xref: /linux-6.15/include/linux/sunrpc/xdr.h (revision 42e4eefb)
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  * 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 
99 #define	rpc_call	cpu_to_be32(RPC_CALL)
100 #define	rpc_reply	cpu_to_be32(RPC_REPLY)
101 
102 #define	rpc_msg_accepted	cpu_to_be32(RPC_MSG_ACCEPTED)
103 
104 #define	rpc_success		cpu_to_be32(RPC_SUCCESS)
105 #define	rpc_prog_unavail	cpu_to_be32(RPC_PROG_UNAVAIL)
106 #define	rpc_prog_mismatch	cpu_to_be32(RPC_PROG_MISMATCH)
107 #define	rpc_proc_unavail	cpu_to_be32(RPC_PROC_UNAVAIL)
108 #define	rpc_garbage_args	cpu_to_be32(RPC_GARBAGE_ARGS)
109 #define	rpc_system_err		cpu_to_be32(RPC_SYSTEM_ERR)
110 #define	rpc_drop_reply		cpu_to_be32(RPC_DROP_REPLY)
111 
112 #define	rpc_mismatch		cpu_to_be32(RPC_MISMATCH)
113 #define	rpc_auth_error		cpu_to_be32(RPC_AUTH_ERROR)
114 
115 #define	rpc_auth_ok		cpu_to_be32(RPC_AUTH_OK)
116 #define	rpc_autherr_badcred	cpu_to_be32(RPC_AUTH_BADCRED)
117 #define	rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED)
118 #define	rpc_autherr_badverf	cpu_to_be32(RPC_AUTH_BADVERF)
119 #define	rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF)
120 #define	rpc_autherr_tooweak	cpu_to_be32(RPC_AUTH_TOOWEAK)
121 #define	rpcsec_gsserr_credproblem	cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
122 #define	rpcsec_gsserr_ctxproblem	cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
123 
124 /*
125  * Miscellaneous XDR helper functions
126  */
127 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
128 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
129 __be32 *xdr_encode_string(__be32 *p, const char *s);
130 __be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
131 			unsigned int maxlen);
132 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
133 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
134 
135 void	xdr_inline_pages(struct xdr_buf *, unsigned int,
136 			 struct page **, unsigned int, unsigned int);
137 void	xdr_terminate_string(const struct xdr_buf *, const u32);
138 size_t	xdr_buf_pagecount(const struct xdr_buf *buf);
139 int	xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp);
140 void	xdr_free_bvec(struct xdr_buf *buf);
141 
142 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
143 {
144 	return xdr_encode_opaque(p, s, len);
145 }
146 
147 /*
148  * Decode 64bit quantities (NFSv3 support)
149  */
150 static inline __be32 *
151 xdr_encode_hyper(__be32 *p, __u64 val)
152 {
153 	put_unaligned_be64(val, p);
154 	return p + 2;
155 }
156 
157 static inline __be32 *
158 xdr_decode_hyper(__be32 *p, __u64 *valp)
159 {
160 	*valp = get_unaligned_be64(p);
161 	return p + 2;
162 }
163 
164 static inline __be32 *
165 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
166 {
167 	memcpy(ptr, p, len);
168 	return p + XDR_QUADLEN(len);
169 }
170 
171 static inline void xdr_netobj_dup(struct xdr_netobj *dst,
172 				  struct xdr_netobj *src, gfp_t gfp_mask)
173 {
174 	dst->data = kmemdup(src->data, src->len, gfp_mask);
175 	dst->len = src->len;
176 }
177 
178 /*
179  * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
180  */
181 static inline int
182 xdr_adjust_iovec(struct kvec *iov, __be32 *p)
183 {
184 	return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
185 }
186 
187 /*
188  * XDR buffer helper functions
189  */
190 extern void xdr_shift_buf(struct xdr_buf *, size_t);
191 extern void xdr_buf_from_iov(const struct kvec *, struct xdr_buf *);
192 extern int xdr_buf_subsegment(const struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
193 extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
194 extern int read_bytes_from_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
195 extern int write_bytes_to_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
196 
197 extern int xdr_encode_word(const struct xdr_buf *, unsigned int, u32);
198 extern int xdr_decode_word(const struct xdr_buf *, unsigned int, u32 *);
199 
200 struct xdr_array2_desc;
201 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
202 struct xdr_array2_desc {
203 	unsigned int elem_size;
204 	unsigned int array_len;
205 	unsigned int array_maxlen;
206 	xdr_xcode_elem_t xcode;
207 };
208 
209 extern int xdr_decode_array2(const struct xdr_buf *buf, unsigned int base,
210 			     struct xdr_array2_desc *desc);
211 extern int xdr_encode_array2(const struct xdr_buf *buf, unsigned int base,
212 			     struct xdr_array2_desc *desc);
213 extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
214 			     size_t len);
215 
216 /*
217  * Provide some simple tools for XDR buffer overflow-checking etc.
218  */
219 struct xdr_stream {
220 	__be32 *p;		/* start of available buffer */
221 	struct xdr_buf *buf;	/* XDR buffer to read/write */
222 
223 	__be32 *end;		/* end of available buffer space */
224 	struct kvec *iov;	/* pointer to the current kvec */
225 	struct kvec scratch;	/* Scratch buffer */
226 	struct page **page_ptr;	/* pointer to the current page */
227 	unsigned int nwords;	/* Remaining decode buffer length */
228 
229 	struct rpc_rqst *rqst;	/* For debugging */
230 };
231 
232 /*
233  * These are the xdr_stream style generic XDR encode and decode functions.
234  */
235 typedef void	(*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
236 		const void *obj);
237 typedef int	(*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
238 		void *obj);
239 
240 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf,
241 			    __be32 *p, struct rpc_rqst *rqst);
242 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
243 extern int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec,
244 		size_t nbytes);
245 extern void xdr_commit_encode(struct xdr_stream *xdr);
246 extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
247 extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen);
248 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
249 		unsigned int base, unsigned int len);
250 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
251 extern unsigned int xdr_page_pos(const struct xdr_stream *xdr);
252 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf,
253 			    __be32 *p, struct rpc_rqst *rqst);
254 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
255 		struct page **pages, unsigned int len);
256 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
257 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
258 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
259 extern int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
260 extern unsigned int xdr_align_data(struct xdr_stream *, unsigned int offset, unsigned int length);
261 extern unsigned int xdr_expand_hole(struct xdr_stream *, unsigned int offset, unsigned int length);
262 extern bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,
263 				  unsigned int len);
264 
265 /**
266  * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
267  * @xdr: pointer to xdr_stream struct
268  * @buf: pointer to an empty buffer
269  * @buflen: size of 'buf'
270  *
271  * The scratch buffer is used when decoding from an array of pages.
272  * If an xdr_inline_decode() call spans across page boundaries, then
273  * we copy the data into the scratch buffer in order to allow linear
274  * access.
275  */
276 static inline void
277 xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen)
278 {
279 	xdr->scratch.iov_base = buf;
280 	xdr->scratch.iov_len = buflen;
281 }
282 
283 /**
284  * xdr_set_scratch_page - Attach a scratch buffer for decoding data
285  * @xdr: pointer to xdr_stream struct
286  * @page: an anonymous page
287  *
288  * See xdr_set_scratch_buffer().
289  */
290 static inline void
291 xdr_set_scratch_page(struct xdr_stream *xdr, struct page *page)
292 {
293 	xdr_set_scratch_buffer(xdr, page_address(page), PAGE_SIZE);
294 }
295 
296 /**
297  * xdr_reset_scratch_buffer - Clear scratch buffer information
298  * @xdr: pointer to xdr_stream struct
299  *
300  * See xdr_set_scratch_buffer().
301  */
302 static inline void
303 xdr_reset_scratch_buffer(struct xdr_stream *xdr)
304 {
305 	xdr_set_scratch_buffer(xdr, NULL, 0);
306 }
307 
308 /**
309  * xdr_stream_remaining - Return the number of bytes remaining in the stream
310  * @xdr: pointer to struct xdr_stream
311  *
312  * Return value:
313  *   Number of bytes remaining in @xdr before xdr->end
314  */
315 static inline size_t
316 xdr_stream_remaining(const struct xdr_stream *xdr)
317 {
318 	return xdr->nwords << 2;
319 }
320 
321 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr,
322 		size_t size);
323 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr,
324 		size_t maxlen, gfp_t gfp_flags);
325 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str,
326 		size_t size);
327 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
328 		size_t maxlen, gfp_t gfp_flags);
329 /**
330  * xdr_align_size - Calculate padded size of an object
331  * @n: Size of an object being XDR encoded (in bytes)
332  *
333  * Return value:
334  *   Size (in bytes) of the object including xdr padding
335  */
336 static inline size_t
337 xdr_align_size(size_t n)
338 {
339 	const size_t mask = XDR_UNIT - 1;
340 
341 	return (n + mask) & ~mask;
342 }
343 
344 /**
345  * xdr_pad_size - Calculate size of an object's pad
346  * @n: Size of an object being XDR encoded (in bytes)
347  *
348  * This implementation avoids the need for conditional
349  * branches or modulo division.
350  *
351  * Return value:
352  *   Size (in bytes) of the needed XDR pad
353  */
354 static inline size_t xdr_pad_size(size_t n)
355 {
356 	return xdr_align_size(n) - n;
357 }
358 
359 /**
360  * xdr_stream_encode_item_present - Encode a "present" list item
361  * @xdr: pointer to xdr_stream
362  *
363  * Return values:
364  *   On success, returns length in bytes of XDR buffer consumed
365  *   %-EMSGSIZE on XDR buffer overflow
366  */
367 static inline ssize_t xdr_stream_encode_item_present(struct xdr_stream *xdr)
368 {
369 	const size_t len = XDR_UNIT;
370 	__be32 *p = xdr_reserve_space(xdr, len);
371 
372 	if (unlikely(!p))
373 		return -EMSGSIZE;
374 	*p = xdr_one;
375 	return len;
376 }
377 
378 /**
379  * xdr_stream_encode_item_absent - Encode a "not present" list item
380  * @xdr: pointer to xdr_stream
381  *
382  * Return values:
383  *   On success, returns length in bytes of XDR buffer consumed
384  *   %-EMSGSIZE on XDR buffer overflow
385  */
386 static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr)
387 {
388 	const size_t len = XDR_UNIT;
389 	__be32 *p = xdr_reserve_space(xdr, len);
390 
391 	if (unlikely(!p))
392 		return -EMSGSIZE;
393 	*p = xdr_zero;
394 	return len;
395 }
396 
397 /**
398  * xdr_stream_encode_u32 - Encode a 32-bit integer
399  * @xdr: pointer to xdr_stream
400  * @n: integer to encode
401  *
402  * Return values:
403  *   On success, returns length in bytes of XDR buffer consumed
404  *   %-EMSGSIZE on XDR buffer overflow
405  */
406 static inline ssize_t
407 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n)
408 {
409 	const size_t len = sizeof(n);
410 	__be32 *p = xdr_reserve_space(xdr, len);
411 
412 	if (unlikely(!p))
413 		return -EMSGSIZE;
414 	*p = cpu_to_be32(n);
415 	return len;
416 }
417 
418 /**
419  * xdr_stream_encode_u64 - Encode a 64-bit integer
420  * @xdr: pointer to xdr_stream
421  * @n: 64-bit integer to encode
422  *
423  * Return values:
424  *   On success, returns length in bytes of XDR buffer consumed
425  *   %-EMSGSIZE on XDR buffer overflow
426  */
427 static inline ssize_t
428 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n)
429 {
430 	const size_t len = sizeof(n);
431 	__be32 *p = xdr_reserve_space(xdr, len);
432 
433 	if (unlikely(!p))
434 		return -EMSGSIZE;
435 	xdr_encode_hyper(p, n);
436 	return len;
437 }
438 
439 /**
440  * xdr_stream_encode_opaque_inline - Encode opaque xdr data
441  * @xdr: pointer to xdr_stream
442  * @ptr: pointer to void pointer
443  * @len: size of object
444  *
445  * Return values:
446  *   On success, returns length in bytes of XDR buffer consumed
447  *   %-EMSGSIZE on XDR buffer overflow
448  */
449 static inline ssize_t
450 xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len)
451 {
452 	size_t count = sizeof(__u32) + xdr_align_size(len);
453 	__be32 *p = xdr_reserve_space(xdr, count);
454 
455 	if (unlikely(!p)) {
456 		*ptr = NULL;
457 		return -EMSGSIZE;
458 	}
459 	xdr_encode_opaque(p, NULL, len);
460 	*ptr = ++p;
461 	return count;
462 }
463 
464 /**
465  * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data
466  * @xdr: pointer to xdr_stream
467  * @ptr: pointer to opaque data object
468  * @len: size of object pointed to by @ptr
469  *
470  * Return values:
471  *   On success, returns length in bytes of XDR buffer consumed
472  *   %-EMSGSIZE on XDR buffer overflow
473  */
474 static inline ssize_t
475 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len)
476 {
477 	__be32 *p = xdr_reserve_space(xdr, len);
478 
479 	if (unlikely(!p))
480 		return -EMSGSIZE;
481 	xdr_encode_opaque_fixed(p, ptr, len);
482 	return xdr_align_size(len);
483 }
484 
485 /**
486  * xdr_stream_encode_opaque - Encode variable length opaque xdr data
487  * @xdr: pointer to xdr_stream
488  * @ptr: pointer to opaque data object
489  * @len: size of object pointed to by @ptr
490  *
491  * Return values:
492  *   On success, returns length in bytes of XDR buffer consumed
493  *   %-EMSGSIZE on XDR buffer overflow
494  */
495 static inline ssize_t
496 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len)
497 {
498 	size_t count = sizeof(__u32) + xdr_align_size(len);
499 	__be32 *p = xdr_reserve_space(xdr, count);
500 
501 	if (unlikely(!p))
502 		return -EMSGSIZE;
503 	xdr_encode_opaque(p, ptr, len);
504 	return count;
505 }
506 
507 /**
508  * xdr_stream_encode_uint32_array - Encode variable length array of integers
509  * @xdr: pointer to xdr_stream
510  * @array: array of integers
511  * @array_size: number of elements in @array
512  *
513  * Return values:
514  *   On success, returns length in bytes of XDR buffer consumed
515  *   %-EMSGSIZE on XDR buffer overflow
516  */
517 static inline ssize_t
518 xdr_stream_encode_uint32_array(struct xdr_stream *xdr,
519 		const __u32 *array, size_t array_size)
520 {
521 	ssize_t ret = (array_size+1) * sizeof(__u32);
522 	__be32 *p = xdr_reserve_space(xdr, ret);
523 
524 	if (unlikely(!p))
525 		return -EMSGSIZE;
526 	*p++ = cpu_to_be32(array_size);
527 	for (; array_size > 0; p++, array++, array_size--)
528 		*p = cpu_to_be32p(array);
529 	return ret;
530 }
531 
532 /**
533  * xdr_item_is_absent - symbolically handle XDR discriminators
534  * @p: pointer to undecoded discriminator
535  *
536  * Return values:
537  *   %true if the following XDR item is absent
538  *   %false if the following XDR item is present
539  */
540 static inline bool xdr_item_is_absent(const __be32 *p)
541 {
542 	return *p == xdr_zero;
543 }
544 
545 /**
546  * xdr_item_is_present - symbolically handle XDR discriminators
547  * @p: pointer to undecoded discriminator
548  *
549  * Return values:
550  *   %true if the following XDR item is present
551  *   %false if the following XDR item is absent
552  */
553 static inline bool xdr_item_is_present(const __be32 *p)
554 {
555 	return *p != xdr_zero;
556 }
557 
558 /**
559  * xdr_stream_decode_bool - Decode a boolean
560  * @xdr: pointer to xdr_stream
561  * @ptr: pointer to a u32 in which to store the result
562  *
563  * Return values:
564  *   %0 on success
565  *   %-EBADMSG on XDR buffer overflow
566  */
567 static inline ssize_t
568 xdr_stream_decode_bool(struct xdr_stream *xdr, __u32 *ptr)
569 {
570 	const size_t count = sizeof(*ptr);
571 	__be32 *p = xdr_inline_decode(xdr, count);
572 
573 	if (unlikely(!p))
574 		return -EBADMSG;
575 	*ptr = (*p != xdr_zero);
576 	return 0;
577 }
578 
579 /**
580  * xdr_stream_decode_u32 - Decode a 32-bit integer
581  * @xdr: pointer to xdr_stream
582  * @ptr: location to store integer
583  *
584  * Return values:
585  *   %0 on success
586  *   %-EBADMSG on XDR buffer overflow
587  */
588 static inline ssize_t
589 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr)
590 {
591 	const size_t count = sizeof(*ptr);
592 	__be32 *p = xdr_inline_decode(xdr, count);
593 
594 	if (unlikely(!p))
595 		return -EBADMSG;
596 	*ptr = be32_to_cpup(p);
597 	return 0;
598 }
599 
600 /**
601  * xdr_stream_decode_u64 - Decode a 64-bit integer
602  * @xdr: pointer to xdr_stream
603  * @ptr: location to store 64-bit integer
604  *
605  * Return values:
606  *   %0 on success
607  *   %-EBADMSG on XDR buffer overflow
608  */
609 static inline ssize_t
610 xdr_stream_decode_u64(struct xdr_stream *xdr, __u64 *ptr)
611 {
612 	const size_t count = sizeof(*ptr);
613 	__be32 *p = xdr_inline_decode(xdr, count);
614 
615 	if (unlikely(!p))
616 		return -EBADMSG;
617 	xdr_decode_hyper(p, ptr);
618 	return 0;
619 }
620 
621 /**
622  * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data
623  * @xdr: pointer to xdr_stream
624  * @ptr: location to store data
625  * @len: size of buffer pointed to by @ptr
626  *
627  * Return values:
628  *   On success, returns size of object stored in @ptr
629  *   %-EBADMSG on XDR buffer overflow
630  */
631 static inline ssize_t
632 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len)
633 {
634 	__be32 *p = xdr_inline_decode(xdr, len);
635 
636 	if (unlikely(!p))
637 		return -EBADMSG;
638 	xdr_decode_opaque_fixed(p, ptr, len);
639 	return len;
640 }
641 
642 /**
643  * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data
644  * @xdr: pointer to xdr_stream
645  * @ptr: location to store pointer to opaque data
646  * @maxlen: maximum acceptable object size
647  *
648  * Note: the pointer stored in @ptr cannot be assumed valid after the XDR
649  * buffer has been destroyed, or even after calling xdr_inline_decode()
650  * on @xdr. It is therefore expected that the object it points to should
651  * be processed immediately.
652  *
653  * Return values:
654  *   On success, returns size of object stored in *@ptr
655  *   %-EBADMSG on XDR buffer overflow
656  *   %-EMSGSIZE if the size of the object would exceed @maxlen
657  */
658 static inline ssize_t
659 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen)
660 {
661 	__be32 *p;
662 	__u32 len;
663 
664 	*ptr = NULL;
665 	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
666 		return -EBADMSG;
667 	if (len != 0) {
668 		p = xdr_inline_decode(xdr, len);
669 		if (unlikely(!p))
670 			return -EBADMSG;
671 		if (unlikely(len > maxlen))
672 			return -EMSGSIZE;
673 		*ptr = p;
674 	}
675 	return len;
676 }
677 
678 /**
679  * xdr_stream_decode_uint32_array - Decode variable length array of integers
680  * @xdr: pointer to xdr_stream
681  * @array: location to store the integer array or NULL
682  * @array_size: number of elements to store
683  *
684  * Return values:
685  *   On success, returns number of elements stored in @array
686  *   %-EBADMSG on XDR buffer overflow
687  *   %-EMSGSIZE if the size of the array exceeds @array_size
688  */
689 static inline ssize_t
690 xdr_stream_decode_uint32_array(struct xdr_stream *xdr,
691 		__u32 *array, size_t array_size)
692 {
693 	__be32 *p;
694 	__u32 len;
695 	ssize_t retval;
696 
697 	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
698 		return -EBADMSG;
699 	p = xdr_inline_decode(xdr, len * sizeof(*p));
700 	if (unlikely(!p))
701 		return -EBADMSG;
702 	if (array == NULL)
703 		return len;
704 	if (len <= array_size) {
705 		if (len < array_size)
706 			memset(array+len, 0, (array_size-len)*sizeof(*array));
707 		array_size = len;
708 		retval = len;
709 	} else
710 		retval = -EMSGSIZE;
711 	for (; array_size > 0; p++, array++, array_size--)
712 		*array = be32_to_cpup(p);
713 	return retval;
714 }
715 
716 #endif /* _SUNRPC_XDR_H_ */
717