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 #ifdef __KERNEL__
15
16 #include <linux/uio.h>
17 #include <asm/byteorder.h>
18 #include <asm/unaligned.h>
19 #include <linux/scatterlist.h>
20
21 struct rpc_rqst;
22
23 /*
24 * Buffer adjustment
25 */
26 #define XDR_QUADLEN(l) (((l) + 3) >> 2)
27
28 /*
29 * Generic opaque `network object.'
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 page ** pages; /* Array of pages */
55 unsigned int page_base, /* Start of page data */
56 page_len, /* Length of page data */
57 flags; /* Flags for data disposition */
58 #define XDRBUF_READ 0x01 /* target of file read */
59 #define XDRBUF_WRITE 0x02 /* source of file write */
60
61 unsigned int buflen, /* Total length of storage buffer */
62 len; /* Length of XDR encoded message */
63 };
64
65 static inline void
xdr_buf_init(struct xdr_buf * buf,void * start,size_t len)66 xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
67 {
68 buf->head[0].iov_base = start;
69 buf->head[0].iov_len = len;
70 buf->tail[0].iov_len = 0;
71 buf->page_len = 0;
72 buf->flags = 0;
73 buf->len = 0;
74 buf->buflen = len;
75 }
76
77 /*
78 * pre-xdr'ed macros.
79 */
80
81 #define xdr_zero cpu_to_be32(0)
82 #define xdr_one cpu_to_be32(1)
83 #define xdr_two cpu_to_be32(2)
84
85 #define rpc_success cpu_to_be32(RPC_SUCCESS)
86 #define rpc_prog_unavail cpu_to_be32(RPC_PROG_UNAVAIL)
87 #define rpc_prog_mismatch cpu_to_be32(RPC_PROG_MISMATCH)
88 #define rpc_proc_unavail cpu_to_be32(RPC_PROC_UNAVAIL)
89 #define rpc_garbage_args cpu_to_be32(RPC_GARBAGE_ARGS)
90 #define rpc_system_err cpu_to_be32(RPC_SYSTEM_ERR)
91 #define rpc_drop_reply cpu_to_be32(RPC_DROP_REPLY)
92
93 #define rpc_auth_ok cpu_to_be32(RPC_AUTH_OK)
94 #define rpc_autherr_badcred cpu_to_be32(RPC_AUTH_BADCRED)
95 #define rpc_autherr_rejectedcred cpu_to_be32(RPC_AUTH_REJECTEDCRED)
96 #define rpc_autherr_badverf cpu_to_be32(RPC_AUTH_BADVERF)
97 #define rpc_autherr_rejectedverf cpu_to_be32(RPC_AUTH_REJECTEDVERF)
98 #define rpc_autherr_tooweak cpu_to_be32(RPC_AUTH_TOOWEAK)
99 #define rpcsec_gsserr_credproblem cpu_to_be32(RPCSEC_GSS_CREDPROBLEM)
100 #define rpcsec_gsserr_ctxproblem cpu_to_be32(RPCSEC_GSS_CTXPROBLEM)
101 #define rpc_autherr_oldseqnum cpu_to_be32(101)
102
103 /*
104 * Miscellaneous XDR helper functions
105 */
106 __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
107 __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
108 __be32 *xdr_encode_string(__be32 *p, const char *s);
109 __be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
110 unsigned int maxlen);
111 __be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
112 __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
113
114 void xdr_inline_pages(struct xdr_buf *, unsigned int,
115 struct page **, unsigned int, unsigned int);
116 void xdr_terminate_string(struct xdr_buf *, const u32);
117
xdr_encode_array(__be32 * p,const void * s,unsigned int len)118 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
119 {
120 return xdr_encode_opaque(p, s, len);
121 }
122
123 /*
124 * Decode 64bit quantities (NFSv3 support)
125 */
126 static inline __be32 *
xdr_encode_hyper(__be32 * p,__u64 val)127 xdr_encode_hyper(__be32 *p, __u64 val)
128 {
129 put_unaligned_be64(val, p);
130 return p + 2;
131 }
132
133 static inline __be32 *
xdr_decode_hyper(__be32 * p,__u64 * valp)134 xdr_decode_hyper(__be32 *p, __u64 *valp)
135 {
136 *valp = get_unaligned_be64(p);
137 return p + 2;
138 }
139
140 static inline __be32 *
xdr_decode_opaque_fixed(__be32 * p,void * ptr,unsigned int len)141 xdr_decode_opaque_fixed(__be32 *p, void *ptr, unsigned int len)
142 {
143 memcpy(ptr, p, len);
144 return p + XDR_QUADLEN(len);
145 }
146
147 /*
148 * Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
149 */
150 static inline int
xdr_adjust_iovec(struct kvec * iov,__be32 * p)151 xdr_adjust_iovec(struct kvec *iov, __be32 *p)
152 {
153 return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
154 }
155
156 /*
157 * XDR buffer helper functions
158 */
159 extern void xdr_shift_buf(struct xdr_buf *, size_t);
160 extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
161 extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
162 extern void xdr_buf_trim(struct xdr_buf *, unsigned int);
163 extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);
164 extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
165 extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
166
167 /*
168 * Helper structure for copying from an sk_buff.
169 */
170 struct xdr_skb_reader {
171 struct sk_buff *skb;
172 unsigned int offset;
173 size_t count;
174 __wsum csum;
175 };
176
177 typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);
178
179 size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len);
180 extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
181 extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
182 struct xdr_skb_reader *, xdr_skb_read_actor);
183
184 extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);
185 extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);
186
187 struct xdr_array2_desc;
188 typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
189 struct xdr_array2_desc {
190 unsigned int elem_size;
191 unsigned int array_len;
192 unsigned int array_maxlen;
193 xdr_xcode_elem_t xcode;
194 };
195
196 extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
197 struct xdr_array2_desc *desc);
198 extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
199 struct xdr_array2_desc *desc);
200 extern void _copy_from_pages(char *p, struct page **pages, size_t pgbase,
201 size_t len);
202
203 /*
204 * Provide some simple tools for XDR buffer overflow-checking etc.
205 */
206 struct xdr_stream {
207 __be32 *p; /* start of available buffer */
208 struct xdr_buf *buf; /* XDR buffer to read/write */
209
210 __be32 *end; /* end of available buffer space */
211 struct kvec *iov; /* pointer to the current kvec */
212 struct kvec scratch; /* Scratch buffer */
213 struct page **page_ptr; /* pointer to the current page */
214 unsigned int nwords; /* Remaining decode buffer length */
215 };
216
217 /*
218 * These are the xdr_stream style generic XDR encode and decode functions.
219 */
220 typedef void (*kxdreproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
221 const void *obj);
222 typedef int (*kxdrdproc_t)(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
223 void *obj);
224
225 extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
226 extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
227 extern void xdr_commit_encode(struct xdr_stream *xdr);
228 extern void xdr_truncate_encode(struct xdr_stream *xdr, size_t len);
229 extern int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen);
230 extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
231 unsigned int base, unsigned int len);
232 extern unsigned int xdr_stream_pos(const struct xdr_stream *xdr);
233 extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
234 extern void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
235 struct page **pages, unsigned int len);
236 extern void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen);
237 extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
238 extern unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
239 extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
240 extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
241
242 /**
243 * xdr_stream_remaining - Return the number of bytes remaining in the stream
244 * @xdr: pointer to struct xdr_stream
245 *
246 * Return value:
247 * Number of bytes remaining in @xdr before xdr->end
248 */
249 static inline size_t
xdr_stream_remaining(const struct xdr_stream * xdr)250 xdr_stream_remaining(const struct xdr_stream *xdr)
251 {
252 return xdr->nwords << 2;
253 }
254
255 ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr,
256 size_t size);
257 ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr,
258 size_t maxlen, gfp_t gfp_flags);
259 ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str,
260 size_t size);
261 ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str,
262 size_t maxlen, gfp_t gfp_flags);
263 /**
264 * xdr_align_size - Calculate padded size of an object
265 * @n: Size of an object being XDR encoded (in bytes)
266 *
267 * Return value:
268 * Size (in bytes) of the object including xdr padding
269 */
270 static inline size_t
xdr_align_size(size_t n)271 xdr_align_size(size_t n)
272 {
273 const size_t mask = sizeof(__u32) - 1;
274
275 return (n + mask) & ~mask;
276 }
277
278 /**
279 * xdr_stream_encode_u32 - Encode a 32-bit integer
280 * @xdr: pointer to xdr_stream
281 * @n: integer to encode
282 *
283 * Return values:
284 * On success, returns length in bytes of XDR buffer consumed
285 * %-EMSGSIZE on XDR buffer overflow
286 */
287 static inline ssize_t
xdr_stream_encode_u32(struct xdr_stream * xdr,__u32 n)288 xdr_stream_encode_u32(struct xdr_stream *xdr, __u32 n)
289 {
290 const size_t len = sizeof(n);
291 __be32 *p = xdr_reserve_space(xdr, len);
292
293 if (unlikely(!p))
294 return -EMSGSIZE;
295 *p = cpu_to_be32(n);
296 return len;
297 }
298
299 /**
300 * xdr_stream_encode_u64 - Encode a 64-bit integer
301 * @xdr: pointer to xdr_stream
302 * @n: 64-bit integer to encode
303 *
304 * Return values:
305 * On success, returns length in bytes of XDR buffer consumed
306 * %-EMSGSIZE on XDR buffer overflow
307 */
308 static inline ssize_t
xdr_stream_encode_u64(struct xdr_stream * xdr,__u64 n)309 xdr_stream_encode_u64(struct xdr_stream *xdr, __u64 n)
310 {
311 const size_t len = sizeof(n);
312 __be32 *p = xdr_reserve_space(xdr, len);
313
314 if (unlikely(!p))
315 return -EMSGSIZE;
316 xdr_encode_hyper(p, n);
317 return len;
318 }
319
320 /**
321 * xdr_stream_encode_opaque_inline - Encode opaque xdr data
322 * @xdr: pointer to xdr_stream
323 * @ptr: pointer to void pointer
324 * @len: size of object
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 ssize_t
xdr_stream_encode_opaque_inline(struct xdr_stream * xdr,void ** ptr,size_t len)331 xdr_stream_encode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t len)
332 {
333 size_t count = sizeof(__u32) + xdr_align_size(len);
334 __be32 *p = xdr_reserve_space(xdr, count);
335
336 if (unlikely(!p)) {
337 *ptr = NULL;
338 return -EMSGSIZE;
339 }
340 xdr_encode_opaque(p, NULL, len);
341 *ptr = ++p;
342 return count;
343 }
344
345 /**
346 * xdr_stream_encode_opaque_fixed - Encode fixed length opaque xdr data
347 * @xdr: pointer to xdr_stream
348 * @ptr: pointer to opaque data object
349 * @len: size of object pointed to by @ptr
350 *
351 * Return values:
352 * On success, returns length in bytes of XDR buffer consumed
353 * %-EMSGSIZE on XDR buffer overflow
354 */
355 static inline ssize_t
xdr_stream_encode_opaque_fixed(struct xdr_stream * xdr,const void * ptr,size_t len)356 xdr_stream_encode_opaque_fixed(struct xdr_stream *xdr, const void *ptr, size_t len)
357 {
358 __be32 *p = xdr_reserve_space(xdr, len);
359
360 if (unlikely(!p))
361 return -EMSGSIZE;
362 xdr_encode_opaque_fixed(p, ptr, len);
363 return xdr_align_size(len);
364 }
365
366 /**
367 * xdr_stream_encode_opaque - Encode variable length opaque xdr data
368 * @xdr: pointer to xdr_stream
369 * @ptr: pointer to opaque data object
370 * @len: size of object pointed to by @ptr
371 *
372 * Return values:
373 * On success, returns length in bytes of XDR buffer consumed
374 * %-EMSGSIZE on XDR buffer overflow
375 */
376 static inline ssize_t
xdr_stream_encode_opaque(struct xdr_stream * xdr,const void * ptr,size_t len)377 xdr_stream_encode_opaque(struct xdr_stream *xdr, const void *ptr, size_t len)
378 {
379 size_t count = sizeof(__u32) + xdr_align_size(len);
380 __be32 *p = xdr_reserve_space(xdr, count);
381
382 if (unlikely(!p))
383 return -EMSGSIZE;
384 xdr_encode_opaque(p, ptr, len);
385 return count;
386 }
387
388 /**
389 * xdr_stream_encode_uint32_array - Encode variable length array of integers
390 * @xdr: pointer to xdr_stream
391 * @array: array of integers
392 * @array_size: number of elements in @array
393 *
394 * Return values:
395 * On success, returns length in bytes of XDR buffer consumed
396 * %-EMSGSIZE on XDR buffer overflow
397 */
398 static inline ssize_t
xdr_stream_encode_uint32_array(struct xdr_stream * xdr,const __u32 * array,size_t array_size)399 xdr_stream_encode_uint32_array(struct xdr_stream *xdr,
400 const __u32 *array, size_t array_size)
401 {
402 ssize_t ret = (array_size+1) * sizeof(__u32);
403 __be32 *p = xdr_reserve_space(xdr, ret);
404
405 if (unlikely(!p))
406 return -EMSGSIZE;
407 *p++ = cpu_to_be32(array_size);
408 for (; array_size > 0; p++, array++, array_size--)
409 *p = cpu_to_be32p(array);
410 return ret;
411 }
412
413 /**
414 * xdr_stream_decode_u32 - Decode a 32-bit integer
415 * @xdr: pointer to xdr_stream
416 * @ptr: location to store integer
417 *
418 * Return values:
419 * %0 on success
420 * %-EBADMSG on XDR buffer overflow
421 */
422 static inline ssize_t
xdr_stream_decode_u32(struct xdr_stream * xdr,__u32 * ptr)423 xdr_stream_decode_u32(struct xdr_stream *xdr, __u32 *ptr)
424 {
425 const size_t count = sizeof(*ptr);
426 __be32 *p = xdr_inline_decode(xdr, count);
427
428 if (unlikely(!p))
429 return -EBADMSG;
430 *ptr = be32_to_cpup(p);
431 return 0;
432 }
433
434 /**
435 * xdr_stream_decode_opaque_fixed - Decode fixed length opaque xdr data
436 * @xdr: pointer to xdr_stream
437 * @ptr: location to store data
438 * @len: size of buffer pointed to by @ptr
439 *
440 * Return values:
441 * On success, returns size of object stored in @ptr
442 * %-EBADMSG on XDR buffer overflow
443 */
444 static inline ssize_t
xdr_stream_decode_opaque_fixed(struct xdr_stream * xdr,void * ptr,size_t len)445 xdr_stream_decode_opaque_fixed(struct xdr_stream *xdr, void *ptr, size_t len)
446 {
447 __be32 *p = xdr_inline_decode(xdr, len);
448
449 if (unlikely(!p))
450 return -EBADMSG;
451 xdr_decode_opaque_fixed(p, ptr, len);
452 return len;
453 }
454
455 /**
456 * xdr_stream_decode_opaque_inline - Decode variable length opaque xdr data
457 * @xdr: pointer to xdr_stream
458 * @ptr: location to store pointer to opaque data
459 * @maxlen: maximum acceptable object size
460 *
461 * Note: the pointer stored in @ptr cannot be assumed valid after the XDR
462 * buffer has been destroyed, or even after calling xdr_inline_decode()
463 * on @xdr. It is therefore expected that the object it points to should
464 * be processed immediately.
465 *
466 * Return values:
467 * On success, returns size of object stored in *@ptr
468 * %-EBADMSG on XDR buffer overflow
469 * %-EMSGSIZE if the size of the object would exceed @maxlen
470 */
471 static inline ssize_t
xdr_stream_decode_opaque_inline(struct xdr_stream * xdr,void ** ptr,size_t maxlen)472 xdr_stream_decode_opaque_inline(struct xdr_stream *xdr, void **ptr, size_t maxlen)
473 {
474 __be32 *p;
475 __u32 len;
476
477 *ptr = NULL;
478 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
479 return -EBADMSG;
480 if (len != 0) {
481 p = xdr_inline_decode(xdr, len);
482 if (unlikely(!p))
483 return -EBADMSG;
484 if (unlikely(len > maxlen))
485 return -EMSGSIZE;
486 *ptr = p;
487 }
488 return len;
489 }
490
491 /**
492 * xdr_stream_decode_uint32_array - Decode variable length array of integers
493 * @xdr: pointer to xdr_stream
494 * @array: location to store the integer array or NULL
495 * @array_size: number of elements to store
496 *
497 * Return values:
498 * On success, returns number of elements stored in @array
499 * %-EBADMSG on XDR buffer overflow
500 * %-EMSGSIZE if the size of the array exceeds @array_size
501 */
502 static inline ssize_t
xdr_stream_decode_uint32_array(struct xdr_stream * xdr,__u32 * array,size_t array_size)503 xdr_stream_decode_uint32_array(struct xdr_stream *xdr,
504 __u32 *array, size_t array_size)
505 {
506 __be32 *p;
507 __u32 len;
508 ssize_t retval;
509
510 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
511 return -EBADMSG;
512 if (len > SIZE_MAX / sizeof(*p))
513 return -EBADMSG;
514 p = xdr_inline_decode(xdr, len * sizeof(*p));
515 if (unlikely(!p))
516 return -EBADMSG;
517 if (array == NULL)
518 return len;
519 if (len <= array_size) {
520 if (len < array_size)
521 memset(array+len, 0, (array_size-len)*sizeof(*array));
522 array_size = len;
523 retval = len;
524 } else
525 retval = -EMSGSIZE;
526 for (; array_size > 0; p++, array++, array_size--)
527 *array = be32_to_cpup(p);
528 return retval;
529 }
530 #endif /* __KERNEL__ */
531
532 #endif /* _SUNRPC_XDR_H_ */
533