forked from syncthing/syncthing
/
service.go
1262 lines (1108 loc) · 37.3 KB
/
service.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// Copyright (C) 2015 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
//go:generate -command counterfeiter go run github.com/maxbrunsfeld/counterfeiter/v6
//go:generate counterfeiter -o mocks/service.go --fake-name Service . Service
package connections
import (
"context"
"crypto/tls"
"crypto/x509"
"errors"
"fmt"
"math"
"net"
"net/url"
"sort"
"strings"
stdsync "sync"
"time"
"github.com/syncthing/syncthing/lib/config"
"github.com/syncthing/syncthing/lib/connections/registry"
"github.com/syncthing/syncthing/lib/discover"
"github.com/syncthing/syncthing/lib/events"
"github.com/syncthing/syncthing/lib/nat"
"github.com/syncthing/syncthing/lib/osutil"
"github.com/syncthing/syncthing/lib/protocol"
"github.com/syncthing/syncthing/lib/svcutil"
"github.com/syncthing/syncthing/lib/sync"
"github.com/syncthing/syncthing/lib/util"
// Registers NAT service providers
_ "github.com/syncthing/syncthing/lib/pmp"
_ "github.com/syncthing/syncthing/lib/upnp"
"github.com/thejerf/suture/v4"
"golang.org/x/time/rate"
)
var (
dialers = make(map[string]dialerFactory)
listeners = make(map[string]listenerFactory)
)
var (
// Dialers and listeners return errUnsupported (or a wrapped variant)
// when they are intentionally out of service due to configuration,
// build, etc. This is not logged loudly.
errUnsupported = errors.New("unsupported protocol")
// These are specific explanations for errUnsupported.
errDisabled = fmt.Errorf("%w: disabled by configuration", errUnsupported)
errDeprecated = fmt.Errorf("%w: deprecated", errUnsupported)
// Various reasons to reject a connection
errNetworkNotAllowed = errors.New("network not allowed")
errDeviceAlreadyConnected = errors.New("already connected to this device")
errDeviceIgnored = errors.New("device is ignored")
errConnLimitReached = errors.New("connection limit reached")
errDevicePaused = errors.New("device is paused")
)
const (
perDeviceWarningIntv = 15 * time.Minute
tlsHandshakeTimeout = 10 * time.Second
minConnectionReplaceAge = 10 * time.Second
minConnectionLoopSleep = 5 * time.Second
stdConnectionLoopSleep = time.Minute
worstDialerPriority = math.MaxInt32
recentlySeenCutoff = 7 * 24 * time.Hour
shortLivedConnectionThreshold = 5 * time.Second
dialMaxParallel = 64
dialMaxParallelPerDevice = 8
)
// From go/src/crypto/tls/cipher_suites.go
var tlsCipherSuiteNames = map[uint16]string{
// TLS 1.2
0x0005: "TLS_RSA_WITH_RC4_128_SHA",
0x000a: "TLS_RSA_WITH_3DES_EDE_CBC_SHA",
0x002f: "TLS_RSA_WITH_AES_128_CBC_SHA",
0x0035: "TLS_RSA_WITH_AES_256_CBC_SHA",
0x003c: "TLS_RSA_WITH_AES_128_CBC_SHA256",
0x009c: "TLS_RSA_WITH_AES_128_GCM_SHA256",
0x009d: "TLS_RSA_WITH_AES_256_GCM_SHA384",
0xc007: "TLS_ECDHE_ECDSA_WITH_RC4_128_SHA",
0xc009: "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA",
0xc00a: "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA",
0xc011: "TLS_ECDHE_RSA_WITH_RC4_128_SHA",
0xc012: "TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA",
0xc013: "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA",
0xc014: "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA",
0xc023: "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256",
0xc027: "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256",
0xc02f: "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
0xc02b: "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256",
0xc030: "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384",
0xc02c: "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384",
0xcca8: "TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305",
0xcca9: "TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305",
// TLS 1.3
0x1301: "TLS_AES_128_GCM_SHA256",
0x1302: "TLS_AES_256_GCM_SHA384",
0x1303: "TLS_CHACHA20_POLY1305_SHA256",
}
var tlsVersionNames = map[uint16]string{
tls.VersionTLS12: "TLS1.2",
tls.VersionTLS13: "TLS1.3",
}
// Service listens and dials all configured unconnected devices, via supported
// dialers. Successful connections are handed to the model.
type Service interface {
suture.Service
discover.AddressLister
ListenerStatus() map[string]ListenerStatusEntry
ConnectionStatus() map[string]ConnectionStatusEntry
NATType() string
}
type ListenerStatusEntry struct {
Error *string `json:"error"`
LANAddresses []string `json:"lanAddresses"`
WANAddresses []string `json:"wanAddresses"`
}
type ConnectionStatusEntry struct {
When time.Time `json:"when"`
Error *string `json:"error"`
}
type connWithHello struct {
c internalConn
hello protocol.Hello
err error
remoteID protocol.DeviceID
remoteCert *x509.Certificate
}
type service struct {
*suture.Supervisor
connectionStatusHandler
cfg config.Wrapper
myID protocol.DeviceID
model Model
tlsCfg *tls.Config
discoverer discover.Finder
conns chan internalConn
hellos chan *connWithHello
bepProtocolName string
tlsDefaultCommonName string
limiter *limiter
natService *nat.Service
evLogger events.Logger
registry *registry.Registry
dialNow chan struct{}
dialNowDevices map[protocol.DeviceID]struct{}
dialNowDevicesMut sync.Mutex
listenersMut sync.RWMutex
listeners map[string]genericListener
listenerTokens map[string]suture.ServiceToken
}
func NewService(cfg config.Wrapper, myID protocol.DeviceID, mdl Model, tlsCfg *tls.Config, discoverer discover.Finder, bepProtocolName string, tlsDefaultCommonName string, evLogger events.Logger, registry *registry.Registry) Service {
spec := svcutil.SpecWithInfoLogger(l)
service := &service{
Supervisor: suture.New("connections.Service", spec),
connectionStatusHandler: newConnectionStatusHandler(),
cfg: cfg,
myID: myID,
model: mdl,
tlsCfg: tlsCfg,
discoverer: discoverer,
conns: make(chan internalConn),
hellos: make(chan *connWithHello),
bepProtocolName: bepProtocolName,
tlsDefaultCommonName: tlsDefaultCommonName,
limiter: newLimiter(myID, cfg),
natService: nat.NewService(myID, cfg),
evLogger: evLogger,
registry: registry,
dialNowDevicesMut: sync.NewMutex(),
dialNow: make(chan struct{}, 1),
dialNowDevices: make(map[protocol.DeviceID]struct{}),
listenersMut: sync.NewRWMutex(),
listeners: make(map[string]genericListener),
listenerTokens: make(map[string]suture.ServiceToken),
}
cfg.Subscribe(service)
raw := cfg.RawCopy()
// Actually starts the listeners and NAT service
// Need to start this before service.connect so that any dials that
// try punch through already have a listener to cling on.
service.CommitConfiguration(raw, raw)
// There are several moving parts here; one routine per listening address
// (handled in configuration changing) to handle incoming connections,
// one routine to periodically attempt outgoing connections, one routine to
// the common handling regardless of whether the connection was
// incoming or outgoing.
service.Add(svcutil.AsService(service.connect, fmt.Sprintf("%s/connect", service)))
service.Add(svcutil.AsService(service.handleConns, fmt.Sprintf("%s/handleConns", service)))
service.Add(svcutil.AsService(service.handleHellos, fmt.Sprintf("%s/handleHellos", service)))
service.Add(service.natService)
svcutil.OnSupervisorDone(service.Supervisor, func() {
service.cfg.Unsubscribe(service.limiter)
service.cfg.Unsubscribe(service)
})
return service
}
func (s *service) handleConns(ctx context.Context) error {
for {
var c internalConn
select {
case <-ctx.Done():
return ctx.Err()
case c = <-s.conns:
}
cs := c.ConnectionState()
// We should have negotiated the next level protocol "bep/1.0" as part
// of the TLS handshake. Unfortunately this can't be a hard error,
// because there are implementations out there that don't support
// protocol negotiation (iOS for one...).
if cs.NegotiatedProtocol != s.bepProtocolName {
l.Infof("Peer at %s did not negotiate bep/1.0", c)
}
// We should have received exactly one certificate from the other
// side. If we didn't, they don't have a device ID and we drop the
// connection.
certs := cs.PeerCertificates
if cl := len(certs); cl != 1 {
l.Infof("Got peer certificate list of length %d != 1 from peer at %s; protocol error", cl, c)
c.Close()
continue
}
remoteCert := certs[0]
remoteID := protocol.NewDeviceID(remoteCert.Raw)
// The device ID should not be that of ourselves. It can happen
// though, especially in the presence of NAT hairpinning, multiple
// clients between the same NAT gateway, and global discovery.
if remoteID == s.myID {
l.Debugf("Connected to myself (%s) at %s", remoteID, c)
c.Close()
continue
}
if err := s.connectionCheckEarly(remoteID, c); err != nil {
l.Infof("Connection from %s at %s (%s) rejected: %v", remoteID, c.RemoteAddr(), c.Type(), err)
c.Close()
continue
}
_ = c.SetDeadline(time.Now().Add(20 * time.Second))
go func() {
hello, err := protocol.ExchangeHello(c, s.model.GetHello(remoteID))
select {
case s.hellos <- &connWithHello{c, hello, err, remoteID, remoteCert}:
case <-ctx.Done():
}
}()
}
}
func (s *service) connectionCheckEarly(remoteID protocol.DeviceID, c internalConn) error {
if s.cfg.IgnoredDevice(remoteID) {
return errDeviceIgnored
}
if max := s.cfg.Options().ConnectionLimitMax; max > 0 && s.model.NumConnections() >= max {
// We're not allowed to accept any more connections.
return errConnLimitReached
}
cfg, ok := s.cfg.Device(remoteID)
if !ok {
// We do go ahead exchanging hello messages to get information about the device.
return nil
}
if cfg.Paused {
return errDevicePaused
}
if len(cfg.AllowedNetworks) > 0 && !IsAllowedNetwork(c.RemoteAddr().String(), cfg.AllowedNetworks) {
// The connection is not from an allowed network.
return errNetworkNotAllowed
}
// Lower priority is better, just like nice etc.
if ct, ok := s.model.Connection(remoteID); ok {
if ct.Priority() > c.priority || time.Since(ct.Statistics().StartedAt) > minConnectionReplaceAge {
l.Debugf("Switching connections %s (existing: %s new: %s)", remoteID, ct, c)
} else {
// We should not already be connected to the other party. TODO: This
// could use some better handling. If the old connection is dead but
// hasn't timed out yet we may want to drop *that* connection and keep
// this one. But in case we are two devices connecting to each other
// in parallel we don't want to do that or we end up with no
// connections still established...
return errDeviceAlreadyConnected
}
}
return nil
}
func (s *service) handleHellos(ctx context.Context) error {
var c internalConn
var hello protocol.Hello
var err error
var remoteID protocol.DeviceID
var remoteCert *x509.Certificate
for {
select {
case <-ctx.Done():
return ctx.Err()
case withHello := <-s.hellos:
c = withHello.c
hello = withHello.hello
err = withHello.err
remoteID = withHello.remoteID
remoteCert = withHello.remoteCert
}
if err != nil {
if protocol.IsVersionMismatch(err) {
// The error will be a relatively user friendly description
// of what's wrong with the version compatibility. By
// default identify the other side by device ID and IP.
remote := fmt.Sprintf("%v (%v)", remoteID, c.RemoteAddr())
if hello.DeviceName != "" {
// If the name was set in the hello return, use that to
// give the user more info about which device is the
// affected one. It probably says more than the remote
// IP.
remote = fmt.Sprintf("%q (%s %s, %v)", hello.DeviceName, hello.ClientName, hello.ClientVersion, remoteID)
}
msg := fmt.Sprintf("Connecting to %s: %s", remote, err)
warningFor(remoteID, msg)
} else {
// It's something else - connection reset or whatever
l.Infof("Failed to exchange Hello messages with %s at %s: %s", remoteID, c, err)
}
c.Close()
continue
}
_ = c.SetDeadline(time.Time{})
// The Model will return an error for devices that we don't want to
// have a connection with for whatever reason, for example unknown devices.
if err := s.model.OnHello(remoteID, c.RemoteAddr(), hello); err != nil {
l.Infof("Connection from %s at %s (%s) rejected: %v", remoteID, c.RemoteAddr(), c.Type(), err)
c.Close()
continue
}
deviceCfg, ok := s.cfg.Device(remoteID)
if !ok {
l.Infof("Device %s removed from config during connection attempt at %s", remoteID, c)
c.Close()
continue
}
// Verify the name on the certificate. By default we set it to
// "syncthing" when generating, but the user may have replaced
// the certificate and used another name.
certName := deviceCfg.CertName
if certName == "" {
certName = s.tlsDefaultCommonName
}
if remoteCert.Subject.CommonName == certName {
// All good. We do this check because our old style certificates
// have "syncthing" in the CommonName field and no SANs, which
// is not accepted by VerifyHostname() any more as of Go 1.15.
} else if err := remoteCert.VerifyHostname(certName); err != nil {
// Incorrect certificate name is something the user most
// likely wants to know about, since it's an advanced
// config. Warn instead of Info.
l.Warnf("Bad certificate from %s at %s: %v", remoteID, c, err)
c.Close()
continue
}
// Wrap the connection in rate limiters. The limiter itself will
// keep up with config changes to the rate and whether or not LAN
// connections are limited.
isLAN := s.isLAN(c.RemoteAddr())
rd, wr := s.limiter.getLimiters(remoteID, c, isLAN)
protoConn := protocol.NewConnection(remoteID, rd, wr, c, s.model, c, deviceCfg.Compression, s.cfg.FolderPasswords(remoteID))
go func() {
<-protoConn.Closed()
s.dialNowDevicesMut.Lock()
s.dialNowDevices[remoteID] = struct{}{}
s.scheduleDialNow()
s.dialNowDevicesMut.Unlock()
}()
l.Infof("Established secure connection to %s at %s", remoteID, c)
s.model.AddConnection(protoConn, hello)
continue
}
}
func (s *service) connect(ctx context.Context) error {
// Map of when to earliest dial each given device + address again
nextDialAt := make(nextDialRegistry)
// Used as delay for the first few connection attempts (adjusted up to
// minConnectionLoopSleep), increased exponentially until it reaches
// stdConnectionLoopSleep, at which time the normal sleep mechanism
// kicks in.
initialRampup := time.Second
for {
cfg := s.cfg.RawCopy()
bestDialerPriority := s.bestDialerPriority(cfg)
isInitialRampup := initialRampup < stdConnectionLoopSleep
l.Debugln("Connection loop")
if isInitialRampup {
l.Debugln("Connection loop in initial rampup")
}
// Used for consistency throughout this loop run, as time passes
// while we try connections etc.
now := time.Now()
// Attempt to dial all devices that are unconnected or can be connection-upgraded
s.dialDevices(ctx, now, cfg, bestDialerPriority, nextDialAt, isInitialRampup)
var sleep time.Duration
if isInitialRampup {
// We are in the initial rampup time, so we slowly, statically
// increase the sleep time.
sleep = initialRampup
initialRampup *= 2
} else {
// The sleep time is until the next dial scheduled in nextDialAt,
// clamped by stdConnectionLoopSleep as we don't want to sleep too
// long (config changes might happen).
sleep = nextDialAt.sleepDurationAndCleanup(now)
}
// ... while making sure not to loop too quickly either.
if sleep < minConnectionLoopSleep {
sleep = minConnectionLoopSleep
}
l.Debugln("Next connection loop in", sleep)
timeout := time.NewTimer(sleep)
select {
case <-s.dialNow:
// Remove affected devices from nextDialAt to dial immediately,
// regardless of when we last dialed it (there's cool down in the
// registry for too many repeat dials).
s.dialNowDevicesMut.Lock()
for device := range s.dialNowDevices {
nextDialAt.redialDevice(device, now)
}
s.dialNowDevices = make(map[protocol.DeviceID]struct{})
s.dialNowDevicesMut.Unlock()
timeout.Stop()
case <-timeout.C:
case <-ctx.Done():
return ctx.Err()
}
}
}
func (*service) bestDialerPriority(cfg config.Configuration) int {
bestDialerPriority := worstDialerPriority
for _, df := range dialers {
if df.Valid(cfg) != nil {
continue
}
if prio := df.Priority(); prio < bestDialerPriority {
bestDialerPriority = prio
}
}
return bestDialerPriority
}
func (s *service) dialDevices(ctx context.Context, now time.Time, cfg config.Configuration, bestDialerPriority int, nextDialAt nextDialRegistry, initial bool) {
// Figure out current connection limits up front to see if there's any
// point in resolving devices and such at all.
allowAdditional := 0 // no limit
connectionLimit := cfg.Options.LowestConnectionLimit()
if connectionLimit > 0 {
current := s.model.NumConnections()
allowAdditional = connectionLimit - current
if allowAdditional <= 0 {
l.Debugf("Skipping dial because we've reached the connection limit, current %d >= limit %d", current, connectionLimit)
return
}
}
// Get device statistics for the last seen time of each device. This
// isn't critical, so ignore the potential error.
stats, _ := s.model.DeviceStatistics()
queue := make(dialQueue, 0, len(cfg.Devices))
for _, deviceCfg := range cfg.Devices {
// Don't attempt to connect to ourselves...
if deviceCfg.DeviceID == s.myID {
continue
}
// Don't attempt to connect to paused devices...
if deviceCfg.Paused {
continue
}
// See if we are already connected and, if so, what our cutoff is
// for dialer priority.
priorityCutoff := worstDialerPriority
connection, connected := s.model.Connection(deviceCfg.DeviceID)
if connected {
priorityCutoff = connection.Priority()
if bestDialerPriority >= priorityCutoff {
// Our best dialer is not any better than what we already
// have, so nothing to do here.
continue
}
}
dialTargets := s.resolveDialTargets(ctx, now, cfg, deviceCfg, nextDialAt, initial, priorityCutoff)
if len(dialTargets) > 0 {
queue = append(queue, dialQueueEntry{
id: deviceCfg.DeviceID,
lastSeen: stats[deviceCfg.DeviceID].LastSeen,
shortLived: stats[deviceCfg.DeviceID].LastConnectionDurationS < shortLivedConnectionThreshold.Seconds(),
targets: dialTargets,
})
}
}
// Sort the queue in an order we think will be useful (most recent
// first, deprioriting unstable devices, randomizing those we haven't
// seen in a long while). If we don't do connection limiting the sorting
// doesn't have much effect, but it may result in getting up and running
// quicker if only a subset of configured devices are actually reachable
// (by prioritizing those that were reachable recently).
queue.Sort()
// Perform dials according to the queue, stopping when we've reached the
// allowed additional number of connections (if limited).
numConns := 0
var numConnsMut stdsync.Mutex
dialSemaphore := util.NewSemaphore(dialMaxParallel)
dialWG := new(stdsync.WaitGroup)
dialCtx, dialCancel := context.WithCancel(ctx)
defer func() {
dialWG.Wait()
dialCancel()
}()
for i := range queue {
select {
case <-dialCtx.Done():
return
default:
}
dialWG.Add(1)
go func(entry dialQueueEntry) {
defer dialWG.Done()
conn, ok := s.dialParallel(dialCtx, entry.id, entry.targets, dialSemaphore)
if !ok {
return
}
numConnsMut.Lock()
if allowAdditional == 0 || numConns < allowAdditional {
select {
case s.conns <- conn:
numConns++
if allowAdditional > 0 && numConns >= allowAdditional {
dialCancel()
}
case <-dialCtx.Done():
}
}
numConnsMut.Unlock()
}(queue[i])
}
}
func (s *service) resolveDialTargets(ctx context.Context, now time.Time, cfg config.Configuration, deviceCfg config.DeviceConfiguration, nextDialAt nextDialRegistry, initial bool, priorityCutoff int) []dialTarget {
deviceID := deviceCfg.DeviceID
addrs := s.resolveDeviceAddrs(ctx, deviceCfg)
l.Debugln("Resolved device", deviceID, "addresses:", addrs)
dialTargets := make([]dialTarget, 0, len(addrs))
for _, addr := range addrs {
// Use both device and address, as you might have two devices connected
// to the same relay
if !initial && nextDialAt.get(deviceID, addr).After(now) {
l.Debugf("Not dialing %s via %v as it's not time yet", deviceID, addr)
continue
}
// If we fail at any step before actually getting the dialer
// retry in a minute
nextDialAt.set(deviceID, addr, now.Add(time.Minute))
uri, err := url.Parse(addr)
if err != nil {
s.setConnectionStatus(addr, err)
l.Infof("Parsing dialer address %s: %v", addr, err)
continue
}
if len(deviceCfg.AllowedNetworks) > 0 {
if !IsAllowedNetwork(uri.Host, deviceCfg.AllowedNetworks) {
s.setConnectionStatus(addr, errors.New("network disallowed"))
l.Debugln("Network for", uri, "is disallowed")
continue
}
}
dialerFactory, err := getDialerFactory(cfg, uri)
if err != nil {
s.setConnectionStatus(addr, err)
}
if errors.Is(err, errUnsupported) {
l.Debugf("Dialer for %v: %v", uri, err)
continue
} else if err != nil {
l.Infof("Dialer for %v: %v", uri, err)
continue
}
priority := dialerFactory.Priority()
if priority >= priorityCutoff {
l.Debugf("Not dialing using %s as priority is not better than current connection (%d >= %d)", dialerFactory, dialerFactory.Priority(), priorityCutoff)
continue
}
dialer := dialerFactory.New(s.cfg.Options(), s.tlsCfg, s.registry)
nextDialAt.set(deviceID, addr, now.Add(dialer.RedialFrequency()))
// For LAN addresses, increase the priority so that we
// try these first.
switch {
case dialerFactory.AlwaysWAN():
// Do nothing.
case s.isLANHost(uri.Host):
priority--
}
dialTargets = append(dialTargets, dialTarget{
addr: addr,
dialer: dialer,
priority: priority,
deviceID: deviceID,
uri: uri,
})
}
return dialTargets
}
func (s *service) resolveDeviceAddrs(ctx context.Context, cfg config.DeviceConfiguration) []string {
var addrs []string
for _, addr := range cfg.Addresses {
if addr == "dynamic" {
if s.discoverer != nil {
if t, err := s.discoverer.Lookup(ctx, cfg.DeviceID); err == nil {
addrs = append(addrs, t...)
}
}
} else {
addrs = append(addrs, addr)
}
}
return util.UniqueTrimmedStrings(addrs)
}
func (s *service) isLANHost(host string) bool {
// Probably we are called with an ip:port combo which we can resolve as
// a TCP address.
if addr, err := net.ResolveTCPAddr("tcp", host); err == nil {
return s.isLAN(addr)
}
// ... but this function looks general enough that someone might try
// with just an IP as well in the future so lets allow that.
if addr, err := net.ResolveIPAddr("ip", host); err == nil {
return s.isLAN(addr)
}
return false
}
func (s *service) isLAN(addr net.Addr) bool {
var ip net.IP
switch addr := addr.(type) {
case *net.IPAddr:
ip = addr.IP
case *net.TCPAddr:
ip = addr.IP
case *net.UDPAddr:
ip = addr.IP
default:
// From the standard library, just Unix sockets.
// If you invent your own, handle it.
return false
}
if ip.IsLoopback() {
return true
}
for _, lan := range s.cfg.Options().AlwaysLocalNets {
_, ipnet, err := net.ParseCIDR(lan)
if err != nil {
l.Debugln("Network", lan, "is malformed:", err)
continue
}
if ipnet.Contains(ip) {
return true
}
}
lans, _ := osutil.GetLans()
for _, lan := range lans {
if lan.Contains(ip) {
return true
}
}
return false
}
func (s *service) createListener(factory listenerFactory, uri *url.URL) bool {
// must be called with listenerMut held
l.Debugln("Starting listener", uri)
listener := factory.New(uri, s.cfg, s.tlsCfg, s.conns, s.natService, s.registry)
listener.OnAddressesChanged(s.logListenAddressesChangedEvent)
// Retrying a listener many times in rapid succession is unlikely to help,
// thus back off quickly. A listener may soon be functional again, e.g. due
// to a network interface coming back online - retry every minute.
spec := svcutil.SpecWithInfoLogger(l)
spec.FailureThreshold = 2
spec.FailureBackoff = time.Minute
sup := suture.New(fmt.Sprintf("listenerSupervisor@%v", listener), spec)
sup.Add(listener)
s.listeners[uri.String()] = listener
s.listenerTokens[uri.String()] = s.Add(sup)
return true
}
func (s *service) logListenAddressesChangedEvent(l ListenerAddresses) {
s.evLogger.Log(events.ListenAddressesChanged, map[string]interface{}{
"address": l.URI,
"lan": l.LANAddresses,
"wan": l.WANAddresses,
})
}
func (s *service) CommitConfiguration(from, to config.Configuration) bool {
newDevices := make(map[protocol.DeviceID]bool, len(to.Devices))
for _, dev := range to.Devices {
newDevices[dev.DeviceID] = true
}
for _, dev := range from.Devices {
if !newDevices[dev.DeviceID] {
warningLimitersMut.Lock()
delete(warningLimiters, dev.DeviceID)
warningLimitersMut.Unlock()
}
}
s.checkAndSignalConnectLoopOnUpdatedDevices(from, to)
s.listenersMut.Lock()
seen := make(map[string]struct{})
for _, addr := range to.Options.ListenAddresses() {
if addr == "" {
// We can get an empty address if there is an empty listener
// element in the config, indicating no listeners should be
// used. This is not an error.
continue
}
uri, err := url.Parse(addr)
if err != nil {
l.Warnf("Skipping malformed listener URL %q: %v", addr, err)
continue
}
// Make sure we always have the canonical representation of the URL.
// This is for consistency as we use it as a map key, but also to
// avoid misunderstandings. We do not just use the canonicalized
// version, because an URL that looks very similar to a human might
// mean something entirely different to the computer (e.g.,
// tcp:/127.0.0.1:22000 in fact being equivalent to tcp://:22000).
if canonical := uri.String(); canonical != addr {
l.Warnf("Skipping malformed listener URL %q (not canonical)", addr)
continue
}
if _, ok := s.listeners[addr]; ok {
seen[addr] = struct{}{}
continue
}
factory, err := getListenerFactory(to, uri)
if errors.Is(err, errUnsupported) {
l.Debugf("Listener for %v: %v", uri, err)
continue
} else if err != nil {
l.Infof("Listener for %v: %v", uri, err)
continue
}
s.createListener(factory, uri)
seen[addr] = struct{}{}
}
for addr, listener := range s.listeners {
if _, ok := seen[addr]; !ok || listener.Factory().Valid(to) != nil {
l.Debugln("Stopping listener", addr)
s.Remove(s.listenerTokens[addr])
delete(s.listenerTokens, addr)
delete(s.listeners, addr)
}
}
s.listenersMut.Unlock()
return true
}
func (s *service) checkAndSignalConnectLoopOnUpdatedDevices(from, to config.Configuration) {
oldDevices := from.DeviceMap()
dial := false
s.dialNowDevicesMut.Lock()
for _, dev := range to.Devices {
if dev.Paused {
continue
}
if oldDev, ok := oldDevices[dev.DeviceID]; !ok || oldDev.Paused {
s.dialNowDevices[dev.DeviceID] = struct{}{}
dial = true
} else if !util.EqualStrings(oldDev.Addresses, dev.Addresses) {
dial = true
}
}
if dial {
s.scheduleDialNow()
}
s.dialNowDevicesMut.Unlock()
}
func (s *service) scheduleDialNow() {
select {
case s.dialNow <- struct{}{}:
default:
// channel is blocked - a config update is already pending for the connection loop.
}
}
func (s *service) AllAddresses() []string {
s.listenersMut.RLock()
var addrs []string
for _, listener := range s.listeners {
for _, lanAddr := range listener.LANAddresses() {
addrs = append(addrs, lanAddr.String())
}
for _, wanAddr := range listener.WANAddresses() {
addrs = append(addrs, wanAddr.String())
}
}
s.listenersMut.RUnlock()
return util.UniqueTrimmedStrings(addrs)
}
func (s *service) ExternalAddresses() []string {
if s.cfg.Options().AnnounceLANAddresses {
return s.AllAddresses()
}
s.listenersMut.RLock()
var addrs []string
for _, listener := range s.listeners {
for _, wanAddr := range listener.WANAddresses() {
addrs = append(addrs, wanAddr.String())
}
}
s.listenersMut.RUnlock()
return util.UniqueTrimmedStrings(addrs)
}
func (s *service) ListenerStatus() map[string]ListenerStatusEntry {
result := make(map[string]ListenerStatusEntry)
s.listenersMut.RLock()
for addr, listener := range s.listeners {
var status ListenerStatusEntry
if err := listener.Error(); err != nil {
errStr := err.Error()
status.Error = &errStr
}
status.LANAddresses = urlsToStrings(listener.LANAddresses())
status.WANAddresses = urlsToStrings(listener.WANAddresses())
result[addr] = status
}
s.listenersMut.RUnlock()
return result
}
type connectionStatusHandler struct {
connectionStatusMut sync.RWMutex
connectionStatus map[string]ConnectionStatusEntry // address -> latest error/status
}
func newConnectionStatusHandler() connectionStatusHandler {
return connectionStatusHandler{
connectionStatusMut: sync.NewRWMutex(),
connectionStatus: make(map[string]ConnectionStatusEntry),
}
}
func (s *connectionStatusHandler) ConnectionStatus() map[string]ConnectionStatusEntry {
result := make(map[string]ConnectionStatusEntry)
s.connectionStatusMut.RLock()
for k, v := range s.connectionStatus {
result[k] = v
}
s.connectionStatusMut.RUnlock()
return result
}
func (s *connectionStatusHandler) setConnectionStatus(address string, err error) {
if errors.Is(err, context.Canceled) {
return
}
status := ConnectionStatusEntry{When: time.Now().UTC().Truncate(time.Second)}
if err != nil {
errStr := err.Error()
status.Error = &errStr
}
s.connectionStatusMut.Lock()
s.connectionStatus[address] = status
s.connectionStatusMut.Unlock()
}
func (s *service) NATType() string {
s.listenersMut.RLock()
defer s.listenersMut.RUnlock()
for _, listener := range s.listeners {
natType := listener.NATType()
if natType != "unknown" {
return natType
}
}
return "unknown"
}
func getDialerFactory(cfg config.Configuration, uri *url.URL) (dialerFactory, error) {
dialerFactory, ok := dialers[uri.Scheme]
if !ok {
return nil, fmt.Errorf("unknown address scheme %q", uri.Scheme)
}
if err := dialerFactory.Valid(cfg); err != nil {
return nil, err
}
return dialerFactory, nil
}