]> Sergey Matveev's repositories - btrtrc.git/blobdiff - client.go
Drop support for go 1.20
[btrtrc.git] / client.go
index 4c2d9123a2f2ba0fedeb8180e24bf5719d4dca78..1ea1d610482551bfef1d621f0ba03bd5cf6f3667 100644 (file)
--- a/client.go
+++ b/client.go
@@ -19,8 +19,6 @@ import (
        "strconv"
        "time"
 
-       "github.com/anacrolix/torrent/internal/panicif"
-
        "github.com/anacrolix/chansync"
        "github.com/anacrolix/chansync/events"
        "github.com/anacrolix/dht/v2"
@@ -37,7 +35,6 @@ import (
        "github.com/dustin/go-humanize"
        gbtree "github.com/google/btree"
        "github.com/pion/datachannel"
-       "golang.org/x/time/rate"
 
        "github.com/anacrolix/torrent/bencode"
        "github.com/anacrolix/torrent/internal/check"
@@ -84,18 +81,15 @@ type Client struct {
        torrents          map[InfoHash]*Torrent
        pieceRequestOrder map[interface{}]*request_strategy.PieceRequestOrder
 
-       acceptLimiter   map[ipStr]int
-       dialRateLimiter *rate.Limiter
-       numHalfOpen     int
+       acceptLimiter map[ipStr]int
+       numHalfOpen   int
 
        websocketTrackers websocketTrackers
 
        activeAnnounceLimiter limiter.Instance
        httpClient            *http.Client
 
-       undialableWithoutHolepunch                                   map[netip.AddrPort]struct{}
-       undialableWithoutHolepunchDialAttemptedAfterHolepunchConnect map[netip.AddrPort]struct{}
-       dialableOnlyAfterHolepunch                                   map[netip.AddrPort]struct{}
+       clientHolepunchAddrSets
 }
 
 type ipStr string
@@ -205,18 +199,20 @@ func (cl *Client) init(cfg *ClientConfig) {
        cl.config = cfg
        g.MakeMap(&cl.dopplegangerAddrs)
        cl.torrents = make(map[metainfo.Hash]*Torrent)
-       cl.dialRateLimiter = rate.NewLimiter(10, 10)
        cl.activeAnnounceLimiter.SlotsPerKey = 2
        cl.event.L = cl.locker()
        cl.ipBlockList = cfg.IPBlocklist
        cl.httpClient = &http.Client{
-               Transport: &http.Transport{
+               Transport: cfg.WebTransport,
+       }
+       if cl.httpClient.Transport == nil {
+               cl.httpClient.Transport = &http.Transport{
                        Proxy:       cfg.HTTPProxy,
                        DialContext: cfg.HTTPDialContext,
                        // I think this value was observed from some webseeds. It seems reasonable to extend it
                        // to other uses of HTTP from the client.
                        MaxConnsPerHost: 10,
-               },
+               }
        }
 }
 
@@ -308,6 +304,7 @@ func NewClient(cfg *ClientConfig) (cl *Client, err error) {
                },
                Proxy:                      cl.config.HTTPProxy,
                WebsocketTrackerHttpHeader: cl.config.WebsocketTrackerHttpHeader,
+               ICEServers:                 cl.config.ICEServers,
                DialContext:                cl.config.TrackerDialContext,
                OnConn: func(dc datachannel.ReadWriteCloser, dcc webtorrent.DataChannelContext) {
                        cl.lock()
@@ -504,6 +501,22 @@ func (cl *Client) acceptConnections(l Listener) {
        for {
                conn, err := l.Accept()
                torrent.Add("client listener accepts", 1)
+               if err == nil {
+                       holepunchAddr, holepunchErr := addrPortFromPeerRemoteAddr(conn.RemoteAddr())
+                       if holepunchErr == nil {
+                               cl.lock()
+                               if g.MapContains(cl.undialableWithoutHolepunch, holepunchAddr) {
+                                       setAdd(&cl.accepted, holepunchAddr)
+                               }
+                               if g.MapContains(
+                                       cl.undialableWithoutHolepunchDialedAfterHolepunchConnect,
+                                       holepunchAddr,
+                               ) {
+                                       setAdd(&cl.probablyOnlyConnectedDueToHolepunch, holepunchAddr)
+                               }
+                               cl.unlock()
+                       }
+               }
                conn = pproffd.WrapNetConn(conn)
                cl.rLock()
                closed := cl.closed.IsSet()
@@ -621,51 +634,14 @@ func (cl *Client) dialFirst(ctx context.Context, addr string) (res DialResult) {
 
 // Returns a connection over UTP or TCP, whichever is first to connect.
 func DialFirst(ctx context.Context, addr string, dialers []Dialer) (res DialResult) {
-       {
-               t := perf.NewTimer(perf.CallerName(0))
-               defer func() {
-                       if res.Conn == nil {
-                               t.Mark(fmt.Sprintf("returned no conn (context: %v)", ctx.Err()))
-                       } else {
-                               t.Mark("returned conn over " + res.Dialer.DialerNetwork())
-                       }
-               }()
+       pool := dialPool{
+               addr: addr,
        }
-       ctx, cancel := context.WithCancel(ctx)
-       // As soon as we return one connection, cancel the others.
-       defer cancel()
-       left := 0
-       resCh := make(chan DialResult, left)
+       defer pool.startDrainer()
        for _, _s := range dialers {
-               left++
-               s := _s
-               go func() {
-                       resCh <- DialResult{
-                               dialFromSocket(ctx, s, addr),
-                               s,
-                       }
-               }()
+               pool.add(ctx, _s)
        }
-       // Wait for a successful connection.
-       func() {
-               defer perf.ScopeTimer()()
-               for ; left > 0 && res.Conn == nil; left-- {
-                       res = <-resCh
-               }
-       }()
-       // There are still uncompleted dials.
-       go func() {
-               for ; left > 0; left-- {
-                       conn := (<-resCh).Conn
-                       if conn != nil {
-                               conn.Close()
-                       }
-               }
-       }()
-       if res.Conn != nil {
-               go torrent.Add(fmt.Sprintf("network dialed first: %s", res.Conn.RemoteAddr().Network()), 1)
-       }
-       return res
+       return pool.getFirst()
 }
 
 func dialFromSocket(ctx context.Context, s Dialer, addr string) net.Conn {
@@ -732,119 +708,18 @@ func (cl *Client) initiateProtocolHandshakes(
        return
 }
 
-func (cl *Client) waitForRendezvousConnect(ctx context.Context, rz *utHolepunchRendezvous) error {
-       for {
-               switch {
-               case rz.gotConnect.IsSet():
-                       return nil
-               case len(rz.relays) == 0:
-                       return errors.New("all relays failed")
-               case ctx.Err() != nil:
-                       return context.Cause(ctx)
-               }
-               relayCond := rz.relayCond.Signaled()
-               cl.unlock()
-               select {
-               case <-rz.gotConnect.Done():
-               case <-relayCond:
-               case <-ctx.Done():
-               }
-               cl.lock()
-       }
-}
-
-// Returns nil connection and nil error if no connection could be established for valid reasons.
-func (cl *Client) initiateRendezvousConnect(
-       t *Torrent, holepunchAddr netip.AddrPort,
-) (ok bool, err error) {
-       cl.lock()
-       defer cl.unlock()
-       rz, err := t.startHolepunchRendezvous(holepunchAddr)
-       if err != nil {
-               return
-       }
-       if rz == nil {
-               return
-       }
-       ok = true
-       ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
-       defer cancel()
-       err = cl.waitForRendezvousConnect(ctx, rz)
-       delete(t.utHolepunchRendezvous, holepunchAddr)
-       if err != nil {
-               err = fmt.Errorf("waiting for rendezvous connect signal: %w", err)
-       }
-       return
-}
-
-// Returns nil connection and nil error if no connection could be established for valid reasons.
-func (cl *Client) establishOutgoingConnEx(
-       opts outgoingConnOpts,
+func doProtocolHandshakeOnDialResult(
+       t *Torrent,
        obfuscatedHeader bool,
+       addr PeerRemoteAddr,
+       dr DialResult,
 ) (
-       _ *PeerConn, err error,
+       c *PeerConn, err error,
 ) {
-       t := opts.t
-       addr := opts.addr
-       holepunchAddr, err := addrPortFromPeerRemoteAddr(addr)
-       var sentRendezvous bool
-       if err == nil {
-               if !opts.skipHolepunchRendezvous {
-                       sentRendezvous, err = cl.initiateRendezvousConnect(t, holepunchAddr)
-                       if err != nil {
-                               err = fmt.Errorf("initiating rendezvous connect: %w", err)
-                       }
-               }
-       }
-       gotHolepunchConnect := (err == nil && sentRendezvous) || opts.receivedHolepunchConnect
-       if opts.requireRendezvous && !sentRendezvous {
-               return nil, err
-       }
-       if err != nil {
-               t.logger.Print(err)
-       }
-       dialCtx, cancel := context.WithTimeout(context.Background(), func() time.Duration {
-               cl.rLock()
-               defer cl.rUnlock()
-               return t.dialTimeout()
-       }())
-       defer cancel()
-       dr := cl.dialFirst(dialCtx, addr.String())
+       cl := t.cl
        nc := dr.Conn
-       cl.lock()
-       if gotHolepunchConnect && g.MapContains(cl.undialableWithoutHolepunch, holepunchAddr) {
-               g.MakeMapIfNilAndSet(
-                       &cl.undialableWithoutHolepunchDialAttemptedAfterHolepunchConnect,
-                       holepunchAddr,
-                       struct{}{},
-               )
-       }
-       cl.unlock()
-       if nc == nil {
-               if !sentRendezvous && !gotHolepunchConnect {
-                       cl.lock()
-                       g.MakeMapIfNilAndSet(&cl.undialableWithoutHolepunch, holepunchAddr, struct{}{})
-                       cl.unlock()
-               }
-               if dialCtx.Err() != nil {
-                       return nil, fmt.Errorf("dialing: %w", dialCtx.Err())
-               }
-               return nil, errors.New("dial failed")
-       }
-       if gotHolepunchConnect {
-               panicif.False(holepunchAddr.IsValid())
-               cl.lock()
-               if g.MapContains(cl.undialableWithoutHolepunchDialAttemptedAfterHolepunchConnect, holepunchAddr) {
-                       g.MakeMapIfNilAndSet(
-                               &cl.dialableOnlyAfterHolepunch,
-                               holepunchAddr,
-                               struct{}{},
-                       )
-               }
-               cl.unlock()
-       }
        addrIpPort, _ := tryIpPortFromNetAddr(addr)
-       c, err := cl.initiateProtocolHandshakes(
+       c, err = cl.initiateProtocolHandshakes(
                context.Background(), nc, t, obfuscatedHeader,
                newConnectionOpts{
                        outgoing:   true,
@@ -860,69 +735,153 @@ func (cl *Client) establishOutgoingConnEx(
        return c, err
 }
 
-// Returns nil connection and nil error if no connection could be established
-// for valid reasons.
-func (cl *Client) establishOutgoingConn(opts outgoingConnOpts) (c *PeerConn, err error) {
+// Returns nil connection and nil error if no connection could be established for valid reasons.
+func (cl *Client) dialAndCompleteHandshake(opts outgoingConnOpts) (c *PeerConn, err error) {
+       // It would be better if dial rate limiting could be tested when considering to open connections
+       // instead. Doing it here means if the limit is low, and the half-open limit is high, we could
+       // end up with lots of outgoing connection attempts pending that were initiated on stale data.
+       {
+               dialReservation := cl.config.DialRateLimiter.Reserve()
+               if !opts.receivedHolepunchConnect {
+                       if !dialReservation.OK() {
+                               err = errors.New("can't make dial limit reservation")
+                               return
+                       }
+                       time.Sleep(dialReservation.Delay())
+               }
+       }
        torrent.Add("establish outgoing connection", 1)
-       obfuscatedHeaderFirst := cl.config.HeaderObfuscationPolicy.Preferred
-       c, err = cl.establishOutgoingConnEx(opts, obfuscatedHeaderFirst)
+       addr := opts.peerInfo.Addr
+       dialPool := dialPool{
+               resCh: make(chan DialResult),
+               addr:  addr.String(),
+       }
+       defer dialPool.startDrainer()
+       dialTimeout := opts.t.getDialTimeoutUnlocked()
+       {
+               ctx, cancel := context.WithTimeout(context.Background(), dialTimeout)
+               defer cancel()
+               for _, d := range cl.dialers {
+                       dialPool.add(ctx, d)
+               }
+       }
+       holepunchAddr, holepunchAddrErr := addrPortFromPeerRemoteAddr(addr)
+       headerObfuscationPolicy := opts.HeaderObfuscationPolicy
+       obfuscatedHeaderFirst := headerObfuscationPolicy.Preferred
+       firstDialResult := dialPool.getFirst()
+       if firstDialResult.Conn == nil {
+               // No dialers worked. Try to initiate a holepunching rendezvous.
+               if holepunchAddrErr == nil {
+                       cl.lock()
+                       if !opts.receivedHolepunchConnect {
+                               g.MakeMapIfNilAndSet(&cl.undialableWithoutHolepunch, holepunchAddr, struct{}{})
+                       }
+                       if !opts.skipHolepunchRendezvous {
+                               opts.t.trySendHolepunchRendezvous(holepunchAddr)
+                       }
+                       cl.unlock()
+               }
+               err = fmt.Errorf("all initial dials failed")
+               return
+       }
+       if opts.receivedHolepunchConnect && holepunchAddrErr == nil {
+               cl.lock()
+               if g.MapContains(cl.undialableWithoutHolepunch, holepunchAddr) {
+                       g.MakeMapIfNilAndSet(&cl.dialableOnlyAfterHolepunch, holepunchAddr, struct{}{})
+               }
+               g.MakeMapIfNil(&cl.dialedSuccessfullyAfterHolepunchConnect)
+               g.MapInsert(cl.dialedSuccessfullyAfterHolepunchConnect, holepunchAddr, struct{}{})
+               cl.unlock()
+       }
+       c, err = doProtocolHandshakeOnDialResult(
+               opts.t,
+               obfuscatedHeaderFirst,
+               addr,
+               firstDialResult,
+       )
        if err == nil {
                torrent.Add("initiated conn with preferred header obfuscation", 1)
                return
        }
-       // cl.logger.Printf("error establishing connection to %s (obfuscatedHeader=%t): %v", addr, obfuscatedHeaderFirst, err)
-       if cl.config.HeaderObfuscationPolicy.RequirePreferred {
-               // We should have just tried with the preferred header obfuscation. If it was required,
-               // there's nothing else to try.
+       c.logger.Levelf(
+               log.Debug,
+               "error doing protocol handshake with header obfuscation %v",
+               obfuscatedHeaderFirst,
+       )
+       firstDialResult.Conn.Close()
+       // We should have just tried with the preferred header obfuscation. If it was required, there's nothing else to try.
+       if headerObfuscationPolicy.RequirePreferred {
                return
        }
-       // Try again with encryption if we didn't earlier, or without if we did.
-       c, err = cl.establishOutgoingConnEx(opts, !obfuscatedHeaderFirst)
+       // Reuse the dialer that returned already but failed to handshake.
+       {
+               ctx, cancel := context.WithTimeout(context.Background(), dialTimeout)
+               defer cancel()
+               dialPool.add(ctx, firstDialResult.Dialer)
+       }
+       secondDialResult := dialPool.getFirst()
+       if secondDialResult.Conn == nil {
+               return
+       }
+       c, err = doProtocolHandshakeOnDialResult(
+               opts.t,
+               !obfuscatedHeaderFirst,
+               addr,
+               secondDialResult,
+       )
        if err == nil {
                torrent.Add("initiated conn with fallback header obfuscation", 1)
+               return
        }
-       // cl.logger.Printf("error establishing fallback connection to %v: %v", addr, err)
+       c.logger.Levelf(
+               log.Debug,
+               "error doing protocol handshake with header obfuscation %v",
+               !obfuscatedHeaderFirst,
+       )
+       secondDialResult.Conn.Close()
        return
 }
 
 type outgoingConnOpts struct {
-       t    *Torrent
-       addr PeerRemoteAddr
+       peerInfo PeerInfo
+       t        *Torrent
        // Don't attempt to connect unless a connect message is received after initiating a rendezvous.
        requireRendezvous bool
        // Don't send rendezvous requests to eligible relays.
        skipHolepunchRendezvous bool
        // Outgoing connection attempt is in response to holepunch connect message.
        receivedHolepunchConnect bool
+       HeaderObfuscationPolicy  HeaderObfuscationPolicy
 }
 
 // Called to dial out and run a connection. The addr we're given is already
 // considered half-open.
 func (cl *Client) outgoingConnection(
        opts outgoingConnOpts,
-       ps PeerSource,
-       trusted bool,
        attemptKey outgoingConnAttemptKey,
 ) {
-       cl.dialRateLimiter.Wait(context.Background())
-       c, err := cl.establishOutgoingConn(opts)
+       c, err := cl.dialAndCompleteHandshake(opts)
        if err == nil {
                c.conn.SetWriteDeadline(time.Time{})
        }
        cl.lock()
        defer cl.unlock()
-       // Don't release lock between here and addPeerConn, unless it's for
-       // failure.
-       cl.noLongerHalfOpen(opts.t, opts.addr.String(), attemptKey)
+       // Don't release lock between here and addPeerConn, unless it's for failure.
+       cl.noLongerHalfOpen(opts.t, opts.peerInfo.Addr.String(), attemptKey)
        if err != nil {
                if cl.config.Debug {
-                       cl.logger.Levelf(log.Debug, "error establishing outgoing connection to %v: %v", opts.addr, err)
+                       cl.logger.Levelf(
+                               log.Debug,
+                               "error establishing outgoing connection to %v: %v",
+                               opts.peerInfo.Addr,
+                               err,
+                       )
                }
                return
        }
        defer c.close()
-       c.Discovery = ps
-       c.trusted = trusted
+       c.Discovery = opts.peerInfo.Source
+       c.trusted = opts.peerInfo.Trusted
        opts.t.runHandshookConnLoggingErr(c)
 }
 
@@ -1342,7 +1301,7 @@ func (cl *Client) newTorrentOpt(opts AddTorrentOpts) (t *Torrent) {
        t.smartBanCache.Hash = sha1.Sum
        t.smartBanCache.Init()
        t.networkingEnabled.Set()
-       t.logger = cl.logger.WithContextValue(t).WithNames("torrent", t.infoHash.HexString()).WithDefaultLevel(log.Debug)
+       t.logger = cl.logger.WithDefaultLevel(log.Debug)
        t.sourcesLogger = t.logger.WithNames("sources")
        if opts.ChunkSize == 0 {
                opts.ChunkSize = defaultChunkSize
@@ -1641,6 +1600,7 @@ func (cl *Client) newConnection(nc net.Conn, opts newConnectionOpts) (c *PeerCon
        }
        c.peerImpl = c
        c.logger = cl.logger.WithDefaultLevel(log.Warning)
+       c.logger = c.logger.WithContextText(fmt.Sprintf("%T %p", c, c))
        c.setRW(connStatsReadWriter{nc, c})
        c.r = &rateLimitedReader{
                l: cl.config.DownloadRateLimiter,
@@ -1648,8 +1608,8 @@ func (cl *Client) newConnection(nc net.Conn, opts newConnectionOpts) (c *PeerCon
        }
        c.logger.Levelf(
                log.Debug,
-               "new PeerConn %p [Client %p remoteAddr %v network %v outgoing %t]",
-               c, cl, opts.remoteAddr, opts.network, opts.outgoing,
+               "inited with remoteAddr %v network %v outgoing %t",
+               opts.remoteAddr, opts.network, opts.outgoing,
        )
        for _, f := range cl.config.Callbacks.NewPeer {
                f(&c.Peer)
@@ -1827,13 +1787,3 @@ func (cl *Client) Stats() ClientStats {
        defer cl.rUnlock()
        return cl.statsLocked()
 }
-
-func (cl *Client) statsLocked() (stats ClientStats) {
-       stats.ConnStats = cl.connStats.Copy()
-       stats.ActiveHalfOpenAttempts = cl.numHalfOpen
-       stats.NumPeersUndialableWithoutHolepunchDialedAfterHolepunchConnect =
-               len(cl.undialableWithoutHolepunchDialAttemptedAfterHolepunchConnect)
-       stats.NumPeersDialableOnlyAfterHolepunch =
-               len(cl.dialableOnlyAfterHolepunch)
-       return
-}