blob: 0afba1b4b65606437d141cb21a64e6d00f3855f4 [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
Cong Wangb8541782011-11-25 23:14:40 +0800125 kaddr = kmap_atomic(buf->pages[0]);
Chuck Leverb4687da2010-09-21 16:55:48 -0400126 kaddr[buf->page_base + len] = '\0';
Cong Wangb8541782011-11-25 23:14:40 +0800127 kunmap_atomic(kaddr);
Chuck Leverb4687da2010-09-21 16:55:48 -0400128}
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132xdr_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}
Trond Myklebust468039e2008-12-23 15:21:31 -0500151EXPORT_SYMBOL_GPL(xdr_inline_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153/*
154 * Helper routines for doing 'memmove' like operations on a struct xdr_buf
Ben Hutchings2c530402012-07-10 10:55:09 +0000155 */
156
157/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 * _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 */
171static 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) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 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
Cong Wangb8541782011-11-25 23:14:40 +0800209 vto = kmap_atomic(*pgto);
210 vfrom = kmap_atomic(*pgfrom);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 memmove(vto + pgto_base, vfrom + pgfrom_base, copy);
Trond Myklebustbce34812006-07-05 13:17:12 -0400212 flush_dcache_page(*pgto);
Cong Wangb8541782011-11-25 23:14:40 +0800213 kunmap_atomic(vfrom);
214 kunmap_atomic(vto);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
216 } while ((len -= copy) != 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217}
218
Ben Hutchings2c530402012-07-10 10:55:09 +0000219/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 * _copy_to_pages
221 * @pages: array of pages
222 * @pgbase: page vector address of destination
223 * @p: pointer to source data
224 * @len: length
225 *
226 * Copies data from an arbitrary memory location into an array of pages
227 * The copy is assumed to be non-overlapping.
228 */
229static void
230_copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len)
231{
232 struct page **pgto;
233 char *vto;
234 size_t copy;
235
236 pgto = pages + (pgbase >> PAGE_CACHE_SHIFT);
237 pgbase &= ~PAGE_CACHE_MASK;
238
Trond Myklebustdaeba892008-03-31 17:02:02 -0400239 for (;;) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 copy = PAGE_CACHE_SIZE - pgbase;
241 if (copy > len)
242 copy = len;
243
Cong Wangb8541782011-11-25 23:14:40 +0800244 vto = kmap_atomic(*pgto);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 memcpy(vto + pgbase, p, copy);
Cong Wangb8541782011-11-25 23:14:40 +0800246 kunmap_atomic(vto);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247
Trond Myklebustdaeba892008-03-31 17:02:02 -0400248 len -= copy;
249 if (len == 0)
250 break;
251
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 pgbase += copy;
253 if (pgbase == PAGE_CACHE_SIZE) {
254 flush_dcache_page(*pgto);
255 pgbase = 0;
256 pgto++;
257 }
258 p += copy;
Trond Myklebustdaeba892008-03-31 17:02:02 -0400259 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 flush_dcache_page(*pgto);
261}
262
Ben Hutchings2c530402012-07-10 10:55:09 +0000263/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 * _copy_from_pages
265 * @p: pointer to destination
266 * @pages: array of pages
267 * @pgbase: offset of source data
268 * @len: length
269 *
270 * Copies data into an arbitrary memory location from an array of pages
271 * The copy is assumed to be non-overlapping.
272 */
Andy Adamsonbf118a32011-12-07 11:55:27 -0500273void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274_copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len)
275{
276 struct page **pgfrom;
277 char *vfrom;
278 size_t copy;
279
280 pgfrom = pages + (pgbase >> PAGE_CACHE_SHIFT);
281 pgbase &= ~PAGE_CACHE_MASK;
282
283 do {
284 copy = PAGE_CACHE_SIZE - pgbase;
285 if (copy > len)
286 copy = len;
287
Cong Wangb8541782011-11-25 23:14:40 +0800288 vfrom = kmap_atomic(*pgfrom);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 memcpy(p, vfrom + pgbase, copy);
Cong Wangb8541782011-11-25 23:14:40 +0800290 kunmap_atomic(vfrom);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291
292 pgbase += copy;
293 if (pgbase == PAGE_CACHE_SIZE) {
294 pgbase = 0;
295 pgfrom++;
296 }
297 p += copy;
298
299 } while ((len -= copy) != 0);
300}
Andy Adamsonbf118a32011-12-07 11:55:27 -0500301EXPORT_SYMBOL_GPL(_copy_from_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302
Ben Hutchings2c530402012-07-10 10:55:09 +0000303/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 * xdr_shrink_bufhead
305 * @buf: xdr_buf
306 * @len: bytes to remove from buf->head[0]
307 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800308 * Shrinks XDR buffer's header kvec buf->head[0] by
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 * 'len' bytes. The extra data is not lost, but is instead
310 * moved into the inlined pages and/or the tail.
311 */
312static void
313xdr_shrink_bufhead(struct xdr_buf *buf, size_t len)
314{
315 struct kvec *head, *tail;
316 size_t copy, offs;
317 unsigned int pglen = buf->page_len;
318
319 tail = buf->tail;
320 head = buf->head;
321 BUG_ON (len > head->iov_len);
322
323 /* Shift the tail first */
324 if (tail->iov_len != 0) {
325 if (tail->iov_len > len) {
326 copy = tail->iov_len - len;
327 memmove((char *)tail->iov_base + len,
328 tail->iov_base, copy);
329 }
330 /* Copy from the inlined pages into the tail */
331 copy = len;
332 if (copy > pglen)
333 copy = pglen;
334 offs = len - copy;
335 if (offs >= tail->iov_len)
336 copy = 0;
337 else if (copy > tail->iov_len - offs)
338 copy = tail->iov_len - offs;
339 if (copy != 0)
340 _copy_from_pages((char *)tail->iov_base + offs,
341 buf->pages,
342 buf->page_base + pglen + offs - len,
343 copy);
344 /* Do we also need to copy data from the head into the tail ? */
345 if (len > pglen) {
346 offs = copy = len - pglen;
347 if (copy > tail->iov_len)
348 copy = tail->iov_len;
349 memcpy(tail->iov_base,
350 (char *)head->iov_base +
351 head->iov_len - offs,
352 copy);
353 }
354 }
355 /* Now handle pages */
356 if (pglen != 0) {
357 if (pglen > len)
358 _shift_data_right_pages(buf->pages,
359 buf->page_base + len,
360 buf->page_base,
361 pglen - len);
362 copy = len;
363 if (len > pglen)
364 copy = pglen;
365 _copy_to_pages(buf->pages, buf->page_base,
366 (char *)head->iov_base + head->iov_len - len,
367 copy);
368 }
369 head->iov_len -= len;
370 buf->buflen -= len;
371 /* Have we truncated the message? */
372 if (buf->len > buf->buflen)
373 buf->len = buf->buflen;
374}
375
Ben Hutchings2c530402012-07-10 10:55:09 +0000376/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 * xdr_shrink_pagelen
378 * @buf: xdr_buf
379 * @len: bytes to remove from buf->pages
380 *
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -0800381 * Shrinks XDR buffer's page array buf->pages by
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 * 'len' bytes. The extra data is not lost, but is instead
383 * moved into the tail.
384 */
385static void
386xdr_shrink_pagelen(struct xdr_buf *buf, size_t len)
387{
388 struct kvec *tail;
389 size_t copy;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 unsigned int pglen = buf->page_len;
Trond Myklebustcf187c22010-08-29 12:13:16 -0400391 unsigned int tailbuf_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392
393 tail = buf->tail;
394 BUG_ON (len > pglen);
395
Trond Myklebustcf187c22010-08-29 12:13:16 -0400396 tailbuf_len = buf->buflen - buf->head->iov_len - buf->page_len;
397
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 /* Shift the tail first */
Trond Myklebustcf187c22010-08-29 12:13:16 -0400399 if (tailbuf_len != 0) {
400 unsigned int free_space = tailbuf_len - tail->iov_len;
401
402 if (len < free_space)
403 free_space = len;
404 tail->iov_len += free_space;
405
Benny Halevy42d6d8a2010-08-29 12:13:15 -0400406 copy = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 if (tail->iov_len > len) {
Benny Halevy0fe62a352010-08-29 12:13:15 -0400408 char *p = (char *)tail->iov_base + len;
Benny Halevy2e29ebb2010-08-29 12:13:15 -0400409 memmove(p, tail->iov_base, tail->iov_len - len);
Benny Halevy42d6d8a2010-08-29 12:13:15 -0400410 } else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 copy = tail->iov_len;
Benny Halevy42d6d8a2010-08-29 12:13:15 -0400412 /* Copy from the inlined pages into the tail */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 _copy_from_pages((char *)tail->iov_base,
414 buf->pages, buf->page_base + pglen - len,
415 copy);
416 }
417 buf->page_len -= len;
418 buf->buflen -= len;
419 /* Have we truncated the message? */
420 if (buf->len > buf->buflen)
421 buf->len = buf->buflen;
422}
423
424void
425xdr_shift_buf(struct xdr_buf *buf, size_t len)
426{
427 xdr_shrink_bufhead(buf, len);
428}
Trond Myklebust468039e2008-12-23 15:21:31 -0500429EXPORT_SYMBOL_GPL(xdr_shift_buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430
431/**
Trond Myklebust4517d522012-06-21 17:14:46 -0400432 * xdr_stream_pos - Return the current offset from the start of the xdr_stream
433 * @xdr: pointer to struct xdr_stream
434 */
435unsigned int xdr_stream_pos(const struct xdr_stream *xdr)
436{
437 return (unsigned int)(XDR_QUADLEN(xdr->buf->len) - xdr->nwords) << 2;
438}
439EXPORT_SYMBOL_GPL(xdr_stream_pos);
440
441/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 * xdr_init_encode - Initialize a struct xdr_stream for sending data.
443 * @xdr: pointer to xdr_stream struct
444 * @buf: pointer to XDR buffer in which to encode data
445 * @p: current pointer inside XDR buffer
446 *
447 * Note: at the moment the RPC client only passes the length of our
448 * scratch buffer in the xdr_buf's header kvec. Previously this
449 * meant we needed to call xdr_adjust_iovec() after encoding the
450 * data. With the new scheme, the xdr_stream manages the details
451 * of the buffer length, and takes care of adjusting the kvec
452 * length for us.
453 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700454void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455{
456 struct kvec *iov = buf->head;
Trond Myklebust334ccfd2005-06-22 17:16:19 +0000457 int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458
Trond Myklebust334ccfd2005-06-22 17:16:19 +0000459 BUG_ON(scratch_len < 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460 xdr->buf = buf;
461 xdr->iov = iov;
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700462 xdr->p = (__be32 *)((char *)iov->iov_base + iov->iov_len);
463 xdr->end = (__be32 *)((char *)iov->iov_base + scratch_len);
Trond Myklebust334ccfd2005-06-22 17:16:19 +0000464 BUG_ON(iov->iov_len > scratch_len);
465
466 if (p != xdr->p && p != NULL) {
467 size_t len;
468
469 BUG_ON(p < xdr->p || p > xdr->end);
470 len = (char *)p - (char *)xdr->p;
471 xdr->p = p;
472 buf->len += len;
473 iov->iov_len += len;
474 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475}
Trond Myklebust468039e2008-12-23 15:21:31 -0500476EXPORT_SYMBOL_GPL(xdr_init_encode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477
478/**
479 * xdr_reserve_space - Reserve buffer space for sending
480 * @xdr: pointer to xdr_stream
481 * @nbytes: number of bytes to reserve
482 *
483 * Checks that we have enough buffer space to encode 'nbytes' more
484 * bytes of data. If so, update the total xdr_buf length, and
485 * adjust the length of the current kvec.
486 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700487__be32 * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488{
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700489 __be32 *p = xdr->p;
490 __be32 *q;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491
492 /* align nbytes on the next 32-bit boundary */
493 nbytes += 3;
494 nbytes &= ~3;
495 q = p + (nbytes >> 2);
496 if (unlikely(q > xdr->end || q < p))
497 return NULL;
498 xdr->p = q;
499 xdr->iov->iov_len += nbytes;
500 xdr->buf->len += nbytes;
501 return p;
502}
Trond Myklebust468039e2008-12-23 15:21:31 -0500503EXPORT_SYMBOL_GPL(xdr_reserve_space);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504
505/**
506 * xdr_write_pages - Insert a list of pages into an XDR buffer for sending
507 * @xdr: pointer to xdr_stream
508 * @pages: list of pages
509 * @base: offset of first byte
510 * @len: length of data in bytes
511 *
512 */
513void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base,
514 unsigned int len)
515{
516 struct xdr_buf *buf = xdr->buf;
517 struct kvec *iov = buf->tail;
518 buf->pages = pages;
519 buf->page_base = base;
520 buf->page_len = len;
521
522 iov->iov_base = (char *)xdr->p;
523 iov->iov_len = 0;
524 xdr->iov = iov;
525
526 if (len & 3) {
527 unsigned int pad = 4 - (len & 3);
528
529 BUG_ON(xdr->p >= xdr->end);
530 iov->iov_base = (char *)xdr->p + (len & 3);
531 iov->iov_len += pad;
532 len += pad;
533 *xdr->p++ = 0;
534 }
535 buf->buflen += len;
536 buf->len += len;
537}
Trond Myklebust468039e2008-12-23 15:21:31 -0500538EXPORT_SYMBOL_GPL(xdr_write_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539
Trond Myklebust66502392011-01-08 17:45:38 -0500540static void xdr_set_iov(struct xdr_stream *xdr, struct kvec *iov,
Trond Myklebust15376932012-06-28 17:17:48 -0400541 unsigned int len)
Trond Myklebust66502392011-01-08 17:45:38 -0500542{
543 if (len > iov->iov_len)
544 len = iov->iov_len;
Trond Myklebust15376932012-06-28 17:17:48 -0400545 xdr->p = (__be32*)iov->iov_base;
Trond Myklebust66502392011-01-08 17:45:38 -0500546 xdr->end = (__be32*)(iov->iov_base + len);
547 xdr->iov = iov;
548 xdr->page_ptr = NULL;
549}
550
551static int xdr_set_page_base(struct xdr_stream *xdr,
552 unsigned int base, unsigned int len)
553{
554 unsigned int pgnr;
555 unsigned int maxlen;
556 unsigned int pgoff;
557 unsigned int pgend;
558 void *kaddr;
559
560 maxlen = xdr->buf->page_len;
561 if (base >= maxlen)
562 return -EINVAL;
563 maxlen -= base;
564 if (len > maxlen)
565 len = maxlen;
566
567 base += xdr->buf->page_base;
568
569 pgnr = base >> PAGE_SHIFT;
570 xdr->page_ptr = &xdr->buf->pages[pgnr];
571 kaddr = page_address(*xdr->page_ptr);
572
573 pgoff = base & ~PAGE_MASK;
574 xdr->p = (__be32*)(kaddr + pgoff);
575
576 pgend = pgoff + len;
577 if (pgend > PAGE_SIZE)
578 pgend = PAGE_SIZE;
579 xdr->end = (__be32*)(kaddr + pgend);
580 xdr->iov = NULL;
581 return 0;
582}
583
584static void xdr_set_next_page(struct xdr_stream *xdr)
585{
586 unsigned int newbase;
587
588 newbase = (1 + xdr->page_ptr - xdr->buf->pages) << PAGE_SHIFT;
589 newbase -= xdr->buf->page_base;
590
591 if (xdr_set_page_base(xdr, newbase, PAGE_SIZE) < 0)
Trond Myklebust15376932012-06-28 17:17:48 -0400592 xdr_set_iov(xdr, xdr->buf->tail, xdr->buf->len);
Trond Myklebust66502392011-01-08 17:45:38 -0500593}
594
595static bool xdr_set_next_buffer(struct xdr_stream *xdr)
596{
597 if (xdr->page_ptr != NULL)
598 xdr_set_next_page(xdr);
599 else if (xdr->iov == xdr->buf->head) {
600 if (xdr_set_page_base(xdr, 0, PAGE_SIZE) < 0)
Trond Myklebust15376932012-06-28 17:17:48 -0400601 xdr_set_iov(xdr, xdr->buf->tail, xdr->buf->len);
Trond Myklebust66502392011-01-08 17:45:38 -0500602 }
603 return xdr->p != xdr->end;
604}
605
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606/**
607 * xdr_init_decode - Initialize an xdr_stream for decoding data.
608 * @xdr: pointer to xdr_stream struct
609 * @buf: pointer to XDR buffer from which to decode data
610 * @p: current pointer inside XDR buffer
611 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700612void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 xdr->buf = buf;
Trond Myklebust66502392011-01-08 17:45:38 -0500615 xdr->scratch.iov_base = NULL;
616 xdr->scratch.iov_len = 0;
Trond Myklebustbfeea1d2012-06-20 09:58:35 -0400617 xdr->nwords = XDR_QUADLEN(buf->len);
Trond Myklebust66502392011-01-08 17:45:38 -0500618 if (buf->head[0].iov_len != 0)
Trond Myklebust15376932012-06-28 17:17:48 -0400619 xdr_set_iov(xdr, buf->head, buf->len);
Trond Myklebust66502392011-01-08 17:45:38 -0500620 else if (buf->page_len != 0)
621 xdr_set_page_base(xdr, 0, buf->len);
Trond Myklebustbfeea1d2012-06-20 09:58:35 -0400622 if (p != NULL && p > xdr->p && xdr->end >= p) {
623 xdr->nwords -= p - xdr->p;
Trond Myklebust15376932012-06-28 17:17:48 -0400624 xdr->p = p;
Trond Myklebustbfeea1d2012-06-20 09:58:35 -0400625 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626}
Trond Myklebust468039e2008-12-23 15:21:31 -0500627EXPORT_SYMBOL_GPL(xdr_init_decode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628
Benny Halevyf7da7a12011-05-19 14:16:47 -0400629/**
630 * xdr_init_decode - Initialize an xdr_stream for decoding data.
631 * @xdr: pointer to xdr_stream struct
632 * @buf: pointer to XDR buffer from which to decode data
633 * @pages: list of pages to decode into
634 * @len: length in bytes of buffer in pages
635 */
636void xdr_init_decode_pages(struct xdr_stream *xdr, struct xdr_buf *buf,
637 struct page **pages, unsigned int len)
638{
639 memset(buf, 0, sizeof(*buf));
640 buf->pages = pages;
641 buf->page_len = len;
642 buf->buflen = len;
643 buf->len = len;
644 xdr_init_decode(xdr, buf, NULL);
645}
646EXPORT_SYMBOL_GPL(xdr_init_decode_pages);
647
Trond Myklebust66502392011-01-08 17:45:38 -0500648static __be32 * __xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
Trond Myklebustba8e4522010-10-19 19:58:49 -0400649{
Trond Myklebustbfeea1d2012-06-20 09:58:35 -0400650 unsigned int nwords = XDR_QUADLEN(nbytes);
Trond Myklebustba8e4522010-10-19 19:58:49 -0400651 __be32 *p = xdr->p;
Trond Myklebustbfeea1d2012-06-20 09:58:35 -0400652 __be32 *q = p + nwords;
Trond Myklebustba8e4522010-10-19 19:58:49 -0400653
Trond Myklebustbfeea1d2012-06-20 09:58:35 -0400654 if (unlikely(nwords > xdr->nwords || q > xdr->end || q < p))
Trond Myklebustba8e4522010-10-19 19:58:49 -0400655 return NULL;
Trond Myklebust66502392011-01-08 17:45:38 -0500656 xdr->p = q;
Trond Myklebustbfeea1d2012-06-20 09:58:35 -0400657 xdr->nwords -= nwords;
Trond Myklebustba8e4522010-10-19 19:58:49 -0400658 return p;
659}
Trond Myklebustba8e4522010-10-19 19:58:49 -0400660
661/**
Trond Myklebust66502392011-01-08 17:45:38 -0500662 * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
663 * @xdr: pointer to xdr_stream struct
664 * @buf: pointer to an empty buffer
665 * @buflen: size of 'buf'
666 *
667 * The scratch buffer is used when decoding from an array of pages.
668 * If an xdr_inline_decode() call spans across page boundaries, then
669 * we copy the data into the scratch buffer in order to allow linear
670 * access.
671 */
672void xdr_set_scratch_buffer(struct xdr_stream *xdr, void *buf, size_t buflen)
673{
674 xdr->scratch.iov_base = buf;
675 xdr->scratch.iov_len = buflen;
676}
677EXPORT_SYMBOL_GPL(xdr_set_scratch_buffer);
678
679static __be32 *xdr_copy_to_scratch(struct xdr_stream *xdr, size_t nbytes)
680{
681 __be32 *p;
682 void *cpdest = xdr->scratch.iov_base;
683 size_t cplen = (char *)xdr->end - (char *)xdr->p;
684
685 if (nbytes > xdr->scratch.iov_len)
686 return NULL;
687 memcpy(cpdest, xdr->p, cplen);
688 cpdest += cplen;
689 nbytes -= cplen;
690 if (!xdr_set_next_buffer(xdr))
691 return NULL;
692 p = __xdr_inline_decode(xdr, nbytes);
693 if (p == NULL)
694 return NULL;
695 memcpy(cpdest, p, nbytes);
696 return xdr->scratch.iov_base;
697}
698
699/**
700 * xdr_inline_decode - Retrieve XDR data to decode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 * @xdr: pointer to xdr_stream struct
702 * @nbytes: number of bytes of data to decode
703 *
704 * Check if the input buffer is long enough to enable us to decode
705 * 'nbytes' more bytes of data starting at the current position.
706 * If so return the current pointer, then update the current
707 * pointer position.
708 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700709__be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710{
Trond Myklebust66502392011-01-08 17:45:38 -0500711 __be32 *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712
Trond Myklebust66502392011-01-08 17:45:38 -0500713 if (nbytes == 0)
714 return xdr->p;
715 if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 return NULL;
Trond Myklebust66502392011-01-08 17:45:38 -0500717 p = __xdr_inline_decode(xdr, nbytes);
718 if (p != NULL)
719 return p;
720 return xdr_copy_to_scratch(xdr, nbytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721}
Trond Myklebust468039e2008-12-23 15:21:31 -0500722EXPORT_SYMBOL_GPL(xdr_inline_decode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723
Trond Myklebust3994ee62012-06-26 12:34:05 -0400724static unsigned int xdr_align_pages(struct xdr_stream *xdr, unsigned int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725{
726 struct xdr_buf *buf = xdr->buf;
727 struct kvec *iov;
Trond Myklebustbfeea1d2012-06-20 09:58:35 -0400728 unsigned int nwords = XDR_QUADLEN(len);
Trond Myklebustb760b312012-06-26 12:19:55 -0400729 unsigned int cur = xdr_stream_pos(xdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730
Trond Myklebustbfeea1d2012-06-20 09:58:35 -0400731 if (xdr->nwords == 0)
Trond Myklebustc337d362012-06-21 17:05:37 -0400732 return 0;
Trond Myklebustbfeea1d2012-06-20 09:58:35 -0400733 if (nwords > xdr->nwords) {
734 nwords = xdr->nwords;
735 len = nwords << 2;
736 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 /* Realign pages to current pointer position */
738 iov = buf->head;
Trond Myklebustb760b312012-06-26 12:19:55 -0400739 if (iov->iov_len > cur)
740 xdr_shrink_bufhead(buf, iov->iov_len - cur);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741
742 /* Truncate page data and move it into the tail */
743 if (buf->page_len > len)
744 xdr_shrink_pagelen(buf, buf->page_len - len);
Trond Myklebustbd00f842012-06-26 13:50:43 -0400745 xdr->nwords = XDR_QUADLEN(buf->len - cur);
Trond Myklebust3994ee62012-06-26 12:34:05 -0400746 return len;
747}
Trond Myklebustbd00f842012-06-26 13:50:43 -0400748
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749/**
750 * xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position
751 * @xdr: pointer to xdr_stream struct
752 * @len: number of bytes of page data
753 *
754 * Moves data beyond the current pointer position from the XDR head[] buffer
755 * into the page list. Any data that lies beyond current position + "len"
756 * bytes is moved into the XDR tail[].
Trond Myklebust3994ee62012-06-26 12:34:05 -0400757 *
758 * Returns the number of XDR encoded bytes now contained in the pages
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759 */
Trond Myklebust3994ee62012-06-26 12:34:05 -0400760unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761{
762 struct xdr_buf *buf = xdr->buf;
763 struct kvec *iov;
Trond Myklebust3994ee62012-06-26 12:34:05 -0400764 unsigned int nwords;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 unsigned int end;
Trond Myklebust3994ee62012-06-26 12:34:05 -0400766 unsigned int padding;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767
Trond Myklebust3994ee62012-06-26 12:34:05 -0400768 len = xdr_align_pages(xdr, len);
769 if (len == 0)
770 return 0;
771 nwords = XDR_QUADLEN(len);
Trond Myklebustbfeea1d2012-06-20 09:58:35 -0400772 padding = (nwords << 2) - len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773 xdr->iov = iov = buf->tail;
774 /* Compute remaining message length. */
Trond Myklebustbd00f842012-06-26 13:50:43 -0400775 end = ((xdr->nwords - nwords) << 2) + padding;
776 if (end > iov->iov_len)
777 end = iov->iov_len;
778
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 /*
780 * Position current pointer at beginning of tail, and
781 * set remaining message length.
782 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700783 xdr->p = (__be32 *)((char *)iov->iov_base + padding);
784 xdr->end = (__be32 *)((char *)iov->iov_base + end);
Trond Myklebust76cacaa2012-06-26 15:32:40 -0400785 xdr->page_ptr = NULL;
Trond Myklebustbfeea1d2012-06-20 09:58:35 -0400786 xdr->nwords = XDR_QUADLEN(end - padding);
Trond Myklebustc337d362012-06-21 17:05:37 -0400787 return len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788}
Trond Myklebust468039e2008-12-23 15:21:31 -0500789EXPORT_SYMBOL_GPL(xdr_read_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790
Trond Myklebust8b23ea72006-06-09 09:34:21 -0400791/**
792 * xdr_enter_page - decode data from the XDR page
793 * @xdr: pointer to xdr_stream struct
794 * @len: number of bytes of page data
795 *
796 * Moves data beyond the current pointer position from the XDR head[] buffer
797 * into the page list. Any data that lies beyond current position + "len"
798 * bytes is moved into the XDR tail[]. The current pointer is then
799 * repositioned at the beginning of the first XDR page.
800 */
801void xdr_enter_page(struct xdr_stream *xdr, unsigned int len)
802{
Trond Myklebustf8bb7f02012-06-21 14:53:10 -0400803 len = xdr_align_pages(xdr, len);
Trond Myklebust8b23ea72006-06-09 09:34:21 -0400804 /*
805 * Position current pointer at beginning of tail, and
806 * set remaining message length.
807 */
Trond Myklebustf8bb7f02012-06-21 14:53:10 -0400808 if (len != 0)
809 xdr_set_page_base(xdr, 0, len);
Trond Myklebust8b23ea72006-06-09 09:34:21 -0400810}
Trond Myklebust468039e2008-12-23 15:21:31 -0500811EXPORT_SYMBOL_GPL(xdr_enter_page);
Trond Myklebust8b23ea72006-06-09 09:34:21 -0400812
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813static struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0};
814
815void
816xdr_buf_from_iov(struct kvec *iov, struct xdr_buf *buf)
817{
818 buf->head[0] = *iov;
819 buf->tail[0] = empty_iov;
820 buf->page_len = 0;
821 buf->buflen = buf->len = iov->iov_len;
822}
Trond Myklebust468039e2008-12-23 15:21:31 -0500823EXPORT_SYMBOL_GPL(xdr_buf_from_iov);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825/* Sets subbuf to the portion of buf of length len beginning base bytes
826 * from the start of buf. Returns -1 if base of length are out of bounds. */
827int
828xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf,
Trond Myklebust1e789572006-08-31 15:09:19 -0400829 unsigned int base, unsigned int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831 subbuf->buflen = subbuf->len = len;
Trond Myklebust1e789572006-08-31 15:09:19 -0400832 if (base < buf->head[0].iov_len) {
833 subbuf->head[0].iov_base = buf->head[0].iov_base + base;
834 subbuf->head[0].iov_len = min_t(unsigned int, len,
835 buf->head[0].iov_len - base);
836 len -= subbuf->head[0].iov_len;
837 base = 0;
838 } else {
839 subbuf->head[0].iov_base = NULL;
840 subbuf->head[0].iov_len = 0;
841 base -= buf->head[0].iov_len;
842 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843
844 if (base < buf->page_len) {
Trond Myklebust1e789572006-08-31 15:09:19 -0400845 subbuf->page_len = min(buf->page_len - base, len);
846 base += buf->page_base;
847 subbuf->page_base = base & ~PAGE_CACHE_MASK;
848 subbuf->pages = &buf->pages[base >> PAGE_CACHE_SHIFT];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849 len -= subbuf->page_len;
850 base = 0;
851 } else {
852 base -= buf->page_len;
853 subbuf->page_len = 0;
854 }
855
Trond Myklebust1e789572006-08-31 15:09:19 -0400856 if (base < buf->tail[0].iov_len) {
857 subbuf->tail[0].iov_base = buf->tail[0].iov_base + base;
858 subbuf->tail[0].iov_len = min_t(unsigned int, len,
859 buf->tail[0].iov_len - base);
860 len -= subbuf->tail[0].iov_len;
861 base = 0;
862 } else {
863 subbuf->tail[0].iov_base = NULL;
864 subbuf->tail[0].iov_len = 0;
865 base -= buf->tail[0].iov_len;
866 }
867
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 if (base || len)
869 return -1;
870 return 0;
871}
Trond Myklebust468039e2008-12-23 15:21:31 -0500872EXPORT_SYMBOL_GPL(xdr_buf_subsegment);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400874static void __read_bytes_from_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875{
Trond Myklebust1e789572006-08-31 15:09:19 -0400876 unsigned int this_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400878 this_len = min_t(unsigned int, len, subbuf->head[0].iov_len);
879 memcpy(obj, subbuf->head[0].iov_base, this_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 len -= this_len;
881 obj += this_len;
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400882 this_len = min_t(unsigned int, len, subbuf->page_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883 if (this_len)
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400884 _copy_from_pages(obj, subbuf->pages, subbuf->page_base, this_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700885 len -= this_len;
886 obj += this_len;
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400887 this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len);
888 memcpy(obj, subbuf->tail[0].iov_base, this_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889}
890
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000891/* obj is assumed to point to allocated memory of size at least len: */
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400892int read_bytes_from_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len)
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000893{
894 struct xdr_buf subbuf;
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000895 int status;
896
897 status = xdr_buf_subsegment(buf, &subbuf, base, len);
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400898 if (status != 0)
899 return status;
900 __read_bytes_from_xdr_buf(&subbuf, obj, len);
901 return 0;
902}
Trond Myklebust468039e2008-12-23 15:21:31 -0500903EXPORT_SYMBOL_GPL(read_bytes_from_xdr_buf);
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400904
905static void __write_bytes_to_xdr_buf(struct xdr_buf *subbuf, void *obj, unsigned int len)
906{
907 unsigned int this_len;
908
909 this_len = min_t(unsigned int, len, subbuf->head[0].iov_len);
910 memcpy(subbuf->head[0].iov_base, obj, this_len);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000911 len -= this_len;
912 obj += this_len;
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400913 this_len = min_t(unsigned int, len, subbuf->page_len);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000914 if (this_len)
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400915 _copy_to_pages(subbuf->pages, subbuf->page_base, obj, this_len);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000916 len -= this_len;
917 obj += this_len;
Trond Myklebust4e3e43a2006-10-17 13:47:24 -0400918 this_len = min_t(unsigned int, len, subbuf->tail[0].iov_len);
919 memcpy(subbuf->tail[0].iov_base, obj, this_len);
920}
921
922/* obj is assumed to point to allocated memory of size at least len: */
923int write_bytes_to_xdr_buf(struct xdr_buf *buf, unsigned int base, void *obj, unsigned int len)
924{
925 struct xdr_buf subbuf;
926 int status;
927
928 status = xdr_buf_subsegment(buf, &subbuf, base, len);
929 if (status != 0)
930 return status;
931 __write_bytes_to_xdr_buf(&subbuf, obj, len);
932 return 0;
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000933}
Kevin Coffmanc43abae2010-03-17 13:02:58 -0400934EXPORT_SYMBOL_GPL(write_bytes_to_xdr_buf);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000935
936int
Trond Myklebust1e789572006-08-31 15:09:19 -0400937xdr_decode_word(struct xdr_buf *buf, unsigned int base, u32 *obj)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938{
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700939 __be32 raw;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700940 int status;
941
942 status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
943 if (status)
944 return status;
Benny Halevy98866b52009-08-14 17:18:49 +0300945 *obj = be32_to_cpu(raw);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946 return 0;
947}
Trond Myklebust468039e2008-12-23 15:21:31 -0500948EXPORT_SYMBOL_GPL(xdr_decode_word);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000950int
Trond Myklebust1e789572006-08-31 15:09:19 -0400951xdr_encode_word(struct xdr_buf *buf, unsigned int base, u32 obj)
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000952{
Benny Halevy9f162d22009-08-14 17:18:44 +0300953 __be32 raw = cpu_to_be32(obj);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000954
955 return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj));
956}
Trond Myklebust468039e2008-12-23 15:21:31 -0500957EXPORT_SYMBOL_GPL(xdr_encode_word);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000958
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959/* If the netobj starting offset bytes from the start of xdr_buf is contained
960 * entirely in the head or the tail, set object to point to it; otherwise
961 * try to find space for it at the end of the tail, copy it there, and
962 * set obj to point to it. */
Trond Myklebustbee57c92006-10-09 22:08:22 -0400963int xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, unsigned int offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964{
Trond Myklebustbee57c92006-10-09 22:08:22 -0400965 struct xdr_buf subbuf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000967 if (xdr_decode_word(buf, offset, &obj->len))
Trond Myklebustbee57c92006-10-09 22:08:22 -0400968 return -EFAULT;
969 if (xdr_buf_subsegment(buf, &subbuf, offset + 4, obj->len))
970 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971
Trond Myklebustbee57c92006-10-09 22:08:22 -0400972 /* Is the obj contained entirely in the head? */
973 obj->data = subbuf.head[0].iov_base;
974 if (subbuf.head[0].iov_len == obj->len)
975 return 0;
976 /* ..or is the obj contained entirely in the tail? */
977 obj->data = subbuf.tail[0].iov_base;
978 if (subbuf.tail[0].iov_len == obj->len)
979 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980
Trond Myklebustbee57c92006-10-09 22:08:22 -0400981 /* use end of tail as storage for obj:
982 * (We don't copy to the beginning because then we'd have
983 * to worry about doing a potentially overlapping copy.
984 * This assumes the object is at most half the length of the
985 * tail.) */
986 if (obj->len > buf->buflen - buf->len)
987 return -ENOMEM;
988 if (buf->tail[0].iov_len != 0)
989 obj->data = buf->tail[0].iov_base + buf->tail[0].iov_len;
990 else
991 obj->data = buf->head[0].iov_base + buf->head[0].iov_len;
992 __read_bytes_from_xdr_buf(&subbuf, obj->data, obj->len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994}
Trond Myklebust468039e2008-12-23 15:21:31 -0500995EXPORT_SYMBOL_GPL(xdr_buf_read_netobj);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +0000996
997/* Returns 0 on success, or else a negative error code. */
998static int
999xdr_xcode_array2(struct xdr_buf *buf, unsigned int base,
1000 struct xdr_array2_desc *desc, int encode)
1001{
1002 char *elem = NULL, *c;
1003 unsigned int copied = 0, todo, avail_here;
1004 struct page **ppages = NULL;
1005 int err;
1006
1007 if (encode) {
1008 if (xdr_encode_word(buf, base, desc->array_len) != 0)
1009 return -EINVAL;
1010 } else {
1011 if (xdr_decode_word(buf, base, &desc->array_len) != 0 ||
Trond Myklebust58fcb8d2005-08-10 18:15:12 -04001012 desc->array_len > desc->array_maxlen ||
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +00001013 (unsigned long) base + 4 + desc->array_len *
1014 desc->elem_size > buf->len)
1015 return -EINVAL;
1016 }
1017 base += 4;
1018
1019 if (!desc->xcode)
1020 return 0;
1021
1022 todo = desc->array_len * desc->elem_size;
1023
1024 /* process head */
1025 if (todo && base < buf->head->iov_len) {
1026 c = buf->head->iov_base + base;
1027 avail_here = min_t(unsigned int, todo,
1028 buf->head->iov_len - base);
1029 todo -= avail_here;
1030
1031 while (avail_here >= desc->elem_size) {
1032 err = desc->xcode(desc, c);
1033 if (err)
1034 goto out;
1035 c += desc->elem_size;
1036 avail_here -= desc->elem_size;
1037 }
1038 if (avail_here) {
1039 if (!elem) {
1040 elem = kmalloc(desc->elem_size, GFP_KERNEL);
1041 err = -ENOMEM;
1042 if (!elem)
1043 goto out;
1044 }
1045 if (encode) {
1046 err = desc->xcode(desc, elem);
1047 if (err)
1048 goto out;
1049 memcpy(c, elem, avail_here);
1050 } else
1051 memcpy(elem, c, avail_here);
1052 copied = avail_here;
1053 }
1054 base = buf->head->iov_len; /* align to start of pages */
1055 }
1056
1057 /* process pages array */
1058 base -= buf->head->iov_len;
1059 if (todo && base < buf->page_len) {
1060 unsigned int avail_page;
1061
1062 avail_here = min(todo, buf->page_len - base);
1063 todo -= avail_here;
1064
1065 base += buf->page_base;
1066 ppages = buf->pages + (base >> PAGE_CACHE_SHIFT);
1067 base &= ~PAGE_CACHE_MASK;
1068 avail_page = min_t(unsigned int, PAGE_CACHE_SIZE - base,
1069 avail_here);
1070 c = kmap(*ppages) + base;
1071
1072 while (avail_here) {
1073 avail_here -= avail_page;
1074 if (copied || avail_page < desc->elem_size) {
1075 unsigned int l = min(avail_page,
1076 desc->elem_size - copied);
1077 if (!elem) {
1078 elem = kmalloc(desc->elem_size,
1079 GFP_KERNEL);
1080 err = -ENOMEM;
1081 if (!elem)
1082 goto out;
1083 }
1084 if (encode) {
1085 if (!copied) {
1086 err = desc->xcode(desc, elem);
1087 if (err)
1088 goto out;
1089 }
1090 memcpy(c, elem + copied, l);
1091 copied += l;
1092 if (copied == desc->elem_size)
1093 copied = 0;
1094 } else {
1095 memcpy(elem + copied, c, l);
1096 copied += l;
1097 if (copied == desc->elem_size) {
1098 err = desc->xcode(desc, elem);
1099 if (err)
1100 goto out;
1101 copied = 0;
1102 }
1103 }
1104 avail_page -= l;
1105 c += l;
1106 }
1107 while (avail_page >= desc->elem_size) {
1108 err = desc->xcode(desc, c);
1109 if (err)
1110 goto out;
1111 c += desc->elem_size;
1112 avail_page -= desc->elem_size;
1113 }
1114 if (avail_page) {
1115 unsigned int l = min(avail_page,
1116 desc->elem_size - copied);
1117 if (!elem) {
1118 elem = kmalloc(desc->elem_size,
1119 GFP_KERNEL);
1120 err = -ENOMEM;
1121 if (!elem)
1122 goto out;
1123 }
1124 if (encode) {
1125 if (!copied) {
1126 err = desc->xcode(desc, elem);
1127 if (err)
1128 goto out;
1129 }
1130 memcpy(c, elem + copied, l);
1131 copied += l;
1132 if (copied == desc->elem_size)
1133 copied = 0;
1134 } else {
1135 memcpy(elem + copied, c, l);
1136 copied += l;
1137 if (copied == desc->elem_size) {
1138 err = desc->xcode(desc, elem);
1139 if (err)
1140 goto out;
1141 copied = 0;
1142 }
1143 }
1144 }
1145 if (avail_here) {
1146 kunmap(*ppages);
1147 ppages++;
1148 c = kmap(*ppages);
1149 }
1150
1151 avail_page = min(avail_here,
1152 (unsigned int) PAGE_CACHE_SIZE);
1153 }
1154 base = buf->page_len; /* align to start of tail */
1155 }
1156
1157 /* process tail */
1158 base -= buf->page_len;
1159 if (todo) {
1160 c = buf->tail->iov_base + base;
1161 if (copied) {
1162 unsigned int l = desc->elem_size - copied;
1163
1164 if (encode)
1165 memcpy(c, elem + copied, l);
1166 else {
1167 memcpy(elem + copied, c, l);
1168 err = desc->xcode(desc, elem);
1169 if (err)
1170 goto out;
1171 }
1172 todo -= l;
1173 c += l;
1174 }
1175 while (todo) {
1176 err = desc->xcode(desc, c);
1177 if (err)
1178 goto out;
1179 c += desc->elem_size;
1180 todo -= desc->elem_size;
1181 }
1182 }
1183 err = 0;
1184
1185out:
Jesper Juhla51482b2005-11-08 09:41:34 -08001186 kfree(elem);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +00001187 if (ppages)
1188 kunmap(*ppages);
1189 return err;
1190}
1191
1192int
1193xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
1194 struct xdr_array2_desc *desc)
1195{
1196 if (base >= buf->len)
1197 return -EINVAL;
1198
1199 return xdr_xcode_array2(buf, base, desc, 0);
1200}
Trond Myklebust468039e2008-12-23 15:21:31 -05001201EXPORT_SYMBOL_GPL(xdr_decode_array2);
Andreas Gruenbacherbd8100e2005-06-22 17:16:24 +00001202
1203int
1204xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
1205 struct xdr_array2_desc *desc)
1206{
1207 if ((unsigned long) base + 4 + desc->array_len * desc->elem_size >
1208 buf->head->iov_len + buf->page_len + buf->tail->iov_len)
1209 return -EINVAL;
1210
1211 return xdr_xcode_array2(buf, base, desc, 1);
1212}
Trond Myklebust468039e2008-12-23 15:21:31 -05001213EXPORT_SYMBOL_GPL(xdr_encode_array2);
Olga Kornievskaia37a4e6c2006-12-04 20:22:33 -05001214
1215int
1216xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len,
YOSHIFUJI Hideakicca51722007-02-09 15:38:13 -08001217 int (*actor)(struct scatterlist *, void *), void *data)
Olga Kornievskaia37a4e6c2006-12-04 20:22:33 -05001218{
1219 int i, ret = 0;
Eric Dumazet95c96172012-04-15 05:58:06 +00001220 unsigned int page_len, thislen, page_offset;
Olga Kornievskaia37a4e6c2006-12-04 20:22:33 -05001221 struct scatterlist sg[1];
1222
Herbert Xu68e3f5d2007-10-27 00:52:07 -07001223 sg_init_table(sg, 1);
1224
Olga Kornievskaia37a4e6c2006-12-04 20:22:33 -05001225 if (offset >= buf->head[0].iov_len) {
1226 offset -= buf->head[0].iov_len;
1227 } else {
1228 thislen = buf->head[0].iov_len - offset;
1229 if (thislen > len)
1230 thislen = len;
1231 sg_set_buf(sg, buf->head[0].iov_base + offset, thislen);
1232 ret = actor(sg, data);
1233 if (ret)
1234 goto out;
1235 offset = 0;
1236 len -= thislen;
1237 }
1238 if (len == 0)
1239 goto out;
1240
1241 if (offset >= buf->page_len) {
1242 offset -= buf->page_len;
1243 } else {
1244 page_len = buf->page_len - offset;
1245 if (page_len > len)
1246 page_len = len;
1247 len -= page_len;
1248 page_offset = (offset + buf->page_base) & (PAGE_CACHE_SIZE - 1);
1249 i = (offset + buf->page_base) >> PAGE_CACHE_SHIFT;
1250 thislen = PAGE_CACHE_SIZE - page_offset;
1251 do {
1252 if (thislen > page_len)
1253 thislen = page_len;
Jens Axboe642f149032007-10-24 11:20:47 +02001254 sg_set_page(sg, buf->pages[i], thislen, page_offset);
Olga Kornievskaia37a4e6c2006-12-04 20:22:33 -05001255 ret = actor(sg, data);
1256 if (ret)
1257 goto out;
1258 page_len -= thislen;
1259 i++;
1260 page_offset = 0;
1261 thislen = PAGE_CACHE_SIZE;
1262 } while (page_len != 0);
1263 offset = 0;
1264 }
1265 if (len == 0)
1266 goto out;
1267 if (offset < buf->tail[0].iov_len) {
1268 thislen = buf->tail[0].iov_len - offset;
1269 if (thislen > len)
1270 thislen = len;
1271 sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen);
1272 ret = actor(sg, data);
1273 len -= thislen;
1274 }
1275 if (len != 0)
1276 ret = -EINVAL;
1277out:
1278 return ret;
1279}
Trond Myklebust468039e2008-12-23 15:21:31 -05001280EXPORT_SYMBOL_GPL(xdr_process_buf);
Olga Kornievskaia37a4e6c2006-12-04 20:22:33 -05001281