summaryrefslogtreecommitdiffstats
path: root/include/linux/sunrpc/xdr.h
blob: 72014c9216fc4688071e473081431bebe3b1e692 (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
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * XDR standard data types and function declarations
 *
 * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
 *
 * Based on:
 *   RFC 4506 "XDR: External Data Representation Standard", May 2006
 */

#ifndef _SUNRPC_XDR_H_
#define _SUNRPC_XDR_H_

#include <linux/uio.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include <linux/scatterlist.h>

struct bio_vec;
struct rpc_rqst;

/*
 * Size of an XDR encoding unit in bytes, i.e. 32 bits,
 * as defined in Section 3 of RFC 4506. All encoded
 * XDR data items are aligned on a boundary of 32 bits.
 */
#define XDR_UNIT		sizeof(__be32)

/*
 * Buffer adjustment
 */
#define XDR_QUADLEN(l)		(((l) + 3) >> 2)

/*
 * Generic opaque `network object.'
 */
#define XDR_MAX_NETOBJ		1024
struct xdr_netobj {
	unsigned int		len;
	u8 *			data;
};

/*
 * Basic structure for transmission/reception of a client XDR message.
 * Features a header (for a linear buffer containing RPC headers
 * and the data payload for short messages), and then an array of
 * pages.
 * The tail iovec allows you to append data after the page array. Its
 * main interest is for appending padding to the pages in order to
 * satisfy the int_32-alignment requirements in RFC1832.
 *
 * For the future, we might want to string several of these together
 * in a list if anybody wants to make use of NFSv4 COMPOUND
 * operations and/or has a need for scatter/gather involving pages.
 */
struct xdr_buf {
	struct kvec	head[1],	/* RPC header + non-page data */
			tail[1];	/* Appended after page data */

	struct bio_vec	*bvec;
	struct page **	pages;		/* Array of pages */
	unsigned int	page_base,	/* Start of page data */
			page_len,	/* Length of page data */
			flags;		/* Flags for data disposition */
#define XDRBUF_READ		0x01		/* target of file read */
#define XDRBUF_WRITE		0x02		/* source of file write */
#define XDRBUF_SPARSE_PAGES	0x04		/* Page array is sparse */

	unsigned int	buflen,		/* Total length of storage buffer */
			len;		/* Length of XDR encoded message */
};

static inline void
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->pages = NULL;
	buf->page_len = 0;
	buf->flags = 0;
	buf->len = 0;
	buf->buflen = len;
}

/*
 * pre-xdr'ed macros.
 */

#define	xdr_zero	cpu_to_be32(0)
#define	xdr_one		cpu_to_be32(1)
#define	xdr_two		cpu_to_be32(2)

#define	rpc_auth_null	cpu_to_be32(RPC_AUTH_NULL)
#define	rpc_auth_unix	cpu_to_be32(RPC_AUTH_UNIX)
#define	rpc_auth_short	cpu_to_be32(RPC_AUTH_SHORT)
#define	rpc_auth_gss	cpu_to_be32(RPC_AUTH_GSS)
#define	rpc_auth_tls	cpu_to_be32(RPC_AUTH_TLS)

#define	rpc_call	cpu_to_be32(RPC_CALL)
#define	rpc_reply	cpu_to_be32(RPC_REPLY)

#define	rpc_msg_accepted	cpu_to_be32(RPC_MSG_ACCEPTED)

#define	rpc_success		cpu_to_be32(RPC_SUCCESS)
#define	rpc_prog_unavail	cpu_to_be32(RPC_PROG_UNAVAIL)
#define	rpc_prog_mismatch	cpu_to_be32(RPC_PROG_MISMATCH)
#define	rpc_proc_unavail	cpu_to_be32(RPC_PROC_UNAVAIL)
#define	rpc_garbage_args	cpu_to_be32(RPC_GARBAGE_ARGS)
#define	rpc_system_err		cpu_to_be32(RPC_SYSTEM_ERR)
#define	rpc_drop_reply		cpu_to_be32(RPC_DROP_REPLY)

#define	rpc_mismatch		cpu_to_be32(RPC_MISMATCH)
#define	rpc_auth_error		cpu_to_be32(RPC_AUTH_ERROR)

#define	rpc_auth_ok		cpu_to_be32(RPC_AUTH_OK)
#define	rpc_autherr_badcred	cpu_to_be32(RPC_AUTH_BADCRED)
#define	rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED)
#define	rpc_autherr_badverf	cpu_to_be32(RPC_AUTH_BADVERF)
#define	rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF)
#define	rpc_autherr_tooweak	cpu_to_be32(RPC_AUTH_TOOWEAK)
#define	rpcsec_gsserr_credproblem	cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
#define	rpcsec_gsserr_ctxproblem	cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)

/*
 * Miscellaneous XDR helper functions
 */
__be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
__be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
__be32 *xdr_encode_string(__be32 *p, const char *s);
__be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
			unsigned int maxlen);
__be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
__be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);

void	xdr_inline_pages(struct xdr_buf *, unsigned int,
			 struct page **, unsigned int, unsigned int);
void	xdr_terminate_string(const struct xdr_buf *, const u32);
size_t	xdr_buf_pagecount(const struct xdr_buf *buf);
int	xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp);
void	xdr_free_bvec(struct xdr_buf *buf);

static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
{
	return xdr_encode_opaque(p, s, len);
}

/*
 * Decode 64bit quantities (NFSv3 support)
 */
static inline __be32 *
xdr_encode_hyper(__be32 *p, __u64 val)
{
	put_unaligned_be64(val, p);
	return p + 2;
}

static inline __be32 *
xdr_decode_hyper(__be32 *p, __u64 *valp)
{
	*valp = get_unaligned_be64(p);
	return p + 2;
}

static inline __be32 *
xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
{
	memcpy(ptr, p, len);
	return p + XDR_QUADLEN(len);
}

static inline void xdr_netobj_dup(struct xdr_netobj *dst,
				  struct xdr_netobj *src, gfp_t gfp_mask)
{
	dst->data = kmemdup(src->data, src->len, gfp_mask);
	dst->len = src->len;
}

/*
 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
 */
static inline int
xdr_adjust_iovec(struct kvec *iov, __be32 *p)
{
	return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
}

/*
 * XDR buffer helper functions
 */
extern void xdr_buf_from_iov(const struct kvec *, struct xdr_buf *);
extern int xdr_buf_subsegment(const struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
extern int read_bytes_from_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
extern int write_bytes_to_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);

extern int xdr_encode_word(const struct xdr_buf *, unsigned int, u32);
extern int xdr_decode_word(const struct xdr_buf *, unsigned int, u32 *);

struct xdr_array2_desc;
typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
struct xdr_array2_desc {
	unsigned int elem_size;
	unsigned int array_len;
	unsigned int array_maxlen;
	xdr_xcode_elem_t xcode;
};

extern int xdr_decode_array2(const struct xdr_buf *buf, unsigned int base,
			     struct xdr_array2_desc *desc);
extern int xdr_encode_array2(const struct xdr_buf *buf, unsigned int base,
			     struct xdr_array2_desc *desc);
extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
			     size_t len);

/*
 * Provide some simple tools for XDR buffer overflow-checking etc.
 */
struct xdr_stream {
	__be32 *p;		/* start of available buffer */
	struct xdr_buf *buf;	/* XDR buffer to read/write */

	__be32 *end;		/* end of available buffer space */
	struct kvec *iov;	/* pointer to the current kvec */
	struct kvec scratch;	/* Scratch buffer */
	struct page **page_ptr;	/* pointer to the current page */
	unsigned int nwords;	/* Remaining decode buffer length */

	struct rpc_rqst *rqst;	/* For debugging */
};

/*
 * These are the xdr_stream style generic XDR encode and decode functions.
 */
typedef void	(*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
		const void *obj);
typedef int	(*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
		void *obj);

extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf,
			    __be32 *p, struct rpc_rqst *rqst);
extern void xdr_init_encode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
			   struct page **pages, struct rpc_rqst *rqst);
extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
extern int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec,
		size_t nbytes);
extern void __xdr_commit_encode(struct xdr_stream *xdr);
extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
extern void xdr_truncate_decode(struct xdr_stream *xdr, size_t len);
extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen);
extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
		unsigned int base, unsigned int len);
extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
extern unsigned int xdr_page_pos(const struct xdr_stream *xdr);
extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf,
			    __be32 *p, struct rpc_rqst *rqst);
extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
		struct page **pages, unsigned int len);
extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
extern int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
extern void xdr_set_pagelen(struct xdr_stream *, unsigned int len);
extern bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,
				  unsigned int len);
extern unsigned int xdr_stream_move_subsegment(struct xdr_stream *xdr, unsigned int offset,
					       unsigned int target, unsigned int length);
extern unsigned int xdr_stream_zero(struct xdr_stream *xdr, unsigned int offset,
				    unsigned int length);

/**
 * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
 * @xdr: pointer to xdr_stream struct
 * @buf: pointer to an empty buffer
 * @buflen: size of 'buf'
 *
 * The scratch buffer is used when decoding from an array of pages.
 * If an xdr_inline_decode() call spans across page boundaries, then
 * we copy the data into the scratch buffer in order to allow linear
 * access.
 */
static inline void
xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen)
{
	xdr->scratch.iov_base = buf;
	xdr->scratch.iov_len = buflen;
}

/**
 * xdr_set_scratch_page - Attach a scratch buffer for decoding data
 * @xdr: pointer to xdr_stream struct
 * @page: an anonymous page
 *
 * See xdr_set_scratch_buffer().
 */
static inline void
xdr_set_scratch_page(struct xdr_stream *xdr, struct page *page)
{
	xdr_set_scratch_buffer(xdr, page_address(page), PAGE_SIZE);
}

/**
 * xdr_reset_scratch_buffer - Clear scratch buffer information
 * @xdr: pointer to xdr_stream struct
 *
 * See xdr_set_scratch_buffer().
 */
static inline void
xdr_reset_scratch_buffer(struct xdr_stream *xdr)
{
	xdr_set_scratch_buffer(xdr, NULL, 0);
}

/**
 * xdr_commit_encode - Ensure all data is written to xdr->buf
 * @xdr: pointer to xdr_stream
 *
 * Handle encoding across page boundaries by giving the caller a
 * temporary location to write to, then later copying the data into
 * place. __xdr_commit_encode() does that copying.
 */
static inline void xdr_commit_encode(struct xdr_stream *xdr)
{
	if (unlikely(xdr->scratch.iov_len))
		__xdr_commit_encode(xdr);
}

/**
 * xdr_stream_remaining - Return the number of bytes remaining in the stream
 * @xdr: pointer to struct xdr_stream
 *
 * Return value:
 *   Number of bytes remaining in @xdr before xdr->end
 */
static inline size_t
xdr_stream_remaining(const struct xdr_stream *xdr)
{
	return xdr->nwords << 2;
}

ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr,
		size_t size);
ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr,
		size_t maxlen, gfp_t gfp_flags);
ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str,
		size_t size);
ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
		size_t maxlen, gfp_t gfp_flags);
ssize_t xdr_stream_decode_opaque_auth(struct xdr_stream *xdr, u32 *flavor,
		void **body, unsigned int *body_len);
ssize_t xdr_stream_encode_opaque_auth(struct xdr_stream *xdr, u32 flavor,
		void *body, unsigned int body_len);

/**
 * xdr_align_size - Calculate padded size of an object
 * @n: Size of an object being XDR encoded (in bytes)
 *
 * Return value:
 *   Size (in bytes) of the object including xdr padding
 */
static inline size_t
xdr_align_size(size_t n)
{
	const size_t mask = XDR_UNIT - 1;

	return (n + mask) & ~mask;
}

/**
 * xdr_pad_size - Calculate size of an object's pad
 * @n: Size of an object being XDR encoded (in bytes)
 *
 * This implementation avoids the need for conditional
 * branches or modulo division.
 *
 * Return value:
 *   Size (in bytes) of the needed XDR pad
 */
static inline size_t xdr_pad_size(size_t n)
{
	return xdr_align_size(n) - n;
}

/**
 * xdr_stream_encode_item_present - Encode a "present" list item
 * @xdr: pointer to xdr_stream
 *
 * Return values:
 *   On success, returns length in bytes of XDR buffer consumed
 *   %-EMSGSIZE on XDR buffer overflow
 */
static inline ssize_t xdr_stream_encode_item_present(struct xdr_stream *xdr)
{
	const size_t len = XDR_UNIT;
	__be32 *p = xdr_reserve_space(xdr, len);

	if (unlikely(!p))
		return -EMSGSIZE;
	*p = xdr_one;
	return len;
}

/**
 * xdr_stream_encode_item_absent - Encode a "not present" list item
 * @xdr: pointer to xdr_stream
 *
 * Return values:
 *   On success, returns length in bytes of XDR buffer consumed
 *   %-EMSGSIZE on XDR buffer overflow
 */
static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr)
{
	const size_t len = XDR_UNIT;
	__be32 *p = xdr_reserve_space(xdr, len);

	if (unlikely(!p))
		return -EMSGSIZE;
	*p = xdr_zero;
	return len;
}

/**
 * xdr_encode_bool - Encode a boolean item
 * @p: address in a buffer into which to encode
 * @n: boolean value to encode
 *
 * Return value:
 *   Address of item following the encoded boolean
 */
static inline __be32 *xdr_encode_bool(__be32 *p, u32 n)
{
	*p++ = n ? xdr_one : xdr_zero;
	return p;
}

/**
 * xdr_stream_encode_bool - Encode a boolean item
 * @xdr: pointer to xdr_stream
 * @n: boolean value to encode
 *
 * Return values:
 *   On success, returns length in bytes of XDR buffer consumed
 *   %-EMSGSIZE on XDR buffer overflow
 */
static inline int xdr_stream_encode_bool(struct xdr_stream *xdr, __u32 n)
{
	const size_t len = XDR_UNIT;
	__be32 *p = xdr_reserve_space(xdr, len);

	if (unlikely(!p))
		return -EMSGSIZE;
	xdr_encode_bool(p, n);
	return len;
}

/**
 * xdr_stream_encode_u32 - Encode a 32-bit integer
 * @xdr: pointer to xdr_stream
 * @n: integer to encode
 *
 * Return values:
 *   On success, returns length in bytes of XDR buffer consumed
 *   %-EMSGSIZE on XDR buffer overflow
 */
static inline ssize_t
xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n)
{
	const size_t len = sizeof(n);
	__be32 *p = xdr_reserve_space(xdr, len);

	if (unlikely(!p))
		return -EMSGSIZE;
	*p = cpu_to_be32(n);
	return len;
}

/**
 * xdr_stream_encode_be32 - Encode a big-endian 32-bit integer
 * @xdr: pointer to xdr_stream
 * @n: integer to encode
 *
 * Return values:
 *   On success, returns length in bytes of XDR buffer consumed
 *   %-EMSGSIZE on XDR buffer overflow
 */
static inline ssize_t
xdr_stream_encode_be32(struct xdr_stream *xdr, __be32 n)
{
	const size_t len = sizeof(n);
	__be32 *p = xdr_reserve_space(xdr, len);

	if (unlikely(!p))
		return -EMSGSIZE;
	*p = n;
	return len;
}

/**
 * xdr_stream_encode_u64 - Encode a 64-bit integer
 * @xdr: pointer to xdr_stream
 * @n: 64-bit integer to encode
 *
 * Return values:
 *   On success, returns length in bytes of XDR buffer consumed
 *   %-EMSGSIZE on XDR buffer overflow
 */
static inline ssize_t
xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n)
{
	const size_t len = sizeof(n);
	__be32 *p = xdr_reserve_space(xdr, len);

	if (unlikely(!p))
		return -EMSGSIZE;
	xdr_encode_hyper(p, n);
	return len;
}

/**
 * xdr_stream_encode_opaque_inline - Encode opaque xdr data
 * @xdr: pointer to xdr_stream
 * @ptr: pointer to void pointer
 * @len: size of object
 *
 * Return values:
 *   On success, returns length in bytes of XDR buffer consumed
 *   %-EMSGSIZE on XDR buffer overflow
 */
static inline ssize_t
xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len)
{
	size_t count = sizeof(__u32) + xdr_align_size(len);
	__be32 *p = xdr_reserve_space(xdr, count);

	if (unlikely(!p)) {
		*ptr = NULL;
		return -EMSGSIZE;
	}
	xdr_encode_opaque(p, NULL, len);
	*ptr = ++p;
	return count;
}

/**
 * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data
 * @xdr: pointer to xdr_stream
 * @ptr: pointer to opaque data object
 * @len: size of object pointed to by @ptr
 *
 * Return values:
 *   On success, returns length in bytes of XDR buffer consumed
 *   %-EMSGSIZE on XDR buffer overflow
 */
static inline ssize_t
xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len)
{
	__be32 *p = xdr_reserve_space(xdr, len);

	if (unlikely(!p))
		return -EMSGSIZE;
	xdr_encode_opaque_fixed(p, ptr, len);
	return xdr_align_size(len);
}

/**
 * xdr_stream_encode_opaque - Encode variable length opaque xdr data
 * @xdr: pointer to xdr_stream
 * @ptr: pointer to opaque data object
 * @len: size of object pointed to by @ptr
 *
 * Return values:
 *   On success, returns length in bytes of XDR buffer consumed
 *   %-EMSGSIZE on XDR buffer overflow
 */
static inline ssize_t
xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len)
{
	size_t count = sizeof(__u32) + xdr_align_size(len);
	__be32 *p = xdr_reserve_space(xdr, count);

	if (unlikely(!p))
		return -EMSGSIZE;
	xdr_encode_opaque(p, ptr, len);
	return count;
}

/**
 * xdr_stream_encode_uint32_array - Encode variable length array of integers
 * @xdr: pointer to xdr_stream
 * @array: array of integers
 * @array_size: number of elements in @array
 *
 * Return values:
 *   On success, returns length in bytes of XDR buffer consumed
 *   %-EMSGSIZE on XDR buffer overflow
 */
static inline ssize_t
xdr_stream_encode_uint32_array(struct xdr_stream *xdr,
		const __u32 *array, size_t array_size)
{
	ssize_t ret = (array_size+1) * sizeof(__u32);
	__be32 *p = xdr_reserve_space(xdr, ret);

	if (unlikely(!p))
		return -EMSGSIZE;
	*p++ = cpu_to_be32(array_size);
	for (; array_size > 0; p++, array++, array_size--)
		*p = cpu_to_be32p(array);
	return ret;
}

/**
 * xdr_item_is_absent - symbolically handle XDR discriminators
 * @p: pointer to undecoded discriminator
 *
 * Return values:
 *   %true if the following XDR item is absent
 *   %false if the following XDR item is present
 */
static inline bool xdr_item_is_absent(const __be32 *p)
{
	return *p == xdr_zero;
}

/**
 * xdr_item_is_present - symbolically handle XDR discriminators
 * @p: pointer to undecoded discriminator
 *
 * Return values:
 *   %true if the following XDR item is present
 *   %false if the following XDR item is absent
 */
static inline bool xdr_item_is_present(const __be32 *p)
{
	return *p != xdr_zero;
}

/**
 * xdr_stream_decode_bool - Decode a boolean
 * @xdr: pointer to xdr_stream
 * @ptr: pointer to a u32 in which to store the result
 *
 * Return values:
 *   %0 on success
 *   %-EBADMSG on XDR buffer overflow
 */
static inline ssize_t
xdr_stream_decode_bool(struct xdr_stream *xdr, __u32 *ptr)
{
	const size_t count = sizeof(*ptr);
	__be32 *p = xdr_inline_decode(xdr, count);

	if (unlikely(!p))
		return -EBADMSG;
	*ptr = (*p != xdr_zero);
	return 0;
}

/**
 * xdr_stream_decode_u32 - Decode a 32-bit integer
 * @xdr: pointer to xdr_stream
 * @ptr: location to store integer
 *
 * Return values:
 *   %0 on success
 *   %-EBADMSG on XDR buffer overflow
 */
static inline ssize_t
xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr)
{
	const size_t count = sizeof(*ptr);
	__be32 *p = xdr_inline_decode(xdr, count);

	if (unlikely(!p))
		return -EBADMSG;
	*ptr = be32_to_cpup(p);
	return 0;
}

/**
 * xdr_stream_decode_u64 - Decode a 64-bit integer
 * @xdr: pointer to xdr_stream
 * @ptr: location to store 64-bit integer
 *
 * Return values:
 *   %0 on success
 *   %-EBADMSG on XDR buffer overflow
 */
static inline ssize_t
xdr_stream_decode_u64(struct xdr_stream *xdr, __u64 *ptr)
{
	const size_t count = sizeof(*ptr);
	__be32 *p = xdr_inline_decode(xdr, count);

	if (unlikely(!p))
		return -EBADMSG;
	xdr_decode_hyper(p, ptr);
	return 0;
}

/**
 * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data
 * @xdr: pointer to xdr_stream
 * @ptr: location to store data
 * @len: size of buffer pointed to by @ptr
 *
 * Return values:
 *   On success, returns size of object stored in @ptr
 *   %-EBADMSG on XDR buffer overflow
 */
static inline ssize_t
xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len)
{
	__be32 *p = xdr_inline_decode(xdr, len);

	if (unlikely(!p))
		return -EBADMSG;
	xdr_decode_opaque_fixed(p, ptr, len);
	return len;
}

/**
 * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data
 * @xdr: pointer to xdr_stream
 * @ptr: location to store pointer to opaque data
 * @maxlen: maximum acceptable object size
 *
 * Note: the pointer stored in @ptr cannot be assumed valid after the XDR
 * buffer has been destroyed, or even after calling xdr_inline_decode()
 * on @xdr. It is therefore expected that the object it points to should
 * be processed immediately.
 *
 * Return values:
 *   On success, returns size of object stored in *@ptr
 *   %-EBADMSG on XDR buffer overflow
 *   %-EMSGSIZE if the size of the object would exceed @maxlen
 */
static inline ssize_t
xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen)
{
	__be32 *p;
	__u32 len;

	*ptr = NULL;
	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
		return -EBADMSG;
	if (len != 0) {
		p = xdr_inline_decode(xdr, len);
		if (unlikely(!p))
			return -EBADMSG;
		if (unlikely(len > maxlen))
			return -EMSGSIZE;
		*ptr = p;
	}
	return len;
}

/**
 * xdr_stream_decode_uint32_array - Decode variable length array of integers
 * @xdr: pointer to xdr_stream
 * @array: location to store the integer array or NULL
 * @array_size: number of elements to store
 *
 * Return values:
 *   On success, returns number of elements stored in @array
 *   %-EBADMSG on XDR buffer overflow
 *   %-EMSGSIZE if the size of the array exceeds @array_size
 */
static inline ssize_t
xdr_stream_decode_uint32_array(struct xdr_stream *xdr,
		__u32 *array, size_t array_size)
{
	__be32 *p;
	__u32 len;
	ssize_t retval;

	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
		return -EBADMSG;
	if (len > SIZE_MAX / sizeof(*p))
		return -EBADMSG;
	p = xdr_inline_decode(xdr, len * sizeof(*p));
	if (unlikely(!p))
		return -EBADMSG;
	if (array == NULL)
		return len;
	if (len <= array_size) {
		if (len < array_size)
			memset(array+len, 0, (array_size-len)*sizeof(*array));
		array_size = len;
		retval = len;
	} else
		retval = -EMSGSIZE;
	for (; array_size > 0; p++, array++, array_size--)
		*array = be32_to_cpup(p);
	return retval;
}

#endif /* _SUNRPC_XDR_H_ */