ia64/linux-2.6.18-xen.hg

view net/sunrpc/xdr.c @ 871:9cbcc9008446

xen/x86: don't initialize cpu_data[]'s apicid field on generic code

Afaict, this is not only redundant with the intialization done in
drivers/xen/core/smpboot.c, but actually results - at least for
secondary CPUs - in the Xen-specific value written to be later
overwritten with whatever the generic code determines (with no
guarantee that the two values are identical).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu May 14 10:09:15 2009 +0100 (2009-05-14)
parents 831230e53067
children
line source
1 /*
2 * linux/net/sunrpc/xdr.c
3 *
4 * Generic XDR support.
5 *
6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
7 */
9 #include <linux/module.h>
10 #include <linux/types.h>
11 #include <linux/string.h>
12 #include <linux/kernel.h>
13 #include <linux/pagemap.h>
14 #include <linux/errno.h>
15 #include <linux/sunrpc/xdr.h>
16 #include <linux/sunrpc/msg_prot.h>
18 /*
19 * XDR functions for basic NFS types
20 */
21 u32 *
22 xdr_encode_netobj(u32 *p, const struct xdr_netobj *obj)
23 {
24 unsigned int quadlen = XDR_QUADLEN(obj->len);
26 p[quadlen] = 0; /* zero trailing bytes */
27 *p++ = htonl(obj->len);
28 memcpy(p, obj->data, obj->len);
29 return p + XDR_QUADLEN(obj->len);
30 }
32 u32 *
33 xdr_decode_netobj(u32 *p, struct xdr_netobj *obj)
34 {
35 unsigned int len;
37 if ((len = ntohl(*p++)) > XDR_MAX_NETOBJ)
38 return NULL;
39 obj->len = len;
40 obj->data = (u8 *) p;
41 return p + XDR_QUADLEN(len);
42 }
44 /**
45 * xdr_encode_opaque_fixed - Encode fixed length opaque data
46 * @p: pointer to current position in XDR buffer.
47 * @ptr: pointer to data to encode (or NULL)
48 * @nbytes: size of data.
49 *
50 * Copy the array of data of length nbytes at ptr to the XDR buffer
51 * at position p, then align to the next 32-bit boundary by padding
52 * with zero bytes (see RFC1832).
53 * Note: if ptr is NULL, only the padding is performed.
54 *
55 * Returns the updated current XDR buffer position
56 *
57 */
58 u32 *xdr_encode_opaque_fixed(u32 *p, const void *ptr, unsigned int nbytes)
59 {
60 if (likely(nbytes != 0)) {
61 unsigned int quadlen = XDR_QUADLEN(nbytes);
62 unsigned int padding = (quadlen << 2) - nbytes;
64 if (ptr != NULL)
65 memcpy(p, ptr, nbytes);
66 if (padding != 0)
67 memset((char *)p + nbytes, 0, padding);
68 p += quadlen;
69 }
70 return p;
71 }
72 EXPORT_SYMBOL(xdr_encode_opaque_fixed);
74 /**
75 * xdr_encode_opaque - Encode variable length opaque data
76 * @p: pointer to current position in XDR buffer.
77 * @ptr: pointer to data to encode (or NULL)
78 * @nbytes: size of data.
79 *
80 * Returns the updated current XDR buffer position
81 */
82 u32 *xdr_encode_opaque(u32 *p, const void *ptr, unsigned int nbytes)
83 {
84 *p++ = htonl(nbytes);
85 return xdr_encode_opaque_fixed(p, ptr, nbytes);
86 }
87 EXPORT_SYMBOL(xdr_encode_opaque);
89 u32 *
90 xdr_encode_string(u32 *p, const char *string)
91 {
92 return xdr_encode_array(p, string, strlen(string));
93 }
95 u32 *
96 xdr_decode_string_inplace(u32 *p, char **sp, int *lenp, int maxlen)
97 {
98 unsigned int len;
100 if ((len = ntohl(*p++)) > maxlen)
101 return NULL;
102 *lenp = len;
103 *sp = (char *) p;
104 return p + XDR_QUADLEN(len);
105 }
107 void
108 xdr_encode_pages(struct xdr_buf *xdr, struct page **pages, unsigned int base,
109 unsigned int len)
110 {
111 struct kvec *tail = xdr->tail;
112 u32 *p;
114 xdr->pages = pages;
115 xdr->page_base = base;
116 xdr->page_len = len;
118 p = (u32 *)xdr->head[0].iov_base + XDR_QUADLEN(xdr->head[0].iov_len);
119 tail->iov_base = p;
120 tail->iov_len = 0;
122 if (len & 3) {
123 unsigned int pad = 4 - (len & 3);
125 *p = 0;
126 tail->iov_base = (char *)p + (len & 3);
127 tail->iov_len = pad;
128 len += pad;
129 }
130 xdr->buflen += len;
131 xdr->len += len;
132 }
134 void
135 xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset,
136 struct page **pages, unsigned int base, unsigned int len)
137 {
138 struct kvec *head = xdr->head;
139 struct kvec *tail = xdr->tail;
140 char *buf = (char *)head->iov_base;
141 unsigned int buflen = head->iov_len;
143 head->iov_len = offset;
145 xdr->pages = pages;
146 xdr->page_base = base;
147 xdr->page_len = len;
149 tail->iov_base = buf + offset;
150 tail->iov_len = buflen - offset;
152 xdr->buflen += len;
153 }
156 /*
157 * Helper routines for doing 'memmove' like operations on a struct xdr_buf
158 *
159 * _shift_data_right_pages
160 * @pages: vector of pages containing both the source and dest memory area.
161 * @pgto_base: page vector address of destination
162 * @pgfrom_base: page vector address of source
163 * @len: number of bytes to copy
164 *
165 * Note: the addresses pgto_base and pgfrom_base are both calculated in
166 * the same way:
167 * if a memory area starts at byte 'base' in page 'pages[i]',
168 * then its address is given as (i << PAGE_CACHE_SHIFT) + base
169 * Also note: pgfrom_base must be < pgto_base, but the memory areas
170 * they point to may overlap.
171 */
172 static void
173 _shift_data_right_pages(struct page **pages, size_t pgto_base,
174 size_t pgfrom_base, size_t len)
175 {
176 struct page **pgfrom, **pgto;
177 char *vfrom, *vto;
178 size_t copy;
180 BUG_ON(pgto_base <= pgfrom_base);
182 pgto_base += len;
183 pgfrom_base += len;
185 pgto = pages + (pgto_base >> PAGE_CACHE_SHIFT);
186 pgfrom = pages + (pgfrom_base >> PAGE_CACHE_SHIFT);
188 pgto_base &= ~PAGE_CACHE_MASK;
189 pgfrom_base &= ~PAGE_CACHE_MASK;
191 do {
192 /* Are any pointers crossing a page boundary? */
193 if (pgto_base == 0) {
194 pgto_base = PAGE_CACHE_SIZE;
195 pgto--;
196 }
197 if (pgfrom_base == 0) {
198 pgfrom_base = PAGE_CACHE_SIZE;
199 pgfrom--;
200 }
202 copy = len;
203 if (copy > pgto_base)
204 copy = pgto_base;
205 if (copy > pgfrom_base)
206 copy = pgfrom_base;
207 pgto_base -= copy;
208 pgfrom_base -= copy;
210 vto = kmap_atomic(*pgto, KM_USER0);
211 vfrom = kmap_atomic(*pgfrom, KM_USER1);
212 memmove(vto + pgto_base, vfrom + pgfrom_base, copy);
213 flush_dcache_page(*pgto);
214 kunmap_atomic(vfrom, KM_USER1);
215 kunmap_atomic(vto, KM_USER0);
217 } while ((len -= copy) != 0);
218 }
220 /*
221 * _copy_to_pages
222 * @pages: array of pages
223 * @pgbase: page vector address of destination
224 * @p: pointer to source data
225 * @len: length
226 *
227 * Copies data from an arbitrary memory location into an array of pages
228 * The copy is assumed to be non-overlapping.
229 */
230 static void
231 _copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len)
232 {
233 struct page **pgto;
234 char *vto;
235 size_t copy;
237 pgto = pages + (pgbase >> PAGE_CACHE_SHIFT);
238 pgbase &= ~PAGE_CACHE_MASK;
240 do {
241 copy = PAGE_CACHE_SIZE - pgbase;
242 if (copy > len)
243 copy = len;
245 vto = kmap_atomic(*pgto, KM_USER0);
246 memcpy(vto + pgbase, p, copy);
247 kunmap_atomic(vto, KM_USER0);
249 pgbase += copy;
250 if (pgbase == PAGE_CACHE_SIZE) {
251 flush_dcache_page(*pgto);
252 pgbase = 0;
253 pgto++;
254 }
255 p += copy;
257 } while ((len -= copy) != 0);
258 flush_dcache_page(*pgto);
259 }
261 /*
262 * _copy_from_pages
263 * @p: pointer to destination
264 * @pages: array of pages
265 * @pgbase: offset of source data
266 * @len: length
267 *
268 * Copies data into an arbitrary memory location from an array of pages
269 * The copy is assumed to be non-overlapping.
270 */
271 static void
272 _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len)
273 {
274 struct page **pgfrom;
275 char *vfrom;
276 size_t copy;
278 pgfrom = pages + (pgbase >> PAGE_CACHE_SHIFT);
279 pgbase &= ~PAGE_CACHE_MASK;
281 do {
282 copy = PAGE_CACHE_SIZE - pgbase;
283 if (copy > len)
284 copy = len;
286 vfrom = kmap_atomic(*pgfrom, KM_USER0);
287 memcpy(p, vfrom + pgbase, copy);
288 kunmap_atomic(vfrom, KM_USER0);
290 pgbase += copy;
291 if (pgbase == PAGE_CACHE_SIZE) {
292 pgbase = 0;
293 pgfrom++;
294 }
295 p += copy;
297 } while ((len -= copy) != 0);
298 }
300 /*
301 * xdr_shrink_bufhead
302 * @buf: xdr_buf
303 * @len: bytes to remove from buf->head[0]
304 *
305 * Shrinks XDR buffer's header kvec buf->head[0] by
306 * 'len' bytes. The extra data is not lost, but is instead
307 * moved into the inlined pages and/or the tail.
308 */
309 static void
310 xdr_shrink_bufhead(struct xdr_buf *buf, size_t len)
311 {
312 struct kvec *head, *tail;
313 size_t copy, offs;
314 unsigned int pglen = buf->page_len;
316 tail = buf->tail;
317 head = buf->head;
318 BUG_ON (len > head->iov_len);
320 /* Shift the tail first */
321 if (tail->iov_len != 0) {
322 if (tail->iov_len > len) {
323 copy = tail->iov_len - len;
324 memmove((char *)tail->iov_base + len,
325 tail->iov_base, copy);
326 }
327 /* Copy from the inlined pages into the tail */
328 copy = len;
329 if (copy > pglen)
330 copy = pglen;
331 offs = len - copy;
332 if (offs >= tail->iov_len)
333 copy = 0;
334 else if (copy > tail->iov_len - offs)
335 copy = tail->iov_len - offs;
336 if (copy != 0)
337 _copy_from_pages((char *)tail->iov_base + offs,
338 buf->pages,
339 buf->page_base + pglen + offs - len,
340 copy);
341 /* Do we also need to copy data from the head into the tail ? */
342 if (len > pglen) {
343 offs = copy = len - pglen;
344 if (copy > tail->iov_len)
345 copy = tail->iov_len;
346 memcpy(tail->iov_base,
347 (char *)head->iov_base +
348 head->iov_len - offs,
349 copy);
350 }
351 }
352 /* Now handle pages */
353 if (pglen != 0) {
354 if (pglen > len)
355 _shift_data_right_pages(buf->pages,
356 buf->page_base + len,
357 buf->page_base,
358 pglen - len);
359 copy = len;
360 if (len > pglen)
361 copy = pglen;
362 _copy_to_pages(buf->pages, buf->page_base,
363 (char *)head->iov_base + head->iov_len - len,
364 copy);
365 }
366 head->iov_len -= len;
367 buf->buflen -= len;
368 /* Have we truncated the message? */
369 if (buf->len > buf->buflen)
370 buf->len = buf->buflen;
371 }
373 /*
374 * xdr_shrink_pagelen
375 * @buf: xdr_buf
376 * @len: bytes to remove from buf->pages
377 *
378 * Shrinks XDR buffer's page array buf->pages by
379 * 'len' bytes. The extra data is not lost, but is instead
380 * moved into the tail.
381 */
382 static void
383 xdr_shrink_pagelen(struct xdr_buf *buf, size_t len)
384 {
385 struct kvec *tail;
386 size_t copy;
387 char *p;
388 unsigned int pglen = buf->page_len;
390 tail = buf->tail;
391 BUG_ON (len > pglen);
393 /* Shift the tail first */
394 if (tail->iov_len != 0) {
395 p = (char *)tail->iov_base + len;
396 if (tail->iov_len > len) {
397 copy = tail->iov_len - len;
398 memmove(p, tail->iov_base, copy);
399 } else
400 buf->buflen -= len;
401 /* Copy from the inlined pages into the tail */
402 copy = len;
403 if (copy > tail->iov_len)
404 copy = tail->iov_len;
405 _copy_from_pages((char *)tail->iov_base,
406 buf->pages, buf->page_base + pglen - len,
407 copy);
408 }
409 buf->page_len -= len;
410 buf->buflen -= len;
411 /* Have we truncated the message? */
412 if (buf->len > buf->buflen)
413 buf->len = buf->buflen;
414 }
416 void
417 xdr_shift_buf(struct xdr_buf *buf, size_t len)
418 {
419 xdr_shrink_bufhead(buf, len);
420 }
422 /**
423 * xdr_init_encode - Initialize a struct xdr_stream for sending data.
424 * @xdr: pointer to xdr_stream struct
425 * @buf: pointer to XDR buffer in which to encode data
426 * @p: current pointer inside XDR buffer
427 *
428 * Note: at the moment the RPC client only passes the length of our
429 * scratch buffer in the xdr_buf's header kvec. Previously this
430 * meant we needed to call xdr_adjust_iovec() after encoding the
431 * data. With the new scheme, the xdr_stream manages the details
432 * of the buffer length, and takes care of adjusting the kvec
433 * length for us.
434 */
435 void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, uint32_t *p)
436 {
437 struct kvec *iov = buf->head;
438 int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len;
440 BUG_ON(scratch_len < 0);
441 xdr->buf = buf;
442 xdr->iov = iov;
443 xdr->p = (uint32_t *)((char *)iov->iov_base + iov->iov_len);
444 xdr->end = (uint32_t *)((char *)iov->iov_base + scratch_len);
445 BUG_ON(iov->iov_len > scratch_len);
447 if (p != xdr->p && p != NULL) {
448 size_t len;
450 BUG_ON(p < xdr->p || p > xdr->end);
451 len = (char *)p - (char *)xdr->p;
452 xdr->p = p;
453 buf->len += len;
454 iov->iov_len += len;
455 }
456 }
457 EXPORT_SYMBOL(xdr_init_encode);
459 /**
460 * xdr_reserve_space - Reserve buffer space for sending
461 * @xdr: pointer to xdr_stream
462 * @nbytes: number of bytes to reserve
463 *
464 * Checks that we have enough buffer space to encode 'nbytes' more
465 * bytes of data. If so, update the total xdr_buf length, and
466 * adjust the length of the current kvec.
467 */
468 uint32_t * xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes)
469 {
470 uint32_t *p = xdr->p;
471 uint32_t *q;
473 /* align nbytes on the next 32-bit boundary */
474 nbytes += 3;
475 nbytes &= ~3;
476 q = p + (nbytes >> 2);
477 if (unlikely(q > xdr->end || q < p))
478 return NULL;
479 xdr->p = q;
480 xdr->iov->iov_len += nbytes;
481 xdr->buf->len += nbytes;
482 return p;
483 }
484 EXPORT_SYMBOL(xdr_reserve_space);
486 /**
487 * xdr_write_pages - Insert a list of pages into an XDR buffer for sending
488 * @xdr: pointer to xdr_stream
489 * @pages: list of pages
490 * @base: offset of first byte
491 * @len: length of data in bytes
492 *
493 */
494 void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int base,
495 unsigned int len)
496 {
497 struct xdr_buf *buf = xdr->buf;
498 struct kvec *iov = buf->tail;
499 buf->pages = pages;
500 buf->page_base = base;
501 buf->page_len = len;
503 iov->iov_base = (char *)xdr->p;
504 iov->iov_len = 0;
505 xdr->iov = iov;
507 if (len & 3) {
508 unsigned int pad = 4 - (len & 3);
510 BUG_ON(xdr->p >= xdr->end);
511 iov->iov_base = (char *)xdr->p + (len & 3);
512 iov->iov_len += pad;
513 len += pad;
514 *xdr->p++ = 0;
515 }
516 buf->buflen += len;
517 buf->len += len;
518 }
519 EXPORT_SYMBOL(xdr_write_pages);
521 /**
522 * xdr_init_decode - Initialize an xdr_stream for decoding data.
523 * @xdr: pointer to xdr_stream struct
524 * @buf: pointer to XDR buffer from which to decode data
525 * @p: current pointer inside XDR buffer
526 */
527 void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, uint32_t *p)
528 {
529 struct kvec *iov = buf->head;
530 unsigned int len = iov->iov_len;
532 if (len > buf->len)
533 len = buf->len;
534 xdr->buf = buf;
535 xdr->iov = iov;
536 xdr->p = p;
537 xdr->end = (uint32_t *)((char *)iov->iov_base + len);
538 }
539 EXPORT_SYMBOL(xdr_init_decode);
541 /**
542 * xdr_inline_decode - Retrieve non-page XDR data to decode
543 * @xdr: pointer to xdr_stream struct
544 * @nbytes: number of bytes of data to decode
545 *
546 * Check if the input buffer is long enough to enable us to decode
547 * 'nbytes' more bytes of data starting at the current position.
548 * If so return the current pointer, then update the current
549 * pointer position.
550 */
551 uint32_t * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
552 {
553 uint32_t *p = xdr->p;
554 uint32_t *q = p + XDR_QUADLEN(nbytes);
556 if (unlikely(q > xdr->end || q < p))
557 return NULL;
558 xdr->p = q;
559 return p;
560 }
561 EXPORT_SYMBOL(xdr_inline_decode);
563 /**
564 * xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position
565 * @xdr: pointer to xdr_stream struct
566 * @len: number of bytes of page data
567 *
568 * Moves data beyond the current pointer position from the XDR head[] buffer
569 * into the page list. Any data that lies beyond current position + "len"
570 * bytes is moved into the XDR tail[].
571 */
572 void xdr_read_pages(struct xdr_stream *xdr, unsigned int len)
573 {
574 struct xdr_buf *buf = xdr->buf;
575 struct kvec *iov;
576 ssize_t shift;
577 unsigned int end;
578 int padding;
580 /* Realign pages to current pointer position */
581 iov = buf->head;
582 shift = iov->iov_len + (char *)iov->iov_base - (char *)xdr->p;
583 if (shift > 0)
584 xdr_shrink_bufhead(buf, shift);
586 /* Truncate page data and move it into the tail */
587 if (buf->page_len > len)
588 xdr_shrink_pagelen(buf, buf->page_len - len);
589 padding = (XDR_QUADLEN(len) << 2) - len;
590 xdr->iov = iov = buf->tail;
591 /* Compute remaining message length. */
592 end = iov->iov_len;
593 shift = buf->buflen - buf->len;
594 if (shift < end)
595 end -= shift;
596 else if (shift > 0)
597 end = 0;
598 /*
599 * Position current pointer at beginning of tail, and
600 * set remaining message length.
601 */
602 xdr->p = (uint32_t *)((char *)iov->iov_base + padding);
603 xdr->end = (uint32_t *)((char *)iov->iov_base + end);
604 }
605 EXPORT_SYMBOL(xdr_read_pages);
607 /**
608 * xdr_enter_page - decode data from the XDR page
609 * @xdr: pointer to xdr_stream struct
610 * @len: number of bytes of page data
611 *
612 * Moves data beyond the current pointer position from the XDR head[] buffer
613 * into the page list. Any data that lies beyond current position + "len"
614 * bytes is moved into the XDR tail[]. The current pointer is then
615 * repositioned at the beginning of the first XDR page.
616 */
617 void xdr_enter_page(struct xdr_stream *xdr, unsigned int len)
618 {
619 char * kaddr = page_address(xdr->buf->pages[0]);
620 xdr_read_pages(xdr, len);
621 /*
622 * Position current pointer at beginning of tail, and
623 * set remaining message length.
624 */
625 if (len > PAGE_CACHE_SIZE - xdr->buf->page_base)
626 len = PAGE_CACHE_SIZE - xdr->buf->page_base;
627 xdr->p = (uint32_t *)(kaddr + xdr->buf->page_base);
628 xdr->end = (uint32_t *)((char *)xdr->p + len);
629 }
630 EXPORT_SYMBOL(xdr_enter_page);
632 static struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0};
634 void
635 xdr_buf_from_iov(struct kvec *iov, struct xdr_buf *buf)
636 {
637 buf->head[0] = *iov;
638 buf->tail[0] = empty_iov;
639 buf->page_len = 0;
640 buf->buflen = buf->len = iov->iov_len;
641 }
643 /* Sets subiov to the intersection of iov with the buffer of length len
644 * starting base bytes after iov. Indicates empty intersection by setting
645 * length of subiov to zero. Decrements len by length of subiov, sets base
646 * to zero (or decrements it by length of iov if subiov is empty). */
647 static void
648 iov_subsegment(struct kvec *iov, struct kvec *subiov, int *base, int *len)
649 {
650 if (*base > iov->iov_len) {
651 subiov->iov_base = NULL;
652 subiov->iov_len = 0;
653 *base -= iov->iov_len;
654 } else {
655 subiov->iov_base = iov->iov_base + *base;
656 subiov->iov_len = min(*len, (int)iov->iov_len - *base);
657 *base = 0;
658 }
659 *len -= subiov->iov_len;
660 }
662 /* Sets subbuf to the portion of buf of length len beginning base bytes
663 * from the start of buf. Returns -1 if base of length are out of bounds. */
664 int
665 xdr_buf_subsegment(struct xdr_buf *buf, struct xdr_buf *subbuf,
666 int base, int len)
667 {
668 int i;
670 subbuf->buflen = subbuf->len = len;
671 iov_subsegment(buf->head, subbuf->head, &base, &len);
673 if (base < buf->page_len) {
674 i = (base + buf->page_base) >> PAGE_CACHE_SHIFT;
675 subbuf->pages = &buf->pages[i];
676 subbuf->page_base = (base + buf->page_base) & ~PAGE_CACHE_MASK;
677 subbuf->page_len = min((int)buf->page_len - base, len);
678 len -= subbuf->page_len;
679 base = 0;
680 } else {
681 base -= buf->page_len;
682 subbuf->page_len = 0;
683 }
685 iov_subsegment(buf->tail, subbuf->tail, &base, &len);
686 if (base || len)
687 return -1;
688 return 0;
689 }
691 /* obj is assumed to point to allocated memory of size at least len: */
692 int
693 read_bytes_from_xdr_buf(struct xdr_buf *buf, int base, void *obj, int len)
694 {
695 struct xdr_buf subbuf;
696 int this_len;
697 int status;
699 status = xdr_buf_subsegment(buf, &subbuf, base, len);
700 if (status)
701 goto out;
702 this_len = min(len, (int)subbuf.head[0].iov_len);
703 memcpy(obj, subbuf.head[0].iov_base, this_len);
704 len -= this_len;
705 obj += this_len;
706 this_len = min(len, (int)subbuf.page_len);
707 if (this_len)
708 _copy_from_pages(obj, subbuf.pages, subbuf.page_base, this_len);
709 len -= this_len;
710 obj += this_len;
711 this_len = min(len, (int)subbuf.tail[0].iov_len);
712 memcpy(obj, subbuf.tail[0].iov_base, this_len);
713 out:
714 return status;
715 }
717 /* obj is assumed to point to allocated memory of size at least len: */
718 int
719 write_bytes_to_xdr_buf(struct xdr_buf *buf, int base, void *obj, int len)
720 {
721 struct xdr_buf subbuf;
722 int this_len;
723 int status;
725 status = xdr_buf_subsegment(buf, &subbuf, base, len);
726 if (status)
727 goto out;
728 this_len = min(len, (int)subbuf.head[0].iov_len);
729 memcpy(subbuf.head[0].iov_base, obj, this_len);
730 len -= this_len;
731 obj += this_len;
732 this_len = min(len, (int)subbuf.page_len);
733 if (this_len)
734 _copy_to_pages(subbuf.pages, subbuf.page_base, obj, this_len);
735 len -= this_len;
736 obj += this_len;
737 this_len = min(len, (int)subbuf.tail[0].iov_len);
738 memcpy(subbuf.tail[0].iov_base, obj, this_len);
739 out:
740 return status;
741 }
743 int
744 xdr_decode_word(struct xdr_buf *buf, int base, u32 *obj)
745 {
746 u32 raw;
747 int status;
749 status = read_bytes_from_xdr_buf(buf, base, &raw, sizeof(*obj));
750 if (status)
751 return status;
752 *obj = ntohl(raw);
753 return 0;
754 }
756 int
757 xdr_encode_word(struct xdr_buf *buf, int base, u32 obj)
758 {
759 u32 raw = htonl(obj);
761 return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj));
762 }
764 /* If the netobj starting offset bytes from the start of xdr_buf is contained
765 * entirely in the head or the tail, set object to point to it; otherwise
766 * try to find space for it at the end of the tail, copy it there, and
767 * set obj to point to it. */
768 int
769 xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, int offset)
770 {
771 u32 tail_offset = buf->head[0].iov_len + buf->page_len;
772 u32 obj_end_offset;
774 if (xdr_decode_word(buf, offset, &obj->len))
775 goto out;
776 obj_end_offset = offset + 4 + obj->len;
778 if (obj_end_offset <= buf->head[0].iov_len) {
779 /* The obj is contained entirely in the head: */
780 obj->data = buf->head[0].iov_base + offset + 4;
781 } else if (offset + 4 >= tail_offset) {
782 if (obj_end_offset - tail_offset
783 > buf->tail[0].iov_len)
784 goto out;
785 /* The obj is contained entirely in the tail: */
786 obj->data = buf->tail[0].iov_base
787 + offset - tail_offset + 4;
788 } else {
789 /* use end of tail as storage for obj:
790 * (We don't copy to the beginning because then we'd have
791 * to worry about doing a potentially overlapping copy.
792 * This assumes the object is at most half the length of the
793 * tail.) */
794 if (obj->len > buf->tail[0].iov_len)
795 goto out;
796 obj->data = buf->tail[0].iov_base + buf->tail[0].iov_len -
797 obj->len;
798 if (read_bytes_from_xdr_buf(buf, offset + 4,
799 obj->data, obj->len))
800 goto out;
802 }
803 return 0;
804 out:
805 return -1;
806 }
808 /* Returns 0 on success, or else a negative error code. */
809 static int
810 xdr_xcode_array2(struct xdr_buf *buf, unsigned int base,
811 struct xdr_array2_desc *desc, int encode)
812 {
813 char *elem = NULL, *c;
814 unsigned int copied = 0, todo, avail_here;
815 struct page **ppages = NULL;
816 int err;
818 if (encode) {
819 if (xdr_encode_word(buf, base, desc->array_len) != 0)
820 return -EINVAL;
821 } else {
822 if (xdr_decode_word(buf, base, &desc->array_len) != 0 ||
823 desc->array_len > desc->array_maxlen ||
824 (unsigned long) base + 4 + desc->array_len *
825 desc->elem_size > buf->len)
826 return -EINVAL;
827 }
828 base += 4;
830 if (!desc->xcode)
831 return 0;
833 todo = desc->array_len * desc->elem_size;
835 /* process head */
836 if (todo && base < buf->head->iov_len) {
837 c = buf->head->iov_base + base;
838 avail_here = min_t(unsigned int, todo,
839 buf->head->iov_len - base);
840 todo -= avail_here;
842 while (avail_here >= desc->elem_size) {
843 err = desc->xcode(desc, c);
844 if (err)
845 goto out;
846 c += desc->elem_size;
847 avail_here -= desc->elem_size;
848 }
849 if (avail_here) {
850 if (!elem) {
851 elem = kmalloc(desc->elem_size, GFP_KERNEL);
852 err = -ENOMEM;
853 if (!elem)
854 goto out;
855 }
856 if (encode) {
857 err = desc->xcode(desc, elem);
858 if (err)
859 goto out;
860 memcpy(c, elem, avail_here);
861 } else
862 memcpy(elem, c, avail_here);
863 copied = avail_here;
864 }
865 base = buf->head->iov_len; /* align to start of pages */
866 }
868 /* process pages array */
869 base -= buf->head->iov_len;
870 if (todo && base < buf->page_len) {
871 unsigned int avail_page;
873 avail_here = min(todo, buf->page_len - base);
874 todo -= avail_here;
876 base += buf->page_base;
877 ppages = buf->pages + (base >> PAGE_CACHE_SHIFT);
878 base &= ~PAGE_CACHE_MASK;
879 avail_page = min_t(unsigned int, PAGE_CACHE_SIZE - base,
880 avail_here);
881 c = kmap(*ppages) + base;
883 while (avail_here) {
884 avail_here -= avail_page;
885 if (copied || avail_page < desc->elem_size) {
886 unsigned int l = min(avail_page,
887 desc->elem_size - copied);
888 if (!elem) {
889 elem = kmalloc(desc->elem_size,
890 GFP_KERNEL);
891 err = -ENOMEM;
892 if (!elem)
893 goto out;
894 }
895 if (encode) {
896 if (!copied) {
897 err = desc->xcode(desc, elem);
898 if (err)
899 goto out;
900 }
901 memcpy(c, elem + copied, l);
902 copied += l;
903 if (copied == desc->elem_size)
904 copied = 0;
905 } else {
906 memcpy(elem + copied, c, l);
907 copied += l;
908 if (copied == desc->elem_size) {
909 err = desc->xcode(desc, elem);
910 if (err)
911 goto out;
912 copied = 0;
913 }
914 }
915 avail_page -= l;
916 c += l;
917 }
918 while (avail_page >= desc->elem_size) {
919 err = desc->xcode(desc, c);
920 if (err)
921 goto out;
922 c += desc->elem_size;
923 avail_page -= desc->elem_size;
924 }
925 if (avail_page) {
926 unsigned int l = min(avail_page,
927 desc->elem_size - copied);
928 if (!elem) {
929 elem = kmalloc(desc->elem_size,
930 GFP_KERNEL);
931 err = -ENOMEM;
932 if (!elem)
933 goto out;
934 }
935 if (encode) {
936 if (!copied) {
937 err = desc->xcode(desc, elem);
938 if (err)
939 goto out;
940 }
941 memcpy(c, elem + copied, l);
942 copied += l;
943 if (copied == desc->elem_size)
944 copied = 0;
945 } else {
946 memcpy(elem + copied, c, l);
947 copied += l;
948 if (copied == desc->elem_size) {
949 err = desc->xcode(desc, elem);
950 if (err)
951 goto out;
952 copied = 0;
953 }
954 }
955 }
956 if (avail_here) {
957 kunmap(*ppages);
958 ppages++;
959 c = kmap(*ppages);
960 }
962 avail_page = min(avail_here,
963 (unsigned int) PAGE_CACHE_SIZE);
964 }
965 base = buf->page_len; /* align to start of tail */
966 }
968 /* process tail */
969 base -= buf->page_len;
970 if (todo) {
971 c = buf->tail->iov_base + base;
972 if (copied) {
973 unsigned int l = desc->elem_size - copied;
975 if (encode)
976 memcpy(c, elem + copied, l);
977 else {
978 memcpy(elem + copied, c, l);
979 err = desc->xcode(desc, elem);
980 if (err)
981 goto out;
982 }
983 todo -= l;
984 c += l;
985 }
986 while (todo) {
987 err = desc->xcode(desc, c);
988 if (err)
989 goto out;
990 c += desc->elem_size;
991 todo -= desc->elem_size;
992 }
993 }
994 err = 0;
996 out:
997 kfree(elem);
998 if (ppages)
999 kunmap(*ppages);
1000 return err;
1003 int
1004 xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
1005 struct xdr_array2_desc *desc)
1007 if (base >= buf->len)
1008 return -EINVAL;
1010 return xdr_xcode_array2(buf, base, desc, 0);
1013 int
1014 xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
1015 struct xdr_array2_desc *desc)
1017 if ((unsigned long) base + 4 + desc->array_len * desc->elem_size >
1018 buf->head->iov_len + buf->page_len + buf->tail->iov_len)
1019 return -EINVAL;
1021 return xdr_xcode_array2(buf, base, desc, 1);