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