fix: 设备数限制某些情况误拒绝旧IP链接BUG

core/xray/app/dispatcher/default.go

@@ -39,23 +39,21 @@ type cachedReader struct {
 	cache  buf.MultiBuffer
 }
 
-func (r *cachedReader) Cache(b *buf.Buffer) {
-	mb, _ := r.reader.ReadMultiBufferTimeout(time.Millisecond * 100)
+func (r *cachedReader) Cache(b *buf.Buffer, deadline time.Duration) error {
+	mb, err := r.reader.ReadMultiBufferTimeout(deadline)
+	if err != nil {
+		return err
+	}
 	r.Lock()
 	if !mb.IsEmpty() {
 		r.cache, _ = buf.MergeMulti(r.cache, mb)
 	}
-	cacheLen := r.cache.Len()
-	if cacheLen <= b.Cap() {
-		b.Clear()
-	} else {
-		b.Release()
-		*b = *buf.NewWithSize(cacheLen)
-	}
-	rawBytes := b.Extend(cacheLen)
+	b.Clear()
+	rawBytes := b.Extend(min(r.cache.Len(), b.Cap()))
 	n := r.cache.Copy(rawBytes)
 	b.Resize(0, int32(n))
 	r.Unlock()
+	return nil
 }
 
 func (r *cachedReader) readInternal() buf.MultiBuffer {
@@ -115,7 +113,7 @@ func init() {
 			core.OptionalFeatures(ctx, func(fdns dns.FakeDNSEngine) {
 				d.fdns = fdns
 			})
-			return d.Init(config.(*Config), om, router, pm, sm, dc)
+			return d.Init(config.(*Config), om, router, pm, sm)
 		}); err != nil {
 			return nil, err
 		}
@@ -124,12 +122,11 @@ func init() {
 }
 
 // Init initializes DefaultDispatcher.
-func (d *DefaultDispatcher) Init(config *Config, om outbound.Manager, router routing.Router, pm policy.Manager, sm stats.Manager, dns dns.Client) error {
+func (d *DefaultDispatcher) Init(config *Config, om outbound.Manager, router routing.Router, pm policy.Manager, sm stats.Manager) error {
 	d.ohm = om
 	d.router = router
 	d.policy = pm
 	d.stats = sm
-	d.dns = dns
 	return nil
 }
 
@@ -364,7 +361,7 @@ func (d *DefaultDispatcher) DispatchLink(ctx context.Context, destination net.De
 				protocol = resComp.ProtocolForDomainResult()
 			}
 			isFakeIP := false
-			if fkr0, ok := d.fdns.(dns.FakeDNSEngineRev0); ok && ob.Target.Address.Family().IsIP() && fkr0.IsIPInIPPool(ob.Target.Address) {
+			if fkr0, ok := d.fdns.(dns.FakeDNSEngineRev0); ok && fkr0.IsIPInIPPool(ob.Target.Address) {
 				isFakeIP = true
 			}
 			if sniffingRequest.RouteOnly && protocol != "fakedns" && protocol != "fakedns+others" && !isFakeIP {
@@ -372,7 +369,6 @@ func (d *DefaultDispatcher) DispatchLink(ctx context.Context, destination net.De
 			} else {
 				ob.Target = destination
 			}
-			destination.Address.Family()
 		}
 		d.routedDispatch(ctx, outbound, destination, nil, content.Protocol)
 	}
@@ -381,7 +377,7 @@ func (d *DefaultDispatcher) DispatchLink(ctx context.Context, destination net.De
 }
 
 func sniffer(ctx context.Context, cReader *cachedReader, metadataOnly bool, network net.Network) (SniffResult, error) {
-	payload := buf.New()
+	payload := buf.NewWithSize(32767)
 	defer payload.Release()
 
 	sniffer := NewSniffer(ctx)
@@ -393,26 +389,36 @@ func sniffer(ctx context.Context, cReader *cachedReader, metadataOnly bool, netw
 	}
 
 	contentResult, contentErr := func() (SniffResult, error) {
+		cacheDeadline := 200 * time.Millisecond
 		totalAttempt := 0
 		for {
 			select {
 			case <-ctx.Done():
 				return nil, ctx.Err()
 			default:
-				totalAttempt++
-				if totalAttempt > 2 {
-					return nil, errSniffingTimeout
+				cachingStartingTimeStamp := time.Now()
+				err := cReader.Cache(payload, cacheDeadline)
+				if err != nil {
+					return nil, err
 				}
+				cachingTimeElapsed := time.Since(cachingStartingTimeStamp)
+				cacheDeadline -= cachingTimeElapsed
 
-				cReader.Cache(payload)
 				if !payload.IsEmpty() {
 					result, err := sniffer.Sniff(ctx, payload.Bytes(), network)
-					if err != common.ErrNoClue {
+					switch err {
+					case common.ErrNoClue: // No Clue: protocol not matches, and sniffer cannot determine whether there will be a match or not
+						totalAttempt++
+					case protocol.ErrProtoNeedMoreData: // Protocol Need More Data: protocol matches, but need more data to complete sniffing
+						// in this case, do not add totalAttempt(allow to read until timeout)
+					default:
 						return result, err
 					}
+				} else {
+					totalAttempt++
 				}
-				if payload.IsFull() {
-					return nil, errUnknownContent
+				if totalAttempt >= 2 || cacheDeadline <= 0 {
+					return nil, errSniffingTimeout
 				}
 			}
 		}
@@ -429,29 +435,10 @@ func sniffer(ctx context.Context, cReader *cachedReader, metadataOnly bool, netw
 func (d *DefaultDispatcher) routedDispatch(ctx context.Context, link *transport.Link, destination net.Destination, l *limiter.Limiter, protocol string) {
 	outbounds := session.OutboundsFromContext(ctx)
 	ob := outbounds[len(outbounds)-1]
-	if hosts, ok := d.dns.(dns.HostsLookup); ok && destination.Address.Family().IsDomain() {
-		proxied := hosts.LookupHosts(ob.Target.String())
-		if proxied != nil {
-			ro := ob.RouteTarget == destination
-			destination.Address = *proxied
-			if ro {
-				ob.RouteTarget = destination
-			} else {
-				ob.Target = destination
-			}
-		}
-	}
 
 	sessionInbound := session.InboundFromContext(ctx)
 	if sessionInbound.User != nil {
-		if l != nil {
-			// del connect count
-			if destination.Network == net.Network_TCP {
-				defer func() {
-					l.ConnLimiter.DelConnCount(sessionInbound.User.Email, sessionInbound.Source.Address.IP().String())
-				}()
-			}
-		} else {
+		if l == nil {
 			var err error
 			l, err = limiter.GetLimiter(sessionInbound.Tag)
 			if err != nil {
@@ -510,7 +497,11 @@ func (d *DefaultDispatcher) routedDispatch(ctx context.Context, link *transport.
 			outTag := route.GetOutboundTag()
 			if h := d.ohm.GetHandler(outTag); h != nil {
 				isPickRoute = 2
-				errors.LogInfo(ctx, "taking detour [", outTag, "] for [", destination, "]")
+				if route.GetRuleTag() == "" {
+					errors.LogInfo(ctx, "taking detour [", outTag, "] for [", destination, "]")
+				} else {
+					errors.LogInfo(ctx, "Hit route rule: [", route.GetRuleTag(), "] so taking detour [", outTag, "] for [", destination, "]")
+				}
 				handler = h
 			} else {
 				errors.LogWarning(ctx, "non existing outTag: ", outTag)
@@ -520,10 +511,6 @@ func (d *DefaultDispatcher) routedDispatch(ctx context.Context, link *transport.
 		}
 	}
 
-	if handler == nil {
-		handler = d.ohm.GetHandler(inTag)
-	}
-
 	if handler == nil {
 		handler = d.ohm.GetDefaultHandler()
 	}
@@ -535,6 +522,7 @@ func (d *DefaultDispatcher) routedDispatch(ctx context.Context, link *transport.
 		return
 	}
 
+	ob.Tag = handler.Tag()
 	if accessMessage := log.AccessMessageFromContext(ctx); accessMessage != nil {
 		if tag := handler.Tag(); tag != "" {
 			if inTag == "" {