예제 #1
0
func (d *UDPClient) sendAnnouncement(remote net.Addr, conn *net.UDPConn) bool {
	if debug {
		l.Debugf("discover %s: broadcast: Sending self announcement to %v", d.url, remote)
	}

	ann := d.announcer.Announcement()
	pkt, err := ann.MarshalXDR()
	if err != nil {
		return false
	}

	myID := protocol.DeviceIDFromBytes(ann.This.ID)

	_, err = conn.WriteTo(pkt, remote)
	if err != nil {
		if debug {
			l.Debugf("discover %s: broadcast: Failed to send self announcement: %s", d.url, err)
		}
		return false
	}

	// Verify that the announce server responds positively for our device ID

	time.Sleep(1 * time.Second)

	ann, err = d.Lookup(myID)
	if err != nil && debug {
		l.Debugf("discover %s: broadcast: Self-lookup failed: %v", d.url, err)
	} else if debug {
		l.Debugf("discover %s: broadcast: Self-lookup returned: %v", d.url, ann.This.Addresses)
	}
	return len(ann.This.Addresses) > 0
}
예제 #2
0
func (d *Discoverer) recvAnnouncements(b beacon.Interface) {
	for {
		buf, addr := b.Recv()

		var pkt Announce
		err := pkt.UnmarshalXDR(buf)
		if err != nil && err != io.EOF {
			if debug {
				l.Debugf("discover: Failed to unmarshal local announcement from %s:\n%s", addr, hex.Dump(buf))
			}
			continue
		}

		if debug {
			l.Debugf("discover: Received local announcement from %s for %s", addr, protocol.DeviceIDFromBytes(pkt.This.ID))
		}

		var newDevice bool
		if bytes.Compare(pkt.This.ID, d.myID[:]) != 0 {
			newDevice = d.registerDevice(addr, pkt.This)
		}

		if newDevice {
			select {
			case d.forcedBcastTick <- time.Now():
			}
		}
	}
}
예제 #3
0
func (d *UDPClient) Start(uri *url.URL, pkt *Announce) error {
	d.url = uri
	d.id = protocol.DeviceIDFromBytes(pkt.This.ID)
	d.stop = make(chan struct{})

	params := uri.Query()
	// The address must not have a port, as otherwise both announce and lookup
	// sockets would try to bind to the same port.
	addr, err := net.ResolveUDPAddr(d.url.Scheme, params.Get("listenaddress")+":0")
	if err != nil {
		return err
	}
	d.listenAddress = addr

	broadcastSeconds, err := strconv.ParseUint(params.Get("broadcast"), 0, 0)
	if err != nil {
		d.globalBroadcastInterval = DefaultGlobalBroadcastInterval
	} else {
		d.globalBroadcastInterval = time.Duration(broadcastSeconds) * time.Second
	}

	retrySeconds, err := strconv.ParseUint(params.Get("retry"), 0, 0)
	if err != nil {
		d.errorRetryInterval = DefaultErrorRetryInternval
	} else {
		d.errorRetryInterval = time.Duration(retrySeconds) * time.Second
	}

	d.wg.Add(1)
	go d.broadcast(pkt.MustMarshalXDR())
	return nil
}
예제 #4
0
파일: leveldb.go 프로젝트: qbit/syncthing
func ldbAvailability(db *leveldb.DB, folder, file []byte) []protocol.DeviceID {
	k := globalKey(folder, file)
	bs, err := db.Get(k, nil)
	if err == leveldb.ErrNotFound {
		return nil
	}
	if err != nil {
		panic(err)
	}

	var vl versionList
	err = vl.UnmarshalXDR(bs)
	if err != nil {
		panic(err)
	}

	var devices []protocol.DeviceID
	for _, v := range vl.versions {
		if v.version != vl.versions[0].version {
			break
		}
		n := protocol.DeviceIDFromBytes(v.device)
		devices = append(devices, n)
	}

	return devices
}
예제 #5
0
파일: leveldb.go 프로젝트: qbit/syncthing
func ldbReplaceWithDelete(db *leveldb.DB, folder, device []byte, fs []protocol.FileInfo) int64 {
	return ldbGenericReplace(db, folder, device, fs, func(db dbReader, batch dbWriter, folder, device, name []byte, dbi iterator.Iterator) int64 {
		var tf FileInfoTruncated
		err := tf.UnmarshalXDR(dbi.Value())
		if err != nil {
			panic(err)
		}
		if !tf.IsDeleted() {
			if debugDB {
				l.Debugf("mark deleted; folder=%q device=%v name=%q", folder, protocol.DeviceIDFromBytes(device), name)
			}
			ts := clock(tf.LocalVersion)
			f := protocol.FileInfo{
				Name:         tf.Name,
				Version:      lamport.Default.Tick(tf.Version),
				LocalVersion: ts,
				Flags:        tf.Flags | protocol.FlagDeleted,
				Modified:     tf.Modified,
			}
			bs, _ := f.MarshalXDR()
			if debugDB {
				l.Debugf("batch.Put %p %x", batch, dbi.Key())
			}
			batch.Put(dbi.Key(), bs)
			ldbUpdateGlobal(db, batch, folder, device, deviceKeyName(dbi.Key()), f.Version)
			return ts
		}
		return 0
	})
}
예제 #6
0
// ldbUpdateGlobal adds this device+version to the version list for the given
// file. If the device is already present in the list, the version is updated.
// If the file does not have an entry in the global list, it is created.
func ldbUpdateGlobal(db dbReader, batch dbWriter, folder, device, file []byte, version protocol.Vector) bool {
	if debugDB {
		l.Debugf("update global; folder=%q device=%v file=%q version=%d", folder, protocol.DeviceIDFromBytes(device), file, version)
	}
	gk := globalKey(folder, file)
	svl, err := db.Get(gk, nil)
	if err != nil && err != leveldb.ErrNotFound {
		panic(err)
	}

	var fl versionList

	// Remove the device from the current version list
	if svl != nil {
		err = fl.UnmarshalXDR(svl)
		if err != nil {
			panic(err)
		}

		for i := range fl.versions {
			if bytes.Compare(fl.versions[i].device, device) == 0 {
				if fl.versions[i].version.Equal(version) {
					// No need to do anything
					return false
				}
				fl.versions = append(fl.versions[:i], fl.versions[i+1:]...)
				break
			}
		}
	}

	nv := fileVersion{
		device:  device,
		version: version,
	}
	for i := range fl.versions {
		// We compare  against ConcurrentLesser as well here because we need
		// to enforce a consistent ordering of versions even in the case of
		// conflicts.
		if comp := fl.versions[i].version.Compare(version); comp == protocol.Equal || comp == protocol.Lesser || comp == protocol.ConcurrentLesser {
			t := append(fl.versions, fileVersion{})
			copy(t[i+1:], t[i:])
			t[i] = nv
			fl.versions = t
			goto done
		}
	}

	fl.versions = append(fl.versions, nv)

done:
	if debugDB {
		l.Debugf("batch.Put %p %x", batch, gk)
		l.Debugf("new global after update: %v", fl)
	}
	batch.Put(gk, fl.MustMarshalXDR())

	return true
}
예제 #7
0
파일: leveldb.go 프로젝트: qbit/syncthing
// ldbUpdateGlobal adds this device+version to the version list for the given
// file. If the device is already present in the list, the version is updated.
// If the file does not have an entry in the global list, it is created.
func ldbUpdateGlobal(db dbReader, batch dbWriter, folder, device, file []byte, version int64) bool {
	if debugDB {
		l.Debugf("update global; folder=%q device=%v file=%q version=%d", folder, protocol.DeviceIDFromBytes(device), file, version)
	}
	gk := globalKey(folder, file)
	svl, err := db.Get(gk, nil)
	if err != nil && err != leveldb.ErrNotFound {
		panic(err)
	}

	var fl versionList
	nv := fileVersion{
		device:  device,
		version: version,
	}
	if svl != nil {
		err = fl.UnmarshalXDR(svl)
		if err != nil {
			panic(err)
		}

		for i := range fl.versions {
			if bytes.Compare(fl.versions[i].device, device) == 0 {
				if fl.versions[i].version == version {
					// No need to do anything
					return false
				}
				fl.versions = append(fl.versions[:i], fl.versions[i+1:]...)
				break
			}
		}
	}

	for i := range fl.versions {
		if fl.versions[i].version <= version {
			t := append(fl.versions, fileVersion{})
			copy(t[i+1:], t[i:])
			t[i] = nv
			fl.versions = t
			goto done
		}
	}

	fl.versions = append(fl.versions, nv)

done:
	if debugDB {
		l.Debugf("batch.Put %p %x", batch, gk)
		l.Debugf("new global after update: %v", fl)
	}
	batch.Put(gk, fl.MustMarshalXDR())

	return true
}
예제 #8
0
파일: leveldb.go 프로젝트: qbit/syncthing
func ldbReplace(db *leveldb.DB, folder, device []byte, fs []protocol.FileInfo) int64 {
	// TODO: Return the remaining maxLocalVer?
	return ldbGenericReplace(db, folder, device, fs, func(db dbReader, batch dbWriter, folder, device, name []byte, dbi iterator.Iterator) int64 {
		// Database has a file that we are missing. Remove it.
		if debugDB {
			l.Debugf("delete; folder=%q device=%v name=%q", folder, protocol.DeviceIDFromBytes(device), name)
		}
		ldbRemoveFromGlobal(db, batch, folder, device, name)
		if debugDB {
			l.Debugf("batch.Delete %p %x", batch, dbi.Key())
		}
		batch.Delete(dbi.Key())
		return 0
	})
}
예제 #9
0
파일: leveldb.go 프로젝트: qbit/syncthing
func ldbInsert(batch dbWriter, folder, device []byte, file protocol.FileInfo) int64 {
	if debugDB {
		l.Debugf("insert; folder=%q device=%v %v", folder, protocol.DeviceIDFromBytes(device), file)
	}

	if file.LocalVersion == 0 {
		file.LocalVersion = clock(0)
	}

	name := []byte(file.Name)
	nk := deviceKey(folder, device, name)
	if debugDB {
		l.Debugf("batch.Put %p %x", batch, nk)
	}
	batch.Put(nk, file.MustMarshalXDR())

	return file.LocalVersion
}
예제 #10
0
파일: leveldb.go 프로젝트: qbit/syncthing
// ldbRemoveFromGlobal removes the device from the global version list for the
// given file. If the version list is empty after this, the file entry is
// removed entirely.
func ldbRemoveFromGlobal(db dbReader, batch dbWriter, folder, device, file []byte) {
	if debugDB {
		l.Debugf("remove from global; folder=%q device=%v file=%q", folder, protocol.DeviceIDFromBytes(device), file)
	}

	gk := globalKey(folder, file)
	svl, err := db.Get(gk, nil)
	if err != nil {
		// We might be called to "remove" a global version that doesn't exist
		// if the first update for the file is already marked invalid.
		return
	}

	var fl versionList
	err = fl.UnmarshalXDR(svl)
	if err != nil {
		panic(err)
	}

	for i := range fl.versions {
		if bytes.Compare(fl.versions[i].device, device) == 0 {
			fl.versions = append(fl.versions[:i], fl.versions[i+1:]...)
			break
		}
	}

	if len(fl.versions) == 0 {
		if debugDB {
			l.Debugf("batch.Delete %p %x", batch, gk)
		}
		batch.Delete(gk)
	} else {
		if debugDB {
			l.Debugf("batch.Put %p %x", batch, gk)
			l.Debugf("new global after remove: %v", fl)
		}
		batch.Put(gk, fl.MustMarshalXDR())
	}
}
예제 #11
0
func (d *UDPClient) broadcast() {
	defer d.wg.Done()

	conn, err := net.ListenUDP(d.url.Scheme, d.listenAddress)
	for err != nil {
		if debug {
			l.Debugf("discover %s: broadcast listen: %v; trying again in %v", d.url, err, d.errorRetryInterval)
		}
		select {
		case <-d.stop:
			return
		case <-time.After(d.errorRetryInterval):
		}
		conn, err = net.ListenUDP(d.url.Scheme, d.listenAddress)
	}
	defer conn.Close()

	remote, err := net.ResolveUDPAddr(d.url.Scheme, d.url.Host)
	for err != nil {
		if debug {
			l.Debugf("discover %s: broadcast resolve: %v; trying again in %v", d.url, err, d.errorRetryInterval)
		}
		select {
		case <-d.stop:
			return
		case <-time.After(d.errorRetryInterval):
		}
		remote, err = net.ResolveUDPAddr(d.url.Scheme, d.url.Host)
	}

	timer := time.NewTimer(0)
	for {
		select {
		case <-d.stop:
			return

		case <-timer.C:
			var ok bool

			if debug {
				l.Debugf("discover %s: broadcast: Sending self announcement to %v", d.url, remote)
			}

			ann := d.announcer.Announcement()
			pkt, err := ann.MarshalXDR()
			if err != nil {
				timer.Reset(d.errorRetryInterval)
				continue
			}

			_, err = conn.WriteTo(pkt, remote)
			if err != nil {
				if debug {
					l.Debugf("discover %s: broadcast: Failed to send self announcement: %s", d.url, err)
				}
				ok = false
			} else {
				// Verify that the announce server responds positively for our device ID

				time.Sleep(1 * time.Second)

				pkt, err := d.Lookup(protocol.DeviceIDFromBytes(ann.This.ID))
				if err != nil && debug {
					l.Debugf("discover %s: broadcast: Self-lookup failed: %v", d.url, err)
				} else if debug {
					l.Debugf("discover %s: broadcast: Self-lookup returned: %v", d.url, pkt.This.Addresses)
				}
				ok = len(pkt.This.Addresses) > 0
			}

			d.mut.Lock()
			d.status = ok
			d.mut.Unlock()

			if ok {
				timer.Reset(d.globalBroadcastInterval)
			} else {
				timer.Reset(d.errorRetryInterval)
			}
		}
	}
}
예제 #12
0
func (i SessionInvitation) String() string {
	return fmt.Sprintf("%s@%s", syncthingprotocol.DeviceIDFromBytes(i.From), i.AddressString())
}
예제 #13
0
파일: leveldb.go 프로젝트: qbit/syncthing
func ldbWithNeed(db *leveldb.DB, folder, device []byte, truncate bool, fn Iterator) {
	runtime.GC()

	start := globalKey(folder, nil)
	limit := globalKey(folder, []byte{0xff, 0xff, 0xff, 0xff})
	snap, err := db.GetSnapshot()
	if err != nil {
		panic(err)
	}
	if debugDB {
		l.Debugf("created snapshot %p", snap)
	}
	defer func() {
		if debugDB {
			l.Debugf("close snapshot %p", snap)
		}
		snap.Release()
	}()

	dbi := snap.NewIterator(&util.Range{Start: start, Limit: limit}, nil)
	defer dbi.Release()

outer:
	for dbi.Next() {
		var vl versionList
		err := vl.UnmarshalXDR(dbi.Value())
		if err != nil {
			panic(err)
		}
		if len(vl.versions) == 0 {
			l.Debugln(dbi.Key())
			panic("no versions?")
		}

		have := false // If we have the file, any version
		need := false // If we have a lower version of the file
		var haveVersion int64
		for _, v := range vl.versions {
			if bytes.Compare(v.device, device) == 0 {
				have = true
				haveVersion = v.version
				need = v.version < vl.versions[0].version
				break
			}
		}

		if need || !have {
			name := globalKeyName(dbi.Key())
			needVersion := vl.versions[0].version
		inner:
			for i := range vl.versions {
				if vl.versions[i].version != needVersion {
					// We haven't found a valid copy of the file with the needed version.
					continue outer
				}
				fk := deviceKey(folder, vl.versions[i].device, name)
				if debugDB {
					l.Debugf("snap.Get %p %x", snap, fk)
				}
				bs, err := snap.Get(fk, nil)
				if err != nil {
					var id protocol.DeviceID
					copy(id[:], device)
					l.Debugf("device: %v", id)
					l.Debugf("need: %v, have: %v", need, have)
					l.Debugf("key: %q (%x)", dbi.Key(), dbi.Key())
					l.Debugf("vl: %v", vl)
					l.Debugf("i: %v", i)
					l.Debugf("fk: %q (%x)", fk, fk)
					l.Debugf("name: %q (%x)", name, name)
					panic(err)
				}

				gf, err := unmarshalTrunc(bs, truncate)
				if err != nil {
					panic(err)
				}

				if gf.IsInvalid() {
					// The file is marked invalid for whatever reason, don't use it.
					continue inner
				}

				if gf.IsDeleted() && !have {
					// We don't need deleted files that we don't have
					continue outer
				}

				if debugDB {
					l.Debugf("need folder=%q device=%v name=%q need=%v have=%v haveV=%d globalV=%d", folder, protocol.DeviceIDFromBytes(device), name, need, have, haveVersion, vl.versions[0].version)
				}

				if cont := fn(gf); !cont {
					return
				}

				// This file is handled, no need to look further in the version list
				continue outer
			}
		}
	}
}
예제 #14
0
파일: leveldb.go 프로젝트: qbit/syncthing
func ldbGenericReplace(db *leveldb.DB, folder, device []byte, fs []protocol.FileInfo, deleteFn deletionHandler) int64 {
	runtime.GC()

	sort.Sort(fileList(fs)) // sort list on name, same as in the database

	start := deviceKey(folder, device, nil)                            // before all folder/device files
	limit := deviceKey(folder, device, []byte{0xff, 0xff, 0xff, 0xff}) // after all folder/device files

	batch := new(leveldb.Batch)
	if debugDB {
		l.Debugf("new batch %p", batch)
	}
	snap, err := db.GetSnapshot()
	if err != nil {
		panic(err)
	}
	if debugDB {
		l.Debugf("created snapshot %p", snap)
	}
	defer func() {
		if debugDB {
			l.Debugf("close snapshot %p", snap)
		}
		snap.Release()
	}()

	dbi := snap.NewIterator(&util.Range{Start: start, Limit: limit}, nil)
	defer dbi.Release()

	moreDb := dbi.Next()
	fsi := 0
	var maxLocalVer int64

	for {
		var newName, oldName []byte
		moreFs := fsi < len(fs)

		if !moreDb && !moreFs {
			break
		}

		if moreFs {
			newName = []byte(fs[fsi].Name)
		}

		if moreDb {
			oldName = deviceKeyName(dbi.Key())
		}

		cmp := bytes.Compare(newName, oldName)

		if debugDB {
			l.Debugf("generic replace; folder=%q device=%v moreFs=%v moreDb=%v cmp=%d newName=%q oldName=%q", folder, protocol.DeviceIDFromBytes(device), moreFs, moreDb, cmp, newName, oldName)
		}

		switch {
		case moreFs && (!moreDb || cmp == -1):
			if debugDB {
				l.Debugln("generic replace; missing - insert")
			}
			// Database is missing this file. Insert it.
			if lv := ldbInsert(batch, folder, device, fs[fsi]); lv > maxLocalVer {
				maxLocalVer = lv
			}
			if fs[fsi].IsInvalid() {
				ldbRemoveFromGlobal(snap, batch, folder, device, newName)
			} else {
				ldbUpdateGlobal(snap, batch, folder, device, newName, fs[fsi].Version)
			}
			fsi++

		case moreFs && moreDb && cmp == 0:
			// File exists on both sides - compare versions. We might get an
			// update with the same version and different flags if a device has
			// marked a file as invalid, so handle that too.
			if debugDB {
				l.Debugln("generic replace; exists - compare")
			}
			var ef FileInfoTruncated
			ef.UnmarshalXDR(dbi.Value())
			if fs[fsi].Version > ef.Version ||
				(fs[fsi].Version == ef.Version && fs[fsi].Flags != ef.Flags) {
				if debugDB {
					l.Debugln("generic replace; differs - insert")
				}
				if lv := ldbInsert(batch, folder, device, fs[fsi]); lv > maxLocalVer {
					maxLocalVer = lv
				}
				if fs[fsi].IsInvalid() {
					ldbRemoveFromGlobal(snap, batch, folder, device, newName)
				} else {
					ldbUpdateGlobal(snap, batch, folder, device, newName, fs[fsi].Version)
				}
			} else if debugDB {
				l.Debugln("generic replace; equal - ignore")
			}

			fsi++
			moreDb = dbi.Next()

		case moreDb && (!moreFs || cmp == 1):
			if debugDB {
				l.Debugln("generic replace; exists - remove")
			}
			if lv := deleteFn(snap, batch, folder, device, oldName, dbi); lv > maxLocalVer {
				maxLocalVer = lv
			}
			moreDb = dbi.Next()
		}
	}

	if debugDB {
		l.Debugf("db.Write %p", batch)
	}
	err = db.Write(batch, nil)
	if err != nil {
		panic(err)
	}

	return maxLocalVer
}
예제 #15
0
// ldbUpdateGlobal adds this device+version to the version list for the given
// file. If the device is already present in the list, the version is updated.
// If the file does not have an entry in the global list, it is created.
func ldbUpdateGlobal(db dbReader, batch dbWriter, folder, device []byte, file protocol.FileInfo) bool {
	if debugDB {
		l.Debugf("update global; folder=%q device=%v file=%q version=%d", folder, protocol.DeviceIDFromBytes(device), file.Name, file.Version)
	}
	name := []byte(file.Name)
	gk := globalKey(folder, name)
	svl, err := db.Get(gk, nil)
	if err != nil && err != leveldb.ErrNotFound {
		panic(err)
	}

	var fl versionList

	// Remove the device from the current version list
	if svl != nil {
		err = fl.UnmarshalXDR(svl)
		if err != nil {
			panic(err)
		}

		for i := range fl.versions {
			if bytes.Compare(fl.versions[i].device, device) == 0 {
				if fl.versions[i].version.Equal(file.Version) {
					// No need to do anything
					return false
				}
				fl.versions = append(fl.versions[:i], fl.versions[i+1:]...)
				break
			}
		}
	}

	nv := fileVersion{
		device:  device,
		version: file.Version,
	}

	// Find a position in the list to insert this file. The file at the front
	// of the list is the newer, the "global".
	for i := range fl.versions {
		switch fl.versions[i].version.Compare(file.Version) {
		case protocol.Equal, protocol.Lesser:
			// The version at this point in the list is equal to or lesser
			// ("older") than us. We insert ourselves in front of it.
			fl.versions = insertVersion(fl.versions, i, nv)
			goto done

		case protocol.ConcurrentLesser, protocol.ConcurrentGreater:
			// The version at this point is in conflict with us. We must pull
			// the actual file metadata to determine who wins. If we win, we
			// insert ourselves in front of the loser here. (The "Lesser" and
			// "Greater" in the condition above is just based on the device
			// IDs in the version vector, which is not the only thing we use
			// to determine the winner.)
			of, ok := ldbGet(db, folder, fl.versions[i].device, name)
			if !ok {
				panic("file referenced in version list does not exist")
			}
			if file.WinsConflict(of) {
				fl.versions = insertVersion(fl.versions, i, nv)
				goto done
			}
		}
	}

	// We didn't find a position for an insert above, so append to the end.
	fl.versions = append(fl.versions, nv)

done:
	if debugDB {
		l.Debugf("batch.Put %p %x", batch, gk)
		l.Debugf("new global after update: %v", fl)
	}
	batch.Put(gk, fl.MustMarshalXDR())

	return true
}
예제 #16
0
func protocolConnectionHandler(tcpConn net.Conn, config *tls.Config) {
	conn := tls.Server(tcpConn, config)
	err := conn.Handshake()
	if err != nil {
		if debug {
			log.Println("Protocol connection TLS handshake:", conn.RemoteAddr(), err)
		}
		conn.Close()
		return
	}

	state := conn.ConnectionState()
	if (!state.NegotiatedProtocolIsMutual || state.NegotiatedProtocol != protocol.ProtocolName) && debug {
		log.Println("Protocol negotiation error")
	}

	certs := state.PeerCertificates
	if len(certs) != 1 {
		if debug {
			log.Println("Certificate list error")
		}
		conn.Close()
		return
	}

	id := syncthingprotocol.NewDeviceID(certs[0].Raw)

	messages := make(chan interface{})
	errors := make(chan error, 1)
	outbox := make(chan interface{})

	// Read messages from the connection and send them on the messages
	// channel. When there is an error, send it on the error channel and
	// return. Applies also when the connection gets closed, so the pattern
	// below is to close the connection on error, then wait for the error
	// signal from messageReader to exit.
	go messageReader(conn, messages, errors)

	pingTicker := time.NewTicker(pingInterval)
	timeoutTicker := time.NewTimer(networkTimeout)
	joined := false

	for {
		select {
		case message := <-messages:
			timeoutTicker.Reset(networkTimeout)
			if debug {
				log.Printf("Message %T from %s", message, id)
			}

			switch msg := message.(type) {
			case protocol.JoinRelayRequest:
				outboxesMut.RLock()
				_, ok := outboxes[id]
				outboxesMut.RUnlock()
				if ok {
					protocol.WriteMessage(conn, protocol.ResponseAlreadyConnected)
					if debug {
						log.Println("Already have a peer with the same ID", id, conn.RemoteAddr())
					}
					conn.Close()
					continue
				}

				outboxesMut.Lock()
				outboxes[id] = outbox
				outboxesMut.Unlock()
				joined = true

				protocol.WriteMessage(conn, protocol.ResponseSuccess)

			case protocol.ConnectRequest:
				requestedPeer := syncthingprotocol.DeviceIDFromBytes(msg.ID)
				outboxesMut.RLock()
				peerOutbox, ok := outboxes[requestedPeer]
				outboxesMut.RUnlock()
				if !ok {
					if debug {
						log.Println(id, "is looking for", requestedPeer, "which does not exist")
					}
					protocol.WriteMessage(conn, protocol.ResponseNotFound)
					conn.Close()
					continue
				}

				ses := newSession(sessionLimiter, globalLimiter)

				go ses.Serve()

				clientInvitation := ses.GetClientInvitationMessage(requestedPeer)
				serverInvitation := ses.GetServerInvitationMessage(id)

				if err := protocol.WriteMessage(conn, clientInvitation); err != nil {
					if debug {
						log.Printf("Error sending invitation from %s to client: %s", id, err)
					}
					conn.Close()
					continue
				}

				peerOutbox <- serverInvitation

				if debug {
					log.Println("Sent invitation from", id, "to", requestedPeer)
				}
				conn.Close()

			case protocol.Pong:
				// Nothing

			default:
				if debug {
					log.Printf("Unknown message %s: %T", id, message)
				}
				protocol.WriteMessage(conn, protocol.ResponseUnexpectedMessage)
				conn.Close()
			}

		case err := <-errors:
			if debug {
				log.Printf("Closing connection %s: %s", id, err)
			}
			close(outbox)

			// Potentially closing a second time.
			conn.Close()

			// Only delete the outbox if the client is joined, as it might be
			// a lookup request coming from the same client.
			if joined {
				outboxesMut.Lock()
				delete(outboxes, id)
				outboxesMut.Unlock()
			}
			return

		case <-pingTicker.C:
			if !joined {
				if debug {
					log.Println(id, "didn't join within", pingInterval)
				}
				conn.Close()
				continue
			}

			if err := protocol.WriteMessage(conn, protocol.Ping{}); err != nil {
				if debug {
					log.Println(id, err)
				}
				conn.Close()
			}

		case <-timeoutTicker.C:
			// We should receive a error from the reader loop, which will cause
			// us to quit this loop.
			if debug {
				log.Printf("%s timed out", id)
			}
			conn.Close()

		case msg := <-outbox:
			if debug {
				log.Printf("Sending message %T to %s", msg, id)
			}
			if err := protocol.WriteMessage(conn, msg); err != nil {
				if debug {
					log.Println(id, err)
				}
				conn.Close()
			}
		}
	}
}