2 * linux/net/sunrpc/xdr.c
6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
9 #include <linux/module.h>
10 #include <linux/slab.h>
11 #include <linux/types.h>
12 #include <linux/string.h>
13 #include <linux/kernel.h>
14 #include <linux/pagemap.h>
15 #include <linux/errno.h>
16 #include <linux/sunrpc/xdr.h>
17 #include <linux/sunrpc/msg_prot.h>
20 * XDR functions for basic NFS types
23 xdr_encode_netobj(__be32
*p
, const struct xdr_netobj
*obj
)
25 unsigned int quadlen
= XDR_QUADLEN(obj
->len
);
27 p
[quadlen
] = 0; /* zero trailing bytes */
28 *p
++ = cpu_to_be32(obj
->len
);
29 memcpy(p
, obj
->data
, obj
->len
);
30 return p
+ XDR_QUADLEN(obj
->len
);
32 EXPORT_SYMBOL_GPL(xdr_encode_netobj
);
35 xdr_decode_netobj(__be32
*p
, struct xdr_netobj
*obj
)
39 if ((len
= be32_to_cpu(*p
++)) > XDR_MAX_NETOBJ
)
43 return p
+ XDR_QUADLEN(len
);
45 EXPORT_SYMBOL_GPL(xdr_decode_netobj
);
48 * xdr_encode_opaque_fixed - Encode fixed length opaque data
49 * @p: pointer to current position in XDR buffer.
50 * @ptr: pointer to data to encode (or NULL)
51 * @nbytes: size of data.
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.
58 * Returns the updated current XDR buffer position
61 __be32
*xdr_encode_opaque_fixed(__be32
*p
, const void *ptr
, unsigned int nbytes
)
63 if (likely(nbytes
!= 0)) {
64 unsigned int quadlen
= XDR_QUADLEN(nbytes
);
65 unsigned int padding
= (quadlen
<< 2) - nbytes
;
68 memcpy(p
, ptr
, nbytes
);
70 memset((char *)p
+ nbytes
, 0, padding
);
75 EXPORT_SYMBOL_GPL(xdr_encode_opaque_fixed
);
78 * xdr_encode_opaque - Encode variable length opaque data
79 * @p: pointer to current position in XDR buffer.
80 * @ptr: pointer to data to encode (or NULL)
81 * @nbytes: size of data.
83 * Returns the updated current XDR buffer position
85 __be32
*xdr_encode_opaque(__be32
*p
, const void *ptr
, unsigned int nbytes
)
87 *p
++ = cpu_to_be32(nbytes
);
88 return xdr_encode_opaque_fixed(p
, ptr
, nbytes
);
90 EXPORT_SYMBOL_GPL(xdr_encode_opaque
);
93 xdr_encode_string(__be32
*p
, const char *string
)
95 return xdr_encode_array(p
, string
, strlen(string
));
97 EXPORT_SYMBOL_GPL(xdr_encode_string
);
100 xdr_decode_string_inplace(__be32
*p
, char **sp
,
101 unsigned int *lenp
, unsigned int maxlen
)
105 len
= be32_to_cpu(*p
++);
110 return p
+ XDR_QUADLEN(len
);
112 EXPORT_SYMBOL_GPL(xdr_decode_string_inplace
);
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
121 xdr_terminate_string(struct xdr_buf
*buf
, const u32 len
)
125 kaddr
= kmap_atomic(buf
->pages
[0]);
126 kaddr
[buf
->page_base
+ len
] = '\0';
127 kunmap_atomic(kaddr
);
129 EXPORT_SYMBOL_GPL(xdr_terminate_string
);
132 xdr_encode_pages(struct xdr_buf
*xdr
, struct page
**pages
, unsigned int base
,
135 struct kvec
*tail
= xdr
->tail
;
139 xdr
->page_base
= base
;
142 p
= (u32
*)xdr
->head
[0].iov_base
+ XDR_QUADLEN(xdr
->head
[0].iov_len
);
147 unsigned int pad
= 4 - (len
& 3);
150 tail
->iov_base
= (char *)p
+ (len
& 3);
157 EXPORT_SYMBOL_GPL(xdr_encode_pages
);
160 xdr_inline_pages(struct xdr_buf
*xdr
, unsigned int offset
,
161 struct page
**pages
, unsigned int base
, unsigned int len
)
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
;
168 head
->iov_len
= offset
;
171 xdr
->page_base
= base
;
174 tail
->iov_base
= buf
+ offset
;
175 tail
->iov_len
= buflen
- offset
;
179 EXPORT_SYMBOL_GPL(xdr_inline_pages
);
182 * Helper routines for doing 'memmove' like operations on a struct xdr_buf
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
190 * Note: the addresses pgto_base and pgfrom_base are both calculated in
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.
198 _shift_data_right_pages(struct page
**pages
, size_t pgto_base
,
199 size_t pgfrom_base
, size_t len
)
201 struct page
**pgfrom
, **pgto
;
205 BUG_ON(pgto_base
<= pgfrom_base
);
210 pgto
= pages
+ (pgto_base
>> PAGE_CACHE_SHIFT
);
211 pgfrom
= pages
+ (pgfrom_base
>> PAGE_CACHE_SHIFT
);
213 pgto_base
&= ~PAGE_CACHE_MASK
;
214 pgfrom_base
&= ~PAGE_CACHE_MASK
;
217 /* Are any pointers crossing a page boundary? */
218 if (pgto_base
== 0) {
219 pgto_base
= PAGE_CACHE_SIZE
;
222 if (pgfrom_base
== 0) {
223 pgfrom_base
= PAGE_CACHE_SIZE
;
228 if (copy
> pgto_base
)
230 if (copy
> pgfrom_base
)
235 vto
= kmap_atomic(*pgto
);
236 vfrom
= kmap_atomic(*pgfrom
);
237 memmove(vto
+ pgto_base
, vfrom
+ pgfrom_base
, copy
);
238 flush_dcache_page(*pgto
);
239 kunmap_atomic(vfrom
);
242 } while ((len
-= copy
) != 0);
247 * @pages: array of pages
248 * @pgbase: page vector address of destination
249 * @p: pointer to source data
252 * Copies data from an arbitrary memory location into an array of pages
253 * The copy is assumed to be non-overlapping.
256 _copy_to_pages(struct page
**pages
, size_t pgbase
, const char *p
, size_t len
)
262 pgto
= pages
+ (pgbase
>> PAGE_CACHE_SHIFT
);
263 pgbase
&= ~PAGE_CACHE_MASK
;
266 copy
= PAGE_CACHE_SIZE
- pgbase
;
270 vto
= kmap_atomic(*pgto
);
271 memcpy(vto
+ pgbase
, p
, copy
);
279 if (pgbase
== PAGE_CACHE_SIZE
) {
280 flush_dcache_page(*pgto
);
286 flush_dcache_page(*pgto
);
291 * @p: pointer to destination
292 * @pages: array of pages
293 * @pgbase: offset of source data
296 * Copies data into an arbitrary memory location from an array of pages
297 * The copy is assumed to be non-overlapping.
300 _copy_from_pages(char *p
, struct page
**pages
, size_t pgbase
, size_t len
)
302 struct page
**pgfrom
;
306 pgfrom
= pages
+ (pgbase
>> PAGE_CACHE_SHIFT
);
307 pgbase
&= ~PAGE_CACHE_MASK
;
310 copy
= PAGE_CACHE_SIZE
- pgbase
;
314 vfrom
= kmap_atomic(*pgfrom
);
315 memcpy(p
, vfrom
+ pgbase
, copy
);
316 kunmap_atomic(vfrom
);
319 if (pgbase
== PAGE_CACHE_SIZE
) {
325 } while ((len
-= copy
) != 0);
327 EXPORT_SYMBOL_GPL(_copy_from_pages
);
332 * @len: bytes to remove from buf->head[0]
334 * Shrinks XDR buffer's header kvec buf->head[0] by
335 * 'len' bytes. The extra data is not lost, but is instead
336 * moved into the inlined pages and/or the tail.
339 xdr_shrink_bufhead(struct xdr_buf
*buf
, size_t len
)
341 struct kvec
*head
, *tail
;
343 unsigned int pglen
= buf
->page_len
;
347 BUG_ON (len
> head
->iov_len
);
349 /* Shift the tail first */
350 if (tail
->iov_len
!= 0) {
351 if (tail
->iov_len
> len
) {
352 copy
= tail
->iov_len
- len
;
353 memmove((char *)tail
->iov_base
+ len
,
354 tail
->iov_base
, copy
);
356 /* Copy from the inlined pages into the tail */
361 if (offs
>= tail
->iov_len
)
363 else if (copy
> tail
->iov_len
- offs
)
364 copy
= tail
->iov_len
- offs
;
366 _copy_from_pages((char *)tail
->iov_base
+ offs
,
368 buf
->page_base
+ pglen
+ offs
- len
,
370 /* Do we also need to copy data from the head into the tail ? */
372 offs
= copy
= len
- pglen
;
373 if (copy
> tail
->iov_len
)
374 copy
= tail
->iov_len
;
375 memcpy(tail
->iov_base
,
376 (char *)head
->iov_base
+
377 head
->iov_len
- offs
,
381 /* Now handle pages */
384 _shift_data_right_pages(buf
->pages
,
385 buf
->page_base
+ len
,
391 _copy_to_pages(buf
->pages
, buf
->page_base
,
392 (char *)head
->iov_base
+ head
->iov_len
- len
,
395 head
->iov_len
-= len
;
397 /* Have we truncated the message? */
398 if (buf
->len
> buf
->buflen
)
399 buf
->len
= buf
->buflen
;
405 * @len: bytes to remove from buf->pages
407 * Shrinks XDR buffer's page array buf->pages by
408 * 'len' bytes. The extra data is not lost, but is instead
409 * moved into the tail.
412 xdr_shrink_pagelen(struct xdr_buf
*buf
, size_t len
)
416 unsigned int pglen
= buf
->page_len
;
417 unsigned int tailbuf_len
;
420 BUG_ON (len
> pglen
);
422 tailbuf_len
= buf
->buflen
- buf
->head
->iov_len
- buf
->page_len
;
424 /* Shift the tail first */
425 if (tailbuf_len
!= 0) {
426 unsigned int free_space
= tailbuf_len
- tail
->iov_len
;
428 if (len
< free_space
)
430 tail
->iov_len
+= free_space
;
433 if (tail
->iov_len
> len
) {
434 char *p
= (char *)tail
->iov_base
+ len
;
435 memmove(p
, tail
->iov_base
, tail
->iov_len
- len
);
437 copy
= tail
->iov_len
;
438 /* Copy from the inlined pages into the tail */
439 _copy_from_pages((char *)tail
->iov_base
,
440 buf
->pages
, buf
->page_base
+ pglen
- len
,
443 buf
->page_len
-= len
;
445 /* Have we truncated the message? */
446 if (buf
->len
> buf
->buflen
)
447 buf
->len
= buf
->buflen
;
451 xdr_shift_buf(struct xdr_buf
*buf
, size_t len
)
453 xdr_shrink_bufhead(buf
, len
);
455 EXPORT_SYMBOL_GPL(xdr_shift_buf
);
458 * xdr_init_encode - Initialize a struct xdr_stream for sending data.
459 * @xdr: pointer to xdr_stream struct
460 * @buf: pointer to XDR buffer in which to encode data
461 * @p: current pointer inside XDR buffer
463 * Note: at the moment the RPC client only passes the length of our
464 * scratch buffer in the xdr_buf's header kvec. Previously this
465 * meant we needed to call xdr_adjust_iovec() after encoding the
466 * data. With the new scheme, the xdr_stream manages the details
467 * of the buffer length, and takes care of adjusting the kvec
470 void xdr_init_encode(struct xdr_stream
*xdr
, struct xdr_buf
*buf
, __be32
*p
)
472 struct kvec
*iov
= buf
->head
;
473 int scratch_len
= buf
->buflen
- buf
->page_len
- buf
->tail
[0].iov_len
;
475 BUG_ON(scratch_len
< 0);
478 xdr
->p
= (__be32
*)((char *)iov
->iov_base
+ iov
->iov_len
);
479 xdr
->end
= (__be32
*)((char *)iov
->iov_base
+ scratch_len
);
480 BUG_ON(iov
->iov_len
> scratch_len
);
482 if (p
!= xdr
->p
&& p
!= NULL
) {
485 BUG_ON(p
< xdr
->p
|| p
> xdr
->end
);
486 len
= (char *)p
- (char *)xdr
->p
;
492 EXPORT_SYMBOL_GPL(xdr_init_encode
);
495 * xdr_reserve_space - Reserve buffer space for sending
496 * @xdr: pointer to xdr_stream
497 * @nbytes: number of bytes to reserve
499 * Checks that we have enough buffer space to encode 'nbytes' more
500 * bytes of data. If so, update the total xdr_buf length, and
501 * adjust the length of the current kvec.
503 __be32
* xdr_reserve_space(struct xdr_stream
*xdr
, size_t nbytes
)
508 /* align nbytes on the next 32-bit boundary */
511 q
= p
+ (nbytes
>> 2);
512 if (unlikely(q
> xdr
->end
|| q
< p
))
515 xdr
->iov
->iov_len
+= nbytes
;
516 xdr
->buf
->len
+= nbytes
;
519 EXPORT_SYMBOL_GPL(xdr_reserve_space
);
522 * xdr_write_pages - Insert a list of pages into an XDR buffer for sending
523 * @xdr: pointer to xdr_stream
524 * @pages: list of pages
525 * @base: offset of first byte
526 * @len: length of data in bytes
529 void xdr_write_pages(struct xdr_stream
*xdr
, struct page
**pages
, unsigned int base
,
532 struct xdr_buf
*buf
= xdr
->buf
;
533 struct kvec
*iov
= buf
->tail
;
535 buf
->page_base
= base
;
538 iov
->iov_base
= (char *)xdr
->p
;
543 unsigned int pad
= 4 - (len
& 3);
545 BUG_ON(xdr
->p
>= xdr
->end
);
546 iov
->iov_base
= (char *)xdr
->p
+ (len
& 3);
554 EXPORT_SYMBOL_GPL(xdr_write_pages
);
556 static void xdr_set_iov(struct xdr_stream
*xdr
, struct kvec
*iov
,
559 if (len
> iov
->iov_len
)
561 xdr
->p
= (__be32
*)iov
->iov_base
;
562 xdr
->end
= (__be32
*)(iov
->iov_base
+ len
);
564 xdr
->page_ptr
= NULL
;
567 static int xdr_set_page_base(struct xdr_stream
*xdr
,
568 unsigned int base
, unsigned int len
)
576 maxlen
= xdr
->buf
->page_len
;
583 base
+= xdr
->buf
->page_base
;
585 pgnr
= base
>> PAGE_SHIFT
;
586 xdr
->page_ptr
= &xdr
->buf
->pages
[pgnr
];
587 kaddr
= page_address(*xdr
->page_ptr
);
589 pgoff
= base
& ~PAGE_MASK
;
590 xdr
->p
= (__be32
*)(kaddr
+ pgoff
);
593 if (pgend
> PAGE_SIZE
)
595 xdr
->end
= (__be32
*)(kaddr
+ pgend
);
600 static void xdr_set_next_page(struct xdr_stream
*xdr
)
602 unsigned int newbase
;
604 newbase
= (1 + xdr
->page_ptr
- xdr
->buf
->pages
) << PAGE_SHIFT
;
605 newbase
-= xdr
->buf
->page_base
;
607 if (xdr_set_page_base(xdr
, newbase
, PAGE_SIZE
) < 0)
608 xdr_set_iov(xdr
, xdr
->buf
->tail
, xdr
->buf
->len
);
611 static bool xdr_set_next_buffer(struct xdr_stream
*xdr
)
613 if (xdr
->page_ptr
!= NULL
)
614 xdr_set_next_page(xdr
);
615 else if (xdr
->iov
== xdr
->buf
->head
) {
616 if (xdr_set_page_base(xdr
, 0, PAGE_SIZE
) < 0)
617 xdr_set_iov(xdr
, xdr
->buf
->tail
, xdr
->buf
->len
);
619 return xdr
->p
!= xdr
->end
;
623 * xdr_init_decode - Initialize an xdr_stream for decoding data.
624 * @xdr: pointer to xdr_stream struct
625 * @buf: pointer to XDR buffer from which to decode data
626 * @p: current pointer inside XDR buffer
628 void xdr_init_decode(struct xdr_stream
*xdr
, struct xdr_buf
*buf
, __be32
*p
)
631 xdr
->scratch
.iov_base
= NULL
;
632 xdr
->scratch
.iov_len
= 0;
633 xdr
->nwords
= XDR_QUADLEN(buf
->len
);
634 if (buf
->head
[0].iov_len
!= 0)
635 xdr_set_iov(xdr
, buf
->head
, buf
->len
);
636 else if (buf
->page_len
!= 0)
637 xdr_set_page_base(xdr
, 0, buf
->len
);
638 if (p
!= NULL
&& p
> xdr
->p
&& xdr
->end
>= p
) {
639 xdr
->nwords
-= p
- xdr
->p
;
643 EXPORT_SYMBOL_GPL(xdr_init_decode
);
646 * xdr_init_decode - Initialize an xdr_stream for decoding data.
647 * @xdr: pointer to xdr_stream struct
648 * @buf: pointer to XDR buffer from which to decode data
649 * @pages: list of pages to decode into
650 * @len: length in bytes of buffer in pages
652 void xdr_init_decode_pages(struct xdr_stream
*xdr
, struct xdr_buf
*buf
,
653 struct page
**pages
, unsigned int len
)
655 memset(buf
, 0, sizeof(*buf
));
660 xdr_init_decode(xdr
, buf
, NULL
);
662 EXPORT_SYMBOL_GPL(xdr_init_decode_pages
);
664 static __be32
* __xdr_inline_decode(struct xdr_stream
*xdr
, size_t nbytes
)
666 unsigned int nwords
= XDR_QUADLEN(nbytes
);
668 __be32
*q
= p
+ nwords
;
670 if (unlikely(nwords
> xdr
->nwords
|| q
> xdr
->end
|| q
< p
))
673 xdr
->nwords
-= nwords
;
678 * xdr_set_scratch_buffer - Attach a scratch buffer for decoding data.
679 * @xdr: pointer to xdr_stream struct
680 * @buf: pointer to an empty buffer
681 * @buflen: size of 'buf'
683 * The scratch buffer is used when decoding from an array of pages.
684 * If an xdr_inline_decode() call spans across page boundaries, then
685 * we copy the data into the scratch buffer in order to allow linear
688 void xdr_set_scratch_buffer(struct xdr_stream
*xdr
, void *buf
, size_t buflen
)
690 xdr
->scratch
.iov_base
= buf
;
691 xdr
->scratch
.iov_len
= buflen
;
693 EXPORT_SYMBOL_GPL(xdr_set_scratch_buffer
);
695 static __be32
*xdr_copy_to_scratch(struct xdr_stream
*xdr
, size_t nbytes
)
698 void *cpdest
= xdr
->scratch
.iov_base
;
699 size_t cplen
= (char *)xdr
->end
- (char *)xdr
->p
;
701 if (nbytes
> xdr
->scratch
.iov_len
)
703 memcpy(cpdest
, xdr
->p
, cplen
);
706 if (!xdr_set_next_buffer(xdr
))
708 p
= __xdr_inline_decode(xdr
, nbytes
);
711 memcpy(cpdest
, p
, nbytes
);
712 return xdr
->scratch
.iov_base
;
716 * xdr_inline_decode - Retrieve XDR data to decode
717 * @xdr: pointer to xdr_stream struct
718 * @nbytes: number of bytes of data to decode
720 * Check if the input buffer is long enough to enable us to decode
721 * 'nbytes' more bytes of data starting at the current position.
722 * If so return the current pointer, then update the current
725 __be32
* xdr_inline_decode(struct xdr_stream
*xdr
, size_t nbytes
)
731 if (xdr
->p
== xdr
->end
&& !xdr_set_next_buffer(xdr
))
733 p
= __xdr_inline_decode(xdr
, nbytes
);
736 return xdr_copy_to_scratch(xdr
, nbytes
);
738 EXPORT_SYMBOL_GPL(xdr_inline_decode
);
741 * xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position
742 * @xdr: pointer to xdr_stream struct
743 * @len: number of bytes of page data
745 * Moves data beyond the current pointer position from the XDR head[] buffer
746 * into the page list. Any data that lies beyond current position + "len"
747 * bytes is moved into the XDR tail[].
749 void xdr_read_pages(struct xdr_stream
*xdr
, unsigned int len
)
751 struct xdr_buf
*buf
= xdr
->buf
;
754 unsigned int nwords
= XDR_QUADLEN(len
);
758 if (xdr
->nwords
== 0)
760 if (nwords
> xdr
->nwords
) {
761 nwords
= xdr
->nwords
;
764 /* Realign pages to current pointer position */
766 shift
= iov
->iov_len
+ (char *)iov
->iov_base
- (char *)xdr
->p
;
768 xdr_shrink_bufhead(buf
, shift
);
770 /* Truncate page data and move it into the tail */
771 if (buf
->page_len
> len
)
772 xdr_shrink_pagelen(buf
, buf
->page_len
- len
);
773 padding
= (nwords
<< 2) - len
;
774 xdr
->iov
= iov
= buf
->tail
;
775 /* Compute remaining message length. */
777 shift
= buf
->buflen
- buf
->len
;
778 if (end
> shift
+ padding
)
783 * Position current pointer at beginning of tail, and
784 * set remaining message length.
786 xdr
->p
= (__be32
*)((char *)iov
->iov_base
+ padding
);
787 xdr
->end
= (__be32
*)((char *)iov
->iov_base
+ end
);
788 xdr
->page_ptr
= NULL
;
789 xdr
->nwords
= XDR_QUADLEN(end
- padding
);
791 EXPORT_SYMBOL_GPL(xdr_read_pages
);
794 * xdr_enter_page - decode data from the XDR page
795 * @xdr: pointer to xdr_stream struct
796 * @len: number of bytes of page data
798 * Moves data beyond the current pointer position from the XDR head[] buffer
799 * into the page list. Any data that lies beyond current position + "len"
800 * bytes is moved into the XDR tail[]. The current pointer is then
801 * repositioned at the beginning of the first XDR page.
803 void xdr_enter_page(struct xdr_stream
*xdr
, unsigned int len
)
805 xdr_read_pages(xdr
, len
);
807 * Position current pointer at beginning of tail, and
808 * set remaining message length.
810 xdr_set_page_base(xdr
, 0, len
);
811 xdr
->nwords
+= XDR_QUADLEN(xdr
->buf
->page_len
);
813 EXPORT_SYMBOL_GPL(xdr_enter_page
);
815 static struct kvec empty_iov
= {.iov_base
= NULL
, .iov_len
= 0};
818 xdr_buf_from_iov(struct kvec
*iov
, struct xdr_buf
*buf
)
821 buf
->tail
[0] = empty_iov
;
823 buf
->buflen
= buf
->len
= iov
->iov_len
;
825 EXPORT_SYMBOL_GPL(xdr_buf_from_iov
);
827 /* Sets subbuf to the portion of buf of length len beginning base bytes
828 * from the start of buf. Returns -1 if base of length are out of bounds. */
830 xdr_buf_subsegment(struct xdr_buf
*buf
, struct xdr_buf
*subbuf
,
831 unsigned int base
, unsigned int len
)
833 subbuf
->buflen
= subbuf
->len
= len
;
834 if (base
< buf
->head
[0].iov_len
) {
835 subbuf
->head
[0].iov_base
= buf
->head
[0].iov_base
+ base
;
836 subbuf
->head
[0].iov_len
= min_t(unsigned int, len
,
837 buf
->head
[0].iov_len
- base
);
838 len
-= subbuf
->head
[0].iov_len
;
841 subbuf
->head
[0].iov_base
= NULL
;
842 subbuf
->head
[0].iov_len
= 0;
843 base
-= buf
->head
[0].iov_len
;
846 if (base
< buf
->page_len
) {
847 subbuf
->page_len
= min(buf
->page_len
- base
, len
);
848 base
+= buf
->page_base
;
849 subbuf
->page_base
= base
& ~PAGE_CACHE_MASK
;
850 subbuf
->pages
= &buf
->pages
[base
>> PAGE_CACHE_SHIFT
];
851 len
-= subbuf
->page_len
;
854 base
-= buf
->page_len
;
855 subbuf
->page_len
= 0;
858 if (base
< buf
->tail
[0].iov_len
) {
859 subbuf
->tail
[0].iov_base
= buf
->tail
[0].iov_base
+ base
;
860 subbuf
->tail
[0].iov_len
= min_t(unsigned int, len
,
861 buf
->tail
[0].iov_len
- base
);
862 len
-= subbuf
->tail
[0].iov_len
;
865 subbuf
->tail
[0].iov_base
= NULL
;
866 subbuf
->tail
[0].iov_len
= 0;
867 base
-= buf
->tail
[0].iov_len
;
874 EXPORT_SYMBOL_GPL(xdr_buf_subsegment
);
876 static void __read_bytes_from_xdr_buf(struct xdr_buf
*subbuf
, void *obj
, unsigned int len
)
878 unsigned int this_len
;
880 this_len
= min_t(unsigned int, len
, subbuf
->head
[0].iov_len
);
881 memcpy(obj
, subbuf
->head
[0].iov_base
, this_len
);
884 this_len
= min_t(unsigned int, len
, subbuf
->page_len
);
886 _copy_from_pages(obj
, subbuf
->pages
, subbuf
->page_base
, this_len
);
889 this_len
= min_t(unsigned int, len
, subbuf
->tail
[0].iov_len
);
890 memcpy(obj
, subbuf
->tail
[0].iov_base
, this_len
);
893 /* obj is assumed to point to allocated memory of size at least len: */
894 int read_bytes_from_xdr_buf(struct xdr_buf
*buf
, unsigned int base
, void *obj
, unsigned int len
)
896 struct xdr_buf subbuf
;
899 status
= xdr_buf_subsegment(buf
, &subbuf
, base
, len
);
902 __read_bytes_from_xdr_buf(&subbuf
, obj
, len
);
905 EXPORT_SYMBOL_GPL(read_bytes_from_xdr_buf
);
907 static void __write_bytes_to_xdr_buf(struct xdr_buf
*subbuf
, void *obj
, unsigned int len
)
909 unsigned int this_len
;
911 this_len
= min_t(unsigned int, len
, subbuf
->head
[0].iov_len
);
912 memcpy(subbuf
->head
[0].iov_base
, obj
, this_len
);
915 this_len
= min_t(unsigned int, len
, subbuf
->page_len
);
917 _copy_to_pages(subbuf
->pages
, subbuf
->page_base
, obj
, this_len
);
920 this_len
= min_t(unsigned int, len
, subbuf
->tail
[0].iov_len
);
921 memcpy(subbuf
->tail
[0].iov_base
, obj
, this_len
);
924 /* obj is assumed to point to allocated memory of size at least len: */
925 int write_bytes_to_xdr_buf(struct xdr_buf
*buf
, unsigned int base
, void *obj
, unsigned int len
)
927 struct xdr_buf subbuf
;
930 status
= xdr_buf_subsegment(buf
, &subbuf
, base
, len
);
933 __write_bytes_to_xdr_buf(&subbuf
, obj
, len
);
936 EXPORT_SYMBOL_GPL(write_bytes_to_xdr_buf
);
939 xdr_decode_word(struct xdr_buf
*buf
, unsigned int base
, u32
*obj
)
944 status
= read_bytes_from_xdr_buf(buf
, base
, &raw
, sizeof(*obj
));
947 *obj
= be32_to_cpu(raw
);
950 EXPORT_SYMBOL_GPL(xdr_decode_word
);
953 xdr_encode_word(struct xdr_buf
*buf
, unsigned int base
, u32 obj
)
955 __be32 raw
= cpu_to_be32(obj
);
957 return write_bytes_to_xdr_buf(buf
, base
, &raw
, sizeof(obj
));
959 EXPORT_SYMBOL_GPL(xdr_encode_word
);
961 /* If the netobj starting offset bytes from the start of xdr_buf is contained
962 * entirely in the head or the tail, set object to point to it; otherwise
963 * try to find space for it at the end of the tail, copy it there, and
964 * set obj to point to it. */
965 int xdr_buf_read_netobj(struct xdr_buf
*buf
, struct xdr_netobj
*obj
, unsigned int offset
)
967 struct xdr_buf subbuf
;
969 if (xdr_decode_word(buf
, offset
, &obj
->len
))
971 if (xdr_buf_subsegment(buf
, &subbuf
, offset
+ 4, obj
->len
))
974 /* Is the obj contained entirely in the head? */
975 obj
->data
= subbuf
.head
[0].iov_base
;
976 if (subbuf
.head
[0].iov_len
== obj
->len
)
978 /* ..or is the obj contained entirely in the tail? */
979 obj
->data
= subbuf
.tail
[0].iov_base
;
980 if (subbuf
.tail
[0].iov_len
== obj
->len
)
983 /* use end of tail as storage for obj:
984 * (We don't copy to the beginning because then we'd have
985 * to worry about doing a potentially overlapping copy.
986 * This assumes the object is at most half the length of the
988 if (obj
->len
> buf
->buflen
- buf
->len
)
990 if (buf
->tail
[0].iov_len
!= 0)
991 obj
->data
= buf
->tail
[0].iov_base
+ buf
->tail
[0].iov_len
;
993 obj
->data
= buf
->head
[0].iov_base
+ buf
->head
[0].iov_len
;
994 __read_bytes_from_xdr_buf(&subbuf
, obj
->data
, obj
->len
);
997 EXPORT_SYMBOL_GPL(xdr_buf_read_netobj
);
999 /* Returns 0 on success, or else a negative error code. */
1001 xdr_xcode_array2(struct xdr_buf
*buf
, unsigned int base
,
1002 struct xdr_array2_desc
*desc
, int encode
)
1004 char *elem
= NULL
, *c
;
1005 unsigned int copied
= 0, todo
, avail_here
;
1006 struct page
**ppages
= NULL
;
1010 if (xdr_encode_word(buf
, base
, desc
->array_len
) != 0)
1013 if (xdr_decode_word(buf
, base
, &desc
->array_len
) != 0 ||
1014 desc
->array_len
> desc
->array_maxlen
||
1015 (unsigned long) base
+ 4 + desc
->array_len
*
1016 desc
->elem_size
> buf
->len
)
1024 todo
= desc
->array_len
* desc
->elem_size
;
1027 if (todo
&& base
< buf
->head
->iov_len
) {
1028 c
= buf
->head
->iov_base
+ base
;
1029 avail_here
= min_t(unsigned int, todo
,
1030 buf
->head
->iov_len
- base
);
1033 while (avail_here
>= desc
->elem_size
) {
1034 err
= desc
->xcode(desc
, c
);
1037 c
+= desc
->elem_size
;
1038 avail_here
-= desc
->elem_size
;
1042 elem
= kmalloc(desc
->elem_size
, GFP_KERNEL
);
1048 err
= desc
->xcode(desc
, elem
);
1051 memcpy(c
, elem
, avail_here
);
1053 memcpy(elem
, c
, avail_here
);
1054 copied
= avail_here
;
1056 base
= buf
->head
->iov_len
; /* align to start of pages */
1059 /* process pages array */
1060 base
-= buf
->head
->iov_len
;
1061 if (todo
&& base
< buf
->page_len
) {
1062 unsigned int avail_page
;
1064 avail_here
= min(todo
, buf
->page_len
- base
);
1067 base
+= buf
->page_base
;
1068 ppages
= buf
->pages
+ (base
>> PAGE_CACHE_SHIFT
);
1069 base
&= ~PAGE_CACHE_MASK
;
1070 avail_page
= min_t(unsigned int, PAGE_CACHE_SIZE
- base
,
1072 c
= kmap(*ppages
) + base
;
1074 while (avail_here
) {
1075 avail_here
-= avail_page
;
1076 if (copied
|| avail_page
< desc
->elem_size
) {
1077 unsigned int l
= min(avail_page
,
1078 desc
->elem_size
- copied
);
1080 elem
= kmalloc(desc
->elem_size
,
1088 err
= desc
->xcode(desc
, elem
);
1092 memcpy(c
, elem
+ copied
, l
);
1094 if (copied
== desc
->elem_size
)
1097 memcpy(elem
+ copied
, c
, l
);
1099 if (copied
== desc
->elem_size
) {
1100 err
= desc
->xcode(desc
, elem
);
1109 while (avail_page
>= desc
->elem_size
) {
1110 err
= desc
->xcode(desc
, c
);
1113 c
+= desc
->elem_size
;
1114 avail_page
-= desc
->elem_size
;
1117 unsigned int l
= min(avail_page
,
1118 desc
->elem_size
- copied
);
1120 elem
= kmalloc(desc
->elem_size
,
1128 err
= desc
->xcode(desc
, elem
);
1132 memcpy(c
, elem
+ copied
, l
);
1134 if (copied
== desc
->elem_size
)
1137 memcpy(elem
+ copied
, c
, l
);
1139 if (copied
== desc
->elem_size
) {
1140 err
= desc
->xcode(desc
, elem
);
1153 avail_page
= min(avail_here
,
1154 (unsigned int) PAGE_CACHE_SIZE
);
1156 base
= buf
->page_len
; /* align to start of tail */
1160 base
-= buf
->page_len
;
1162 c
= buf
->tail
->iov_base
+ base
;
1164 unsigned int l
= desc
->elem_size
- copied
;
1167 memcpy(c
, elem
+ copied
, l
);
1169 memcpy(elem
+ copied
, c
, l
);
1170 err
= desc
->xcode(desc
, elem
);
1178 err
= desc
->xcode(desc
, c
);
1181 c
+= desc
->elem_size
;
1182 todo
-= desc
->elem_size
;
1195 xdr_decode_array2(struct xdr_buf
*buf
, unsigned int base
,
1196 struct xdr_array2_desc
*desc
)
1198 if (base
>= buf
->len
)
1201 return xdr_xcode_array2(buf
, base
, desc
, 0);
1203 EXPORT_SYMBOL_GPL(xdr_decode_array2
);
1206 xdr_encode_array2(struct xdr_buf
*buf
, unsigned int base
,
1207 struct xdr_array2_desc
*desc
)
1209 if ((unsigned long) base
+ 4 + desc
->array_len
* desc
->elem_size
>
1210 buf
->head
->iov_len
+ buf
->page_len
+ buf
->tail
->iov_len
)
1213 return xdr_xcode_array2(buf
, base
, desc
, 1);
1215 EXPORT_SYMBOL_GPL(xdr_encode_array2
);
1218 xdr_process_buf(struct xdr_buf
*buf
, unsigned int offset
, unsigned int len
,
1219 int (*actor
)(struct scatterlist
*, void *), void *data
)
1222 unsigned int page_len
, thislen
, page_offset
;
1223 struct scatterlist sg
[1];
1225 sg_init_table(sg
, 1);
1227 if (offset
>= buf
->head
[0].iov_len
) {
1228 offset
-= buf
->head
[0].iov_len
;
1230 thislen
= buf
->head
[0].iov_len
- offset
;
1233 sg_set_buf(sg
, buf
->head
[0].iov_base
+ offset
, thislen
);
1234 ret
= actor(sg
, data
);
1243 if (offset
>= buf
->page_len
) {
1244 offset
-= buf
->page_len
;
1246 page_len
= buf
->page_len
- offset
;
1250 page_offset
= (offset
+ buf
->page_base
) & (PAGE_CACHE_SIZE
- 1);
1251 i
= (offset
+ buf
->page_base
) >> PAGE_CACHE_SHIFT
;
1252 thislen
= PAGE_CACHE_SIZE
- page_offset
;
1254 if (thislen
> page_len
)
1256 sg_set_page(sg
, buf
->pages
[i
], thislen
, page_offset
);
1257 ret
= actor(sg
, data
);
1260 page_len
-= thislen
;
1263 thislen
= PAGE_CACHE_SIZE
;
1264 } while (page_len
!= 0);
1269 if (offset
< buf
->tail
[0].iov_len
) {
1270 thislen
= buf
->tail
[0].iov_len
- offset
;
1273 sg_set_buf(sg
, buf
->tail
[0].iov_base
+ offset
, thislen
);
1274 ret
= actor(sg
, data
);
1282 EXPORT_SYMBOL_GPL(xdr_process_buf
);