // https://github.com/pion/datachannel/issues/59 is fixed.
459 writeBufferHighWaterLen = 1 << 15
460 writeBufferLowWaterLen = writeBufferHighWaterLen / 2
463 // Writes a message into the write buffer. Returns whether it's okay to keep writing. Writing is
464 // done asynchronously, so it may be that we're not able to honour backpressure from this method.
465 func (cn *PeerConn) write(msg pp.Message) bool {
466 torrent.Add(fmt.Sprintf("messages written of type %s", msg.Type.String()), 1)
467 // We don't need to track bytes here because the connection's Writer has that behaviour injected
468 // (although there's some delay between us buffering the message, and the connection writer
469 // flushing it out.).
470 notFull := cn.messageWriter.write(msg)
471 // Last I checked only Piece messages affect stats, and we don't write those.
477 func (cn *PeerConn) requestMetadataPiece(index int) {
478 eID := cn.PeerExtensionIDs[pp.ExtensionNameMetadata]
479 if eID == pp.ExtensionDeleteNumber {
482 if index < len(cn.metadataRequests) && cn.metadataRequests[index] {
485 cn.logger.WithDefaultLevel(log.Debug).Printf("requesting metadata piece %d", index)
486 cn.write(pp.MetadataExtensionRequestMsg(eID, index))
487 for index >= len(cn.metadataRequests) {
488 cn.metadataRequests = append(cn.metadataRequests, false)
490 cn.metadataRequests[index] = true
493 func (cn *PeerConn) requestedMetadataPiece(index int) bool {
494 return index < len(cn.metadataRequests) && cn.metadataRequests[index]
498 interestedMsgLen = len(pp.Message{Type: pp.Interested}.MustMarshalBinary())
499 requestMsgLen = len(pp.Message{Type: pp.Request}.MustMarshalBinary())
500 // This is the maximum request count that could fit in the write buffer if it's at or below the
501 // low water mark when we run maybeUpdateActualRequestState.
502 maxLocalToRemoteRequests = (writeBufferHighWaterLen - writeBufferLowWaterLen - interestedMsgLen) / requestMsgLen
505 // The actual value to use as the maximum outbound requests.
506 func (cn *Peer) nominalMaxRequests() maxRequests {
507 return maxRequests(maxInt(1, minInt(cn.PeerMaxRequests, cn.peakRequests*2, maxLocalToRemoteRequests)))
510 func (cn *Peer) totalExpectingTime() (ret time.Duration) {
511 ret = cn.cumulativeExpectedToReceiveChunks
512 if !cn.lastStartedExpectingToReceiveChunks.IsZero() {
513 ret += time.Since(cn.lastStartedExpectingToReceiveChunks)
518 func (cn *PeerConn) onPeerSentCancel(r Request) {
519 if _, ok := cn.peerRequests[r]; !ok {
520 torrent.Add("unexpected cancels received", 1)
523 if cn.fastEnabled() {
526 delete(cn.peerRequests, r)
530 func (cn *PeerConn) choke(msg messageWriter) (more bool) {
535 more = msg(pp.Message{
538 if !cn.fastEnabled() {
539 cn.peerRequests = nil
544 func (cn *PeerConn) unchoke(msg func(pp.Message) bool) bool {
549 return msg(pp.Message{
554 func (cn *Peer) setInterested(interested bool) bool {
555 if cn.requestState.Interested == interested {
558 cn.requestState.Interested = interested
560 cn.lastBecameInterested = time.Now()
561 } else if !cn.lastBecameInterested.IsZero() {
562 cn.priorInterest += time.Since(cn.lastBecameInterested)
564 cn.updateExpectingChunks()
565 // log.Printf("%p: setting interest: %v", cn, interested)
566 return cn.writeInterested(interested)
569 func (pc *PeerConn) writeInterested(interested bool) bool {
570 return pc.write(pp.Message{
571 Type: func() pp.MessageType {
575 return pp.NotInterested
581 // The function takes a message to be sent, and returns true if more messages
583 type messageWriter func(pp.Message) bool
585 // This function seems to only used by Peer.request. It's all logic checks, so maybe we can no-op it
586 // when we want to go fast.
587 func (cn *Peer) shouldRequest(r RequestIndex) error {
588 pi := cn.t.pieceIndexOfRequestIndex(r)
589 if cn.requestState.Cancelled.Contains(r) {
590 return errors.New("request is cancelled and waiting acknowledgement")
592 if !cn.peerHasPiece(pi) {
593 return errors.New("requesting piece peer doesn't have")
595 if !cn.t.peerIsActive(cn) {
596 panic("requesting but not in active conns")
598 if cn.closed.IsSet() {
599 panic("requesting when connection is closed")
601 if cn.t.hashingPiece(pi) {
602 panic("piece is being hashed")
604 if cn.t.pieceQueuedForHash(pi) {
605 panic("piece is queued for hash")
607 if cn.peerChoking && !cn.peerAllowedFast.Contains(pi) {
608 // This could occur if we made a request with the fast extension, and then got choked and
609 // haven't had the request rejected yet.
610 if !cn.requestState.Requests.Contains(r) {
611 panic("peer choking and piece not allowed fast")
617 func (cn *Peer) mustRequest(r RequestIndex) bool {
618 more, err := cn.request(r)
625 func (cn *Peer) request(r RequestIndex) (more bool, err error) {
626 if err := cn.shouldRequest(r); err != nil {
629 if cn.requestState.Requests.Contains(r) {
632 if maxRequests(cn.requestState.Requests.GetCardinality()) >= cn.nominalMaxRequests() {
633 return true, errors.New("too many outstanding requests")
635 cn.requestState.Requests.Add(r)
636 if cn.validReceiveChunks == nil {
637 cn.validReceiveChunks = make(map[RequestIndex]int)
639 cn.validReceiveChunks[r]++
640 cn.t.pendingRequests[r] = cn
641 cn.t.lastRequested[r] = time.Now()
642 cn.updateExpectingChunks()
643 ppReq := cn.t.requestIndexToRequest(r)
644 for _, f := range cn.callbacks.SentRequest {
645 f(PeerRequestEvent{cn, ppReq})
647 return cn.peerImpl._request(ppReq), nil
650 func (me *PeerConn) _request(r Request) bool {
651 return me.write(pp.Message{
659 func (me *Peer) cancel(r RequestIndex) {
660 if !me.deleteRequest(r) {
661 panic("request not existing should have been guarded")
664 if !me.requestState.Cancelled.CheckedAdd(r) {
665 panic("request already cancelled")
669 if me.isLowOnRequests() {
670 me.updateRequests("Peer.cancel")
674 func (me *PeerConn) _cancel(r RequestIndex) bool {
675 me.write(makeCancelMessage(me.t.requestIndexToRequest(r)))
676 // Transmission does not send rejects for received cancels. See
677 // https://github.com/transmission/transmission/pull/2275.
678 return me.fastEnabled() && !me.remoteIsTransmission()
681 func (cn *PeerConn) fillWriteBuffer() {
682 if cn.messageWriter.writeBuffer.Len() > writeBufferLowWaterLen {
683 // Fully committing to our max requests requires sufficient space (see
684 // maxLocalToRemoteRequests). Flush what we have instead. We also prefer always to make
685 // requests than to do PEX or upload, so we short-circuit before handling those. Any update
686 // request reason will not be cleared, so we'll come right back here when there's space. We
687 // can't do this in maybeUpdateActualRequestState because it's a method on Peer and has no
688 // knowledge of write buffers.
690 cn.maybeUpdateActualRequestState()
691 if cn.pex.IsEnabled() {
692 if flow := cn.pex.Share(cn.write); !flow {
699 func (cn *PeerConn) have(piece pieceIndex) {
700 if cn.sentHaves.Get(bitmap.BitIndex(piece)) {
705 Index: pp.Integer(piece),
707 cn.sentHaves.Add(bitmap.BitIndex(piece))
710 func (cn *PeerConn) postBitfield() {
711 if cn.sentHaves.Len() != 0 {
712 panic("bitfield must be first have-related message sent")
714 if !cn.t.haveAnyPieces() {
719 Bitfield: cn.t.bitfield(),
721 cn.sentHaves = bitmap.Bitmap{cn.t._completedPieces.Clone()}
724 // Sets a reason to update requests, and if there wasn't already one, handle it.
725 func (cn *Peer) updateRequests(reason string) {
726 if cn.needRequestUpdate != "" {
729 if reason != peerUpdateRequestsTimerReason && !cn.isLowOnRequests() {
732 cn.needRequestUpdate = reason
733 cn.handleUpdateRequests()
736 func (cn *PeerConn) handleUpdateRequests() {
737 // The writer determines the request state as needed when it can write.
741 // Emits the indices in the Bitmaps bms in order, never repeating any index.
742 // skip is mutated during execution, and its initial values will never be
744 func iterBitmapsDistinct(skip *bitmap.Bitmap, bms ...bitmap.Bitmap) iter.Func {
745 return func(cb iter.Callback) {
746 for _, bm := range bms {
748 func(_i interface{}) bool {
750 if skip.Contains(bitmap.BitIndex(i)) {
753 skip.Add(bitmap.BitIndex(i))
764 func (cn *Peer) peerPiecesChanged() {
765 cn.t.maybeDropMutuallyCompletePeer(cn)
768 func (cn *PeerConn) raisePeerMinPieces(newMin pieceIndex) {
769 if newMin > cn.peerMinPieces {
770 cn.peerMinPieces = newMin
774 func (cn *PeerConn) peerSentHave(piece pieceIndex) error {
775 if cn.t.haveInfo() && piece >= cn.t.numPieces() || piece < 0 {
776 return errors.New("invalid piece")
778 if cn.peerHasPiece(piece) {
781 cn.raisePeerMinPieces(piece + 1)
782 if !cn.peerHasPiece(piece) {
783 cn.t.incPieceAvailability(piece)
785 cn._peerPieces.Add(uint32(piece))
786 if cn.t.wantPieceIndex(piece) {
787 cn.updateRequests("have")
789 cn.peerPiecesChanged()
793 func (cn *PeerConn) peerSentBitfield(bf []bool) error {
795 panic("expected bitfield length divisible by 8")
797 // We know that the last byte means that at most the last 7 bits are wasted.
798 cn.raisePeerMinPieces(pieceIndex(len(bf) - 7))
799 if cn.t.haveInfo() && len(bf) > int(cn.t.numPieces()) {
800 // Ignore known excess pieces.
801 bf = bf[:cn.t.numPieces()]
803 bm := boolSliceToBitmap(bf)
804 if cn.t.haveInfo() && pieceIndex(bm.GetCardinality()) == cn.t.numPieces() {
805 cn.onPeerHasAllPieces()
809 cn.raisePeerMinPieces(pieceIndex(bm.Maximum()) + 1)
811 shouldUpdateRequests := false
812 if cn.peerSentHaveAll {
813 if !cn.t.deleteConnWithAllPieces(&cn.Peer) {
816 cn.peerSentHaveAll = false
817 if !cn._peerPieces.IsEmpty() {
818 panic("if peer has all, we expect no individual peer pieces to be set")
821 bm.Xor(&cn._peerPieces)
823 cn.peerSentHaveAll = false
824 // bm is now 'on' for pieces that are changing
825 bm.Iterate(func(x uint32) bool {
827 if cn._peerPieces.Contains(x) {
828 // Then we must be losing this piece
829 cn.t.decPieceAvailability(pi)
831 if !shouldUpdateRequests && cn.t.wantPieceIndex(pieceIndex(x)) {
832 shouldUpdateRequests = true
834 // We must be gaining this piece
835 cn.t.incPieceAvailability(pieceIndex(x))
839 // Apply the changes. If we had everything previously, this should be empty, so xor is the same
841 cn._peerPieces.Xor(&bm)
842 if shouldUpdateRequests {
843 cn.updateRequests("bitfield")
845 // We didn't guard this before, I see no reason to do it now.
846 cn.peerPiecesChanged()
850 func (cn *PeerConn) onPeerHasAllPieces() {
853 cn._peerPieces.Iterate(func(x uint32) bool {
854 t.decPieceAvailability(pieceIndex(x))
858 t.addConnWithAllPieces(&cn.Peer)
859 cn.peerSentHaveAll = true
860 cn._peerPieces.Clear()
861 if !cn.t._pendingPieces.IsEmpty() {
862 cn.updateRequests("Peer.onPeerHasAllPieces")
864 cn.peerPiecesChanged()
867 func (cn *PeerConn) onPeerSentHaveAll() error {
868 cn.onPeerHasAllPieces()
872 func (cn *PeerConn) peerSentHaveNone() error {
873 if cn.peerSentHaveAll {
874 cn.t.decPeerPieceAvailability(&cn.Peer)
876 cn._peerPieces.Clear()
877 cn.peerSentHaveAll = false
878 cn.peerPiecesChanged()
882 func (c *PeerConn) requestPendingMetadata() {
886 if c.PeerExtensionIDs[pp.ExtensionNameMetadata] == 0 {
887 // Peer doesn't support this.
890 // Request metadata pieces that we don't have in a random order.
892 for index := 0; index < c.t.metadataPieceCount(); index++ {
893 if !c.t.haveMetadataPiece(index) && !c.requestedMetadataPiece(index) {
894 pending = append(pending, index)
897 rand.Shuffle(len(pending), func(i, j int) { pending[i], pending[j] = pending[j], pending[i] })
898 for _, i := range pending {
899 c.requestMetadataPiece(i)
903 func (cn *PeerConn) wroteMsg(msg *pp.Message) {
904 torrent.Add(fmt.Sprintf("messages written of type %s", msg.Type.String()), 1)
905 if msg.Type == pp.Extended {
906 for name, id := range cn.PeerExtensionIDs {
907 if id != msg.ExtendedID {
910 torrent.Add(fmt.Sprintf("Extended messages written for protocol %q", name), 1)
913 cn.allStats(func(cs *ConnStats) { cs.wroteMsg(msg) })
916 // After handshake, we know what Torrent and Client stats to include for a
918 func (cn *Peer) postHandshakeStats(f func(*ConnStats)) {
924 // All ConnStats that include this connection. Some objects are not known
925 // until the handshake is complete, after which it's expected to reconcile the
927 func (cn *Peer) allStats(f func(*ConnStats)) {
929 if cn.reconciledHandshakeStats {
930 cn.postHandshakeStats(f)
934 func (cn *PeerConn) wroteBytes(n int64) {
935 cn.allStats(add(n, func(cs *ConnStats) *Count { return &cs.BytesWritten }))
938 func (cn *Peer) readBytes(n int64) {
939 cn.allStats(add(n, func(cs *ConnStats) *Count { return &cs.BytesRead }))
942 // Returns whether the connection could be useful to us. We're seeding and
943 // they want data, we don't have metainfo and they can provide it, etc.
944 func (c *Peer) useful() bool {
946 if c.closed.IsSet() {
950 return c.supportsExtension("ut_metadata")
952 if t.seeding() && c.peerInterested {
955 if c.peerHasWantedPieces() {
961 func (c *Peer) lastHelpful() (ret time.Time) {
962 ret = c.lastUsefulChunkReceived
963 if c.t.seeding() && c.lastChunkSent.After(ret) {
964 ret = c.lastChunkSent
969 func (c *PeerConn) fastEnabled() bool {
970 return c.PeerExtensionBytes.SupportsFast() && c.t.cl.config.Extensions.SupportsFast()
973 func (c *PeerConn) reject(r Request) {
974 if !c.fastEnabled() {
975 panic("fast not enabled")
977 c.write(r.ToMsg(pp.Reject))
978 delete(c.peerRequests, r)
981 func (c *PeerConn) onReadRequest(r Request) error {
982 requestedChunkLengths.Add(strconv.FormatUint(r.Length.Uint64(), 10), 1)
983 if _, ok := c.peerRequests[r]; ok {
984 torrent.Add("duplicate requests received", 1)
988 torrent.Add("requests received while choking", 1)
990 torrent.Add("requests rejected while choking", 1)
995 // TODO: What if they've already requested this?
996 if len(c.peerRequests) >= localClientReqq {
997 torrent.Add("requests received while queue full", 1)
1001 // BEP 6 says we may close here if we choose.
1004 if !c.t.havePiece(pieceIndex(r.Index)) {
1005 // This isn't necessarily them screwing up. We can drop pieces
1006 // from our storage, and can't communicate this to peers
1007 // except by reconnecting.
1008 requestsReceivedForMissingPieces.Add(1)
1009 return fmt.Errorf("peer requested piece we don't have: %v", r.Index.Int())
1011 // Check this after we know we have the piece, so that the piece length will be known.
1012 if r.Begin+r.Length > c.t.pieceLength(pieceIndex(r.Index)) {
1013 torrent.Add("bad requests received", 1)
1014 return errors.New("bad Request")
1016 if c.peerRequests == nil {
1017 c.peerRequests = make(map[Request]*peerRequestState, localClientReqq)
1019 value := &peerRequestState{}
1020 c.peerRequests[r] = value
1021 go c.peerRequestDataReader(r, value)
1025 func (c *PeerConn) peerRequestDataReader(r Request, prs *peerRequestState) {
1026 b, err := readPeerRequestData(r, c)
1028 defer c.locker().Unlock()
1030 c.peerRequestDataReadFailed(err, r)
1033 panic("data must be non-nil to trigger send")
1035 torrent.Add("peer request data read successes", 1)
1041 // If this is maintained correctly, we might be able to support optional synchronous reading for
1042 // chunk sending, the way it used to work.
1043 func (c *PeerConn) peerRequestDataReadFailed(err error, r Request) {
1044 torrent.Add("peer request data read failures", 1)
1045 logLevel := log.Warning
1046 if c.t.hasStorageCap() {
1047 // It's expected that pieces might drop. See
1048 // https://github.com/anacrolix/torrent/issues/702#issuecomment-1000953313.
1049 logLevel = log.Debug
1051 c.logger.WithDefaultLevel(logLevel).Printf("error reading chunk for peer Request %v: %v", r, err)
1052 if c.t.closed.IsSet() {
1055 i := pieceIndex(r.Index)
1056 if c.t.pieceComplete(i) {
1057 // There used to be more code here that just duplicated the following break. Piece
1058 // completions are currently cached, so I'm not sure how helpful this update is, except to
1059 // pull any completion changes pushed to the storage backend in failed reads that got us
1061 c.t.updatePieceCompletion(i)
1063 // We've probably dropped a piece from storage, but there's no way to communicate this to the
1064 // peer. If they ask for it again, we kick them allowing us to send them updated piece states if
1065 // we reconnect. TODO: Instead, we could just try to update them with Bitfield or HaveNone and
1066 // if they kick us for breaking protocol, on reconnect we will be compliant again (at least
1068 if c.fastEnabled() {
1072 // If fast isn't enabled, I think we would have wiped all peer requests when we last
1073 // choked, and requests while we're choking would be ignored. It could be possible that
1074 // a peer request data read completed concurrently to it being deleted elsewhere.
1075 c.logger.WithDefaultLevel(log.Warning).Printf("already choking peer, requests might not be rejected correctly")
1077 // Choking a non-fast peer should cause them to flush all their requests.
1082 func readPeerRequestData(r Request, c *PeerConn) ([]byte, error) {
1083 b := make([]byte, r.Length)
1084 p := c.t.info.Piece(int(r.Index))
1085 n, err := c.t.readAt(b, p.Offset()+int64(r.Begin))
1092 panic("expected error")
1098 func runSafeExtraneous(f func()) {
1106 func (c *PeerConn) logProtocolBehaviour(level log.Level, format string, arg ...interface{}) {
1107 c.logger.WithContextText(fmt.Sprintf(
1108 "peer id %q, ext v %q", c.PeerID, c.PeerClientName.Load(),
1109 )).SkipCallers(1).Levelf(level, format, arg...)
1112 // Processes incoming BitTorrent wire-protocol messages. The client lock is held upon entry and
1113 // exit. Returning will end the connection.
1114 func (c *PeerConn) mainReadLoop() (err error) {
1117 torrent.Add("connection.mainReadLoop returned with error", 1)
1119 torrent.Add("connection.mainReadLoop returned with no error", 1)
1125 decoder := pp.Decoder{
1126 R: bufio.NewReaderSize(c.r, 1<<17),
1127 MaxLength: 4 * pp.Integer(max(int64(t.chunkSize), defaultChunkSize)),
1135 err = decoder.Decode(&msg)
1137 if cb := c.callbacks.ReadMessage; cb != nil && err == nil {
1140 if t.closed.IsSet() || c.closed.IsSet() {
1146 c.lastMessageReceived = time.Now()
1148 receivedKeepalives.Add(1)
1151 messageTypesReceived.Add(msg.Type.String(), 1)
1152 if msg.Type.FastExtension() && !c.fastEnabled() {
1153 runSafeExtraneous(func() { torrent.Add("fast messages received when extension is disabled", 1) })
1154 return fmt.Errorf("received fast extension message (type=%v) but extension is disabled", msg.Type)
1161 if !c.fastEnabled() {
1162 c.deleteAllRequests("choked by non-fast PeerConn")
1164 // We don't decrement pending requests here, let's wait for the peer to either
1165 // reject or satisfy the outstanding requests. Additionally, some peers may unchoke
1166 // us and resume where they left off, we don't want to have piled on to those chunks
1167 // in the meanwhile. I think a peer's ability to abuse this should be limited: they
1168 // could let us request a lot of stuff, then choke us and never reject, but they're
1169 // only a single peer, our chunk balancing should smooth over this abuse.
1171 c.peerChoking = true
1172 c.updateExpectingChunks()
1175 // Some clients do this for some reason. Transmission doesn't error on this, so we
1176 // won't for consistency.
1177 c.logProtocolBehaviour(log.Debug, "received unchoke when already unchoked")
1180 c.peerChoking = false
1182 c.requestState.Requests.Iterate(func(x RequestIndex) bool {
1183 if !c.peerAllowedFast.Contains(c.t.pieceIndexOfRequestIndex(x)) {
1188 if preservedCount != 0 {
1189 // TODO: Yes this is a debug log but I'm not happy with the state of the logging lib
1191 c.logger.Levelf(log.Debug,
1192 "%v requests were preserved while being choked (fast=%v)",
1196 torrent.Add("requestsPreservedThroughChoking", int64(preservedCount))
1198 if !c.t._pendingPieces.IsEmpty() {
1199 c.updateRequests("unchoked")
1201 c.updateExpectingChunks()
1203 c.peerInterested = true
1205 case pp.NotInterested:
1206 c.peerInterested = false
1207 // We don't clear their requests since it isn't clear in the spec.
1208 // We'll probably choke them for this, which will clear them if
1209 // appropriate, and is clearly specified.
1211 err = c.peerSentHave(pieceIndex(msg.Index))
1213 err = c.peerSentBitfield(msg.Bitfield)
1215 r := newRequestFromMessage(&msg)
1216 err = c.onReadRequest(r)
1218 c.doChunkReadStats(int64(len(msg.Piece)))
1219 err = c.receiveChunk(&msg)
1220 if len(msg.Piece) == int(t.chunkSize) {
1221 t.chunkPool.Put(&msg.Piece)
1224 err = fmt.Errorf("receiving chunk: %w", err)
1227 req := newRequestFromMessage(&msg)
1228 c.onPeerSentCancel(req)
1230 ipa, ok := tryIpPortFromNetAddr(c.RemoteAddr)
1234 pingAddr := net.UDPAddr{
1239 pingAddr.Port = int(msg.Port)
1241 cl.eachDhtServer(func(s DhtServer) {
1242 go s.Ping(&pingAddr)
1245 torrent.Add("suggests received", 1)
1246 log.Fmsg("peer suggested piece %d", msg.Index).AddValues(c, msg.Index).LogLevel(log.Debug, c.t.logger)
1247 c.updateRequests("suggested")
1249 err = c.onPeerSentHaveAll()
1251 err = c.peerSentHaveNone()
1253 req := newRequestFromMessage(&msg)
1254 if !c.remoteRejectedRequest(c.t.requestIndexFromRequest(req)) {
1255 c.logger.Printf("received invalid reject [request=%v, peer=%v]", req, c)
1256 err = fmt.Errorf("received invalid reject [request=%v]", req)
1258 case pp.AllowedFast:
1259 torrent.Add("allowed fasts received", 1)
1260 log.Fmsg("peer allowed fast: %d", msg.Index).AddValues(c).LogLevel(log.Debug, c.t.logger)
1261 c.updateRequests("PeerConn.mainReadLoop allowed fast")
1263 err = c.onReadExtendedMsg(msg.ExtendedID, msg.ExtendedPayload)
1265 err = fmt.Errorf("received unknown message type: %#v", msg.Type)
1273 // Returns true if it was valid to reject the request.
1274 func (c *Peer) remoteRejectedRequest(r RequestIndex) bool {
1275 if c.deleteRequest(r) {
1277 } else if !c.requestState.Cancelled.CheckedRemove(r) {
1280 if c.isLowOnRequests() {
1281 c.updateRequests("Peer.remoteRejectedRequest")
1283 c.decExpectedChunkReceive(r)
1287 func (c *Peer) decExpectedChunkReceive(r RequestIndex) {
1288 count := c.validReceiveChunks[r]
1290 delete(c.validReceiveChunks, r)
1291 } else if count > 1 {
1292 c.validReceiveChunks[r] = count - 1
1298 func (c *PeerConn) onReadExtendedMsg(id pp.ExtensionNumber, payload []byte) (err error) {
1300 // TODO: Should we still do this?
1302 // These clients use their own extension IDs for outgoing message
1303 // types, which is incorrect.
1304 if bytes.HasPrefix(c.PeerID[:], []byte("-SD0100-")) || strings.HasPrefix(string(c.PeerID[:]), "-XL0012-") {
1312 case pp.HandshakeExtendedID:
1313 var d pp.ExtendedHandshakeMessage
1314 if err := bencode.Unmarshal(payload, &d); err != nil {
1315 c.logger.Printf("error parsing extended handshake message %q: %s", payload, err)
1316 return fmt.Errorf("unmarshalling extended handshake payload: %w", err)
1318 if cb := c.callbacks.ReadExtendedHandshake; cb != nil {
1321 // c.logger.WithDefaultLevel(log.Debug).Printf("received extended handshake message:\n%s", spew.Sdump(d))
1323 c.PeerMaxRequests = d.Reqq
1325 c.PeerClientName.Store(d.V)
1326 if c.PeerExtensionIDs == nil {
1327 c.PeerExtensionIDs = make(map[pp.ExtensionName]pp.ExtensionNumber, len(d.M))
1329 c.PeerListenPort = d.Port
1330 c.PeerPrefersEncryption = d.Encryption
1331 for name, id := range d.M {
1332 if _, ok := c.PeerExtensionIDs[name]; !ok {
1333 peersSupportingExtension.Add(
1334 // expvar.Var.String must produce valid JSON. "ut_payme\xeet_address" was being
1335 // entered here which caused problems later when unmarshalling.
1336 strconv.Quote(string(name)),
1339 c.PeerExtensionIDs[name] = id
1341 if d.MetadataSize != 0 {
1342 if err = t.setMetadataSize(d.MetadataSize); err != nil {
1343 return fmt.Errorf("setting metadata size to %d: %w", d.MetadataSize, err)
1346 c.requestPendingMetadata()
1347 if !t.cl.config.DisablePEX {
1348 t.pex.Add(c) // we learnt enough now
1352 case metadataExtendedId:
1353 err := cl.gotMetadataExtensionMsg(payload, t, c)
1355 return fmt.Errorf("handling metadata extension message: %w", err)
1359 if !c.pex.IsEnabled() {
1360 return nil // or hang-up maybe?
1362 return c.pex.Recv(payload)
1364 return fmt.Errorf("unexpected extended message ID: %v", id)
1368 // Set both the Reader and Writer for the connection from a single ReadWriter.
1369 func (cn *PeerConn) setRW(rw io.ReadWriter) {
1374 // Returns the Reader and Writer as a combined ReadWriter.
1375 func (cn *PeerConn) rw() io.ReadWriter {
1382 func (c *Peer) doChunkReadStats(size int64) {
1383 c.allStats(func(cs *ConnStats) { cs.receivedChunk(size) })
1386 // Handle a received chunk from a peer.
1387 func (c *Peer) receiveChunk(msg *pp.Message) error {
1388 chunksReceived.Add("total", 1)
1390 ppReq := newRequestFromMessage(msg)
1391 req := c.t.requestIndexFromRequest(ppReq)
1394 if c.bannableAddr.Ok() {
1395 t.smartBanCache.RecordBlock(c.bannableAddr.Value(), req, msg.Piece)
1399 chunksReceived.Add("while choked", 1)
1402 if c.validReceiveChunks[req] <= 0 {
1403 chunksReceived.Add("unexpected", 1)
1404 return errors.New("received unexpected chunk")
1406 c.decExpectedChunkReceive(req)
1408 if c.peerChoking && c.peerAllowedFast.Contains(pieceIndex(ppReq.Index)) {
1409 chunksReceived.Add("due to allowed fast", 1)
1412 // The request needs to be deleted immediately to prevent cancels occurring asynchronously when
1413 // have actually already received the piece, while we have the Client unlocked to write the data
1417 if c.requestState.Requests.Contains(req) {
1418 for _, f := range c.callbacks.ReceivedRequested {
1419 f(PeerMessageEvent{c, msg})
1422 // Request has been satisfied.
1423 if c.deleteRequest(req) || c.requestState.Cancelled.CheckedRemove(req) {
1426 c._chunksReceivedWhileExpecting++
1428 if c.isLowOnRequests() {
1429 c.updateRequests("Peer.receiveChunk deleted request")
1432 chunksReceived.Add("unintended", 1)
1438 // Do we actually want this chunk?
1439 if t.haveChunk(ppReq) {
1440 // panic(fmt.Sprintf("%+v", ppReq))
1441 chunksReceived.Add("redundant", 1)
1442 c.allStats(add(1, func(cs *ConnStats) *Count { return &cs.ChunksReadWasted }))
1446 piece := &t.pieces[ppReq.Index]
1448 c.allStats(add(1, func(cs *ConnStats) *Count { return &cs.ChunksReadUseful }))
1449 c.allStats(add(int64(len(msg.Piece)), func(cs *ConnStats) *Count { return &cs.BytesReadUsefulData }))
1451 c.piecesReceivedSinceLastRequestUpdate++
1452 c.allStats(add(int64(len(msg.Piece)), func(cs *ConnStats) *Count { return &cs.BytesReadUsefulIntendedData }))
1454 for _, f := range c.t.cl.config.Callbacks.ReceivedUsefulData {
1455 f(ReceivedUsefulDataEvent{c, msg})
1457 c.lastUsefulChunkReceived = time.Now()
1459 // Need to record that it hasn't been written yet, before we attempt to do
1460 // anything with it.
1461 piece.incrementPendingWrites()
1462 // Record that we have the chunk, so we aren't trying to download it while
1463 // waiting for it to be written to storage.
1464 piece.unpendChunkIndex(chunkIndexFromChunkSpec(ppReq.ChunkSpec, t.chunkSize))
1466 // Cancel pending requests for this chunk from *other* peers.
1467 if p := t.pendingRequests[req]; p != nil {
1469 panic("should not be pending request from conn that just received it")
1474 err := func() error {
1477 concurrentChunkWrites.Add(1)
1478 defer concurrentChunkWrites.Add(-1)
1479 // Write the chunk out. Note that the upper bound on chunk writing concurrency will be the
1480 // number of connections. We write inline with receiving the chunk (with this lock dance),
1481 // because we want to handle errors synchronously and I haven't thought of a nice way to
1482 // defer any concurrency to the storage and have that notify the client of errors. TODO: Do
1484 return t.writeChunk(int(msg.Index), int64(msg.Begin), msg.Piece)
1487 piece.decrementPendingWrites()
1490 c.logger.WithDefaultLevel(log.Error).Printf("writing received chunk %v: %v", req, err)
1492 // Necessary to pass TestReceiveChunkStorageFailureSeederFastExtensionDisabled. I think a
1493 // request update runs while we're writing the chunk that just failed. Then we never do a
1494 // fresh update after pending the failed request.
1495 c.updateRequests("Peer.receiveChunk error writing chunk")
1496 t.onWriteChunkErr(err)
1500 c.onDirtiedPiece(pieceIndex(ppReq.Index))
1502 // We need to ensure the piece is only queued once, so only the last chunk writer gets this job.
1503 if t.pieceAllDirty(pieceIndex(ppReq.Index)) && piece.pendingWrites == 0 {
1504 t.queuePieceCheck(pieceIndex(ppReq.Index))
1505 // We don't pend all chunks here anymore because we don't want code dependent on the dirty
1506 // chunk status (such as the haveChunk call above) to have to check all the various other
1507 // piece states like queued for hash, hashing etc. This does mean that we need to be sure
1508 // that chunk pieces are pended at an appropriate time later however.
1511 cl.event.Broadcast()
1512 // We do this because we've written a chunk, and may change PieceState.Partial.
1513 t.publishPieceChange(pieceIndex(ppReq.Index))
1518 func (c *Peer) onDirtiedPiece(piece pieceIndex) {
1519 if c.peerTouchedPieces == nil {
1520 c.peerTouchedPieces = make(map[pieceIndex]struct{})
1522 c.peerTouchedPieces[piece] = struct{}{}
1523 ds := &c.t.pieces[piece].dirtiers
1525 *ds = make(map[*Peer]struct{})
1527 (*ds)[c] = struct{}{}
1530 func (c *PeerConn) uploadAllowed() bool {
1531 if c.t.cl.config.NoUpload {
1534 if c.t.dataUploadDisallowed {
1540 if !c.peerHasWantedPieces() {
1543 // Don't upload more than 100 KiB more than we download.
1544 if c._stats.BytesWrittenData.Int64() >= c._stats.BytesReadData.Int64()+100<<10 {
1550 func (c *PeerConn) setRetryUploadTimer(delay time.Duration) {
1551 if c.uploadTimer == nil {
1552 c.uploadTimer = time.AfterFunc(delay, c.tickleWriter)
1554 c.uploadTimer.Reset(delay)
1558 // Also handles choking and unchoking of the remote peer.
1559 func (c *PeerConn) upload(msg func(pp.Message) bool) bool {
1560 // Breaking or completing this loop means we don't want to upload to the
1561 // peer anymore, and we choke them.
1563 for c.uploadAllowed() {
1564 // We want to upload to the peer.
1565 if !c.unchoke(msg) {
1568 for r, state := range c.peerRequests {
1569 if state.data == nil {
1572 res := c.t.cl.config.UploadRateLimiter.ReserveN(time.Now(), int(r.Length))
1574 panic(fmt.Sprintf("upload rate limiter burst size < %d", r.Length))
1576 delay := res.Delay()
1579 c.setRetryUploadTimer(delay)
1580 // Hard to say what to return here.
1583 more := c.sendChunk(r, msg, state)
1584 delete(c.peerRequests, r)
1595 func (cn *PeerConn) drop() {
1596 cn.t.dropConnection(cn)
1599 func (cn *PeerConn) ban() {
1600 cn.t.cl.banPeerIP(cn.remoteIp())
1603 func (cn *Peer) netGoodPiecesDirtied() int64 {
1604 return cn._stats.PiecesDirtiedGood.Int64() - cn._stats.PiecesDirtiedBad.Int64()
1607 func (c *Peer) peerHasWantedPieces() bool {
1608 if all, _ := c.peerHasAllPieces(); all {
1609 return !c.t.haveAllPieces() && !c.t._pendingPieces.IsEmpty()
1611 if !c.t.haveInfo() {
1612 return !c.peerPieces().IsEmpty()
1614 return c.peerPieces().Intersects(&c.t._pendingPieces)
1617 // Returns true if an outstanding request is removed. Cancelled requests should be handled
1619 func (c *Peer) deleteRequest(r RequestIndex) bool {
1620 if !c.requestState.Requests.CheckedRemove(r) {
1623 for _, f := range c.callbacks.DeletedRequest {
1624 f(PeerRequestEvent{c, c.t.requestIndexToRequest(r)})
1626 c.updateExpectingChunks()
1627 if c.t.requestingPeer(r) != c {
1628 panic("only one peer should have a given request at a time")
1630 delete(c.t.pendingRequests, r)
1631 delete(c.t.lastRequested, r)
1632 // c.t.iterPeers(func(p *Peer) {
1633 // if p.isLowOnRequests() {
1634 // p.updateRequests("Peer.deleteRequest")
1640 func (c *Peer) deleteAllRequests(reason string) {
1641 if c.requestState.Requests.IsEmpty() {
1644 c.requestState.Requests.IterateSnapshot(func(x RequestIndex) bool {
1645 if !c.deleteRequest(x) {
1646 panic("request should exist")
1650 c.assertNoRequests()
1651 c.t.iterPeers(func(p *Peer) {
1652 if p.isLowOnRequests() {
1653 p.updateRequests(reason)
1659 func (c *Peer) assertNoRequests() {
1660 if !c.requestState.Requests.IsEmpty() {
1661 panic(c.requestState.Requests.GetCardinality())
1665 func (c *Peer) cancelAllRequests() {
1666 c.requestState.Requests.IterateSnapshot(func(x RequestIndex) bool {
1670 c.assertNoRequests()
1674 // This is called when something has changed that should wake the writer, such as putting stuff into
1675 // the writeBuffer, or changing some state that the writer can act on.
1676 func (c *PeerConn) tickleWriter() {
1677 c.messageWriter.writeCond.Broadcast()
1680 func (c *PeerConn) sendChunk(r Request, msg func(pp.Message) bool, state *peerRequestState) (more bool) {
1681 c.lastChunkSent = time.Now()
1682 return msg(pp.Message{
1690 func (c *PeerConn) setTorrent(t *Torrent) {
1692 panic("connection already associated with a torrent")
1695 c.logger.WithDefaultLevel(log.Debug).Printf("set torrent=%v", t)
1696 t.reconcileHandshakeStats(c)
1699 func (c *Peer) peerPriority() (peerPriority, error) {
1700 return bep40Priority(c.remoteIpPort(), c.t.cl.publicAddr(c.remoteIp()))
1703 func (c *Peer) remoteIp() net.IP {
1704 host, _, _ := net.SplitHostPort(c.RemoteAddr.String())
1705 return net.ParseIP(host)
1708 func (c *Peer) remoteIpPort() IpPort {
1709 ipa, _ := tryIpPortFromNetAddr(c.RemoteAddr)
1710 return IpPort{ipa.IP, uint16(ipa.Port)}
1713 func (c *PeerConn) pexPeerFlags() pp.PexPeerFlags {
1714 f := pp.PexPeerFlags(0)
1715 if c.PeerPrefersEncryption {
1716 f |= pp.PexPrefersEncryption
1719 f |= pp.PexOutgoingConn
1722 f |= pp.PexSupportsUtp
1727 // This returns the address to use if we want to dial the peer again. It incorporates the peer's
1728 // advertised listen port.
1729 func (c *PeerConn) dialAddr() PeerRemoteAddr {
1730 if !c.outgoing && c.PeerListenPort != 0 {
1731 switch addr := c.RemoteAddr.(type) {
1734 dialAddr.Port = c.PeerListenPort
1738 dialAddr.Port = c.PeerListenPort
1745 func (c *PeerConn) pexEvent(t pexEventType) pexEvent {
1746 f := c.pexPeerFlags()
1747 addr := c.dialAddr()
1748 return pexEvent{t, addr, f, nil}
1751 func (c *PeerConn) String() string {
1752 return fmt.Sprintf("%T %p [id=%q, exts=%v, v=%q]", c, c, c.PeerID, c.PeerExtensionBytes, c.PeerClientName.Load())
1755 func (c *Peer) trust() connectionTrust {
1756 return connectionTrust{c.trusted, c.netGoodPiecesDirtied()}
1759 type connectionTrust struct {
1761 NetGoodPiecesDirted int64
1764 func (l connectionTrust) Less(r connectionTrust) bool {
1765 return multiless.New().Bool(l.Implicit, r.Implicit).Int64(l.NetGoodPiecesDirted, r.NetGoodPiecesDirted).Less()
1768 // Returns the pieces the peer could have based on their claims. If we don't know how many pieces
1769 // are in the torrent, it could be a very large range the peer has sent HaveAll.
1770 func (cn *PeerConn) PeerPieces() *roaring.Bitmap {
1772 defer cn.locker().RUnlock()
1773 return cn.newPeerPieces()
1776 // Returns a new Bitmap that includes bits for all pieces the peer could have based on their claims.
1777 func (cn *Peer) newPeerPieces() *roaring.Bitmap {
1778 // TODO: Can we use copy on write?
1779 ret := cn.peerPieces().Clone()
1780 if all, _ := cn.peerHasAllPieces(); all {
1781 if cn.t.haveInfo() {
1782 ret.AddRange(0, bitmap.BitRange(cn.t.numPieces()))
1784 ret.AddRange(0, bitmap.ToEnd)
1790 func (cn *Peer) stats() *ConnStats {
1794 func (p *Peer) TryAsPeerConn() (*PeerConn, bool) {
1795 pc, ok := p.peerImpl.(*PeerConn)
1799 func (p *Peer) uncancelledRequests() uint64 {
1800 return p.requestState.Requests.GetCardinality()
1803 func (pc *PeerConn) remoteIsTransmission() bool {
1804 return bytes.HasPrefix(pc.PeerID[:], []byte("-TR")) && pc.PeerID[7] == '-'