1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * XDR standard data types and function declarations
4 *
5 * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
6 *
7 * Based on:
8 * RFC 4506 "XDR: External Data Representation Standard", May 2006
9 */
10
11 #ifndef _SUNRPC_XDR_H_
12 #define _SUNRPC_XDR_H_
13
14 #include <linux/uio.h>
15 #include <asm/byteorder.h>
16 #include <asm/unaligned.h>
17 #include <linux/scatterlist.h>
18
19 struct bio_vec;
20 struct rpc_rqst;
21
22 /*
23 * Size of an XDR encoding unit in bytes, i.e. 32 bits,
24 * as defined in Section 3 of RFC 4506. All encoded
25 * XDR data items are aligned on a boundary of 32 bits.
26 */
27 #define XDR_UNIT sizeof(__be32)
28
29 /*
30 * Buffer adjustment
31 */
32 #define XDR_QUADLEN(l) (((l) + 3) >> 2)
33
34 /*
35 * Generic opaque `network object.'
36 */
37 #define XDR_MAX_NETOBJ 1024
38 struct xdr_netobj {
39 unsigned int len;
40 u8 * data;
41 };
42
43 /*
44 * Basic structure for transmission/reception of a client XDR message.
45 * Features a header (for a linear buffer containing RPC headers
46 * and the data payload for short messages), and then an array of
47 * pages.
48 * The tail iovec allows you to append data after the page array. Its
49 * main interest is for appending padding to the pages in order to
50 * satisfy the int_32-alignment requirements in RFC1832.
51 *
52 * For the future, we might want to string several of these together
53 * in a list if anybody wants to make use of NFSv4 COMPOUND
54 * operations and/or has a need for scatter/gather involving pages.
55 */
56 struct xdr_buf {
57 struct kvec head[1], /* RPC header + non-page data */
58 tail[1]; /* Appended after page data */
59
60 struct bio_vec *bvec;
61 struct page ** pages; /* Array of pages */
62 unsigned int page_base, /* Start of page data */
63 page_len, /* Length of page data */
64 flags; /* Flags for data disposition */
65 #define XDRBUF_READ 0x01 /* target of file read */
66 #define XDRBUF_WRITE 0x02 /* source of file write */
67 #define XDRBUF_SPARSE_PAGES 0x04 /* Page array is sparse */
68
69 unsigned int buflen, /* Total length of storage buffer */
70 len; /* Length of XDR encoded message */
71 };
72
73 static inline void
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
xdr_encode_array(__be32 * p,const void * s,unsigned int len)143 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
144 {
145 return xdr_encode_opaque(p, s, len);
146 }
147
148 /*
149 * Decode 64bit quantities (NFSv3 support)
150 */
151 static inline __be32 *
xdr_encode_hyper(__be32 * p,__u64 val)152 xdr_encode_hyper(__be32 *p, __u64 val)
153 {
154 put_unaligned_be64(val, p);
155 return p + 2;
156 }
157
158 static inline __be32 *
xdr_decode_hyper(__be32 * p,__u64 * valp)159 xdr_decode_hyper(__be32 *p, __u64 *valp)
160 {
161 *valp = get_unaligned_be64(p);
162 return p + 2;
163 }
164
165 static inline __be32 *
xdr_decode_opaque_fixed(__be32 * p,void * ptr,unsigned int len)166 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
167 {
168 memcpy(ptr, p, len);
169 return p + XDR_QUADLEN(len);
170 }
171
xdr_netobj_dup(struct xdr_netobj * dst,struct xdr_netobj * src,gfp_t gfp_mask)172 static inline void xdr_netobj_dup(struct xdr_netobj *dst,
173 struct xdr_netobj *src, gfp_t gfp_mask)
174 {
175 dst->data = kmemdup(src->data, src->len, gfp_mask);
176 dst->len = src->len;
177 }
178
179 /*
180 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
181 */
182 static inline int
xdr_adjust_iovec(struct kvec * iov,__be32 * p)183 xdr_adjust_iovec(struct kvec *iov, __be32 *p)
184 {
185 return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
186 }
187
188 /*
189 * XDR buffer helper functions
190 */
191 extern void xdr_shift_buf(struct xdr_buf *, size_t);
192 extern void xdr_buf_from_iov(const struct kvec *, struct xdr_buf *);
193 extern int xdr_buf_subsegment(const struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
194 extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
195 extern int read_bytes_from_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
196 extern int write_bytes_to_xdr_buf(const struct xdr_buf *, unsigned int, void *, unsigned int);
197
198 extern int xdr_encode_word(const struct xdr_buf *, unsigned int, u32);
199 extern int xdr_decode_word(const struct xdr_buf *, unsigned int, u32 *);
200
201 struct xdr_array2_desc;
202 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
203 struct xdr_array2_desc {
204 unsigned int elem_size;
205 unsigned int array_len;
206 unsigned int array_maxlen;
207 xdr_xcode_elem_t xcode;
208 };
209
210 extern int xdr_decode_array2(const struct xdr_buf *buf, unsigned int base,
211 struct xdr_array2_desc *desc);
212 extern int xdr_encode_array2(const struct xdr_buf *buf, unsigned int base,
213 struct xdr_array2_desc *desc);
214 extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
215 size_t len);
216
217 /*
218 * Provide some simple tools for XDR buffer overflow-checking etc.
219 */
220 struct xdr_stream {
221 __be32 *p; /* start of available buffer */
222 struct xdr_buf *buf; /* XDR buffer to read/write */
223
224 __be32 *end; /* end of available buffer space */
225 struct kvec *iov; /* pointer to the current kvec */
226 struct kvec scratch; /* Scratch buffer */
227 struct page **page_ptr; /* pointer to the current page */
228 unsigned int nwords; /* Remaining decode buffer length */
229
230 struct rpc_rqst *rqst; /* For debugging */
231 };
232
233 /*
234 * These are the xdr_stream style generic XDR encode and decode functions.
235 */
236 typedef void (*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
237 const void *obj);
238 typedef int (*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
239 void *obj);
240
241 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf,
242 __be32 *p, struct rpc_rqst *rqst);
243 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
244 extern int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec,
245 size_t nbytes);
246 extern void xdr_commit_encode(struct xdr_stream *xdr);
247 extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
248 extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen);
249 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
250 unsigned int base, unsigned int len);
251 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
252 extern unsigned int xdr_page_pos(const struct xdr_stream *xdr);
253 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf,
254 __be32 *p, struct rpc_rqst *rqst);
255 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
256 struct page **pages, unsigned int len);
257 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
258 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
259 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
260 extern int xdr_process_buf(const struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
261 extern unsigned int xdr_align_data(struct xdr_stream *, unsigned int offset, unsigned int length);
262 extern unsigned int xdr_expand_hole(struct xdr_stream *, unsigned int offset, unsigned int length);
263 extern bool xdr_stream_subsegment(struct xdr_stream *xdr, struct xdr_buf *subbuf,
264 unsigned int len);
265
266 /**
267 * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
268 * @xdr: pointer to xdr_stream struct
269 * @buf: pointer to an empty buffer
270 * @buflen: size of 'buf'
271 *
272 * The scratch buffer is used when decoding from an array of pages.
273 * If an xdr_inline_decode() call spans across page boundaries, then
274 * we copy the data into the scratch buffer in order to allow linear
275 * access.
276 */
277 static inline void
xdr_set_scratch_buffer(struct xdr_stream * xdr,void * buf,size_t buflen)278 xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen)
279 {
280 xdr->scratch.iov_base = buf;
281 xdr->scratch.iov_len = buflen;
282 }
283
284 /**
285 * xdr_set_scratch_page - Attach a scratch buffer for decoding data
286 * @xdr: pointer to xdr_stream struct
287 * @page: an anonymous page
288 *
289 * See xdr_set_scratch_buffer().
290 */
291 static inline void
xdr_set_scratch_page(struct xdr_stream * xdr,struct page * page)292 xdr_set_scratch_page(struct xdr_stream *xdr, struct page *page)
293 {
294 xdr_set_scratch_buffer(xdr, page_address(page), PAGE_SIZE);
295 }
296
297 /**
298 * xdr_reset_scratch_buffer - Clear scratch buffer information
299 * @xdr: pointer to xdr_stream struct
300 *
301 * See xdr_set_scratch_buffer().
302 */
303 static inline void
xdr_reset_scratch_buffer(struct xdr_stream * xdr)304 xdr_reset_scratch_buffer(struct xdr_stream *xdr)
305 {
306 xdr_set_scratch_buffer(xdr, NULL, 0);
307 }
308
309 /**
310 * xdr_stream_remaining - Return the number of bytes remaining in the stream
311 * @xdr: pointer to struct xdr_stream
312 *
313 * Return value:
314 * Number of bytes remaining in @xdr before xdr->end
315 */
316 static inline size_t
xdr_stream_remaining(const struct xdr_stream * xdr)317 xdr_stream_remaining(const struct xdr_stream *xdr)
318 {
319 return xdr->nwords << 2;
320 }
321
322 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr,
323 size_t size);
324 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr,
325 size_t maxlen, gfp_t gfp_flags);
326 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str,
327 size_t size);
328 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
329 size_t maxlen, gfp_t gfp_flags);
330 /**
331 * xdr_align_size - Calculate padded size of an object
332 * @n: Size of an object being XDR encoded (in bytes)
333 *
334 * Return value:
335 * Size (in bytes) of the object including xdr padding
336 */
337 static inline size_t
xdr_align_size(size_t n)338 xdr_align_size(size_t n)
339 {
340 const size_t mask = XDR_UNIT - 1;
341
342 return (n + mask) & ~mask;
343 }
344
345 /**
346 * xdr_pad_size - Calculate size of an object's pad
347 * @n: Size of an object being XDR encoded (in bytes)
348 *
349 * This implementation avoids the need for conditional
350 * branches or modulo division.
351 *
352 * Return value:
353 * Size (in bytes) of the needed XDR pad
354 */
xdr_pad_size(size_t n)355 static inline size_t xdr_pad_size(size_t n)
356 {
357 return xdr_align_size(n) - n;
358 }
359
360 /**
361 * xdr_stream_encode_item_present - Encode a "present" list item
362 * @xdr: pointer to xdr_stream
363 *
364 * Return values:
365 * On success, returns length in bytes of XDR buffer consumed
366 * %-EMSGSIZE on XDR buffer overflow
367 */
xdr_stream_encode_item_present(struct xdr_stream * xdr)368 static inline ssize_t xdr_stream_encode_item_present(struct xdr_stream *xdr)
369 {
370 const size_t len = XDR_UNIT;
371 __be32 *p = xdr_reserve_space(xdr, len);
372
373 if (unlikely(!p))
374 return -EMSGSIZE;
375 *p = xdr_one;
376 return len;
377 }
378
379 /**
380 * xdr_stream_encode_item_absent - Encode a "not present" list item
381 * @xdr: pointer to xdr_stream
382 *
383 * Return values:
384 * On success, returns length in bytes of XDR buffer consumed
385 * %-EMSGSIZE on XDR buffer overflow
386 */
xdr_stream_encode_item_absent(struct xdr_stream * xdr)387 static inline int xdr_stream_encode_item_absent(struct xdr_stream *xdr)
388 {
389 const size_t len = XDR_UNIT;
390 __be32 *p = xdr_reserve_space(xdr, len);
391
392 if (unlikely(!p))
393 return -EMSGSIZE;
394 *p = xdr_zero;
395 return len;
396 }
397
398 /**
399 * xdr_encode_bool - Encode a boolean item
400 * @p: address in a buffer into which to encode
401 * @n: boolean value to encode
402 *
403 * Return value:
404 * Address of item following the encoded boolean
405 */
xdr_encode_bool(__be32 * p,u32 n)406 static inline __be32 *xdr_encode_bool(__be32 *p, u32 n)
407 {
408 *p = n ? xdr_one : xdr_zero;
409 return p++;
410 }
411
412 /**
413 * xdr_stream_encode_bool - Encode a boolean item
414 * @xdr: pointer to xdr_stream
415 * @n: boolean value to encode
416 *
417 * Return values:
418 * On success, returns length in bytes of XDR buffer consumed
419 * %-EMSGSIZE on XDR buffer overflow
420 */
xdr_stream_encode_bool(struct xdr_stream * xdr,__u32 n)421 static inline int xdr_stream_encode_bool(struct xdr_stream *xdr, __u32 n)
422 {
423 const size_t len = XDR_UNIT;
424 __be32 *p = xdr_reserve_space(xdr, len);
425
426 if (unlikely(!p))
427 return -EMSGSIZE;
428 xdr_encode_bool(p, n);
429 return len;
430 }
431
432 /**
433 * xdr_stream_encode_u32 - Encode a 32-bit integer
434 * @xdr: pointer to xdr_stream
435 * @n: integer to encode
436 *
437 * Return values:
438 * On success, returns length in bytes of XDR buffer consumed
439 * %-EMSGSIZE on XDR buffer overflow
440 */
441 static inline ssize_t
xdr_stream_encode_u32(struct xdr_stream * xdr,__u32 n)442 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n)
443 {
444 const size_t len = sizeof(n);
445 __be32 *p = xdr_reserve_space(xdr, len);
446
447 if (unlikely(!p))
448 return -EMSGSIZE;
449 *p = cpu_to_be32(n);
450 return len;
451 }
452
453 /**
454 * xdr_stream_encode_u64 - Encode a 64-bit integer
455 * @xdr: pointer to xdr_stream
456 * @n: 64-bit integer to encode
457 *
458 * Return values:
459 * On success, returns length in bytes of XDR buffer consumed
460 * %-EMSGSIZE on XDR buffer overflow
461 */
462 static inline ssize_t
xdr_stream_encode_u64(struct xdr_stream * xdr,__u64 n)463 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n)
464 {
465 const size_t len = sizeof(n);
466 __be32 *p = xdr_reserve_space(xdr, len);
467
468 if (unlikely(!p))
469 return -EMSGSIZE;
470 xdr_encode_hyper(p, n);
471 return len;
472 }
473
474 /**
475 * xdr_stream_encode_opaque_inline - Encode opaque xdr data
476 * @xdr: pointer to xdr_stream
477 * @ptr: pointer to void pointer
478 * @len: size of object
479 *
480 * Return values:
481 * On success, returns length in bytes of XDR buffer consumed
482 * %-EMSGSIZE on XDR buffer overflow
483 */
484 static inline ssize_t
xdr_stream_encode_opaque_inline(struct xdr_stream * xdr,void ** ptr,size_t len)485 xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len)
486 {
487 size_t count = sizeof(__u32) + xdr_align_size(len);
488 __be32 *p = xdr_reserve_space(xdr, count);
489
490 if (unlikely(!p)) {
491 *ptr = NULL;
492 return -EMSGSIZE;
493 }
494 xdr_encode_opaque(p, NULL, len);
495 *ptr = ++p;
496 return count;
497 }
498
499 /**
500 * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data
501 * @xdr: pointer to xdr_stream
502 * @ptr: pointer to opaque data object
503 * @len: size of object pointed to by @ptr
504 *
505 * Return values:
506 * On success, returns length in bytes of XDR buffer consumed
507 * %-EMSGSIZE on XDR buffer overflow
508 */
509 static inline ssize_t
xdr_stream_encode_opaque_fixed(struct xdr_stream * xdr,const void * ptr,size_t len)510 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len)
511 {
512 __be32 *p = xdr_reserve_space(xdr, len);
513
514 if (unlikely(!p))
515 return -EMSGSIZE;
516 xdr_encode_opaque_fixed(p, ptr, len);
517 return xdr_align_size(len);
518 }
519
520 /**
521 * xdr_stream_encode_opaque - Encode variable length opaque xdr data
522 * @xdr: pointer to xdr_stream
523 * @ptr: pointer to opaque data object
524 * @len: size of object pointed to by @ptr
525 *
526 * Return values:
527 * On success, returns length in bytes of XDR buffer consumed
528 * %-EMSGSIZE on XDR buffer overflow
529 */
530 static inline ssize_t
xdr_stream_encode_opaque(struct xdr_stream * xdr,const void * ptr,size_t len)531 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len)
532 {
533 size_t count = sizeof(__u32) + xdr_align_size(len);
534 __be32 *p = xdr_reserve_space(xdr, count);
535
536 if (unlikely(!p))
537 return -EMSGSIZE;
538 xdr_encode_opaque(p, ptr, len);
539 return count;
540 }
541
542 /**
543 * xdr_stream_encode_uint32_array - Encode variable length array of integers
544 * @xdr: pointer to xdr_stream
545 * @array: array of integers
546 * @array_size: number of elements in @array
547 *
548 * Return values:
549 * On success, returns length in bytes of XDR buffer consumed
550 * %-EMSGSIZE on XDR buffer overflow
551 */
552 static inline ssize_t
xdr_stream_encode_uint32_array(struct xdr_stream * xdr,const __u32 * array,size_t array_size)553 xdr_stream_encode_uint32_array(struct xdr_stream *xdr,
554 const __u32 *array, size_t array_size)
555 {
556 ssize_t ret = (array_size+1) * sizeof(__u32);
557 __be32 *p = xdr_reserve_space(xdr, ret);
558
559 if (unlikely(!p))
560 return -EMSGSIZE;
561 *p++ = cpu_to_be32(array_size);
562 for (; array_size > 0; p++, array++, array_size--)
563 *p = cpu_to_be32p(array);
564 return ret;
565 }
566
567 /**
568 * xdr_item_is_absent - symbolically handle XDR discriminators
569 * @p: pointer to undecoded discriminator
570 *
571 * Return values:
572 * %true if the following XDR item is absent
573 * %false if the following XDR item is present
574 */
xdr_item_is_absent(const __be32 * p)575 static inline bool xdr_item_is_absent(const __be32 *p)
576 {
577 return *p == xdr_zero;
578 }
579
580 /**
581 * xdr_item_is_present - symbolically handle XDR discriminators
582 * @p: pointer to undecoded discriminator
583 *
584 * Return values:
585 * %true if the following XDR item is present
586 * %false if the following XDR item is absent
587 */
xdr_item_is_present(const __be32 * p)588 static inline bool xdr_item_is_present(const __be32 *p)
589 {
590 return *p != xdr_zero;
591 }
592
593 /**
594 * xdr_stream_decode_bool - Decode a boolean
595 * @xdr: pointer to xdr_stream
596 * @ptr: pointer to a u32 in which to store the result
597 *
598 * Return values:
599 * %0 on success
600 * %-EBADMSG on XDR buffer overflow
601 */
602 static inline ssize_t
xdr_stream_decode_bool(struct xdr_stream * xdr,__u32 * ptr)603 xdr_stream_decode_bool(struct xdr_stream *xdr, __u32 *ptr)
604 {
605 const size_t count = sizeof(*ptr);
606 __be32 *p = xdr_inline_decode(xdr, count);
607
608 if (unlikely(!p))
609 return -EBADMSG;
610 *ptr = (*p != xdr_zero);
611 return 0;
612 }
613
614 /**
615 * xdr_stream_decode_u32 - Decode a 32-bit integer
616 * @xdr: pointer to xdr_stream
617 * @ptr: location to store integer
618 *
619 * Return values:
620 * %0 on success
621 * %-EBADMSG on XDR buffer overflow
622 */
623 static inline ssize_t
xdr_stream_decode_u32(struct xdr_stream * xdr,__u32 * ptr)624 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr)
625 {
626 const size_t count = sizeof(*ptr);
627 __be32 *p = xdr_inline_decode(xdr, count);
628
629 if (unlikely(!p))
630 return -EBADMSG;
631 *ptr = be32_to_cpup(p);
632 return 0;
633 }
634
635 /**
636 * xdr_stream_decode_u64 - Decode a 64-bit integer
637 * @xdr: pointer to xdr_stream
638 * @ptr: location to store 64-bit integer
639 *
640 * Return values:
641 * %0 on success
642 * %-EBADMSG on XDR buffer overflow
643 */
644 static inline ssize_t
xdr_stream_decode_u64(struct xdr_stream * xdr,__u64 * ptr)645 xdr_stream_decode_u64(struct xdr_stream *xdr, __u64 *ptr)
646 {
647 const size_t count = sizeof(*ptr);
648 __be32 *p = xdr_inline_decode(xdr, count);
649
650 if (unlikely(!p))
651 return -EBADMSG;
652 xdr_decode_hyper(p, ptr);
653 return 0;
654 }
655
656 /**
657 * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data
658 * @xdr: pointer to xdr_stream
659 * @ptr: location to store data
660 * @len: size of buffer pointed to by @ptr
661 *
662 * Return values:
663 * On success, returns size of object stored in @ptr
664 * %-EBADMSG on XDR buffer overflow
665 */
666 static inline ssize_t
xdr_stream_decode_opaque_fixed(struct xdr_stream * xdr,void * ptr,size_t len)667 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len)
668 {
669 __be32 *p = xdr_inline_decode(xdr, len);
670
671 if (unlikely(!p))
672 return -EBADMSG;
673 xdr_decode_opaque_fixed(p, ptr, len);
674 return len;
675 }
676
677 /**
678 * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data
679 * @xdr: pointer to xdr_stream
680 * @ptr: location to store pointer to opaque data
681 * @maxlen: maximum acceptable object size
682 *
683 * Note: the pointer stored in @ptr cannot be assumed valid after the XDR
684 * buffer has been destroyed, or even after calling xdr_inline_decode()
685 * on @xdr. It is therefore expected that the object it points to should
686 * be processed immediately.
687 *
688 * Return values:
689 * On success, returns size of object stored in *@ptr
690 * %-EBADMSG on XDR buffer overflow
691 * %-EMSGSIZE if the size of the object would exceed @maxlen
692 */
693 static inline ssize_t
xdr_stream_decode_opaque_inline(struct xdr_stream * xdr,void ** ptr,size_t maxlen)694 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen)
695 {
696 __be32 *p;
697 __u32 len;
698
699 *ptr = NULL;
700 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
701 return -EBADMSG;
702 if (len != 0) {
703 p = xdr_inline_decode(xdr, len);
704 if (unlikely(!p))
705 return -EBADMSG;
706 if (unlikely(len > maxlen))
707 return -EMSGSIZE;
708 *ptr = p;
709 }
710 return len;
711 }
712
713 /**
714 * xdr_stream_decode_uint32_array - Decode variable length array of integers
715 * @xdr: pointer to xdr_stream
716 * @array: location to store the integer array or NULL
717 * @array_size: number of elements to store
718 *
719 * Return values:
720 * On success, returns number of elements stored in @array
721 * %-EBADMSG on XDR buffer overflow
722 * %-EMSGSIZE if the size of the array exceeds @array_size
723 */
724 static inline ssize_t
xdr_stream_decode_uint32_array(struct xdr_stream * xdr,__u32 * array,size_t array_size)725 xdr_stream_decode_uint32_array(struct xdr_stream *xdr,
726 __u32 *array, size_t array_size)
727 {
728 __be32 *p;
729 __u32 len;
730 ssize_t retval;
731
732 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
733 return -EBADMSG;
734 p = xdr_inline_decode(xdr, len * sizeof(*p));
735 if (unlikely(!p))
736 return -EBADMSG;
737 if (array == NULL)
738 return len;
739 if (len <= array_size) {
740 if (len < array_size)
741 memset(array+len, 0, (array_size-len)*sizeof(*array));
742 array_size = len;
743 retval = len;
744 } else
745 retval = -EMSGSIZE;
746 for (; array_size > 0; p++, array++, array_size--)
747 *array = be32_to_cpup(p);
748 return retval;
749 }
750
751 #endif /* _SUNRPC_XDR_H_ */
752