"crypto/rand"
"crypto/sha1"
"encoding/binary"
+ "encoding/hex"
"errors"
"expvar"
"fmt"
"strconv"
"time"
- "github.com/anacrolix/torrent/internal/panicif"
-
"github.com/anacrolix/chansync"
"github.com/anacrolix/chansync/events"
"github.com/anacrolix/dht/v2"
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
log.Fmsg("error accepting connection: %s", err).LogLevel(log.Debug, cl.logger)
continue
}
+ {
+ holepunchAddr, holepunchErr := addrPortFromPeerRemoteAddr(conn.RemoteAddr())
+ if holepunchErr == nil {
+ cl.lock()
+ if g.MapContains(
+ cl.undialableWithoutHolepunchDialedAfterHolepunchConnect,
+ holepunchAddr,
+ ) {
+ g.MakeMapIfNil(&cl.probablyOnlyConnectedDueToHolepunch)
+ g.MapInsert(cl.probablyOnlyConnectedDueToHolepunch, holepunchAddr, struct{}{})
+ }
+ cl.unlock()
+ }
+ }
go func() {
if reject != nil {
torrent.Add("rejected accepted connections", 1)
// 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,
- }
- }()
- }
- // 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)
+ pool.add(ctx, _s)
}
- return res
+ return pool.getFirst()
}
func dialFromSocket(ctx context.Context, s Dialer, addr string) net.Conn {
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,
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) {
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)
+ if holepunchAddrErr == nil && opts.receivedHolepunchConnect {
+ cl.lock()
+ if g.MapContains(cl.undialableWithoutHolepunch, holepunchAddr) {
+ g.MakeMapIfNilAndSet(
+ &cl.undialableWithoutHolepunchDialedAfterHolepunchConnect,
+ holepunchAddr,
+ struct{}{},
+ )
+ }
+ cl.unlock()
+ }
+ 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{}{})
+ }
+ opts.t.startHolepunchRendezvous(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.
+ // We should have just tried with the preferred header obfuscation. If it was required, there's nothing else to try.
+ if headerObfuscationPolicy.RequirePreferred {
+ return
+ }
+ // 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
}
- // Try again with encryption if we didn't earlier, or without if we did.
- c, err = cl.establishOutgoingConnEx(opts, !obfuscatedHeaderFirst)
+ 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)
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)
}
if err != nil {
return
}
- successfulPeerWireProtocolHandshakePeerReservedBytes.Add(res.PeerExtensionBits.String(), 1)
+ successfulPeerWireProtocolHandshakePeerReservedBytes.Add(
+ hex.EncodeToString(res.PeerExtensionBits[:]), 1)
ret = res.Hash
c.PeerExtensionBytes = res.PeerExtensionBits
c.PeerID = res.PeerID
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
-}