import (
"bufio"
"bytes"
+ "context"
+ "errors"
"fmt"
"io"
"math/rand"
"net"
+ "net/netip"
"strconv"
"strings"
- "sync"
+ "sync/atomic"
"time"
+ "github.com/RoaringBitmap/roaring"
+ "github.com/anacrolix/generics"
+ . "github.com/anacrolix/generics"
"github.com/anacrolix/log"
- "github.com/anacrolix/missinggo"
- "github.com/anacrolix/missinggo/iter"
"github.com/anacrolix/missinggo/v2/bitmap"
- "github.com/anacrolix/missinggo/v2/prioritybitmap"
"github.com/anacrolix/multiless"
- "github.com/anacrolix/torrent/metainfo"
- "github.com/pkg/errors"
+ "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"
+ utHolepunch "github.com/anacrolix/torrent/peer_protocol/ut-holepunch"
)
-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"
-)
-
-type peer struct {
- // First to ensure 64-bit alignment for atomics. See #262.
- _stats ConnStats
-
- t *Torrent
-
- peerImpl
-
- outgoing bool
- network string
- RemoteAddr net.Addr
- // True if the connection is operating over MSE obfuscation.
- headerEncrypted bool
- cryptoMethod mse.CryptoMethod
- Discovery PeerSource
- trusted bool
- closed missinggo.Event
- // 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.
- interested bool
- lastBecameInterested time.Time
- priorInterest time.Duration
-
- lastStartedExpectingToReceiveChunks time.Time
- cumulativeExpectedToReceiveChunks time.Duration
- _chunksReceivedWhileExpecting int64
-
- choking bool
- requests map[request]struct{}
- requestsLowWater int
- // 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.
- validReceiveChunks map[request]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]struct{}
- PeerPrefersEncryption bool // as indicated by 'e' field in extension handshake
- PeerListenPort int
- // The pieces the peer has claimed to have.
- _peerPieces bitmap.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
- // 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 bitmap.Bitmap
-
- PeerMaxRequests int // Maximum pending requests the peer allows.
- PeerExtensionIDs map[pp.ExtensionName]pp.ExtensionNumber
- PeerClientName string
-
- pieceInclination []int
- _pieceRequestOrder prioritybitmap.PriorityBitmap
-
- logger log.Logger
-}
-
// Maintains the state of a BitTorrent-protocol based connection with a peer.
type PeerConn struct {
- peer
+ Peer
// A string that should identify the PeerConn's net.Conn endpoints. The net.Conn could
// be wrapping WebRTC, uTP, or TCP etc. Used in writing the conn status for peers.
// See BEP 3 etc.
PeerID PeerID
PeerExtensionBytes pp.PeerExtensionBits
+ PeerListenPort int
- // The actual Conn, used for closing, and setting socket options.
+ // The actual Conn, used for closing, and setting socket options. Do not use methods on this
+ // while holding any mutexes.
conn net.Conn
// The Reader and Writer for this Conn, with hooks installed for stats,
// limiting, deadlines etc.
w io.Writer
r io.Reader
- writeBuffer *bytes.Buffer
- uploadTimer *time.Timer
- writerCond sync.Cond
+ messageWriter peerConnMsgWriter
- pex pexConnState
+ PeerExtensionIDs map[pp.ExtensionName]pp.ExtensionNumber
+ PeerClientName atomic.Value
+ uploadTimer *time.Timer
+ pex pexConnState
- callbacks *Callbacks
-}
+ // 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
+
+ peerRequestDataAllocLimiter alloclim.Limiter
-func (cn *PeerConn) connStatusString() string {
- return fmt.Sprintf("%+-55q %s %s", cn.PeerID, cn.PeerExtensionBytes, cn.connString)
+ outstandingHolepunchingRendezvous map[netip.AddrPort]struct{}
}
-func (cn *peer) updateExpectingChunks() {
- if cn.expectingChunks() {
- if cn.lastStartedExpectingToReceiveChunks.IsZero() {
- cn.lastStartedExpectingToReceiveChunks = time.Now()
- }
+func (cn *PeerConn) pexStatus() string {
+ if !cn.bitExtensionEnabled(pp.ExtensionBitLtep) {
+ return "extended protocol disabled"
+ }
+ if cn.PeerExtensionIDs == nil {
+ return "pending extended handshake"
+ }
+ 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 {
- if !cn.lastStartedExpectingToReceiveChunks.IsZero() {
- cn.cumulativeExpectedToReceiveChunks += time.Since(cn.lastStartedExpectingToReceiveChunks)
- cn.lastStartedExpectingToReceiveChunks = time.Time{}
- }
+ // 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(),
+ )
}
}
-func (cn *peer) expectingChunks() bool {
- return cn.interested && !cn.peerChoking
+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.
func (cn *PeerConn) ipv6() bool {
- ip := addrIpOrNil(cn.RemoteAddr)
+ ip := cn.remoteIp()
if ip.To4() != nil {
return false
}
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,
// considering only their networking properties. If ok is false, we can't
// decide.
-func (l *PeerConn) hasPreferredNetworkOver(r *PeerConn) (left, ok bool) {
- var ml multiLess
- ml.NextBool(l.isPreferredDirection(), r.isPreferredDirection())
- ml.NextBool(!l.utp(), !r.utp())
- ml.NextBool(l.ipv6(), r.ipv6())
- return ml.FinalOk()
+func (l *PeerConn) hasPreferredNetworkOver(r *PeerConn) bool {
+ var ml multiless.Computation
+ ml = ml.Bool(r.isPreferredDirection(), l.isPreferredDirection())
+ ml = ml.Bool(l.utp(), r.utp())
+ ml = ml.Bool(r.ipv6(), l.ipv6())
+ return ml.Less()
}
-func (cn *peer) cumInterest() time.Duration {
- ret := cn.priorInterest
- if cn.interested {
- ret += time.Since(cn.lastBecameInterested)
- }
- return ret
-}
-
-func (cn *PeerConn) peerHasAllPieces() (all bool, known bool) {
+func (cn *PeerConn) peerHasAllPieces() (all, known bool) {
if cn.peerSentHaveAll {
return true, true
}
if !cn.t.haveInfo() {
return false, false
}
- return bitmap.Flip(cn._peerPieces, 0, bitmap.BitIndex(cn.t.numPieces())).IsEmpty(), true
-}
-
-func (cn *PeerConn) locker() *lockWithDeferreds {
- return cn.t.cl.locker()
-}
-
-func (cn *PeerConn) localAddr() net.Addr {
- return cn.conn.LocalAddr()
-}
-
-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.Len())
- if cn.peerSentHaveAll {
- have = cn.bestPeerNumPieces()
- }
- return fmt.Sprintf("%d/%d", have, cn.bestPeerNumPieces())
+ return cn._peerPieces.GetCardinality() == uint64(cn.t.numPieces()), true
}
func (cn *PeerConn) onGotInfo(info *metainfo.Info) {
// Correct the PeerPieces slice length. Return false if the existing slice is invalid, such as by
// receiving badly sized BITFIELD, or invalid HAVE messages.
func (cn *PeerConn) setNumPieces(num pieceIndex) {
- cn._peerPieces.RemoveRange(bitmap.BitIndex(num), bitmap.ToEnd)
+ cn._peerPieces.RemoveRange(bitmap.BitRange(num), bitmap.ToEnd)
cn.peerPiecesChanged()
}
-func eventAgeString(t time.Time) string {
- if t.IsZero() {
- return "never"
- }
- return fmt.Sprintf("%.2fs ago", time.Since(t).Seconds())
+func (cn *PeerConn) peerPieces() *roaring.Bitmap {
+ return &cn._peerPieces
}
func (cn *PeerConn) connectionFlags() (ret string) {
}
func (cn *PeerConn) utp() bool {
- 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.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 *connection) String() string {
-// var buf bytes.Buffer
-// cn.writeStatus(&buf, nil)
-// return buf.String()
-// }
-
-func (cn *peer) downloadRate() float64 {
- return float64(cn._stats.BytesReadUsefulData.Int64()) / cn.cumInterest().Seconds()
-}
-
-func (cn *peer) writeStatus(w io.Writer, t *Torrent) {
- // \t isn't preserved in <pre> blocks?
- fmt.Fprintln(w, cn.connStatusString())
- 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,%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.requestsLowWater,
- cn.numLocalRequests(),
- cn.nominalMaxRequests(),
- len(cn.peerRequests),
- cn.statusFlags(),
- cn.downloadRate()/(1<<10),
- )
- fmt.Fprintf(w, " next pieces: %v%s\n",
- iter.ToSlice(iter.Head(10, cn.iterPendingPiecesUntyped)),
- func() string {
- if cn == t.fastestPeer {
- return " (fastest)"
- } else {
- return ""
- }
- }(),
- )
-}
-
-func (cn *peer) close() {
- if !cn.closed.Set() {
- return
- }
- cn.discardPieceInclination()
- cn._pieceRequestOrder.Clear()
- cn.peerImpl._close()
+ return parseNetworkString(cn.Network).Udp
}
-func (cn *PeerConn) _close() {
+func (cn *PeerConn) onClose() {
if cn.pex.IsEnabled() {
cn.pex.Close()
}
cn.tickleWriter()
if cn.conn != nil {
- cn.conn.Close()
+ go cn.conn.Close()
}
if cb := cn.callbacks.PeerConnClosed; cb != nil {
cb(cn)
}
}
-func (cn *peer) peerHasPiece(piece pieceIndex) bool {
- return cn.peerSentHaveAll || cn._peerPieces.Contains(bitmap.BitIndex(piece))
-}
-
-// Writes a message into the write buffer.
-func (cn *PeerConn) post(msg pp.Message) {
- torrent.Add(fmt.Sprintf("messages posted of type %s", msg.Type.String()), 1)
- // We don't need to track bytes here because a connection.w Writer wrapper
- // takes care of that (although there's some delay between us recording
- // the message, and the connection writer flushing it out.).
- cn.writeBuffer.Write(msg.MustMarshalBinary())
- // Last I checked only Piece messages affect stats, and we don't post
- // those.
- cn.wroteMsg(&msg)
- cn.tickleWriter()
-}
-
-// Returns true if there's room to write more.
+// 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 {
+ torrent.Add(fmt.Sprintf("messages written of type %s", msg.Type.String()), 1)
+ // We don't need to track bytes here because the connection's Writer has that behaviour injected
+ // (although there's some delay between us buffering the message, and the connection writer
+ // flushing it out.).
+ notFull := cn.messageWriter.write(msg)
+ // Last I checked only Piece messages affect stats, and we don't write those.
cn.wroteMsg(&msg)
- cn.writeBuffer.Write(msg.MustMarshalBinary())
- torrent.Add(fmt.Sprintf("messages filled of type %s", msg.Type.String()), 1)
- // 64KiB, but temporarily less to work around an issue with WebRTC. TODO: Update
- // when https://github.com/pion/datachannel/issues/59 is fixed.
- return cn.writeBuffer.Len() < 1<<15
+ cn.tickleWriter()
+ return notFull
}
func (cn *PeerConn) requestMetadataPiece(index int) {
eID := cn.PeerExtensionIDs[pp.ExtensionNameMetadata]
- if eID == 0 {
+ if eID == pp.ExtensionDeleteNumber {
return
}
if index < len(cn.metadataRequests) && cn.metadataRequests[index] {
return
}
cn.logger.WithDefaultLevel(log.Debug).Printf("requesting metadata piece %d", index)
- cn.post(pp.Message{
- Type: pp.Extended,
- ExtendedID: eID,
- ExtendedPayload: func() []byte {
- b, err := bencode.Marshal(map[string]int{
- "msg_type": pp.RequestMetadataExtensionMsgType,
- "piece": index,
- })
- if err != nil {
- panic(err)
- }
- return b
- }(),
- })
+ cn.write(pp.MetadataExtensionRequestMsg(eID, index))
for index >= len(cn.metadataRequests) {
cn.metadataRequests = append(cn.metadataRequests, false)
}
return index < len(cn.metadataRequests) && cn.metadataRequests[index]
}
-// The actual value to use as the maximum outbound requests.
-func (cn *peer) nominalMaxRequests() (ret int) {
- return int(clamp(
- 1,
- int64(cn.PeerMaxRequests),
- int64(cn.t.requestStrategy.nominalMaxRequests(cn.requestStrategyConnection())),
- ))
-}
-
-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) {
+func (cn *PeerConn) onPeerSentCancel(r Request) {
if _, ok := cn.peerRequests[r]; !ok {
torrent.Add("unexpected cancels received", 1)
return
more = msg(pp.Message{
Type: pp.Choke,
})
- if cn.fastEnabled() {
- for r := range cn.peerRequests {
- // TODO: Don't reject pieces in allowed fast set.
- cn.reject(r)
- }
- } else {
- cn.peerRequests = nil
+ if !cn.fastEnabled() {
+ 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.interested == interested {
- return true
- }
- cn.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
-
-func (cn *peer) request(r request) bool {
- if _, ok := cn.requests[r]; ok {
- panic("chunk already requested")
- }
- if !cn.peerHasPiece(pieceIndex(r.Index)) {
- panic("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.peerChoking {
- if cn.peerAllowedFast.Get(int(r.Index)) {
- torrent.Add("allowed fast requests sent", 1)
- } else {
- panic("requesting while choking and not allowed fast")
- }
- }
- if cn.t.hashingPiece(pieceIndex(r.Index)) {
- panic("piece is being hashed")
- }
- if cn.t.pieceQueuedForHash(pieceIndex(r.Index)) {
- panic("piece is queued for hash")
- }
- if cn.requests == nil {
- cn.requests = make(map[request]struct{})
- }
- cn.requests[r] = struct{}{}
- if cn.validReceiveChunks == nil {
- cn.validReceiveChunks = make(map[request]int)
- }
- cn.validReceiveChunks[r]++
- cn.t.pendingRequests[r]++
- cn.t.requestStrategy.hooks().sentRequest(r)
- cn.updateExpectingChunks()
- return cn.peerImpl.request(r)
-}
-
-func (me *PeerConn) request(r request) bool {
+func (me *PeerConn) _request(r Request) bool {
return me.write(pp.Message{
Type: pp.Request,
Index: r.Index,
})
}
-func (me *PeerConn) cancel(r request) bool {
- return me.write(makeCancelMessage(r))
-}
-
-func (cn *peer) doRequestState() bool {
- if !cn.t.networkingEnabled || cn.t.dataDownloadDisallowed {
- if !cn.setInterested(false) {
- return false
- }
- if len(cn.requests) != 0 {
- for r := range cn.requests {
- cn.deleteRequest(r)
- // log.Printf("%p: cancelling request: %v", cn, r)
- if !cn.peerImpl.cancel(r) {
- return false
- }
- }
- }
- } else if len(cn.requests) <= cn.requestsLowWater {
- filledBuffer := false
- cn.iterPendingPieces(func(pieceIndex pieceIndex) bool {
- cn.iterPendingRequests(pieceIndex, func(r request) bool {
- if !cn.setInterested(true) {
- filledBuffer = true
- return false
- }
- if len(cn.requests) >= cn.nominalMaxRequests() {
- return false
- }
- // Choking is looked at here because our interest is dependent
- // on whether we'd make requests in its absence.
- if cn.peerChoking {
- if !cn.peerAllowedFast.Get(bitmap.BitIndex(r.Index)) {
- return false
- }
- }
- if _, ok := cn.requests[r]; ok {
- return true
- }
- filledBuffer = !cn.request(r)
- return !filledBuffer
- })
- return !filledBuffer
- })
- if filledBuffer {
- // If we didn't completely top up the requests, we shouldn't mark
- // the low water, since we'll want to top up the requests as soon
- // as we have more write buffer space.
- return false
- }
- cn.requestsLowWater = len(cn.requests) / 2
- }
- return true
+func (me *PeerConn) _cancel(r RequestIndex) bool {
+ me.write(makeCancelMessage(me.t.requestIndexToRequest(r)))
+ // Transmission does not send rejects for received cancels. See
+ // https://github.com/transmission/transmission/pull/2275.
+ return me.fastEnabled() && !me.remoteIsTransmission()
}
func (cn *PeerConn) fillWriteBuffer() {
- if !cn.doRequestState() {
- return
- }
+ if cn.messageWriter.writeBuffer.Len() > writeBufferLowWaterLen {
+ // Fully committing to our max requests requires sufficient space (see
+ // maxLocalToRemoteRequests). Flush what we have instead. We also prefer always to make
+ // requests than to do PEX or upload, so we short-circuit before handling those. Any update
+ // request reason will not be cleared, so we'll come right back here when there's space. We
+ // can't do this in maybeUpdateActualRequestState because it's a method on Peer and has no
+ // knowledge of write buffers.
+ }
+ cn.maybeUpdateActualRequestState()
if cn.pex.IsEnabled() {
if flow := cn.pex.Share(cn.write); !flow {
return
cn.upload(cn.write)
}
-// Routine that writes to the peer. Some of what to write is buffered by
-// activity elsewhere in the Client, and some is determined locally when the
-// connection is writable.
-func (cn *PeerConn) writer(keepAliveTimeout time.Duration) {
- var (
- lastWrite time.Time = time.Now()
- keepAliveTimer *time.Timer
- )
- keepAliveTimer = time.AfterFunc(keepAliveTimeout, func() {
- cn.locker().Lock()
- defer cn.locker().Unlock()
- if time.Since(lastWrite) >= keepAliveTimeout {
- cn.tickleWriter()
- }
- keepAliveTimer.Reset(keepAliveTimeout)
- })
- cn.locker().Lock()
- defer cn.locker().Unlock()
- defer cn.close()
- defer keepAliveTimer.Stop()
- frontBuf := new(bytes.Buffer)
- for {
- if cn.closed.IsSet() {
- return
- }
- if cn.writeBuffer.Len() == 0 {
- cn.fillWriteBuffer()
- }
- if cn.writeBuffer.Len() == 0 && time.Since(lastWrite) >= keepAliveTimeout {
- cn.writeBuffer.Write(pp.Message{Keepalive: true}.MustMarshalBinary())
- postedKeepalives.Add(1)
- }
- if cn.writeBuffer.Len() == 0 {
- // TODO: Minimize wakeups....
- cn.writerCond.Wait()
- continue
- }
- // Flip the buffers.
- frontBuf, cn.writeBuffer = cn.writeBuffer, frontBuf
- cn.locker().Unlock()
- n, err := cn.w.Write(frontBuf.Bytes())
- cn.locker().Lock()
- if n != 0 {
- lastWrite = time.Now()
- keepAliveTimer.Reset(keepAliveTimeout)
- }
- if err != nil {
- cn.logger.WithDefaultLevel(log.Debug).Printf("error writing: %v", err)
- return
- }
- if n != frontBuf.Len() {
- panic("short write")
- }
- frontBuf.Reset()
- }
-}
-
func (cn *PeerConn) have(piece pieceIndex) {
if cn.sentHaves.Get(bitmap.BitIndex(piece)) {
return
}
- cn.post(pp.Message{
+ cn.write(pp.Message{
Type: pp.Have,
Index: pp.Integer(piece),
})
if !cn.t.haveAnyPieces() {
return
}
- cn.post(pp.Message{
+ cn.write(pp.Message{
Type: pp.Bitfield,
Bitfield: cn.t.bitfield(),
})
- cn.sentHaves = cn.t._completedPieces.Copy()
+ cn.sentHaves = bitmap.Bitmap{cn.t._completedPieces.Clone()}
}
-func (cn *PeerConn) updateRequests() {
- // log.Print("update requests")
+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 {
- skip.Add(i.(int))
- return cb(i)
- },
- bitmap.Sub(bm, *skip).Iter,
- ) {
- return
- }
- }
- }
-}
-
-func iterUnbiasedPieceRequestOrder(cn requestStrategyConnection, f func(piece pieceIndex) bool) bool {
- now, readahead := cn.torrent().readerPiecePriorities()
- skip := bitmap.Flip(cn.peerPieces(), 0, cn.torrent().numPieces())
- skip.Union(cn.torrent().ignorePieces())
- // Return an iterator over the different priority classes, minus the skip pieces.
- return iter.All(
- func(_piece interface{}) bool {
- return f(pieceIndex(_piece.(bitmap.BitIndex)))
- },
- iterBitmapsDistinct(&skip, now, readahead),
- // We have to iterate _pendingPieces separately because it isn't a Bitmap.
- func(cb iter.Callback) {
- cn.torrent().pendingPieces().IterTyped(func(piece int) bool {
- if skip.Contains(piece) {
- return true
- }
- more := cb(piece)
- skip.Add(piece)
- return more
- })
- },
- )
-}
-
-// The connection should download highest priority pieces first, without any inclination toward
-// avoiding wastage. Generally we might do this if there's a single connection, or this is the
-// fastest connection, and we have active readers that signal an ordering preference. It's
-// conceivable that the best connection should do this, since it's least likely to waste our time if
-// assigned to the highest priority pieces, and assigning more than one this role would cause
-// significant wasted bandwidth.
-func (cn *peer) shouldRequestWithoutBias() bool {
- return cn.t.requestStrategy.shouldRequestWithoutBias(cn.requestStrategyConnection())
-}
-
-func (cn *peer) iterPendingPieces(f func(pieceIndex) bool) bool {
- if !cn.t.haveInfo() {
- return false
- }
- return cn.t.requestStrategy.iterPendingPieces(cn, f)
-}
-func (cn *peer) iterPendingPiecesUntyped(f iter.Callback) {
- cn.iterPendingPieces(func(i pieceIndex) bool { return f(i) })
-}
-
-func (cn *peer) iterPendingRequests(piece pieceIndex, f func(request) bool) bool {
- return cn.t.requestStrategy.iterUndirtiedChunks(
- cn.t.piece(piece).requestStrategyPiece(),
- func(cs chunkSpec) bool {
- return f(request{pp.Integer(piece), cs})
- },
- )
-}
-
-// check callers updaterequests
-func (cn *peer) stopRequestingPiece(piece pieceIndex) bool {
- return cn._pieceRequestOrder.Remove(bitmap.BitIndex(piece))
-}
-
-// This is distinct from Torrent piece priority, which is the user's
-// preference. Connection piece priority is specific to a connection and is
-// used to pseudorandomly avoid connections always requesting the same pieces
-// and thus wasting effort.
-func (cn *peer) updatePiecePriority(piece pieceIndex) bool {
- tpp := cn.t.piecePriority(piece)
- if !cn.peerHasPiece(piece) {
- tpp = PiecePriorityNone
- }
- if tpp == PiecePriorityNone {
- return cn.stopRequestingPiece(piece)
- }
- prio := cn.getPieceInclination()[piece]
- prio = cn.t.requestStrategy.piecePriority(cn, piece, tpp, prio)
- return cn._pieceRequestOrder.Set(bitmap.BitIndex(piece), prio) || cn.shouldRequestWithoutBias()
-}
-
-func (cn *peer) getPieceInclination() []int {
- if cn.pieceInclination == nil {
- cn.pieceInclination = cn.t.getConnPieceInclination()
- }
- return cn.pieceInclination
-}
-
-func (cn *peer) discardPieceInclination() {
- if cn.pieceInclination == nil {
- return
- }
- cn.t.putPieceInclination(cn.pieceInclination)
- cn.pieceInclination = nil
-}
-
-func (cn *PeerConn) peerPiecesChanged() {
- if cn.t.haveInfo() {
- prioritiesChanged := false
- for i := pieceIndex(0); i < cn.t.numPieces(); i++ {
- if cn.updatePiecePriority(i) {
- prioritiesChanged = true
- }
- }
- if prioritiesChanged {
- cn.updateRequests()
- }
- }
-}
-
func (cn *PeerConn) raisePeerMinPieces(newMin pieceIndex) {
if newMin > cn.peerMinPieces {
cn.peerMinPieces = newMin
return nil
}
cn.raisePeerMinPieces(piece + 1)
- cn._peerPieces.Set(bitmap.BitIndex(piece), true)
- if cn.updatePiecePriority(piece) {
- cn.updateRequests()
+ if !cn.peerHasPiece(piece) {
+ cn.t.incPieceAvailability(piece)
+ }
+ cn._peerPieces.Add(uint32(piece))
+ if cn.t.wantPieceIndex(piece) {
+ cn.updateRequests("have")
}
+ cn.peerPiecesChanged()
return nil
}
func (cn *PeerConn) peerSentBitfield(bf []bool) error {
- cn.peerSentHaveAll = false
if len(bf)%8 != 0 {
panic("expected bitfield length divisible by 8")
}
- // We know that the last byte means that at most the last 7 bits are
- // wasted.
+ // We know that the last byte means that at most the last 7 bits are wasted.
cn.raisePeerMinPieces(pieceIndex(len(bf) - 7))
if cn.t.haveInfo() && len(bf) > int(cn.t.numPieces()) {
// Ignore known excess pieces.
bf = bf[:cn.t.numPieces()]
}
- for i, have := range bf {
- if have {
- cn.raisePeerMinPieces(pieceIndex(i) + 1)
+ bm := boolSliceToBitmap(bf)
+ if cn.t.haveInfo() && pieceIndex(bm.GetCardinality()) == cn.t.numPieces() {
+ cn.onPeerHasAllPieces()
+ return nil
+ }
+ if !bm.IsEmpty() {
+ cn.raisePeerMinPieces(pieceIndex(bm.Maximum()) + 1)
+ }
+ shouldUpdateRequests := false
+ if cn.peerSentHaveAll {
+ if !cn.t.deleteConnWithAllPieces(&cn.Peer) {
+ panic(cn)
+ }
+ cn.peerSentHaveAll = false
+ if !cn._peerPieces.IsEmpty() {
+ panic("if peer has all, we expect no individual peer pieces to be set")
+ }
+ } else {
+ bm.Xor(&cn._peerPieces)
+ }
+ cn.peerSentHaveAll = false
+ // bm is now 'on' for pieces that are changing
+ bm.Iterate(func(x uint32) bool {
+ pi := pieceIndex(x)
+ if cn._peerPieces.Contains(x) {
+ // Then we must be losing this piece
+ cn.t.decPieceAvailability(pi)
+ } else {
+ if !shouldUpdateRequests && cn.t.wantPieceIndex(pieceIndex(x)) {
+ shouldUpdateRequests = true
+ }
+ // We must be gaining this piece
+ cn.t.incPieceAvailability(pieceIndex(x))
}
- cn._peerPieces.Set(i, have)
+ return true
+ })
+ // Apply the changes. If we had everything previously, this should be empty, so xor is the same
+ // as or.
+ cn._peerPieces.Xor(&bm)
+ if shouldUpdateRequests {
+ cn.updateRequests("bitfield")
}
+ // We didn't guard this before, I see no reason to do it now.
cn.peerPiecesChanged()
return nil
}
-func (cn *PeerConn) onPeerSentHaveAll() error {
+func (cn *PeerConn) onPeerHasAllPieces() {
+ t := cn.t
+ if t.haveInfo() {
+ cn._peerPieces.Iterate(func(x uint32) bool {
+ t.decPieceAvailability(pieceIndex(x))
+ return true
+ })
+ }
+ t.addConnWithAllPieces(&cn.Peer)
cn.peerSentHaveAll = true
cn._peerPieces.Clear()
+ if !cn.t._pendingPieces.IsEmpty() {
+ cn.updateRequests("Peer.onPeerHasAllPieces")
+ }
cn.peerPiecesChanged()
+}
+
+func (cn *PeerConn) onPeerSentHaveAll() error {
+ cn.onPeerHasAllPieces()
return nil
}
func (cn *PeerConn) peerSentHaveNone() error {
+ if !cn.peerSentHaveAll {
+ cn.t.decPeerPieceAvailability(&cn.Peer)
+ }
cn._peerPieces.Clear()
cn.peerSentHaveAll = false
cn.peerPiecesChanged()
cn.allStats(func(cs *ConnStats) { cs.wroteMsg(msg) })
}
-func (cn *PeerConn) readMsg(msg *pp.Message) {
- cn.allStats(func(cs *ConnStats) { cs.readMsg(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 *PeerConn) 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()
}
-func (c *PeerConn) reject(r request) {
+func (c *PeerConn) reject(r Request) {
if !c.fastEnabled() {
panic("fast not enabled")
}
- c.post(r.ToMsg(pp.Reject))
- delete(c.peerRequests, r)
+ c.write(r.ToMsg(pp.Reject))
+ // 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) onReadRequest(r request) error {
+func (c *PeerConn) maximumPeerRequestChunkLength() (_ Option[int]) {
+ uploadRateLimiter := c.t.cl.config.UploadRateLimiter
+ if uploadRateLimiter.Limit() == rate.Inf {
+ return
+ }
+ return Some(uploadRateLimiter.Burst())
+}
+
+// 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 {
}
return nil
}
- if len(c.peerRequests) >= maxRequests {
+ // TODO: What if they've already requested this?
+ if len(c.peerRequests) >= localClientReqq {
torrent.Add("requests received while queue full", 1)
if c.fastEnabled() {
c.reject(r)
// 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]struct{}, maxRequests)
+ c.peerRequests = make(map[Request]*peerRequestState, localClientReqq)
+ }
+ value := &peerRequestState{
+ allocReservation: c.peerRequestDataAllocLimiter.Reserve(int64(r.Length)),
+ }
+ c.peerRequests[r] = value
+ if startFetch {
+ // TODO: Limit peer request data read concurrency.
+ go c.peerRequestDataReader(r, value)
}
- c.peerRequests[r] = struct{}{}
- c.tickleWriter()
return nil
}
-func runSafeExtraneous(f func()) {
- if true {
- go f()
+func (c *PeerConn) peerRequestDataReader(r Request, prs *peerRequestState) {
+ // 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 {
+ c.peerRequestDataReadFailed(err, r)
+ } else {
+ if b == nil {
+ panic("data must be non-nil to trigger send")
+ }
+ 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()
+ }
+}
+
+// If this is maintained correctly, we might be able to support optional synchronous reading for
+// chunk sending, the way it used to work.
+func (c *PeerConn) peerRequestDataReadFailed(err error, r Request) {
+ torrent.Add("peer request data read failures", 1)
+ logLevel := log.Warning
+ if c.t.hasStorageCap() {
+ // It's expected that pieces might drop. See
+ // https://github.com/anacrolix/torrent/issues/702#issuecomment-1000953313.
+ logLevel = log.Debug
+ }
+ c.logger.Levelf(logLevel, "error reading chunk for peer Request %v: %v", r, err)
+ if c.t.closed.IsSet() {
+ return
+ }
+ i := pieceIndex(r.Index)
+ if c.t.pieceComplete(i) {
+ // There used to be more code here that just duplicated the following break. Piece
+ // completions are currently cached, so I'm not sure how helpful this update is, except to
+ // pull any completion changes pushed to the storage backend in failed reads that got us
+ // here.
+ c.t.updatePieceCompletion(i)
+ }
+ // We've probably dropped a piece from storage, but there's no way to communicate this to the
+ // peer. If they ask for it again, we kick them allowing us to send them updated piece states if
+ // we reconnect. TODO: Instead, we could just try to update them with Bitfield or HaveNone and
+ // if they kick us for breaking protocol, on reconnect we will be compliant again (at least
+ // initially).
+ if c.fastEnabled() {
+ c.reject(r)
+ } else {
+ if c.choking {
+ // If fast isn't enabled, I think we would have wiped all peer requests when we last
+ // choked, and requests while we're choking would be ignored. It could be possible that
+ // a peer request data read completed concurrently to it being deleted elsewhere.
+ c.logger.WithDefaultLevel(log.Warning).Printf("already choking peer, requests might not be rejected correctly")
+ }
+ // Choking a non-fast peer should cause them to flush all their requests.
+ c.choke(c.write)
+ }
+}
+
+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))
+ if n == len(b) {
+ if err == io.EOF {
+ err = nil
+ }
} else {
- f()
+ if err == nil {
+ panic("expected error")
+ }
}
+ return b, err
+}
+
+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(),
+ )).SkipCallers(1).Levelf(level, format, arg...)
}
// Processes incoming BitTorrent wire-protocol messages. The client lock is held upon entry and
decoder := pp.Decoder{
R: bufio.NewReaderSize(c.r, 1<<17),
- MaxLength: 256 * 1024,
- Pool: t.chunkPool,
+ MaxLength: 4 * pp.Integer(max(int64(t.chunkSize), defaultChunkSize)),
+ Pool: &t.chunkPool,
}
for {
var msg pp.Message
if err != nil {
return err
}
- c.readMsg(&msg)
c.lastMessageReceived = time.Now()
if msg.Keepalive {
receivedKeepalives.Add(1)
}
switch msg.Type {
case pp.Choke:
- c.peerChoking = true
+ if c.peerChoking {
+ break
+ }
if !c.fastEnabled() {
- c.deleteAllRequests()
+ c.deleteAllRequests("choked by non-fast PeerConn")
+ } else {
+ // We don't decrement pending requests here, let's wait for the peer to either
+ // reject or satisfy the outstanding requests. Additionally, some peers may unchoke
+ // us and resume where they left off, we don't want to have piled on to those chunks
+ // in the meanwhile. I think a peer's ability to abuse this should be limited: they
+ // could let us request a lot of stuff, then choke us and never reject, but they're
+ // only a single peer, our chunk balancing should smooth over this abuse.
}
- // We can then reset our interest.
- c.updateRequests()
+ c.peerChoking = true
c.updateExpectingChunks()
case pp.Unchoke:
+ if !c.peerChoking {
+ // Some clients do this for some reason. Transmission doesn't error on this, so we
+ // won't for consistency.
+ c.logProtocolBehaviour(log.Debug, "received unchoke when already unchoked")
+ break
+ }
c.peerChoking = false
- c.tickleWriter()
+ preservedCount := 0
+ c.requestState.Requests.Iterate(func(x RequestIndex) bool {
+ if !c.peerAllowedFast.Contains(c.t.pieceIndexOfRequestIndex(x)) {
+ preservedCount++
+ }
+ return true
+ })
+ if preservedCount != 0 {
+ // TODO: Yes this is a debug log but I'm not happy with the state of the logging lib
+ // right now.
+ c.logger.Levelf(log.Debug,
+ "%v requests were preserved while being choked (fast=%v)",
+ preservedCount,
+ c.fastEnabled())
+
+ torrent.Add("requestsPreservedThroughChoking", int64(preservedCount))
+ }
+ if !c.t._pendingPieces.IsEmpty() {
+ c.updateRequests("unchoked")
+ }
c.updateExpectingChunks()
case pp.Interested:
c.peerInterested = true
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)
if len(msg.Piece) == int(t.chunkSize) {
t.chunkPool.Put(&msg.Piece)
}
if err != nil {
- err = fmt.Errorf("receiving chunk: %s", err)
+ err = fmt.Errorf("receiving chunk: %w", err)
}
case pp.Cancel:
req := newRequestFromMessage(&msg)
})
case pp.Suggest:
torrent.Add("suggests received", 1)
- log.Fmsg("peer suggested piece %d", msg.Index).AddValues(c, msg.Index).SetLevel(log.Debug).Log(c.t.logger)
- c.updateRequests()
+ log.Fmsg("peer suggested piece %d", msg.Index).AddValues(c, msg.Index).LogLevel(log.Debug, c.t.logger)
+ c.updateRequests("suggested")
case pp.HaveAll:
err = c.onPeerSentHaveAll()
case pp.HaveNone:
err = c.peerSentHaveNone()
case pp.Reject:
- c.remoteRejectedRequest(newRequestFromMessage(&msg))
+ req := newRequestFromMessage(&msg)
+ if !c.remoteRejectedRequest(c.t.requestIndexFromRequest(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)
- log.Fmsg("peer allowed fast: %d", msg.Index).AddValues(c).SetLevel(log.Debug).Log(c.t.logger)
- c.peerAllowedFast.Add(int(msg.Index))
- c.updateRequests()
+ log.Fmsg("peer allowed fast: %d", msg.Index).AddValues(c).LogLevel(log.Debug, c.t.logger)
+ c.updateRequests("PeerConn.mainReadLoop allowed fast")
case pp.Extended:
err = c.onReadExtendedMsg(msg.ExtendedID, msg.ExtendedPayload)
default:
}
}
-func (c *peer) remoteRejectedRequest(r request) {
- if c.deleteRequest(r) {
- c.decExpectedChunkReceive(r)
- }
-}
-
-func (c *peer) decExpectedChunkReceive(r request) {
- 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?
var d pp.ExtendedHandshakeMessage
if err := bencode.Unmarshal(payload, &d); err != nil {
c.logger.Printf("error parsing extended handshake message %q: %s", payload, err)
- return errors.Wrap(err, "unmarshalling extended handshake payload")
+ return fmt.Errorf("unmarshalling extended handshake payload: %w", err)
}
if cb := c.callbacks.ReadExtendedHandshake; cb != nil {
cb(c, &d)
}
- //c.logger.WithDefaultLevel(log.Debug).Printf("received extended handshake message:\n%s", spew.Sdump(d))
+ // c.logger.WithDefaultLevel(log.Debug).Printf("received extended handshake message:\n%s", spew.Sdump(d))
if d.Reqq != 0 {
c.PeerMaxRequests = d.Reqq
}
- c.PeerClientName = d.V
+ c.PeerClientName.Store(d.V)
if c.PeerExtensionIDs == nil {
c.PeerExtensionIDs = make(map[pp.ExtensionName]pp.ExtensionNumber, len(d.M))
}
c.PeerPrefersEncryption = d.Encryption
for name, id := range d.M {
if _, ok := c.PeerExtensionIDs[name]; !ok {
- torrent.Add(fmt.Sprintf("peers supporting extension %q", name), 1)
+ peersSupportingExtension.Add(
+ // expvar.Var.String must produce valid JSON. "ut_payme\xeet_address" was being
+ // entered here which caused problems later when unmarshalling.
+ strconv.Quote(string(name)),
+ 1)
}
c.PeerExtensionIDs[name] = id
}
if d.MetadataSize != 0 {
if err = t.setMetadataSize(d.MetadataSize); err != nil {
- return errors.Wrapf(err, "setting metadata size to %d", d.MetadataSize)
+ return fmt.Errorf("setting metadata size to %d: %w", d.MetadataSize, err)
}
}
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}
}
-// Handle a received chunk from a peer.
-func (c *peer) receiveChunk(msg *pp.Message) error {
- t := c.t
- cl := t.cl
- torrent.Add("chunks received", 1)
-
- req := newRequestFromMessage(msg)
-
- if c.peerChoking {
- torrent.Add("chunks received while choking", 1)
- }
-
- if c.validReceiveChunks[req] <= 0 {
- torrent.Add("chunks received unexpected", 1)
- return errors.New("received unexpected chunk")
- }
- c.decExpectedChunkReceive(req)
-
- if c.peerChoking && c.peerAllowedFast.Get(int(req.Index)) {
- torrent.Add("chunks received due to allowed fast", 1)
- }
-
- // Request has been satisfied.
- if c.deleteRequest(req) {
- if c.expectingChunks() {
- c._chunksReceivedWhileExpecting++
- }
- } else {
- torrent.Add("chunks received unwanted", 1)
- }
-
- // Do we actually want this chunk?
- if t.haveChunk(req) {
- torrent.Add("chunks received wasted", 1)
- c.allStats(add(1, func(cs *ConnStats) *Count { return &cs.ChunksReadWasted }))
- return nil
- }
-
- piece := &t.pieces[req.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 }))
- c.lastUsefulChunkReceived = time.Now()
- // if t.fastestPeer != c {
- // log.Printf("setting fastest connection %p", c)
- // }
- t.fastestPeer = c
-
- // 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(chunkIndex(req.chunkSpec, t.chunkSize))
-
- // Cancel pending requests for this chunk.
- for c := range t.conns {
- c._postCancel(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)
- //t.updatePieceCompletion(pieceIndex(msg.Index))
- t.onWriteChunkErr(err)
- return nil
- }
-
- c.onDirtiedPiece(pieceIndex(req.Index))
-
- if t.pieceAllDirty(pieceIndex(req.Index)) {
- t.queuePieceCheck(pieceIndex(req.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(req.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
func (c *PeerConn) setRetryUploadTimer(delay time.Duration) {
if c.uploadTimer == nil {
- c.uploadTimer = time.AfterFunc(delay, c.writerCond.Broadcast)
+ c.uploadTimer = time.AfterFunc(delay, c.tickleWriter)
} else {
c.uploadTimer.Reset(delay)
}
if !c.unchoke(msg) {
return false
}
- for r := range c.peerRequests {
+ for r, state := range c.peerRequests {
+ if state.data == nil {
+ continue
+ }
res := c.t.cl.config.UploadRateLimiter.ReserveN(time.Now(), int(r.Length))
if !res.OK() {
panic(fmt.Sprintf("upload rate limiter burst size < %d", r.Length))
// Hard to say what to return here.
return true
}
- more, err := c.sendChunk(r, msg)
- if err != nil {
- c.logger.WithDefaultLevel(log.Warning).Printf("sending chunk to peer: %v", err)
- i := pieceIndex(r.Index)
- if c.t.pieceComplete(i) {
- // There used to be more code here that just duplicated the following break.
- // Piece completions are currently cached, so I'm not sure how helpful this
- // update is, except to pull any completion changes pushed to the storage
- // backend in failed reads that got us here.
- c.t.updatePieceCompletion(i)
- }
- // If we failed to send a chunk, choke the peer by breaking out of the loop here to
- // ensure they flush all their requests. We've probably dropped a piece from
- // storage, but there's no way to communicate this to the peer. If they ask for it
- // again, we'll kick them to allow us to send them an updated bitfield on the next
- // connect.
- if c.choking {
- c.logger.WithDefaultLevel(log.Warning).Printf("already choking peer, requests might not be rejected correctly")
- }
- break another
- }
+ more := c.sendChunk(r, msg, state)
delete(c.peerRequests, r)
if !more {
return false
cn.t.dropConnection(cn)
}
-func (cn *peer) netGoodPiecesDirtied() int64 {
- return cn._stats.PiecesDirtiedGood.Int64() - cn._stats.PiecesDirtiedBad.Int64()
-}
-
-func (c *peer) peerHasWantedPieces() bool {
- return !c._pieceRequestOrder.IsEmpty()
-}
-
-func (c *peer) numLocalRequests() int {
- return len(c.requests)
-}
-
-func (c *peer) deleteRequest(r request) bool {
- if _, ok := c.requests[r]; !ok {
- return false
- }
- delete(c.requests, r)
- c.updateExpectingChunks()
- c.t.requestStrategy.hooks().deletedRequest(r)
- pr := c.t.pendingRequests
- pr[r]--
- n := pr[r]
- if n == 0 {
- delete(pr, r)
- }
- if n < 0 {
- panic(n)
- }
- // If a request is rejected, updating the requests for the current peer first will miss the
- // opportunity to try other peers for that request instead. I'm not sure about the interested
- // check in the following loop however.
- if false {
- c.updateRequests()
- }
- c.t.iterPeers(func(_c *peer) {
- if !_c.interested && _c != c && c.peerHasPiece(pieceIndex(r.Index)) {
- _c.updateRequests()
- }
- })
- return true
-}
-
-func (c *peer) deleteAllRequests() {
- for r := range c.requests {
- c.deleteRequest(r)
- }
- if len(c.requests) != 0 {
- panic(len(c.requests))
- }
- // for c := range c.t.conns {
- // c.tickleWriter()
- // }
+func (cn *PeerConn) ban() {
+ cn.t.cl.banPeerIP(cn.remoteIp())
}
+// 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() {
- c.writerCond.Broadcast()
+ c.messageWriter.writeCond.Broadcast()
}
-func (c *peer) postCancel(r request) bool {
- if !c.deleteRequest(r) {
- return false
- }
- c.peerImpl._postCancel(r)
- return true
-}
-
-func (c *PeerConn) _postCancel(r request) {
- c.post(makeCancelMessage(r))
-}
-
-func (c *PeerConn) sendChunk(r request, msg func(pp.Message) bool) (more bool, err error) {
- // Count the chunk being sent, even if it isn't.
- b := make([]byte, r.Length)
- p := c.t.info.Piece(int(r.Index))
- n, err := c.t.readAt(b, p.Offset()+int64(r.Begin))
- if n != len(b) {
- if err == nil {
- panic("expected error")
- }
- return
- } else if err == io.EOF {
- err = nil
- }
- more = msg(pp.Message{
+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,
Begin: r.Begin,
- Piece: b,
+ Piece: state.data,
})
- c.lastChunkSent = time.Now()
- return
}
func (c *PeerConn) setTorrent(t *Torrent) {
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 {
- return addrIpOrNil(c.RemoteAddr)
-}
-
-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 {
if c.outgoing {
f |= pp.PexOutgoingConn
}
- if c.RemoteAddr != nil && strings.Contains(c.RemoteAddr.Network(), "udp") {
+ if c.utp() {
f |= pp.PexSupportsUtp
}
return f
// 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() net.Addr {
- 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
- }
+func (c *PeerConn) dialAddr() PeerRemoteAddr {
+ if c.outgoing || c.PeerListenPort == 0 {
+ return c.RemoteAddr
}
- 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 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}
+ 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("connection %p", c)
-}
-
-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())
}
-func (cn *peer) requestStrategyConnection() requestStrategyConnection {
- return cn
+// Returns the pieces the peer could have based on their claims. If we don't know how many pieces
+// are in the torrent, it could be a very large range the peer has sent HaveAll.
+func (cn *PeerConn) PeerPieces() *roaring.Bitmap {
+ cn.locker().RLock()
+ defer cn.locker().RUnlock()
+ return cn.newPeerPieces()
}
-func (cn *peer) chunksReceivedWhileExpecting() int64 {
- return cn._chunksReceivedWhileExpecting
+func (pc *PeerConn) remoteIsTransmission() bool {
+ return bytes.HasPrefix(pc.PeerID[:], []byte("-TR")) && pc.PeerID[7] == '-'
}
-func (cn *peer) fastest() bool {
- return cn == cn.t.fastestPeer
+func (pc *PeerConn) remoteDialAddrPort() (netip.AddrPort, error) {
+ dialAddr := pc.dialAddr()
+ return addrPortFromPeerRemoteAddr(dialAddr)
}
-func (cn *peer) peerMaxRequests() int {
- return cn.PeerMaxRequests
+func (pc *PeerConn) bitExtensionEnabled(bit pp.ExtensionBit) bool {
+ return pc.t.cl.config.Extensions.GetBit(bit) && pc.PeerExtensionBytes.GetBit(bit)
}
-// Returns the pieces the peer has claimed to have.
-func (cn *PeerConn) PeerPieces() bitmap.Bitmap {
- cn.locker().RLock()
- defer cn.locker().RUnlock()
- return cn.peerPieces()
+func (cn *PeerConn) peerPiecesChanged() {
+ cn.t.maybeDropMutuallyCompletePeer(cn)
}
-func (cn *peer) peerPieces() bitmap.Bitmap {
- ret := cn._peerPieces.Copy()
- if cn.peerSentHaveAll {
- ret.AddRange(0, cn.t.numPieces())
+// 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
}
- return ret
-}
-
-func (cn *peer) pieceRequestOrder() *prioritybitmap.PriorityBitmap {
- return &cn._pieceRequestOrder
-}
-
-func (cn *peer) stats() *ConnStats {
- return &cn._stats
-}
-
-func (cn *peer) torrent() requestStrategyTorrent {
- return cn.t.requestStrategyTorrent()
+ if !t.haveInfo() {
+ return c.supportsExtension("ut_metadata")
+ }
+ if t.seeding() && c.peerInterested {
+ return true
+ }
+ if c.peerHasWantedPieces() {
+ return true
+ }
+ return false
}