xref: /linux-6.15/include/linux/sunrpc/xdr.h (revision e8e507a8)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * XDR standard data types and function declarations
4  *
5  * Copyright (C) 1995-1997 Olaf Kirch <[email protected]>
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  * Buffer adjustment
24  */
25 #define XDR_QUADLEN(l)		(((l) + 3) >> 2)
26 
27 /*
28  * Generic opaque `network object.' At the kernel level, this type
29  * is used only by lockd.
30  */
31 #define XDR_MAX_NETOBJ		1024
32 struct xdr_netobj {
33 	unsigned int		len;
34 	u8 *			data;
35 };
36 
37 /*
38  * Basic structure for transmission/reception of a client XDR message.
39  * Features a header (for a linear buffer containing RPC headers
40  * and the data payload for short messages), and then an array of
41  * pages.
42  * The tail iovec allows you to append data after the page array. Its
43  * main interest is for appending padding to the pages in order to
44  * satisfy the int_32-alignment requirements in RFC1832.
45  *
46  * For the future, we might want to string several of these together
47  * in a list if anybody wants to make use of NFSv4 COMPOUND
48  * operations and/or has a need for scatter/gather involving pages.
49  */
50 struct xdr_buf {
51 	struct kvec	head[1],	/* RPC header + non-page data */
52 			tail[1];	/* Appended after page data */
53 
54 	struct bio_vec	*bvec;
55 	struct page **	pages;		/* Array of pages */
56 	unsigned int	page_base,	/* Start of page data */
57 			page_len,	/* Length of page data */
58 			flags;		/* Flags for data disposition */
59 #define XDRBUF_READ		0x01		/* target of file read */
60 #define XDRBUF_WRITE		0x02		/* source of file write */
61 #define XDRBUF_SPARSE_PAGES	0x04		/* Page array is sparse */
62 
63 	unsigned int	buflen,		/* Total length of storage buffer */
64 			len;		/* Length of XDR encoded message */
65 };
66 
67 static inline void
68 xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
69 {
70 	buf->head[0].iov_base = start;
71 	buf->head[0].iov_len = len;
72 	buf->tail[0].iov_len = 0;
73 	buf->pages = NULL;
74 	buf->page_len = 0;
75 	buf->flags = 0;
76 	buf->len = 0;
77 	buf->buflen = len;
78 }
79 
80 /*
81  * pre-xdr'ed macros.
82  */
83 
84 #define	xdr_zero	cpu_to_be32(0)
85 #define	xdr_one		cpu_to_be32(1)
86 #define	xdr_two		cpu_to_be32(2)
87 
88 #define	rpc_auth_null	cpu_to_be32(RPC_AUTH_NULL)
89 #define	rpc_auth_unix	cpu_to_be32(RPC_AUTH_UNIX)
90 #define	rpc_auth_short	cpu_to_be32(RPC_AUTH_SHORT)
91 #define	rpc_auth_gss	cpu_to_be32(RPC_AUTH_GSS)
92 
93 #define	rpc_call	cpu_to_be32(RPC_CALL)
94 #define	rpc_reply	cpu_to_be32(RPC_REPLY)
95 
96 #define	rpc_msg_accepted	cpu_to_be32(RPC_MSG_ACCEPTED)
97 
98 #define	rpc_success		cpu_to_be32(RPC_SUCCESS)
99 #define	rpc_prog_unavail	cpu_to_be32(RPC_PROG_UNAVAIL)
100 #define	rpc_prog_mismatch	cpu_to_be32(RPC_PROG_MISMATCH)
101 #define	rpc_proc_unavail	cpu_to_be32(RPC_PROC_UNAVAIL)
102 #define	rpc_garbage_args	cpu_to_be32(RPC_GARBAGE_ARGS)
103 #define	rpc_system_err		cpu_to_be32(RPC_SYSTEM_ERR)
104 #define	rpc_drop_reply		cpu_to_be32(RPC_DROP_REPLY)
105 
106 #define	rpc_mismatch		cpu_to_be32(RPC_MISMATCH)
107 #define	rpc_auth_error		cpu_to_be32(RPC_AUTH_ERROR)
108 
109 #define	rpc_auth_ok		cpu_to_be32(RPC_AUTH_OK)
110 #define	rpc_autherr_badcred	cpu_to_be32(RPC_AUTH_BADCRED)
111 #define	rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED)
112 #define	rpc_autherr_badverf	cpu_to_be32(RPC_AUTH_BADVERF)
113 #define	rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF)
114 #define	rpc_autherr_tooweak	cpu_to_be32(RPC_AUTH_TOOWEAK)
115 #define	rpcsec_gsserr_credproblem	cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
116 #define	rpcsec_gsserr_ctxproblem	cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
117 
118 /*
119  * Miscellaneous XDR helper functions
120  */
121 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
122 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
123 __be32 *xdr_encode_string(__be32 *p, const char *s);
124 __be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
125 			unsigned int maxlen);
126 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
127 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
128 
129 void	xdr_inline_pages(struct xdr_buf *, unsigned int,
130 			 struct page **, unsigned int, unsigned int);
131 void	xdr_terminate_string(const struct xdr_buf *, const u32);
132 size_t	xdr_buf_pagecount(const struct xdr_buf *buf);
133 int	xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp);
134 void	xdr_free_bvec(struct xdr_buf *buf);
135 
136 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
137 {
138 	return xdr_encode_opaque(p, s, len);
139 }
140 
141 /*
142  * Decode 64bit quantities (NFSv3 support)
143  */
144 static inline __be32 *
145 xdr_encode_hyper(__be32 *p, __u64 val)
146 {
147 	put_unaligned_be64(val, p);
148 	return p + 2;
149 }
150 
151 static inline __be32 *
152 xdr_decode_hyper(__be32 *p, __u64 *valp)
153 {
154 	*valp = get_unaligned_be64(p);
155 	return p + 2;
156 }
157 
158 static inline __be32 *
159 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
160 {
161 	memcpy(ptr, p, len);
162 	return p + XDR_QUADLEN(len);
163 }
164 
165 static inline void xdr_netobj_dup(struct xdr_netobj *dst,
166 				  struct xdr_netobj *src, gfp_t gfp_mask)
167 {
168 	dst->data = kmemdup(src->data, src->len, gfp_mask);
169 	dst->len = src->len;
170 }
171 
172 /*
173  * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
174  */
175 static inline int
176 xdr_adjust_iovec(struct kvec *iov, __be32 *p)
177 {
178 	return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
179 }
180 
181 /*
182  * XDR buffer helper functions
183  */
184 extern void xdr_shift_buf(struct xdr_buf *, size_t);
185 extern void xdr_buf_from_iov(const struct kvec *, struct xdr_buf *);
186 extern int xdr_buf_subsegment(const struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
187 extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
188 extern int read_bytes_from_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
189 extern int write_bytes_to_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
190 
191 extern int xdr_encode_word(const struct xdr_buf *, unsigned int, u32);
192 extern int xdr_decode_word(const struct xdr_buf *, unsigned int, u32 *);
193 
194 struct xdr_array2_desc;
195 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
196 struct xdr_array2_desc {
197 	unsigned int elem_size;
198 	unsigned int array_len;
199 	unsigned int array_maxlen;
200 	xdr_xcode_elem_t xcode;
201 };
202 
203 extern int xdr_decode_array2(const struct xdr_buf *buf, unsigned int base,
204 			     struct xdr_array2_desc *desc);
205 extern int xdr_encode_array2(const struct xdr_buf *buf, unsigned int base,
206 			     struct xdr_array2_desc *desc);
207 extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
208 			     size_t len);
209 
210 /*
211  * Provide some simple tools for XDR buffer overflow-checking etc.
212  */
213 struct xdr_stream {
214 	__be32 *p;		/* start of available buffer */
215 	struct xdr_buf *buf;	/* XDR buffer to read/write */
216 
217 	__be32 *end;		/* end of available buffer space */
218 	struct kvec *iov;	/* pointer to the current kvec */
219 	struct kvec scratch;	/* Scratch buffer */
220 	struct page **page_ptr;	/* pointer to the current page */
221 	unsigned int nwords;	/* Remaining decode buffer length */
222 
223 	struct rpc_rqst *rqst;	/* For debugging */
224 };
225 
226 /*
227  * These are the xdr_stream style generic XDR encode and decode functions.
228  */
229 typedef void	(*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
230 		const void *obj);
231 typedef int	(*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
232 		void *obj);
233 
234 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf,
235 			    __be32 *p, struct rpc_rqst *rqst);
236 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
237 extern int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec,
238 		size_t nbytes);
239 extern void xdr_commit_encode(struct xdr_stream *xdr);
240 extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
241 extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen);
242 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
243 		unsigned int base, unsigned int len);
244 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
245 extern unsigned int xdr_page_pos(const struct xdr_stream *xdr);
246 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf,
247 			    __be32 *p, struct rpc_rqst *rqst);
248 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
249 		struct page **pages, unsigned int len);
250 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
251 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
252 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
253 extern int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
254 extern unsigned int xdr_align_data(struct xdr_stream *, unsigned int offset, unsigned int length);
255 extern unsigned int xdr_expand_hole(struct xdr_stream *, unsigned int offset, unsigned int length);
256 extern bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,
257 				  unsigned int len);
258 
259 /**
260  * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
261  * @xdr: pointer to xdr_stream struct
262  * @buf: pointer to an empty buffer
263  * @buflen: size of 'buf'
264  *
265  * The scratch buffer is used when decoding from an array of pages.
266  * If an xdr_inline_decode() call spans across page boundaries, then
267  * we copy the data into the scratch buffer in order to allow linear
268  * access.
269  */
270 static inline void
271 xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen)
272 {
273 	xdr->scratch.iov_base = buf;
274 	xdr->scratch.iov_len = buflen;
275 }
276 
277 /**
278  * xdr_set_scratch_page - Attach a scratch buffer for decoding data
279  * @xdr: pointer to xdr_stream struct
280  * @page: an anonymous page
281  *
282  * See xdr_set_scratch_buffer().
283  */
284 static inline void
285 xdr_set_scratch_page(struct xdr_stream *xdr, struct page *page)
286 {
287 	xdr_set_scratch_buffer(xdr, page_address(page), PAGE_SIZE);
288 }
289 
290 /**
291  * xdr_reset_scratch_buffer - Clear scratch buffer information
292  * @xdr: pointer to xdr_stream struct
293  *
294  * See xdr_set_scratch_buffer().
295  */
296 static inline void
297 xdr_reset_scratch_buffer(struct xdr_stream *xdr)
298 {
299 	xdr_set_scratch_buffer(xdr, NULL, 0);
300 }
301 
302 /**
303  * xdr_stream_remaining - Return the number of bytes remaining in the stream
304  * @xdr: pointer to struct xdr_stream
305  *
306  * Return value:
307  *   Number of bytes remaining in @xdr before xdr->end
308  */
309 static inline size_t
310 xdr_stream_remaining(const struct xdr_stream *xdr)
311 {
312 	return xdr->nwords << 2;
313 }
314 
315 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr,
316 		size_t size);
317 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr,
318 		size_t maxlen, gfp_t gfp_flags);
319 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str,
320 		size_t size);
321 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
322 		size_t maxlen, gfp_t gfp_flags);
323 /**
324  * xdr_align_size - Calculate padded size of an object
325  * @n: Size of an object being XDR encoded (in bytes)
326  *
327  * Return value:
328  *   Size (in bytes) of the object including xdr padding
329  */
330 static inline size_t
331 xdr_align_size(size_t n)
332 {
333 	const size_t mask = sizeof(__u32) - 1;
334 
335 	return (n + mask) & ~mask;
336 }
337 
338 /**
339  * xdr_pad_size - Calculate size of an object's pad
340  * @n: Size of an object being XDR encoded (in bytes)
341  *
342  * This implementation avoids the need for conditional
343  * branches or modulo division.
344  *
345  * Return value:
346  *   Size (in bytes) of the needed XDR pad
347  */
348 static inline size_t xdr_pad_size(size_t n)
349 {
350 	return xdr_align_size(n) - n;
351 }
352 
353 /**
354  * xdr_stream_encode_item_present - Encode a "present" list item
355  * @xdr: pointer to xdr_stream
356  *
357  * Return values:
358  *   On success, returns length in bytes of XDR buffer consumed
359  *   %-EMSGSIZE on XDR buffer overflow
360  */
361 static inline ssize_t xdr_stream_encode_item_present(struct xdr_stream *xdr)
362 {
363 	const size_t len = sizeof(__be32);
364 	__be32 *p = xdr_reserve_space(xdr, len);
365 
366 	if (unlikely(!p))
367 		return -EMSGSIZE;
368 	*p = xdr_one;
369 	return len;
370 }
371 
372 /**
373  * xdr_stream_encode_item_absent - Encode a "not present" list item
374  * @xdr: pointer to xdr_stream
375  *
376  * Return values:
377  *   On success, returns length in bytes of XDR buffer consumed
378  *   %-EMSGSIZE on XDR buffer overflow
379  */
380 static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr)
381 {
382 	const size_t len = sizeof(__be32);
383 	__be32 *p = xdr_reserve_space(xdr, len);
384 
385 	if (unlikely(!p))
386 		return -EMSGSIZE;
387 	*p = xdr_zero;
388 	return len;
389 }
390 
391 /**
392  * xdr_stream_encode_u32 - Encode a 32-bit integer
393  * @xdr: pointer to xdr_stream
394  * @n: integer to encode
395  *
396  * Return values:
397  *   On success, returns length in bytes of XDR buffer consumed
398  *   %-EMSGSIZE on XDR buffer overflow
399  */
400 static inline ssize_t
401 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n)
402 {
403 	const size_t len = sizeof(n);
404 	__be32 *p = xdr_reserve_space(xdr, len);
405 
406 	if (unlikely(!p))
407 		return -EMSGSIZE;
408 	*p = cpu_to_be32(n);
409 	return len;
410 }
411 
412 /**
413  * xdr_stream_encode_u64 - Encode a 64-bit integer
414  * @xdr: pointer to xdr_stream
415  * @n: 64-bit integer to encode
416  *
417  * Return values:
418  *   On success, returns length in bytes of XDR buffer consumed
419  *   %-EMSGSIZE on XDR buffer overflow
420  */
421 static inline ssize_t
422 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n)
423 {
424 	const size_t len = sizeof(n);
425 	__be32 *p = xdr_reserve_space(xdr, len);
426 
427 	if (unlikely(!p))
428 		return -EMSGSIZE;
429 	xdr_encode_hyper(p, n);
430 	return len;
431 }
432 
433 /**
434  * xdr_stream_encode_opaque_inline - Encode opaque xdr data
435  * @xdr: pointer to xdr_stream
436  * @ptr: pointer to void pointer
437  * @len: size of object
438  *
439  * Return values:
440  *   On success, returns length in bytes of XDR buffer consumed
441  *   %-EMSGSIZE on XDR buffer overflow
442  */
443 static inline ssize_t
444 xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len)
445 {
446 	size_t count = sizeof(__u32) + xdr_align_size(len);
447 	__be32 *p = xdr_reserve_space(xdr, count);
448 
449 	if (unlikely(!p)) {
450 		*ptr = NULL;
451 		return -EMSGSIZE;
452 	}
453 	xdr_encode_opaque(p, NULL, len);
454 	*ptr = ++p;
455 	return count;
456 }
457 
458 /**
459  * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data
460  * @xdr: pointer to xdr_stream
461  * @ptr: pointer to opaque data object
462  * @len: size of object pointed to by @ptr
463  *
464  * Return values:
465  *   On success, returns length in bytes of XDR buffer consumed
466  *   %-EMSGSIZE on XDR buffer overflow
467  */
468 static inline ssize_t
469 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len)
470 {
471 	__be32 *p = xdr_reserve_space(xdr, len);
472 
473 	if (unlikely(!p))
474 		return -EMSGSIZE;
475 	xdr_encode_opaque_fixed(p, ptr, len);
476 	return xdr_align_size(len);
477 }
478 
479 /**
480  * xdr_stream_encode_opaque - Encode variable length opaque xdr data
481  * @xdr: pointer to xdr_stream
482  * @ptr: pointer to opaque data object
483  * @len: size of object pointed to by @ptr
484  *
485  * Return values:
486  *   On success, returns length in bytes of XDR buffer consumed
487  *   %-EMSGSIZE on XDR buffer overflow
488  */
489 static inline ssize_t
490 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len)
491 {
492 	size_t count = sizeof(__u32) + xdr_align_size(len);
493 	__be32 *p = xdr_reserve_space(xdr, count);
494 
495 	if (unlikely(!p))
496 		return -EMSGSIZE;
497 	xdr_encode_opaque(p, ptr, len);
498 	return count;
499 }
500 
501 /**
502  * xdr_stream_encode_uint32_array - Encode variable length array of integers
503  * @xdr: pointer to xdr_stream
504  * @array: array of integers
505  * @array_size: number of elements in @array
506  *
507  * Return values:
508  *   On success, returns length in bytes of XDR buffer consumed
509  *   %-EMSGSIZE on XDR buffer overflow
510  */
511 static inline ssize_t
512 xdr_stream_encode_uint32_array(struct xdr_stream *xdr,
513 		const __u32 *array, size_t array_size)
514 {
515 	ssize_t ret = (array_size+1) * sizeof(__u32);
516 	__be32 *p = xdr_reserve_space(xdr, ret);
517 
518 	if (unlikely(!p))
519 		return -EMSGSIZE;
520 	*p++ = cpu_to_be32(array_size);
521 	for (; array_size > 0; p++, array++, array_size--)
522 		*p = cpu_to_be32p(array);
523 	return ret;
524 }
525 
526 /**
527  * xdr_item_is_absent - symbolically handle XDR discriminators
528  * @p: pointer to undecoded discriminator
529  *
530  * Return values:
531  *   %true if the following XDR item is absent
532  *   %false if the following XDR item is present
533  */
534 static inline bool xdr_item_is_absent(const __be32 *p)
535 {
536 	return *p == xdr_zero;
537 }
538 
539 /**
540  * xdr_item_is_present - symbolically handle XDR discriminators
541  * @p: pointer to undecoded discriminator
542  *
543  * Return values:
544  *   %true if the following XDR item is present
545  *   %false if the following XDR item is absent
546  */
547 static inline bool xdr_item_is_present(const __be32 *p)
548 {
549 	return *p != xdr_zero;
550 }
551 
552 /**
553  * xdr_stream_decode_bool - Decode a boolean
554  * @xdr: pointer to xdr_stream
555  * @ptr: pointer to a u32 in which to store the result
556  *
557  * Return values:
558  *   %0 on success
559  *   %-EBADMSG on XDR buffer overflow
560  */
561 static inline ssize_t
562 xdr_stream_decode_bool(struct xdr_stream *xdr, __u32 *ptr)
563 {
564 	const size_t count = sizeof(*ptr);
565 	__be32 *p = xdr_inline_decode(xdr, count);
566 
567 	if (unlikely(!p))
568 		return -EBADMSG;
569 	*ptr = (*p != xdr_zero);
570 	return 0;
571 }
572 
573 /**
574  * xdr_stream_decode_u32 - Decode a 32-bit integer
575  * @xdr: pointer to xdr_stream
576  * @ptr: location to store integer
577  *
578  * Return values:
579  *   %0 on success
580  *   %-EBADMSG on XDR buffer overflow
581  */
582 static inline ssize_t
583 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr)
584 {
585 	const size_t count = sizeof(*ptr);
586 	__be32 *p = xdr_inline_decode(xdr, count);
587 
588 	if (unlikely(!p))
589 		return -EBADMSG;
590 	*ptr = be32_to_cpup(p);
591 	return 0;
592 }
593 
594 /**
595  * xdr_stream_decode_u64 - Decode a 64-bit integer
596  * @xdr: pointer to xdr_stream
597  * @ptr: location to store 64-bit integer
598  *
599  * Return values:
600  *   %0 on success
601  *   %-EBADMSG on XDR buffer overflow
602  */
603 static inline ssize_t
604 xdr_stream_decode_u64(struct xdr_stream *xdr, __u64 *ptr)
605 {
606 	const size_t count = sizeof(*ptr);
607 	__be32 *p = xdr_inline_decode(xdr, count);
608 
609 	if (unlikely(!p))
610 		return -EBADMSG;
611 	xdr_decode_hyper(p, ptr);
612 	return 0;
613 }
614 
615 /**
616  * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data
617  * @xdr: pointer to xdr_stream
618  * @ptr: location to store data
619  * @len: size of buffer pointed to by @ptr
620  *
621  * Return values:
622  *   On success, returns size of object stored in @ptr
623  *   %-EBADMSG on XDR buffer overflow
624  */
625 static inline ssize_t
626 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len)
627 {
628 	__be32 *p = xdr_inline_decode(xdr, len);
629 
630 	if (unlikely(!p))
631 		return -EBADMSG;
632 	xdr_decode_opaque_fixed(p, ptr, len);
633 	return len;
634 }
635 
636 /**
637  * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data
638  * @xdr: pointer to xdr_stream
639  * @ptr: location to store pointer to opaque data
640  * @maxlen: maximum acceptable object size
641  *
642  * Note: the pointer stored in @ptr cannot be assumed valid after the XDR
643  * buffer has been destroyed, or even after calling xdr_inline_decode()
644  * on @xdr. It is therefore expected that the object it points to should
645  * be processed immediately.
646  *
647  * Return values:
648  *   On success, returns size of object stored in *@ptr
649  *   %-EBADMSG on XDR buffer overflow
650  *   %-EMSGSIZE if the size of the object would exceed @maxlen
651  */
652 static inline ssize_t
653 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen)
654 {
655 	__be32 *p;
656 	__u32 len;
657 
658 	*ptr = NULL;
659 	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
660 		return -EBADMSG;
661 	if (len != 0) {
662 		p = xdr_inline_decode(xdr, len);
663 		if (unlikely(!p))
664 			return -EBADMSG;
665 		if (unlikely(len > maxlen))
666 			return -EMSGSIZE;
667 		*ptr = p;
668 	}
669 	return len;
670 }
671 
672 /**
673  * xdr_stream_decode_uint32_array - Decode variable length array of integers
674  * @xdr: pointer to xdr_stream
675  * @array: location to store the integer array or NULL
676  * @array_size: number of elements to store
677  *
678  * Return values:
679  *   On success, returns number of elements stored in @array
680  *   %-EBADMSG on XDR buffer overflow
681  *   %-EMSGSIZE if the size of the array exceeds @array_size
682  */
683 static inline ssize_t
684 xdr_stream_decode_uint32_array(struct xdr_stream *xdr,
685 		__u32 *array, size_t array_size)
686 {
687 	__be32 *p;
688 	__u32 len;
689 	ssize_t retval;
690 
691 	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
692 		return -EBADMSG;
693 	p = xdr_inline_decode(xdr, len * sizeof(*p));
694 	if (unlikely(!p))
695 		return -EBADMSG;
696 	if (array == NULL)
697 		return len;
698 	if (len <= array_size) {
699 		if (len < array_size)
700 			memset(array+len, 0, (array_size-len)*sizeof(*array));
701 		array_size = len;
702 		retval = len;
703 	} else
704 		retval = -EMSGSIZE;
705 	for (; array_size > 0; p++, array++, array_size--)
706 		*array = be32_to_cpup(p);
707 	return retval;
708 }
709 
710 #endif /* _SUNRPC_XDR_H_ */
711