summaryrefslogtreecommitdiffstats
path: root/net/sunrpc/clnt.c
blob: 52429b1ffcc1d8d33bf7cf116bab5bfa0ceb052c (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
/*
 *  linux/net/sunrpc/clnt.c
 *
 *  This file contains the high-level RPC interface.
 *  It is modeled as a finite state machine to support both synchronous
 *  and asynchronous requests.
 *
 *  -	RPC header generation and argument serialization.
 *  -	Credential refresh.
 *  -	TCP connect handling.
 *  -	Retry of operation when it is suspected the operation failed because
 *	of uid squashing on the server, or when the credentials were stale
 *	and need to be refreshed, or when a packet was damaged in transit.
 *	This may be have to be moved to the VFS layer.
 *
 *  NB: BSD uses a more intelligent approach to guessing when a request
 *  or reply has been lost by keeping the RTO estimate for each procedure.
 *  We currently make do with a constant timeout value.
 *
 *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
 *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
 */

#include <asm/system.h>

#include <linux/module.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/utsname.h>
#include <linux/workqueue.h>

#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/sunrpc/metrics.h>


#ifdef RPC_DEBUG
# define RPCDBG_FACILITY	RPCDBG_CALL
#endif

#define dprint_status(t)					\
	dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,		\
			__FUNCTION__, t->tk_status)

/*
 * All RPC clients are linked into this list
 */
static LIST_HEAD(all_clients);
static DEFINE_SPINLOCK(rpc_client_lock);

static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);


static void	call_start(struct rpc_task *task);
static void	call_reserve(struct rpc_task *task);
static void	call_reserveresult(struct rpc_task *task);
static void	call_allocate(struct rpc_task *task);
static void	call_encode(struct rpc_task *task);
static void	call_decode(struct rpc_task *task);
static void	call_bind(struct rpc_task *task);
static void	call_bind_status(struct rpc_task *task);
static void	call_transmit(struct rpc_task *task);
static void	call_status(struct rpc_task *task);
static void	call_transmit_status(struct rpc_task *task);
static void	call_refresh(struct rpc_task *task);
static void	call_refreshresult(struct rpc_task *task);
static void	call_timeout(struct rpc_task *task);
static void	call_connect(struct rpc_task *task);
static void	call_connect_status(struct rpc_task *task);
static __be32 *	call_header(struct rpc_task *task);
static __be32 *	call_verify(struct rpc_task *task);

static int	rpc_ping(struct rpc_clnt *clnt, int flags);

static void rpc_register_client(struct rpc_clnt *clnt)
{
	spin_lock(&rpc_client_lock);
	list_add(&clnt->cl_clients, &all_clients);
	spin_unlock(&rpc_client_lock);
}

static void rpc_unregister_client(struct rpc_clnt *clnt)
{
	spin_lock(&rpc_client_lock);
	list_del(&clnt->cl_clients);
	spin_unlock(&rpc_client_lock);
}

static int
rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
{
	static uint32_t clntid;
	int error;

	clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
	clnt->cl_dentry = ERR_PTR(-ENOENT);
	if (dir_name == NULL)
		return 0;

	clnt->cl_vfsmnt = rpc_get_mount();
	if (IS_ERR(clnt->cl_vfsmnt))
		return PTR_ERR(clnt->cl_vfsmnt);

	for (;;) {
		snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
				"%s/clnt%x", dir_name,
				(unsigned int)clntid++);
		clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
		clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
		if (!IS_ERR(clnt->cl_dentry))
			return 0;
		error = PTR_ERR(clnt->cl_dentry);
		if (error != -EEXIST) {
			printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
					clnt->cl_pathname, error);
			rpc_put_mount();
			return error;
		}
	}
}

static struct rpc_clnt * rpc_new_client(struct rpc_xprt *xprt, char *servname, struct rpc_program *program, u32 vers, rpc_authflavor_t flavor)
{
	struct rpc_version	*version;
	struct rpc_clnt		*clnt = NULL;
	struct rpc_auth		*auth;
	int err;
	int len;

	dprintk("RPC:       creating %s client for %s (xprt %p)\n",
			program->name, servname, xprt);

	err = rpciod_up();
	if (err)
		goto out_no_rpciod;
	err = -EINVAL;
	if (!xprt)
		goto out_no_xprt;
	if (vers >= program->nrvers || !(version = program->version[vers]))
		goto out_err;

	err = -ENOMEM;
	clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
	if (!clnt)
		goto out_err;
	clnt->cl_parent = clnt;

	clnt->cl_server = clnt->cl_inline_name;
	len = strlen(servname) + 1;
	if (len > sizeof(clnt->cl_inline_name)) {
		char *buf = kmalloc(len, GFP_KERNEL);
		if (buf != 0)
			clnt->cl_server = buf;
		else
			len = sizeof(clnt->cl_inline_name);
	}
	strlcpy(clnt->cl_server, servname, len);

	clnt->cl_xprt     = xprt;
	clnt->cl_procinfo = version->procs;
	clnt->cl_maxproc  = version->nrprocs;
	clnt->cl_protname = program->name;
	clnt->cl_prog     = program->number;
	clnt->cl_vers     = version->number;
	clnt->cl_stats    = program->stats;
	clnt->cl_metrics  = rpc_alloc_iostats(clnt);
	err = -ENOMEM;
	if (clnt->cl_metrics == NULL)
		goto out_no_stats;
	clnt->cl_program  = program;
	INIT_LIST_HEAD(&clnt->cl_tasks);
	spin_lock_init(&clnt->cl_lock);

	if (!xprt_bound(clnt->cl_xprt))
		clnt->cl_autobind = 1;

	clnt->cl_rtt = &clnt->cl_rtt_default;
	rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);

	kref_init(&clnt->cl_kref);

	err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
	if (err < 0)
		goto out_no_path;

	auth = rpcauth_create(flavor, clnt);
	if (IS_ERR(auth)) {
		printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
				flavor);
		err = PTR_ERR(auth);
		goto out_no_auth;
	}

	/* save the nodename */
	clnt->cl_nodelen = strlen(utsname()->nodename);
	if (clnt->cl_nodelen > UNX_MAXNODENAME)
		clnt->cl_nodelen = UNX_MAXNODENAME;
	memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen);
	rpc_register_client(clnt);
	return clnt;

out_no_auth:
	if (!IS_ERR(clnt->cl_dentry)) {
		rpc_rmdir(clnt->cl_dentry);
		rpc_put_mount();
	}
out_no_path:
	rpc_free_iostats(clnt->cl_metrics);
out_no_stats:
	if (clnt->cl_server != clnt->cl_inline_name)
		kfree(clnt->cl_server);
	kfree(clnt);
out_err:
	xprt_put(xprt);
out_no_xprt:
	rpciod_down();
out_no_rpciod:
	return ERR_PTR(err);
}

/*
 * rpc_create - create an RPC client and transport with one call
 * @args: rpc_clnt create argument structure
 *
 * Creates and initializes an RPC transport and an RPC client.
 *
 * It can ping the server in order to determine if it is up, and to see if
 * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 * this behavior so asynchronous tasks can also use rpc_create.
 */
struct rpc_clnt *rpc_create(struct rpc_create_args *args)
{
	struct rpc_xprt *xprt;
	struct rpc_clnt *clnt;
	struct rpc_xprtsock_create xprtargs = {
		.proto = args->protocol,
		.srcaddr = args->saddress,
		.dstaddr = args->address,
		.addrlen = args->addrsize,
		.timeout = args->timeout
	};
	char servername[20];

	xprt = xprt_create_transport(&xprtargs);
	if (IS_ERR(xprt))
		return (struct rpc_clnt *)xprt;

	/*
	 * If the caller chooses not to specify a hostname, whip
	 * up a string representation of the passed-in address.
	 */
	if (args->servername == NULL) {
		struct sockaddr_in *addr =
					(struct sockaddr_in *) &args->address;
		snprintf(servername, sizeof(servername), NIPQUAD_FMT,
			NIPQUAD(addr->sin_addr.s_addr));
		args->servername = servername;
	}

	/*
	 * By default, kernel RPC client connects from a reserved port.
	 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
	 * but it is always enabled for rpciod, which handles the connect
	 * operation.
	 */
	xprt->resvport = 1;
	if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
		xprt->resvport = 0;

	dprintk("RPC:       creating %s client for %s (xprt %p)\n",
			args->program->name, args->servername, xprt);

	clnt = rpc_new_client(xprt, args->servername, args->program,
				args->version, args->authflavor);
	if (IS_ERR(clnt))
		return clnt;

	if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
		int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
		if (err != 0) {
			rpc_shutdown_client(clnt);
			return ERR_PTR(err);
		}
	}

	clnt->cl_softrtry = 1;
	if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
		clnt->cl_softrtry = 0;

	if (args->flags & RPC_CLNT_CREATE_INTR)
		clnt->cl_intr = 1;
	if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
		clnt->cl_autobind = 1;
	if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
		clnt->cl_discrtry = 1;

	return clnt;
}
EXPORT_SYMBOL_GPL(rpc_create);

/*
 * This function clones the RPC client structure. It allows us to share the
 * same transport while varying parameters such as the authentication
 * flavour.
 */
struct rpc_clnt *
rpc_clone_client(struct rpc_clnt *clnt)
{
	struct rpc_clnt *new;
	int err = -ENOMEM;

	new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
	if (!new)
		goto out_no_clnt;
	new->cl_parent = clnt;
	/* Turn off autobind on clones */
	new->cl_autobind = 0;
	INIT_LIST_HEAD(&new->cl_tasks);
	spin_lock_init(&new->cl_lock);
	rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
	new->cl_metrics = rpc_alloc_iostats(clnt);
	if (new->cl_metrics == NULL)
		goto out_no_stats;
	kref_init(&new->cl_kref);
	err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
	if (err != 0)
		goto out_no_path;
	if (new->cl_auth)
		atomic_inc(&new->cl_auth->au_count);
	xprt_get(clnt->cl_xprt);
	kref_get(&clnt->cl_kref);
	rpc_register_client(new);
	rpciod_up();
	return new;
out_no_path:
	rpc_free_iostats(new->cl_metrics);
out_no_stats:
	kfree(new);
out_no_clnt:
	dprintk("RPC:       %s: returned error %d\n", __FUNCTION__, err);
	return ERR_PTR(err);
}

/*
 * Properly shut down an RPC client, terminating all outstanding
 * requests.
 */
void rpc_shutdown_client(struct rpc_clnt *clnt)
{
	dprintk("RPC:       shutting down %s client for %s\n",
			clnt->cl_protname, clnt->cl_server);

	while (!list_empty(&clnt->cl_tasks)) {
		rpc_killall_tasks(clnt);
		wait_event_timeout(destroy_wait,
			list_empty(&clnt->cl_tasks), 1*HZ);
	}

	rpc_release_client(clnt);
}

/*
 * Free an RPC client
 */
static void
rpc_free_client(struct kref *kref)
{
	struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);

	dprintk("RPC:       destroying %s client for %s\n",
			clnt->cl_protname, clnt->cl_server);
	if (!IS_ERR(clnt->cl_dentry)) {
		rpc_rmdir(clnt->cl_dentry);
		rpc_put_mount();
	}
	if (clnt->cl_parent != clnt) {
		rpc_release_client(clnt->cl_parent);
		goto out_free;
	}
	if (clnt->cl_server != clnt->cl_inline_name)
		kfree(clnt->cl_server);
out_free:
	rpc_unregister_client(clnt);
	rpc_free_iostats(clnt->cl_metrics);
	clnt->cl_metrics = NULL;
	xprt_put(clnt->cl_xprt);
	rpciod_down();
	kfree(clnt);
}

/*
 * Free an RPC client
 */
static void
rpc_free_auth(struct kref *kref)
{
	struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);

	if (clnt->cl_auth == NULL) {
		rpc_free_client(kref);
		return;
	}

	/*
	 * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
	 *       release remaining GSS contexts. This mechanism ensures
	 *       that it can do so safely.
	 */
	kref_init(kref);
	rpcauth_release(clnt->cl_auth);
	clnt->cl_auth = NULL;
	kref_put(kref, rpc_free_client);
}

/*
 * Release reference to the RPC client
 */
void
rpc_release_client(struct rpc_clnt *clnt)
{
	dprintk("RPC:       rpc_release_client(%p)\n", clnt);

	if (list_empty(&clnt->cl_tasks))
		wake_up(&destroy_wait);
	kref_put(&clnt->cl_kref, rpc_free_auth);
}

/**
 * rpc_bind_new_program - bind a new RPC program to an existing client
 * @old - old rpc_client
 * @program - rpc program to set
 * @vers - rpc program version
 *
 * Clones the rpc client and sets up a new RPC program. This is mainly
 * of use for enabling different RPC programs to share the same transport.
 * The Sun NFSv2/v3 ACL protocol can do this.
 */
struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
				      struct rpc_program *program,
				      int vers)
{
	struct rpc_clnt *clnt;
	struct rpc_version *version;
	int err;

	BUG_ON(vers >= program->nrvers || !program->version[vers]);
	version = program->version[vers];
	clnt = rpc_clone_client(old);
	if (IS_ERR(clnt))
		goto out;
	clnt->cl_procinfo = version->procs;
	clnt->cl_maxproc  = version->nrprocs;
	clnt->cl_protname = program->name;
	clnt->cl_prog     = program->number;
	clnt->cl_vers     = version->number;
	clnt->cl_stats    = program->stats;
	err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
	if (err != 0) {
		rpc_shutdown_client(clnt);
		clnt = ERR_PTR(err);
	}
out:
	return clnt;
}

/*
 * Default callback for async RPC calls
 */
static void
rpc_default_callback(struct rpc_task *task, void *data)
{
}

static const struct rpc_call_ops rpc_default_ops = {
	.rpc_call_done = rpc_default_callback,
};

/*
 *	Export the signal mask handling for synchronous code that
 *	sleeps on RPC calls
 */
#define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))

static void rpc_save_sigmask(sigset_t *oldset, int intr)
{
	unsigned long	sigallow = sigmask(SIGKILL);
	sigset_t sigmask;

	/* Block all signals except those listed in sigallow */
	if (intr)
		sigallow |= RPC_INTR_SIGNALS;
	siginitsetinv(&sigmask, sigallow);
	sigprocmask(SIG_BLOCK, &sigmask, oldset);
}

static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
{
	rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
}

static inline void rpc_restore_sigmask(sigset_t *oldset)
{
	sigprocmask(SIG_SETMASK, oldset, NULL);
}

void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
{
	rpc_save_sigmask(oldset, clnt->cl_intr);
}

void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
{
	rpc_restore_sigmask(oldset);
}

static
struct rpc_task *rpc_do_run_task(struct rpc_clnt *clnt,
		struct rpc_message *msg,
		int flags,
		const struct rpc_call_ops *ops,
		void *data)
{
	struct rpc_task *task, *ret;
	sigset_t oldset;

	task = rpc_new_task(clnt, flags, ops, data);
	if (task == NULL) {
		rpc_release_calldata(ops, data);
		return ERR_PTR(-ENOMEM);
	}

	/* Mask signals on synchronous RPC calls and RPCSEC_GSS upcalls */
	rpc_task_sigmask(task, &oldset);
	if (msg != NULL) {
		rpc_call_setup(task, msg, 0);
		if (task->tk_status != 0) {
			ret = ERR_PTR(task->tk_status);
			rpc_put_task(task);
			goto out;
		}
	}
	atomic_inc(&task->tk_count);
	rpc_execute(task);
	ret = task;
out:
	rpc_restore_sigmask(&oldset);
	return ret;
}

/**
 * rpc_call_sync - Perform a synchronous RPC call
 * @clnt: pointer to RPC client
 * @msg: RPC call parameters
 * @flags: RPC call flags
 */
int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
{
	struct rpc_task	*task;
	int status;

	BUG_ON(flags & RPC_TASK_ASYNC);

	task = rpc_do_run_task(clnt, msg, flags, &rpc_default_ops, NULL);
	if (IS_ERR(task))
		return PTR_ERR(task);
	status = task->tk_status;
	rpc_put_task(task);
	return status;
}

/**
 * rpc_call_async - Perform an asynchronous RPC call
 * @clnt: pointer to RPC client
 * @msg: RPC call parameters
 * @flags: RPC call flags
 * @ops: RPC call ops
 * @data: user call data
 */
int
rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
	       const struct rpc_call_ops *tk_ops, void *data)
{
	struct rpc_task	*task;

	task = rpc_do_run_task(clnt, msg, flags|RPC_TASK_ASYNC, tk_ops, data);
	if (IS_ERR(task))
		return PTR_ERR(task);
	rpc_put_task(task);
	return 0;
}

/**
 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 * @clnt: pointer to RPC client
 * @flags: RPC flags
 * @ops: RPC call ops
 * @data: user call data
 */
struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags,
					const struct rpc_call_ops *tk_ops,
					void *data)
{
	return rpc_do_run_task(clnt, NULL, flags, tk_ops, data);
}
EXPORT_SYMBOL(rpc_run_task);

void
rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
{
	task->tk_msg   = *msg;
	task->tk_flags |= flags;
	/* Bind the user cred */
	if (task->tk_msg.rpc_cred != NULL)
		rpcauth_holdcred(task);
	else
		rpcauth_bindcred(task);

	if (task->tk_status == 0)
		task->tk_action = call_start;
	else
		task->tk_action = rpc_exit_task;
}

/**
 * rpc_peeraddr - extract remote peer address from clnt's xprt
 * @clnt: RPC client structure
 * @buf: target buffer
 * @size: length of target buffer
 *
 * Returns the number of bytes that are actually in the stored address.
 */
size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
{
	size_t bytes;
	struct rpc_xprt *xprt = clnt->cl_xprt;

	bytes = sizeof(xprt->addr);
	if (bytes > bufsize)
		bytes = bufsize;
	memcpy(buf, &clnt->cl_xprt->addr, bytes);
	return xprt->addrlen;
}
EXPORT_SYMBOL_GPL(rpc_peeraddr);

/**
 * rpc_peeraddr2str - return remote peer address in printable format
 * @clnt: RPC client structure
 * @format: address format
 *
 */
char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format)
{
	struct rpc_xprt *xprt = clnt->cl_xprt;

	if (xprt->address_strings[format] != NULL)
		return xprt->address_strings[format];
	else
		return "unprintable";
}
EXPORT_SYMBOL_GPL(rpc_peeraddr2str);

void
rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
{
	struct rpc_xprt *xprt = clnt->cl_xprt;
	if (xprt->ops->set_buffer_size)
		xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
}

/*
 * Return size of largest payload RPC client can support, in bytes
 *
 * For stream transports, this is one RPC record fragment (see RFC
 * 1831), as we don't support multi-record requests yet.  For datagram
 * transports, this is the size of an IP packet minus the IP, UDP, and
 * RPC header sizes.
 */
size_t rpc_max_payload(struct rpc_clnt *clnt)
{
	return clnt->cl_xprt->max_payload;
}
EXPORT_SYMBOL_GPL(rpc_max_payload);

/**
 * rpc_force_rebind - force transport to check that remote port is unchanged
 * @clnt: client to rebind
 *
 */
void rpc_force_rebind(struct rpc_clnt *clnt)
{
	if (clnt->cl_autobind)
		xprt_clear_bound(clnt->cl_xprt);
}
EXPORT_SYMBOL_GPL(rpc_force_rebind);

/*
 * Restart an (async) RPC call. Usually called from within the
 * exit handler.
 */
void
rpc_restart_call(struct rpc_task *task)
{
	if (RPC_ASSASSINATED(task))
		return;

	task->tk_action = call_start;
}

/*
 * 0.  Initial state
 *
 *     Other FSM states can be visited zero or more times, but
 *     this state is visited exactly once for each RPC.
 */
static void
call_start(struct rpc_task *task)
{
	struct rpc_clnt	*clnt = task->tk_client;

	dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid,
			clnt->cl_protname, clnt->cl_vers,
			task->tk_msg.rpc_proc->p_proc,
			(RPC_IS_ASYNC(task) ? "async" : "sync"));

	/* Increment call count */
	task->tk_msg.rpc_proc->p_count++;
	clnt->cl_stats->rpccnt++;
	task->tk_action = call_reserve;
}

/*
 * 1.	Reserve an RPC call slot
 */
static void
call_reserve(struct rpc_task *task)
{
	dprint_status(task);

	if (!rpcauth_uptodatecred(task)) {
		task->tk_action = call_refresh;
		return;
	}

	task->tk_status  = 0;
	task->tk_action  = call_reserveresult;
	xprt_reserve(task);
}

/*
 * 1b.	Grok the result of xprt_reserve()
 */
static void
call_reserveresult(struct rpc_task *task)
{
	int status = task->tk_status;

	dprint_status(task);

	/*
	 * After a call to xprt_reserve(), we must have either
	 * a request slot or else an error status.
	 */
	task->tk_status = 0;
	if (status >= 0) {
		if (task->tk_rqstp) {
			task->tk_action = call_allocate;
			return;
		}

		printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
				__FUNCTION__, status);
		rpc_exit(task, -EIO);
		return;
	}

	/*
	 * Even though there was an error, we may have acquired
	 * a request slot somehow.  Make sure not to leak it.
	 */
	if (task->tk_rqstp) {
		printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
				__FUNCTION__, status);
		xprt_release(task);
	}

	switch (status) {
	case -EAGAIN:	/* woken up; retry */
		task->tk_action = call_reserve;
		return;
	case -EIO:	/* probably a shutdown */
		break;
	default:
		printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
				__FUNCTION__, status);
		break;
	}
	rpc_exit(task, status);
}

/*
 * 2.	Allocate the buffer. For details, see sched.c:rpc_malloc.
 *	(Note: buffer memory is freed in xprt_release).
 */
static void
call_allocate(struct rpc_task *task)
{
	unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
	struct rpc_rqst *req = task->tk_rqstp;
	struct rpc_xprt *xprt = task->tk_xprt;
	struct rpc_procinfo *proc = task->tk_msg.rpc_proc;

	dprint_status(task);

	task->tk_status = 0;
	task->tk_action = call_bind;

	if (req->rq_buffer)
		return;

	if (proc->p_proc != 0) {
		BUG_ON(proc->p_arglen == 0);
		if (proc->p_decode != NULL)
			BUG_ON(proc->p_replen == 0);
	}

	/*
	 * Calculate the size (in quads) of the RPC call
	 * and reply headers, and convert both values
	 * to byte sizes.
	 */
	req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
	req->rq_callsize <<= 2;
	req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
	req->rq_rcvsize <<= 2;

	req->rq_buffer = xprt->ops->buf_alloc(task,
					req->rq_callsize + req->rq_rcvsize);
	if (req->rq_buffer != NULL)
		return;

	dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);

	if (RPC_IS_ASYNC(task) || !signalled()) {
		xprt_release(task);
		task->tk_action = call_reserve;
		rpc_delay(task, HZ>>4);
		return;
	}

	rpc_exit(task, -ERESTARTSYS);
}

static inline int
rpc_task_need_encode(struct rpc_task *task)
{
	return task->tk_rqstp->rq_snd_buf.len == 0;
}

static inline void
rpc_task_force_reencode(struct rpc_task *task)
{
	task->tk_rqstp->rq_snd_buf.len = 0;
}

static inline void
rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
{
	buf->head[0].iov_base = start;
	buf->head[0].iov_len = len;
	buf->tail[0].iov_len = 0;
	buf->page_len = 0;
	buf->len = 0;
	buf->buflen = len;
}

/*
 * 3.	Encode arguments of an RPC call
 */
static void
call_encode(struct rpc_task *task)
{
	struct rpc_rqst	*req = task->tk_rqstp;
	kxdrproc_t	encode;
	__be32		*p;

	dprint_status(task);

	rpc_xdr_buf_init(&req->rq_snd_buf,
			 req->rq_buffer,
			 req->rq_callsize);
	rpc_xdr_buf_init(&req->rq_rcv_buf,
			 (char *)req->rq_buffer + req->rq_callsize,
			 req->rq_rcvsize);

	/* Encode header and provided arguments */
	encode = task->tk_msg.rpc_proc->p_encode;
	if (!(p = call_header(task))) {
		printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
		rpc_exit(task, -EIO);
		return;
	}
	if (encode == NULL)
		return;

	task->tk_status = rpcauth_wrap_req(task, encode, req, p,
			task->tk_msg.rpc_argp);
	if (task->tk_status == -ENOMEM) {
		/* XXX: Is this sane? */
		rpc_delay(task, 3*HZ);
		task->tk_status = -EAGAIN;
	}
}

/*
 * 4.	Get the server port number if not yet set
 */
static void
call_bind(struct rpc_task *task)
{
	struct rpc_xprt *xprt = task->tk_xprt;

	dprint_status(task);

	task->tk_action = call_connect;
	if (!xprt_bound(xprt)) {
		task->tk_action = call_bind_status;
		task->tk_timeout = xprt->bind_timeout;
		xprt->ops->rpcbind(task);
	}
}

/*
 * 4a.	Sort out bind result
 */
static void
call_bind_status(struct rpc_task *task)
{
	int status = -EACCES;

	if (task->tk_status >= 0) {
		dprint_status(task);
		task->tk_status = 0;
		task->tk_action = call_connect;
		return;
	}

	switch (task->tk_status) {
	case -EACCES:
		dprintk("RPC: %5u remote rpcbind: RPC program/version "
				"unavailable\n", task->tk_pid);
		rpc_delay(task, 3*HZ);
		goto retry_timeout;
	case -ETIMEDOUT:
		dprintk("RPC: %5u rpcbind request timed out\n",
				task->tk_pid);
		goto retry_timeout;
	case -EPFNOSUPPORT:
		dprintk("RPC: %5u remote rpcbind service unavailable\n",
				task->tk_pid);
		break;
	case -EPROTONOSUPPORT:
		dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
				task->tk_pid);
		task->tk_status = 0;
		task->tk_action = call_bind;
		return;
	default:
		dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
				task->tk_pid, -task->tk_status);
		status = -EIO;
	}

	rpc_exit(task, status);
	return;

retry_timeout:
	task->tk_action = call_timeout;
}

/*
 * 4b.	Connect to the RPC server
 */
static void
call_connect(struct rpc_task *task)
{
	struct rpc_xprt *xprt = task->tk_xprt;

	dprintk("RPC: %5u call_connect xprt %p %s connected\n",
			task->tk_pid, xprt,
			(xprt_connected(xprt) ? "is" : "is not"));

	task->tk_action = call_transmit;
	if (!xprt_connected(xprt)) {
		task->tk_action = call_connect_status;
		if (task->tk_status < 0)
			return;
		xprt_connect(task);
	}
}

/*
 * 4c.	Sort out connect result
 */
static void
call_connect_status(struct rpc_task *task)
{
	struct rpc_clnt *clnt = task->tk_client;
	int status = task->tk_status;

	dprint_status(task);

	task->tk_status = 0;
	if (status >= 0) {
		clnt->cl_stats->netreconn++;
		task->tk_action = call_transmit;
		return;
	}

	/* Something failed: remote service port may have changed */
	rpc_force_rebind(clnt);

	switch (status) {
	case -ENOTCONN:
	case -EAGAIN:
		task->tk_action = call_bind;
		if (!RPC_IS_SOFT(task))
			return;
		/* if soft mounted, test if we've timed out */
	case -ETIMEDOUT:
		task->tk_action = call_timeout;
		return;
	}
	rpc_exit(task, -EIO);
}

/*
 * 5.	Transmit the RPC request, and wait for reply
 */
static void
call_transmit(struct rpc_task *task)
{
	dprint_status(task);

	task->tk_action = call_status;
	if (task->tk_status < 0)
		return;
	task->tk_status = xprt_prepare_transmit(task);
	if (task->tk_status != 0)
		return;
	task->tk_action = call_transmit_status;
	/* Encode here so that rpcsec_gss can use correct sequence number. */
	if (rpc_task_need_encode(task)) {
		BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
		call_encode(task);
		/* Did the encode result in an error condition? */
		if (task->tk_status != 0)
			return;
	}
	xprt_transmit(task);
	if (task->tk_status < 0)
		return;
	/*
	 * On success, ensure that we call xprt_end_transmit() before sleeping
	 * in order to allow access to the socket to other RPC requests.
	 */
	call_transmit_status(task);
	if (task->tk_msg.rpc_proc->p_decode != NULL)
		return;
	task->tk_action = rpc_exit_task;
	rpc_wake_up_task(task);
}

/*
 * 5a.	Handle cleanup after a transmission
 */
static void
call_transmit_status(struct rpc_task *task)
{
	task->tk_action = call_status;
	/*
	 * Special case: if we've been waiting on the socket's write_space()
	 * callback, then don't call xprt_end_transmit().
	 */
	if (task->tk_status == -EAGAIN)
		return;
	xprt_end_transmit(task);
	rpc_task_force_reencode(task);
}

/*
 * 6.	Sort out the RPC call status
 */
static void
call_status(struct rpc_task *task)
{
	struct rpc_clnt	*clnt = task->tk_client;
	struct rpc_rqst	*req = task->tk_rqstp;
	int		status;

	if (req->rq_received > 0 && !req->rq_bytes_sent)
		task->tk_status = req->rq_received;

	dprint_status(task);

	status = task->tk_status;
	if (status >= 0) {
		task->tk_action = call_decode;
		return;
	}

	task->tk_status = 0;
	switch(status) {
	case -EHOSTDOWN:
	case -EHOSTUNREACH:
	case -ENETUNREACH:
		/*
		 * Delay any retries for 3 seconds, then handle as if it
		 * were a timeout.
		 */
		rpc_delay(task, 3*HZ);
	case -ETIMEDOUT:
		task->tk_action = call_timeout;
		if (task->tk_client->cl_discrtry)
			xprt_disconnect(task->tk_xprt);
		break;
	case -ECONNREFUSED:
	case -ENOTCONN:
		rpc_force_rebind(clnt);
		task->tk_action = call_bind;
		break;
	case -EAGAIN:
		task->tk_action = call_transmit;
		break;
	case -EIO:
		/* shutdown or soft timeout */
		rpc_exit(task, status);
		break;
	default:
		printk("%s: RPC call returned error %d\n",
			       clnt->cl_protname, -status);
		rpc_exit(task, status);
	}
}

/*
 * 6a.	Handle RPC timeout
 * 	We do not release the request slot, so we keep using the
 *	same XID for all retransmits.
 */
static void
call_timeout(struct rpc_task *task)
{
	struct rpc_clnt	*clnt = task->tk_client;

	if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
		dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
		goto retry;
	}

	dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
	task->tk_timeouts++;

	if (RPC_IS_SOFT(task)) {
		printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
				clnt->cl_protname, clnt->cl_server);
		rpc_exit(task, -EIO);
		return;
	}

	if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
		task->tk_flags |= RPC_CALL_MAJORSEEN;
		printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
			clnt->cl_protname, clnt->cl_server);
	}
	rpc_force_rebind(clnt);

retry:
	clnt->cl_stats->rpcretrans++;
	task->tk_action = call_bind;
	task->tk_status = 0;
}

/*
 * 7.	Decode the RPC reply
 */
static void
call_decode(struct rpc_task *task)
{
	struct rpc_clnt	*clnt = task->tk_client;
	struct rpc_rqst	*req = task->tk_rqstp;
	kxdrproc_t	decode = task->tk_msg.rpc_proc->p_decode;
	__be32		*p;

	dprintk("RPC: %5u call_decode (status %d)\n",
			task->tk_pid, task->tk_status);

	if (task->tk_flags & RPC_CALL_MAJORSEEN) {
		printk(KERN_NOTICE "%s: server %s OK\n",
			clnt->cl_protname, clnt->cl_server);
		task->tk_flags &= ~RPC_CALL_MAJORSEEN;
	}

	if (task->tk_status < 12) {
		if (!RPC_IS_SOFT(task)) {
			task->tk_action = call_bind;
			clnt->cl_stats->rpcretrans++;
			goto out_retry;
		}
		dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
				clnt->cl_protname, task->tk_status);
		task->tk_action = call_timeout;
		goto out_retry;
	}

	/*
	 * Ensure that we see all writes made by xprt_complete_rqst()
	 * before it changed req->rq_received.
	 */
	smp_rmb();
	req->rq_rcv_buf.len = req->rq_private_buf.len;

	/* Check that the softirq receive buffer is valid */
	WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
				sizeof(req->rq_rcv_buf)) != 0);

	/* Verify the RPC header */
	p = call_verify(task);
	if (IS_ERR(p)) {
		if (p == ERR_PTR(-EAGAIN))
			goto out_retry;
		return;
	}

	task->tk_action = rpc_exit_task;

	if (decode) {
		task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
						      task->tk_msg.rpc_resp);
	}
	dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
			task->tk_status);
	return;
out_retry:
	req->rq_received = req->rq_private_buf.len = 0;
	task->tk_status = 0;
	if (task->tk_client->cl_discrtry)
		xprt_disconnect(task->tk_xprt);
}

/*
 * 8.	Refresh the credentials if rejected by the server
 */
static void
call_refresh(struct rpc_task *task)
{
	dprint_status(task);

	xprt_release(task);	/* Must do to obtain new XID */
	task->tk_action = call_refreshresult;
	task->tk_status = 0;
	task->tk_client->cl_stats->rpcauthrefresh++;
	rpcauth_refreshcred(task);
}

/*
 * 8a.	Process the results of a credential refresh
 */
static void
call_refreshresult(struct rpc_task *task)
{
	int status = task->tk_status;

	dprint_status(task);

	task->tk_status = 0;
	task->tk_action = call_reserve;
	if (status >= 0 && rpcauth_uptodatecred(task))
		return;
	if (status == -EACCES) {
		rpc_exit(task, -EACCES);
		return;
	}
	task->tk_action = call_refresh;
	if (status != -ETIMEDOUT)
		rpc_delay(task, 3*HZ);
	return;
}

/*
 * Call header serialization
 */
static __be32 *
call_header(struct rpc_task *task)
{
	struct rpc_clnt *clnt = task->tk_client;
	struct rpc_rqst	*req = task->tk_rqstp;
	__be32		*p = req->rq_svec[0].iov_base;

	/* FIXME: check buffer size? */

	p = xprt_skip_transport_header(task->tk_xprt, p);
	*p++ = req->rq_xid;		/* XID */
	*p++ = htonl(RPC_CALL);		/* CALL */
	*p++ = htonl(RPC_VERSION);	/* RPC version */
	*p++ = htonl(clnt->cl_prog);	/* program number */
	*p++ = htonl(clnt->cl_vers);	/* program version */
	*p++ = htonl(task->tk_msg.rpc_proc->p_proc);	/* procedure */
	p = rpcauth_marshcred(task, p);
	req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
	return p;
}

/*
 * Reply header verification
 */
static __be32 *
call_verify(struct rpc_task *task)
{
	struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
	int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
	__be32	*p = iov->iov_base;
	u32 n;
	int error = -EACCES;

	if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
		/* RFC-1014 says that the representation of XDR data must be a
		 * multiple of four bytes
		 * - if it isn't pointer subtraction in the NFS client may give
		 *   undefined results
		 */
		dprintk("RPC: %5u %s: XDR representation not a multiple of"
		       " 4 bytes: 0x%x\n", task->tk_pid, __FUNCTION__,
		       task->tk_rqstp->rq_rcv_buf.len);
		goto out_eio;
	}
	if ((len -= 3) < 0)
		goto out_overflow;
	p += 1;	/* skip XID */

	if ((n = ntohl(*p++)) != RPC_REPLY) {
		dprintk("RPC: %5u %s: not an RPC reply: %x\n",
				task->tk_pid, __FUNCTION__, n);
		goto out_garbage;
	}
	if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
		if (--len < 0)
			goto out_overflow;
		switch ((n = ntohl(*p++))) {
			case RPC_AUTH_ERROR:
				break;
			case RPC_MISMATCH:
				dprintk("RPC: %5u %s: RPC call version "
						"mismatch!\n",
						task->tk_pid, __FUNCTION__);
				error = -EPROTONOSUPPORT;
				goto out_err;
			default:
				dprintk("RPC: %5u %s: RPC call rejected, "
						"unknown error: %x\n",
						task->tk_pid, __FUNCTION__, n);
				goto out_eio;
		}
		if (--len < 0)
			goto out_overflow;
		switch ((n = ntohl(*p++))) {
		case RPC_AUTH_REJECTEDCRED:
		case RPC_AUTH_REJECTEDVERF:
		case RPCSEC_GSS_CREDPROBLEM:
		case RPCSEC_GSS_CTXPROBLEM:
			if (!task->tk_cred_retry)
				break;
			task->tk_cred_retry--;
			dprintk("RPC: %5u %s: retry stale creds\n",
					task->tk_pid, __FUNCTION__);
			rpcauth_invalcred(task);
			task->tk_action = call_refresh;
			goto out_retry;
		case RPC_AUTH_BADCRED:
		case RPC_AUTH_BADVERF:
			/* possibly garbled cred/verf? */
			if (!task->tk_garb_retry)
				break;
			task->tk_garb_retry--;
			dprintk("RPC: %5u %s: retry garbled creds\n",
					task->tk_pid, __FUNCTION__);
			task->tk_action = call_bind;
			goto out_retry;
		case RPC_AUTH_TOOWEAK:
			printk(KERN_NOTICE "call_verify: server %s requires stronger "
			       "authentication.\n", task->tk_client->cl_server);
			break;
		default:
			dprintk("RPC: %5u %s: unknown auth error: %x\n",
					task->tk_pid, __FUNCTION__, n);
			error = -EIO;
		}
		dprintk("RPC: %5u %s: call rejected %d\n",
				task->tk_pid, __FUNCTION__, n);
		goto out_err;
	}
	if (!(p = rpcauth_checkverf(task, p))) {
		dprintk("RPC: %5u %s: auth check failed\n",
				task->tk_pid, __FUNCTION__);
		goto out_garbage;		/* bad verifier, retry */
	}
	len = p - (__be32 *)iov->iov_base - 1;
	if (len < 0)
		goto out_overflow;
	switch ((n = ntohl(*p++))) {
	case RPC_SUCCESS:
		return p;
	case RPC_PROG_UNAVAIL:
		dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
				task->tk_pid, __FUNCTION__,
				(unsigned int)task->tk_client->cl_prog,
				task->tk_client->cl_server);
		error = -EPFNOSUPPORT;
		goto out_err;
	case RPC_PROG_MISMATCH:
		dprintk("RPC: %5u %s: program %u, version %u unsupported by "
				"server %s\n", task->tk_pid, __FUNCTION__,
				(unsigned int)task->tk_client->cl_prog,
				(unsigned int)task->tk_client->cl_vers,
				task->tk_client->cl_server);
		error = -EPROTONOSUPPORT;
		goto out_err;
	case RPC_PROC_UNAVAIL:
		dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
				"version %u on server %s\n",
				task->tk_pid, __FUNCTION__,
				task->tk_msg.rpc_proc,
				task->tk_client->cl_prog,
				task->tk_client->cl_vers,
				task->tk_client->cl_server);
		error = -EOPNOTSUPP;
		goto out_err;
	case RPC_GARBAGE_ARGS:
		dprintk("RPC: %5u %s: server saw garbage\n",
				task->tk_pid, __FUNCTION__);
		break;			/* retry */
	default:
		dprintk("RPC: %5u %s: server accept status: %x\n",
				task->tk_pid, __FUNCTION__, n);
		/* Also retry */
	}

out_garbage:
	task->tk_client->cl_stats->rpcgarbage++;
	if (task->tk_garb_retry) {
		task->tk_garb_retry--;
		dprintk("RPC: %5u %s: retrying\n",
				task->tk_pid, __FUNCTION__);
		task->tk_action = call_bind;
out_retry:
		return ERR_PTR(-EAGAIN);
	}
out_eio:
	error = -EIO;
out_err:
	rpc_exit(task, error);
	dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
			__FUNCTION__, error);
	return ERR_PTR(error);
out_overflow:
	dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
			__FUNCTION__);
	goto out_garbage;
}

static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
{
	return 0;
}

static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
{
	return 0;
}

static struct rpc_procinfo rpcproc_null = {
	.p_encode = rpcproc_encode_null,
	.p_decode = rpcproc_decode_null,
};

static int rpc_ping(struct rpc_clnt *clnt, int flags)
{
	struct rpc_message msg = {
		.rpc_proc = &rpcproc_null,
	};
	int err;
	msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
	err = rpc_call_sync(clnt, &msg, flags);
	put_rpccred(msg.rpc_cred);
	return err;
}

struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
{
	struct rpc_message msg = {
		.rpc_proc = &rpcproc_null,
		.rpc_cred = cred,
	};
	return rpc_do_run_task(clnt, &msg, flags, &rpc_default_ops, NULL);
}
EXPORT_SYMBOL(rpc_call_null);

#ifdef RPC_DEBUG
void rpc_show_tasks(void)
{
	struct rpc_clnt *clnt;
	struct rpc_task *t;

	spin_lock(&rpc_client_lock);
	if (list_empty(&all_clients))
		goto out;
	printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
		"-rpcwait -action- ---ops--\n");
	list_for_each_entry(clnt, &all_clients, cl_clients) {
		if (list_empty(&clnt->cl_tasks))
			continue;
		spin_lock(&clnt->cl_lock);
		list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
			const char *rpc_waitq = "none";

			if (RPC_IS_QUEUED(t))
				rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);

			printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
				t->tk_pid,
				(t->tk_msg.rpc_proc ? t->tk_msg.rpc_proc->p_proc : -1),
				t->tk_flags, t->tk_status,
				t->tk_client,
				(t->tk_client ? t->tk_client->cl_prog : 0),
				t->tk_rqstp, t->tk_timeout,
				rpc_waitq,
				t->tk_action, t->tk_ops);
		}
		spin_unlock(&clnt->cl_lock);
	}
out:
	spin_unlock(&rpc_client_lock);
}
#endif
OpenPOWER on IntegriCloud