blob: 277ebd4bf095fd973af455363a2bf0fc476511bd [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Chuck Levera246b012005-08-11 16:25:23 -04009#include <linux/module.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090010#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/string.h>
13#include <linux/kernel.h>
14#include <linux/pagemap.h>
15#include <linux/errno.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/sunrpc/xdr.h>
17#include <linux/sunrpc/msg_prot.h>
18
19/*
20 * XDR functions for basic NFS types
21 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -070022__be32 *
23xdr_encode_netobj(__be32 *p, const struct xdr_netobj *obj)
Linus Torvalds1da177e2005-04-16 15:20:36 -070024{
25 unsigned int quadlen = XDR_QUADLEN(obj->len);
26
27 p[quadlen] = 0; /* zero trailing bytes */
Benny Halevy9f162d22009-08-14 17:18:44 +030028 *p++ = cpu_to_be32(obj->len);
Linus Torvalds1da177e2005-04-16 15:20:36 -070029 memcpy(p, obj->data, obj->len);
30 return p + XDR_QUADLEN(obj->len);
31}
Trond Myklebust468039e2008-12-23 15:21:31 -050032EXPORT_SYMBOL_GPL(xdr_encode_netobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
Alexey Dobriyand8ed0292006-09-26 22:29:38 -070034__be32 *
35xdr_decode_netobj(__be32 *p, struct xdr_netobj *obj)
Linus Torvalds1da177e2005-04-16 15:20:36 -070036{
37 unsigned int len;
38
Benny Halevy98866b52009-08-14 17:18:49 +030039 if ((len = be32_to_cpu(*p++)) > XDR_MAX_NETOBJ)
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 return NULL;
41 obj->len = len;
42 obj->data = (u8 *) p;
43 return p + XDR_QUADLEN(len);
44}
Trond Myklebust468039e2008-12-23 15:21:31 -050045EXPORT_SYMBOL_GPL(xdr_decode_netobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -070046
47/**
48 * xdr_encode_opaque_fixed - Encode fixed length opaque data
Pavel Pisa4dc3b162005-05-01 08:59:25 -070049 * @p: pointer to current position in XDR buffer.
50 * @ptr: pointer to data to encode (or NULL)
51 * @nbytes: size of data.
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 *
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 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -070061__be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int nbytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -070062{
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}
Trond Myklebust468039e2008-12-23 15:21:31 -050075EXPORT_SYMBOL_GPL(xdr_encode_opaque_fixed);
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
77/**
78 * xdr_encode_opaque - Encode variable length opaque data
Pavel Pisa4dc3b162005-05-01 08:59:25 -070079 * @p: pointer to current position in XDR buffer.
80 * @ptr: pointer to data to encode (or NULL)
81 * @nbytes: size of data.
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 *
83 * Returns the updated current XDR buffer position
84 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -070085__be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int nbytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -070086{
Benny Halevy9f162d22009-08-14 17:18:44 +030087 *p++ = cpu_to_be32(nbytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 return xdr_encode_opaque_fixed(p, ptr, nbytes);
89}
Trond Myklebust468039e2008-12-23 15:21:31 -050090EXPORT_SYMBOL_GPL(xdr_encode_opaque);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
Alexey Dobriyand8ed0292006-09-26 22:29:38 -070092__be32 *
93xdr_encode_string(__be32 *p, const char *string)
Linus Torvalds1da177e2005-04-16 15:20:36 -070094{
95 return xdr_encode_array(p, string, strlen(string));
96}
Trond Myklebust468039e2008-12-23 15:21:31 -050097EXPORT_SYMBOL_GPL(xdr_encode_string);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
Alexey Dobriyand8ed0292006-09-26 22:29:38 -070099__be32 *
Chuck Levere5cff482007-11-01 16:56:47 -0400100xdr_decode_string_inplace(__be32 *p, char **sp,
101 unsigned int *lenp, unsigned int maxlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102{
Chuck Levere5cff482007-11-01 16:56:47 -0400103 u32 len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
Benny Halevy98866b52009-08-14 17:18:49 +0300105 len = be32_to_cpu(*p++);
Chuck Levere5cff482007-11-01 16:56:47 -0400106 if (len > maxlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 return NULL;
108 *lenp = len;
109 *sp = (char *) p;
110 return p + XDR_QUADLEN(len);
111}
Trond Myklebust468039e2008-12-23 15:21:31 -0500112EXPORT_SYMBOL_GPL(xdr_decode_string_inplace);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113
Chuck Leverb4687da2010-09-21 16:55:48 -0400114/**
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 */
120void
121xdr_terminate_string(struct xdr_buf *buf, const u32 len)
122{
123 char *kaddr;
124
125 kaddr = kmap_atomic(buf->pages[0], KM_USER0);
126 kaddr[buf->page_base + len] = '\0';
127 kunmap_atomic(kaddr, KM_USER0);
128}
Trond Myklebust0d961aa2011-07-13 19:24:15 -0400129EXPORT_SYMBOL_GPL(xdr_terminate_string);
Chuck Leverb4687da2010-09-21 16:55:48 -0400130
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131void
132xdr_encode_pages(struct xdr_buf *xdr, struct page **pages, unsigned int base,
133 unsigned int len)
134{
135 struct kvec *tail = xdr->tail;
136 u32 *p;
137
138 xdr->pages = pages;
139 xdr->page_base = base;
140 xdr->page_len = len;
141
142 p = (u32 *)xdr->head[0].iov_base + XDR_QUADLEN(xdr->head[0].iov_len);
143 tail->iov_base = p;
144 tail->iov_len = 0;
145
146 if (len & 3) {
147 unsigned int pad = 4 - (len & 3);
148
149 *p = 0;
150 tail->iov_base = (char *)p + (len & 3);
151 tail->iov_len = pad;
152 len += pad;
153 }
154 xdr->buflen += len;
155 xdr->len += len;
156}
Trond Myklebust468039e2008-12-23 15:21:31 -0500157EXPORT_SYMBOL_GPL(xdr_encode_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158
159void
160xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset,
161 struct page **pages, unsigned int base, unsigned int len)
162{
163 struct kvec *head = xdr->head;
164 struct kvec *tail = xdr->tail;
165 char *buf = (char *)head->iov_base;
166 unsigned int buflen = head->iov_len;
167
168 head->iov_len = offset;
169
170 xdr->pages = pages;
171 xdr->page_base = base;
172 xdr->page_len = len;
173
174 tail->iov_base = buf + offset;
175 tail->iov_len = buflen - offset;
176
177 xdr->buflen += len;
178}
Trond Myklebust468039e2008-12-23 15:21:31 -0500179EXPORT_SYMBOL_GPL(xdr_inline_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181/*
182 * Helper routines for doing 'memmove' like operations on a struct xdr_buf
183 *
184 * _shift_data_right_pages
185 * @pages: vector of pages containing both the source and dest memory area.
186 * @pgto_base: page vector address of destination
187 * @pgfrom_base: page vector address of source
188 * @len: number of bytes to copy
189 *
190 * Note: the addresses pgto_base and pgfrom_base are both calculated in
191 * the same way:
192 * if a memory area starts at byte 'base' in page 'pages[i]',
193 * then its address is given as (i << PAGE_CACHE_SHIFT) + base
194 * Also note: pgfrom_base must be < pgto_base, but the memory areas
195 * they point to may overlap.
196 */
197static void
198_shift_data_right_pages(struct page **pages, size_t pgto_base,
199 size_t pgfrom_base, size_t len)
200{
201 struct page **pgfrom, **pgto;
202 char *vfrom, *vto;
203 size_t copy;
204
205 BUG_ON(pgto_base <= pgfrom_base);
206
207 pgto_base += len;
208 pgfrom_base += len;
209
210 pgto = pages + (pgto_base >> PAGE_CACHE_SHIFT);
211 pgfrom = pages + (pgfrom_base >> PAGE_CACHE_SHIFT);
212
213 pgto_base &= ~PAGE_CACHE_MASK;
214 pgfrom_base &= ~PAGE_CACHE_MASK;
215
216 do {
217 /* Are any pointers crossing a page boundary? */
218 if (pgto_base == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 pgto_base = PAGE_CACHE_SIZE;
220 pgto--;
221 }
222 if (pgfrom_base == 0) {
223 pgfrom_base = PAGE_CACHE_SIZE;
224 pgfrom--;
225 }
226
227 copy = len;
228 if (copy > pgto_base)
229 copy = pgto_base;
230 if (copy > pgfrom_base)
231 copy = pgfrom_base;
232 pgto_base -= copy;
233 pgfrom_base -= copy;
234
235 vto = kmap_atomic(*pgto, KM_USER0);
236 vfrom = kmap_atomic(*pgfrom, KM_USER1);
237 memmove(vto + pgto_base, vfrom + pgfrom_base, copy);
Trond Myklebustbce34812006-07-05 13:17:12 -0400238 flush_dcache_page(*pgto);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 kunmap_atomic(vfrom, KM_USER1);
240 kunmap_atomic(vto, KM_USER0);
241
242 } while ((len -= copy) != 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243}
244
245/*
246 * _copy_to_pages
247 * @pages: array of pages
248 * @pgbase: page vector address of destination
249 * @p: pointer to source data
250 * @len: length
251 *
252 * Copies data from an arbitrary memory location into an array of pages
253 * The copy is assumed to be non-overlapping.
254 */
255static void
256_copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len)
257{
258 struct page **pgto;
259 char *vto;
260 size_t copy;
261
262 pgto = pages + (pgbase >> PAGE_CACHE_SHIFT);
263 pgbase &= ~PAGE_CACHE_MASK;
264
Trond Myklebustdaeba892008-03-31 17:02:02 -0400265 for (;;) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 copy = PAGE_CACHE_SIZE - pgbase;
267 if (copy > len)
268 copy = len;
269
270 vto = kmap_atomic(*pgto, KM_USER0);
271 memcpy(vto + pgbase, p, copy);
272 kunmap_atomic(vto, KM_USER0);
273
Trond Myklebustdaeba892008-03-31 17:02:02 -0400274 len -= copy;
275 if (len == 0)
276 break;
277
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 pgbase += copy;
279 if (pgbase == PAGE_CACHE_SIZE) {
280 flush_dcache_page(*pgto);
281 pgbase = 0;
282 pgto++;
283 }
284 p += copy;
Trond Myklebustdaeba892008-03-31 17:02:02 -0400285 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 flush_dcache_page(*pgto);
287}
288
289/*
290 * _copy_from_pages
291 * @p: pointer to destination
292 * @pages: array of pages
293 * @pgbase: offset of source data
294 * @len: length
295 *
296 * Copies data into an arbitrary memory location from an array of pages
297 * The copy is assumed to be non-overlapping.
298 */
299static void
300_copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len)
301{
302 struct page **pgfrom;
303 char *vfrom;
304 size_t copy;
305
306 pgfrom = pages + (pgbase >> PAGE_CACHE_SHIFT);
307 pgbase &= ~PAGE_CACHE_MASK;
308
309 do {
310 copy = PAGE_CACHE_SIZE - pgbase;
311 if (copy > len)
312 copy = len;
313
314 vfrom = kmap_atomic(*pgfrom, KM_USER0);
315 memcpy(p, vfrom + pgbase, copy);
316 kunmap_atomic(vfrom, KM_USER0);
317
318 pgbase += copy;
319 if (pgbase == PAGE_CACHE_SIZE) {
320 pgbase = 0;
321 pgfrom++;
322 }
323 p += copy;
324
325 } while ((len -= copy) != 0);
326}
327
328/*
329 * xdr_shrink_bufhead
330 * @buf: xdr_buf
331 * @len: bytes to remove from buf->head[0]
332 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800333 * Shrinks XDR buffer's header kvec buf->head[0] by
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 * 'len' bytes. The extra data is not lost, but is instead
335 * moved into the inlined pages and/or the tail.
336 */
337static void
338xdr_shrink_bufhead(struct xdr_buf *buf, size_t len)
339{
340 struct kvec *head, *tail;
341 size_t copy, offs;
342 unsigned int pglen = buf->page_len;
343
344 tail = buf->tail;
345 head = buf->head;
346 BUG_ON (len > head->iov_len);
347
348 /* Shift the tail first */
349 if (tail->iov_len != 0) {
350 if (tail->iov_len > len) {
351 copy = tail->iov_len - len;
352 memmove((char *)tail->iov_base + len,
353 tail->iov_base, copy);
354 }
355 /* Copy from the inlined pages into the tail */
356 copy = len;
357 if (copy > pglen)
358 copy = pglen;
359 offs = len - copy;
360 if (offs >= tail->iov_len)
361 copy = 0;
362 else if (copy > tail->iov_len - offs)
363 copy = tail->iov_len - offs;
364 if (copy != 0)
365 _copy_from_pages((char *)tail->iov_base + offs,
366 buf->pages,
367 buf->page_base + pglen + offs - len,
368 copy);
369 /* Do we also need to copy data from the head into the tail ? */
370 if (len > pglen) {
371 offs = copy = len - pglen;
372 if (copy > tail->iov_len)
373 copy = tail->iov_len;
374 memcpy(tail->iov_base,
375 (char *)head->iov_base +
376 head->iov_len - offs,
377 copy);
378 }
379 }
380 /* Now handle pages */
381 if (pglen != 0) {
382 if (pglen > len)
383 _shift_data_right_pages(buf->pages,
384 buf->page_base + len,
385 buf->page_base,
386 pglen - len);
387 copy = len;
388 if (len > pglen)
389 copy = pglen;
390 _copy_to_pages(buf->pages, buf->page_base,
391 (char *)head->iov_base + head->iov_len - len,
392 copy);
393 }
394 head->iov_len -= len;
395 buf->buflen -= len;
396 /* Have we truncated the message? */
397 if (buf->len > buf->buflen)
398 buf->len = buf->buflen;
399}
400
401/*
402 * xdr_shrink_pagelen
403 * @buf: xdr_buf
404 * @len: bytes to remove from buf->pages
405 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800406 * Shrinks XDR buffer's page array buf->pages by
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 * 'len' bytes. The extra data is not lost, but is instead
408 * moved into the tail.
409 */
410static void
411xdr_shrink_pagelen(struct xdr_buf *buf, size_t len)
412{
413 struct kvec *tail;
414 size_t copy;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 unsigned int pglen = buf->page_len;
Trond Myklebustcf187c22010-08-29 12:13:16 -0400416 unsigned int tailbuf_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
418 tail = buf->tail;
419 BUG_ON (len > pglen);
420
Trond Myklebustcf187c22010-08-29 12:13:16 -0400421 tailbuf_len = buf->buflen - buf->head->iov_len - buf->page_len;
422
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 /* Shift the tail first */
Trond Myklebustcf187c22010-08-29 12:13:16 -0400424 if (tailbuf_len != 0) {
425 unsigned int free_space = tailbuf_len - tail->iov_len;
426
427 if (len < free_space)
428 free_space = len;
429 tail->iov_len += free_space;
430
Benny Halevy42d6d8a2010-08-29 12:13:15 -0400431 copy = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 if (tail->iov_len > len) {
Benny Halevy0fe62a32010-08-29 12:13:15 -0400433 char *p = (char *)tail->iov_base + len;
Benny Halevy2e29ebb2010-08-29 12:13:15 -0400434 memmove(p, tail->iov_base, tail->iov_len - len);
Benny Halevy42d6d8a2010-08-29 12:13:15 -0400435 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 copy = tail->iov_len;
Benny Halevy42d6d8a2010-08-29 12:13:15 -0400437 /* Copy from the inlined pages into the tail */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 _copy_from_pages((char *)tail->iov_base,
439 buf->pages, buf->page_base + pglen - len,
440 copy);
441 }
442 buf->page_len -= len;
443 buf->buflen -= len;
444 /* Have we truncated the message? */
445 if (buf->len > buf->buflen)
446 buf->len = buf->buflen;
447}
448
449void
450xdr_shift_buf(struct xdr_buf *buf, size_t len)
451{
452 xdr_shrink_bufhead(buf, len);
453}
Trond Myklebust468039e2008-12-23 15:21:31 -0500454EXPORT_SYMBOL_GPL(xdr_shift_buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455
456/**
457 * xdr_init_encode - Initialize a struct xdr_stream for sending data.
458 * @xdr: pointer to xdr_stream struct
459 * @buf: pointer to XDR buffer in which to encode data
460 * @p: current pointer inside XDR buffer
461 *
462 * Note: at the moment the RPC client only passes the length of our
463 * scratch buffer in the xdr_buf's header kvec. Previously this
464 * meant we needed to call xdr_adjust_iovec() after encoding the
465 * data. With the new scheme, the xdr_stream manages the details
466 * of the buffer length, and takes care of adjusting the kvec
467 * length for us.
468 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700469void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470{
471 struct kvec *iov = buf->head;
Trond Myklebust334ccfd2005-06-22 17:16:19 +0000472 int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473
Trond Myklebust334ccfd2005-06-22 17:16:19 +0000474 BUG_ON(scratch_len < 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 xdr->buf = buf;
476 xdr->iov = iov;
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700477 xdr->p = (__be32 *)((char *)iov->iov_base + iov->iov_len);
478 xdr->end = (__be32 *)((char *)iov->iov_base + scratch_len);
Trond Myklebust334ccfd2005-06-22 17:16:19 +0000479 BUG_ON(iov->iov_len > scratch_len);
480
481 if (p != xdr->p && p != NULL) {
482 size_t len;
483
484 BUG_ON(p < xdr->p || p > xdr->end);
485 len = (char *)p - (char *)xdr->p;
486 xdr->p = p;
487 buf->len += len;
488 iov->iov_len += len;
489 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490}
Trond Myklebust468039e2008-12-23 15:21:31 -0500491EXPORT_SYMBOL_GPL(xdr_init_encode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492
493/**
494 * xdr_reserve_space - Reserve buffer space for sending
495 * @xdr: pointer to xdr_stream
496 * @nbytes: number of bytes to reserve
497 *
498 * Checks that we have enough buffer space to encode 'nbytes' more
499 * bytes of data. If so, update the total xdr_buf length, and
500 * adjust the length of the current kvec.
501 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700502__be32 * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503{
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700504 __be32 *p = xdr->p;
505 __be32 *q;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506
507 /* align nbytes on the next 32-bit boundary */
508 nbytes += 3;
509 nbytes &= ~3;
510 q = p + (nbytes >> 2);
511 if (unlikely(q > xdr->end || q < p))
512 return NULL;
513 xdr->p = q;
514 xdr->iov->iov_len += nbytes;
515 xdr->buf->len += nbytes;
516 return p;
517}
Trond Myklebust468039e2008-12-23 15:21:31 -0500518EXPORT_SYMBOL_GPL(xdr_reserve_space);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519
520/**
521 * xdr_write_pages - Insert a list of pages into an XDR buffer for sending
522 * @xdr: pointer to xdr_stream
523 * @pages: list of pages
524 * @base: offset of first byte
525 * @len: length of data in bytes
526 *
527 */
528void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base,
529 unsigned int len)
530{
531 struct xdr_buf *buf = xdr->buf;
532 struct kvec *iov = buf->tail;
533 buf->pages = pages;
534 buf->page_base = base;
535 buf->page_len = len;
536
537 iov->iov_base = (char *)xdr->p;
538 iov->iov_len = 0;
539 xdr->iov = iov;
540
541 if (len & 3) {
542 unsigned int pad = 4 - (len & 3);
543
544 BUG_ON(xdr->p >= xdr->end);
545 iov->iov_base = (char *)xdr->p + (len & 3);
546 iov->iov_len += pad;
547 len += pad;
548 *xdr->p++ = 0;
549 }
550 buf->buflen += len;
551 buf->len += len;
552}
Trond Myklebust468039e2008-12-23 15:21:31 -0500553EXPORT_SYMBOL_GPL(xdr_write_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554
Trond Myklebust66502392011-01-08 17:45:38 -0500555static void xdr_set_iov(struct xdr_stream *xdr, struct kvec *iov,
556 __be32 *p, unsigned int len)
557{
558 if (len > iov->iov_len)
559 len = iov->iov_len;
560 if (p == NULL)
561 p = (__be32*)iov->iov_base;
562 xdr->p = p;
563 xdr->end = (__be32*)(iov->iov_base + len);
564 xdr->iov = iov;
565 xdr->page_ptr = NULL;
566}
567
568static int xdr_set_page_base(struct xdr_stream *xdr,
569 unsigned int base, unsigned int len)
570{
571 unsigned int pgnr;
572 unsigned int maxlen;
573 unsigned int pgoff;
574 unsigned int pgend;
575 void *kaddr;
576
577 maxlen = xdr->buf->page_len;
578 if (base >= maxlen)
579 return -EINVAL;
580 maxlen -= base;
581 if (len > maxlen)
582 len = maxlen;
583
584 base += xdr->buf->page_base;
585
586 pgnr = base >> PAGE_SHIFT;
587 xdr->page_ptr = &xdr->buf->pages[pgnr];
588 kaddr = page_address(*xdr->page_ptr);
589
590 pgoff = base & ~PAGE_MASK;
591 xdr->p = (__be32*)(kaddr + pgoff);
592
593 pgend = pgoff + len;
594 if (pgend > PAGE_SIZE)
595 pgend = PAGE_SIZE;
596 xdr->end = (__be32*)(kaddr + pgend);
597 xdr->iov = NULL;
598 return 0;
599}
600
601static void xdr_set_next_page(struct xdr_stream *xdr)
602{
603 unsigned int newbase;
604
605 newbase = (1 + xdr->page_ptr - xdr->buf->pages) << PAGE_SHIFT;
606 newbase -= xdr->buf->page_base;
607
608 if (xdr_set_page_base(xdr, newbase, PAGE_SIZE) < 0)
609 xdr_set_iov(xdr, xdr->buf->tail, NULL, xdr->buf->len);
610}
611
612static bool xdr_set_next_buffer(struct xdr_stream *xdr)
613{
614 if (xdr->page_ptr != NULL)
615 xdr_set_next_page(xdr);
616 else if (xdr->iov == xdr->buf->head) {
617 if (xdr_set_page_base(xdr, 0, PAGE_SIZE) < 0)
618 xdr_set_iov(xdr, xdr->buf->tail, NULL, xdr->buf->len);
619 }
620 return xdr->p != xdr->end;
621}
622
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623/**
624 * xdr_init_decode - Initialize an xdr_stream for decoding data.
625 * @xdr: pointer to xdr_stream struct
626 * @buf: pointer to XDR buffer from which to decode data
627 * @p: current pointer inside XDR buffer
628 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700629void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 xdr->buf = buf;
Trond Myklebust66502392011-01-08 17:45:38 -0500632 xdr->scratch.iov_base = NULL;
633 xdr->scratch.iov_len = 0;
634 if (buf->head[0].iov_len != 0)
635 xdr_set_iov(xdr, buf->head, p, buf->len);
636 else if (buf->page_len != 0)
637 xdr_set_page_base(xdr, 0, buf->len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638}
Trond Myklebust468039e2008-12-23 15:21:31 -0500639EXPORT_SYMBOL_GPL(xdr_init_decode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640
Benny Halevyf7da7a12011-05-19 14:16:47 -0400641/**
642 * xdr_init_decode - Initialize an xdr_stream for decoding data.
643 * @xdr: pointer to xdr_stream struct
644 * @buf: pointer to XDR buffer from which to decode data
645 * @pages: list of pages to decode into
646 * @len: length in bytes of buffer in pages
647 */
648void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
649 struct page **pages, unsigned int len)
650{
651 memset(buf, 0, sizeof(*buf));
652 buf->pages = pages;
653 buf->page_len = len;
654 buf->buflen = len;
655 buf->len = len;
656 xdr_init_decode(xdr, buf, NULL);
657}
658EXPORT_SYMBOL_GPL(xdr_init_decode_pages);
659
Trond Myklebust66502392011-01-08 17:45:38 -0500660static __be32 * __xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
Trond Myklebustba8e4522010-10-19 19:58:49 -0400661{
662 __be32 *p = xdr->p;
663 __be32 *q = p + XDR_QUADLEN(nbytes);
664
665 if (unlikely(q > xdr->end || q < p))
666 return NULL;
Trond Myklebust66502392011-01-08 17:45:38 -0500667 xdr->p = q;
Trond Myklebustba8e4522010-10-19 19:58:49 -0400668 return p;
669}
Trond Myklebustba8e4522010-10-19 19:58:49 -0400670
671/**
Trond Myklebust66502392011-01-08 17:45:38 -0500672 * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
673 * @xdr: pointer to xdr_stream struct
674 * @buf: pointer to an empty buffer
675 * @buflen: size of 'buf'
676 *
677 * The scratch buffer is used when decoding from an array of pages.
678 * If an xdr_inline_decode() call spans across page boundaries, then
679 * we copy the data into the scratch buffer in order to allow linear
680 * access.
681 */
682void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen)
683{
684 xdr->scratch.iov_base = buf;
685 xdr->scratch.iov_len = buflen;
686}
687EXPORT_SYMBOL_GPL(xdr_set_scratch_buffer);
688
689static __be32 *xdr_copy_to_scratch(struct xdr_stream *xdr, size_t nbytes)
690{
691 __be32 *p;
692 void *cpdest = xdr->scratch.iov_base;
693 size_t cplen = (char *)xdr->end - (char *)xdr->p;
694
695 if (nbytes > xdr->scratch.iov_len)
696 return NULL;
697 memcpy(cpdest, xdr->p, cplen);
698 cpdest += cplen;
699 nbytes -= cplen;
700 if (!xdr_set_next_buffer(xdr))
701 return NULL;
702 p = __xdr_inline_decode(xdr, nbytes);
703 if (p == NULL)
704 return NULL;
705 memcpy(cpdest, p, nbytes);
706 return xdr->scratch.iov_base;
707}
708
709/**
710 * xdr_inline_decode - Retrieve XDR data to decode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 * @xdr: pointer to xdr_stream struct
712 * @nbytes: number of bytes of data to decode
713 *
714 * Check if the input buffer is long enough to enable us to decode
715 * 'nbytes' more bytes of data starting at the current position.
716 * If so return the current pointer, then update the current
717 * pointer position.
718 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700719__be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720{
Trond Myklebust66502392011-01-08 17:45:38 -0500721 __be32 *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722
Trond Myklebust66502392011-01-08 17:45:38 -0500723 if (nbytes == 0)
724 return xdr->p;
725 if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 return NULL;
Trond Myklebust66502392011-01-08 17:45:38 -0500727 p = __xdr_inline_decode(xdr, nbytes);
728 if (p != NULL)
729 return p;
730 return xdr_copy_to_scratch(xdr, nbytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731}
Trond Myklebust468039e2008-12-23 15:21:31 -0500732EXPORT_SYMBOL_GPL(xdr_inline_decode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733
734/**
735 * xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position
736 * @xdr: pointer to xdr_stream struct
737 * @len: number of bytes of page data
738 *
739 * Moves data beyond the current pointer position from the XDR head[] buffer
740 * into the page list. Any data that lies beyond current position + "len"
Trond Myklebust8b23ea72006-06-09 09:34:21 -0400741 * bytes is moved into the XDR tail[].
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 */
743void xdr_read_pages(struct xdr_stream *xdr, unsigned int len)
744{
745 struct xdr_buf *buf = xdr->buf;
746 struct kvec *iov;
747 ssize_t shift;
748 unsigned int end;
749 int padding;
750
751 /* Realign pages to current pointer position */
752 iov = buf->head;
753 shift = iov->iov_len + (char *)iov->iov_base - (char *)xdr->p;
754 if (shift > 0)
755 xdr_shrink_bufhead(buf, shift);
756
757 /* Truncate page data and move it into the tail */
758 if (buf->page_len > len)
759 xdr_shrink_pagelen(buf, buf->page_len - len);
760 padding = (XDR_QUADLEN(len) << 2) - len;
761 xdr->iov = iov = buf->tail;
762 /* Compute remaining message length. */
763 end = iov->iov_len;
764 shift = buf->buflen - buf->len;
765 if (shift < end)
766 end -= shift;
767 else if (shift > 0)
768 end = 0;
769 /*
770 * Position current pointer at beginning of tail, and
771 * set remaining message length.
772 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700773 xdr->p = (__be32 *)((char *)iov->iov_base + padding);
774 xdr->end = (__be32 *)((char *)iov->iov_base + end);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775}
Trond Myklebust468039e2008-12-23 15:21:31 -0500776EXPORT_SYMBOL_GPL(xdr_read_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777
Trond Myklebust8b23ea72006-06-09 09:34:21 -0400778/**
779 * xdr_enter_page - decode data from the XDR page
780 * @xdr: pointer to xdr_stream struct
781 * @len: number of bytes of page data
782 *
783 * Moves data beyond the current pointer position from the XDR head[] buffer
784 * into the page list. Any data that lies beyond current position + "len"
785 * bytes is moved into the XDR tail[]. The current pointer is then
786 * repositioned at the beginning of the first XDR page.
787 */
788void xdr_enter_page(struct xdr_stream *xdr, unsigned int len)
789{
Trond Myklebust8b23ea72006-06-09 09:34:21 -0400790 xdr_read_pages(xdr, len);
791 /*
792 * Position current pointer at beginning of tail, and
793 * set remaining message length.
794 */
Trond Myklebust66502392011-01-08 17:45:38 -0500795 xdr_set_page_base(xdr, 0, len);
Trond Myklebust8b23ea72006-06-09 09:34:21 -0400796}
Trond Myklebust468039e2008-12-23 15:21:31 -0500797EXPORT_SYMBOL_GPL(xdr_enter_page);
Trond Myklebust8b23ea72006-06-09 09:34:21 -0400798
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799static struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0};
800
801void
802xdr_buf_from_iov(struct kvec *iov, struct xdr_buf *buf)
803{
804 buf->head[0] = *iov;
805 buf->tail[0] = empty_iov;
806 buf->page_len = 0;
807 buf->buflen = buf->len = iov->iov_len;
808}
Trond Myklebust468039e2008-12-23 15:21:31 -0500809EXPORT_SYMBOL_GPL(xdr_buf_from_iov);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811/* Sets subbuf to the portion of buf of length len beginning base bytes
812 * from the start of buf. Returns -1 if base of length are out of bounds. */
813int
814xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf,
Trond Myklebust1e789572006-08-31 15:09:19 -0400815 unsigned int base, unsigned int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817 subbuf->buflen = subbuf->len = len;
Trond Myklebust1e789572006-08-31 15:09:19 -0400818 if (base < buf->head[0].iov_len) {
819 subbuf->head[0].iov_base = buf->head[0].iov_base + base;
820 subbuf->head[0].iov_len = min_t(unsigned int, len,
821 buf->head[0].iov_len - base);
822 len -= subbuf->head[0].iov_len;
823 base = 0;
824 } else {
825 subbuf->head[0].iov_base = NULL;
826 subbuf->head[0].iov_len = 0;
827 base -= buf->head[0].iov_len;
828 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829
830 if (base < buf->page_len) {
Trond Myklebust1e789572006-08-31 15:09:19 -0400831 subbuf->page_len = min(buf->page_len - base, len);
832 base += buf->page_base;
833 subbuf->page_base = base & ~PAGE_CACHE_MASK;
834 subbuf->pages = &buf->pages[base >> PAGE_CACHE_SHIFT];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835 len -= subbuf->page_len;
836 base = 0;
837 } else {
838 base -= buf->page_len;
839 subbuf->page_len = 0;
840 }
841
Trond Myklebust1e789572006-08-31 15:09:19 -0400842 if (base < buf->tail[0].iov_len) {
843 subbuf->tail[0].iov_base = buf->tail[0].iov_base + base;
844 subbuf->tail[0].iov_len = min_t(unsigned int, len,
845 buf->tail[0].iov_len - base);
846 len -= subbuf->tail[0].iov_len;
847 base = 0;
848 } else {
849 subbuf->tail[0].iov_base = NULL;
850 subbuf->tail[0].iov_len = 0;
851 base -= buf->tail[0].iov_len;
852 }
853
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 if (base || len)
855 return -1;
856 return 0;
857}
Trond Myklebust468039e2008-12-23 15:21:31 -0500858EXPORT_SYMBOL_GPL(xdr_buf_subsegment);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400860static void __read_bytes_from_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861{
Trond Myklebust1e789572006-08-31 15:09:19 -0400862 unsigned int this_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400864 this_len = min_t(unsigned int, len, subbuf->head[0].iov_len);
865 memcpy(obj, subbuf->head[0].iov_base, this_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 len -= this_len;
867 obj += this_len;
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400868 this_len = min_t(unsigned int, len, subbuf->page_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869 if (this_len)
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400870 _copy_from_pages(obj, subbuf->pages, subbuf->page_base, this_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 len -= this_len;
872 obj += this_len;
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400873 this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len);
874 memcpy(obj, subbuf->tail[0].iov_base, this_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875}
876
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000877/* obj is assumed to point to allocated memory of size at least len: */
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400878int read_bytes_from_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len)
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000879{
880 struct xdr_buf subbuf;
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000881 int status;
882
883 status = xdr_buf_subsegment(buf, &subbuf, base, len);
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400884 if (status != 0)
885 return status;
886 __read_bytes_from_xdr_buf(&subbuf, obj, len);
887 return 0;
888}
Trond Myklebust468039e2008-12-23 15:21:31 -0500889EXPORT_SYMBOL_GPL(read_bytes_from_xdr_buf);
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400890
891static void __write_bytes_to_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len)
892{
893 unsigned int this_len;
894
895 this_len = min_t(unsigned int, len, subbuf->head[0].iov_len);
896 memcpy(subbuf->head[0].iov_base, obj, this_len);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000897 len -= this_len;
898 obj += this_len;
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400899 this_len = min_t(unsigned int, len, subbuf->page_len);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000900 if (this_len)
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400901 _copy_to_pages(subbuf->pages, subbuf->page_base, obj, this_len);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000902 len -= this_len;
903 obj += this_len;
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400904 this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len);
905 memcpy(subbuf->tail[0].iov_base, obj, this_len);
906}
907
908/* obj is assumed to point to allocated memory of size at least len: */
909int write_bytes_to_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len)
910{
911 struct xdr_buf subbuf;
912 int status;
913
914 status = xdr_buf_subsegment(buf, &subbuf, base, len);
915 if (status != 0)
916 return status;
917 __write_bytes_to_xdr_buf(&subbuf, obj, len);
918 return 0;
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000919}
Kevin Coffmanc43abae2010-03-17 13:02:58 -0400920EXPORT_SYMBOL_GPL(write_bytes_to_xdr_buf);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000921
922int
Trond Myklebust1e789572006-08-31 15:09:19 -0400923xdr_decode_word(struct xdr_buf *buf, unsigned int base, u32 *obj)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924{
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700925 __be32 raw;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 int status;
927
928 status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
929 if (status)
930 return status;
Benny Halevy98866b52009-08-14 17:18:49 +0300931 *obj = be32_to_cpu(raw);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 return 0;
933}
Trond Myklebust468039e2008-12-23 15:21:31 -0500934EXPORT_SYMBOL_GPL(xdr_decode_word);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000936int
Trond Myklebust1e789572006-08-31 15:09:19 -0400937xdr_encode_word(struct xdr_buf *buf, unsigned int base, u32 obj)
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000938{
Benny Halevy9f162d22009-08-14 17:18:44 +0300939 __be32 raw = cpu_to_be32(obj);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000940
941 return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj));
942}
Trond Myklebust468039e2008-12-23 15:21:31 -0500943EXPORT_SYMBOL_GPL(xdr_encode_word);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000944
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945/* If the netobj starting offset bytes from the start of xdr_buf is contained
946 * entirely in the head or the tail, set object to point to it; otherwise
947 * try to find space for it at the end of the tail, copy it there, and
948 * set obj to point to it. */
Trond Myklebustbee57c92006-10-09 22:08:22 -0400949int xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, unsigned int offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950{
Trond Myklebustbee57c92006-10-09 22:08:22 -0400951 struct xdr_buf subbuf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000953 if (xdr_decode_word(buf, offset, &obj->len))
Trond Myklebustbee57c92006-10-09 22:08:22 -0400954 return -EFAULT;
955 if (xdr_buf_subsegment(buf, &subbuf, offset + 4, obj->len))
956 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957
Trond Myklebustbee57c92006-10-09 22:08:22 -0400958 /* Is the obj contained entirely in the head? */
959 obj->data = subbuf.head[0].iov_base;
960 if (subbuf.head[0].iov_len == obj->len)
961 return 0;
962 /* ..or is the obj contained entirely in the tail? */
963 obj->data = subbuf.tail[0].iov_base;
964 if (subbuf.tail[0].iov_len == obj->len)
965 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966
Trond Myklebustbee57c92006-10-09 22:08:22 -0400967 /* use end of tail as storage for obj:
968 * (We don't copy to the beginning because then we'd have
969 * to worry about doing a potentially overlapping copy.
970 * This assumes the object is at most half the length of the
971 * tail.) */
972 if (obj->len > buf->buflen - buf->len)
973 return -ENOMEM;
974 if (buf->tail[0].iov_len != 0)
975 obj->data = buf->tail[0].iov_base + buf->tail[0].iov_len;
976 else
977 obj->data = buf->head[0].iov_base + buf->head[0].iov_len;
978 __read_bytes_from_xdr_buf(&subbuf, obj->data, obj->len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980}
Trond Myklebust468039e2008-12-23 15:21:31 -0500981EXPORT_SYMBOL_GPL(xdr_buf_read_netobj);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000982
983/* Returns 0 on success, or else a negative error code. */
984static int
985xdr_xcode_array2(struct xdr_buf *buf, unsigned int base,
986 struct xdr_array2_desc *desc, int encode)
987{
988 char *elem = NULL, *c;
989 unsigned int copied = 0, todo, avail_here;
990 struct page **ppages = NULL;
991 int err;
992
993 if (encode) {
994 if (xdr_encode_word(buf, base, desc->array_len) != 0)
995 return -EINVAL;
996 } else {
997 if (xdr_decode_word(buf, base, &desc->array_len) != 0 ||
Trond Myklebust58fcb8d2005-08-10 18:15:12 -0400998 desc->array_len > desc->array_maxlen ||
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000999 (unsigned long) base + 4 + desc->array_len *
1000 desc->elem_size > buf->len)
1001 return -EINVAL;
1002 }
1003 base += 4;
1004
1005 if (!desc->xcode)
1006 return 0;
1007
1008 todo = desc->array_len * desc->elem_size;
1009
1010 /* process head */
1011 if (todo && base < buf->head->iov_len) {
1012 c = buf->head->iov_base + base;
1013 avail_here = min_t(unsigned int, todo,
1014 buf->head->iov_len - base);
1015 todo -= avail_here;
1016
1017 while (avail_here >= desc->elem_size) {
1018 err = desc->xcode(desc, c);
1019 if (err)
1020 goto out;
1021 c += desc->elem_size;
1022 avail_here -= desc->elem_size;
1023 }
1024 if (avail_here) {
1025 if (!elem) {
1026 elem = kmalloc(desc->elem_size, GFP_KERNEL);
1027 err = -ENOMEM;
1028 if (!elem)
1029 goto out;
1030 }
1031 if (encode) {
1032 err = desc->xcode(desc, elem);
1033 if (err)
1034 goto out;
1035 memcpy(c, elem, avail_here);
1036 } else
1037 memcpy(elem, c, avail_here);
1038 copied = avail_here;
1039 }
1040 base = buf->head->iov_len; /* align to start of pages */
1041 }
1042
1043 /* process pages array */
1044 base -= buf->head->iov_len;
1045 if (todo && base < buf->page_len) {
1046 unsigned int avail_page;
1047
1048 avail_here = min(todo, buf->page_len - base);
1049 todo -= avail_here;
1050
1051 base += buf->page_base;
1052 ppages = buf->pages + (base >> PAGE_CACHE_SHIFT);
1053 base &= ~PAGE_CACHE_MASK;
1054 avail_page = min_t(unsigned int, PAGE_CACHE_SIZE - base,
1055 avail_here);
1056 c = kmap(*ppages) + base;
1057
1058 while (avail_here) {
1059 avail_here -= avail_page;
1060 if (copied || avail_page < desc->elem_size) {
1061 unsigned int l = min(avail_page,
1062 desc->elem_size - copied);
1063 if (!elem) {
1064 elem = kmalloc(desc->elem_size,
1065 GFP_KERNEL);
1066 err = -ENOMEM;
1067 if (!elem)
1068 goto out;
1069 }
1070 if (encode) {
1071 if (!copied) {
1072 err = desc->xcode(desc, elem);
1073 if (err)
1074 goto out;
1075 }
1076 memcpy(c, elem + copied, l);
1077 copied += l;
1078 if (copied == desc->elem_size)
1079 copied = 0;
1080 } else {
1081 memcpy(elem + copied, c, l);
1082 copied += l;
1083 if (copied == desc->elem_size) {
1084 err = desc->xcode(desc, elem);
1085 if (err)
1086 goto out;
1087 copied = 0;
1088 }
1089 }
1090 avail_page -= l;
1091 c += l;
1092 }
1093 while (avail_page >= desc->elem_size) {
1094 err = desc->xcode(desc, c);
1095 if (err)
1096 goto out;
1097 c += desc->elem_size;
1098 avail_page -= desc->elem_size;
1099 }
1100 if (avail_page) {
1101 unsigned int l = min(avail_page,
1102 desc->elem_size - copied);
1103 if (!elem) {
1104 elem = kmalloc(desc->elem_size,
1105 GFP_KERNEL);
1106 err = -ENOMEM;
1107 if (!elem)
1108 goto out;
1109 }
1110 if (encode) {
1111 if (!copied) {
1112 err = desc->xcode(desc, elem);
1113 if (err)
1114 goto out;
1115 }
1116 memcpy(c, elem + copied, l);
1117 copied += l;
1118 if (copied == desc->elem_size)
1119 copied = 0;
1120 } else {
1121 memcpy(elem + copied, c, l);
1122 copied += l;
1123 if (copied == desc->elem_size) {
1124 err = desc->xcode(desc, elem);
1125 if (err)
1126 goto out;
1127 copied = 0;
1128 }
1129 }
1130 }
1131 if (avail_here) {
1132 kunmap(*ppages);
1133 ppages++;
1134 c = kmap(*ppages);
1135 }
1136
1137 avail_page = min(avail_here,
1138 (unsigned int) PAGE_CACHE_SIZE);
1139 }
1140 base = buf->page_len; /* align to start of tail */
1141 }
1142
1143 /* process tail */
1144 base -= buf->page_len;
1145 if (todo) {
1146 c = buf->tail->iov_base + base;
1147 if (copied) {
1148 unsigned int l = desc->elem_size - copied;
1149
1150 if (encode)
1151 memcpy(c, elem + copied, l);
1152 else {
1153 memcpy(elem + copied, c, l);
1154 err = desc->xcode(desc, elem);
1155 if (err)
1156 goto out;
1157 }
1158 todo -= l;
1159 c += l;
1160 }
1161 while (todo) {
1162 err = desc->xcode(desc, c);
1163 if (err)
1164 goto out;
1165 c += desc->elem_size;
1166 todo -= desc->elem_size;
1167 }
1168 }
1169 err = 0;
1170
1171out:
Jesper Juhla51482b2005-11-08 09:41:34 -08001172 kfree(elem);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +00001173 if (ppages)
1174 kunmap(*ppages);
1175 return err;
1176}
1177
1178int
1179xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
1180 struct xdr_array2_desc *desc)
1181{
1182 if (base >= buf->len)
1183 return -EINVAL;
1184
1185 return xdr_xcode_array2(buf, base, desc, 0);
1186}
Trond Myklebust468039e2008-12-23 15:21:31 -05001187EXPORT_SYMBOL_GPL(xdr_decode_array2);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +00001188
1189int
1190xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
1191 struct xdr_array2_desc *desc)
1192{
1193 if ((unsigned long) base + 4 + desc->array_len * desc->elem_size >
1194 buf->head->iov_len + buf->page_len + buf->tail->iov_len)
1195 return -EINVAL;
1196
1197 return xdr_xcode_array2(buf, base, desc, 1);
1198}
Trond Myklebust468039e2008-12-23 15:21:31 -05001199EXPORT_SYMBOL_GPL(xdr_encode_array2);
Olga Kornievskaia37a4e6c2006-12-04 20:22:33 -05001200
1201int
1202xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len,
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001203 int (*actor)(struct scatterlist *, void *), void *data)
Olga Kornievskaia37a4e6c2006-12-04 20:22:33 -05001204{
1205 int i, ret = 0;
1206 unsigned page_len, thislen, page_offset;
1207 struct scatterlist sg[1];
1208
Herbert Xu68e3f5d2007-10-27 00:52:07 -07001209 sg_init_table(sg, 1);
1210
Olga Kornievskaia37a4e6c2006-12-04 20:22:33 -05001211 if (offset >= buf->head[0].iov_len) {
1212 offset -= buf->head[0].iov_len;
1213 } else {
1214 thislen = buf->head[0].iov_len - offset;
1215 if (thislen > len)
1216 thislen = len;
1217 sg_set_buf(sg, buf->head[0].iov_base + offset, thislen);
1218 ret = actor(sg, data);
1219 if (ret)
1220 goto out;
1221 offset = 0;
1222 len -= thislen;
1223 }
1224 if (len == 0)
1225 goto out;
1226
1227 if (offset >= buf->page_len) {
1228 offset -= buf->page_len;
1229 } else {
1230 page_len = buf->page_len - offset;
1231 if (page_len > len)
1232 page_len = len;
1233 len -= page_len;
1234 page_offset = (offset + buf->page_base) & (PAGE_CACHE_SIZE - 1);
1235 i = (offset + buf->page_base) >> PAGE_CACHE_SHIFT;
1236 thislen = PAGE_CACHE_SIZE - page_offset;
1237 do {
1238 if (thislen > page_len)
1239 thislen = page_len;
Jens Axboe642f1492007-10-24 11:20:47 +02001240 sg_set_page(sg, buf->pages[i], thislen, page_offset);
Olga Kornievskaia37a4e6c2006-12-04 20:22:33 -05001241 ret = actor(sg, data);
1242 if (ret)
1243 goto out;
1244 page_len -= thislen;
1245 i++;
1246 page_offset = 0;
1247 thislen = PAGE_CACHE_SIZE;
1248 } while (page_len != 0);
1249 offset = 0;
1250 }
1251 if (len == 0)
1252 goto out;
1253 if (offset < buf->tail[0].iov_len) {
1254 thislen = buf->tail[0].iov_len - offset;
1255 if (thislen > len)
1256 thislen = len;
1257 sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen);
1258 ret = actor(sg, data);
1259 len -= thislen;
1260 }
1261 if (len != 0)
1262 ret = -EINVAL;
1263out:
1264 return ret;
1265}
Trond Myklebust468039e2008-12-23 15:21:31 -05001266EXPORT_SYMBOL_GPL(xdr_process_buf);
Olga Kornievskaia37a4e6c2006-12-04 20:22:33 -05001267