summaryrefslogtreecommitdiff
path: root/net/iucv/af_iucv.c
blob: 49ecbe8d176acd0b8350d1d50d23c202aa57008b (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
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  IUCV protocol stack for Linux on zSeries
 *
 *  Copyright IBM Corp. 2006, 2009
 *
 *  Author(s):	Jennifer Hunt <jenhunt@us.ibm.com>
 *		Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
 *  PM functions:
 *		Ursula Braun <ursula.braun@de.ibm.com>
 */

#define KMSG_COMPONENT "af_iucv"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/limits.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/security.h>
#include <net/sock.h>
#include <asm/ebcdic.h>
#include <asm/cpcmd.h>
#include <linux/kmod.h>

#include <net/iucv/af_iucv.h>

#define VERSION "1.2"

static char iucv_userid[80];

static struct proto iucv_proto = {
	.name		= "AF_IUCV",
	.owner		= THIS_MODULE,
	.obj_size	= sizeof(struct iucv_sock),
};

static struct iucv_interface *pr_iucv;
static struct iucv_handler af_iucv_handler;

/* special AF_IUCV IPRM messages */
static const u8 iprm_shutdown[8] =
	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};

#define TRGCLS_SIZE	sizeof_field(struct iucv_message, class)

#define __iucv_sock_wait(sk, condition, timeo, ret)			\
do {									\
	DEFINE_WAIT(__wait);						\
	long __timeo = timeo;						\
	ret = 0;							\
	prepare_to_wait(sk_sleep(sk), &__wait, TASK_INTERRUPTIBLE);	\
	while (!(condition)) {						\
		if (!__timeo) {						\
			ret = -EAGAIN;					\
			break;						\
		}							\
		if (signal_pending(current)) {				\
			ret = sock_intr_errno(__timeo);			\
			break;						\
		}							\
		release_sock(sk);					\
		__timeo = schedule_timeout(__timeo);			\
		lock_sock(sk);						\
		ret = sock_error(sk);					\
		if (ret)						\
			break;						\
	}								\
	finish_wait(sk_sleep(sk), &__wait);				\
} while (0)

#define iucv_sock_wait(sk, condition, timeo)				\
({									\
	int __ret = 0;							\
	if (!(condition))						\
		__iucv_sock_wait(sk, condition, timeo, __ret);		\
	__ret;								\
})

static struct sock *iucv_accept_dequeue(struct sock *parent,
					struct socket *newsock);
static void iucv_sock_kill(struct sock *sk);
static void iucv_sock_close(struct sock *sk);

static void afiucv_hs_callback_txnotify(struct sock *sk, enum iucv_tx_notify);

static struct iucv_sock_list iucv_sk_list = {
	.lock = __RW_LOCK_UNLOCKED(iucv_sk_list.lock),
	.autobind_name = ATOMIC_INIT(0)
};

static inline void high_nmcpy(unsigned char *dst, char *src)
{
       memcpy(dst, src, 8);
}

static inline void low_nmcpy(unsigned char *dst, char *src)
{
       memcpy(&dst[8], src, 8);
}

/**
 * iucv_msg_length() - Returns the length of an iucv message.
 * @msg:	Pointer to struct iucv_message, MUST NOT be NULL
 *
 * The function returns the length of the specified iucv message @msg of data
 * stored in a buffer and of data stored in the parameter list (PRMDATA).
 *
 * For IUCV_IPRMDATA, AF_IUCV uses the following convention to transport socket
 * data:
 *	PRMDATA[0..6]	socket data (max 7 bytes);
 *	PRMDATA[7]	socket data length value (len is 0xff - PRMDATA[7])
 *
 * The socket data length is computed by subtracting the socket data length
 * value from 0xFF.
 * If the socket data len is greater 7, then PRMDATA can be used for special
 * notifications (see iucv_sock_shutdown); and further,
 * if the socket data len is > 7, the function returns 8.
 *
 * Use this function to allocate socket buffers to store iucv message data.
 */
static inline size_t iucv_msg_length(struct iucv_message *msg)
{
	size_t datalen;

	if (msg->flags & IUCV_IPRMDATA) {
		datalen = 0xff - msg->rmmsg[7];
		return (datalen < 8) ? datalen : 8;
	}
	return msg->length;
}

/**
 * iucv_sock_in_state() - check for specific states
 * @sk:		sock structure
 * @state:	first iucv sk state
 * @state2:	second iucv sk state
 *
 * Returns true if the socket in either in the first or second state.
 */
static int iucv_sock_in_state(struct sock *sk, int state, int state2)
{
	return (sk->sk_state == state || sk->sk_state == state2);
}

/**
 * iucv_below_msglim() - function to check if messages can be sent
 * @sk:		sock structure
 *
 * Returns true if the send queue length is lower than the message limit.
 * Always returns true if the socket is not connected (no iucv path for
 * checking the message limit).
 */
static inline int iucv_below_msglim(struct sock *sk)
{
	struct iucv_sock *iucv = iucv_sk(sk);

	if (sk->sk_state != IUCV_CONNECTED)
		return 1;
	if (iucv->transport == AF_IUCV_TRANS_IUCV)
		return (atomic_read(&iucv->skbs_in_xmit) < iucv->path->msglim);
	else
		return ((atomic_read(&iucv->msg_sent) < iucv->msglimit_peer) &&
			(atomic_read(&iucv->pendings) <= 0));
}

/*
 * iucv_sock_wake_msglim() - Wake up thread waiting on msg limit
 */
static void iucv_sock_wake_msglim(struct sock *sk)
{
	struct socket_wq *wq;

	rcu_read_lock();
	wq = rcu_dereference(sk->sk_wq);
	if (skwq_has_sleeper(wq))
		wake_up_interruptible_all(&wq->wait);
	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
	rcu_read_unlock();
}

/*
 * afiucv_hs_send() - send a message through HiperSockets transport
 */
static int afiucv_hs_send(struct iucv_message *imsg, struct sock *sock,
		   struct sk_buff *skb, u8 flags)
{
	struct iucv_sock *iucv = iucv_sk(sock);
	struct af_iucv_trans_hdr *phs_hdr;
	int err, confirm_recv = 0;

	phs_hdr = skb_push(skb, sizeof(*phs_hdr));
	memset(phs_hdr, 0, sizeof(*phs_hdr));
	skb_reset_network_header(skb);

	phs_hdr->magic = ETH_P_AF_IUCV;
	phs_hdr->version = 1;
	phs_hdr->flags = flags;
	if (flags == AF_IUCV_FLAG_SYN)
		phs_hdr->window = iucv->msglimit;
	else if ((flags == AF_IUCV_FLAG_WIN) || !flags) {
		confirm_recv = atomic_read(&iucv->msg_recv);
		phs_hdr->window = confirm_recv;
		if (confirm_recv)
			phs_hdr->flags = phs_hdr->flags | AF_IUCV_FLAG_WIN;
	}
	memcpy(phs_hdr->destUserID, iucv->dst_user_id, 8);
	memcpy(phs_hdr->destAppName, iucv->dst_name, 8);
	memcpy(phs_hdr->srcUserID, iucv->src_user_id, 8);
	memcpy(phs_hdr->srcAppName, iucv->src_name, 8);
	ASCEBC(phs_hdr->destUserID, sizeof(phs_hdr->destUserID));
	ASCEBC(phs_hdr->destAppName, sizeof(phs_hdr->destAppName));
	ASCEBC(phs_hdr->srcUserID, sizeof(phs_hdr->srcUserID));
	ASCEBC(phs_hdr->srcAppName, sizeof(phs_hdr->srcAppName));
	if (imsg)
		memcpy(&phs_hdr->iucv_hdr, imsg, sizeof(struct iucv_message));

	skb->dev = iucv->hs_dev;
	if (!skb->dev) {
		err = -ENODEV;
		goto err_free;
	}

	dev_hard_header(skb, skb->dev, ETH_P_AF_IUCV, NULL, NULL, skb->len);

	if (!(skb->dev->flags & IFF_UP) || !netif_carrier_ok(skb->dev)) {
		err = -ENETDOWN;
		goto err_free;
	}
	if (skb->len > skb->dev->mtu) {
		if (sock->sk_type == SOCK_SEQPACKET) {
			err = -EMSGSIZE;
			goto err_free;
		}
		err = pskb_trim(skb, skb->dev->mtu);
		if (err)
			goto err_free;
	}
	skb->protocol = cpu_to_be16(ETH_P_AF_IUCV);

	atomic_inc(&iucv->skbs_in_xmit);
	err = dev_queue_xmit(skb);
	if (net_xmit_eval(err)) {
		atomic_dec(&iucv->skbs_in_xmit);
	} else {
		atomic_sub(confirm_recv, &iucv->msg_recv);
		WARN_ON(atomic_read(&iucv->msg_recv) < 0);
	}
	return net_xmit_eval(err);

err_free:
	kfree_skb(skb);
	return err;
}

static struct sock *__iucv_get_sock_by_name(char *nm)
{
	struct sock *sk;

	sk_for_each(sk, &iucv_sk_list.head)
		if (!memcmp(&iucv_sk(sk)->src_name, nm, 8))
			return sk;

	return NULL;
}

static void iucv_sock_destruct(struct sock *sk)
{
	skb_queue_purge(&sk->sk_receive_queue);
	skb_queue_purge(&sk->sk_error_queue);

	sk_mem_reclaim(sk);

	if (!sock_flag(sk, SOCK_DEAD)) {
		pr_err("Attempt to release alive iucv socket %p\n", sk);
		return;
	}

	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
	WARN_ON(refcount_read(&sk->sk_wmem_alloc));
	WARN_ON(sk->sk_wmem_queued);
	WARN_ON(sk->sk_forward_alloc);
}

/* Cleanup Listen */
static void iucv_sock_cleanup_listen(struct sock *parent)
{
	struct sock *sk;

	/* Close non-accepted connections */
	while ((sk = iucv_accept_dequeue(parent, NULL))) {
		iucv_sock_close(sk);
		iucv_sock_kill(sk);
	}

	parent->sk_state = IUCV_CLOSED;
}

static void iucv_sock_link(struct iucv_sock_list *l, struct sock *sk)
{
	write_lock_bh(&l->lock);
	sk_add_node(sk, &l->head);
	write_unlock_bh(&l->lock);
}

static void iucv_sock_unlink(struct iucv_sock_list *l, struct sock *sk)
{
	write_lock_bh(&l->lock);
	sk_del_node_init(sk);
	write_unlock_bh(&l->lock);
}

/* Kill socket (only if zapped and orphaned) */
static void iucv_sock_kill(struct sock *sk)
{
	if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
		return;

	iucv_sock_unlink(&iucv_sk_list, sk);
	sock_set_flag(sk, SOCK_DEAD);
	sock_put(sk);
}

/* Terminate an IUCV path */
static void iucv_sever_path(struct sock *sk, int with_user_data)
{
	unsigned char user_data[16];
	struct iucv_sock *iucv = iucv_sk(sk);
	struct iucv_path *path = iucv->path;

	if (iucv->path) {
		iucv->path = NULL;
		if (with_user_data) {
			low_nmcpy(user_data, iucv->src_name);
			high_nmcpy(user_data, iucv->dst_name);
			ASCEBC(user_data, sizeof(user_data));
			pr_iucv->path_sever(path, user_data);
		} else
			pr_iucv->path_sever(path, NULL);
		iucv_path_free(path);
	}
}

/* Send controlling flags through an IUCV socket for HIPER transport */
static int iucv_send_ctrl(struct sock *sk, u8 flags)
{
	struct iucv_sock *iucv = iucv_sk(sk);
	int err = 0;
	int blen;
	struct sk_buff *skb;
	u8 shutdown = 0;

	blen = sizeof(struct af_iucv_trans_hdr) +
	       LL_RESERVED_SPACE(iucv->hs_dev);
	if (sk->sk_shutdown & SEND_SHUTDOWN) {
		/* controlling flags should be sent anyway */
		shutdown = sk->sk_shutdown;
		sk->sk_shutdown &= RCV_SHUTDOWN;
	}
	skb = sock_alloc_send_skb(sk, blen, 1, &err);
	if (skb) {
		skb_reserve(skb, blen);
		err = afiucv_hs_send(NULL, sk, skb, flags);
	}
	if (shutdown)
		sk->sk_shutdown = shutdown;
	return err;
}

/* Close an IUCV socket */
static void iucv_sock_close(struct sock *sk)
{
	struct iucv_sock *iucv = iucv_sk(sk);
	unsigned long timeo;
	int err = 0;

	lock_sock(sk);

	switch (sk->sk_state) {
	case IUCV_LISTEN:
		iucv_sock_cleanup_listen(sk);
		break;

	case IUCV_CONNECTED:
		if (iucv->transport == AF_IUCV_TRANS_HIPER) {
			err = iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
			sk->sk_state = IUCV_DISCONN;
			sk->sk_state_change(sk);
		}
		fallthrough;

	case IUCV_DISCONN:
		sk->sk_state = IUCV_CLOSING;
		sk->sk_state_change(sk);

		if (!err && atomic_read(&iucv->skbs_in_xmit) > 0) {
			if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
				timeo = sk->sk_lingertime;
			else
				timeo = IUCV_DISCONN_TIMEOUT;
			iucv_sock_wait(sk,
					iucv_sock_in_state(sk, IUCV_CLOSED, 0),
					timeo);
		}
		fallthrough;

	case IUCV_CLOSING:
		sk->sk_state = IUCV_CLOSED;
		sk->sk_state_change(sk);

		sk->sk_err = ECONNRESET;
		sk->sk_state_change(sk);

		skb_queue_purge(&iucv->send_skb_q);
		skb_queue_purge(&iucv->backlog_skb_q);
		fallthrough;

	default:
		iucv_sever_path(sk, 1);
	}

	if (iucv->hs_dev) {
		dev_put(iucv->hs_dev);
		iucv->hs_dev = NULL;
		sk->sk_bound_dev_if = 0;
	}

	/* mark socket for deletion by iucv_sock_kill() */
	sock_set_flag(sk, SOCK_ZAPPED);

	release_sock(sk);
}

static void iucv_sock_init(struct sock *sk, struct sock *parent)
{
	if (parent) {
		sk->sk_type = parent->sk_type;
		security_sk_clone(parent, sk);
	}
}

static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio, int kern)
{
	struct sock *sk;
	struct iucv_sock *iucv;

	sk = sk_alloc(&init_net, PF_IUCV, prio, &iucv_proto, kern);
	if (!sk)
		return NULL;
	iucv = iucv_sk(sk);

	sock_init_data(sock, sk);
	INIT_LIST_HEAD(&iucv->accept_q);
	spin_lock_init(&iucv->accept_q_lock);
	skb_queue_head_init(&iucv->send_skb_q);
	INIT_LIST_HEAD(&iucv->message_q.list);
	spin_lock_init(&iucv->message_q.lock);
	skb_queue_head_init(&iucv->backlog_skb_q);
	iucv->send_tag = 0;
	atomic_set(&iucv->pendings, 0);
	iucv->flags = 0;
	iucv->msglimit = 0;
	atomic_set(&iucv->skbs_in_xmit, 0);
	atomic_set(&iucv->msg_sent, 0);
	atomic_set(&iucv->msg_recv, 0);
	iucv->path = NULL;
	iucv->sk_txnotify = afiucv_hs_callback_txnotify;
	memset(&iucv->init, 0, sizeof(iucv->init));
	if (pr_iucv)
		iucv->transport = AF_IUCV_TRANS_IUCV;
	else
		iucv->transport = AF_IUCV_TRANS_HIPER;

	sk->sk_destruct = iucv_sock_destruct;
	sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;

	sock_reset_flag(sk, SOCK_ZAPPED);

	sk->sk_protocol = proto;
	sk->sk_state	= IUCV_OPEN;

	iucv_sock_link(&iucv_sk_list, sk);
	return sk;
}

static void iucv_accept_enqueue(struct sock *parent, struct sock *sk)
{
	unsigned long flags;
	struct iucv_sock *par = iucv_sk(parent);

	sock_hold(sk);
	spin_lock_irqsave(&par->accept_q_lock, flags);
	list_add_tail(&iucv_sk(sk)->accept_q, &par->accept_q);
	spin_unlock_irqrestore(&par->accept_q_lock, flags);
	iucv_sk(sk)->parent = parent;
	sk_acceptq_added(parent);
}

static void iucv_accept_unlink(struct sock *sk)
{
	unsigned long flags;
	struct iucv_sock *par = iucv_sk(iucv_sk(sk)->parent);

	spin_lock_irqsave(&par->accept_q_lock, flags);
	list_del_init(&iucv_sk(sk)->accept_q);
	spin_unlock_irqrestore(&par->accept_q_lock, flags);
	sk_acceptq_removed(iucv_sk(sk)->parent);
	iucv_sk(sk)->parent = NULL;
	sock_put(sk);
}

static struct sock *iucv_accept_dequeue(struct sock *parent,
					struct socket *newsock)
{
	struct iucv_sock *isk, *n;
	struct sock *sk;

	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
		sk = (struct sock *) isk;
		lock_sock(sk);

		if (sk->sk_state == IUCV_CLOSED) {
			iucv_accept_unlink(sk);
			release_sock(sk);
			continue;
		}

		if (sk->sk_state == IUCV_CONNECTED ||
		    sk->sk_state == IUCV_DISCONN ||
		    !newsock) {
			iucv_accept_unlink(sk);
			if (newsock)
				sock_graft(sk, newsock);

			release_sock(sk);
			return sk;
		}

		release_sock(sk);
	}
	return NULL;
}

static void __iucv_auto_name(struct iucv_sock *iucv)
{
	char name[12];

	sprintf(name, "%08x", atomic_inc_return(&iucv_sk_list.autobind_name));
	while (__iucv_get_sock_by_name(name)) {
		sprintf(name, "%08x",
			atomic_inc_return(&iucv_sk_list.autobind_name));
	}
	memcpy(iucv->src_name, name, 8);
}

/* Bind an unbound socket */
static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
			  int addr_len)
{
	DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
	char uid[sizeof(sa->siucv_user_id)];
	struct sock *sk = sock->sk;
	struct iucv_sock *iucv;
	int err = 0;
	struct net_device *dev;

	/* Verify the input sockaddr */
	if (addr_len < sizeof(struct sockaddr_iucv) ||
	    addr->sa_family != AF_IUCV)
		return -EINVAL;

	lock_sock(sk);
	if (sk->sk_state != IUCV_OPEN) {
		err = -EBADFD;
		goto done;
	}

	write_lock_bh(&iucv_sk_list.lock);

	iucv = iucv_sk(sk);
	if (__iucv_get_sock_by_name(sa->siucv_name)) {
		err = -EADDRINUSE;
		goto done_unlock;
	}
	if (iucv->path)
		goto done_unlock;

	/* Bind the socket */
	if (pr_iucv)
		if (!memcmp(sa->siucv_user_id, iucv_userid, 8))
			goto vm_bind; /* VM IUCV transport */

	/* try hiper transport */
	memcpy(uid, sa->siucv_user_id, sizeof(uid));
	ASCEBC(uid, 8);
	rcu_read_lock();
	for_each_netdev_rcu(&init_net, dev) {
		if (!memcmp(dev->perm_addr, uid, 8)) {
			memcpy(iucv->src_user_id, sa->siucv_user_id, 8);
			/* Check for uninitialized siucv_name */
			if (strncmp(sa->siucv_name, "        ", 8) == 0)
				__iucv_auto_name(iucv);
			else
				memcpy(iucv->src_name, sa->siucv_name, 8);
			sk->sk_bound_dev_if = dev->ifindex;
			iucv->hs_dev = dev;
			dev_hold(dev);
			sk->sk_state = IUCV_BOUND;
			iucv->transport = AF_IUCV_TRANS_HIPER;
			if (!iucv->msglimit)
				iucv->msglimit = IUCV_HIPER_MSGLIM_DEFAULT;
			rcu_read_unlock();
			goto done_unlock;
		}
	}
	rcu_read_unlock();
vm_bind:
	if (pr_iucv) {
		/* use local userid for backward compat */
		memcpy(iucv->src_name, sa->siucv_name, 8);
		memcpy(iucv->src_user_id, iucv_userid, 8);
		sk->sk_state = IUCV_BOUND;
		iucv->transport = AF_IUCV_TRANS_IUCV;
		sk->sk_allocation |= GFP_DMA;
		if (!iucv->msglimit)
			iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
		goto done_unlock;
	}
	/* found no dev to bind */
	err = -ENODEV;
done_unlock:
	/* Release the socket list lock */
	write_unlock_bh(&iucv_sk_list.lock);
done:
	release_sock(sk);
	return err;
}

/* Automatically bind an unbound socket */
static int iucv_sock_autobind(struct sock *sk)
{
	struct iucv_sock *iucv = iucv_sk(sk);
	int err = 0;

	if (unlikely(!pr_iucv))
		return -EPROTO;

	memcpy(iucv->src_user_id, iucv_userid, 8);
	iucv->transport = AF_IUCV_TRANS_IUCV;
	sk->sk_allocation |= GFP_DMA;

	write_lock_bh(&iucv_sk_list.lock);
	__iucv_auto_name(iucv);
	write_unlock_bh(&iucv_sk_list.lock);

	if (!iucv->msglimit)
		iucv->msglimit = IUCV_QUEUELEN_DEFAULT;

	return err;
}

static int afiucv_path_connect(struct socket *sock, struct sockaddr *addr)
{
	DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
	struct sock *sk = sock->sk;
	struct iucv_sock *iucv = iucv_sk(sk);
	unsigned char user_data[16];
	int err;

	high_nmcpy(user_data, sa->siucv_name);
	low_nmcpy(user_data, iucv->src_name);
	ASCEBC(user_data, sizeof(user_data));

	/* Create path. */
	iucv->path = iucv_path_alloc(iucv->msglimit,
				     IUCV_IPRMDATA, GFP_KERNEL);
	if (!iucv->path) {
		err = -ENOMEM;
		goto done;
	}
	err = pr_iucv->path_connect(iucv->path, &af_iucv_handler,
				    sa->siucv_user_id, NULL, user_data,
				    sk);
	if (err) {
		iucv_path_free(iucv->path);
		iucv->path = NULL;
		switch (err) {
		case 0x0b:	/* Target communicator is not logged on */
			err = -ENETUNREACH;
			break;
		case 0x0d:	/* Max connections for this guest exceeded */
		case 0x0e:	/* Max connections for target guest exceeded */
			err = -EAGAIN;
			break;
		case 0x0f:	/* Missing IUCV authorization */
			err = -EACCES;
			break;
		default:
			err = -ECONNREFUSED;
			break;
		}
	}
done:
	return err;
}

/* Connect an unconnected socket */
static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
			     int alen, int flags)
{
	DECLARE_SOCKADDR(struct sockaddr_iucv *, sa, addr);
	struct sock *sk = sock->sk;
	struct iucv_sock *iucv = iucv_sk(sk);
	int err;

	if (alen < sizeof(struct sockaddr_iucv) || addr->sa_family != AF_IUCV)
		return -EINVAL;

	if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
		return -EBADFD;

	if (sk->sk_state == IUCV_OPEN &&
	    iucv->transport == AF_IUCV_TRANS_HIPER)
		return -EBADFD; /* explicit bind required */

	if (sk->sk_type != SOCK_STREAM && sk->sk_type != SOCK_SEQPACKET)
		return -EINVAL;

	if (sk->sk_state == IUCV_OPEN) {
		err = iucv_sock_autobind(sk);
		if (unlikely(err))
			return err;
	}

	lock_sock(sk);

	/* Set the destination information */
	memcpy(iucv->dst_user_id, sa->siucv_user_id, 8);
	memcpy(iucv->dst_name, sa->siucv_name, 8);

	if (iucv->transport == AF_IUCV_TRANS_HIPER)
		err = iucv_send_ctrl(sock->sk, AF_IUCV_FLAG_SYN);
	else
		err = afiucv_path_connect(sock, addr);
	if (err)
		goto done;

	if (sk->sk_state != IUCV_CONNECTED)
		err = iucv_sock_wait(sk, iucv_sock_in_state(sk, IUCV_CONNECTED,
							    IUCV_DISCONN),
				     sock_sndtimeo(sk, flags & O_NONBLOCK));

	if (sk->sk_state == IUCV_DISCONN || sk->sk_state == IUCV_CLOSED)
		err = -ECONNREFUSED;

	if (err && iucv->transport == AF_IUCV_TRANS_IUCV)
		iucv_sever_path(sk, 0);

done:
	release_sock(sk);
	return err;
}

/* Move a socket into listening state. */
static int iucv_sock_listen(struct socket *sock, int backlog)
{
	struct sock *sk = sock->sk;
	int err;

	lock_sock(sk);

	err = -EINVAL;
	if (sk->sk_state != IUCV_BOUND)
		goto done;

	if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
		goto done;

	sk->sk_max_ack_backlog = backlog;
	sk->sk_ack_backlog = 0;
	sk->sk_state = IUCV_LISTEN;
	err = 0;

done:
	release_sock(sk);
	return err;
}

/* Accept a pending connection */
static int iucv_sock_accept(struct socket *sock, struct socket *newsock,
			    int flags, bool kern)
{
	DECLARE_WAITQUEUE(wait, current);
	struct sock *sk = sock->sk, *nsk;
	long timeo;
	int err = 0;

	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);

	if (sk->sk_state != IUCV_LISTEN) {
		err = -EBADFD;
		goto done;
	}

	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);

	/* Wait for an incoming connection */
	add_wait_queue_exclusive(sk_sleep(sk), &wait);
	while (!(nsk = iucv_accept_dequeue(sk, newsock))) {
		set_current_state(TASK_INTERRUPTIBLE);
		if (!timeo) {
			err = -EAGAIN;
			break;
		}

		release_sock(sk);
		timeo = schedule_timeout(timeo);
		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);

		if (sk->sk_state != IUCV_LISTEN) {
			err = -EBADFD;
			break;
		}

		if (signal_pending(current)) {
			err = sock_intr_errno(timeo);
			break;
		}
	}

	set_current_state(TASK_RUNNING);
	remove_wait_queue(sk_sleep(sk), &wait);

	if (err)
		goto done;

	newsock->state = SS_CONNECTED;

done:
	release_sock(sk);
	return err;
}

static int iucv_sock_getname(struct socket *sock, struct sockaddr *addr,
			     int peer)
{
	DECLARE_SOCKADDR(struct sockaddr_iucv *, siucv, addr);
	struct sock *sk = sock->sk;
	struct iucv_sock *iucv = iucv_sk(sk);

	addr->sa_family = AF_IUCV;

	if (peer) {
		memcpy(siucv->siucv_user_id, iucv->dst_user_id, 8);
		memcpy(siucv->siucv_name, iucv->dst_name, 8);
	} else {
		memcpy(siucv->siucv_user_id, iucv->src_user_id, 8);
		memcpy(siucv->siucv_name, iucv->src_name, 8);
	}
	memset(&siucv->siucv_port, 0, sizeof(siucv->siucv_port));
	memset(&siucv->siucv_addr, 0, sizeof(siucv->siucv_addr));
	memset(&siucv->siucv_nodeid, 0, sizeof(siucv->siucv_nodeid));

	return sizeof(struct sockaddr_iucv);
}

/**
 * iucv_send_iprm() - Send socket data in parameter list of an iucv message.
 * @path:	IUCV path
 * @msg:	Pointer to a struct iucv_message
 * @skb:	The socket data to send, skb->len MUST BE <= 7
 *
 * Send the socket data in the parameter list in the iucv message
 * (IUCV_IPRMDATA). The socket data is stored at index 0 to 6 in the parameter
 * list and the socket data len at index 7 (last byte).
 * See also iucv_msg_length().
 *
 * Returns the error code from the iucv_message_send() call.
 */
static int iucv_send_iprm(struct iucv_path *path, struct iucv_message *msg,
			  struct sk_buff *skb)
{
	u8 prmdata[8];

	memcpy(prmdata, (void *) skb->data, skb->len);
	prmdata[7] = 0xff - (u8) skb->len;
	return pr_iucv->message_send(path, msg, IUCV_IPRMDATA, 0,
				 (void *) prmdata, 8);
}

static int iucv_sock_sendmsg(struct socket *sock, struct msghdr *msg,
			     size_t len)
{
	struct sock *sk = sock->sk;
	struct iucv_sock *iucv = iucv_sk(sk);
	size_t headroom = 0;
	size_t linear;
	struct sk_buff *skb;
	struct iucv_message txmsg = {0};
	struct cmsghdr *cmsg;
	int cmsg_done;
	long timeo;
	char user_id[9];
	char appl_id[9];
	int err;
	int noblock = msg->msg_flags & MSG_DONTWAIT;

	err = sock_error(sk);
	if (err)
		return err;

	if (msg->msg_flags & MSG_OOB)
		return -EOPNOTSUPP;

	/* SOCK_SEQPACKET: we do not support segmented records */
	if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
		return -EOPNOTSUPP;

	lock_sock(sk);

	if (sk->sk_shutdown & SEND_SHUTDOWN) {
		err = -EPIPE;
		goto out;
	}

	/* Return if the socket is not in connected state */
	if (sk->sk_state != IUCV_CONNECTED) {
		err = -ENOTCONN;
		goto out;
	}

	/* initialize defaults */
	cmsg_done   = 0;	/* check for duplicate headers */

	/* iterate over control messages */
	for_each_cmsghdr(cmsg, msg) {
		if (!CMSG_OK(msg, cmsg)) {
			err = -EINVAL;
			goto out;
		}

		if (cmsg->cmsg_level != SOL_IUCV)
			continue;

		if (cmsg->cmsg_type & cmsg_done) {
			err = -EINVAL;
			goto out;
		}
		cmsg_done |= cmsg->cmsg_type;

		switch (cmsg->cmsg_type) {
		case SCM_IUCV_TRGCLS:
			if (cmsg->cmsg_len != CMSG_LEN(TRGCLS_SIZE)) {
				err = -EINVAL;
				goto out;
			}

			/* set iucv message target class */
			memcpy(&txmsg.class,
				(void *) CMSG_DATA(cmsg), TRGCLS_SIZE);

			break;

		default:
			err = -EINVAL;
			goto out;
		}
	}

	/* allocate one skb for each iucv message:
	 * this is fine for SOCK_SEQPACKET (unless we want to support
	 * segmented records using the MSG_EOR flag), but
	 * for SOCK_STREAM we might want to improve it in future */
	if (iucv->transport == AF_IUCV_TRANS_HIPER) {
		headroom = sizeof(struct af_iucv_trans_hdr) +
			   LL_RESERVED_SPACE(iucv->hs_dev);
		linear = min(len, PAGE_SIZE - headroom);
	} else {
		if (len < PAGE_SIZE) {
			linear = len;
		} else {
			/* In nonlinear "classic" iucv skb,
			 * reserve space for iucv_array
			 */
			headroom = sizeof(struct iucv_array) *
				   (MAX_SKB_FRAGS + 1);
			linear = PAGE_SIZE - headroom;
		}
	}
	skb = sock_alloc_send_pskb(sk, headroom + linear, len - linear,
				   noblock, &err, 0);
	if (!skb)
		goto out;
	if (headroom)
		skb_reserve(skb, headroom);
	skb_put(skb, linear);
	skb->len = len;
	skb->data_len = len - linear;
	err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, len);
	if (err)
		goto fail;

	/* wait if outstanding messages for iucv path has reached */
	timeo = sock_sndtimeo(sk, noblock);
	err = iucv_sock_wait(sk, iucv_below_msglim(sk), timeo);
	if (err)
		goto fail;

	/* return -ECONNRESET if the socket is no longer connected */
	if (sk->sk_state != IUCV_CONNECTED) {
		err = -ECONNRESET;
		goto fail;
	}

	/* increment and save iucv message tag for msg_completion cbk */
	txmsg.tag = iucv->send_tag++;
	IUCV_SKB_CB(skb)->tag = txmsg.tag;

	if (iucv->transport == AF_IUCV_TRANS_HIPER) {
		atomic_inc(&iucv->msg_sent);
		err = afiucv_hs_send(&txmsg, sk, skb, 0);
		if (err) {
			atomic_dec(&iucv->msg_sent);
			goto out;
		}
	} else { /* Classic VM IUCV transport */
		skb_queue_tail(&iucv->send_skb_q, skb);
		atomic_inc(&iucv->skbs_in_xmit);

		if (((iucv->path->flags & IUCV_IPRMDATA) & iucv->flags) &&
		    skb->len <= 7) {
			err = iucv_send_iprm(iucv->path, &txmsg, skb);

			/* on success: there is no message_complete callback */
			/* for an IPRMDATA msg; remove skb from send queue   */
			if (err == 0) {
				atomic_dec(&iucv->skbs_in_xmit);
				skb_unlink(skb, &iucv->send_skb_q);
				consume_skb(skb);
			}

			/* this error should never happen since the	*/
			/* IUCV_IPRMDATA path flag is set... sever path */
			if (err == 0x15) {
				pr_iucv->path_sever(iucv->path, NULL);
				atomic_dec(&iucv->skbs_in_xmit);
				skb_unlink(skb, &iucv->send_skb_q);
				err = -EPIPE;
				goto fail;
			}
		} else if (skb_is_nonlinear(skb)) {
			struct iucv_array *iba = (struct iucv_array *)skb->head;
			int i;

			/* skip iucv_array lying in the headroom */
			iba[0].address = (u32)(addr_t)skb->data;
			iba[0].length = (u32)skb_headlen(skb);
			for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
				skb_frag_t *frag = &skb_shinfo(skb)->frags[i];

				iba[i + 1].address =
					(u32)(addr_t)skb_frag_address(frag);
				iba[i + 1].length = (u32)skb_frag_size(frag);
			}
			err = pr_iucv->message_send(iucv->path, &txmsg,
						    IUCV_IPBUFLST, 0,
						    (void *)iba, skb->len);
		} else { /* non-IPRM Linear skb */
			err = pr_iucv->message_send(iucv->path, &txmsg,
					0, 0, (void *)skb->data, skb->len);
		}
		if (err) {
			if (err == 3) {
				user_id[8] = 0;
				memcpy(user_id, iucv->dst_user_id, 8);
				appl_id[8] = 0;
				memcpy(appl_id, iucv->dst_name, 8);
				pr_err(
		"Application %s on z/VM guest %s exceeds message limit\n",
					appl_id, user_id);
				err = -EAGAIN;
			} else {
				err = -EPIPE;
			}

			atomic_dec(&iucv->skbs_in_xmit);
			skb_unlink(skb, &iucv->send_skb_q);
			goto fail;
		}
	}

	release_sock(sk);
	return len;

fail:
	kfree_skb(skb);
out:
	release_sock(sk);
	return err;
}

static struct sk_buff *alloc_iucv_recv_skb(unsigned long len)
{
	size_t headroom, linear;
	struct sk_buff *skb;
	int err;

	if (len < PAGE_SIZE) {
		headroom = 0;
		linear = len;
	} else {
		headroom = sizeof(struct iucv_array) * (MAX_SKB_FRAGS + 1);
		linear = PAGE_SIZE - headroom;
	}
	skb = alloc_skb_with_frags(headroom + linear, len - linear,
				   0, &err, GFP_ATOMIC | GFP_DMA);
	WARN_ONCE(!skb,
		  "alloc of recv iucv skb len=%lu failed with errcode=%d\n",
		  len, err);
	if (skb) {
		if (headroom)
			skb_reserve(skb, headroom);
		skb_put(skb, linear);
		skb->len = len;
		skb->data_len = len - linear;
	}
	return skb;
}

/* iucv_process_message() - Receive a single outstanding IUCV message
 *
 * Locking: must be called with message_q.lock held
 */
static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
				 struct iucv_path *path,
				 struct iucv_message *msg)
{
	int rc;
	unsigned int len;

	len = iucv_msg_length(msg);

	/* store msg target class in the second 4 bytes of skb ctrl buffer */
	/* Note: the first 4 bytes are reserved for msg tag */
	IUCV_SKB_CB(skb)->class = msg->class;

	/* check for special IPRM messages (e.g. iucv_sock_shutdown) */
	if ((msg->flags & IUCV_IPRMDATA) && len > 7) {
		if (memcmp(msg->rmmsg, iprm_shutdown, 8) == 0) {
			skb->data = NULL;
			skb->len = 0;
		}
	} else {
		if (skb_is_nonlinear(skb)) {
			struct iucv_array *iba = (struct iucv_array *)skb->head;
			int i;

			iba[0].address = (u32)(addr_t)skb->data;
			iba[0].length = (u32)skb_headlen(skb);
			for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
				skb_frag_t *frag = &skb_shinfo(skb)->frags[i];

				iba[i + 1].address =
					(u32)(addr_t)skb_frag_address(frag);
				iba[i + 1].length = (u32)skb_frag_size(frag);
			}
			rc = pr_iucv->message_receive(path, msg,
					      IUCV_IPBUFLST,
					      (void *)iba, len, NULL);
		} else {
			rc = pr_iucv->message_receive(path, msg,
					      msg->flags & IUCV_IPRMDATA,
					      skb->data, len, NULL);
		}
		if (rc) {
			kfree_skb(skb);
			return;
		}
		WARN_ON_ONCE(skb->len != len);
	}

	IUCV_SKB_CB(skb)->offset = 0;
	if (sk_filter(sk, skb)) {
		atomic_inc(&sk->sk_drops);	/* skb rejected by filter */
		kfree_skb(skb);
		return;
	}
	if (__sock_queue_rcv_skb(sk, skb))	/* handle rcv queue full */
		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
}

/* iucv_process_message_q() - Process outstanding IUCV messages
 *
 * Locking: must be called with message_q.lock held
 */
static void iucv_process_message_q(struct sock *sk)
{
	struct iucv_sock *iucv = iucv_sk(sk);
	struct sk_buff *skb;
	struct sock_msg_q *p, *n;

	list_for_each_entry_safe(p, n, &iucv->message_q.list, list) {
		skb = alloc_iucv_recv_skb(iucv_msg_length(&p->msg));
		if (!skb)
			break;
		iucv_process_message(sk, skb, p->path, &p->msg);
		list_del(&p->list);
		kfree(p);
		if (!skb_queue_empty(&iucv->backlog_skb_q))
			break;
	}
}

static int iucv_sock_recvmsg(struct socket *sock, struct msghdr *msg,
			     size_t len, int flags)
{
	int noblock = flags & MSG_DONTWAIT;
	struct sock *sk = sock->sk;
	struct iucv_sock *iucv = iucv_sk(sk);
	unsigned int copied, rlen;
	struct sk_buff *skb, *rskb, *cskb;
	int err = 0;
	u32 offset;

	if ((sk->sk_state == IUCV_DISCONN) &&
	    skb_queue_empty(&iucv->backlog_skb_q) &&
	    skb_queue_empty(&sk->sk_receive_queue) &&
	    list_empty(&iucv->message_q.list))
		return 0;

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

	/* receive/dequeue next skb:
	 * the function understands MSG_PEEK and, thus, does not dequeue skb */
	skb = skb_recv_datagram(sk, flags, noblock, &err);
	if (!skb) {
		if (sk->sk_shutdown & RCV_SHUTDOWN)
			return 0;
		return err;
	}

	offset = IUCV_SKB_CB(skb)->offset;
	rlen   = skb->len - offset;		/* real length of skb */
	copied = min_t(unsigned int, rlen, len);
	if (!rlen)
		sk->sk_shutdown = sk->sk_shutdown | RCV_SHUTDOWN;

	cskb = skb;
	if (skb_copy_datagram_msg(cskb, offset, msg, copied)) {
		if (!(flags & MSG_PEEK))
			skb_queue_head(&sk->sk_receive_queue, skb);
		return -EFAULT;
	}

	/* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
	if (sk->sk_type == SOCK_SEQPACKET) {
		if (copied < rlen)
			msg->msg_flags |= MSG_TRUNC;
		/* each iucv message contains a complete record */
		msg->msg_flags |= MSG_EOR;
	}

	/* create control message to store iucv msg target class:
	 * get the trgcls from the control buffer of the skb due to
	 * fragmentation of original iucv message. */
	err = put_cmsg(msg, SOL_IUCV, SCM_IUCV_TRGCLS,
		       sizeof(IUCV_SKB_CB(skb)->class),
		       (void *)&IUCV_SKB_CB(skb)->class);
	if (err) {
		if (!(flags & MSG_PEEK))
			skb_queue_head(&sk->sk_receive_queue, skb);
		return err;
	}

	/* Mark read part of skb as used */
	if (!(flags & MSG_PEEK)) {

		/* SOCK_STREAM: re-queue skb if it contains unreceived data */
		if (sk->sk_type == SOCK_STREAM) {
			if (copied < rlen) {
				IUCV_SKB_CB(skb)->offset = offset + copied;
				skb_queue_head(&sk->sk_receive_queue, skb);
				goto done;
			}
		}

		consume_skb(skb);
		if (iucv->transport == AF_IUCV_TRANS_HIPER) {
			atomic_inc(&iucv->msg_recv);
			if (atomic_read(&iucv->msg_recv) > iucv->msglimit) {
				WARN_ON(1);
				iucv_sock_close(sk);
				return -EFAULT;
			}
		}

		/* Queue backlog skbs */
		spin_lock_bh(&iucv->message_q.lock);
		rskb = skb_dequeue(&iucv->backlog_skb_q);
		while (rskb) {
			IUCV_SKB_CB(rskb)->offset = 0;
			if (__sock_queue_rcv_skb(sk, rskb)) {
				/* handle rcv queue full */
				skb_queue_head(&iucv->backlog_skb_q,
						rskb);
				break;
			}
			rskb = skb_dequeue(&iucv->backlog_skb_q);
		}
		if (skb_queue_empty(&iucv->backlog_skb_q)) {
			if (!list_empty(&iucv->message_q.list))
				iucv_process_message_q(sk);
			if (atomic_read(&iucv->msg_recv) >=
							iucv->msglimit / 2) {
				err = iucv_send_ctrl(sk, AF_IUCV_FLAG_WIN);
				if (err) {
					sk->sk_state = IUCV_DISCONN;
					sk->sk_state_change(sk);
				}
			}
		}
		spin_unlock_bh(&iucv->message_q.lock);
	}

done:
	/* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
	if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
		copied = rlen;

	return copied;
}

static inline __poll_t iucv_accept_poll(struct sock *parent)
{
	struct iucv_sock *isk, *n;
	struct sock *sk;

	list_for_each_entry_safe(isk, n, &iucv_sk(parent)->accept_q, accept_q) {
		sk = (struct sock *) isk;

		if (sk->sk_state == IUCV_CONNECTED)
			return EPOLLIN | EPOLLRDNORM;
	}

	return 0;
}

static __poll_t iucv_sock_poll(struct file *file, struct socket *sock,
			       poll_table *wait)
{
	struct sock *sk = sock->sk;
	__poll_t mask = 0;

	sock_poll_wait(file, sock, wait);

	if (sk->sk_state == IUCV_LISTEN)
		return iucv_accept_poll(sk);

	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
		mask |= EPOLLERR |
			(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);

	if (sk->sk_shutdown & RCV_SHUTDOWN)
		mask |= EPOLLRDHUP;

	if (sk->sk_shutdown == SHUTDOWN_MASK)
		mask |= EPOLLHUP;

	if (!skb_queue_empty(&sk->sk_receive_queue) ||
	    (sk->sk_shutdown & RCV_SHUTDOWN))
		mask |= EPOLLIN | EPOLLRDNORM;

	if (sk->sk_state == IUCV_CLOSED)
		mask |= EPOLLHUP;

	if (sk->sk_state == IUCV_DISCONN)
		mask |= EPOLLIN;

	if (sock_writeable(sk) && iucv_below_msglim(sk))
		mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
	else
		sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);

	return mask;
}

static int iucv_sock_shutdown(struct socket *sock, int how)
{
	struct sock *sk = sock->sk;
	struct iucv_sock *iucv = iucv_sk(sk);
	struct iucv_message txmsg;
	int err = 0;

	how++;

	if ((how & ~SHUTDOWN_MASK) || !how)
		return -EINVAL;

	lock_sock(sk);
	switch (sk->sk_state) {
	case IUCV_LISTEN:
	case IUCV_DISCONN:
	case IUCV_CLOSING:
	case IUCV_CLOSED:
		err = -ENOTCONN;
		goto fail;
	default:
		break;
	}

	if ((how == SEND_SHUTDOWN || how == SHUTDOWN_MASK) &&
	    sk->sk_state == IUCV_CONNECTED) {
		if (iucv->transport == AF_IUCV_TRANS_IUCV) {
			txmsg.class = 0;
			txmsg.tag = 0;
			err = pr_iucv->message_send(iucv->path, &txmsg,
				IUCV_IPRMDATA, 0, (void *) iprm_shutdown, 8);
			if (err) {
				switch (err) {
				case 1:
					err = -ENOTCONN;
					break;
				case 2:
					err = -ECONNRESET;
					break;
				default:
					err = -ENOTCONN;
					break;
				}
			}
		} else
			iucv_send_ctrl(sk, AF_IUCV_FLAG_SHT);
	}

	sk->sk_shutdown |= how;
	if (how == RCV_SHUTDOWN || how == SHUTDOWN_MASK) {
		if ((iucv->transport == AF_IUCV_TRANS_IUCV) &&
		    iucv->path) {
			err = pr_iucv->path_quiesce(iucv->path, NULL);
			if (err)
				err = -ENOTCONN;
/*			skb_queue_purge(&sk->sk_receive_queue); */
		}
		skb_queue_purge(&sk->sk_receive_queue);
	}

	/* Wake up anyone sleeping in poll */
	sk->sk_state_change(sk);

fail:
	release_sock(sk);
	return err;
}

static int iucv_sock_release(struct socket *sock)
{
	struct sock *sk = sock->sk;
	int err = 0;

	if (!sk)
		return 0;

	iucv_sock_close(sk);

	sock_orphan(sk);
	iucv_sock_kill(sk);
	return err;
}

/* getsockopt and setsockopt */
static int iucv_sock_setsockopt(struct socket *sock, int level, int optname,
				sockptr_t optval, unsigned int optlen)
{
	struct sock *sk = sock->sk;
	struct iucv_sock *iucv = iucv_sk(sk);
	int val;
	int rc;

	if (level != SOL_IUCV)
		return -ENOPROTOOPT;

	if (optlen < sizeof(int))
		return -EINVAL;

	if (copy_from_sockptr(&val, optval, sizeof(int)))
		return -EFAULT;

	rc = 0;

	lock_sock(sk);
	switch (optname) {
	case SO_IPRMDATA_MSG:
		if (val)
			iucv->flags |= IUCV_IPRMDATA;
		else
			iucv->flags &= ~IUCV_IPRMDATA;
		break;
	case SO_MSGLIMIT:
		switch (sk->sk_state) {
		case IUCV_OPEN:
		case IUCV_BOUND:
			if (val < 1 || val > U16_MAX)
				rc = -EINVAL;
			else
				iucv->msglimit = val;
			break;
		default:
			rc = -EINVAL;
			break;
		}
		break;
	default:
		rc = -ENOPROTOOPT;
		break;
	}
	release_sock(sk);

	return rc;
}

static int iucv_sock_getsockopt(struct socket *sock, int level, int optname,
				char __user *optval, int __user *optlen)
{
	struct sock *sk = sock->sk;
	struct iucv_sock *iucv = iucv_sk(sk);
	unsigned int val;
	int len;

	if (level != SOL_IUCV)
		return -ENOPROTOOPT;

	if (get_user(len, optlen))
		return -EFAULT;

	if (len < 0)
		return -EINVAL;

	len = min_t(unsigned int, len, sizeof(int));

	switch (optname) {
	case SO_IPRMDATA_MSG:
		val = (iucv->flags & IUCV_IPRMDATA) ? 1 : 0;
		break;
	case SO_MSGLIMIT:
		lock_sock(sk);
		val = (iucv->path != NULL) ? iucv->path->msglim	/* connected */
					   : iucv->msglimit;	/* default */
		release_sock(sk);
		break;
	case SO_MSGSIZE:
		if (sk->sk_state == IUCV_OPEN)
			return -EBADFD;
		val = (iucv->hs_dev) ? iucv->hs_dev->mtu -
				sizeof(struct af_iucv_trans_hdr) - ETH_HLEN :
				0x7fffffff;
		break;
	default:
		return -ENOPROTOOPT;
	}

	if (put_user(len, optlen))
		return -EFAULT;
	if (copy_to_user(optval, &val, len))
		return -EFAULT;

	return 0;
}


/* Callback wrappers - called from iucv base support */
static int iucv_callback_connreq(struct iucv_path *path,
				 u8 ipvmid[8], u8 ipuser[16])
{
	unsigned char user_data[16];
	unsigned char nuser_data[16];
	unsigned char src_name[8];
	struct sock *sk, *nsk;
	struct iucv_sock *iucv, *niucv;
	int err;

	memcpy(src_name, ipuser, 8);
	EBCASC(src_name, 8);
	/* Find out if this path belongs to af_iucv. */
	read_lock(&iucv_sk_list.lock);
	iucv = NULL;
	sk = NULL;
	sk_for_each(sk, &iucv_sk_list.head)
		if (sk->sk_state == IUCV_LISTEN &&
		    !memcmp(&iucv_sk(sk)->src_name, src_name, 8)) {
			/*
			 * Found a listening socket with
			 * src_name == ipuser[0-7].
			 */
			iucv = iucv_sk(sk);
			break;
		}
	read_unlock(&iucv_sk_list.lock);
	if (!iucv)
		/* No socket found, not one of our paths. */
		return -EINVAL;

	bh_lock_sock(sk);

	/* Check if parent socket is listening */
	low_nmcpy(user_data, iucv->src_name);
	high_nmcpy(user_data, iucv->dst_name);
	ASCEBC(user_data, sizeof(user_data));
	if (sk->sk_state != IUCV_LISTEN) {
		err = pr_iucv->path_sever(path, user_data);
		iucv_path_free(path);
		goto fail;
	}

	/* Check for backlog size */
	if (sk_acceptq_is_full(sk)) {
		err = pr_iucv->path_sever(path, user_data);
		iucv_path_free(path);
		goto fail;
	}

	/* Create the new socket */
	nsk = iucv_sock_alloc(NULL, sk->sk_protocol, GFP_ATOMIC, 0);
	if (!nsk) {
		err = pr_iucv->path_sever(path, user_data);
		iucv_path_free(path);
		goto fail;
	}

	niucv = iucv_sk(nsk);
	iucv_sock_init(nsk, sk);
	niucv->transport = AF_IUCV_TRANS_IUCV;
	nsk->sk_allocation |= GFP_DMA;

	/* Set the new iucv_sock */
	memcpy(niucv->dst_name, ipuser + 8, 8);
	EBCASC(niucv->dst_name, 8);
	memcpy(niucv->dst_user_id, ipvmid, 8);
	memcpy(niucv->src_name, iucv->src_name, 8);
	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
	niucv->path = path;

	/* Call iucv_accept */
	high_nmcpy(nuser_data, ipuser + 8);
	memcpy(nuser_data + 8, niucv->src_name, 8);
	ASCEBC(nuser_data + 8, 8);

	/* set message limit for path based on msglimit of accepting socket */
	niucv->msglimit = iucv->msglimit;
	path->msglim = iucv->msglimit;
	err = pr_iucv->path_accept(path, &af_iucv_handler, nuser_data, nsk);
	if (err) {
		iucv_sever_path(nsk, 1);
		iucv_sock_kill(nsk);
		goto fail;
	}

	iucv_accept_enqueue(sk, nsk);

	/* Wake up accept */
	nsk->sk_state = IUCV_CONNECTED;
	sk->sk_data_ready(sk);
	err = 0;
fail:
	bh_unlock_sock(sk);
	return 0;
}

static void iucv_callback_connack(struct iucv_path *path, u8 ipuser[16])
{
	struct sock *sk = path->private;

	sk->sk_state = IUCV_CONNECTED;
	sk->sk_state_change(sk);
}

static void iucv_callback_rx(struct iucv_path *path, struct iucv_message *msg)
{
	struct sock *sk = path->private;
	struct iucv_sock *iucv = iucv_sk(sk);
	struct sk_buff *skb;
	struct sock_msg_q *save_msg;
	int len;

	if (sk->sk_shutdown & RCV_SHUTDOWN) {
		pr_iucv->message_reject(path, msg);
		return;
	}

	spin_lock(&iucv->message_q.lock);

	if (!list_empty(&iucv->message_q.list) ||
	    !skb_queue_empty(&iucv->backlog_skb_q))
		goto save_message;

	len = atomic_read(&sk->sk_rmem_alloc);
	len += SKB_TRUESIZE(iucv_msg_length(msg));
	if (len > sk->sk_rcvbuf)
		goto save_message;

	skb = alloc_iucv_recv_skb(iucv_msg_length(msg));
	if (!skb)
		goto save_message;

	iucv_process_message(sk, skb, path, msg);
	goto out_unlock;

save_message:
	save_msg = kzalloc(sizeof(struct sock_msg_q), GFP_ATOMIC | GFP_DMA);
	if (!save_msg)
		goto out_unlock;
	save_msg->path = path;
	save_msg->msg = *msg;

	list_add_tail(&save_msg->list, &iucv->message_q.list);

out_unlock:
	spin_unlock(&iucv->message_q.lock);
}

static void iucv_callback_txdone(struct iucv_path *path,
				 struct iucv_message *msg)
{
	struct sock *sk = path->private;
	struct sk_buff *this = NULL;
	struct sk_buff_head *list;
	struct sk_buff *list_skb;
	struct iucv_sock *iucv;
	unsigned long flags;

	iucv = iucv_sk(sk);
	list = &iucv->send_skb_q;

	bh_lock_sock(sk);

	spin_lock_irqsave(&list->lock, flags);
	skb_queue_walk(list, list_skb) {
		if (msg->tag == IUCV_SKB_CB(list_skb)->tag) {
			this = list_skb;
			break;
		}
	}
	if (this) {
		atomic_dec(&iucv->skbs_in_xmit);
		__skb_unlink(this, list);
	}

	spin_unlock_irqrestore(&list->lock, flags);

	if (this) {
		consume_skb(this);
		/* wake up any process waiting for sending */
		iucv_sock_wake_msglim(sk);
	}

	if (sk->sk_state == IUCV_CLOSING) {
		if (atomic_read(&iucv->skbs_in_xmit) == 0) {
			sk->sk_state = IUCV_CLOSED;
			sk->sk_state_change(sk);
		}
	}
	bh_unlock_sock(sk);

}

static void iucv_callback_connrej(struct iucv_path *path, u8 ipuser[16])
{
	struct sock *sk = path->private;

	if (sk->sk_state == IUCV_CLOSED)
		return;

	bh_lock_sock(sk);
	iucv_sever_path(sk, 1);
	sk->sk_state = IUCV_DISCONN;

	sk->sk_state_change(sk);
	bh_unlock_sock(sk);
}

/* called if the other communication side shuts down its RECV direction;
 * in turn, the callback sets SEND_SHUTDOWN to disable sending of data.
 */
static void iucv_callback_shutdown(struct iucv_path *path, u8 ipuser[16])
{
	struct sock *sk = path->private;

	bh_lock_sock(sk);
	if (sk->sk_state != IUCV_CLOSED) {
		sk->sk_shutdown |= SEND_SHUTDOWN;
		sk->sk_state_change(sk);
	}
	bh_unlock_sock(sk);
}

static struct iucv_handler af_iucv_handler = {
	.path_pending		= iucv_callback_connreq,
	.path_complete		= iucv_callback_connack,
	.path_severed		= iucv_callback_connrej,
	.message_pending	= iucv_callback_rx,
	.message_complete	= iucv_callback_txdone,
	.path_quiesced		= iucv_callback_shutdown,
};

/***************** HiperSockets transport callbacks ********************/
static void afiucv_swap_src_dest(struct sk_buff *skb)
{
	struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
	char tmpID[8];
	char tmpName[8];

	ASCEBC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
	ASCEBC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
	ASCEBC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
	ASCEBC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
	memcpy(tmpID, trans_hdr->srcUserID, 8);
	memcpy(tmpName, trans_hdr->srcAppName, 8);
	memcpy(trans_hdr->srcUserID, trans_hdr->destUserID, 8);
	memcpy(trans_hdr->srcAppName, trans_hdr->destAppName, 8);
	memcpy(trans_hdr->destUserID, tmpID, 8);
	memcpy(trans_hdr->destAppName, tmpName, 8);
	skb_push(skb, ETH_HLEN);
	memset(skb->data, 0, ETH_HLEN);
}

/*
 * afiucv_hs_callback_syn - react on received SYN
 */
static int afiucv_hs_callback_syn(struct sock *sk, struct sk_buff *skb)
{
	struct af_iucv_trans_hdr *trans_hdr = iucv_trans_hdr(skb);
	struct sock *nsk;
	struct iucv_sock *iucv, *niucv;
	int err;

	iucv = iucv_sk(sk);
	if (!iucv) {
		/* no sock - connection refused */
		afiucv_swap_src_dest(skb);
		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
		err = dev_queue_xmit(skb);
		goto out;
	}

	nsk = iucv_sock_alloc(NULL, sk->sk_protocol, GFP_ATOMIC, 0);
	bh_lock_sock(sk);
	if ((sk->sk_state != IUCV_LISTEN) ||
	    sk_acceptq_is_full(sk) ||
	    !nsk) {
		/* error on server socket - connection refused */
		afiucv_swap_src_dest(skb);
		trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN;
		err = dev_queue_xmit(skb);
		iucv_sock_kill(nsk);
		bh_unlock_sock(sk);
		goto out;
	}

	niucv = iucv_sk(nsk);
	iucv_sock_init(nsk, sk);
	niucv->transport = AF_IUCV_TRANS_HIPER;
	niucv->msglimit = iucv->msglimit;
	if (!trans_hdr->window)
		niucv->msglimit_peer = IUCV_HIPER_MSGLIM_DEFAULT;
	else
		niucv->msglimit_peer = trans_hdr->window;
	memcpy(niucv->dst_name, trans_hdr->srcAppName, 8);
	memcpy(niucv->dst_user_id, trans_hdr->srcUserID, 8);
	memcpy(niucv->src_name, iucv->src_name, 8);
	memcpy(niucv->src_user_id, iucv->src_user_id, 8);
	nsk->sk_bound_dev_if = sk->sk_bound_dev_if;
	niucv->hs_dev = iucv->hs_dev;
	dev_hold(niucv->hs_dev);
	afiucv_swap_src_dest(skb);
	trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK;
	trans_hdr->window = niucv->msglimit;
	/* if receiver acks the xmit connection is established */
	err = dev_queue_xmit(skb);
	if (!err) {
		iucv_accept_enqueue(sk, nsk);
		nsk->sk_state = IUCV_CONNECTED;
		sk->sk_data_ready(sk);
	} else
		iucv_sock_kill(nsk);
	bh_unlock_sock(sk);

out:
	return NET_RX_SUCCESS;
}

/*
 * afiucv_hs_callback_synack() - react on received SYN-ACK
 */
static int afiucv_hs_callback_synack(struct sock *sk, struct sk_buff *skb)
{
	struct iucv_sock *iucv = iucv_sk(sk);

	if (!iucv || sk->sk_state != IUCV_BOUND) {
		kfree_skb(skb);
		return NET_RX_SUCCESS;
	}

	bh_lock_sock(sk);
	iucv->msglimit_peer = iucv_trans_hdr(skb)->window;
	sk->sk_state = IUCV_CONNECTED;
	sk->sk_state_change(sk);
	bh_unlock_sock(sk);
	consume_skb(skb);
	return NET_RX_SUCCESS;
}

/*
 * afiucv_hs_callback_synfin() - react on received SYN_FIN
 */
static int afiucv_hs_callback_synfin(struct sock *sk, struct sk_buff *skb)
{
	struct iucv_sock *iucv = iucv_sk(sk);

	if (!iucv || sk->sk_state != IUCV_BOUND) {
		kfree_skb(skb);
		return NET_RX_SUCCESS;
	}

	bh_lock_sock(sk);
	sk->sk_state = IUCV_DISCONN;
	sk->sk_state_change(sk);
	bh_unlock_sock(sk);
	consume_skb(skb);
	return NET_RX_SUCCESS;
}

/*
 * afiucv_hs_callback_fin() - react on received FIN
 */
static int afiucv_hs_callback_fin(struct sock *sk, struct sk_buff *skb)
{
	struct iucv_sock *iucv = iucv_sk(sk);

	/* other end of connection closed */
	if (!iucv) {
		kfree_skb(skb);
		return NET_RX_SUCCESS;
	}

	bh_lock_sock(sk);
	if (sk->sk_state == IUCV_CONNECTED) {
		sk->sk_state = IUCV_DISCONN;
		sk->sk_state_change(sk);
	}
	bh_unlock_sock(sk);
	consume_skb(skb);
	return NET_RX_SUCCESS;
}

/*
 * afiucv_hs_callback_win() - react on received WIN
 */
static int afiucv_hs_callback_win(struct sock *sk, struct sk_buff *skb)
{
	struct iucv_sock *iucv = iucv_sk(sk);

	if (!iucv)
		return NET_RX_SUCCESS;

	if (sk->sk_state != IUCV_CONNECTED)
		return NET_RX_SUCCESS;

	atomic_sub(iucv_trans_hdr(skb)->window, &iucv->msg_sent);
	iucv_sock_wake_msglim(sk);
	return NET_RX_SUCCESS;
}

/*
 * afiucv_hs_callback_rx() - react on received data
 */
static int afiucv_hs_callback_rx(struct sock *sk, struct sk_buff *skb)
{
	struct iucv_sock *iucv = iucv_sk(sk);

	if (!iucv) {
		kfree_skb(skb);
		return NET_RX_SUCCESS;
	}

	if (sk->sk_state != IUCV_CONNECTED) {
		kfree_skb(skb);
		return NET_RX_SUCCESS;
	}

	if (sk->sk_shutdown & RCV_SHUTDOWN) {
		kfree_skb(skb);
		return NET_RX_SUCCESS;
	}

	/* write stuff from iucv_msg to skb cb */
	skb_pull(skb, sizeof(struct af_iucv_trans_hdr));
	skb_reset_transport_header(skb);
	skb_reset_network_header(skb);
	IUCV_SKB_CB(skb)->offset = 0;
	if (sk_filter(sk, skb)) {
		atomic_inc(&sk->sk_drops);	/* skb rejected by filter */
		kfree_skb(skb);
		return NET_RX_SUCCESS;
	}

	spin_lock(&iucv->message_q.lock);
	if (skb_queue_empty(&iucv->backlog_skb_q)) {
		if (__sock_queue_rcv_skb(sk, skb))
			/* handle rcv queue full */
			skb_queue_tail(&iucv->backlog_skb_q, skb);
	} else
		skb_queue_tail(&iucv_sk(sk)->backlog_skb_q, skb);
	spin_unlock(&iucv->message_q.lock);
	return NET_RX_SUCCESS;
}

/*
 * afiucv_hs_rcv() - base function for arriving data through HiperSockets
 *                   transport
 *                   called from netif RX softirq
 */
static int afiucv_hs_rcv(struct sk_buff *skb, struct net_device *dev,
	struct packet_type *pt, struct net_device *orig_dev)
{
	struct sock *sk;
	struct iucv_sock *iucv;
	struct af_iucv_trans_hdr *trans_hdr;
	int err = NET_RX_SUCCESS;
	char nullstring[8];

	if (!pskb_may_pull(skb, sizeof(*trans_hdr))) {
		kfree_skb(skb);
		return NET_RX_SUCCESS;
	}

	trans_hdr = iucv_trans_hdr(skb);
	EBCASC(trans_hdr->destAppName, sizeof(trans_hdr->destAppName));
	EBCASC(trans_hdr->destUserID, sizeof(trans_hdr->destUserID));
	EBCASC(trans_hdr->srcAppName, sizeof(trans_hdr->srcAppName));
	EBCASC(trans_hdr->srcUserID, sizeof(trans_hdr->srcUserID));
	memset(nullstring, 0, sizeof(nullstring));
	iucv = NULL;
	sk = NULL;
	read_lock(&iucv_sk_list.lock);
	sk_for_each(sk, &iucv_sk_list.head) {
		if (trans_hdr->flags == AF_IUCV_FLAG_SYN) {
			if ((!memcmp(&iucv_sk(sk)->src_name,
				     trans_hdr->destAppName, 8)) &&
			    (!memcmp(&iucv_sk(sk)->src_user_id,
				     trans_hdr->destUserID, 8)) &&
			    (!memcmp(&iucv_sk(sk)->dst_name, nullstring, 8)) &&
			    (!memcmp(&iucv_sk(sk)->dst_user_id,
				     nullstring, 8))) {
				iucv = iucv_sk(sk);
				break;
			}
		} else {
			if ((!memcmp(&iucv_sk(sk)->src_name,
				     trans_hdr->destAppName, 8)) &&
			    (!memcmp(&iucv_sk(sk)->src_user_id,
				     trans_hdr->destUserID, 8)) &&
			    (!memcmp(&iucv_sk(sk)->dst_name,
				     trans_hdr->srcAppName, 8)) &&
			    (!memcmp(&iucv_sk(sk)->dst_user_id,
				     trans_hdr->srcUserID, 8))) {
				iucv = iucv_sk(sk);
				break;
			}
		}
	}
	read_unlock(&iucv_sk_list.lock);
	if (!iucv)
		sk = NULL;

	/* no sock
	how should we send with no sock
	1) send without sock no send rc checking?
	2) introduce default sock to handle this cases

	 SYN -> send SYN|ACK in good case, send SYN|FIN in bad case
	 data -> send FIN
	 SYN|ACK, SYN|FIN, FIN -> no action? */

	switch (trans_hdr->flags) {
	case AF_IUCV_FLAG_SYN:
		/* connect request */
		err = afiucv_hs_callback_syn(sk, skb);
		break;
	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_ACK):
		/* connect request confirmed */
		err = afiucv_hs_callback_synack(sk, skb);
		break;
	case (AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN):
		/* connect request refused */
		err = afiucv_hs_callback_synfin(sk, skb);
		break;
	case (AF_IUCV_FLAG_FIN):
		/* close request */
		err = afiucv_hs_callback_fin(sk, skb);
		break;
	case (AF_IUCV_FLAG_WIN):
		err = afiucv_hs_callback_win(sk, skb);
		if (skb->len == sizeof(struct af_iucv_trans_hdr)) {
			consume_skb(skb);
			break;
		}
		fallthrough;	/* and receive non-zero length data */
	case (AF_IUCV_FLAG_SHT):
		/* shutdown request */
		fallthrough;	/* and receive zero length data */
	case 0:
		/* plain data frame */
		IUCV_SKB_CB(skb)->class = trans_hdr->iucv_hdr.class;
		err = afiucv_hs_callback_rx(sk, skb);
		break;
	default:
		kfree_skb(skb);
	}

	return err;
}

/*
 * afiucv_hs_callback_txnotify() - handle send notifications from HiperSockets
 *                                 transport
 */
static void afiucv_hs_callback_txnotify(struct sock *sk, enum iucv_tx_notify n)
{
	struct iucv_sock *iucv = iucv_sk(sk);

	if (sock_flag(sk, SOCK_ZAPPED))
		return;

	switch (n) {
	case TX_NOTIFY_OK:
		atomic_dec(&iucv->skbs_in_xmit);
		iucv_sock_wake_msglim(sk);
		break;
	case TX_NOTIFY_PENDING:
		atomic_inc(&iucv->pendings);
		break;
	case TX_NOTIFY_DELAYED_OK:
		atomic_dec(&iucv->skbs_in_xmit);
		if (atomic_dec_return(&iucv->pendings) <= 0)
			iucv_sock_wake_msglim(sk);
		break;
	default:
		atomic_dec(&iucv->skbs_in_xmit);
		if (sk->sk_state == IUCV_CONNECTED) {
			sk->sk_state = IUCV_DISCONN;
			sk->sk_state_change(sk);
		}
	}

	if (sk->sk_state == IUCV_CLOSING) {
		if (atomic_read(&iucv->skbs_in_xmit) == 0) {
			sk->sk_state = IUCV_CLOSED;
			sk->sk_state_change(sk);
		}
	}
}

/*
 * afiucv_netdev_event: handle netdev notifier chain events
 */
static int afiucv_netdev_event(struct notifier_block *this,
			       unsigned long event, void *ptr)
{
	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);
	struct sock *sk;
	struct iucv_sock *iucv;

	switch (event) {
	case NETDEV_REBOOT:
	case NETDEV_GOING_DOWN:
		sk_for_each(sk, &iucv_sk_list.head) {
			iucv = iucv_sk(sk);
			if ((iucv->hs_dev == event_dev) &&
			    (sk->sk_state == IUCV_CONNECTED)) {
				if (event == NETDEV_GOING_DOWN)
					iucv_send_ctrl(sk, AF_IUCV_FLAG_FIN);
				sk->sk_state = IUCV_DISCONN;
				sk->sk_state_change(sk);
			}
		}
		break;
	case NETDEV_DOWN:
	case NETDEV_UNREGISTER:
	default:
		break;
	}
	return NOTIFY_DONE;
}

static struct notifier_block afiucv_netdev_notifier = {
	.notifier_call = afiucv_netdev_event,
};

static const struct proto_ops iucv_sock_ops = {
	.family		= PF_IUCV,
	.owner		= THIS_MODULE,
	.release	= iucv_sock_release,
	.bind		= iucv_sock_bind,
	.connect	= iucv_sock_connect,
	.listen		= iucv_sock_listen,
	.accept		= iucv_sock_accept,
	.getname	= iucv_sock_getname,
	.sendmsg	= iucv_sock_sendmsg,
	.recvmsg	= iucv_sock_recvmsg,
	.poll		= iucv_sock_poll,
	.ioctl		= sock_no_ioctl,
	.mmap		= sock_no_mmap,
	.socketpair	= sock_no_socketpair,
	.shutdown	= iucv_sock_shutdown,
	.setsockopt	= iucv_sock_setsockopt,
	.getsockopt	= iucv_sock_getsockopt,
};

static int iucv_sock_create(struct net *net, struct socket *sock, int protocol,
			    int kern)
{
	struct sock *sk;

	if (protocol && protocol != PF_IUCV)
		return -EPROTONOSUPPORT;

	sock->state = SS_UNCONNECTED;

	switch (sock->type) {
	case SOCK_STREAM:
	case SOCK_SEQPACKET:
		/* currently, proto ops can handle both sk types */
		sock->ops = &iucv_sock_ops;
		break;
	default:
		return -ESOCKTNOSUPPORT;
	}

	sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL, kern);
	if (!sk)
		return -ENOMEM;

	iucv_sock_init(sk, NULL);

	return 0;
}

static const struct net_proto_family iucv_sock_family_ops = {
	.family	= AF_IUCV,
	.owner	= THIS_MODULE,
	.create	= iucv_sock_create,
};

static struct packet_type iucv_packet_type = {
	.type = cpu_to_be16(ETH_P_AF_IUCV),
	.func = afiucv_hs_rcv,
};

static int __init afiucv_init(void)
{
	int err;

	if (MACHINE_IS_VM && IS_ENABLED(CONFIG_IUCV)) {
		cpcmd("QUERY USERID", iucv_userid, sizeof(iucv_userid), &err);
		if (unlikely(err)) {
			WARN_ON(err);
			err = -EPROTONOSUPPORT;
			goto out;
		}

		pr_iucv = &iucv_if;
	} else {
		memset(&iucv_userid, 0, sizeof(iucv_userid));
		pr_iucv = NULL;
	}

	err = proto_register(&iucv_proto, 0);
	if (err)
		goto out;
	err = sock_register(&iucv_sock_family_ops);
	if (err)
		goto out_proto;

	if (pr_iucv) {
		err = pr_iucv->iucv_register(&af_iucv_handler, 0);
		if (err)
			goto out_sock;
	}

	err = register_netdevice_notifier(&afiucv_netdev_notifier);
	if (err)
		goto out_notifier;

	dev_add_pack(&iucv_packet_type);
	return 0;

out_notifier:
	if (pr_iucv)
		pr_iucv->iucv_unregister(&af_iucv_handler, 0);
out_sock:
	sock_unregister(PF_IUCV);
out_proto:
	proto_unregister(&iucv_proto);
out:
	return err;
}

static void __exit afiucv_exit(void)
{
	if (pr_iucv)
		pr_iucv->iucv_unregister(&af_iucv_handler, 0);

	unregister_netdevice_notifier(&afiucv_netdev_notifier);
	dev_remove_pack(&iucv_packet_type);
	sock_unregister(PF_IUCV);
	proto_unregister(&iucv_proto);
}

module_init(afiucv_init);
module_exit(afiucv_exit);

MODULE_AUTHOR("Jennifer Hunt <jenhunt@us.ibm.com>");
MODULE_DESCRIPTION("IUCV Sockets ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_IUCV);