aboutsummaryrefslogtreecommitdiff
path: root/fs/nfs/nfs2xdr.c
blob: baf759bccd054d562d24d9adf43af18915da8267 (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
/*
 * linux/fs/nfs/nfs2xdr.c
 *
 * XDR functions to encode/decode NFS RPC arguments and results.
 *
 * Copyright (C) 1992, 1993, 1994  Rick Sladkey
 * Copyright (C) 1996 Olaf Kirch
 * 04 Aug 1998  Ion Badulescu <ionut@cs.columbia.edu>
 * 		FIFO's need special handling in NFSv2
 */

#include <linux/param.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/in.h>
#include <linux/pagemap.h>
#include <linux/proc_fs.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs2.h>
#include <linux/nfs_fs.h>
#include "internal.h"

#define NFSDBG_FACILITY		NFSDBG_XDR

/* Mapping from NFS error code to "errno" error code. */
#define errno_NFSERR_IO		EIO

/*
 * Declare the space requirements for NFS arguments and replies as
 * number of 32bit-words
 */
#define NFS_fhandle_sz		(8)
#define NFS_sattr_sz		(8)
#define NFS_filename_sz		(1+(NFS2_MAXNAMLEN>>2))
#define NFS_path_sz		(1+(NFS2_MAXPATHLEN>>2))
#define NFS_fattr_sz		(17)
#define NFS_info_sz		(5)
#define NFS_entry_sz		(NFS_filename_sz+3)

#define NFS_diropargs_sz	(NFS_fhandle_sz+NFS_filename_sz)
#define NFS_removeargs_sz	(NFS_fhandle_sz+NFS_filename_sz)
#define NFS_sattrargs_sz	(NFS_fhandle_sz+NFS_sattr_sz)
#define NFS_readlinkargs_sz	(NFS_fhandle_sz)
#define NFS_readargs_sz		(NFS_fhandle_sz+3)
#define NFS_writeargs_sz	(NFS_fhandle_sz+4)
#define NFS_createargs_sz	(NFS_diropargs_sz+NFS_sattr_sz)
#define NFS_renameargs_sz	(NFS_diropargs_sz+NFS_diropargs_sz)
#define NFS_linkargs_sz		(NFS_fhandle_sz+NFS_diropargs_sz)
#define NFS_symlinkargs_sz	(NFS_diropargs_sz+1+NFS_sattr_sz)
#define NFS_readdirargs_sz	(NFS_fhandle_sz+2)

#define NFS_attrstat_sz		(1+NFS_fattr_sz)
#define NFS_diropres_sz		(1+NFS_fhandle_sz+NFS_fattr_sz)
#define NFS_readlinkres_sz	(2)
#define NFS_readres_sz		(1+NFS_fattr_sz+1)
#define NFS_writeres_sz         (NFS_attrstat_sz)
#define NFS_stat_sz		(1)
#define NFS_readdirres_sz	(1)
#define NFS_statfsres_sz	(1+NFS_info_sz)

static int nfs_stat_to_errno(enum nfs_stat);

/*
 * While encoding arguments, set up the reply buffer in advance to
 * receive reply data directly into the page cache.
 */
static void prepare_reply_buffer(struct rpc_rqst *req, struct page **pages,
				 unsigned int base, unsigned int len,
				 unsigned int bufsize)
{
	struct rpc_auth	*auth = req->rq_cred->cr_auth;
	unsigned int replen;

	replen = RPC_REPHDRSIZE + auth->au_rslack + bufsize;
	xdr_inline_pages(&req->rq_rcv_buf, replen << 2, pages, base, len);
}

/*
 * Handle decode buffer overflows out-of-line.
 */
static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
{
	dprintk("NFS: %s prematurely hit the end of our receive buffer. "
		"Remaining buffer length is %tu words.\n",
		func, xdr->end - xdr->p);
}


/*
 * Encode/decode NFSv2 basic data types
 *
 * Basic NFSv2 data types are defined in section 2.3 of RFC 1094:
 * "NFS: Network File System Protocol Specification".
 *
 * Not all basic data types have their own encoding and decoding
 * functions.  For run-time efficiency, some data types are encoded
 * or decoded inline.
 */

/*
 *	typedef opaque	nfsdata<>;
 */
static int decode_nfsdata(struct xdr_stream *xdr, struct nfs_readres *result)
{
	u32 recvd, count;
	size_t hdrlen;
	__be32 *p;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(p == NULL))
		goto out_overflow;
	count = be32_to_cpup(p);
	hdrlen = (u8 *)xdr->p - (u8 *)xdr->iov->iov_base;
	recvd = xdr->buf->len - hdrlen;
	if (unlikely(count > recvd))
		goto out_cheating;
out:
	xdr_read_pages(xdr, count);
	result->eof = 0;	/* NFSv2 does not pass EOF flag on the wire. */
	result->count = count;
	return count;
out_cheating:
	dprintk("NFS: server cheating in read result: "
		"count %u > recvd %u\n", count, recvd);
	count = recvd;
	goto out;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

/*
 *	enum stat {
 *		NFS_OK = 0,
 *		NFSERR_PERM = 1,
 *		NFSERR_NOENT = 2,
 *		NFSERR_IO = 5,
 *		NFSERR_NXIO = 6,
 *		NFSERR_ACCES = 13,
 *		NFSERR_EXIST = 17,
 *		NFSERR_NODEV = 19,
 *		NFSERR_NOTDIR = 20,
 *		NFSERR_ISDIR = 21,
 *		NFSERR_FBIG = 27,
 *		NFSERR_NOSPC = 28,
 *		NFSERR_ROFS = 30,
 *		NFSERR_NAMETOOLONG = 63,
 *		NFSERR_NOTEMPTY = 66,
 *		NFSERR_DQUOT = 69,
 *		NFSERR_STALE = 70,
 *		NFSERR_WFLUSH = 99
 *	};
 */
static int decode_stat(struct xdr_stream *xdr, enum nfs_stat *status)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(p == NULL))
		goto out_overflow;
	*status = be32_to_cpup(p);
	return 0;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

/*
 * 2.3.2.  ftype
 *
 *	enum ftype {
 *		NFNON = 0,
 *		NFREG = 1,
 *		NFDIR = 2,
 *		NFBLK = 3,
 *		NFCHR = 4,
 *		NFLNK = 5
 *	};
 *
 */
static __be32 *xdr_decode_ftype(__be32 *p, u32 *type)
{
	*type = be32_to_cpup(p++);
	if (unlikely(*type > NF2FIFO))
		*type = NFBAD;
	return p;
}

/*
 * 2.3.3.  fhandle
 *
 *	typedef opaque fhandle[FHSIZE];
 */
static void encode_fhandle(struct xdr_stream *xdr, const struct nfs_fh *fh)
{
	__be32 *p;

	BUG_ON(fh->size != NFS2_FHSIZE);
	p = xdr_reserve_space(xdr, NFS2_FHSIZE);
	memcpy(p, fh->data, NFS2_FHSIZE);
}

static int decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, NFS2_FHSIZE);
	if (unlikely(p == NULL))
		goto out_overflow;
	fh->size = NFS2_FHSIZE;
	memcpy(fh->data, p, NFS2_FHSIZE);
	return 0;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

/*
 * 2.3.4.  timeval
 *
 *	struct timeval {
 *		unsigned int seconds;
 *		unsigned int useconds;
 *	};
 */
static __be32 *xdr_encode_time(__be32 *p, const struct timespec *timep)
{
	*p++ = cpu_to_be32(timep->tv_sec);
	if (timep->tv_nsec != 0)
		*p++ = cpu_to_be32(timep->tv_nsec / NSEC_PER_USEC);
	else
		*p++ = cpu_to_be32(0);
	return p;
}

/*
 * Passing the invalid value useconds=1000000 is a Sun convention for
 * "set to current server time".  It's needed to make permissions checks
 * for the "touch" program across v2 mounts to Solaris and Irix servers
 * work correctly.  See description of sattr in section 6.1 of "NFS
 * Illustrated" by Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5.
 */
static __be32 *xdr_encode_current_server_time(__be32 *p,
					      const struct timespec *timep)
{
	*p++ = cpu_to_be32(timep->tv_sec);
	*p++ = cpu_to_be32(1000000);
	return p;
}

static __be32 *xdr_decode_time(__be32 *p, struct timespec *timep)
{
	timep->tv_sec = be32_to_cpup(p++);
	timep->tv_nsec = be32_to_cpup(p++) * NSEC_PER_USEC;
	return p;
}

/*
 * 2.3.5.  fattr
 *
 *	struct fattr {
 *		ftype		type;
 *		unsigned int	mode;
 *		unsigned int	nlink;
 *		unsigned int	uid;
 *		unsigned int	gid;
 *		unsigned int	size;
 *		unsigned int	blocksize;
 *		unsigned int	rdev;
 *		unsigned int	blocks;
 *		unsigned int	fsid;
 *		unsigned int	fileid;
 *		timeval		atime;
 *		timeval		mtime;
 *		timeval		ctime;
 *	};
 *
 */
static int decode_fattr(struct xdr_stream *xdr, struct nfs_fattr *fattr)
{
	u32 rdev, type;
	__be32 *p;

	p = xdr_inline_decode(xdr, NFS_fattr_sz << 2);
	if (unlikely(p == NULL))
		goto out_overflow;

	fattr->valid |= NFS_ATTR_FATTR_V2;

	p = xdr_decode_ftype(p, &type);

	fattr->mode = be32_to_cpup(p++);
	fattr->nlink = be32_to_cpup(p++);
	fattr->uid = be32_to_cpup(p++);
	fattr->gid = be32_to_cpup(p++);
	fattr->size = be32_to_cpup(p++);
	fattr->du.nfs2.blocksize = be32_to_cpup(p++);

	rdev = be32_to_cpup(p++);
	fattr->rdev = new_decode_dev(rdev);
	if (type == (u32)NFCHR && rdev == (u32)NFS2_FIFO_DEV) {
		fattr->mode = (fattr->mode & ~S_IFMT) | S_IFIFO;
		fattr->rdev = 0;
	}

	fattr->du.nfs2.blocks = be32_to_cpup(p++);
	fattr->fsid.major = be32_to_cpup(p++);
	fattr->fsid.minor = 0;
	fattr->fileid = be32_to_cpup(p++);

	p = xdr_decode_time(p, &fattr->atime);
	p = xdr_decode_time(p, &fattr->mtime);
	xdr_decode_time(p, &fattr->ctime);
	fattr->change_attr = nfs_timespec_to_change_attr(&fattr->ctime);

	return 0;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

/*
 * 2.3.6.  sattr
 *
 *	struct sattr {
 *		unsigned int	mode;
 *		unsigned int	uid;
 *		unsigned int	gid;
 *		unsigned int	size;
 *		timeval		atime;
 *		timeval		mtime;
 *	};
 */

#define NFS2_SATTR_NOT_SET	(0xffffffff)

static __be32 *xdr_time_not_set(__be32 *p)
{
	*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
	*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
	return p;
}

static void encode_sattr(struct xdr_stream *xdr, const struct iattr *attr)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, NFS_sattr_sz << 2);

	if (attr->ia_valid & ATTR_MODE)
		*p++ = cpu_to_be32(attr->ia_mode);
	else
		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
	if (attr->ia_valid & ATTR_UID)
		*p++ = cpu_to_be32(attr->ia_uid);
	else
		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
	if (attr->ia_valid & ATTR_GID)
		*p++ = cpu_to_be32(attr->ia_gid);
	else
		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
	if (attr->ia_valid & ATTR_SIZE)
		*p++ = cpu_to_be32((u32)attr->ia_size);
	else
		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);

	if (attr->ia_valid & ATTR_ATIME_SET)
		p = xdr_encode_time(p, &attr->ia_atime);
	else if (attr->ia_valid & ATTR_ATIME)
		p = xdr_encode_current_server_time(p, &attr->ia_atime);
	else
		p = xdr_time_not_set(p);
	if (attr->ia_valid & ATTR_MTIME_SET)
		xdr_encode_time(p, &attr->ia_mtime);
	else if (attr->ia_valid & ATTR_MTIME)
		xdr_encode_current_server_time(p, &attr->ia_mtime);
	else
		xdr_time_not_set(p);
}

/*
 * 2.3.7.  filename
 *
 *	typedef string filename<MAXNAMLEN>;
 */
static void encode_filename(struct xdr_stream *xdr,
			    const char *name, u32 length)
{
	__be32 *p;

	BUG_ON(length > NFS2_MAXNAMLEN);
	p = xdr_reserve_space(xdr, 4 + length);
	xdr_encode_opaque(p, name, length);
}

static int decode_filename_inline(struct xdr_stream *xdr,
				  const char **name, u32 *length)
{
	__be32 *p;
	u32 count;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(p == NULL))
		goto out_overflow;
	count = be32_to_cpup(p);
	if (count > NFS3_MAXNAMLEN)
		goto out_nametoolong;
	p = xdr_inline_decode(xdr, count);
	if (unlikely(p == NULL))
		goto out_overflow;
	*name = (const char *)p;
	*length = count;
	return 0;
out_nametoolong:
	dprintk("NFS: returned filename too long: %u\n", count);
	return -ENAMETOOLONG;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

/*
 * 2.3.8.  path
 *
 *	typedef string path<MAXPATHLEN>;
 */
static void encode_path(struct xdr_stream *xdr, struct page **pages, u32 length)
{
	__be32 *p;

	BUG_ON(length > NFS2_MAXPATHLEN);
	p = xdr_reserve_space(xdr, 4);
	*p = cpu_to_be32(length);
	xdr_write_pages(xdr, pages, 0, length);
}

static int decode_path(struct xdr_stream *xdr)
{
	u32 length, recvd;
	size_t hdrlen;
	__be32 *p;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(p == NULL))
		goto out_overflow;
	length = be32_to_cpup(p);
	if (unlikely(length >= xdr->buf->page_len || length > NFS_MAXPATHLEN))
		goto out_size;
	hdrlen = (u8 *)xdr->p - (u8 *)xdr->iov->iov_base;
	recvd = xdr->buf->len - hdrlen;
	if (unlikely(length > recvd))
		goto out_cheating;

	xdr_read_pages(xdr, length);
	xdr_terminate_string(xdr->buf, length);
	return 0;
out_size:
	dprintk("NFS: returned pathname too long: %u\n", length);
	return -ENAMETOOLONG;
out_cheating:
	dprintk("NFS: server cheating in pathname result: "
		"length %u > received %u\n", length, recvd);
	return -EIO;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

/*
 * 2.3.9.  attrstat
 *
 *	union attrstat switch (stat status) {
 *	case NFS_OK:
 *		fattr attributes;
 *	default:
 *		void;
 *	};
 */
static int decode_attrstat(struct xdr_stream *xdr, struct nfs_fattr *result)
{
	enum nfs_stat status;
	int error;

	error = decode_stat(xdr, &status);
	if (unlikely(error))
		goto out;
	if (status != NFS_OK)
		goto out_default;
	error = decode_fattr(xdr, result);
out:
	return error;
out_default:
	return nfs_stat_to_errno(status);
}

/*
 * 2.3.10.  diropargs
 *
 *	struct diropargs {
 *		fhandle  dir;
 *		filename name;
 *	};
 */
static void encode_diropargs(struct xdr_stream *xdr, const struct nfs_fh *fh,
			     const char *name, u32 length)
{
	encode_fhandle(xdr, fh);
	encode_filename(xdr, name, length);
}

/*
 * 2.3.11.  diropres
 *
 *	union diropres switch (stat status) {
 *	case NFS_OK:
 *		struct {
 *			fhandle file;
 *			fattr   attributes;
 *		} diropok;
 *	default:
 *		void;
 *	};
 */
static int decode_diropok(struct xdr_stream *xdr, struct nfs_diropok *result)
{
	int error;

	error = decode_fhandle(xdr, result->fh);
	if (unlikely(error))
		goto out;
	error = decode_fattr(xdr, result->fattr);
out:
	return error;
}

static int decode_diropres(struct xdr_stream *xdr, struct nfs_diropok *result)
{
	enum nfs_stat status;
	int error;

	error = decode_stat(xdr, &status);
	if (unlikely(error))
		goto out;
	if (status != NFS_OK)
		goto out_default;
	error = decode_diropok(xdr, result);
out:
	return error;
out_default:
	return nfs_stat_to_errno(status);
}


/*
 * NFSv2 XDR encode functions
 *
 * NFSv2 argument types are defined in section 2.2 of RFC 1094:
 * "NFS: Network File System Protocol Specification".
 */

static void nfs2_xdr_enc_fhandle(struct rpc_rqst *req,
				 struct xdr_stream *xdr,
				 const struct nfs_fh *fh)
{
	encode_fhandle(xdr, fh);
}

/*
 * 2.2.3.  sattrargs
 *
 *	struct sattrargs {
 *		fhandle file;
 *		sattr attributes;
 *	};
 */
static void nfs2_xdr_enc_sattrargs(struct rpc_rqst *req,
				   struct xdr_stream *xdr,
				   const struct nfs_sattrargs *args)
{
	encode_fhandle(xdr, args->fh);
	encode_sattr(xdr, args->sattr);
}

static void nfs2_xdr_enc_diropargs(struct rpc_rqst *req,
				   struct xdr_stream *xdr,
				   const struct nfs_diropargs *args)
{
	encode_diropargs(xdr, args->fh, args->name, args->len);
}

static void nfs2_xdr_enc_readlinkargs(struct rpc_rqst *req,
				      struct xdr_stream *xdr,
				      const struct nfs_readlinkargs *args)
{
	encode_fhandle(xdr, args->fh);
	prepare_reply_buffer(req, args->pages, args->pgbase,
					args->pglen, NFS_readlinkres_sz);
}

/*
 * 2.2.7.  readargs
 *
 *	struct readargs {
 *		fhandle file;
 *		unsigned offset;
 *		unsigned count;
 *		unsigned totalcount;
 *	};
 */
static void encode_readargs(struct xdr_stream *xdr,
			    const struct nfs_readargs *args)
{
	u32 offset = args->offset;
	u32 count = args->count;
	__be32 *p;

	encode_fhandle(xdr, args->fh);

	p = xdr_reserve_space(xdr, 4 + 4 + 4);
	*p++ = cpu_to_be32(offset);
	*p++ = cpu_to_be32(count);
	*p = cpu_to_be32(count);
}

static void nfs2_xdr_enc_readargs(struct rpc_rqst *req,
				  struct xdr_stream *xdr,
				  const struct nfs_readargs *args)
{
	encode_readargs(xdr, args);
	prepare_reply_buffer(req, args->pages, args->pgbase,
					args->count, NFS_readres_sz);
	req->rq_rcv_buf.flags |= XDRBUF_READ;
}

/*
 * 2.2.9.  writeargs
 *
 *	struct writeargs {
 *		fhandle file;
 *		unsigned beginoffset;
 *		unsigned offset;
 *		unsigned totalcount;
 *		nfsdata data;
 *	};
 */
static void encode_writeargs(struct xdr_stream *xdr,
			     const struct nfs_writeargs *args)
{
	u32 offset = args->offset;
	u32 count = args->count;
	__be32 *p;

	encode_fhandle(xdr, args->fh);

	p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
	*p++ = cpu_to_be32(offset);
	*p++ = cpu_to_be32(offset);
	*p++ = cpu_to_be32(count);

	/* nfsdata */
	*p = cpu_to_be32(count);
	xdr_write_pages(xdr, args->pages, args->pgbase, count);
}

static void nfs2_xdr_enc_writeargs(struct rpc_rqst *req,
				   struct xdr_stream *xdr,
				   const struct nfs_writeargs *args)
{
	encode_writeargs(xdr, args);
	xdr->buf->flags |= XDRBUF_WRITE;
}

/*
 * 2.2.10.  createargs
 *
 *	struct createargs {
 *		diropargs where;
 *		sattr attributes;
 *	};
 */
static void nfs2_xdr_enc_createargs(struct rpc_rqst *req,
				    struct xdr_stream *xdr,
				    const struct nfs_createargs *args)
{
	encode_diropargs(xdr, args->fh, args->name, args->len);
	encode_sattr(xdr, args->sattr);
}

static void nfs2_xdr_enc_removeargs(struct rpc_rqst *req,
				    struct xdr_stream *xdr,
				    const struct nfs_removeargs *args)
{
	encode_diropargs(xdr, args->fh, args->name.name, args->name.len);
}

/*
 * 2.2.12.  renameargs
 *
 *	struct renameargs {
 *		diropargs from;
 *		diropargs to;
 *	};
 */
static void nfs2_xdr_enc_renameargs(struct rpc_rqst *req,
				    struct xdr_stream *xdr,
				    const struct nfs_renameargs *args)
{
	const struct qstr *old = args->old_name;
	const struct qstr *new = args->new_name;

	encode_diropargs(xdr, args->old_dir, old->name, old->len);
	encode_diropargs(xdr, args->new_dir, new->name, new->len);
}

/*
 * 2.2.13.  linkargs
 *
 *	struct linkargs {
 *		fhandle from;
 *		diropargs to;
 *	};
 */
static void nfs2_xdr_enc_linkargs(struct rpc_rqst *req,
				  struct xdr_stream *xdr,
				  const struct nfs_linkargs *args)
{
	encode_fhandle(xdr, args->fromfh);
	encode_diropargs(xdr, args->tofh, args->toname, args->tolen);
}

/*
 * 2.2.14.  symlinkargs
 *
 *	struct symlinkargs {
 *		diropargs from;
 *		path to;
 *		sattr attributes;
 *	};
 */
static void nfs2_xdr_enc_symlinkargs(struct rpc_rqst *req,
				     struct xdr_stream *xdr,
				     const struct nfs_symlinkargs *args)
{
	encode_diropargs(xdr, args->fromfh, args->fromname, args->fromlen);
	encode_path(xdr, args->pages, args->pathlen);
	encode_sattr(xdr, args->sattr);
}

/*
 * 2.2.17.  readdirargs
 *
 *	struct readdirargs {
 *		fhandle dir;
 *		nfscookie cookie;
 *		unsigned count;
 *	};
 */
static void encode_readdirargs(struct xdr_stream *xdr,
			       const struct nfs_readdirargs *args)
{
	__be32 *p;

	encode_fhandle(xdr, args->fh);

	p = xdr_reserve_space(xdr, 4 + 4);
	*p++ = cpu_to_be32(args->cookie);
	*p = cpu_to_be32(args->count);
}

static void nfs2_xdr_enc_readdirargs(struct rpc_rqst *req,
				     struct xdr_stream *xdr,
				     const struct nfs_readdirargs *args)
{
	encode_readdirargs(xdr, args);
	prepare_reply_buffer(req, args->pages, 0,
					args->count, NFS_readdirres_sz);
}

/*
 * NFSv2 XDR decode functions
 *
 * NFSv2 result types are defined in section 2.2 of RFC 1094:
 * "NFS: Network File System Protocol Specification".
 */

static int nfs2_xdr_dec_stat(struct rpc_rqst *req, struct xdr_stream *xdr,
			     void *__unused)
{
	enum nfs_stat status;
	int error;

	error = decode_stat(xdr, &status);
	if (unlikely(error))
		goto out;
	if (status != NFS_OK)
		goto out_default;
out:
	return error;
out_default:
	return nfs_stat_to_errno(status);
}

static int nfs2_xdr_dec_attrstat(struct rpc_rqst *req, struct xdr_stream *xdr,
				 struct nfs_fattr *result)
{
	return decode_attrstat(xdr, result);
}

static int nfs2_xdr_dec_diropres(struct rpc_rqst *req, struct xdr_stream *xdr,
				 struct nfs_diropok *result)
{
	return decode_diropres(xdr, result);
}

/*
 * 2.2.6.  readlinkres
 *
 *	union readlinkres switch (stat status) {
 *	case NFS_OK:
 *		path data;
 *	default:
 *		void;
 *	};
 */
static int nfs2_xdr_dec_readlinkres(struct rpc_rqst *req,
				    struct xdr_stream *xdr, void *__unused)
{
	enum nfs_stat status;
	int error;

	error = decode_stat(xdr, &status);
	if (unlikely(error))
		goto out;
	if (status != NFS_OK)
		goto out_default;
	error = decode_path(xdr);
out:
	return error;
out_default:
	return nfs_stat_to_errno(status);
}

/*
 * 2.2.7.  readres
 *
 *	union readres switch (stat status) {
 *	case NFS_OK:
 *		fattr attributes;
 *		nfsdata data;
 *	default:
 *		void;
 *	};
 */
static int nfs2_xdr_dec_readres(struct rpc_rqst *req, struct xdr_stream *xdr,
				struct nfs_readres *result)
{
	enum nfs_stat status;
	int error;

	error = decode_stat(xdr, &status);
	if (unlikely(error))
		goto out;
	if (status != NFS_OK)
		goto out_default;
	error = decode_fattr(xdr, result->fattr);
	if (unlikely(error))
		goto out;
	error = decode_nfsdata(xdr, result);
out:
	return error;
out_default:
	return nfs_stat_to_errno(status);
}

static int nfs2_xdr_dec_writeres(struct rpc_rqst *req, struct xdr_stream *xdr,
				 struct nfs_writeres *result)
{
	/* All NFSv2 writes are "file sync" writes */
	result->verf->committed = NFS_FILE_SYNC;
	return decode_attrstat(xdr, result->fattr);
}

/**
 * nfs2_decode_dirent - Decode a single NFSv2 directory entry stored in
 *                      the local page cache.
 * @xdr: XDR stream where entry resides
 * @entry: buffer to fill in with entry data
 * @plus: boolean indicating whether this should be a readdirplus entry
 *
 * Returns zero if successful, otherwise a negative errno value is
 * returned.
 *
 * This function is not invoked during READDIR reply decoding, but
 * rather whenever an application invokes the getdents(2) system call
 * on a directory already in our cache.
 *
 * 2.2.17.  entry
 *
 *	struct entry {
 *		unsigned	fileid;
 *		filename	name;
 *		nfscookie	cookie;
 *		entry		*nextentry;
 *	};
 */
int nfs2_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
		       int plus)
{
	__be32 *p;
	int error;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(p == NULL))
		goto out_overflow;
	if (*p++ == xdr_zero) {
		p = xdr_inline_decode(xdr, 4);
		if (unlikely(p == NULL))
			goto out_overflow;
		if (*p++ == xdr_zero)
			return -EAGAIN;
		entry->eof = 1;
		return -EBADCOOKIE;
	}

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(p == NULL))
		goto out_overflow;
	entry->ino = be32_to_cpup(p);

	error = decode_filename_inline(xdr, &entry->name, &entry->len);
	if (unlikely(error))
		return error;

	/*
	 * The type (size and byte order) of nfscookie isn't defined in
	 * RFC 1094.  This implementation assumes that it's an XDR uint32.
	 */
	entry->prev_cookie = entry->cookie;
	p = xdr_inline_decode(xdr, 4);
	if (unlikely(p == NULL))
		goto out_overflow;
	entry->cookie = be32_to_cpup(p);

	entry->d_type = DT_UNKNOWN;

	return 0;

out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EAGAIN;
}

/*
 * 2.2.17.  readdirres
 *
 *	union readdirres switch (stat status) {
 *	case NFS_OK:
 *		struct {
 *			entry *entries;
 *			bool eof;
 *		} readdirok;
 *	default:
 *		void;
 *	};
 *
 * Read the directory contents into the page cache, but don't
 * touch them.  The actual decoding is done by nfs2_decode_dirent()
 * during subsequent nfs_readdir() calls.
 */
static int decode_readdirok(struct xdr_stream *xdr)
{
	u32 recvd, pglen;
	size_t hdrlen;

	pglen = xdr->buf->page_len;
	hdrlen = (u8 *)xdr->p - (u8 *)xdr->iov->iov_base;
	recvd = xdr->buf->len - hdrlen;
	if (unlikely(pglen > recvd))
		goto out_cheating;
out:
	xdr_read_pages(xdr, pglen);
	return pglen;
out_cheating:
	dprintk("NFS: server cheating in readdir result: "
		"pglen %u > recvd %u\n", pglen, recvd);
	pglen = recvd;
	goto out;
}

static int nfs2_xdr_dec_readdirres(struct rpc_rqst *req,
				   struct xdr_stream *xdr, void *__unused)
{
	enum nfs_stat status;
	int error;

	error = decode_stat(xdr, &status);
	if (unlikely(error))
		goto out;
	if (status != NFS_OK)
		goto out_default;
	error = decode_readdirok(xdr);
out:
	return error;
out_default:
	return nfs_stat_to_errno(status);
}

/*
 * 2.2.18.  statfsres
 *
 *	union statfsres (stat status) {
 *	case NFS_OK:
 *		struct {
 *			unsigned tsize;
 *			unsigned bsize;
 *			unsigned blocks;
 *			unsigned bfree;
 *			unsigned bavail;
 *		} info;
 *	default:
 *		void;
 *	};
 */
static int decode_info(struct xdr_stream *xdr, struct nfs2_fsstat *result)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, NFS_info_sz << 2);
	if (unlikely(p == NULL))
		goto out_overflow;
	result->tsize  = be32_to_cpup(p++);
	result->bsize  = be32_to_cpup(p++);
	result->blocks = be32_to_cpup(p++);
	result->bfree  = be32_to_cpup(p++);
	result->bavail = be32_to_cpup(p);
	return 0;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

static int nfs2_xdr_dec_statfsres(struct rpc_rqst *req, struct xdr_stream *xdr,
				  struct nfs2_fsstat *result)
{
	enum nfs_stat status;
	int error;

	error = decode_stat(xdr, &status);
	if (unlikely(error))
		goto out;
	if (status != NFS_OK)
		goto out_default;
	error = decode_info(xdr, result);
out:
	return error;
out_default:
	return nfs_stat_to_errno(status);
}


/*
 * We need to translate between nfs status return values and
 * the local errno values which may not be the same.
 */
static const struct {
	int stat;
	int errno;
} nfs_errtbl[] = {
	{ NFS_OK,		0		},
	{ NFSERR_PERM,		-EPERM		},
	{ NFSERR_NOENT,		-ENOENT		},
	{ NFSERR_IO,		-errno_NFSERR_IO},
	{ NFSERR_NXIO,		-ENXIO		},
/*	{ NFSERR_EAGAIN,	-EAGAIN		}, */
	{ NFSERR_ACCES,		-EACCES		},
	{ NFSERR_EXIST,		-EEXIST		},
	{ NFSERR_XDEV,		-EXDEV		},
	{ NFSERR_NODEV,		-ENODEV		},
	{ NFSERR_NOTDIR,	-ENOTDIR	},
	{ NFSERR_ISDIR,		-EISDIR		},
	{ NFSERR_INVAL,		-EINVAL		},
	{ NFSERR_FBIG,		-EFBIG		},
	{ NFSERR_NOSPC,		-ENOSPC		},
	{ NFSERR_ROFS,		-EROFS		},
	{ NFSERR_MLINK,		-EMLINK		},
	{ NFSERR_NAMETOOLONG,	-ENAMETOOLONG	},
	{ NFSERR_NOTEMPTY,	-ENOTEMPTY	},
	{ NFSERR_DQUOT,		-EDQUOT		},
	{ NFSERR_STALE,		-ESTALE		},
	{ NFSERR_REMOTE,	-EREMOTE	},
#ifdef EWFLUSH
	{ NFSERR_WFLUSH,	-EWFLUSH	},
#endif
	{ NFSERR_BADHANDLE,	-EBADHANDLE	},
	{ NFSERR_NOT_SYNC,	-ENOTSYNC	},
	{ NFSERR_BAD_COOKIE,	-EBADCOOKIE	},
	{ NFSERR_NOTSUPP,	-ENOTSUPP	},
	{ NFSERR_TOOSMALL,	-ETOOSMALL	},
	{ NFSERR_SERVERFAULT,	-EREMOTEIO	},
	{ NFSERR_BADTYPE,	-EBADTYPE	},
	{ NFSERR_JUKEBOX,	-EJUKEBOX	},
	{ -1,			-EIO		}
};

/**
 * nfs_stat_to_errno - convert an NFS status code to a local errno
 * @status: NFS status code to convert
 *
 * Returns a local errno value, or -EIO if the NFS status code is
 * not recognized.  This function is used jointly by NFSv2 and NFSv3.
 */
static int nfs_stat_to_errno(enum nfs_stat status)
{
	int i;

	for (i = 0; nfs_errtbl[i].stat != -1; i++) {
		if (nfs_errtbl[i].stat == (int)status)
			return nfs_errtbl[i].errno;
	}
	dprintk("NFS: Unrecognized nfs status value: %u\n", status);
	return nfs_errtbl[i].errno;
}

#define PROC(proc, argtype, restype, timer)				\
[NFSPROC_##proc] = {							\
	.p_proc	    =  NFSPROC_##proc,					\
	.p_encode   =  (kxdreproc_t)nfs2_xdr_enc_##argtype,		\
	.p_decode   =  (kxdrdproc_t)nfs2_xdr_dec_##restype,		\
	.p_arglen   =  NFS_##argtype##_sz,				\
	.p_replen   =  NFS_##restype##_sz,				\
	.p_timer    =  timer,						\
	.p_statidx  =  NFSPROC_##proc,					\
	.p_name     =  #proc,						\
	}
struct rpc_procinfo	nfs_procedures[] = {
	PROC(GETATTR,	fhandle,	attrstat,	1),
	PROC(SETATTR,	sattrargs,	attrstat,	0),
	PROC(LOOKUP,	diropargs,	diropres,	2),
	PROC(READLINK,	readlinkargs,	readlinkres,	3),
	PROC(READ,	readargs,	readres,	3),
	PROC(WRITE,	writeargs,	writeres,	4),
	PROC(CREATE,	createargs,	diropres,	0),
	PROC(REMOVE,	removeargs,	stat,		0),
	PROC(RENAME,	renameargs,	stat,		0),
	PROC(LINK,	linkargs,	stat,		0),
	PROC(SYMLINK,	symlinkargs,	stat,		0),
	PROC(MKDIR,	createargs,	diropres,	0),
	PROC(RMDIR,	diropargs,	stat,		0),
	PROC(READDIR,	readdirargs,	readdirres,	3),
	PROC(STATFS,	fhandle,	statfsres,	0),
};

const struct rpc_version nfs_version2 = {
	.number			= 2,
	.nrprocs		= ARRAY_SIZE(nfs_procedures),
	.procs			= nfs_procedures
};