lightning 0.0.13

A Bitcoin Lightning library in Rust. Does most of the hard work, without implying a specific runtime, requiring clients implement basic network logic, chain interactions and disk storage. Still missing tons of error-handling. See GitHub issues for suggested projects if you want to contribute. Don't have to bother telling you not to use this for anything serious, because you'd have to build a client around it to even try.
Documentation
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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
// This file is Copyright its original authors, visible in version control
// history.
//
// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
// You may not use this file except in accordance with one or both of these
// licenses.

//! Top level peer message handling and socket handling logic lives here.
//!
//! Instead of actually servicing sockets ourselves we require that you implement the
//! SocketDescriptor interface and use that to receive actions which you should perform on the
//! socket, and call into PeerManager with bytes read from the socket. The PeerManager will then
//! call into the provided message handlers (probably a ChannelManager and NetGraphmsgHandler) with messages
//! they should handle, and encoding/sending response messages.

use bitcoin::secp256k1::key::{SecretKey,PublicKey};

use ln::features::InitFeatures;
use ln::msgs;
use ln::msgs::{ChannelMessageHandler, LightningError, RoutingMessageHandler};
use ln::channelmanager::{SimpleArcChannelManager, SimpleRefChannelManager};
use util::ser::{VecWriter, Writeable};
use ln::peer_channel_encryptor::{PeerChannelEncryptor,NextNoiseStep};
use ln::wire;
use ln::wire::Encode;
use util::byte_utils;
use util::events::{MessageSendEvent, MessageSendEventsProvider};
use util::logger::Logger;
use routing::network_graph::NetGraphMsgHandler;

use std::collections::{HashMap,hash_map,HashSet,LinkedList};
use std::sync::{Arc, Mutex};
use std::sync::atomic::{AtomicUsize, Ordering};
use std::{cmp, error, hash, fmt, mem};
use std::ops::Deref;

use bitcoin::hashes::sha256::Hash as Sha256;
use bitcoin::hashes::sha256::HashEngine as Sha256Engine;
use bitcoin::hashes::{HashEngine, Hash};

/// A dummy struct which implements `RoutingMessageHandler` without storing any routing information
/// or doing any processing. You can provide one of these as the route_handler in a MessageHandler.
pub struct IgnoringMessageHandler{}
impl MessageSendEventsProvider for IgnoringMessageHandler {
	fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent> { Vec::new() }
}
impl RoutingMessageHandler for IgnoringMessageHandler {
	fn handle_node_announcement(&self, _msg: &msgs::NodeAnnouncement) -> Result<bool, LightningError> { Ok(false) }
	fn handle_channel_announcement(&self, _msg: &msgs::ChannelAnnouncement) -> Result<bool, LightningError> { Ok(false) }
	fn handle_channel_update(&self, _msg: &msgs::ChannelUpdate) -> Result<bool, LightningError> { Ok(false) }
	fn handle_htlc_fail_channel_update(&self, _update: &msgs::HTLCFailChannelUpdate) {}
	fn get_next_channel_announcements(&self, _starting_point: u64, _batch_amount: u8) ->
		Vec<(msgs::ChannelAnnouncement, Option<msgs::ChannelUpdate>, Option<msgs::ChannelUpdate>)> { Vec::new() }
	fn get_next_node_announcements(&self, _starting_point: Option<&PublicKey>, _batch_amount: u8) -> Vec<msgs::NodeAnnouncement> { Vec::new() }
	fn sync_routing_table(&self, _their_node_id: &PublicKey, _init: &msgs::Init) {}
	fn handle_reply_channel_range(&self, _their_node_id: &PublicKey, _msg: msgs::ReplyChannelRange) -> Result<(), LightningError> { Ok(()) }
	fn handle_reply_short_channel_ids_end(&self, _their_node_id: &PublicKey, _msg: msgs::ReplyShortChannelIdsEnd) -> Result<(), LightningError> { Ok(()) }
	fn handle_query_channel_range(&self, _their_node_id: &PublicKey, _msg: msgs::QueryChannelRange) -> Result<(), LightningError> { Ok(()) }
	fn handle_query_short_channel_ids(&self, _their_node_id: &PublicKey, _msg: msgs::QueryShortChannelIds) -> Result<(), LightningError> { Ok(()) }
}
impl Deref for IgnoringMessageHandler {
	type Target = IgnoringMessageHandler;
	fn deref(&self) -> &Self { self }
}

/// A dummy struct which implements `ChannelMessageHandler` without having any channels.
/// You can provide one of these as the route_handler in a MessageHandler.
pub struct ErroringMessageHandler {
	message_queue: Mutex<Vec<MessageSendEvent>>
}
impl ErroringMessageHandler {
	/// Constructs a new ErroringMessageHandler
	pub fn new() -> Self {
		Self { message_queue: Mutex::new(Vec::new()) }
	}
	fn push_error(&self, node_id: &PublicKey, channel_id: [u8; 32]) {
		self.message_queue.lock().unwrap().push(MessageSendEvent::HandleError {
			action: msgs::ErrorAction::SendErrorMessage {
				msg: msgs::ErrorMessage { channel_id, data: "We do not support channel messages, sorry.".to_owned() },
			},
			node_id: node_id.clone(),
		});
	}
}
impl MessageSendEventsProvider for ErroringMessageHandler {
	fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent> {
		let mut res = Vec::new();
		mem::swap(&mut res, &mut self.message_queue.lock().unwrap());
		res
	}
}
impl ChannelMessageHandler for ErroringMessageHandler {
	// Any messages which are related to a specific channel generate an error message to let the
	// peer know we don't care about channels.
	fn handle_open_channel(&self, their_node_id: &PublicKey, _their_features: InitFeatures, msg: &msgs::OpenChannel) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.temporary_channel_id);
	}
	fn handle_accept_channel(&self, their_node_id: &PublicKey, _their_features: InitFeatures, msg: &msgs::AcceptChannel) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.temporary_channel_id);
	}
	fn handle_funding_created(&self, their_node_id: &PublicKey, msg: &msgs::FundingCreated) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.temporary_channel_id);
	}
	fn handle_funding_signed(&self, their_node_id: &PublicKey, msg: &msgs::FundingSigned) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.channel_id);
	}
	fn handle_funding_locked(&self, their_node_id: &PublicKey, msg: &msgs::FundingLocked) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.channel_id);
	}
	fn handle_shutdown(&self, their_node_id: &PublicKey, _their_features: &InitFeatures, msg: &msgs::Shutdown) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.channel_id);
	}
	fn handle_closing_signed(&self, their_node_id: &PublicKey, msg: &msgs::ClosingSigned) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.channel_id);
	}
	fn handle_update_add_htlc(&self, their_node_id: &PublicKey, msg: &msgs::UpdateAddHTLC) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.channel_id);
	}
	fn handle_update_fulfill_htlc(&self, their_node_id: &PublicKey, msg: &msgs::UpdateFulfillHTLC) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.channel_id);
	}
	fn handle_update_fail_htlc(&self, their_node_id: &PublicKey, msg: &msgs::UpdateFailHTLC) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.channel_id);
	}
	fn handle_update_fail_malformed_htlc(&self, their_node_id: &PublicKey, msg: &msgs::UpdateFailMalformedHTLC) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.channel_id);
	}
	fn handle_commitment_signed(&self, their_node_id: &PublicKey, msg: &msgs::CommitmentSigned) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.channel_id);
	}
	fn handle_revoke_and_ack(&self, their_node_id: &PublicKey, msg: &msgs::RevokeAndACK) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.channel_id);
	}
	fn handle_update_fee(&self, their_node_id: &PublicKey, msg: &msgs::UpdateFee) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.channel_id);
	}
	fn handle_announcement_signatures(&self, their_node_id: &PublicKey, msg: &msgs::AnnouncementSignatures) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.channel_id);
	}
	fn handle_channel_reestablish(&self, their_node_id: &PublicKey, msg: &msgs::ChannelReestablish) {
		ErroringMessageHandler::push_error(self, their_node_id, msg.channel_id);
	}
	fn peer_disconnected(&self, _their_node_id: &PublicKey, _no_connection_possible: bool) {}
	fn peer_connected(&self, _their_node_id: &PublicKey, _msg: &msgs::Init) {}
	fn handle_error(&self, _their_node_id: &PublicKey, _msg: &msgs::ErrorMessage) {}
}
impl Deref for ErroringMessageHandler {
	type Target = ErroringMessageHandler;
	fn deref(&self) -> &Self { self }
}

/// Provides references to trait impls which handle different types of messages.
pub struct MessageHandler<CM: Deref, RM: Deref> where
		CM::Target: ChannelMessageHandler,
		RM::Target: RoutingMessageHandler {
	/// A message handler which handles messages specific to channels. Usually this is just a
	/// ChannelManager object or a ErroringMessageHandler.
	pub chan_handler: CM,
	/// A message handler which handles messages updating our knowledge of the network channel
	/// graph. Usually this is just a NetGraphMsgHandlerMonitor object or an IgnoringMessageHandler.
	pub route_handler: RM,
}

/// Provides an object which can be used to send data to and which uniquely identifies a connection
/// to a remote host. You will need to be able to generate multiple of these which meet Eq and
/// implement Hash to meet the PeerManager API.
///
/// For efficiency, Clone should be relatively cheap for this type.
///
/// You probably want to just extend an int and put a file descriptor in a struct and implement
/// send_data. Note that if you are using a higher-level net library that may call close() itself,
/// be careful to ensure you don't have races whereby you might register a new connection with an
/// fd which is the same as a previous one which has yet to be removed via
/// PeerManager::socket_disconnected().
pub trait SocketDescriptor : cmp::Eq + hash::Hash + Clone {
	/// Attempts to send some data from the given slice to the peer.
	///
	/// Returns the amount of data which was sent, possibly 0 if the socket has since disconnected.
	/// Note that in the disconnected case, socket_disconnected must still fire and further write
	/// attempts may occur until that time.
	///
	/// If the returned size is smaller than data.len(), a write_available event must
	/// trigger the next time more data can be written. Additionally, until the a send_data event
	/// completes fully, no further read_events should trigger on the same peer!
	///
	/// If a read_event on this descriptor had previously returned true (indicating that read
	/// events should be paused to prevent DoS in the send buffer), resume_read may be set
	/// indicating that read events on this descriptor should resume. A resume_read of false does
	/// *not* imply that further read events should be paused.
	fn send_data(&mut self, data: &[u8], resume_read: bool) -> usize;
	/// Disconnect the socket pointed to by this SocketDescriptor. Once this function returns, no
	/// more calls to write_buffer_space_avail, read_event or socket_disconnected may be made with
	/// this descriptor. No socket_disconnected call should be generated as a result of this call,
	/// though races may occur whereby disconnect_socket is called after a call to
	/// socket_disconnected but prior to socket_disconnected returning.
	fn disconnect_socket(&mut self);
}

/// Error for PeerManager errors. If you get one of these, you must disconnect the socket and
/// generate no further read_event/write_buffer_space_avail/socket_disconnected calls for the
/// descriptor.
#[derive(Clone)]
pub struct PeerHandleError {
	/// Used to indicate that we probably can't make any future connections to this peer, implying
	/// we should go ahead and force-close any channels we have with it.
	pub no_connection_possible: bool,
}
impl fmt::Debug for PeerHandleError {
	fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
		formatter.write_str("Peer Sent Invalid Data")
	}
}
impl fmt::Display for PeerHandleError {
	fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
		formatter.write_str("Peer Sent Invalid Data")
	}
}
impl error::Error for PeerHandleError {
	fn description(&self) -> &str {
		"Peer Sent Invalid Data"
	}
}

enum InitSyncTracker{
	NoSyncRequested,
	ChannelsSyncing(u64),
	NodesSyncing(PublicKey),
}

struct Peer {
	channel_encryptor: PeerChannelEncryptor,
	outbound: bool,
	their_node_id: Option<PublicKey>,
	their_features: Option<InitFeatures>,

	pending_outbound_buffer: LinkedList<Vec<u8>>,
	pending_outbound_buffer_first_msg_offset: usize,
	awaiting_write_event: bool,

	pending_read_buffer: Vec<u8>,
	pending_read_buffer_pos: usize,
	pending_read_is_header: bool,

	sync_status: InitSyncTracker,

	awaiting_pong: bool,
}

impl Peer {
	/// Returns true if the channel announcements/updates for the given channel should be
	/// forwarded to this peer.
	/// If we are sending our routing table to this peer and we have not yet sent channel
	/// announcements/updates for the given channel_id then we will send it when we get to that
	/// point and we shouldn't send it yet to avoid sending duplicate updates. If we've already
	/// sent the old versions, we should send the update, and so return true here.
	fn should_forward_channel_announcement(&self, channel_id: u64)->bool{
		match self.sync_status {
			InitSyncTracker::NoSyncRequested => true,
			InitSyncTracker::ChannelsSyncing(i) => i < channel_id,
			InitSyncTracker::NodesSyncing(_) => true,
		}
	}

	/// Similar to the above, but for node announcements indexed by node_id.
	fn should_forward_node_announcement(&self, node_id: PublicKey) -> bool {
		match self.sync_status {
			InitSyncTracker::NoSyncRequested => true,
			InitSyncTracker::ChannelsSyncing(_) => false,
			InitSyncTracker::NodesSyncing(pk) => pk < node_id,
		}
	}
}

struct PeerHolder<Descriptor: SocketDescriptor> {
	peers: HashMap<Descriptor, Peer>,
	/// Added to by do_read_event for cases where we pushed a message onto the send buffer but
	/// didn't call do_attempt_write_data to avoid reentrancy. Cleared in process_events()
	peers_needing_send: HashSet<Descriptor>,
	/// Only add to this set when noise completes:
	node_id_to_descriptor: HashMap<PublicKey, Descriptor>,
}

#[cfg(not(any(target_pointer_width = "32", target_pointer_width = "64")))]
fn _check_usize_is_32_or_64() {
	// See below, less than 32 bit pointers may be unsafe here!
	unsafe { mem::transmute::<*const usize, [u8; 4]>(panic!()); }
}

/// SimpleArcPeerManager is useful when you need a PeerManager with a static lifetime, e.g.
/// when you're using lightning-net-tokio (since tokio::spawn requires parameters with static
/// lifetimes). Other times you can afford a reference, which is more efficient, in which case
/// SimpleRefPeerManager is the more appropriate type. Defining these type aliases prevents
/// issues such as overly long function definitions.
pub type SimpleArcPeerManager<SD, M, T, F, C, L> = PeerManager<SD, Arc<SimpleArcChannelManager<M, T, F, L>>, Arc<NetGraphMsgHandler<Arc<C>, Arc<L>>>, Arc<L>>;

/// SimpleRefPeerManager is a type alias for a PeerManager reference, and is the reference
/// counterpart to the SimpleArcPeerManager type alias. Use this type by default when you don't
/// need a PeerManager with a static lifetime. You'll need a static lifetime in cases such as
/// usage of lightning-net-tokio (since tokio::spawn requires parameters with static lifetimes).
/// But if this is not necessary, using a reference is more efficient. Defining these type aliases
/// helps with issues such as long function definitions.
pub type SimpleRefPeerManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, SD, M, T, F, C, L> = PeerManager<SD, SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, M, T, F, L>, &'e NetGraphMsgHandler<&'g C, &'f L>, &'f L>;

/// A PeerManager manages a set of peers, described by their SocketDescriptor and marshalls socket
/// events into messages which it passes on to its MessageHandlers.
///
/// Rather than using a plain PeerManager, it is preferable to use either a SimpleArcPeerManager
/// a SimpleRefPeerManager, for conciseness. See their documentation for more details, but
/// essentially you should default to using a SimpleRefPeerManager, and use a
/// SimpleArcPeerManager when you require a PeerManager with a static lifetime, such as when
/// you're using lightning-net-tokio.
pub struct PeerManager<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> where
		CM::Target: ChannelMessageHandler,
		RM::Target: RoutingMessageHandler,
		L::Target: Logger {
	message_handler: MessageHandler<CM, RM>,
	peers: Mutex<PeerHolder<Descriptor>>,
	our_node_secret: SecretKey,
	ephemeral_key_midstate: Sha256Engine,

	// Usize needs to be at least 32 bits to avoid overflowing both low and high. If usize is 64
	// bits we will never realistically count into high:
	peer_counter_low: AtomicUsize,
	peer_counter_high: AtomicUsize,

	logger: L,
}

enum MessageHandlingError {
	PeerHandleError(PeerHandleError),
	LightningError(LightningError),
}

impl From<PeerHandleError> for MessageHandlingError {
	fn from(error: PeerHandleError) -> Self {
		MessageHandlingError::PeerHandleError(error)
	}
}

impl From<LightningError> for MessageHandlingError {
	fn from(error: LightningError) -> Self {
		MessageHandlingError::LightningError(error)
	}
}

macro_rules! encode_msg {
	($msg: expr) => {{
		let mut buffer = VecWriter(Vec::new());
		wire::write($msg, &mut buffer).unwrap();
		buffer.0
	}}
}

impl<Descriptor: SocketDescriptor, CM: Deref, L: Deref> PeerManager<Descriptor, CM, IgnoringMessageHandler, L> where
		CM::Target: ChannelMessageHandler,
		L::Target: Logger {
	/// Constructs a new PeerManager with the given ChannelMessageHandler. No routing message
	/// handler is used and network graph messages are ignored.
	///
	/// ephemeral_random_data is used to derive per-connection ephemeral keys and must be
	/// cryptographically secure random bytes.
	///
	/// (C-not exported) as we can't export a PeerManager with a dummy route handler
	pub fn new_channel_only(channel_message_handler: CM, our_node_secret: SecretKey, ephemeral_random_data: &[u8; 32], logger: L) -> Self {
		Self::new(MessageHandler {
			chan_handler: channel_message_handler,
			route_handler: IgnoringMessageHandler{},
		}, our_node_secret, ephemeral_random_data, logger)
	}
}

impl<Descriptor: SocketDescriptor, RM: Deref, L: Deref> PeerManager<Descriptor, ErroringMessageHandler, RM, L> where
		RM::Target: RoutingMessageHandler,
		L::Target: Logger {
	/// Constructs a new PeerManager with the given RoutingMessageHandler. No channel message
	/// handler is used and messages related to channels will be ignored (or generate error
	/// messages). Note that some other lightning implementations time-out connections after some
	/// time if no channel is built with the peer.
	///
	/// ephemeral_random_data is used to derive per-connection ephemeral keys and must be
	/// cryptographically secure random bytes.
	///
	/// (C-not exported) as we can't export a PeerManager with a dummy channel handler
	pub fn new_routing_only(routing_message_handler: RM, our_node_secret: SecretKey, ephemeral_random_data: &[u8; 32], logger: L) -> Self {
		Self::new(MessageHandler {
			chan_handler: ErroringMessageHandler::new(),
			route_handler: routing_message_handler,
		}, our_node_secret, ephemeral_random_data, logger)
	}
}

/// Manages and reacts to connection events. You probably want to use file descriptors as PeerIds.
/// PeerIds may repeat, but only after socket_disconnected() has been called.
impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, L: Deref> PeerManager<Descriptor, CM, RM, L> where
		CM::Target: ChannelMessageHandler,
		RM::Target: RoutingMessageHandler,
		L::Target: Logger {
	/// Constructs a new PeerManager with the given message handlers and node_id secret key
	/// ephemeral_random_data is used to derive per-connection ephemeral keys and must be
	/// cryptographically secure random bytes.
	pub fn new(message_handler: MessageHandler<CM, RM>, our_node_secret: SecretKey, ephemeral_random_data: &[u8; 32], logger: L) -> Self {
		let mut ephemeral_key_midstate = Sha256::engine();
		ephemeral_key_midstate.input(ephemeral_random_data);

		PeerManager {
			message_handler,
			peers: Mutex::new(PeerHolder {
				peers: HashMap::new(),
				peers_needing_send: HashSet::new(),
				node_id_to_descriptor: HashMap::new()
			}),
			our_node_secret,
			ephemeral_key_midstate,
			peer_counter_low: AtomicUsize::new(0),
			peer_counter_high: AtomicUsize::new(0),
			logger,
		}
	}

	/// Get the list of node ids for peers which have completed the initial handshake.
	///
	/// For outbound connections, this will be the same as the their_node_id parameter passed in to
	/// new_outbound_connection, however entries will only appear once the initial handshake has
	/// completed and we are sure the remote peer has the private key for the given node_id.
	pub fn get_peer_node_ids(&self) -> Vec<PublicKey> {
		let peers = self.peers.lock().unwrap();
		peers.peers.values().filter_map(|p| {
			if !p.channel_encryptor.is_ready_for_encryption() || p.their_features.is_none() {
				return None;
			}
			p.their_node_id
		}).collect()
	}

	fn get_ephemeral_key(&self) -> SecretKey {
		let mut ephemeral_hash = self.ephemeral_key_midstate.clone();
		let low = self.peer_counter_low.fetch_add(1, Ordering::AcqRel);
		let high = if low == 0 {
			self.peer_counter_high.fetch_add(1, Ordering::AcqRel)
		} else {
			self.peer_counter_high.load(Ordering::Acquire)
		};
		ephemeral_hash.input(&byte_utils::le64_to_array(low as u64));
		ephemeral_hash.input(&byte_utils::le64_to_array(high as u64));
		SecretKey::from_slice(&Sha256::from_engine(ephemeral_hash).into_inner()).expect("You broke SHA-256!")
	}

	/// Indicates a new outbound connection has been established to a node with the given node_id.
	/// Note that if an Err is returned here you MUST NOT call socket_disconnected for the new
	/// descriptor but must disconnect the connection immediately.
	///
	/// Returns a small number of bytes to send to the remote node (currently always 50).
	///
	/// Panics if descriptor is duplicative with some other descriptor which has not yet had a
	/// socket_disconnected().
	pub fn new_outbound_connection(&self, their_node_id: PublicKey, descriptor: Descriptor) -> Result<Vec<u8>, PeerHandleError> {
		let mut peer_encryptor = PeerChannelEncryptor::new_outbound(their_node_id.clone(), self.get_ephemeral_key());
		let res = peer_encryptor.get_act_one().to_vec();
		let pending_read_buffer = [0; 50].to_vec(); // Noise act two is 50 bytes

		let mut peers = self.peers.lock().unwrap();
		if peers.peers.insert(descriptor, Peer {
			channel_encryptor: peer_encryptor,
			outbound: true,
			their_node_id: None,
			their_features: None,

			pending_outbound_buffer: LinkedList::new(),
			pending_outbound_buffer_first_msg_offset: 0,
			awaiting_write_event: false,

			pending_read_buffer,
			pending_read_buffer_pos: 0,
			pending_read_is_header: false,

			sync_status: InitSyncTracker::NoSyncRequested,

			awaiting_pong: false,
		}).is_some() {
			panic!("PeerManager driver duplicated descriptors!");
		};
		Ok(res)
	}

	/// Indicates a new inbound connection has been established.
	///
	/// May refuse the connection by returning an Err, but will never write bytes to the remote end
	/// (outbound connector always speaks first). Note that if an Err is returned here you MUST NOT
	/// call socket_disconnected for the new descriptor but must disconnect the connection
	/// immediately.
	///
	/// Panics if descriptor is duplicative with some other descriptor which has not yet had
	/// socket_disconnected called.
	pub fn new_inbound_connection(&self, descriptor: Descriptor) -> Result<(), PeerHandleError> {
		let peer_encryptor = PeerChannelEncryptor::new_inbound(&self.our_node_secret);
		let pending_read_buffer = [0; 50].to_vec(); // Noise act one is 50 bytes

		let mut peers = self.peers.lock().unwrap();
		if peers.peers.insert(descriptor, Peer {
			channel_encryptor: peer_encryptor,
			outbound: false,
			their_node_id: None,
			their_features: None,

			pending_outbound_buffer: LinkedList::new(),
			pending_outbound_buffer_first_msg_offset: 0,
			awaiting_write_event: false,

			pending_read_buffer,
			pending_read_buffer_pos: 0,
			pending_read_is_header: false,

			sync_status: InitSyncTracker::NoSyncRequested,

			awaiting_pong: false,
		}).is_some() {
			panic!("PeerManager driver duplicated descriptors!");
		};
		Ok(())
	}

	fn do_attempt_write_data(&self, descriptor: &mut Descriptor, peer: &mut Peer) {
		macro_rules! encode_and_send_msg {
			($msg: expr) => {
				{
					log_trace!(self.logger, "Encoding and sending sync update message of type {} to {}", $msg.type_id(), log_pubkey!(peer.their_node_id.unwrap()));
					peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!($msg)[..]));
				}
			}
		}
		const MSG_BUFF_SIZE: usize = 10;
		while !peer.awaiting_write_event {
			if peer.pending_outbound_buffer.len() < MSG_BUFF_SIZE {
				match peer.sync_status {
					InitSyncTracker::NoSyncRequested => {},
					InitSyncTracker::ChannelsSyncing(c) if c < 0xffff_ffff_ffff_ffff => {
						let steps = ((MSG_BUFF_SIZE - peer.pending_outbound_buffer.len() + 2) / 3) as u8;
						let all_messages = self.message_handler.route_handler.get_next_channel_announcements(c, steps);
						for &(ref announce, ref update_a_option, ref update_b_option) in all_messages.iter() {
							encode_and_send_msg!(announce);
							if let &Some(ref update_a) = update_a_option {
								encode_and_send_msg!(update_a);
							}
							if let &Some(ref update_b) = update_b_option {
								encode_and_send_msg!(update_b);
							}
							peer.sync_status = InitSyncTracker::ChannelsSyncing(announce.contents.short_channel_id + 1);
						}
						if all_messages.is_empty() || all_messages.len() != steps as usize {
							peer.sync_status = InitSyncTracker::ChannelsSyncing(0xffff_ffff_ffff_ffff);
						}
					},
					InitSyncTracker::ChannelsSyncing(c) if c == 0xffff_ffff_ffff_ffff => {
						let steps = (MSG_BUFF_SIZE - peer.pending_outbound_buffer.len()) as u8;
						let all_messages = self.message_handler.route_handler.get_next_node_announcements(None, steps);
						for msg in all_messages.iter() {
							encode_and_send_msg!(msg);
							peer.sync_status = InitSyncTracker::NodesSyncing(msg.contents.node_id);
						}
						if all_messages.is_empty() || all_messages.len() != steps as usize {
							peer.sync_status = InitSyncTracker::NoSyncRequested;
						}
					},
					InitSyncTracker::ChannelsSyncing(_) => unreachable!(),
					InitSyncTracker::NodesSyncing(key) => {
						let steps = (MSG_BUFF_SIZE - peer.pending_outbound_buffer.len()) as u8;
						let all_messages = self.message_handler.route_handler.get_next_node_announcements(Some(&key), steps);
						for msg in all_messages.iter() {
							encode_and_send_msg!(msg);
							peer.sync_status = InitSyncTracker::NodesSyncing(msg.contents.node_id);
						}
						if all_messages.is_empty() || all_messages.len() != steps as usize {
							peer.sync_status = InitSyncTracker::NoSyncRequested;
						}
					},
				}
			}

			if {
				let next_buff = match peer.pending_outbound_buffer.front() {
					None => return,
					Some(buff) => buff,
				};

				let should_be_reading = peer.pending_outbound_buffer.len() < MSG_BUFF_SIZE;
				let pending = &next_buff[peer.pending_outbound_buffer_first_msg_offset..];
				let data_sent = descriptor.send_data(pending, should_be_reading);
				peer.pending_outbound_buffer_first_msg_offset += data_sent;
				if peer.pending_outbound_buffer_first_msg_offset == next_buff.len() { true } else { false }
			} {
				peer.pending_outbound_buffer_first_msg_offset = 0;
				peer.pending_outbound_buffer.pop_front();
			} else {
				peer.awaiting_write_event = true;
			}
		}
	}

	/// Indicates that there is room to write data to the given socket descriptor.
	///
	/// May return an Err to indicate that the connection should be closed.
	///
	/// Will most likely call send_data on the descriptor passed in (or the descriptor handed into
	/// new_*\_connection) before returning. Thus, be very careful with reentrancy issues! The
	/// invariants around calling write_buffer_space_avail in case a write did not fully complete
	/// must still hold - be ready to call write_buffer_space_avail again if a write call generated
	/// here isn't sufficient! Panics if the descriptor was not previously registered in a
	/// new_\*_connection event.
	pub fn write_buffer_space_avail(&self, descriptor: &mut Descriptor) -> Result<(), PeerHandleError> {
		let mut peers = self.peers.lock().unwrap();
		match peers.peers.get_mut(descriptor) {
			None => panic!("Descriptor for write_event is not already known to PeerManager"),
			Some(peer) => {
				peer.awaiting_write_event = false;
				self.do_attempt_write_data(descriptor, peer);
			}
		};
		Ok(())
	}

	/// Indicates that data was read from the given socket descriptor.
	///
	/// May return an Err to indicate that the connection should be closed.
	///
	/// Will *not* call back into send_data on any descriptors to avoid reentrancy complexity.
	/// Thus, however, you almost certainly want to call process_events() after any read_event to
	/// generate send_data calls to handle responses.
	///
	/// If Ok(true) is returned, further read_events should not be triggered until a send_data call
	/// on this file descriptor has resume_read set (preventing DoS issues in the send buffer).
	///
	/// Panics if the descriptor was not previously registered in a new_*_connection event.
	pub fn read_event(&self, peer_descriptor: &mut Descriptor, data: &[u8]) -> Result<bool, PeerHandleError> {
		match self.do_read_event(peer_descriptor, data) {
			Ok(res) => Ok(res),
			Err(e) => {
				self.disconnect_event_internal(peer_descriptor, e.no_connection_possible);
				Err(e)
			}
		}
	}

	/// Append a message to a peer's pending outbound/write buffer, and update the map of peers needing sends accordingly.
	fn enqueue_message<M: Encode + Writeable>(&self, peers_needing_send: &mut HashSet<Descriptor>, peer: &mut Peer, descriptor: Descriptor, message: &M) {
		let mut buffer = VecWriter(Vec::new());
		wire::write(message, &mut buffer).unwrap(); // crash if the write failed
		let encoded_message = buffer.0;

		log_trace!(self.logger, "Enqueueing message of type {} to {}", message.type_id(), log_pubkey!(peer.their_node_id.unwrap()));
		peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_message[..]));
		peers_needing_send.insert(descriptor);
	}

	fn do_read_event(&self, peer_descriptor: &mut Descriptor, data: &[u8]) -> Result<bool, PeerHandleError> {
		let pause_read = {
			let mut peers_lock = self.peers.lock().unwrap();
			let peers = &mut *peers_lock;
			let pause_read = match peers.peers.get_mut(peer_descriptor) {
				None => panic!("Descriptor for read_event is not already known to PeerManager"),
				Some(peer) => {
					assert!(peer.pending_read_buffer.len() > 0);
					assert!(peer.pending_read_buffer.len() > peer.pending_read_buffer_pos);

					let mut read_pos = 0;
					while read_pos < data.len() {
						{
							let data_to_copy = cmp::min(peer.pending_read_buffer.len() - peer.pending_read_buffer_pos, data.len() - read_pos);
							peer.pending_read_buffer[peer.pending_read_buffer_pos..peer.pending_read_buffer_pos + data_to_copy].copy_from_slice(&data[read_pos..read_pos + data_to_copy]);
							read_pos += data_to_copy;
							peer.pending_read_buffer_pos += data_to_copy;
						}

						if peer.pending_read_buffer_pos == peer.pending_read_buffer.len() {
							peer.pending_read_buffer_pos = 0;

							macro_rules! try_potential_handleerror {
								($thing: expr) => {
									match $thing {
										Ok(x) => x,
										Err(e) => {
											match e.action {
												msgs::ErrorAction::DisconnectPeer { msg: _ } => {
													//TODO: Try to push msg
													log_trace!(self.logger, "Got Err handling message, disconnecting peer because {}", e.err);
													return Err(PeerHandleError{ no_connection_possible: false });
												},
												msgs::ErrorAction::IgnoreError => {
													log_trace!(self.logger, "Got Err handling message, ignoring because {}", e.err);
													continue;
												},
												msgs::ErrorAction::SendErrorMessage { msg } => {
													log_trace!(self.logger, "Got Err handling message, sending Error message because {}", e.err);
													self.enqueue_message(&mut peers.peers_needing_send, peer, peer_descriptor.clone(), &msg);
													continue;
												},
											}
										}
									};
								}
							}

							macro_rules! insert_node_id {
								() => {
									match peers.node_id_to_descriptor.entry(peer.their_node_id.unwrap()) {
										hash_map::Entry::Occupied(_) => {
											log_trace!(self.logger, "Got second connection with {}, closing", log_pubkey!(peer.their_node_id.unwrap()));
											peer.their_node_id = None; // Unset so that we don't generate a peer_disconnected event
											return Err(PeerHandleError{ no_connection_possible: false })
										},
										hash_map::Entry::Vacant(entry) => {
											log_trace!(self.logger, "Finished noise handshake for connection with {}", log_pubkey!(peer.their_node_id.unwrap()));
											entry.insert(peer_descriptor.clone())
										},
									};
								}
							}

							let next_step = peer.channel_encryptor.get_noise_step();
							match next_step {
								NextNoiseStep::ActOne => {
									let act_two = try_potential_handleerror!(peer.channel_encryptor.process_act_one_with_keys(&peer.pending_read_buffer[..], &self.our_node_secret, self.get_ephemeral_key())).to_vec();
									peer.pending_outbound_buffer.push_back(act_two);
									peer.pending_read_buffer = [0; 66].to_vec(); // act three is 66 bytes long
								},
								NextNoiseStep::ActTwo => {
									let (act_three, their_node_id) = try_potential_handleerror!(peer.channel_encryptor.process_act_two(&peer.pending_read_buffer[..], &self.our_node_secret));
									peer.pending_outbound_buffer.push_back(act_three.to_vec());
									peer.pending_read_buffer = [0; 18].to_vec(); // Message length header is 18 bytes
									peer.pending_read_is_header = true;

									peer.their_node_id = Some(their_node_id);
									insert_node_id!();
									let features = InitFeatures::known();
									let resp = msgs::Init { features };
									self.enqueue_message(&mut peers.peers_needing_send, peer, peer_descriptor.clone(), &resp);
								},
								NextNoiseStep::ActThree => {
									let their_node_id = try_potential_handleerror!(peer.channel_encryptor.process_act_three(&peer.pending_read_buffer[..]));
									peer.pending_read_buffer = [0; 18].to_vec(); // Message length header is 18 bytes
									peer.pending_read_is_header = true;
									peer.their_node_id = Some(their_node_id);
									insert_node_id!();
								},
								NextNoiseStep::NoiseComplete => {
									if peer.pending_read_is_header {
										let msg_len = try_potential_handleerror!(peer.channel_encryptor.decrypt_length_header(&peer.pending_read_buffer[..]));
										peer.pending_read_buffer = Vec::with_capacity(msg_len as usize + 16);
										peer.pending_read_buffer.resize(msg_len as usize + 16, 0);
										if msg_len < 2 { // Need at least the message type tag
											return Err(PeerHandleError{ no_connection_possible: false });
										}
										peer.pending_read_is_header = false;
									} else {
										let msg_data = try_potential_handleerror!(peer.channel_encryptor.decrypt_message(&peer.pending_read_buffer[..]));
										assert!(msg_data.len() >= 2);

										// Reset read buffer
										peer.pending_read_buffer = [0; 18].to_vec();
										peer.pending_read_is_header = true;

										let mut reader = ::std::io::Cursor::new(&msg_data[..]);
										let message_result = wire::read(&mut reader);
										let message = match message_result {
											Ok(x) => x,
											Err(e) => {
												match e {
													msgs::DecodeError::UnknownVersion => return Err(PeerHandleError { no_connection_possible: false }),
													msgs::DecodeError::UnknownRequiredFeature => {
														log_debug!(self.logger, "Got a channel/node announcement with an known required feature flag, you may want to update!");
														continue;
													}
													msgs::DecodeError::InvalidValue => {
														log_debug!(self.logger, "Got an invalid value while deserializing message");
														return Err(PeerHandleError { no_connection_possible: false });
													}
													msgs::DecodeError::ShortRead => {
														log_debug!(self.logger, "Deserialization failed due to shortness of message");
														return Err(PeerHandleError { no_connection_possible: false });
													}
													msgs::DecodeError::BadLengthDescriptor => return Err(PeerHandleError { no_connection_possible: false }),
													msgs::DecodeError::Io(_) => return Err(PeerHandleError { no_connection_possible: false }),
												}
											}
										};

										if let Err(handling_error) = self.handle_message(&mut peers.peers_needing_send, peer, peer_descriptor.clone(), message){
											match handling_error {
												MessageHandlingError::PeerHandleError(e) => { return Err(e) },
												MessageHandlingError::LightningError(e) => {
													try_potential_handleerror!(Err(e));
												},
											}
										}
									}
								}
							}
						}
					}

					self.do_attempt_write_data(peer_descriptor, peer);

					peer.pending_outbound_buffer.len() > 10 // pause_read
				}
			};

			pause_read
		};

		Ok(pause_read)
	}

	/// Process an incoming message and return a decision (ok, lightning error, peer handling error) regarding the next action with the peer
	fn handle_message(&self, peers_needing_send: &mut HashSet<Descriptor>, peer: &mut Peer, peer_descriptor: Descriptor, message: wire::Message) -> Result<(), MessageHandlingError> {
		log_trace!(self.logger, "Received message of type {} from {}", message.type_id(), log_pubkey!(peer.their_node_id.unwrap()));

		// Need an Init as first message
		if let wire::Message::Init(_) = message {
		} else if peer.their_features.is_none() {
			log_trace!(self.logger, "Peer {} sent non-Init first message", log_pubkey!(peer.their_node_id.unwrap()));
			return Err(PeerHandleError{ no_connection_possible: false }.into());
		}

		match message {
			// Setup and Control messages:
			wire::Message::Init(msg) => {
				if msg.features.requires_unknown_bits() {
					log_info!(self.logger, "Peer features required unknown version bits");
					return Err(PeerHandleError{ no_connection_possible: true }.into());
				}
				if peer.their_features.is_some() {
					return Err(PeerHandleError{ no_connection_possible: false }.into());
				}

				log_info!(
					self.logger, "Received peer Init message: data_loss_protect: {}, initial_routing_sync: {}, upfront_shutdown_script: {}, gossip_queries: {}, static_remote_key: {}, unknown flags (local and global): {}",
					if msg.features.supports_data_loss_protect() { "supported" } else { "not supported"},
					if msg.features.initial_routing_sync() { "requested" } else { "not requested" },
					if msg.features.supports_upfront_shutdown_script() { "supported" } else { "not supported"},
					if msg.features.supports_gossip_queries() { "supported" } else { "not supported" },
					if msg.features.supports_static_remote_key() { "supported" } else { "not supported"},
					if msg.features.supports_unknown_bits() { "present" } else { "none" }
				);

				if msg.features.initial_routing_sync() {
					peer.sync_status = InitSyncTracker::ChannelsSyncing(0);
					peers_needing_send.insert(peer_descriptor.clone());
				}
				if !msg.features.supports_static_remote_key() {
					log_debug!(self.logger, "Peer {} does not support static remote key, disconnecting with no_connection_possible", log_pubkey!(peer.their_node_id.unwrap()));
					return Err(PeerHandleError{ no_connection_possible: true }.into());
				}

				if !peer.outbound {
					let features = InitFeatures::known();
					let resp = msgs::Init { features };
					self.enqueue_message(peers_needing_send, peer, peer_descriptor.clone(), &resp);
				}

				self.message_handler.route_handler.sync_routing_table(&peer.their_node_id.unwrap(), &msg);

				self.message_handler.chan_handler.peer_connected(&peer.their_node_id.unwrap(), &msg);
				peer.their_features = Some(msg.features);
			},
			wire::Message::Error(msg) => {
				let mut data_is_printable = true;
				for b in msg.data.bytes() {
					if b < 32 || b > 126 {
						data_is_printable = false;
						break;
					}
				}

				if data_is_printable {
					log_debug!(self.logger, "Got Err message from {}: {}", log_pubkey!(peer.their_node_id.unwrap()), msg.data);
				} else {
					log_debug!(self.logger, "Got Err message from {} with non-ASCII error message", log_pubkey!(peer.their_node_id.unwrap()));
				}
				self.message_handler.chan_handler.handle_error(&peer.their_node_id.unwrap(), &msg);
				if msg.channel_id == [0; 32] {
					return Err(PeerHandleError{ no_connection_possible: true }.into());
				}
			},

			wire::Message::Ping(msg) => {
				if msg.ponglen < 65532 {
					let resp = msgs::Pong { byteslen: msg.ponglen };
					self.enqueue_message(peers_needing_send, peer, peer_descriptor.clone(), &resp);
				}
			},
			wire::Message::Pong(_msg) => {
				peer.awaiting_pong = false;
			},

			// Channel messages:
			wire::Message::OpenChannel(msg) => {
				self.message_handler.chan_handler.handle_open_channel(&peer.their_node_id.unwrap(), peer.their_features.clone().unwrap(), &msg);
			},
			wire::Message::AcceptChannel(msg) => {
				self.message_handler.chan_handler.handle_accept_channel(&peer.their_node_id.unwrap(), peer.their_features.clone().unwrap(), &msg);
			},

			wire::Message::FundingCreated(msg) => {
				self.message_handler.chan_handler.handle_funding_created(&peer.their_node_id.unwrap(), &msg);
			},
			wire::Message::FundingSigned(msg) => {
				self.message_handler.chan_handler.handle_funding_signed(&peer.their_node_id.unwrap(), &msg);
			},
			wire::Message::FundingLocked(msg) => {
				self.message_handler.chan_handler.handle_funding_locked(&peer.their_node_id.unwrap(), &msg);
			},

			wire::Message::Shutdown(msg) => {
				self.message_handler.chan_handler.handle_shutdown(&peer.their_node_id.unwrap(), peer.their_features.as_ref().unwrap(), &msg);
			},
			wire::Message::ClosingSigned(msg) => {
				self.message_handler.chan_handler.handle_closing_signed(&peer.their_node_id.unwrap(), &msg);
			},

			// Commitment messages:
			wire::Message::UpdateAddHTLC(msg) => {
				self.message_handler.chan_handler.handle_update_add_htlc(&peer.their_node_id.unwrap(), &msg);
			},
			wire::Message::UpdateFulfillHTLC(msg) => {
				self.message_handler.chan_handler.handle_update_fulfill_htlc(&peer.their_node_id.unwrap(), &msg);
			},
			wire::Message::UpdateFailHTLC(msg) => {
				self.message_handler.chan_handler.handle_update_fail_htlc(&peer.their_node_id.unwrap(), &msg);
			},
			wire::Message::UpdateFailMalformedHTLC(msg) => {
				self.message_handler.chan_handler.handle_update_fail_malformed_htlc(&peer.their_node_id.unwrap(), &msg);
			},

			wire::Message::CommitmentSigned(msg) => {
				self.message_handler.chan_handler.handle_commitment_signed(&peer.their_node_id.unwrap(), &msg);
			},
			wire::Message::RevokeAndACK(msg) => {
				self.message_handler.chan_handler.handle_revoke_and_ack(&peer.their_node_id.unwrap(), &msg);
			},
			wire::Message::UpdateFee(msg) => {
				self.message_handler.chan_handler.handle_update_fee(&peer.their_node_id.unwrap(), &msg);
			},
			wire::Message::ChannelReestablish(msg) => {
				self.message_handler.chan_handler.handle_channel_reestablish(&peer.their_node_id.unwrap(), &msg);
			},

			// Routing messages:
			wire::Message::AnnouncementSignatures(msg) => {
				self.message_handler.chan_handler.handle_announcement_signatures(&peer.their_node_id.unwrap(), &msg);
			},
			wire::Message::ChannelAnnouncement(msg) => {
				let should_forward = match self.message_handler.route_handler.handle_channel_announcement(&msg) {
					Ok(v) => v,
					Err(e) => { return Err(e.into()); },
				};

				if should_forward {
					// TODO: forward msg along to all our other peers!
				}
			},
			wire::Message::NodeAnnouncement(msg) => {
				let should_forward = match self.message_handler.route_handler.handle_node_announcement(&msg) {
					Ok(v) => v,
					Err(e) => { return Err(e.into()); },
				};

				if should_forward {
					// TODO: forward msg along to all our other peers!
				}
			},
			wire::Message::ChannelUpdate(msg) => {
				let should_forward = match self.message_handler.route_handler.handle_channel_update(&msg) {
					Ok(v) => v,
					Err(e) => { return Err(e.into()); },
				};

				if should_forward {
					// TODO: forward msg along to all our other peers!
				}
			},
			wire::Message::QueryShortChannelIds(msg) => {
				self.message_handler.route_handler.handle_query_short_channel_ids(&peer.their_node_id.unwrap(), msg)?;
			},
			wire::Message::ReplyShortChannelIdsEnd(msg) => {
				self.message_handler.route_handler.handle_reply_short_channel_ids_end(&peer.their_node_id.unwrap(), msg)?;
			},
			wire::Message::QueryChannelRange(msg) => {
				self.message_handler.route_handler.handle_query_channel_range(&peer.their_node_id.unwrap(), msg)?;
			},
			wire::Message::ReplyChannelRange(msg) => {
				self.message_handler.route_handler.handle_reply_channel_range(&peer.their_node_id.unwrap(), msg)?;
			},
			wire::Message::GossipTimestampFilter(_msg) => {
				// TODO: handle message
			},

			// Unknown messages:
			wire::Message::Unknown(msg_type) if msg_type.is_even() => {
				log_debug!(self.logger, "Received unknown even message of type {}, disconnecting peer!", msg_type);
				// Fail the channel if message is an even, unknown type as per BOLT #1.
				return Err(PeerHandleError{ no_connection_possible: true }.into());
			},
			wire::Message::Unknown(msg_type) => {
				log_trace!(self.logger, "Received unknown odd message of type {}, ignoring", msg_type);
			}
		};
		Ok(())
	}

	/// Checks for any events generated by our handlers and processes them. Includes sending most
	/// response messages as well as messages generated by calls to handler functions directly (eg
	/// functions like ChannelManager::process_pending_htlc_forward or send_payment).
	pub fn process_events(&self) {
		{
			// TODO: There are some DoS attacks here where you can flood someone's outbound send
			// buffer by doing things like announcing channels on another node. We should be willing to
			// drop optional-ish messages when send buffers get full!

			let mut events_generated = self.message_handler.chan_handler.get_and_clear_pending_msg_events();
			events_generated.append(&mut self.message_handler.route_handler.get_and_clear_pending_msg_events());
			let mut peers_lock = self.peers.lock().unwrap();
			let peers = &mut *peers_lock;
			for event in events_generated.drain(..) {
				macro_rules! get_peer_for_forwarding {
					($node_id: expr, $handle_no_such_peer: block) => {
						{
							let descriptor = match peers.node_id_to_descriptor.get($node_id) {
								Some(descriptor) => descriptor.clone(),
								None => {
									$handle_no_such_peer;
									continue;
								},
							};
							match peers.peers.get_mut(&descriptor) {
								Some(peer) => {
									if peer.their_features.is_none() {
										$handle_no_such_peer;
										continue;
									}
									(descriptor, peer)
								},
								None => panic!("Inconsistent peers set state!"),
							}
						}
					}
				}
				match event {
					MessageSendEvent::SendAcceptChannel { ref node_id, ref msg } => {
						log_trace!(self.logger, "Handling SendAcceptChannel event in peer_handler for node {} for channel {}",
								log_pubkey!(node_id),
								log_bytes!(msg.temporary_channel_id));
						let (mut descriptor, peer) = get_peer_for_forwarding!(node_id, {
								//TODO: Drop the pending channel? (or just let it timeout, but that sucks)
							});
						peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						self.do_attempt_write_data(&mut descriptor, peer);
					},
					MessageSendEvent::SendOpenChannel { ref node_id, ref msg } => {
						log_trace!(self.logger, "Handling SendOpenChannel event in peer_handler for node {} for channel {}",
								log_pubkey!(node_id),
								log_bytes!(msg.temporary_channel_id));
						let (mut descriptor, peer) = get_peer_for_forwarding!(node_id, {
								//TODO: Drop the pending channel? (or just let it timeout, but that sucks)
							});
						peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						self.do_attempt_write_data(&mut descriptor, peer);
					},
					MessageSendEvent::SendFundingCreated { ref node_id, ref msg } => {
						log_trace!(self.logger, "Handling SendFundingCreated event in peer_handler for node {} for channel {} (which becomes {})",
								log_pubkey!(node_id),
								log_bytes!(msg.temporary_channel_id),
								log_funding_channel_id!(msg.funding_txid, msg.funding_output_index));
						let (mut descriptor, peer) = get_peer_for_forwarding!(node_id, {
								//TODO: generate a DiscardFunding event indicating to the wallet that
								//they should just throw away this funding transaction
							});
						peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						self.do_attempt_write_data(&mut descriptor, peer);
					},
					MessageSendEvent::SendFundingSigned { ref node_id, ref msg } => {
						log_trace!(self.logger, "Handling SendFundingSigned event in peer_handler for node {} for channel {}",
								log_pubkey!(node_id),
								log_bytes!(msg.channel_id));
						let (mut descriptor, peer) = get_peer_for_forwarding!(node_id, {
								//TODO: generate a DiscardFunding event indicating to the wallet that
								//they should just throw away this funding transaction
							});
						peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						self.do_attempt_write_data(&mut descriptor, peer);
					},
					MessageSendEvent::SendFundingLocked { ref node_id, ref msg } => {
						log_trace!(self.logger, "Handling SendFundingLocked event in peer_handler for node {} for channel {}",
								log_pubkey!(node_id),
								log_bytes!(msg.channel_id));
						let (mut descriptor, peer) = get_peer_for_forwarding!(node_id, {
								//TODO: Do whatever we're gonna do for handling dropped messages
							});
						peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						self.do_attempt_write_data(&mut descriptor, peer);
					},
					MessageSendEvent::SendAnnouncementSignatures { ref node_id, ref msg } => {
						log_trace!(self.logger, "Handling SendAnnouncementSignatures event in peer_handler for node {} for channel {})",
								log_pubkey!(node_id),
								log_bytes!(msg.channel_id));
						let (mut descriptor, peer) = get_peer_for_forwarding!(node_id, {
								//TODO: generate a DiscardFunding event indicating to the wallet that
								//they should just throw away this funding transaction
							});
						peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						self.do_attempt_write_data(&mut descriptor, peer);
					},
					MessageSendEvent::UpdateHTLCs { ref node_id, updates: msgs::CommitmentUpdate { ref update_add_htlcs, ref update_fulfill_htlcs, ref update_fail_htlcs, ref update_fail_malformed_htlcs, ref update_fee, ref commitment_signed } } => {
						log_trace!(self.logger, "Handling UpdateHTLCs event in peer_handler for node {} with {} adds, {} fulfills, {} fails for channel {}",
								log_pubkey!(node_id),
								update_add_htlcs.len(),
								update_fulfill_htlcs.len(),
								update_fail_htlcs.len(),
								log_bytes!(commitment_signed.channel_id));
						let (mut descriptor, peer) = get_peer_for_forwarding!(node_id, {
								//TODO: Do whatever we're gonna do for handling dropped messages
							});
						for msg in update_add_htlcs {
							peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						}
						for msg in update_fulfill_htlcs {
							peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						}
						for msg in update_fail_htlcs {
							peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						}
						for msg in update_fail_malformed_htlcs {
							peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						}
						if let &Some(ref msg) = update_fee {
							peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						}
						peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(commitment_signed)));
						self.do_attempt_write_data(&mut descriptor, peer);
					},
					MessageSendEvent::SendRevokeAndACK { ref node_id, ref msg } => {
						log_trace!(self.logger, "Handling SendRevokeAndACK event in peer_handler for node {} for channel {}",
								log_pubkey!(node_id),
								log_bytes!(msg.channel_id));
						let (mut descriptor, peer) = get_peer_for_forwarding!(node_id, {
								//TODO: Do whatever we're gonna do for handling dropped messages
							});
						peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						self.do_attempt_write_data(&mut descriptor, peer);
					},
					MessageSendEvent::SendClosingSigned { ref node_id, ref msg } => {
						log_trace!(self.logger, "Handling SendClosingSigned event in peer_handler for node {} for channel {}",
								log_pubkey!(node_id),
								log_bytes!(msg.channel_id));
						let (mut descriptor, peer) = get_peer_for_forwarding!(node_id, {
								//TODO: Do whatever we're gonna do for handling dropped messages
							});
						peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						self.do_attempt_write_data(&mut descriptor, peer);
					},
					MessageSendEvent::SendShutdown { ref node_id, ref msg } => {
						log_trace!(self.logger, "Handling Shutdown event in peer_handler for node {} for channel {}",
								log_pubkey!(node_id),
								log_bytes!(msg.channel_id));
						let (mut descriptor, peer) = get_peer_for_forwarding!(node_id, {
								//TODO: Do whatever we're gonna do for handling dropped messages
							});
						peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						self.do_attempt_write_data(&mut descriptor, peer);
					},
					MessageSendEvent::SendChannelReestablish { ref node_id, ref msg } => {
						log_trace!(self.logger, "Handling SendChannelReestablish event in peer_handler for node {} for channel {}",
								log_pubkey!(node_id),
								log_bytes!(msg.channel_id));
						let (mut descriptor, peer) = get_peer_for_forwarding!(node_id, {
								//TODO: Do whatever we're gonna do for handling dropped messages
							});
						peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						self.do_attempt_write_data(&mut descriptor, peer);
					},
					MessageSendEvent::BroadcastChannelAnnouncement { ref msg, ref update_msg } => {
						log_trace!(self.logger, "Handling BroadcastChannelAnnouncement event in peer_handler for short channel id {}", msg.contents.short_channel_id);
						if self.message_handler.route_handler.handle_channel_announcement(msg).is_ok() && self.message_handler.route_handler.handle_channel_update(update_msg).is_ok() {
							let encoded_msg = encode_msg!(msg);
							let encoded_update_msg = encode_msg!(update_msg);

							for (ref descriptor, ref mut peer) in peers.peers.iter_mut() {
								if !peer.channel_encryptor.is_ready_for_encryption() || peer.their_features.is_none() ||
										!peer.should_forward_channel_announcement(msg.contents.short_channel_id) {
									continue
								}
								match peer.their_node_id {
									None => continue,
									Some(their_node_id) => {
										if their_node_id == msg.contents.node_id_1 || their_node_id == msg.contents.node_id_2 {
											continue
										}
									}
								}
								peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_msg[..]));
								peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_update_msg[..]));
								self.do_attempt_write_data(&mut (*descriptor).clone(), peer);
							}
						}
					},
					MessageSendEvent::BroadcastNodeAnnouncement { ref msg } => {
						log_trace!(self.logger, "Handling BroadcastNodeAnnouncement event in peer_handler");
						if self.message_handler.route_handler.handle_node_announcement(msg).is_ok() {
							let encoded_msg = encode_msg!(msg);

							for (ref descriptor, ref mut peer) in peers.peers.iter_mut() {
								if !peer.channel_encryptor.is_ready_for_encryption() || peer.their_features.is_none() ||
										!peer.should_forward_node_announcement(msg.contents.node_id) {
									continue
								}
								peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_msg[..]));
								self.do_attempt_write_data(&mut (*descriptor).clone(), peer);
							}
						}
					},
					MessageSendEvent::BroadcastChannelUpdate { ref msg } => {
						log_trace!(self.logger, "Handling BroadcastChannelUpdate event in peer_handler for short channel id {}", msg.contents.short_channel_id);
						if self.message_handler.route_handler.handle_channel_update(msg).is_ok() {
							let encoded_msg = encode_msg!(msg);

							for (ref descriptor, ref mut peer) in peers.peers.iter_mut() {
								if !peer.channel_encryptor.is_ready_for_encryption() || peer.their_features.is_none() ||
										!peer.should_forward_channel_announcement(msg.contents.short_channel_id)  {
									continue
								}
								peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encoded_msg[..]));
								self.do_attempt_write_data(&mut (*descriptor).clone(), peer);
							}
						}
					},
					MessageSendEvent::PaymentFailureNetworkUpdate { ref update } => {
						self.message_handler.route_handler.handle_htlc_fail_channel_update(update);
					},
					MessageSendEvent::HandleError { ref node_id, ref action } => {
						match *action {
							msgs::ErrorAction::DisconnectPeer { ref msg } => {
								if let Some(mut descriptor) = peers.node_id_to_descriptor.remove(node_id) {
									peers.peers_needing_send.remove(&descriptor);
									if let Some(mut peer) = peers.peers.remove(&descriptor) {
										if let Some(ref msg) = *msg {
											log_trace!(self.logger, "Handling DisconnectPeer HandleError event in peer_handler for node {} with message {}",
													log_pubkey!(node_id),
													msg.data);
											peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
											// This isn't guaranteed to work, but if there is enough free
											// room in the send buffer, put the error message there...
											self.do_attempt_write_data(&mut descriptor, &mut peer);
										} else {
											log_trace!(self.logger, "Handling DisconnectPeer HandleError event in peer_handler for node {} with no message", log_pubkey!(node_id));
										}
									}
									descriptor.disconnect_socket();
									self.message_handler.chan_handler.peer_disconnected(&node_id, false);
								}
							},
							msgs::ErrorAction::IgnoreError => {},
							msgs::ErrorAction::SendErrorMessage { ref msg } => {
								log_trace!(self.logger, "Handling SendErrorMessage HandleError event in peer_handler for node {} with message {}",
										log_pubkey!(node_id),
										msg.data);
								let (mut descriptor, peer) = get_peer_for_forwarding!(node_id, {
									//TODO: Do whatever we're gonna do for handling dropped messages
								});
								peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
								self.do_attempt_write_data(&mut descriptor, peer);
							},
						}
					},
					MessageSendEvent::SendChannelRangeQuery { ref node_id, ref msg } => {
						let (mut descriptor, peer) = get_peer_for_forwarding!(node_id, {});
						peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						self.do_attempt_write_data(&mut descriptor, peer);
					},
					MessageSendEvent::SendShortIdsQuery { ref node_id, ref msg } => {
						let (mut descriptor, peer) = get_peer_for_forwarding!(node_id, {});
						peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(msg)));
						self.do_attempt_write_data(&mut descriptor, peer);
					}
				}
			}

			for mut descriptor in peers.peers_needing_send.drain() {
				match peers.peers.get_mut(&descriptor) {
					Some(peer) => self.do_attempt_write_data(&mut descriptor, peer),
					None => panic!("Inconsistent peers set state!"),
				}
			}
		}
	}

	/// Indicates that the given socket descriptor's connection is now closed.
	///
	/// This must only be called if the socket has been disconnected by the peer or your own
	/// decision to disconnect it and must NOT be called in any case where other parts of this
	/// library (eg PeerHandleError, explicit disconnect_socket calls) instruct you to disconnect
	/// the peer.
	///
	/// Panics if the descriptor was not previously registered in a successful new_*_connection event.
	pub fn socket_disconnected(&self, descriptor: &Descriptor) {
		self.disconnect_event_internal(descriptor, false);
	}

	fn disconnect_event_internal(&self, descriptor: &Descriptor, no_connection_possible: bool) {
		let mut peers = self.peers.lock().unwrap();
		peers.peers_needing_send.remove(descriptor);
		let peer_option = peers.peers.remove(descriptor);
		match peer_option {
			None => panic!("Descriptor for disconnect_event is not already known to PeerManager"),
			Some(peer) => {
				match peer.their_node_id {
					Some(node_id) => {
						peers.node_id_to_descriptor.remove(&node_id);
						self.message_handler.chan_handler.peer_disconnected(&node_id, no_connection_possible);
					},
					None => {}
				}
			}
		};
	}

	/// Disconnect a peer given its node id.
	///
	/// Set no_connection_possible to true to prevent any further connection with this peer,
	/// force-closing any channels we have with it.
	///
	/// If a peer is connected, this will call `disconnect_socket` on the descriptor for the peer,
	/// so be careful about reentrancy issues.
	pub fn disconnect_by_node_id(&self, node_id: PublicKey, no_connection_possible: bool) {
		let mut peers_lock = self.peers.lock().unwrap();
		if let Some(mut descriptor) = peers_lock.node_id_to_descriptor.remove(&node_id) {
			log_trace!(self.logger, "Disconnecting peer with id {} due to client request", node_id);
			peers_lock.peers.remove(&descriptor);
			peers_lock.peers_needing_send.remove(&descriptor);
			self.message_handler.chan_handler.peer_disconnected(&node_id, no_connection_possible);
			descriptor.disconnect_socket();
		}
	}

	/// This function should be called roughly once every 30 seconds.
	/// It will send pings to each peer and disconnect those which did not respond to the last round of pings.

	/// Will most likely call send_data on all of the registered descriptors, thus, be very careful with reentrancy issues!
	pub fn timer_tick_occurred(&self) {
		let mut peers_lock = self.peers.lock().unwrap();
		{
			let peers = &mut *peers_lock;
			let peers_needing_send = &mut peers.peers_needing_send;
			let node_id_to_descriptor = &mut peers.node_id_to_descriptor;
			let peers = &mut peers.peers;
			let mut descriptors_needing_disconnect = Vec::new();

			peers.retain(|descriptor, peer| {
				if peer.awaiting_pong {
					peers_needing_send.remove(descriptor);
					descriptors_needing_disconnect.push(descriptor.clone());
					match peer.their_node_id {
						Some(node_id) => {
							log_trace!(self.logger, "Disconnecting peer with id {} due to ping timeout", node_id);
							node_id_to_descriptor.remove(&node_id);
							self.message_handler.chan_handler.peer_disconnected(&node_id, false);
						}
						None => {
							// This can't actually happen as we should have hit
							// is_ready_for_encryption() previously on this same peer.
							unreachable!();
						},
					}
					return false;
				}

				if !peer.channel_encryptor.is_ready_for_encryption() {
					// The peer needs to complete its handshake before we can exchange messages
					return true;
				}

				let ping = msgs::Ping {
					ponglen: 0,
					byteslen: 64,
				};
				peer.pending_outbound_buffer.push_back(peer.channel_encryptor.encrypt_message(&encode_msg!(&ping)));

				let mut descriptor_clone = descriptor.clone();
				self.do_attempt_write_data(&mut descriptor_clone, peer);

				peer.awaiting_pong = true;
				true
			});

			for mut descriptor in descriptors_needing_disconnect.drain(..) {
				descriptor.disconnect_socket();
			}
		}
	}
}

#[cfg(test)]
mod tests {
	use ln::peer_handler::{PeerManager, MessageHandler, SocketDescriptor};
	use ln::msgs;
	use util::events;
	use util::test_utils;

	use bitcoin::secp256k1::Secp256k1;
	use bitcoin::secp256k1::key::{SecretKey, PublicKey};

	use std;
	use std::sync::{Arc, Mutex};
	use std::sync::atomic::Ordering;

	#[derive(Clone)]
	struct FileDescriptor {
		fd: u16,
		outbound_data: Arc<Mutex<Vec<u8>>>,
	}
	impl PartialEq for FileDescriptor {
		fn eq(&self, other: &Self) -> bool {
			self.fd == other.fd
		}
	}
	impl Eq for FileDescriptor { }
	impl std::hash::Hash for FileDescriptor {
		fn hash<H: std::hash::Hasher>(&self, hasher: &mut H) {
			self.fd.hash(hasher)
		}
	}

	impl SocketDescriptor for FileDescriptor {
		fn send_data(&mut self, data: &[u8], _resume_read: bool) -> usize {
			self.outbound_data.lock().unwrap().extend_from_slice(data);
			data.len()
		}

		fn disconnect_socket(&mut self) {}
	}

	struct PeerManagerCfg {
		chan_handler: test_utils::TestChannelMessageHandler,
		routing_handler: test_utils::TestRoutingMessageHandler,
		logger: test_utils::TestLogger,
	}

	fn create_peermgr_cfgs(peer_count: usize) -> Vec<PeerManagerCfg> {
		let mut cfgs = Vec::new();
		for _ in 0..peer_count {
			cfgs.push(
				PeerManagerCfg{
					chan_handler: test_utils::TestChannelMessageHandler::new(),
					logger: test_utils::TestLogger::new(),
					routing_handler: test_utils::TestRoutingMessageHandler::new(),
				}
			);
		}

		cfgs
	}

	fn create_network<'a>(peer_count: usize, cfgs: &'a Vec<PeerManagerCfg>) -> Vec<PeerManager<FileDescriptor, &'a test_utils::TestChannelMessageHandler, &'a test_utils::TestRoutingMessageHandler, &'a test_utils::TestLogger>> {
		let mut peers = Vec::new();
		for i in 0..peer_count {
			let node_secret = SecretKey::from_slice(&[42 + i as u8; 32]).unwrap();
			let ephemeral_bytes = [i as u8; 32];
			let msg_handler = MessageHandler { chan_handler: &cfgs[i].chan_handler, route_handler: &cfgs[i].routing_handler };
			let peer = PeerManager::new(msg_handler, node_secret, &ephemeral_bytes, &cfgs[i].logger);
			peers.push(peer);
		}

		peers
	}

	fn establish_connection<'a>(peer_a: &PeerManager<FileDescriptor, &'a test_utils::TestChannelMessageHandler, &'a test_utils::TestRoutingMessageHandler, &'a test_utils::TestLogger>, peer_b: &PeerManager<FileDescriptor, &'a test_utils::TestChannelMessageHandler, &'a test_utils::TestRoutingMessageHandler, &'a test_utils::TestLogger>) -> (FileDescriptor, FileDescriptor) {
		let secp_ctx = Secp256k1::new();
		let a_id = PublicKey::from_secret_key(&secp_ctx, &peer_a.our_node_secret);
		let mut fd_a = FileDescriptor { fd: 1, outbound_data: Arc::new(Mutex::new(Vec::new())) };
		let mut fd_b = FileDescriptor { fd: 1, outbound_data: Arc::new(Mutex::new(Vec::new())) };
		let initial_data = peer_b.new_outbound_connection(a_id, fd_b.clone()).unwrap();
		peer_a.new_inbound_connection(fd_a.clone()).unwrap();
		assert_eq!(peer_a.read_event(&mut fd_a, &initial_data).unwrap(), false);
		assert_eq!(peer_b.read_event(&mut fd_b, &fd_a.outbound_data.lock().unwrap().split_off(0)).unwrap(), false);
		assert_eq!(peer_a.read_event(&mut fd_a, &fd_b.outbound_data.lock().unwrap().split_off(0)).unwrap(), false);
		(fd_a.clone(), fd_b.clone())
	}

	#[test]
	fn test_disconnect_peer() {
		// Simple test which builds a network of PeerManager, connects and brings them to NoiseState::Finished and
		// push a DisconnectPeer event to remove the node flagged by id
		let cfgs = create_peermgr_cfgs(2);
		let chan_handler = test_utils::TestChannelMessageHandler::new();
		let mut peers = create_network(2, &cfgs);
		establish_connection(&peers[0], &peers[1]);
		assert_eq!(peers[0].peers.lock().unwrap().peers.len(), 1);

		let secp_ctx = Secp256k1::new();
		let their_id = PublicKey::from_secret_key(&secp_ctx, &peers[1].our_node_secret);

		chan_handler.pending_events.lock().unwrap().push(events::MessageSendEvent::HandleError {
			node_id: their_id,
			action: msgs::ErrorAction::DisconnectPeer { msg: None },
		});
		assert_eq!(chan_handler.pending_events.lock().unwrap().len(), 1);
		peers[0].message_handler.chan_handler = &chan_handler;

		peers[0].process_events();
		assert_eq!(peers[0].peers.lock().unwrap().peers.len(), 0);
	}

	#[test]
	fn test_timer_tick_occurred() {
		// Create peers, a vector of two peer managers, perform initial set up and check that peers[0] has one Peer.
		let cfgs = create_peermgr_cfgs(2);
		let peers = create_network(2, &cfgs);
		establish_connection(&peers[0], &peers[1]);
		assert_eq!(peers[0].peers.lock().unwrap().peers.len(), 1);

		// peers[0] awaiting_pong is set to true, but the Peer is still connected
		peers[0].timer_tick_occurred();
		assert_eq!(peers[0].peers.lock().unwrap().peers.len(), 1);

		// Since timer_tick_occurred() is called again when awaiting_pong is true, all Peers are disconnected
		peers[0].timer_tick_occurred();
		assert_eq!(peers[0].peers.lock().unwrap().peers.len(), 0);
	}

	#[test]
	fn test_do_attempt_write_data() {
		// Create 2 peers with custom TestRoutingMessageHandlers and connect them.
		let cfgs = create_peermgr_cfgs(2);
		cfgs[0].routing_handler.request_full_sync.store(true, Ordering::Release);
		cfgs[1].routing_handler.request_full_sync.store(true, Ordering::Release);
		let peers = create_network(2, &cfgs);

		// By calling establish_connect, we trigger do_attempt_write_data between
		// the peers. Previously this function would mistakenly enter an infinite loop
		// when there were more channel messages available than could fit into a peer's
		// buffer. This issue would now be detected by this test (because we use custom
		// RoutingMessageHandlers that intentionally return more channel messages
		// than can fit into a peer's buffer).
		let (mut fd_a, mut fd_b) = establish_connection(&peers[0], &peers[1]);

		// Make each peer to read the messages that the other peer just wrote to them.
		peers[1].read_event(&mut fd_b, &fd_a.outbound_data.lock().unwrap().split_off(0)).unwrap();
		peers[0].read_event(&mut fd_a, &fd_b.outbound_data.lock().unwrap().split_off(0)).unwrap();

		// Check that each peer has received the expected number of channel updates and channel
		// announcements.
		assert_eq!(cfgs[0].routing_handler.chan_upds_recvd.load(Ordering::Acquire), 100);
		assert_eq!(cfgs[0].routing_handler.chan_anns_recvd.load(Ordering::Acquire), 50);
		assert_eq!(cfgs[1].routing_handler.chan_upds_recvd.load(Ordering::Acquire), 100);
		assert_eq!(cfgs[1].routing_handler.chan_anns_recvd.load(Ordering::Acquire), 50);
	}
}