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Commit | Line | Data |
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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> |
5a0e3ad6 | 10 | #include <linux/slab.h> |
1da177e4 | 11 | #include <linux/types.h> |
1da177e4 LT |
12 | #include <linux/string.h> |
13 | #include <linux/kernel.h> | |
14 | #include <linux/pagemap.h> | |
15 | #include <linux/errno.h> | |
1da177e4 LT |
16 | #include <linux/sunrpc/xdr.h> |
17 | #include <linux/sunrpc/msg_prot.h> | |
18 | ||
19 | /* | |
20 | * XDR functions for basic NFS types | |
21 | */ | |
d8ed029d AD |
22 | __be32 * |
23 | xdr_encode_netobj(__be32 *p, const struct xdr_netobj *obj) | |
1da177e4 LT |
24 | { |
25 | unsigned int quadlen = XDR_QUADLEN(obj->len); | |
26 | ||
27 | p[quadlen] = 0; /* zero trailing bytes */ | |
9f162d2a | 28 | *p++ = cpu_to_be32(obj->len); |
1da177e4 LT |
29 | memcpy(p, obj->data, obj->len); |
30 | return p + XDR_QUADLEN(obj->len); | |
31 | } | |
468039ee | 32 | EXPORT_SYMBOL_GPL(xdr_encode_netobj); |
1da177e4 | 33 | |
d8ed029d AD |
34 | __be32 * |
35 | xdr_decode_netobj(__be32 *p, struct xdr_netobj *obj) | |
1da177e4 LT |
36 | { |
37 | unsigned int len; | |
38 | ||
98866b5a | 39 | if ((len = be32_to_cpu(*p++)) > XDR_MAX_NETOBJ) |
1da177e4 LT |
40 | return NULL; |
41 | obj->len = len; | |
42 | obj->data = (u8 *) p; | |
43 | return p + XDR_QUADLEN(len); | |
44 | } | |
468039ee | 45 | EXPORT_SYMBOL_GPL(xdr_decode_netobj); |
1da177e4 LT |
46 | |
47 | /** | |
48 | * xdr_encode_opaque_fixed - Encode fixed length opaque data | |
4dc3b16b PP |
49 | * @p: pointer to current position in XDR buffer. |
50 | * @ptr: pointer to data to encode (or NULL) | |
51 | * @nbytes: size of data. | |
1da177e4 LT |
52 | * |
53 | * Copy the array of data of length nbytes at ptr to the XDR buffer | |
54 | * at position p, then align to the next 32-bit boundary by padding | |
55 | * with zero bytes (see RFC1832). | |
56 | * Note: if ptr is NULL, only the padding is performed. | |
57 | * | |
58 | * Returns the updated current XDR buffer position | |
59 | * | |
60 | */ | |
d8ed029d | 61 | __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int nbytes) |
1da177e4 LT |
62 | { |
63 | if (likely(nbytes != 0)) { | |
64 | unsigned int quadlen = XDR_QUADLEN(nbytes); | |
65 | unsigned int padding = (quadlen << 2) - nbytes; | |
66 | ||
67 | if (ptr != NULL) | |
68 | memcpy(p, ptr, nbytes); | |
69 | if (padding != 0) | |
70 | memset((char *)p + nbytes, 0, padding); | |
71 | p += quadlen; | |
72 | } | |
73 | return p; | |
74 | } | |
468039ee | 75 | EXPORT_SYMBOL_GPL(xdr_encode_opaque_fixed); |
1da177e4 LT |
76 | |
77 | /** | |
78 | * xdr_encode_opaque - Encode variable length opaque data | |
4dc3b16b PP |
79 | * @p: pointer to current position in XDR buffer. |
80 | * @ptr: pointer to data to encode (or NULL) | |
81 | * @nbytes: size of data. | |
1da177e4 LT |
82 | * |
83 | * Returns the updated current XDR buffer position | |
84 | */ | |
d8ed029d | 85 | __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int nbytes) |
1da177e4 | 86 | { |
9f162d2a | 87 | *p++ = cpu_to_be32(nbytes); |
1da177e4 LT |
88 | return xdr_encode_opaque_fixed(p, ptr, nbytes); |
89 | } | |
468039ee | 90 | EXPORT_SYMBOL_GPL(xdr_encode_opaque); |
1da177e4 | 91 | |
d8ed029d AD |
92 | __be32 * |
93 | xdr_encode_string(__be32 *p, const char *string) | |
1da177e4 LT |
94 | { |
95 | return xdr_encode_array(p, string, strlen(string)); | |
96 | } | |
468039ee | 97 | EXPORT_SYMBOL_GPL(xdr_encode_string); |
1da177e4 | 98 | |
d8ed029d | 99 | __be32 * |
e5cff482 CL |
100 | xdr_decode_string_inplace(__be32 *p, char **sp, |
101 | unsigned int *lenp, unsigned int maxlen) | |
1da177e4 | 102 | { |
e5cff482 | 103 | u32 len; |
1da177e4 | 104 | |
98866b5a | 105 | len = be32_to_cpu(*p++); |
e5cff482 | 106 | if (len > maxlen) |
1da177e4 LT |
107 | return NULL; |
108 | *lenp = len; | |
109 | *sp = (char *) p; | |
110 | return p + XDR_QUADLEN(len); | |
111 | } | |
468039ee | 112 | EXPORT_SYMBOL_GPL(xdr_decode_string_inplace); |
1da177e4 | 113 | |
b4687da7 CL |
114 | /** |
115 | * xdr_terminate_string - '\0'-terminate a string residing in an xdr_buf | |
116 | * @buf: XDR buffer where string resides | |
117 | * @len: length of string, in bytes | |
118 | * | |
119 | */ | |
120 | void | |
121 | xdr_terminate_string(struct xdr_buf *buf, const u32 len) | |
122 | { | |
123 | char *kaddr; | |
124 | ||
125 | kaddr = kmap_atomic(buf->pages[0], KM_USER0); | |
126 | kaddr[buf->page_base + len] = '\0'; | |
127 | kunmap_atomic(kaddr, KM_USER0); | |
128 | } | |
129 | EXPORT_SYMBOL(xdr_terminate_string); | |
130 | ||
1da177e4 LT |
131 | void |
132 | xdr_encode_pages(struct xdr_buf *xdr, struct page **pages, unsigned int base, | |
133 | unsigned int len) | |
134 | { | |
135 | struct kvec *tail = xdr->tail; | |
136 | u32 *p; | |
137 | ||
138 | xdr->pages = pages; | |
139 | xdr->page_base = base; | |
140 | xdr->page_len = len; | |
141 | ||
142 | p = (u32 *)xdr->head[0].iov_base + XDR_QUADLEN(xdr->head[0].iov_len); | |
143 | tail->iov_base = p; | |
144 | tail->iov_len = 0; | |
145 | ||
146 | if (len & 3) { | |
147 | unsigned int pad = 4 - (len & 3); | |
148 | ||
149 | *p = 0; | |
150 | tail->iov_base = (char *)p + (len & 3); | |
151 | tail->iov_len = pad; | |
152 | len += pad; | |
153 | } | |
154 | xdr->buflen += len; | |
155 | xdr->len += len; | |
156 | } | |
468039ee | 157 | EXPORT_SYMBOL_GPL(xdr_encode_pages); |
1da177e4 LT |
158 | |
159 | void | |
160 | xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset, | |
161 | struct page **pages, unsigned int base, unsigned int len) | |
162 | { | |
163 | struct kvec *head = xdr->head; | |
164 | struct kvec *tail = xdr->tail; | |
165 | char *buf = (char *)head->iov_base; | |
166 | unsigned int buflen = head->iov_len; | |
167 | ||
168 | head->iov_len = offset; | |
169 | ||
170 | xdr->pages = pages; | |
171 | xdr->page_base = base; | |
172 | xdr->page_len = len; | |
173 | ||
174 | tail->iov_base = buf + offset; | |
175 | tail->iov_len = buflen - offset; | |
176 | ||
177 | xdr->buflen += len; | |
178 | } | |
468039ee | 179 | EXPORT_SYMBOL_GPL(xdr_inline_pages); |
1da177e4 | 180 | |
1da177e4 LT |
181 | /* |
182 | * Helper routines for doing 'memmove' like operations on a struct xdr_buf | |
183 | * | |
184 | * _shift_data_right_pages | |
185 | * @pages: vector of pages containing both the source and dest memory area. | |
186 | * @pgto_base: page vector address of destination | |
187 | * @pgfrom_base: page vector address of source | |
188 | * @len: number of bytes to copy | |
189 | * | |
190 | * Note: the addresses pgto_base and pgfrom_base are both calculated in | |
191 | * the same way: | |
192 | * if a memory area starts at byte 'base' in page 'pages[i]', | |
193 | * then its address is given as (i << PAGE_CACHE_SHIFT) + base | |
194 | * Also note: pgfrom_base must be < pgto_base, but the memory areas | |
195 | * they point to may overlap. | |
196 | */ | |
197 | static void | |
198 | _shift_data_right_pages(struct page **pages, size_t pgto_base, | |
199 | size_t pgfrom_base, size_t len) | |
200 | { | |
201 | struct page **pgfrom, **pgto; | |
202 | char *vfrom, *vto; | |
203 | size_t copy; | |
204 | ||
205 | BUG_ON(pgto_base <= pgfrom_base); | |
206 | ||
207 | pgto_base += len; | |
208 | pgfrom_base += len; | |
209 | ||
210 | pgto = pages + (pgto_base >> PAGE_CACHE_SHIFT); | |
211 | pgfrom = pages + (pgfrom_base >> PAGE_CACHE_SHIFT); | |
212 | ||
213 | pgto_base &= ~PAGE_CACHE_MASK; | |
214 | pgfrom_base &= ~PAGE_CACHE_MASK; | |
215 | ||
216 | do { | |
217 | /* Are any pointers crossing a page boundary? */ | |
218 | if (pgto_base == 0) { | |
1da177e4 LT |
219 | pgto_base = PAGE_CACHE_SIZE; |
220 | pgto--; | |
221 | } | |
222 | if (pgfrom_base == 0) { | |
223 | pgfrom_base = PAGE_CACHE_SIZE; | |
224 | pgfrom--; | |
225 | } | |
226 | ||
227 | copy = len; | |
228 | if (copy > pgto_base) | |
229 | copy = pgto_base; | |
230 | if (copy > pgfrom_base) | |
231 | copy = pgfrom_base; | |
232 | pgto_base -= copy; | |
233 | pgfrom_base -= copy; | |
234 | ||
235 | vto = kmap_atomic(*pgto, KM_USER0); | |
236 | vfrom = kmap_atomic(*pgfrom, KM_USER1); | |
237 | memmove(vto + pgto_base, vfrom + pgfrom_base, copy); | |
bce3481c | 238 | flush_dcache_page(*pgto); |
1da177e4 LT |
239 | kunmap_atomic(vfrom, KM_USER1); |
240 | kunmap_atomic(vto, KM_USER0); | |
241 | ||
242 | } while ((len -= copy) != 0); | |
1da177e4 LT |
243 | } |
244 | ||
245 | /* | |
246 | * _copy_to_pages | |
247 | * @pages: array of pages | |
248 | * @pgbase: page vector address of destination | |
249 | * @p: pointer to source data | |
250 | * @len: length | |
251 | * | |
252 | * Copies data from an arbitrary memory location into an array of pages | |
253 | * The copy is assumed to be non-overlapping. | |
254 | */ | |
255 | static void | |
256 | _copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len) | |
257 | { | |
258 | struct page **pgto; | |
259 | char *vto; | |
260 | size_t copy; | |
261 | ||
262 | pgto = pages + (pgbase >> PAGE_CACHE_SHIFT); | |
263 | pgbase &= ~PAGE_CACHE_MASK; | |
264 | ||
daeba89d | 265 | for (;;) { |
1da177e4 LT |
266 | copy = PAGE_CACHE_SIZE - pgbase; |
267 | if (copy > len) | |
268 | copy = len; | |
269 | ||
270 | vto = kmap_atomic(*pgto, KM_USER0); | |
271 | memcpy(vto + pgbase, p, copy); | |
272 | kunmap_atomic(vto, KM_USER0); | |
273 | ||
daeba89d TM |
274 | len -= copy; |
275 | if (len == 0) | |
276 | break; | |
277 | ||
1da177e4 LT |
278 | pgbase += copy; |
279 | if (pgbase == PAGE_CACHE_SIZE) { | |
280 | flush_dcache_page(*pgto); | |
281 | pgbase = 0; | |
282 | pgto++; | |
283 | } | |
284 | p += copy; | |
daeba89d | 285 | } |
1da177e4 LT |
286 | flush_dcache_page(*pgto); |
287 | } | |
288 | ||
289 | /* | |
290 | * _copy_from_pages | |
291 | * @p: pointer to destination | |
292 | * @pages: array of pages | |
293 | * @pgbase: offset of source data | |
294 | * @len: length | |
295 | * | |
296 | * Copies data into an arbitrary memory location from an array of pages | |
297 | * The copy is assumed to be non-overlapping. | |
298 | */ | |
299 | static void | |
300 | _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len) | |
301 | { | |
302 | struct page **pgfrom; | |
303 | char *vfrom; | |
304 | size_t copy; | |
305 | ||
306 | pgfrom = pages + (pgbase >> PAGE_CACHE_SHIFT); | |
307 | pgbase &= ~PAGE_CACHE_MASK; | |
308 | ||
309 | do { | |
310 | copy = PAGE_CACHE_SIZE - pgbase; | |
311 | if (copy > len) | |
312 | copy = len; | |
313 | ||
314 | vfrom = kmap_atomic(*pgfrom, KM_USER0); | |
315 | memcpy(p, vfrom + pgbase, copy); | |
316 | kunmap_atomic(vfrom, KM_USER0); | |
317 | ||
318 | pgbase += copy; | |
319 | if (pgbase == PAGE_CACHE_SIZE) { | |
320 | pgbase = 0; | |
321 | pgfrom++; | |
322 | } | |
323 | p += copy; | |
324 | ||
325 | } while ((len -= copy) != 0); | |
326 | } | |
327 | ||
328 | /* | |
329 | * xdr_shrink_bufhead | |
330 | * @buf: xdr_buf | |
331 | * @len: bytes to remove from buf->head[0] | |
332 | * | |
cca5172a | 333 | * Shrinks XDR buffer's header kvec buf->head[0] by |
1da177e4 LT |
334 | * 'len' bytes. The extra data is not lost, but is instead |
335 | * moved into the inlined pages and/or the tail. | |
336 | */ | |
337 | static void | |
338 | xdr_shrink_bufhead(struct xdr_buf *buf, size_t len) | |
339 | { | |
340 | struct kvec *head, *tail; | |
341 | size_t copy, offs; | |
342 | unsigned int pglen = buf->page_len; | |
343 | ||
344 | tail = buf->tail; | |
345 | head = buf->head; | |
346 | BUG_ON (len > head->iov_len); | |
347 | ||
348 | /* Shift the tail first */ | |
349 | if (tail->iov_len != 0) { | |
350 | if (tail->iov_len > len) { | |
351 | copy = tail->iov_len - len; | |
352 | memmove((char *)tail->iov_base + len, | |
353 | tail->iov_base, copy); | |
354 | } | |
355 | /* Copy from the inlined pages into the tail */ | |
356 | copy = len; | |
357 | if (copy > pglen) | |
358 | copy = pglen; | |
359 | offs = len - copy; | |
360 | if (offs >= tail->iov_len) | |
361 | copy = 0; | |
362 | else if (copy > tail->iov_len - offs) | |
363 | copy = tail->iov_len - offs; | |
364 | if (copy != 0) | |
365 | _copy_from_pages((char *)tail->iov_base + offs, | |
366 | buf->pages, | |
367 | buf->page_base + pglen + offs - len, | |
368 | copy); | |
369 | /* Do we also need to copy data from the head into the tail ? */ | |
370 | if (len > pglen) { | |
371 | offs = copy = len - pglen; | |
372 | if (copy > tail->iov_len) | |
373 | copy = tail->iov_len; | |
374 | memcpy(tail->iov_base, | |
375 | (char *)head->iov_base + | |
376 | head->iov_len - offs, | |
377 | copy); | |
378 | } | |
379 | } | |
380 | /* Now handle pages */ | |
381 | if (pglen != 0) { | |
382 | if (pglen > len) | |
383 | _shift_data_right_pages(buf->pages, | |
384 | buf->page_base + len, | |
385 | buf->page_base, | |
386 | pglen - len); | |
387 | copy = len; | |
388 | if (len > pglen) | |
389 | copy = pglen; | |
390 | _copy_to_pages(buf->pages, buf->page_base, | |
391 | (char *)head->iov_base + head->iov_len - len, | |
392 | copy); | |
393 | } | |
394 | head->iov_len -= len; | |
395 | buf->buflen -= len; | |
396 | /* Have we truncated the message? */ | |
397 | if (buf->len > buf->buflen) | |
398 | buf->len = buf->buflen; | |
399 | } | |
400 | ||
401 | /* | |
402 | * xdr_shrink_pagelen | |
403 | * @buf: xdr_buf | |
404 | * @len: bytes to remove from buf->pages | |
405 | * | |
cca5172a | 406 | * Shrinks XDR buffer's page array buf->pages by |
1da177e4 LT |
407 | * 'len' bytes. The extra data is not lost, but is instead |
408 | * moved into the tail. | |
409 | */ | |
410 | static void | |
411 | xdr_shrink_pagelen(struct xdr_buf *buf, size_t len) | |
412 | { | |
413 | struct kvec *tail; | |
414 | size_t copy; | |
1da177e4 | 415 | unsigned int pglen = buf->page_len; |
cf187c2d | 416 | unsigned int tailbuf_len; |
1da177e4 LT |
417 | |
418 | tail = buf->tail; | |
419 | BUG_ON (len > pglen); | |
420 | ||
cf187c2d TM |
421 | tailbuf_len = buf->buflen - buf->head->iov_len - buf->page_len; |
422 | ||
1da177e4 | 423 | /* Shift the tail first */ |
cf187c2d TM |
424 | if (tailbuf_len != 0) { |
425 | unsigned int free_space = tailbuf_len - tail->iov_len; | |
426 | ||
427 | if (len < free_space) | |
428 | free_space = len; | |
429 | tail->iov_len += free_space; | |
430 | ||
42d6d8ab | 431 | copy = len; |
1da177e4 | 432 | if (tail->iov_len > len) { |
0fe62a35 | 433 | char *p = (char *)tail->iov_base + len; |
2e29ebb8 | 434 | memmove(p, tail->iov_base, tail->iov_len - len); |
42d6d8ab | 435 | } else |
1da177e4 | 436 | copy = tail->iov_len; |
42d6d8ab | 437 | /* Copy from the inlined pages into the tail */ |
1da177e4 LT |
438 | _copy_from_pages((char *)tail->iov_base, |
439 | buf->pages, buf->page_base + pglen - len, | |
440 | copy); | |
441 | } | |
442 | buf->page_len -= len; | |
443 | buf->buflen -= len; | |
444 | /* Have we truncated the message? */ | |
445 | if (buf->len > buf->buflen) | |
446 | buf->len = buf->buflen; | |
447 | } | |
448 | ||
449 | void | |
450 | xdr_shift_buf(struct xdr_buf *buf, size_t len) | |
451 | { | |
452 | xdr_shrink_bufhead(buf, len); | |
453 | } | |
468039ee | 454 | EXPORT_SYMBOL_GPL(xdr_shift_buf); |
1da177e4 LT |
455 | |
456 | /** | |
457 | * xdr_init_encode - Initialize a struct xdr_stream for sending data. | |
458 | * @xdr: pointer to xdr_stream struct | |
459 | * @buf: pointer to XDR buffer in which to encode data | |
460 | * @p: current pointer inside XDR buffer | |
461 | * | |
462 | * Note: at the moment the RPC client only passes the length of our | |
463 | * scratch buffer in the xdr_buf's header kvec. Previously this | |
464 | * meant we needed to call xdr_adjust_iovec() after encoding the | |
465 | * data. With the new scheme, the xdr_stream manages the details | |
466 | * of the buffer length, and takes care of adjusting the kvec | |
467 | * length for us. | |
468 | */ | |
d8ed029d | 469 | void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p) |
1da177e4 LT |
470 | { |
471 | struct kvec *iov = buf->head; | |
334ccfd5 | 472 | int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len; |
1da177e4 | 473 | |
334ccfd5 | 474 | BUG_ON(scratch_len < 0); |
1da177e4 LT |
475 | xdr->buf = buf; |
476 | xdr->iov = iov; | |
d8ed029d AD |
477 | xdr->p = (__be32 *)((char *)iov->iov_base + iov->iov_len); |
478 | xdr->end = (__be32 *)((char *)iov->iov_base + scratch_len); | |
334ccfd5 TM |
479 | BUG_ON(iov->iov_len > scratch_len); |
480 | ||
481 | if (p != xdr->p && p != NULL) { | |
482 | size_t len; | |
483 | ||
484 | BUG_ON(p < xdr->p || p > xdr->end); | |
485 | len = (char *)p - (char *)xdr->p; | |
486 | xdr->p = p; | |
487 | buf->len += len; | |
488 | iov->iov_len += len; | |
489 | } | |
1da177e4 | 490 | } |
468039ee | 491 | EXPORT_SYMBOL_GPL(xdr_init_encode); |
1da177e4 LT |
492 | |
493 | /** | |
494 | * xdr_reserve_space - Reserve buffer space for sending | |
495 | * @xdr: pointer to xdr_stream | |
496 | * @nbytes: number of bytes to reserve | |
497 | * | |
498 | * Checks that we have enough buffer space to encode 'nbytes' more | |
499 | * bytes of data. If so, update the total xdr_buf length, and | |
500 | * adjust the length of the current kvec. | |
501 | */ | |
d8ed029d | 502 | __be32 * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes) |
1da177e4 | 503 | { |
d8ed029d AD |
504 | __be32 *p = xdr->p; |
505 | __be32 *q; | |
1da177e4 LT |
506 | |
507 | /* align nbytes on the next 32-bit boundary */ | |
508 | nbytes += 3; | |
509 | nbytes &= ~3; | |
510 | q = p + (nbytes >> 2); | |
511 | if (unlikely(q > xdr->end || q < p)) | |
512 | return NULL; | |
513 | xdr->p = q; | |
514 | xdr->iov->iov_len += nbytes; | |
515 | xdr->buf->len += nbytes; | |
516 | return p; | |
517 | } | |
468039ee | 518 | EXPORT_SYMBOL_GPL(xdr_reserve_space); |
1da177e4 LT |
519 | |
520 | /** | |
521 | * xdr_write_pages - Insert a list of pages into an XDR buffer for sending | |
522 | * @xdr: pointer to xdr_stream | |
523 | * @pages: list of pages | |
524 | * @base: offset of first byte | |
525 | * @len: length of data in bytes | |
526 | * | |
527 | */ | |
528 | void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base, | |
529 | unsigned int len) | |
530 | { | |
531 | struct xdr_buf *buf = xdr->buf; | |
532 | struct kvec *iov = buf->tail; | |
533 | buf->pages = pages; | |
534 | buf->page_base = base; | |
535 | buf->page_len = len; | |
536 | ||
537 | iov->iov_base = (char *)xdr->p; | |
538 | iov->iov_len = 0; | |
539 | xdr->iov = iov; | |
540 | ||
541 | if (len & 3) { | |
542 | unsigned int pad = 4 - (len & 3); | |
543 | ||
544 | BUG_ON(xdr->p >= xdr->end); | |
545 | iov->iov_base = (char *)xdr->p + (len & 3); | |
546 | iov->iov_len += pad; | |
547 | len += pad; | |
548 | *xdr->p++ = 0; | |
549 | } | |
550 | buf->buflen += len; | |
551 | buf->len += len; | |
552 | } | |
468039ee | 553 | EXPORT_SYMBOL_GPL(xdr_write_pages); |
1da177e4 LT |
554 | |
555 | /** | |
556 | * xdr_init_decode - Initialize an xdr_stream for decoding data. | |
557 | * @xdr: pointer to xdr_stream struct | |
558 | * @buf: pointer to XDR buffer from which to decode data | |
559 | * @p: current pointer inside XDR buffer | |
560 | */ | |
d8ed029d | 561 | void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p) |
1da177e4 LT |
562 | { |
563 | struct kvec *iov = buf->head; | |
564 | unsigned int len = iov->iov_len; | |
565 | ||
566 | if (len > buf->len) | |
567 | len = buf->len; | |
568 | xdr->buf = buf; | |
569 | xdr->iov = iov; | |
570 | xdr->p = p; | |
d8ed029d | 571 | xdr->end = (__be32 *)((char *)iov->iov_base + len); |
1da177e4 | 572 | } |
468039ee | 573 | EXPORT_SYMBOL_GPL(xdr_init_decode); |
1da177e4 | 574 | |
ba8e452a TM |
575 | /** |
576 | * xdr_inline_peek - Allow read-ahead in the XDR data stream | |
577 | * @xdr: pointer to xdr_stream struct | |
578 | * @nbytes: number of bytes of data to decode | |
579 | * | |
580 | * Check if the input buffer is long enough to enable us to decode | |
581 | * 'nbytes' more bytes of data starting at the current position. | |
582 | * If so return the current pointer without updating the current | |
583 | * pointer position. | |
584 | */ | |
585 | __be32 * xdr_inline_peek(struct xdr_stream *xdr, size_t nbytes) | |
586 | { | |
587 | __be32 *p = xdr->p; | |
588 | __be32 *q = p + XDR_QUADLEN(nbytes); | |
589 | ||
590 | if (unlikely(q > xdr->end || q < p)) | |
591 | return NULL; | |
592 | return p; | |
593 | } | |
594 | EXPORT_SYMBOL_GPL(xdr_inline_peek); | |
595 | ||
1da177e4 LT |
596 | /** |
597 | * xdr_inline_decode - Retrieve non-page XDR data to decode | |
598 | * @xdr: pointer to xdr_stream struct | |
599 | * @nbytes: number of bytes of data to decode | |
600 | * | |
601 | * Check if the input buffer is long enough to enable us to decode | |
602 | * 'nbytes' more bytes of data starting at the current position. | |
603 | * If so return the current pointer, then update the current | |
604 | * pointer position. | |
605 | */ | |
d8ed029d | 606 | __be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes) |
1da177e4 | 607 | { |
d8ed029d AD |
608 | __be32 *p = xdr->p; |
609 | __be32 *q = p + XDR_QUADLEN(nbytes); | |
1da177e4 LT |
610 | |
611 | if (unlikely(q > xdr->end || q < p)) | |
612 | return NULL; | |
613 | xdr->p = q; | |
614 | return p; | |
615 | } | |
468039ee | 616 | EXPORT_SYMBOL_GPL(xdr_inline_decode); |
1da177e4 LT |
617 | |
618 | /** | |
619 | * xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position | |
620 | * @xdr: pointer to xdr_stream struct | |
621 | * @len: number of bytes of page data | |
622 | * | |
623 | * Moves data beyond the current pointer position from the XDR head[] buffer | |
624 | * into the page list. Any data that lies beyond current position + "len" | |
8b23ea7b | 625 | * bytes is moved into the XDR tail[]. |
1da177e4 LT |
626 | */ |
627 | void xdr_read_pages(struct xdr_stream *xdr, unsigned int len) | |
628 | { | |
629 | struct xdr_buf *buf = xdr->buf; | |
630 | struct kvec *iov; | |
631 | ssize_t shift; | |
632 | unsigned int end; | |
633 | int padding; | |
634 | ||
635 | /* Realign pages to current pointer position */ | |
636 | iov = buf->head; | |
637 | shift = iov->iov_len + (char *)iov->iov_base - (char *)xdr->p; | |
638 | if (shift > 0) | |
639 | xdr_shrink_bufhead(buf, shift); | |
640 | ||
641 | /* Truncate page data and move it into the tail */ | |
642 | if (buf->page_len > len) | |
643 | xdr_shrink_pagelen(buf, buf->page_len - len); | |
644 | padding = (XDR_QUADLEN(len) << 2) - len; | |
645 | xdr->iov = iov = buf->tail; | |
646 | /* Compute remaining message length. */ | |
647 | end = iov->iov_len; | |
648 | shift = buf->buflen - buf->len; | |
649 | if (shift < end) | |
650 | end -= shift; | |
651 | else if (shift > 0) | |
652 | end = 0; | |
653 | /* | |
654 | * Position current pointer at beginning of tail, and | |
655 | * set remaining message length. | |
656 | */ | |
d8ed029d AD |
657 | xdr->p = (__be32 *)((char *)iov->iov_base + padding); |
658 | xdr->end = (__be32 *)((char *)iov->iov_base + end); | |
1da177e4 | 659 | } |
468039ee | 660 | EXPORT_SYMBOL_GPL(xdr_read_pages); |
1da177e4 | 661 | |
8b23ea7b TM |
662 | /** |
663 | * xdr_enter_page - decode data from the XDR page | |
664 | * @xdr: pointer to xdr_stream struct | |
665 | * @len: number of bytes of page data | |
666 | * | |
667 | * Moves data beyond the current pointer position from the XDR head[] buffer | |
668 | * into the page list. Any data that lies beyond current position + "len" | |
669 | * bytes is moved into the XDR tail[]. The current pointer is then | |
670 | * repositioned at the beginning of the first XDR page. | |
671 | */ | |
672 | void xdr_enter_page(struct xdr_stream *xdr, unsigned int len) | |
673 | { | |
674 | char * kaddr = page_address(xdr->buf->pages[0]); | |
675 | xdr_read_pages(xdr, len); | |
676 | /* | |
677 | * Position current pointer at beginning of tail, and | |
678 | * set remaining message length. | |
679 | */ | |
680 | if (len > PAGE_CACHE_SIZE - xdr->buf->page_base) | |
681 | len = PAGE_CACHE_SIZE - xdr->buf->page_base; | |
d8ed029d AD |
682 | xdr->p = (__be32 *)(kaddr + xdr->buf->page_base); |
683 | xdr->end = (__be32 *)((char *)xdr->p + len); | |
8b23ea7b | 684 | } |
468039ee | 685 | EXPORT_SYMBOL_GPL(xdr_enter_page); |
8b23ea7b | 686 | |
1da177e4 LT |
687 | static struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0}; |
688 | ||
689 | void | |
690 | xdr_buf_from_iov(struct kvec *iov, struct xdr_buf *buf) | |
691 | { | |
692 | buf->head[0] = *iov; | |
693 | buf->tail[0] = empty_iov; | |
694 | buf->page_len = 0; | |
695 | buf->buflen = buf->len = iov->iov_len; | |
696 | } | |
468039ee | 697 | EXPORT_SYMBOL_GPL(xdr_buf_from_iov); |
1da177e4 | 698 | |
1da177e4 LT |
699 | /* Sets subbuf to the portion of buf of length len beginning base bytes |
700 | * from the start of buf. Returns -1 if base of length are out of bounds. */ | |
701 | int | |
702 | xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf, | |
1e78957e | 703 | unsigned int base, unsigned int len) |
1da177e4 | 704 | { |
1da177e4 | 705 | subbuf->buflen = subbuf->len = len; |
1e78957e TM |
706 | if (base < buf->head[0].iov_len) { |
707 | subbuf->head[0].iov_base = buf->head[0].iov_base + base; | |
708 | subbuf->head[0].iov_len = min_t(unsigned int, len, | |
709 | buf->head[0].iov_len - base); | |
710 | len -= subbuf->head[0].iov_len; | |
711 | base = 0; | |
712 | } else { | |
713 | subbuf->head[0].iov_base = NULL; | |
714 | subbuf->head[0].iov_len = 0; | |
715 | base -= buf->head[0].iov_len; | |
716 | } | |
1da177e4 LT |
717 | |
718 | if (base < buf->page_len) { | |
1e78957e TM |
719 | subbuf->page_len = min(buf->page_len - base, len); |
720 | base += buf->page_base; | |
721 | subbuf->page_base = base & ~PAGE_CACHE_MASK; | |
722 | subbuf->pages = &buf->pages[base >> PAGE_CACHE_SHIFT]; | |
1da177e4 LT |
723 | len -= subbuf->page_len; |
724 | base = 0; | |
725 | } else { | |
726 | base -= buf->page_len; | |
727 | subbuf->page_len = 0; | |
728 | } | |
729 | ||
1e78957e TM |
730 | if (base < buf->tail[0].iov_len) { |
731 | subbuf->tail[0].iov_base = buf->tail[0].iov_base + base; | |
732 | subbuf->tail[0].iov_len = min_t(unsigned int, len, | |
733 | buf->tail[0].iov_len - base); | |
734 | len -= subbuf->tail[0].iov_len; | |
735 | base = 0; | |
736 | } else { | |
737 | subbuf->tail[0].iov_base = NULL; | |
738 | subbuf->tail[0].iov_len = 0; | |
739 | base -= buf->tail[0].iov_len; | |
740 | } | |
741 | ||
1da177e4 LT |
742 | if (base || len) |
743 | return -1; | |
744 | return 0; | |
745 | } | |
468039ee | 746 | EXPORT_SYMBOL_GPL(xdr_buf_subsegment); |
1da177e4 | 747 | |
4e3e43ad | 748 | static void __read_bytes_from_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len) |
1da177e4 | 749 | { |
1e78957e | 750 | unsigned int this_len; |
1da177e4 | 751 | |
4e3e43ad TM |
752 | this_len = min_t(unsigned int, len, subbuf->head[0].iov_len); |
753 | memcpy(obj, subbuf->head[0].iov_base, this_len); | |
1da177e4 LT |
754 | len -= this_len; |
755 | obj += this_len; | |
4e3e43ad | 756 | this_len = min_t(unsigned int, len, subbuf->page_len); |
1da177e4 | 757 | if (this_len) |
4e3e43ad | 758 | _copy_from_pages(obj, subbuf->pages, subbuf->page_base, this_len); |
1da177e4 LT |
759 | len -= this_len; |
760 | obj += this_len; | |
4e3e43ad TM |
761 | this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len); |
762 | memcpy(obj, subbuf->tail[0].iov_base, this_len); | |
1da177e4 LT |
763 | } |
764 | ||
bd8100e7 | 765 | /* obj is assumed to point to allocated memory of size at least len: */ |
4e3e43ad | 766 | int read_bytes_from_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len) |
bd8100e7 AG |
767 | { |
768 | struct xdr_buf subbuf; | |
bd8100e7 AG |
769 | int status; |
770 | ||
771 | status = xdr_buf_subsegment(buf, &subbuf, base, len); | |
4e3e43ad TM |
772 | if (status != 0) |
773 | return status; | |
774 | __read_bytes_from_xdr_buf(&subbuf, obj, len); | |
775 | return 0; | |
776 | } | |
468039ee | 777 | EXPORT_SYMBOL_GPL(read_bytes_from_xdr_buf); |
4e3e43ad TM |
778 | |
779 | static void __write_bytes_to_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len) | |
780 | { | |
781 | unsigned int this_len; | |
782 | ||
783 | this_len = min_t(unsigned int, len, subbuf->head[0].iov_len); | |
784 | memcpy(subbuf->head[0].iov_base, obj, this_len); | |
bd8100e7 AG |
785 | len -= this_len; |
786 | obj += this_len; | |
4e3e43ad | 787 | this_len = min_t(unsigned int, len, subbuf->page_len); |
bd8100e7 | 788 | if (this_len) |
4e3e43ad | 789 | _copy_to_pages(subbuf->pages, subbuf->page_base, obj, this_len); |
bd8100e7 AG |
790 | len -= this_len; |
791 | obj += this_len; | |
4e3e43ad TM |
792 | this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len); |
793 | memcpy(subbuf->tail[0].iov_base, obj, this_len); | |
794 | } | |
795 | ||
796 | /* obj is assumed to point to allocated memory of size at least len: */ | |
797 | int write_bytes_to_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len) | |
798 | { | |
799 | struct xdr_buf subbuf; | |
800 | int status; | |
801 | ||
802 | status = xdr_buf_subsegment(buf, &subbuf, base, len); | |
803 | if (status != 0) | |
804 | return status; | |
805 | __write_bytes_to_xdr_buf(&subbuf, obj, len); | |
806 | return 0; | |
bd8100e7 | 807 | } |
c43abaed | 808 | EXPORT_SYMBOL_GPL(write_bytes_to_xdr_buf); |
bd8100e7 AG |
809 | |
810 | int | |
1e78957e | 811 | xdr_decode_word(struct xdr_buf *buf, unsigned int base, u32 *obj) |
1da177e4 | 812 | { |
d8ed029d | 813 | __be32 raw; |
1da177e4 LT |
814 | int status; |
815 | ||
816 | status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj)); | |
817 | if (status) | |
818 | return status; | |
98866b5a | 819 | *obj = be32_to_cpu(raw); |
1da177e4 LT |
820 | return 0; |
821 | } | |
468039ee | 822 | EXPORT_SYMBOL_GPL(xdr_decode_word); |
1da177e4 | 823 | |
bd8100e7 | 824 | int |
1e78957e | 825 | xdr_encode_word(struct xdr_buf *buf, unsigned int base, u32 obj) |
bd8100e7 | 826 | { |
9f162d2a | 827 | __be32 raw = cpu_to_be32(obj); |
bd8100e7 AG |
828 | |
829 | return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj)); | |
830 | } | |
468039ee | 831 | EXPORT_SYMBOL_GPL(xdr_encode_word); |
bd8100e7 | 832 | |
1da177e4 LT |
833 | /* If the netobj starting offset bytes from the start of xdr_buf is contained |
834 | * entirely in the head or the tail, set object to point to it; otherwise | |
835 | * try to find space for it at the end of the tail, copy it there, and | |
836 | * set obj to point to it. */ | |
bee57c99 | 837 | int xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, unsigned int offset) |
1da177e4 | 838 | { |
bee57c99 | 839 | struct xdr_buf subbuf; |
1da177e4 | 840 | |
bd8100e7 | 841 | if (xdr_decode_word(buf, offset, &obj->len)) |
bee57c99 TM |
842 | return -EFAULT; |
843 | if (xdr_buf_subsegment(buf, &subbuf, offset + 4, obj->len)) | |
844 | return -EFAULT; | |
845 | ||
846 | /* Is the obj contained entirely in the head? */ | |
847 | obj->data = subbuf.head[0].iov_base; | |
848 | if (subbuf.head[0].iov_len == obj->len) | |
849 | return 0; | |
850 | /* ..or is the obj contained entirely in the tail? */ | |
851 | obj->data = subbuf.tail[0].iov_base; | |
852 | if (subbuf.tail[0].iov_len == obj->len) | |
853 | return 0; | |
854 | ||
855 | /* use end of tail as storage for obj: | |
856 | * (We don't copy to the beginning because then we'd have | |
857 | * to worry about doing a potentially overlapping copy. | |
858 | * This assumes the object is at most half the length of the | |
859 | * tail.) */ | |
860 | if (obj->len > buf->buflen - buf->len) | |
861 | return -ENOMEM; | |
862 | if (buf->tail[0].iov_len != 0) | |
863 | obj->data = buf->tail[0].iov_base + buf->tail[0].iov_len; | |
864 | else | |
865 | obj->data = buf->head[0].iov_base + buf->head[0].iov_len; | |
866 | __read_bytes_from_xdr_buf(&subbuf, obj->data, obj->len); | |
1da177e4 | 867 | return 0; |
1da177e4 | 868 | } |
468039ee | 869 | EXPORT_SYMBOL_GPL(xdr_buf_read_netobj); |
bd8100e7 AG |
870 | |
871 | /* Returns 0 on success, or else a negative error code. */ | |
872 | static int | |
873 | xdr_xcode_array2(struct xdr_buf *buf, unsigned int base, | |
874 | struct xdr_array2_desc *desc, int encode) | |
875 | { | |
876 | char *elem = NULL, *c; | |
877 | unsigned int copied = 0, todo, avail_here; | |
878 | struct page **ppages = NULL; | |
879 | int err; | |
880 | ||
881 | if (encode) { | |
882 | if (xdr_encode_word(buf, base, desc->array_len) != 0) | |
883 | return -EINVAL; | |
884 | } else { | |
885 | if (xdr_decode_word(buf, base, &desc->array_len) != 0 || | |
58fcb8df | 886 | desc->array_len > desc->array_maxlen || |
bd8100e7 AG |
887 | (unsigned long) base + 4 + desc->array_len * |
888 | desc->elem_size > buf->len) | |
889 | return -EINVAL; | |
890 | } | |
891 | base += 4; | |
892 | ||
893 | if (!desc->xcode) | |
894 | return 0; | |
895 | ||
896 | todo = desc->array_len * desc->elem_size; | |
897 | ||
898 | /* process head */ | |
899 | if (todo && base < buf->head->iov_len) { | |
900 | c = buf->head->iov_base + base; | |
901 | avail_here = min_t(unsigned int, todo, | |
902 | buf->head->iov_len - base); | |
903 | todo -= avail_here; | |
904 | ||
905 | while (avail_here >= desc->elem_size) { | |
906 | err = desc->xcode(desc, c); | |
907 | if (err) | |
908 | goto out; | |
909 | c += desc->elem_size; | |
910 | avail_here -= desc->elem_size; | |
911 | } | |
912 | if (avail_here) { | |
913 | if (!elem) { | |
914 | elem = kmalloc(desc->elem_size, GFP_KERNEL); | |
915 | err = -ENOMEM; | |
916 | if (!elem) | |
917 | goto out; | |
918 | } | |
919 | if (encode) { | |
920 | err = desc->xcode(desc, elem); | |
921 | if (err) | |
922 | goto out; | |
923 | memcpy(c, elem, avail_here); | |
924 | } else | |
925 | memcpy(elem, c, avail_here); | |
926 | copied = avail_here; | |
927 | } | |
928 | base = buf->head->iov_len; /* align to start of pages */ | |
929 | } | |
930 | ||
931 | /* process pages array */ | |
932 | base -= buf->head->iov_len; | |
933 | if (todo && base < buf->page_len) { | |
934 | unsigned int avail_page; | |
935 | ||
936 | avail_here = min(todo, buf->page_len - base); | |
937 | todo -= avail_here; | |
938 | ||
939 | base += buf->page_base; | |
940 | ppages = buf->pages + (base >> PAGE_CACHE_SHIFT); | |
941 | base &= ~PAGE_CACHE_MASK; | |
942 | avail_page = min_t(unsigned int, PAGE_CACHE_SIZE - base, | |
943 | avail_here); | |
944 | c = kmap(*ppages) + base; | |
945 | ||
946 | while (avail_here) { | |
947 | avail_here -= avail_page; | |
948 | if (copied || avail_page < desc->elem_size) { | |
949 | unsigned int l = min(avail_page, | |
950 | desc->elem_size - copied); | |
951 | if (!elem) { | |
952 | elem = kmalloc(desc->elem_size, | |
953 | GFP_KERNEL); | |
954 | err = -ENOMEM; | |
955 | if (!elem) | |
956 | goto out; | |
957 | } | |
958 | if (encode) { | |
959 | if (!copied) { | |
960 | err = desc->xcode(desc, elem); | |
961 | if (err) | |
962 | goto out; | |
963 | } | |
964 | memcpy(c, elem + copied, l); | |
965 | copied += l; | |
966 | if (copied == desc->elem_size) | |
967 | copied = 0; | |
968 | } else { | |
969 | memcpy(elem + copied, c, l); | |
970 | copied += l; | |
971 | if (copied == desc->elem_size) { | |
972 | err = desc->xcode(desc, elem); | |
973 | if (err) | |
974 | goto out; | |
975 | copied = 0; | |
976 | } | |
977 | } | |
978 | avail_page -= l; | |
979 | c += l; | |
980 | } | |
981 | while (avail_page >= desc->elem_size) { | |
982 | err = desc->xcode(desc, c); | |
983 | if (err) | |
984 | goto out; | |
985 | c += desc->elem_size; | |
986 | avail_page -= desc->elem_size; | |
987 | } | |
988 | if (avail_page) { | |
989 | unsigned int l = min(avail_page, | |
990 | desc->elem_size - copied); | |
991 | if (!elem) { | |
992 | elem = kmalloc(desc->elem_size, | |
993 | GFP_KERNEL); | |
994 | err = -ENOMEM; | |
995 | if (!elem) | |
996 | goto out; | |
997 | } | |
998 | if (encode) { | |
999 | if (!copied) { | |
1000 | err = desc->xcode(desc, elem); | |
1001 | if (err) | |
1002 | goto out; | |
1003 | } | |
1004 | memcpy(c, elem + copied, l); | |
1005 | copied += l; | |
1006 | if (copied == desc->elem_size) | |
1007 | copied = 0; | |
1008 | } else { | |
1009 | memcpy(elem + copied, c, l); | |
1010 | copied += l; | |
1011 | if (copied == desc->elem_size) { | |
1012 | err = desc->xcode(desc, elem); | |
1013 | if (err) | |
1014 | goto out; | |
1015 | copied = 0; | |
1016 | } | |
1017 | } | |
1018 | } | |
1019 | if (avail_here) { | |
1020 | kunmap(*ppages); | |
1021 | ppages++; | |
1022 | c = kmap(*ppages); | |
1023 | } | |
1024 | ||
1025 | avail_page = min(avail_here, | |
1026 | (unsigned int) PAGE_CACHE_SIZE); | |
1027 | } | |
1028 | base = buf->page_len; /* align to start of tail */ | |
1029 | } | |
1030 | ||
1031 | /* process tail */ | |
1032 | base -= buf->page_len; | |
1033 | if (todo) { | |
1034 | c = buf->tail->iov_base + base; | |
1035 | if (copied) { | |
1036 | unsigned int l = desc->elem_size - copied; | |
1037 | ||
1038 | if (encode) | |
1039 | memcpy(c, elem + copied, l); | |
1040 | else { | |
1041 | memcpy(elem + copied, c, l); | |
1042 | err = desc->xcode(desc, elem); | |
1043 | if (err) | |
1044 | goto out; | |
1045 | } | |
1046 | todo -= l; | |
1047 | c += l; | |
1048 | } | |
1049 | while (todo) { | |
1050 | err = desc->xcode(desc, c); | |
1051 | if (err) | |
1052 | goto out; | |
1053 | c += desc->elem_size; | |
1054 | todo -= desc->elem_size; | |
1055 | } | |
1056 | } | |
1057 | err = 0; | |
1058 | ||
1059 | out: | |
a51482bd | 1060 | kfree(elem); |
bd8100e7 AG |
1061 | if (ppages) |
1062 | kunmap(*ppages); | |
1063 | return err; | |
1064 | } | |
1065 | ||
1066 | int | |
1067 | xdr_decode_array2(struct xdr_buf *buf, unsigned int base, | |
1068 | struct xdr_array2_desc *desc) | |
1069 | { | |
1070 | if (base >= buf->len) | |
1071 | return -EINVAL; | |
1072 | ||
1073 | return xdr_xcode_array2(buf, base, desc, 0); | |
1074 | } | |
468039ee | 1075 | EXPORT_SYMBOL_GPL(xdr_decode_array2); |
bd8100e7 AG |
1076 | |
1077 | int | |
1078 | xdr_encode_array2(struct xdr_buf *buf, unsigned int base, | |
1079 | struct xdr_array2_desc *desc) | |
1080 | { | |
1081 | if ((unsigned long) base + 4 + desc->array_len * desc->elem_size > | |
1082 | buf->head->iov_len + buf->page_len + buf->tail->iov_len) | |
1083 | return -EINVAL; | |
1084 | ||
1085 | return xdr_xcode_array2(buf, base, desc, 1); | |
1086 | } | |
468039ee | 1087 | EXPORT_SYMBOL_GPL(xdr_encode_array2); |
37a4e6cb OK |
1088 | |
1089 | int | |
1090 | xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, | |
cca5172a | 1091 | int (*actor)(struct scatterlist *, void *), void *data) |
37a4e6cb OK |
1092 | { |
1093 | int i, ret = 0; | |
1094 | unsigned page_len, thislen, page_offset; | |
1095 | struct scatterlist sg[1]; | |
1096 | ||
68e3f5dd HX |
1097 | sg_init_table(sg, 1); |
1098 | ||
37a4e6cb OK |
1099 | if (offset >= buf->head[0].iov_len) { |
1100 | offset -= buf->head[0].iov_len; | |
1101 | } else { | |
1102 | thislen = buf->head[0].iov_len - offset; | |
1103 | if (thislen > len) | |
1104 | thislen = len; | |
1105 | sg_set_buf(sg, buf->head[0].iov_base + offset, thislen); | |
1106 | ret = actor(sg, data); | |
1107 | if (ret) | |
1108 | goto out; | |
1109 | offset = 0; | |
1110 | len -= thislen; | |
1111 | } | |
1112 | if (len == 0) | |
1113 | goto out; | |
1114 | ||
1115 | if (offset >= buf->page_len) { | |
1116 | offset -= buf->page_len; | |
1117 | } else { | |
1118 | page_len = buf->page_len - offset; | |
1119 | if (page_len > len) | |
1120 | page_len = len; | |
1121 | len -= page_len; | |
1122 | page_offset = (offset + buf->page_base) & (PAGE_CACHE_SIZE - 1); | |
1123 | i = (offset + buf->page_base) >> PAGE_CACHE_SHIFT; | |
1124 | thislen = PAGE_CACHE_SIZE - page_offset; | |
1125 | do { | |
1126 | if (thislen > page_len) | |
1127 | thislen = page_len; | |
642f1490 | 1128 | sg_set_page(sg, buf->pages[i], thislen, page_offset); |
37a4e6cb OK |
1129 | ret = actor(sg, data); |
1130 | if (ret) | |
1131 | goto out; | |
1132 | page_len -= thislen; | |
1133 | i++; | |
1134 | page_offset = 0; | |
1135 | thislen = PAGE_CACHE_SIZE; | |
1136 | } while (page_len != 0); | |
1137 | offset = 0; | |
1138 | } | |
1139 | if (len == 0) | |
1140 | goto out; | |
1141 | if (offset < buf->tail[0].iov_len) { | |
1142 | thislen = buf->tail[0].iov_len - offset; | |
1143 | if (thislen > len) | |
1144 | thislen = len; | |
1145 | sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen); | |
1146 | ret = actor(sg, data); | |
1147 | len -= thislen; | |
1148 | } | |
1149 | if (len != 0) | |
1150 | ret = -EINVAL; | |
1151 | out: | |
1152 | return ret; | |
1153 | } | |
468039ee | 1154 | EXPORT_SYMBOL_GPL(xdr_process_buf); |
37a4e6cb | 1155 |