Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/net/sunrpc/xdr.c | |
4 | * | |
5 | * Generic XDR support. | |
6 | * | |
7 | * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> | |
8 | */ | |
9 | ||
a246b010 | 10 | #include <linux/module.h> |
5a0e3ad6 | 11 | #include <linux/slab.h> |
1da177e4 | 12 | #include <linux/types.h> |
1da177e4 LT |
13 | #include <linux/string.h> |
14 | #include <linux/kernel.h> | |
15 | #include <linux/pagemap.h> | |
16 | #include <linux/errno.h> | |
1da177e4 LT |
17 | #include <linux/sunrpc/xdr.h> |
18 | #include <linux/sunrpc/msg_prot.h> | |
9d96acbc | 19 | #include <linux/bvec.h> |
5582863f | 20 | #include <trace/events/sunrpc.h> |
1da177e4 LT |
21 | |
22 | /* | |
23 | * XDR functions for basic NFS types | |
24 | */ | |
d8ed029d AD |
25 | __be32 * |
26 | xdr_encode_netobj(__be32 *p, const struct xdr_netobj *obj) | |
1da177e4 LT |
27 | { |
28 | unsigned int quadlen = XDR_QUADLEN(obj->len); | |
29 | ||
30 | p[quadlen] = 0; /* zero trailing bytes */ | |
9f162d2a | 31 | *p++ = cpu_to_be32(obj->len); |
1da177e4 LT |
32 | memcpy(p, obj->data, obj->len); |
33 | return p + XDR_QUADLEN(obj->len); | |
34 | } | |
468039ee | 35 | EXPORT_SYMBOL_GPL(xdr_encode_netobj); |
1da177e4 | 36 | |
d8ed029d AD |
37 | __be32 * |
38 | xdr_decode_netobj(__be32 *p, struct xdr_netobj *obj) | |
1da177e4 LT |
39 | { |
40 | unsigned int len; | |
41 | ||
98866b5a | 42 | if ((len = be32_to_cpu(*p++)) > XDR_MAX_NETOBJ) |
1da177e4 LT |
43 | return NULL; |
44 | obj->len = len; | |
45 | obj->data = (u8 *) p; | |
46 | return p + XDR_QUADLEN(len); | |
47 | } | |
468039ee | 48 | EXPORT_SYMBOL_GPL(xdr_decode_netobj); |
1da177e4 LT |
49 | |
50 | /** | |
51 | * xdr_encode_opaque_fixed - Encode fixed length opaque data | |
4dc3b16b PP |
52 | * @p: pointer to current position in XDR buffer. |
53 | * @ptr: pointer to data to encode (or NULL) | |
54 | * @nbytes: size of data. | |
1da177e4 LT |
55 | * |
56 | * Copy the array of data of length nbytes at ptr to the XDR buffer | |
57 | * at position p, then align to the next 32-bit boundary by padding | |
58 | * with zero bytes (see RFC1832). | |
59 | * Note: if ptr is NULL, only the padding is performed. | |
60 | * | |
61 | * Returns the updated current XDR buffer position | |
62 | * | |
63 | */ | |
d8ed029d | 64 | __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int nbytes) |
1da177e4 LT |
65 | { |
66 | if (likely(nbytes != 0)) { | |
67 | unsigned int quadlen = XDR_QUADLEN(nbytes); | |
68 | unsigned int padding = (quadlen << 2) - nbytes; | |
69 | ||
70 | if (ptr != NULL) | |
71 | memcpy(p, ptr, nbytes); | |
72 | if (padding != 0) | |
73 | memset((char *)p + nbytes, 0, padding); | |
74 | p += quadlen; | |
75 | } | |
76 | return p; | |
77 | } | |
468039ee | 78 | EXPORT_SYMBOL_GPL(xdr_encode_opaque_fixed); |
1da177e4 LT |
79 | |
80 | /** | |
81 | * xdr_encode_opaque - Encode variable length opaque data | |
4dc3b16b PP |
82 | * @p: pointer to current position in XDR buffer. |
83 | * @ptr: pointer to data to encode (or NULL) | |
84 | * @nbytes: size of data. | |
1da177e4 LT |
85 | * |
86 | * Returns the updated current XDR buffer position | |
87 | */ | |
d8ed029d | 88 | __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int nbytes) |
1da177e4 | 89 | { |
9f162d2a | 90 | *p++ = cpu_to_be32(nbytes); |
1da177e4 LT |
91 | return xdr_encode_opaque_fixed(p, ptr, nbytes); |
92 | } | |
468039ee | 93 | EXPORT_SYMBOL_GPL(xdr_encode_opaque); |
1da177e4 | 94 | |
d8ed029d AD |
95 | __be32 * |
96 | xdr_encode_string(__be32 *p, const char *string) | |
1da177e4 LT |
97 | { |
98 | return xdr_encode_array(p, string, strlen(string)); | |
99 | } | |
468039ee | 100 | EXPORT_SYMBOL_GPL(xdr_encode_string); |
1da177e4 | 101 | |
d8ed029d | 102 | __be32 * |
e5cff482 CL |
103 | xdr_decode_string_inplace(__be32 *p, char **sp, |
104 | unsigned int *lenp, unsigned int maxlen) | |
1da177e4 | 105 | { |
e5cff482 | 106 | u32 len; |
1da177e4 | 107 | |
98866b5a | 108 | len = be32_to_cpu(*p++); |
e5cff482 | 109 | if (len > maxlen) |
1da177e4 LT |
110 | return NULL; |
111 | *lenp = len; | |
112 | *sp = (char *) p; | |
113 | return p + XDR_QUADLEN(len); | |
114 | } | |
468039ee | 115 | EXPORT_SYMBOL_GPL(xdr_decode_string_inplace); |
1da177e4 | 116 | |
b4687da7 CL |
117 | /** |
118 | * xdr_terminate_string - '\0'-terminate a string residing in an xdr_buf | |
119 | * @buf: XDR buffer where string resides | |
120 | * @len: length of string, in bytes | |
121 | * | |
122 | */ | |
123 | void | |
124 | xdr_terminate_string(struct xdr_buf *buf, const u32 len) | |
125 | { | |
126 | char *kaddr; | |
127 | ||
b8541786 | 128 | kaddr = kmap_atomic(buf->pages[0]); |
b4687da7 | 129 | kaddr[buf->page_base + len] = '\0'; |
b8541786 | 130 | kunmap_atomic(kaddr); |
b4687da7 | 131 | } |
0d961aa9 | 132 | EXPORT_SYMBOL_GPL(xdr_terminate_string); |
b4687da7 | 133 | |
9d96acbc TM |
134 | size_t |
135 | xdr_buf_pagecount(struct xdr_buf *buf) | |
136 | { | |
137 | if (!buf->page_len) | |
138 | return 0; | |
139 | return (buf->page_base + buf->page_len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
140 | } | |
141 | ||
142 | int | |
143 | xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp) | |
144 | { | |
145 | size_t i, n = xdr_buf_pagecount(buf); | |
146 | ||
147 | if (n != 0 && buf->bvec == NULL) { | |
148 | buf->bvec = kmalloc_array(n, sizeof(buf->bvec[0]), gfp); | |
149 | if (!buf->bvec) | |
150 | return -ENOMEM; | |
151 | for (i = 0; i < n; i++) { | |
152 | buf->bvec[i].bv_page = buf->pages[i]; | |
153 | buf->bvec[i].bv_len = PAGE_SIZE; | |
154 | buf->bvec[i].bv_offset = 0; | |
155 | } | |
156 | } | |
157 | return 0; | |
158 | } | |
159 | ||
160 | void | |
161 | xdr_free_bvec(struct xdr_buf *buf) | |
162 | { | |
163 | kfree(buf->bvec); | |
164 | buf->bvec = NULL; | |
165 | } | |
166 | ||
cf500bac CL |
167 | /** |
168 | * xdr_inline_pages - Prepare receive buffer for a large reply | |
169 | * @xdr: xdr_buf into which reply will be placed | |
170 | * @offset: expected offset where data payload will start, in bytes | |
171 | * @pages: vector of struct page pointers | |
172 | * @base: offset in first page where receive should start, in bytes | |
173 | * @len: expected size of the upper layer data payload, in bytes | |
174 | * | |
175 | */ | |
1da177e4 LT |
176 | void |
177 | xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset, | |
178 | struct page **pages, unsigned int base, unsigned int len) | |
179 | { | |
180 | struct kvec *head = xdr->head; | |
181 | struct kvec *tail = xdr->tail; | |
182 | char *buf = (char *)head->iov_base; | |
183 | unsigned int buflen = head->iov_len; | |
184 | ||
185 | head->iov_len = offset; | |
186 | ||
187 | xdr->pages = pages; | |
188 | xdr->page_base = base; | |
189 | xdr->page_len = len; | |
190 | ||
191 | tail->iov_base = buf + offset; | |
192 | tail->iov_len = buflen - offset; | |
02ef04e4 CL |
193 | if ((xdr->page_len & 3) == 0) |
194 | tail->iov_len -= sizeof(__be32); | |
1da177e4 LT |
195 | |
196 | xdr->buflen += len; | |
197 | } | |
468039ee | 198 | EXPORT_SYMBOL_GPL(xdr_inline_pages); |
1da177e4 | 199 | |
1da177e4 LT |
200 | /* |
201 | * Helper routines for doing 'memmove' like operations on a struct xdr_buf | |
2c53040f BH |
202 | */ |
203 | ||
204 | /** | |
1da177e4 LT |
205 | * _shift_data_right_pages |
206 | * @pages: vector of pages containing both the source and dest memory area. | |
207 | * @pgto_base: page vector address of destination | |
208 | * @pgfrom_base: page vector address of source | |
209 | * @len: number of bytes to copy | |
210 | * | |
211 | * Note: the addresses pgto_base and pgfrom_base are both calculated in | |
212 | * the same way: | |
213 | * if a memory area starts at byte 'base' in page 'pages[i]', | |
ea1754a0 | 214 | * then its address is given as (i << PAGE_SHIFT) + base |
1da177e4 LT |
215 | * Also note: pgfrom_base must be < pgto_base, but the memory areas |
216 | * they point to may overlap. | |
217 | */ | |
218 | static void | |
219 | _shift_data_right_pages(struct page **pages, size_t pgto_base, | |
220 | size_t pgfrom_base, size_t len) | |
221 | { | |
222 | struct page **pgfrom, **pgto; | |
223 | char *vfrom, *vto; | |
224 | size_t copy; | |
225 | ||
226 | BUG_ON(pgto_base <= pgfrom_base); | |
227 | ||
228 | pgto_base += len; | |
229 | pgfrom_base += len; | |
230 | ||
09cbfeaf KS |
231 | pgto = pages + (pgto_base >> PAGE_SHIFT); |
232 | pgfrom = pages + (pgfrom_base >> PAGE_SHIFT); | |
1da177e4 | 233 | |
09cbfeaf KS |
234 | pgto_base &= ~PAGE_MASK; |
235 | pgfrom_base &= ~PAGE_MASK; | |
1da177e4 LT |
236 | |
237 | do { | |
238 | /* Are any pointers crossing a page boundary? */ | |
239 | if (pgto_base == 0) { | |
09cbfeaf | 240 | pgto_base = PAGE_SIZE; |
1da177e4 LT |
241 | pgto--; |
242 | } | |
243 | if (pgfrom_base == 0) { | |
09cbfeaf | 244 | pgfrom_base = PAGE_SIZE; |
1da177e4 LT |
245 | pgfrom--; |
246 | } | |
247 | ||
248 | copy = len; | |
249 | if (copy > pgto_base) | |
250 | copy = pgto_base; | |
251 | if (copy > pgfrom_base) | |
252 | copy = pgfrom_base; | |
253 | pgto_base -= copy; | |
254 | pgfrom_base -= copy; | |
255 | ||
b8541786 | 256 | vto = kmap_atomic(*pgto); |
347e2233 TM |
257 | if (*pgto != *pgfrom) { |
258 | vfrom = kmap_atomic(*pgfrom); | |
259 | memcpy(vto + pgto_base, vfrom + pgfrom_base, copy); | |
260 | kunmap_atomic(vfrom); | |
261 | } else | |
262 | memmove(vto + pgto_base, vto + pgfrom_base, copy); | |
bce3481c | 263 | flush_dcache_page(*pgto); |
b8541786 | 264 | kunmap_atomic(vto); |
1da177e4 LT |
265 | |
266 | } while ((len -= copy) != 0); | |
1da177e4 LT |
267 | } |
268 | ||
2c53040f | 269 | /** |
1da177e4 LT |
270 | * _copy_to_pages |
271 | * @pages: array of pages | |
272 | * @pgbase: page vector address of destination | |
273 | * @p: pointer to source data | |
274 | * @len: length | |
275 | * | |
276 | * Copies data from an arbitrary memory location into an array of pages | |
277 | * The copy is assumed to be non-overlapping. | |
278 | */ | |
279 | static void | |
280 | _copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len) | |
281 | { | |
282 | struct page **pgto; | |
283 | char *vto; | |
284 | size_t copy; | |
285 | ||
09cbfeaf KS |
286 | pgto = pages + (pgbase >> PAGE_SHIFT); |
287 | pgbase &= ~PAGE_MASK; | |
1da177e4 | 288 | |
daeba89d | 289 | for (;;) { |
09cbfeaf | 290 | copy = PAGE_SIZE - pgbase; |
1da177e4 LT |
291 | if (copy > len) |
292 | copy = len; | |
293 | ||
b8541786 | 294 | vto = kmap_atomic(*pgto); |
1da177e4 | 295 | memcpy(vto + pgbase, p, copy); |
b8541786 | 296 | kunmap_atomic(vto); |
1da177e4 | 297 | |
daeba89d TM |
298 | len -= copy; |
299 | if (len == 0) | |
300 | break; | |
301 | ||
1da177e4 | 302 | pgbase += copy; |
09cbfeaf | 303 | if (pgbase == PAGE_SIZE) { |
1da177e4 LT |
304 | flush_dcache_page(*pgto); |
305 | pgbase = 0; | |
306 | pgto++; | |
307 | } | |
308 | p += copy; | |
daeba89d | 309 | } |
1da177e4 LT |
310 | flush_dcache_page(*pgto); |
311 | } | |
312 | ||
2c53040f | 313 | /** |
1da177e4 LT |
314 | * _copy_from_pages |
315 | * @p: pointer to destination | |
316 | * @pages: array of pages | |
317 | * @pgbase: offset of source data | |
318 | * @len: length | |
319 | * | |
320 | * Copies data into an arbitrary memory location from an array of pages | |
321 | * The copy is assumed to be non-overlapping. | |
322 | */ | |
bf118a34 | 323 | void |
1da177e4 LT |
324 | _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len) |
325 | { | |
326 | struct page **pgfrom; | |
327 | char *vfrom; | |
328 | size_t copy; | |
329 | ||
09cbfeaf KS |
330 | pgfrom = pages + (pgbase >> PAGE_SHIFT); |
331 | pgbase &= ~PAGE_MASK; | |
1da177e4 LT |
332 | |
333 | do { | |
09cbfeaf | 334 | copy = PAGE_SIZE - pgbase; |
1da177e4 LT |
335 | if (copy > len) |
336 | copy = len; | |
337 | ||
b8541786 | 338 | vfrom = kmap_atomic(*pgfrom); |
1da177e4 | 339 | memcpy(p, vfrom + pgbase, copy); |
b8541786 | 340 | kunmap_atomic(vfrom); |
1da177e4 LT |
341 | |
342 | pgbase += copy; | |
09cbfeaf | 343 | if (pgbase == PAGE_SIZE) { |
1da177e4 LT |
344 | pgbase = 0; |
345 | pgfrom++; | |
346 | } | |
347 | p += copy; | |
348 | ||
349 | } while ((len -= copy) != 0); | |
350 | } | |
bf118a34 | 351 | EXPORT_SYMBOL_GPL(_copy_from_pages); |
1da177e4 | 352 | |
2c53040f | 353 | /** |
1da177e4 LT |
354 | * xdr_shrink_bufhead |
355 | * @buf: xdr_buf | |
356 | * @len: bytes to remove from buf->head[0] | |
357 | * | |
cca5172a | 358 | * Shrinks XDR buffer's header kvec buf->head[0] by |
1da177e4 LT |
359 | * 'len' bytes. The extra data is not lost, but is instead |
360 | * moved into the inlined pages and/or the tail. | |
361 | */ | |
7be9cea3 | 362 | static unsigned int |
1da177e4 LT |
363 | xdr_shrink_bufhead(struct xdr_buf *buf, size_t len) |
364 | { | |
365 | struct kvec *head, *tail; | |
366 | size_t copy, offs; | |
367 | unsigned int pglen = buf->page_len; | |
7be9cea3 | 368 | unsigned int result; |
1da177e4 | 369 | |
7be9cea3 | 370 | result = 0; |
1da177e4 LT |
371 | tail = buf->tail; |
372 | head = buf->head; | |
18e624ad WAA |
373 | |
374 | WARN_ON_ONCE(len > head->iov_len); | |
375 | if (len > head->iov_len) | |
376 | len = head->iov_len; | |
1da177e4 LT |
377 | |
378 | /* Shift the tail first */ | |
379 | if (tail->iov_len != 0) { | |
380 | if (tail->iov_len > len) { | |
381 | copy = tail->iov_len - len; | |
382 | memmove((char *)tail->iov_base + len, | |
383 | tail->iov_base, copy); | |
7be9cea3 | 384 | result += copy; |
1da177e4 LT |
385 | } |
386 | /* Copy from the inlined pages into the tail */ | |
387 | copy = len; | |
388 | if (copy > pglen) | |
389 | copy = pglen; | |
390 | offs = len - copy; | |
391 | if (offs >= tail->iov_len) | |
392 | copy = 0; | |
393 | else if (copy > tail->iov_len - offs) | |
394 | copy = tail->iov_len - offs; | |
7be9cea3 | 395 | if (copy != 0) { |
1da177e4 LT |
396 | _copy_from_pages((char *)tail->iov_base + offs, |
397 | buf->pages, | |
398 | buf->page_base + pglen + offs - len, | |
399 | copy); | |
7be9cea3 CL |
400 | result += copy; |
401 | } | |
1da177e4 LT |
402 | /* Do we also need to copy data from the head into the tail ? */ |
403 | if (len > pglen) { | |
404 | offs = copy = len - pglen; | |
405 | if (copy > tail->iov_len) | |
406 | copy = tail->iov_len; | |
407 | memcpy(tail->iov_base, | |
408 | (char *)head->iov_base + | |
409 | head->iov_len - offs, | |
410 | copy); | |
7be9cea3 | 411 | result += copy; |
1da177e4 LT |
412 | } |
413 | } | |
414 | /* Now handle pages */ | |
415 | if (pglen != 0) { | |
416 | if (pglen > len) | |
417 | _shift_data_right_pages(buf->pages, | |
418 | buf->page_base + len, | |
419 | buf->page_base, | |
420 | pglen - len); | |
421 | copy = len; | |
422 | if (len > pglen) | |
423 | copy = pglen; | |
424 | _copy_to_pages(buf->pages, buf->page_base, | |
425 | (char *)head->iov_base + head->iov_len - len, | |
426 | copy); | |
7be9cea3 | 427 | result += copy; |
1da177e4 LT |
428 | } |
429 | head->iov_len -= len; | |
430 | buf->buflen -= len; | |
431 | /* Have we truncated the message? */ | |
432 | if (buf->len > buf->buflen) | |
433 | buf->len = buf->buflen; | |
7be9cea3 CL |
434 | |
435 | return result; | |
1da177e4 LT |
436 | } |
437 | ||
2c53040f | 438 | /** |
1da177e4 LT |
439 | * xdr_shrink_pagelen |
440 | * @buf: xdr_buf | |
441 | * @len: bytes to remove from buf->pages | |
442 | * | |
cca5172a | 443 | * Shrinks XDR buffer's page array buf->pages by |
1da177e4 LT |
444 | * 'len' bytes. The extra data is not lost, but is instead |
445 | * moved into the tail. | |
446 | */ | |
7be9cea3 | 447 | static unsigned int |
1da177e4 LT |
448 | xdr_shrink_pagelen(struct xdr_buf *buf, size_t len) |
449 | { | |
450 | struct kvec *tail; | |
451 | size_t copy; | |
1da177e4 | 452 | unsigned int pglen = buf->page_len; |
cf187c2d | 453 | unsigned int tailbuf_len; |
7be9cea3 | 454 | unsigned int result; |
1da177e4 | 455 | |
7be9cea3 | 456 | result = 0; |
1da177e4 LT |
457 | tail = buf->tail; |
458 | BUG_ON (len > pglen); | |
459 | ||
cf187c2d TM |
460 | tailbuf_len = buf->buflen - buf->head->iov_len - buf->page_len; |
461 | ||
1da177e4 | 462 | /* Shift the tail first */ |
cf187c2d TM |
463 | if (tailbuf_len != 0) { |
464 | unsigned int free_space = tailbuf_len - tail->iov_len; | |
465 | ||
466 | if (len < free_space) | |
467 | free_space = len; | |
468 | tail->iov_len += free_space; | |
469 | ||
42d6d8ab | 470 | copy = len; |
1da177e4 | 471 | if (tail->iov_len > len) { |
0fe62a35 | 472 | char *p = (char *)tail->iov_base + len; |
2e29ebb8 | 473 | memmove(p, tail->iov_base, tail->iov_len - len); |
7be9cea3 | 474 | result += tail->iov_len - len; |
42d6d8ab | 475 | } else |
1da177e4 | 476 | copy = tail->iov_len; |
42d6d8ab | 477 | /* Copy from the inlined pages into the tail */ |
1da177e4 LT |
478 | _copy_from_pages((char *)tail->iov_base, |
479 | buf->pages, buf->page_base + pglen - len, | |
480 | copy); | |
7be9cea3 | 481 | result += copy; |
1da177e4 LT |
482 | } |
483 | buf->page_len -= len; | |
484 | buf->buflen -= len; | |
485 | /* Have we truncated the message? */ | |
486 | if (buf->len > buf->buflen) | |
487 | buf->len = buf->buflen; | |
7be9cea3 CL |
488 | |
489 | return result; | |
1da177e4 LT |
490 | } |
491 | ||
492 | void | |
493 | xdr_shift_buf(struct xdr_buf *buf, size_t len) | |
494 | { | |
495 | xdr_shrink_bufhead(buf, len); | |
496 | } | |
468039ee | 497 | EXPORT_SYMBOL_GPL(xdr_shift_buf); |
1da177e4 | 498 | |
4517d526 TM |
499 | /** |
500 | * xdr_stream_pos - Return the current offset from the start of the xdr_stream | |
501 | * @xdr: pointer to struct xdr_stream | |
502 | */ | |
503 | unsigned int xdr_stream_pos(const struct xdr_stream *xdr) | |
504 | { | |
505 | return (unsigned int)(XDR_QUADLEN(xdr->buf->len) - xdr->nwords) << 2; | |
506 | } | |
507 | EXPORT_SYMBOL_GPL(xdr_stream_pos); | |
508 | ||
1da177e4 LT |
509 | /** |
510 | * xdr_init_encode - Initialize a struct xdr_stream for sending data. | |
511 | * @xdr: pointer to xdr_stream struct | |
512 | * @buf: pointer to XDR buffer in which to encode data | |
513 | * @p: current pointer inside XDR buffer | |
0ccc61b1 | 514 | * @rqst: pointer to controlling rpc_rqst, for debugging |
1da177e4 LT |
515 | * |
516 | * Note: at the moment the RPC client only passes the length of our | |
517 | * scratch buffer in the xdr_buf's header kvec. Previously this | |
518 | * meant we needed to call xdr_adjust_iovec() after encoding the | |
519 | * data. With the new scheme, the xdr_stream manages the details | |
520 | * of the buffer length, and takes care of adjusting the kvec | |
521 | * length for us. | |
522 | */ | |
0ccc61b1 CL |
523 | void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p, |
524 | struct rpc_rqst *rqst) | |
1da177e4 LT |
525 | { |
526 | struct kvec *iov = buf->head; | |
334ccfd5 | 527 | int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len; |
1da177e4 | 528 | |
2825a7f9 | 529 | xdr_set_scratch_buffer(xdr, NULL, 0); |
334ccfd5 | 530 | BUG_ON(scratch_len < 0); |
1da177e4 LT |
531 | xdr->buf = buf; |
532 | xdr->iov = iov; | |
d8ed029d AD |
533 | xdr->p = (__be32 *)((char *)iov->iov_base + iov->iov_len); |
534 | xdr->end = (__be32 *)((char *)iov->iov_base + scratch_len); | |
334ccfd5 TM |
535 | BUG_ON(iov->iov_len > scratch_len); |
536 | ||
537 | if (p != xdr->p && p != NULL) { | |
538 | size_t len; | |
539 | ||
540 | BUG_ON(p < xdr->p || p > xdr->end); | |
541 | len = (char *)p - (char *)xdr->p; | |
542 | xdr->p = p; | |
543 | buf->len += len; | |
544 | iov->iov_len += len; | |
545 | } | |
0ccc61b1 | 546 | xdr->rqst = rqst; |
1da177e4 | 547 | } |
468039ee | 548 | EXPORT_SYMBOL_GPL(xdr_init_encode); |
1da177e4 | 549 | |
2825a7f9 BF |
550 | /** |
551 | * xdr_commit_encode - Ensure all data is written to buffer | |
552 | * @xdr: pointer to xdr_stream | |
553 | * | |
554 | * We handle encoding across page boundaries by giving the caller a | |
555 | * temporary location to write to, then later copying the data into | |
556 | * place; xdr_commit_encode does that copying. | |
557 | * | |
558 | * Normally the caller doesn't need to call this directly, as the | |
559 | * following xdr_reserve_space will do it. But an explicit call may be | |
560 | * required at the end of encoding, or any other time when the xdr_buf | |
561 | * data might be read. | |
562 | */ | |
563 | void xdr_commit_encode(struct xdr_stream *xdr) | |
564 | { | |
565 | int shift = xdr->scratch.iov_len; | |
566 | void *page; | |
567 | ||
568 | if (shift == 0) | |
569 | return; | |
570 | page = page_address(*xdr->page_ptr); | |
571 | memcpy(xdr->scratch.iov_base, page, shift); | |
572 | memmove(page, page + shift, (void *)xdr->p - page); | |
573 | xdr->scratch.iov_len = 0; | |
574 | } | |
575 | EXPORT_SYMBOL_GPL(xdr_commit_encode); | |
576 | ||
22cb4385 TM |
577 | static __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr, |
578 | size_t nbytes) | |
2825a7f9 | 579 | { |
025911a5 | 580 | __be32 *p; |
2825a7f9 BF |
581 | int space_left; |
582 | int frag1bytes, frag2bytes; | |
583 | ||
584 | if (nbytes > PAGE_SIZE) | |
5582863f | 585 | goto out_overflow; /* Bigger buffers require special handling */ |
2825a7f9 | 586 | if (xdr->buf->len + nbytes > xdr->buf->buflen) |
5582863f | 587 | goto out_overflow; /* Sorry, we're totally out of space */ |
2825a7f9 BF |
588 | frag1bytes = (xdr->end - xdr->p) << 2; |
589 | frag2bytes = nbytes - frag1bytes; | |
590 | if (xdr->iov) | |
591 | xdr->iov->iov_len += frag1bytes; | |
05638dc7 | 592 | else |
2825a7f9 | 593 | xdr->buf->page_len += frag1bytes; |
05638dc7 | 594 | xdr->page_ptr++; |
2825a7f9 BF |
595 | xdr->iov = NULL; |
596 | /* | |
597 | * If the last encode didn't end exactly on a page boundary, the | |
598 | * next one will straddle boundaries. Encode into the next | |
599 | * page, then copy it back later in xdr_commit_encode. We use | |
600 | * the "scratch" iov to track any temporarily unused fragment of | |
601 | * space at the end of the previous buffer: | |
602 | */ | |
603 | xdr->scratch.iov_base = xdr->p; | |
604 | xdr->scratch.iov_len = frag1bytes; | |
605 | p = page_address(*xdr->page_ptr); | |
606 | /* | |
607 | * Note this is where the next encode will start after we've | |
608 | * shifted this one back: | |
609 | */ | |
610 | xdr->p = (void *)p + frag2bytes; | |
611 | space_left = xdr->buf->buflen - xdr->buf->len; | |
612 | xdr->end = (void *)p + min_t(int, space_left, PAGE_SIZE); | |
613 | xdr->buf->page_len += frag2bytes; | |
614 | xdr->buf->len += nbytes; | |
615 | return p; | |
5582863f CL |
616 | out_overflow: |
617 | trace_rpc_xdr_overflow(xdr, nbytes); | |
618 | return NULL; | |
2825a7f9 BF |
619 | } |
620 | ||
1da177e4 LT |
621 | /** |
622 | * xdr_reserve_space - Reserve buffer space for sending | |
623 | * @xdr: pointer to xdr_stream | |
624 | * @nbytes: number of bytes to reserve | |
625 | * | |
626 | * Checks that we have enough buffer space to encode 'nbytes' more | |
627 | * bytes of data. If so, update the total xdr_buf length, and | |
628 | * adjust the length of the current kvec. | |
629 | */ | |
d8ed029d | 630 | __be32 * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes) |
1da177e4 | 631 | { |
d8ed029d AD |
632 | __be32 *p = xdr->p; |
633 | __be32 *q; | |
1da177e4 | 634 | |
2825a7f9 | 635 | xdr_commit_encode(xdr); |
1da177e4 LT |
636 | /* align nbytes on the next 32-bit boundary */ |
637 | nbytes += 3; | |
638 | nbytes &= ~3; | |
639 | q = p + (nbytes >> 2); | |
640 | if (unlikely(q > xdr->end || q < p)) | |
2825a7f9 | 641 | return xdr_get_next_encode_buffer(xdr, nbytes); |
1da177e4 | 642 | xdr->p = q; |
2825a7f9 BF |
643 | if (xdr->iov) |
644 | xdr->iov->iov_len += nbytes; | |
645 | else | |
646 | xdr->buf->page_len += nbytes; | |
1da177e4 LT |
647 | xdr->buf->len += nbytes; |
648 | return p; | |
649 | } | |
468039ee | 650 | EXPORT_SYMBOL_GPL(xdr_reserve_space); |
1da177e4 | 651 | |
3e19ce76 BF |
652 | /** |
653 | * xdr_truncate_encode - truncate an encode buffer | |
654 | * @xdr: pointer to xdr_stream | |
655 | * @len: new length of buffer | |
656 | * | |
657 | * Truncates the xdr stream, so that xdr->buf->len == len, | |
658 | * and xdr->p points at offset len from the start of the buffer, and | |
659 | * head, tail, and page lengths are adjusted to correspond. | |
660 | * | |
661 | * If this means moving xdr->p to a different buffer, we assume that | |
662 | * that the end pointer should be set to the end of the current page, | |
663 | * except in the case of the head buffer when we assume the head | |
664 | * buffer's current length represents the end of the available buffer. | |
665 | * | |
666 | * This is *not* safe to use on a buffer that already has inlined page | |
667 | * cache pages (as in a zero-copy server read reply), except for the | |
668 | * simple case of truncating from one position in the tail to another. | |
669 | * | |
670 | */ | |
671 | void xdr_truncate_encode(struct xdr_stream *xdr, size_t len) | |
672 | { | |
673 | struct xdr_buf *buf = xdr->buf; | |
674 | struct kvec *head = buf->head; | |
675 | struct kvec *tail = buf->tail; | |
676 | int fraglen; | |
49a068f8 | 677 | int new; |
3e19ce76 BF |
678 | |
679 | if (len > buf->len) { | |
680 | WARN_ON_ONCE(1); | |
681 | return; | |
682 | } | |
2825a7f9 | 683 | xdr_commit_encode(xdr); |
3e19ce76 BF |
684 | |
685 | fraglen = min_t(int, buf->len - len, tail->iov_len); | |
686 | tail->iov_len -= fraglen; | |
687 | buf->len -= fraglen; | |
ed38c069 | 688 | if (tail->iov_len) { |
3e19ce76 | 689 | xdr->p = tail->iov_base + tail->iov_len; |
280caac0 BF |
690 | WARN_ON_ONCE(!xdr->end); |
691 | WARN_ON_ONCE(!xdr->iov); | |
3e19ce76 BF |
692 | return; |
693 | } | |
694 | WARN_ON_ONCE(fraglen); | |
695 | fraglen = min_t(int, buf->len - len, buf->page_len); | |
696 | buf->page_len -= fraglen; | |
697 | buf->len -= fraglen; | |
698 | ||
699 | new = buf->page_base + buf->page_len; | |
49a068f8 BF |
700 | |
701 | xdr->page_ptr = buf->pages + (new >> PAGE_SHIFT); | |
3e19ce76 | 702 | |
ed38c069 | 703 | if (buf->page_len) { |
3e19ce76 BF |
704 | xdr->p = page_address(*xdr->page_ptr); |
705 | xdr->end = (void *)xdr->p + PAGE_SIZE; | |
706 | xdr->p = (void *)xdr->p + (new % PAGE_SIZE); | |
280caac0 | 707 | WARN_ON_ONCE(xdr->iov); |
3e19ce76 BF |
708 | return; |
709 | } | |
5d7a5bcb | 710 | if (fraglen) |
3e19ce76 BF |
711 | xdr->end = head->iov_base + head->iov_len; |
712 | /* (otherwise assume xdr->end is already set) */ | |
5d7a5bcb | 713 | xdr->page_ptr--; |
3e19ce76 BF |
714 | head->iov_len = len; |
715 | buf->len = len; | |
716 | xdr->p = head->iov_base + head->iov_len; | |
717 | xdr->iov = buf->head; | |
718 | } | |
719 | EXPORT_SYMBOL(xdr_truncate_encode); | |
720 | ||
db3f58a9 BF |
721 | /** |
722 | * xdr_restrict_buflen - decrease available buffer space | |
723 | * @xdr: pointer to xdr_stream | |
724 | * @newbuflen: new maximum number of bytes available | |
725 | * | |
726 | * Adjust our idea of how much space is available in the buffer. | |
727 | * If we've already used too much space in the buffer, returns -1. | |
728 | * If the available space is already smaller than newbuflen, returns 0 | |
729 | * and does nothing. Otherwise, adjusts xdr->buf->buflen to newbuflen | |
730 | * and ensures xdr->end is set at most offset newbuflen from the start | |
731 | * of the buffer. | |
732 | */ | |
733 | int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen) | |
734 | { | |
735 | struct xdr_buf *buf = xdr->buf; | |
736 | int left_in_this_buf = (void *)xdr->end - (void *)xdr->p; | |
737 | int end_offset = buf->len + left_in_this_buf; | |
738 | ||
739 | if (newbuflen < 0 || newbuflen < buf->len) | |
740 | return -1; | |
741 | if (newbuflen > buf->buflen) | |
742 | return 0; | |
743 | if (newbuflen < end_offset) | |
744 | xdr->end = (void *)xdr->end + newbuflen - end_offset; | |
745 | buf->buflen = newbuflen; | |
746 | return 0; | |
747 | } | |
748 | EXPORT_SYMBOL(xdr_restrict_buflen); | |
749 | ||
1da177e4 LT |
750 | /** |
751 | * xdr_write_pages - Insert a list of pages into an XDR buffer for sending | |
752 | * @xdr: pointer to xdr_stream | |
753 | * @pages: list of pages | |
754 | * @base: offset of first byte | |
755 | * @len: length of data in bytes | |
756 | * | |
757 | */ | |
758 | void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base, | |
759 | unsigned int len) | |
760 | { | |
761 | struct xdr_buf *buf = xdr->buf; | |
762 | struct kvec *iov = buf->tail; | |
763 | buf->pages = pages; | |
764 | buf->page_base = base; | |
765 | buf->page_len = len; | |
766 | ||
767 | iov->iov_base = (char *)xdr->p; | |
768 | iov->iov_len = 0; | |
769 | xdr->iov = iov; | |
770 | ||
771 | if (len & 3) { | |
772 | unsigned int pad = 4 - (len & 3); | |
773 | ||
774 | BUG_ON(xdr->p >= xdr->end); | |
775 | iov->iov_base = (char *)xdr->p + (len & 3); | |
776 | iov->iov_len += pad; | |
777 | len += pad; | |
778 | *xdr->p++ = 0; | |
779 | } | |
780 | buf->buflen += len; | |
781 | buf->len += len; | |
782 | } | |
468039ee | 783 | EXPORT_SYMBOL_GPL(xdr_write_pages); |
1da177e4 | 784 | |
6650239a | 785 | static void xdr_set_iov(struct xdr_stream *xdr, struct kvec *iov, |
1537693c | 786 | unsigned int len) |
6650239a TM |
787 | { |
788 | if (len > iov->iov_len) | |
789 | len = iov->iov_len; | |
1537693c | 790 | xdr->p = (__be32*)iov->iov_base; |
6650239a TM |
791 | xdr->end = (__be32*)(iov->iov_base + len); |
792 | xdr->iov = iov; | |
793 | xdr->page_ptr = NULL; | |
794 | } | |
795 | ||
796 | static int xdr_set_page_base(struct xdr_stream *xdr, | |
797 | unsigned int base, unsigned int len) | |
798 | { | |
799 | unsigned int pgnr; | |
800 | unsigned int maxlen; | |
801 | unsigned int pgoff; | |
802 | unsigned int pgend; | |
803 | void *kaddr; | |
804 | ||
805 | maxlen = xdr->buf->page_len; | |
806 | if (base >= maxlen) | |
807 | return -EINVAL; | |
808 | maxlen -= base; | |
809 | if (len > maxlen) | |
810 | len = maxlen; | |
811 | ||
812 | base += xdr->buf->page_base; | |
813 | ||
814 | pgnr = base >> PAGE_SHIFT; | |
815 | xdr->page_ptr = &xdr->buf->pages[pgnr]; | |
816 | kaddr = page_address(*xdr->page_ptr); | |
817 | ||
818 | pgoff = base & ~PAGE_MASK; | |
819 | xdr->p = (__be32*)(kaddr + pgoff); | |
820 | ||
821 | pgend = pgoff + len; | |
822 | if (pgend > PAGE_SIZE) | |
823 | pgend = PAGE_SIZE; | |
824 | xdr->end = (__be32*)(kaddr + pgend); | |
825 | xdr->iov = NULL; | |
826 | return 0; | |
827 | } | |
828 | ||
829 | static void xdr_set_next_page(struct xdr_stream *xdr) | |
830 | { | |
831 | unsigned int newbase; | |
832 | ||
833 | newbase = (1 + xdr->page_ptr - xdr->buf->pages) << PAGE_SHIFT; | |
834 | newbase -= xdr->buf->page_base; | |
835 | ||
836 | if (xdr_set_page_base(xdr, newbase, PAGE_SIZE) < 0) | |
a6cebd41 | 837 | xdr_set_iov(xdr, xdr->buf->tail, xdr->nwords << 2); |
6650239a TM |
838 | } |
839 | ||
840 | static bool xdr_set_next_buffer(struct xdr_stream *xdr) | |
841 | { | |
842 | if (xdr->page_ptr != NULL) | |
843 | xdr_set_next_page(xdr); | |
844 | else if (xdr->iov == xdr->buf->head) { | |
845 | if (xdr_set_page_base(xdr, 0, PAGE_SIZE) < 0) | |
a6cebd41 | 846 | xdr_set_iov(xdr, xdr->buf->tail, xdr->nwords << 2); |
6650239a TM |
847 | } |
848 | return xdr->p != xdr->end; | |
849 | } | |
850 | ||
1da177e4 LT |
851 | /** |
852 | * xdr_init_decode - Initialize an xdr_stream for decoding data. | |
853 | * @xdr: pointer to xdr_stream struct | |
854 | * @buf: pointer to XDR buffer from which to decode data | |
855 | * @p: current pointer inside XDR buffer | |
0ccc61b1 | 856 | * @rqst: pointer to controlling rpc_rqst, for debugging |
1da177e4 | 857 | */ |
0ccc61b1 CL |
858 | void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p, |
859 | struct rpc_rqst *rqst) | |
1da177e4 | 860 | { |
1da177e4 | 861 | xdr->buf = buf; |
6650239a TM |
862 | xdr->scratch.iov_base = NULL; |
863 | xdr->scratch.iov_len = 0; | |
bfeea1dc | 864 | xdr->nwords = XDR_QUADLEN(buf->len); |
6650239a | 865 | if (buf->head[0].iov_len != 0) |
1537693c | 866 | xdr_set_iov(xdr, buf->head, buf->len); |
6650239a TM |
867 | else if (buf->page_len != 0) |
868 | xdr_set_page_base(xdr, 0, buf->len); | |
06ef26a0 BC |
869 | else |
870 | xdr_set_iov(xdr, buf->head, buf->len); | |
bfeea1dc TM |
871 | if (p != NULL && p > xdr->p && xdr->end >= p) { |
872 | xdr->nwords -= p - xdr->p; | |
1537693c | 873 | xdr->p = p; |
bfeea1dc | 874 | } |
0ccc61b1 | 875 | xdr->rqst = rqst; |
1da177e4 | 876 | } |
468039ee | 877 | EXPORT_SYMBOL_GPL(xdr_init_decode); |
1da177e4 | 878 | |
f7da7a12 | 879 | /** |
7ecce75f | 880 | * xdr_init_decode_pages - Initialize an xdr_stream for decoding into pages |
f7da7a12 BH |
881 | * @xdr: pointer to xdr_stream struct |
882 | * @buf: pointer to XDR buffer from which to decode data | |
883 | * @pages: list of pages to decode into | |
884 | * @len: length in bytes of buffer in pages | |
885 | */ | |
886 | void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf, | |
887 | struct page **pages, unsigned int len) | |
888 | { | |
889 | memset(buf, 0, sizeof(*buf)); | |
890 | buf->pages = pages; | |
891 | buf->page_len = len; | |
892 | buf->buflen = len; | |
893 | buf->len = len; | |
0ccc61b1 | 894 | xdr_init_decode(xdr, buf, NULL, NULL); |
f7da7a12 BH |
895 | } |
896 | EXPORT_SYMBOL_GPL(xdr_init_decode_pages); | |
897 | ||
6650239a | 898 | static __be32 * __xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes) |
ba8e452a | 899 | { |
bfeea1dc | 900 | unsigned int nwords = XDR_QUADLEN(nbytes); |
ba8e452a | 901 | __be32 *p = xdr->p; |
bfeea1dc | 902 | __be32 *q = p + nwords; |
ba8e452a | 903 | |
bfeea1dc | 904 | if (unlikely(nwords > xdr->nwords || q > xdr->end || q < p)) |
ba8e452a | 905 | return NULL; |
6650239a | 906 | xdr->p = q; |
bfeea1dc | 907 | xdr->nwords -= nwords; |
ba8e452a TM |
908 | return p; |
909 | } | |
ba8e452a | 910 | |
1da177e4 | 911 | /** |
6650239a TM |
912 | * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data. |
913 | * @xdr: pointer to xdr_stream struct | |
914 | * @buf: pointer to an empty buffer | |
915 | * @buflen: size of 'buf' | |
916 | * | |
917 | * The scratch buffer is used when decoding from an array of pages. | |
918 | * If an xdr_inline_decode() call spans across page boundaries, then | |
919 | * we copy the data into the scratch buffer in order to allow linear | |
920 | * access. | |
921 | */ | |
922 | void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen) | |
923 | { | |
924 | xdr->scratch.iov_base = buf; | |
925 | xdr->scratch.iov_len = buflen; | |
926 | } | |
927 | EXPORT_SYMBOL_GPL(xdr_set_scratch_buffer); | |
928 | ||
929 | static __be32 *xdr_copy_to_scratch(struct xdr_stream *xdr, size_t nbytes) | |
930 | { | |
931 | __be32 *p; | |
ace0e14f | 932 | char *cpdest = xdr->scratch.iov_base; |
6650239a TM |
933 | size_t cplen = (char *)xdr->end - (char *)xdr->p; |
934 | ||
935 | if (nbytes > xdr->scratch.iov_len) | |
5582863f | 936 | goto out_overflow; |
ace0e14f TM |
937 | p = __xdr_inline_decode(xdr, cplen); |
938 | if (p == NULL) | |
939 | return NULL; | |
940 | memcpy(cpdest, p, cplen); | |
5582863f CL |
941 | if (!xdr_set_next_buffer(xdr)) |
942 | goto out_overflow; | |
6650239a TM |
943 | cpdest += cplen; |
944 | nbytes -= cplen; | |
6650239a TM |
945 | p = __xdr_inline_decode(xdr, nbytes); |
946 | if (p == NULL) | |
947 | return NULL; | |
948 | memcpy(cpdest, p, nbytes); | |
949 | return xdr->scratch.iov_base; | |
5582863f CL |
950 | out_overflow: |
951 | trace_rpc_xdr_overflow(xdr, nbytes); | |
952 | return NULL; | |
6650239a TM |
953 | } |
954 | ||
955 | /** | |
956 | * xdr_inline_decode - Retrieve XDR data to decode | |
1da177e4 LT |
957 | * @xdr: pointer to xdr_stream struct |
958 | * @nbytes: number of bytes of data to decode | |
959 | * | |
960 | * Check if the input buffer is long enough to enable us to decode | |
961 | * 'nbytes' more bytes of data starting at the current position. | |
962 | * If so return the current pointer, then update the current | |
963 | * pointer position. | |
964 | */ | |
d8ed029d | 965 | __be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes) |
1da177e4 | 966 | { |
6650239a | 967 | __be32 *p; |
1da177e4 | 968 | |
5582863f | 969 | if (unlikely(nbytes == 0)) |
6650239a TM |
970 | return xdr->p; |
971 | if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr)) | |
5582863f | 972 | goto out_overflow; |
6650239a TM |
973 | p = __xdr_inline_decode(xdr, nbytes); |
974 | if (p != NULL) | |
975 | return p; | |
976 | return xdr_copy_to_scratch(xdr, nbytes); | |
5582863f CL |
977 | out_overflow: |
978 | trace_rpc_xdr_overflow(xdr, nbytes); | |
979 | return NULL; | |
1da177e4 | 980 | } |
468039ee | 981 | EXPORT_SYMBOL_GPL(xdr_inline_decode); |
1da177e4 | 982 | |
3994ee6f | 983 | static unsigned int xdr_align_pages(struct xdr_stream *xdr, unsigned int len) |
1da177e4 LT |
984 | { |
985 | struct xdr_buf *buf = xdr->buf; | |
986 | struct kvec *iov; | |
bfeea1dc | 987 | unsigned int nwords = XDR_QUADLEN(len); |
b760b313 | 988 | unsigned int cur = xdr_stream_pos(xdr); |
7be9cea3 | 989 | unsigned int copied, offset; |
1da177e4 | 990 | |
bfeea1dc | 991 | if (xdr->nwords == 0) |
c337d365 | 992 | return 0; |
7be9cea3 | 993 | |
1da177e4 | 994 | /* Realign pages to current pointer position */ |
7be9cea3 | 995 | iov = buf->head; |
a11a2bf4 | 996 | if (iov->iov_len > cur) { |
7be9cea3 CL |
997 | offset = iov->iov_len - cur; |
998 | copied = xdr_shrink_bufhead(buf, offset); | |
999 | trace_rpc_xdr_alignment(xdr, offset, copied); | |
a11a2bf4 TM |
1000 | xdr->nwords = XDR_QUADLEN(buf->len - cur); |
1001 | } | |
1da177e4 | 1002 | |
a11a2bf4 TM |
1003 | if (nwords > xdr->nwords) { |
1004 | nwords = xdr->nwords; | |
1005 | len = nwords << 2; | |
1006 | } | |
1007 | if (buf->page_len <= len) | |
8a9a8b83 | 1008 | len = buf->page_len; |
a11a2bf4 TM |
1009 | else if (nwords < xdr->nwords) { |
1010 | /* Truncate page data and move it into the tail */ | |
7be9cea3 CL |
1011 | offset = buf->page_len - len; |
1012 | copied = xdr_shrink_pagelen(buf, offset); | |
1013 | trace_rpc_xdr_alignment(xdr, offset, copied); | |
a11a2bf4 TM |
1014 | xdr->nwords = XDR_QUADLEN(buf->len - cur); |
1015 | } | |
3994ee6f TM |
1016 | return len; |
1017 | } | |
bd00f84b | 1018 | |
1da177e4 LT |
1019 | /** |
1020 | * xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position | |
1021 | * @xdr: pointer to xdr_stream struct | |
1022 | * @len: number of bytes of page data | |
1023 | * | |
1024 | * Moves data beyond the current pointer position from the XDR head[] buffer | |
1025 | * into the page list. Any data that lies beyond current position + "len" | |
8b23ea7b | 1026 | * bytes is moved into the XDR tail[]. |
3994ee6f TM |
1027 | * |
1028 | * Returns the number of XDR encoded bytes now contained in the pages | |
1da177e4 | 1029 | */ |
3994ee6f | 1030 | unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len) |
1da177e4 LT |
1031 | { |
1032 | struct xdr_buf *buf = xdr->buf; | |
1033 | struct kvec *iov; | |
3994ee6f | 1034 | unsigned int nwords; |
1da177e4 | 1035 | unsigned int end; |
3994ee6f | 1036 | unsigned int padding; |
1da177e4 | 1037 | |
3994ee6f TM |
1038 | len = xdr_align_pages(xdr, len); |
1039 | if (len == 0) | |
1040 | return 0; | |
1041 | nwords = XDR_QUADLEN(len); | |
bfeea1dc | 1042 | padding = (nwords << 2) - len; |
1da177e4 LT |
1043 | xdr->iov = iov = buf->tail; |
1044 | /* Compute remaining message length. */ | |
bd00f84b TM |
1045 | end = ((xdr->nwords - nwords) << 2) + padding; |
1046 | if (end > iov->iov_len) | |
1047 | end = iov->iov_len; | |
1048 | ||
1da177e4 LT |
1049 | /* |
1050 | * Position current pointer at beginning of tail, and | |
1051 | * set remaining message length. | |
1052 | */ | |
d8ed029d AD |
1053 | xdr->p = (__be32 *)((char *)iov->iov_base + padding); |
1054 | xdr->end = (__be32 *)((char *)iov->iov_base + end); | |
76cacaab | 1055 | xdr->page_ptr = NULL; |
bfeea1dc | 1056 | xdr->nwords = XDR_QUADLEN(end - padding); |
c337d365 | 1057 | return len; |
1da177e4 | 1058 | } |
468039ee | 1059 | EXPORT_SYMBOL_GPL(xdr_read_pages); |
1da177e4 | 1060 | |
8b23ea7b TM |
1061 | /** |
1062 | * xdr_enter_page - decode data from the XDR page | |
1063 | * @xdr: pointer to xdr_stream struct | |
1064 | * @len: number of bytes of page data | |
1065 | * | |
1066 | * Moves data beyond the current pointer position from the XDR head[] buffer | |
1067 | * into the page list. Any data that lies beyond current position + "len" | |
1068 | * bytes is moved into the XDR tail[]. The current pointer is then | |
1069 | * repositioned at the beginning of the first XDR page. | |
1070 | */ | |
1071 | void xdr_enter_page(struct xdr_stream *xdr, unsigned int len) | |
1072 | { | |
f8bb7f08 | 1073 | len = xdr_align_pages(xdr, len); |
8b23ea7b TM |
1074 | /* |
1075 | * Position current pointer at beginning of tail, and | |
1076 | * set remaining message length. | |
1077 | */ | |
f8bb7f08 TM |
1078 | if (len != 0) |
1079 | xdr_set_page_base(xdr, 0, len); | |
8b23ea7b | 1080 | } |
468039ee | 1081 | EXPORT_SYMBOL_GPL(xdr_enter_page); |
8b23ea7b | 1082 | |
1da177e4 LT |
1083 | static struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0}; |
1084 | ||
1085 | void | |
1086 | xdr_buf_from_iov(struct kvec *iov, struct xdr_buf *buf) | |
1087 | { | |
1088 | buf->head[0] = *iov; | |
1089 | buf->tail[0] = empty_iov; | |
1090 | buf->page_len = 0; | |
1091 | buf->buflen = buf->len = iov->iov_len; | |
1092 | } | |
468039ee | 1093 | EXPORT_SYMBOL_GPL(xdr_buf_from_iov); |
1da177e4 | 1094 | |
de4aee2e BF |
1095 | /** |
1096 | * xdr_buf_subsegment - set subbuf to a portion of buf | |
1097 | * @buf: an xdr buffer | |
1098 | * @subbuf: the result buffer | |
1099 | * @base: beginning of range in bytes | |
1100 | * @len: length of range in bytes | |
1101 | * | |
1102 | * sets @subbuf to an xdr buffer representing the portion of @buf of | |
1103 | * length @len starting at offset @base. | |
1104 | * | |
1105 | * @buf and @subbuf may be pointers to the same struct xdr_buf. | |
1106 | * | |
1107 | * Returns -1 if base of length are out of bounds. | |
1108 | */ | |
1da177e4 LT |
1109 | int |
1110 | xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf, | |
1e78957e | 1111 | unsigned int base, unsigned int len) |
1da177e4 | 1112 | { |
1da177e4 | 1113 | subbuf->buflen = subbuf->len = len; |
1e78957e TM |
1114 | if (base < buf->head[0].iov_len) { |
1115 | subbuf->head[0].iov_base = buf->head[0].iov_base + base; | |
1116 | subbuf->head[0].iov_len = min_t(unsigned int, len, | |
1117 | buf->head[0].iov_len - base); | |
1118 | len -= subbuf->head[0].iov_len; | |
1119 | base = 0; | |
1120 | } else { | |
1e78957e | 1121 | base -= buf->head[0].iov_len; |
de4aee2e | 1122 | subbuf->head[0].iov_len = 0; |
1e78957e | 1123 | } |
1da177e4 LT |
1124 | |
1125 | if (base < buf->page_len) { | |
1e78957e TM |
1126 | subbuf->page_len = min(buf->page_len - base, len); |
1127 | base += buf->page_base; | |
09cbfeaf KS |
1128 | subbuf->page_base = base & ~PAGE_MASK; |
1129 | subbuf->pages = &buf->pages[base >> PAGE_SHIFT]; | |
1da177e4 LT |
1130 | len -= subbuf->page_len; |
1131 | base = 0; | |
1132 | } else { | |
1133 | base -= buf->page_len; | |
1134 | subbuf->page_len = 0; | |
1135 | } | |
1136 | ||
1e78957e TM |
1137 | if (base < buf->tail[0].iov_len) { |
1138 | subbuf->tail[0].iov_base = buf->tail[0].iov_base + base; | |
1139 | subbuf->tail[0].iov_len = min_t(unsigned int, len, | |
1140 | buf->tail[0].iov_len - base); | |
1141 | len -= subbuf->tail[0].iov_len; | |
1142 | base = 0; | |
1143 | } else { | |
1e78957e | 1144 | base -= buf->tail[0].iov_len; |
de4aee2e | 1145 | subbuf->tail[0].iov_len = 0; |
1e78957e TM |
1146 | } |
1147 | ||
1da177e4 LT |
1148 | if (base || len) |
1149 | return -1; | |
1150 | return 0; | |
1151 | } | |
468039ee | 1152 | EXPORT_SYMBOL_GPL(xdr_buf_subsegment); |
1da177e4 | 1153 | |
4e3e43ad | 1154 | static void __read_bytes_from_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len) |
1da177e4 | 1155 | { |
1e78957e | 1156 | unsigned int this_len; |
1da177e4 | 1157 | |
4e3e43ad TM |
1158 | this_len = min_t(unsigned int, len, subbuf->head[0].iov_len); |
1159 | memcpy(obj, subbuf->head[0].iov_base, this_len); | |
1da177e4 LT |
1160 | len -= this_len; |
1161 | obj += this_len; | |
4e3e43ad | 1162 | this_len = min_t(unsigned int, len, subbuf->page_len); |
1da177e4 | 1163 | if (this_len) |
4e3e43ad | 1164 | _copy_from_pages(obj, subbuf->pages, subbuf->page_base, this_len); |
1da177e4 LT |
1165 | len -= this_len; |
1166 | obj += this_len; | |
4e3e43ad TM |
1167 | this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len); |
1168 | memcpy(obj, subbuf->tail[0].iov_base, this_len); | |
1da177e4 LT |
1169 | } |
1170 | ||
bd8100e7 | 1171 | /* obj is assumed to point to allocated memory of size at least len: */ |
4e3e43ad | 1172 | int read_bytes_from_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len) |
bd8100e7 AG |
1173 | { |
1174 | struct xdr_buf subbuf; | |
bd8100e7 AG |
1175 | int status; |
1176 | ||
1177 | status = xdr_buf_subsegment(buf, &subbuf, base, len); | |
4e3e43ad TM |
1178 | if (status != 0) |
1179 | return status; | |
1180 | __read_bytes_from_xdr_buf(&subbuf, obj, len); | |
1181 | return 0; | |
1182 | } | |
468039ee | 1183 | EXPORT_SYMBOL_GPL(read_bytes_from_xdr_buf); |
4e3e43ad TM |
1184 | |
1185 | static void __write_bytes_to_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len) | |
1186 | { | |
1187 | unsigned int this_len; | |
1188 | ||
1189 | this_len = min_t(unsigned int, len, subbuf->head[0].iov_len); | |
1190 | memcpy(subbuf->head[0].iov_base, obj, this_len); | |
bd8100e7 AG |
1191 | len -= this_len; |
1192 | obj += this_len; | |
4e3e43ad | 1193 | this_len = min_t(unsigned int, len, subbuf->page_len); |
bd8100e7 | 1194 | if (this_len) |
4e3e43ad | 1195 | _copy_to_pages(subbuf->pages, subbuf->page_base, obj, this_len); |
bd8100e7 AG |
1196 | len -= this_len; |
1197 | obj += this_len; | |
4e3e43ad TM |
1198 | this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len); |
1199 | memcpy(subbuf->tail[0].iov_base, obj, this_len); | |
1200 | } | |
1201 | ||
1202 | /* obj is assumed to point to allocated memory of size at least len: */ | |
1203 | int write_bytes_to_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len) | |
1204 | { | |
1205 | struct xdr_buf subbuf; | |
1206 | int status; | |
1207 | ||
1208 | status = xdr_buf_subsegment(buf, &subbuf, base, len); | |
1209 | if (status != 0) | |
1210 | return status; | |
1211 | __write_bytes_to_xdr_buf(&subbuf, obj, len); | |
1212 | return 0; | |
bd8100e7 | 1213 | } |
c43abaed | 1214 | EXPORT_SYMBOL_GPL(write_bytes_to_xdr_buf); |
bd8100e7 AG |
1215 | |
1216 | int | |
1e78957e | 1217 | xdr_decode_word(struct xdr_buf *buf, unsigned int base, u32 *obj) |
1da177e4 | 1218 | { |
d8ed029d | 1219 | __be32 raw; |
1da177e4 LT |
1220 | int status; |
1221 | ||
1222 | status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj)); | |
1223 | if (status) | |
1224 | return status; | |
98866b5a | 1225 | *obj = be32_to_cpu(raw); |
1da177e4 LT |
1226 | return 0; |
1227 | } | |
468039ee | 1228 | EXPORT_SYMBOL_GPL(xdr_decode_word); |
1da177e4 | 1229 | |
bd8100e7 | 1230 | int |
1e78957e | 1231 | xdr_encode_word(struct xdr_buf *buf, unsigned int base, u32 obj) |
bd8100e7 | 1232 | { |
9f162d2a | 1233 | __be32 raw = cpu_to_be32(obj); |
bd8100e7 AG |
1234 | |
1235 | return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj)); | |
1236 | } | |
468039ee | 1237 | EXPORT_SYMBOL_GPL(xdr_encode_word); |
bd8100e7 | 1238 | |
1da177e4 LT |
1239 | /* If the netobj starting offset bytes from the start of xdr_buf is contained |
1240 | * entirely in the head or the tail, set object to point to it; otherwise | |
1241 | * try to find space for it at the end of the tail, copy it there, and | |
1242 | * set obj to point to it. */ | |
bee57c99 | 1243 | int xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, unsigned int offset) |
1da177e4 | 1244 | { |
bee57c99 | 1245 | struct xdr_buf subbuf; |
1da177e4 | 1246 | |
bd8100e7 | 1247 | if (xdr_decode_word(buf, offset, &obj->len)) |
bee57c99 TM |
1248 | return -EFAULT; |
1249 | if (xdr_buf_subsegment(buf, &subbuf, offset + 4, obj->len)) | |
1250 | return -EFAULT; | |
1251 | ||
1252 | /* Is the obj contained entirely in the head? */ | |
1253 | obj->data = subbuf.head[0].iov_base; | |
1254 | if (subbuf.head[0].iov_len == obj->len) | |
1255 | return 0; | |
1256 | /* ..or is the obj contained entirely in the tail? */ | |
1257 | obj->data = subbuf.tail[0].iov_base; | |
1258 | if (subbuf.tail[0].iov_len == obj->len) | |
1259 | return 0; | |
1260 | ||
1261 | /* use end of tail as storage for obj: | |
1262 | * (We don't copy to the beginning because then we'd have | |
1263 | * to worry about doing a potentially overlapping copy. | |
1264 | * This assumes the object is at most half the length of the | |
1265 | * tail.) */ | |
1266 | if (obj->len > buf->buflen - buf->len) | |
1267 | return -ENOMEM; | |
1268 | if (buf->tail[0].iov_len != 0) | |
1269 | obj->data = buf->tail[0].iov_base + buf->tail[0].iov_len; | |
1270 | else | |
1271 | obj->data = buf->head[0].iov_base + buf->head[0].iov_len; | |
1272 | __read_bytes_from_xdr_buf(&subbuf, obj->data, obj->len); | |
1da177e4 | 1273 | return 0; |
1da177e4 | 1274 | } |
468039ee | 1275 | EXPORT_SYMBOL_GPL(xdr_buf_read_netobj); |
bd8100e7 AG |
1276 | |
1277 | /* Returns 0 on success, or else a negative error code. */ | |
1278 | static int | |
1279 | xdr_xcode_array2(struct xdr_buf *buf, unsigned int base, | |
1280 | struct xdr_array2_desc *desc, int encode) | |
1281 | { | |
1282 | char *elem = NULL, *c; | |
1283 | unsigned int copied = 0, todo, avail_here; | |
1284 | struct page **ppages = NULL; | |
1285 | int err; | |
1286 | ||
1287 | if (encode) { | |
1288 | if (xdr_encode_word(buf, base, desc->array_len) != 0) | |
1289 | return -EINVAL; | |
1290 | } else { | |
1291 | if (xdr_decode_word(buf, base, &desc->array_len) != 0 || | |
58fcb8df | 1292 | desc->array_len > desc->array_maxlen || |
bd8100e7 AG |
1293 | (unsigned long) base + 4 + desc->array_len * |
1294 | desc->elem_size > buf->len) | |
1295 | return -EINVAL; | |
1296 | } | |
1297 | base += 4; | |
1298 | ||
1299 | if (!desc->xcode) | |
1300 | return 0; | |
1301 | ||
1302 | todo = desc->array_len * desc->elem_size; | |
1303 | ||
1304 | /* process head */ | |
1305 | if (todo && base < buf->head->iov_len) { | |
1306 | c = buf->head->iov_base + base; | |
1307 | avail_here = min_t(unsigned int, todo, | |
1308 | buf->head->iov_len - base); | |
1309 | todo -= avail_here; | |
1310 | ||
1311 | while (avail_here >= desc->elem_size) { | |
1312 | err = desc->xcode(desc, c); | |
1313 | if (err) | |
1314 | goto out; | |
1315 | c += desc->elem_size; | |
1316 | avail_here -= desc->elem_size; | |
1317 | } | |
1318 | if (avail_here) { | |
1319 | if (!elem) { | |
1320 | elem = kmalloc(desc->elem_size, GFP_KERNEL); | |
1321 | err = -ENOMEM; | |
1322 | if (!elem) | |
1323 | goto out; | |
1324 | } | |
1325 | if (encode) { | |
1326 | err = desc->xcode(desc, elem); | |
1327 | if (err) | |
1328 | goto out; | |
1329 | memcpy(c, elem, avail_here); | |
1330 | } else | |
1331 | memcpy(elem, c, avail_here); | |
1332 | copied = avail_here; | |
1333 | } | |
1334 | base = buf->head->iov_len; /* align to start of pages */ | |
1335 | } | |
1336 | ||
1337 | /* process pages array */ | |
1338 | base -= buf->head->iov_len; | |
1339 | if (todo && base < buf->page_len) { | |
1340 | unsigned int avail_page; | |
1341 | ||
1342 | avail_here = min(todo, buf->page_len - base); | |
1343 | todo -= avail_here; | |
1344 | ||
1345 | base += buf->page_base; | |
09cbfeaf KS |
1346 | ppages = buf->pages + (base >> PAGE_SHIFT); |
1347 | base &= ~PAGE_MASK; | |
1348 | avail_page = min_t(unsigned int, PAGE_SIZE - base, | |
bd8100e7 AG |
1349 | avail_here); |
1350 | c = kmap(*ppages) + base; | |
1351 | ||
1352 | while (avail_here) { | |
1353 | avail_here -= avail_page; | |
1354 | if (copied || avail_page < desc->elem_size) { | |
1355 | unsigned int l = min(avail_page, | |
1356 | desc->elem_size - copied); | |
1357 | if (!elem) { | |
1358 | elem = kmalloc(desc->elem_size, | |
1359 | GFP_KERNEL); | |
1360 | err = -ENOMEM; | |
1361 | if (!elem) | |
1362 | goto out; | |
1363 | } | |
1364 | if (encode) { | |
1365 | if (!copied) { | |
1366 | err = desc->xcode(desc, elem); | |
1367 | if (err) | |
1368 | goto out; | |
1369 | } | |
1370 | memcpy(c, elem + copied, l); | |
1371 | copied += l; | |
1372 | if (copied == desc->elem_size) | |
1373 | copied = 0; | |
1374 | } else { | |
1375 | memcpy(elem + copied, c, l); | |
1376 | copied += l; | |
1377 | if (copied == desc->elem_size) { | |
1378 | err = desc->xcode(desc, elem); | |
1379 | if (err) | |
1380 | goto out; | |
1381 | copied = 0; | |
1382 | } | |
1383 | } | |
1384 | avail_page -= l; | |
1385 | c += l; | |
1386 | } | |
1387 | while (avail_page >= desc->elem_size) { | |
1388 | err = desc->xcode(desc, c); | |
1389 | if (err) | |
1390 | goto out; | |
1391 | c += desc->elem_size; | |
1392 | avail_page -= desc->elem_size; | |
1393 | } | |
1394 | if (avail_page) { | |
1395 | unsigned int l = min(avail_page, | |
1396 | desc->elem_size - copied); | |
1397 | if (!elem) { | |
1398 | elem = kmalloc(desc->elem_size, | |
1399 | GFP_KERNEL); | |
1400 | err = -ENOMEM; | |
1401 | if (!elem) | |
1402 | goto out; | |
1403 | } | |
1404 | if (encode) { | |
1405 | if (!copied) { | |
1406 | err = desc->xcode(desc, elem); | |
1407 | if (err) | |
1408 | goto out; | |
1409 | } | |
1410 | memcpy(c, elem + copied, l); | |
1411 | copied += l; | |
1412 | if (copied == desc->elem_size) | |
1413 | copied = 0; | |
1414 | } else { | |
1415 | memcpy(elem + copied, c, l); | |
1416 | copied += l; | |
1417 | if (copied == desc->elem_size) { | |
1418 | err = desc->xcode(desc, elem); | |
1419 | if (err) | |
1420 | goto out; | |
1421 | copied = 0; | |
1422 | } | |
1423 | } | |
1424 | } | |
1425 | if (avail_here) { | |
1426 | kunmap(*ppages); | |
1427 | ppages++; | |
1428 | c = kmap(*ppages); | |
1429 | } | |
1430 | ||
1431 | avail_page = min(avail_here, | |
09cbfeaf | 1432 | (unsigned int) PAGE_SIZE); |
bd8100e7 AG |
1433 | } |
1434 | base = buf->page_len; /* align to start of tail */ | |
1435 | } | |
1436 | ||
1437 | /* process tail */ | |
1438 | base -= buf->page_len; | |
1439 | if (todo) { | |
1440 | c = buf->tail->iov_base + base; | |
1441 | if (copied) { | |
1442 | unsigned int l = desc->elem_size - copied; | |
1443 | ||
1444 | if (encode) | |
1445 | memcpy(c, elem + copied, l); | |
1446 | else { | |
1447 | memcpy(elem + copied, c, l); | |
1448 | err = desc->xcode(desc, elem); | |
1449 | if (err) | |
1450 | goto out; | |
1451 | } | |
1452 | todo -= l; | |
1453 | c += l; | |
1454 | } | |
1455 | while (todo) { | |
1456 | err = desc->xcode(desc, c); | |
1457 | if (err) | |
1458 | goto out; | |
1459 | c += desc->elem_size; | |
1460 | todo -= desc->elem_size; | |
1461 | } | |
1462 | } | |
1463 | err = 0; | |
1464 | ||
1465 | out: | |
a51482bd | 1466 | kfree(elem); |
bd8100e7 AG |
1467 | if (ppages) |
1468 | kunmap(*ppages); | |
1469 | return err; | |
1470 | } | |
1471 | ||
1472 | int | |
1473 | xdr_decode_array2(struct xdr_buf *buf, unsigned int base, | |
1474 | struct xdr_array2_desc *desc) | |
1475 | { | |
1476 | if (base >= buf->len) | |
1477 | return -EINVAL; | |
1478 | ||
1479 | return xdr_xcode_array2(buf, base, desc, 0); | |
1480 | } | |
468039ee | 1481 | EXPORT_SYMBOL_GPL(xdr_decode_array2); |
bd8100e7 AG |
1482 | |
1483 | int | |
1484 | xdr_encode_array2(struct xdr_buf *buf, unsigned int base, | |
1485 | struct xdr_array2_desc *desc) | |
1486 | { | |
1487 | if ((unsigned long) base + 4 + desc->array_len * desc->elem_size > | |
1488 | buf->head->iov_len + buf->page_len + buf->tail->iov_len) | |
1489 | return -EINVAL; | |
1490 | ||
1491 | return xdr_xcode_array2(buf, base, desc, 1); | |
1492 | } | |
468039ee | 1493 | EXPORT_SYMBOL_GPL(xdr_encode_array2); |
37a4e6cb OK |
1494 | |
1495 | int | |
1496 | xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, | |
cca5172a | 1497 | int (*actor)(struct scatterlist *, void *), void *data) |
37a4e6cb OK |
1498 | { |
1499 | int i, ret = 0; | |
95c96174 | 1500 | unsigned int page_len, thislen, page_offset; |
37a4e6cb OK |
1501 | struct scatterlist sg[1]; |
1502 | ||
68e3f5dd HX |
1503 | sg_init_table(sg, 1); |
1504 | ||
37a4e6cb OK |
1505 | if (offset >= buf->head[0].iov_len) { |
1506 | offset -= buf->head[0].iov_len; | |
1507 | } else { | |
1508 | thislen = buf->head[0].iov_len - offset; | |
1509 | if (thislen > len) | |
1510 | thislen = len; | |
1511 | sg_set_buf(sg, buf->head[0].iov_base + offset, thislen); | |
1512 | ret = actor(sg, data); | |
1513 | if (ret) | |
1514 | goto out; | |
1515 | offset = 0; | |
1516 | len -= thislen; | |
1517 | } | |
1518 | if (len == 0) | |
1519 | goto out; | |
1520 | ||
1521 | if (offset >= buf->page_len) { | |
1522 | offset -= buf->page_len; | |
1523 | } else { | |
1524 | page_len = buf->page_len - offset; | |
1525 | if (page_len > len) | |
1526 | page_len = len; | |
1527 | len -= page_len; | |
09cbfeaf KS |
1528 | page_offset = (offset + buf->page_base) & (PAGE_SIZE - 1); |
1529 | i = (offset + buf->page_base) >> PAGE_SHIFT; | |
1530 | thislen = PAGE_SIZE - page_offset; | |
37a4e6cb OK |
1531 | do { |
1532 | if (thislen > page_len) | |
1533 | thislen = page_len; | |
642f1490 | 1534 | sg_set_page(sg, buf->pages[i], thislen, page_offset); |
37a4e6cb OK |
1535 | ret = actor(sg, data); |
1536 | if (ret) | |
1537 | goto out; | |
1538 | page_len -= thislen; | |
1539 | i++; | |
1540 | page_offset = 0; | |
09cbfeaf | 1541 | thislen = PAGE_SIZE; |
37a4e6cb OK |
1542 | } while (page_len != 0); |
1543 | offset = 0; | |
1544 | } | |
1545 | if (len == 0) | |
1546 | goto out; | |
1547 | if (offset < buf->tail[0].iov_len) { | |
1548 | thislen = buf->tail[0].iov_len - offset; | |
1549 | if (thislen > len) | |
1550 | thislen = len; | |
1551 | sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen); | |
1552 | ret = actor(sg, data); | |
1553 | len -= thislen; | |
1554 | } | |
1555 | if (len != 0) | |
1556 | ret = -EINVAL; | |
1557 | out: | |
1558 | return ret; | |
1559 | } | |
468039ee | 1560 | EXPORT_SYMBOL_GPL(xdr_process_buf); |
37a4e6cb | 1561 | |
0e779aa7 TM |
1562 | /** |
1563 | * xdr_stream_decode_opaque - Decode variable length opaque | |
1564 | * @xdr: pointer to xdr_stream | |
1565 | * @ptr: location to store opaque data | |
1566 | * @size: size of storage buffer @ptr | |
1567 | * | |
1568 | * Return values: | |
1569 | * On success, returns size of object stored in *@ptr | |
1570 | * %-EBADMSG on XDR buffer overflow | |
1571 | * %-EMSGSIZE on overflow of storage buffer @ptr | |
1572 | */ | |
1573 | ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr, size_t size) | |
1574 | { | |
1575 | ssize_t ret; | |
1576 | void *p; | |
1577 | ||
1578 | ret = xdr_stream_decode_opaque_inline(xdr, &p, size); | |
1579 | if (ret <= 0) | |
1580 | return ret; | |
1581 | memcpy(ptr, p, ret); | |
1582 | return ret; | |
1583 | } | |
1584 | EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque); | |
1585 | ||
1586 | /** | |
1587 | * xdr_stream_decode_opaque_dup - Decode and duplicate variable length opaque | |
1588 | * @xdr: pointer to xdr_stream | |
1589 | * @ptr: location to store pointer to opaque data | |
1590 | * @maxlen: maximum acceptable object size | |
1591 | * @gfp_flags: GFP mask to use | |
1592 | * | |
1593 | * Return values: | |
1594 | * On success, returns size of object stored in *@ptr | |
1595 | * %-EBADMSG on XDR buffer overflow | |
1596 | * %-EMSGSIZE if the size of the object would exceed @maxlen | |
1597 | * %-ENOMEM on memory allocation failure | |
1598 | */ | |
1599 | ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr, | |
1600 | size_t maxlen, gfp_t gfp_flags) | |
1601 | { | |
1602 | ssize_t ret; | |
1603 | void *p; | |
1604 | ||
1605 | ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen); | |
1606 | if (ret > 0) { | |
1607 | *ptr = kmemdup(p, ret, gfp_flags); | |
1608 | if (*ptr != NULL) | |
1609 | return ret; | |
1610 | ret = -ENOMEM; | |
1611 | } | |
1612 | *ptr = NULL; | |
1613 | return ret; | |
1614 | } | |
1615 | EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque_dup); | |
1616 | ||
1617 | /** | |
1618 | * xdr_stream_decode_string - Decode variable length string | |
1619 | * @xdr: pointer to xdr_stream | |
1620 | * @str: location to store string | |
1621 | * @size: size of storage buffer @str | |
1622 | * | |
1623 | * Return values: | |
1624 | * On success, returns length of NUL-terminated string stored in *@str | |
1625 | * %-EBADMSG on XDR buffer overflow | |
1626 | * %-EMSGSIZE on overflow of storage buffer @str | |
1627 | */ | |
1628 | ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str, size_t size) | |
1629 | { | |
1630 | ssize_t ret; | |
1631 | void *p; | |
1632 | ||
1633 | ret = xdr_stream_decode_opaque_inline(xdr, &p, size); | |
1634 | if (ret > 0) { | |
1635 | memcpy(str, p, ret); | |
1636 | str[ret] = '\0'; | |
1637 | return strlen(str); | |
1638 | } | |
1639 | *str = '\0'; | |
1640 | return ret; | |
1641 | } | |
1642 | EXPORT_SYMBOL_GPL(xdr_stream_decode_string); | |
1643 | ||
5c741d4f TM |
1644 | /** |
1645 | * xdr_stream_decode_string_dup - Decode and duplicate variable length string | |
1646 | * @xdr: pointer to xdr_stream | |
1647 | * @str: location to store pointer to string | |
1648 | * @maxlen: maximum acceptable string length | |
1649 | * @gfp_flags: GFP mask to use | |
1650 | * | |
1651 | * Return values: | |
1652 | * On success, returns length of NUL-terminated string stored in *@ptr | |
1653 | * %-EBADMSG on XDR buffer overflow | |
1654 | * %-EMSGSIZE if the size of the string would exceed @maxlen | |
1655 | * %-ENOMEM on memory allocation failure | |
1656 | */ | |
1657 | ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str, | |
1658 | size_t maxlen, gfp_t gfp_flags) | |
1659 | { | |
1660 | void *p; | |
1661 | ssize_t ret; | |
1662 | ||
1663 | ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen); | |
1664 | if (ret > 0) { | |
1665 | char *s = kmalloc(ret + 1, gfp_flags); | |
1666 | if (s != NULL) { | |
1667 | memcpy(s, p, ret); | |
1668 | s[ret] = '\0'; | |
1669 | *str = s; | |
1670 | return strlen(s); | |
1671 | } | |
1672 | ret = -ENOMEM; | |
1673 | } | |
1674 | *str = NULL; | |
1675 | return ret; | |
1676 | } | |
1677 | EXPORT_SYMBOL_GPL(xdr_stream_decode_string_dup); |