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