Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/net/sunrpc/xdr.c | |
3 | * | |
4 | * Generic XDR support. | |
5 | * | |
6 | * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> | |
7 | */ | |
8 | ||
a246b010 | 9 | #include <linux/module.h> |
1da177e4 | 10 | #include <linux/types.h> |
1da177e4 LT |
11 | #include <linux/string.h> |
12 | #include <linux/kernel.h> | |
13 | #include <linux/pagemap.h> | |
14 | #include <linux/errno.h> | |
1da177e4 LT |
15 | #include <linux/sunrpc/xdr.h> |
16 | #include <linux/sunrpc/msg_prot.h> | |
17 | ||
18 | /* | |
19 | * XDR functions for basic NFS types | |
20 | */ | |
d8ed029d AD |
21 | __be32 * |
22 | xdr_encode_netobj(__be32 *p, const struct xdr_netobj *obj) | |
1da177e4 LT |
23 | { |
24 | unsigned int quadlen = XDR_QUADLEN(obj->len); | |
25 | ||
26 | p[quadlen] = 0; /* zero trailing bytes */ | |
27 | *p++ = htonl(obj->len); | |
28 | memcpy(p, obj->data, obj->len); | |
29 | return p + XDR_QUADLEN(obj->len); | |
30 | } | |
a6eaf8bd | 31 | EXPORT_SYMBOL(xdr_encode_netobj); |
1da177e4 | 32 | |
d8ed029d AD |
33 | __be32 * |
34 | xdr_decode_netobj(__be32 *p, struct xdr_netobj *obj) | |
1da177e4 LT |
35 | { |
36 | unsigned int len; | |
37 | ||
38 | if ((len = ntohl(*p++)) > XDR_MAX_NETOBJ) | |
39 | return NULL; | |
40 | obj->len = len; | |
41 | obj->data = (u8 *) p; | |
42 | return p + XDR_QUADLEN(len); | |
43 | } | |
a6eaf8bd | 44 | EXPORT_SYMBOL(xdr_decode_netobj); |
1da177e4 LT |
45 | |
46 | /** | |
47 | * xdr_encode_opaque_fixed - Encode fixed length opaque data | |
4dc3b16b PP |
48 | * @p: pointer to current position in XDR buffer. |
49 | * @ptr: pointer to data to encode (or NULL) | |
50 | * @nbytes: size of data. | |
1da177e4 LT |
51 | * |
52 | * Copy the array of data of length nbytes at ptr to the XDR buffer | |
53 | * at position p, then align to the next 32-bit boundary by padding | |
54 | * with zero bytes (see RFC1832). | |
55 | * Note: if ptr is NULL, only the padding is performed. | |
56 | * | |
57 | * Returns the updated current XDR buffer position | |
58 | * | |
59 | */ | |
d8ed029d | 60 | __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int nbytes) |
1da177e4 LT |
61 | { |
62 | if (likely(nbytes != 0)) { | |
63 | unsigned int quadlen = XDR_QUADLEN(nbytes); | |
64 | unsigned int padding = (quadlen << 2) - nbytes; | |
65 | ||
66 | if (ptr != NULL) | |
67 | memcpy(p, ptr, nbytes); | |
68 | if (padding != 0) | |
69 | memset((char *)p + nbytes, 0, padding); | |
70 | p += quadlen; | |
71 | } | |
72 | return p; | |
73 | } | |
74 | EXPORT_SYMBOL(xdr_encode_opaque_fixed); | |
75 | ||
76 | /** | |
77 | * xdr_encode_opaque - Encode variable length opaque data | |
4dc3b16b PP |
78 | * @p: pointer to current position in XDR buffer. |
79 | * @ptr: pointer to data to encode (or NULL) | |
80 | * @nbytes: size of data. | |
1da177e4 LT |
81 | * |
82 | * Returns the updated current XDR buffer position | |
83 | */ | |
d8ed029d | 84 | __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int nbytes) |
1da177e4 LT |
85 | { |
86 | *p++ = htonl(nbytes); | |
87 | return xdr_encode_opaque_fixed(p, ptr, nbytes); | |
88 | } | |
89 | EXPORT_SYMBOL(xdr_encode_opaque); | |
90 | ||
d8ed029d AD |
91 | __be32 * |
92 | xdr_encode_string(__be32 *p, const char *string) | |
1da177e4 LT |
93 | { |
94 | return xdr_encode_array(p, string, strlen(string)); | |
95 | } | |
a6eaf8bd | 96 | EXPORT_SYMBOL(xdr_encode_string); |
1da177e4 | 97 | |
d8ed029d AD |
98 | __be32 * |
99 | xdr_decode_string_inplace(__be32 *p, char **sp, int *lenp, int maxlen) | |
1da177e4 LT |
100 | { |
101 | unsigned int len; | |
102 | ||
103 | if ((len = ntohl(*p++)) > maxlen) | |
104 | return NULL; | |
105 | *lenp = len; | |
106 | *sp = (char *) p; | |
107 | return p + XDR_QUADLEN(len); | |
108 | } | |
a6eaf8bd | 109 | EXPORT_SYMBOL(xdr_decode_string_inplace); |
1da177e4 LT |
110 | |
111 | void | |
112 | xdr_encode_pages(struct xdr_buf *xdr, struct page **pages, unsigned int base, | |
113 | unsigned int len) | |
114 | { | |
115 | struct kvec *tail = xdr->tail; | |
116 | u32 *p; | |
117 | ||
118 | xdr->pages = pages; | |
119 | xdr->page_base = base; | |
120 | xdr->page_len = len; | |
121 | ||
122 | p = (u32 *)xdr->head[0].iov_base + XDR_QUADLEN(xdr->head[0].iov_len); | |
123 | tail->iov_base = p; | |
124 | tail->iov_len = 0; | |
125 | ||
126 | if (len & 3) { | |
127 | unsigned int pad = 4 - (len & 3); | |
128 | ||
129 | *p = 0; | |
130 | tail->iov_base = (char *)p + (len & 3); | |
131 | tail->iov_len = pad; | |
132 | len += pad; | |
133 | } | |
134 | xdr->buflen += len; | |
135 | xdr->len += len; | |
136 | } | |
a6eaf8bd | 137 | EXPORT_SYMBOL(xdr_encode_pages); |
1da177e4 LT |
138 | |
139 | void | |
140 | xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset, | |
141 | struct page **pages, unsigned int base, unsigned int len) | |
142 | { | |
143 | struct kvec *head = xdr->head; | |
144 | struct kvec *tail = xdr->tail; | |
145 | char *buf = (char *)head->iov_base; | |
146 | unsigned int buflen = head->iov_len; | |
147 | ||
148 | head->iov_len = offset; | |
149 | ||
150 | xdr->pages = pages; | |
151 | xdr->page_base = base; | |
152 | xdr->page_len = len; | |
153 | ||
154 | tail->iov_base = buf + offset; | |
155 | tail->iov_len = buflen - offset; | |
156 | ||
157 | xdr->buflen += len; | |
158 | } | |
a6eaf8bd | 159 | EXPORT_SYMBOL(xdr_inline_pages); |
1da177e4 | 160 | |
1da177e4 LT |
161 | /* |
162 | * Helper routines for doing 'memmove' like operations on a struct xdr_buf | |
163 | * | |
164 | * _shift_data_right_pages | |
165 | * @pages: vector of pages containing both the source and dest memory area. | |
166 | * @pgto_base: page vector address of destination | |
167 | * @pgfrom_base: page vector address of source | |
168 | * @len: number of bytes to copy | |
169 | * | |
170 | * Note: the addresses pgto_base and pgfrom_base are both calculated in | |
171 | * the same way: | |
172 | * if a memory area starts at byte 'base' in page 'pages[i]', | |
173 | * then its address is given as (i << PAGE_CACHE_SHIFT) + base | |
174 | * Also note: pgfrom_base must be < pgto_base, but the memory areas | |
175 | * they point to may overlap. | |
176 | */ | |
177 | static void | |
178 | _shift_data_right_pages(struct page **pages, size_t pgto_base, | |
179 | size_t pgfrom_base, size_t len) | |
180 | { | |
181 | struct page **pgfrom, **pgto; | |
182 | char *vfrom, *vto; | |
183 | size_t copy; | |
184 | ||
185 | BUG_ON(pgto_base <= pgfrom_base); | |
186 | ||
187 | pgto_base += len; | |
188 | pgfrom_base += len; | |
189 | ||
190 | pgto = pages + (pgto_base >> PAGE_CACHE_SHIFT); | |
191 | pgfrom = pages + (pgfrom_base >> PAGE_CACHE_SHIFT); | |
192 | ||
193 | pgto_base &= ~PAGE_CACHE_MASK; | |
194 | pgfrom_base &= ~PAGE_CACHE_MASK; | |
195 | ||
196 | do { | |
197 | /* Are any pointers crossing a page boundary? */ | |
198 | if (pgto_base == 0) { | |
1da177e4 LT |
199 | pgto_base = PAGE_CACHE_SIZE; |
200 | pgto--; | |
201 | } | |
202 | if (pgfrom_base == 0) { | |
203 | pgfrom_base = PAGE_CACHE_SIZE; | |
204 | pgfrom--; | |
205 | } | |
206 | ||
207 | copy = len; | |
208 | if (copy > pgto_base) | |
209 | copy = pgto_base; | |
210 | if (copy > pgfrom_base) | |
211 | copy = pgfrom_base; | |
212 | pgto_base -= copy; | |
213 | pgfrom_base -= copy; | |
214 | ||
215 | vto = kmap_atomic(*pgto, KM_USER0); | |
216 | vfrom = kmap_atomic(*pgfrom, KM_USER1); | |
217 | memmove(vto + pgto_base, vfrom + pgfrom_base, copy); | |
bce3481c | 218 | flush_dcache_page(*pgto); |
1da177e4 LT |
219 | kunmap_atomic(vfrom, KM_USER1); |
220 | kunmap_atomic(vto, KM_USER0); | |
221 | ||
222 | } while ((len -= copy) != 0); | |
1da177e4 LT |
223 | } |
224 | ||
225 | /* | |
226 | * _copy_to_pages | |
227 | * @pages: array of pages | |
228 | * @pgbase: page vector address of destination | |
229 | * @p: pointer to source data | |
230 | * @len: length | |
231 | * | |
232 | * Copies data from an arbitrary memory location into an array of pages | |
233 | * The copy is assumed to be non-overlapping. | |
234 | */ | |
235 | static void | |
236 | _copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len) | |
237 | { | |
238 | struct page **pgto; | |
239 | char *vto; | |
240 | size_t copy; | |
241 | ||
242 | pgto = pages + (pgbase >> PAGE_CACHE_SHIFT); | |
243 | pgbase &= ~PAGE_CACHE_MASK; | |
244 | ||
245 | do { | |
246 | copy = PAGE_CACHE_SIZE - pgbase; | |
247 | if (copy > len) | |
248 | copy = len; | |
249 | ||
250 | vto = kmap_atomic(*pgto, KM_USER0); | |
251 | memcpy(vto + pgbase, p, copy); | |
252 | kunmap_atomic(vto, KM_USER0); | |
253 | ||
254 | pgbase += copy; | |
255 | if (pgbase == PAGE_CACHE_SIZE) { | |
256 | flush_dcache_page(*pgto); | |
257 | pgbase = 0; | |
258 | pgto++; | |
259 | } | |
260 | p += copy; | |
261 | ||
262 | } while ((len -= copy) != 0); | |
263 | flush_dcache_page(*pgto); | |
264 | } | |
265 | ||
266 | /* | |
267 | * _copy_from_pages | |
268 | * @p: pointer to destination | |
269 | * @pages: array of pages | |
270 | * @pgbase: offset of source data | |
271 | * @len: length | |
272 | * | |
273 | * Copies data into an arbitrary memory location from an array of pages | |
274 | * The copy is assumed to be non-overlapping. | |
275 | */ | |
276 | static void | |
277 | _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len) | |
278 | { | |
279 | struct page **pgfrom; | |
280 | char *vfrom; | |
281 | size_t copy; | |
282 | ||
283 | pgfrom = pages + (pgbase >> PAGE_CACHE_SHIFT); | |
284 | pgbase &= ~PAGE_CACHE_MASK; | |
285 | ||
286 | do { | |
287 | copy = PAGE_CACHE_SIZE - pgbase; | |
288 | if (copy > len) | |
289 | copy = len; | |
290 | ||
291 | vfrom = kmap_atomic(*pgfrom, KM_USER0); | |
292 | memcpy(p, vfrom + pgbase, copy); | |
293 | kunmap_atomic(vfrom, KM_USER0); | |
294 | ||
295 | pgbase += copy; | |
296 | if (pgbase == PAGE_CACHE_SIZE) { | |
297 | pgbase = 0; | |
298 | pgfrom++; | |
299 | } | |
300 | p += copy; | |
301 | ||
302 | } while ((len -= copy) != 0); | |
303 | } | |
304 | ||
305 | /* | |
306 | * xdr_shrink_bufhead | |
307 | * @buf: xdr_buf | |
308 | * @len: bytes to remove from buf->head[0] | |
309 | * | |
cca5172a | 310 | * Shrinks XDR buffer's header kvec buf->head[0] by |
1da177e4 LT |
311 | * 'len' bytes. The extra data is not lost, but is instead |
312 | * moved into the inlined pages and/or the tail. | |
313 | */ | |
314 | static void | |
315 | xdr_shrink_bufhead(struct xdr_buf *buf, size_t len) | |
316 | { | |
317 | struct kvec *head, *tail; | |
318 | size_t copy, offs; | |
319 | unsigned int pglen = buf->page_len; | |
320 | ||
321 | tail = buf->tail; | |
322 | head = buf->head; | |
323 | BUG_ON (len > head->iov_len); | |
324 | ||
325 | /* Shift the tail first */ | |
326 | if (tail->iov_len != 0) { | |
327 | if (tail->iov_len > len) { | |
328 | copy = tail->iov_len - len; | |
329 | memmove((char *)tail->iov_base + len, | |
330 | tail->iov_base, copy); | |
331 | } | |
332 | /* Copy from the inlined pages into the tail */ | |
333 | copy = len; | |
334 | if (copy > pglen) | |
335 | copy = pglen; | |
336 | offs = len - copy; | |
337 | if (offs >= tail->iov_len) | |
338 | copy = 0; | |
339 | else if (copy > tail->iov_len - offs) | |
340 | copy = tail->iov_len - offs; | |
341 | if (copy != 0) | |
342 | _copy_from_pages((char *)tail->iov_base + offs, | |
343 | buf->pages, | |
344 | buf->page_base + pglen + offs - len, | |
345 | copy); | |
346 | /* Do we also need to copy data from the head into the tail ? */ | |
347 | if (len > pglen) { | |
348 | offs = copy = len - pglen; | |
349 | if (copy > tail->iov_len) | |
350 | copy = tail->iov_len; | |
351 | memcpy(tail->iov_base, | |
352 | (char *)head->iov_base + | |
353 | head->iov_len - offs, | |
354 | copy); | |
355 | } | |
356 | } | |
357 | /* Now handle pages */ | |
358 | if (pglen != 0) { | |
359 | if (pglen > len) | |
360 | _shift_data_right_pages(buf->pages, | |
361 | buf->page_base + len, | |
362 | buf->page_base, | |
363 | pglen - len); | |
364 | copy = len; | |
365 | if (len > pglen) | |
366 | copy = pglen; | |
367 | _copy_to_pages(buf->pages, buf->page_base, | |
368 | (char *)head->iov_base + head->iov_len - len, | |
369 | copy); | |
370 | } | |
371 | head->iov_len -= len; | |
372 | buf->buflen -= len; | |
373 | /* Have we truncated the message? */ | |
374 | if (buf->len > buf->buflen) | |
375 | buf->len = buf->buflen; | |
376 | } | |
377 | ||
378 | /* | |
379 | * xdr_shrink_pagelen | |
380 | * @buf: xdr_buf | |
381 | * @len: bytes to remove from buf->pages | |
382 | * | |
cca5172a | 383 | * Shrinks XDR buffer's page array buf->pages by |
1da177e4 LT |
384 | * 'len' bytes. The extra data is not lost, but is instead |
385 | * moved into the tail. | |
386 | */ | |
387 | static void | |
388 | xdr_shrink_pagelen(struct xdr_buf *buf, size_t len) | |
389 | { | |
390 | struct kvec *tail; | |
391 | size_t copy; | |
392 | char *p; | |
393 | unsigned int pglen = buf->page_len; | |
394 | ||
395 | tail = buf->tail; | |
396 | BUG_ON (len > pglen); | |
397 | ||
398 | /* Shift the tail first */ | |
399 | if (tail->iov_len != 0) { | |
400 | p = (char *)tail->iov_base + len; | |
401 | if (tail->iov_len > len) { | |
402 | copy = tail->iov_len - len; | |
403 | memmove(p, tail->iov_base, copy); | |
404 | } else | |
405 | buf->buflen -= len; | |
406 | /* Copy from the inlined pages into the tail */ | |
407 | copy = len; | |
408 | if (copy > tail->iov_len) | |
409 | copy = tail->iov_len; | |
410 | _copy_from_pages((char *)tail->iov_base, | |
411 | buf->pages, buf->page_base + pglen - len, | |
412 | copy); | |
413 | } | |
414 | buf->page_len -= len; | |
415 | buf->buflen -= len; | |
416 | /* Have we truncated the message? */ | |
417 | if (buf->len > buf->buflen) | |
418 | buf->len = buf->buflen; | |
419 | } | |
420 | ||
421 | void | |
422 | xdr_shift_buf(struct xdr_buf *buf, size_t len) | |
423 | { | |
424 | xdr_shrink_bufhead(buf, len); | |
425 | } | |
a6eaf8bd | 426 | EXPORT_SYMBOL(xdr_shift_buf); |
1da177e4 LT |
427 | |
428 | /** | |
429 | * xdr_init_encode - Initialize a struct xdr_stream for sending data. | |
430 | * @xdr: pointer to xdr_stream struct | |
431 | * @buf: pointer to XDR buffer in which to encode data | |
432 | * @p: current pointer inside XDR buffer | |
433 | * | |
434 | * Note: at the moment the RPC client only passes the length of our | |
435 | * scratch buffer in the xdr_buf's header kvec. Previously this | |
436 | * meant we needed to call xdr_adjust_iovec() after encoding the | |
437 | * data. With the new scheme, the xdr_stream manages the details | |
438 | * of the buffer length, and takes care of adjusting the kvec | |
439 | * length for us. | |
440 | */ | |
d8ed029d | 441 | void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p) |
1da177e4 LT |
442 | { |
443 | struct kvec *iov = buf->head; | |
334ccfd5 | 444 | int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len; |
1da177e4 | 445 | |
334ccfd5 | 446 | BUG_ON(scratch_len < 0); |
1da177e4 LT |
447 | xdr->buf = buf; |
448 | xdr->iov = iov; | |
d8ed029d AD |
449 | xdr->p = (__be32 *)((char *)iov->iov_base + iov->iov_len); |
450 | xdr->end = (__be32 *)((char *)iov->iov_base + scratch_len); | |
334ccfd5 TM |
451 | BUG_ON(iov->iov_len > scratch_len); |
452 | ||
453 | if (p != xdr->p && p != NULL) { | |
454 | size_t len; | |
455 | ||
456 | BUG_ON(p < xdr->p || p > xdr->end); | |
457 | len = (char *)p - (char *)xdr->p; | |
458 | xdr->p = p; | |
459 | buf->len += len; | |
460 | iov->iov_len += len; | |
461 | } | |
1da177e4 LT |
462 | } |
463 | EXPORT_SYMBOL(xdr_init_encode); | |
464 | ||
465 | /** | |
466 | * xdr_reserve_space - Reserve buffer space for sending | |
467 | * @xdr: pointer to xdr_stream | |
468 | * @nbytes: number of bytes to reserve | |
469 | * | |
470 | * Checks that we have enough buffer space to encode 'nbytes' more | |
471 | * bytes of data. If so, update the total xdr_buf length, and | |
472 | * adjust the length of the current kvec. | |
473 | */ | |
d8ed029d | 474 | __be32 * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes) |
1da177e4 | 475 | { |
d8ed029d AD |
476 | __be32 *p = xdr->p; |
477 | __be32 *q; | |
1da177e4 LT |
478 | |
479 | /* align nbytes on the next 32-bit boundary */ | |
480 | nbytes += 3; | |
481 | nbytes &= ~3; | |
482 | q = p + (nbytes >> 2); | |
483 | if (unlikely(q > xdr->end || q < p)) | |
484 | return NULL; | |
485 | xdr->p = q; | |
486 | xdr->iov->iov_len += nbytes; | |
487 | xdr->buf->len += nbytes; | |
488 | return p; | |
489 | } | |
490 | EXPORT_SYMBOL(xdr_reserve_space); | |
491 | ||
492 | /** | |
493 | * xdr_write_pages - Insert a list of pages into an XDR buffer for sending | |
494 | * @xdr: pointer to xdr_stream | |
495 | * @pages: list of pages | |
496 | * @base: offset of first byte | |
497 | * @len: length of data in bytes | |
498 | * | |
499 | */ | |
500 | void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base, | |
501 | unsigned int len) | |
502 | { | |
503 | struct xdr_buf *buf = xdr->buf; | |
504 | struct kvec *iov = buf->tail; | |
505 | buf->pages = pages; | |
506 | buf->page_base = base; | |
507 | buf->page_len = len; | |
508 | ||
509 | iov->iov_base = (char *)xdr->p; | |
510 | iov->iov_len = 0; | |
511 | xdr->iov = iov; | |
512 | ||
513 | if (len & 3) { | |
514 | unsigned int pad = 4 - (len & 3); | |
515 | ||
516 | BUG_ON(xdr->p >= xdr->end); | |
517 | iov->iov_base = (char *)xdr->p + (len & 3); | |
518 | iov->iov_len += pad; | |
519 | len += pad; | |
520 | *xdr->p++ = 0; | |
521 | } | |
522 | buf->buflen += len; | |
523 | buf->len += len; | |
524 | } | |
525 | EXPORT_SYMBOL(xdr_write_pages); | |
526 | ||
527 | /** | |
528 | * xdr_init_decode - Initialize an xdr_stream for decoding data. | |
529 | * @xdr: pointer to xdr_stream struct | |
530 | * @buf: pointer to XDR buffer from which to decode data | |
531 | * @p: current pointer inside XDR buffer | |
532 | */ | |
d8ed029d | 533 | void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p) |
1da177e4 LT |
534 | { |
535 | struct kvec *iov = buf->head; | |
536 | unsigned int len = iov->iov_len; | |
537 | ||
538 | if (len > buf->len) | |
539 | len = buf->len; | |
540 | xdr->buf = buf; | |
541 | xdr->iov = iov; | |
542 | xdr->p = p; | |
d8ed029d | 543 | xdr->end = (__be32 *)((char *)iov->iov_base + len); |
1da177e4 LT |
544 | } |
545 | EXPORT_SYMBOL(xdr_init_decode); | |
546 | ||
547 | /** | |
548 | * xdr_inline_decode - Retrieve non-page XDR data to decode | |
549 | * @xdr: pointer to xdr_stream struct | |
550 | * @nbytes: number of bytes of data to decode | |
551 | * | |
552 | * Check if the input buffer is long enough to enable us to decode | |
553 | * 'nbytes' more bytes of data starting at the current position. | |
554 | * If so return the current pointer, then update the current | |
555 | * pointer position. | |
556 | */ | |
d8ed029d | 557 | __be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes) |
1da177e4 | 558 | { |
d8ed029d AD |
559 | __be32 *p = xdr->p; |
560 | __be32 *q = p + XDR_QUADLEN(nbytes); | |
1da177e4 LT |
561 | |
562 | if (unlikely(q > xdr->end || q < p)) | |
563 | return NULL; | |
564 | xdr->p = q; | |
565 | return p; | |
566 | } | |
567 | EXPORT_SYMBOL(xdr_inline_decode); | |
568 | ||
569 | /** | |
570 | * xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position | |
571 | * @xdr: pointer to xdr_stream struct | |
572 | * @len: number of bytes of page data | |
573 | * | |
574 | * Moves data beyond the current pointer position from the XDR head[] buffer | |
575 | * into the page list. Any data that lies beyond current position + "len" | |
8b23ea7b | 576 | * bytes is moved into the XDR tail[]. |
1da177e4 LT |
577 | */ |
578 | void xdr_read_pages(struct xdr_stream *xdr, unsigned int len) | |
579 | { | |
580 | struct xdr_buf *buf = xdr->buf; | |
581 | struct kvec *iov; | |
582 | ssize_t shift; | |
583 | unsigned int end; | |
584 | int padding; | |
585 | ||
586 | /* Realign pages to current pointer position */ | |
587 | iov = buf->head; | |
588 | shift = iov->iov_len + (char *)iov->iov_base - (char *)xdr->p; | |
589 | if (shift > 0) | |
590 | xdr_shrink_bufhead(buf, shift); | |
591 | ||
592 | /* Truncate page data and move it into the tail */ | |
593 | if (buf->page_len > len) | |
594 | xdr_shrink_pagelen(buf, buf->page_len - len); | |
595 | padding = (XDR_QUADLEN(len) << 2) - len; | |
596 | xdr->iov = iov = buf->tail; | |
597 | /* Compute remaining message length. */ | |
598 | end = iov->iov_len; | |
599 | shift = buf->buflen - buf->len; | |
600 | if (shift < end) | |
601 | end -= shift; | |
602 | else if (shift > 0) | |
603 | end = 0; | |
604 | /* | |
605 | * Position current pointer at beginning of tail, and | |
606 | * set remaining message length. | |
607 | */ | |
d8ed029d AD |
608 | xdr->p = (__be32 *)((char *)iov->iov_base + padding); |
609 | xdr->end = (__be32 *)((char *)iov->iov_base + end); | |
1da177e4 LT |
610 | } |
611 | EXPORT_SYMBOL(xdr_read_pages); | |
612 | ||
8b23ea7b TM |
613 | /** |
614 | * xdr_enter_page - decode data from the XDR page | |
615 | * @xdr: pointer to xdr_stream struct | |
616 | * @len: number of bytes of page data | |
617 | * | |
618 | * Moves data beyond the current pointer position from the XDR head[] buffer | |
619 | * into the page list. Any data that lies beyond current position + "len" | |
620 | * bytes is moved into the XDR tail[]. The current pointer is then | |
621 | * repositioned at the beginning of the first XDR page. | |
622 | */ | |
623 | void xdr_enter_page(struct xdr_stream *xdr, unsigned int len) | |
624 | { | |
625 | char * kaddr = page_address(xdr->buf->pages[0]); | |
626 | xdr_read_pages(xdr, len); | |
627 | /* | |
628 | * Position current pointer at beginning of tail, and | |
629 | * set remaining message length. | |
630 | */ | |
631 | if (len > PAGE_CACHE_SIZE - xdr->buf->page_base) | |
632 | len = PAGE_CACHE_SIZE - xdr->buf->page_base; | |
d8ed029d AD |
633 | xdr->p = (__be32 *)(kaddr + xdr->buf->page_base); |
634 | xdr->end = (__be32 *)((char *)xdr->p + len); | |
8b23ea7b TM |
635 | } |
636 | EXPORT_SYMBOL(xdr_enter_page); | |
637 | ||
1da177e4 LT |
638 | static struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0}; |
639 | ||
640 | void | |
641 | xdr_buf_from_iov(struct kvec *iov, struct xdr_buf *buf) | |
642 | { | |
643 | buf->head[0] = *iov; | |
644 | buf->tail[0] = empty_iov; | |
645 | buf->page_len = 0; | |
646 | buf->buflen = buf->len = iov->iov_len; | |
647 | } | |
a6eaf8bd | 648 | EXPORT_SYMBOL(xdr_buf_from_iov); |
1da177e4 | 649 | |
1da177e4 LT |
650 | /* Sets subbuf to the portion of buf of length len beginning base bytes |
651 | * from the start of buf. Returns -1 if base of length are out of bounds. */ | |
652 | int | |
653 | xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf, | |
1e78957e | 654 | unsigned int base, unsigned int len) |
1da177e4 | 655 | { |
1da177e4 | 656 | subbuf->buflen = subbuf->len = len; |
1e78957e TM |
657 | if (base < buf->head[0].iov_len) { |
658 | subbuf->head[0].iov_base = buf->head[0].iov_base + base; | |
659 | subbuf->head[0].iov_len = min_t(unsigned int, len, | |
660 | buf->head[0].iov_len - base); | |
661 | len -= subbuf->head[0].iov_len; | |
662 | base = 0; | |
663 | } else { | |
664 | subbuf->head[0].iov_base = NULL; | |
665 | subbuf->head[0].iov_len = 0; | |
666 | base -= buf->head[0].iov_len; | |
667 | } | |
1da177e4 LT |
668 | |
669 | if (base < buf->page_len) { | |
1e78957e TM |
670 | subbuf->page_len = min(buf->page_len - base, len); |
671 | base += buf->page_base; | |
672 | subbuf->page_base = base & ~PAGE_CACHE_MASK; | |
673 | subbuf->pages = &buf->pages[base >> PAGE_CACHE_SHIFT]; | |
1da177e4 LT |
674 | len -= subbuf->page_len; |
675 | base = 0; | |
676 | } else { | |
677 | base -= buf->page_len; | |
678 | subbuf->page_len = 0; | |
679 | } | |
680 | ||
1e78957e TM |
681 | if (base < buf->tail[0].iov_len) { |
682 | subbuf->tail[0].iov_base = buf->tail[0].iov_base + base; | |
683 | subbuf->tail[0].iov_len = min_t(unsigned int, len, | |
684 | buf->tail[0].iov_len - base); | |
685 | len -= subbuf->tail[0].iov_len; | |
686 | base = 0; | |
687 | } else { | |
688 | subbuf->tail[0].iov_base = NULL; | |
689 | subbuf->tail[0].iov_len = 0; | |
690 | base -= buf->tail[0].iov_len; | |
691 | } | |
692 | ||
1da177e4 LT |
693 | if (base || len) |
694 | return -1; | |
695 | return 0; | |
696 | } | |
a6eaf8bd | 697 | EXPORT_SYMBOL(xdr_buf_subsegment); |
1da177e4 | 698 | |
4e3e43ad | 699 | static void __read_bytes_from_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len) |
1da177e4 | 700 | { |
1e78957e | 701 | unsigned int this_len; |
1da177e4 | 702 | |
4e3e43ad TM |
703 | this_len = min_t(unsigned int, len, subbuf->head[0].iov_len); |
704 | memcpy(obj, subbuf->head[0].iov_base, this_len); | |
1da177e4 LT |
705 | len -= this_len; |
706 | obj += this_len; | |
4e3e43ad | 707 | this_len = min_t(unsigned int, len, subbuf->page_len); |
1da177e4 | 708 | if (this_len) |
4e3e43ad | 709 | _copy_from_pages(obj, subbuf->pages, subbuf->page_base, this_len); |
1da177e4 LT |
710 | len -= this_len; |
711 | obj += this_len; | |
4e3e43ad TM |
712 | this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len); |
713 | memcpy(obj, subbuf->tail[0].iov_base, this_len); | |
1da177e4 LT |
714 | } |
715 | ||
bd8100e7 | 716 | /* obj is assumed to point to allocated memory of size at least len: */ |
4e3e43ad | 717 | int read_bytes_from_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len) |
bd8100e7 AG |
718 | { |
719 | struct xdr_buf subbuf; | |
bd8100e7 AG |
720 | int status; |
721 | ||
722 | status = xdr_buf_subsegment(buf, &subbuf, base, len); | |
4e3e43ad TM |
723 | if (status != 0) |
724 | return status; | |
725 | __read_bytes_from_xdr_buf(&subbuf, obj, len); | |
726 | return 0; | |
727 | } | |
a6eaf8bd | 728 | EXPORT_SYMBOL(read_bytes_from_xdr_buf); |
4e3e43ad TM |
729 | |
730 | static void __write_bytes_to_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len) | |
731 | { | |
732 | unsigned int this_len; | |
733 | ||
734 | this_len = min_t(unsigned int, len, subbuf->head[0].iov_len); | |
735 | memcpy(subbuf->head[0].iov_base, obj, this_len); | |
bd8100e7 AG |
736 | len -= this_len; |
737 | obj += this_len; | |
4e3e43ad | 738 | this_len = min_t(unsigned int, len, subbuf->page_len); |
bd8100e7 | 739 | if (this_len) |
4e3e43ad | 740 | _copy_to_pages(subbuf->pages, subbuf->page_base, obj, this_len); |
bd8100e7 AG |
741 | len -= this_len; |
742 | obj += this_len; | |
4e3e43ad TM |
743 | this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len); |
744 | memcpy(subbuf->tail[0].iov_base, obj, this_len); | |
745 | } | |
746 | ||
747 | /* obj is assumed to point to allocated memory of size at least len: */ | |
748 | int write_bytes_to_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len) | |
749 | { | |
750 | struct xdr_buf subbuf; | |
751 | int status; | |
752 | ||
753 | status = xdr_buf_subsegment(buf, &subbuf, base, len); | |
754 | if (status != 0) | |
755 | return status; | |
756 | __write_bytes_to_xdr_buf(&subbuf, obj, len); | |
757 | return 0; | |
bd8100e7 AG |
758 | } |
759 | ||
760 | int | |
1e78957e | 761 | xdr_decode_word(struct xdr_buf *buf, unsigned int base, u32 *obj) |
1da177e4 | 762 | { |
d8ed029d | 763 | __be32 raw; |
1da177e4 LT |
764 | int status; |
765 | ||
766 | status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj)); | |
767 | if (status) | |
768 | return status; | |
769 | *obj = ntohl(raw); | |
770 | return 0; | |
771 | } | |
a6eaf8bd | 772 | EXPORT_SYMBOL(xdr_decode_word); |
1da177e4 | 773 | |
bd8100e7 | 774 | int |
1e78957e | 775 | xdr_encode_word(struct xdr_buf *buf, unsigned int base, u32 obj) |
bd8100e7 | 776 | { |
d8ed029d | 777 | __be32 raw = htonl(obj); |
bd8100e7 AG |
778 | |
779 | return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj)); | |
780 | } | |
a6eaf8bd | 781 | EXPORT_SYMBOL(xdr_encode_word); |
bd8100e7 | 782 | |
1da177e4 LT |
783 | /* If the netobj starting offset bytes from the start of xdr_buf is contained |
784 | * entirely in the head or the tail, set object to point to it; otherwise | |
785 | * try to find space for it at the end of the tail, copy it there, and | |
786 | * set obj to point to it. */ | |
bee57c99 | 787 | int xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, unsigned int offset) |
1da177e4 | 788 | { |
bee57c99 | 789 | struct xdr_buf subbuf; |
1da177e4 | 790 | |
bd8100e7 | 791 | if (xdr_decode_word(buf, offset, &obj->len)) |
bee57c99 TM |
792 | return -EFAULT; |
793 | if (xdr_buf_subsegment(buf, &subbuf, offset + 4, obj->len)) | |
794 | return -EFAULT; | |
795 | ||
796 | /* Is the obj contained entirely in the head? */ | |
797 | obj->data = subbuf.head[0].iov_base; | |
798 | if (subbuf.head[0].iov_len == obj->len) | |
799 | return 0; | |
800 | /* ..or is the obj contained entirely in the tail? */ | |
801 | obj->data = subbuf.tail[0].iov_base; | |
802 | if (subbuf.tail[0].iov_len == obj->len) | |
803 | return 0; | |
804 | ||
805 | /* use end of tail as storage for obj: | |
806 | * (We don't copy to the beginning because then we'd have | |
807 | * to worry about doing a potentially overlapping copy. | |
808 | * This assumes the object is at most half the length of the | |
809 | * tail.) */ | |
810 | if (obj->len > buf->buflen - buf->len) | |
811 | return -ENOMEM; | |
812 | if (buf->tail[0].iov_len != 0) | |
813 | obj->data = buf->tail[0].iov_base + buf->tail[0].iov_len; | |
814 | else | |
815 | obj->data = buf->head[0].iov_base + buf->head[0].iov_len; | |
816 | __read_bytes_from_xdr_buf(&subbuf, obj->data, obj->len); | |
1da177e4 | 817 | return 0; |
1da177e4 | 818 | } |
a6eaf8bd | 819 | EXPORT_SYMBOL(xdr_buf_read_netobj); |
bd8100e7 AG |
820 | |
821 | /* Returns 0 on success, or else a negative error code. */ | |
822 | static int | |
823 | xdr_xcode_array2(struct xdr_buf *buf, unsigned int base, | |
824 | struct xdr_array2_desc *desc, int encode) | |
825 | { | |
826 | char *elem = NULL, *c; | |
827 | unsigned int copied = 0, todo, avail_here; | |
828 | struct page **ppages = NULL; | |
829 | int err; | |
830 | ||
831 | if (encode) { | |
832 | if (xdr_encode_word(buf, base, desc->array_len) != 0) | |
833 | return -EINVAL; | |
834 | } else { | |
835 | if (xdr_decode_word(buf, base, &desc->array_len) != 0 || | |
58fcb8df | 836 | desc->array_len > desc->array_maxlen || |
bd8100e7 AG |
837 | (unsigned long) base + 4 + desc->array_len * |
838 | desc->elem_size > buf->len) | |
839 | return -EINVAL; | |
840 | } | |
841 | base += 4; | |
842 | ||
843 | if (!desc->xcode) | |
844 | return 0; | |
845 | ||
846 | todo = desc->array_len * desc->elem_size; | |
847 | ||
848 | /* process head */ | |
849 | if (todo && base < buf->head->iov_len) { | |
850 | c = buf->head->iov_base + base; | |
851 | avail_here = min_t(unsigned int, todo, | |
852 | buf->head->iov_len - base); | |
853 | todo -= avail_here; | |
854 | ||
855 | while (avail_here >= desc->elem_size) { | |
856 | err = desc->xcode(desc, c); | |
857 | if (err) | |
858 | goto out; | |
859 | c += desc->elem_size; | |
860 | avail_here -= desc->elem_size; | |
861 | } | |
862 | if (avail_here) { | |
863 | if (!elem) { | |
864 | elem = kmalloc(desc->elem_size, GFP_KERNEL); | |
865 | err = -ENOMEM; | |
866 | if (!elem) | |
867 | goto out; | |
868 | } | |
869 | if (encode) { | |
870 | err = desc->xcode(desc, elem); | |
871 | if (err) | |
872 | goto out; | |
873 | memcpy(c, elem, avail_here); | |
874 | } else | |
875 | memcpy(elem, c, avail_here); | |
876 | copied = avail_here; | |
877 | } | |
878 | base = buf->head->iov_len; /* align to start of pages */ | |
879 | } | |
880 | ||
881 | /* process pages array */ | |
882 | base -= buf->head->iov_len; | |
883 | if (todo && base < buf->page_len) { | |
884 | unsigned int avail_page; | |
885 | ||
886 | avail_here = min(todo, buf->page_len - base); | |
887 | todo -= avail_here; | |
888 | ||
889 | base += buf->page_base; | |
890 | ppages = buf->pages + (base >> PAGE_CACHE_SHIFT); | |
891 | base &= ~PAGE_CACHE_MASK; | |
892 | avail_page = min_t(unsigned int, PAGE_CACHE_SIZE - base, | |
893 | avail_here); | |
894 | c = kmap(*ppages) + base; | |
895 | ||
896 | while (avail_here) { | |
897 | avail_here -= avail_page; | |
898 | if (copied || avail_page < desc->elem_size) { | |
899 | unsigned int l = min(avail_page, | |
900 | desc->elem_size - copied); | |
901 | if (!elem) { | |
902 | elem = kmalloc(desc->elem_size, | |
903 | GFP_KERNEL); | |
904 | err = -ENOMEM; | |
905 | if (!elem) | |
906 | goto out; | |
907 | } | |
908 | if (encode) { | |
909 | if (!copied) { | |
910 | err = desc->xcode(desc, elem); | |
911 | if (err) | |
912 | goto out; | |
913 | } | |
914 | memcpy(c, elem + copied, l); | |
915 | copied += l; | |
916 | if (copied == desc->elem_size) | |
917 | copied = 0; | |
918 | } else { | |
919 | memcpy(elem + copied, c, l); | |
920 | copied += l; | |
921 | if (copied == desc->elem_size) { | |
922 | err = desc->xcode(desc, elem); | |
923 | if (err) | |
924 | goto out; | |
925 | copied = 0; | |
926 | } | |
927 | } | |
928 | avail_page -= l; | |
929 | c += l; | |
930 | } | |
931 | while (avail_page >= desc->elem_size) { | |
932 | err = desc->xcode(desc, c); | |
933 | if (err) | |
934 | goto out; | |
935 | c += desc->elem_size; | |
936 | avail_page -= desc->elem_size; | |
937 | } | |
938 | if (avail_page) { | |
939 | unsigned int l = min(avail_page, | |
940 | desc->elem_size - copied); | |
941 | if (!elem) { | |
942 | elem = kmalloc(desc->elem_size, | |
943 | GFP_KERNEL); | |
944 | err = -ENOMEM; | |
945 | if (!elem) | |
946 | goto out; | |
947 | } | |
948 | if (encode) { | |
949 | if (!copied) { | |
950 | err = desc->xcode(desc, elem); | |
951 | if (err) | |
952 | goto out; | |
953 | } | |
954 | memcpy(c, elem + copied, l); | |
955 | copied += l; | |
956 | if (copied == desc->elem_size) | |
957 | copied = 0; | |
958 | } else { | |
959 | memcpy(elem + copied, c, l); | |
960 | copied += l; | |
961 | if (copied == desc->elem_size) { | |
962 | err = desc->xcode(desc, elem); | |
963 | if (err) | |
964 | goto out; | |
965 | copied = 0; | |
966 | } | |
967 | } | |
968 | } | |
969 | if (avail_here) { | |
970 | kunmap(*ppages); | |
971 | ppages++; | |
972 | c = kmap(*ppages); | |
973 | } | |
974 | ||
975 | avail_page = min(avail_here, | |
976 | (unsigned int) PAGE_CACHE_SIZE); | |
977 | } | |
978 | base = buf->page_len; /* align to start of tail */ | |
979 | } | |
980 | ||
981 | /* process tail */ | |
982 | base -= buf->page_len; | |
983 | if (todo) { | |
984 | c = buf->tail->iov_base + base; | |
985 | if (copied) { | |
986 | unsigned int l = desc->elem_size - copied; | |
987 | ||
988 | if (encode) | |
989 | memcpy(c, elem + copied, l); | |
990 | else { | |
991 | memcpy(elem + copied, c, l); | |
992 | err = desc->xcode(desc, elem); | |
993 | if (err) | |
994 | goto out; | |
995 | } | |
996 | todo -= l; | |
997 | c += l; | |
998 | } | |
999 | while (todo) { | |
1000 | err = desc->xcode(desc, c); | |
1001 | if (err) | |
1002 | goto out; | |
1003 | c += desc->elem_size; | |
1004 | todo -= desc->elem_size; | |
1005 | } | |
1006 | } | |
1007 | err = 0; | |
1008 | ||
1009 | out: | |
a51482bd | 1010 | kfree(elem); |
bd8100e7 AG |
1011 | if (ppages) |
1012 | kunmap(*ppages); | |
1013 | return err; | |
1014 | } | |
1015 | ||
1016 | int | |
1017 | xdr_decode_array2(struct xdr_buf *buf, unsigned int base, | |
1018 | struct xdr_array2_desc *desc) | |
1019 | { | |
1020 | if (base >= buf->len) | |
1021 | return -EINVAL; | |
1022 | ||
1023 | return xdr_xcode_array2(buf, base, desc, 0); | |
1024 | } | |
a6eaf8bd | 1025 | EXPORT_SYMBOL(xdr_decode_array2); |
bd8100e7 AG |
1026 | |
1027 | int | |
1028 | xdr_encode_array2(struct xdr_buf *buf, unsigned int base, | |
1029 | struct xdr_array2_desc *desc) | |
1030 | { | |
1031 | if ((unsigned long) base + 4 + desc->array_len * desc->elem_size > | |
1032 | buf->head->iov_len + buf->page_len + buf->tail->iov_len) | |
1033 | return -EINVAL; | |
1034 | ||
1035 | return xdr_xcode_array2(buf, base, desc, 1); | |
1036 | } | |
a6eaf8bd | 1037 | EXPORT_SYMBOL(xdr_encode_array2); |
37a4e6cb OK |
1038 | |
1039 | int | |
1040 | xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, | |
cca5172a | 1041 | int (*actor)(struct scatterlist *, void *), void *data) |
37a4e6cb OK |
1042 | { |
1043 | int i, ret = 0; | |
1044 | unsigned page_len, thislen, page_offset; | |
1045 | struct scatterlist sg[1]; | |
1046 | ||
68e3f5dd HX |
1047 | sg_init_table(sg, 1); |
1048 | ||
37a4e6cb OK |
1049 | if (offset >= buf->head[0].iov_len) { |
1050 | offset -= buf->head[0].iov_len; | |
1051 | } else { | |
1052 | thislen = buf->head[0].iov_len - offset; | |
1053 | if (thislen > len) | |
1054 | thislen = len; | |
1055 | sg_set_buf(sg, buf->head[0].iov_base + offset, thislen); | |
1056 | ret = actor(sg, data); | |
1057 | if (ret) | |
1058 | goto out; | |
1059 | offset = 0; | |
1060 | len -= thislen; | |
1061 | } | |
1062 | if (len == 0) | |
1063 | goto out; | |
1064 | ||
1065 | if (offset >= buf->page_len) { | |
1066 | offset -= buf->page_len; | |
1067 | } else { | |
1068 | page_len = buf->page_len - offset; | |
1069 | if (page_len > len) | |
1070 | page_len = len; | |
1071 | len -= page_len; | |
1072 | page_offset = (offset + buf->page_base) & (PAGE_CACHE_SIZE - 1); | |
1073 | i = (offset + buf->page_base) >> PAGE_CACHE_SHIFT; | |
1074 | thislen = PAGE_CACHE_SIZE - page_offset; | |
1075 | do { | |
1076 | if (thislen > page_len) | |
1077 | thislen = page_len; | |
642f1490 | 1078 | sg_set_page(sg, buf->pages[i], thislen, page_offset); |
37a4e6cb OK |
1079 | ret = actor(sg, data); |
1080 | if (ret) | |
1081 | goto out; | |
1082 | page_len -= thislen; | |
1083 | i++; | |
1084 | page_offset = 0; | |
1085 | thislen = PAGE_CACHE_SIZE; | |
1086 | } while (page_len != 0); | |
1087 | offset = 0; | |
1088 | } | |
1089 | if (len == 0) | |
1090 | goto out; | |
1091 | if (offset < buf->tail[0].iov_len) { | |
1092 | thislen = buf->tail[0].iov_len - offset; | |
1093 | if (thislen > len) | |
1094 | thislen = len; | |
1095 | sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen); | |
1096 | ret = actor(sg, data); | |
1097 | len -= thislen; | |
1098 | } | |
1099 | if (len != 0) | |
1100 | ret = -EINVAL; | |
1101 | out: | |
1102 | return ret; | |
1103 | } | |
1104 | EXPORT_SYMBOL(xdr_process_buf); | |
1105 |