xdr.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * XDR standard data types and function declarations
  4 *
  5 * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
  6 *
  7 * Based on:
  8 *   RFC 4506 "XDR: External Data Representation Standard", May 2006
  9 */
 10
 11#ifndef _SUNRPC_XDR_H_
 12#define _SUNRPC_XDR_H_
 13
 14#include <linux/uio.h>
 15#include <asm/byteorder.h>
 16#include <linux/unaligned.h>
 17#include <linux/scatterlist.h>
 18
 19struct bio_vec;
 20struct rpc_rqst;
 21
 22/*
 23 * Size of an XDR encoding unit in bytes, i.e. 32 bits,
 24 * as defined in Section 3 of RFC 4506. All encoded
 25 * XDR data items are aligned on a boundary of 32 bits.
 26 */
 27#define XDR_UNIT		sizeof(__be32)
 28
 29/*
 30 * Buffer adjustment
 31 */
 32#define XDR_QUADLEN(l)		(((l) + 3) >> 2)
 33
 34/*
 35 * Generic opaque `network object.'
 36 */
 37#define XDR_MAX_NETOBJ		1024
 38struct xdr_netobj {
 39	unsigned int		len;
 40	u8 *			data;
 41};
 42
 43/*
 44 * Basic structure for transmission/reception of a client XDR message.
 45 * Features a header (for a linear buffer containing RPC headers
 46 * and the data payload for short messages), and then an array of
 47 * pages.
 48 * The tail iovec allows you to append data after the page array. Its
 49 * main interest is for appending padding to the pages in order to
 50 * satisfy the int_32-alignment requirements in RFC1832.
 51 *
 52 * For the future, we might want to string several of these together
 53 * in a list if anybody wants to make use of NFSv4 COMPOUND
 54 * operations and/or has a need for scatter/gather involving pages.
 55 */
 56struct xdr_buf {
 57	struct kvec	head[1],	/* RPC header + non-page data */
 58			tail[1];	/* Appended after page data */
 59
 60	struct bio_vec	*bvec;
 61	struct page **	pages;		/* Array of pages */
 62	unsigned int	page_base,	/* Start of page data */
 63			page_len,	/* Length of page data */
 64			flags;		/* Flags for data disposition */
 65#define XDRBUF_READ		0x01		/* target of file read */
 66#define XDRBUF_WRITE		0x02		/* source of file write */
 67#define XDRBUF_SPARSE_PAGES	0x04		/* Page array is sparse */
 68
 69	unsigned int	buflen,		/* Total length of storage buffer */
 70			len;		/* Length of XDR encoded message */
 71};
 72
 73static inline void
 74xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 75{
 76	buf->head[0].iov_base = start;
 77	buf->head[0].iov_len = len;
 78	buf->tail[0].iov_len = 0;
 79	buf->pages = NULL;
 80	buf->page_len = 0;
 81	buf->flags = 0;
 82	buf->len = 0;
 83	buf->buflen = len;
 84}
 85
 86/*
 87 * pre-xdr'ed macros.
 88 */
 89
 90#define	xdr_zero	cpu_to_be32(0)
 91#define	xdr_one		cpu_to_be32(1)
 92#define	xdr_two		cpu_to_be32(2)
 93
 94#define	rpc_auth_null	cpu_to_be32(RPC_AUTH_NULL)
 95#define	rpc_auth_unix	cpu_to_be32(RPC_AUTH_UNIX)
 96#define	rpc_auth_short	cpu_to_be32(RPC_AUTH_SHORT)
 97#define	rpc_auth_gss	cpu_to_be32(RPC_AUTH_GSS)
 98#define	rpc_auth_tls	cpu_to_be32(RPC_AUTH_TLS)
 99
100#define	rpc_call	cpu_to_be32(RPC_CALL)
101#define	rpc_reply	cpu_to_be32(RPC_REPLY)
102
103#define	rpc_msg_accepted	cpu_to_be32(RPC_MSG_ACCEPTED)
104
105#define	rpc_success		cpu_to_be32(RPC_SUCCESS)
106#define	rpc_prog_unavail	cpu_to_be32(RPC_PROG_UNAVAIL)
107#define	rpc_prog_mismatch	cpu_to_be32(RPC_PROG_MISMATCH)
108#define	rpc_proc_unavail	cpu_to_be32(RPC_PROC_UNAVAIL)
109#define	rpc_garbage_args	cpu_to_be32(RPC_GARBAGE_ARGS)
110#define	rpc_system_err		cpu_to_be32(RPC_SYSTEM_ERR)
111#define	rpc_drop_reply		cpu_to_be32(RPC_DROP_REPLY)
112
113#define	rpc_mismatch		cpu_to_be32(RPC_MISMATCH)
114#define	rpc_auth_error		cpu_to_be32(RPC_AUTH_ERROR)
115
116#define	rpc_auth_ok		cpu_to_be32(RPC_AUTH_OK)
117#define	rpc_autherr_badcred	cpu_to_be32(RPC_AUTH_BADCRED)
118#define	rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED)
119#define	rpc_autherr_badverf	cpu_to_be32(RPC_AUTH_BADVERF)
120#define	rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF)
121#define	rpc_autherr_tooweak	cpu_to_be32(RPC_AUTH_TOOWEAK)
122#define	rpc_autherr_invalidresp	cpu_to_be32(RPC_AUTH_INVALIDRESP)
123#define	rpc_autherr_failed	cpu_to_be32(RPC_AUTH_FAILED)
124#define	rpcsec_gsserr_credproblem	cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
125#define	rpcsec_gsserr_ctxproblem	cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
126
127/*
128 * Miscellaneous XDR helper functions
129 */
130__be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
131__be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
132__be32 *xdr_encode_string(__be32 *p, const char *s);
133__be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
134
135void	xdr_inline_pages(struct xdr_buf *, unsigned int,
136			 struct page **, unsigned int, unsigned int);
137void	xdr_terminate_string(const struct xdr_buf *, const u32);
138size_t	xdr_buf_pagecount(const struct xdr_buf *buf);
139int	xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp);
140void	xdr_free_bvec(struct xdr_buf *buf);
141unsigned int xdr_buf_to_bvec(struct bio_vec *bvec, unsigned int bvec_size,
142			     const struct xdr_buf *xdr);
143
144static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
145{
146	return xdr_encode_opaque(p, s, len);
147}
148
149/*
150 * Decode 64bit quantities (NFSv3 support)
151 */
152static inline __be32 *
153xdr_encode_hyper(__be32 *p, __u64 val)
154{
155	put_unaligned_be64(val, p);
156	return p + 2;
157}
158
159static inline __be32 *
160xdr_decode_hyper(__be32 *p, __u64 *valp)
161{
162	*valp = get_unaligned_be64(p);
163	return p + 2;
164}
165
166static inline __be32 *
167xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
168{
169	memcpy(ptr, p, len);
170	return p + XDR_QUADLEN(len);
171}
172
173static inline void xdr_netobj_dup(struct xdr_netobj *dst,
174				  struct xdr_netobj *src, gfp_t gfp_mask)
175{
176	dst->data = kmemdup(src->data, src->len, gfp_mask);
177	dst->len = src->len;
178}
179
180/*
181 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
182 */
183static inline int
184xdr_adjust_iovec(struct kvec *iov, __be32 *p)
185{
186	return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
187}
188
189/*
190 * XDR buffer helper functions
191 */
192extern void xdr_buf_from_iov(const struct kvec *, struct xdr_buf *);
193extern int xdr_buf_subsegment(const struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
194extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
195extern int read_bytes_from_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
196extern int write_bytes_to_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
197
198extern int xdr_encode_word(const struct xdr_buf *, unsigned int, u32);
199extern int xdr_decode_word(const struct xdr_buf *, unsigned int, u32 *);
200
201struct xdr_array2_desc;
202typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
203struct xdr_array2_desc {
204	unsigned int elem_size;
205	unsigned int array_len;
206	unsigned int array_maxlen;
207	xdr_xcode_elem_t xcode;
208};
209
210extern int xdr_decode_array2(const struct xdr_buf *buf, unsigned int base,
211			     struct xdr_array2_desc *desc);
212extern int xdr_encode_array2(const struct xdr_buf *buf, unsigned int base,
213			     struct xdr_array2_desc *desc);
214extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
215			     size_t len);
216
217/*
218 * Provide some simple tools for XDR buffer overflow-checking etc.
219 */
220struct xdr_stream {
221	__be32 *p;		/* start of available buffer */
222	struct xdr_buf *buf;	/* XDR buffer to read/write */
223
224	__be32 *end;		/* end of available buffer space */
225	struct kvec *iov;	/* pointer to the current kvec */
226	struct kvec scratch;	/* Scratch buffer */
227	struct page **page_ptr;	/* pointer to the current page */
228	void *page_kaddr;	/* kmapped address of the current page */
229	unsigned int nwords;	/* Remaining decode buffer length */
230
231	struct rpc_rqst *rqst;	/* For debugging */
232};
233
234/*
235 * These are the xdr_stream style generic XDR encode and decode functions.
236 */
237typedef void	(*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
238		const void *obj);
239typedef int	(*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
240		void *obj);
241
242extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf,
243			    __be32 *p, struct rpc_rqst *rqst);
244void xdr_init_encode_pages(struct xdr_stream *xdr, struct xdr_buf *buf);
245extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
246extern int xdr_reserve_space_vec(struct xdr_stream *xdr, size_t nbytes);
247extern void __xdr_commit_encode(struct xdr_stream *xdr);
248extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
249extern void xdr_truncate_decode(struct xdr_stream *xdr, size_t len);
250extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen);
251extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
252		unsigned int base, unsigned int len);
253extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
254extern unsigned int xdr_page_pos(const struct xdr_stream *xdr);
255extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf,
256			    __be32 *p, struct rpc_rqst *rqst);
257extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
258		struct page **pages, unsigned int len);
259extern void xdr_finish_decode(struct xdr_stream *xdr);
260extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
261extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
262extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
263extern int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
264extern void xdr_set_pagelen(struct xdr_stream *, unsigned int len);
265extern bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,
266				  unsigned int len);
267extern unsigned int xdr_stream_move_subsegment(struct xdr_stream *xdr, unsigned int offset,
268					       unsigned int target, unsigned int length);
269extern unsigned int xdr_stream_zero(struct xdr_stream *xdr, unsigned int offset,
270				    unsigned int length);
271
272/**
273 * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
274 * @xdr: pointer to xdr_stream struct
275 * @buf: pointer to an empty buffer
276 * @buflen: size of 'buf'
277 *
278 * The scratch buffer is used when decoding from an array of pages.
279 * If an xdr_inline_decode() call spans across page boundaries, then
280 * we copy the data into the scratch buffer in order to allow linear
281 * access.
282 */
283static inline void
284xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen)
285{
286	xdr->scratch.iov_base = buf;
287	xdr->scratch.iov_len = buflen;
288}
289
290/**
291 * xdr_set_scratch_folio - Attach a scratch buffer for decoding data
292 * @xdr: pointer to xdr_stream struct
293 * @page: an anonymous folio
294 *
295 * See xdr_set_scratch_buffer().
296 */
297static inline void
298xdr_set_scratch_folio(struct xdr_stream *xdr, struct folio *folio)
299{
300	xdr_set_scratch_buffer(xdr, folio_address(folio), folio_size(folio));
301}
302
303/**
304 * xdr_reset_scratch_buffer - Clear scratch buffer information
305 * @xdr: pointer to xdr_stream struct
306 *
307 * See xdr_set_scratch_buffer().
308 */
309static inline void
310xdr_reset_scratch_buffer(struct xdr_stream *xdr)
311{
312	xdr_set_scratch_buffer(xdr, NULL, 0);
313}
314
315/**
316 * xdr_commit_encode - Ensure all data is written to xdr->buf
317 * @xdr: pointer to xdr_stream
318 *
319 * Handle encoding across page boundaries by giving the caller a
320 * temporary location to write to, then later copying the data into
321 * place. __xdr_commit_encode() does that copying.
322 */
323static inline void xdr_commit_encode(struct xdr_stream *xdr)
324{
325	if (unlikely(xdr->scratch.iov_len))
326		__xdr_commit_encode(xdr);
327}
328
329/**
330 * xdr_stream_remaining - Return the number of bytes remaining in the stream
331 * @xdr: pointer to struct xdr_stream
332 *
333 * Return value:
334 *   Number of bytes remaining in @xdr before xdr->end
335 */
336static inline size_t
337xdr_stream_remaining(const struct xdr_stream *xdr)
338{
339	return xdr->nwords << 2;
340}
341
342ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
343		size_t maxlen, gfp_t gfp_flags);
344ssize_t xdr_stream_decode_opaque_auth(struct xdr_stream *xdr, u32 *flavor,
345		void **body, unsigned int *body_len);
346ssize_t xdr_stream_encode_opaque_auth(struct xdr_stream *xdr, u32 flavor,
347		void *body, unsigned int body_len);
348
349/**
350 * xdr_align_size - Calculate padded size of an object
351 * @n: Size of an object being XDR encoded (in bytes)
352 *
353 * Return value:
354 *   Size (in bytes) of the object including xdr padding
355 */
356static inline size_t
357xdr_align_size(size_t n)
358{
359	const size_t mask = XDR_UNIT - 1;
360
361	return (n + mask) & ~mask;
362}
363
364/**
365 * xdr_pad_size - Calculate size of an object's pad
366 * @n: Size of an object being XDR encoded (in bytes)
367 *
368 * This implementation avoids the need for conditional
369 * branches or modulo division.
370 *
371 * Return value:
372 *   Size (in bytes) of the needed XDR pad
373 */
374static inline size_t xdr_pad_size(size_t n)
375{
376	return xdr_align_size(n) - n;
377}
378
379/**
380 * xdr_stream_encode_item_present - Encode a "present" list item
381 * @xdr: pointer to xdr_stream
382 *
383 * Return values:
384 *   On success, returns length in bytes of XDR buffer consumed
385 *   %-EMSGSIZE on XDR buffer overflow
386 */
387static inline ssize_t xdr_stream_encode_item_present(struct xdr_stream *xdr)
388{
389	const size_t len = XDR_UNIT;
390	__be32 *p = xdr_reserve_space(xdr, len);
391
392	if (unlikely(!p))
393		return -EMSGSIZE;
394	*p = xdr_one;
395	return len;
396}
397
398/**
399 * xdr_stream_encode_item_absent - Encode a "not present" list item
400 * @xdr: pointer to xdr_stream
401 *
402 * Return values:
403 *   On success, returns length in bytes of XDR buffer consumed
404 *   %-EMSGSIZE on XDR buffer overflow
405 */
406static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr)
407{
408	const size_t len = XDR_UNIT;
409	__be32 *p = xdr_reserve_space(xdr, len);
410
411	if (unlikely(!p))
412		return -EMSGSIZE;
413	*p = xdr_zero;
414	return len;
415}
416
417/**
418 * xdr_encode_bool - Encode a boolean item
419 * @p: address in a buffer into which to encode
420 * @n: boolean value to encode
421 *
422 * Return value:
423 *   Address of item following the encoded boolean
424 */
425static inline __be32 *xdr_encode_bool(__be32 *p, u32 n)
426{
427	*p++ = n ? xdr_one : xdr_zero;
428	return p;
429}
430
431/**
432 * xdr_stream_encode_bool - Encode a boolean item
433 * @xdr: pointer to xdr_stream
434 * @n: boolean value to encode
435 *
436 * Return values:
437 *   On success, returns length in bytes of XDR buffer consumed
438 *   %-EMSGSIZE on XDR buffer overflow
439 */
440static inline int xdr_stream_encode_bool(struct xdr_stream *xdr, __u32 n)
441{
442	const size_t len = XDR_UNIT;
443	__be32 *p = xdr_reserve_space(xdr, len);
444
445	if (unlikely(!p))
446		return -EMSGSIZE;
447	xdr_encode_bool(p, n);
448	return len;
449}
450
451/**
452 * xdr_stream_encode_u32 - Encode a 32-bit integer
453 * @xdr: pointer to xdr_stream
454 * @n: integer to encode
455 *
456 * Return values:
457 *   On success, returns length in bytes of XDR buffer consumed
458 *   %-EMSGSIZE on XDR buffer overflow
459 */
460static inline ssize_t
461xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n)
462{
463	const size_t len = sizeof(n);
464	__be32 *p = xdr_reserve_space(xdr, len);
465
466	if (unlikely(!p))
467		return -EMSGSIZE;
468	*p = cpu_to_be32(n);
469	return len;
470}
471
472/**
473 * xdr_stream_encode_be32 - Encode a big-endian 32-bit integer
474 * @xdr: pointer to xdr_stream
475 * @n: integer to encode
476 *
477 * Return values:
478 *   On success, returns length in bytes of XDR buffer consumed
479 *   %-EMSGSIZE on XDR buffer overflow
480 */
481static inline ssize_t
482xdr_stream_encode_be32(struct xdr_stream *xdr, __be32 n)
483{
484	const size_t len = sizeof(n);
485	__be32 *p = xdr_reserve_space(xdr, len);
486
487	if (unlikely(!p))
488		return -EMSGSIZE;
489	*p = n;
490	return len;
491}
492
493/**
494 * xdr_stream_encode_u64 - Encode a 64-bit integer
495 * @xdr: pointer to xdr_stream
496 * @n: 64-bit integer to encode
497 *
498 * Return values:
499 *   On success, returns length in bytes of XDR buffer consumed
500 *   %-EMSGSIZE on XDR buffer overflow
501 */
502static inline ssize_t
503xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n)
504{
505	const size_t len = sizeof(n);
506	__be32 *p = xdr_reserve_space(xdr, len);
507
508	if (unlikely(!p))
509		return -EMSGSIZE;
510	xdr_encode_hyper(p, n);
511	return len;
512}
513
514/**
515 * xdr_stream_encode_opaque_inline - Encode opaque xdr data
516 * @xdr: pointer to xdr_stream
517 * @ptr: pointer to void pointer
518 * @len: size of object
519 *
520 * Return values:
521 *   On success, returns length in bytes of XDR buffer consumed
522 *   %-EMSGSIZE on XDR buffer overflow
523 */
524static inline ssize_t
525xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len)
526{
527	size_t count = sizeof(__u32) + xdr_align_size(len);
528	__be32 *p = xdr_reserve_space(xdr, count);
529
530	if (unlikely(!p)) {
531		*ptr = NULL;
532		return -EMSGSIZE;
533	}
534	xdr_encode_opaque(p, NULL, len);
535	*ptr = ++p;
536	return count;
537}
538
539/**
540 * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data
541 * @xdr: pointer to xdr_stream
542 * @ptr: pointer to opaque data object
543 * @len: size of object pointed to by @ptr
544 *
545 * Return values:
546 *   On success, returns length in bytes of XDR buffer consumed
547 *   %-EMSGSIZE on XDR buffer overflow
548 */
549static inline ssize_t
550xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len)
551{
552	__be32 *p = xdr_reserve_space(xdr, len);
553
554	if (unlikely(!p))
555		return -EMSGSIZE;
556	xdr_encode_opaque_fixed(p, ptr, len);
557	return xdr_align_size(len);
558}
559
560/**
561 * xdr_stream_encode_opaque - Encode variable length opaque xdr data
562 * @xdr: pointer to xdr_stream
563 * @ptr: pointer to opaque data object
564 * @len: size of object pointed to by @ptr
565 *
566 * Return values:
567 *   On success, returns length in bytes of XDR buffer consumed
568 *   %-EMSGSIZE on XDR buffer overflow
569 */
570static inline ssize_t
571xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len)
572{
573	size_t count = sizeof(__u32) + xdr_align_size(len);
574	__be32 *p = xdr_reserve_space(xdr, count);
575
576	if (unlikely(!p))
577		return -EMSGSIZE;
578	xdr_encode_opaque(p, ptr, len);
579	return count;
580}
581
582/**
583 * xdr_stream_encode_uint32_array - Encode variable length array of integers
584 * @xdr: pointer to xdr_stream
585 * @array: array of integers
586 * @array_size: number of elements in @array
587 *
588 * Return values:
589 *   On success, returns length in bytes of XDR buffer consumed
590 *   %-EMSGSIZE on XDR buffer overflow
591 */
592static inline ssize_t
593xdr_stream_encode_uint32_array(struct xdr_stream *xdr,
594		const __u32 *array, size_t array_size)
595{
596	ssize_t ret = (array_size+1) * sizeof(__u32);
597	__be32 *p = xdr_reserve_space(xdr, ret);
598
599	if (unlikely(!p))
600		return -EMSGSIZE;
601	*p++ = cpu_to_be32(array_size);
602	for (; array_size > 0; p++, array++, array_size--)
603		*p = cpu_to_be32p(array);
604	return ret;
605}
606
607/**
608 * xdr_item_is_absent - symbolically handle XDR discriminators
609 * @p: pointer to undecoded discriminator
610 *
611 * Return values:
612 *   %true if the following XDR item is absent
613 *   %false if the following XDR item is present
614 */
615static inline bool xdr_item_is_absent(const __be32 *p)
616{
617	return *p == xdr_zero;
618}
619
620/**
621 * xdr_item_is_present - symbolically handle XDR discriminators
622 * @p: pointer to undecoded discriminator
623 *
624 * Return values:
625 *   %true if the following XDR item is present
626 *   %false if the following XDR item is absent
627 */
628static inline bool xdr_item_is_present(const __be32 *p)
629{
630	return *p != xdr_zero;
631}
632
633/**
634 * xdr_stream_decode_bool - Decode a boolean
635 * @xdr: pointer to xdr_stream
636 * @ptr: pointer to a u32 in which to store the result
637 *
638 * Return values:
639 *   %0 on success
640 *   %-EBADMSG on XDR buffer overflow
641 */
642static inline ssize_t
643xdr_stream_decode_bool(struct xdr_stream *xdr, __u32 *ptr)
644{
645	const size_t count = sizeof(*ptr);
646	__be32 *p = xdr_inline_decode(xdr, count);
647
648	if (unlikely(!p))
649		return -EBADMSG;
650	*ptr = (*p != xdr_zero);
651	return 0;
652}
653
654/**
655 * xdr_stream_decode_u32 - Decode a 32-bit integer
656 * @xdr: pointer to xdr_stream
657 * @ptr: location to store integer
658 *
659 * Return values:
660 *   %0 on success
661 *   %-EBADMSG on XDR buffer overflow
662 */
663static inline ssize_t
664xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr)
665{
666	const size_t count = sizeof(*ptr);
667	__be32 *p = xdr_inline_decode(xdr, count);
668
669	if (unlikely(!p))
670		return -EBADMSG;
671	*ptr = be32_to_cpup(p);
672	return 0;
673}
674
675/**
676 * xdr_stream_decode_be32 - Decode a big-endian 32-bit integer
677 * @xdr: pointer to xdr_stream
678 * @ptr: location to store integer
679 *
680 * Return values:
681 *   %0 on success
682 *   %-EBADMSG on XDR buffer overflow
683 */
684static inline ssize_t
685xdr_stream_decode_be32(struct xdr_stream *xdr, __be32 *ptr)
686{
687	const size_t count = sizeof(*ptr);
688	__be32 *p = xdr_inline_decode(xdr, count);
689
690	if (unlikely(!p))
691		return -EBADMSG;
692	*ptr = *p;
693	return 0;
694}
695
696/**
697 * xdr_stream_decode_u64 - Decode a 64-bit integer
698 * @xdr: pointer to xdr_stream
699 * @ptr: location to store 64-bit integer
700 *
701 * Return values:
702 *   %0 on success
703 *   %-EBADMSG on XDR buffer overflow
704 */
705static inline ssize_t
706xdr_stream_decode_u64(struct xdr_stream *xdr, __u64 *ptr)
707{
708	const size_t count = sizeof(*ptr);
709	__be32 *p = xdr_inline_decode(xdr, count);
710
711	if (unlikely(!p))
712		return -EBADMSG;
713	xdr_decode_hyper(p, ptr);
714	return 0;
715}
716
717/**
718 * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data
719 * @xdr: pointer to xdr_stream
720 * @ptr: location to store data
721 * @len: size of buffer pointed to by @ptr
722 *
723 * Return values:
724 *   %0 on success
725 *   %-EBADMSG on XDR buffer overflow
726 */
727static inline ssize_t
728xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len)
729{
730	__be32 *p = xdr_inline_decode(xdr, len);
731
732	if (unlikely(!p))
733		return -EBADMSG;
734	xdr_decode_opaque_fixed(p, ptr, len);
735	return 0;
736}
737
738/**
739 * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data
740 * @xdr: pointer to xdr_stream
741 * @ptr: location to store pointer to opaque data
742 * @maxlen: maximum acceptable object size
743 *
744 * Note: the pointer stored in @ptr cannot be assumed valid after the XDR
745 * buffer has been destroyed, or even after calling xdr_inline_decode()
746 * on @xdr. It is therefore expected that the object it points to should
747 * be processed immediately.
748 *
749 * Return values:
750 *   On success, returns size of object stored in *@ptr
751 *   %-EBADMSG on XDR buffer overflow
752 *   %-EMSGSIZE if the size of the object would exceed @maxlen
753 */
754static inline ssize_t
755xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen)
756{
757	__be32 *p;
758	__u32 len;
759
760	*ptr = NULL;
761	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
762		return -EBADMSG;
763	if (len != 0) {
764		p = xdr_inline_decode(xdr, len);
765		if (unlikely(!p))
766			return -EBADMSG;
767		if (unlikely(len > maxlen))
768			return -EMSGSIZE;
769		*ptr = p;
770	}
771	return len;
772}
773
774/**
775 * xdr_stream_decode_uint32_array - Decode variable length array of integers
776 * @xdr: pointer to xdr_stream
777 * @array: location to store the integer array or NULL
778 * @array_size: number of elements to store
779 *
780 * Return values:
781 *   On success, returns number of elements stored in @array
782 *   %-EBADMSG on XDR buffer overflow
783 *   %-EMSGSIZE if the size of the array exceeds @array_size
784 */
785static inline ssize_t
786xdr_stream_decode_uint32_array(struct xdr_stream *xdr,
787		__u32 *array, size_t array_size)
788{
789	__be32 *p;
790	__u32 len;
791	ssize_t retval;
792
793	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
794		return -EBADMSG;
795	if (U32_MAX >= SIZE_MAX / sizeof(*p) && len > SIZE_MAX / sizeof(*p))
796		return -EBADMSG;
797	p = xdr_inline_decode(xdr, len * sizeof(*p));
798	if (unlikely(!p))
799		return -EBADMSG;
800	if (array == NULL)
801		return len;
802	if (len <= array_size) {
803		if (len < array_size)
804			memset(array+len, 0, (array_size-len)*sizeof(*array));
805		array_size = len;
806		retval = len;
807	} else
808		retval = -EMSGSIZE;
809	for (; array_size > 0; p++, array++, array_size--)
810		*array = be32_to_cpup(p);
811	return retval;
812}
813
814#endif /* _SUNRPC_XDR_H_ */