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