summaryrefslogtreecommitdiffstats
path: root/sys/rpc/svc.c
blob: 8af9e80f019860bf99f15d3842da060423521ccf (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
/*	$NetBSD: svc.c,v 1.21 2000/07/06 03:10:35 christos Exp $	*/

/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 *
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 *
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char *sccsid2 = "@(#)svc.c 1.44 88/02/08 Copyr 1984 Sun Micro";
static char *sccsid = "@(#)svc.c	2.4 88/08/11 4.0 RPCSRC";
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/*
 * svc.c, Server-side remote procedure call interface.
 *
 * There are two sets of procedures here.  The xprt routines are
 * for handling transport handles.  The svc routines handle the
 * list of service routines.
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 */

#include <sys/param.h>
#include <sys/lock.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/socketvar.h>
#include <sys/systm.h>
#include <sys/ucred.h>

#include <rpc/rpc.h>
#include <rpc/rpcb_clnt.h>
#include <rpc/replay.h>

#include <rpc/rpc_com.h>

#define SVC_VERSQUIET 0x0001		/* keep quiet about vers mismatch */
#define version_keepquiet(xp) (SVC_EXT(xp)->xp_flags & SVC_VERSQUIET)

static struct svc_callout *svc_find(SVCPOOL *pool, rpcprog_t, rpcvers_t,
    char *);
static void svc_new_thread(SVCPOOL *pool);
static void xprt_unregister_locked(SVCXPRT *xprt);

/* ***************  SVCXPRT related stuff **************** */

static int svcpool_minthread_sysctl(SYSCTL_HANDLER_ARGS);
static int svcpool_maxthread_sysctl(SYSCTL_HANDLER_ARGS);

SVCPOOL*
svcpool_create(const char *name, struct sysctl_oid_list *sysctl_base)
{
	SVCPOOL *pool;

	pool = malloc(sizeof(SVCPOOL), M_RPC, M_WAITOK|M_ZERO);
	
	mtx_init(&pool->sp_lock, "sp_lock", NULL, MTX_DEF);
	pool->sp_name = name;
	pool->sp_state = SVCPOOL_INIT;
	pool->sp_proc = NULL;
	TAILQ_INIT(&pool->sp_xlist);
	TAILQ_INIT(&pool->sp_active);
	TAILQ_INIT(&pool->sp_callouts);
	LIST_INIT(&pool->sp_threads);
	LIST_INIT(&pool->sp_idlethreads);
	pool->sp_minthreads = 1;
	pool->sp_maxthreads = 1;
	pool->sp_threadcount = 0;

	/*
	 * Don't use more than a quarter of mbuf clusters or more than
	 * 45Mb buffering requests.
	 */
	pool->sp_space_high = nmbclusters * MCLBYTES / 4;
	if (pool->sp_space_high > 45 << 20)
		pool->sp_space_high = 45 << 20;
	pool->sp_space_low = 2 * pool->sp_space_high / 3;

	sysctl_ctx_init(&pool->sp_sysctl);
	if (sysctl_base) {
		SYSCTL_ADD_PROC(&pool->sp_sysctl, sysctl_base, OID_AUTO,
		    "minthreads", CTLTYPE_INT | CTLFLAG_RW,
		    pool, 0, svcpool_minthread_sysctl, "I", "");
		SYSCTL_ADD_PROC(&pool->sp_sysctl, sysctl_base, OID_AUTO,
		    "maxthreads", CTLTYPE_INT | CTLFLAG_RW,
		    pool, 0, svcpool_maxthread_sysctl, "I", "");
		SYSCTL_ADD_INT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
		    "threads", CTLFLAG_RD, &pool->sp_threadcount, 0, "");

		SYSCTL_ADD_UINT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
		    "request_space_used", CTLFLAG_RD,
		    &pool->sp_space_used, 0,
		    "Space in parsed but not handled requests.");

		SYSCTL_ADD_UINT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
		    "request_space_used_highest", CTLFLAG_RD,
		    &pool->sp_space_used_highest, 0,
		    "Highest space used since reboot.");

		SYSCTL_ADD_UINT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
		    "request_space_high", CTLFLAG_RW,
		    &pool->sp_space_high, 0,
		    "Maximum space in parsed but not handled requests.");

		SYSCTL_ADD_UINT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
		    "request_space_low", CTLFLAG_RW,
		    &pool->sp_space_low, 0,
		    "Low water mark for request space.");

		SYSCTL_ADD_UINT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
		    "request_space_throttled", CTLFLAG_RD,
		    &pool->sp_space_throttled, 0,
		    "Whether nfs requests are currently throttled");

		SYSCTL_ADD_UINT(&pool->sp_sysctl, sysctl_base, OID_AUTO,
		    "request_space_throttle_count", CTLFLAG_RD,
		    &pool->sp_space_throttle_count, 0,
		    "Count of times throttling based on request space has occurred");
	}

	return pool;
}

void
svcpool_destroy(SVCPOOL *pool)
{
	SVCXPRT *xprt, *nxprt;
	struct svc_callout *s;
	struct svcxprt_list cleanup;

	TAILQ_INIT(&cleanup);
	mtx_lock(&pool->sp_lock);

	while (TAILQ_FIRST(&pool->sp_xlist)) {
		xprt = TAILQ_FIRST(&pool->sp_xlist);
		xprt_unregister_locked(xprt);
		TAILQ_INSERT_TAIL(&cleanup, xprt, xp_link);
	}

	while (TAILQ_FIRST(&pool->sp_callouts)) {
		s = TAILQ_FIRST(&pool->sp_callouts);
		mtx_unlock(&pool->sp_lock);
		svc_unreg(pool, s->sc_prog, s->sc_vers);
		mtx_lock(&pool->sp_lock);
	}

	mtx_destroy(&pool->sp_lock);

	TAILQ_FOREACH_SAFE(xprt, &cleanup, xp_link, nxprt) {
		SVC_RELEASE(xprt);
	}

	if (pool->sp_rcache)
		replay_freecache(pool->sp_rcache);

	sysctl_ctx_free(&pool->sp_sysctl);
	free(pool, M_RPC);
}

static bool_t
svcpool_active(SVCPOOL *pool)
{
	enum svcpool_state state = pool->sp_state;

	if (state == SVCPOOL_INIT || state == SVCPOOL_CLOSING)
		return (FALSE);
	return (TRUE);
}

/*
 * Sysctl handler to set the minimum thread count on a pool
 */
static int
svcpool_minthread_sysctl(SYSCTL_HANDLER_ARGS)
{
	SVCPOOL *pool;
	int newminthreads, error, n;

	pool = oidp->oid_arg1;
	newminthreads = pool->sp_minthreads;
	error = sysctl_handle_int(oidp, &newminthreads, 0, req);
	if (error == 0 && newminthreads != pool->sp_minthreads) {
		if (newminthreads > pool->sp_maxthreads)
			return (EINVAL);
		mtx_lock(&pool->sp_lock);
		if (newminthreads > pool->sp_minthreads
		    && svcpool_active(pool)) {
			/*
			 * If the pool is running and we are
			 * increasing, create some more threads now.
			 */
			n = newminthreads - pool->sp_threadcount;
			if (n > 0) {
				mtx_unlock(&pool->sp_lock);
				while (n--)
					svc_new_thread(pool);
				mtx_lock(&pool->sp_lock);
			}
		}
		pool->sp_minthreads = newminthreads;
		mtx_unlock(&pool->sp_lock);
	}
	return (error);
}

/*
 * Sysctl handler to set the maximum thread count on a pool
 */
static int
svcpool_maxthread_sysctl(SYSCTL_HANDLER_ARGS)
{
	SVCPOOL *pool;
	SVCTHREAD *st;
	int newmaxthreads, error;

	pool = oidp->oid_arg1;
	newmaxthreads = pool->sp_maxthreads;
	error = sysctl_handle_int(oidp, &newmaxthreads, 0, req);
	if (error == 0 && newmaxthreads != pool->sp_maxthreads) {
		if (newmaxthreads < pool->sp_minthreads)
			return (EINVAL);
		mtx_lock(&pool->sp_lock);
		if (newmaxthreads < pool->sp_maxthreads
		    && svcpool_active(pool)) {
			/*
			 * If the pool is running and we are
			 * decreasing, wake up some idle threads to
			 * encourage them to exit.
			 */
			LIST_FOREACH(st, &pool->sp_idlethreads, st_ilink)
				cv_signal(&st->st_cond);
		}
		pool->sp_maxthreads = newmaxthreads;
		mtx_unlock(&pool->sp_lock);
	}
	return (error);
}

/*
 * Activate a transport handle.
 */
void
xprt_register(SVCXPRT *xprt)
{
	SVCPOOL *pool = xprt->xp_pool;

	mtx_lock(&pool->sp_lock);
	xprt->xp_registered = TRUE;
	xprt->xp_active = FALSE;
	TAILQ_INSERT_TAIL(&pool->sp_xlist, xprt, xp_link);
	mtx_unlock(&pool->sp_lock);
}

/*
 * De-activate a transport handle. Note: the locked version doesn't
 * release the transport - caller must do that after dropping the pool
 * lock.
 */
static void
xprt_unregister_locked(SVCXPRT *xprt)
{
	SVCPOOL *pool = xprt->xp_pool;

	if (xprt->xp_active) {
		TAILQ_REMOVE(&pool->sp_active, xprt, xp_alink);
		xprt->xp_active = FALSE;
	}
	TAILQ_REMOVE(&pool->sp_xlist, xprt, xp_link);
	xprt->xp_registered = FALSE;
}

void
xprt_unregister(SVCXPRT *xprt)
{
	SVCPOOL *pool = xprt->xp_pool;

	mtx_lock(&pool->sp_lock);
	xprt_unregister_locked(xprt);
	mtx_unlock(&pool->sp_lock);

	SVC_RELEASE(xprt);
}

static void
xprt_assignthread(SVCXPRT *xprt)
{
	SVCPOOL *pool = xprt->xp_pool;
	SVCTHREAD *st;

	/*
	 * Attempt to assign a service thread to this
	 * transport.
	 */
	LIST_FOREACH(st, &pool->sp_idlethreads, st_ilink) {
		if (st->st_xprt == NULL && STAILQ_EMPTY(&st->st_reqs))
			break;
	}
	if (st) {
		SVC_ACQUIRE(xprt);
		xprt->xp_thread = st;
		st->st_xprt = xprt;
		cv_signal(&st->st_cond);
	} else {
		/*
		 * See if we can create a new thread. The
		 * actual thread creation happens in
		 * svc_run_internal because our locking state
		 * is poorly defined (we are typically called
		 * from a socket upcall). Don't create more
		 * than one thread per second.
		 */
		if (pool->sp_state == SVCPOOL_ACTIVE
		    && pool->sp_lastcreatetime < time_uptime
		    && pool->sp_threadcount < pool->sp_maxthreads) {
			pool->sp_state = SVCPOOL_THREADWANTED;
		}
	}
}

void
xprt_active(SVCXPRT *xprt)
{
	SVCPOOL *pool = xprt->xp_pool;

	if (!xprt->xp_registered) {
		/*
		 * Race with xprt_unregister - we lose.
		 */
		return;
	}

	mtx_lock(&pool->sp_lock);

	if (!xprt->xp_active) {
		TAILQ_INSERT_TAIL(&pool->sp_active, xprt, xp_alink);
		xprt->xp_active = TRUE;
		xprt_assignthread(xprt);
	}

	mtx_unlock(&pool->sp_lock);
}

void
xprt_inactive_locked(SVCXPRT *xprt)
{
	SVCPOOL *pool = xprt->xp_pool;

	if (xprt->xp_active) {
		TAILQ_REMOVE(&pool->sp_active, xprt, xp_alink);
		xprt->xp_active = FALSE;
	}
}

void
xprt_inactive(SVCXPRT *xprt)
{
	SVCPOOL *pool = xprt->xp_pool;

	mtx_lock(&pool->sp_lock);
	xprt_inactive_locked(xprt);
	mtx_unlock(&pool->sp_lock);
}

/*
 * Add a service program to the callout list.
 * The dispatch routine will be called when a rpc request for this
 * program number comes in.
 */
bool_t
svc_reg(SVCXPRT *xprt, const rpcprog_t prog, const rpcvers_t vers,
    void (*dispatch)(struct svc_req *, SVCXPRT *),
    const struct netconfig *nconf)
{
	SVCPOOL *pool = xprt->xp_pool;
	struct svc_callout *s;
	char *netid = NULL;
	int flag = 0;

/* VARIABLES PROTECTED BY svc_lock: s, svc_head */

	if (xprt->xp_netid) {
		netid = strdup(xprt->xp_netid, M_RPC);
		flag = 1;
	} else if (nconf && nconf->nc_netid) {
		netid = strdup(nconf->nc_netid, M_RPC);
		flag = 1;
	} /* must have been created with svc_raw_create */
	if ((netid == NULL) && (flag == 1)) {
		return (FALSE);
	}

	mtx_lock(&pool->sp_lock);
	if ((s = svc_find(pool, prog, vers, netid)) != NULL) {
		if (netid)
			free(netid, M_RPC);
		if (s->sc_dispatch == dispatch)
			goto rpcb_it; /* he is registering another xptr */
		mtx_unlock(&pool->sp_lock);
		return (FALSE);
	}
	s = malloc(sizeof (struct svc_callout), M_RPC, M_NOWAIT);
	if (s == NULL) {
		if (netid)
			free(netid, M_RPC);
		mtx_unlock(&pool->sp_lock);
		return (FALSE);
	}

	s->sc_prog = prog;
	s->sc_vers = vers;
	s->sc_dispatch = dispatch;
	s->sc_netid = netid;
	TAILQ_INSERT_TAIL(&pool->sp_callouts, s, sc_link);

	if ((xprt->xp_netid == NULL) && (flag == 1) && netid)
		((SVCXPRT *) xprt)->xp_netid = strdup(netid, M_RPC);

rpcb_it:
	mtx_unlock(&pool->sp_lock);
	/* now register the information with the local binder service */
	if (nconf) {
		bool_t dummy;
		struct netconfig tnc;
		struct netbuf nb;
		tnc = *nconf;
		nb.buf = &xprt->xp_ltaddr;
		nb.len = xprt->xp_ltaddr.ss_len;
		dummy = rpcb_set(prog, vers, &tnc, &nb);
		return (dummy);
	}
	return (TRUE);
}

/*
 * Remove a service program from the callout list.
 */
void
svc_unreg(SVCPOOL *pool, const rpcprog_t prog, const rpcvers_t vers)
{
	struct svc_callout *s;

	/* unregister the information anyway */
	(void) rpcb_unset(prog, vers, NULL);
	mtx_lock(&pool->sp_lock);
	while ((s = svc_find(pool, prog, vers, NULL)) != NULL) {
		TAILQ_REMOVE(&pool->sp_callouts, s, sc_link);
		if (s->sc_netid)
			mem_free(s->sc_netid, sizeof (s->sc_netid) + 1);
		mem_free(s, sizeof (struct svc_callout));
	}
	mtx_unlock(&pool->sp_lock);
}

/* ********************** CALLOUT list related stuff ************* */

/*
 * Search the callout list for a program number, return the callout
 * struct.
 */
static struct svc_callout *
svc_find(SVCPOOL *pool, rpcprog_t prog, rpcvers_t vers, char *netid)
{
	struct svc_callout *s;

	mtx_assert(&pool->sp_lock, MA_OWNED);
	TAILQ_FOREACH(s, &pool->sp_callouts, sc_link) {
		if (s->sc_prog == prog && s->sc_vers == vers
		    && (netid == NULL || s->sc_netid == NULL ||
			strcmp(netid, s->sc_netid) == 0))
			break;
	}

	return (s);
}

/* ******************* REPLY GENERATION ROUTINES  ************ */

static bool_t
svc_sendreply_common(struct svc_req *rqstp, struct rpc_msg *rply,
    struct mbuf *body)
{
	SVCXPRT *xprt = rqstp->rq_xprt;
	bool_t ok;

	if (rqstp->rq_args) {
		m_freem(rqstp->rq_args);
		rqstp->rq_args = NULL;
	}

	if (xprt->xp_pool->sp_rcache)
		replay_setreply(xprt->xp_pool->sp_rcache,
		    rply, svc_getrpccaller(rqstp), body);

	if (!SVCAUTH_WRAP(&rqstp->rq_auth, &body))
		return (FALSE);

	ok = SVC_REPLY(xprt, rply, rqstp->rq_addr, body); 
	if (rqstp->rq_addr) {
		free(rqstp->rq_addr, M_SONAME);
		rqstp->rq_addr = NULL;
	}

	return (ok);
}

/*
 * Send a reply to an rpc request
 */
bool_t
svc_sendreply(struct svc_req *rqstp, xdrproc_t xdr_results, void * xdr_location)
{
	struct rpc_msg rply; 
	struct mbuf *m;
	XDR xdrs;
	bool_t ok;

	rply.rm_xid = rqstp->rq_xid;
	rply.rm_direction = REPLY;  
	rply.rm_reply.rp_stat = MSG_ACCEPTED; 
	rply.acpted_rply.ar_verf = rqstp->rq_verf; 
	rply.acpted_rply.ar_stat = SUCCESS;
	rply.acpted_rply.ar_results.where = NULL;
	rply.acpted_rply.ar_results.proc = (xdrproc_t) xdr_void;

	MGET(m, M_WAIT, MT_DATA);
	MCLGET(m, M_WAIT);
	m->m_len = 0;
	xdrmbuf_create(&xdrs, m, XDR_ENCODE);
	ok = xdr_results(&xdrs, xdr_location);
	XDR_DESTROY(&xdrs);

	if (ok) {
		return (svc_sendreply_common(rqstp, &rply, m));
	} else {
		m_freem(m);
		return (FALSE);
	}
}

bool_t
svc_sendreply_mbuf(struct svc_req *rqstp, struct mbuf *m)
{
	struct rpc_msg rply; 

	rply.rm_xid = rqstp->rq_xid;
	rply.rm_direction = REPLY;  
	rply.rm_reply.rp_stat = MSG_ACCEPTED; 
	rply.acpted_rply.ar_verf = rqstp->rq_verf; 
	rply.acpted_rply.ar_stat = SUCCESS;
	rply.acpted_rply.ar_results.where = NULL;
	rply.acpted_rply.ar_results.proc = (xdrproc_t) xdr_void;

	return (svc_sendreply_common(rqstp, &rply, m));
}

/*
 * No procedure error reply
 */
void
svcerr_noproc(struct svc_req *rqstp)
{
	SVCXPRT *xprt = rqstp->rq_xprt;
	struct rpc_msg rply;

	rply.rm_xid = rqstp->rq_xid;
	rply.rm_direction = REPLY;
	rply.rm_reply.rp_stat = MSG_ACCEPTED;
	rply.acpted_rply.ar_verf = rqstp->rq_verf;
	rply.acpted_rply.ar_stat = PROC_UNAVAIL;

	if (xprt->xp_pool->sp_rcache)
		replay_setreply(xprt->xp_pool->sp_rcache,
		    &rply, svc_getrpccaller(rqstp), NULL);

	svc_sendreply_common(rqstp, &rply, NULL);
}

/*
 * Can't decode args error reply
 */
void
svcerr_decode(struct svc_req *rqstp)
{
	SVCXPRT *xprt = rqstp->rq_xprt;
	struct rpc_msg rply; 

	rply.rm_xid = rqstp->rq_xid;
	rply.rm_direction = REPLY; 
	rply.rm_reply.rp_stat = MSG_ACCEPTED; 
	rply.acpted_rply.ar_verf = rqstp->rq_verf;
	rply.acpted_rply.ar_stat = GARBAGE_ARGS;

	if (xprt->xp_pool->sp_rcache)
		replay_setreply(xprt->xp_pool->sp_rcache,
		    &rply, (struct sockaddr *) &xprt->xp_rtaddr, NULL);

	svc_sendreply_common(rqstp, &rply, NULL);
}

/*
 * Some system error
 */
void
svcerr_systemerr(struct svc_req *rqstp)
{
	SVCXPRT *xprt = rqstp->rq_xprt;
	struct rpc_msg rply; 

	rply.rm_xid = rqstp->rq_xid;
	rply.rm_direction = REPLY; 
	rply.rm_reply.rp_stat = MSG_ACCEPTED; 
	rply.acpted_rply.ar_verf = rqstp->rq_verf;
	rply.acpted_rply.ar_stat = SYSTEM_ERR;

	if (xprt->xp_pool->sp_rcache)
		replay_setreply(xprt->xp_pool->sp_rcache,
		    &rply, svc_getrpccaller(rqstp), NULL);

	svc_sendreply_common(rqstp, &rply, NULL);
}

/*
 * Authentication error reply
 */
void
svcerr_auth(struct svc_req *rqstp, enum auth_stat why)
{
	SVCXPRT *xprt = rqstp->rq_xprt;
	struct rpc_msg rply;

	rply.rm_xid = rqstp->rq_xid;
	rply.rm_direction = REPLY;
	rply.rm_reply.rp_stat = MSG_DENIED;
	rply.rjcted_rply.rj_stat = AUTH_ERROR;
	rply.rjcted_rply.rj_why = why;

	if (xprt->xp_pool->sp_rcache)
		replay_setreply(xprt->xp_pool->sp_rcache,
		    &rply, svc_getrpccaller(rqstp), NULL);

	svc_sendreply_common(rqstp, &rply, NULL);
}

/*
 * Auth too weak error reply
 */
void
svcerr_weakauth(struct svc_req *rqstp)
{

	svcerr_auth(rqstp, AUTH_TOOWEAK);
}

/*
 * Program unavailable error reply
 */
void 
svcerr_noprog(struct svc_req *rqstp)
{
	SVCXPRT *xprt = rqstp->rq_xprt;
	struct rpc_msg rply;  

	rply.rm_xid = rqstp->rq_xid;
	rply.rm_direction = REPLY;   
	rply.rm_reply.rp_stat = MSG_ACCEPTED;  
	rply.acpted_rply.ar_verf = rqstp->rq_verf;  
	rply.acpted_rply.ar_stat = PROG_UNAVAIL;

	if (xprt->xp_pool->sp_rcache)
		replay_setreply(xprt->xp_pool->sp_rcache,
		    &rply, svc_getrpccaller(rqstp), NULL);

	svc_sendreply_common(rqstp, &rply, NULL);
}

/*
 * Program version mismatch error reply
 */
void  
svcerr_progvers(struct svc_req *rqstp, rpcvers_t low_vers, rpcvers_t high_vers)
{
	SVCXPRT *xprt = rqstp->rq_xprt;
	struct rpc_msg rply;

	rply.rm_xid = rqstp->rq_xid;
	rply.rm_direction = REPLY;
	rply.rm_reply.rp_stat = MSG_ACCEPTED;
	rply.acpted_rply.ar_verf = rqstp->rq_verf;
	rply.acpted_rply.ar_stat = PROG_MISMATCH;
	rply.acpted_rply.ar_vers.low = (uint32_t)low_vers;
	rply.acpted_rply.ar_vers.high = (uint32_t)high_vers;

	if (xprt->xp_pool->sp_rcache)
		replay_setreply(xprt->xp_pool->sp_rcache,
		    &rply, svc_getrpccaller(rqstp), NULL);

	svc_sendreply_common(rqstp, &rply, NULL);
}

/*
 * Allocate a new server transport structure. All fields are
 * initialized to zero and xp_p3 is initialized to point at an
 * extension structure to hold various flags and authentication
 * parameters.
 */
SVCXPRT *
svc_xprt_alloc()
{
	SVCXPRT *xprt;
	SVCXPRT_EXT *ext;

	xprt = mem_alloc(sizeof(SVCXPRT));
	memset(xprt, 0, sizeof(SVCXPRT));
	ext = mem_alloc(sizeof(SVCXPRT_EXT));
	memset(ext, 0, sizeof(SVCXPRT_EXT));
	xprt->xp_p3 = ext;
	refcount_init(&xprt->xp_refs, 1);

	return (xprt);
}

/*
 * Free a server transport structure.
 */
void
svc_xprt_free(xprt)
	SVCXPRT *xprt;
{

	mem_free(xprt->xp_p3, sizeof(SVCXPRT_EXT));
	mem_free(xprt, sizeof(SVCXPRT));
}

/* ******************* SERVER INPUT STUFF ******************* */

/*
 * Read RPC requests from a transport and queue them to be
 * executed. We handle authentication and replay cache replies here.
 * Actually dispatching the RPC is deferred till svc_executereq.
 */
static enum xprt_stat
svc_getreq(SVCXPRT *xprt, struct svc_req **rqstp_ret)
{
	SVCPOOL *pool = xprt->xp_pool;
	struct svc_req *r;
	struct rpc_msg msg;
	struct mbuf *args;
	enum xprt_stat stat;

	/* now receive msgs from xprtprt (support batch calls) */
	r = malloc(sizeof(*r), M_RPC, M_WAITOK|M_ZERO);

	msg.rm_call.cb_cred.oa_base = r->rq_credarea;
	msg.rm_call.cb_verf.oa_base = &r->rq_credarea[MAX_AUTH_BYTES];
	r->rq_clntcred = &r->rq_credarea[2*MAX_AUTH_BYTES];
	if (SVC_RECV(xprt, &msg, &r->rq_addr, &args)) {
		enum auth_stat why;

		/*
		 * Handle replays and authenticate before queuing the
		 * request to be executed.
		 */
		SVC_ACQUIRE(xprt);
		r->rq_xprt = xprt;
		if (pool->sp_rcache) {
			struct rpc_msg repmsg;
			struct mbuf *repbody;
			enum replay_state rs;
			rs = replay_find(pool->sp_rcache, &msg,
			    svc_getrpccaller(r), &repmsg, &repbody);
			switch (rs) {
			case RS_NEW:
				break;
			case RS_DONE:
				SVC_REPLY(xprt, &repmsg, r->rq_addr,
				    repbody);
				if (r->rq_addr) {
					free(r->rq_addr, M_SONAME);
					r->rq_addr = NULL;
				}
				goto call_done;

			default:
				goto call_done;
			}
		}

		r->rq_xid = msg.rm_xid;
		r->rq_prog = msg.rm_call.cb_prog;
		r->rq_vers = msg.rm_call.cb_vers;
		r->rq_proc = msg.rm_call.cb_proc;
		r->rq_size = sizeof(*r) + m_length(args, NULL);
		r->rq_args = args;
		if ((why = _authenticate(r, &msg)) != AUTH_OK) {
			/*
			 * RPCSEC_GSS uses this return code
			 * for requests that form part of its
			 * context establishment protocol and
			 * should not be dispatched to the
			 * application.
			 */
			if (why != RPCSEC_GSS_NODISPATCH)
				svcerr_auth(r, why);
			goto call_done;
		}

		if (!SVCAUTH_UNWRAP(&r->rq_auth, &r->rq_args)) {
			svcerr_decode(r);
			goto call_done;
		}

		/*
		 * Everything checks out, return request to caller.
		 */
		*rqstp_ret = r;
		r = NULL;
	}
call_done:
	if (r) {
		svc_freereq(r);
		r = NULL;
	}
	if ((stat = SVC_STAT(xprt)) == XPRT_DIED) {
		xprt_unregister(xprt);
	}

	return (stat);
}

static void
svc_executereq(struct svc_req *rqstp)
{
	SVCXPRT *xprt = rqstp->rq_xprt;
	SVCPOOL *pool = xprt->xp_pool;
	int prog_found;
	rpcvers_t low_vers;
	rpcvers_t high_vers;
	struct svc_callout *s;

	/* now match message with a registered service*/
	prog_found = FALSE;
	low_vers = (rpcvers_t) -1L;
	high_vers = (rpcvers_t) 0L;
	TAILQ_FOREACH(s, &pool->sp_callouts, sc_link) {
		if (s->sc_prog == rqstp->rq_prog) {
			if (s->sc_vers == rqstp->rq_vers) {
				/*
				 * We hand ownership of r to the
				 * dispatch method - they must call
				 * svc_freereq.
				 */
				(*s->sc_dispatch)(rqstp, xprt);
				return;
			}  /* found correct version */
			prog_found = TRUE;
			if (s->sc_vers < low_vers)
				low_vers = s->sc_vers;
			if (s->sc_vers > high_vers)
				high_vers = s->sc_vers;
		}   /* found correct program */
	}

	/*
	 * if we got here, the program or version
	 * is not served ...
	 */
	if (prog_found)
		svcerr_progvers(rqstp, low_vers, high_vers);
	else
		svcerr_noprog(rqstp);

	svc_freereq(rqstp);
}

static void
svc_checkidle(SVCPOOL *pool)
{
	SVCXPRT *xprt, *nxprt;
	time_t timo;
	struct svcxprt_list cleanup;

	TAILQ_INIT(&cleanup);
	TAILQ_FOREACH_SAFE(xprt, &pool->sp_xlist, xp_link, nxprt) {
		/*
		 * Only some transports have idle timers. Don't time
		 * something out which is just waking up.
		 */
		if (!xprt->xp_idletimeout || xprt->xp_thread)
			continue;

		timo = xprt->xp_lastactive + xprt->xp_idletimeout;
		if (time_uptime > timo) {
			xprt_unregister_locked(xprt);
			TAILQ_INSERT_TAIL(&cleanup, xprt, xp_link);
		}
	}

	mtx_unlock(&pool->sp_lock);
	TAILQ_FOREACH_SAFE(xprt, &cleanup, xp_link, nxprt) {
		SVC_RELEASE(xprt);
	}
	mtx_lock(&pool->sp_lock);

}

static void
svc_assign_waiting_sockets(SVCPOOL *pool)
{
	SVCXPRT *xprt;

	TAILQ_FOREACH(xprt, &pool->sp_active, xp_alink) {
		if (!xprt->xp_thread) {
			xprt_assignthread(xprt);
		}
	}
}

static bool_t
svc_request_space_available(SVCPOOL *pool)
{

	mtx_assert(&pool->sp_lock, MA_OWNED);

	if (pool->sp_space_throttled) {
		/*
		 * Below the low-water yet? If so, assign any waiting sockets.
		 */
		if (pool->sp_space_used < pool->sp_space_low) {
			pool->sp_space_throttled = FALSE;
			svc_assign_waiting_sockets(pool);
			return TRUE;
		}
		
		return FALSE;
	} else {
		if (pool->sp_space_used
		    >= pool->sp_space_high) {
			pool->sp_space_throttled = TRUE;
			pool->sp_space_throttle_count++;
			return FALSE;
		}

		return TRUE;
	}
}

static void
svc_run_internal(SVCPOOL *pool, bool_t ismaster)
{
	SVCTHREAD *st, *stpref;
	SVCXPRT *xprt;
	enum xprt_stat stat;
	struct svc_req *rqstp;
	int error;

	st = mem_alloc(sizeof(*st));
	st->st_xprt = NULL;
	STAILQ_INIT(&st->st_reqs);
	cv_init(&st->st_cond, "rpcsvc");

	mtx_lock(&pool->sp_lock);
	LIST_INSERT_HEAD(&pool->sp_threads, st, st_link);

	/*
	 * If we are a new thread which was spawned to cope with
	 * increased load, set the state back to SVCPOOL_ACTIVE.
	 */
	if (pool->sp_state == SVCPOOL_THREADSTARTING)
		pool->sp_state = SVCPOOL_ACTIVE;

	while (pool->sp_state != SVCPOOL_CLOSING) {
		/*
		 * Check for idle transports once per second.
		 */
		if (time_uptime > pool->sp_lastidlecheck) {
			pool->sp_lastidlecheck = time_uptime;
			svc_checkidle(pool);
		}

		xprt = st->st_xprt;
		if (!xprt && STAILQ_EMPTY(&st->st_reqs)) {
			/*
			 * Enforce maxthreads count.
			 */
			if (pool->sp_threadcount > pool->sp_maxthreads)
				break;

			/*
			 * Before sleeping, see if we can find an
			 * active transport which isn't being serviced
			 * by a thread.
			 */
			if (svc_request_space_available(pool)) {
				TAILQ_FOREACH(xprt, &pool->sp_active,
				    xp_alink) {
					if (!xprt->xp_thread) {
						SVC_ACQUIRE(xprt);
						xprt->xp_thread = st;
						st->st_xprt = xprt;
						break;
					}
				}
			}
			if (st->st_xprt)
				continue;

			LIST_INSERT_HEAD(&pool->sp_idlethreads, st, st_ilink);
			error = cv_timedwait_sig(&st->st_cond, &pool->sp_lock,
				5 * hz);
			LIST_REMOVE(st, st_ilink);

			/*
			 * Reduce worker thread count when idle.
			 */
			if (error == EWOULDBLOCK) {
				if (!ismaster
				    && (pool->sp_threadcount
					> pool->sp_minthreads)
					&& !st->st_xprt
					&& STAILQ_EMPTY(&st->st_reqs))
					break;
			}
			if (error == EWOULDBLOCK)
				continue;
			if (error) {
				if (pool->sp_state != SVCPOOL_CLOSING) {
					mtx_unlock(&pool->sp_lock);
					svc_exit(pool);
					mtx_lock(&pool->sp_lock);
				}
				break;
			}

			if (pool->sp_state == SVCPOOL_THREADWANTED) {
				pool->sp_state = SVCPOOL_THREADSTARTING;
				pool->sp_lastcreatetime = time_uptime;
				mtx_unlock(&pool->sp_lock);
				svc_new_thread(pool);
				mtx_lock(&pool->sp_lock);
			}
			continue;
		}

		if (xprt) {
			/*
			 * Drain the transport socket and queue up any
			 * RPCs.
			 */
			xprt->xp_lastactive = time_uptime;
			stat = XPRT_IDLE;
			do {
				if (!svc_request_space_available(pool))
					break;
				rqstp = NULL;
				mtx_unlock(&pool->sp_lock);
				stat = svc_getreq(xprt, &rqstp);
				mtx_lock(&pool->sp_lock);
				if (rqstp) {
					/*
					 * See if the application has
					 * a preference for some other
					 * thread.
					 */
					stpref = st;
					if (pool->sp_assign)
						stpref = pool->sp_assign(st,
						    rqstp);
					
					pool->sp_space_used +=
						rqstp->rq_size;
					if (pool->sp_space_used
					    > pool->sp_space_used_highest)
						pool->sp_space_used_highest =
							pool->sp_space_used;
					rqstp->rq_thread = stpref;
					STAILQ_INSERT_TAIL(&stpref->st_reqs,
					    rqstp, rq_link);
					stpref->st_reqcount++;

					/*
					 * If we assigned the request
					 * to another thread, make
					 * sure its awake and continue
					 * reading from the
					 * socket. Otherwise, try to
					 * find some other thread to
					 * read from the socket and
					 * execute the request
					 * immediately.
					 */
					if (stpref != st) {
						cv_signal(&stpref->st_cond);
						continue;
					} else {
						break;
					}
				}
			} while (stat == XPRT_MOREREQS
			    && pool->sp_state != SVCPOOL_CLOSING);
		       
			/*
			 * Move this transport to the end of the
			 * active list to ensure fairness when
			 * multiple transports are active. If this was
			 * the last queued request, svc_getreq will
			 * end up calling xprt_inactive to remove from
			 * the active list.
			 */
			xprt->xp_thread = NULL;
			st->st_xprt = NULL;
			if (xprt->xp_active) {
				xprt_assignthread(xprt);
				TAILQ_REMOVE(&pool->sp_active, xprt, xp_alink);
				TAILQ_INSERT_TAIL(&pool->sp_active, xprt,
				    xp_alink);
			}
			mtx_unlock(&pool->sp_lock);
			SVC_RELEASE(xprt);
			mtx_lock(&pool->sp_lock);
		}

		/*
		 * Execute what we have queued.
		 */
		while ((rqstp = STAILQ_FIRST(&st->st_reqs)) != NULL) {
			size_t sz = rqstp->rq_size;
			mtx_unlock(&pool->sp_lock);
			svc_executereq(rqstp);
			mtx_lock(&pool->sp_lock);
			pool->sp_space_used -= sz;
		}
	}

	if (st->st_xprt) {
		xprt = st->st_xprt;
		st->st_xprt = NULL;
		SVC_RELEASE(xprt);
	}

	KASSERT(STAILQ_EMPTY(&st->st_reqs), ("stray reqs on exit"));
	LIST_REMOVE(st, st_link);
	pool->sp_threadcount--;

	mtx_unlock(&pool->sp_lock);

	cv_destroy(&st->st_cond);
	mem_free(st, sizeof(*st));

	if (!ismaster)
		wakeup(pool);
}

static void
svc_thread_start(void *arg)
{

	svc_run_internal((SVCPOOL *) arg, FALSE);
	kthread_exit();
}

static void
svc_new_thread(SVCPOOL *pool)
{
	struct thread *td;

	pool->sp_threadcount++;
	kthread_add(svc_thread_start, pool,
	    pool->sp_proc, &td, 0, 0,
	    "%s: service", pool->sp_name);
}

void
svc_run(SVCPOOL *pool)
{
	int i;
	struct proc *p;
	struct thread *td;

	p = curproc;
	td = curthread;
	snprintf(td->td_name, sizeof(td->td_name),
	    "%s: master", pool->sp_name);
	pool->sp_state = SVCPOOL_ACTIVE;
	pool->sp_proc = p;
	pool->sp_lastcreatetime = time_uptime;
	pool->sp_threadcount = 1;

	for (i = 1; i < pool->sp_minthreads; i++) {
		svc_new_thread(pool);
	}

	svc_run_internal(pool, TRUE);

	mtx_lock(&pool->sp_lock);
	while (pool->sp_threadcount > 0)
		msleep(pool, &pool->sp_lock, 0, "svcexit", 0);
	mtx_unlock(&pool->sp_lock);
}

void
svc_exit(SVCPOOL *pool)
{
	SVCTHREAD *st;

	mtx_lock(&pool->sp_lock);

	pool->sp_state = SVCPOOL_CLOSING;
	LIST_FOREACH(st, &pool->sp_idlethreads, st_ilink)
		cv_signal(&st->st_cond);

	mtx_unlock(&pool->sp_lock);
}

bool_t
svc_getargs(struct svc_req *rqstp, xdrproc_t xargs, void *args)
{
	struct mbuf *m;
	XDR xdrs;
	bool_t stat;

	m = rqstp->rq_args;
	rqstp->rq_args = NULL;

	xdrmbuf_create(&xdrs, m, XDR_DECODE);
	stat = xargs(&xdrs, args);
	XDR_DESTROY(&xdrs);

	return (stat);
}

bool_t
svc_freeargs(struct svc_req *rqstp, xdrproc_t xargs, void *args)
{
	XDR xdrs;

	if (rqstp->rq_addr) {
		free(rqstp->rq_addr, M_SONAME);
		rqstp->rq_addr = NULL;
	}

	xdrs.x_op = XDR_FREE;
	return (xargs(&xdrs, args));
}

void
svc_freereq(struct svc_req *rqstp)
{
	SVCTHREAD *st;
	SVCXPRT *xprt;
	SVCPOOL *pool;

	st = rqstp->rq_thread;
	xprt = rqstp->rq_xprt;
	if (xprt)
		pool = xprt->xp_pool;
	else
		pool = NULL;
	if (st) {
		mtx_lock(&pool->sp_lock);
		KASSERT(rqstp == STAILQ_FIRST(&st->st_reqs),
		    ("Freeing request out of order"));
		STAILQ_REMOVE_HEAD(&st->st_reqs, rq_link);
		st->st_reqcount--;
		if (pool->sp_done)
			pool->sp_done(st, rqstp);
		mtx_unlock(&pool->sp_lock);
	}

	if (rqstp->rq_auth.svc_ah_ops)
		SVCAUTH_RELEASE(&rqstp->rq_auth);

	if (rqstp->rq_xprt) {
		SVC_RELEASE(rqstp->rq_xprt);
	}

	if (rqstp->rq_addr)
		free(rqstp->rq_addr, M_SONAME);

	if (rqstp->rq_args)
		m_freem(rqstp->rq_args);

	free(rqstp, M_RPC);
}
OpenPOWER on IntegriCloud