import (
"bufio"
"bytes"
+ "context"
"errors"
"fmt"
"io"
"math/rand"
"net"
+ "net/netip"
"strconv"
"strings"
"sync/atomic"
"time"
"github.com/RoaringBitmap/roaring"
- "github.com/anacrolix/chansync"
+ "github.com/anacrolix/generics"
. "github.com/anacrolix/generics"
"github.com/anacrolix/log"
- "github.com/anacrolix/missinggo/iter"
"github.com/anacrolix/missinggo/v2/bitmap"
"github.com/anacrolix/multiless"
+ "golang.org/x/exp/maps"
+ "golang.org/x/time/rate"
+
"github.com/anacrolix/torrent/bencode"
+ "github.com/anacrolix/torrent/internal/alloclim"
"github.com/anacrolix/torrent/metainfo"
"github.com/anacrolix/torrent/mse"
pp "github.com/anacrolix/torrent/peer_protocol"
- request_strategy "github.com/anacrolix/torrent/request-strategy"
- "github.com/anacrolix/torrent/typed-roaring"
-)
-
-type PeerSource string
-
-const (
- PeerSourceTracker = "Tr"
- PeerSourceIncoming = "I"
- PeerSourceDhtGetPeers = "Hg" // Peers we found by searching a DHT.
- PeerSourceDhtAnnouncePeer = "Ha" // Peers that were announced to us by a DHT.
- PeerSourcePex = "X"
- // The peer was given directly, such as through a magnet link.
- PeerSourceDirect = "M"
+ utHolepunch "github.com/anacrolix/torrent/peer_protocol/ut-holepunch"
)
-type peerRequestState struct {
- data []byte
-}
-
-type PeerRemoteAddr interface {
- String() string
-}
-
-type (
- // Since we have to store all the requests in memory, we can't reasonably exceed what could be
- // indexed with the memory space available.
- maxRequests = int
-)
-
-type Peer struct {
- // First to ensure 64-bit alignment for atomics. See #262.
- _stats ConnStats
-
- t *Torrent
-
- peerImpl
- callbacks *Callbacks
-
- outgoing bool
- Network string
- RemoteAddr PeerRemoteAddr
- bannableAddr Option[bannableAddr]
- // True if the connection is operating over MSE obfuscation.
- headerEncrypted bool
- cryptoMethod mse.CryptoMethod
- Discovery PeerSource
- trusted bool
- closed chansync.SetOnce
- // Set true after we've added our ConnStats generated during handshake to
- // other ConnStat instances as determined when the *Torrent became known.
- reconciledHandshakeStats bool
-
- lastMessageReceived time.Time
- completedHandshake time.Time
- lastUsefulChunkReceived time.Time
- lastChunkSent time.Time
-
- // Stuff controlled by the local peer.
- needRequestUpdate string
- requestState request_strategy.PeerRequestState
- updateRequestsTimer *time.Timer
- lastRequestUpdate time.Time
- peakRequests maxRequests
- lastBecameInterested time.Time
- priorInterest time.Duration
-
- lastStartedExpectingToReceiveChunks time.Time
- cumulativeExpectedToReceiveChunks time.Duration
- _chunksReceivedWhileExpecting int64
-
- choking bool
- piecesReceivedSinceLastRequestUpdate maxRequests
- maxPiecesReceivedBetweenRequestUpdates maxRequests
- // Chunks that we might reasonably expect to receive from the peer. Due to latency, buffering,
- // and implementation differences, we may receive chunks that are no longer in the set of
- // requests actually want. This could use a roaring.BSI if the memory use becomes noticeable.
- validReceiveChunks map[RequestIndex]int
- // Indexed by metadata piece, set to true if posted and pending a
- // response.
- metadataRequests []bool
- sentHaves bitmap.Bitmap
-
- // Stuff controlled by the remote peer.
- peerInterested bool
- peerChoking bool
- peerRequests map[Request]*peerRequestState
- PeerPrefersEncryption bool // as indicated by 'e' field in extension handshake
- PeerListenPort int
- // The highest possible number of pieces the torrent could have based on
- // communication with the peer. Generally only useful until we have the
- // torrent info.
- peerMinPieces pieceIndex
- // Pieces we've accepted chunks for from the peer.
- peerTouchedPieces map[pieceIndex]struct{}
- peerAllowedFast typedRoaring.Bitmap[pieceIndex]
-
- PeerMaxRequests maxRequests // Maximum pending requests the peer allows.
- PeerExtensionIDs map[pp.ExtensionName]pp.ExtensionNumber
- PeerClientName atomic.Value
-
- logger log.Logger
-}
-
-type peerRequests = orderedBitmap[RequestIndex]
-
-func (p *Peer) initRequestState() {
- p.requestState.Requests = &peerRequests{}
-}
-
// Maintains the state of a BitTorrent-protocol based connection with a peer.
type PeerConn struct {
Peer
// See BEP 3 etc.
PeerID PeerID
PeerExtensionBytes pp.PeerExtensionBits
+ PeerListenPort int
// The actual Conn, used for closing, and setting socket options. Do not use methods on this
// while holding any mutexes.
messageWriter peerConnMsgWriter
- uploadTimer *time.Timer
- pex pexConnState
+ PeerExtensionIDs map[pp.ExtensionName]pp.ExtensionNumber
+ PeerClientName atomic.Value
+ uploadTimer *time.Timer
+ pex pexConnState
// The pieces the peer has claimed to have.
_peerPieces roaring.Bitmap
// The peer has everything. This can occur due to a special message, when
// we may not even know the number of pieces in the torrent yet.
peerSentHaveAll bool
-}
-func (cn *PeerConn) connStatusString() string {
- return fmt.Sprintf("%+-55q %s %s", cn.PeerID, cn.PeerExtensionBytes, cn.connString)
-}
+ peerRequestDataAllocLimiter alloclim.Limiter
-func (cn *Peer) updateExpectingChunks() {
- if cn.expectingChunks() {
- if cn.lastStartedExpectingToReceiveChunks.IsZero() {
- cn.lastStartedExpectingToReceiveChunks = time.Now()
- }
- } else {
- if !cn.lastStartedExpectingToReceiveChunks.IsZero() {
- cn.cumulativeExpectedToReceiveChunks += time.Since(cn.lastStartedExpectingToReceiveChunks)
- cn.lastStartedExpectingToReceiveChunks = time.Time{}
- }
- }
+ outstandingHolepunchingRendezvous map[netip.AddrPort]struct{}
}
-func (cn *Peer) expectingChunks() bool {
- if cn.requestState.Requests.IsEmpty() {
- return false
+func (cn *PeerConn) pexStatus() string {
+ if !cn.bitExtensionEnabled(pp.ExtensionBitLtep) {
+ return "extended protocol disabled"
}
- if !cn.requestState.Interested {
- return false
+ if cn.PeerExtensionIDs == nil {
+ return "pending extended handshake"
}
- if !cn.peerChoking {
- return true
+ if !cn.supportsExtension(pp.ExtensionNamePex) {
+ return "unsupported"
+ }
+ if true {
+ return fmt.Sprintf(
+ "%v conns, %v unsent events",
+ len(cn.pex.remoteLiveConns),
+ cn.pex.numPending(),
+ )
+ } else {
+ // This alternative branch prints out the remote live conn addresses.
+ return fmt.Sprintf(
+ "%v conns, %v unsent events",
+ strings.Join(generics.SliceMap(
+ maps.Keys(cn.pex.remoteLiveConns),
+ func(from netip.AddrPort) string {
+ return from.String()
+ }), ","),
+ cn.pex.numPending(),
+ )
}
- haveAllowedFastRequests := false
- cn.peerAllowedFast.Iterate(func(i pieceIndex) bool {
- haveAllowedFastRequests = roaringBitmapRangeCardinality[RequestIndex](
- cn.requestState.Requests,
- cn.t.pieceRequestIndexOffset(i),
- cn.t.pieceRequestIndexOffset(i+1),
- ) == 0
- return !haveAllowedFastRequests
- })
- return haveAllowedFastRequests
}
-func (cn *Peer) remoteChokingPiece(piece pieceIndex) bool {
- return cn.peerChoking && !cn.peerAllowedFast.Contains(piece)
+func (cn *PeerConn) peerImplStatusLines() []string {
+ return []string{
+ cn.connString,
+ fmt.Sprintf("peer id: %+q", cn.PeerID),
+ fmt.Sprintf("extensions: %v", cn.PeerExtensionBytes),
+ fmt.Sprintf("ltep extensions: %v", cn.PeerExtensionIDs),
+ fmt.Sprintf("pex: %s", cn.pexStatus()),
+ }
}
// Returns true if the connection is over IPv6.
return len(ip) == net.IPv6len
}
-// Returns true the if the dialer/initiator has the lower client peer ID. TODO: Find the
-// specification for this.
+// Returns true the if the dialer/initiator has the higher client peer ID. See
+// https://github.com/arvidn/libtorrent/blame/272828e1cc37b042dfbbafa539222d8533e99755/src/bt_peer_connection.cpp#L3536-L3557.
+// As far as I can tell, Transmission just keeps the oldest connection.
func (cn *PeerConn) isPreferredDirection() bool {
- return bytes.Compare(cn.t.cl.peerID[:], cn.PeerID[:]) < 0 == cn.outgoing
+ // True if our client peer ID is higher than the remote's peer ID.
+ return bytes.Compare(cn.PeerID[:], cn.t.cl.peerID[:]) < 0 == cn.outgoing
}
// Returns whether the left connection should be preferred over the right one,
return ml.Less()
}
-func (cn *Peer) cumInterest() time.Duration {
- ret := cn.priorInterest
- if cn.requestState.Interested {
- ret += time.Since(cn.lastBecameInterested)
- }
- return ret
-}
-
func (cn *PeerConn) peerHasAllPieces() (all, known bool) {
if cn.peerSentHaveAll {
return true, true
return cn._peerPieces.GetCardinality() == uint64(cn.t.numPieces()), true
}
-func (cn *Peer) locker() *lockWithDeferreds {
- return cn.t.cl.locker()
-}
-
-func (cn *Peer) supportsExtension(ext pp.ExtensionName) bool {
- _, ok := cn.PeerExtensionIDs[ext]
- return ok
-}
-
-// The best guess at number of pieces in the torrent for this peer.
-func (cn *Peer) bestPeerNumPieces() pieceIndex {
- if cn.t.haveInfo() {
- return cn.t.numPieces()
- }
- return cn.peerMinPieces
-}
-
-func (cn *Peer) completedString() string {
- have := pieceIndex(cn.peerPieces().GetCardinality())
- if all, _ := cn.peerHasAllPieces(); all {
- have = cn.bestPeerNumPieces()
- }
- return fmt.Sprintf("%d/%d", have, cn.bestPeerNumPieces())
-}
-
func (cn *PeerConn) onGotInfo(info *metainfo.Info) {
cn.setNumPieces(info.NumPieces())
}
return &cn._peerPieces
}
-func eventAgeString(t time.Time) string {
- if t.IsZero() {
- return "never"
- }
- return fmt.Sprintf("%.2fs ago", time.Since(t).Seconds())
-}
-
func (cn *PeerConn) connectionFlags() (ret string) {
c := func(b byte) {
ret += string([]byte{b})
return parseNetworkString(cn.Network).Udp
}
-// Inspired by https://github.com/transmission/transmission/wiki/Peer-Status-Text.
-func (cn *Peer) statusFlags() (ret string) {
- c := func(b byte) {
- ret += string([]byte{b})
- }
- if cn.requestState.Interested {
- c('i')
- }
- if cn.choking {
- c('c')
- }
- c('-')
- ret += cn.connectionFlags()
- c('-')
- if cn.peerInterested {
- c('i')
- }
- if cn.peerChoking {
- c('c')
- }
- return
-}
-
-func (cn *Peer) downloadRate() float64 {
- num := cn._stats.BytesReadUsefulData.Int64()
- if num == 0 {
- return 0
- }
- return float64(num) / cn.totalExpectingTime().Seconds()
-}
-
-func (cn *Peer) iterContiguousPieceRequests(f func(piece pieceIndex, count int)) {
- var last Option[pieceIndex]
- var count int
- next := func(item Option[pieceIndex]) {
- if item == last {
- count++
- } else {
- if count != 0 {
- f(last.Value(), count)
- }
- last = item
- count = 1
- }
- }
- cn.requestState.Requests.Iterate(func(requestIndex request_strategy.RequestIndex) bool {
- next(Some(cn.t.pieceIndexOfRequestIndex(requestIndex)))
- return true
- })
- next(None[pieceIndex]())
-}
-
-func (cn *Peer) writeStatus(w io.Writer, t *Torrent) {
- // \t isn't preserved in <pre> blocks?
- if cn.closed.IsSet() {
- fmt.Fprint(w, "CLOSED: ")
- }
- fmt.Fprintln(w, cn.connStatusString())
- prio, err := cn.peerPriority()
- prioStr := fmt.Sprintf("%08x", prio)
- if err != nil {
- prioStr += ": " + err.Error()
- }
- fmt.Fprintf(w, " bep40-prio: %v\n", prioStr)
- fmt.Fprintf(w, " last msg: %s, connected: %s, last helpful: %s, itime: %s, etime: %s\n",
- eventAgeString(cn.lastMessageReceived),
- eventAgeString(cn.completedHandshake),
- eventAgeString(cn.lastHelpful()),
- cn.cumInterest(),
- cn.totalExpectingTime(),
- )
- fmt.Fprintf(w,
- " %s completed, %d pieces touched, good chunks: %v/%v:%v reqq: %d+%v/(%d/%d):%d/%d, flags: %s, dr: %.1f KiB/s\n",
- cn.completedString(),
- len(cn.peerTouchedPieces),
- &cn._stats.ChunksReadUseful,
- &cn._stats.ChunksRead,
- &cn._stats.ChunksWritten,
- cn.requestState.Requests.GetCardinality(),
- cn.requestState.Cancelled.GetCardinality(),
- cn.nominalMaxRequests(),
- cn.PeerMaxRequests,
- len(cn.peerRequests),
- localClientReqq,
- cn.statusFlags(),
- cn.downloadRate()/(1<<10),
- )
- fmt.Fprintf(w, " requested pieces:")
- cn.iterContiguousPieceRequests(func(piece pieceIndex, count int) {
- fmt.Fprintf(w, " %v(%v)", piece, count)
- })
- fmt.Fprintf(w, "\n")
-}
-
-func (p *Peer) close() {
- if !p.closed.Set() {
- return
- }
- if p.updateRequestsTimer != nil {
- p.updateRequestsTimer.Stop()
- }
- p.peerImpl.onClose()
- if p.t != nil {
- p.t.decPeerPieceAvailability(p)
- }
- for _, f := range p.callbacks.PeerClosed {
- f(p)
- }
-}
-
func (cn *PeerConn) onClose() {
if cn.pex.IsEnabled() {
cn.pex.Close()
}
}
-// Peer definitely has a piece, for purposes of requesting. So it's not sufficient that we think
-// they do (known=true).
-func (cn *Peer) peerHasPiece(piece pieceIndex) bool {
- if all, known := cn.peerHasAllPieces(); all && known {
- return true
- }
- return cn.peerPieces().ContainsInt(piece)
-}
-
-// 64KiB, but temporarily less to work around an issue with WebRTC. TODO: Update when
-// https://github.com/pion/datachannel/issues/59 is fixed.
-const (
- writeBufferHighWaterLen = 1 << 15
- writeBufferLowWaterLen = writeBufferHighWaterLen / 2
-)
-
// Writes a message into the write buffer. Returns whether it's okay to keep writing. Writing is
// done asynchronously, so it may be that we're not able to honour backpressure from this method.
func (cn *PeerConn) write(msg pp.Message) bool {
return index < len(cn.metadataRequests) && cn.metadataRequests[index]
}
-var (
- interestedMsgLen = len(pp.Message{Type: pp.Interested}.MustMarshalBinary())
- requestMsgLen = len(pp.Message{Type: pp.Request}.MustMarshalBinary())
- // This is the maximum request count that could fit in the write buffer if it's at or below the
- // low water mark when we run maybeUpdateActualRequestState.
- maxLocalToRemoteRequests = (writeBufferHighWaterLen - writeBufferLowWaterLen - interestedMsgLen) / requestMsgLen
-)
-
-// The actual value to use as the maximum outbound requests.
-func (cn *Peer) nominalMaxRequests() maxRequests {
- return maxRequests(maxInt(1, minInt(cn.PeerMaxRequests, cn.peakRequests*2, maxLocalToRemoteRequests)))
-}
-
-func (cn *Peer) totalExpectingTime() (ret time.Duration) {
- ret = cn.cumulativeExpectedToReceiveChunks
- if !cn.lastStartedExpectingToReceiveChunks.IsZero() {
- ret += time.Since(cn.lastStartedExpectingToReceiveChunks)
- }
- return
-}
-
func (cn *PeerConn) onPeerSentCancel(r Request) {
if _, ok := cn.peerRequests[r]; !ok {
torrent.Add("unexpected cancels received", 1)
Type: pp.Choke,
})
if !cn.fastEnabled() {
- cn.peerRequests = nil
+ cn.deleteAllPeerRequests()
}
return
}
+func (cn *PeerConn) deleteAllPeerRequests() {
+ for _, state := range cn.peerRequests {
+ state.allocReservation.Drop()
+ }
+ cn.peerRequests = nil
+}
+
func (cn *PeerConn) unchoke(msg func(pp.Message) bool) bool {
if !cn.choking {
return true
})
}
-func (cn *Peer) setInterested(interested bool) bool {
- if cn.requestState.Interested == interested {
- return true
- }
- cn.requestState.Interested = interested
- if interested {
- cn.lastBecameInterested = time.Now()
- } else if !cn.lastBecameInterested.IsZero() {
- cn.priorInterest += time.Since(cn.lastBecameInterested)
- }
- cn.updateExpectingChunks()
- // log.Printf("%p: setting interest: %v", cn, interested)
- return cn.writeInterested(interested)
-}
-
func (pc *PeerConn) writeInterested(interested bool) bool {
return pc.write(pp.Message{
Type: func() pp.MessageType {
})
}
-// The function takes a message to be sent, and returns true if more messages
-// are okay.
-type messageWriter func(pp.Message) bool
-
-// This function seems to only used by Peer.request. It's all logic checks, so maybe we can no-op it
-// when we want to go fast.
-func (cn *Peer) shouldRequest(r RequestIndex) error {
- pi := cn.t.pieceIndexOfRequestIndex(r)
- if cn.requestState.Cancelled.Contains(r) {
- return errors.New("request is cancelled and waiting acknowledgement")
- }
- if !cn.peerHasPiece(pi) {
- return errors.New("requesting piece peer doesn't have")
- }
- if !cn.t.peerIsActive(cn) {
- panic("requesting but not in active conns")
- }
- if cn.closed.IsSet() {
- panic("requesting when connection is closed")
- }
- if cn.t.hashingPiece(pi) {
- panic("piece is being hashed")
- }
- if cn.t.pieceQueuedForHash(pi) {
- panic("piece is queued for hash")
- }
- if cn.peerChoking && !cn.peerAllowedFast.Contains(pi) {
- // This could occur if we made a request with the fast extension, and then got choked and
- // haven't had the request rejected yet.
- if !cn.requestState.Requests.Contains(r) {
- panic("peer choking and piece not allowed fast")
- }
- }
- return nil
-}
-
-func (cn *Peer) mustRequest(r RequestIndex) bool {
- more, err := cn.request(r)
- if err != nil {
- panic(err)
- }
- return more
-}
-
-func (cn *Peer) request(r RequestIndex) (more bool, err error) {
- if err := cn.shouldRequest(r); err != nil {
- panic(err)
- }
- if cn.requestState.Requests.Contains(r) {
- return true, nil
- }
- if maxRequests(cn.requestState.Requests.GetCardinality()) >= cn.nominalMaxRequests() {
- return true, errors.New("too many outstanding requests")
- }
- cn.requestState.Requests.Add(r)
- if cn.validReceiveChunks == nil {
- cn.validReceiveChunks = make(map[RequestIndex]int)
- }
- cn.validReceiveChunks[r]++
- cn.t.requestState[r] = requestState{
- peer: cn,
- when: time.Now(),
- }
- cn.updateExpectingChunks()
- ppReq := cn.t.requestIndexToRequest(r)
- for _, f := range cn.callbacks.SentRequest {
- f(PeerRequestEvent{cn, ppReq})
- }
- return cn.peerImpl._request(ppReq), nil
-}
-
func (me *PeerConn) _request(r Request) bool {
return me.write(pp.Message{
Type: pp.Request,
})
}
-func (me *Peer) cancel(r RequestIndex) {
- if !me.deleteRequest(r) {
- panic("request not existing should have been guarded")
- }
- if me._cancel(r) {
- if !me.requestState.Cancelled.CheckedAdd(r) {
- panic("request already cancelled")
- }
- }
- me.decPeakRequests()
- if me.isLowOnRequests() {
- me.updateRequests("Peer.cancel")
- }
-}
-
func (me *PeerConn) _cancel(r RequestIndex) bool {
me.write(makeCancelMessage(me.t.requestIndexToRequest(r)))
// Transmission does not send rejects for received cancels. See
cn.sentHaves = bitmap.Bitmap{cn.t._completedPieces.Clone()}
}
-// Sets a reason to update requests, and if there wasn't already one, handle it.
-func (cn *Peer) updateRequests(reason string) {
- if cn.needRequestUpdate != "" {
- return
- }
- if reason != peerUpdateRequestsTimerReason && !cn.isLowOnRequests() {
- return
- }
- cn.needRequestUpdate = reason
- cn.handleUpdateRequests()
-}
-
func (cn *PeerConn) handleUpdateRequests() {
// The writer determines the request state as needed when it can write.
cn.tickleWriter()
}
-// Emits the indices in the Bitmaps bms in order, never repeating any index.
-// skip is mutated during execution, and its initial values will never be
-// emitted.
-func iterBitmapsDistinct(skip *bitmap.Bitmap, bms ...bitmap.Bitmap) iter.Func {
- return func(cb iter.Callback) {
- for _, bm := range bms {
- if !iter.All(
- func(_i interface{}) bool {
- i := _i.(int)
- if skip.Contains(bitmap.BitIndex(i)) {
- return true
- }
- skip.Add(bitmap.BitIndex(i))
- return cb(i)
- },
- bm.Iter,
- ) {
- return
- }
- }
- }
-}
-
-func (cn *Peer) peerPiecesChanged() {
- cn.t.maybeDropMutuallyCompletePeer(cn)
-}
-
func (cn *PeerConn) raisePeerMinPieces(newMin pieceIndex) {
if newMin > cn.peerMinPieces {
cn.peerMinPieces = newMin
}
func (cn *PeerConn) peerSentHaveNone() error {
- if cn.peerSentHaveAll {
+ if !cn.peerSentHaveAll {
cn.t.decPeerPieceAvailability(&cn.Peer)
}
cn._peerPieces.Clear()
cn.allStats(func(cs *ConnStats) { cs.wroteMsg(msg) })
}
-// After handshake, we know what Torrent and Client stats to include for a
-// connection.
-func (cn *Peer) postHandshakeStats(f func(*ConnStats)) {
- t := cn.t
- f(&t.stats)
- f(&t.cl.stats)
-}
-
-// All ConnStats that include this connection. Some objects are not known
-// until the handshake is complete, after which it's expected to reconcile the
-// differences.
-func (cn *Peer) allStats(f func(*ConnStats)) {
- f(&cn._stats)
- if cn.reconciledHandshakeStats {
- cn.postHandshakeStats(f)
- }
-}
-
func (cn *PeerConn) wroteBytes(n int64) {
cn.allStats(add(n, func(cs *ConnStats) *Count { return &cs.BytesWritten }))
}
-func (cn *Peer) readBytes(n int64) {
- cn.allStats(add(n, func(cs *ConnStats) *Count { return &cs.BytesRead }))
-}
-
-// Returns whether the connection could be useful to us. We're seeding and
-// they want data, we don't have metainfo and they can provide it, etc.
-func (c *Peer) useful() bool {
- t := c.t
- if c.closed.IsSet() {
- return false
- }
- if !t.haveInfo() {
- return c.supportsExtension("ut_metadata")
- }
- if t.seeding() && c.peerInterested {
- return true
- }
- if c.peerHasWantedPieces() {
- return true
- }
- return false
-}
-
-func (c *Peer) lastHelpful() (ret time.Time) {
- ret = c.lastUsefulChunkReceived
- if c.t.seeding() && c.lastChunkSent.After(ret) {
- ret = c.lastChunkSent
- }
- return
-}
-
func (c *PeerConn) fastEnabled() bool {
return c.PeerExtensionBytes.SupportsFast() && c.t.cl.config.Extensions.SupportsFast()
}
panic("fast not enabled")
}
c.write(r.ToMsg(pp.Reject))
- delete(c.peerRequests, r)
+ // It is possible to reject a request before it is added to peer requests due to being invalid.
+ if state, ok := c.peerRequests[r]; ok {
+ state.allocReservation.Drop()
+ delete(c.peerRequests, r)
+ }
+}
+
+func (c *PeerConn) maximumPeerRequestChunkLength() (_ Option[int]) {
+ uploadRateLimiter := c.t.cl.config.UploadRateLimiter
+ if uploadRateLimiter.Limit() == rate.Inf {
+ return
+ }
+ return Some(uploadRateLimiter.Burst())
}
-func (c *PeerConn) onReadRequest(r Request) error {
+// startFetch is for testing purposes currently.
+func (c *PeerConn) onReadRequest(r Request, startFetch bool) error {
requestedChunkLengths.Add(strconv.FormatUint(r.Length.Uint64(), 10), 1)
if _, ok := c.peerRequests[r]; ok {
torrent.Add("duplicate requests received", 1)
+ if c.fastEnabled() {
+ return errors.New("received duplicate request with fast enabled")
+ }
return nil
}
if c.choking {
// BEP 6 says we may close here if we choose.
return nil
}
+ if opt := c.maximumPeerRequestChunkLength(); opt.Ok && int(r.Length) > opt.Value {
+ err := fmt.Errorf("peer requested chunk too long (%v)", r.Length)
+ c.logger.Levelf(log.Warning, err.Error())
+ if c.fastEnabled() {
+ c.reject(r)
+ return nil
+ } else {
+ return err
+ }
+ }
if !c.t.havePiece(pieceIndex(r.Index)) {
- // This isn't necessarily them screwing up. We can drop pieces
- // from our storage, and can't communicate this to peers
- // except by reconnecting.
+ // TODO: Tell the peer we don't have the piece, and reject this request.
requestsReceivedForMissingPieces.Add(1)
return fmt.Errorf("peer requested piece we don't have: %v", r.Index.Int())
}
+ pieceLength := c.t.pieceLength(pieceIndex(r.Index))
// Check this after we know we have the piece, so that the piece length will be known.
- if r.Begin+r.Length > c.t.pieceLength(pieceIndex(r.Index)) {
+ if chunkOverflowsPiece(r.ChunkSpec, pieceLength) {
torrent.Add("bad requests received", 1)
- return errors.New("bad Request")
+ return errors.New("chunk overflows piece")
}
if c.peerRequests == nil {
c.peerRequests = make(map[Request]*peerRequestState, localClientReqq)
}
- value := &peerRequestState{}
+ value := &peerRequestState{
+ allocReservation: c.peerRequestDataAllocLimiter.Reserve(int64(r.Length)),
+ }
c.peerRequests[r] = value
- go c.peerRequestDataReader(r, value)
+ if startFetch {
+ // TODO: Limit peer request data read concurrency.
+ go c.peerRequestDataReader(r, value)
+ }
return nil
}
func (c *PeerConn) peerRequestDataReader(r Request, prs *peerRequestState) {
- b, err := readPeerRequestData(r, c)
+ // Should we depend on Torrent closure here? I think it's okay to get cancelled from elsewhere,
+ // or fail to read and then cleanup. Also, we used to hang here if the reservation was never
+ // dropped, that was fixed.
+ ctx := context.Background()
+ err := prs.allocReservation.Wait(ctx)
+ if err != nil {
+ c.logger.WithDefaultLevel(log.Debug).Levelf(log.ErrorLevel(err), "waiting for alloc limit reservation: %v", err)
+ return
+ }
+ b, err := c.readPeerRequestData(r)
c.locker().Lock()
defer c.locker().Unlock()
if err != nil {
}
torrent.Add("peer request data read successes", 1)
prs.data = b
+ // This might be required for the error case too (#752 and #753).
c.tickleWriter()
}
}
// https://github.com/anacrolix/torrent/issues/702#issuecomment-1000953313.
logLevel = log.Debug
}
- c.logger.WithDefaultLevel(logLevel).Printf("error reading chunk for peer Request %v: %v", r, err)
+ c.logger.Levelf(logLevel, "error reading chunk for peer Request %v: %v", r, err)
if c.t.closed.IsSet() {
return
}
}
}
-func readPeerRequestData(r Request, c *PeerConn) ([]byte, error) {
+func (c *PeerConn) readPeerRequestData(r Request) ([]byte, error) {
b := make([]byte, r.Length)
p := c.t.info.Piece(int(r.Index))
n, err := c.t.readAt(b, p.Offset()+int64(r.Begin))
return b, err
}
-func runSafeExtraneous(f func()) {
- if true {
- go f()
- } else {
- f()
- }
-}
-
func (c *PeerConn) logProtocolBehaviour(level log.Level, format string, arg ...interface{}) {
c.logger.WithContextText(fmt.Sprintf(
"peer id %q, ext v %q", c.PeerID, c.PeerClientName.Load(),
err = c.peerSentBitfield(msg.Bitfield)
case pp.Request:
r := newRequestFromMessage(&msg)
- err = c.onReadRequest(r)
+ err = c.onReadRequest(r, true)
+ if err != nil {
+ err = fmt.Errorf("on reading request %v: %w", r, err)
+ }
case pp.Piece:
c.doChunkReadStats(int64(len(msg.Piece)))
err = c.receiveChunk(&msg)
case pp.Reject:
req := newRequestFromMessage(&msg)
if !c.remoteRejectedRequest(c.t.requestIndexFromRequest(req)) {
- c.logger.Printf("received invalid reject [request=%v, peer=%v]", req, c)
- err = fmt.Errorf("received invalid reject [request=%v]", req)
+ err = fmt.Errorf("received invalid reject for request %v", req)
+ c.logger.Levelf(log.Debug, "%v", err)
}
case pp.AllowedFast:
torrent.Add("allowed fasts received", 1)
}
}
-// Returns true if it was valid to reject the request.
-func (c *Peer) remoteRejectedRequest(r RequestIndex) bool {
- if c.deleteRequest(r) {
- c.decPeakRequests()
- } else if !c.requestState.Cancelled.CheckedRemove(r) {
- return false
- }
- if c.isLowOnRequests() {
- c.updateRequests("Peer.remoteRejectedRequest")
- }
- c.decExpectedChunkReceive(r)
- return true
-}
-
-func (c *Peer) decExpectedChunkReceive(r RequestIndex) {
- count := c.validReceiveChunks[r]
- if count == 1 {
- delete(c.validReceiveChunks, r)
- } else if count > 1 {
- c.validReceiveChunks[r] = count - 1
- } else {
- panic(r)
- }
-}
-
func (c *PeerConn) onReadExtendedMsg(id pp.ExtensionNumber, payload []byte) (err error) {
defer func() {
// TODO: Should we still do this?
c.requestPendingMetadata()
if !t.cl.config.DisablePEX {
t.pex.Add(c) // we learnt enough now
+ // This checks the extension is supported internally.
c.pex.Init(c)
}
return nil
if !c.pex.IsEnabled() {
return nil // or hang-up maybe?
}
- return c.pex.Recv(payload)
+ err = c.pex.Recv(payload)
+ if err != nil {
+ err = fmt.Errorf("receiving pex message: %w", err)
+ }
+ return
+ case utHolepunchExtendedId:
+ var msg utHolepunch.Msg
+ err = msg.UnmarshalBinary(payload)
+ if err != nil {
+ err = fmt.Errorf("unmarshalling ut_holepunch message: %w", err)
+ return
+ }
+ err = c.t.handleReceivedUtHolepunchMsg(msg, c)
+ return
default:
return fmt.Errorf("unexpected extended message ID: %v", id)
}
}{cn.r, cn.w}
}
-func (c *Peer) doChunkReadStats(size int64) {
- c.allStats(func(cs *ConnStats) { cs.receivedChunk(size) })
-}
-
-// Handle a received chunk from a peer.
-func (c *Peer) receiveChunk(msg *pp.Message) error {
- chunksReceived.Add("total", 1)
-
- ppReq := newRequestFromMessage(msg)
- req := c.t.requestIndexFromRequest(ppReq)
- t := c.t
-
- if c.bannableAddr.Ok() {
- t.smartBanCache.RecordBlock(c.bannableAddr.Value(), req, msg.Piece)
- }
-
- if c.peerChoking {
- chunksReceived.Add("while choked", 1)
- }
-
- if c.validReceiveChunks[req] <= 0 {
- chunksReceived.Add("unexpected", 1)
- return errors.New("received unexpected chunk")
- }
- c.decExpectedChunkReceive(req)
-
- if c.peerChoking && c.peerAllowedFast.Contains(pieceIndex(ppReq.Index)) {
- chunksReceived.Add("due to allowed fast", 1)
- }
-
- // The request needs to be deleted immediately to prevent cancels occurring asynchronously when
- // have actually already received the piece, while we have the Client unlocked to write the data
- // out.
- intended := false
- {
- if c.requestState.Requests.Contains(req) {
- for _, f := range c.callbacks.ReceivedRequested {
- f(PeerMessageEvent{c, msg})
- }
- }
- // Request has been satisfied.
- if c.deleteRequest(req) || c.requestState.Cancelled.CheckedRemove(req) {
- intended = true
- if !c.peerChoking {
- c._chunksReceivedWhileExpecting++
- }
- if c.isLowOnRequests() {
- c.updateRequests("Peer.receiveChunk deleted request")
- }
- } else {
- chunksReceived.Add("unintended", 1)
- }
- }
-
- cl := t.cl
-
- // Do we actually want this chunk?
- if t.haveChunk(ppReq) {
- // panic(fmt.Sprintf("%+v", ppReq))
- chunksReceived.Add("redundant", 1)
- c.allStats(add(1, func(cs *ConnStats) *Count { return &cs.ChunksReadWasted }))
- return nil
- }
-
- piece := &t.pieces[ppReq.Index]
-
- c.allStats(add(1, func(cs *ConnStats) *Count { return &cs.ChunksReadUseful }))
- c.allStats(add(int64(len(msg.Piece)), func(cs *ConnStats) *Count { return &cs.BytesReadUsefulData }))
- if intended {
- c.piecesReceivedSinceLastRequestUpdate++
- c.allStats(add(int64(len(msg.Piece)), func(cs *ConnStats) *Count { return &cs.BytesReadUsefulIntendedData }))
- }
- for _, f := range c.t.cl.config.Callbacks.ReceivedUsefulData {
- f(ReceivedUsefulDataEvent{c, msg})
- }
- c.lastUsefulChunkReceived = time.Now()
-
- // Need to record that it hasn't been written yet, before we attempt to do
- // anything with it.
- piece.incrementPendingWrites()
- // Record that we have the chunk, so we aren't trying to download it while
- // waiting for it to be written to storage.
- piece.unpendChunkIndex(chunkIndexFromChunkSpec(ppReq.ChunkSpec, t.chunkSize))
-
- // Cancel pending requests for this chunk from *other* peers.
- if p := t.requestingPeer(req); p != nil {
- if p == c {
- panic("should not be pending request from conn that just received it")
- }
- p.cancel(req)
- }
-
- err := func() error {
- cl.unlock()
- defer cl.lock()
- concurrentChunkWrites.Add(1)
- defer concurrentChunkWrites.Add(-1)
- // Write the chunk out. Note that the upper bound on chunk writing concurrency will be the
- // number of connections. We write inline with receiving the chunk (with this lock dance),
- // because we want to handle errors synchronously and I haven't thought of a nice way to
- // defer any concurrency to the storage and have that notify the client of errors. TODO: Do
- // that instead.
- return t.writeChunk(int(msg.Index), int64(msg.Begin), msg.Piece)
- }()
-
- piece.decrementPendingWrites()
-
- if err != nil {
- c.logger.WithDefaultLevel(log.Error).Printf("writing received chunk %v: %v", req, err)
- t.pendRequest(req)
- // Necessary to pass TestReceiveChunkStorageFailureSeederFastExtensionDisabled. I think a
- // request update runs while we're writing the chunk that just failed. Then we never do a
- // fresh update after pending the failed request.
- c.updateRequests("Peer.receiveChunk error writing chunk")
- t.onWriteChunkErr(err)
- return nil
- }
-
- c.onDirtiedPiece(pieceIndex(ppReq.Index))
-
- // We need to ensure the piece is only queued once, so only the last chunk writer gets this job.
- if t.pieceAllDirty(pieceIndex(ppReq.Index)) && piece.pendingWrites == 0 {
- t.queuePieceCheck(pieceIndex(ppReq.Index))
- // We don't pend all chunks here anymore because we don't want code dependent on the dirty
- // chunk status (such as the haveChunk call above) to have to check all the various other
- // piece states like queued for hash, hashing etc. This does mean that we need to be sure
- // that chunk pieces are pended at an appropriate time later however.
- }
-
- cl.event.Broadcast()
- // We do this because we've written a chunk, and may change PieceState.Partial.
- t.publishPieceChange(pieceIndex(ppReq.Index))
-
- return nil
-}
-
-func (c *Peer) onDirtiedPiece(piece pieceIndex) {
- if c.peerTouchedPieces == nil {
- c.peerTouchedPieces = make(map[pieceIndex]struct{})
- }
- c.peerTouchedPieces[piece] = struct{}{}
- ds := &c.t.pieces[piece].dirtiers
- if *ds == nil {
- *ds = make(map[*Peer]struct{})
- }
- (*ds)[c] = struct{}{}
-}
-
func (c *PeerConn) uploadAllowed() bool {
if c.t.cl.config.NoUpload {
return false
cn.t.cl.banPeerIP(cn.remoteIp())
}
-func (cn *Peer) netGoodPiecesDirtied() int64 {
- return cn._stats.PiecesDirtiedGood.Int64() - cn._stats.PiecesDirtiedBad.Int64()
-}
-
-func (c *Peer) peerHasWantedPieces() bool {
- if all, _ := c.peerHasAllPieces(); all {
- return !c.t.haveAllPieces() && !c.t._pendingPieces.IsEmpty()
- }
- if !c.t.haveInfo() {
- return !c.peerPieces().IsEmpty()
- }
- return c.peerPieces().Intersects(&c.t._pendingPieces)
-}
-
-// Returns true if an outstanding request is removed. Cancelled requests should be handled
-// separately.
-func (c *Peer) deleteRequest(r RequestIndex) bool {
- if !c.requestState.Requests.CheckedRemove(r) {
- return false
- }
- for _, f := range c.callbacks.DeletedRequest {
- f(PeerRequestEvent{c, c.t.requestIndexToRequest(r)})
- }
- c.updateExpectingChunks()
- if c.t.requestingPeer(r) != c {
- panic("only one peer should have a given request at a time")
- }
- delete(c.t.requestState, r)
- // c.t.iterPeers(func(p *Peer) {
- // if p.isLowOnRequests() {
- // p.updateRequests("Peer.deleteRequest")
- // }
- // })
- return true
-}
-
-func (c *Peer) deleteAllRequests(reason string) {
- if c.requestState.Requests.IsEmpty() {
- return
- }
- c.requestState.Requests.IterateSnapshot(func(x RequestIndex) bool {
- if !c.deleteRequest(x) {
- panic("request should exist")
- }
- return true
- })
- c.assertNoRequests()
- c.t.iterPeers(func(p *Peer) {
- if p.isLowOnRequests() {
- p.updateRequests(reason)
- }
- })
- return
-}
-
-func (c *Peer) assertNoRequests() {
- if !c.requestState.Requests.IsEmpty() {
- panic(c.requestState.Requests.GetCardinality())
- }
-}
-
-func (c *Peer) cancelAllRequests() {
- c.requestState.Requests.IterateSnapshot(func(x RequestIndex) bool {
- c.cancel(x)
- return true
- })
- c.assertNoRequests()
- return
-}
-
// This is called when something has changed that should wake the writer, such as putting stuff into
// the writeBuffer, or changing some state that the writer can act on.
func (c *PeerConn) tickleWriter() {
func (c *PeerConn) sendChunk(r Request, msg func(pp.Message) bool, state *peerRequestState) (more bool) {
c.lastChunkSent = time.Now()
+ state.allocReservation.Release()
return msg(pp.Message{
Type: pp.Piece,
Index: r.Index,
t.reconcileHandshakeStats(c)
}
-func (c *Peer) peerPriority() (peerPriority, error) {
- return bep40Priority(c.remoteIpPort(), c.t.cl.publicAddr(c.remoteIp()))
-}
-
-func (c *Peer) remoteIp() net.IP {
- host, _, _ := net.SplitHostPort(c.RemoteAddr.String())
- return net.ParseIP(host)
-}
-
-func (c *Peer) remoteIpPort() IpPort {
- ipa, _ := tryIpPortFromNetAddr(c.RemoteAddr)
- return IpPort{ipa.IP, uint16(ipa.Port)}
-}
-
func (c *PeerConn) pexPeerFlags() pp.PexPeerFlags {
f := pp.PexPeerFlags(0)
if c.PeerPrefersEncryption {
// This returns the address to use if we want to dial the peer again. It incorporates the peer's
// advertised listen port.
func (c *PeerConn) dialAddr() PeerRemoteAddr {
- if !c.outgoing && c.PeerListenPort != 0 {
- switch addr := c.RemoteAddr.(type) {
- case *net.TCPAddr:
- dialAddr := *addr
- dialAddr.Port = c.PeerListenPort
- return &dialAddr
- case *net.UDPAddr:
- dialAddr := *addr
- dialAddr.Port = c.PeerListenPort
- return &dialAddr
- }
+ if c.outgoing || c.PeerListenPort == 0 {
+ return c.RemoteAddr
+ }
+ addrPort, err := addrPortFromPeerRemoteAddr(c.RemoteAddr)
+ if err != nil {
+ c.logger.Levelf(
+ log.Warning,
+ "error parsing %q for alternate dial port: %v",
+ c.RemoteAddr,
+ err,
+ )
+ return c.RemoteAddr
}
- return c.RemoteAddr
+ return netip.AddrPortFrom(addrPort.Addr(), uint16(c.PeerListenPort))
}
-func (c *PeerConn) pexEvent(t pexEventType) pexEvent {
+func (c *PeerConn) pexEvent(t pexEventType) (_ pexEvent, err error) {
f := c.pexPeerFlags()
- addr := c.dialAddr()
- return pexEvent{t, addr, f, nil}
+ dialAddr := c.dialAddr()
+ addr, err := addrPortFromPeerRemoteAddr(dialAddr)
+ if err != nil || !addr.IsValid() {
+ err = fmt.Errorf("parsing dial addr %q: %w", dialAddr, err)
+ return
+ }
+ return pexEvent{t, addr, f, nil}, nil
}
func (c *PeerConn) String() string {
- return fmt.Sprintf("%T %p [id=%q, exts=%v, v=%q]", c, c, c.PeerID, c.PeerExtensionBytes, c.PeerClientName.Load())
-}
-
-func (c *Peer) trust() connectionTrust {
- return connectionTrust{c.trusted, c.netGoodPiecesDirtied()}
-}
-
-type connectionTrust struct {
- Implicit bool
- NetGoodPiecesDirted int64
-}
-
-func (l connectionTrust) Less(r connectionTrust) bool {
- return multiless.New().Bool(l.Implicit, r.Implicit).Int64(l.NetGoodPiecesDirted, r.NetGoodPiecesDirted).Less()
+ return fmt.Sprintf("%T %p [id=%+q, exts=%v, v=%q]", c, c, c.PeerID, c.PeerExtensionBytes, c.PeerClientName.Load())
}
// Returns the pieces the peer could have based on their claims. If we don't know how many pieces
return cn.newPeerPieces()
}
-// Returns a new Bitmap that includes bits for all pieces the peer could have based on their claims.
-func (cn *Peer) newPeerPieces() *roaring.Bitmap {
- // TODO: Can we use copy on write?
- ret := cn.peerPieces().Clone()
- if all, _ := cn.peerHasAllPieces(); all {
- if cn.t.haveInfo() {
- ret.AddRange(0, bitmap.BitRange(cn.t.numPieces()))
- } else {
- ret.AddRange(0, bitmap.ToEnd)
- }
- }
- return ret
+func (pc *PeerConn) remoteIsTransmission() bool {
+ return bytes.HasPrefix(pc.PeerID[:], []byte("-TR")) && pc.PeerID[7] == '-'
}
-func (cn *Peer) stats() *ConnStats {
- return &cn._stats
+func (pc *PeerConn) remoteDialAddrPort() (netip.AddrPort, error) {
+ dialAddr := pc.dialAddr()
+ return addrPortFromPeerRemoteAddr(dialAddr)
}
-func (p *Peer) TryAsPeerConn() (*PeerConn, bool) {
- pc, ok := p.peerImpl.(*PeerConn)
- return pc, ok
+func (pc *PeerConn) bitExtensionEnabled(bit pp.ExtensionBit) bool {
+ return pc.t.cl.config.Extensions.GetBit(bit) && pc.PeerExtensionBytes.GetBit(bit)
}
-func (p *Peer) uncancelledRequests() uint64 {
- return p.requestState.Requests.GetCardinality()
+func (cn *PeerConn) peerPiecesChanged() {
+ cn.t.maybeDropMutuallyCompletePeer(cn)
}
-func (pc *PeerConn) remoteIsTransmission() bool {
- return bytes.HasPrefix(pc.PeerID[:], []byte("-TR")) && pc.PeerID[7] == '-'
+// Returns whether the connection could be useful to us. We're seeding and
+// they want data, we don't have metainfo and they can provide it, etc.
+func (c *PeerConn) useful() bool {
+ t := c.t
+ if c.closed.IsSet() {
+ return false
+ }
+ if !t.haveInfo() {
+ return c.supportsExtension("ut_metadata")
+ }
+ if t.seeding() && c.peerInterested {
+ return true
+ }
+ if c.peerHasWantedPieces() {
+ return true
+ }
+ return false
}