xref: /linux/include/linux/sunrpc/xdr.h (revision ce3f5bb7504ca802efa710280a4601a06545bd2e)
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	rpc_autherr_invalidresp	cpu_to_be32(RPC_AUTH_INVALIDRESP)
123 #define	rpc_autherr_failed	cpu_to_be32(RPC_AUTH_FAILED)
124 #define	rpcsec_gsserr_credproblem	cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
125 #define	rpcsec_gsserr_ctxproblem	cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
126 
127 /*
128  * Miscellaneous XDR helper functions
129  */
130 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
131 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
132 __be32 *xdr_encode_string(__be32 *p, const char *s);
133 __be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
134 			unsigned int maxlen);
135 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
136 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
137 
138 void	xdr_inline_pages(struct xdr_buf *, unsigned int,
139 			 struct page **, unsigned int, unsigned int);
140 void	xdr_terminate_string(const struct xdr_buf *, const u32);
141 size_t	xdr_buf_pagecount(const struct xdr_buf *buf);
142 int	xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp);
143 void	xdr_free_bvec(struct xdr_buf *buf);
144 unsigned int xdr_buf_to_bvec(struct bio_vec *bvec, unsigned int bvec_size,
145 			     const struct xdr_buf *xdr);
146 
xdr_encode_array(__be32 * p,const void * s,unsigned int len)147 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
148 {
149 	return xdr_encode_opaque(p, s, len);
150 }
151 
152 /*
153  * Decode 64bit quantities (NFSv3 support)
154  */
155 static inline __be32 *
xdr_encode_hyper(__be32 * p,__u64 val)156 xdr_encode_hyper(__be32 *p, __u64 val)
157 {
158 	put_unaligned_be64(val, p);
159 	return p + 2;
160 }
161 
162 static inline __be32 *
xdr_decode_hyper(__be32 * p,__u64 * valp)163 xdr_decode_hyper(__be32 *p, __u64 *valp)
164 {
165 	*valp = get_unaligned_be64(p);
166 	return p + 2;
167 }
168 
169 static inline __be32 *
xdr_decode_opaque_fixed(__be32 * p,void * ptr,unsigned int len)170 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
171 {
172 	memcpy(ptr, p, len);
173 	return p + XDR_QUADLEN(len);
174 }
175 
xdr_netobj_dup(struct xdr_netobj * dst,struct xdr_netobj * src,gfp_t gfp_mask)176 static inline void xdr_netobj_dup(struct xdr_netobj *dst,
177 				  struct xdr_netobj *src, gfp_t gfp_mask)
178 {
179 	dst->data = kmemdup(src->data, src->len, gfp_mask);
180 	dst->len = src->len;
181 }
182 
183 /*
184  * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
185  */
186 static inline int
xdr_adjust_iovec(struct kvec * iov,__be32 * p)187 xdr_adjust_iovec(struct kvec *iov, __be32 *p)
188 {
189 	return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
190 }
191 
192 /*
193  * XDR buffer helper functions
194  */
195 extern void xdr_buf_from_iov(const struct kvec *, struct xdr_buf *);
196 extern int xdr_buf_subsegment(const struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
197 extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
198 extern int read_bytes_from_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
199 extern int write_bytes_to_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
200 
201 extern int xdr_encode_word(const struct xdr_buf *, unsigned int, u32);
202 extern int xdr_decode_word(const struct xdr_buf *, unsigned int, u32 *);
203 
204 struct xdr_array2_desc;
205 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
206 struct xdr_array2_desc {
207 	unsigned int elem_size;
208 	unsigned int array_len;
209 	unsigned int array_maxlen;
210 	xdr_xcode_elem_t xcode;
211 };
212 
213 extern int xdr_decode_array2(const struct xdr_buf *buf, unsigned int base,
214 			     struct xdr_array2_desc *desc);
215 extern int xdr_encode_array2(const struct xdr_buf *buf, unsigned int base,
216 			     struct xdr_array2_desc *desc);
217 extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
218 			     size_t len);
219 
220 /*
221  * Provide some simple tools for XDR buffer overflow-checking etc.
222  */
223 struct xdr_stream {
224 	__be32 *p;		/* start of available buffer */
225 	struct xdr_buf *buf;	/* XDR buffer to read/write */
226 
227 	__be32 *end;		/* end of available buffer space */
228 	struct kvec *iov;	/* pointer to the current kvec */
229 	struct kvec scratch;	/* Scratch buffer */
230 	struct page **page_ptr;	/* pointer to the current page */
231 	void *page_kaddr;	/* kmapped address of the current page */
232 	unsigned int nwords;	/* Remaining decode buffer length */
233 
234 	struct rpc_rqst *rqst;	/* For debugging */
235 };
236 
237 /*
238  * These are the xdr_stream style generic XDR encode and decode functions.
239  */
240 typedef void	(*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
241 		const void *obj);
242 typedef int	(*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
243 		void *obj);
244 
245 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf,
246 			    __be32 *p, struct rpc_rqst *rqst);
247 void xdr_init_encode_pages(struct xdr_stream *xdr, struct xdr_buf *buf);
248 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
249 extern int xdr_reserve_space_vec(struct xdr_stream *xdr, size_t nbytes);
250 extern void __xdr_commit_encode(struct xdr_stream *xdr);
251 extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
252 extern void xdr_truncate_decode(struct xdr_stream *xdr, size_t len);
253 extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen);
254 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
255 		unsigned int base, unsigned int len);
256 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
257 extern unsigned int xdr_page_pos(const struct xdr_stream *xdr);
258 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf,
259 			    __be32 *p, struct rpc_rqst *rqst);
260 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
261 		struct page **pages, unsigned int len);
262 extern void xdr_finish_decode(struct xdr_stream *xdr);
263 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
264 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
265 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
266 extern int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
267 extern void xdr_set_pagelen(struct xdr_stream *, unsigned int len);
268 extern bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,
269 				  unsigned int len);
270 extern unsigned int xdr_stream_move_subsegment(struct xdr_stream *xdr, unsigned int offset,
271 					       unsigned int target, unsigned int length);
272 extern unsigned int xdr_stream_zero(struct xdr_stream *xdr, unsigned int offset,
273 				    unsigned int length);
274 
275 /**
276  * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
277  * @xdr: pointer to xdr_stream struct
278  * @buf: pointer to an empty buffer
279  * @buflen: size of 'buf'
280  *
281  * The scratch buffer is used when decoding from an array of pages.
282  * If an xdr_inline_decode() call spans across page boundaries, then
283  * we copy the data into the scratch buffer in order to allow linear
284  * access.
285  */
286 static inline void
xdr_set_scratch_buffer(struct xdr_stream * xdr,void * buf,size_t buflen)287 xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen)
288 {
289 	xdr->scratch.iov_base = buf;
290 	xdr->scratch.iov_len = buflen;
291 }
292 
293 /**
294  * xdr_set_scratch_page - Attach a scratch buffer for decoding data
295  * @xdr: pointer to xdr_stream struct
296  * @page: an anonymous page
297  *
298  * See xdr_set_scratch_buffer().
299  */
300 static inline void
xdr_set_scratch_page(struct xdr_stream * xdr,struct page * page)301 xdr_set_scratch_page(struct xdr_stream *xdr, struct page *page)
302 {
303 	xdr_set_scratch_buffer(xdr, page_address(page), PAGE_SIZE);
304 }
305 
306 /**
307  * xdr_reset_scratch_buffer - Clear scratch buffer information
308  * @xdr: pointer to xdr_stream struct
309  *
310  * See xdr_set_scratch_buffer().
311  */
312 static inline void
xdr_reset_scratch_buffer(struct xdr_stream * xdr)313 xdr_reset_scratch_buffer(struct xdr_stream *xdr)
314 {
315 	xdr_set_scratch_buffer(xdr, NULL, 0);
316 }
317 
318 /**
319  * xdr_commit_encode - Ensure all data is written to xdr->buf
320  * @xdr: pointer to xdr_stream
321  *
322  * Handle encoding across page boundaries by giving the caller a
323  * temporary location to write to, then later copying the data into
324  * place. __xdr_commit_encode() does that copying.
325  */
xdr_commit_encode(struct xdr_stream * xdr)326 static inline void xdr_commit_encode(struct xdr_stream *xdr)
327 {
328 	if (unlikely(xdr->scratch.iov_len))
329 		__xdr_commit_encode(xdr);
330 }
331 
332 /**
333  * xdr_stream_remaining - Return the number of bytes remaining in the stream
334  * @xdr: pointer to struct xdr_stream
335  *
336  * Return value:
337  *   Number of bytes remaining in @xdr before xdr->end
338  */
339 static inline size_t
xdr_stream_remaining(const struct xdr_stream * xdr)340 xdr_stream_remaining(const struct xdr_stream *xdr)
341 {
342 	return xdr->nwords << 2;
343 }
344 
345 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr,
346 		size_t size);
347 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr,
348 		size_t maxlen, gfp_t gfp_flags);
349 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str,
350 		size_t size);
351 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
352 		size_t maxlen, gfp_t gfp_flags);
353 ssize_t xdr_stream_decode_opaque_auth(struct xdr_stream *xdr, u32 *flavor,
354 		void **body, unsigned int *body_len);
355 ssize_t xdr_stream_encode_opaque_auth(struct xdr_stream *xdr, u32 flavor,
356 		void *body, unsigned int body_len);
357 
358 /**
359  * xdr_align_size - Calculate padded size of an object
360  * @n: Size of an object being XDR encoded (in bytes)
361  *
362  * Return value:
363  *   Size (in bytes) of the object including xdr padding
364  */
365 static inline size_t
xdr_align_size(size_t n)366 xdr_align_size(size_t n)
367 {
368 	const size_t mask = XDR_UNIT - 1;
369 
370 	return (n + mask) & ~mask;
371 }
372 
373 /**
374  * xdr_pad_size - Calculate size of an object's pad
375  * @n: Size of an object being XDR encoded (in bytes)
376  *
377  * This implementation avoids the need for conditional
378  * branches or modulo division.
379  *
380  * Return value:
381  *   Size (in bytes) of the needed XDR pad
382  */
xdr_pad_size(size_t n)383 static inline size_t xdr_pad_size(size_t n)
384 {
385 	return xdr_align_size(n) - n;
386 }
387 
388 /**
389  * xdr_stream_encode_item_present - Encode a "present" list item
390  * @xdr: pointer to xdr_stream
391  *
392  * Return values:
393  *   On success, returns length in bytes of XDR buffer consumed
394  *   %-EMSGSIZE on XDR buffer overflow
395  */
xdr_stream_encode_item_present(struct xdr_stream * xdr)396 static inline ssize_t xdr_stream_encode_item_present(struct xdr_stream *xdr)
397 {
398 	const size_t len = XDR_UNIT;
399 	__be32 *p = xdr_reserve_space(xdr, len);
400 
401 	if (unlikely(!p))
402 		return -EMSGSIZE;
403 	*p = xdr_one;
404 	return len;
405 }
406 
407 /**
408  * xdr_stream_encode_item_absent - Encode a "not present" list item
409  * @xdr: pointer to xdr_stream
410  *
411  * Return values:
412  *   On success, returns length in bytes of XDR buffer consumed
413  *   %-EMSGSIZE on XDR buffer overflow
414  */
xdr_stream_encode_item_absent(struct xdr_stream * xdr)415 static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr)
416 {
417 	const size_t len = XDR_UNIT;
418 	__be32 *p = xdr_reserve_space(xdr, len);
419 
420 	if (unlikely(!p))
421 		return -EMSGSIZE;
422 	*p = xdr_zero;
423 	return len;
424 }
425 
426 /**
427  * xdr_encode_bool - Encode a boolean item
428  * @p: address in a buffer into which to encode
429  * @n: boolean value to encode
430  *
431  * Return value:
432  *   Address of item following the encoded boolean
433  */
xdr_encode_bool(__be32 * p,u32 n)434 static inline __be32 *xdr_encode_bool(__be32 *p, u32 n)
435 {
436 	*p++ = n ? xdr_one : xdr_zero;
437 	return p;
438 }
439 
440 /**
441  * xdr_stream_encode_bool - Encode a boolean item
442  * @xdr: pointer to xdr_stream
443  * @n: boolean value to encode
444  *
445  * Return values:
446  *   On success, returns length in bytes of XDR buffer consumed
447  *   %-EMSGSIZE on XDR buffer overflow
448  */
xdr_stream_encode_bool(struct xdr_stream * xdr,__u32 n)449 static inline int xdr_stream_encode_bool(struct xdr_stream *xdr, __u32 n)
450 {
451 	const size_t len = XDR_UNIT;
452 	__be32 *p = xdr_reserve_space(xdr, len);
453 
454 	if (unlikely(!p))
455 		return -EMSGSIZE;
456 	xdr_encode_bool(p, n);
457 	return len;
458 }
459 
460 /**
461  * xdr_stream_encode_u32 - Encode a 32-bit integer
462  * @xdr: pointer to xdr_stream
463  * @n: integer to encode
464  *
465  * Return values:
466  *   On success, returns length in bytes of XDR buffer consumed
467  *   %-EMSGSIZE on XDR buffer overflow
468  */
469 static inline ssize_t
xdr_stream_encode_u32(struct xdr_stream * xdr,__u32 n)470 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n)
471 {
472 	const size_t len = sizeof(n);
473 	__be32 *p = xdr_reserve_space(xdr, len);
474 
475 	if (unlikely(!p))
476 		return -EMSGSIZE;
477 	*p = cpu_to_be32(n);
478 	return len;
479 }
480 
481 /**
482  * xdr_stream_encode_be32 - Encode a big-endian 32-bit integer
483  * @xdr: pointer to xdr_stream
484  * @n: integer to encode
485  *
486  * Return values:
487  *   On success, returns length in bytes of XDR buffer consumed
488  *   %-EMSGSIZE on XDR buffer overflow
489  */
490 static inline ssize_t
xdr_stream_encode_be32(struct xdr_stream * xdr,__be32 n)491 xdr_stream_encode_be32(struct xdr_stream *xdr, __be32 n)
492 {
493 	const size_t len = sizeof(n);
494 	__be32 *p = xdr_reserve_space(xdr, len);
495 
496 	if (unlikely(!p))
497 		return -EMSGSIZE;
498 	*p = n;
499 	return len;
500 }
501 
502 /**
503  * xdr_stream_encode_u64 - Encode a 64-bit integer
504  * @xdr: pointer to xdr_stream
505  * @n: 64-bit integer to encode
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
xdr_stream_encode_u64(struct xdr_stream * xdr,__u64 n)512 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n)
513 {
514 	const size_t len = sizeof(n);
515 	__be32 *p = xdr_reserve_space(xdr, len);
516 
517 	if (unlikely(!p))
518 		return -EMSGSIZE;
519 	xdr_encode_hyper(p, n);
520 	return len;
521 }
522 
523 /**
524  * xdr_stream_encode_opaque_inline - Encode opaque xdr data
525  * @xdr: pointer to xdr_stream
526  * @ptr: pointer to void pointer
527  * @len: size of object
528  *
529  * Return values:
530  *   On success, returns length in bytes of XDR buffer consumed
531  *   %-EMSGSIZE on XDR buffer overflow
532  */
533 static inline ssize_t
xdr_stream_encode_opaque_inline(struct xdr_stream * xdr,void ** ptr,size_t len)534 xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len)
535 {
536 	size_t count = sizeof(__u32) + xdr_align_size(len);
537 	__be32 *p = xdr_reserve_space(xdr, count);
538 
539 	if (unlikely(!p)) {
540 		*ptr = NULL;
541 		return -EMSGSIZE;
542 	}
543 	xdr_encode_opaque(p, NULL, len);
544 	*ptr = ++p;
545 	return count;
546 }
547 
548 /**
549  * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data
550  * @xdr: pointer to xdr_stream
551  * @ptr: pointer to opaque data object
552  * @len: size of object pointed to by @ptr
553  *
554  * Return values:
555  *   On success, returns length in bytes of XDR buffer consumed
556  *   %-EMSGSIZE on XDR buffer overflow
557  */
558 static inline ssize_t
xdr_stream_encode_opaque_fixed(struct xdr_stream * xdr,const void * ptr,size_t len)559 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len)
560 {
561 	__be32 *p = xdr_reserve_space(xdr, len);
562 
563 	if (unlikely(!p))
564 		return -EMSGSIZE;
565 	xdr_encode_opaque_fixed(p, ptr, len);
566 	return xdr_align_size(len);
567 }
568 
569 /**
570  * xdr_stream_encode_opaque - Encode variable length opaque xdr data
571  * @xdr: pointer to xdr_stream
572  * @ptr: pointer to opaque data object
573  * @len: size of object pointed to by @ptr
574  *
575  * Return values:
576  *   On success, returns length in bytes of XDR buffer consumed
577  *   %-EMSGSIZE on XDR buffer overflow
578  */
579 static inline ssize_t
xdr_stream_encode_opaque(struct xdr_stream * xdr,const void * ptr,size_t len)580 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len)
581 {
582 	size_t count = sizeof(__u32) + xdr_align_size(len);
583 	__be32 *p = xdr_reserve_space(xdr, count);
584 
585 	if (unlikely(!p))
586 		return -EMSGSIZE;
587 	xdr_encode_opaque(p, ptr, len);
588 	return count;
589 }
590 
591 /**
592  * xdr_stream_encode_uint32_array - Encode variable length array of integers
593  * @xdr: pointer to xdr_stream
594  * @array: array of integers
595  * @array_size: number of elements in @array
596  *
597  * Return values:
598  *   On success, returns length in bytes of XDR buffer consumed
599  *   %-EMSGSIZE on XDR buffer overflow
600  */
601 static inline ssize_t
xdr_stream_encode_uint32_array(struct xdr_stream * xdr,const __u32 * array,size_t array_size)602 xdr_stream_encode_uint32_array(struct xdr_stream *xdr,
603 		const __u32 *array, size_t array_size)
604 {
605 	ssize_t ret = (array_size+1) * sizeof(__u32);
606 	__be32 *p = xdr_reserve_space(xdr, ret);
607 
608 	if (unlikely(!p))
609 		return -EMSGSIZE;
610 	*p++ = cpu_to_be32(array_size);
611 	for (; array_size > 0; p++, array++, array_size--)
612 		*p = cpu_to_be32p(array);
613 	return ret;
614 }
615 
616 /**
617  * xdr_item_is_absent - symbolically handle XDR discriminators
618  * @p: pointer to undecoded discriminator
619  *
620  * Return values:
621  *   %true if the following XDR item is absent
622  *   %false if the following XDR item is present
623  */
xdr_item_is_absent(const __be32 * p)624 static inline bool xdr_item_is_absent(const __be32 *p)
625 {
626 	return *p == xdr_zero;
627 }
628 
629 /**
630  * xdr_item_is_present - symbolically handle XDR discriminators
631  * @p: pointer to undecoded discriminator
632  *
633  * Return values:
634  *   %true if the following XDR item is present
635  *   %false if the following XDR item is absent
636  */
xdr_item_is_present(const __be32 * p)637 static inline bool xdr_item_is_present(const __be32 *p)
638 {
639 	return *p != xdr_zero;
640 }
641 
642 /**
643  * xdr_stream_decode_bool - Decode a boolean
644  * @xdr: pointer to xdr_stream
645  * @ptr: pointer to a u32 in which to store the result
646  *
647  * Return values:
648  *   %0 on success
649  *   %-EBADMSG on XDR buffer overflow
650  */
651 static inline ssize_t
xdr_stream_decode_bool(struct xdr_stream * xdr,__u32 * ptr)652 xdr_stream_decode_bool(struct xdr_stream *xdr, __u32 *ptr)
653 {
654 	const size_t count = sizeof(*ptr);
655 	__be32 *p = xdr_inline_decode(xdr, count);
656 
657 	if (unlikely(!p))
658 		return -EBADMSG;
659 	*ptr = (*p != xdr_zero);
660 	return 0;
661 }
662 
663 /**
664  * xdr_stream_decode_u32 - Decode a 32-bit integer
665  * @xdr: pointer to xdr_stream
666  * @ptr: location to store integer
667  *
668  * Return values:
669  *   %0 on success
670  *   %-EBADMSG on XDR buffer overflow
671  */
672 static inline ssize_t
xdr_stream_decode_u32(struct xdr_stream * xdr,__u32 * ptr)673 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr)
674 {
675 	const size_t count = sizeof(*ptr);
676 	__be32 *p = xdr_inline_decode(xdr, count);
677 
678 	if (unlikely(!p))
679 		return -EBADMSG;
680 	*ptr = be32_to_cpup(p);
681 	return 0;
682 }
683 
684 /**
685  * xdr_stream_decode_be32 - Decode a big-endian 32-bit integer
686  * @xdr: pointer to xdr_stream
687  * @ptr: location to store integer
688  *
689  * Return values:
690  *   %0 on success
691  *   %-EBADMSG on XDR buffer overflow
692  */
693 static inline ssize_t
xdr_stream_decode_be32(struct xdr_stream * xdr,__be32 * ptr)694 xdr_stream_decode_be32(struct xdr_stream *xdr, __be32 *ptr)
695 {
696 	const size_t count = sizeof(*ptr);
697 	__be32 *p = xdr_inline_decode(xdr, count);
698 
699 	if (unlikely(!p))
700 		return -EBADMSG;
701 	*ptr = *p;
702 	return 0;
703 }
704 
705 /**
706  * xdr_stream_decode_u64 - Decode a 64-bit integer
707  * @xdr: pointer to xdr_stream
708  * @ptr: location to store 64-bit integer
709  *
710  * Return values:
711  *   %0 on success
712  *   %-EBADMSG on XDR buffer overflow
713  */
714 static inline ssize_t
xdr_stream_decode_u64(struct xdr_stream * xdr,__u64 * ptr)715 xdr_stream_decode_u64(struct xdr_stream *xdr, __u64 *ptr)
716 {
717 	const size_t count = sizeof(*ptr);
718 	__be32 *p = xdr_inline_decode(xdr, count);
719 
720 	if (unlikely(!p))
721 		return -EBADMSG;
722 	xdr_decode_hyper(p, ptr);
723 	return 0;
724 }
725 
726 /**
727  * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data
728  * @xdr: pointer to xdr_stream
729  * @ptr: location to store data
730  * @len: size of buffer pointed to by @ptr
731  *
732  * Return values:
733  *   On success, returns size of object stored in @ptr
734  *   %-EBADMSG on XDR buffer overflow
735  */
736 static inline ssize_t
xdr_stream_decode_opaque_fixed(struct xdr_stream * xdr,void * ptr,size_t len)737 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len)
738 {
739 	__be32 *p = xdr_inline_decode(xdr, len);
740 
741 	if (unlikely(!p))
742 		return -EBADMSG;
743 	xdr_decode_opaque_fixed(p, ptr, len);
744 	return len;
745 }
746 
747 /**
748  * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data
749  * @xdr: pointer to xdr_stream
750  * @ptr: location to store pointer to opaque data
751  * @maxlen: maximum acceptable object size
752  *
753  * Note: the pointer stored in @ptr cannot be assumed valid after the XDR
754  * buffer has been destroyed, or even after calling xdr_inline_decode()
755  * on @xdr. It is therefore expected that the object it points to should
756  * be processed immediately.
757  *
758  * Return values:
759  *   On success, returns size of object stored in *@ptr
760  *   %-EBADMSG on XDR buffer overflow
761  *   %-EMSGSIZE if the size of the object would exceed @maxlen
762  */
763 static inline ssize_t
xdr_stream_decode_opaque_inline(struct xdr_stream * xdr,void ** ptr,size_t maxlen)764 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen)
765 {
766 	__be32 *p;
767 	__u32 len;
768 
769 	*ptr = NULL;
770 	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
771 		return -EBADMSG;
772 	if (len != 0) {
773 		p = xdr_inline_decode(xdr, len);
774 		if (unlikely(!p))
775 			return -EBADMSG;
776 		if (unlikely(len > maxlen))
777 			return -EMSGSIZE;
778 		*ptr = p;
779 	}
780 	return len;
781 }
782 
783 /**
784  * xdr_stream_decode_uint32_array - Decode variable length array of integers
785  * @xdr: pointer to xdr_stream
786  * @array: location to store the integer array or NULL
787  * @array_size: number of elements to store
788  *
789  * Return values:
790  *   On success, returns number of elements stored in @array
791  *   %-EBADMSG on XDR buffer overflow
792  *   %-EMSGSIZE if the size of the array exceeds @array_size
793  */
794 static inline ssize_t
xdr_stream_decode_uint32_array(struct xdr_stream * xdr,__u32 * array,size_t array_size)795 xdr_stream_decode_uint32_array(struct xdr_stream *xdr,
796 		__u32 *array, size_t array_size)
797 {
798 	__be32 *p;
799 	__u32 len;
800 	ssize_t retval;
801 
802 	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
803 		return -EBADMSG;
804 	if (U32_MAX >= SIZE_MAX / sizeof(*p) && len > SIZE_MAX / sizeof(*p))
805 		return -EBADMSG;
806 	p = xdr_inline_decode(xdr, len * sizeof(*p));
807 	if (unlikely(!p))
808 		return -EBADMSG;
809 	if (array == NULL)
810 		return len;
811 	if (len <= array_size) {
812 		if (len < array_size)
813 			memset(array+len, 0, (array_size-len)*sizeof(*array));
814 		array_size = len;
815 		retval = len;
816 	} else
817 		retval = -EMSGSIZE;
818 	for (; array_size > 0; p++, array++, array_size--)
819 		*array = be32_to_cpup(p);
820 	return retval;
821 }
822 
823 #endif /* _SUNRPC_XDR_H_ */
824