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
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
mod loss_compression;
mod srt;

pub use srt::*;

use std::{
    convert::TryFrom,
    convert::TryInto,
    fmt::{self, Debug, Display, Formatter},
    iter::FromIterator,
    mem::size_of,
    net::{IpAddr, Ipv4Addr, Ipv6Addr},
    ops::{Add, Range, RangeInclusive, Sub},
};

use bitflags::bitflags;
use bytes::{Buf, BufMut};
use log::warn;

use crate::{
    options::{PacketCount, PacketSize},
    protocol::time::Rtt,
};

use super::*;

use loss_compression::{compress_loss_list, decompress_loss_list};

/// A UDP packet carrying control information
///
/// ```ignore,
///  0                   1                   2                   3
///  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
///  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
///  |1|             Type            |            Reserved           |
///  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
///  |     |                    Additional Info                      |
///  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
///  |                            Time Stamp                         |
///  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
///  |                    Destination Socket ID                      |
///  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
///  |                                                               |
///  ~                 Control Information Field                     ~
///  |                                                               |
///  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/// ```
/// (from <https://tools.ietf.org/html/draft-gg-udt-03#page-5>)
#[derive(Clone, PartialEq, Eq)]
pub struct ControlPacket {
    /// The timestamp, relative to the socket start time (wrapping every 2^32 microseconds)
    pub timestamp: TimeStamp,

    /// The dest socket ID, used for multiplexing
    pub dest_sockid: SocketId,

    /// The extra data
    pub control_type: ControlTypes,
}

impl ControlPacket {
    pub const HEADER_SIZE: usize = super::Packet::HEADER_SIZE.0 as usize;
}

/// The different kind of control packets
#[derive(Clone, PartialEq, Eq)]
#[allow(clippy::large_enum_variant)]
pub enum ControlTypes {
    /// The control packet for initiating connections, type 0x0
    /// Does not use Additional Info
    Handshake(HandshakeControlInfo),

    /// To keep a connection alive
    /// Does not use Additional Info or Control Info, type 0x1
    KeepAlive,

    /// ACK packet, type 0x2
    Ack(Acknowledgement),

    /// NAK packet, type 0x3
    /// Additional Info isn't used
    Nak(CompressedLossList),

    // Congestion warning packet, type 0x4
    CongestionWarning,

    /// Shutdown packet, type 0x5
    Shutdown,

    /// Acknowledgement of Acknowledgement (ACK2) 0x6
    /// Additional Info (the i32) is the ACK sequence number to acknowldege
    Ack2(FullAckSeqNumber),

    /// Drop request, type 0x7
    DropRequest {
        /// The message to drop
        /// Stored in the "addditional info" field of the packet.
        msg_to_drop: MsgNumber,

        /// The range of sequence numbers in the message to drop
        range: RangeInclusive<SeqNumber>,
    },

    // Peer error, type 0x8
    PeerError(u32),

    /// Srt control packets
    /// These use the UDT extension type 0xFF
    Srt(SrtControlPacket),
}

bitflags! {
    /// Used to describe the extension types in the packet
    struct ExtFlags: u16 {
        /// The packet has a handshake extension
        const HS = 0b1;
        /// The packet has a kmreq extension
        const KM = 0b10;
        /// The packet has a config extension (SID or smoother or filter or group)
        const CONFIG = 0b100;
    }
}

#[derive(Clone, PartialEq, Eq, Debug, Default)]
pub struct HsV5Info {
    /// the crypto size in bytes, either 0 (no encryption), 16, 24, or 32 (stored /8)
    /// source: https://github.com/Haivision/srt/blob/master/docs/stransmit.md#medium-srt
    pub crypto_size: u8,

    /// The extension HSReq/HSResp
    pub ext_hs: Option<SrtControlPacket>,

    /// The extension KMREQ/KMRESP
    pub ext_km: Option<SrtControlPacket>,

    pub ext_group: Option<SrtControlPacket>,

    /// The SID
    pub sid: Option<String>,
}

/// HS-version dependenent data
#[derive(Clone, PartialEq, Eq)]
#[allow(clippy::large_enum_variant)]
pub enum HandshakeVsInfo {
    V4(SocketType),
    V5(HsV5Info),
}

/// The control info for handshake packets
#[derive(Clone, PartialEq, Eq)]
pub struct HandshakeControlInfo {
    /// The initial sequence number, usually randomly initialized
    pub init_seq_num: SeqNumber,

    /// Max packet size, including UDP/IP headers. 1500 by default
    pub max_packet_size: PacketSize,

    /// Max flow window size, by default 25600
    pub max_flow_size: PacketCount,

    /// Designates where in the handshake process this packet lies
    pub shake_type: ShakeType,

    /// The socket ID that this request is originating from
    pub socket_id: SocketId,

    /// SYN cookie
    ///
    /// "generates a cookie value according to the client address and a
    /// secret key and sends it back to the client. The client must then send
    /// back the same cookie to the server."
    pub syn_cookie: i32,

    /// The IP address of the connecting client
    pub peer_addr: IpAddr,

    /// The rest of the data, which is HS version specific
    pub info: HandshakeVsInfo,
}

#[derive(Clone, PartialEq, Eq, Debug)]
pub struct AckStatistics {
    /// Round trip time+variance
    pub rtt: Rtt,
    /// available buffer, in packets
    pub buffer_available: u32,
    /// receive rate, in packets/sec
    pub packet_receive_rate: Option<u32>,
    /// Estimated Link capacity in packets/sec
    pub estimated_link_capacity: Option<u32>,
    /// Receive rate, in bytes/sec
    pub data_receive_rate: Option<u32>,
}

#[derive(Clone, PartialEq, Eq, Debug, Copy, Ord, PartialOrd)]
pub struct FullAckSeqNumber(u32);

/// Data included in a ACK packet. [spec](https://datatracker.ietf.org/doc/html/draft-sharabayko-mops-srt-00#section-3.2.3)
///
/// There are three types of ACK packets:
/// * Full - includes all the fields
/// * Lite - no optional fields
/// * Small - Includes rtt, rtt_variance, and buffer_available
///
/// However, these aren't necessarily clean categories--there may be some
/// amount of overlap so full acks are allowed to have no extra info and short acks
/// are allowed to have all the info
///
/// SeqNumber is the packet sequence number that all packets have been received until (excluding)
///
#[derive(Clone, PartialEq, Eq, Debug)]
pub enum Acknowledgement {
    Lite(SeqNumber),
    Small(SeqNumber, AckStatistics),
    Full(SeqNumber, AckStatistics, FullAckSeqNumber),
}

#[derive(Clone, Eq, PartialEq)]
pub struct CompressedLossList(Vec<u32>);

/// The socket type for a handshake.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum SocketType {
    /// A stream socket, 1 when serialized
    Stream = 1,

    /// A datagram socket, 2 when serialied
    Datagram = 2,
}

/// See <https://tools.ietf.org/html/draft-gg-udt-03#page-10>
///
/// More applicably,
///
/// Note: the client-server connection uses:
/// --> INDUCTION (empty)
/// <-- INDUCTION (cookie)
/// --> CONCLUSION (cookie)
/// <-- CONCLUSION (ok)
///
/// The rendezvous HSv4 (legacy):
/// --> WAVEAHAND (effective only if peer is also connecting)
/// <-- CONCLUSION (empty) (consider yourself connected upon reception)
/// --> AGREEMENT (sent as a response for conclusion, requires no response)
///
/// The rendezvous HSv5 (using SRT extensions):
/// --> WAVEAHAND (with cookie)
/// --- (selecting INITIATOR/RESPONDER by cookie contest - comparing one another's cookie)
/// <-- CONCLUSION (without extensions, if RESPONDER, with extensions, if INITIATOR)
/// --> CONCLUSION (with response extensions, if RESPONDER)
/// <-- AGREEMENT (sent exclusively by INITIATOR upon reception of CONCLUSIOn with response extensions)
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ShakeType {
    /// First handshake exchange in client-server connection
    Induction,

    /// A rendezvous connection, initial connect request, 0
    Waveahand,

    /// A rendezvous connection, response to initial connect request, -1
    /// Also a regular connection client response to the second handshake
    Conclusion,

    /// Final rendezvous check, -2
    Agreement,

    /// Reject
    Rejection(RejectReason),
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[non_exhaustive]
pub enum CoreRejectReason {
    System = 1001,
    Peer = 1002,
    Resource = 1003,
    Rogue = 1004,
    Backlog = 1005,
    Ipe = 1006,
    Close = 1007,
    Version = 1008,
    RdvCookie = 1009,
    BadSecret = 1010,
    Unsecure = 1011,
    MessageApi = 1012,
    Congestion = 1013,
    Filter = 1014,
    Group = 1015,
    Timeout = 1016,
}

#[non_exhaustive]
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ServerRejectReason {
    Fallback = 2000,
    KeyNotSup = 2001,
    Filepath = 2002,
    HostNotFound = 2003,
    BadRequest = 2400,
    Unauthorized = 2401,
    Overload = 2402,
    Forbidden = 2403,
    Notfound = 2404,
    BadMode = 2405,
    Unacceptable = 2406,
    Conflict = 2409,
    NotSupMedia = 2415,
    Locked = 2423,
    FailedDepend = 2424,
    InternalServerError = 2500,
    Unimplemented = 2501,
    Gateway = 2502,
    Down = 2503,
    Version = 2505,
    NoRoom = 2507,
}

/// Reject code
/// *must* be >= 1000
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum RejectReason {
    /// Core reject codes, [1000, 2000)
    Core(CoreRejectReason),
    CoreUnrecognized(i32),

    /// Server reject codes, [2000, 3000)
    Server(ServerRejectReason),
    ServerUnrecognized(i32),

    /// User reject code, >3000
    User(i32),
}

impl HandshakeVsInfo {
    /// Get the type (V4) or ext flags (V5)
    /// the shake_type is required to decide to encode the magic code
    fn type_flags(&self, shake_type: ShakeType) -> u32 {
        match self {
            HandshakeVsInfo::V4(ty) => *ty as u32,
            HandshakeVsInfo::V5(hs) => {
                if shake_type == ShakeType::Induction
                    && (hs.ext_hs.is_some() || hs.ext_km.is_some() || hs.sid.is_some())
                {
                    // induction does not include any extensions, and instead has the
                    // magic code. this is an incompatialbe place to be.
                    panic!("Handshake is both induction and has SRT extensions, not valid");
                }

                let mut flags = ExtFlags::empty();

                if hs.ext_hs.is_some() {
                    flags |= ExtFlags::HS;
                }
                if hs.ext_km.is_some() {
                    flags |= ExtFlags::KM;
                }
                if hs.sid.is_some() {
                    flags |= ExtFlags::CONFIG;
                }
                // take the crypto size, get rid of the frist three (guaranteed zero) bits, then shift it into the
                // most significant 2-byte word
                (u32::from(hs.crypto_size) >> 3 << 16)
                    // when this is an induction packet, includ the magic code instead of flags
                    | if shake_type == ShakeType::Induction {
                    u32::from(SRT_MAGIC_CODE)
                } else {
                    u32::from(flags.bits())
                }
            }
        }
    }

    /// Get the UDT version
    pub fn version(&self) -> u32 {
        match self {
            HandshakeVsInfo::V4(_) => 4,
            HandshakeVsInfo::V5 { .. } => 5,
        }
    }
}

impl SocketType {
    /// Turns a u32 into a SocketType. If the u32 wasn't valid (only 1 and 2 are valid), than it returns Err(num)
    pub fn from_u16(num: u16) -> Result<SocketType, u16> {
        match num {
            1 => Ok(SocketType::Stream),
            2 => Ok(SocketType::Datagram),
            i => Err(i),
        }
    }
}

impl ControlPacket {
    pub fn parse(buf: &mut impl Buf, is_ipv6: bool) -> Result<ControlPacket, PacketParseError> {
        let control_type = buf.get_u16() << 1 >> 1; // clear first bit

        // get reserved data, which is the last two bytes of the first four bytes
        let reserved = buf.get_u16();
        let add_info = buf.get_u32();
        let timestamp = TimeStamp::from_micros(buf.get_u32());
        let dest_sockid = buf.get_u32();

        Ok(ControlPacket {
            timestamp,
            dest_sockid: SocketId(dest_sockid),
            // just match against the second byte, as everything is in that
            control_type: ControlTypes::deserialize(
                control_type,
                reserved,
                add_info,
                buf,
                is_ipv6,
            )?,
        })
    }

    pub fn serialize<T: BufMut>(&self, into: &mut T) {
        // first half of first row, the control type and the 1st bit which is a one
        into.put_u16(self.control_type.id_byte() | (0b1 << 15));

        // finish that row, which is reserved
        into.put_u16(self.control_type.reserved());

        // the additonal info line
        into.put_u32(self.control_type.additional_info());

        // timestamp
        into.put_u32(self.timestamp.as_micros());

        // dest sock id
        into.put_u32(self.dest_sockid.0);

        // the rest of the info
        self.control_type.serialize(into);
    }

    pub fn handshake(&self) -> Option<&HandshakeControlInfo> {
        if let ControlTypes::Handshake(hs) = &self.control_type {
            Some(hs)
        } else {
            None
        }
    }

    pub fn wire_size(&self) -> usize {
        // 20 bytes IPv4 + 8 bytes of UDP + 16 bytes SRT header.
        Self::HEADER_SIZE
            + match &self.control_type {
                ControlTypes::Handshake(hs) => hs.serialized_size(),
                ControlTypes::Ack(ack) => ack.serialized_size(),
                ControlTypes::Nak(nak) => nak.0.len() * size_of::<u32>(),
                ControlTypes::DropRequest { .. } => 2 * size_of::<u32>(),
                ControlTypes::Srt(srt) => usize::from(srt.size_words()) * size_of::<u32>(),
                ControlTypes::CongestionWarning
                | ControlTypes::Ack2(_)
                | ControlTypes::Shutdown
                | ControlTypes::KeepAlive
                | ControlTypes::PeerError(_) => 4,
            }
    }
}

impl Debug for ControlPacket {
    fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
        write!(
            f,
            "{{{:?} ts={:?} dst={:?}}}",
            self.control_type, self.timestamp, self.dest_sockid,
        )
    }
}

// I definitely don't totally understand this yet.
// Points of interest: handshake.h:wrapFlags
// core.cpp:8176 (processConnectionRequest -> if INDUCTION)
const SRT_MAGIC_CODE: u16 = 0x4A17;

impl ControlTypes {
    pub fn new_drop_request(msg_to_drop: MsgNumber, drop_range: Range<SeqNumber>) -> Self {
        assert!(!drop_range.is_empty());
        Self::DropRequest {
            msg_to_drop,
            range: RangeInclusive::new(drop_range.start, drop_range.end - 1),
        }
    }

    pub fn new_key_refresh_request(key_material: KeyingMaterialMessage) -> ControlTypes {
        ControlTypes::Srt(SrtControlPacket::KeyRefreshRequest(key_material))
    }

    /// Deserialize a control info
    /// * `packet_type` - The packet ID byte, the second byte in the first row
    /// * `reserved` - the second 16 bytes of the first row, reserved for custom packets
    fn deserialize<T: Buf>(
        packet_type: u16,
        reserved: u16,
        extra_info: u32,
        mut buf: T,
        is_ipv6: bool,
    ) -> Result<ControlTypes, PacketParseError> {
        match packet_type {
            0x0 => {
                // Handshake
                // make sure the packet is large enough -- 8 32-bit words, 1 128 (ip)
                if buf.remaining() < 8 * 4 + 16 {
                    return Err(PacketParseError::NotEnoughData);
                }

                let udt_version = buf.get_i32();
                if udt_version != 4 && udt_version != 5 {
                    return Err(PacketParseError::BadUdtVersion(udt_version));
                }

                // the second 32 bit word is always socket type under UDT4
                // under SRT HSv5, it is a bit more complex:
                //
                // byte 1-2: the crypto key size, rightshifted by three. For example 0b11 would translate to a crypto size of 24
                //           source: https://github.com/Haivision/srt/blob/4f7f2beb2e1e306111b9b11402049a90cb6d3787/srtcore/handshake.h#L123-L125
                let crypto_size = buf.get_u16() << 3;
                // byte 3-4: the SRT_MAGIC_CODE, to make sure a client is HSv5 or the ExtFlags if this is an induction response
                //           else, this is the extension flags
                //
                // it's ok to only have the lower 16 bits here for the socket type because socket types always have a zero upper 16 bits
                let type_ext_socket_type = buf.get_u16();

                let init_seq_num = SeqNumber::new_truncate(buf.get_u32()); // TODO: should this truncate?
                let max_packet_size = PacketSize(buf.get_u32() as u64);
                let max_flow_size = PacketCount(buf.get_u32() as u64);
                let shake_type = match ShakeType::try_from(buf.get_i32()) {
                    Ok(ct) => ct,
                    Err(err_ct) => return Err(PacketParseError::BadConnectionType(err_ct)),
                };
                let socket_id = SocketId(buf.get_u32());
                let syn_cookie = buf.get_i32();

                let peer_addr = if !is_ipv6 {
                    let ip = buf.get_u32_le();
                    buf.get_u32();
                    buf.get_u32();
                    buf.get_u32();
                    IpAddr::from(Ipv4Addr::from(ip))
                } else {
                    let mut ip_buf = [0u8; 16];
                    buf.copy_to_slice(&mut ip_buf);
                    IpAddr::from(Ipv6Addr::from(ip_buf))
                };

                let info = match udt_version {
                    4 => HandshakeVsInfo::V4(match SocketType::from_u16(type_ext_socket_type) {
                        Ok(t) => t,
                        Err(e) => return Err(PacketParseError::BadSocketType(e)),
                    }),
                    5 => {
                        // make sure crypto size is of a valid variant
                        let crypto_size = match crypto_size {
                            0 | 16 | 24 | 32 => crypto_size as u8,
                            c => {
                                warn!(
                                    "Unrecognized crypto key length: {}, disabling encryption. Should be 0, 16, 24, or 32 bytes.",
                                    c
                                );
                                0
                            }
                        };

                        if shake_type == ShakeType::Induction {
                            if type_ext_socket_type != SRT_MAGIC_CODE {
                                // TODO: should this bail? What does the reference implementation do?
                                warn!("HSv5 induction response did not have SRT_MAGIC_CODE, which is suspicious")
                            }

                            HandshakeVsInfo::V5(HsV5Info::default())
                        } else {
                            // if this is not induction, this is the extension flags
                            let extensions = match ExtFlags::from_bits(type_ext_socket_type) {
                                Some(i) => i,
                                None => {
                                    warn!(
                                        "Unnecessary bits in extensions flags: {:b}",
                                        type_ext_socket_type
                                    );

                                    ExtFlags::from_bits_truncate(type_ext_socket_type)
                                }
                            };

                            // parse out extensions

                            let mut sid = None;
                            let mut ext_hs = None;
                            let mut ext_km = None;

                            while buf.remaining() > 4 {
                                let pack_type = buf.get_u16();

                                let pack_size_words = buf.get_u16();
                                let pack_size = usize::from(pack_size_words) * 4;

                                if buf.remaining() < pack_size {
                                    return Err(PacketParseError::NotEnoughData);
                                }

                                let mut buffer = buf.take(pack_size);
                                match pack_type {
                                    1 | 2 => {
                                        if !extensions.contains(ExtFlags::HS) {
                                            warn!("Handshake contains handshake extension type {} without HSREQ flag!", pack_type);
                                        }
                                        if ext_hs.is_some() {
                                            warn!("Handshake contains multiple handshake extensions, only the last will be applied!");
                                        }
                                        ext_hs =
                                            Some(SrtControlPacket::parse(pack_type, &mut buffer)?);
                                    }
                                    3 | 4 => {
                                        if !extensions.contains(ExtFlags::KM) {
                                            warn!("Handshake contains key material extension type {} without KMREQ flag!", pack_type);
                                        }
                                        if ext_km.is_some() {
                                            warn!("Handshake contains multiple key material extensions, only the last will be applied!");
                                        }
                                        ext_km =
                                            Some(SrtControlPacket::parse(pack_type, &mut buffer)?);
                                    }
                                    _ => {
                                        if !extensions.contains(ExtFlags::CONFIG) {
                                            warn!("Handshake contains config extension type {} without CONFIG flag!", pack_type);
                                        }
                                        match SrtControlPacket::parse(pack_type, &mut buffer)? {
                                            //5 = sid:
                                            SrtControlPacket::StreamId(stream_id) => {
                                                sid = Some(stream_id)
                                            }
                                            _ => unimplemented!("Implement other kinds"),
                                        }
                                    }
                                }
                                buf = buffer.into_inner();
                            }

                            if buf.remaining() != 0 {
                                warn!("Handshake has data left, but not enough for an extension!");
                            }
                            if ext_hs.is_none() && extensions.contains(ExtFlags::HS) {
                                warn!("Handshake has HSREQ flag, but contains no handshake extensions!");
                            }
                            if ext_km.is_none() && extensions.contains(ExtFlags::KM) {
                                warn!("Handshake has KMREQ flag, but contains no key material extensions!");
                            }

                            HandshakeVsInfo::V5(HsV5Info {
                                crypto_size,
                                ext_hs,
                                ext_km,
                                ext_group: None,
                                sid,
                            })
                        }
                    }
                    _ => unreachable!(), // this is already checked for above
                };

                Ok(ControlTypes::Handshake(HandshakeControlInfo {
                    init_seq_num,
                    max_packet_size,
                    max_flow_size,
                    shake_type,
                    socket_id,
                    syn_cookie,
                    peer_addr,
                    info,
                }))
            }
            0x1 => {
                // discard the "unused" packet field, if it exists
                if buf.remaining() >= 4 {
                    buf.get_u32();
                }
                Ok(ControlTypes::KeepAlive)
            }
            0x2 => {
                // ACK

                // make sure there are enough bytes -- only one required field
                if buf.remaining() < 4 {
                    return Err(PacketParseError::NotEnoughData);
                }

                // read control info
                let ack_number = SeqNumber::new_truncate(buf.get_u32());
                let full_ack_seq_number = FullAckSeqNumber::new(extra_info);

                let ack = if buf.remaining() < 3 * size_of::<u32>() {
                    Acknowledgement::Lite(ack_number)
                } else {
                    // short/full
                    let rtt_mean = TimeSpan::from_micros(buf.get_i32());
                    let rtt_variance = TimeSpan::from_micros(buf.get_i32());
                    let buffer_available = buf.get_u32();

                    let packet_receive_rate =
                        (buf.remaining() >= size_of::<u32>()).then(|| buf.get_u32());
                    let estimated_link_capacity =
                        (buf.remaining() >= size_of::<u32>()).then(|| buf.get_u32());
                    let data_receive_rate =
                        (buf.remaining() >= size_of::<u32>()).then(|| buf.get_u32());

                    let stats = AckStatistics {
                        rtt: Rtt::new(rtt_mean, rtt_variance),
                        buffer_available,
                        packet_receive_rate,
                        estimated_link_capacity,
                        data_receive_rate,
                    };

                    match full_ack_seq_number {
                        None => Acknowledgement::Small(ack_number, stats),
                        Some(full_ack) => Acknowledgement::Full(ack_number, stats, full_ack),
                    }
                };
                Ok(ControlTypes::Ack(ack))
            }
            0x3 => {
                // NAK

                let mut loss_info = Vec::new();
                while buf.remaining() >= 4 {
                    loss_info.push(buf.get_u32());
                }

                Ok(ControlTypes::Nak(CompressedLossList(loss_info)))
            }
            0x4 => {
                if buf.remaining() >= 4 {
                    buf.get_u32(); // discard "unused" packet field
                }
                Ok(ControlTypes::CongestionWarning)
            }
            0x5 => {
                if buf.remaining() >= 4 {
                    buf.get_u32(); // discard "unused" packet field
                }
                Ok(ControlTypes::Shutdown)
            }
            0x6 => {
                // ACK2
                if buf.remaining() >= 4 {
                    buf.get_u32(); // discard "unused" packet field
                }
                if let Some(ack_seq_no) = FullAckSeqNumber::new(extra_info) {
                    Ok(ControlTypes::Ack2(ack_seq_no))
                } else {
                    Err(PacketParseError::ZeroAckSequenceNumber)
                }
            }
            0x7 => {
                // Drop request
                if buf.remaining() < 2 * 4 {
                    return Err(PacketParseError::NotEnoughData);
                }

                let start = SeqNumber::new_truncate(buf.get_u32());
                let end = SeqNumber::new_truncate(buf.get_u32());

                Ok(ControlTypes::DropRequest {
                    msg_to_drop: MsgNumber::new_truncate(extra_info), // cast is safe, just reinterpret
                    range: RangeInclusive::new(start, end),
                })
            }
            0x8 => {
                // Peer error
                if buf.remaining() >= 4 {
                    buf.get_u32(); // discard "unused" packet field
                }
                Ok(ControlTypes::PeerError(extra_info))
            }
            0x7FFF => {
                // Srt
                Ok(ControlTypes::Srt(SrtControlPacket::parse(
                    reserved, &mut buf,
                )?))
            }
            x => Err(PacketParseError::BadControlType(x)),
        }
    }

    fn id_byte(&self) -> u16 {
        match *self {
            ControlTypes::Handshake(_) => 0x0,
            ControlTypes::KeepAlive => 0x1,
            ControlTypes::Ack { .. } => 0x2,
            ControlTypes::Nak(_) => 0x3,
            ControlTypes::CongestionWarning => 0x4,
            ControlTypes::Shutdown => 0x5,
            ControlTypes::Ack2(_) => 0x6,
            ControlTypes::DropRequest { .. } => 0x7,
            ControlTypes::PeerError(_) => 0x8,
            ControlTypes::Srt(_) => 0x7FFF,
        }
    }

    fn additional_info(&self) -> u32 {
        match self {
            // These types have additional info
            ControlTypes::DropRequest { msg_to_drop, .. } => msg_to_drop.as_raw(),
            ControlTypes::Ack2(a) | ControlTypes::Ack(Acknowledgement::Full(_, _, a)) => {
                (*a).into()
            }
            ControlTypes::PeerError(err) => *err,
            // These do not, just use zero
            ControlTypes::Ack(_)
            | ControlTypes::Handshake(_)
            | ControlTypes::KeepAlive
            | ControlTypes::Nak(_)
            | ControlTypes::CongestionWarning
            | ControlTypes::Shutdown
            | ControlTypes::Srt(_) => 0,
        }
    }

    fn reserved(&self) -> u16 {
        match self {
            ControlTypes::Srt(srt) => srt.type_id(),
            _ => 0,
        }
    }

    fn serialize<T: BufMut>(&self, into: &mut T) {
        match self {
            ControlTypes::Handshake(ref c) => c.serialize(into),
            ControlTypes::Ack(ack) => ack.serialize(into),
            ControlTypes::Nak(ref n) => {
                for loss in n.iter_compressed() {
                    into.put_u32(loss);
                }
            }
            ControlTypes::DropRequest {
                msg_to_drop: _,
                range,
            } => {
                into.put_u32(range.start().as_raw());
                into.put_u32(range.end().as_raw());
            }
            ControlTypes::CongestionWarning
            | ControlTypes::Ack2(_)
            | ControlTypes::Shutdown
            | ControlTypes::KeepAlive
            | ControlTypes::PeerError(_) => {
                // The reference implementation appends one (4 byte) word at the end of these packets, which wireshark labels as 'Unused'
                // I have no idea why, but wireshark reports it as a "malformed packet" without it. For the record,
                // this is NOT in the UDT specification. I wonder if this was carried over from the original UDT implementation.
                // https://github.com/Haivision/srt/blob/86013826b5e0c4d8e531cf18a30c6ad4b16c1b3b/srtcore/packet.cpp#L309
                into.put_u32(0x0);
            }
            ControlTypes::Srt(srt) => {
                srt.serialize(into);
            }
        };
    }
}

impl Debug for ControlTypes {
    fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
        match self {
            ControlTypes::Handshake(hs) => write!(f, "{hs:?}"),
            ControlTypes::KeepAlive => write!(f, "KeepAlive"),
            ControlTypes::Ack(aci) => write!(f, "{aci:?}"),
            ControlTypes::Nak(nak) => {
                write!(f, "Nak({nak:?})") // TODO could be better, show ranges
            }
            ControlTypes::CongestionWarning => write!(f, "CongestionWarning"),
            ControlTypes::Shutdown => write!(f, "Shutdown"),
            ControlTypes::Ack2(ackno) => write!(f, "Ack2({})", ackno.0),
            ControlTypes::DropRequest { msg_to_drop, range } => {
                write!(f, "DropReq(msg={msg_to_drop} {range:?})")
            }
            ControlTypes::PeerError(e) => write!(f, "PeerError({e})"),
            ControlTypes::Srt(srt) => write!(f, "{srt:?}"),
        }
    }
}

impl CompressedLossList {
    pub fn try_from_iter(iter: impl Iterator<Item = SeqNumber>) -> Option<CompressedLossList> {
        let loss_list = compress_loss_list(iter).collect::<Vec<_>>();
        if loss_list.is_empty() {
            None
        } else {
            Some(CompressedLossList(loss_list))
        }
    }

    pub fn try_from_range(r: Range<SeqNumber>) -> Option<CompressedLossList> {
        if r.is_empty() {
            None
        } else if r.start + 1 == r.end {
            Some(CompressedLossList(vec![r.start.as_raw()]))
        } else {
            Some(CompressedLossList(vec![
                (1 << 31) | r.start.as_raw(),
                (r.end - 1).as_raw(),
            ]))
        }
    }

    pub fn iter_compressed(&self) -> impl Iterator<Item = u32> + '_ {
        self.0.iter().copied()
    }

    pub fn iter_decompressed(&self) -> impl Iterator<Item = SeqNumber> + '_ {
        decompress_loss_list(self.iter_compressed())
    }

    pub fn into_iter_decompressed(self) -> impl Iterator<Item = SeqNumber> {
        decompress_loss_list(self.0.into_iter())
    }
}

impl FromIterator<SeqNumber> for CompressedLossList {
    fn from_iter<T: IntoIterator<Item = SeqNumber>>(iter: T) -> Self {
        Self::try_from_iter(iter.into_iter()).unwrap()
    }
}

impl<'a> FromIterator<&'a SeqNumber> for CompressedLossList {
    fn from_iter<T: IntoIterator<Item = &'a SeqNumber>>(iter: T) -> Self {
        Self::try_from_iter(iter.into_iter().copied()).unwrap()
    }
}

impl From<Range<SeqNumber>> for CompressedLossList {
    fn from(range: Range<SeqNumber>) -> Self {
        Self::try_from_range(range).unwrap()
    }
}

impl Debug for CompressedLossList {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        let mut iter = self.0.iter();
        while let Some(a) = iter.next() {
            if a & 0x80000000 != 0 {
                let b = iter.next().expect("Unterminated list");
                write!(f, "{}..={},", a & 0x7fffffff, b)?;
            } else {
                write!(f, "{a},")?;
            }
        }
        Ok(())
    }
}

impl FullAckSeqNumber {
    pub const INITIAL: FullAckSeqNumber = FullAckSeqNumber(1);

    pub fn new(raw: u32) -> Option<FullAckSeqNumber> {
        if raw == 0 {
            None
        } else {
            Some(FullAckSeqNumber(raw))
        }
    }

    pub fn is_full(&self) -> bool {
        self.0 != 0
    }
}

impl From<FullAckSeqNumber> for u32 {
    fn from(u: FullAckSeqNumber) -> Self {
        u.0
    }
}

impl Add<u32> for FullAckSeqNumber {
    type Output = FullAckSeqNumber;

    fn add(self, rhs: u32) -> Self::Output {
        FullAckSeqNumber(self.0 + rhs)
    }
}

impl Sub<FullAckSeqNumber> for FullAckSeqNumber {
    type Output = usize;

    fn sub(self, rhs: FullAckSeqNumber) -> Self::Output {
        (self.0 - rhs.0).try_into().unwrap()
    }
}

impl Acknowledgement {
    pub fn ack_number(&self) -> SeqNumber {
        match self {
            Acknowledgement::Lite(seq_number)
            | Acknowledgement::Small(seq_number, _)
            | Acknowledgement::Full(seq_number, _, _) => *seq_number,
        }
    }

    pub fn full_ack_seq_number(&self) -> Option<FullAckSeqNumber> {
        match self {
            Acknowledgement::Full(_, _, full_ack_seq_number) => Some(*full_ack_seq_number),
            Acknowledgement::Lite(_) | Acknowledgement::Small(_, _) => None,
        }
    }

    pub fn rtt(&self) -> Option<Rtt> {
        match self {
            Acknowledgement::Full(_, stats, _) | Acknowledgement::Small(_, stats) => {
                Some(stats.rtt)
            }
            Acknowledgement::Lite(_) => None,
        }
    }

    pub fn statistics(&self) -> Option<&AckStatistics> {
        match self {
            Acknowledgement::Small(_, stats) | Acknowledgement::Full(_, stats, _) => Some(stats),
            Acknowledgement::Lite(_) => None,
        }
    }

    pub fn serialize(&self, into: &mut impl BufMut) {
        into.put_u32(self.ack_number().as_raw());
        if let Some(stats) = self.statistics() {
            into.put_i32(stats.rtt.mean().as_micros());
            into.put_i32(stats.rtt.variance().as_micros());
            into.put_u32(stats.buffer_available);

            // Make sure fields are always in the right order
            // Would rather not transmit than transmit incorrectly
            if let Some(prr) = stats.packet_receive_rate {
                into.put_u32(prr);
                if let Some(elc) = stats.estimated_link_capacity {
                    into.put_u32(elc);
                    if let Some(drr) = stats.data_receive_rate {
                        into.put_u32(drr);
                    }
                }
            }
        }
    }

    fn serialized_size(&self) -> usize {
        size_of::<u32>() // ack number
            + self.statistics().map(AckStatistics::serialized_size).unwrap_or(0)
    }
}

impl Debug for HandshakeControlInfo {
    fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
        write!(
            f,
            "HS {:?} from={:?} {:?}",
            self.shake_type, self.socket_id, self.info
        )
    }
}

impl Debug for HandshakeVsInfo {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        match self {
            HandshakeVsInfo::V4(stype) => write!(f, "UDT: {stype:?}"),
            HandshakeVsInfo::V5(hs) => {
                write!(f, "SRT: crypto={:?}", hs.crypto_size)?;
                if let Some(pack) = &hs.ext_hs {
                    write!(f, " hs={pack:?}")?;
                }
                if let Some(pack) = &hs.ext_km {
                    write!(f, " km={pack:?}")?;
                }
                if let Some(sid) = &hs.sid {
                    write!(f, " sid={sid:?}")?;
                }
                Ok(())
            }
        }
    }
}

impl TryFrom<i32> for ShakeType {
    /// Turns an i32 into a `ConnectionType`, returning Err(num) if no valid one was passed.
    type Error = i32;
    fn try_from(value: i32) -> Result<Self, Self::Error> {
        match value {
            1 => Ok(ShakeType::Induction),
            0 => Ok(ShakeType::Waveahand),
            -1 => Ok(ShakeType::Conclusion),
            -2 => Ok(ShakeType::Agreement),
            i if i < 1000 => Err(i), // not a basic type and not a rejection code
            i => Ok(ShakeType::Rejection(RejectReason::try_from(i).unwrap())), // unwrap is safe--will always be >= 1000
        }
    }
}

impl From<ShakeType> for i32 {
    fn from(st: ShakeType) -> i32 {
        match st {
            ShakeType::Induction => 1,
            ShakeType::Waveahand => 0,
            ShakeType::Conclusion => -1,
            ShakeType::Agreement => -2,
            ShakeType::Rejection(rej) => rej.into(),
        }
    }
}

/// Returns error if value < 1000
impl TryFrom<i32> for RejectReason {
    type Error = i32;
    fn try_from(value: i32) -> Result<Self, Self::Error> {
        match value {
            v if v < 1000 => Err(v),
            v if v < 2000 => Ok(match CoreRejectReason::try_from(v) {
                Ok(rr) => RejectReason::Core(rr),
                Err(rr) => RejectReason::CoreUnrecognized(rr),
            }),
            v if v < 3000 => Ok(match ServerRejectReason::try_from(v) {
                Ok(rr) => RejectReason::Server(rr),
                Err(rr) => RejectReason::ServerUnrecognized(rr),
            }),
            v => Ok(RejectReason::User(v)),
        }
    }
}

impl From<RejectReason> for i32 {
    fn from(rr: RejectReason) -> i32 {
        match rr {
            RejectReason::Core(c) => c.into(),
            RejectReason::CoreUnrecognized(c) => c,
            RejectReason::Server(s) => s.into(),
            RejectReason::ServerUnrecognized(s) => s,
            RejectReason::User(u) => u,
        }
    }
}

impl Display for RejectReason {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        match self {
            RejectReason::Core(c) => write!(f, "{c}"),
            RejectReason::CoreUnrecognized(c) => write!(f, "Unrecognized core error: {c}"),
            RejectReason::Server(s) => write!(f, "{s}"),
            RejectReason::ServerUnrecognized(s) => write!(f, "Unrecognized server error: {s}"),
            RejectReason::User(u) => write!(f, "User error: {u}"),
        }
    }
}

impl From<CoreRejectReason> for RejectReason {
    fn from(rr: CoreRejectReason) -> RejectReason {
        RejectReason::Core(rr)
    }
}

impl TryFrom<i32> for CoreRejectReason {
    type Error = i32;
    fn try_from(value: i32) -> Result<Self, Self::Error> {
        use CoreRejectReason::*;
        Ok(match value {
            1001 => System,
            1002 => Peer,
            1003 => Resource,
            1004 => Rogue,
            1005 => Backlog,
            1006 => Ipe,
            1007 => Close,
            1008 => Version,
            1009 => RdvCookie,
            1010 => BadSecret,
            1011 => Unsecure,
            1012 => MessageApi,
            1013 => Congestion,
            1014 => Filter,
            1015 => Group,
            1016 => Timeout,
            other => return Err(other),
        })
    }
}

impl From<CoreRejectReason> for i32 {
    fn from(rr: CoreRejectReason) -> i32 {
        rr as i32
    }
}

impl Display for CoreRejectReason {
    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
        match self {
            CoreRejectReason::System => write!(f, "broken due to system function error"),
            CoreRejectReason::Peer => write!(f, "connection was rejected by peer"),
            CoreRejectReason::Resource => write!(f, "internal problem with resource allocation"),
            CoreRejectReason::Rogue => write!(f, "incorrect data in handshake messages"),
            CoreRejectReason::Backlog => write!(f, "listener's backlog exceeded"),
            CoreRejectReason::Ipe => write!(f, "internal program error"),
            CoreRejectReason::Close => write!(f, "socket is closing"),
            CoreRejectReason::Version => {
                write!(f, "peer is older version than agent's minimum set")
            }
            CoreRejectReason::RdvCookie => write!(f, "rendezvous cookie collision"),
            CoreRejectReason::BadSecret => write!(f, "wrong password"),
            CoreRejectReason::Unsecure => write!(f, "password required or unexpected"),
            CoreRejectReason::MessageApi => write!(f, "streamapi/messageapi collision"),
            CoreRejectReason::Congestion => write!(f, "incompatible congestion-controller type"),
            CoreRejectReason::Filter => write!(f, "incompatible packet filter"),
            CoreRejectReason::Group => write!(f, "incompatible group"),
            CoreRejectReason::Timeout => write!(f, "connection timeout"),
        }
    }
}

impl From<ServerRejectReason> for RejectReason {
    fn from(rr: ServerRejectReason) -> RejectReason {
        RejectReason::Server(rr)
    }
}

impl TryFrom<i32> for ServerRejectReason {
    type Error = i32;
    fn try_from(value: i32) -> Result<Self, Self::Error> {
        Ok(match value {
            2000 => ServerRejectReason::Fallback,
            2001 => ServerRejectReason::KeyNotSup,
            2002 => ServerRejectReason::Filepath,
            2003 => ServerRejectReason::HostNotFound,
            2400 => ServerRejectReason::BadRequest,
            2401 => ServerRejectReason::Unauthorized,
            2402 => ServerRejectReason::Overload,
            2403 => ServerRejectReason::Forbidden,
            2404 => ServerRejectReason::Notfound,
            2405 => ServerRejectReason::BadMode,
            2406 => ServerRejectReason::Unacceptable,
            2409 => ServerRejectReason::Conflict,
            2415 => ServerRejectReason::NotSupMedia,
            2423 => ServerRejectReason::Locked,
            2424 => ServerRejectReason::FailedDepend,
            2500 => ServerRejectReason::InternalServerError,
            2501 => ServerRejectReason::Unimplemented,
            2502 => ServerRejectReason::Gateway,
            2503 => ServerRejectReason::Down,
            2505 => ServerRejectReason::Version,
            2507 => ServerRejectReason::NoRoom,
            unrecog => return Err(unrecog),
        })
    }
}

impl From<ServerRejectReason> for i32 {
    fn from(rr: ServerRejectReason) -> i32 {
        rr as i32
    }
}

impl Display for ServerRejectReason {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            ServerRejectReason::Fallback =>
                write!(f, "the application wants to report some problem, but can't precisely specify it"),
            ServerRejectReason::KeyNotSup =>
                write!(f, "The key used in the StreamID keyed string is not supported by the service"),
            ServerRejectReason::Filepath =>write!(f, "The resource type designates a file and the path is either wrong syntax or not found"),
            ServerRejectReason::HostNotFound => write!(f, "The `h` host specification was not recognized by the service"),
            ServerRejectReason::BadRequest => write!(f, "General syntax error in the SocketID specification (also a fallback code for undefined cases)"),
            ServerRejectReason::Unauthorized => write!(f, "Authentication failed, provided that the user was correctly identified and access to the required resource would be granted"),
            ServerRejectReason::Overload => write!(f, "The server is too heavily loaded, or you have exceeded credits for accessing the service and the resource"),
            ServerRejectReason::Forbidden => write!(f, "Access denied to the resource by any kind of reason"),
            ServerRejectReason::Notfound => write!(f, "Resource not found at this time"),
            ServerRejectReason::BadMode => write!(f, "The mode specified in `m` key in StreamID is not supported for this request"),
            ServerRejectReason::Unacceptable => write!(f, "The requested parameters specified in SocketID cannot be satisfied for the requested resource. Also when m=publish and the data format is not acceptable"),
            ServerRejectReason::Conflict => write!(f, "The resource being accessed is already locked for modification. This is in case of m=publish and the specified resource is currently read-only"),
            ServerRejectReason::NotSupMedia => write!(f, "The media type is not supported by the application. This is the `t` key that specifies the media type as stream, file and auth, possibly extended by the application"),
            ServerRejectReason::Locked => write!(f, "The resource being accessed is locked for any access"),
            ServerRejectReason::FailedDepend => write!(f, "The request failed because it specified a dependent session ID that has been disconnected"),
            ServerRejectReason::InternalServerError => write!(f, "Unexpected internal server error"),
            ServerRejectReason::Unimplemented => write!(f, "The request was recognized, but the current version doesn't support it (unimplemented)"),
            ServerRejectReason::Gateway => write!(f, "The server acts as a gateway and the target endpoint rejected the connection"),
            ServerRejectReason::Down => write!(f, "The service has been temporarily taken over by a stub reporting this error. The real service can be down for maintenance or crashed"),
            ServerRejectReason::Version => write!(f, "SRT version not supported. This might be either unsupported backward compatibility, or an upper value of a version"),
            ServerRejectReason::NoRoom => write!(f, "The data stream cannot be archived due to lacking storage space. This is in case when the request type was to send a file or the live stream to be archived"),
        }
    }
}

impl HandshakeControlInfo {
    #[allow(clippy::manual_bits)]
    fn serialized_size(&self) -> usize {
        8 * size_of::<u32>() +  // version/cookie/etc
        size_of::<u128>() + // ip address
        match &self.info {
            HandshakeVsInfo::V4(_) => 0,
            HandshakeVsInfo::V5(info) => {
                info.ext_hs.as_ref().map(|hs| 2 * size_of::<u16>() + usize::from(hs.size_words()) * size_of::<u32>()).unwrap_or(0)
                +
                info.ext_km.as_ref().map(|hs| 2 * size_of::<u16>() + usize::from(hs.size_words()) * size_of::<u32>()).unwrap_or(0)
                +
                info.sid.as_ref().map(|sid| 2 * size_of::<u16>() + ((sid.len() + 3) / 4 * 4)).unwrap_or(0)
            }
        }
    }

    fn serialize(&self, into: &mut impl BufMut) {
        into.put_u32(self.info.version());
        into.put_u32(self.info.type_flags(self.shake_type));
        into.put_u32(self.init_seq_num.as_raw());
        into.put_u32(self.max_packet_size.0 as u32);
        into.put_u32(self.max_flow_size.0 as u32);
        into.put_i32(self.shake_type.into());
        into.put_u32(self.socket_id.0);
        into.put_i32(self.syn_cookie);

        match self.peer_addr {
            IpAddr::V4(four) => {
                let v = u32::from(four);
                into.put_u32_le(v);

                // the data structure reuiqres enough space for an ipv6, so pad the end with 16 - 4 = 12 bytes
                into.put(&[0; 12][..]);
            }
            IpAddr::V6(six) => {
                let v = u128::from(six);

                into.put_u128(v);
            }
        }

        // serialzie extensions
        if let HandshakeVsInfo::V5(hs) = &self.info {
            for ext in [
                &hs.ext_hs,
                &hs.ext_km,
                &hs.sid.clone().map(SrtControlPacket::StreamId),
            ]
            .into_iter()
            .filter_map(|s| s.as_ref())
            {
                into.put_u16(ext.type_id());
                // put the size in 32-bit integers
                into.put_u16(ext.size_words());
                ext.serialize(into);
            }
        }
    }
}

impl AckStatistics {
    fn serialized_size(&self) -> usize {
        size_of::<u32>()
            * (3 + match self {
                Self {
                    packet_receive_rate: None,
                    ..
                } => 0,
                Self {
                    estimated_link_capacity: None,
                    ..
                } => 1,
                Self {
                    data_receive_rate: None,
                    ..
                } => 2,
                _ => 3,
            })
    }
}

#[cfg(test)]
mod test {
    use super::*;

    use std::{convert::TryInto, io::Cursor, time::Duration};

    use crate::options::*;

    fn ser_des_test(pack: ControlPacket) -> Vec<u8> {
        let mut buf = vec![];
        pack.serialize(&mut buf);

        let mut cursor = Cursor::new(&buf);
        let des = ControlPacket::parse(&mut cursor, false).unwrap();
        assert_eq!(cursor.remaining(), 0);
        assert_eq!(pack, des);
        assert_eq!(
            pack.wire_size(),
            buf.len() + 28,
            "Packet {pack:?} wrong wire size"
        ); // 28 is is IP+UDP buffer

        buf
    }

    #[test]
    fn lite_ack_ser_des_test() {
        ser_des_test(ControlPacket {
            timestamp: TimeStamp::from_micros(1234),
            dest_sockid: SocketId(0),
            control_type: ControlTypes::Ack(Acknowledgement::Lite(SeqNumber::new_truncate(1234))),
        });
    }

    #[test]
    fn handshake_ser_des_test() {
        ser_des_test(ControlPacket {
            timestamp: TimeStamp::from_micros(0),
            dest_sockid: SocketId(0),
            control_type: ControlTypes::Handshake(HandshakeControlInfo {
                init_seq_num: SeqNumber::new_truncate(1_827_131),
                max_packet_size: PacketSize(1500),
                max_flow_size: PacketCount(25600),
                shake_type: ShakeType::Conclusion,
                socket_id: SocketId(1231),
                syn_cookie: 0,
                peer_addr: "127.0.0.1".parse().unwrap(),
                info: HandshakeVsInfo::V5(HsV5Info {
                    crypto_size: 0, // TODO: implement
                    ext_hs: Some(SrtControlPacket::HandshakeResponse(SrtHandshake {
                        version: SrtVersion::CURRENT,
                        flags: SrtShakeFlags::NAKREPORT | SrtShakeFlags::TSBPDSND,
                        send_latency: Duration::from_millis(3000),
                        recv_latency: Duration::from_millis(12345),
                    })),
                    ext_km: None,
                    ext_group: None,
                    sid: None,
                }),
            }),
        });
    }

    #[test]
    fn ack_ser_des_test() {
        ser_des_test(ControlPacket {
            timestamp: TimeStamp::from_micros(113_703),
            dest_sockid: SocketId(2_453_706_529),
            control_type: ControlTypes::Ack(Acknowledgement::Full(
                SeqNumber::new_truncate(282_049_186),
                AckStatistics {
                    rtt: Rtt::new(TimeSpan::from_micros(10_002), TimeSpan::from_micros(1000)),
                    buffer_available: 1314,
                    packet_receive_rate: Some(0),
                    estimated_link_capacity: Some(0),
                    data_receive_rate: Some(0),
                },
                FullAckSeqNumber::new(1).unwrap(),
            )),
        });
    }

    #[test]
    fn ack2_ser_des_test() {
        let buf = ser_des_test(ControlPacket {
            timestamp: TimeStamp::from_micros(125_812),
            dest_sockid: SocketId(8313),
            control_type: ControlTypes::Ack2(FullAckSeqNumber::new(831).unwrap()),
        });

        // dword 2 should have 831 in big endian, so the last two bits of the second dword
        assert_eq!((u32::from(buf[6]) << 8) + u32::from(buf[7]), 831);
    }

    #[test]
    fn enc_size_ser_des_test() {
        ser_des_test(ControlPacket {
            timestamp: TimeStamp::from_micros(0),
            dest_sockid: SocketId(0),
            control_type: ControlTypes::Handshake(HandshakeControlInfo {
                init_seq_num: SeqNumber(0),
                max_packet_size: PacketSize(1816),
                max_flow_size: PacketCount(0),
                shake_type: ShakeType::Conclusion,
                socket_id: SocketId(0),
                syn_cookie: 0,
                peer_addr: [127, 0, 0, 1].into(),
                info: HandshakeVsInfo::V5(HsV5Info {
                    crypto_size: 16,
                    ext_km: None,
                    ext_hs: None,
                    ext_group: None,
                    sid: None,
                }),
            }),
        });
    }

    #[test]
    fn sid_ser_des_test() {
        ser_des_test(ControlPacket {
            timestamp: TimeStamp::from_micros(0),
            dest_sockid: SocketId(0),
            control_type: ControlTypes::Handshake(HandshakeControlInfo {
                init_seq_num: SeqNumber(0),
                max_packet_size: PacketSize(1816),
                max_flow_size: PacketCount(0),
                shake_type: ShakeType::Conclusion,
                socket_id: SocketId(0),
                syn_cookie: 0,
                peer_addr: [127, 0, 0, 1].into(),
                info: HandshakeVsInfo::V5(HsV5Info {
                    crypto_size: 0,
                    ext_km: None,
                    ext_hs: None,
                    ext_group: None,
                    sid: Some("Hello hello".into()),
                }),
            }),
        });
    }

    #[test]
    fn keepalive_ser_des_test() {
        ser_des_test(ControlPacket {
            timestamp: TimeStamp::from_micros(0),
            dest_sockid: SocketId(0),
            control_type: ControlTypes::KeepAlive,
        });
    }

    #[test]
    fn congestion_warning_ser_des_test() {
        ser_des_test(ControlPacket {
            timestamp: TimeStamp::from_micros(100),
            dest_sockid: rand::random(),
            control_type: ControlTypes::CongestionWarning,
        });
    }

    #[test]
    fn peer_error_ser_des_test() {
        ser_des_test(ControlPacket {
            timestamp: TimeStamp::from_micros(100),
            dest_sockid: rand::random(),
            control_type: ControlTypes::PeerError(1234),
        });
    }

    #[test]
    fn congestion_ser_des_test() {
        ser_des_test(ControlPacket {
            timestamp: TimeStamp::from_micros(100),
            dest_sockid: rand::random(),
            control_type: ControlTypes::Srt(SrtControlPacket::Congestion("live".to_string())),
        });
    }

    #[test]
    fn group_ser_des_test() {
        ser_des_test(ControlPacket {
            timestamp: TimeStamp::from_micros(100),
            dest_sockid: rand::random(),
            control_type: ControlTypes::Srt(SrtControlPacket::Group {
                ty: GroupType::MainBackup,
                flags: GroupFlags::MSG_SYNC,
                weight: 123,
            }),
        });
    }

    #[test]
    fn drop_request_ser_des_test() {
        ser_des_test(ControlPacket {
            timestamp: TimeStamp::from_micros(100),
            dest_sockid: rand::random(),
            control_type: ControlTypes::DropRequest {
                msg_to_drop: MsgNumber(123),
                range: SeqNumber(13)..=SeqNumber(100),
            },
        });
    }

    #[test]
    fn filter_ser_des_test() {
        ser_des_test(ControlPacket {
            timestamp: TimeStamp::from_micros(100),
            dest_sockid: rand::random(),
            control_type: ControlTypes::Srt(SrtControlPacket::Filter(FilterSpec(
                [("hi".to_string(), "bye".to_string())]
                    .into_iter()
                    .collect(),
            ))),
        });
    }

    #[test]
    fn raw_srt_packet_test() {
        // this was taken from wireshark on a packet from stransmit that crashed
        // it is a SRT reject message
        let packet_data =
            hex::decode("FFFF000000000000000189702BFFEFF2000103010000001E00000078").unwrap();

        let packet = ControlPacket::parse(&mut Cursor::new(packet_data), false).unwrap();

        assert_eq!(
            packet,
            ControlPacket {
                timestamp: TimeStamp::from_micros(100_720),
                dest_sockid: SocketId(738_193_394),
                control_type: ControlTypes::Srt(SrtControlPacket::Reject)
            }
        )
    }

    #[test]
    fn raw_handshake_ipv6() {
        let packet_data = hex::decode("8000000000000000000002b00000000000000004000000023c3b0296000005dc00002000000000010669ead20000000000000000000000000000000001000000").unwrap();
        let packet = ControlPacket::parse(&mut Cursor::new(&packet_data[..]), true).unwrap();

        let r = ControlPacket {
            timestamp: TimeStamp::from_micros(688),
            dest_sockid: SocketId(0),
            control_type: ControlTypes::Handshake(HandshakeControlInfo {
                init_seq_num: SeqNumber(1010500246),
                max_packet_size: PacketSize(1500),
                max_flow_size: PacketCount(8192),
                shake_type: ShakeType::Induction,
                socket_id: SocketId(0x0669EAD2),
                syn_cookie: 0,
                peer_addr: "::1.0.0.0".parse().unwrap(),
                info: HandshakeVsInfo::V4(SocketType::Datagram),
            }),
        };

        assert_eq!(packet, r);

        // reserialize it
        let mut buf = vec![];
        packet.serialize(&mut buf);

        assert_eq!(&buf[..], &packet_data[..]);
    }

    #[test]
    fn raw_handshake_srt() {
        // this is a example HSv5 conclusion packet from the reference implementation
        let packet_data = hex::decode("8000000000000000000F9EC400000000000000050000000144BEA60D000005DC00002000FFFFFFFF3D6936B6E3E405DD0100007F00000000000000000000000000010003000103010000002F00780000").unwrap();
        let packet = ControlPacket::parse(&mut Cursor::new(&packet_data[..]), false).unwrap();
        assert_eq!(
            packet,
            ControlPacket {
                timestamp: TimeStamp::from_micros(1_023_684),
                dest_sockid: SocketId(0),
                control_type: ControlTypes::Handshake(HandshakeControlInfo {
                    init_seq_num: SeqNumber(1_153_345_037),
                    max_packet_size: PacketSize(1500),
                    max_flow_size: PacketCount(8192),
                    shake_type: ShakeType::Conclusion,
                    socket_id: SocketId(1_030_305_462),
                    syn_cookie: -471_595_555,
                    peer_addr: "127.0.0.1".parse().unwrap(),
                    info: HandshakeVsInfo::V5(HsV5Info {
                        crypto_size: 0,
                        ext_hs: Some(SrtControlPacket::HandshakeRequest(SrtHandshake {
                            version: SrtVersion::new(1, 3, 1),
                            flags: SrtShakeFlags::TSBPDSND
                                | SrtShakeFlags::TSBPDRCV
                                | SrtShakeFlags::HAICRYPT
                                | SrtShakeFlags::TLPKTDROP
                                | SrtShakeFlags::REXMITFLG,
                            send_latency: Duration::from_millis(120),
                            recv_latency: Duration::new(0, 0)
                        })),
                        ext_km: None,
                        ext_group: None,
                        sid: None,
                    })
                })
            }
        );

        // reserialize it
        let mut buf = vec![];
        packet.serialize(&mut buf);

        assert_eq!(&buf[..], &packet_data[..]);
    }

    #[test]
    fn raw_handshake_sid() {
        // this is an example HSv5 conclusion packet from the reference implementation that has a
        // stream id.
        let packet_data = hex::decode("800000000000000000000b1400000000000000050000000563444b2e000005dc00002000ffffffff37eb0ee52154fbd60100007f0000000000000000000000000001000300010401000000bf0014001400050003646362616867666500006a69").unwrap();
        let packet = ControlPacket::parse(&mut Cursor::new(&packet_data[..]), false).unwrap();
        assert_eq!(
            packet,
            ControlPacket {
                timestamp: TimeStamp::from_micros(2836),
                dest_sockid: SocketId(0),
                control_type: ControlTypes::Handshake(HandshakeControlInfo {
                    init_seq_num: SeqNumber(1_665_420_078),
                    max_packet_size: PacketSize(1500),
                    max_flow_size: PacketCount(8192),
                    shake_type: ShakeType::Conclusion,
                    socket_id: SocketId(0x37eb0ee5),
                    syn_cookie: 559_217_622,
                    peer_addr: "127.0.0.1".parse().unwrap(),
                    info: HandshakeVsInfo::V5(HsV5Info {
                        crypto_size: 0,
                        ext_hs: Some(SrtControlPacket::HandshakeRequest(SrtHandshake {
                            version: SrtVersion::new(1, 4, 1),
                            flags: SrtShakeFlags::TSBPDSND
                                | SrtShakeFlags::TSBPDRCV
                                | SrtShakeFlags::HAICRYPT
                                | SrtShakeFlags::REXMITFLG
                                | SrtShakeFlags::TLPKTDROP
                                | SrtShakeFlags::NAKREPORT
                                | SrtShakeFlags::PACKET_FILTER,
                            send_latency: Duration::from_millis(20),
                            recv_latency: Duration::from_millis(20)
                        })),
                        ext_km: None,
                        ext_group: None,
                        sid: Some(String::from("abcdefghij")),
                    })
                })
            }
        );

        // reserialize it
        let mut buf = vec![];
        packet.serialize(&mut buf);

        assert_eq!(&buf[..], &packet_data[..]);
    }

    #[test]
    fn raw_handshake_crypto() {
        // this is an example HSv5 conclusion packet from the reference implementation that has crypto data embedded.
        let packet_data = hex::decode("800000000000000000175E8A0000000000000005000000036FEFB8D8000005DC00002000FFFFFFFF35E790ED5D16CCEA0100007F00000000000000000000000000010003000103010000002F01F401F40003000E122029010000000002000200000004049D75B0AC924C6E4C9EC40FEB4FE973DB1D215D426C18A2871EBF77E2646D9BAB15DBD7689AEF60EC").unwrap();
        let packet = ControlPacket::parse(&mut Cursor::new(&packet_data[..]), false).unwrap();

        assert_eq!(
            packet,
            ControlPacket {
                timestamp: TimeStamp::from_micros(1_531_530),
                dest_sockid: SocketId(0),
                control_type: ControlTypes::Handshake(HandshakeControlInfo {
                    init_seq_num: SeqNumber(1_877_981_400),
                    max_packet_size: PacketSize(1_500),
                    max_flow_size: PacketCount(8_192),
                    shake_type: ShakeType::Conclusion,
                    socket_id: SocketId(904_368_365),
                    syn_cookie: 1_561_775_338,
                    peer_addr: "127.0.0.1".parse().unwrap(),
                    info: HandshakeVsInfo::V5(HsV5Info {
                        crypto_size: 0,
                        ext_hs: Some(SrtControlPacket::HandshakeRequest(SrtHandshake {
                            version: SrtVersion::new(1, 3, 1),
                            flags: SrtShakeFlags::TSBPDSND
                                | SrtShakeFlags::TSBPDRCV
                                | SrtShakeFlags::HAICRYPT
                                | SrtShakeFlags::TLPKTDROP
                                | SrtShakeFlags::REXMITFLG,
                            send_latency: Duration::from_millis(500),
                            recv_latency: Duration::from_millis(500)
                        })),
                        ext_km: Some(SrtControlPacket::KeyRefreshRequest(KeyingMaterialMessage {
                            pt: PacketType::KeyingMaterial,
                            key_flags: KeyFlags::EVEN,
                            keki: 0,
                            cipher: CipherType::Ctr,
                            auth: Auth::None,
                            salt: hex::decode("9D75B0AC924C6E4C9EC40FEB4FE973DB").unwrap(),
                            wrapped_keys: hex::decode(
                                "1D215D426C18A2871EBF77E2646D9BAB15DBD7689AEF60EC"
                            )
                            .unwrap()
                        })),
                        ext_group: None,
                        sid: None,
                    })
                })
            }
        );

        let mut buf = vec![];
        packet.serialize(&mut buf);

        assert_eq!(&buf[..], &packet_data[..])
    }

    #[test]
    fn raw_handshake_crypto_pt2() {
        let packet_data = hex::decode("8000000000000000000000000C110D94000000050000000374B7526E000005DC00002000FFFFFFFF18C1CED1F3819B720100007F00000000000000000000000000020003000103010000003F03E803E80004000E12202901000000000200020000000404D3B3D84BE1188A4EBDA4DA16EA65D522D82DE544E1BE06B6ED8128BF15AA4E18EC50EAA95546B101").unwrap();
        let _packet = ControlPacket::parse(&mut Cursor::new(&packet_data[..]), false).unwrap();
        dbg!(&_packet);
    }

    #[test]
    fn short_ack() {
        // this is a packet received from the reference implementation that crashed the parser
        let packet_data =
            hex::decode("800200000000000e000246e5d96d5e1a389c24780000452900007bb000001fa9")
                .unwrap();

        let _cp = ControlPacket::parse(&mut Cursor::new(packet_data), false).unwrap();
    }

    #[test]
    fn test_reject_reason_deser_ser() {
        assert_eq!(
            Ok(RejectReason::Server(ServerRejectReason::Unimplemented)),
            <i32 as TryInto<RejectReason>>::try_into(
                RejectReason::Server(ServerRejectReason::Unimplemented).into()
            )
        );
    }

    #[test]
    fn test_unordered_hs_extensions() {
        //Taken from Wireshark dump of FFMPEG connection handshake
        let packet_data = hex::decode(concat!(
            "80000000000000000000dea800000000",
            "000000050004000751dca3b8000005b8",
            "00002000ffffffff025c84b8da7ee4e7",
            "0100007f000000000000000000000000",
            "0001000300010402000000bf003c003c",
            "000500033a3a212365683d7500000078",
            "00030012122029010000000002000200",
            "00000408437937d8c23ce2090754c5a7",
            "a9e608c14631aef7ac0b8a46b77b8c0b",
            "97d4061e565dcb86e4c5cc3701e1f992",
            "a5b2de3651c937c94f3333a6"
        ))
        .unwrap();

        let packet = ControlPacket::parse(&mut Cursor::new(packet_data), false).unwrap();
        let reference = ControlPacket {
            timestamp: TimeStamp::from_micros(57000),
            dest_sockid: SocketId(0),
            control_type: ControlTypes::Handshake(HandshakeControlInfo {
                init_seq_num: SeqNumber(1373414328),
                max_packet_size: PacketSize(1464),
                max_flow_size: PacketCount(8192),
                shake_type: ShakeType::Conclusion,
                socket_id: SocketId(0x025C84B8),
                syn_cookie: 0xda7ee4e7u32 as i32,
                peer_addr: [127, 0, 0, 1].into(),
                info: HandshakeVsInfo::V5(HsV5Info {
                    crypto_size: 32,
                    ext_hs: Some(SrtControlPacket::HandshakeRequest(SrtHandshake {
                        version: SrtVersion::new(1, 4, 2),
                        flags: SrtShakeFlags::TSBPDSND
                            | SrtShakeFlags::TSBPDRCV
                            | SrtShakeFlags::HAICRYPT
                            | SrtShakeFlags::TLPKTDROP
                            | SrtShakeFlags::NAKREPORT
                            | SrtShakeFlags::REXMITFLG
                            | SrtShakeFlags::PACKET_FILTER,
                        send_latency: Duration::from_millis(60),
                        recv_latency: Duration::from_millis(60)
                    })),
                    ext_km: Some(SrtControlPacket::KeyRefreshRequest(KeyingMaterialMessage {
                        pt: PacketType::KeyingMaterial,
                        key_flags: KeyFlags::EVEN,
                        keki: 0,
                        cipher: CipherType::Ctr,
                        auth: Auth::None,
                        salt: hex::decode("437937d8c23ce2090754c5a7a9e608c1").unwrap(),
                        wrapped_keys: hex::decode(
                            "4631aef7ac0b8a46b77b8c0b97d4061e565dcb86e4c5cc3701e1f992a5b2de3651c937c94f3333a6"
                        )
                            .unwrap()
                    })),
                    ext_group: None,
                    sid: Some("#!::u=hex".into()),
                }),
            }),
        };

        assert_eq!(packet, reference);
    }

    #[test]
    fn drop_request() {}
}