summaryrefslogtreecommitdiffstats
path: root/src/quic_rx.c
blob: d5b45d672f6c3c0c2d482dc62fbe0cac8e3a53a9 (plain)
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
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
/*
 * QUIC protocol implementation. Lower layer with internal features implemented
 * here such as QUIC encryption, idle timeout, acknowledgement and
 * retransmission.
 *
 * Copyright 2020 HAProxy Technologies, Frederic Lecaille <flecaille@haproxy.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 */

#include <haproxy/quic_rx.h>

#include <haproxy/h3.h>
#include <haproxy/list.h>
#include <haproxy/ncbuf.h>
#include <haproxy/proto_quic.h>
#include <haproxy/quic_ack.h>
#include <haproxy/quic_cid.h>
#include <haproxy/quic_retransmit.h>
#include <haproxy/quic_retry.h>
#include <haproxy/quic_sock.h>
#include <haproxy/quic_stream.h>
#include <haproxy/quic_ssl.h>
#include <haproxy/quic_tls.h>
#include <haproxy/quic_trace.h>
#include <haproxy/quic_tx.h>
#include <haproxy/ssl_sock.h>
#include <haproxy/trace.h>

DECLARE_POOL(pool_head_quic_conn_rxbuf, "quic_conn_rxbuf", QUIC_CONN_RX_BUFSZ);
DECLARE_POOL(pool_head_quic_dgram, "quic_dgram", sizeof(struct quic_dgram));
DECLARE_POOL(pool_head_quic_rx_packet, "quic_rx_packet", sizeof(struct quic_rx_packet));

/* Decode an expected packet number from <truncated_on> its truncated value,
 * depending on <largest_pn> the largest received packet number, and <pn_nbits>
 * the number of bits used to encode this packet number (its length in bytes * 8).
 * See https://quicwg.org/base-drafts/draft-ietf-quic-transport.html#packet-encoding
 */
static uint64_t decode_packet_number(uint64_t largest_pn,
                                     uint32_t truncated_pn, unsigned int pn_nbits)
{
	uint64_t expected_pn = largest_pn + 1;
	uint64_t pn_win = (uint64_t)1 << pn_nbits;
	uint64_t pn_hwin = pn_win / 2;
	uint64_t pn_mask = pn_win - 1;
	uint64_t candidate_pn;


	candidate_pn = (expected_pn & ~pn_mask) | truncated_pn;
	/* Note that <pn_win> > <pn_hwin>. */
	if (candidate_pn < QUIC_MAX_PACKET_NUM - pn_win &&
	    candidate_pn + pn_hwin <= expected_pn)
		return candidate_pn + pn_win;

	if (candidate_pn > expected_pn + pn_hwin && candidate_pn >= pn_win)
		return candidate_pn - pn_win;

	return candidate_pn;
}

/* Remove the header protection of <pkt> QUIC packet using <tls_ctx> as QUIC TLS
 * cryptographic context.
 * <largest_pn> is the largest received packet number and <pn> the address of
 * the packet number field for this packet with <byte0> address of its first byte.
 * <end> points to one byte past the end of this packet.
 * Returns 1 if succeeded, 0 if not.
 */
static int qc_do_rm_hp(struct quic_conn *qc,
                       struct quic_rx_packet *pkt, struct quic_tls_ctx *tls_ctx,
                       int64_t largest_pn, unsigned char *pn, unsigned char *byte0)
{
	int ret, i, pnlen;
	uint64_t packet_number;
	uint32_t truncated_pn = 0;
	unsigned char mask[5] = {0};
	unsigned char *sample;

	TRACE_ENTER(QUIC_EV_CONN_RMHP, qc);

	ret = 0;

	/* Check there is enough data in this packet. */
	if (pkt->len - (pn - byte0) < QUIC_PACKET_PN_MAXLEN + sizeof mask) {
		TRACE_PROTO("too short packet", QUIC_EV_CONN_RMHP, qc, pkt);
		goto leave;
	}

	sample = pn + QUIC_PACKET_PN_MAXLEN;

	if (!quic_tls_aes_decrypt(mask, sample, sizeof mask, tls_ctx->rx.hp_ctx)) {
		TRACE_ERROR("HP removing failed", QUIC_EV_CONN_RMHP, qc, pkt);
		goto leave;
	}

	*byte0 ^= mask[0] & (*byte0 & QUIC_PACKET_LONG_HEADER_BIT ? 0xf : 0x1f);
	pnlen = (*byte0 & QUIC_PACKET_PNL_BITMASK) + 1;
	for (i = 0; i < pnlen; i++) {
		pn[i] ^= mask[i + 1];
		truncated_pn = (truncated_pn << 8) | pn[i];
	}

	packet_number = decode_packet_number(largest_pn, truncated_pn, pnlen * 8);
	/* Store remaining information for this unprotected header */
	pkt->pn = packet_number;
	pkt->pnl = pnlen;

	ret = 1;
 leave:
	TRACE_LEAVE(QUIC_EV_CONN_RMHP, qc);
	return ret;
}

/* Decrypt <pkt> packet using encryption level <qel> for <qc> connection.
 * Decryption is done in place in packet buffer.
 *
 * Returns 1 on success else 0.
 */
static int qc_pkt_decrypt(struct quic_conn *qc, struct quic_enc_level *qel,
                          struct quic_rx_packet *pkt)
{
	int ret, kp_changed;
	unsigned char iv[QUIC_TLS_IV_LEN];
	struct quic_tls_ctx *tls_ctx =
		qc_select_tls_ctx(qc, qel, pkt->type, pkt->version);
	EVP_CIPHER_CTX *rx_ctx = tls_ctx->rx.ctx;
	unsigned char *rx_iv = tls_ctx->rx.iv;
	size_t rx_iv_sz = tls_ctx->rx.ivlen;
	unsigned char *rx_key = tls_ctx->rx.key;

	TRACE_ENTER(QUIC_EV_CONN_RXPKT, qc);

	ret = 0;
	kp_changed = 0;

	if (pkt->type == QUIC_PACKET_TYPE_SHORT) {
		/* The two tested bits are not at the same position,
		 * this is why they are first both inversed.
		 */
		if (!(*pkt->data & QUIC_PACKET_KEY_PHASE_BIT) ^ !(tls_ctx->flags & QUIC_FL_TLS_KP_BIT_SET)) {
			if (pkt->pn < tls_ctx->rx.pn) {
				/* The lowest packet number of a previous key phase
				 * cannot be null if it really stores previous key phase
				 * secrets.
				 */
				// TODO: check if BUG_ON() more suitable
				if (!qc->ku.prv_rx.pn) {
					TRACE_ERROR("null previous packet number", QUIC_EV_CONN_RXPKT, qc);
					goto leave;
				}

				rx_ctx = qc->ku.prv_rx.ctx;
				rx_iv  = qc->ku.prv_rx.iv;
				rx_key = qc->ku.prv_rx.key;
			}
			else if (pkt->pn > qel->pktns->rx.largest_pn) {
				/* Next key phase */
				TRACE_PROTO("Key phase changed", QUIC_EV_CONN_RXPKT, qc);
				kp_changed = 1;
				rx_ctx = qc->ku.nxt_rx.ctx;
				rx_iv  = qc->ku.nxt_rx.iv;
				rx_key = qc->ku.nxt_rx.key;
			}
		}
	}

	quic_aead_iv_build(iv, sizeof iv, rx_iv, rx_iv_sz, pkt->pn);

	ret = quic_tls_decrypt(pkt->data + pkt->aad_len, pkt->len - pkt->aad_len,
	                       pkt->data, pkt->aad_len,
	                       rx_ctx, tls_ctx->rx.aead, rx_key, iv);
	if (!ret) {
		TRACE_ERROR("quic_tls_decrypt() failed", QUIC_EV_CONN_RXPKT, qc);
		goto leave;
	}

	/* Update the keys only if the packet decryption succeeded. */
	if (kp_changed) {
		quic_tls_rotate_keys(qc);
		/* Toggle the Key Phase bit */
		tls_ctx->flags ^= QUIC_FL_TLS_KP_BIT_SET;
		/* Store the lowest packet number received for the current key phase */
		tls_ctx->rx.pn = pkt->pn;
		/* Prepare the next key update */
		if (!quic_tls_key_update(qc)) {
			TRACE_ERROR("quic_tls_key_update() failed", QUIC_EV_CONN_RXPKT, qc);
			goto leave;
		}
	}

	/* Update the packet length (required to parse the frames). */
	pkt->len -= QUIC_TLS_TAG_LEN;
	ret = 1;
 leave:
	TRACE_LEAVE(QUIC_EV_CONN_RXPKT, qc);
	return ret;
}

/* Remove from <stream> the acknowledged frames.
 *
 * Returns 1 if at least one frame was removed else 0.
 */
static int quic_stream_try_to_consume(struct quic_conn *qc,
                                      struct qc_stream_desc *stream)
{
	int ret;
	struct eb64_node *frm_node;

	TRACE_ENTER(QUIC_EV_CONN_ACKSTRM, qc);

	ret = 0;
	frm_node = eb64_first(&stream->acked_frms);
	while (frm_node) {
		struct qf_stream *strm_frm;
		struct quic_frame *frm;
		size_t offset, len;

		strm_frm = eb64_entry(frm_node, struct qf_stream, offset);
		offset = strm_frm->offset.key;
		len = strm_frm->len;

		if (offset > stream->ack_offset)
			break;

		if (qc_stream_desc_ack(&stream, offset, len)) {
			/* cf. next comment : frame may be freed at this stage. */
			TRACE_DEVEL("stream consumed", QUIC_EV_CONN_ACKSTRM,
			            qc, stream ? strm_frm : NULL, stream);
			ret = 1;
		}

		/* If stream is NULL after qc_stream_desc_ack(), it means frame
		 * has been freed. with the stream frames tree. Nothing to do
		 * anymore in here.
		 */
		if (!stream) {
			qc_check_close_on_released_mux(qc);
			ret = 1;
			goto leave;
		}

		frm_node = eb64_next(frm_node);
		eb64_delete(&strm_frm->offset);

		frm = container_of(strm_frm, struct quic_frame, stream);
		qc_release_frm(qc, frm);
	}

 leave:
	TRACE_LEAVE(QUIC_EV_CONN_ACKSTRM, qc);
	return ret;
}

/* Handle <frm> frame whose packet it is attached to has just been acknowledged. The memory allocated
 * for this frame will be at least released in every cases.
 * Never fail.
 */
static void qc_handle_newly_acked_frm(struct quic_conn *qc, struct quic_frame *frm)
{
	TRACE_ENTER(QUIC_EV_CONN_PRSAFRM, qc);
	TRACE_PROTO("RX ack TX frm", QUIC_EV_CONN_PRSAFRM, qc, frm);

	switch (frm->type) {
	case QUIC_FT_STREAM_8 ... QUIC_FT_STREAM_F:
	{
		struct qf_stream *strm_frm = &frm->stream;
		struct eb64_node *node = NULL;
		struct qc_stream_desc *stream = NULL;
		const size_t offset = strm_frm->offset.key;
		const size_t len = strm_frm->len;

		/* do not use strm_frm->stream as the qc_stream_desc instance
		 * might be freed at this stage. Use the id to do a proper
		 * lookup.
		 *
		 * TODO if lookup operation impact on the perf is noticeable,
		 * implement a refcount on qc_stream_desc instances.
		 */
		node = eb64_lookup(&qc->streams_by_id, strm_frm->id);
		if (!node) {
			TRACE_DEVEL("acked stream for released stream", QUIC_EV_CONN_ACKSTRM, qc, strm_frm);
			qc_release_frm(qc, frm);
			/* early return */
			goto leave;
		}
		stream = eb64_entry(node, struct qc_stream_desc, by_id);

		TRACE_DEVEL("acked stream", QUIC_EV_CONN_ACKSTRM, qc, strm_frm, stream);
		if (offset <= stream->ack_offset) {
			if (qc_stream_desc_ack(&stream, offset, len)) {
				TRACE_DEVEL("stream consumed", QUIC_EV_CONN_ACKSTRM,
				            qc, strm_frm, stream);
			}

			if (!stream) {
				/* no need to continue if stream freed. */
				TRACE_DEVEL("stream released and freed", QUIC_EV_CONN_ACKSTRM, qc);
				qc_release_frm(qc, frm);
				qc_check_close_on_released_mux(qc);
				break;
			}

			TRACE_DEVEL("stream consumed", QUIC_EV_CONN_ACKSTRM,
			            qc, strm_frm, stream);
			qc_release_frm(qc, frm);
		}
		else {
			eb64_insert(&stream->acked_frms, &strm_frm->offset);
		}

		quic_stream_try_to_consume(qc, stream);
	}
	break;
	default:
		qc_release_frm(qc, frm);
	}

 leave:
	TRACE_LEAVE(QUIC_EV_CONN_PRSAFRM, qc);
}

/* Collect newly acknowledged TX packets from <pkts> ebtree into <newly_acked_pkts>
 * list depending on <largest> and <smallest> packet number of a range of acknowledged
 * packets announced in an ACK frame. <largest_node> may be provided to start
 * looking from this packet node.
 */
static void qc_newly_acked_pkts(struct quic_conn *qc, struct eb_root *pkts,
                                struct list *newly_acked_pkts,
                                struct eb64_node *largest_node,
                                uint64_t largest, uint64_t smallest)
{
	struct eb64_node *node;
	struct quic_tx_packet *pkt;

	TRACE_ENTER(QUIC_EV_CONN_PRSAFRM, qc);

	node = eb64_lookup_ge(pkts, smallest);
	if (!node)
		goto leave;

	largest_node = largest_node ? largest_node : eb64_lookup_le(pkts, largest);
	if (!largest_node)
		goto leave;

	while (node && node->key <= largest_node->key) {
		pkt = eb64_entry(node, struct quic_tx_packet, pn_node);
		LIST_APPEND(newly_acked_pkts, &pkt->list);
		node = eb64_next(node);
		eb64_delete(&pkt->pn_node);
	}

 leave:
	TRACE_LEAVE(QUIC_EV_CONN_PRSAFRM, qc);
}

/* Handle <newly_acked_pkts> list of newly acknowledged TX packets */
static void qc_handle_newly_acked_pkts(struct quic_conn *qc,
                                       unsigned int *pkt_flags, struct list *newly_acked_pkts)
{
	struct quic_tx_packet *pkt, *tmp;

	TRACE_ENTER(QUIC_EV_CONN_PRSAFRM, qc);

	list_for_each_entry_safe(pkt, tmp, newly_acked_pkts, list) {
		struct quic_frame *frm, *frmbak;

		*pkt_flags |= pkt->flags;
		TRACE_DEVEL("Removing packet #", QUIC_EV_CONN_PRSAFRM, qc, NULL, &pkt->pn_node.key);
		list_for_each_entry_safe(frm, frmbak, &pkt->frms, list)
			qc_handle_newly_acked_frm(qc, frm);
		/* If there are others packet in the same datagram <pkt> is attached to,
		 * detach the previous one and the next one from <pkt>.
		 */
		quic_tx_packet_dgram_detach(pkt);
		eb64_delete(&pkt->pn_node);
	}

 leave:
	TRACE_LEAVE(QUIC_EV_CONN_PRSAFRM, qc);
}

/* Handle all frames sent from <pkt> packet and reinsert them in the same order
 * they have been sent into <pktns_frm_list>. The loss counter of each frame is
 * incremented and checked if it does not exceed retransmission limit.
 *
 * Returns 1 on success, 0 if a frame loss limit is exceeded. A
 * CONNECTION_CLOSE is scheduled in this case.
 */
int qc_handle_frms_of_lost_pkt(struct quic_conn *qc,
                               struct quic_tx_packet *pkt,
                               struct list *pktns_frm_list)
{
	struct quic_frame *frm, *frmbak;
	struct list *pkt_frm_list = &pkt->frms;
	uint64_t pn = pkt->pn_node.key;
	int close = 0;

	TRACE_ENTER(QUIC_EV_CONN_PRSAFRM, qc);

	list_for_each_entry_safe(frm, frmbak, pkt_frm_list, list) {
		/* First remove this frame from the packet it was attached to */
		LIST_DEL_INIT(&frm->list);
		quic_tx_packet_refdec(pkt);
		/* At this time, this frame is not freed but removed from its packet */
		frm->pkt = NULL;
		/* Remove any reference to this frame */
		qc_frm_unref(frm, qc);
		switch (frm->type) {
		case QUIC_FT_STREAM_8 ... QUIC_FT_STREAM_F:
		{
			struct qf_stream *strm_frm = &frm->stream;
			struct eb64_node *node = NULL;
			struct qc_stream_desc *stream_desc;

			node = eb64_lookup(&qc->streams_by_id, strm_frm->id);
			if (!node) {
				TRACE_DEVEL("released stream", QUIC_EV_CONN_PRSAFRM, qc, frm);
				TRACE_DEVEL("freeing frame from packet", QUIC_EV_CONN_PRSAFRM,
				            qc, frm, &pn);
				qc_frm_free(qc, &frm);
				continue;
			}

			stream_desc = eb64_entry(node, struct qc_stream_desc, by_id);
			/* Do not resend this frame if in the "already acked range" */
			if (strm_frm->offset.key + strm_frm->len <= stream_desc->ack_offset) {
				TRACE_DEVEL("ignored frame in already acked range",
				            QUIC_EV_CONN_PRSAFRM, qc, frm);
				qc_frm_free(qc, &frm);
				continue;
			}
			else if (strm_frm->offset.key < stream_desc->ack_offset) {
				uint64_t diff = stream_desc->ack_offset - strm_frm->offset.key;

				qc_stream_frm_mv_fwd(frm, diff);
				TRACE_DEVEL("updated partially acked frame",
				            QUIC_EV_CONN_PRSAFRM, qc, frm);
			}
			break;
		}

		default:
			break;
		}

		/* Do not resend probing packet with old data */
		if (pkt->flags & QUIC_FL_TX_PACKET_PROBE_WITH_OLD_DATA) {
			TRACE_DEVEL("ignored frame with old data from packet", QUIC_EV_CONN_PRSAFRM,
				    qc, frm, &pn);
			if (frm->origin)
				LIST_DEL_INIT(&frm->ref);
			qc_frm_free(qc, &frm);
			continue;
		}

		if (frm->flags & QUIC_FL_TX_FRAME_ACKED) {
			TRACE_DEVEL("already acked frame", QUIC_EV_CONN_PRSAFRM, qc, frm);
			TRACE_DEVEL("freeing frame from packet", QUIC_EV_CONN_PRSAFRM,
			            qc, frm, &pn);
			qc_frm_free(qc, &frm);
		}
		else {
			if (++frm->loss_count >= global.tune.quic_max_frame_loss) {
				TRACE_ERROR("retransmission limit reached, closing the connection", QUIC_EV_CONN_PRSAFRM, qc);
				quic_set_connection_close(qc, quic_err_transport(QC_ERR_INTERNAL_ERROR));
				qc_notify_err(qc);
				close = 1;
			}

			LIST_APPEND(pktns_frm_list, &frm->list);
			TRACE_DEVEL("frame requeued", QUIC_EV_CONN_PRSAFRM, qc, frm);
		}
	}

 end:
	TRACE_LEAVE(QUIC_EV_CONN_PRSAFRM, qc);
	return !close;
}

/* Send a packet ack event nofication for each newly acked packet of
 * <newly_acked_pkts> list and free them.
 * Always succeeds.
 */
static void qc_notify_cc_of_newly_acked_pkts(struct quic_conn *qc,
                                             struct list *newly_acked_pkts)
{
	struct quic_tx_packet *pkt, *tmp;
	struct quic_cc_event ev = { .type = QUIC_CC_EVT_ACK, };

	TRACE_ENTER(QUIC_EV_CONN_PRSAFRM, qc);

	list_for_each_entry_safe(pkt, tmp, newly_acked_pkts, list) {
		pkt->pktns->tx.in_flight -= pkt->in_flight_len;
		qc->path->prep_in_flight -= pkt->in_flight_len;
		qc->path->in_flight -= pkt->in_flight_len;
		if (pkt->flags & QUIC_FL_TX_PACKET_ACK_ELICITING)
			qc->path->ifae_pkts--;
		/* If this packet contained an ACK frame, proceed to the
		 * acknowledging of range of acks from the largest acknowledged
		 * packet number which was sent in an ACK frame by this packet.
		 */
		if (pkt->largest_acked_pn != -1)
			qc_treat_ack_of_ack(qc, &pkt->pktns->rx.arngs, pkt->largest_acked_pn);
		ev.ack.acked = pkt->in_flight_len;
		ev.ack.time_sent = pkt->time_sent;
		ev.ack.pn = pkt->pn_node.key;
		quic_cc_event(&qc->path->cc, &ev);
		LIST_DEL_INIT(&pkt->list);
		quic_tx_packet_refdec(pkt);
	}

	TRACE_LEAVE(QUIC_EV_CONN_PRSAFRM, qc);

}

/* Parse ACK frame into <frm> from a buffer at <buf> address with <end> being at
 * one byte past the end of this buffer. Also update <rtt_sample> if needed, i.e.
 * if the largest acked packet was newly acked and if there was at least one newly
 * acked ack-eliciting packet.
 * Return 1, if succeeded, 0 if not.
 */
static int qc_parse_ack_frm(struct quic_conn *qc,
                            struct quic_frame *frm,
                            struct quic_enc_level *qel,
                            unsigned int *rtt_sample,
                            const unsigned char **pos, const unsigned char *end)
{
	struct qf_ack *ack_frm = &frm->ack;
	uint64_t smallest, largest;
	struct eb_root *pkts;
	struct eb64_node *largest_node;
	unsigned int time_sent, pkt_flags;
	struct list newly_acked_pkts = LIST_HEAD_INIT(newly_acked_pkts);
	struct list lost_pkts = LIST_HEAD_INIT(lost_pkts);
	int ret = 0, new_largest_acked_pn = 0;
	struct quic_tx_packet *pkt, *tmp;

	TRACE_ENTER(QUIC_EV_CONN_PRSAFRM, qc);

	pkts = &qel->pktns->tx.pkts;
	if (ack_frm->largest_ack > qel->pktns->tx.next_pn) {
		TRACE_DEVEL("ACK for not sent packet", QUIC_EV_CONN_PRSAFRM,
		            qc, NULL, &ack_frm->largest_ack);
		goto err;
	}

	if (ack_frm->first_ack_range > ack_frm->largest_ack) {
		TRACE_DEVEL("too big first ACK range", QUIC_EV_CONN_PRSAFRM,
		            qc, NULL, &ack_frm->first_ack_range);
		goto err;
	}

	largest = ack_frm->largest_ack;
	smallest = largest - ack_frm->first_ack_range;
	pkt_flags = 0;
	largest_node = NULL;
	time_sent = 0;

	if ((int64_t)ack_frm->largest_ack > qel->pktns->rx.largest_acked_pn) {
		largest_node = eb64_lookup(pkts, largest);
		if (!largest_node) {
			TRACE_DEVEL("Largest acked packet not found",
			            QUIC_EV_CONN_PRSAFRM, qc);
		}
		else {
			time_sent = eb64_entry(largest_node,
			                       struct quic_tx_packet, pn_node)->time_sent;
			new_largest_acked_pn = 1;
		}
	}

	TRACE_PROTO("RX ack range", QUIC_EV_CONN_PRSAFRM,
	            qc, NULL, &largest, &smallest);
	do {
		uint64_t gap, ack_range;

		qc_newly_acked_pkts(qc, pkts, &newly_acked_pkts,
		                    largest_node, largest, smallest);
		if (!ack_frm->ack_range_num--)
			break;

		if (!quic_dec_int(&gap, pos, end)) {
			TRACE_ERROR("quic_dec_int(gap) failed", QUIC_EV_CONN_PRSAFRM, qc);
			goto err;
		}

		if (smallest < gap + 2) {
			TRACE_DEVEL("wrong gap value", QUIC_EV_CONN_PRSAFRM,
			            qc, NULL, &gap, &smallest);
			goto err;
		}

		largest = smallest - gap - 2;
		if (!quic_dec_int(&ack_range, pos, end)) {
			TRACE_ERROR("quic_dec_int(ack_range) failed", QUIC_EV_CONN_PRSAFRM, qc);
			goto err;
		}

		if (largest < ack_range) {
			TRACE_DEVEL("wrong ack range value", QUIC_EV_CONN_PRSAFRM,
			            qc, NULL, &largest, &ack_range);
			goto err;
		}

		/* Do not use this node anymore. */
		largest_node = NULL;
		/* Next range */
		smallest = largest - ack_range;

		TRACE_PROTO("RX next ack range", QUIC_EV_CONN_PRSAFRM,
		            qc, NULL, &largest, &smallest);
	} while (1);

	if (!LIST_ISEMPTY(&newly_acked_pkts)) {
		qc_handle_newly_acked_pkts(qc, &pkt_flags, &newly_acked_pkts);
		if (new_largest_acked_pn && (pkt_flags & QUIC_FL_TX_PACKET_ACK_ELICITING)) {
			*rtt_sample = tick_remain(time_sent, now_ms);
			qel->pktns->rx.largest_acked_pn = ack_frm->largest_ack;
		}

		if (!eb_is_empty(&qel->pktns->tx.pkts)) {
			qc_packet_loss_lookup(qel->pktns, qc, &lost_pkts);
			if (!qc_release_lost_pkts(qc, qel->pktns, &lost_pkts, now_ms))
				goto leave;
		}
		qc_notify_cc_of_newly_acked_pkts(qc, &newly_acked_pkts);
		if (quic_peer_validated_addr(qc))
			qc->path->loss.pto_count = 0;
		qc_set_timer(qc);
		qc_notify_send(qc);
	}

	ret = 1;
 leave:
	TRACE_LEAVE(QUIC_EV_CONN_PRSAFRM, qc);
	return ret;

 err:
	/* Move back these packets into their tree. */
	list_for_each_entry_safe(pkt, tmp, &newly_acked_pkts, list) {
		LIST_DEL_INIT(&pkt->list);
		eb64_insert(pkts, &pkt->pn_node);
	}
	goto leave;
}

/* Parse a STREAM frame <strm_frm> received in <pkt> packet for <qc>
 * connection. <fin> is true if FIN bit is set on frame type.
 *
 * Return 1 on success. On error, 0 is returned. In this case, the packet
 * containing the frame must not be acknowledged.
 */
static int qc_handle_strm_frm(struct quic_rx_packet *pkt,
                              struct qf_stream *strm_frm,
                              struct quic_conn *qc, char fin)
{
	int ret;

	/* RFC9000 13.1.  Packet Processing
	 *
	 * A packet MUST NOT be acknowledged until packet protection has been
	 * successfully removed and all frames contained in the packet have
	 * been processed. For STREAM frames, this means the data has been
	 * enqueued in preparation to be received by the application protocol,
	 * but it does not require that data be delivered and consumed.
	 */
	TRACE_ENTER(QUIC_EV_CONN_PRSFRM, qc);

	ret = qcc_recv(qc->qcc, strm_frm->id, strm_frm->len,
	               strm_frm->offset.key, fin, (char *)strm_frm->data);

	/* frame rejected - packet must not be acknowledeged */
	TRACE_LEAVE(QUIC_EV_CONN_PRSFRM, qc);
	return !ret;
}

/* Parse <frm> CRYPTO frame coming with <pkt> packet at <qel> <qc> connectionn.
 * Returns 1 if succeeded, 0 if not. Also set <*fast_retrans> to 1 if the
 * speed up handshake completion may be run after having received duplicated
 * CRYPTO data.
 */
static int qc_handle_crypto_frm(struct quic_conn *qc,
                                struct qf_crypto *crypto_frm, struct quic_rx_packet *pkt,
                                struct quic_enc_level *qel, int *fast_retrans)
{
	int ret = 0;
	enum ncb_ret ncb_ret;
	/* XXX TO DO: <cfdebug> is used only for the traces. */
	struct quic_rx_crypto_frm cfdebug = {
		.offset_node.key = crypto_frm->offset,
		.len = crypto_frm->len,
	};
	struct quic_cstream *cstream = qel->cstream;
	struct ncbuf *ncbuf = &qel->cstream->rx.ncbuf;

	TRACE_ENTER(QUIC_EV_CONN_PRSHPKT, qc);

	if (unlikely(crypto_frm->offset < cstream->rx.offset)) {
		size_t diff;

		if (crypto_frm->offset + crypto_frm->len <= cstream->rx.offset) {
			/* Nothing to do */
			TRACE_PROTO("Already received CRYPTO data",
						QUIC_EV_CONN_RXPKT, qc, pkt, &cfdebug);
			if (qc_is_listener(qc) && qel == qc->iel &&
				!(qc->flags & QUIC_FL_CONN_HANDSHAKE_SPEED_UP))
				*fast_retrans = 1;
			goto done;
		}

		TRACE_PROTO("Partially already received CRYPTO data",
		            QUIC_EV_CONN_RXPKT, qc, pkt, &cfdebug);

		diff = cstream->rx.offset - crypto_frm->offset;
		crypto_frm->len -= diff;
		crypto_frm->data += diff;
		crypto_frm->offset = cstream->rx.offset;
	}

	if (!quic_get_ncbuf(ncbuf) || ncb_is_null(ncbuf)) {
		TRACE_ERROR("CRYPTO ncbuf allocation failed", QUIC_EV_CONN_PRSHPKT, qc);
		goto leave;
	}

	/* crypto_frm->offset > cstream-trx.offset */
	ncb_ret = ncb_add(ncbuf, crypto_frm->offset - cstream->rx.offset,
	                  (const char *)crypto_frm->data, crypto_frm->len, NCB_ADD_COMPARE);
	if (ncb_ret != NCB_RET_OK) {
		if (ncb_ret == NCB_RET_DATA_REJ) {
			TRACE_ERROR("overlapping data rejected", QUIC_EV_CONN_PRSHPKT, qc);
			quic_set_connection_close(qc, quic_err_transport(QC_ERR_PROTOCOL_VIOLATION));
			qc_notify_err(qc);
		}
		else if (ncb_ret == NCB_RET_GAP_SIZE) {
			TRACE_ERROR("cannot bufferize frame due to gap size limit",
			            QUIC_EV_CONN_PRSHPKT, qc);
		}
		goto leave;
	}

	/* Reschedule with TASK_HEAVY if CRYPTO data ready for decoding. */
	if (ncb_data(ncbuf, 0)) {
		HA_ATOMIC_OR(&qc->wait_event.tasklet->state, TASK_HEAVY);
		tasklet_wakeup(qc->wait_event.tasklet);
	}

 done:
	ret = 1;
 leave:
	TRACE_LEAVE(QUIC_EV_CONN_PRSHPKT, qc);
	return ret;
}

/* Handle RETIRE_CONNECTION_ID frame from <frm> frame.
 * Return 1 if succeeded, 0 if not. If succeeded, also set <to_retire>
 * to the CID to be retired if not already retired.
 */
static int qc_handle_retire_connection_id_frm(struct quic_conn *qc,
                                              struct quic_frame *frm,
                                              struct quic_cid *dcid,
                                              struct quic_connection_id **to_retire)
{
	int ret = 0;
	struct qf_retire_connection_id *rcid_frm = &frm->retire_connection_id;
	struct eb64_node *node;
	struct quic_connection_id *conn_id;

	TRACE_ENTER(QUIC_EV_CONN_PRSHPKT, qc);

	/* RFC 9000 19.16. RETIRE_CONNECTION_ID Frames:
	 * Receipt of a RETIRE_CONNECTION_ID frame containing a sequence number greater
	 * than any previously sent to the peer MUST be treated as a connection error
	 * of type PROTOCOL_VIOLATION.
	 */
	if (rcid_frm->seq_num >= qc->next_cid_seq_num) {
		TRACE_PROTO("CID seq. number too big", QUIC_EV_CONN_PSTRM, qc, frm);
		goto protocol_violation;
	}

	/* RFC 9000 19.16. RETIRE_CONNECTION_ID Frames:
	 * The sequence number specified in a RETIRE_CONNECTION_ID frame MUST NOT refer to
	 * the Destination Connection ID field of the packet in which the frame is contained.
	 * The peer MAY treat this as a connection error of type PROTOCOL_VIOLATION.
	 */
	node = eb64_lookup(qc->cids, rcid_frm->seq_num);
	if (!node) {
		TRACE_PROTO("CID already retired", QUIC_EV_CONN_PSTRM, qc, frm);
		goto out;
	}

	conn_id = eb64_entry(node, struct quic_connection_id, seq_num);
	/* Note that the length of <dcid> has already been checked. It must match the
	 * length of the CIDs which have been provided to the peer.
	 */
	if (!memcmp(dcid->data, conn_id->cid.data, QUIC_HAP_CID_LEN)) {
		TRACE_PROTO("cannot retire the current CID", QUIC_EV_CONN_PSTRM, qc, frm);
		goto protocol_violation;
	}

	*to_retire = conn_id;
 out:
	ret = 1;
 leave:
	TRACE_LEAVE(QUIC_EV_CONN_PRSHPKT, qc);
	return ret;
 protocol_violation:
	quic_set_connection_close(qc, quic_err_transport(QC_ERR_PROTOCOL_VIOLATION));
	qc_notify_err(qc);
	goto leave;
}

/* Returns the <ack_delay> field value in milliseconds from <ack_frm> ACK frame for
 * <conn> QUIC connection. Note that the value of <ack_delay> coming from
 * ACK frame is in microseconds.
 */
static inline unsigned int quic_ack_delay_ms(struct qf_ack *ack_frm,
                                             struct quic_conn *conn)
{
	return (ack_frm->ack_delay << conn->tx.params.ack_delay_exponent) / 1000;
}

/* Parse all the frames of <pkt> QUIC packet for QUIC connection <qc> and <qel>
 * as encryption level.
 * Returns 1 if succeeded, 0 if failed.
 */
static int qc_parse_pkt_frms(struct quic_conn *qc, struct quic_rx_packet *pkt,
                             struct quic_enc_level *qel)
{
	struct quic_frame frm;
	const unsigned char *pos, *end;
	int fast_retrans = 0, ret = 0;

	TRACE_ENTER(QUIC_EV_CONN_PRSHPKT, qc);
	/* Skip the AAD */
	pos = pkt->data + pkt->aad_len;
	end = pkt->data + pkt->len;

	/* Packet with no frame. */
	if (pos == end) {
		/* RFC9000 12.4. Frames and Frame Types
		 *
		 * The payload of a packet that contains frames MUST contain at least
		 * one frame, and MAY contain multiple frames and multiple frame types.
		 * An endpoint MUST treat receipt of a packet containing no frames as a
		 * connection error of type PROTOCOL_VIOLATION. Frames always fit within
		 * a single QUIC packet and cannot span multiple packets.
		 */
		quic_set_connection_close(qc, quic_err_transport(QC_ERR_PROTOCOL_VIOLATION));
		goto leave;
	}

	while (pos < end) {
		if (!qc_parse_frm(&frm, pkt, &pos, end, qc)) {
			// trace already emitted by function above
			goto leave;
		}

		switch (frm.type) {
		case QUIC_FT_PADDING:
			break;
		case QUIC_FT_PING:
			break;
		case QUIC_FT_ACK:
		case QUIC_FT_ACK_ECN:
		{
			unsigned int rtt_sample;
			rtt_sample = UINT_MAX;

			if (!qc_parse_ack_frm(qc, &frm, qel, &rtt_sample, &pos, end)) {
				// trace already emitted by function above
				goto leave;
			}

			if (rtt_sample != UINT_MAX) {
				unsigned int ack_delay;

				ack_delay = !quic_application_pktns(qel->pktns, qc) ? 0 :
					qc->state >= QUIC_HS_ST_CONFIRMED ?
					MS_TO_TICKS(QUIC_MIN(quic_ack_delay_ms(&frm.ack, qc), qc->max_ack_delay)) :
					MS_TO_TICKS(quic_ack_delay_ms(&frm.ack, qc));
				quic_loss_srtt_update(&qc->path->loss, rtt_sample, ack_delay, qc);
			}
			break;
		}
		case QUIC_FT_RESET_STREAM:
			if (qc->mux_state == QC_MUX_READY) {
				struct qf_reset_stream *rs_frm = &frm.reset_stream;
				qcc_recv_reset_stream(qc->qcc, rs_frm->id, rs_frm->app_error_code, rs_frm->final_size);
			}
			break;
		case QUIC_FT_STOP_SENDING:
		{
			struct qf_stop_sending *ss_frm = &frm.stop_sending;
			if (qc->mux_state == QC_MUX_READY) {
				if (qcc_recv_stop_sending(qc->qcc, ss_frm->id,
				                          ss_frm->app_error_code)) {
					TRACE_ERROR("qcc_recv_stop_sending() failed", QUIC_EV_CONN_PRSHPKT, qc);
					goto leave;
				}
			}
			break;
		}
		case QUIC_FT_CRYPTO:
			if (!qc_handle_crypto_frm(qc, &frm.crypto, pkt, qel, &fast_retrans))
				goto leave;
			break;
		case QUIC_FT_NEW_TOKEN:
			/* TODO */
			break;
		case QUIC_FT_STREAM_8 ... QUIC_FT_STREAM_F:
		{
			struct qf_stream *strm_frm = &frm.stream;
			unsigned nb_streams = qc->rx.strms[qcs_id_type(strm_frm->id)].nb_streams;
			const char fin = frm.type & QUIC_STREAM_FRAME_TYPE_FIN_BIT;

			/* The upper layer may not be allocated. */
			if (qc->mux_state != QC_MUX_READY) {
				if ((strm_frm->id >> QCS_ID_TYPE_SHIFT) < nb_streams) {
					TRACE_DATA("Already closed stream", QUIC_EV_CONN_PRSHPKT, qc);
				}
				else {
					TRACE_DEVEL("No mux for new stream", QUIC_EV_CONN_PRSHPKT, qc);
					if (qc->app_ops == &h3_ops) {
						if (!qc_h3_request_reject(qc, strm_frm->id)) {
							TRACE_ERROR("error on request rejection", QUIC_EV_CONN_PRSHPKT, qc);
							/* This packet will not be acknowledged */
							goto leave;
						}
					}
					else {
						/* This packet will not be acknowledged */
						goto leave;
					}
				}

				break;
			}

			if (!qc_handle_strm_frm(pkt, strm_frm, qc, fin)) {
				TRACE_ERROR("qc_handle_strm_frm() failed", QUIC_EV_CONN_PRSHPKT, qc);
				goto leave;
			}

			break;
		}
		case QUIC_FT_MAX_DATA:
			if (qc->mux_state == QC_MUX_READY) {
				struct qf_max_data *md_frm = &frm.max_data;
				qcc_recv_max_data(qc->qcc, md_frm->max_data);
			}
			break;
		case QUIC_FT_MAX_STREAM_DATA:
			if (qc->mux_state == QC_MUX_READY) {
				struct qf_max_stream_data *msd_frm = &frm.max_stream_data;
				if (qcc_recv_max_stream_data(qc->qcc, msd_frm->id,
				                              msd_frm->max_stream_data)) {
					TRACE_ERROR("qcc_recv_max_stream_data() failed", QUIC_EV_CONN_PRSHPKT, qc);
					goto leave;
				}
			}
			break;
		case QUIC_FT_MAX_STREAMS_BIDI:
		case QUIC_FT_MAX_STREAMS_UNI:
			break;
		case QUIC_FT_DATA_BLOCKED:
			qc->cntrs.data_blocked++;
			break;
		case QUIC_FT_STREAM_DATA_BLOCKED:
			qc->cntrs.stream_data_blocked++;
			break;
		case QUIC_FT_STREAMS_BLOCKED_BIDI:
			qc->cntrs.streams_blocked_bidi++;
			break;
		case QUIC_FT_STREAMS_BLOCKED_UNI:
			qc->cntrs.streams_blocked_uni++;
			break;
		case QUIC_FT_NEW_CONNECTION_ID:
			/* XXX TO DO XXX */
			break;
		case QUIC_FT_RETIRE_CONNECTION_ID:
		{
			struct quic_cid_tree *tree __maybe_unused;
			struct quic_connection_id *conn_id = NULL;

			if (!qc_handle_retire_connection_id_frm(qc, &frm, &pkt->dcid, &conn_id))
				goto leave;

			if (!conn_id)
				break;

			tree = &quic_cid_trees[quic_cid_tree_idx(&conn_id->cid)];
			HA_RWLOCK_WRLOCK(QC_CID_LOCK, &tree->lock);
			ebmb_delete(&conn_id->node);
			HA_RWLOCK_WRUNLOCK(QC_CID_LOCK, &tree->lock);
			eb64_delete(&conn_id->seq_num);
			pool_free(pool_head_quic_connection_id, conn_id);
			TRACE_PROTO("CID retired", QUIC_EV_CONN_PSTRM, qc);

			conn_id = new_quic_cid(qc->cids, qc, NULL, NULL);
			if (!conn_id) {
				TRACE_ERROR("CID allocation error", QUIC_EV_CONN_IO_CB, qc);
			}
			else {
				quic_cid_insert(conn_id);
				qc_build_new_connection_id_frm(qc, conn_id);
			}
			break;
		}
		case QUIC_FT_PATH_CHALLENGE:
		case QUIC_FT_PATH_RESPONSE:
			/* TODO */
			break;
		case QUIC_FT_CONNECTION_CLOSE:
		case QUIC_FT_CONNECTION_CLOSE_APP:
			/* Increment the error counters */
			quic_conn_closed_err_count_inc(qc, &frm);
			if (!(qc->flags & QUIC_FL_CONN_DRAINING)) {
				TRACE_STATE("Entering draining state", QUIC_EV_CONN_PRSHPKT, qc);
				/* RFC 9000 10.2. Immediate Close:
				 * The closing and draining connection states exist to ensure
				 * that connections close cleanly and that delayed or reordered
				 * packets are properly discarded. These states SHOULD persist
				 * for at least three times the current PTO interval...
				 *
				 * Rearm the idle timeout only one time when entering draining
				 * state.
				 */
				qc->flags |= QUIC_FL_CONN_DRAINING|QUIC_FL_CONN_IMMEDIATE_CLOSE;
				qc_detach_th_ctx_list(qc, 1);
				qc_idle_timer_do_rearm(qc, 0);
				qc_notify_err(qc);
			}
			break;
		case QUIC_FT_HANDSHAKE_DONE:
			if (qc_is_listener(qc)) {
				TRACE_ERROR("non accepted QUIC_FT_HANDSHAKE_DONE frame",
				            QUIC_EV_CONN_PRSHPKT, qc);

				/* RFC 9000 19.20. HANDSHAKE_DONE Frames
				 *
				 * A
				 * server MUST treat receipt of a HANDSHAKE_DONE frame as a connection
				 * error of type PROTOCOL_VIOLATION.
				 */
				quic_set_connection_close(qc, quic_err_transport(QC_ERR_PROTOCOL_VIOLATION));
				goto leave;
			}

			qc->state = QUIC_HS_ST_CONFIRMED;
			break;
		default:
			/* Unknown frame type must be rejected by qc_parse_frm(). */
			ABORT_NOW();
		}
	}

	if (fast_retrans && qc->iel && qc->hel) {
		struct quic_enc_level *iqel = qc->iel;
		struct quic_enc_level *hqel = qc->hel;

		TRACE_PROTO("speeding up handshake completion", QUIC_EV_CONN_PRSHPKT, qc);
		qc_prep_hdshk_fast_retrans(qc, &iqel->pktns->tx.frms, &hqel->pktns->tx.frms);
		qc->flags |= QUIC_FL_CONN_HANDSHAKE_SPEED_UP;
	}

	/* The server must switch from INITIAL to HANDSHAKE handshake state when it
	 * has successfully parse a Handshake packet. The Initial encryption must also
	 * be discarded.
	 */
	if (pkt->type == QUIC_PACKET_TYPE_HANDSHAKE && qc_is_listener(qc)) {
	    if (qc->state >= QUIC_HS_ST_SERVER_INITIAL) {
			if (qc->ipktns && !quic_tls_pktns_is_dcd(qc, qc->ipktns)) {
				/* Discard the handshake packet number space. */
				TRACE_PROTO("discarding Initial pktns", QUIC_EV_CONN_PRSHPKT, qc);
				quic_pktns_discard(qc->ipktns, qc);
				qc_set_timer(qc);
				qc_el_rx_pkts_del(qc->iel);
				qc_release_pktns_frms(qc, qc->ipktns);
			}
		    if (qc->state < QUIC_HS_ST_SERVER_HANDSHAKE)
			    qc->state = QUIC_HS_ST_SERVER_HANDSHAKE;
	    }
	}

	ret = 1;
 leave:
	TRACE_LEAVE(QUIC_EV_CONN_PRSHPKT, qc);
	return ret;
}

/* Detect the value of the spin bit to be used. */
static inline void qc_handle_spin_bit(struct quic_conn *qc, struct quic_rx_packet *pkt,
                                      struct quic_enc_level *qel)
{
	uint64_t largest_pn = qel->pktns->rx.largest_pn;

	if (qel != qc->ael || largest_pn == -1 ||
	    pkt->pn <= largest_pn)
		return;

	if (qc_is_listener(qc)) {
		if (pkt->flags & QUIC_FL_RX_PACKET_SPIN_BIT)
			qc->flags |= QUIC_FL_CONN_SPIN_BIT;
		else
			qc->flags &= ~QUIC_FL_CONN_SPIN_BIT;
	}
	else {
		if (pkt->flags & QUIC_FL_RX_PACKET_SPIN_BIT)
			qc->flags &= ~QUIC_FL_CONN_SPIN_BIT;
		else
			qc->flags |= QUIC_FL_CONN_SPIN_BIT;
	}
}

/* Remove the header protection of packets at <el> encryption level.
 * Always succeeds.
 */
static void qc_rm_hp_pkts(struct quic_conn *qc, struct quic_enc_level *el)
{
	struct quic_rx_packet *pqpkt, *pkttmp;

	TRACE_ENTER(QUIC_EV_CONN_ELRMHP, qc);
	/* A server must not process incoming 1-RTT packets before the handshake is complete. */
	if (el == qc->ael && qc_is_listener(qc) && qc->state < QUIC_HS_ST_COMPLETE) {
		TRACE_PROTO("RX hp not removed (handshake not completed)",
		            QUIC_EV_CONN_ELRMHP, qc);
		goto out;
	}

	list_for_each_entry_safe(pqpkt, pkttmp, &el->rx.pqpkts, list) {
		struct quic_tls_ctx *tls_ctx;

		tls_ctx = qc_select_tls_ctx(qc, el, pqpkt->type, pqpkt->version);
		if (!qc_do_rm_hp(qc, pqpkt, tls_ctx, el->pktns->rx.largest_pn,
		                 pqpkt->data + pqpkt->pn_offset, pqpkt->data)) {
			TRACE_ERROR("RX hp removing error", QUIC_EV_CONN_ELRMHP, qc);
		}
		else {
			qc_handle_spin_bit(qc, pqpkt, el);
			/* The AAD includes the packet number field */
			pqpkt->aad_len = pqpkt->pn_offset + pqpkt->pnl;
			/* Store the packet into the tree of packets to decrypt. */
			pqpkt->pn_node.key = pqpkt->pn;
			eb64_insert(&el->rx.pkts, &pqpkt->pn_node);
			quic_rx_packet_refinc(pqpkt);
			TRACE_PROTO("RX hp removed", QUIC_EV_CONN_ELRMHP, qc, pqpkt);
		}
		LIST_DELETE(&pqpkt->list);
		quic_rx_packet_refdec(pqpkt);
	}

  out:
	TRACE_LEAVE(QUIC_EV_CONN_ELRMHP, qc);
}

/* Check if it's possible to remove header protection for packets related to
 * encryption level <qel>. If <qel> is NULL, assume it's false.
 *
 * Return true if the operation is possible else false.
 */
static int qc_qel_may_rm_hp(struct quic_conn *qc, struct quic_enc_level *qel)
{
	int ret = 0;

	TRACE_ENTER(QUIC_EV_CONN_TRMHP, qc);

	if (!qel)
		goto cant_rm_hp;

	if (!quic_tls_has_rx_sec(qel)) {
		TRACE_PROTO("non available secrets", QUIC_EV_CONN_TRMHP, qc);
		goto cant_rm_hp;
	}

	if (qel == qc->ael && qc->state < QUIC_HS_ST_COMPLETE) {
		TRACE_PROTO("handshake not complete", QUIC_EV_CONN_TRMHP, qc);
		goto cant_rm_hp;
	}

	/* check if the connection layer is ready before using app level */
	if ((qel == qc->ael || qel == qc->eel) &&
	    qc->mux_state == QC_MUX_NULL) {
		TRACE_PROTO("connection layer not ready", QUIC_EV_CONN_TRMHP, qc);
		goto cant_rm_hp;
	}

	ret = 1;
 cant_rm_hp:
	TRACE_LEAVE(QUIC_EV_CONN_TRMHP, qc);
	return ret;
}

/* Process all the packets for all the encryption levels listed in <qc> QUIC connection.
 * Return 1 if succeeded, 0 if not.
 */
int qc_treat_rx_pkts(struct quic_conn *qc)
{
	int ret = 0;
	struct eb64_node *node;
	int64_t largest_pn = -1;
	unsigned int largest_pn_time_received = 0;
	struct quic_enc_level *qel, *qelbak;

	TRACE_ENTER(QUIC_EV_CONN_RXPKT, qc);

	list_for_each_entry_safe(qel, qelbak, &qc->qel_list, list) {
		/* Treat packets waiting for header packet protection decryption */
		if (!LIST_ISEMPTY(&qel->rx.pqpkts) && qc_qel_may_rm_hp(qc, qel))
			qc_rm_hp_pkts(qc, qel);

		node = eb64_first(&qel->rx.pkts);
		while (node) {
			struct quic_rx_packet *pkt;

			pkt = eb64_entry(node, struct quic_rx_packet, pn_node);
			TRACE_DATA("new packet", QUIC_EV_CONN_RXPKT,
			           qc, pkt, NULL, qc->xprt_ctx->ssl);
			if (!qc_pkt_decrypt(qc, qel, pkt)) {
				/* Drop the packet */
				TRACE_ERROR("packet decryption failed -> dropped",
				            QUIC_EV_CONN_RXPKT, qc, pkt);
			}
			else {
				if (!qc_parse_pkt_frms(qc, pkt, qel)) {
					/* Drop the packet */
					TRACE_ERROR("packet parsing failed -> dropped",
					            QUIC_EV_CONN_RXPKT, qc, pkt);
					qc->cntrs.dropped_parsing++;
				}
				else {
					struct quic_arng ar = { .first = pkt->pn, .last = pkt->pn };

					/* RFC 9000 8.1. Address Validation during Connection Establishment
					 *
					 * Connection establishment implicitly provides address validation for
					 * both endpoints. In particular, receipt of a packet protected with
					 * Handshake keys confirms that the peer successfully processed an
					 * Initial packet.
					 */
					if (qel == qc->hel &&
					    !(qc->flags & QUIC_FL_CONN_PEER_VALIDATED_ADDR)) {
						TRACE_STATE("validate peer address on handshake packet",
						            QUIC_EV_CONN_RXPKT, qc, pkt);
						qc->flags |= QUIC_FL_CONN_PEER_VALIDATED_ADDR;
						BUG_ON(!qc->prx_counters->half_open_conn);
						HA_ATOMIC_DEC(&qc->prx_counters->half_open_conn);
					}

					/* Update the list of ranges to acknowledge. */
					if (quic_update_ack_ranges_list(qc, &qel->pktns->rx.arngs, &ar)) {
						if (pkt->flags & QUIC_FL_RX_PACKET_ACK_ELICITING) {
							int arm_ack_timer =
								qc->state >= QUIC_HS_ST_COMPLETE &&
								qel->pktns == qc->apktns;

							qel->pktns->flags |= QUIC_FL_PKTNS_ACK_REQUIRED;
							qel->pktns->rx.nb_aepkts_since_last_ack++;
							qc_idle_timer_rearm(qc, 1, arm_ack_timer);
						}

						if (pkt->pn > largest_pn) {
							largest_pn = pkt->pn;
							largest_pn_time_received = pkt->time_received;
						}
					}
					else {
						TRACE_ERROR("Could not update ack range list",
						            QUIC_EV_CONN_RXPKT, qc);
					}
				}
			}
			node = eb64_next(node);
			eb64_delete(&pkt->pn_node);
			quic_rx_packet_refdec(pkt);
		}

		if (largest_pn != -1 && largest_pn > qel->pktns->rx.largest_pn) {
			/* Update the largest packet number. */
			qel->pktns->rx.largest_pn = largest_pn;
			/* Update the largest acknowledged packet timestamps */
			qel->pktns->rx.largest_time_received = largest_pn_time_received;
			qel->pktns->flags |= QUIC_FL_PKTNS_NEW_LARGEST_PN;
		}

		/* Release the Initial encryption level and packet number space. */
		if ((qc->flags & QUIC_FL_CONN_IPKTNS_DCD) && qel == qc->iel) {
			qc_enc_level_free(qc, &qc->iel);
			quic_pktns_release(qc, &qc->ipktns);
		}

		largest_pn = -1;
	}

 out:
	ret = 1;
 leave:
	TRACE_LEAVE(QUIC_EV_CONN_RXPKT, qc);
	return ret;
}

/* Parse into <pkt> a long header located at <*pos> position, <end> begin a pointer to the end
 * past one byte of this buffer.
 */
static inline int quic_packet_read_long_header(unsigned char **pos, const unsigned char *end,
                                               struct quic_rx_packet *pkt)
{
	int ret = 0;
	unsigned char dcid_len, scid_len;

	TRACE_ENTER(QUIC_EV_CONN_RXPKT);

	if (end == *pos) {
		TRACE_ERROR("buffer data consumed",  QUIC_EV_CONN_RXPKT);
		goto leave;
	}

	/* Destination Connection ID Length */
	dcid_len = *(*pos)++;
	/* We want to be sure we can read <dcid_len> bytes and one more for <scid_len> value */
	if (dcid_len > QUIC_CID_MAXLEN || end - *pos < dcid_len + 1) {
		TRACE_ERROR("too long DCID",  QUIC_EV_CONN_RXPKT);
		goto leave;
	}

	if (dcid_len) {
		/* Check that the length of this received DCID matches the CID lengths
		 * of our implementation for non Initials packets only.
		 */
		if (pkt->version && pkt->version->num &&
		    pkt->type != QUIC_PACKET_TYPE_INITIAL &&
		    pkt->type != QUIC_PACKET_TYPE_0RTT &&
		    dcid_len != QUIC_HAP_CID_LEN) {
			TRACE_ERROR("wrong DCID length", QUIC_EV_CONN_RXPKT);
			goto leave;
		}

		memcpy(pkt->dcid.data, *pos, dcid_len);
	}

	pkt->dcid.len = dcid_len;
	*pos += dcid_len;

	/* Source Connection ID Length */
	scid_len = *(*pos)++;
	if (scid_len > QUIC_CID_MAXLEN || end - *pos < scid_len) {
		TRACE_ERROR("too long SCID",  QUIC_EV_CONN_RXPKT);
		goto leave;
	}

	if (scid_len)
		memcpy(pkt->scid.data, *pos, scid_len);
	pkt->scid.len = scid_len;
	*pos += scid_len;

	ret = 1;
 leave:
	TRACE_LEAVE(QUIC_EV_CONN_RXPKT);
	return ret;
}

/* Try to remove the header protection of <pkt> QUIC packet with <beg> the
 * address of the packet first byte, using the keys from encryption level <el>.
 *
 * If header protection has been successfully removed, packet data are copied
 * into <qc> Rx buffer. If <el> secrets are not yet available, the copy is also
 * proceeded, and the packet is inserted into <qc> protected packets tree. In
 * both cases, packet can now be considered handled by the <qc> connection.
 *
 * If header protection cannot be removed due to <el> secrets already
 * discarded, no operation is conducted.
 *
 * Returns 1 on success : packet data is now handled by the connection. On
 * error 0 is returned : packet should be dropped by the caller.
 */
static int qc_try_rm_hp(struct quic_conn *qc, struct quic_rx_packet *pkt,
                        unsigned char *beg, struct quic_enc_level **el)
{
	int ret = 0;
	unsigned char *pn = NULL; /* Packet number field */
	enum quic_tls_enc_level tel;
	struct quic_enc_level *qel;
	/* Only for traces. */

	TRACE_ENTER(QUIC_EV_CONN_TRMHP, qc);
	BUG_ON(!pkt->pn_offset);

	/* The packet number is here. This is also the start minus
	 * QUIC_PACKET_PN_MAXLEN of the sample used to add/remove the header
	 * protection.
	 */
	pn = beg + pkt->pn_offset;

	tel = quic_packet_type_enc_level(pkt->type);
	qel = qc_quic_enc_level(qc, tel);
	if (!qel) {
		struct quic_enc_level **qc_qel = qel_to_qel_addr(qc, tel);
		struct quic_pktns **qc_pktns = qel_to_quic_pktns(qc, tel);

		if (!qc_enc_level_alloc(qc, qc_pktns, qc_qel, quic_to_ssl_enc_level(tel))) {
			TRACE_PROTO("Could not allocated an encryption level", QUIC_EV_CONN_ADDDATA, qc);
			goto out;
		}

		qel = *qc_qel;
	}

	if (qc_qel_may_rm_hp(qc, qel)) {
		struct quic_tls_ctx *tls_ctx =
			qc_select_tls_ctx(qc, qel, pkt->type, pkt->version);

		 /* Note that the following function enables us to unprotect the packet
		 * number and its length subsequently used to decrypt the entire
		 * packets.
		 */
		if (!qc_do_rm_hp(qc, pkt, tls_ctx,
		                 qel->pktns->rx.largest_pn, pn, beg)) {
			TRACE_PROTO("hp error", QUIC_EV_CONN_TRMHP, qc);
			goto out;
		}

		qc_handle_spin_bit(qc, pkt, qel);
		/* The AAD includes the packet number field. */
		pkt->aad_len = pkt->pn_offset + pkt->pnl;
		if (pkt->len - pkt->aad_len < QUIC_TLS_TAG_LEN) {
			TRACE_PROTO("Too short packet", QUIC_EV_CONN_TRMHP, qc);
			goto out;
		}

		TRACE_PROTO("RX hp removed", QUIC_EV_CONN_TRMHP, qc, pkt);
	}
	else {
		TRACE_PROTO("RX hp not removed", QUIC_EV_CONN_TRMHP, qc, pkt);
		LIST_APPEND(&qel->rx.pqpkts, &pkt->list);
		quic_rx_packet_refinc(pkt);
	}

	*el = qel;
	/* No reference counter incrementation here!!! */
	LIST_APPEND(&qc->rx.pkt_list, &pkt->qc_rx_pkt_list);
	memcpy(b_tail(&qc->rx.buf), beg, pkt->len);
	pkt->data = (unsigned char *)b_tail(&qc->rx.buf);
	b_add(&qc->rx.buf, pkt->len);

	ret = 1;
 out:
	TRACE_LEAVE(QUIC_EV_CONN_TRMHP, qc);
	return ret;
}

/* Return a 32-bits integer in <val> from QUIC packet with <buf> as address.
 * Makes <buf> point to the data after this 32-bits value if succeeded.
 * Note that these 32-bits integers are network bytes ordered.
 * Returns 0 if failed (not enough data in the buffer), 1 if succeeded.
 */
static inline int quic_read_uint32(uint32_t *val,
                                   const unsigned char **buf,
                                   const unsigned char *end)
{
	if (end - *buf < sizeof *val)
		return 0;

	*val = ntohl(read_u32(*buf));
	*buf += sizeof *val;

	return 1;
}

/* Parse a QUIC packet header starting at <pos> position without exceeding <end>.
 * Version and type are stored in <pkt> packet instance. Type is set to unknown
 * on two occasions : for unsupported version, in this case version field is
 * set to NULL; for Version Negotiation packet with version number set to 0.
 *
 * Returns 1 on success else 0.
 */
int qc_parse_hd_form(struct quic_rx_packet *pkt,
                     unsigned char **pos, const unsigned char *end)
{
	uint32_t version;
	int ret = 0;
	const unsigned char byte0 = **pos;

	TRACE_ENTER(QUIC_EV_CONN_RXPKT);
	pkt->version = NULL;
	pkt->type = QUIC_PACKET_TYPE_UNKNOWN;

	(*pos)++;
	if (byte0 & QUIC_PACKET_LONG_HEADER_BIT) {
		unsigned char type =
			(byte0 >> QUIC_PACKET_TYPE_SHIFT) & QUIC_PACKET_TYPE_BITMASK;

		/* Version */
		if (!quic_read_uint32(&version, (const unsigned char **)pos, end)) {
			TRACE_ERROR("could not read the packet version", QUIC_EV_CONN_RXPKT);
			goto out;
		}

		pkt->version = qc_supported_version(version);
		if (version && pkt->version) {
			if (version != QUIC_PROTOCOL_VERSION_2) {
				pkt->type = type;
			}
			else {
				switch (type) {
				case 0:
					pkt->type = QUIC_PACKET_TYPE_RETRY;
					break;
				case 1:
					pkt->type = QUIC_PACKET_TYPE_INITIAL;
					break;
				case 2:
					pkt->type = QUIC_PACKET_TYPE_0RTT;
					break;
				case 3:
					pkt->type = QUIC_PACKET_TYPE_HANDSHAKE;
					break;
				}
			}
		}
	}
	else {
		if (byte0 & QUIC_PACKET_SPIN_BIT)
			pkt->flags |= QUIC_FL_RX_PACKET_SPIN_BIT;
		pkt->type = QUIC_PACKET_TYPE_SHORT;
	}

	ret = 1;
 out:
	TRACE_LEAVE(QUIC_EV_CONN_RXPKT);
	return ret;
}

/* Check that all the bytes between <pos> included and <end> address
 * excluded are null. This is the responsibility of the caller to
 * check that there is at least one byte between <pos> end <end>.
 * Return 1 if this all the bytes are null, 0 if not.
 */
static inline int quic_padding_check(const unsigned char *pos,
                                     const unsigned char *end)
{
	while (pos < end && !*pos)
		pos++;

	return pos == end;
}

/* Find the associated connection to the packet <pkt> or create a new one if
 * this is an Initial packet. <dgram> is the datagram containing the packet and
 * <l> is the listener instance on which it was received.
 *
 * By default, <new_tid> is set to -1. However, if thread affinity has been
 * chanbed, it will be set to its new thread ID.
 *
 * Returns the quic-conn instance or NULL if not found or thread affinity
 * changed.
 */
static struct quic_conn *quic_rx_pkt_retrieve_conn(struct quic_rx_packet *pkt,
                                                   struct quic_dgram *dgram,
                                                   struct listener *l,
                                                   int *new_tid)
{
	struct quic_cid token_odcid = { .len = 0 };
	struct quic_conn *qc = NULL;
	struct proxy *prx;
	struct quic_counters *prx_counters;

	TRACE_ENTER(QUIC_EV_CONN_LPKT);

	*new_tid = -1;

	prx = l->bind_conf->frontend;
	prx_counters = EXTRA_COUNTERS_GET(prx->extra_counters_fe, &quic_stats_module);

	qc = retrieve_qc_conn_from_cid(pkt, &dgram->saddr, new_tid);

	/* If connection already created or rebinded on another thread. */
	if (!qc && *new_tid != -1 && tid != *new_tid)
		goto out;

	if (pkt->type == QUIC_PACKET_TYPE_INITIAL) {
		BUG_ON(!pkt->version); /* This must not happen. */

		if (!qc) {
			struct quic_cid_tree *tree;
			struct ebmb_node *node;
			struct quic_connection_id *conn_id;
			int ipv4;

			/* Reject INITIAL early if listener limits reached. */
			if (unlikely(HA_ATOMIC_LOAD(&l->rx.quic_curr_handshake) >=
			             quic_listener_max_handshake(l))) {
				TRACE_DATA("Drop INITIAL on max handshake",
				            QUIC_EV_CONN_LPKT, NULL, NULL, NULL, pkt->version);
				goto out;
			}

			if (unlikely(HA_ATOMIC_LOAD(&l->rx.quic_curr_accept) >=
			             quic_listener_max_accept(l))) {
				TRACE_DATA("Drop INITIAL on max accept",
				            QUIC_EV_CONN_LPKT, NULL, NULL, NULL, pkt->version);
				goto out;
			}

			if (pkt->token_len) {
				/* Validate the token only when connection is unknown. */
				if (!quic_retry_token_check(pkt, dgram, l, qc, &token_odcid))
					goto err;
			}
			else if (!(l->bind_conf->options & BC_O_QUIC_FORCE_RETRY) &&
			         HA_ATOMIC_LOAD(&prx_counters->half_open_conn) >= global.tune.quic_retry_threshold) {
				TRACE_PROTO("Initial without token, sending retry",
				            QUIC_EV_CONN_LPKT, NULL, NULL, NULL, pkt->version);
				if (send_retry(l->rx.fd, &dgram->saddr, pkt, pkt->version)) {
					TRACE_ERROR("Error during Retry generation",
					            QUIC_EV_CONN_LPKT, NULL, NULL, NULL, pkt->version);
					goto out;
				}

				HA_ATOMIC_INC(&prx_counters->retry_sent);
				goto out;
			}

			/* RFC 9000 7.2. Negotiating Connection IDs:
			 * When an Initial packet is sent by a client that has not previously
			 * received an Initial or Retry packet from the server, the client
			 * populates the Destination Connection ID field with an unpredictable
			 * value. This Destination Connection ID MUST be at least 8 bytes in length.
			 */
			if (pkt->dcid.len < QUIC_ODCID_MINLEN) {
				TRACE_PROTO("dropped packet",
				            QUIC_EV_CONN_LPKT, NULL, NULL, NULL, pkt->version);
				goto err;
			}

			pkt->saddr = dgram->saddr;
			ipv4 = dgram->saddr.ss_family == AF_INET;

			/* Generate the first connection CID. This is derived from the client
			 * ODCID and address. This allows to retrieve the connection from the
			 * ODCID without storing it in the CID tree. This is an interesting
			 * optimization as the client is expected to stop using its ODCID in
			 * favor of our generated value.
			 */
			conn_id = new_quic_cid(NULL, NULL, &pkt->dcid, &pkt->saddr);
			if (!conn_id)
				goto err;

			qc = qc_new_conn(pkt->version, ipv4, &pkt->dcid, &pkt->scid, &token_odcid,
			                 conn_id, &dgram->daddr, &pkt->saddr, 1,
			                 !!pkt->token_len, l);
			if (qc == NULL) {
				pool_free(pool_head_quic_connection_id, conn_id);
				goto err;
			}

			/* Compute and store into the quic_conn the hash used to compute extra CIDs */
			if (quic_hash64_from_cid)
				qc->hash64 = quic_hash64_from_cid(conn_id->cid.data, conn_id->cid.len,
								  global.cluster_secret, sizeof(global.cluster_secret));

			tree = &quic_cid_trees[quic_cid_tree_idx(&conn_id->cid)];
			HA_RWLOCK_WRLOCK(QC_CID_LOCK, &tree->lock);
			node = ebmb_insert(&tree->root, &conn_id->node, conn_id->cid.len);
			if (node != &conn_id->node) {
				pool_free(pool_head_quic_connection_id, conn_id);

				conn_id = ebmb_entry(node, struct quic_connection_id, node);
				*new_tid = HA_ATOMIC_LOAD(&conn_id->tid);
				quic_conn_release(qc);
				qc = NULL;
			}
			else {
				/* From here, <qc> is the correct connection for this <pkt> Initial
				 * packet. <conn_id> must be inserted in the CIDs tree for this
				 * connection.
				 */
				eb64_insert(qc->cids, &conn_id->seq_num);
				/* Initialize the next CID sequence number to be used for this connection. */
				qc->next_cid_seq_num = 1;
			}
			HA_RWLOCK_WRUNLOCK(QC_CID_LOCK, &tree->lock);

			if (*new_tid != -1)
				goto out;
		}
	}
	else if (!qc) {
		/* Stateless Reset sent even for Long header packets as haproxy
		 * emits stateless_reset_token in its TPs.
		 */
		TRACE_PROTO("RX non Initial pkt without connection", QUIC_EV_CONN_LPKT, NULL, NULL, NULL, pkt->version);
		if (!send_stateless_reset(l, &dgram->saddr, pkt))
			TRACE_ERROR("stateless reset not sent", QUIC_EV_CONN_LPKT, qc);
		goto err;
	}

 out:
	TRACE_LEAVE(QUIC_EV_CONN_LPKT, qc);
	return qc;

 err:
	HA_ATOMIC_INC(&prx_counters->dropped_pkt);

	TRACE_LEAVE(QUIC_EV_CONN_LPKT);
	return NULL;
}

/* Parse a QUIC packet starting at <pos>. Data won't be read after <end> even
 * if the packet is incomplete. This function will populate fields of <pkt>
 * instance, most notably its length. <dgram> is the UDP datagram which
 * contains the parsed packet. <l> is the listener instance on which it was
 * received.
 *
 * Returns 0 on success else non-zero. Packet length is guaranteed to be set to
 * the real packet value or to cover all data between <pos> and <end> : this is
 * useful to reject a whole datagram.
 */
static int quic_rx_pkt_parse(struct quic_rx_packet *pkt,
                             unsigned char *pos, const unsigned char *end,
                             struct quic_dgram *dgram, struct listener *l)
{
	const unsigned char *beg = pos;
	struct proxy *prx;
	struct quic_counters *prx_counters;

	TRACE_ENTER(QUIC_EV_CONN_LPKT);

	prx = l->bind_conf->frontend;
	prx_counters = EXTRA_COUNTERS_GET(prx->extra_counters_fe, &quic_stats_module);

	if (end <= pos) {
		TRACE_PROTO("Packet dropped", QUIC_EV_CONN_LPKT);
		goto drop;
	}

	/* Fixed bit */
	if (!(*pos & QUIC_PACKET_FIXED_BIT)) {
		if (!(pkt->flags & QUIC_FL_RX_PACKET_DGRAM_FIRST) &&
		    quic_padding_check(pos, end)) {
			/* Some browsers may pad the remaining datagram space with null bytes.
			 * That is what we called add padding out of QUIC packets. Such
			 * datagrams must be considered as valid. But we can only consume
			 * the remaining space.
			 */
			pkt->len = end - pos;
			goto drop_silent;
		}

		TRACE_PROTO("Packet dropped", QUIC_EV_CONN_LPKT);
		goto drop;
	}

	/* Header form */
	if (!qc_parse_hd_form(pkt, &pos, end)) {
		TRACE_PROTO("Packet dropped", QUIC_EV_CONN_LPKT);
		goto drop;
	}

	if (pkt->type != QUIC_PACKET_TYPE_SHORT) {
		uint64_t len;
		TRACE_PROTO("long header packet received", QUIC_EV_CONN_LPKT);

		if (!quic_packet_read_long_header(&pos, end, pkt)) {
			TRACE_PROTO("Packet dropped", QUIC_EV_CONN_LPKT);
			goto drop;
		}

		/* When multiple QUIC packets are coalesced on the same UDP datagram,
		 * they must have the same DCID.
		 */
		if (!(pkt->flags & QUIC_FL_RX_PACKET_DGRAM_FIRST) &&
		    (pkt->dcid.len != dgram->dcid_len ||
		     memcmp(dgram->dcid, pkt->dcid.data, pkt->dcid.len))) {
			TRACE_PROTO("Packet dropped", QUIC_EV_CONN_LPKT);
			goto drop;
		}

		/* Retry of Version Negotiation packets are only sent by servers */
		if (pkt->type == QUIC_PACKET_TYPE_RETRY ||
		    (pkt->version && !pkt->version->num)) {
			TRACE_PROTO("Packet dropped", QUIC_EV_CONN_LPKT);
			goto drop;
		}

		/* RFC9000 6. Version Negotiation */
		if (!pkt->version) {
			 /* unsupported version, send Negotiation packet */
			if (send_version_negotiation(l->rx.fd, &dgram->saddr, pkt)) {
				TRACE_ERROR("VN packet not sent", QUIC_EV_CONN_LPKT);
				goto drop_silent;
			}

			TRACE_PROTO("VN packet sent", QUIC_EV_CONN_LPKT);
			goto drop_silent;
		}

		/* For Initial packets, and for servers (QUIC clients connections),
		 * there is no Initial connection IDs storage.
		 */
		if (pkt->type == QUIC_PACKET_TYPE_INITIAL) {
			uint64_t token_len;

			if (!quic_dec_int(&token_len, (const unsigned char **)&pos, end) ||
				end - pos < token_len) {
				TRACE_PROTO("Packet dropped",
				            QUIC_EV_CONN_LPKT, NULL, NULL, NULL, pkt->version);
				goto drop;
			}

			/* TODO Retry should be automatically activated if
			 * suspect network usage is detected.
			 */
			if (!token_len) {
				if (l->bind_conf->options & BC_O_QUIC_FORCE_RETRY) {
					TRACE_PROTO("Initial without token, sending retry",
					            QUIC_EV_CONN_LPKT, NULL, NULL, NULL, pkt->version);
					if (send_retry(l->rx.fd, &dgram->saddr, pkt, pkt->version)) {
						TRACE_PROTO("Error during Retry generation",
						            QUIC_EV_CONN_LPKT, NULL, NULL, NULL, pkt->version);
						goto drop_silent;
					}

					HA_ATOMIC_INC(&prx_counters->retry_sent);
					goto drop_silent;
				}
			}

			pkt->token = pos;
			pkt->token_len = token_len;
			pos += pkt->token_len;
		}
		else if (pkt->type != QUIC_PACKET_TYPE_0RTT) {
			if (pkt->dcid.len != QUIC_HAP_CID_LEN) {
				TRACE_PROTO("Packet dropped",
				            QUIC_EV_CONN_LPKT, NULL, NULL, NULL, pkt->version);
				goto drop;
			}
		}

		if (!quic_dec_int(&len, (const unsigned char **)&pos, end) ||
			end - pos < len) {
			TRACE_PROTO("Packet dropped",
			            QUIC_EV_CONN_LPKT, NULL, NULL, NULL, pkt->version);
			goto drop;
		}

		/* Packet Number is stored here. Packet Length totalizes the
		 * rest of the content.
		 */
		pkt->pn_offset = pos - beg;
		pkt->len = pkt->pn_offset + len;

		/* RFC 9000. Initial Datagram Size
		 *
		 * A server MUST discard an Initial packet that is carried in a UDP datagram
		 * with a payload that is smaller than the smallest allowed maximum datagram
		 * size of 1200 bytes.
		 */
		if (pkt->type == QUIC_PACKET_TYPE_INITIAL &&
		    dgram->len < QUIC_INITIAL_PACKET_MINLEN) {
			TRACE_PROTO("RX too short datagram with an Initial packet", QUIC_EV_CONN_LPKT);
			HA_ATOMIC_INC(&prx_counters->too_short_initial_dgram);
			goto drop;
		}

		/* Interrupt parsing after packet length retrieval : this
		 * ensures that only the packet is dropped but not the whole
		 * datagram.
		 */
		if (pkt->type == QUIC_PACKET_TYPE_0RTT && !l->bind_conf->ssl_conf.early_data) {
			TRACE_PROTO("RX 0-RTT packet not supported", QUIC_EV_CONN_LPKT);
			goto drop;
		}
	}
	else {
		TRACE_PROTO("RX short header packet", QUIC_EV_CONN_LPKT);
		if (end - pos < QUIC_HAP_CID_LEN) {
			TRACE_PROTO("RX pkt dropped", QUIC_EV_CONN_LPKT);
			goto drop;
		}

		memcpy(pkt->dcid.data, pos, QUIC_HAP_CID_LEN);
		pkt->dcid.len = QUIC_HAP_CID_LEN;

		/* When multiple QUIC packets are coalesced on the same UDP datagram,
		 * they must have the same DCID.
		 */
		if (!(pkt->flags & QUIC_FL_RX_PACKET_DGRAM_FIRST) &&
		    (pkt->dcid.len != dgram->dcid_len ||
		     memcmp(dgram->dcid, pkt->dcid.data, pkt->dcid.len))) {
			TRACE_PROTO("RX pkt dropped", QUIC_EV_CONN_LPKT);
			goto drop;
		}

		pos += QUIC_HAP_CID_LEN;

		pkt->pn_offset = pos - beg;
		/* A short packet is the last one of a UDP datagram. */
		pkt->len = end - beg;
	}

	TRACE_PROTO("RX pkt parsed", QUIC_EV_CONN_LPKT, NULL, pkt, NULL, pkt->version);
	TRACE_LEAVE(QUIC_EV_CONN_LPKT);
	return 0;

 drop:
	HA_ATOMIC_INC(&prx_counters->dropped_pkt);
 drop_silent:
	if (!pkt->len)
		pkt->len = end - beg;
	TRACE_PROTO("RX pkt parsing failed", QUIC_EV_CONN_LPKT, NULL, pkt, NULL, pkt->version);
	TRACE_LEAVE(QUIC_EV_CONN_LPKT);
	return -1;
}

/* Check if received packet <pkt> should be drop due to <qc> already in closing
 * state. This can be true if a CONNECTION_CLOSE has already been emitted for
 * this connection.
 *
 * Returns false if connection is not in closing state else true. The caller
 * should drop the whole datagram in the last case to not mess up <qc>
 * CONNECTION_CLOSE rate limit counter.
 */
static int qc_rx_check_closing(struct quic_conn *qc,
                               struct quic_rx_packet *pkt)
{
	if (!(qc->flags & QUIC_FL_CONN_CLOSING))
		return 0;

	TRACE_STATE("Closing state connection", QUIC_EV_CONN_LPKT, qc, NULL, NULL, pkt->version);

	/* Check if CONNECTION_CLOSE rate reemission is reached. */
	if (++qc->nb_pkt_since_cc >= qc->nb_pkt_for_cc) {
		qc->flags |= QUIC_FL_CONN_IMMEDIATE_CLOSE;
		qc->nb_pkt_for_cc++;
		qc->nb_pkt_since_cc = 0;
	}

	return 1;
}

/* Release the memory for the RX packets which are no more referenced
 * and consume their payloads which have been copied to the RX buffer
 * for the connection.
 * Always succeeds.
 */
static void quic_rx_pkts_del(struct quic_conn *qc)
{
	struct quic_rx_packet *pkt, *pktback;

	list_for_each_entry_safe(pkt, pktback, &qc->rx.pkt_list, qc_rx_pkt_list) {
		TRACE_PRINTF(TRACE_LEVEL_DEVELOPER, QUIC_EV_CONN_LPKT, qc, 0, 0, 0,
		             "pkt #%lld(type=%d,len=%llu,rawlen=%llu,refcnt=%u) (diff: %zd)",
		             (long long)pkt->pn_node.key,
		             pkt->type, (ull)pkt->len, (ull)pkt->raw_len, pkt->refcnt,
		             (unsigned char *)b_head(&qc->rx.buf) - pkt->data);
		if (pkt->data != (unsigned char *)b_head(&qc->rx.buf)) {
			size_t cdata;

			cdata = b_contig_data(&qc->rx.buf, 0);
			TRACE_PRINTF(TRACE_LEVEL_DEVELOPER, QUIC_EV_CONN_LPKT, qc, 0, 0, 0,
			             "cdata=%llu *b_head()=0x%x", (ull)cdata, *b_head(&qc->rx.buf));
			if (cdata && !*b_head(&qc->rx.buf)) {
				/* Consume the remaining data */
				b_del(&qc->rx.buf, cdata);
			}
			break;
		}

		if (pkt->refcnt)
			break;

		b_del(&qc->rx.buf, pkt->raw_len);
		LIST_DELETE(&pkt->qc_rx_pkt_list);
		pool_free(pool_head_quic_rx_packet, pkt);
	}

	/* In frequent cases the buffer will be emptied at this stage. */
	b_realign_if_empty(&qc->rx.buf);
}

/* Handle a parsed packet <pkt> by the connection <qc>. Data will be copied
 * into <qc> receive buffer after header protection removal procedure.
 *
 * <dgram> must be set to the datagram which contains the QUIC packet. <beg>
 * must point to packet buffer first byte.
 *
 * <tasklist_head> may be non-NULL when the caller treat several datagrams for
 * different quic-conn. In this case, each quic-conn tasklet will be appended
 * to it in order to be woken up after the current task.
 *
 * The caller can safely removed the packet data. If packet refcount was not
 * incremented by this function, it means that the connection did not handled
 * it and it should be freed by the caller.
 */
static void qc_rx_pkt_handle(struct quic_conn *qc, struct quic_rx_packet *pkt,
                             struct quic_dgram *dgram, unsigned char *beg,
                             struct list **tasklist_head)
{
	const struct quic_version *qv = pkt->version;
	struct quic_enc_level *qel = NULL;
	size_t b_cspace;

	TRACE_ENTER(QUIC_EV_CONN_LPKT, qc);
	TRACE_PROTO("RX pkt", QUIC_EV_CONN_LPKT, qc, pkt, NULL, qv);

	if (pkt->flags & QUIC_FL_RX_PACKET_DGRAM_FIRST &&
	    qc->flags & QUIC_FL_CONN_ANTI_AMPLIFICATION_REACHED) {
		TRACE_PROTO("PTO timer must be armed after anti-amplication was reached",
					QUIC_EV_CONN_LPKT, qc, NULL, NULL, qv);
		TRACE_DEVEL("needs to wakeup the timer task after the amplification limit was reached",
		            QUIC_EV_CONN_LPKT, qc);
		/* Reset the anti-amplification bit. It will be set again
		 * when sending the next packet if reached again.
		 */
		qc->flags &= ~QUIC_FL_CONN_ANTI_AMPLIFICATION_REACHED;
		qc_set_timer(qc);
		if (qc->timer_task && tick_isset(qc->timer) && tick_is_lt(qc->timer, now_ms))
			task_wakeup(qc->timer_task, TASK_WOKEN_MSG);
	}

	/* Drop asap packet whose packet number space is discarded. */
	if (quic_tls_pkt_type_pktns_dcd(qc, pkt->type)) {
		TRACE_PROTO("Discarded packet number space", QUIC_EV_CONN_TRMHP, qc);
		goto drop_silent;
	}

	if (qc->flags & QUIC_FL_CONN_IMMEDIATE_CLOSE) {
		TRACE_PROTO("Connection error",
		            QUIC_EV_CONN_LPKT, qc, NULL, NULL, qv);
		goto out;
	}

	pkt->raw_len = pkt->len;
	quic_rx_pkts_del(qc);
	b_cspace = b_contig_space(&qc->rx.buf);
	if (b_cspace < pkt->len) {
		TRACE_PRINTF(TRACE_LEVEL_DEVELOPER, QUIC_EV_CONN_LPKT, qc, 0, 0, 0,
		             "bspace=%llu pkt->len=%llu", (ull)b_cspace, (ull)pkt->len);
		/* Do not consume buf if space not at the end. */
		if (b_tail(&qc->rx.buf) + b_cspace < b_wrap(&qc->rx.buf)) {
			TRACE_PROTO("Packet dropped",
			            QUIC_EV_CONN_LPKT, qc, NULL, NULL, qv);
			qc->cntrs.dropped_pkt_bufoverrun++;
			goto drop_silent;
		}

		/* Let us consume the remaining contiguous space. */
		if (b_cspace) {
			b_putchr(&qc->rx.buf, 0x00);
			b_cspace--;
		}
		b_add(&qc->rx.buf, b_cspace);
		if (b_contig_space(&qc->rx.buf) < pkt->len) {
			TRACE_PROTO("Too big packet",
			            QUIC_EV_CONN_LPKT, qc, pkt, &pkt->len, qv);
			qc->cntrs.dropped_pkt_bufoverrun++;
			goto drop_silent;
		}
	}

	if (!qc_try_rm_hp(qc, pkt, beg, &qel)) {
		TRACE_PROTO("Packet dropped", QUIC_EV_CONN_LPKT, qc, NULL, NULL, qv);
		goto drop;
	}

	TRACE_DATA("New packet", QUIC_EV_CONN_LPKT, qc, pkt, NULL, qv);
	if (pkt->aad_len) {
		/* Insert this RX packet in its encryption level tree */
		pkt->pn_node.key = pkt->pn;
		quic_rx_packet_refinc(pkt);
		eb64_insert(&qel->rx.pkts, &pkt->pn_node);
	}
 out:
	*tasklist_head = tasklet_wakeup_after(*tasklist_head,
	                                      qc->wait_event.tasklet);

 drop_silent:
	TRACE_PROTO("RX pkt", QUIC_EV_CONN_LPKT, qc ? qc : NULL, pkt, NULL, qv);
	TRACE_LEAVE(QUIC_EV_CONN_LPKT, qc ? qc : NULL);
	return;

 drop:
	qc->cntrs.dropped_pkt++;
	TRACE_PROTO("packet drop", QUIC_EV_CONN_LPKT, qc, pkt, NULL, qv);
	TRACE_LEAVE(QUIC_EV_CONN_LPKT, qc);
}

/* Handle a new <dgram> received. Parse each QUIC packets and copied their
 * content to a quic-conn instance. The datagram content can be released after
 * this function.
 *
 * If datagram has been received on a quic-conn owned FD, <from_qc> must be set
 * to the connection instance. <li> is the attached listener. The caller is
 * responsible to ensure that the first packet is destined to this connection
 * by comparing CIDs.
 *
 * If datagram has been received on a receiver FD, <from_qc> will be NULL. This
 * function will thus retrieve the connection from the CID tree or allocate a
 * new one if possible. <li> is the listener attached to the receiver.
 *
 * Returns 0 on success else non-zero. If an error happens, some packets from
 * the datagram may not have been parsed.
 */
int quic_dgram_parse(struct quic_dgram *dgram, struct quic_conn *from_qc,
                     struct listener *li)
{
	struct quic_rx_packet *pkt;
	struct quic_conn *qc = NULL;
	unsigned char *pos, *end;
	struct list *tasklist_head = NULL;

	TRACE_ENTER(QUIC_EV_CONN_LPKT);

	pos = dgram->buf;
	end = pos + dgram->len;
	do {
		pkt = pool_alloc(pool_head_quic_rx_packet);
		if (!pkt) {
			TRACE_ERROR("RX packet allocation failed", QUIC_EV_CONN_LPKT);
			goto err;
		}

		LIST_INIT(&pkt->qc_rx_pkt_list);
		pkt->version = NULL;
		pkt->type = QUIC_PACKET_TYPE_UNKNOWN;
		pkt->pn_offset = 0;
		pkt->len = 0;
		pkt->raw_len = 0;
		pkt->token = NULL;
		pkt->token_len = 0;
		pkt->aad_len = 0;
		pkt->data = NULL;
		pkt->pn_node.key = (uint64_t)-1;
		pkt->refcnt = 0;
		pkt->flags = 0;
		pkt->time_received = now_ms;

		/* Set flag if pkt is the first one in dgram. */
		if (pos == dgram->buf)
			pkt->flags |= QUIC_FL_RX_PACKET_DGRAM_FIRST;

		quic_rx_packet_refinc(pkt);
		if (quic_rx_pkt_parse(pkt, pos, end, dgram, li))
			goto next;

		/* Search quic-conn instance for first packet of the datagram.
		 * quic_rx_packet_parse() is responsible to discard packets
		 * with different DCID as the first one in the same datagram.
		 */
		if (!qc) {
			int new_tid = -1;

			qc = from_qc ? from_qc : quic_rx_pkt_retrieve_conn(pkt, dgram, li, &new_tid);
			/* qc is NULL if receiving a non Initial packet for an
			 * unknown connection or on connection affinity rebind.
			 */
			if (!qc) {
				if (new_tid >= 0) {
					MT_LIST_APPEND(&quic_dghdlrs[new_tid].dgrams,
					               &dgram->handler_list);
					tasklet_wakeup(quic_dghdlrs[new_tid].task);
					pool_free(pool_head_quic_rx_packet, pkt);
					goto out;
				}

				/* Skip the entire datagram. */
				pkt->len = end - pos;
				goto next;
			}

			dgram->qc = qc;
		}

		/* Ensure thread connection migration is finalized ASAP. */
		if (qc->flags & QUIC_FL_CONN_AFFINITY_CHANGED)
			qc_finalize_affinity_rebind(qc);

		if (qc_rx_check_closing(qc, pkt)) {
			/* Skip the entire datagram. */
			pkt->len = end - pos;
			goto next;
		}

		/* Detect QUIC connection migration. */
		if (ipcmp(&qc->peer_addr, &dgram->saddr, 1)) {
			if (qc_handle_conn_migration(qc, &dgram->saddr, &dgram->daddr)) {
				/* Skip the entire datagram. */
				TRACE_ERROR("error during connection migration, datagram dropped", QUIC_EV_CONN_LPKT, qc);
				pkt->len = end - pos;
				goto next;
			}
		}

		qc_rx_pkt_handle(qc, pkt, dgram, pos, &tasklist_head);

 next:
		pos += pkt->len;
		quic_rx_packet_refdec(pkt);

		/* Free rejected packets */
		if (!pkt->refcnt) {
			BUG_ON(LIST_INLIST(&pkt->qc_rx_pkt_list));
			pool_free(pool_head_quic_rx_packet, pkt);
		}
	} while (pos < end);

	/* Increasing the received bytes counter by the UDP datagram length
	 * if this datagram could be associated to a connection.
	 */
	if (dgram->qc)
		dgram->qc->bytes.rx += dgram->len;

	/* This must never happen. */
	BUG_ON(pos > end);
	BUG_ON(pos < end || pos > dgram->buf + dgram->len);
	/* Mark this datagram as consumed */
	HA_ATOMIC_STORE(&dgram->buf, NULL);

 out:
	TRACE_LEAVE(QUIC_EV_CONN_LPKT);
	return 0;

 err:
	/* Mark this datagram as consumed as maybe at least some packets were parsed. */
	HA_ATOMIC_STORE(&dgram->buf, NULL);
	TRACE_LEAVE(QUIC_EV_CONN_LPKT);
	return -1;
}

/*
 * Local variables:
 *  c-indent-level: 8
 *  c-basic-offset: 8
 * End:
 */