summaryrefslogtreecommitdiff
path: root/net/vmw_vsock/vmci_transport.c
blob: c1c03895297369089ca1eb765803518cfb55aceb (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
/*
 * VMware vSockets Driver
 *
 * Copyright (C) 2007-2013 VMware, Inc. All rights reserved.
 *
 * 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 version 2 and no later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */

#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/cred.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/kmod.h>
#include <linux/list.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/net.h>
#include <linux/poll.h>
#include <linux/skbuff.h>
#include <linux/smp.h>
#include <linux/socket.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <net/sock.h>
#include <net/af_vsock.h>

#include "vmci_transport_notify.h"

static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg);
static int vmci_transport_recv_stream_cb(void *data, struct vmci_datagram *dg);
static void vmci_transport_peer_attach_cb(u32 sub_id,
					  const struct vmci_event_data *ed,
					  void *client_data);
static void vmci_transport_peer_detach_cb(u32 sub_id,
					  const struct vmci_event_data *ed,
					  void *client_data);
static void vmci_transport_recv_pkt_work(struct work_struct *work);
static int vmci_transport_recv_listen(struct sock *sk,
				      struct vmci_transport_packet *pkt);
static int vmci_transport_recv_connecting_server(
					struct sock *sk,
					struct sock *pending,
					struct vmci_transport_packet *pkt);
static int vmci_transport_recv_connecting_client(
					struct sock *sk,
					struct vmci_transport_packet *pkt);
static int vmci_transport_recv_connecting_client_negotiate(
					struct sock *sk,
					struct vmci_transport_packet *pkt);
static int vmci_transport_recv_connecting_client_invalid(
					struct sock *sk,
					struct vmci_transport_packet *pkt);
static int vmci_transport_recv_connected(struct sock *sk,
					 struct vmci_transport_packet *pkt);
static bool vmci_transport_old_proto_override(bool *old_pkt_proto);
static u16 vmci_transport_new_proto_supported_versions(void);
static bool vmci_transport_proto_to_notify_struct(struct sock *sk, u16 *proto,
						  bool old_pkt_proto);

struct vmci_transport_recv_pkt_info {
	struct work_struct work;
	struct sock *sk;
	struct vmci_transport_packet pkt;
};

static struct vmci_handle vmci_transport_stream_handle = { VMCI_INVALID_ID,
							   VMCI_INVALID_ID };
static u32 vmci_transport_qp_resumed_sub_id = VMCI_INVALID_ID;

static int PROTOCOL_OVERRIDE = -1;

#define VMCI_TRANSPORT_DEFAULT_QP_SIZE_MIN   128
#define VMCI_TRANSPORT_DEFAULT_QP_SIZE       262144
#define VMCI_TRANSPORT_DEFAULT_QP_SIZE_MAX   262144

/* The default peer timeout indicates how long we will wait for a peer response
 * to a control message.
 */
#define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)

#define SS_LISTEN 255

/* Helper function to convert from a VMCI error code to a VSock error code. */

static s32 vmci_transport_error_to_vsock_error(s32 vmci_error)
{
	int err;

	switch (vmci_error) {
	case VMCI_ERROR_NO_MEM:
		err = ENOMEM;
		break;
	case VMCI_ERROR_DUPLICATE_ENTRY:
	case VMCI_ERROR_ALREADY_EXISTS:
		err = EADDRINUSE;
		break;
	case VMCI_ERROR_NO_ACCESS:
		err = EPERM;
		break;
	case VMCI_ERROR_NO_RESOURCES:
		err = ENOBUFS;
		break;
	case VMCI_ERROR_INVALID_RESOURCE:
		err = EHOSTUNREACH;
		break;
	case VMCI_ERROR_INVALID_ARGS:
	default:
		err = EINVAL;
	}

	return err > 0 ? -err : err;
}

static u32 vmci_transport_peer_rid(u32 peer_cid)
{
	if (VMADDR_CID_HYPERVISOR == peer_cid)
		return VMCI_TRANSPORT_HYPERVISOR_PACKET_RID;

	return VMCI_TRANSPORT_PACKET_RID;
}

static inline void
vmci_transport_packet_init(struct vmci_transport_packet *pkt,
			   struct sockaddr_vm *src,
			   struct sockaddr_vm *dst,
			   u8 type,
			   u64 size,
			   u64 mode,
			   struct vmci_transport_waiting_info *wait,
			   u16 proto,
			   struct vmci_handle handle)
{
	/* We register the stream control handler as an any cid handle so we
	 * must always send from a source address of VMADDR_CID_ANY
	 */
	pkt->dg.src = vmci_make_handle(VMADDR_CID_ANY,
				       VMCI_TRANSPORT_PACKET_RID);
	pkt->dg.dst = vmci_make_handle(dst->svm_cid,
				       vmci_transport_peer_rid(dst->svm_cid));
	pkt->dg.payload_size = sizeof(*pkt) - sizeof(pkt->dg);
	pkt->version = VMCI_TRANSPORT_PACKET_VERSION;
	pkt->type = type;
	pkt->src_port = src->svm_port;
	pkt->dst_port = dst->svm_port;
	memset(&pkt->proto, 0, sizeof(pkt->proto));
	memset(&pkt->_reserved2, 0, sizeof(pkt->_reserved2));

	switch (pkt->type) {
	case VMCI_TRANSPORT_PACKET_TYPE_INVALID:
		pkt->u.size = 0;
		break;

	case VMCI_TRANSPORT_PACKET_TYPE_REQUEST:
	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE:
		pkt->u.size = size;
		break;

	case VMCI_TRANSPORT_PACKET_TYPE_OFFER:
	case VMCI_TRANSPORT_PACKET_TYPE_ATTACH:
		pkt->u.handle = handle;
		break;

	case VMCI_TRANSPORT_PACKET_TYPE_WROTE:
	case VMCI_TRANSPORT_PACKET_TYPE_READ:
	case VMCI_TRANSPORT_PACKET_TYPE_RST:
		pkt->u.size = 0;
		break;

	case VMCI_TRANSPORT_PACKET_TYPE_SHUTDOWN:
		pkt->u.mode = mode;
		break;

	case VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ:
	case VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE:
		memcpy(&pkt->u.wait, wait, sizeof(pkt->u.wait));
		break;

	case VMCI_TRANSPORT_PACKET_TYPE_REQUEST2:
	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2:
		pkt->u.size = size;
		pkt->proto = proto;
		break;
	}
}

static inline void
vmci_transport_packet_get_addresses(struct vmci_transport_packet *pkt,
				    struct sockaddr_vm *local,
				    struct sockaddr_vm *remote)
{
	vsock_addr_init(local, pkt->dg.dst.context, pkt->dst_port);
	vsock_addr_init(remote, pkt->dg.src.context, pkt->src_port);
}

static int
__vmci_transport_send_control_pkt(struct vmci_transport_packet *pkt,
				  struct sockaddr_vm *src,
				  struct sockaddr_vm *dst,
				  enum vmci_transport_packet_type type,
				  u64 size,
				  u64 mode,
				  struct vmci_transport_waiting_info *wait,
				  u16 proto,
				  struct vmci_handle handle,
				  bool convert_error)
{
	int err;

	vmci_transport_packet_init(pkt, src, dst, type, size, mode, wait,
				   proto, handle);
	err = vmci_datagram_send(&pkt->dg);
	if (convert_error && (err < 0))
		return vmci_transport_error_to_vsock_error(err);

	return err;
}

static int
vmci_transport_reply_control_pkt_fast(struct vmci_transport_packet *pkt,
				      enum vmci_transport_packet_type type,
				      u64 size,
				      u64 mode,
				      struct vmci_transport_waiting_info *wait,
				      struct vmci_handle handle)
{
	struct vmci_transport_packet reply;
	struct sockaddr_vm src, dst;

	if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST) {
		return 0;
	} else {
		vmci_transport_packet_get_addresses(pkt, &src, &dst);
		return __vmci_transport_send_control_pkt(&reply, &src, &dst,
							 type,
							 size, mode, wait,
							 VSOCK_PROTO_INVALID,
							 handle, true);
	}
}

static int
vmci_transport_send_control_pkt_bh(struct sockaddr_vm *src,
				   struct sockaddr_vm *dst,
				   enum vmci_transport_packet_type type,
				   u64 size,
				   u64 mode,
				   struct vmci_transport_waiting_info *wait,
				   struct vmci_handle handle)
{
	/* Note that it is safe to use a single packet across all CPUs since
	 * two tasklets of the same type are guaranteed to not ever run
	 * simultaneously. If that ever changes, or VMCI stops using tasklets,
	 * we can use per-cpu packets.
	 */
	static struct vmci_transport_packet pkt;

	return __vmci_transport_send_control_pkt(&pkt, src, dst, type,
						 size, mode, wait,
						 VSOCK_PROTO_INVALID, handle,
						 false);
}

static int
vmci_transport_send_control_pkt(struct sock *sk,
				enum vmci_transport_packet_type type,
				u64 size,
				u64 mode,
				struct vmci_transport_waiting_info *wait,
				u16 proto,
				struct vmci_handle handle)
{
	struct vmci_transport_packet *pkt;
	struct vsock_sock *vsk;
	int err;

	vsk = vsock_sk(sk);

	if (!vsock_addr_bound(&vsk->local_addr))
		return -EINVAL;

	if (!vsock_addr_bound(&vsk->remote_addr))
		return -EINVAL;

	pkt = kmalloc(sizeof(*pkt), GFP_KERNEL);
	if (!pkt)
		return -ENOMEM;

	err = __vmci_transport_send_control_pkt(pkt, &vsk->local_addr,
						&vsk->remote_addr, type, size,
						mode, wait, proto, handle,
						true);
	kfree(pkt);

	return err;
}

static int vmci_transport_send_reset_bh(struct sockaddr_vm *dst,
					struct sockaddr_vm *src,
					struct vmci_transport_packet *pkt)
{
	if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST)
		return 0;
	return vmci_transport_send_control_pkt_bh(
					dst, src,
					VMCI_TRANSPORT_PACKET_TYPE_RST, 0,
					0, NULL, VMCI_INVALID_HANDLE);
}

static int vmci_transport_send_reset(struct sock *sk,
				     struct vmci_transport_packet *pkt)
{
	if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST)
		return 0;
	return vmci_transport_send_control_pkt(sk,
					VMCI_TRANSPORT_PACKET_TYPE_RST,
					0, 0, NULL, VSOCK_PROTO_INVALID,
					VMCI_INVALID_HANDLE);
}

static int vmci_transport_send_negotiate(struct sock *sk, size_t size)
{
	return vmci_transport_send_control_pkt(
					sk,
					VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE,
					size, 0, NULL,
					VSOCK_PROTO_INVALID,
					VMCI_INVALID_HANDLE);
}

static int vmci_transport_send_negotiate2(struct sock *sk, size_t size,
					  u16 version)
{
	return vmci_transport_send_control_pkt(
					sk,
					VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2,
					size, 0, NULL, version,
					VMCI_INVALID_HANDLE);
}

static int vmci_transport_send_qp_offer(struct sock *sk,
					struct vmci_handle handle)
{
	return vmci_transport_send_control_pkt(
					sk, VMCI_TRANSPORT_PACKET_TYPE_OFFER, 0,
					0, NULL,
					VSOCK_PROTO_INVALID, handle);
}

static int vmci_transport_send_attach(struct sock *sk,
				      struct vmci_handle handle)
{
	return vmci_transport_send_control_pkt(
					sk, VMCI_TRANSPORT_PACKET_TYPE_ATTACH,
					0, 0, NULL, VSOCK_PROTO_INVALID,
					handle);
}

static int vmci_transport_reply_reset(struct vmci_transport_packet *pkt)
{
	return vmci_transport_reply_control_pkt_fast(
						pkt,
						VMCI_TRANSPORT_PACKET_TYPE_RST,
						0, 0, NULL,
						VMCI_INVALID_HANDLE);
}

static int vmci_transport_send_invalid_bh(struct sockaddr_vm *dst,
					  struct sockaddr_vm *src)
{
	return vmci_transport_send_control_pkt_bh(
					dst, src,
					VMCI_TRANSPORT_PACKET_TYPE_INVALID,
					0, 0, NULL, VMCI_INVALID_HANDLE);
}

int vmci_transport_send_wrote_bh(struct sockaddr_vm *dst,
				 struct sockaddr_vm *src)
{
	return vmci_transport_send_control_pkt_bh(
					dst, src,
					VMCI_TRANSPORT_PACKET_TYPE_WROTE, 0,
					0, NULL, VMCI_INVALID_HANDLE);
}

int vmci_transport_send_read_bh(struct sockaddr_vm *dst,
				struct sockaddr_vm *src)
{
	return vmci_transport_send_control_pkt_bh(
					dst, src,
					VMCI_TRANSPORT_PACKET_TYPE_READ, 0,
					0, NULL, VMCI_INVALID_HANDLE);
}

int vmci_transport_send_wrote(struct sock *sk)
{
	return vmci_transport_send_control_pkt(
					sk, VMCI_TRANSPORT_PACKET_TYPE_WROTE, 0,
					0, NULL, VSOCK_PROTO_INVALID,
					VMCI_INVALID_HANDLE);
}

int vmci_transport_send_read(struct sock *sk)
{
	return vmci_transport_send_control_pkt(
					sk, VMCI_TRANSPORT_PACKET_TYPE_READ, 0,
					0, NULL, VSOCK_PROTO_INVALID,
					VMCI_INVALID_HANDLE);
}

int vmci_transport_send_waiting_write(struct sock *sk,
				      struct vmci_transport_waiting_info *wait)
{
	return vmci_transport_send_control_pkt(
				sk, VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE,
				0, 0, wait, VSOCK_PROTO_INVALID,
				VMCI_INVALID_HANDLE);
}

int vmci_transport_send_waiting_read(struct sock *sk,
				     struct vmci_transport_waiting_info *wait)
{
	return vmci_transport_send_control_pkt(
				sk, VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ,
				0, 0, wait, VSOCK_PROTO_INVALID,
				VMCI_INVALID_HANDLE);
}

static int vmci_transport_shutdown(struct vsock_sock *vsk, int mode)
{
	return vmci_transport_send_control_pkt(
					&vsk->sk,
					VMCI_TRANSPORT_PACKET_TYPE_SHUTDOWN,
					0, mode, NULL,
					VSOCK_PROTO_INVALID,
					VMCI_INVALID_HANDLE);
}

static int vmci_transport_send_conn_request(struct sock *sk, size_t size)
{
	return vmci_transport_send_control_pkt(sk,
					VMCI_TRANSPORT_PACKET_TYPE_REQUEST,
					size, 0, NULL,
					VSOCK_PROTO_INVALID,
					VMCI_INVALID_HANDLE);
}

static int vmci_transport_send_conn_request2(struct sock *sk, size_t size,
					     u16 version)
{
	return vmci_transport_send_control_pkt(
					sk, VMCI_TRANSPORT_PACKET_TYPE_REQUEST2,
					size, 0, NULL, version,
					VMCI_INVALID_HANDLE);
}

static struct sock *vmci_transport_get_pending(
					struct sock *listener,
					struct vmci_transport_packet *pkt)
{
	struct vsock_sock *vlistener;
	struct vsock_sock *vpending;
	struct sock *pending;
	struct sockaddr_vm src;

	vsock_addr_init(&src, pkt->dg.src.context, pkt->src_port);

	vlistener = vsock_sk(listener);

	list_for_each_entry(vpending, &vlistener->pending_links,
			    pending_links) {
		if (vsock_addr_equals_addr(&src, &vpending->remote_addr) &&
		    pkt->dst_port == vpending->local_addr.svm_port) {
			pending = sk_vsock(vpending);
			sock_hold(pending);
			goto found;
		}
	}

	pending = NULL;
found:
	return pending;

}

static void vmci_transport_release_pending(struct sock *pending)
{
	sock_put(pending);
}

/* We allow two kinds of sockets to communicate with a restricted VM: 1)
 * trusted sockets 2) sockets from applications running as the same user as the
 * VM (this is only true for the host side and only when using hosted products)
 */

static bool vmci_transport_is_trusted(struct vsock_sock *vsock, u32 peer_cid)
{
	return vsock->trusted ||
	       vmci_is_context_owner(peer_cid, vsock->owner->uid);
}

/* We allow sending datagrams to and receiving datagrams from a restricted VM
 * only if it is trusted as described in vmci_transport_is_trusted.
 */

static bool vmci_transport_allow_dgram(struct vsock_sock *vsock, u32 peer_cid)
{
	if (VMADDR_CID_HYPERVISOR == peer_cid)
		return true;

	if (vsock->cached_peer != peer_cid) {
		vsock->cached_peer = peer_cid;
		if (!vmci_transport_is_trusted(vsock, peer_cid) &&
		    (vmci_context_get_priv_flags(peer_cid) &
		     VMCI_PRIVILEGE_FLAG_RESTRICTED)) {
			vsock->cached_peer_allow_dgram = false;
		} else {
			vsock->cached_peer_allow_dgram = true;
		}
	}

	return vsock->cached_peer_allow_dgram;
}

static int
vmci_transport_queue_pair_alloc(struct vmci_qp **qpair,
				struct vmci_handle *handle,
				u64 produce_size,
				u64 consume_size,
				u32 peer, u32 flags, bool trusted)
{
	int err = 0;

	if (trusted) {
		/* Try to allocate our queue pair as trusted. This will only
		 * work if vsock is running in the host.
		 */

		err = vmci_qpair_alloc(qpair, handle, produce_size,
				       consume_size,
				       peer, flags,
				       VMCI_PRIVILEGE_FLAG_TRUSTED);
		if (err != VMCI_ERROR_NO_ACCESS)
			goto out;

	}

	err = vmci_qpair_alloc(qpair, handle, produce_size, consume_size,
			       peer, flags, VMCI_NO_PRIVILEGE_FLAGS);
out:
	if (err < 0) {
		pr_err("Could not attach to queue pair with %d\n",
		       err);
		err = vmci_transport_error_to_vsock_error(err);
	}

	return err;
}

static int
vmci_transport_datagram_create_hnd(u32 resource_id,
				   u32 flags,
				   vmci_datagram_recv_cb recv_cb,
				   void *client_data,
				   struct vmci_handle *out_handle)
{
	int err = 0;

	/* Try to allocate our datagram handler as trusted. This will only work
	 * if vsock is running in the host.
	 */

	err = vmci_datagram_create_handle_priv(resource_id, flags,
					       VMCI_PRIVILEGE_FLAG_TRUSTED,
					       recv_cb,
					       client_data, out_handle);

	if (err == VMCI_ERROR_NO_ACCESS)
		err = vmci_datagram_create_handle(resource_id, flags,
						  recv_cb, client_data,
						  out_handle);

	return err;
}

/* This is invoked as part of a tasklet that's scheduled when the VMCI
 * interrupt fires.  This is run in bottom-half context and if it ever needs to
 * sleep it should defer that work to a work queue.
 */

static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg)
{
	struct sock *sk;
	size_t size;
	struct sk_buff *skb;
	struct vsock_sock *vsk;

	sk = (struct sock *)data;

	/* This handler is privileged when this module is running on the host.
	 * We will get datagrams from all endpoints (even VMs that are in a
	 * restricted context). If we get one from a restricted context then
	 * the destination socket must be trusted.
	 *
	 * NOTE: We access the socket struct without holding the lock here.
	 * This is ok because the field we are interested is never modified
	 * outside of the create and destruct socket functions.
	 */
	vsk = vsock_sk(sk);
	if (!vmci_transport_allow_dgram(vsk, dg->src.context))
		return VMCI_ERROR_NO_ACCESS;

	size = VMCI_DG_SIZE(dg);

	/* Attach the packet to the socket's receive queue as an sk_buff. */
	skb = alloc_skb(size, GFP_ATOMIC);
	if (!skb)
		return VMCI_ERROR_NO_MEM;

	/* sk_receive_skb() will do a sock_put(), so hold here. */
	sock_hold(sk);
	skb_put(skb, size);
	memcpy(skb->data, dg, size);
	sk_receive_skb(sk, skb, 0);

	return VMCI_SUCCESS;
}

static bool vmci_transport_stream_allow(u32 cid, u32 port)
{
	static const u32 non_socket_contexts[] = {
		VMADDR_CID_RESERVED,
	};
	int i;

	BUILD_BUG_ON(sizeof(cid) != sizeof(*non_socket_contexts));

	for (i = 0; i < ARRAY_SIZE(non_socket_contexts); i++) {
		if (cid == non_socket_contexts[i])
			return false;
	}

	return true;
}

/* This is invoked as part of a tasklet that's scheduled when the VMCI
 * interrupt fires.  This is run in bottom-half context but it defers most of
 * its work to the packet handling work queue.
 */

static int vmci_transport_recv_stream_cb(void *data, struct vmci_datagram *dg)
{
	struct sock *sk;
	struct sockaddr_vm dst;
	struct sockaddr_vm src;
	struct vmci_transport_packet *pkt;
	struct vsock_sock *vsk;
	bool bh_process_pkt;
	int err;

	sk = NULL;
	err = VMCI_SUCCESS;
	bh_process_pkt = false;

	/* Ignore incoming packets from contexts without sockets, or resources
	 * that aren't vsock implementations.
	 */

	if (!vmci_transport_stream_allow(dg->src.context, -1)
	    || vmci_transport_peer_rid(dg->src.context) != dg->src.resource)
		return VMCI_ERROR_NO_ACCESS;

	if (VMCI_DG_SIZE(dg) < sizeof(*pkt))
		/* Drop datagrams that do not contain full VSock packets. */
		return VMCI_ERROR_INVALID_ARGS;

	pkt = (struct vmci_transport_packet *)dg;

	/* Find the socket that should handle this packet.  First we look for a
	 * connected socket and if there is none we look for a socket bound to
	 * the destintation address.
	 */
	vsock_addr_init(&src, pkt->dg.src.context, pkt->src_port);
	vsock_addr_init(&dst, pkt->dg.dst.context, pkt->dst_port);

	sk = vsock_find_connected_socket(&src, &dst);
	if (!sk) {
		sk = vsock_find_bound_socket(&dst);
		if (!sk) {
			/* We could not find a socket for this specified
			 * address.  If this packet is a RST, we just drop it.
			 * If it is another packet, we send a RST.  Note that
			 * we do not send a RST reply to RSTs so that we do not
			 * continually send RSTs between two endpoints.
			 *
			 * Note that since this is a reply, dst is src and src
			 * is dst.
			 */
			if (vmci_transport_send_reset_bh(&dst, &src, pkt) < 0)
				pr_err("unable to send reset\n");

			err = VMCI_ERROR_NOT_FOUND;
			goto out;
		}
	}

	/* If the received packet type is beyond all types known to this
	 * implementation, reply with an invalid message.  Hopefully this will
	 * help when implementing backwards compatibility in the future.
	 */
	if (pkt->type >= VMCI_TRANSPORT_PACKET_TYPE_MAX) {
		vmci_transport_send_invalid_bh(&dst, &src);
		err = VMCI_ERROR_INVALID_ARGS;
		goto out;
	}

	/* This handler is privileged when this module is running on the host.
	 * We will get datagram connect requests from all endpoints (even VMs
	 * that are in a restricted context). If we get one from a restricted
	 * context then the destination socket must be trusted.
	 *
	 * NOTE: We access the socket struct without holding the lock here.
	 * This is ok because the field we are interested is never modified
	 * outside of the create and destruct socket functions.
	 */
	vsk = vsock_sk(sk);
	if (!vmci_transport_allow_dgram(vsk, pkt->dg.src.context)) {
		err = VMCI_ERROR_NO_ACCESS;
		goto out;
	}

	/* We do most everything in a work queue, but let's fast path the
	 * notification of reads and writes to help data transfer performance.
	 * We can only do this if there is no process context code executing
	 * for this socket since that may change the state.
	 */
	bh_lock_sock(sk);

	if (!sock_owned_by_user(sk)) {
		/* The local context ID may be out of date, update it. */
		vsk->local_addr.svm_cid = dst.svm_cid;

		if (sk->sk_state == SS_CONNECTED)
			vmci_trans(vsk)->notify_ops->handle_notify_pkt(
					sk, pkt, true, &dst, &src,
					&bh_process_pkt);
	}

	bh_unlock_sock(sk);

	if (!bh_process_pkt) {
		struct vmci_transport_recv_pkt_info *recv_pkt_info;

		recv_pkt_info = kmalloc(sizeof(*recv_pkt_info), GFP_ATOMIC);
		if (!recv_pkt_info) {
			if (vmci_transport_send_reset_bh(&dst, &src, pkt) < 0)
				pr_err("unable to send reset\n");

			err = VMCI_ERROR_NO_MEM;
			goto out;
		}

		recv_pkt_info->sk = sk;
		memcpy(&recv_pkt_info->pkt, pkt, sizeof(recv_pkt_info->pkt));
		INIT_WORK(&recv_pkt_info->work, vmci_transport_recv_pkt_work);

		schedule_work(&recv_pkt_info->work);
		/* Clear sk so that the reference count incremented by one of
		 * the Find functions above is not decremented below.  We need
		 * that reference count for the packet handler we've scheduled
		 * to run.
		 */
		sk = NULL;
	}

out:
	if (sk)
		sock_put(sk);

	return err;
}

static void vmci_transport_peer_attach_cb(u32 sub_id,
					  const struct vmci_event_data *e_data,
					  void *client_data)
{
	struct sock *sk = client_data;
	const struct vmci_event_payload_qp *e_payload;
	struct vsock_sock *vsk;

	e_payload = vmci_event_data_const_payload(e_data);

	vsk = vsock_sk(sk);

	/* We don't ask for delayed CBs when we subscribe to this event (we
	 * pass 0 as flags to vmci_event_subscribe()).  VMCI makes no
	 * guarantees in that case about what context we might be running in,
	 * so it could be BH or process, blockable or non-blockable.  So we
	 * need to account for all possible contexts here.
	 */
	local_bh_disable();
	bh_lock_sock(sk);

	/* XXX This is lame, we should provide a way to lookup sockets by
	 * qp_handle.
	 */
	if (vmci_handle_is_equal(vmci_trans(vsk)->qp_handle,
				 e_payload->handle)) {
		/* XXX This doesn't do anything, but in the future we may want
		 * to set a flag here to verify the attach really did occur and
		 * we weren't just sent a datagram claiming it was.
		 */
		goto out;
	}

out:
	bh_unlock_sock(sk);
	local_bh_enable();
}

static void vmci_transport_handle_detach(struct sock *sk)
{
	struct vsock_sock *vsk;

	vsk = vsock_sk(sk);
	if (!vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle)) {
		sock_set_flag(sk, SOCK_DONE);

		/* On a detach the peer will not be sending or receiving
		 * anymore.
		 */
		vsk->peer_shutdown = SHUTDOWN_MASK;

		/* We should not be sending anymore since the peer won't be
		 * there to receive, but we can still receive if there is data
		 * left in our consume queue.
		 */
		if (vsock_stream_has_data(vsk) <= 0) {
			if (sk->sk_state == SS_CONNECTING) {
				/* The peer may detach from a queue pair while
				 * we are still in the connecting state, i.e.,
				 * if the peer VM is killed after attaching to
				 * a queue pair, but before we complete the
				 * handshake. In that case, we treat the detach
				 * event like a reset.
				 */

				sk->sk_state = SS_UNCONNECTED;
				sk->sk_err = ECONNRESET;
				sk->sk_error_report(sk);
				return;
			}
			sk->sk_state = SS_UNCONNECTED;
		}
		sk->sk_state_change(sk);
	}
}

static void vmci_transport_peer_detach_cb(u32 sub_id,
					  const struct vmci_event_data *e_data,
					  void *client_data)
{
	struct sock *sk = client_data;
	const struct vmci_event_payload_qp *e_payload;
	struct vsock_sock *vsk;

	e_payload = vmci_event_data_const_payload(e_data);
	vsk = vsock_sk(sk);
	if (vmci_handle_is_invalid(e_payload->handle))
		return;

	/* Same rules for locking as for peer_attach_cb(). */
	local_bh_disable();
	bh_lock_sock(sk);

	/* XXX This is lame, we should provide a way to lookup sockets by
	 * qp_handle.
	 */
	if (vmci_handle_is_equal(vmci_trans(vsk)->qp_handle,
				 e_payload->handle))
		vmci_transport_handle_detach(sk);

	bh_unlock_sock(sk);
	local_bh_enable();
}

static void vmci_transport_qp_resumed_cb(u32 sub_id,
					 const struct vmci_event_data *e_data,
					 void *client_data)
{
	vsock_for_each_connected_socket(vmci_transport_handle_detach);
}

static void vmci_transport_recv_pkt_work(struct work_struct *work)
{
	struct vmci_transport_recv_pkt_info *recv_pkt_info;
	struct vmci_transport_packet *pkt;
	struct sock *sk;

	recv_pkt_info =
		container_of(work, struct vmci_transport_recv_pkt_info, work);
	sk = recv_pkt_info->sk;
	pkt = &recv_pkt_info->pkt;

	lock_sock(sk);

	/* The local context ID may be out of date. */
	vsock_sk(sk)->local_addr.svm_cid = pkt->dg.dst.context;

	switch (sk->sk_state) {
	case SS_LISTEN:
		vmci_transport_recv_listen(sk, pkt);
		break;
	case SS_CONNECTING:
		/* Processing of pending connections for servers goes through
		 * the listening socket, so see vmci_transport_recv_listen()
		 * for that path.
		 */
		vmci_transport_recv_connecting_client(sk, pkt);
		break;
	case SS_CONNECTED:
		vmci_transport_recv_connected(sk, pkt);
		break;
	default:
		/* Because this function does not run in the same context as
		 * vmci_transport_recv_stream_cb it is possible that the
		 * socket has closed. We need to let the other side know or it
		 * could be sitting in a connect and hang forever. Send a
		 * reset to prevent that.
		 */
		vmci_transport_send_reset(sk, pkt);
		break;
	}

	release_sock(sk);
	kfree(recv_pkt_info);
	/* Release reference obtained in the stream callback when we fetched
	 * this socket out of the bound or connected list.
	 */
	sock_put(sk);
}

static int vmci_transport_recv_listen(struct sock *sk,
				      struct vmci_transport_packet *pkt)
{
	struct sock *pending;
	struct vsock_sock *vpending;
	int err;
	u64 qp_size;
	bool old_request = false;
	bool old_pkt_proto = false;

	err = 0;

	/* Because we are in the listen state, we could be receiving a packet
	 * for ourself or any previous connection requests that we received.
	 * If it's the latter, we try to find a socket in our list of pending
	 * connections and, if we do, call the appropriate handler for the
	 * state that that socket is in.  Otherwise we try to service the
	 * connection request.
	 */
	pending = vmci_transport_get_pending(sk, pkt);
	if (pending) {
		lock_sock(pending);

		/* The local context ID may be out of date. */
		vsock_sk(pending)->local_addr.svm_cid = pkt->dg.dst.context;

		switch (pending->sk_state) {
		case SS_CONNECTING:
			err = vmci_transport_recv_connecting_server(sk,
								    pending,
								    pkt);
			break;
		default:
			vmci_transport_send_reset(pending, pkt);
			err = -EINVAL;
		}

		if (err < 0)
			vsock_remove_pending(sk, pending);

		release_sock(pending);
		vmci_transport_release_pending(pending);

		return err;
	}

	/* The listen state only accepts connection requests.  Reply with a
	 * reset unless we received a reset.
	 */

	if (!(pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST ||
	      pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST2)) {
		vmci_transport_reply_reset(pkt);
		return -EINVAL;
	}

	if (pkt->u.size == 0) {
		vmci_transport_reply_reset(pkt);
		return -EINVAL;
	}

	/* If this socket can't accommodate this connection request, we send a
	 * reset.  Otherwise we create and initialize a child socket and reply
	 * with a connection negotiation.
	 */
	if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog) {
		vmci_transport_reply_reset(pkt);
		return -ECONNREFUSED;
	}

	pending = __vsock_create(sock_net(sk), NULL, sk, GFP_KERNEL,
				 sk->sk_type);
	if (!pending) {
		vmci_transport_send_reset(sk, pkt);
		return -ENOMEM;
	}

	vpending = vsock_sk(pending);

	vsock_addr_init(&vpending->local_addr, pkt->dg.dst.context,
			pkt->dst_port);
	vsock_addr_init(&vpending->remote_addr, pkt->dg.src.context,
			pkt->src_port);

	/* If the proposed size fits within our min/max, accept it. Otherwise
	 * propose our own size.
	 */
	if (pkt->u.size >= vmci_trans(vpending)->queue_pair_min_size &&
	    pkt->u.size <= vmci_trans(vpending)->queue_pair_max_size) {
		qp_size = pkt->u.size;
	} else {
		qp_size = vmci_trans(vpending)->queue_pair_size;
	}

	/* Figure out if we are using old or new requests based on the
	 * overrides pkt types sent by our peer.
	 */
	if (vmci_transport_old_proto_override(&old_pkt_proto)) {
		old_request = old_pkt_proto;
	} else {
		if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST)
			old_request = true;
		else if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_REQUEST2)
			old_request = false;

	}

	if (old_request) {
		/* Handle a REQUEST (or override) */
		u16 version = VSOCK_PROTO_INVALID;
		if (vmci_transport_proto_to_notify_struct(
			pending, &version, true))
			err = vmci_transport_send_negotiate(pending, qp_size);
		else
			err = -EINVAL;

	} else {
		/* Handle a REQUEST2 (or override) */
		int proto_int = pkt->proto;
		int pos;
		u16 active_proto_version = 0;

		/* The list of possible protocols is the intersection of all
		 * protocols the client supports ... plus all the protocols we
		 * support.
		 */
		proto_int &= vmci_transport_new_proto_supported_versions();

		/* We choose the highest possible protocol version and use that
		 * one.
		 */
		pos = fls(proto_int);
		if (pos) {
			active_proto_version = (1 << (pos - 1));
			if (vmci_transport_proto_to_notify_struct(
				pending, &active_proto_version, false))
				err = vmci_transport_send_negotiate2(pending,
							qp_size,
							active_proto_version);
			else
				err = -EINVAL;

		} else {
			err = -EINVAL;
		}
	}

	if (err < 0) {
		vmci_transport_send_reset(sk, pkt);
		sock_put(pending);
		err = vmci_transport_error_to_vsock_error(err);
		goto out;
	}

	vsock_add_pending(sk, pending);
	sk->sk_ack_backlog++;

	pending->sk_state = SS_CONNECTING;
	vmci_trans(vpending)->produce_size =
		vmci_trans(vpending)->consume_size = qp_size;
	vmci_trans(vpending)->queue_pair_size = qp_size;

	vmci_trans(vpending)->notify_ops->process_request(pending);

	/* We might never receive another message for this socket and it's not
	 * connected to any process, so we have to ensure it gets cleaned up
	 * ourself.  Our delayed work function will take care of that.  Note
	 * that we do not ever cancel this function since we have few
	 * guarantees about its state when calling cancel_delayed_work().
	 * Instead we hold a reference on the socket for that function and make
	 * it capable of handling cases where it needs to do nothing but
	 * release that reference.
	 */
	vpending->listener = sk;
	sock_hold(sk);
	sock_hold(pending);
	INIT_DELAYED_WORK(&vpending->dwork, vsock_pending_work);
	schedule_delayed_work(&vpending->dwork, HZ);

out:
	return err;
}

static int
vmci_transport_recv_connecting_server(struct sock *listener,
				      struct sock *pending,
				      struct vmci_transport_packet *pkt)
{
	struct vsock_sock *vpending;
	struct vmci_handle handle;
	struct vmci_qp *qpair;
	bool is_local;
	u32 flags;
	u32 detach_sub_id;
	int err;
	int skerr;

	vpending = vsock_sk(pending);
	detach_sub_id = VMCI_INVALID_ID;

	switch (pkt->type) {
	case VMCI_TRANSPORT_PACKET_TYPE_OFFER:
		if (vmci_handle_is_invalid(pkt->u.handle)) {
			vmci_transport_send_reset(pending, pkt);
			skerr = EPROTO;
			err = -EINVAL;
			goto destroy;
		}
		break;
	default:
		/* Close and cleanup the connection. */
		vmci_transport_send_reset(pending, pkt);
		skerr = EPROTO;
		err = pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST ? 0 : -EINVAL;
		goto destroy;
	}

	/* In order to complete the connection we need to attach to the offered
	 * queue pair and send an attach notification.  We also subscribe to the
	 * detach event so we know when our peer goes away, and we do that
	 * before attaching so we don't miss an event.  If all this succeeds,
	 * we update our state and wakeup anything waiting in accept() for a
	 * connection.
	 */

	/* We don't care about attach since we ensure the other side has
	 * attached by specifying the ATTACH_ONLY flag below.
	 */
	err = vmci_event_subscribe(VMCI_EVENT_QP_PEER_DETACH,
				   vmci_transport_peer_detach_cb,
				   pending, &detach_sub_id);
	if (err < VMCI_SUCCESS) {
		vmci_transport_send_reset(pending, pkt);
		err = vmci_transport_error_to_vsock_error(err);
		skerr = -err;
		goto destroy;
	}

	vmci_trans(vpending)->detach_sub_id = detach_sub_id;

	/* Now attach to the queue pair the client created. */
	handle = pkt->u.handle;

	/* vpending->local_addr always has a context id so we do not need to
	 * worry about VMADDR_CID_ANY in this case.
	 */
	is_local =
	    vpending->remote_addr.svm_cid == vpending->local_addr.svm_cid;
	flags = VMCI_QPFLAG_ATTACH_ONLY;
	flags |= is_local ? VMCI_QPFLAG_LOCAL : 0;

	err = vmci_transport_queue_pair_alloc(
					&qpair,
					&handle,
					vmci_trans(vpending)->produce_size,
					vmci_trans(vpending)->consume_size,
					pkt->dg.src.context,
					flags,
					vmci_transport_is_trusted(
						vpending,
						vpending->remote_addr.svm_cid));
	if (err < 0) {
		vmci_transport_send_reset(pending, pkt);
		skerr = -err;
		goto destroy;
	}

	vmci_trans(vpending)->qp_handle = handle;
	vmci_trans(vpending)->qpair = qpair;

	/* When we send the attach message, we must be ready to handle incoming
	 * control messages on the newly connected socket. So we move the
	 * pending socket to the connected state before sending the attach
	 * message. Otherwise, an incoming packet triggered by the attach being
	 * received by the peer may be processed concurrently with what happens
	 * below after sending the attach message, and that incoming packet
	 * will find the listening socket instead of the (currently) pending
	 * socket. Note that enqueueing the socket increments the reference
	 * count, so even if a reset comes before the connection is accepted,
	 * the socket will be valid until it is removed from the queue.
	 *
	 * If we fail sending the attach below, we remove the socket from the
	 * connected list and move the socket to SS_UNCONNECTED before
	 * releasing the lock, so a pending slow path processing of an incoming
	 * packet will not see the socket in the connected state in that case.
	 */
	pending->sk_state = SS_CONNECTED;

	vsock_insert_connected(vpending);

	/* Notify our peer of our attach. */
	err = vmci_transport_send_attach(pending, handle);
	if (err < 0) {
		vsock_remove_connected(vpending);
		pr_err("Could not send attach\n");
		vmci_transport_send_reset(pending, pkt);
		err = vmci_transport_error_to_vsock_error(err);
		skerr = -err;
		goto destroy;
	}

	/* We have a connection. Move the now connected socket from the
	 * listener's pending list to the accept queue so callers of accept()
	 * can find it.
	 */
	vsock_remove_pending(listener, pending);
	vsock_enqueue_accept(listener, pending);

	/* Callers of accept() will be be waiting on the listening socket, not
	 * the pending socket.
	 */
	listener->sk_state_change(listener);

	return 0;

destroy:
	pending->sk_err = skerr;
	pending->sk_state = SS_UNCONNECTED;
	/* As long as we drop our reference, all necessary cleanup will handle
	 * when the cleanup function drops its reference and our destruct
	 * implementation is called.  Note that since the listen handler will
	 * remove pending from the pending list upon our failure, the cleanup
	 * function won't drop the additional reference, which is why we do it
	 * here.
	 */
	sock_put(pending);

	return err;
}

static int
vmci_transport_recv_connecting_client(struct sock *sk,
				      struct vmci_transport_packet *pkt)
{
	struct vsock_sock *vsk;
	int err;
	int skerr;

	vsk = vsock_sk(sk);

	switch (pkt->type) {
	case VMCI_TRANSPORT_PACKET_TYPE_ATTACH:
		if (vmci_handle_is_invalid(pkt->u.handle) ||
		    !vmci_handle_is_equal(pkt->u.handle,
					  vmci_trans(vsk)->qp_handle)) {
			skerr = EPROTO;
			err = -EINVAL;
			goto destroy;
		}

		/* Signify the socket is connected and wakeup the waiter in
		 * connect(). Also place the socket in the connected table for
		 * accounting (it can already be found since it's in the bound
		 * table).
		 */
		sk->sk_state = SS_CONNECTED;
		sk->sk_socket->state = SS_CONNECTED;
		vsock_insert_connected(vsk);
		sk->sk_state_change(sk);

		break;
	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE:
	case VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2:
		if (pkt->u.size == 0
		    || pkt->dg.src.context != vsk->remote_addr.svm_cid
		    || pkt->src_port != vsk->remote_addr.svm_port
		    || !vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle)
		    || vmci_trans(vsk)->qpair
		    || vmci_trans(vsk)->produce_size != 0
		    || vmci_trans(vsk)->consume_size != 0
		    || vmci_trans(vsk)->attach_sub_id != VMCI_INVALID_ID
		    || vmci_trans(vsk)->detach_sub_id != VMCI_INVALID_ID) {
			skerr = EPROTO;
			err = -EINVAL;

			goto destroy;
		}

		err = vmci_transport_recv_connecting_client_negotiate(sk, pkt);
		if (err) {
			skerr = -err;
			goto destroy;
		}

		break;
	case VMCI_TRANSPORT_PACKET_TYPE_INVALID:
		err = vmci_transport_recv_connecting_client_invalid(sk, pkt);
		if (err) {
			skerr = -err;
			goto destroy;
		}

		break;
	case VMCI_TRANSPORT_PACKET_TYPE_RST:
		/* Older versions of the linux code (WS 6.5 / ESX 4.0) used to
		 * continue processing here after they sent an INVALID packet.
		 * This meant that we got a RST after the INVALID. We ignore a
		 * RST after an INVALID. The common code doesn't send the RST
		 * ... so we can hang if an old version of the common code
		 * fails between getting a REQUEST and sending an OFFER back.
		 * Not much we can do about it... except hope that it doesn't
		 * happen.
		 */
		if (vsk->ignore_connecting_rst) {
			vsk->ignore_connecting_rst = false;
		} else {
			skerr = ECONNRESET;
			err = 0;
			goto destroy;
		}

		break;
	default:
		/* Close and cleanup the connection. */
		skerr = EPROTO;
		err = -EINVAL;
		goto destroy;
	}

	return 0;

destroy:
	vmci_transport_send_reset(sk, pkt);

	sk->sk_state = SS_UNCONNECTED;
	sk->sk_err = skerr;
	sk->sk_error_report(sk);
	return err;
}

static int vmci_transport_recv_connecting_client_negotiate(
					struct sock *sk,
					struct vmci_transport_packet *pkt)
{
	int err;
	struct vsock_sock *vsk;
	struct vmci_handle handle;
	struct vmci_qp *qpair;
	u32 attach_sub_id;
	u32 detach_sub_id;
	bool is_local;
	u32 flags;
	bool old_proto = true;
	bool old_pkt_proto;
	u16 version;

	vsk = vsock_sk(sk);
	handle = VMCI_INVALID_HANDLE;
	attach_sub_id = VMCI_INVALID_ID;
	detach_sub_id = VMCI_INVALID_ID;

	/* If we have gotten here then we should be past the point where old
	 * linux vsock could have sent the bogus rst.
	 */
	vsk->sent_request = false;
	vsk->ignore_connecting_rst = false;

	/* Verify that we're OK with the proposed queue pair size */
	if (pkt->u.size < vmci_trans(vsk)->queue_pair_min_size ||
	    pkt->u.size > vmci_trans(vsk)->queue_pair_max_size) {
		err = -EINVAL;
		goto destroy;
	}

	/* At this point we know the CID the peer is using to talk to us. */

	if (vsk->local_addr.svm_cid == VMADDR_CID_ANY)
		vsk->local_addr.svm_cid = pkt->dg.dst.context;

	/* Setup the notify ops to be the highest supported version that both
	 * the server and the client support.
	 */

	if (vmci_transport_old_proto_override(&old_pkt_proto)) {
		old_proto = old_pkt_proto;
	} else {
		if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE)
			old_proto = true;
		else if (pkt->type == VMCI_TRANSPORT_PACKET_TYPE_NEGOTIATE2)
			old_proto = false;

	}

	if (old_proto)
		version = VSOCK_PROTO_INVALID;
	else
		version = pkt->proto;

	if (!vmci_transport_proto_to_notify_struct(sk, &version, old_proto)) {
		err = -EINVAL;
		goto destroy;
	}

	/* Subscribe to attach and detach events first.
	 *
	 * XXX We attach once for each queue pair created for now so it is easy
	 * to find the socket (it's provided), but later we should only
	 * subscribe once and add a way to lookup sockets by queue pair handle.
	 */
	err = vmci_event_subscribe(VMCI_EVENT_QP_PEER_ATTACH,
				   vmci_transport_peer_attach_cb,
				   sk, &attach_sub_id);
	if (err < VMCI_SUCCESS) {
		err = vmci_transport_error_to_vsock_error(err);
		goto destroy;
	}

	err = vmci_event_subscribe(VMCI_EVENT_QP_PEER_DETACH,
				   vmci_transport_peer_detach_cb,
				   sk, &detach_sub_id);
	if (err < VMCI_SUCCESS) {
		err = vmci_transport_error_to_vsock_error(err);
		goto destroy;
	}

	/* Make VMCI select the handle for us. */
	handle = VMCI_INVALID_HANDLE;
	is_local = vsk->remote_addr.svm_cid == vsk->local_addr.svm_cid;
	flags = is_local ? VMCI_QPFLAG_LOCAL : 0;

	err = vmci_transport_queue_pair_alloc(&qpair,
					      &handle,
					      pkt->u.size,
					      pkt->u.size,
					      vsk->remote_addr.svm_cid,
					      flags,
					      vmci_transport_is_trusted(
						  vsk,
						  vsk->
						  remote_addr.svm_cid));
	if (err < 0)
		goto destroy;

	err = vmci_transport_send_qp_offer(sk, handle);
	if (err < 0) {
		err = vmci_transport_error_to_vsock_error(err);
		goto destroy;
	}

	vmci_trans(vsk)->qp_handle = handle;
	vmci_trans(vsk)->qpair = qpair;

	vmci_trans(vsk)->produce_size = vmci_trans(vsk)->consume_size =
		pkt->u.size;

	vmci_trans(vsk)->attach_sub_id = attach_sub_id;
	vmci_trans(vsk)->detach_sub_id = detach_sub_id;

	vmci_trans(vsk)->notify_ops->process_negotiate(sk);

	return 0;

destroy:
	if (attach_sub_id != VMCI_INVALID_ID)
		vmci_event_unsubscribe(attach_sub_id);

	if (detach_sub_id != VMCI_INVALID_ID)
		vmci_event_unsubscribe(detach_sub_id);

	if (!vmci_handle_is_invalid(handle))
		vmci_qpair_detach(&qpair);

	return err;
}

static int
vmci_transport_recv_connecting_client_invalid(struct sock *sk,
					      struct vmci_transport_packet *pkt)
{
	int err = 0;
	struct vsock_sock *vsk = vsock_sk(sk);

	if (vsk->sent_request) {
		vsk->sent_request = false;
		vsk->ignore_connecting_rst = true;

		err = vmci_transport_send_conn_request(
			sk, vmci_trans(vsk)->queue_pair_size);
		if (err < 0)
			err = vmci_transport_error_to_vsock_error(err);
		else
			err = 0;

	}

	return err;
}

static int vmci_transport_recv_connected(struct sock *sk,
					 struct vmci_transport_packet *pkt)
{
	struct vsock_sock *vsk;
	bool pkt_processed = false;

	/* In cases where we are closing the connection, it's sufficient to
	 * mark the state change (and maybe error) and wake up any waiting
	 * threads. Since this is a connected socket, it's owned by a user
	 * process and will be cleaned up when the failure is passed back on
	 * the current or next system call.  Our system call implementations
	 * must therefore check for error and state changes on entry and when
	 * being awoken.
	 */
	switch (pkt->type) {
	case VMCI_TRANSPORT_PACKET_TYPE_SHUTDOWN:
		if (pkt->u.mode) {
			vsk = vsock_sk(sk);

			vsk->peer_shutdown |= pkt->u.mode;
			sk->sk_state_change(sk);
		}
		break;

	case VMCI_TRANSPORT_PACKET_TYPE_RST:
		vsk = vsock_sk(sk);
		/* It is possible that we sent our peer a message (e.g a
		 * WAITING_READ) right before we got notified that the peer had
		 * detached. If that happens then we can get a RST pkt back
		 * from our peer even though there is data available for us to
		 * read. In that case, don't shutdown the socket completely but
		 * instead allow the local client to finish reading data off
		 * the queuepair. Always treat a RST pkt in connected mode like
		 * a clean shutdown.
		 */
		sock_set_flag(sk, SOCK_DONE);
		vsk->peer_shutdown = SHUTDOWN_MASK;
		if (vsock_stream_has_data(vsk) <= 0)
			sk->sk_state = SS_DISCONNECTING;

		sk->sk_state_change(sk);
		break;

	default:
		vsk = vsock_sk(sk);
		vmci_trans(vsk)->notify_ops->handle_notify_pkt(
				sk, pkt, false, NULL, NULL,
				&pkt_processed);
		if (!pkt_processed)
			return -EINVAL;

		break;
	}

	return 0;
}

static int vmci_transport_socket_init(struct vsock_sock *vsk,
				      struct vsock_sock *psk)
{
	vsk->trans = kmalloc(sizeof(struct vmci_transport), GFP_KERNEL);
	if (!vsk->trans)
		return -ENOMEM;

	vmci_trans(vsk)->dg_handle = VMCI_INVALID_HANDLE;
	vmci_trans(vsk)->qp_handle = VMCI_INVALID_HANDLE;
	vmci_trans(vsk)->qpair = NULL;
	vmci_trans(vsk)->produce_size = vmci_trans(vsk)->consume_size = 0;
	vmci_trans(vsk)->attach_sub_id = vmci_trans(vsk)->detach_sub_id =
		VMCI_INVALID_ID;
	vmci_trans(vsk)->notify_ops = NULL;
	if (psk) {
		vmci_trans(vsk)->queue_pair_size =
			vmci_trans(psk)->queue_pair_size;
		vmci_trans(vsk)->queue_pair_min_size =
			vmci_trans(psk)->queue_pair_min_size;
		vmci_trans(vsk)->queue_pair_max_size =
			vmci_trans(psk)->queue_pair_max_size;
	} else {
		vmci_trans(vsk)->queue_pair_size =
			VMCI_TRANSPORT_DEFAULT_QP_SIZE;
		vmci_trans(vsk)->queue_pair_min_size =
			 VMCI_TRANSPORT_DEFAULT_QP_SIZE_MIN;
		vmci_trans(vsk)->queue_pair_max_size =
			VMCI_TRANSPORT_DEFAULT_QP_SIZE_MAX;
	}

	return 0;
}

static void vmci_transport_destruct(struct vsock_sock *vsk)
{
	if (vmci_trans(vsk)->attach_sub_id != VMCI_INVALID_ID) {
		vmci_event_unsubscribe(vmci_trans(vsk)->attach_sub_id);
		vmci_trans(vsk)->attach_sub_id = VMCI_INVALID_ID;
	}

	if (vmci_trans(vsk)->detach_sub_id != VMCI_INVALID_ID) {
		vmci_event_unsubscribe(vmci_trans(vsk)->detach_sub_id);
		vmci_trans(vsk)->detach_sub_id = VMCI_INVALID_ID;
	}

	if (!vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle)) {
		vmci_qpair_detach(&vmci_trans(vsk)->qpair);
		vmci_trans(vsk)->qp_handle = VMCI_INVALID_HANDLE;
		vmci_trans(vsk)->produce_size = 0;
		vmci_trans(vsk)->consume_size = 0;
	}

	if (vmci_trans(vsk)->notify_ops)
		vmci_trans(vsk)->notify_ops->socket_destruct(vsk);

	kfree(vsk->trans);
	vsk->trans = NULL;
}

static void vmci_transport_release(struct vsock_sock *vsk)
{
	if (!vmci_handle_is_invalid(vmci_trans(vsk)->dg_handle)) {
		vmci_datagram_destroy_handle(vmci_trans(vsk)->dg_handle);
		vmci_trans(vsk)->dg_handle = VMCI_INVALID_HANDLE;
	}
}

static int vmci_transport_dgram_bind(struct vsock_sock *vsk,
				     struct sockaddr_vm *addr)
{
	u32 port;
	u32 flags;
	int err;

	/* VMCI will select a resource ID for us if we provide
	 * VMCI_INVALID_ID.
	 */
	port = addr->svm_port == VMADDR_PORT_ANY ?
			VMCI_INVALID_ID : addr->svm_port;

	if (port <= LAST_RESERVED_PORT && !capable(CAP_NET_BIND_SERVICE))
		return -EACCES;

	flags = addr->svm_cid == VMADDR_CID_ANY ?
				VMCI_FLAG_ANYCID_DG_HND : 0;

	err = vmci_transport_datagram_create_hnd(port, flags,
						 vmci_transport_recv_dgram_cb,
						 &vsk->sk,
						 &vmci_trans(vsk)->dg_handle);
	if (err < VMCI_SUCCESS)
		return vmci_transport_error_to_vsock_error(err);
	vsock_addr_init(&vsk->local_addr, addr->svm_cid,
			vmci_trans(vsk)->dg_handle.resource);

	return 0;
}

static int vmci_transport_dgram_enqueue(
	struct vsock_sock *vsk,
	struct sockaddr_vm *remote_addr,
	struct msghdr *msg,
	size_t len)
{
	int err;
	struct vmci_datagram *dg;

	if (len > VMCI_MAX_DG_PAYLOAD_SIZE)
		return -EMSGSIZE;

	if (!vmci_transport_allow_dgram(vsk, remote_addr->svm_cid))
		return -EPERM;

	/* Allocate a buffer for the user's message and our packet header. */
	dg = kmalloc(len + sizeof(*dg), GFP_KERNEL);
	if (!dg)
		return -ENOMEM;

	memcpy_from_msg(VMCI_DG_PAYLOAD(dg), msg, len);

	dg->dst = vmci_make_handle(remote_addr->svm_cid,
				   remote_addr->svm_port);
	dg->src = vmci_make_handle(vsk->local_addr.svm_cid,
				   vsk->local_addr.svm_port);
	dg->payload_size = len;

	err = vmci_datagram_send(dg);
	kfree(dg);
	if (err < 0)
		return vmci_transport_error_to_vsock_error(err);

	return err - sizeof(*dg);
}

static int vmci_transport_dgram_dequeue(struct kiocb *kiocb,
					struct vsock_sock *vsk,
					struct msghdr *msg, size_t len,
					int flags)
{
	int err;
	int noblock;
	struct vmci_datagram *dg;
	size_t payload_len;
	struct sk_buff *skb;

	noblock = flags & MSG_DONTWAIT;

	if (flags & MSG_OOB || flags & MSG_ERRQUEUE)
		return -EOPNOTSUPP;

	/* Retrieve the head sk_buff from the socket's receive queue. */
	err = 0;
	skb = skb_recv_datagram(&vsk->sk, flags, noblock, &err);
	if (err)
		return err;

	if (!skb)
		return -EAGAIN;

	dg = (struct vmci_datagram *)skb->data;
	if (!dg)
		/* err is 0, meaning we read zero bytes. */
		goto out;

	payload_len = dg->payload_size;
	/* Ensure the sk_buff matches the payload size claimed in the packet. */
	if (payload_len != skb->len - sizeof(*dg)) {
		err = -EINVAL;
		goto out;
	}

	if (payload_len > len) {
		payload_len = len;
		msg->msg_flags |= MSG_TRUNC;
	}

	/* Place the datagram payload in the user's iovec. */
	err = skb_copy_datagram_msg(skb, sizeof(*dg), msg, payload_len);
	if (err)
		goto out;

	if (msg->msg_name) {
		/* Provide the address of the sender. */
		DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name);
		vsock_addr_init(vm_addr, dg->src.context, dg->src.resource);
		msg->msg_namelen = sizeof(*vm_addr);
	}
	err = payload_len;

out:
	skb_free_datagram(&vsk->sk, skb);
	return err;
}

static bool vmci_transport_dgram_allow(u32 cid, u32 port)
{
	if (cid == VMADDR_CID_HYPERVISOR) {
		/* Registrations of PBRPC Servers do not modify VMX/Hypervisor
		 * state and are allowed.
		 */
		return port == VMCI_UNITY_PBRPC_REGISTER;
	}

	return true;
}

static int vmci_transport_connect(struct vsock_sock *vsk)
{
	int err;
	bool old_pkt_proto = false;
	struct sock *sk = &vsk->sk;

	if (vmci_transport_old_proto_override(&old_pkt_proto) &&
		old_pkt_proto) {
		err = vmci_transport_send_conn_request(
			sk, vmci_trans(vsk)->queue_pair_size);
		if (err < 0) {
			sk->sk_state = SS_UNCONNECTED;
			return err;
		}
	} else {
		int supported_proto_versions =
			vmci_transport_new_proto_supported_versions();
		err = vmci_transport_send_conn_request2(
				sk, vmci_trans(vsk)->queue_pair_size,
				supported_proto_versions);
		if (err < 0) {
			sk->sk_state = SS_UNCONNECTED;
			return err;
		}

		vsk->sent_request = true;
	}

	return err;
}

static ssize_t vmci_transport_stream_dequeue(
	struct vsock_sock *vsk,
	struct msghdr *msg,
	size_t len,
	int flags)
{
	if (flags & MSG_PEEK)
		return vmci_qpair_peekv(vmci_trans(vsk)->qpair, msg->msg_iov, len, 0);
	else
		return vmci_qpair_dequev(vmci_trans(vsk)->qpair, msg->msg_iov, len, 0);
}

static ssize_t vmci_transport_stream_enqueue(
	struct vsock_sock *vsk,
	struct msghdr *msg,
	size_t len)
{
	return vmci_qpair_enquev(vmci_trans(vsk)->qpair, msg->msg_iov, len, 0);
}

static s64 vmci_transport_stream_has_data(struct vsock_sock *vsk)
{
	return vmci_qpair_consume_buf_ready(vmci_trans(vsk)->qpair);
}

static s64 vmci_transport_stream_has_space(struct vsock_sock *vsk)
{
	return vmci_qpair_produce_free_space(vmci_trans(vsk)->qpair);
}

static u64 vmci_transport_stream_rcvhiwat(struct vsock_sock *vsk)
{
	return vmci_trans(vsk)->consume_size;
}

static bool vmci_transport_stream_is_active(struct vsock_sock *vsk)
{
	return !vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle);
}

static u64 vmci_transport_get_buffer_size(struct vsock_sock *vsk)
{
	return vmci_trans(vsk)->queue_pair_size;
}

static u64 vmci_transport_get_min_buffer_size(struct vsock_sock *vsk)
{
	return vmci_trans(vsk)->queue_pair_min_size;
}

static u64 vmci_transport_get_max_buffer_size(struct vsock_sock *vsk)
{
	return vmci_trans(vsk)->queue_pair_max_size;
}

static void vmci_transport_set_buffer_size(struct vsock_sock *vsk, u64 val)
{
	if (val < vmci_trans(vsk)->queue_pair_min_size)
		vmci_trans(vsk)->queue_pair_min_size = val;
	if (val > vmci_trans(vsk)->queue_pair_max_size)
		vmci_trans(vsk)->queue_pair_max_size = val;
	vmci_trans(vsk)->queue_pair_size = val;
}

static void vmci_transport_set_min_buffer_size(struct vsock_sock *vsk,
					       u64 val)
{
	if (val > vmci_trans(vsk)->queue_pair_size)
		vmci_trans(vsk)->queue_pair_size = val;
	vmci_trans(vsk)->queue_pair_min_size = val;
}

static void vmci_transport_set_max_buffer_size(struct vsock_sock *vsk,
					       u64 val)
{
	if (val < vmci_trans(vsk)->queue_pair_size)
		vmci_trans(vsk)->queue_pair_size = val;
	vmci_trans(vsk)->queue_pair_max_size = val;
}

static int vmci_transport_notify_poll_in(
	struct vsock_sock *vsk,
	size_t target,
	bool *data_ready_now)
{
	return vmci_trans(vsk)->notify_ops->poll_in(
			&vsk->sk, target, data_ready_now);
}

static int vmci_transport_notify_poll_out(
	struct vsock_sock *vsk,
	size_t target,
	bool *space_available_now)
{
	return vmci_trans(vsk)->notify_ops->poll_out(
			&vsk->sk, target, space_available_now);
}

static int vmci_transport_notify_recv_init(
	struct vsock_sock *vsk,
	size_t target,
	struct vsock_transport_recv_notify_data *data)
{
	return vmci_trans(vsk)->notify_ops->recv_init(
			&vsk->sk, target,
			(struct vmci_transport_recv_notify_data *)data);
}

static int vmci_transport_notify_recv_pre_block(
	struct vsock_sock *vsk,
	size_t target,
	struct vsock_transport_recv_notify_data *data)
{
	return vmci_trans(vsk)->notify_ops->recv_pre_block(
			&vsk->sk, target,
			(struct vmci_transport_recv_notify_data *)data);
}

static int vmci_transport_notify_recv_pre_dequeue(
	struct vsock_sock *vsk,
	size_t target,
	struct vsock_transport_recv_notify_data *data)
{
	return vmci_trans(vsk)->notify_ops->recv_pre_dequeue(
			&vsk->sk, target,
			(struct vmci_transport_recv_notify_data *)data);
}

static int vmci_transport_notify_recv_post_dequeue(
	struct vsock_sock *vsk,
	size_t target,
	ssize_t copied,
	bool data_read,
	struct vsock_transport_recv_notify_data *data)
{
	return vmci_trans(vsk)->notify_ops->recv_post_dequeue(
			&vsk->sk, target, copied, data_read,
			(struct vmci_transport_recv_notify_data *)data);
}

static int vmci_transport_notify_send_init(
	struct vsock_sock *vsk,
	struct vsock_transport_send_notify_data *data)
{
	return vmci_trans(vsk)->notify_ops->send_init(
			&vsk->sk,
			(struct vmci_transport_send_notify_data *)data);
}

static int vmci_transport_notify_send_pre_block(
	struct vsock_sock *vsk,
	struct vsock_transport_send_notify_data *data)
{
	return vmci_trans(vsk)->notify_ops->send_pre_block(
			&vsk->sk,
			(struct vmci_transport_send_notify_data *)data);
}

static int vmci_transport_notify_send_pre_enqueue(
	struct vsock_sock *vsk,
	struct vsock_transport_send_notify_data *data)
{
	return vmci_trans(vsk)->notify_ops->send_pre_enqueue(
			&vsk->sk,
			(struct vmci_transport_send_notify_data *)data);
}

static int vmci_transport_notify_send_post_enqueue(
	struct vsock_sock *vsk,
	ssize_t written,
	struct vsock_transport_send_notify_data *data)
{
	return vmci_trans(vsk)->notify_ops->send_post_enqueue(
			&vsk->sk, written,
			(struct vmci_transport_send_notify_data *)data);
}

static bool vmci_transport_old_proto_override(bool *old_pkt_proto)
{
	if (PROTOCOL_OVERRIDE != -1) {
		if (PROTOCOL_OVERRIDE == 0)
			*old_pkt_proto = true;
		else
			*old_pkt_proto = false;

		pr_info("Proto override in use\n");
		return true;
	}

	return false;
}

static bool vmci_transport_proto_to_notify_struct(struct sock *sk,
						  u16 *proto,
						  bool old_pkt_proto)
{
	struct vsock_sock *vsk = vsock_sk(sk);

	if (old_pkt_proto) {
		if (*proto != VSOCK_PROTO_INVALID) {
			pr_err("Can't set both an old and new protocol\n");
			return false;
		}
		vmci_trans(vsk)->notify_ops = &vmci_transport_notify_pkt_ops;
		goto exit;
	}

	switch (*proto) {
	case VSOCK_PROTO_PKT_ON_NOTIFY:
		vmci_trans(vsk)->notify_ops =
			&vmci_transport_notify_pkt_q_state_ops;
		break;
	default:
		pr_err("Unknown notify protocol version\n");
		return false;
	}

exit:
	vmci_trans(vsk)->notify_ops->socket_init(sk);
	return true;
}

static u16 vmci_transport_new_proto_supported_versions(void)
{
	if (PROTOCOL_OVERRIDE != -1)
		return PROTOCOL_OVERRIDE;

	return VSOCK_PROTO_ALL_SUPPORTED;
}

static u32 vmci_transport_get_local_cid(void)
{
	return vmci_get_context_id();
}

static struct vsock_transport vmci_transport = {
	.init = vmci_transport_socket_init,
	.destruct = vmci_transport_destruct,
	.release = vmci_transport_release,
	.connect = vmci_transport_connect,
	.dgram_bind = vmci_transport_dgram_bind,
	.dgram_dequeue = vmci_transport_dgram_dequeue,
	.dgram_enqueue = vmci_transport_dgram_enqueue,
	.dgram_allow = vmci_transport_dgram_allow,
	.stream_dequeue = vmci_transport_stream_dequeue,
	.stream_enqueue = vmci_transport_stream_enqueue,
	.stream_has_data = vmci_transport_stream_has_data,
	.stream_has_space = vmci_transport_stream_has_space,
	.stream_rcvhiwat = vmci_transport_stream_rcvhiwat,
	.stream_is_active = vmci_transport_stream_is_active,
	.stream_allow = vmci_transport_stream_allow,
	.notify_poll_in = vmci_transport_notify_poll_in,
	.notify_poll_out = vmci_transport_notify_poll_out,
	.notify_recv_init = vmci_transport_notify_recv_init,
	.notify_recv_pre_block = vmci_transport_notify_recv_pre_block,
	.notify_recv_pre_dequeue = vmci_transport_notify_recv_pre_dequeue,
	.notify_recv_post_dequeue = vmci_transport_notify_recv_post_dequeue,
	.notify_send_init = vmci_transport_notify_send_init,
	.notify_send_pre_block = vmci_transport_notify_send_pre_block,
	.notify_send_pre_enqueue = vmci_transport_notify_send_pre_enqueue,
	.notify_send_post_enqueue = vmci_transport_notify_send_post_enqueue,
	.shutdown = vmci_transport_shutdown,
	.set_buffer_size = vmci_transport_set_buffer_size,
	.set_min_buffer_size = vmci_transport_set_min_buffer_size,
	.set_max_buffer_size = vmci_transport_set_max_buffer_size,
	.get_buffer_size = vmci_transport_get_buffer_size,
	.get_min_buffer_size = vmci_transport_get_min_buffer_size,
	.get_max_buffer_size = vmci_transport_get_max_buffer_size,
	.get_local_cid = vmci_transport_get_local_cid,
};

static int __init vmci_transport_init(void)
{
	int err;

	/* Create the datagram handle that we will use to send and receive all
	 * VSocket control messages for this context.
	 */
	err = vmci_transport_datagram_create_hnd(VMCI_TRANSPORT_PACKET_RID,
						 VMCI_FLAG_ANYCID_DG_HND,
						 vmci_transport_recv_stream_cb,
						 NULL,
						 &vmci_transport_stream_handle);
	if (err < VMCI_SUCCESS) {
		pr_err("Unable to create datagram handle. (%d)\n", err);
		return vmci_transport_error_to_vsock_error(err);
	}

	err = vmci_event_subscribe(VMCI_EVENT_QP_RESUMED,
				   vmci_transport_qp_resumed_cb,
				   NULL, &vmci_transport_qp_resumed_sub_id);
	if (err < VMCI_SUCCESS) {
		pr_err("Unable to subscribe to resumed event. (%d)\n", err);
		err = vmci_transport_error_to_vsock_error(err);
		vmci_transport_qp_resumed_sub_id = VMCI_INVALID_ID;
		goto err_destroy_stream_handle;
	}

	err = vsock_core_init(&vmci_transport);
	if (err < 0)
		goto err_unsubscribe;

	return 0;

err_unsubscribe:
	vmci_event_unsubscribe(vmci_transport_qp_resumed_sub_id);
err_destroy_stream_handle:
	vmci_datagram_destroy_handle(vmci_transport_stream_handle);
	return err;
}
module_init(vmci_transport_init);

static void __exit vmci_transport_exit(void)
{
	if (!vmci_handle_is_invalid(vmci_transport_stream_handle)) {
		if (vmci_datagram_destroy_handle(
			vmci_transport_stream_handle) != VMCI_SUCCESS)
			pr_err("Couldn't destroy datagram handle\n");
		vmci_transport_stream_handle = VMCI_INVALID_HANDLE;
	}

	if (vmci_transport_qp_resumed_sub_id != VMCI_INVALID_ID) {
		vmci_event_unsubscribe(vmci_transport_qp_resumed_sub_id);
		vmci_transport_qp_resumed_sub_id = VMCI_INVALID_ID;
	}

	vsock_core_exit();
}
module_exit(vmci_transport_exit);

MODULE_AUTHOR("VMware, Inc.");
MODULE_DESCRIPTION("VMCI transport for Virtual Sockets");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("vmware_vsock");
MODULE_ALIAS_NETPROTO(PF_VSOCK);