xref: /openbmc/linux/include/linux/sunrpc/xdr.h (revision 0df499ea)
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 <asm/unaligned.h>
17 #include <linux/scatterlist.h>
18 
19 struct bio_vec;
20 struct 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
38 struct 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  */
56 struct 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 
73 static inline void
74 xdr_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	rpcsec_gsserr_credproblem	cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
123 #define	rpcsec_gsserr_ctxproblem	cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
124 
125 /*
126  * Miscellaneous XDR helper functions
127  */
128 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
129 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
130 __be32 *xdr_encode_string(__be32 *p, const char *s);
131 __be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
132 			unsigned int maxlen);
133 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
134 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
135 
136 void	xdr_inline_pages(struct xdr_buf *, unsigned int,
137 			 struct page **, unsigned int, unsigned int);
138 void	xdr_terminate_string(const struct xdr_buf *, const u32);
139 size_t	xdr_buf_pagecount(const struct xdr_buf *buf);
140 int	xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp);
141 void	xdr_free_bvec(struct xdr_buf *buf);
142 
143 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
144 {
145 	return xdr_encode_opaque(p, s, len);
146 }
147 
148 /*
149  * Decode 64bit quantities (NFSv3 support)
150  */
151 static inline __be32 *
152 xdr_encode_hyper(__be32 *p, __u64 val)
153 {
154 	put_unaligned_be64(val, p);
155 	return p + 2;
156 }
157 
158 static inline __be32 *
159 xdr_decode_hyper(__be32 *p, __u64 *valp)
160 {
161 	*valp = get_unaligned_be64(p);
162 	return p + 2;
163 }
164 
165 static inline __be32 *
166 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
167 {
168 	memcpy(ptr, p, len);
169 	return p + XDR_QUADLEN(len);
170 }
171 
172 static inline void xdr_netobj_dup(struct xdr_netobj *dst,
173 				  struct xdr_netobj *src, gfp_t gfp_mask)
174 {
175 	dst->data = kmemdup(src->data, src->len, gfp_mask);
176 	dst->len = src->len;
177 }
178 
179 /*
180  * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
181  */
182 static inline int
183 xdr_adjust_iovec(struct kvec *iov, __be32 *p)
184 {
185 	return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
186 }
187 
188 /*
189  * XDR buffer helper functions
190  */
191 extern void xdr_shift_buf(struct xdr_buf *, size_t);
192 extern void xdr_buf_from_iov(const struct kvec *, struct xdr_buf *);
193 extern int xdr_buf_subsegment(const struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
194 extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
195 extern int read_bytes_from_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
196 extern int write_bytes_to_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
197 
198 extern int xdr_encode_word(const struct xdr_buf *, unsigned int, u32);
199 extern int xdr_decode_word(const struct xdr_buf *, unsigned int, u32 *);
200 
201 struct xdr_array2_desc;
202 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
203 struct 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 
210 extern int xdr_decode_array2(const struct xdr_buf *buf, unsigned int base,
211 			     struct xdr_array2_desc *desc);
212 extern int xdr_encode_array2(const struct xdr_buf *buf, unsigned int base,
213 			     struct xdr_array2_desc *desc);
214 extern 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  */
220 struct 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 	unsigned int nwords;	/* Remaining decode buffer length */
229 
230 	struct rpc_rqst *rqst;	/* For debugging */
231 };
232 
233 /*
234  * These are the xdr_stream style generic XDR encode and decode functions.
235  */
236 typedef void	(*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
237 		const void *obj);
238 typedef int	(*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
239 		void *obj);
240 
241 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf,
242 			    __be32 *p, struct rpc_rqst *rqst);
243 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
244 extern int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec,
245 		size_t nbytes);
246 extern void __xdr_commit_encode(struct xdr_stream *xdr);
247 extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
248 extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen);
249 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
250 		unsigned int base, unsigned int len);
251 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
252 extern unsigned int xdr_page_pos(const struct xdr_stream *xdr);
253 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf,
254 			    __be32 *p, struct rpc_rqst *rqst);
255 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
256 		struct page **pages, unsigned int len);
257 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
258 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
259 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
260 extern int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
261 extern void xdr_set_pagelen(struct xdr_stream *, unsigned int len);
262 extern bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,
263 				  unsigned int len);
264 extern unsigned int xdr_stream_move_subsegment(struct xdr_stream *xdr, unsigned int offset,
265 					       unsigned int target, unsigned int length);
266 extern unsigned int xdr_stream_zero(struct xdr_stream *xdr, unsigned int offset,
267 				    unsigned int length);
268 
269 /**
270  * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
271  * @xdr: pointer to xdr_stream struct
272  * @buf: pointer to an empty buffer
273  * @buflen: size of 'buf'
274  *
275  * The scratch buffer is used when decoding from an array of pages.
276  * If an xdr_inline_decode() call spans across page boundaries, then
277  * we copy the data into the scratch buffer in order to allow linear
278  * access.
279  */
280 static inline void
281 xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen)
282 {
283 	xdr->scratch.iov_base = buf;
284 	xdr->scratch.iov_len = buflen;
285 }
286 
287 /**
288  * xdr_set_scratch_page - Attach a scratch buffer for decoding data
289  * @xdr: pointer to xdr_stream struct
290  * @page: an anonymous page
291  *
292  * See xdr_set_scratch_buffer().
293  */
294 static inline void
295 xdr_set_scratch_page(struct xdr_stream *xdr, struct page *page)
296 {
297 	xdr_set_scratch_buffer(xdr, page_address(page), PAGE_SIZE);
298 }
299 
300 /**
301  * xdr_reset_scratch_buffer - Clear scratch buffer information
302  * @xdr: pointer to xdr_stream struct
303  *
304  * See xdr_set_scratch_buffer().
305  */
306 static inline void
307 xdr_reset_scratch_buffer(struct xdr_stream *xdr)
308 {
309 	xdr_set_scratch_buffer(xdr, NULL, 0);
310 }
311 
312 /**
313  * xdr_commit_encode - Ensure all data is written to xdr->buf
314  * @xdr: pointer to xdr_stream
315  *
316  * Handle encoding across page boundaries by giving the caller a
317  * temporary location to write to, then later copying the data into
318  * place. __xdr_commit_encode() does that copying.
319  */
320 static inline void xdr_commit_encode(struct xdr_stream *xdr)
321 {
322 	if (unlikely(xdr->scratch.iov_len))
323 		__xdr_commit_encode(xdr);
324 }
325 
326 /**
327  * xdr_stream_remaining - Return the number of bytes remaining in the stream
328  * @xdr: pointer to struct xdr_stream
329  *
330  * Return value:
331  *   Number of bytes remaining in @xdr before xdr->end
332  */
333 static inline size_t
334 xdr_stream_remaining(const struct xdr_stream *xdr)
335 {
336 	return xdr->nwords << 2;
337 }
338 
339 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr,
340 		size_t size);
341 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr,
342 		size_t maxlen, gfp_t gfp_flags);
343 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str,
344 		size_t size);
345 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
346 		size_t maxlen, gfp_t gfp_flags);
347 /**
348  * xdr_align_size - Calculate padded size of an object
349  * @n: Size of an object being XDR encoded (in bytes)
350  *
351  * Return value:
352  *   Size (in bytes) of the object including xdr padding
353  */
354 static inline size_t
355 xdr_align_size(size_t n)
356 {
357 	const size_t mask = XDR_UNIT - 1;
358 
359 	return (n + mask) & ~mask;
360 }
361 
362 /**
363  * xdr_pad_size - Calculate size of an object's pad
364  * @n: Size of an object being XDR encoded (in bytes)
365  *
366  * This implementation avoids the need for conditional
367  * branches or modulo division.
368  *
369  * Return value:
370  *   Size (in bytes) of the needed XDR pad
371  */
372 static inline size_t xdr_pad_size(size_t n)
373 {
374 	return xdr_align_size(n) - n;
375 }
376 
377 /**
378  * xdr_stream_encode_item_present - Encode a "present" list item
379  * @xdr: pointer to xdr_stream
380  *
381  * Return values:
382  *   On success, returns length in bytes of XDR buffer consumed
383  *   %-EMSGSIZE on XDR buffer overflow
384  */
385 static inline ssize_t xdr_stream_encode_item_present(struct xdr_stream *xdr)
386 {
387 	const size_t len = XDR_UNIT;
388 	__be32 *p = xdr_reserve_space(xdr, len);
389 
390 	if (unlikely(!p))
391 		return -EMSGSIZE;
392 	*p = xdr_one;
393 	return len;
394 }
395 
396 /**
397  * xdr_stream_encode_item_absent - Encode a "not present" list item
398  * @xdr: pointer to xdr_stream
399  *
400  * Return values:
401  *   On success, returns length in bytes of XDR buffer consumed
402  *   %-EMSGSIZE on XDR buffer overflow
403  */
404 static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr)
405 {
406 	const size_t len = XDR_UNIT;
407 	__be32 *p = xdr_reserve_space(xdr, len);
408 
409 	if (unlikely(!p))
410 		return -EMSGSIZE;
411 	*p = xdr_zero;
412 	return len;
413 }
414 
415 /**
416  * xdr_encode_bool - Encode a boolean item
417  * @p: address in a buffer into which to encode
418  * @n: boolean value to encode
419  *
420  * Return value:
421  *   Address of item following the encoded boolean
422  */
423 static inline __be32 *xdr_encode_bool(__be32 *p, u32 n)
424 {
425 	*p++ = n ? xdr_one : xdr_zero;
426 	return p;
427 }
428 
429 /**
430  * xdr_stream_encode_bool - Encode a boolean item
431  * @xdr: pointer to xdr_stream
432  * @n: boolean value to encode
433  *
434  * Return values:
435  *   On success, returns length in bytes of XDR buffer consumed
436  *   %-EMSGSIZE on XDR buffer overflow
437  */
438 static inline int xdr_stream_encode_bool(struct xdr_stream *xdr, __u32 n)
439 {
440 	const size_t len = XDR_UNIT;
441 	__be32 *p = xdr_reserve_space(xdr, len);
442 
443 	if (unlikely(!p))
444 		return -EMSGSIZE;
445 	xdr_encode_bool(p, n);
446 	return len;
447 }
448 
449 /**
450  * xdr_stream_encode_u32 - Encode a 32-bit integer
451  * @xdr: pointer to xdr_stream
452  * @n: integer to encode
453  *
454  * Return values:
455  *   On success, returns length in bytes of XDR buffer consumed
456  *   %-EMSGSIZE on XDR buffer overflow
457  */
458 static inline ssize_t
459 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n)
460 {
461 	const size_t len = sizeof(n);
462 	__be32 *p = xdr_reserve_space(xdr, len);
463 
464 	if (unlikely(!p))
465 		return -EMSGSIZE;
466 	*p = cpu_to_be32(n);
467 	return len;
468 }
469 
470 /**
471  * xdr_stream_encode_u64 - Encode a 64-bit integer
472  * @xdr: pointer to xdr_stream
473  * @n: 64-bit integer to encode
474  *
475  * Return values:
476  *   On success, returns length in bytes of XDR buffer consumed
477  *   %-EMSGSIZE on XDR buffer overflow
478  */
479 static inline ssize_t
480 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n)
481 {
482 	const size_t len = sizeof(n);
483 	__be32 *p = xdr_reserve_space(xdr, len);
484 
485 	if (unlikely(!p))
486 		return -EMSGSIZE;
487 	xdr_encode_hyper(p, n);
488 	return len;
489 }
490 
491 /**
492  * xdr_stream_encode_opaque_inline - Encode opaque xdr data
493  * @xdr: pointer to xdr_stream
494  * @ptr: pointer to void pointer
495  * @len: size of object
496  *
497  * Return values:
498  *   On success, returns length in bytes of XDR buffer consumed
499  *   %-EMSGSIZE on XDR buffer overflow
500  */
501 static inline ssize_t
502 xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len)
503 {
504 	size_t count = sizeof(__u32) + xdr_align_size(len);
505 	__be32 *p = xdr_reserve_space(xdr, count);
506 
507 	if (unlikely(!p)) {
508 		*ptr = NULL;
509 		return -EMSGSIZE;
510 	}
511 	xdr_encode_opaque(p, NULL, len);
512 	*ptr = ++p;
513 	return count;
514 }
515 
516 /**
517  * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data
518  * @xdr: pointer to xdr_stream
519  * @ptr: pointer to opaque data object
520  * @len: size of object pointed to by @ptr
521  *
522  * Return values:
523  *   On success, returns length in bytes of XDR buffer consumed
524  *   %-EMSGSIZE on XDR buffer overflow
525  */
526 static inline ssize_t
527 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len)
528 {
529 	__be32 *p = xdr_reserve_space(xdr, len);
530 
531 	if (unlikely(!p))
532 		return -EMSGSIZE;
533 	xdr_encode_opaque_fixed(p, ptr, len);
534 	return xdr_align_size(len);
535 }
536 
537 /**
538  * xdr_stream_encode_opaque - Encode variable length opaque xdr data
539  * @xdr: pointer to xdr_stream
540  * @ptr: pointer to opaque data object
541  * @len: size of object pointed to by @ptr
542  *
543  * Return values:
544  *   On success, returns length in bytes of XDR buffer consumed
545  *   %-EMSGSIZE on XDR buffer overflow
546  */
547 static inline ssize_t
548 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len)
549 {
550 	size_t count = sizeof(__u32) + xdr_align_size(len);
551 	__be32 *p = xdr_reserve_space(xdr, count);
552 
553 	if (unlikely(!p))
554 		return -EMSGSIZE;
555 	xdr_encode_opaque(p, ptr, len);
556 	return count;
557 }
558 
559 /**
560  * xdr_stream_encode_uint32_array - Encode variable length array of integers
561  * @xdr: pointer to xdr_stream
562  * @array: array of integers
563  * @array_size: number of elements in @array
564  *
565  * Return values:
566  *   On success, returns length in bytes of XDR buffer consumed
567  *   %-EMSGSIZE on XDR buffer overflow
568  */
569 static inline ssize_t
570 xdr_stream_encode_uint32_array(struct xdr_stream *xdr,
571 		const __u32 *array, size_t array_size)
572 {
573 	ssize_t ret = (array_size+1) * sizeof(__u32);
574 	__be32 *p = xdr_reserve_space(xdr, ret);
575 
576 	if (unlikely(!p))
577 		return -EMSGSIZE;
578 	*p++ = cpu_to_be32(array_size);
579 	for (; array_size > 0; p++, array++, array_size--)
580 		*p = cpu_to_be32p(array);
581 	return ret;
582 }
583 
584 /**
585  * xdr_item_is_absent - symbolically handle XDR discriminators
586  * @p: pointer to undecoded discriminator
587  *
588  * Return values:
589  *   %true if the following XDR item is absent
590  *   %false if the following XDR item is present
591  */
592 static inline bool xdr_item_is_absent(const __be32 *p)
593 {
594 	return *p == xdr_zero;
595 }
596 
597 /**
598  * xdr_item_is_present - symbolically handle XDR discriminators
599  * @p: pointer to undecoded discriminator
600  *
601  * Return values:
602  *   %true if the following XDR item is present
603  *   %false if the following XDR item is absent
604  */
605 static inline bool xdr_item_is_present(const __be32 *p)
606 {
607 	return *p != xdr_zero;
608 }
609 
610 /**
611  * xdr_stream_decode_bool - Decode a boolean
612  * @xdr: pointer to xdr_stream
613  * @ptr: pointer to a u32 in which to store the result
614  *
615  * Return values:
616  *   %0 on success
617  *   %-EBADMSG on XDR buffer overflow
618  */
619 static inline ssize_t
620 xdr_stream_decode_bool(struct xdr_stream *xdr, __u32 *ptr)
621 {
622 	const size_t count = sizeof(*ptr);
623 	__be32 *p = xdr_inline_decode(xdr, count);
624 
625 	if (unlikely(!p))
626 		return -EBADMSG;
627 	*ptr = (*p != xdr_zero);
628 	return 0;
629 }
630 
631 /**
632  * xdr_stream_decode_u32 - Decode a 32-bit integer
633  * @xdr: pointer to xdr_stream
634  * @ptr: location to store integer
635  *
636  * Return values:
637  *   %0 on success
638  *   %-EBADMSG on XDR buffer overflow
639  */
640 static inline ssize_t
641 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr)
642 {
643 	const size_t count = sizeof(*ptr);
644 	__be32 *p = xdr_inline_decode(xdr, count);
645 
646 	if (unlikely(!p))
647 		return -EBADMSG;
648 	*ptr = be32_to_cpup(p);
649 	return 0;
650 }
651 
652 /**
653  * xdr_stream_decode_u64 - Decode a 64-bit integer
654  * @xdr: pointer to xdr_stream
655  * @ptr: location to store 64-bit integer
656  *
657  * Return values:
658  *   %0 on success
659  *   %-EBADMSG on XDR buffer overflow
660  */
661 static inline ssize_t
662 xdr_stream_decode_u64(struct xdr_stream *xdr, __u64 *ptr)
663 {
664 	const size_t count = sizeof(*ptr);
665 	__be32 *p = xdr_inline_decode(xdr, count);
666 
667 	if (unlikely(!p))
668 		return -EBADMSG;
669 	xdr_decode_hyper(p, ptr);
670 	return 0;
671 }
672 
673 /**
674  * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data
675  * @xdr: pointer to xdr_stream
676  * @ptr: location to store data
677  * @len: size of buffer pointed to by @ptr
678  *
679  * Return values:
680  *   On success, returns size of object stored in @ptr
681  *   %-EBADMSG on XDR buffer overflow
682  */
683 static inline ssize_t
684 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len)
685 {
686 	__be32 *p = xdr_inline_decode(xdr, len);
687 
688 	if (unlikely(!p))
689 		return -EBADMSG;
690 	xdr_decode_opaque_fixed(p, ptr, len);
691 	return len;
692 }
693 
694 /**
695  * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data
696  * @xdr: pointer to xdr_stream
697  * @ptr: location to store pointer to opaque data
698  * @maxlen: maximum acceptable object size
699  *
700  * Note: the pointer stored in @ptr cannot be assumed valid after the XDR
701  * buffer has been destroyed, or even after calling xdr_inline_decode()
702  * on @xdr. It is therefore expected that the object it points to should
703  * be processed immediately.
704  *
705  * Return values:
706  *   On success, returns size of object stored in *@ptr
707  *   %-EBADMSG on XDR buffer overflow
708  *   %-EMSGSIZE if the size of the object would exceed @maxlen
709  */
710 static inline ssize_t
711 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen)
712 {
713 	__be32 *p;
714 	__u32 len;
715 
716 	*ptr = NULL;
717 	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
718 		return -EBADMSG;
719 	if (len != 0) {
720 		p = xdr_inline_decode(xdr, len);
721 		if (unlikely(!p))
722 			return -EBADMSG;
723 		if (unlikely(len > maxlen))
724 			return -EMSGSIZE;
725 		*ptr = p;
726 	}
727 	return len;
728 }
729 
730 /**
731  * xdr_stream_decode_uint32_array - Decode variable length array of integers
732  * @xdr: pointer to xdr_stream
733  * @array: location to store the integer array or NULL
734  * @array_size: number of elements to store
735  *
736  * Return values:
737  *   On success, returns number of elements stored in @array
738  *   %-EBADMSG on XDR buffer overflow
739  *   %-EMSGSIZE if the size of the array exceeds @array_size
740  */
741 static inline ssize_t
742 xdr_stream_decode_uint32_array(struct xdr_stream *xdr,
743 		__u32 *array, size_t array_size)
744 {
745 	__be32 *p;
746 	__u32 len;
747 	ssize_t retval;
748 
749 	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
750 		return -EBADMSG;
751 	if (len > SIZE_MAX / sizeof(*p))
752 		return -EBADMSG;
753 	p = xdr_inline_decode(xdr, len * sizeof(*p));
754 	if (unlikely(!p))
755 		return -EBADMSG;
756 	if (array == NULL)
757 		return len;
758 	if (len <= array_size) {
759 		if (len < array_size)
760 			memset(array+len, 0, (array_size-len)*sizeof(*array));
761 		array_size = len;
762 		retval = len;
763 	} else
764 		retval = -EMSGSIZE;
765 	for (; array_size > 0; p++, array++, array_size--)
766 		*array = be32_to_cpup(p);
767 	return retval;
768 }
769 
770 #endif /* _SUNRPC_XDR_H_ */
771