xref: /linux/include/linux/sunrpc/xdr.h (revision 7ec462100ef9142344ddbf86f2c3008b97acddbe)
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 
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
xdr_buf_init(struct xdr_buf * buf,void * start,size_t len)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 unsigned int xdr_buf_to_bvec(struct bio_vec *bvec, unsigned int bvec_size,
143 			     const struct xdr_buf *xdr);
144 
xdr_encode_array(__be32 * p,const void * s,unsigned int len)145 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
146 {
147 	return xdr_encode_opaque(p, s, len);
148 }
149 
150 /*
151  * Decode 64bit quantities (NFSv3 support)
152  */
153 static inline __be32 *
xdr_encode_hyper(__be32 * p,__u64 val)154 xdr_encode_hyper(__be32 *p, __u64 val)
155 {
156 	put_unaligned_be64(val, p);
157 	return p + 2;
158 }
159 
160 static inline __be32 *
xdr_decode_hyper(__be32 * p,__u64 * valp)161 xdr_decode_hyper(__be32 *p, __u64 *valp)
162 {
163 	*valp = get_unaligned_be64(p);
164 	return p + 2;
165 }
166 
167 static inline __be32 *
xdr_decode_opaque_fixed(__be32 * p,void * ptr,unsigned int len)168 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
169 {
170 	memcpy(ptr, p, len);
171 	return p + XDR_QUADLEN(len);
172 }
173 
xdr_netobj_dup(struct xdr_netobj * dst,struct xdr_netobj * src,gfp_t gfp_mask)174 static inline void xdr_netobj_dup(struct xdr_netobj *dst,
175 				  struct xdr_netobj *src, gfp_t gfp_mask)
176 {
177 	dst->data = kmemdup(src->data, src->len, gfp_mask);
178 	dst->len = src->len;
179 }
180 
181 /*
182  * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
183  */
184 static inline int
xdr_adjust_iovec(struct kvec * iov,__be32 * p)185 xdr_adjust_iovec(struct kvec *iov, __be32 *p)
186 {
187 	return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
188 }
189 
190 /*
191  * XDR buffer helper functions
192  */
193 extern void xdr_buf_from_iov(const struct kvec *, struct xdr_buf *);
194 extern int xdr_buf_subsegment(const struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
195 extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
196 extern int read_bytes_from_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
197 extern int write_bytes_to_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
198 
199 extern int xdr_encode_word(const struct xdr_buf *, unsigned int, u32);
200 extern int xdr_decode_word(const struct xdr_buf *, unsigned int, u32 *);
201 
202 struct xdr_array2_desc;
203 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
204 struct xdr_array2_desc {
205 	unsigned int elem_size;
206 	unsigned int array_len;
207 	unsigned int array_maxlen;
208 	xdr_xcode_elem_t xcode;
209 };
210 
211 extern int xdr_decode_array2(const struct xdr_buf *buf, unsigned int base,
212 			     struct xdr_array2_desc *desc);
213 extern int xdr_encode_array2(const struct xdr_buf *buf, unsigned int base,
214 			     struct xdr_array2_desc *desc);
215 extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
216 			     size_t len);
217 
218 /*
219  * Provide some simple tools for XDR buffer overflow-checking etc.
220  */
221 struct xdr_stream {
222 	__be32 *p;		/* start of available buffer */
223 	struct xdr_buf *buf;	/* XDR buffer to read/write */
224 
225 	__be32 *end;		/* end of available buffer space */
226 	struct kvec *iov;	/* pointer to the current kvec */
227 	struct kvec scratch;	/* Scratch buffer */
228 	struct page **page_ptr;	/* pointer to the current page */
229 	void *page_kaddr;	/* kmapped address of the current page */
230 	unsigned int nwords;	/* Remaining decode buffer length */
231 
232 	struct rpc_rqst *rqst;	/* For debugging */
233 };
234 
235 /*
236  * These are the xdr_stream style generic XDR encode and decode functions.
237  */
238 typedef void	(*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
239 		const void *obj);
240 typedef int	(*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
241 		void *obj);
242 
243 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf,
244 			    __be32 *p, struct rpc_rqst *rqst);
245 extern void xdr_init_encode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
246 			   struct page **pages, struct rpc_rqst *rqst);
247 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
248 extern int xdr_reserve_space_vec(struct xdr_stream *xdr, size_t nbytes);
249 extern void __xdr_commit_encode(struct xdr_stream *xdr);
250 extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
251 extern void xdr_truncate_decode(struct xdr_stream *xdr, size_t len);
252 extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen);
253 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
254 		unsigned int base, unsigned int len);
255 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
256 extern unsigned int xdr_page_pos(const struct xdr_stream *xdr);
257 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf,
258 			    __be32 *p, struct rpc_rqst *rqst);
259 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
260 		struct page **pages, unsigned int len);
261 extern void xdr_finish_decode(struct xdr_stream *xdr);
262 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
263 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
264 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
265 extern int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
266 extern void xdr_set_pagelen(struct xdr_stream *, unsigned int len);
267 extern bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,
268 				  unsigned int len);
269 extern unsigned int xdr_stream_move_subsegment(struct xdr_stream *xdr, unsigned int offset,
270 					       unsigned int target, unsigned int length);
271 extern unsigned int xdr_stream_zero(struct xdr_stream *xdr, unsigned int offset,
272 				    unsigned int length);
273 
274 /**
275  * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
276  * @xdr: pointer to xdr_stream struct
277  * @buf: pointer to an empty buffer
278  * @buflen: size of 'buf'
279  *
280  * The scratch buffer is used when decoding from an array of pages.
281  * If an xdr_inline_decode() call spans across page boundaries, then
282  * we copy the data into the scratch buffer in order to allow linear
283  * access.
284  */
285 static inline void
xdr_set_scratch_buffer(struct xdr_stream * xdr,void * buf,size_t buflen)286 xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen)
287 {
288 	xdr->scratch.iov_base = buf;
289 	xdr->scratch.iov_len = buflen;
290 }
291 
292 /**
293  * xdr_set_scratch_page - Attach a scratch buffer for decoding data
294  * @xdr: pointer to xdr_stream struct
295  * @page: an anonymous page
296  *
297  * See xdr_set_scratch_buffer().
298  */
299 static inline void
xdr_set_scratch_page(struct xdr_stream * xdr,struct page * page)300 xdr_set_scratch_page(struct xdr_stream *xdr, struct page *page)
301 {
302 	xdr_set_scratch_buffer(xdr, page_address(page), PAGE_SIZE);
303 }
304 
305 /**
306  * xdr_reset_scratch_buffer - Clear scratch buffer information
307  * @xdr: pointer to xdr_stream struct
308  *
309  * See xdr_set_scratch_buffer().
310  */
311 static inline void
xdr_reset_scratch_buffer(struct xdr_stream * xdr)312 xdr_reset_scratch_buffer(struct xdr_stream *xdr)
313 {
314 	xdr_set_scratch_buffer(xdr, NULL, 0);
315 }
316 
317 /**
318  * xdr_commit_encode - Ensure all data is written to xdr->buf
319  * @xdr: pointer to xdr_stream
320  *
321  * Handle encoding across page boundaries by giving the caller a
322  * temporary location to write to, then later copying the data into
323  * place. __xdr_commit_encode() does that copying.
324  */
xdr_commit_encode(struct xdr_stream * xdr)325 static inline void xdr_commit_encode(struct xdr_stream *xdr)
326 {
327 	if (unlikely(xdr->scratch.iov_len))
328 		__xdr_commit_encode(xdr);
329 }
330 
331 /**
332  * xdr_stream_remaining - Return the number of bytes remaining in the stream
333  * @xdr: pointer to struct xdr_stream
334  *
335  * Return value:
336  *   Number of bytes remaining in @xdr before xdr->end
337  */
338 static inline size_t
xdr_stream_remaining(const struct xdr_stream * xdr)339 xdr_stream_remaining(const struct xdr_stream *xdr)
340 {
341 	return xdr->nwords << 2;
342 }
343 
344 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr,
345 		size_t size);
346 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr,
347 		size_t maxlen, gfp_t gfp_flags);
348 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str,
349 		size_t size);
350 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
351 		size_t maxlen, gfp_t gfp_flags);
352 ssize_t xdr_stream_decode_opaque_auth(struct xdr_stream *xdr, u32 *flavor,
353 		void **body, unsigned int *body_len);
354 ssize_t xdr_stream_encode_opaque_auth(struct xdr_stream *xdr, u32 flavor,
355 		void *body, unsigned int body_len);
356 
357 /**
358  * xdr_align_size - Calculate padded size of an object
359  * @n: Size of an object being XDR encoded (in bytes)
360  *
361  * Return value:
362  *   Size (in bytes) of the object including xdr padding
363  */
364 static inline size_t
xdr_align_size(size_t n)365 xdr_align_size(size_t n)
366 {
367 	const size_t mask = XDR_UNIT - 1;
368 
369 	return (n + mask) & ~mask;
370 }
371 
372 /**
373  * xdr_pad_size - Calculate size of an object's pad
374  * @n: Size of an object being XDR encoded (in bytes)
375  *
376  * This implementation avoids the need for conditional
377  * branches or modulo division.
378  *
379  * Return value:
380  *   Size (in bytes) of the needed XDR pad
381  */
xdr_pad_size(size_t n)382 static inline size_t xdr_pad_size(size_t n)
383 {
384 	return xdr_align_size(n) - n;
385 }
386 
387 /**
388  * xdr_stream_encode_item_present - Encode a "present" list item
389  * @xdr: pointer to xdr_stream
390  *
391  * Return values:
392  *   On success, returns length in bytes of XDR buffer consumed
393  *   %-EMSGSIZE on XDR buffer overflow
394  */
xdr_stream_encode_item_present(struct xdr_stream * xdr)395 static inline ssize_t xdr_stream_encode_item_present(struct xdr_stream *xdr)
396 {
397 	const size_t len = XDR_UNIT;
398 	__be32 *p = xdr_reserve_space(xdr, len);
399 
400 	if (unlikely(!p))
401 		return -EMSGSIZE;
402 	*p = xdr_one;
403 	return len;
404 }
405 
406 /**
407  * xdr_stream_encode_item_absent - Encode a "not present" list item
408  * @xdr: pointer to xdr_stream
409  *
410  * Return values:
411  *   On success, returns length in bytes of XDR buffer consumed
412  *   %-EMSGSIZE on XDR buffer overflow
413  */
xdr_stream_encode_item_absent(struct xdr_stream * xdr)414 static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr)
415 {
416 	const size_t len = XDR_UNIT;
417 	__be32 *p = xdr_reserve_space(xdr, len);
418 
419 	if (unlikely(!p))
420 		return -EMSGSIZE;
421 	*p = xdr_zero;
422 	return len;
423 }
424 
425 /**
426  * xdr_encode_bool - Encode a boolean item
427  * @p: address in a buffer into which to encode
428  * @n: boolean value to encode
429  *
430  * Return value:
431  *   Address of item following the encoded boolean
432  */
xdr_encode_bool(__be32 * p,u32 n)433 static inline __be32 *xdr_encode_bool(__be32 *p, u32 n)
434 {
435 	*p++ = n ? xdr_one : xdr_zero;
436 	return p;
437 }
438 
439 /**
440  * xdr_stream_encode_bool - Encode a boolean item
441  * @xdr: pointer to xdr_stream
442  * @n: boolean value to encode
443  *
444  * Return values:
445  *   On success, returns length in bytes of XDR buffer consumed
446  *   %-EMSGSIZE on XDR buffer overflow
447  */
xdr_stream_encode_bool(struct xdr_stream * xdr,__u32 n)448 static inline int xdr_stream_encode_bool(struct xdr_stream *xdr, __u32 n)
449 {
450 	const size_t len = XDR_UNIT;
451 	__be32 *p = xdr_reserve_space(xdr, len);
452 
453 	if (unlikely(!p))
454 		return -EMSGSIZE;
455 	xdr_encode_bool(p, n);
456 	return len;
457 }
458 
459 /**
460  * xdr_stream_encode_u32 - Encode a 32-bit integer
461  * @xdr: pointer to xdr_stream
462  * @n: integer to encode
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
xdr_stream_encode_u32(struct xdr_stream * xdr,__u32 n)469 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n)
470 {
471 	const size_t len = sizeof(n);
472 	__be32 *p = xdr_reserve_space(xdr, len);
473 
474 	if (unlikely(!p))
475 		return -EMSGSIZE;
476 	*p = cpu_to_be32(n);
477 	return len;
478 }
479 
480 /**
481  * xdr_stream_encode_be32 - Encode a big-endian 32-bit integer
482  * @xdr: pointer to xdr_stream
483  * @n: integer to encode
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
xdr_stream_encode_be32(struct xdr_stream * xdr,__be32 n)490 xdr_stream_encode_be32(struct xdr_stream *xdr, __be32 n)
491 {
492 	const size_t len = sizeof(n);
493 	__be32 *p = xdr_reserve_space(xdr, len);
494 
495 	if (unlikely(!p))
496 		return -EMSGSIZE;
497 	*p = n;
498 	return len;
499 }
500 
501 /**
502  * xdr_stream_encode_u64 - Encode a 64-bit integer
503  * @xdr: pointer to xdr_stream
504  * @n: 64-bit integer to encode
505  *
506  * Return values:
507  *   On success, returns length in bytes of XDR buffer consumed
508  *   %-EMSGSIZE on XDR buffer overflow
509  */
510 static inline ssize_t
xdr_stream_encode_u64(struct xdr_stream * xdr,__u64 n)511 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n)
512 {
513 	const size_t len = sizeof(n);
514 	__be32 *p = xdr_reserve_space(xdr, len);
515 
516 	if (unlikely(!p))
517 		return -EMSGSIZE;
518 	xdr_encode_hyper(p, n);
519 	return len;
520 }
521 
522 /**
523  * xdr_stream_encode_opaque_inline - Encode opaque xdr data
524  * @xdr: pointer to xdr_stream
525  * @ptr: pointer to void pointer
526  * @len: size of object
527  *
528  * Return values:
529  *   On success, returns length in bytes of XDR buffer consumed
530  *   %-EMSGSIZE on XDR buffer overflow
531  */
532 static inline ssize_t
xdr_stream_encode_opaque_inline(struct xdr_stream * xdr,void ** ptr,size_t len)533 xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len)
534 {
535 	size_t count = sizeof(__u32) + xdr_align_size(len);
536 	__be32 *p = xdr_reserve_space(xdr, count);
537 
538 	if (unlikely(!p)) {
539 		*ptr = NULL;
540 		return -EMSGSIZE;
541 	}
542 	xdr_encode_opaque(p, NULL, len);
543 	*ptr = ++p;
544 	return count;
545 }
546 
547 /**
548  * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data
549  * @xdr: pointer to xdr_stream
550  * @ptr: pointer to opaque data object
551  * @len: size of object pointed to by @ptr
552  *
553  * Return values:
554  *   On success, returns length in bytes of XDR buffer consumed
555  *   %-EMSGSIZE on XDR buffer overflow
556  */
557 static inline ssize_t
xdr_stream_encode_opaque_fixed(struct xdr_stream * xdr,const void * ptr,size_t len)558 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len)
559 {
560 	__be32 *p = xdr_reserve_space(xdr, len);
561 
562 	if (unlikely(!p))
563 		return -EMSGSIZE;
564 	xdr_encode_opaque_fixed(p, ptr, len);
565 	return xdr_align_size(len);
566 }
567 
568 /**
569  * xdr_stream_encode_opaque - Encode variable length opaque xdr data
570  * @xdr: pointer to xdr_stream
571  * @ptr: pointer to opaque data object
572  * @len: size of object pointed to by @ptr
573  *
574  * Return values:
575  *   On success, returns length in bytes of XDR buffer consumed
576  *   %-EMSGSIZE on XDR buffer overflow
577  */
578 static inline ssize_t
xdr_stream_encode_opaque(struct xdr_stream * xdr,const void * ptr,size_t len)579 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len)
580 {
581 	size_t count = sizeof(__u32) + xdr_align_size(len);
582 	__be32 *p = xdr_reserve_space(xdr, count);
583 
584 	if (unlikely(!p))
585 		return -EMSGSIZE;
586 	xdr_encode_opaque(p, ptr, len);
587 	return count;
588 }
589 
590 /**
591  * xdr_stream_encode_uint32_array - Encode variable length array of integers
592  * @xdr: pointer to xdr_stream
593  * @array: array of integers
594  * @array_size: number of elements in @array
595  *
596  * Return values:
597  *   On success, returns length in bytes of XDR buffer consumed
598  *   %-EMSGSIZE on XDR buffer overflow
599  */
600 static inline ssize_t
xdr_stream_encode_uint32_array(struct xdr_stream * xdr,const __u32 * array,size_t array_size)601 xdr_stream_encode_uint32_array(struct xdr_stream *xdr,
602 		const __u32 *array, size_t array_size)
603 {
604 	ssize_t ret = (array_size+1) * sizeof(__u32);
605 	__be32 *p = xdr_reserve_space(xdr, ret);
606 
607 	if (unlikely(!p))
608 		return -EMSGSIZE;
609 	*p++ = cpu_to_be32(array_size);
610 	for (; array_size > 0; p++, array++, array_size--)
611 		*p = cpu_to_be32p(array);
612 	return ret;
613 }
614 
615 /**
616  * xdr_item_is_absent - symbolically handle XDR discriminators
617  * @p: pointer to undecoded discriminator
618  *
619  * Return values:
620  *   %true if the following XDR item is absent
621  *   %false if the following XDR item is present
622  */
xdr_item_is_absent(const __be32 * p)623 static inline bool xdr_item_is_absent(const __be32 *p)
624 {
625 	return *p == xdr_zero;
626 }
627 
628 /**
629  * xdr_item_is_present - symbolically handle XDR discriminators
630  * @p: pointer to undecoded discriminator
631  *
632  * Return values:
633  *   %true if the following XDR item is present
634  *   %false if the following XDR item is absent
635  */
xdr_item_is_present(const __be32 * p)636 static inline bool xdr_item_is_present(const __be32 *p)
637 {
638 	return *p != xdr_zero;
639 }
640 
641 /**
642  * xdr_stream_decode_bool - Decode a boolean
643  * @xdr: pointer to xdr_stream
644  * @ptr: pointer to a u32 in which to store the result
645  *
646  * Return values:
647  *   %0 on success
648  *   %-EBADMSG on XDR buffer overflow
649  */
650 static inline ssize_t
xdr_stream_decode_bool(struct xdr_stream * xdr,__u32 * ptr)651 xdr_stream_decode_bool(struct xdr_stream *xdr, __u32 *ptr)
652 {
653 	const size_t count = sizeof(*ptr);
654 	__be32 *p = xdr_inline_decode(xdr, count);
655 
656 	if (unlikely(!p))
657 		return -EBADMSG;
658 	*ptr = (*p != xdr_zero);
659 	return 0;
660 }
661 
662 /**
663  * xdr_stream_decode_u32 - Decode a 32-bit integer
664  * @xdr: pointer to xdr_stream
665  * @ptr: location to store integer
666  *
667  * Return values:
668  *   %0 on success
669  *   %-EBADMSG on XDR buffer overflow
670  */
671 static inline ssize_t
xdr_stream_decode_u32(struct xdr_stream * xdr,__u32 * ptr)672 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr)
673 {
674 	const size_t count = sizeof(*ptr);
675 	__be32 *p = xdr_inline_decode(xdr, count);
676 
677 	if (unlikely(!p))
678 		return -EBADMSG;
679 	*ptr = be32_to_cpup(p);
680 	return 0;
681 }
682 
683 /**
684  * xdr_stream_decode_u64 - Decode a 64-bit integer
685  * @xdr: pointer to xdr_stream
686  * @ptr: location to store 64-bit integer
687  *
688  * Return values:
689  *   %0 on success
690  *   %-EBADMSG on XDR buffer overflow
691  */
692 static inline ssize_t
xdr_stream_decode_u64(struct xdr_stream * xdr,__u64 * ptr)693 xdr_stream_decode_u64(struct xdr_stream *xdr, __u64 *ptr)
694 {
695 	const size_t count = sizeof(*ptr);
696 	__be32 *p = xdr_inline_decode(xdr, count);
697 
698 	if (unlikely(!p))
699 		return -EBADMSG;
700 	xdr_decode_hyper(p, ptr);
701 	return 0;
702 }
703 
704 /**
705  * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data
706  * @xdr: pointer to xdr_stream
707  * @ptr: location to store data
708  * @len: size of buffer pointed to by @ptr
709  *
710  * Return values:
711  *   On success, returns size of object stored in @ptr
712  *   %-EBADMSG on XDR buffer overflow
713  */
714 static inline ssize_t
xdr_stream_decode_opaque_fixed(struct xdr_stream * xdr,void * ptr,size_t len)715 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len)
716 {
717 	__be32 *p = xdr_inline_decode(xdr, len);
718 
719 	if (unlikely(!p))
720 		return -EBADMSG;
721 	xdr_decode_opaque_fixed(p, ptr, len);
722 	return len;
723 }
724 
725 /**
726  * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data
727  * @xdr: pointer to xdr_stream
728  * @ptr: location to store pointer to opaque data
729  * @maxlen: maximum acceptable object size
730  *
731  * Note: the pointer stored in @ptr cannot be assumed valid after the XDR
732  * buffer has been destroyed, or even after calling xdr_inline_decode()
733  * on @xdr. It is therefore expected that the object it points to should
734  * be processed immediately.
735  *
736  * Return values:
737  *   On success, returns size of object stored in *@ptr
738  *   %-EBADMSG on XDR buffer overflow
739  *   %-EMSGSIZE if the size of the object would exceed @maxlen
740  */
741 static inline ssize_t
xdr_stream_decode_opaque_inline(struct xdr_stream * xdr,void ** ptr,size_t maxlen)742 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen)
743 {
744 	__be32 *p;
745 	__u32 len;
746 
747 	*ptr = NULL;
748 	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
749 		return -EBADMSG;
750 	if (len != 0) {
751 		p = xdr_inline_decode(xdr, len);
752 		if (unlikely(!p))
753 			return -EBADMSG;
754 		if (unlikely(len > maxlen))
755 			return -EMSGSIZE;
756 		*ptr = p;
757 	}
758 	return len;
759 }
760 
761 /**
762  * xdr_stream_decode_uint32_array - Decode variable length array of integers
763  * @xdr: pointer to xdr_stream
764  * @array: location to store the integer array or NULL
765  * @array_size: number of elements to store
766  *
767  * Return values:
768  *   On success, returns number of elements stored in @array
769  *   %-EBADMSG on XDR buffer overflow
770  *   %-EMSGSIZE if the size of the array exceeds @array_size
771  */
772 static inline ssize_t
xdr_stream_decode_uint32_array(struct xdr_stream * xdr,__u32 * array,size_t array_size)773 xdr_stream_decode_uint32_array(struct xdr_stream *xdr,
774 		__u32 *array, size_t array_size)
775 {
776 	__be32 *p;
777 	__u32 len;
778 	ssize_t retval;
779 
780 	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
781 		return -EBADMSG;
782 	if (U32_MAX >= SIZE_MAX / sizeof(*p) && len > SIZE_MAX / sizeof(*p))
783 		return -EBADMSG;
784 	p = xdr_inline_decode(xdr, len * sizeof(*p));
785 	if (unlikely(!p))
786 		return -EBADMSG;
787 	if (array == NULL)
788 		return len;
789 	if (len <= array_size) {
790 		if (len < array_size)
791 			memset(array+len, 0, (array_size-len)*sizeof(*array));
792 		array_size = len;
793 		retval = len;
794 	} else
795 		retval = -EMSGSIZE;
796 	for (; array_size > 0; p++, array++, array_size--)
797 		*array = be32_to_cpup(p);
798 	return retval;
799 }
800 
801 #endif /* _SUNRPC_XDR_H_ */
802