Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/net/sunrpc/xdr.c | |
3 | * | |
4 | * Generic XDR support. | |
5 | * | |
6 | * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> | |
7 | */ | |
8 | ||
a246b010 | 9 | #include <linux/module.h> |
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> | |
9d96acbc | 18 | #include <linux/bvec.h> |
5582863f | 19 | #include <trace/events/sunrpc.h> |
1da177e4 LT |
20 | |
21 | /* | |
22 | * XDR functions for basic NFS types | |
23 | */ | |
d8ed029d AD |
24 | __be32 * |
25 | xdr_encode_netobj(__be32 *p, const struct xdr_netobj *obj) | |
1da177e4 LT |
26 | { |
27 | unsigned int quadlen = XDR_QUADLEN(obj->len); | |
28 | ||
29 | p[quadlen] = 0; /* zero trailing bytes */ | |
9f162d2a | 30 | *p++ = cpu_to_be32(obj->len); |
1da177e4 LT |
31 | memcpy(p, obj->data, obj->len); |
32 | return p + XDR_QUADLEN(obj->len); | |
33 | } | |
468039ee | 34 | EXPORT_SYMBOL_GPL(xdr_encode_netobj); |
1da177e4 | 35 | |
d8ed029d AD |
36 | __be32 * |
37 | xdr_decode_netobj(__be32 *p, struct xdr_netobj *obj) | |
1da177e4 LT |
38 | { |
39 | unsigned int len; | |
40 | ||
98866b5a | 41 | if ((len = be32_to_cpu(*p++)) > XDR_MAX_NETOBJ) |
1da177e4 LT |
42 | return NULL; |
43 | obj->len = len; | |
44 | obj->data = (u8 *) p; | |
45 | return p + XDR_QUADLEN(len); | |
46 | } | |
468039ee | 47 | EXPORT_SYMBOL_GPL(xdr_decode_netobj); |
1da177e4 LT |
48 | |
49 | /** | |
50 | * xdr_encode_opaque_fixed - Encode fixed length opaque data | |
4dc3b16b PP |
51 | * @p: pointer to current position in XDR buffer. |
52 | * @ptr: pointer to data to encode (or NULL) | |
53 | * @nbytes: size of data. | |
1da177e4 LT |
54 | * |
55 | * Copy the array of data of length nbytes at ptr to the XDR buffer | |
56 | * at position p, then align to the next 32-bit boundary by padding | |
57 | * with zero bytes (see RFC1832). | |
58 | * Note: if ptr is NULL, only the padding is performed. | |
59 | * | |
60 | * Returns the updated current XDR buffer position | |
61 | * | |
62 | */ | |
d8ed029d | 63 | __be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int nbytes) |
1da177e4 LT |
64 | { |
65 | if (likely(nbytes != 0)) { | |
66 | unsigned int quadlen = XDR_QUADLEN(nbytes); | |
67 | unsigned int padding = (quadlen << 2) - nbytes; | |
68 | ||
69 | if (ptr != NULL) | |
70 | memcpy(p, ptr, nbytes); | |
71 | if (padding != 0) | |
72 | memset((char *)p + nbytes, 0, padding); | |
73 | p += quadlen; | |
74 | } | |
75 | return p; | |
76 | } | |
468039ee | 77 | EXPORT_SYMBOL_GPL(xdr_encode_opaque_fixed); |
1da177e4 LT |
78 | |
79 | /** | |
80 | * xdr_encode_opaque - Encode variable length opaque data | |
4dc3b16b PP |
81 | * @p: pointer to current position in XDR buffer. |
82 | * @ptr: pointer to data to encode (or NULL) | |
83 | * @nbytes: size of data. | |
1da177e4 LT |
84 | * |
85 | * Returns the updated current XDR buffer position | |
86 | */ | |
d8ed029d | 87 | __be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int nbytes) |
1da177e4 | 88 | { |
9f162d2a | 89 | *p++ = cpu_to_be32(nbytes); |
1da177e4 LT |
90 | return xdr_encode_opaque_fixed(p, ptr, nbytes); |
91 | } | |
468039ee | 92 | EXPORT_SYMBOL_GPL(xdr_encode_opaque); |
1da177e4 | 93 | |
d8ed029d AD |
94 | __be32 * |
95 | xdr_encode_string(__be32 *p, const char *string) | |
1da177e4 LT |
96 | { |
97 | return xdr_encode_array(p, string, strlen(string)); | |
98 | } | |
468039ee | 99 | EXPORT_SYMBOL_GPL(xdr_encode_string); |
1da177e4 | 100 | |
d8ed029d | 101 | __be32 * |
e5cff482 CL |
102 | xdr_decode_string_inplace(__be32 *p, char **sp, |
103 | unsigned int *lenp, unsigned int maxlen) | |
1da177e4 | 104 | { |
e5cff482 | 105 | u32 len; |
1da177e4 | 106 | |
98866b5a | 107 | len = be32_to_cpu(*p++); |
e5cff482 | 108 | if (len > maxlen) |
1da177e4 LT |
109 | return NULL; |
110 | *lenp = len; | |
111 | *sp = (char *) p; | |
112 | return p + XDR_QUADLEN(len); | |
113 | } | |
468039ee | 114 | EXPORT_SYMBOL_GPL(xdr_decode_string_inplace); |
1da177e4 | 115 | |
b4687da7 CL |
116 | /** |
117 | * xdr_terminate_string - '\0'-terminate a string residing in an xdr_buf | |
118 | * @buf: XDR buffer where string resides | |
119 | * @len: length of string, in bytes | |
120 | * | |
121 | */ | |
122 | void | |
123 | xdr_terminate_string(struct xdr_buf *buf, const u32 len) | |
124 | { | |
125 | char *kaddr; | |
126 | ||
b8541786 | 127 | kaddr = kmap_atomic(buf->pages[0]); |
b4687da7 | 128 | kaddr[buf->page_base + len] = '\0'; |
b8541786 | 129 | kunmap_atomic(kaddr); |
b4687da7 | 130 | } |
0d961aa9 | 131 | EXPORT_SYMBOL_GPL(xdr_terminate_string); |
b4687da7 | 132 | |
9d96acbc TM |
133 | size_t |
134 | xdr_buf_pagecount(struct xdr_buf *buf) | |
135 | { | |
136 | if (!buf->page_len) | |
137 | return 0; | |
138 | return (buf->page_base + buf->page_len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
139 | } | |
140 | ||
141 | int | |
142 | xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp) | |
143 | { | |
144 | size_t i, n = xdr_buf_pagecount(buf); | |
145 | ||
146 | if (n != 0 && buf->bvec == NULL) { | |
147 | buf->bvec = kmalloc_array(n, sizeof(buf->bvec[0]), gfp); | |
148 | if (!buf->bvec) | |
149 | return -ENOMEM; | |
150 | for (i = 0; i < n; i++) { | |
151 | buf->bvec[i].bv_page = buf->pages[i]; | |
152 | buf->bvec[i].bv_len = PAGE_SIZE; | |
153 | buf->bvec[i].bv_offset = 0; | |
154 | } | |
155 | } | |
156 | return 0; | |
157 | } | |
158 | ||
159 | void | |
160 | xdr_free_bvec(struct xdr_buf *buf) | |
161 | { | |
162 | kfree(buf->bvec); | |
163 | buf->bvec = NULL; | |
164 | } | |
165 | ||
1da177e4 LT |
166 | void |
167 | xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset, | |
168 | struct page **pages, unsigned int base, unsigned int len) | |
169 | { | |
170 | struct kvec *head = xdr->head; | |
171 | struct kvec *tail = xdr->tail; | |
172 | char *buf = (char *)head->iov_base; | |
173 | unsigned int buflen = head->iov_len; | |
174 | ||
175 | head->iov_len = offset; | |
176 | ||
177 | xdr->pages = pages; | |
178 | xdr->page_base = base; | |
179 | xdr->page_len = len; | |
180 | ||
181 | tail->iov_base = buf + offset; | |
182 | tail->iov_len = buflen - offset; | |
183 | ||
184 | xdr->buflen += len; | |
185 | } | |
468039ee | 186 | EXPORT_SYMBOL_GPL(xdr_inline_pages); |
1da177e4 | 187 | |
1da177e4 LT |
188 | /* |
189 | * Helper routines for doing 'memmove' like operations on a struct xdr_buf | |
2c53040f BH |
190 | */ |
191 | ||
192 | /** | |
1da177e4 LT |
193 | * _shift_data_right_pages |
194 | * @pages: vector of pages containing both the source and dest memory area. | |
195 | * @pgto_base: page vector address of destination | |
196 | * @pgfrom_base: page vector address of source | |
197 | * @len: number of bytes to copy | |
198 | * | |
199 | * Note: the addresses pgto_base and pgfrom_base are both calculated in | |
200 | * the same way: | |
201 | * if a memory area starts at byte 'base' in page 'pages[i]', | |
ea1754a0 | 202 | * then its address is given as (i << PAGE_SHIFT) + base |
1da177e4 LT |
203 | * Also note: pgfrom_base must be < pgto_base, but the memory areas |
204 | * they point to may overlap. | |
205 | */ | |
206 | static void | |
207 | _shift_data_right_pages(struct page **pages, size_t pgto_base, | |
208 | size_t pgfrom_base, size_t len) | |
209 | { | |
210 | struct page **pgfrom, **pgto; | |
211 | char *vfrom, *vto; | |
212 | size_t copy; | |
213 | ||
214 | BUG_ON(pgto_base <= pgfrom_base); | |
215 | ||
216 | pgto_base += len; | |
217 | pgfrom_base += len; | |
218 | ||
09cbfeaf KS |
219 | pgto = pages + (pgto_base >> PAGE_SHIFT); |
220 | pgfrom = pages + (pgfrom_base >> PAGE_SHIFT); | |
1da177e4 | 221 | |
09cbfeaf KS |
222 | pgto_base &= ~PAGE_MASK; |
223 | pgfrom_base &= ~PAGE_MASK; | |
1da177e4 LT |
224 | |
225 | do { | |
226 | /* Are any pointers crossing a page boundary? */ | |
227 | if (pgto_base == 0) { | |
09cbfeaf | 228 | pgto_base = PAGE_SIZE; |
1da177e4 LT |
229 | pgto--; |
230 | } | |
231 | if (pgfrom_base == 0) { | |
09cbfeaf | 232 | pgfrom_base = PAGE_SIZE; |
1da177e4 LT |
233 | pgfrom--; |
234 | } | |
235 | ||
236 | copy = len; | |
237 | if (copy > pgto_base) | |
238 | copy = pgto_base; | |
239 | if (copy > pgfrom_base) | |
240 | copy = pgfrom_base; | |
241 | pgto_base -= copy; | |
242 | pgfrom_base -= copy; | |
243 | ||
b8541786 | 244 | vto = kmap_atomic(*pgto); |
347e2233 TM |
245 | if (*pgto != *pgfrom) { |
246 | vfrom = kmap_atomic(*pgfrom); | |
247 | memcpy(vto + pgto_base, vfrom + pgfrom_base, copy); | |
248 | kunmap_atomic(vfrom); | |
249 | } else | |
250 | memmove(vto + pgto_base, vto + pgfrom_base, copy); | |
bce3481c | 251 | flush_dcache_page(*pgto); |
b8541786 | 252 | kunmap_atomic(vto); |
1da177e4 LT |
253 | |
254 | } while ((len -= copy) != 0); | |
1da177e4 LT |
255 | } |
256 | ||
2c53040f | 257 | /** |
1da177e4 LT |
258 | * _copy_to_pages |
259 | * @pages: array of pages | |
260 | * @pgbase: page vector address of destination | |
261 | * @p: pointer to source data | |
262 | * @len: length | |
263 | * | |
264 | * Copies data from an arbitrary memory location into an array of pages | |
265 | * The copy is assumed to be non-overlapping. | |
266 | */ | |
267 | static void | |
268 | _copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len) | |
269 | { | |
270 | struct page **pgto; | |
271 | char *vto; | |
272 | size_t copy; | |
273 | ||
09cbfeaf KS |
274 | pgto = pages + (pgbase >> PAGE_SHIFT); |
275 | pgbase &= ~PAGE_MASK; | |
1da177e4 | 276 | |
daeba89d | 277 | for (;;) { |
09cbfeaf | 278 | copy = PAGE_SIZE - pgbase; |
1da177e4 LT |
279 | if (copy > len) |
280 | copy = len; | |
281 | ||
b8541786 | 282 | vto = kmap_atomic(*pgto); |
1da177e4 | 283 | memcpy(vto + pgbase, p, copy); |
b8541786 | 284 | kunmap_atomic(vto); |
1da177e4 | 285 | |
daeba89d TM |
286 | len -= copy; |
287 | if (len == 0) | |
288 | break; | |
289 | ||
1da177e4 | 290 | pgbase += copy; |
09cbfeaf | 291 | if (pgbase == PAGE_SIZE) { |
1da177e4 LT |
292 | flush_dcache_page(*pgto); |
293 | pgbase = 0; | |
294 | pgto++; | |
295 | } | |
296 | p += copy; | |
daeba89d | 297 | } |
1da177e4 LT |
298 | flush_dcache_page(*pgto); |
299 | } | |
300 | ||
2c53040f | 301 | /** |
1da177e4 LT |
302 | * _copy_from_pages |
303 | * @p: pointer to destination | |
304 | * @pages: array of pages | |
305 | * @pgbase: offset of source data | |
306 | * @len: length | |
307 | * | |
308 | * Copies data into an arbitrary memory location from an array of pages | |
309 | * The copy is assumed to be non-overlapping. | |
310 | */ | |
bf118a34 | 311 | void |
1da177e4 LT |
312 | _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len) |
313 | { | |
314 | struct page **pgfrom; | |
315 | char *vfrom; | |
316 | size_t copy; | |
317 | ||
09cbfeaf KS |
318 | pgfrom = pages + (pgbase >> PAGE_SHIFT); |
319 | pgbase &= ~PAGE_MASK; | |
1da177e4 LT |
320 | |
321 | do { | |
09cbfeaf | 322 | copy = PAGE_SIZE - pgbase; |
1da177e4 LT |
323 | if (copy > len) |
324 | copy = len; | |
325 | ||
b8541786 | 326 | vfrom = kmap_atomic(*pgfrom); |
1da177e4 | 327 | memcpy(p, vfrom + pgbase, copy); |
b8541786 | 328 | kunmap_atomic(vfrom); |
1da177e4 LT |
329 | |
330 | pgbase += copy; | |
09cbfeaf | 331 | if (pgbase == PAGE_SIZE) { |
1da177e4 LT |
332 | pgbase = 0; |
333 | pgfrom++; | |
334 | } | |
335 | p += copy; | |
336 | ||
337 | } while ((len -= copy) != 0); | |
338 | } | |
bf118a34 | 339 | EXPORT_SYMBOL_GPL(_copy_from_pages); |
1da177e4 | 340 | |
2c53040f | 341 | /** |
1da177e4 LT |
342 | * xdr_shrink_bufhead |
343 | * @buf: xdr_buf | |
344 | * @len: bytes to remove from buf->head[0] | |
345 | * | |
cca5172a | 346 | * Shrinks XDR buffer's header kvec buf->head[0] by |
1da177e4 LT |
347 | * 'len' bytes. The extra data is not lost, but is instead |
348 | * moved into the inlined pages and/or the tail. | |
349 | */ | |
7be9cea3 | 350 | static unsigned int |
1da177e4 LT |
351 | xdr_shrink_bufhead(struct xdr_buf *buf, size_t len) |
352 | { | |
353 | struct kvec *head, *tail; | |
354 | size_t copy, offs; | |
355 | unsigned int pglen = buf->page_len; | |
7be9cea3 | 356 | unsigned int result; |
1da177e4 | 357 | |
7be9cea3 | 358 | result = 0; |
1da177e4 LT |
359 | tail = buf->tail; |
360 | head = buf->head; | |
18e624ad WAA |
361 | |
362 | WARN_ON_ONCE(len > head->iov_len); | |
363 | if (len > head->iov_len) | |
364 | len = head->iov_len; | |
1da177e4 LT |
365 | |
366 | /* Shift the tail first */ | |
367 | if (tail->iov_len != 0) { | |
368 | if (tail->iov_len > len) { | |
369 | copy = tail->iov_len - len; | |
370 | memmove((char *)tail->iov_base + len, | |
371 | tail->iov_base, copy); | |
7be9cea3 | 372 | result += copy; |
1da177e4 LT |
373 | } |
374 | /* Copy from the inlined pages into the tail */ | |
375 | copy = len; | |
376 | if (copy > pglen) | |
377 | copy = pglen; | |
378 | offs = len - copy; | |
379 | if (offs >= tail->iov_len) | |
380 | copy = 0; | |
381 | else if (copy > tail->iov_len - offs) | |
382 | copy = tail->iov_len - offs; | |
7be9cea3 | 383 | if (copy != 0) { |
1da177e4 LT |
384 | _copy_from_pages((char *)tail->iov_base + offs, |
385 | buf->pages, | |
386 | buf->page_base + pglen + offs - len, | |
387 | copy); | |
7be9cea3 CL |
388 | result += copy; |
389 | } | |
1da177e4 LT |
390 | /* Do we also need to copy data from the head into the tail ? */ |
391 | if (len > pglen) { | |
392 | offs = copy = len - pglen; | |
393 | if (copy > tail->iov_len) | |
394 | copy = tail->iov_len; | |
395 | memcpy(tail->iov_base, | |
396 | (char *)head->iov_base + | |
397 | head->iov_len - offs, | |
398 | copy); | |
7be9cea3 | 399 | result += copy; |
1da177e4 LT |
400 | } |
401 | } | |
402 | /* Now handle pages */ | |
403 | if (pglen != 0) { | |
404 | if (pglen > len) | |
405 | _shift_data_right_pages(buf->pages, | |
406 | buf->page_base + len, | |
407 | buf->page_base, | |
408 | pglen - len); | |
409 | copy = len; | |
410 | if (len > pglen) | |
411 | copy = pglen; | |
412 | _copy_to_pages(buf->pages, buf->page_base, | |
413 | (char *)head->iov_base + head->iov_len - len, | |
414 | copy); | |
7be9cea3 | 415 | result += copy; |
1da177e4 LT |
416 | } |
417 | head->iov_len -= len; | |
418 | buf->buflen -= len; | |
419 | /* Have we truncated the message? */ | |
420 | if (buf->len > buf->buflen) | |
421 | buf->len = buf->buflen; | |
7be9cea3 CL |
422 | |
423 | return result; | |
1da177e4 LT |
424 | } |
425 | ||
2c53040f | 426 | /** |
1da177e4 LT |
427 | * xdr_shrink_pagelen |
428 | * @buf: xdr_buf | |
429 | * @len: bytes to remove from buf->pages | |
430 | * | |
cca5172a | 431 | * Shrinks XDR buffer's page array buf->pages by |
1da177e4 LT |
432 | * 'len' bytes. The extra data is not lost, but is instead |
433 | * moved into the tail. | |
434 | */ | |
7be9cea3 | 435 | static unsigned int |
1da177e4 LT |
436 | xdr_shrink_pagelen(struct xdr_buf *buf, size_t len) |
437 | { | |
438 | struct kvec *tail; | |
439 | size_t copy; | |
1da177e4 | 440 | unsigned int pglen = buf->page_len; |
cf187c2d | 441 | unsigned int tailbuf_len; |
7be9cea3 | 442 | unsigned int result; |
1da177e4 | 443 | |
7be9cea3 | 444 | result = 0; |
1da177e4 LT |
445 | tail = buf->tail; |
446 | BUG_ON (len > pglen); | |
447 | ||
cf187c2d TM |
448 | tailbuf_len = buf->buflen - buf->head->iov_len - buf->page_len; |
449 | ||
1da177e4 | 450 | /* Shift the tail first */ |
cf187c2d TM |
451 | if (tailbuf_len != 0) { |
452 | unsigned int free_space = tailbuf_len - tail->iov_len; | |
453 | ||
454 | if (len < free_space) | |
455 | free_space = len; | |
456 | tail->iov_len += free_space; | |
457 | ||
42d6d8ab | 458 | copy = len; |
1da177e4 | 459 | if (tail->iov_len > len) { |
0fe62a35 | 460 | char *p = (char *)tail->iov_base + len; |
2e29ebb8 | 461 | memmove(p, tail->iov_base, tail->iov_len - len); |
7be9cea3 | 462 | result += tail->iov_len - len; |
42d6d8ab | 463 | } else |
1da177e4 | 464 | copy = tail->iov_len; |
42d6d8ab | 465 | /* Copy from the inlined pages into the tail */ |
1da177e4 LT |
466 | _copy_from_pages((char *)tail->iov_base, |
467 | buf->pages, buf->page_base + pglen - len, | |
468 | copy); | |
7be9cea3 | 469 | result += copy; |
1da177e4 LT |
470 | } |
471 | buf->page_len -= len; | |
472 | buf->buflen -= len; | |
473 | /* Have we truncated the message? */ | |
474 | if (buf->len > buf->buflen) | |
475 | buf->len = buf->buflen; | |
7be9cea3 CL |
476 | |
477 | return result; | |
1da177e4 LT |
478 | } |
479 | ||
480 | void | |
481 | xdr_shift_buf(struct xdr_buf *buf, size_t len) | |
482 | { | |
483 | xdr_shrink_bufhead(buf, len); | |
484 | } | |
468039ee | 485 | EXPORT_SYMBOL_GPL(xdr_shift_buf); |
1da177e4 | 486 | |
4517d526 TM |
487 | /** |
488 | * xdr_stream_pos - Return the current offset from the start of the xdr_stream | |
489 | * @xdr: pointer to struct xdr_stream | |
490 | */ | |
491 | unsigned int xdr_stream_pos(const struct xdr_stream *xdr) | |
492 | { | |
493 | return (unsigned int)(XDR_QUADLEN(xdr->buf->len) - xdr->nwords) << 2; | |
494 | } | |
495 | EXPORT_SYMBOL_GPL(xdr_stream_pos); | |
496 | ||
1da177e4 LT |
497 | /** |
498 | * xdr_init_encode - Initialize a struct xdr_stream for sending data. | |
499 | * @xdr: pointer to xdr_stream struct | |
500 | * @buf: pointer to XDR buffer in which to encode data | |
501 | * @p: current pointer inside XDR buffer | |
0ccc61b1 | 502 | * @rqst: pointer to controlling rpc_rqst, for debugging |
1da177e4 LT |
503 | * |
504 | * Note: at the moment the RPC client only passes the length of our | |
505 | * scratch buffer in the xdr_buf's header kvec. Previously this | |
506 | * meant we needed to call xdr_adjust_iovec() after encoding the | |
507 | * data. With the new scheme, the xdr_stream manages the details | |
508 | * of the buffer length, and takes care of adjusting the kvec | |
509 | * length for us. | |
510 | */ | |
0ccc61b1 CL |
511 | void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p, |
512 | struct rpc_rqst *rqst) | |
1da177e4 LT |
513 | { |
514 | struct kvec *iov = buf->head; | |
334ccfd5 | 515 | int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len; |
1da177e4 | 516 | |
2825a7f9 | 517 | xdr_set_scratch_buffer(xdr, NULL, 0); |
334ccfd5 | 518 | BUG_ON(scratch_len < 0); |
1da177e4 LT |
519 | xdr->buf = buf; |
520 | xdr->iov = iov; | |
d8ed029d AD |
521 | xdr->p = (__be32 *)((char *)iov->iov_base + iov->iov_len); |
522 | xdr->end = (__be32 *)((char *)iov->iov_base + scratch_len); | |
334ccfd5 TM |
523 | BUG_ON(iov->iov_len > scratch_len); |
524 | ||
525 | if (p != xdr->p && p != NULL) { | |
526 | size_t len; | |
527 | ||
528 | BUG_ON(p < xdr->p || p > xdr->end); | |
529 | len = (char *)p - (char *)xdr->p; | |
530 | xdr->p = p; | |
531 | buf->len += len; | |
532 | iov->iov_len += len; | |
533 | } | |
0ccc61b1 | 534 | xdr->rqst = rqst; |
1da177e4 | 535 | } |
468039ee | 536 | EXPORT_SYMBOL_GPL(xdr_init_encode); |
1da177e4 | 537 | |
2825a7f9 BF |
538 | /** |
539 | * xdr_commit_encode - Ensure all data is written to buffer | |
540 | * @xdr: pointer to xdr_stream | |
541 | * | |
542 | * We handle encoding across page boundaries by giving the caller a | |
543 | * temporary location to write to, then later copying the data into | |
544 | * place; xdr_commit_encode does that copying. | |
545 | * | |
546 | * Normally the caller doesn't need to call this directly, as the | |
547 | * following xdr_reserve_space will do it. But an explicit call may be | |
548 | * required at the end of encoding, or any other time when the xdr_buf | |
549 | * data might be read. | |
550 | */ | |
551 | void xdr_commit_encode(struct xdr_stream *xdr) | |
552 | { | |
553 | int shift = xdr->scratch.iov_len; | |
554 | void *page; | |
555 | ||
556 | if (shift == 0) | |
557 | return; | |
558 | page = page_address(*xdr->page_ptr); | |
559 | memcpy(xdr->scratch.iov_base, page, shift); | |
560 | memmove(page, page + shift, (void *)xdr->p - page); | |
561 | xdr->scratch.iov_len = 0; | |
562 | } | |
563 | EXPORT_SYMBOL_GPL(xdr_commit_encode); | |
564 | ||
22cb4385 TM |
565 | static __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr, |
566 | size_t nbytes) | |
2825a7f9 | 567 | { |
025911a5 | 568 | __be32 *p; |
2825a7f9 BF |
569 | int space_left; |
570 | int frag1bytes, frag2bytes; | |
571 | ||
572 | if (nbytes > PAGE_SIZE) | |
5582863f | 573 | goto out_overflow; /* Bigger buffers require special handling */ |
2825a7f9 | 574 | if (xdr->buf->len + nbytes > xdr->buf->buflen) |
5582863f | 575 | goto out_overflow; /* Sorry, we're totally out of space */ |
2825a7f9 BF |
576 | frag1bytes = (xdr->end - xdr->p) << 2; |
577 | frag2bytes = nbytes - frag1bytes; | |
578 | if (xdr->iov) | |
579 | xdr->iov->iov_len += frag1bytes; | |
05638dc7 | 580 | else |
2825a7f9 | 581 | xdr->buf->page_len += frag1bytes; |
05638dc7 | 582 | xdr->page_ptr++; |
2825a7f9 BF |
583 | xdr->iov = NULL; |
584 | /* | |
585 | * If the last encode didn't end exactly on a page boundary, the | |
586 | * next one will straddle boundaries. Encode into the next | |
587 | * page, then copy it back later in xdr_commit_encode. We use | |
588 | * the "scratch" iov to track any temporarily unused fragment of | |
589 | * space at the end of the previous buffer: | |
590 | */ | |
591 | xdr->scratch.iov_base = xdr->p; | |
592 | xdr->scratch.iov_len = frag1bytes; | |
593 | p = page_address(*xdr->page_ptr); | |
594 | /* | |
595 | * Note this is where the next encode will start after we've | |
596 | * shifted this one back: | |
597 | */ | |
598 | xdr->p = (void *)p + frag2bytes; | |
599 | space_left = xdr->buf->buflen - xdr->buf->len; | |
600 | xdr->end = (void *)p + min_t(int, space_left, PAGE_SIZE); | |
601 | xdr->buf->page_len += frag2bytes; | |
602 | xdr->buf->len += nbytes; | |
603 | return p; | |
5582863f CL |
604 | out_overflow: |
605 | trace_rpc_xdr_overflow(xdr, nbytes); | |
606 | return NULL; | |
2825a7f9 BF |
607 | } |
608 | ||
1da177e4 LT |
609 | /** |
610 | * xdr_reserve_space - Reserve buffer space for sending | |
611 | * @xdr: pointer to xdr_stream | |
612 | * @nbytes: number of bytes to reserve | |
613 | * | |
614 | * Checks that we have enough buffer space to encode 'nbytes' more | |
615 | * bytes of data. If so, update the total xdr_buf length, and | |
616 | * adjust the length of the current kvec. | |
617 | */ | |
d8ed029d | 618 | __be32 * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes) |
1da177e4 | 619 | { |
d8ed029d AD |
620 | __be32 *p = xdr->p; |
621 | __be32 *q; | |
1da177e4 | 622 | |
2825a7f9 | 623 | xdr_commit_encode(xdr); |
1da177e4 LT |
624 | /* align nbytes on the next 32-bit boundary */ |
625 | nbytes += 3; | |
626 | nbytes &= ~3; | |
627 | q = p + (nbytes >> 2); | |
628 | if (unlikely(q > xdr->end || q < p)) | |
2825a7f9 | 629 | return xdr_get_next_encode_buffer(xdr, nbytes); |
1da177e4 | 630 | xdr->p = q; |
2825a7f9 BF |
631 | if (xdr->iov) |
632 | xdr->iov->iov_len += nbytes; | |
633 | else | |
634 | xdr->buf->page_len += nbytes; | |
1da177e4 LT |
635 | xdr->buf->len += nbytes; |
636 | return p; | |
637 | } | |
468039ee | 638 | EXPORT_SYMBOL_GPL(xdr_reserve_space); |
1da177e4 | 639 | |
3e19ce76 BF |
640 | /** |
641 | * xdr_truncate_encode - truncate an encode buffer | |
642 | * @xdr: pointer to xdr_stream | |
643 | * @len: new length of buffer | |
644 | * | |
645 | * Truncates the xdr stream, so that xdr->buf->len == len, | |
646 | * and xdr->p points at offset len from the start of the buffer, and | |
647 | * head, tail, and page lengths are adjusted to correspond. | |
648 | * | |
649 | * If this means moving xdr->p to a different buffer, we assume that | |
650 | * that the end pointer should be set to the end of the current page, | |
651 | * except in the case of the head buffer when we assume the head | |
652 | * buffer's current length represents the end of the available buffer. | |
653 | * | |
654 | * This is *not* safe to use on a buffer that already has inlined page | |
655 | * cache pages (as in a zero-copy server read reply), except for the | |
656 | * simple case of truncating from one position in the tail to another. | |
657 | * | |
658 | */ | |
659 | void xdr_truncate_encode(struct xdr_stream *xdr, size_t len) | |
660 | { | |
661 | struct xdr_buf *buf = xdr->buf; | |
662 | struct kvec *head = buf->head; | |
663 | struct kvec *tail = buf->tail; | |
664 | int fraglen; | |
49a068f8 | 665 | int new; |
3e19ce76 BF |
666 | |
667 | if (len > buf->len) { | |
668 | WARN_ON_ONCE(1); | |
669 | return; | |
670 | } | |
2825a7f9 | 671 | xdr_commit_encode(xdr); |
3e19ce76 BF |
672 | |
673 | fraglen = min_t(int, buf->len - len, tail->iov_len); | |
674 | tail->iov_len -= fraglen; | |
675 | buf->len -= fraglen; | |
ed38c069 | 676 | if (tail->iov_len) { |
3e19ce76 | 677 | xdr->p = tail->iov_base + tail->iov_len; |
280caac0 BF |
678 | WARN_ON_ONCE(!xdr->end); |
679 | WARN_ON_ONCE(!xdr->iov); | |
3e19ce76 BF |
680 | return; |
681 | } | |
682 | WARN_ON_ONCE(fraglen); | |
683 | fraglen = min_t(int, buf->len - len, buf->page_len); | |
684 | buf->page_len -= fraglen; | |
685 | buf->len -= fraglen; | |
686 | ||
687 | new = buf->page_base + buf->page_len; | |
49a068f8 BF |
688 | |
689 | xdr->page_ptr = buf->pages + (new >> PAGE_SHIFT); | |
3e19ce76 | 690 | |
ed38c069 | 691 | if (buf->page_len) { |
3e19ce76 BF |
692 | xdr->p = page_address(*xdr->page_ptr); |
693 | xdr->end = (void *)xdr->p + PAGE_SIZE; | |
694 | xdr->p = (void *)xdr->p + (new % PAGE_SIZE); | |
280caac0 | 695 | WARN_ON_ONCE(xdr->iov); |
3e19ce76 BF |
696 | return; |
697 | } | |
5d7a5bcb | 698 | if (fraglen) |
3e19ce76 BF |
699 | xdr->end = head->iov_base + head->iov_len; |
700 | /* (otherwise assume xdr->end is already set) */ | |
5d7a5bcb | 701 | xdr->page_ptr--; |
3e19ce76 BF |
702 | head->iov_len = len; |
703 | buf->len = len; | |
704 | xdr->p = head->iov_base + head->iov_len; | |
705 | xdr->iov = buf->head; | |
706 | } | |
707 | EXPORT_SYMBOL(xdr_truncate_encode); | |
708 | ||
db3f58a9 BF |
709 | /** |
710 | * xdr_restrict_buflen - decrease available buffer space | |
711 | * @xdr: pointer to xdr_stream | |
712 | * @newbuflen: new maximum number of bytes available | |
713 | * | |
714 | * Adjust our idea of how much space is available in the buffer. | |
715 | * If we've already used too much space in the buffer, returns -1. | |
716 | * If the available space is already smaller than newbuflen, returns 0 | |
717 | * and does nothing. Otherwise, adjusts xdr->buf->buflen to newbuflen | |
718 | * and ensures xdr->end is set at most offset newbuflen from the start | |
719 | * of the buffer. | |
720 | */ | |
721 | int xdr_restrict_buflen(struct xdr_stream *xdr, int newbuflen) | |
722 | { | |
723 | struct xdr_buf *buf = xdr->buf; | |
724 | int left_in_this_buf = (void *)xdr->end - (void *)xdr->p; | |
725 | int end_offset = buf->len + left_in_this_buf; | |
726 | ||
727 | if (newbuflen < 0 || newbuflen < buf->len) | |
728 | return -1; | |
729 | if (newbuflen > buf->buflen) | |
730 | return 0; | |
731 | if (newbuflen < end_offset) | |
732 | xdr->end = (void *)xdr->end + newbuflen - end_offset; | |
733 | buf->buflen = newbuflen; | |
734 | return 0; | |
735 | } | |
736 | EXPORT_SYMBOL(xdr_restrict_buflen); | |
737 | ||
1da177e4 LT |
738 | /** |
739 | * xdr_write_pages - Insert a list of pages into an XDR buffer for sending | |
740 | * @xdr: pointer to xdr_stream | |
741 | * @pages: list of pages | |
742 | * @base: offset of first byte | |
743 | * @len: length of data in bytes | |
744 | * | |
745 | */ | |
746 | void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base, | |
747 | unsigned int len) | |
748 | { | |
749 | struct xdr_buf *buf = xdr->buf; | |
750 | struct kvec *iov = buf->tail; | |
751 | buf->pages = pages; | |
752 | buf->page_base = base; | |
753 | buf->page_len = len; | |
754 | ||
755 | iov->iov_base = (char *)xdr->p; | |
756 | iov->iov_len = 0; | |
757 | xdr->iov = iov; | |
758 | ||
759 | if (len & 3) { | |
760 | unsigned int pad = 4 - (len & 3); | |
761 | ||
762 | BUG_ON(xdr->p >= xdr->end); | |
763 | iov->iov_base = (char *)xdr->p + (len & 3); | |
764 | iov->iov_len += pad; | |
765 | len += pad; | |
766 | *xdr->p++ = 0; | |
767 | } | |
768 | buf->buflen += len; | |
769 | buf->len += len; | |
770 | } | |
468039ee | 771 | EXPORT_SYMBOL_GPL(xdr_write_pages); |
1da177e4 | 772 | |
6650239a | 773 | static void xdr_set_iov(struct xdr_stream *xdr, struct kvec *iov, |
1537693c | 774 | unsigned int len) |
6650239a TM |
775 | { |
776 | if (len > iov->iov_len) | |
777 | len = iov->iov_len; | |
1537693c | 778 | xdr->p = (__be32*)iov->iov_base; |
6650239a TM |
779 | xdr->end = (__be32*)(iov->iov_base + len); |
780 | xdr->iov = iov; | |
781 | xdr->page_ptr = NULL; | |
782 | } | |
783 | ||
784 | static int xdr_set_page_base(struct xdr_stream *xdr, | |
785 | unsigned int base, unsigned int len) | |
786 | { | |
787 | unsigned int pgnr; | |
788 | unsigned int maxlen; | |
789 | unsigned int pgoff; | |
790 | unsigned int pgend; | |
791 | void *kaddr; | |
792 | ||
793 | maxlen = xdr->buf->page_len; | |
794 | if (base >= maxlen) | |
795 | return -EINVAL; | |
796 | maxlen -= base; | |
797 | if (len > maxlen) | |
798 | len = maxlen; | |
799 | ||
800 | base += xdr->buf->page_base; | |
801 | ||
802 | pgnr = base >> PAGE_SHIFT; | |
803 | xdr->page_ptr = &xdr->buf->pages[pgnr]; | |
804 | kaddr = page_address(*xdr->page_ptr); | |
805 | ||
806 | pgoff = base & ~PAGE_MASK; | |
807 | xdr->p = (__be32*)(kaddr + pgoff); | |
808 | ||
809 | pgend = pgoff + len; | |
810 | if (pgend > PAGE_SIZE) | |
811 | pgend = PAGE_SIZE; | |
812 | xdr->end = (__be32*)(kaddr + pgend); | |
813 | xdr->iov = NULL; | |
814 | return 0; | |
815 | } | |
816 | ||
817 | static void xdr_set_next_page(struct xdr_stream *xdr) | |
818 | { | |
819 | unsigned int newbase; | |
820 | ||
821 | newbase = (1 + xdr->page_ptr - xdr->buf->pages) << PAGE_SHIFT; | |
822 | newbase -= xdr->buf->page_base; | |
823 | ||
824 | if (xdr_set_page_base(xdr, newbase, PAGE_SIZE) < 0) | |
a6cebd41 | 825 | xdr_set_iov(xdr, xdr->buf->tail, xdr->nwords << 2); |
6650239a TM |
826 | } |
827 | ||
828 | static bool xdr_set_next_buffer(struct xdr_stream *xdr) | |
829 | { | |
830 | if (xdr->page_ptr != NULL) | |
831 | xdr_set_next_page(xdr); | |
832 | else if (xdr->iov == xdr->buf->head) { | |
833 | if (xdr_set_page_base(xdr, 0, PAGE_SIZE) < 0) | |
a6cebd41 | 834 | xdr_set_iov(xdr, xdr->buf->tail, xdr->nwords << 2); |
6650239a TM |
835 | } |
836 | return xdr->p != xdr->end; | |
837 | } | |
838 | ||
1da177e4 LT |
839 | /** |
840 | * xdr_init_decode - Initialize an xdr_stream for decoding data. | |
841 | * @xdr: pointer to xdr_stream struct | |
842 | * @buf: pointer to XDR buffer from which to decode data | |
843 | * @p: current pointer inside XDR buffer | |
0ccc61b1 | 844 | * @rqst: pointer to controlling rpc_rqst, for debugging |
1da177e4 | 845 | */ |
0ccc61b1 CL |
846 | void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p, |
847 | struct rpc_rqst *rqst) | |
1da177e4 | 848 | { |
1da177e4 | 849 | xdr->buf = buf; |
6650239a TM |
850 | xdr->scratch.iov_base = NULL; |
851 | xdr->scratch.iov_len = 0; | |
bfeea1dc | 852 | xdr->nwords = XDR_QUADLEN(buf->len); |
6650239a | 853 | if (buf->head[0].iov_len != 0) |
1537693c | 854 | xdr_set_iov(xdr, buf->head, buf->len); |
6650239a TM |
855 | else if (buf->page_len != 0) |
856 | xdr_set_page_base(xdr, 0, buf->len); | |
06ef26a0 BC |
857 | else |
858 | xdr_set_iov(xdr, buf->head, buf->len); | |
bfeea1dc TM |
859 | if (p != NULL && p > xdr->p && xdr->end >= p) { |
860 | xdr->nwords -= p - xdr->p; | |
1537693c | 861 | xdr->p = p; |
bfeea1dc | 862 | } |
0ccc61b1 | 863 | xdr->rqst = rqst; |
1da177e4 | 864 | } |
468039ee | 865 | EXPORT_SYMBOL_GPL(xdr_init_decode); |
1da177e4 | 866 | |
f7da7a12 | 867 | /** |
7ecce75f | 868 | * xdr_init_decode_pages - Initialize an xdr_stream for decoding into pages |
f7da7a12 BH |
869 | * @xdr: pointer to xdr_stream struct |
870 | * @buf: pointer to XDR buffer from which to decode data | |
871 | * @pages: list of pages to decode into | |
872 | * @len: length in bytes of buffer in pages | |
873 | */ | |
874 | void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf, | |
875 | struct page **pages, unsigned int len) | |
876 | { | |
877 | memset(buf, 0, sizeof(*buf)); | |
878 | buf->pages = pages; | |
879 | buf->page_len = len; | |
880 | buf->buflen = len; | |
881 | buf->len = len; | |
0ccc61b1 | 882 | xdr_init_decode(xdr, buf, NULL, NULL); |
f7da7a12 BH |
883 | } |
884 | EXPORT_SYMBOL_GPL(xdr_init_decode_pages); | |
885 | ||
6650239a | 886 | static __be32 * __xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes) |
ba8e452a | 887 | { |
bfeea1dc | 888 | unsigned int nwords = XDR_QUADLEN(nbytes); |
ba8e452a | 889 | __be32 *p = xdr->p; |
bfeea1dc | 890 | __be32 *q = p + nwords; |
ba8e452a | 891 | |
bfeea1dc | 892 | if (unlikely(nwords > xdr->nwords || q > xdr->end || q < p)) |
ba8e452a | 893 | return NULL; |
6650239a | 894 | xdr->p = q; |
bfeea1dc | 895 | xdr->nwords -= nwords; |
ba8e452a TM |
896 | return p; |
897 | } | |
ba8e452a | 898 | |
1da177e4 | 899 | /** |
6650239a TM |
900 | * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data. |
901 | * @xdr: pointer to xdr_stream struct | |
902 | * @buf: pointer to an empty buffer | |
903 | * @buflen: size of 'buf' | |
904 | * | |
905 | * The scratch buffer is used when decoding from an array of pages. | |
906 | * If an xdr_inline_decode() call spans across page boundaries, then | |
907 | * we copy the data into the scratch buffer in order to allow linear | |
908 | * access. | |
909 | */ | |
910 | void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen) | |
911 | { | |
912 | xdr->scratch.iov_base = buf; | |
913 | xdr->scratch.iov_len = buflen; | |
914 | } | |
915 | EXPORT_SYMBOL_GPL(xdr_set_scratch_buffer); | |
916 | ||
917 | static __be32 *xdr_copy_to_scratch(struct xdr_stream *xdr, size_t nbytes) | |
918 | { | |
919 | __be32 *p; | |
ace0e14f | 920 | char *cpdest = xdr->scratch.iov_base; |
6650239a TM |
921 | size_t cplen = (char *)xdr->end - (char *)xdr->p; |
922 | ||
923 | if (nbytes > xdr->scratch.iov_len) | |
5582863f | 924 | goto out_overflow; |
ace0e14f TM |
925 | p = __xdr_inline_decode(xdr, cplen); |
926 | if (p == NULL) | |
927 | return NULL; | |
928 | memcpy(cpdest, p, cplen); | |
5582863f CL |
929 | if (!xdr_set_next_buffer(xdr)) |
930 | goto out_overflow; | |
6650239a TM |
931 | cpdest += cplen; |
932 | nbytes -= cplen; | |
6650239a TM |
933 | p = __xdr_inline_decode(xdr, nbytes); |
934 | if (p == NULL) | |
935 | return NULL; | |
936 | memcpy(cpdest, p, nbytes); | |
937 | return xdr->scratch.iov_base; | |
5582863f CL |
938 | out_overflow: |
939 | trace_rpc_xdr_overflow(xdr, nbytes); | |
940 | return NULL; | |
6650239a TM |
941 | } |
942 | ||
943 | /** | |
944 | * xdr_inline_decode - Retrieve XDR data to decode | |
1da177e4 LT |
945 | * @xdr: pointer to xdr_stream struct |
946 | * @nbytes: number of bytes of data to decode | |
947 | * | |
948 | * Check if the input buffer is long enough to enable us to decode | |
949 | * 'nbytes' more bytes of data starting at the current position. | |
950 | * If so return the current pointer, then update the current | |
951 | * pointer position. | |
952 | */ | |
d8ed029d | 953 | __be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes) |
1da177e4 | 954 | { |
6650239a | 955 | __be32 *p; |
1da177e4 | 956 | |
5582863f | 957 | if (unlikely(nbytes == 0)) |
6650239a TM |
958 | return xdr->p; |
959 | if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr)) | |
5582863f | 960 | goto out_overflow; |
6650239a TM |
961 | p = __xdr_inline_decode(xdr, nbytes); |
962 | if (p != NULL) | |
963 | return p; | |
964 | return xdr_copy_to_scratch(xdr, nbytes); | |
5582863f CL |
965 | out_overflow: |
966 | trace_rpc_xdr_overflow(xdr, nbytes); | |
967 | return NULL; | |
1da177e4 | 968 | } |
468039ee | 969 | EXPORT_SYMBOL_GPL(xdr_inline_decode); |
1da177e4 | 970 | |
3994ee6f | 971 | static unsigned int xdr_align_pages(struct xdr_stream *xdr, unsigned int len) |
1da177e4 LT |
972 | { |
973 | struct xdr_buf *buf = xdr->buf; | |
974 | struct kvec *iov; | |
bfeea1dc | 975 | unsigned int nwords = XDR_QUADLEN(len); |
b760b313 | 976 | unsigned int cur = xdr_stream_pos(xdr); |
7be9cea3 | 977 | unsigned int copied, offset; |
1da177e4 | 978 | |
bfeea1dc | 979 | if (xdr->nwords == 0) |
c337d365 | 980 | return 0; |
7be9cea3 | 981 | |
1da177e4 | 982 | /* Realign pages to current pointer position */ |
7be9cea3 | 983 | iov = buf->head; |
a11a2bf4 | 984 | if (iov->iov_len > cur) { |
7be9cea3 CL |
985 | offset = iov->iov_len - cur; |
986 | copied = xdr_shrink_bufhead(buf, offset); | |
987 | trace_rpc_xdr_alignment(xdr, offset, copied); | |
a11a2bf4 TM |
988 | xdr->nwords = XDR_QUADLEN(buf->len - cur); |
989 | } | |
1da177e4 | 990 | |
a11a2bf4 TM |
991 | if (nwords > xdr->nwords) { |
992 | nwords = xdr->nwords; | |
993 | len = nwords << 2; | |
994 | } | |
995 | if (buf->page_len <= len) | |
8a9a8b83 | 996 | len = buf->page_len; |
a11a2bf4 TM |
997 | else if (nwords < xdr->nwords) { |
998 | /* Truncate page data and move it into the tail */ | |
7be9cea3 CL |
999 | offset = buf->page_len - len; |
1000 | copied = xdr_shrink_pagelen(buf, offset); | |
1001 | trace_rpc_xdr_alignment(xdr, offset, copied); | |
a11a2bf4 TM |
1002 | xdr->nwords = XDR_QUADLEN(buf->len - cur); |
1003 | } | |
3994ee6f TM |
1004 | return len; |
1005 | } | |
bd00f84b | 1006 | |
1da177e4 LT |
1007 | /** |
1008 | * xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position | |
1009 | * @xdr: pointer to xdr_stream struct | |
1010 | * @len: number of bytes of page data | |
1011 | * | |
1012 | * Moves data beyond the current pointer position from the XDR head[] buffer | |
1013 | * into the page list. Any data that lies beyond current position + "len" | |
8b23ea7b | 1014 | * bytes is moved into the XDR tail[]. |
3994ee6f TM |
1015 | * |
1016 | * Returns the number of XDR encoded bytes now contained in the pages | |
1da177e4 | 1017 | */ |
3994ee6f | 1018 | unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len) |
1da177e4 LT |
1019 | { |
1020 | struct xdr_buf *buf = xdr->buf; | |
1021 | struct kvec *iov; | |
3994ee6f | 1022 | unsigned int nwords; |
1da177e4 | 1023 | unsigned int end; |
3994ee6f | 1024 | unsigned int padding; |
1da177e4 | 1025 | |
3994ee6f TM |
1026 | len = xdr_align_pages(xdr, len); |
1027 | if (len == 0) | |
1028 | return 0; | |
1029 | nwords = XDR_QUADLEN(len); | |
bfeea1dc | 1030 | padding = (nwords << 2) - len; |
1da177e4 LT |
1031 | xdr->iov = iov = buf->tail; |
1032 | /* Compute remaining message length. */ | |
bd00f84b TM |
1033 | end = ((xdr->nwords - nwords) << 2) + padding; |
1034 | if (end > iov->iov_len) | |
1035 | end = iov->iov_len; | |
1036 | ||
1da177e4 LT |
1037 | /* |
1038 | * Position current pointer at beginning of tail, and | |
1039 | * set remaining message length. | |
1040 | */ | |
d8ed029d AD |
1041 | xdr->p = (__be32 *)((char *)iov->iov_base + padding); |
1042 | xdr->end = (__be32 *)((char *)iov->iov_base + end); | |
76cacaab | 1043 | xdr->page_ptr = NULL; |
bfeea1dc | 1044 | xdr->nwords = XDR_QUADLEN(end - padding); |
c337d365 | 1045 | return len; |
1da177e4 | 1046 | } |
468039ee | 1047 | EXPORT_SYMBOL_GPL(xdr_read_pages); |
1da177e4 | 1048 | |
8b23ea7b TM |
1049 | /** |
1050 | * xdr_enter_page - decode data from the XDR page | |
1051 | * @xdr: pointer to xdr_stream struct | |
1052 | * @len: number of bytes of page data | |
1053 | * | |
1054 | * Moves data beyond the current pointer position from the XDR head[] buffer | |
1055 | * into the page list. Any data that lies beyond current position + "len" | |
1056 | * bytes is moved into the XDR tail[]. The current pointer is then | |
1057 | * repositioned at the beginning of the first XDR page. | |
1058 | */ | |
1059 | void xdr_enter_page(struct xdr_stream *xdr, unsigned int len) | |
1060 | { | |
f8bb7f08 | 1061 | len = xdr_align_pages(xdr, len); |
8b23ea7b TM |
1062 | /* |
1063 | * Position current pointer at beginning of tail, and | |
1064 | * set remaining message length. | |
1065 | */ | |
f8bb7f08 TM |
1066 | if (len != 0) |
1067 | xdr_set_page_base(xdr, 0, len); | |
8b23ea7b | 1068 | } |
468039ee | 1069 | EXPORT_SYMBOL_GPL(xdr_enter_page); |
8b23ea7b | 1070 | |
1da177e4 LT |
1071 | static struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0}; |
1072 | ||
1073 | void | |
1074 | xdr_buf_from_iov(struct kvec *iov, struct xdr_buf *buf) | |
1075 | { | |
1076 | buf->head[0] = *iov; | |
1077 | buf->tail[0] = empty_iov; | |
1078 | buf->page_len = 0; | |
1079 | buf->buflen = buf->len = iov->iov_len; | |
1080 | } | |
468039ee | 1081 | EXPORT_SYMBOL_GPL(xdr_buf_from_iov); |
1da177e4 | 1082 | |
de4aee2e BF |
1083 | /** |
1084 | * xdr_buf_subsegment - set subbuf to a portion of buf | |
1085 | * @buf: an xdr buffer | |
1086 | * @subbuf: the result buffer | |
1087 | * @base: beginning of range in bytes | |
1088 | * @len: length of range in bytes | |
1089 | * | |
1090 | * sets @subbuf to an xdr buffer representing the portion of @buf of | |
1091 | * length @len starting at offset @base. | |
1092 | * | |
1093 | * @buf and @subbuf may be pointers to the same struct xdr_buf. | |
1094 | * | |
1095 | * Returns -1 if base of length are out of bounds. | |
1096 | */ | |
1da177e4 LT |
1097 | int |
1098 | xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf, | |
1e78957e | 1099 | unsigned int base, unsigned int len) |
1da177e4 | 1100 | { |
1da177e4 | 1101 | subbuf->buflen = subbuf->len = len; |
1e78957e TM |
1102 | if (base < buf->head[0].iov_len) { |
1103 | subbuf->head[0].iov_base = buf->head[0].iov_base + base; | |
1104 | subbuf->head[0].iov_len = min_t(unsigned int, len, | |
1105 | buf->head[0].iov_len - base); | |
1106 | len -= subbuf->head[0].iov_len; | |
1107 | base = 0; | |
1108 | } else { | |
1e78957e | 1109 | base -= buf->head[0].iov_len; |
de4aee2e | 1110 | subbuf->head[0].iov_len = 0; |
1e78957e | 1111 | } |
1da177e4 LT |
1112 | |
1113 | if (base < buf->page_len) { | |
1e78957e TM |
1114 | subbuf->page_len = min(buf->page_len - base, len); |
1115 | base += buf->page_base; | |
09cbfeaf KS |
1116 | subbuf->page_base = base & ~PAGE_MASK; |
1117 | subbuf->pages = &buf->pages[base >> PAGE_SHIFT]; | |
1da177e4 LT |
1118 | len -= subbuf->page_len; |
1119 | base = 0; | |
1120 | } else { | |
1121 | base -= buf->page_len; | |
1122 | subbuf->page_len = 0; | |
1123 | } | |
1124 | ||
1e78957e TM |
1125 | if (base < buf->tail[0].iov_len) { |
1126 | subbuf->tail[0].iov_base = buf->tail[0].iov_base + base; | |
1127 | subbuf->tail[0].iov_len = min_t(unsigned int, len, | |
1128 | buf->tail[0].iov_len - base); | |
1129 | len -= subbuf->tail[0].iov_len; | |
1130 | base = 0; | |
1131 | } else { | |
1e78957e | 1132 | base -= buf->tail[0].iov_len; |
de4aee2e | 1133 | subbuf->tail[0].iov_len = 0; |
1e78957e TM |
1134 | } |
1135 | ||
1da177e4 LT |
1136 | if (base || len) |
1137 | return -1; | |
1138 | return 0; | |
1139 | } | |
468039ee | 1140 | EXPORT_SYMBOL_GPL(xdr_buf_subsegment); |
1da177e4 | 1141 | |
4c190e2f JL |
1142 | /** |
1143 | * xdr_buf_trim - lop at most "len" bytes off the end of "buf" | |
1144 | * @buf: buf to be trimmed | |
1145 | * @len: number of bytes to reduce "buf" by | |
1146 | * | |
1147 | * Trim an xdr_buf by the given number of bytes by fixing up the lengths. Note | |
1148 | * that it's possible that we'll trim less than that amount if the xdr_buf is | |
1149 | * too small, or if (for instance) it's all in the head and the parser has | |
1150 | * already read too far into it. | |
1151 | */ | |
1152 | void xdr_buf_trim(struct xdr_buf *buf, unsigned int len) | |
1153 | { | |
1154 | size_t cur; | |
1155 | unsigned int trim = len; | |
1156 | ||
1157 | if (buf->tail[0].iov_len) { | |
1158 | cur = min_t(size_t, buf->tail[0].iov_len, trim); | |
1159 | buf->tail[0].iov_len -= cur; | |
1160 | trim -= cur; | |
1161 | if (!trim) | |
1162 | goto fix_len; | |
1163 | } | |
1164 | ||
1165 | if (buf->page_len) { | |
1166 | cur = min_t(unsigned int, buf->page_len, trim); | |
1167 | buf->page_len -= cur; | |
1168 | trim -= cur; | |
1169 | if (!trim) | |
1170 | goto fix_len; | |
1171 | } | |
1172 | ||
1173 | if (buf->head[0].iov_len) { | |
1174 | cur = min_t(size_t, buf->head[0].iov_len, trim); | |
1175 | buf->head[0].iov_len -= cur; | |
1176 | trim -= cur; | |
1177 | } | |
1178 | fix_len: | |
1179 | buf->len -= (len - trim); | |
1180 | } | |
1181 | EXPORT_SYMBOL_GPL(xdr_buf_trim); | |
1182 | ||
4e3e43ad | 1183 | static void __read_bytes_from_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len) |
1da177e4 | 1184 | { |
1e78957e | 1185 | unsigned int this_len; |
1da177e4 | 1186 | |
4e3e43ad TM |
1187 | this_len = min_t(unsigned int, len, subbuf->head[0].iov_len); |
1188 | memcpy(obj, subbuf->head[0].iov_base, this_len); | |
1da177e4 LT |
1189 | len -= this_len; |
1190 | obj += this_len; | |
4e3e43ad | 1191 | this_len = min_t(unsigned int, len, subbuf->page_len); |
1da177e4 | 1192 | if (this_len) |
4e3e43ad | 1193 | _copy_from_pages(obj, subbuf->pages, subbuf->page_base, this_len); |
1da177e4 LT |
1194 | len -= this_len; |
1195 | obj += this_len; | |
4e3e43ad TM |
1196 | this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len); |
1197 | memcpy(obj, subbuf->tail[0].iov_base, this_len); | |
1da177e4 LT |
1198 | } |
1199 | ||
bd8100e7 | 1200 | /* obj is assumed to point to allocated memory of size at least len: */ |
4e3e43ad | 1201 | int read_bytes_from_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len) |
bd8100e7 AG |
1202 | { |
1203 | struct xdr_buf subbuf; | |
bd8100e7 AG |
1204 | int status; |
1205 | ||
1206 | status = xdr_buf_subsegment(buf, &subbuf, base, len); | |
4e3e43ad TM |
1207 | if (status != 0) |
1208 | return status; | |
1209 | __read_bytes_from_xdr_buf(&subbuf, obj, len); | |
1210 | return 0; | |
1211 | } | |
468039ee | 1212 | EXPORT_SYMBOL_GPL(read_bytes_from_xdr_buf); |
4e3e43ad TM |
1213 | |
1214 | static void __write_bytes_to_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len) | |
1215 | { | |
1216 | unsigned int this_len; | |
1217 | ||
1218 | this_len = min_t(unsigned int, len, subbuf->head[0].iov_len); | |
1219 | memcpy(subbuf->head[0].iov_base, obj, this_len); | |
bd8100e7 AG |
1220 | len -= this_len; |
1221 | obj += this_len; | |
4e3e43ad | 1222 | this_len = min_t(unsigned int, len, subbuf->page_len); |
bd8100e7 | 1223 | if (this_len) |
4e3e43ad | 1224 | _copy_to_pages(subbuf->pages, subbuf->page_base, obj, this_len); |
bd8100e7 AG |
1225 | len -= this_len; |
1226 | obj += this_len; | |
4e3e43ad TM |
1227 | this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len); |
1228 | memcpy(subbuf->tail[0].iov_base, obj, this_len); | |
1229 | } | |
1230 | ||
1231 | /* obj is assumed to point to allocated memory of size at least len: */ | |
1232 | int write_bytes_to_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len) | |
1233 | { | |
1234 | struct xdr_buf subbuf; | |
1235 | int status; | |
1236 | ||
1237 | status = xdr_buf_subsegment(buf, &subbuf, base, len); | |
1238 | if (status != 0) | |
1239 | return status; | |
1240 | __write_bytes_to_xdr_buf(&subbuf, obj, len); | |
1241 | return 0; | |
bd8100e7 | 1242 | } |
c43abaed | 1243 | EXPORT_SYMBOL_GPL(write_bytes_to_xdr_buf); |
bd8100e7 AG |
1244 | |
1245 | int | |
1e78957e | 1246 | xdr_decode_word(struct xdr_buf *buf, unsigned int base, u32 *obj) |
1da177e4 | 1247 | { |
d8ed029d | 1248 | __be32 raw; |
1da177e4 LT |
1249 | int status; |
1250 | ||
1251 | status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj)); | |
1252 | if (status) | |
1253 | return status; | |
98866b5a | 1254 | *obj = be32_to_cpu(raw); |
1da177e4 LT |
1255 | return 0; |
1256 | } | |
468039ee | 1257 | EXPORT_SYMBOL_GPL(xdr_decode_word); |
1da177e4 | 1258 | |
bd8100e7 | 1259 | int |
1e78957e | 1260 | xdr_encode_word(struct xdr_buf *buf, unsigned int base, u32 obj) |
bd8100e7 | 1261 | { |
9f162d2a | 1262 | __be32 raw = cpu_to_be32(obj); |
bd8100e7 AG |
1263 | |
1264 | return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj)); | |
1265 | } | |
468039ee | 1266 | EXPORT_SYMBOL_GPL(xdr_encode_word); |
bd8100e7 | 1267 | |
1da177e4 LT |
1268 | /* If the netobj starting offset bytes from the start of xdr_buf is contained |
1269 | * entirely in the head or the tail, set object to point to it; otherwise | |
1270 | * try to find space for it at the end of the tail, copy it there, and | |
1271 | * set obj to point to it. */ | |
bee57c99 | 1272 | int xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, unsigned int offset) |
1da177e4 | 1273 | { |
bee57c99 | 1274 | struct xdr_buf subbuf; |
1da177e4 | 1275 | |
bd8100e7 | 1276 | if (xdr_decode_word(buf, offset, &obj->len)) |
bee57c99 TM |
1277 | return -EFAULT; |
1278 | if (xdr_buf_subsegment(buf, &subbuf, offset + 4, obj->len)) | |
1279 | return -EFAULT; | |
1280 | ||
1281 | /* Is the obj contained entirely in the head? */ | |
1282 | obj->data = subbuf.head[0].iov_base; | |
1283 | if (subbuf.head[0].iov_len == obj->len) | |
1284 | return 0; | |
1285 | /* ..or is the obj contained entirely in the tail? */ | |
1286 | obj->data = subbuf.tail[0].iov_base; | |
1287 | if (subbuf.tail[0].iov_len == obj->len) | |
1288 | return 0; | |
1289 | ||
1290 | /* use end of tail as storage for obj: | |
1291 | * (We don't copy to the beginning because then we'd have | |
1292 | * to worry about doing a potentially overlapping copy. | |
1293 | * This assumes the object is at most half the length of the | |
1294 | * tail.) */ | |
1295 | if (obj->len > buf->buflen - buf->len) | |
1296 | return -ENOMEM; | |
1297 | if (buf->tail[0].iov_len != 0) | |
1298 | obj->data = buf->tail[0].iov_base + buf->tail[0].iov_len; | |
1299 | else | |
1300 | obj->data = buf->head[0].iov_base + buf->head[0].iov_len; | |
1301 | __read_bytes_from_xdr_buf(&subbuf, obj->data, obj->len); | |
1da177e4 | 1302 | return 0; |
1da177e4 | 1303 | } |
468039ee | 1304 | EXPORT_SYMBOL_GPL(xdr_buf_read_netobj); |
bd8100e7 AG |
1305 | |
1306 | /* Returns 0 on success, or else a negative error code. */ | |
1307 | static int | |
1308 | xdr_xcode_array2(struct xdr_buf *buf, unsigned int base, | |
1309 | struct xdr_array2_desc *desc, int encode) | |
1310 | { | |
1311 | char *elem = NULL, *c; | |
1312 | unsigned int copied = 0, todo, avail_here; | |
1313 | struct page **ppages = NULL; | |
1314 | int err; | |
1315 | ||
1316 | if (encode) { | |
1317 | if (xdr_encode_word(buf, base, desc->array_len) != 0) | |
1318 | return -EINVAL; | |
1319 | } else { | |
1320 | if (xdr_decode_word(buf, base, &desc->array_len) != 0 || | |
58fcb8df | 1321 | desc->array_len > desc->array_maxlen || |
bd8100e7 AG |
1322 | (unsigned long) base + 4 + desc->array_len * |
1323 | desc->elem_size > buf->len) | |
1324 | return -EINVAL; | |
1325 | } | |
1326 | base += 4; | |
1327 | ||
1328 | if (!desc->xcode) | |
1329 | return 0; | |
1330 | ||
1331 | todo = desc->array_len * desc->elem_size; | |
1332 | ||
1333 | /* process head */ | |
1334 | if (todo && base < buf->head->iov_len) { | |
1335 | c = buf->head->iov_base + base; | |
1336 | avail_here = min_t(unsigned int, todo, | |
1337 | buf->head->iov_len - base); | |
1338 | todo -= avail_here; | |
1339 | ||
1340 | while (avail_here >= desc->elem_size) { | |
1341 | err = desc->xcode(desc, c); | |
1342 | if (err) | |
1343 | goto out; | |
1344 | c += desc->elem_size; | |
1345 | avail_here -= desc->elem_size; | |
1346 | } | |
1347 | if (avail_here) { | |
1348 | if (!elem) { | |
1349 | elem = kmalloc(desc->elem_size, GFP_KERNEL); | |
1350 | err = -ENOMEM; | |
1351 | if (!elem) | |
1352 | goto out; | |
1353 | } | |
1354 | if (encode) { | |
1355 | err = desc->xcode(desc, elem); | |
1356 | if (err) | |
1357 | goto out; | |
1358 | memcpy(c, elem, avail_here); | |
1359 | } else | |
1360 | memcpy(elem, c, avail_here); | |
1361 | copied = avail_here; | |
1362 | } | |
1363 | base = buf->head->iov_len; /* align to start of pages */ | |
1364 | } | |
1365 | ||
1366 | /* process pages array */ | |
1367 | base -= buf->head->iov_len; | |
1368 | if (todo && base < buf->page_len) { | |
1369 | unsigned int avail_page; | |
1370 | ||
1371 | avail_here = min(todo, buf->page_len - base); | |
1372 | todo -= avail_here; | |
1373 | ||
1374 | base += buf->page_base; | |
09cbfeaf KS |
1375 | ppages = buf->pages + (base >> PAGE_SHIFT); |
1376 | base &= ~PAGE_MASK; | |
1377 | avail_page = min_t(unsigned int, PAGE_SIZE - base, | |
bd8100e7 AG |
1378 | avail_here); |
1379 | c = kmap(*ppages) + base; | |
1380 | ||
1381 | while (avail_here) { | |
1382 | avail_here -= avail_page; | |
1383 | if (copied || avail_page < desc->elem_size) { | |
1384 | unsigned int l = min(avail_page, | |
1385 | desc->elem_size - copied); | |
1386 | if (!elem) { | |
1387 | elem = kmalloc(desc->elem_size, | |
1388 | GFP_KERNEL); | |
1389 | err = -ENOMEM; | |
1390 | if (!elem) | |
1391 | goto out; | |
1392 | } | |
1393 | if (encode) { | |
1394 | if (!copied) { | |
1395 | err = desc->xcode(desc, elem); | |
1396 | if (err) | |
1397 | goto out; | |
1398 | } | |
1399 | memcpy(c, elem + copied, l); | |
1400 | copied += l; | |
1401 | if (copied == desc->elem_size) | |
1402 | copied = 0; | |
1403 | } else { | |
1404 | memcpy(elem + copied, c, l); | |
1405 | copied += l; | |
1406 | if (copied == desc->elem_size) { | |
1407 | err = desc->xcode(desc, elem); | |
1408 | if (err) | |
1409 | goto out; | |
1410 | copied = 0; | |
1411 | } | |
1412 | } | |
1413 | avail_page -= l; | |
1414 | c += l; | |
1415 | } | |
1416 | while (avail_page >= desc->elem_size) { | |
1417 | err = desc->xcode(desc, c); | |
1418 | if (err) | |
1419 | goto out; | |
1420 | c += desc->elem_size; | |
1421 | avail_page -= desc->elem_size; | |
1422 | } | |
1423 | if (avail_page) { | |
1424 | unsigned int l = min(avail_page, | |
1425 | desc->elem_size - copied); | |
1426 | if (!elem) { | |
1427 | elem = kmalloc(desc->elem_size, | |
1428 | GFP_KERNEL); | |
1429 | err = -ENOMEM; | |
1430 | if (!elem) | |
1431 | goto out; | |
1432 | } | |
1433 | if (encode) { | |
1434 | if (!copied) { | |
1435 | err = desc->xcode(desc, elem); | |
1436 | if (err) | |
1437 | goto out; | |
1438 | } | |
1439 | memcpy(c, elem + copied, l); | |
1440 | copied += l; | |
1441 | if (copied == desc->elem_size) | |
1442 | copied = 0; | |
1443 | } else { | |
1444 | memcpy(elem + copied, c, l); | |
1445 | copied += l; | |
1446 | if (copied == desc->elem_size) { | |
1447 | err = desc->xcode(desc, elem); | |
1448 | if (err) | |
1449 | goto out; | |
1450 | copied = 0; | |
1451 | } | |
1452 | } | |
1453 | } | |
1454 | if (avail_here) { | |
1455 | kunmap(*ppages); | |
1456 | ppages++; | |
1457 | c = kmap(*ppages); | |
1458 | } | |
1459 | ||
1460 | avail_page = min(avail_here, | |
09cbfeaf | 1461 | (unsigned int) PAGE_SIZE); |
bd8100e7 AG |
1462 | } |
1463 | base = buf->page_len; /* align to start of tail */ | |
1464 | } | |
1465 | ||
1466 | /* process tail */ | |
1467 | base -= buf->page_len; | |
1468 | if (todo) { | |
1469 | c = buf->tail->iov_base + base; | |
1470 | if (copied) { | |
1471 | unsigned int l = desc->elem_size - copied; | |
1472 | ||
1473 | if (encode) | |
1474 | memcpy(c, elem + copied, l); | |
1475 | else { | |
1476 | memcpy(elem + copied, c, l); | |
1477 | err = desc->xcode(desc, elem); | |
1478 | if (err) | |
1479 | goto out; | |
1480 | } | |
1481 | todo -= l; | |
1482 | c += l; | |
1483 | } | |
1484 | while (todo) { | |
1485 | err = desc->xcode(desc, c); | |
1486 | if (err) | |
1487 | goto out; | |
1488 | c += desc->elem_size; | |
1489 | todo -= desc->elem_size; | |
1490 | } | |
1491 | } | |
1492 | err = 0; | |
1493 | ||
1494 | out: | |
a51482bd | 1495 | kfree(elem); |
bd8100e7 AG |
1496 | if (ppages) |
1497 | kunmap(*ppages); | |
1498 | return err; | |
1499 | } | |
1500 | ||
1501 | int | |
1502 | xdr_decode_array2(struct xdr_buf *buf, unsigned int base, | |
1503 | struct xdr_array2_desc *desc) | |
1504 | { | |
1505 | if (base >= buf->len) | |
1506 | return -EINVAL; | |
1507 | ||
1508 | return xdr_xcode_array2(buf, base, desc, 0); | |
1509 | } | |
468039ee | 1510 | EXPORT_SYMBOL_GPL(xdr_decode_array2); |
bd8100e7 AG |
1511 | |
1512 | int | |
1513 | xdr_encode_array2(struct xdr_buf *buf, unsigned int base, | |
1514 | struct xdr_array2_desc *desc) | |
1515 | { | |
1516 | if ((unsigned long) base + 4 + desc->array_len * desc->elem_size > | |
1517 | buf->head->iov_len + buf->page_len + buf->tail->iov_len) | |
1518 | return -EINVAL; | |
1519 | ||
1520 | return xdr_xcode_array2(buf, base, desc, 1); | |
1521 | } | |
468039ee | 1522 | EXPORT_SYMBOL_GPL(xdr_encode_array2); |
37a4e6cb OK |
1523 | |
1524 | int | |
1525 | xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, | |
cca5172a | 1526 | int (*actor)(struct scatterlist *, void *), void *data) |
37a4e6cb OK |
1527 | { |
1528 | int i, ret = 0; | |
95c96174 | 1529 | unsigned int page_len, thislen, page_offset; |
37a4e6cb OK |
1530 | struct scatterlist sg[1]; |
1531 | ||
68e3f5dd HX |
1532 | sg_init_table(sg, 1); |
1533 | ||
37a4e6cb OK |
1534 | if (offset >= buf->head[0].iov_len) { |
1535 | offset -= buf->head[0].iov_len; | |
1536 | } else { | |
1537 | thislen = buf->head[0].iov_len - offset; | |
1538 | if (thislen > len) | |
1539 | thislen = len; | |
1540 | sg_set_buf(sg, buf->head[0].iov_base + offset, thislen); | |
1541 | ret = actor(sg, data); | |
1542 | if (ret) | |
1543 | goto out; | |
1544 | offset = 0; | |
1545 | len -= thislen; | |
1546 | } | |
1547 | if (len == 0) | |
1548 | goto out; | |
1549 | ||
1550 | if (offset >= buf->page_len) { | |
1551 | offset -= buf->page_len; | |
1552 | } else { | |
1553 | page_len = buf->page_len - offset; | |
1554 | if (page_len > len) | |
1555 | page_len = len; | |
1556 | len -= page_len; | |
09cbfeaf KS |
1557 | page_offset = (offset + buf->page_base) & (PAGE_SIZE - 1); |
1558 | i = (offset + buf->page_base) >> PAGE_SHIFT; | |
1559 | thislen = PAGE_SIZE - page_offset; | |
37a4e6cb OK |
1560 | do { |
1561 | if (thislen > page_len) | |
1562 | thislen = page_len; | |
642f1490 | 1563 | sg_set_page(sg, buf->pages[i], thislen, page_offset); |
37a4e6cb OK |
1564 | ret = actor(sg, data); |
1565 | if (ret) | |
1566 | goto out; | |
1567 | page_len -= thislen; | |
1568 | i++; | |
1569 | page_offset = 0; | |
09cbfeaf | 1570 | thislen = PAGE_SIZE; |
37a4e6cb OK |
1571 | } while (page_len != 0); |
1572 | offset = 0; | |
1573 | } | |
1574 | if (len == 0) | |
1575 | goto out; | |
1576 | if (offset < buf->tail[0].iov_len) { | |
1577 | thislen = buf->tail[0].iov_len - offset; | |
1578 | if (thislen > len) | |
1579 | thislen = len; | |
1580 | sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen); | |
1581 | ret = actor(sg, data); | |
1582 | len -= thislen; | |
1583 | } | |
1584 | if (len != 0) | |
1585 | ret = -EINVAL; | |
1586 | out: | |
1587 | return ret; | |
1588 | } | |
468039ee | 1589 | EXPORT_SYMBOL_GPL(xdr_process_buf); |
37a4e6cb | 1590 | |
0e779aa7 TM |
1591 | /** |
1592 | * xdr_stream_decode_opaque - Decode variable length opaque | |
1593 | * @xdr: pointer to xdr_stream | |
1594 | * @ptr: location to store opaque data | |
1595 | * @size: size of storage buffer @ptr | |
1596 | * | |
1597 | * Return values: | |
1598 | * On success, returns size of object stored in *@ptr | |
1599 | * %-EBADMSG on XDR buffer overflow | |
1600 | * %-EMSGSIZE on overflow of storage buffer @ptr | |
1601 | */ | |
1602 | ssize_t xdr_stream_decode_opaque(struct xdr_stream *xdr, void *ptr, size_t size) | |
1603 | { | |
1604 | ssize_t ret; | |
1605 | void *p; | |
1606 | ||
1607 | ret = xdr_stream_decode_opaque_inline(xdr, &p, size); | |
1608 | if (ret <= 0) | |
1609 | return ret; | |
1610 | memcpy(ptr, p, ret); | |
1611 | return ret; | |
1612 | } | |
1613 | EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque); | |
1614 | ||
1615 | /** | |
1616 | * xdr_stream_decode_opaque_dup - Decode and duplicate variable length opaque | |
1617 | * @xdr: pointer to xdr_stream | |
1618 | * @ptr: location to store pointer to opaque data | |
1619 | * @maxlen: maximum acceptable object size | |
1620 | * @gfp_flags: GFP mask to use | |
1621 | * | |
1622 | * Return values: | |
1623 | * On success, returns size of object stored in *@ptr | |
1624 | * %-EBADMSG on XDR buffer overflow | |
1625 | * %-EMSGSIZE if the size of the object would exceed @maxlen | |
1626 | * %-ENOMEM on memory allocation failure | |
1627 | */ | |
1628 | ssize_t xdr_stream_decode_opaque_dup(struct xdr_stream *xdr, void **ptr, | |
1629 | size_t maxlen, gfp_t gfp_flags) | |
1630 | { | |
1631 | ssize_t ret; | |
1632 | void *p; | |
1633 | ||
1634 | ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen); | |
1635 | if (ret > 0) { | |
1636 | *ptr = kmemdup(p, ret, gfp_flags); | |
1637 | if (*ptr != NULL) | |
1638 | return ret; | |
1639 | ret = -ENOMEM; | |
1640 | } | |
1641 | *ptr = NULL; | |
1642 | return ret; | |
1643 | } | |
1644 | EXPORT_SYMBOL_GPL(xdr_stream_decode_opaque_dup); | |
1645 | ||
1646 | /** | |
1647 | * xdr_stream_decode_string - Decode variable length string | |
1648 | * @xdr: pointer to xdr_stream | |
1649 | * @str: location to store string | |
1650 | * @size: size of storage buffer @str | |
1651 | * | |
1652 | * Return values: | |
1653 | * On success, returns length of NUL-terminated string stored in *@str | |
1654 | * %-EBADMSG on XDR buffer overflow | |
1655 | * %-EMSGSIZE on overflow of storage buffer @str | |
1656 | */ | |
1657 | ssize_t xdr_stream_decode_string(struct xdr_stream *xdr, char *str, size_t size) | |
1658 | { | |
1659 | ssize_t ret; | |
1660 | void *p; | |
1661 | ||
1662 | ret = xdr_stream_decode_opaque_inline(xdr, &p, size); | |
1663 | if (ret > 0) { | |
1664 | memcpy(str, p, ret); | |
1665 | str[ret] = '\0'; | |
1666 | return strlen(str); | |
1667 | } | |
1668 | *str = '\0'; | |
1669 | return ret; | |
1670 | } | |
1671 | EXPORT_SYMBOL_GPL(xdr_stream_decode_string); | |
1672 | ||
5c741d4f TM |
1673 | /** |
1674 | * xdr_stream_decode_string_dup - Decode and duplicate variable length string | |
1675 | * @xdr: pointer to xdr_stream | |
1676 | * @str: location to store pointer to string | |
1677 | * @maxlen: maximum acceptable string length | |
1678 | * @gfp_flags: GFP mask to use | |
1679 | * | |
1680 | * Return values: | |
1681 | * On success, returns length of NUL-terminated string stored in *@ptr | |
1682 | * %-EBADMSG on XDR buffer overflow | |
1683 | * %-EMSGSIZE if the size of the string would exceed @maxlen | |
1684 | * %-ENOMEM on memory allocation failure | |
1685 | */ | |
1686 | ssize_t xdr_stream_decode_string_dup(struct xdr_stream *xdr, char **str, | |
1687 | size_t maxlen, gfp_t gfp_flags) | |
1688 | { | |
1689 | void *p; | |
1690 | ssize_t ret; | |
1691 | ||
1692 | ret = xdr_stream_decode_opaque_inline(xdr, &p, maxlen); | |
1693 | if (ret > 0) { | |
1694 | char *s = kmalloc(ret + 1, gfp_flags); | |
1695 | if (s != NULL) { | |
1696 | memcpy(s, p, ret); | |
1697 | s[ret] = '\0'; | |
1698 | *str = s; | |
1699 | return strlen(s); | |
1700 | } | |
1701 | ret = -ENOMEM; | |
1702 | } | |
1703 | *str = NULL; | |
1704 | return ret; | |
1705 | } | |
1706 | EXPORT_SYMBOL_GPL(xdr_stream_decode_string_dup); |